linux/drivers/base/cacheinfo.c

1047 lines
26 KiB

drivers: base: support cpu cache information interface to userspace via sysfs This patch adds initial support for providing processor cache information to userspace through sysfs interface. This is based on already existing implementations(x86, ia64, s390 and powerpc) and hence the interface is intended to be fully compatible. The main purpose of this generic support is to avoid further code duplication to support new architectures and also to unify all the existing different implementations. This implementation maintains the hierarchy of cache objects which reflects the system's cache topology. Cache devices are instantiated as needed as CPUs come online. The cache information is replicated per-cpu even if they are shared. A per-cpu array of cache information maintained is used mainly for sysfs-related book keeping. It also implements the shared_cpu_map attribute, which is essential for enabling both kernel and user-space to discover the system's overall cache topology. This patch also add the missing ABI documentation for the cacheinfo sysfs interface already, which is well defined and widely used. Signed-off-by: Sudeep Holla <sudeep.holla@arm.com> Reviewed-by: Stephen Boyd <sboyd@codeaurora.org> Tested-by: Stephen Boyd <sboyd@codeaurora.org> Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org> Cc: linux-api@vger.kernel.org Cc: linux390@de.ibm.com Cc: linux-arm-kernel@lists.infradead.org Cc: linux-ia64@vger.kernel.org Cc: linuxppc-dev@lists.ozlabs.org Cc: linux-s390@vger.kernel.org Cc: x86@kernel.org Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2014-09-30 14:48:25 +01:00
2025-07-11 18:27:41 +00:00
drivers: base: support cpu cache information interface to userspace via sysfs This patch adds initial support for providing processor cache information to userspace through sysfs interface. This is based on already existing implementations(x86, ia64, s390 and powerpc) and hence the interface is intended to be fully compatible. The main purpose of this generic support is to avoid further code duplication to support new architectures and also to unify all the existing different implementations. This implementation maintains the hierarchy of cache objects which reflects the system's cache topology. Cache devices are instantiated as needed as CPUs come online. The cache information is replicated per-cpu even if they are shared. A per-cpu array of cache information maintained is used mainly for sysfs-related book keeping. It also implements the shared_cpu_map attribute, which is essential for enabling both kernel and user-space to discover the system's overall cache topology. This patch also add the missing ABI documentation for the cacheinfo sysfs interface already, which is well defined and widely used. Signed-off-by: Sudeep Holla <sudeep.holla@arm.com> Reviewed-by: Stephen Boyd <sboyd@codeaurora.org> Tested-by: Stephen Boyd <sboyd@codeaurora.org> Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org> Cc: linux-api@vger.kernel.org Cc: linux390@de.ibm.com Cc: linux-arm-kernel@lists.infradead.org Cc: linux-ia64@vger.kernel.org Cc: linuxppc-dev@lists.ozlabs.org Cc: linux-s390@vger.kernel.org Cc: x86@kernel.org Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2014-09-30 14:48:25 +01:00
drivers: base: support cpu cache information interface to userspace via sysfs This patch adds initial support for providing processor cache information to userspace through sysfs interface. This is based on already existing implementations(x86, ia64, s390 and powerpc) and hence the interface is intended to be fully compatible. The main purpose of this generic support is to avoid further code duplication to support new architectures and also to unify all the existing different implementations. This implementation maintains the hierarchy of cache objects which reflects the system's cache topology. Cache devices are instantiated as needed as CPUs come online. The cache information is replicated per-cpu even if they are shared. A per-cpu array of cache information maintained is used mainly for sysfs-related book keeping. It also implements the shared_cpu_map attribute, which is essential for enabling both kernel and user-space to discover the system's overall cache topology. This patch also add the missing ABI documentation for the cacheinfo sysfs interface already, which is well defined and widely used. Signed-off-by: Sudeep Holla <sudeep.holla@arm.com> Reviewed-by: Stephen Boyd <sboyd@codeaurora.org> Tested-by: Stephen Boyd <sboyd@codeaurora.org> Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org> Cc: linux-api@vger.kernel.org Cc: linux390@de.ibm.com Cc: linux-arm-kernel@lists.infradead.org Cc: linux-ia64@vger.kernel.org Cc: linuxppc-dev@lists.ozlabs.org Cc: linux-s390@vger.kernel.org Cc: x86@kernel.org Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2014-09-30 14:48:25 +01:00
drivers: base: support cpu cache information interface to userspace via sysfs This patch adds initial support for providing processor cache information to userspace through sysfs interface. This is based on already existing implementations(x86, ia64, s390 and powerpc) and hence the interface is intended to be fully compatible. The main purpose of this generic support is to avoid further code duplication to support new architectures and also to unify all the existing different implementations. This implementation maintains the hierarchy of cache objects which reflects the system's cache topology. Cache devices are instantiated as needed as CPUs come online. The cache information is replicated per-cpu even if they are shared. A per-cpu array of cache information maintained is used mainly for sysfs-related book keeping. It also implements the shared_cpu_map attribute, which is essential for enabling both kernel and user-space to discover the system's overall cache topology. This patch also add the missing ABI documentation for the cacheinfo sysfs interface already, which is well defined and widely used. Signed-off-by: Sudeep Holla <sudeep.holla@arm.com> Reviewed-by: Stephen Boyd <sboyd@codeaurora.org> Tested-by: Stephen Boyd <sboyd@codeaurora.org> Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org> Cc: linux-api@vger.kernel.org Cc: linux390@de.ibm.com Cc: linux-arm-kernel@lists.infradead.org Cc: linux-ia64@vger.kernel.org Cc: linuxppc-dev@lists.ozlabs.org Cc: linux-s390@vger.kernel.org Cc: x86@kernel.org Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2014-09-30 14:48:25 +01:00
drivers: base: support cpu cache information interface to userspace via sysfs This patch adds initial support for providing processor cache information to userspace through sysfs interface. This is based on already existing implementations(x86, ia64, s390 and powerpc) and hence the interface is intended to be fully compatible. The main purpose of this generic support is to avoid further code duplication to support new architectures and also to unify all the existing different implementations. This implementation maintains the hierarchy of cache objects which reflects the system's cache topology. Cache devices are instantiated as needed as CPUs come online. The cache information is replicated per-cpu even if they are shared. A per-cpu array of cache information maintained is used mainly for sysfs-related book keeping. It also implements the shared_cpu_map attribute, which is essential for enabling both kernel and user-space to discover the system's overall cache topology. This patch also add the missing ABI documentation for the cacheinfo sysfs interface already, which is well defined and widely used. Signed-off-by: Sudeep Holla <sudeep.holla@arm.com> Reviewed-by: Stephen Boyd <sboyd@codeaurora.org> Tested-by: Stephen Boyd <sboyd@codeaurora.org> Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org> Cc: linux-api@vger.kernel.org Cc: linux390@de.ibm.com Cc: linux-arm-kernel@lists.infradead.org Cc: linux-ia64@vger.kernel.org Cc: linuxppc-dev@lists.ozlabs.org Cc: linux-s390@vger.kernel.org Cc: x86@kernel.org Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2014-09-30 14:48:25 +01:00
drivers: base: support cpu cache information interface to userspace via sysfs This patch adds initial support for providing processor cache information to userspace through sysfs interface. This is based on already existing implementations(x86, ia64, s390 and powerpc) and hence the interface is intended to be fully compatible. The main purpose of this generic support is to avoid further code duplication to support new architectures and also to unify all the existing different implementations. This implementation maintains the hierarchy of cache objects which reflects the system's cache topology. Cache devices are instantiated as needed as CPUs come online. The cache information is replicated per-cpu even if they are shared. A per-cpu array of cache information maintained is used mainly for sysfs-related book keeping. It also implements the shared_cpu_map attribute, which is essential for enabling both kernel and user-space to discover the system's overall cache topology. This patch also add the missing ABI documentation for the cacheinfo sysfs interface already, which is well defined and widely used. Signed-off-by: Sudeep Holla <sudeep.holla@arm.com> Reviewed-by: Stephen Boyd <sboyd@codeaurora.org> Tested-by: Stephen Boyd <sboyd@codeaurora.org> Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org> Cc: linux-api@vger.kernel.org Cc: linux390@de.ibm.com Cc: linux-arm-kernel@lists.infradead.org Cc: linux-ia64@vger.kernel.org Cc: linuxppc-dev@lists.ozlabs.org Cc: linux-s390@vger.kernel.org Cc: x86@kernel.org Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2014-09-30 14:48:25 +01:00
cacheinfo: Allocate memory during CPU hotplug if not done from the primary CPU Commit 5944ce092b97 ("arch_topology: Build cacheinfo from primary CPU") adds functionality that architectures can use to optionally allocate and build cacheinfo early during boot. Commit 6539cffa9495 ("cacheinfo: Add arch specific early level initializer") lets secondary CPUs correct (and reallocate memory) cacheinfo data if needed. If the early build functionality is not used and cacheinfo does not need correction, memory for cacheinfo is never allocated. x86 does not use the early build functionality. Consequently, during the cacheinfo CPU hotplug callback, last_level_cache_is_valid() attempts to dereference a NULL pointer: BUG: kernel NULL pointer dereference, address: 0000000000000100 #PF: supervisor read access in kernel mode #PF: error_code(0x0000) - not present page PGD 0 P4D 0 Oops: 0000 [#1] PREEPMT SMP NOPTI CPU: 0 PID 19 Comm: cpuhp/0 Not tainted 6.4.0-rc2 #1 RIP: 0010: last_level_cache_is_valid+0x95/0xe0a Allocate memory for cacheinfo during the cacheinfo CPU hotplug callback if not done earlier. Moreover, before determining the validity of the last-level cache info, ensure that it has been allocated. Simply checking for non-zero cache_leaves() is not sufficient, as some architectures (e.g., Intel processors) have non-zero cache_leaves() before allocation. Dereferencing NULL cacheinfo can occur in update_per_cpu_data_slice_size(). This function iterates over all online CPUs. However, a CPU may have come online recently, but its cacheinfo may not have been allocated yet. While here, remove an unnecessary indentation in allocate_cache_info(). [ bp: Massage. ] Fixes: 6539cffa9495 ("cacheinfo: Add arch specific early level initializer") Signed-off-by: Ricardo Neri <ricardo.neri-calderon@linux.intel.com> Signed-off-by: Borislav Petkov (AMD) <bp@alien8.de> Reviewed-by: Radu Rendec <rrendec@redhat.com> Reviewed-by: Nikolay Borisov <nik.borisov@suse.com> Reviewed-by: Andreas Herrmann <aherrmann@suse.de> Reviewed-by: Sudeep Holla <sudeep.holla@arm.com> Cc: stable@vger.kernel.org # 6.3+ Link: https://lore.kernel.org/r/20241128002247.26726-2-ricardo.neri-calderon@linux.intel.com
2024-11-27 16:22:46 -08:00
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2025-07-11 18:27:41 +00:00
2025-07-11 18:27:41 +00:00
2025-07-11 18:27:41 +00:00
2018-05-11 18:57:57 -05:00
2018-05-11 18:57:57 -05:00
2025-07-11 18:27:41 +00:00
2018-05-11 18:57:57 -05:00
drivers: base: support cpu cache information interface to userspace via sysfs This patch adds initial support for providing processor cache information to userspace through sysfs interface. This is based on already existing implementations(x86, ia64, s390 and powerpc) and hence the interface is intended to be fully compatible. The main purpose of this generic support is to avoid further code duplication to support new architectures and also to unify all the existing different implementations. This implementation maintains the hierarchy of cache objects which reflects the system's cache topology. Cache devices are instantiated as needed as CPUs come online. The cache information is replicated per-cpu even if they are shared. A per-cpu array of cache information maintained is used mainly for sysfs-related book keeping. It also implements the shared_cpu_map attribute, which is essential for enabling both kernel and user-space to discover the system's overall cache topology. This patch also add the missing ABI documentation for the cacheinfo sysfs interface already, which is well defined and widely used. Signed-off-by: Sudeep Holla <sudeep.holla@arm.com> Reviewed-by: Stephen Boyd <sboyd@codeaurora.org> Tested-by: Stephen Boyd <sboyd@codeaurora.org> Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org> Cc: linux-api@vger.kernel.org Cc: linux390@de.ibm.com Cc: linux-arm-kernel@lists.infradead.org Cc: linux-ia64@vger.kernel.org Cc: linuxppc-dev@lists.ozlabs.org Cc: linux-s390@vger.kernel.org Cc: x86@kernel.org Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2014-09-30 14:48:25 +01:00
drivers: base: support cpu cache information interface to userspace via sysfs This patch adds initial support for providing processor cache information to userspace through sysfs interface. This is based on already existing implementations(x86, ia64, s390 and powerpc) and hence the interface is intended to be fully compatible. The main purpose of this generic support is to avoid further code duplication to support new architectures and also to unify all the existing different implementations. This implementation maintains the hierarchy of cache objects which reflects the system's cache topology. Cache devices are instantiated as needed as CPUs come online. The cache information is replicated per-cpu even if they are shared. A per-cpu array of cache information maintained is used mainly for sysfs-related book keeping. It also implements the shared_cpu_map attribute, which is essential for enabling both kernel and user-space to discover the system's overall cache topology. This patch also add the missing ABI documentation for the cacheinfo sysfs interface already, which is well defined and widely used. Signed-off-by: Sudeep Holla <sudeep.holla@arm.com> Reviewed-by: Stephen Boyd <sboyd@codeaurora.org> Tested-by: Stephen Boyd <sboyd@codeaurora.org> Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org> Cc: linux-api@vger.kernel.org Cc: linux390@de.ibm.com Cc: linux-arm-kernel@lists.infradead.org Cc: linux-ia64@vger.kernel.org Cc: linuxppc-dev@lists.ozlabs.org Cc: linux-s390@vger.kernel.org Cc: x86@kernel.org Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2014-09-30 14:48:25 +01:00
drivers: base: support cpu cache information interface to userspace via sysfs This patch adds initial support for providing processor cache information to userspace through sysfs interface. This is based on already existing implementations(x86, ia64, s390 and powerpc) and hence the interface is intended to be fully compatible. The main purpose of this generic support is to avoid further code duplication to support new architectures and also to unify all the existing different implementations. This implementation maintains the hierarchy of cache objects which reflects the system's cache topology. Cache devices are instantiated as needed as CPUs come online. The cache information is replicated per-cpu even if they are shared. A per-cpu array of cache information maintained is used mainly for sysfs-related book keeping. It also implements the shared_cpu_map attribute, which is essential for enabling both kernel and user-space to discover the system's overall cache topology. This patch also add the missing ABI documentation for the cacheinfo sysfs interface already, which is well defined and widely used. Signed-off-by: Sudeep Holla <sudeep.holla@arm.com> Reviewed-by: Stephen Boyd <sboyd@codeaurora.org> Tested-by: Stephen Boyd <sboyd@codeaurora.org> Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org> Cc: linux-api@vger.kernel.org Cc: linux390@de.ibm.com Cc: linux-arm-kernel@lists.infradead.org Cc: linux-ia64@vger.kernel.org Cc: linuxppc-dev@lists.ozlabs.org Cc: linux-s390@vger.kernel.org Cc: x86@kernel.org Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2014-09-30 14:48:25 +01:00
drivers: base: support cpu cache information interface to userspace via sysfs This patch adds initial support for providing processor cache information to userspace through sysfs interface. This is based on already existing implementations(x86, ia64, s390 and powerpc) and hence the interface is intended to be fully compatible. The main purpose of this generic support is to avoid further code duplication to support new architectures and also to unify all the existing different implementations. This implementation maintains the hierarchy of cache objects which reflects the system's cache topology. Cache devices are instantiated as needed as CPUs come online. The cache information is replicated per-cpu even if they are shared. A per-cpu array of cache information maintained is used mainly for sysfs-related book keeping. It also implements the shared_cpu_map attribute, which is essential for enabling both kernel and user-space to discover the system's overall cache topology. This patch also add the missing ABI documentation for the cacheinfo sysfs interface already, which is well defined and widely used. Signed-off-by: Sudeep Holla <sudeep.holla@arm.com> Reviewed-by: Stephen Boyd <sboyd@codeaurora.org> Tested-by: Stephen Boyd <sboyd@codeaurora.org> Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org> Cc: linux-api@vger.kernel.org Cc: linux390@de.ibm.com Cc: linux-arm-kernel@lists.infradead.org Cc: linux-ia64@vger.kernel.org Cc: linuxppc-dev@lists.ozlabs.org Cc: linux-s390@vger.kernel.org Cc: x86@kernel.org Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2014-09-30 14:48:25 +01:00
drivers: base: support cpu cache information interface to userspace via sysfs This patch adds initial support for providing processor cache information to userspace through sysfs interface. This is based on already existing implementations(x86, ia64, s390 and powerpc) and hence the interface is intended to be fully compatible. The main purpose of this generic support is to avoid further code duplication to support new architectures and also to unify all the existing different implementations. This implementation maintains the hierarchy of cache objects which reflects the system's cache topology. Cache devices are instantiated as needed as CPUs come online. The cache information is replicated per-cpu even if they are shared. A per-cpu array of cache information maintained is used mainly for sysfs-related book keeping. It also implements the shared_cpu_map attribute, which is essential for enabling both kernel and user-space to discover the system's overall cache topology. This patch also add the missing ABI documentation for the cacheinfo sysfs interface already, which is well defined and widely used. Signed-off-by: Sudeep Holla <sudeep.holla@arm.com> Reviewed-by: Stephen Boyd <sboyd@codeaurora.org> Tested-by: Stephen Boyd <sboyd@codeaurora.org> Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org> Cc: linux-api@vger.kernel.org Cc: linux390@de.ibm.com Cc: linux-arm-kernel@lists.infradead.org Cc: linux-ia64@vger.kernel.org Cc: linuxppc-dev@lists.ozlabs.org Cc: linux-s390@vger.kernel.org Cc: x86@kernel.org Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2014-09-30 14:48:25 +01:00
drivers: base: support cpu cache information interface to userspace via sysfs This patch adds initial support for providing processor cache information to userspace through sysfs interface. This is based on already existing implementations(x86, ia64, s390 and powerpc) and hence the interface is intended to be fully compatible. The main purpose of this generic support is to avoid further code duplication to support new architectures and also to unify all the existing different implementations. This implementation maintains the hierarchy of cache objects which reflects the system's cache topology. Cache devices are instantiated as needed as CPUs come online. The cache information is replicated per-cpu even if they are shared. A per-cpu array of cache information maintained is used mainly for sysfs-related book keeping. It also implements the shared_cpu_map attribute, which is essential for enabling both kernel and user-space to discover the system's overall cache topology. This patch also add the missing ABI documentation for the cacheinfo sysfs interface already, which is well defined and widely used. Signed-off-by: Sudeep Holla <sudeep.holla@arm.com> Reviewed-by: Stephen Boyd <sboyd@codeaurora.org> Tested-by: Stephen Boyd <sboyd@codeaurora.org> Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org> Cc: linux-api@vger.kernel.org Cc: linux390@de.ibm.com Cc: linux-arm-kernel@lists.infradead.org Cc: linux-ia64@vger.kernel.org Cc: linuxppc-dev@lists.ozlabs.org Cc: linux-s390@vger.kernel.org Cc: x86@kernel.org Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2014-09-30 14:48:25 +01:00
drivers: base: support cpu cache information interface to userspace via sysfs This patch adds initial support for providing processor cache information to userspace through sysfs interface. This is based on already existing implementations(x86, ia64, s390 and powerpc) and hence the interface is intended to be fully compatible. The main purpose of this generic support is to avoid further code duplication to support new architectures and also to unify all the existing different implementations. This implementation maintains the hierarchy of cache objects which reflects the system's cache topology. Cache devices are instantiated as needed as CPUs come online. The cache information is replicated per-cpu even if they are shared. A per-cpu array of cache information maintained is used mainly for sysfs-related book keeping. It also implements the shared_cpu_map attribute, which is essential for enabling both kernel and user-space to discover the system's overall cache topology. This patch also add the missing ABI documentation for the cacheinfo sysfs interface already, which is well defined and widely used. Signed-off-by: Sudeep Holla <sudeep.holla@arm.com> Reviewed-by: Stephen Boyd <sboyd@codeaurora.org> Tested-by: Stephen Boyd <sboyd@codeaurora.org> Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org> Cc: linux-api@vger.kernel.org Cc: linux390@de.ibm.com Cc: linux-arm-kernel@lists.infradead.org Cc: linux-ia64@vger.kernel.org Cc: linuxppc-dev@lists.ozlabs.org Cc: linux-s390@vger.kernel.org Cc: x86@kernel.org Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2014-09-30 14:48:25 +01:00
drivers: base: cacheinfo: Fix shared_cpu_map changes in event of CPU hotplug While building the shared_cpu_map, check if the cache level and cache type matches. On certain systems that build the cache topology based on the instance ID, there are cases where the same ID may repeat across multiple cache levels, leading inaccurate topology. In event of CPU offlining, the cache_shared_cpu_map_remove() does not consider if IDs at same level are being compared. As a result, when same IDs repeat across different cache levels, the CPU going offline is not removed from all the shared_cpu_map. Below is the output of cache topology of CPU8 and it's SMT sibling after CPU8 is offlined on a dual socket 3rd Generation AMD EPYC processor (2 x 64C/128T) running kernel release v6.3: # for i in /sys/devices/system/cpu/cpu8/cache/index*/shared_cpu_list; do echo -n "$i: "; cat $i; done /sys/devices/system/cpu/cpu8/cache/index0/shared_cpu_list: 8,136 /sys/devices/system/cpu/cpu8/cache/index1/shared_cpu_list: 8,136 /sys/devices/system/cpu/cpu8/cache/index2/shared_cpu_list: 8,136 /sys/devices/system/cpu/cpu8/cache/index3/shared_cpu_list: 8-15,136-143 # echo 0 > /sys/devices/system/cpu/cpu8/online # for i in /sys/devices/system/cpu/cpu136/cache/index*/shared_cpu_list; do echo -n "$i: "; cat $i; done /sys/devices/system/cpu/cpu136/cache/index0/shared_cpu_list: 136 /sys/devices/system/cpu/cpu136/cache/index1/shared_cpu_list: 8,136 /sys/devices/system/cpu/cpu136/cache/index2/shared_cpu_list: 8,136 /sys/devices/system/cpu/cpu136/cache/index3/shared_cpu_list: 9-15,136-143 CPU8 is removed from index0 (L1i) but remains in the shared_cpu_list of index1 (L1d) and index2 (L2). Since L1i, L1d, and L2 are shared by the SMT siblings, and they have the same cache instance ID, CPU 2 is only removed from the first index with matching ID which is index1 (L1i) in this case. With this fix, the results are as expected when performing the same experiment on the same system: # for i in /sys/devices/system/cpu/cpu8/cache/index*/shared_cpu_list; do echo -n "$i: "; cat $i; done /sys/devices/system/cpu/cpu8/cache/index0/shared_cpu_list: 8,136 /sys/devices/system/cpu/cpu8/cache/index1/shared_cpu_list: 8,136 /sys/devices/system/cpu/cpu8/cache/index2/shared_cpu_list: 8,136 /sys/devices/system/cpu/cpu8/cache/index3/shared_cpu_list: 8-15,136-143 # echo 0 > /sys/devices/system/cpu/cpu8/online # for i in /sys/devices/system/cpu/cpu136/cache/index*/shared_cpu_list; do echo -n "$i: "; cat $i; done /sys/devices/system/cpu/cpu136/cache/index0/shared_cpu_list: 136 /sys/devices/system/cpu/cpu136/cache/index1/shared_cpu_list: 136 /sys/devices/system/cpu/cpu136/cache/index2/shared_cpu_list: 136 /sys/devices/system/cpu/cpu136/cache/index3/shared_cpu_list: 9-15,136-143 When rebuilding topology, the same problem appears as cache_shared_cpu_map_setup() implements a similar logic. Consider the same 3rd Generation EPYC processor: CPUs in Core 1, that share the L1 and L2 caches, have L1 and L2 instance ID as 1. For all the CPUs on the second chiplet, the L3 ID is also 1 leading to grouping on CPUs from Core 1 (1, 17) and the entire second chiplet (8-15, 24-31) as CPUs sharing one cache domain. This went undetected since x86 processors depended on arch specific populate_cache_leaves() method to repopulate the shared_cpus_map when CPU came back online until kernel release v6.3-rc5. Fixes: 198102c9103f ("cacheinfo: Fix shared_cpu_map to handle shared caches at different levels") Signed-off-by: K Prateek Nayak <kprateek.nayak@amd.com> Reviewed-by: Sudeep Holla <sudeep.holla@arm.com> Link: https://lore.kernel.org/r/20230508084115.1157-2-kprateek.nayak@amd.com Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2023-05-08 14:11:14 +05:30
drivers: base: support cpu cache information interface to userspace via sysfs This patch adds initial support for providing processor cache information to userspace through sysfs interface. This is based on already existing implementations(x86, ia64, s390 and powerpc) and hence the interface is intended to be fully compatible. The main purpose of this generic support is to avoid further code duplication to support new architectures and also to unify all the existing different implementations. This implementation maintains the hierarchy of cache objects which reflects the system's cache topology. Cache devices are instantiated as needed as CPUs come online. The cache information is replicated per-cpu even if they are shared. A per-cpu array of cache information maintained is used mainly for sysfs-related book keeping. It also implements the shared_cpu_map attribute, which is essential for enabling both kernel and user-space to discover the system's overall cache topology. This patch also add the missing ABI documentation for the cacheinfo sysfs interface already, which is well defined and widely used. Signed-off-by: Sudeep Holla <sudeep.holla@arm.com> Reviewed-by: Stephen Boyd <sboyd@codeaurora.org> Tested-by: Stephen Boyd <sboyd@codeaurora.org> Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org> Cc: linux-api@vger.kernel.org Cc: linux390@de.ibm.com Cc: linux-arm-kernel@lists.infradead.org Cc: linux-ia64@vger.kernel.org Cc: linuxppc-dev@lists.ozlabs.org Cc: linux-s390@vger.kernel.org Cc: x86@kernel.org Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2014-09-30 14:48:25 +01:00
drivers: base: support cpu cache information interface to userspace via sysfs This patch adds initial support for providing processor cache information to userspace through sysfs interface. This is based on already existing implementations(x86, ia64, s390 and powerpc) and hence the interface is intended to be fully compatible. The main purpose of this generic support is to avoid further code duplication to support new architectures and also to unify all the existing different implementations. This implementation maintains the hierarchy of cache objects which reflects the system's cache topology. Cache devices are instantiated as needed as CPUs come online. The cache information is replicated per-cpu even if they are shared. A per-cpu array of cache information maintained is used mainly for sysfs-related book keeping. It also implements the shared_cpu_map attribute, which is essential for enabling both kernel and user-space to discover the system's overall cache topology. This patch also add the missing ABI documentation for the cacheinfo sysfs interface already, which is well defined and widely used. Signed-off-by: Sudeep Holla <sudeep.holla@arm.com> Reviewed-by: Stephen Boyd <sboyd@codeaurora.org> Tested-by: Stephen Boyd <sboyd@codeaurora.org> Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org> Cc: linux-api@vger.kernel.org Cc: linux390@de.ibm.com Cc: linux-arm-kernel@lists.infradead.org Cc: linux-ia64@vger.kernel.org Cc: linuxppc-dev@lists.ozlabs.org Cc: linux-s390@vger.kernel.org Cc: x86@kernel.org Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2014-09-30 14:48:25 +01:00
drivers: base: cacheinfo: Update cpu_map_populated during CPU Hotplug Until commit 5c2712387d48 ("cacheinfo: Fix LLC is not exported through sysfs"), cacheinfo called populate_cache_leaves() for CPU coming online which let the arch specific functions handle (at least on x86) populating the shared_cpu_map. However, with the changes in the aforementioned commit, populate_cache_leaves() is not called when a CPU comes online as a result of hotplug since last_level_cache_is_valid() returns true as the cacheinfo data is not discarded. The CPU coming online is not present in shared_cpu_map, however, it will not be added since the cpu_cacheinfo->cpu_map_populated flag is set (it is set in populate_cache_leaves() when cacheinfo is first populated for x86) This can lead to inconsistencies in the shared_cpu_map when an offlined CPU comes online again. Example below depicts the inconsistency in the shared_cpu_list in cacheinfo when CPU8 is offlined and onlined again on a 3rd Generation EPYC processor: # for i in /sys/devices/system/cpu/cpu8/cache/index*/shared_cpu_list; do echo -n "$i: "; cat $i; done /sys/devices/system/cpu/cpu8/cache/index0/shared_cpu_list: 8,136 /sys/devices/system/cpu/cpu8/cache/index1/shared_cpu_list: 8,136 /sys/devices/system/cpu/cpu8/cache/index2/shared_cpu_list: 8,136 /sys/devices/system/cpu/cpu8/cache/index3/shared_cpu_list: 8-15,136-143 # echo 0 > /sys/devices/system/cpu/cpu8/online # echo 1 > /sys/devices/system/cpu/cpu8/online # for i in /sys/devices/system/cpu/cpu8/cache/index*/shared_cpu_list; do echo -n "$i: "; cat $i; done /sys/devices/system/cpu/cpu8/cache/index0/shared_cpu_list: 8 /sys/devices/system/cpu/cpu8/cache/index1/shared_cpu_list: 8 /sys/devices/system/cpu/cpu8/cache/index2/shared_cpu_list: 8 /sys/devices/system/cpu/cpu8/cache/index3/shared_cpu_list: 8 # cat /sys/devices/system/cpu/cpu136/cache/index0/shared_cpu_list 136 # cat /sys/devices/system/cpu/cpu136/cache/index3/shared_cpu_list 9-15,136-143 Clear the flag when the CPU is removed from shared_cpu_map when cache_shared_cpu_map_remove() is called during CPU hotplug. This will allow cache_shared_cpu_map_setup() to add the CPU coming back online in the shared_cpu_map. Set the flag again when the shared_cpu_map is setup. Following are results of performing the same test as described above with the changes: # for i in /sys/devices/system/cpu/cpu8/cache/index*/shared_cpu_list; do echo -n "$i: "; cat $i; done /sys/devices/system/cpu/cpu8/cache/index0/shared_cpu_list: 8,136 /sys/devices/system/cpu/cpu8/cache/index1/shared_cpu_list: 8,136 /sys/devices/system/cpu/cpu8/cache/index2/shared_cpu_list: 8,136 /sys/devices/system/cpu/cpu8/cache/index3/shared_cpu_list: 8-15,136-143 # echo 0 > /sys/devices/system/cpu/cpu8/online # echo 1 > /sys/devices/system/cpu/cpu8/online # for i in /sys/devices/system/cpu/cpu8/cache/index*/shared_cpu_list; do echo -n "$i: "; cat $i; done /sys/devices/system/cpu/cpu8/cache/index0/shared_cpu_list: 8,136 /sys/devices/system/cpu/cpu8/cache/index1/shared_cpu_list: 8,136 /sys/devices/system/cpu/cpu8/cache/index2/shared_cpu_list: 8,136 /sys/devices/system/cpu/cpu8/cache/index3/shared_cpu_list: 8-15,136-143 # cat /sys/devices/system/cpu/cpu136/cache/index0/shared_cpu_list 8,136 # cat /sys/devices/system/cpu/cpu136/cache/index3/shared_cpu_list 8-15,136-143 Fixes: 5c2712387d48 ("cacheinfo: Fix LLC is not exported through sysfs") Signed-off-by: K Prateek Nayak <kprateek.nayak@amd.com> Reviewed-by: Yicong Yang <yangyicong@hisilicon.com> Reviewed-by: Sudeep Holla <sudeep.holla@arm.com> Link: https://lore.kernel.org/r/20230508084115.1157-3-kprateek.nayak@amd.com Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2023-05-08 14:11:15 +05:30
drivers: base: support cpu cache information interface to userspace via sysfs This patch adds initial support for providing processor cache information to userspace through sysfs interface. This is based on already existing implementations(x86, ia64, s390 and powerpc) and hence the interface is intended to be fully compatible. The main purpose of this generic support is to avoid further code duplication to support new architectures and also to unify all the existing different implementations. This implementation maintains the hierarchy of cache objects which reflects the system's cache topology. Cache devices are instantiated as needed as CPUs come online. The cache information is replicated per-cpu even if they are shared. A per-cpu array of cache information maintained is used mainly for sysfs-related book keeping. It also implements the shared_cpu_map attribute, which is essential for enabling both kernel and user-space to discover the system's overall cache topology. This patch also add the missing ABI documentation for the cacheinfo sysfs interface already, which is well defined and widely used. Signed-off-by: Sudeep Holla <sudeep.holla@arm.com> Reviewed-by: Stephen Boyd <sboyd@codeaurora.org> Tested-by: Stephen Boyd <sboyd@codeaurora.org> Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org> Cc: linux-api@vger.kernel.org Cc: linux390@de.ibm.com Cc: linux-arm-kernel@lists.infradead.org Cc: linux-ia64@vger.kernel.org Cc: linuxppc-dev@lists.ozlabs.org Cc: linux-s390@vger.kernel.org Cc: x86@kernel.org Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2014-09-30 14:48:25 +01:00
drivers: base: cacheinfo: Update cpu_map_populated during CPU Hotplug Until commit 5c2712387d48 ("cacheinfo: Fix LLC is not exported through sysfs"), cacheinfo called populate_cache_leaves() for CPU coming online which let the arch specific functions handle (at least on x86) populating the shared_cpu_map. However, with the changes in the aforementioned commit, populate_cache_leaves() is not called when a CPU comes online as a result of hotplug since last_level_cache_is_valid() returns true as the cacheinfo data is not discarded. The CPU coming online is not present in shared_cpu_map, however, it will not be added since the cpu_cacheinfo->cpu_map_populated flag is set (it is set in populate_cache_leaves() when cacheinfo is first populated for x86) This can lead to inconsistencies in the shared_cpu_map when an offlined CPU comes online again. Example below depicts the inconsistency in the shared_cpu_list in cacheinfo when CPU8 is offlined and onlined again on a 3rd Generation EPYC processor: # for i in /sys/devices/system/cpu/cpu8/cache/index*/shared_cpu_list; do echo -n "$i: "; cat $i; done /sys/devices/system/cpu/cpu8/cache/index0/shared_cpu_list: 8,136 /sys/devices/system/cpu/cpu8/cache/index1/shared_cpu_list: 8,136 /sys/devices/system/cpu/cpu8/cache/index2/shared_cpu_list: 8,136 /sys/devices/system/cpu/cpu8/cache/index3/shared_cpu_list: 8-15,136-143 # echo 0 > /sys/devices/system/cpu/cpu8/online # echo 1 > /sys/devices/system/cpu/cpu8/online # for i in /sys/devices/system/cpu/cpu8/cache/index*/shared_cpu_list; do echo -n "$i: "; cat $i; done /sys/devices/system/cpu/cpu8/cache/index0/shared_cpu_list: 8 /sys/devices/system/cpu/cpu8/cache/index1/shared_cpu_list: 8 /sys/devices/system/cpu/cpu8/cache/index2/shared_cpu_list: 8 /sys/devices/system/cpu/cpu8/cache/index3/shared_cpu_list: 8 # cat /sys/devices/system/cpu/cpu136/cache/index0/shared_cpu_list 136 # cat /sys/devices/system/cpu/cpu136/cache/index3/shared_cpu_list 9-15,136-143 Clear the flag when the CPU is removed from shared_cpu_map when cache_shared_cpu_map_remove() is called during CPU hotplug. This will allow cache_shared_cpu_map_setup() to add the CPU coming back online in the shared_cpu_map. Set the flag again when the shared_cpu_map is setup. Following are results of performing the same test as described above with the changes: # for i in /sys/devices/system/cpu/cpu8/cache/index*/shared_cpu_list; do echo -n "$i: "; cat $i; done /sys/devices/system/cpu/cpu8/cache/index0/shared_cpu_list: 8,136 /sys/devices/system/cpu/cpu8/cache/index1/shared_cpu_list: 8,136 /sys/devices/system/cpu/cpu8/cache/index2/shared_cpu_list: 8,136 /sys/devices/system/cpu/cpu8/cache/index3/shared_cpu_list: 8-15,136-143 # echo 0 > /sys/devices/system/cpu/cpu8/online # echo 1 > /sys/devices/system/cpu/cpu8/online # for i in /sys/devices/system/cpu/cpu8/cache/index*/shared_cpu_list; do echo -n "$i: "; cat $i; done /sys/devices/system/cpu/cpu8/cache/index0/shared_cpu_list: 8,136 /sys/devices/system/cpu/cpu8/cache/index1/shared_cpu_list: 8,136 /sys/devices/system/cpu/cpu8/cache/index2/shared_cpu_list: 8,136 /sys/devices/system/cpu/cpu8/cache/index3/shared_cpu_list: 8-15,136-143 # cat /sys/devices/system/cpu/cpu136/cache/index0/shared_cpu_list 8,136 # cat /sys/devices/system/cpu/cpu136/cache/index3/shared_cpu_list 8-15,136-143 Fixes: 5c2712387d48 ("cacheinfo: Fix LLC is not exported through sysfs") Signed-off-by: K Prateek Nayak <kprateek.nayak@amd.com> Reviewed-by: Yicong Yang <yangyicong@hisilicon.com> Reviewed-by: Sudeep Holla <sudeep.holla@arm.com> Link: https://lore.kernel.org/r/20230508084115.1157-3-kprateek.nayak@amd.com Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2023-05-08 14:11:15 +05:30
drivers: base: support cpu cache information interface to userspace via sysfs This patch adds initial support for providing processor cache information to userspace through sysfs interface. This is based on already existing implementations(x86, ia64, s390 and powerpc) and hence the interface is intended to be fully compatible. The main purpose of this generic support is to avoid further code duplication to support new architectures and also to unify all the existing different implementations. This implementation maintains the hierarchy of cache objects which reflects the system's cache topology. Cache devices are instantiated as needed as CPUs come online. The cache information is replicated per-cpu even if they are shared. A per-cpu array of cache information maintained is used mainly for sysfs-related book keeping. It also implements the shared_cpu_map attribute, which is essential for enabling both kernel and user-space to discover the system's overall cache topology. This patch also add the missing ABI documentation for the cacheinfo sysfs interface already, which is well defined and widely used. Signed-off-by: Sudeep Holla <sudeep.holla@arm.com> Reviewed-by: Stephen Boyd <sboyd@codeaurora.org> Tested-by: Stephen Boyd <sboyd@codeaurora.org> Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org> Cc: linux-api@vger.kernel.org Cc: linux390@de.ibm.com Cc: linux-arm-kernel@lists.infradead.org Cc: linux-ia64@vger.kernel.org Cc: linuxppc-dev@lists.ozlabs.org Cc: linux-s390@vger.kernel.org Cc: x86@kernel.org Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2014-09-30 14:48:25 +01:00
drivers: base: support cpu cache information interface to userspace via sysfs This patch adds initial support for providing processor cache information to userspace through sysfs interface. This is based on already existing implementations(x86, ia64, s390 and powerpc) and hence the interface is intended to be fully compatible. The main purpose of this generic support is to avoid further code duplication to support new architectures and also to unify all the existing different implementations. This implementation maintains the hierarchy of cache objects which reflects the system's cache topology. Cache devices are instantiated as needed as CPUs come online. The cache information is replicated per-cpu even if they are shared. A per-cpu array of cache information maintained is used mainly for sysfs-related book keeping. It also implements the shared_cpu_map attribute, which is essential for enabling both kernel and user-space to discover the system's overall cache topology. This patch also add the missing ABI documentation for the cacheinfo sysfs interface already, which is well defined and widely used. Signed-off-by: Sudeep Holla <sudeep.holla@arm.com> Reviewed-by: Stephen Boyd <sboyd@codeaurora.org> Tested-by: Stephen Boyd <sboyd@codeaurora.org> Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org> Cc: linux-api@vger.kernel.org Cc: linux390@de.ibm.com Cc: linux-arm-kernel@lists.infradead.org Cc: linux-ia64@vger.kernel.org Cc: linuxppc-dev@lists.ozlabs.org Cc: linux-s390@vger.kernel.org Cc: x86@kernel.org Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2014-09-30 14:48:25 +01:00
drivers: base: support cpu cache information interface to userspace via sysfs This patch adds initial support for providing processor cache information to userspace through sysfs interface. This is based on already existing implementations(x86, ia64, s390 and powerpc) and hence the interface is intended to be fully compatible. The main purpose of this generic support is to avoid further code duplication to support new architectures and also to unify all the existing different implementations. This implementation maintains the hierarchy of cache objects which reflects the system's cache topology. Cache devices are instantiated as needed as CPUs come online. The cache information is replicated per-cpu even if they are shared. A per-cpu array of cache information maintained is used mainly for sysfs-related book keeping. It also implements the shared_cpu_map attribute, which is essential for enabling both kernel and user-space to discover the system's overall cache topology. This patch also add the missing ABI documentation for the cacheinfo sysfs interface already, which is well defined and widely used. Signed-off-by: Sudeep Holla <sudeep.holla@arm.com> Reviewed-by: Stephen Boyd <sboyd@codeaurora.org> Tested-by: Stephen Boyd <sboyd@codeaurora.org> Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org> Cc: linux-api@vger.kernel.org Cc: linux390@de.ibm.com Cc: linux-arm-kernel@lists.infradead.org Cc: linux-ia64@vger.kernel.org Cc: linuxppc-dev@lists.ozlabs.org Cc: linux-s390@vger.kernel.org Cc: x86@kernel.org Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2014-09-30 14:48:25 +01:00
drivers: base: cacheinfo: Fix shared_cpu_map changes in event of CPU hotplug While building the shared_cpu_map, check if the cache level and cache type matches. On certain systems that build the cache topology based on the instance ID, there are cases where the same ID may repeat across multiple cache levels, leading inaccurate topology. In event of CPU offlining, the cache_shared_cpu_map_remove() does not consider if IDs at same level are being compared. As a result, when same IDs repeat across different cache levels, the CPU going offline is not removed from all the shared_cpu_map. Below is the output of cache topology of CPU8 and it's SMT sibling after CPU8 is offlined on a dual socket 3rd Generation AMD EPYC processor (2 x 64C/128T) running kernel release v6.3: # for i in /sys/devices/system/cpu/cpu8/cache/index*/shared_cpu_list; do echo -n "$i: "; cat $i; done /sys/devices/system/cpu/cpu8/cache/index0/shared_cpu_list: 8,136 /sys/devices/system/cpu/cpu8/cache/index1/shared_cpu_list: 8,136 /sys/devices/system/cpu/cpu8/cache/index2/shared_cpu_list: 8,136 /sys/devices/system/cpu/cpu8/cache/index3/shared_cpu_list: 8-15,136-143 # echo 0 > /sys/devices/system/cpu/cpu8/online # for i in /sys/devices/system/cpu/cpu136/cache/index*/shared_cpu_list; do echo -n "$i: "; cat $i; done /sys/devices/system/cpu/cpu136/cache/index0/shared_cpu_list: 136 /sys/devices/system/cpu/cpu136/cache/index1/shared_cpu_list: 8,136 /sys/devices/system/cpu/cpu136/cache/index2/shared_cpu_list: 8,136 /sys/devices/system/cpu/cpu136/cache/index3/shared_cpu_list: 9-15,136-143 CPU8 is removed from index0 (L1i) but remains in the shared_cpu_list of index1 (L1d) and index2 (L2). Since L1i, L1d, and L2 are shared by the SMT siblings, and they have the same cache instance ID, CPU 2 is only removed from the first index with matching ID which is index1 (L1i) in this case. With this fix, the results are as expected when performing the same experiment on the same system: # for i in /sys/devices/system/cpu/cpu8/cache/index*/shared_cpu_list; do echo -n "$i: "; cat $i; done /sys/devices/system/cpu/cpu8/cache/index0/shared_cpu_list: 8,136 /sys/devices/system/cpu/cpu8/cache/index1/shared_cpu_list: 8,136 /sys/devices/system/cpu/cpu8/cache/index2/shared_cpu_list: 8,136 /sys/devices/system/cpu/cpu8/cache/index3/shared_cpu_list: 8-15,136-143 # echo 0 > /sys/devices/system/cpu/cpu8/online # for i in /sys/devices/system/cpu/cpu136/cache/index*/shared_cpu_list; do echo -n "$i: "; cat $i; done /sys/devices/system/cpu/cpu136/cache/index0/shared_cpu_list: 136 /sys/devices/system/cpu/cpu136/cache/index1/shared_cpu_list: 136 /sys/devices/system/cpu/cpu136/cache/index2/shared_cpu_list: 136 /sys/devices/system/cpu/cpu136/cache/index3/shared_cpu_list: 9-15,136-143 When rebuilding topology, the same problem appears as cache_shared_cpu_map_setup() implements a similar logic. Consider the same 3rd Generation EPYC processor: CPUs in Core 1, that share the L1 and L2 caches, have L1 and L2 instance ID as 1. For all the CPUs on the second chiplet, the L3 ID is also 1 leading to grouping on CPUs from Core 1 (1, 17) and the entire second chiplet (8-15, 24-31) as CPUs sharing one cache domain. This went undetected since x86 processors depended on arch specific populate_cache_leaves() method to repopulate the shared_cpus_map when CPU came back online until kernel release v6.3-rc5. Fixes: 198102c9103f ("cacheinfo: Fix shared_cpu_map to handle shared caches at different levels") Signed-off-by: K Prateek Nayak <kprateek.nayak@amd.com> Reviewed-by: Sudeep Holla <sudeep.holla@arm.com> Link: https://lore.kernel.org/r/20230508084115.1157-2-kprateek.nayak@amd.com Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2023-05-08 14:11:14 +05:30
drivers: base: support cpu cache information interface to userspace via sysfs This patch adds initial support for providing processor cache information to userspace through sysfs interface. This is based on already existing implementations(x86, ia64, s390 and powerpc) and hence the interface is intended to be fully compatible. The main purpose of this generic support is to avoid further code duplication to support new architectures and also to unify all the existing different implementations. This implementation maintains the hierarchy of cache objects which reflects the system's cache topology. Cache devices are instantiated as needed as CPUs come online. The cache information is replicated per-cpu even if they are shared. A per-cpu array of cache information maintained is used mainly for sysfs-related book keeping. It also implements the shared_cpu_map attribute, which is essential for enabling both kernel and user-space to discover the system's overall cache topology. This patch also add the missing ABI documentation for the cacheinfo sysfs interface already, which is well defined and widely used. Signed-off-by: Sudeep Holla <sudeep.holla@arm.com> Reviewed-by: Stephen Boyd <sboyd@codeaurora.org> Tested-by: Stephen Boyd <sboyd@codeaurora.org> Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org> Cc: linux-api@vger.kernel.org Cc: linux390@de.ibm.com Cc: linux-arm-kernel@lists.infradead.org Cc: linux-ia64@vger.kernel.org Cc: linuxppc-dev@lists.ozlabs.org Cc: linux-s390@vger.kernel.org Cc: x86@kernel.org Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2014-09-30 14:48:25 +01:00
drivers: base: cacheinfo: Update cpu_map_populated during CPU Hotplug Until commit 5c2712387d48 ("cacheinfo: Fix LLC is not exported through sysfs"), cacheinfo called populate_cache_leaves() for CPU coming online which let the arch specific functions handle (at least on x86) populating the shared_cpu_map. However, with the changes in the aforementioned commit, populate_cache_leaves() is not called when a CPU comes online as a result of hotplug since last_level_cache_is_valid() returns true as the cacheinfo data is not discarded. The CPU coming online is not present in shared_cpu_map, however, it will not be added since the cpu_cacheinfo->cpu_map_populated flag is set (it is set in populate_cache_leaves() when cacheinfo is first populated for x86) This can lead to inconsistencies in the shared_cpu_map when an offlined CPU comes online again. Example below depicts the inconsistency in the shared_cpu_list in cacheinfo when CPU8 is offlined and onlined again on a 3rd Generation EPYC processor: # for i in /sys/devices/system/cpu/cpu8/cache/index*/shared_cpu_list; do echo -n "$i: "; cat $i; done /sys/devices/system/cpu/cpu8/cache/index0/shared_cpu_list: 8,136 /sys/devices/system/cpu/cpu8/cache/index1/shared_cpu_list: 8,136 /sys/devices/system/cpu/cpu8/cache/index2/shared_cpu_list: 8,136 /sys/devices/system/cpu/cpu8/cache/index3/shared_cpu_list: 8-15,136-143 # echo 0 > /sys/devices/system/cpu/cpu8/online # echo 1 > /sys/devices/system/cpu/cpu8/online # for i in /sys/devices/system/cpu/cpu8/cache/index*/shared_cpu_list; do echo -n "$i: "; cat $i; done /sys/devices/system/cpu/cpu8/cache/index0/shared_cpu_list: 8 /sys/devices/system/cpu/cpu8/cache/index1/shared_cpu_list: 8 /sys/devices/system/cpu/cpu8/cache/index2/shared_cpu_list: 8 /sys/devices/system/cpu/cpu8/cache/index3/shared_cpu_list: 8 # cat /sys/devices/system/cpu/cpu136/cache/index0/shared_cpu_list 136 # cat /sys/devices/system/cpu/cpu136/cache/index3/shared_cpu_list 9-15,136-143 Clear the flag when the CPU is removed from shared_cpu_map when cache_shared_cpu_map_remove() is called during CPU hotplug. This will allow cache_shared_cpu_map_setup() to add the CPU coming back online in the shared_cpu_map. Set the flag again when the shared_cpu_map is setup. Following are results of performing the same test as described above with the changes: # for i in /sys/devices/system/cpu/cpu8/cache/index*/shared_cpu_list; do echo -n "$i: "; cat $i; done /sys/devices/system/cpu/cpu8/cache/index0/shared_cpu_list: 8,136 /sys/devices/system/cpu/cpu8/cache/index1/shared_cpu_list: 8,136 /sys/devices/system/cpu/cpu8/cache/index2/shared_cpu_list: 8,136 /sys/devices/system/cpu/cpu8/cache/index3/shared_cpu_list: 8-15,136-143 # echo 0 > /sys/devices/system/cpu/cpu8/online # echo 1 > /sys/devices/system/cpu/cpu8/online # for i in /sys/devices/system/cpu/cpu8/cache/index*/shared_cpu_list; do echo -n "$i: "; cat $i; done /sys/devices/system/cpu/cpu8/cache/index0/shared_cpu_list: 8,136 /sys/devices/system/cpu/cpu8/cache/index1/shared_cpu_list: 8,136 /sys/devices/system/cpu/cpu8/cache/index2/shared_cpu_list: 8,136 /sys/devices/system/cpu/cpu8/cache/index3/shared_cpu_list: 8-15,136-143 # cat /sys/devices/system/cpu/cpu136/cache/index0/shared_cpu_list 8,136 # cat /sys/devices/system/cpu/cpu136/cache/index3/shared_cpu_list 8-15,136-143 Fixes: 5c2712387d48 ("cacheinfo: Fix LLC is not exported through sysfs") Signed-off-by: K Prateek Nayak <kprateek.nayak@amd.com> Reviewed-by: Yicong Yang <yangyicong@hisilicon.com> Reviewed-by: Sudeep Holla <sudeep.holla@arm.com> Link: https://lore.kernel.org/r/20230508084115.1157-3-kprateek.nayak@amd.com Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2023-05-08 14:11:15 +05:30
drivers: base: support cpu cache information interface to userspace via sysfs This patch adds initial support for providing processor cache information to userspace through sysfs interface. This is based on already existing implementations(x86, ia64, s390 and powerpc) and hence the interface is intended to be fully compatible. The main purpose of this generic support is to avoid further code duplication to support new architectures and also to unify all the existing different implementations. This implementation maintains the hierarchy of cache objects which reflects the system's cache topology. Cache devices are instantiated as needed as CPUs come online. The cache information is replicated per-cpu even if they are shared. A per-cpu array of cache information maintained is used mainly for sysfs-related book keeping. It also implements the shared_cpu_map attribute, which is essential for enabling both kernel and user-space to discover the system's overall cache topology. This patch also add the missing ABI documentation for the cacheinfo sysfs interface already, which is well defined and widely used. Signed-off-by: Sudeep Holla <sudeep.holla@arm.com> Reviewed-by: Stephen Boyd <sboyd@codeaurora.org> Tested-by: Stephen Boyd <sboyd@codeaurora.org> Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org> Cc: linux-api@vger.kernel.org Cc: linux390@de.ibm.com Cc: linux-arm-kernel@lists.infradead.org Cc: linux-ia64@vger.kernel.org Cc: linuxppc-dev@lists.ozlabs.org Cc: linux-s390@vger.kernel.org Cc: x86@kernel.org Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2014-09-30 14:48:25 +01:00
drivers: base: support cpu cache information interface to userspace via sysfs This patch adds initial support for providing processor cache information to userspace through sysfs interface. This is based on already existing implementations(x86, ia64, s390 and powerpc) and hence the interface is intended to be fully compatible. The main purpose of this generic support is to avoid further code duplication to support new architectures and also to unify all the existing different implementations. This implementation maintains the hierarchy of cache objects which reflects the system's cache topology. Cache devices are instantiated as needed as CPUs come online. The cache information is replicated per-cpu even if they are shared. A per-cpu array of cache information maintained is used mainly for sysfs-related book keeping. It also implements the shared_cpu_map attribute, which is essential for enabling both kernel and user-space to discover the system's overall cache topology. This patch also add the missing ABI documentation for the cacheinfo sysfs interface already, which is well defined and widely used. Signed-off-by: Sudeep Holla <sudeep.holla@arm.com> Reviewed-by: Stephen Boyd <sboyd@codeaurora.org> Tested-by: Stephen Boyd <sboyd@codeaurora.org> Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org> Cc: linux-api@vger.kernel.org Cc: linux390@de.ibm.com Cc: linux-arm-kernel@lists.infradead.org Cc: linux-ia64@vger.kernel.org Cc: linuxppc-dev@lists.ozlabs.org Cc: linux-s390@vger.kernel.org Cc: x86@kernel.org Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2014-09-30 14:48:25 +01:00
cacheinfo: Add arch specific early level initializer This patch gives architecture specific code the ability to initialize the cache level and allocate cacheinfo memory early, when cache level initialization runs on the primary CPU for all possible CPUs. This is part of a patch series that attempts to further the work in commit 5944ce092b97 ("arch_topology: Build cacheinfo from primary CPU"). Previously, in the absence of any DT/ACPI cache info, architecture specific cache detection and info allocation for secondary CPUs would happen in non-preemptible context during early CPU initialization and trigger a "BUG: sleeping function called from invalid context" splat on an RT kernel. More specifically, this patch adds the early_cache_level() function, which is called by fetch_cache_info() as a fallback when the number of cache leaves cannot be extracted from DT/ACPI. In the default generic (weak) implementation, this new function returns -ENOENT, which preserves the original behavior for architectures that do not implement the function. Since early detection can get the number of cache leaves wrong in some cases*, additional logic is added to still call init_cache_level() later on the secondary CPU, therefore giving the architecture specific code an opportunity to go back and fix the initial guess. Again, the original behavior is preserved for architectures that do not implement the new function. * For example, on arm64, CLIDR_EL1 detection works only when it runs on the current CPU. In other words, a CPU cannot detect the cache depth for any other CPU than itself. Signed-off-by: Radu Rendec <rrendec@redhat.com> Reviewed-by: Pierre Gondois <pierre.gondois@arm.com> Link: https://lore.kernel.org/r/20230412185759.755408-2-rrendec@redhat.com Signed-off-by: Sudeep Holla <sudeep.holla@arm.com>
2023-04-12 14:57:57 -04:00
drivers: base: support cpu cache information interface to userspace via sysfs This patch adds initial support for providing processor cache information to userspace through sysfs interface. This is based on already existing implementations(x86, ia64, s390 and powerpc) and hence the interface is intended to be fully compatible. The main purpose of this generic support is to avoid further code duplication to support new architectures and also to unify all the existing different implementations. This implementation maintains the hierarchy of cache objects which reflects the system's cache topology. Cache devices are instantiated as needed as CPUs come online. The cache information is replicated per-cpu even if they are shared. A per-cpu array of cache information maintained is used mainly for sysfs-related book keeping. It also implements the shared_cpu_map attribute, which is essential for enabling both kernel and user-space to discover the system's overall cache topology. This patch also add the missing ABI documentation for the cacheinfo sysfs interface already, which is well defined and widely used. Signed-off-by: Sudeep Holla <sudeep.holla@arm.com> Reviewed-by: Stephen Boyd <sboyd@codeaurora.org> Tested-by: Stephen Boyd <sboyd@codeaurora.org> Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org> Cc: linux-api@vger.kernel.org Cc: linux390@de.ibm.com Cc: linux-arm-kernel@lists.infradead.org Cc: linux-ia64@vger.kernel.org Cc: linuxppc-dev@lists.ozlabs.org Cc: linux-s390@vger.kernel.org Cc: x86@kernel.org Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2014-09-30 14:48:25 +01:00
cacheinfo: Allocate memory during CPU hotplug if not done from the primary CPU Commit 5944ce092b97 ("arch_topology: Build cacheinfo from primary CPU") adds functionality that architectures can use to optionally allocate and build cacheinfo early during boot. Commit 6539cffa9495 ("cacheinfo: Add arch specific early level initializer") lets secondary CPUs correct (and reallocate memory) cacheinfo data if needed. If the early build functionality is not used and cacheinfo does not need correction, memory for cacheinfo is never allocated. x86 does not use the early build functionality. Consequently, during the cacheinfo CPU hotplug callback, last_level_cache_is_valid() attempts to dereference a NULL pointer: BUG: kernel NULL pointer dereference, address: 0000000000000100 #PF: supervisor read access in kernel mode #PF: error_code(0x0000) - not present page PGD 0 P4D 0 Oops: 0000 [#1] PREEPMT SMP NOPTI CPU: 0 PID 19 Comm: cpuhp/0 Not tainted 6.4.0-rc2 #1 RIP: 0010: last_level_cache_is_valid+0x95/0xe0a Allocate memory for cacheinfo during the cacheinfo CPU hotplug callback if not done earlier. Moreover, before determining the validity of the last-level cache info, ensure that it has been allocated. Simply checking for non-zero cache_leaves() is not sufficient, as some architectures (e.g., Intel processors) have non-zero cache_leaves() before allocation. Dereferencing NULL cacheinfo can occur in update_per_cpu_data_slice_size(). This function iterates over all online CPUs. However, a CPU may have come online recently, but its cacheinfo may not have been allocated yet. While here, remove an unnecessary indentation in allocate_cache_info(). [ bp: Massage. ] Fixes: 6539cffa9495 ("cacheinfo: Add arch specific early level initializer") Signed-off-by: Ricardo Neri <ricardo.neri-calderon@linux.intel.com> Signed-off-by: Borislav Petkov (AMD) <bp@alien8.de> Reviewed-by: Radu Rendec <rrendec@redhat.com> Reviewed-by: Nikolay Borisov <nik.borisov@suse.com> Reviewed-by: Andreas Herrmann <aherrmann@suse.de> Reviewed-by: Sudeep Holla <sudeep.holla@arm.com> Cc: stable@vger.kernel.org # 6.3+ Link: https://lore.kernel.org/r/20241128002247.26726-2-ricardo.neri-calderon@linux.intel.com
2024-11-27 16:22:46 -08:00
arch_topology: Build cacheinfo from primary CPU commit 3fcbf1c77d08 ("arch_topology: Fix cache attributes detection in the CPU hotplug path") adds a call to detect_cache_attributes() to populate the cacheinfo before updating the siblings mask. detect_cache_attributes() allocates memory and can take the PPTT mutex (on ACPI platforms). On PREEMPT_RT kernels, on secondary CPUs, this triggers a: 'BUG: sleeping function called from invalid context' [1] as the code is executed with preemption and interrupts disabled. The primary CPU was previously storing the cache information using the now removed (struct cpu_topology).llc_id: commit 5b8dc787ce4a ("arch_topology: Drop LLC identifier stash from the CPU topology") allocate_cache_info() tries to build the cacheinfo from the primary CPU prior secondary CPUs boot, if the DT/ACPI description contains cache information. If allocate_cache_info() fails, then fallback to the current state for the cacheinfo allocation. [1] will be triggered in such case. When unplugging a CPU, the cacheinfo memory cannot be freed. If it was, then the memory would be allocated early by the re-plugged CPU and would trigger [1]. Note that populate_cache_leaves() might be called multiple times due to populate_leaves being moved up. This is required since detect_cache_attributes() might be called with per_cpu_cacheinfo(cpu) being allocated but not populated. [1]: | BUG: sleeping function called from invalid context at kernel/locking/spinlock_rt.c:46 | in_atomic(): 1, irqs_disabled(): 128, non_block: 0, pid: 0, name: swapper/111 | preempt_count: 1, expected: 0 | RCU nest depth: 1, expected: 1 | 3 locks held by swapper/111/0: | #0: (&pcp->lock){+.+.}-{3:3}, at: get_page_from_freelist+0x218/0x12c8 | #1: (rcu_read_lock){....}-{1:3}, at: rt_spin_trylock+0x48/0xf0 | #2: (&zone->lock){+.+.}-{3:3}, at: rmqueue_bulk+0x64/0xa80 | irq event stamp: 0 | hardirqs last enabled at (0): 0x0 | hardirqs last disabled at (0): copy_process+0x5dc/0x1ab8 | softirqs last enabled at (0): copy_process+0x5dc/0x1ab8 | softirqs last disabled at (0): 0x0 | Preemption disabled at: | migrate_enable+0x30/0x130 | CPU: 111 PID: 0 Comm: swapper/111 Tainted: G W 6.0.0-rc4-rt6-[...] | Call trace: | __kmalloc+0xbc/0x1e8 | detect_cache_attributes+0x2d4/0x5f0 | update_siblings_masks+0x30/0x368 | store_cpu_topology+0x78/0xb8 | secondary_start_kernel+0xd0/0x198 | __secondary_switched+0xb0/0xb4 Signed-off-by: Pierre Gondois <pierre.gondois@arm.com> Reviewed-by: Sudeep Holla <sudeep.holla@arm.com> Acked-by: Palmer Dabbelt <palmer@rivosinc.com> Link: https://lore.kernel.org/r/20230104183033.755668-7-pierre.gondois@arm.com Signed-off-by: Sudeep Holla <sudeep.holla@arm.com>
2023-01-04 19:30:29 +01:00
cacheinfo: Allocate memory during CPU hotplug if not done from the primary CPU Commit 5944ce092b97 ("arch_topology: Build cacheinfo from primary CPU") adds functionality that architectures can use to optionally allocate and build cacheinfo early during boot. Commit 6539cffa9495 ("cacheinfo: Add arch specific early level initializer") lets secondary CPUs correct (and reallocate memory) cacheinfo data if needed. If the early build functionality is not used and cacheinfo does not need correction, memory for cacheinfo is never allocated. x86 does not use the early build functionality. Consequently, during the cacheinfo CPU hotplug callback, last_level_cache_is_valid() attempts to dereference a NULL pointer: BUG: kernel NULL pointer dereference, address: 0000000000000100 #PF: supervisor read access in kernel mode #PF: error_code(0x0000) - not present page PGD 0 P4D 0 Oops: 0000 [#1] PREEPMT SMP NOPTI CPU: 0 PID 19 Comm: cpuhp/0 Not tainted 6.4.0-rc2 #1 RIP: 0010: last_level_cache_is_valid+0x95/0xe0a Allocate memory for cacheinfo during the cacheinfo CPU hotplug callback if not done earlier. Moreover, before determining the validity of the last-level cache info, ensure that it has been allocated. Simply checking for non-zero cache_leaves() is not sufficient, as some architectures (e.g., Intel processors) have non-zero cache_leaves() before allocation. Dereferencing NULL cacheinfo can occur in update_per_cpu_data_slice_size(). This function iterates over all online CPUs. However, a CPU may have come online recently, but its cacheinfo may not have been allocated yet. While here, remove an unnecessary indentation in allocate_cache_info(). [ bp: Massage. ] Fixes: 6539cffa9495 ("cacheinfo: Add arch specific early level initializer") Signed-off-by: Ricardo Neri <ricardo.neri-calderon@linux.intel.com> Signed-off-by: Borislav Petkov (AMD) <bp@alien8.de> Reviewed-by: Radu Rendec <rrendec@redhat.com> Reviewed-by: Nikolay Borisov <nik.borisov@suse.com> Reviewed-by: Andreas Herrmann <aherrmann@suse.de> Reviewed-by: Sudeep Holla <sudeep.holla@arm.com> Cc: stable@vger.kernel.org # 6.3+ Link: https://lore.kernel.org/r/20241128002247.26726-2-ricardo.neri-calderon@linux.intel.com
2024-11-27 16:22:46 -08:00
arch_topology: Build cacheinfo from primary CPU commit 3fcbf1c77d08 ("arch_topology: Fix cache attributes detection in the CPU hotplug path") adds a call to detect_cache_attributes() to populate the cacheinfo before updating the siblings mask. detect_cache_attributes() allocates memory and can take the PPTT mutex (on ACPI platforms). On PREEMPT_RT kernels, on secondary CPUs, this triggers a: 'BUG: sleeping function called from invalid context' [1] as the code is executed with preemption and interrupts disabled. The primary CPU was previously storing the cache information using the now removed (struct cpu_topology).llc_id: commit 5b8dc787ce4a ("arch_topology: Drop LLC identifier stash from the CPU topology") allocate_cache_info() tries to build the cacheinfo from the primary CPU prior secondary CPUs boot, if the DT/ACPI description contains cache information. If allocate_cache_info() fails, then fallback to the current state for the cacheinfo allocation. [1] will be triggered in such case. When unplugging a CPU, the cacheinfo memory cannot be freed. If it was, then the memory would be allocated early by the re-plugged CPU and would trigger [1]. Note that populate_cache_leaves() might be called multiple times due to populate_leaves being moved up. This is required since detect_cache_attributes() might be called with per_cpu_cacheinfo(cpu) being allocated but not populated. [1]: | BUG: sleeping function called from invalid context at kernel/locking/spinlock_rt.c:46 | in_atomic(): 1, irqs_disabled(): 128, non_block: 0, pid: 0, name: swapper/111 | preempt_count: 1, expected: 0 | RCU nest depth: 1, expected: 1 | 3 locks held by swapper/111/0: | #0: (&pcp->lock){+.+.}-{3:3}, at: get_page_from_freelist+0x218/0x12c8 | #1: (rcu_read_lock){....}-{1:3}, at: rt_spin_trylock+0x48/0xf0 | #2: (&zone->lock){+.+.}-{3:3}, at: rmqueue_bulk+0x64/0xa80 | irq event stamp: 0 | hardirqs last enabled at (0): 0x0 | hardirqs last disabled at (0): copy_process+0x5dc/0x1ab8 | softirqs last enabled at (0): copy_process+0x5dc/0x1ab8 | softirqs last disabled at (0): 0x0 | Preemption disabled at: | migrate_enable+0x30/0x130 | CPU: 111 PID: 0 Comm: swapper/111 Tainted: G W 6.0.0-rc4-rt6-[...] | Call trace: | __kmalloc+0xbc/0x1e8 | detect_cache_attributes+0x2d4/0x5f0 | update_siblings_masks+0x30/0x368 | store_cpu_topology+0x78/0xb8 | secondary_start_kernel+0xd0/0x198 | __secondary_switched+0xb0/0xb4 Signed-off-by: Pierre Gondois <pierre.gondois@arm.com> Reviewed-by: Sudeep Holla <sudeep.holla@arm.com> Acked-by: Palmer Dabbelt <palmer@rivosinc.com> Link: https://lore.kernel.org/r/20230104183033.755668-7-pierre.gondois@arm.com Signed-off-by: Sudeep Holla <sudeep.holla@arm.com>
2023-01-04 19:30:29 +01:00
cacheinfo: Add arch specific early level initializer This patch gives architecture specific code the ability to initialize the cache level and allocate cacheinfo memory early, when cache level initialization runs on the primary CPU for all possible CPUs. This is part of a patch series that attempts to further the work in commit 5944ce092b97 ("arch_topology: Build cacheinfo from primary CPU"). Previously, in the absence of any DT/ACPI cache info, architecture specific cache detection and info allocation for secondary CPUs would happen in non-preemptible context during early CPU initialization and trigger a "BUG: sleeping function called from invalid context" splat on an RT kernel. More specifically, this patch adds the early_cache_level() function, which is called by fetch_cache_info() as a fallback when the number of cache leaves cannot be extracted from DT/ACPI. In the default generic (weak) implementation, this new function returns -ENOENT, which preserves the original behavior for architectures that do not implement the function. Since early detection can get the number of cache leaves wrong in some cases*, additional logic is added to still call init_cache_level() later on the secondary CPU, therefore giving the architecture specific code an opportunity to go back and fix the initial guess. Again, the original behavior is preserved for architectures that do not implement the new function. * For example, on arm64, CLIDR_EL1 detection works only when it runs on the current CPU. In other words, a CPU cannot detect the cache depth for any other CPU than itself. Signed-off-by: Radu Rendec <rrendec@redhat.com> Reviewed-by: Pierre Gondois <pierre.gondois@arm.com> Link: https://lore.kernel.org/r/20230412185759.755408-2-rrendec@redhat.com Signed-off-by: Sudeep Holla <sudeep.holla@arm.com>
2023-04-12 14:57:57 -04:00
arch_topology: Build cacheinfo from primary CPU commit 3fcbf1c77d08 ("arch_topology: Fix cache attributes detection in the CPU hotplug path") adds a call to detect_cache_attributes() to populate the cacheinfo before updating the siblings mask. detect_cache_attributes() allocates memory and can take the PPTT mutex (on ACPI platforms). On PREEMPT_RT kernels, on secondary CPUs, this triggers a: 'BUG: sleeping function called from invalid context' [1] as the code is executed with preemption and interrupts disabled. The primary CPU was previously storing the cache information using the now removed (struct cpu_topology).llc_id: commit 5b8dc787ce4a ("arch_topology: Drop LLC identifier stash from the CPU topology") allocate_cache_info() tries to build the cacheinfo from the primary CPU prior secondary CPUs boot, if the DT/ACPI description contains cache information. If allocate_cache_info() fails, then fallback to the current state for the cacheinfo allocation. [1] will be triggered in such case. When unplugging a CPU, the cacheinfo memory cannot be freed. If it was, then the memory would be allocated early by the re-plugged CPU and would trigger [1]. Note that populate_cache_leaves() might be called multiple times due to populate_leaves being moved up. This is required since detect_cache_attributes() might be called with per_cpu_cacheinfo(cpu) being allocated but not populated. [1]: | BUG: sleeping function called from invalid context at kernel/locking/spinlock_rt.c:46 | in_atomic(): 1, irqs_disabled(): 128, non_block: 0, pid: 0, name: swapper/111 | preempt_count: 1, expected: 0 | RCU nest depth: 1, expected: 1 | 3 locks held by swapper/111/0: | #0: (&pcp->lock){+.+.}-{3:3}, at: get_page_from_freelist+0x218/0x12c8 | #1: (rcu_read_lock){....}-{1:3}, at: rt_spin_trylock+0x48/0xf0 | #2: (&zone->lock){+.+.}-{3:3}, at: rmqueue_bulk+0x64/0xa80 | irq event stamp: 0 | hardirqs last enabled at (0): 0x0 | hardirqs last disabled at (0): copy_process+0x5dc/0x1ab8 | softirqs last enabled at (0): copy_process+0x5dc/0x1ab8 | softirqs last disabled at (0): 0x0 | Preemption disabled at: | migrate_enable+0x30/0x130 | CPU: 111 PID: 0 Comm: swapper/111 Tainted: G W 6.0.0-rc4-rt6-[...] | Call trace: | __kmalloc+0xbc/0x1e8 | detect_cache_attributes+0x2d4/0x5f0 | update_siblings_masks+0x30/0x368 | store_cpu_topology+0x78/0xb8 | secondary_start_kernel+0xd0/0x198 | __secondary_switched+0xb0/0xb4 Signed-off-by: Pierre Gondois <pierre.gondois@arm.com> Reviewed-by: Sudeep Holla <sudeep.holla@arm.com> Acked-by: Palmer Dabbelt <palmer@rivosinc.com> Link: https://lore.kernel.org/r/20230104183033.755668-7-pierre.gondois@arm.com Signed-off-by: Sudeep Holla <sudeep.holla@arm.com>
2023-01-04 19:30:29 +01:00
cacheinfo: Add arch specific early level initializer This patch gives architecture specific code the ability to initialize the cache level and allocate cacheinfo memory early, when cache level initialization runs on the primary CPU for all possible CPUs. This is part of a patch series that attempts to further the work in commit 5944ce092b97 ("arch_topology: Build cacheinfo from primary CPU"). Previously, in the absence of any DT/ACPI cache info, architecture specific cache detection and info allocation for secondary CPUs would happen in non-preemptible context during early CPU initialization and trigger a "BUG: sleeping function called from invalid context" splat on an RT kernel. More specifically, this patch adds the early_cache_level() function, which is called by fetch_cache_info() as a fallback when the number of cache leaves cannot be extracted from DT/ACPI. In the default generic (weak) implementation, this new function returns -ENOENT, which preserves the original behavior for architectures that do not implement the function. Since early detection can get the number of cache leaves wrong in some cases*, additional logic is added to still call init_cache_level() later on the secondary CPU, therefore giving the architecture specific code an opportunity to go back and fix the initial guess. Again, the original behavior is preserved for architectures that do not implement the new function. * For example, on arm64, CLIDR_EL1 detection works only when it runs on the current CPU. In other words, a CPU cannot detect the cache depth for any other CPU than itself. Signed-off-by: Radu Rendec <rrendec@redhat.com> Reviewed-by: Pierre Gondois <pierre.gondois@arm.com> Link: https://lore.kernel.org/r/20230412185759.755408-2-rrendec@redhat.com Signed-off-by: Sudeep Holla <sudeep.holla@arm.com>
2023-04-12 14:57:57 -04:00
arch_topology: Build cacheinfo from primary CPU commit 3fcbf1c77d08 ("arch_topology: Fix cache attributes detection in the CPU hotplug path") adds a call to detect_cache_attributes() to populate the cacheinfo before updating the siblings mask. detect_cache_attributes() allocates memory and can take the PPTT mutex (on ACPI platforms). On PREEMPT_RT kernels, on secondary CPUs, this triggers a: 'BUG: sleeping function called from invalid context' [1] as the code is executed with preemption and interrupts disabled. The primary CPU was previously storing the cache information using the now removed (struct cpu_topology).llc_id: commit 5b8dc787ce4a ("arch_topology: Drop LLC identifier stash from the CPU topology") allocate_cache_info() tries to build the cacheinfo from the primary CPU prior secondary CPUs boot, if the DT/ACPI description contains cache information. If allocate_cache_info() fails, then fallback to the current state for the cacheinfo allocation. [1] will be triggered in such case. When unplugging a CPU, the cacheinfo memory cannot be freed. If it was, then the memory would be allocated early by the re-plugged CPU and would trigger [1]. Note that populate_cache_leaves() might be called multiple times due to populate_leaves being moved up. This is required since detect_cache_attributes() might be called with per_cpu_cacheinfo(cpu) being allocated but not populated. [1]: | BUG: sleeping function called from invalid context at kernel/locking/spinlock_rt.c:46 | in_atomic(): 1, irqs_disabled(): 128, non_block: 0, pid: 0, name: swapper/111 | preempt_count: 1, expected: 0 | RCU nest depth: 1, expected: 1 | 3 locks held by swapper/111/0: | #0: (&pcp->lock){+.+.}-{3:3}, at: get_page_from_freelist+0x218/0x12c8 | #1: (rcu_read_lock){....}-{1:3}, at: rt_spin_trylock+0x48/0xf0 | #2: (&zone->lock){+.+.}-{3:3}, at: rmqueue_bulk+0x64/0xa80 | irq event stamp: 0 | hardirqs last enabled at (0): 0x0 | hardirqs last disabled at (0): copy_process+0x5dc/0x1ab8 | softirqs last enabled at (0): copy_process+0x5dc/0x1ab8 | softirqs last disabled at (0): 0x0 | Preemption disabled at: | migrate_enable+0x30/0x130 | CPU: 111 PID: 0 Comm: swapper/111 Tainted: G W 6.0.0-rc4-rt6-[...] | Call trace: | __kmalloc+0xbc/0x1e8 | detect_cache_attributes+0x2d4/0x5f0 | update_siblings_masks+0x30/0x368 | store_cpu_topology+0x78/0xb8 | secondary_start_kernel+0xd0/0x198 | __secondary_switched+0xb0/0xb4 Signed-off-by: Pierre Gondois <pierre.gondois@arm.com> Reviewed-by: Sudeep Holla <sudeep.holla@arm.com> Acked-by: Palmer Dabbelt <palmer@rivosinc.com> Link: https://lore.kernel.org/r/20230104183033.755668-7-pierre.gondois@arm.com Signed-off-by: Sudeep Holla <sudeep.holla@arm.com>
2023-01-04 19:30:29 +01:00
cacheinfo: Add arch specific early level initializer This patch gives architecture specific code the ability to initialize the cache level and allocate cacheinfo memory early, when cache level initialization runs on the primary CPU for all possible CPUs. This is part of a patch series that attempts to further the work in commit 5944ce092b97 ("arch_topology: Build cacheinfo from primary CPU"). Previously, in the absence of any DT/ACPI cache info, architecture specific cache detection and info allocation for secondary CPUs would happen in non-preemptible context during early CPU initialization and trigger a "BUG: sleeping function called from invalid context" splat on an RT kernel. More specifically, this patch adds the early_cache_level() function, which is called by fetch_cache_info() as a fallback when the number of cache leaves cannot be extracted from DT/ACPI. In the default generic (weak) implementation, this new function returns -ENOENT, which preserves the original behavior for architectures that do not implement the function. Since early detection can get the number of cache leaves wrong in some cases*, additional logic is added to still call init_cache_level() later on the secondary CPU, therefore giving the architecture specific code an opportunity to go back and fix the initial guess. Again, the original behavior is preserved for architectures that do not implement the new function. * For example, on arm64, CLIDR_EL1 detection works only when it runs on the current CPU. In other words, a CPU cannot detect the cache depth for any other CPU than itself. Signed-off-by: Radu Rendec <rrendec@redhat.com> Reviewed-by: Pierre Gondois <pierre.gondois@arm.com> Link: https://lore.kernel.org/r/20230412185759.755408-2-rrendec@redhat.com Signed-off-by: Sudeep Holla <sudeep.holla@arm.com>
2023-04-12 14:57:57 -04:00
arch_topology: Build cacheinfo from primary CPU commit 3fcbf1c77d08 ("arch_topology: Fix cache attributes detection in the CPU hotplug path") adds a call to detect_cache_attributes() to populate the cacheinfo before updating the siblings mask. detect_cache_attributes() allocates memory and can take the PPTT mutex (on ACPI platforms). On PREEMPT_RT kernels, on secondary CPUs, this triggers a: 'BUG: sleeping function called from invalid context' [1] as the code is executed with preemption and interrupts disabled. The primary CPU was previously storing the cache information using the now removed (struct cpu_topology).llc_id: commit 5b8dc787ce4a ("arch_topology: Drop LLC identifier stash from the CPU topology") allocate_cache_info() tries to build the cacheinfo from the primary CPU prior secondary CPUs boot, if the DT/ACPI description contains cache information. If allocate_cache_info() fails, then fallback to the current state for the cacheinfo allocation. [1] will be triggered in such case. When unplugging a CPU, the cacheinfo memory cannot be freed. If it was, then the memory would be allocated early by the re-plugged CPU and would trigger [1]. Note that populate_cache_leaves() might be called multiple times due to populate_leaves being moved up. This is required since detect_cache_attributes() might be called with per_cpu_cacheinfo(cpu) being allocated but not populated. [1]: | BUG: sleeping function called from invalid context at kernel/locking/spinlock_rt.c:46 | in_atomic(): 1, irqs_disabled(): 128, non_block: 0, pid: 0, name: swapper/111 | preempt_count: 1, expected: 0 | RCU nest depth: 1, expected: 1 | 3 locks held by swapper/111/0: | #0: (&pcp->lock){+.+.}-{3:3}, at: get_page_from_freelist+0x218/0x12c8 | #1: (rcu_read_lock){....}-{1:3}, at: rt_spin_trylock+0x48/0xf0 | #2: (&zone->lock){+.+.}-{3:3}, at: rmqueue_bulk+0x64/0xa80 | irq event stamp: 0 | hardirqs last enabled at (0): 0x0 | hardirqs last disabled at (0): copy_process+0x5dc/0x1ab8 | softirqs last enabled at (0): copy_process+0x5dc/0x1ab8 | softirqs last disabled at (0): 0x0 | Preemption disabled at: | migrate_enable+0x30/0x130 | CPU: 111 PID: 0 Comm: swapper/111 Tainted: G W 6.0.0-rc4-rt6-[...] | Call trace: | __kmalloc+0xbc/0x1e8 | detect_cache_attributes+0x2d4/0x5f0 | update_siblings_masks+0x30/0x368 | store_cpu_topology+0x78/0xb8 | secondary_start_kernel+0xd0/0x198 | __secondary_switched+0xb0/0xb4 Signed-off-by: Pierre Gondois <pierre.gondois@arm.com> Reviewed-by: Sudeep Holla <sudeep.holla@arm.com> Acked-by: Palmer Dabbelt <palmer@rivosinc.com> Link: https://lore.kernel.org/r/20230104183033.755668-7-pierre.gondois@arm.com Signed-off-by: Sudeep Holla <sudeep.holla@arm.com>
2023-01-04 19:30:29 +01:00
cacheinfo: Add arch specific early level initializer This patch gives architecture specific code the ability to initialize the cache level and allocate cacheinfo memory early, when cache level initialization runs on the primary CPU for all possible CPUs. This is part of a patch series that attempts to further the work in commit 5944ce092b97 ("arch_topology: Build cacheinfo from primary CPU"). Previously, in the absence of any DT/ACPI cache info, architecture specific cache detection and info allocation for secondary CPUs would happen in non-preemptible context during early CPU initialization and trigger a "BUG: sleeping function called from invalid context" splat on an RT kernel. More specifically, this patch adds the early_cache_level() function, which is called by fetch_cache_info() as a fallback when the number of cache leaves cannot be extracted from DT/ACPI. In the default generic (weak) implementation, this new function returns -ENOENT, which preserves the original behavior for architectures that do not implement the function. Since early detection can get the number of cache leaves wrong in some cases*, additional logic is added to still call init_cache_level() later on the secondary CPU, therefore giving the architecture specific code an opportunity to go back and fix the initial guess. Again, the original behavior is preserved for architectures that do not implement the new function. * For example, on arm64, CLIDR_EL1 detection works only when it runs on the current CPU. In other words, a CPU cannot detect the cache depth for any other CPU than itself. Signed-off-by: Radu Rendec <rrendec@redhat.com> Reviewed-by: Pierre Gondois <pierre.gondois@arm.com> Link: https://lore.kernel.org/r/20230412185759.755408-2-rrendec@redhat.com Signed-off-by: Sudeep Holla <sudeep.holla@arm.com>
2023-04-12 14:57:57 -04:00
drivers: base: support cpu cache information interface to userspace via sysfs This patch adds initial support for providing processor cache information to userspace through sysfs interface. This is based on already existing implementations(x86, ia64, s390 and powerpc) and hence the interface is intended to be fully compatible. The main purpose of this generic support is to avoid further code duplication to support new architectures and also to unify all the existing different implementations. This implementation maintains the hierarchy of cache objects which reflects the system's cache topology. Cache devices are instantiated as needed as CPUs come online. The cache information is replicated per-cpu even if they are shared. A per-cpu array of cache information maintained is used mainly for sysfs-related book keeping. It also implements the shared_cpu_map attribute, which is essential for enabling both kernel and user-space to discover the system's overall cache topology. This patch also add the missing ABI documentation for the cacheinfo sysfs interface already, which is well defined and widely used. Signed-off-by: Sudeep Holla <sudeep.holla@arm.com> Reviewed-by: Stephen Boyd <sboyd@codeaurora.org> Tested-by: Stephen Boyd <sboyd@codeaurora.org> Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org> Cc: linux-api@vger.kernel.org Cc: linux390@de.ibm.com Cc: linux-arm-kernel@lists.infradead.org Cc: linux-ia64@vger.kernel.org Cc: linuxppc-dev@lists.ozlabs.org Cc: linux-s390@vger.kernel.org Cc: x86@kernel.org Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2014-09-30 14:48:25 +01:00
cacheinfo: Add arch specific early level initializer This patch gives architecture specific code the ability to initialize the cache level and allocate cacheinfo memory early, when cache level initialization runs on the primary CPU for all possible CPUs. This is part of a patch series that attempts to further the work in commit 5944ce092b97 ("arch_topology: Build cacheinfo from primary CPU"). Previously, in the absence of any DT/ACPI cache info, architecture specific cache detection and info allocation for secondary CPUs would happen in non-preemptible context during early CPU initialization and trigger a "BUG: sleeping function called from invalid context" splat on an RT kernel. More specifically, this patch adds the early_cache_level() function, which is called by fetch_cache_info() as a fallback when the number of cache leaves cannot be extracted from DT/ACPI. In the default generic (weak) implementation, this new function returns -ENOENT, which preserves the original behavior for architectures that do not implement the function. Since early detection can get the number of cache leaves wrong in some cases*, additional logic is added to still call init_cache_level() later on the secondary CPU, therefore giving the architecture specific code an opportunity to go back and fix the initial guess. Again, the original behavior is preserved for architectures that do not implement the new function. * For example, on arm64, CLIDR_EL1 detection works only when it runs on the current CPU. In other words, a CPU cannot detect the cache depth for any other CPU than itself. Signed-off-by: Radu Rendec <rrendec@redhat.com> Reviewed-by: Pierre Gondois <pierre.gondois@arm.com> Link: https://lore.kernel.org/r/20230412185759.755408-2-rrendec@redhat.com Signed-off-by: Sudeep Holla <sudeep.holla@arm.com>
2023-04-12 14:57:57 -04:00
drivers: base: support cpu cache information interface to userspace via sysfs This patch adds initial support for providing processor cache information to userspace through sysfs interface. This is based on already existing implementations(x86, ia64, s390 and powerpc) and hence the interface is intended to be fully compatible. The main purpose of this generic support is to avoid further code duplication to support new architectures and also to unify all the existing different implementations. This implementation maintains the hierarchy of cache objects which reflects the system's cache topology. Cache devices are instantiated as needed as CPUs come online. The cache information is replicated per-cpu even if they are shared. A per-cpu array of cache information maintained is used mainly for sysfs-related book keeping. It also implements the shared_cpu_map attribute, which is essential for enabling both kernel and user-space to discover the system's overall cache topology. This patch also add the missing ABI documentation for the cacheinfo sysfs interface already, which is well defined and widely used. Signed-off-by: Sudeep Holla <sudeep.holla@arm.com> Reviewed-by: Stephen Boyd <sboyd@codeaurora.org> Tested-by: Stephen Boyd <sboyd@codeaurora.org> Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org> Cc: linux-api@vger.kernel.org Cc: linux390@de.ibm.com Cc: linux-arm-kernel@lists.infradead.org Cc: linux-ia64@vger.kernel.org Cc: linuxppc-dev@lists.ozlabs.org Cc: linux-s390@vger.kernel.org Cc: x86@kernel.org Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2014-09-30 14:48:25 +01:00
arch_topology: Build cacheinfo from primary CPU commit 3fcbf1c77d08 ("arch_topology: Fix cache attributes detection in the CPU hotplug path") adds a call to detect_cache_attributes() to populate the cacheinfo before updating the siblings mask. detect_cache_attributes() allocates memory and can take the PPTT mutex (on ACPI platforms). On PREEMPT_RT kernels, on secondary CPUs, this triggers a: 'BUG: sleeping function called from invalid context' [1] as the code is executed with preemption and interrupts disabled. The primary CPU was previously storing the cache information using the now removed (struct cpu_topology).llc_id: commit 5b8dc787ce4a ("arch_topology: Drop LLC identifier stash from the CPU topology") allocate_cache_info() tries to build the cacheinfo from the primary CPU prior secondary CPUs boot, if the DT/ACPI description contains cache information. If allocate_cache_info() fails, then fallback to the current state for the cacheinfo allocation. [1] will be triggered in such case. When unplugging a CPU, the cacheinfo memory cannot be freed. If it was, then the memory would be allocated early by the re-plugged CPU and would trigger [1]. Note that populate_cache_leaves() might be called multiple times due to populate_leaves being moved up. This is required since detect_cache_attributes() might be called with per_cpu_cacheinfo(cpu) being allocated but not populated. [1]: | BUG: sleeping function called from invalid context at kernel/locking/spinlock_rt.c:46 | in_atomic(): 1, irqs_disabled(): 128, non_block: 0, pid: 0, name: swapper/111 | preempt_count: 1, expected: 0 | RCU nest depth: 1, expected: 1 | 3 locks held by swapper/111/0: | #0: (&pcp->lock){+.+.}-{3:3}, at: get_page_from_freelist+0x218/0x12c8 | #1: (rcu_read_lock){....}-{1:3}, at: rt_spin_trylock+0x48/0xf0 | #2: (&zone->lock){+.+.}-{3:3}, at: rmqueue_bulk+0x64/0xa80 | irq event stamp: 0 | hardirqs last enabled at (0): 0x0 | hardirqs last disabled at (0): copy_process+0x5dc/0x1ab8 | softirqs last enabled at (0): copy_process+0x5dc/0x1ab8 | softirqs last disabled at (0): 0x0 | Preemption disabled at: | migrate_enable+0x30/0x130 | CPU: 111 PID: 0 Comm: swapper/111 Tainted: G W 6.0.0-rc4-rt6-[...] | Call trace: | __kmalloc+0xbc/0x1e8 | detect_cache_attributes+0x2d4/0x5f0 | update_siblings_masks+0x30/0x368 | store_cpu_topology+0x78/0xb8 | secondary_start_kernel+0xd0/0x198 | __secondary_switched+0xb0/0xb4 Signed-off-by: Pierre Gondois <pierre.gondois@arm.com> Reviewed-by: Sudeep Holla <sudeep.holla@arm.com> Acked-by: Palmer Dabbelt <palmer@rivosinc.com> Link: https://lore.kernel.org/r/20230104183033.755668-7-pierre.gondois@arm.com Signed-off-by: Sudeep Holla <sudeep.holla@arm.com>
2023-01-04 19:30:29 +01:00
cacheinfo: Add arch specific early level initializer This patch gives architecture specific code the ability to initialize the cache level and allocate cacheinfo memory early, when cache level initialization runs on the primary CPU for all possible CPUs. This is part of a patch series that attempts to further the work in commit 5944ce092b97 ("arch_topology: Build cacheinfo from primary CPU"). Previously, in the absence of any DT/ACPI cache info, architecture specific cache detection and info allocation for secondary CPUs would happen in non-preemptible context during early CPU initialization and trigger a "BUG: sleeping function called from invalid context" splat on an RT kernel. More specifically, this patch adds the early_cache_level() function, which is called by fetch_cache_info() as a fallback when the number of cache leaves cannot be extracted from DT/ACPI. In the default generic (weak) implementation, this new function returns -ENOENT, which preserves the original behavior for architectures that do not implement the function. Since early detection can get the number of cache leaves wrong in some cases*, additional logic is added to still call init_cache_level() later on the secondary CPU, therefore giving the architecture specific code an opportunity to go back and fix the initial guess. Again, the original behavior is preserved for architectures that do not implement the new function. * For example, on arm64, CLIDR_EL1 detection works only when it runs on the current CPU. In other words, a CPU cannot detect the cache depth for any other CPU than itself. Signed-off-by: Radu Rendec <rrendec@redhat.com> Reviewed-by: Pierre Gondois <pierre.gondois@arm.com> Link: https://lore.kernel.org/r/20230412185759.755408-2-rrendec@redhat.com Signed-off-by: Sudeep Holla <sudeep.holla@arm.com>
2023-04-12 14:57:57 -04:00
cacheinfo: Add arch specific early level initializer This patch gives architecture specific code the ability to initialize the cache level and allocate cacheinfo memory early, when cache level initialization runs on the primary CPU for all possible CPUs. This is part of a patch series that attempts to further the work in commit 5944ce092b97 ("arch_topology: Build cacheinfo from primary CPU"). Previously, in the absence of any DT/ACPI cache info, architecture specific cache detection and info allocation for secondary CPUs would happen in non-preemptible context during early CPU initialization and trigger a "BUG: sleeping function called from invalid context" splat on an RT kernel. More specifically, this patch adds the early_cache_level() function, which is called by fetch_cache_info() as a fallback when the number of cache leaves cannot be extracted from DT/ACPI. In the default generic (weak) implementation, this new function returns -ENOENT, which preserves the original behavior for architectures that do not implement the function. Since early detection can get the number of cache leaves wrong in some cases*, additional logic is added to still call init_cache_level() later on the secondary CPU, therefore giving the architecture specific code an opportunity to go back and fix the initial guess. Again, the original behavior is preserved for architectures that do not implement the new function. * For example, on arm64, CLIDR_EL1 detection works only when it runs on the current CPU. In other words, a CPU cannot detect the cache depth for any other CPU than itself. Signed-off-by: Radu Rendec <rrendec@redhat.com> Reviewed-by: Pierre Gondois <pierre.gondois@arm.com> Link: https://lore.kernel.org/r/20230412185759.755408-2-rrendec@redhat.com Signed-off-by: Sudeep Holla <sudeep.holla@arm.com>
2023-04-12 14:57:57 -04:00
drivers: base: support cpu cache information interface to userspace via sysfs This patch adds initial support for providing processor cache information to userspace through sysfs interface. This is based on already existing implementations(x86, ia64, s390 and powerpc) and hence the interface is intended to be fully compatible. The main purpose of this generic support is to avoid further code duplication to support new architectures and also to unify all the existing different implementations. This implementation maintains the hierarchy of cache objects which reflects the system's cache topology. Cache devices are instantiated as needed as CPUs come online. The cache information is replicated per-cpu even if they are shared. A per-cpu array of cache information maintained is used mainly for sysfs-related book keeping. It also implements the shared_cpu_map attribute, which is essential for enabling both kernel and user-space to discover the system's overall cache topology. This patch also add the missing ABI documentation for the cacheinfo sysfs interface already, which is well defined and widely used. Signed-off-by: Sudeep Holla <sudeep.holla@arm.com> Reviewed-by: Stephen Boyd <sboyd@codeaurora.org> Tested-by: Stephen Boyd <sboyd@codeaurora.org> Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org> Cc: linux-api@vger.kernel.org Cc: linux390@de.ibm.com Cc: linux-arm-kernel@lists.infradead.org Cc: linux-ia64@vger.kernel.org Cc: linuxppc-dev@lists.ozlabs.org Cc: linux-s390@vger.kernel.org Cc: x86@kernel.org Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2014-09-30 14:48:25 +01:00
cacheinfo: Add arch specific early level initializer This patch gives architecture specific code the ability to initialize the cache level and allocate cacheinfo memory early, when cache level initialization runs on the primary CPU for all possible CPUs. This is part of a patch series that attempts to further the work in commit 5944ce092b97 ("arch_topology: Build cacheinfo from primary CPU"). Previously, in the absence of any DT/ACPI cache info, architecture specific cache detection and info allocation for secondary CPUs would happen in non-preemptible context during early CPU initialization and trigger a "BUG: sleeping function called from invalid context" splat on an RT kernel. More specifically, this patch adds the early_cache_level() function, which is called by fetch_cache_info() as a fallback when the number of cache leaves cannot be extracted from DT/ACPI. In the default generic (weak) implementation, this new function returns -ENOENT, which preserves the original behavior for architectures that do not implement the function. Since early detection can get the number of cache leaves wrong in some cases*, additional logic is added to still call init_cache_level() later on the secondary CPU, therefore giving the architecture specific code an opportunity to go back and fix the initial guess. Again, the original behavior is preserved for architectures that do not implement the new function. * For example, on arm64, CLIDR_EL1 detection works only when it runs on the current CPU. In other words, a CPU cannot detect the cache depth for any other CPU than itself. Signed-off-by: Radu Rendec <rrendec@redhat.com> Reviewed-by: Pierre Gondois <pierre.gondois@arm.com> Link: https://lore.kernel.org/r/20230412185759.755408-2-rrendec@redhat.com Signed-off-by: Sudeep Holla <sudeep.holla@arm.com>
2023-04-12 14:57:57 -04:00
cacheinfo: Allocate memory during CPU hotplug if not done from the primary CPU Commit 5944ce092b97 ("arch_topology: Build cacheinfo from primary CPU") adds functionality that architectures can use to optionally allocate and build cacheinfo early during boot. Commit 6539cffa9495 ("cacheinfo: Add arch specific early level initializer") lets secondary CPUs correct (and reallocate memory) cacheinfo data if needed. If the early build functionality is not used and cacheinfo does not need correction, memory for cacheinfo is never allocated. x86 does not use the early build functionality. Consequently, during the cacheinfo CPU hotplug callback, last_level_cache_is_valid() attempts to dereference a NULL pointer: BUG: kernel NULL pointer dereference, address: 0000000000000100 #PF: supervisor read access in kernel mode #PF: error_code(0x0000) - not present page PGD 0 P4D 0 Oops: 0000 [#1] PREEPMT SMP NOPTI CPU: 0 PID 19 Comm: cpuhp/0 Not tainted 6.4.0-rc2 #1 RIP: 0010: last_level_cache_is_valid+0x95/0xe0a Allocate memory for cacheinfo during the cacheinfo CPU hotplug callback if not done earlier. Moreover, before determining the validity of the last-level cache info, ensure that it has been allocated. Simply checking for non-zero cache_leaves() is not sufficient, as some architectures (e.g., Intel processors) have non-zero cache_leaves() before allocation. Dereferencing NULL cacheinfo can occur in update_per_cpu_data_slice_size(). This function iterates over all online CPUs. However, a CPU may have come online recently, but its cacheinfo may not have been allocated yet. While here, remove an unnecessary indentation in allocate_cache_info(). [ bp: Massage. ] Fixes: 6539cffa9495 ("cacheinfo: Add arch specific early level initializer") Signed-off-by: Ricardo Neri <ricardo.neri-calderon@linux.intel.com> Signed-off-by: Borislav Petkov (AMD) <bp@alien8.de> Reviewed-by: Radu Rendec <rrendec@redhat.com> Reviewed-by: Nikolay Borisov <nik.borisov@suse.com> Reviewed-by: Andreas Herrmann <aherrmann@suse.de> Reviewed-by: Sudeep Holla <sudeep.holla@arm.com> Cc: stable@vger.kernel.org # 6.3+ Link: https://lore.kernel.org/r/20241128002247.26726-2-ricardo.neri-calderon@linux.intel.com
2024-11-27 16:22:46 -08:00
cacheinfo: Add arch specific early level initializer This patch gives architecture specific code the ability to initialize the cache level and allocate cacheinfo memory early, when cache level initialization runs on the primary CPU for all possible CPUs. This is part of a patch series that attempts to further the work in commit 5944ce092b97 ("arch_topology: Build cacheinfo from primary CPU"). Previously, in the absence of any DT/ACPI cache info, architecture specific cache detection and info allocation for secondary CPUs would happen in non-preemptible context during early CPU initialization and trigger a "BUG: sleeping function called from invalid context" splat on an RT kernel. More specifically, this patch adds the early_cache_level() function, which is called by fetch_cache_info() as a fallback when the number of cache leaves cannot be extracted from DT/ACPI. In the default generic (weak) implementation, this new function returns -ENOENT, which preserves the original behavior for architectures that do not implement the function. Since early detection can get the number of cache leaves wrong in some cases*, additional logic is added to still call init_cache_level() later on the secondary CPU, therefore giving the architecture specific code an opportunity to go back and fix the initial guess. Again, the original behavior is preserved for architectures that do not implement the new function. * For example, on arm64, CLIDR_EL1 detection works only when it runs on the current CPU. In other words, a CPU cannot detect the cache depth for any other CPU than itself. Signed-off-by: Radu Rendec <rrendec@redhat.com> Reviewed-by: Pierre Gondois <pierre.gondois@arm.com> Link: https://lore.kernel.org/r/20230412185759.755408-2-rrendec@redhat.com Signed-off-by: Sudeep Holla <sudeep.holla@arm.com>
2023-04-12 14:57:57 -04:00
arch_topology: Build cacheinfo from primary CPU commit 3fcbf1c77d08 ("arch_topology: Fix cache attributes detection in the CPU hotplug path") adds a call to detect_cache_attributes() to populate the cacheinfo before updating the siblings mask. detect_cache_attributes() allocates memory and can take the PPTT mutex (on ACPI platforms). On PREEMPT_RT kernels, on secondary CPUs, this triggers a: 'BUG: sleeping function called from invalid context' [1] as the code is executed with preemption and interrupts disabled. The primary CPU was previously storing the cache information using the now removed (struct cpu_topology).llc_id: commit 5b8dc787ce4a ("arch_topology: Drop LLC identifier stash from the CPU topology") allocate_cache_info() tries to build the cacheinfo from the primary CPU prior secondary CPUs boot, if the DT/ACPI description contains cache information. If allocate_cache_info() fails, then fallback to the current state for the cacheinfo allocation. [1] will be triggered in such case. When unplugging a CPU, the cacheinfo memory cannot be freed. If it was, then the memory would be allocated early by the re-plugged CPU and would trigger [1]. Note that populate_cache_leaves() might be called multiple times due to populate_leaves being moved up. This is required since detect_cache_attributes() might be called with per_cpu_cacheinfo(cpu) being allocated but not populated. [1]: | BUG: sleeping function called from invalid context at kernel/locking/spinlock_rt.c:46 | in_atomic(): 1, irqs_disabled(): 128, non_block: 0, pid: 0, name: swapper/111 | preempt_count: 1, expected: 0 | RCU nest depth: 1, expected: 1 | 3 locks held by swapper/111/0: | #0: (&pcp->lock){+.+.}-{3:3}, at: get_page_from_freelist+0x218/0x12c8 | #1: (rcu_read_lock){....}-{1:3}, at: rt_spin_trylock+0x48/0xf0 | #2: (&zone->lock){+.+.}-{3:3}, at: rmqueue_bulk+0x64/0xa80 | irq event stamp: 0 | hardirqs last enabled at (0): 0x0 | hardirqs last disabled at (0): copy_process+0x5dc/0x1ab8 | softirqs last enabled at (0): copy_process+0x5dc/0x1ab8 | softirqs last disabled at (0): 0x0 | Preemption disabled at: | migrate_enable+0x30/0x130 | CPU: 111 PID: 0 Comm: swapper/111 Tainted: G W 6.0.0-rc4-rt6-[...] | Call trace: | __kmalloc+0xbc/0x1e8 | detect_cache_attributes+0x2d4/0x5f0 | update_siblings_masks+0x30/0x368 | store_cpu_topology+0x78/0xb8 | secondary_start_kernel+0xd0/0x198 | __secondary_switched+0xb0/0xb4 Signed-off-by: Pierre Gondois <pierre.gondois@arm.com> Reviewed-by: Sudeep Holla <sudeep.holla@arm.com> Acked-by: Palmer Dabbelt <palmer@rivosinc.com> Link: https://lore.kernel.org/r/20230104183033.755668-7-pierre.gondois@arm.com Signed-off-by: Sudeep Holla <sudeep.holla@arm.com>
2023-01-04 19:30:29 +01:00
drivers: base: support cpu cache information interface to userspace via sysfs This patch adds initial support for providing processor cache information to userspace through sysfs interface. This is based on already existing implementations(x86, ia64, s390 and powerpc) and hence the interface is intended to be fully compatible. The main purpose of this generic support is to avoid further code duplication to support new architectures and also to unify all the existing different implementations. This implementation maintains the hierarchy of cache objects which reflects the system's cache topology. Cache devices are instantiated as needed as CPUs come online. The cache information is replicated per-cpu even if they are shared. A per-cpu array of cache information maintained is used mainly for sysfs-related book keeping. It also implements the shared_cpu_map attribute, which is essential for enabling both kernel and user-space to discover the system's overall cache topology. This patch also add the missing ABI documentation for the cacheinfo sysfs interface already, which is well defined and widely used. Signed-off-by: Sudeep Holla <sudeep.holla@arm.com> Reviewed-by: Stephen Boyd <sboyd@codeaurora.org> Tested-by: Stephen Boyd <sboyd@codeaurora.org> Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org> Cc: linux-api@vger.kernel.org Cc: linux390@de.ibm.com Cc: linux-arm-kernel@lists.infradead.org Cc: linux-ia64@vger.kernel.org Cc: linuxppc-dev@lists.ozlabs.org Cc: linux-s390@vger.kernel.org Cc: x86@kernel.org Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2014-09-30 14:48:25 +01:00
2018-05-11 18:57:57 -05:00
cacheinfo: Fix LLC is not exported through sysfs After entering 6.3-rc1 the LLC cacheinfo is not exported on our ACPI based arm64 server. This is because the LLC cacheinfo is partly reset when secondary CPUs boot up. On arm64 the primary cpu will allocate and setup cacheinfo: init_cpu_topology() for_each_possible_cpu() fetch_cache_info() // Allocate cacheinfo and init levels detect_cache_attributes() cache_shared_cpu_map_setup() if (!last_level_cache_is_valid()) // not valid, setup LLC cache_setup_properties() // setup LLC On secondary CPU boot up: detect_cache_attributes() populate_cache_leaves() get_cache_type() // Get cache type from clidr_el1, // for LLC type=CACHE_TYPE_NOCACHE cache_shared_cpu_map_setup() if (!last_level_cache_is_valid()) // Valid and won't go to this branch, // leave LLC's type=CACHE_TYPE_NOCACHE The last_level_cache_is_valid() use cacheinfo->{attributes, fw_token} to test it's valid or not, but populate_cache_leaves() will only reset LLC's type, so we won't try to re-setup LLC's type and leave it CACHE_TYPE_NOCACHE and won't export it through sysfs. This patch tries to fix this by not re-populating the cache leaves if the LLC is valid. Fixes: 5944ce092b97 ("arch_topology: Build cacheinfo from primary CPU") Signed-off-by: Yicong Yang <yangyicong@hisilicon.com> Reviewed-by: Pierre Gondois <pierre.gondois@arm.com> Reviewed-by: Sudeep Holla <sudeep.holla@arm.com> Link: https://lore.kernel.org/r/20230328114915.33340-1-yangyicong@huawei.com Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2023-03-28 19:49:15 +08:00
2018-05-11 18:57:57 -05:00
cacheinfo: Fix LLC is not exported through sysfs After entering 6.3-rc1 the LLC cacheinfo is not exported on our ACPI based arm64 server. This is because the LLC cacheinfo is partly reset when secondary CPUs boot up. On arm64 the primary cpu will allocate and setup cacheinfo: init_cpu_topology() for_each_possible_cpu() fetch_cache_info() // Allocate cacheinfo and init levels detect_cache_attributes() cache_shared_cpu_map_setup() if (!last_level_cache_is_valid()) // not valid, setup LLC cache_setup_properties() // setup LLC On secondary CPU boot up: detect_cache_attributes() populate_cache_leaves() get_cache_type() // Get cache type from clidr_el1, // for LLC type=CACHE_TYPE_NOCACHE cache_shared_cpu_map_setup() if (!last_level_cache_is_valid()) // Valid and won't go to this branch, // leave LLC's type=CACHE_TYPE_NOCACHE The last_level_cache_is_valid() use cacheinfo->{attributes, fw_token} to test it's valid or not, but populate_cache_leaves() will only reset LLC's type, so we won't try to re-setup LLC's type and leave it CACHE_TYPE_NOCACHE and won't export it through sysfs. This patch tries to fix this by not re-populating the cache leaves if the LLC is valid. Fixes: 5944ce092b97 ("arch_topology: Build cacheinfo from primary CPU") Signed-off-by: Yicong Yang <yangyicong@hisilicon.com> Reviewed-by: Pierre Gondois <pierre.gondois@arm.com> Reviewed-by: Sudeep Holla <sudeep.holla@arm.com> Link: https://lore.kernel.org/r/20230328114915.33340-1-yangyicong@huawei.com Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2023-03-28 19:49:15 +08:00
drivers: base: support cpu cache information interface to userspace via sysfs This patch adds initial support for providing processor cache information to userspace through sysfs interface. This is based on already existing implementations(x86, ia64, s390 and powerpc) and hence the interface is intended to be fully compatible. The main purpose of this generic support is to avoid further code duplication to support new architectures and also to unify all the existing different implementations. This implementation maintains the hierarchy of cache objects which reflects the system's cache topology. Cache devices are instantiated as needed as CPUs come online. The cache information is replicated per-cpu even if they are shared. A per-cpu array of cache information maintained is used mainly for sysfs-related book keeping. It also implements the shared_cpu_map attribute, which is essential for enabling both kernel and user-space to discover the system's overall cache topology. This patch also add the missing ABI documentation for the cacheinfo sysfs interface already, which is well defined and widely used. Signed-off-by: Sudeep Holla <sudeep.holla@arm.com> Reviewed-by: Stephen Boyd <sboyd@codeaurora.org> Tested-by: Stephen Boyd <sboyd@codeaurora.org> Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org> Cc: linux-api@vger.kernel.org Cc: linux390@de.ibm.com Cc: linux-arm-kernel@lists.infradead.org Cc: linux-ia64@vger.kernel.org Cc: linuxppc-dev@lists.ozlabs.org Cc: linux-s390@vger.kernel.org Cc: x86@kernel.org Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2014-09-30 14:48:25 +01:00
drivers: base: support cpu cache information interface to userspace via sysfs This patch adds initial support for providing processor cache information to userspace through sysfs interface. This is based on already existing implementations(x86, ia64, s390 and powerpc) and hence the interface is intended to be fully compatible. The main purpose of this generic support is to avoid further code duplication to support new architectures and also to unify all the existing different implementations. This implementation maintains the hierarchy of cache objects which reflects the system's cache topology. Cache devices are instantiated as needed as CPUs come online. The cache information is replicated per-cpu even if they are shared. A per-cpu array of cache information maintained is used mainly for sysfs-related book keeping. It also implements the shared_cpu_map attribute, which is essential for enabling both kernel and user-space to discover the system's overall cache topology. This patch also add the missing ABI documentation for the cacheinfo sysfs interface already, which is well defined and widely used. Signed-off-by: Sudeep Holla <sudeep.holla@arm.com> Reviewed-by: Stephen Boyd <sboyd@codeaurora.org> Tested-by: Stephen Boyd <sboyd@codeaurora.org> Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org> Cc: linux-api@vger.kernel.org Cc: linux390@de.ibm.com Cc: linux-arm-kernel@lists.infradead.org Cc: linux-ia64@vger.kernel.org Cc: linuxppc-dev@lists.ozlabs.org Cc: linux-s390@vger.kernel.org Cc: x86@kernel.org Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2014-09-30 14:48:25 +01:00
drivers: base: support cpu cache information interface to userspace via sysfs This patch adds initial support for providing processor cache information to userspace through sysfs interface. This is based on already existing implementations(x86, ia64, s390 and powerpc) and hence the interface is intended to be fully compatible. The main purpose of this generic support is to avoid further code duplication to support new architectures and also to unify all the existing different implementations. This implementation maintains the hierarchy of cache objects which reflects the system's cache topology. Cache devices are instantiated as needed as CPUs come online. The cache information is replicated per-cpu even if they are shared. A per-cpu array of cache information maintained is used mainly for sysfs-related book keeping. It also implements the shared_cpu_map attribute, which is essential for enabling both kernel and user-space to discover the system's overall cache topology. This patch also add the missing ABI documentation for the cacheinfo sysfs interface already, which is well defined and widely used. Signed-off-by: Sudeep Holla <sudeep.holla@arm.com> Reviewed-by: Stephen Boyd <sboyd@codeaurora.org> Tested-by: Stephen Boyd <sboyd@codeaurora.org> Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org> Cc: linux-api@vger.kernel.org Cc: linux390@de.ibm.com Cc: linux-arm-kernel@lists.infradead.org Cc: linux-ia64@vger.kernel.org Cc: linuxppc-dev@lists.ozlabs.org Cc: linux-s390@vger.kernel.org Cc: x86@kernel.org Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2014-09-30 14:48:25 +01:00
drivers: base: support cpu cache information interface to userspace via sysfs This patch adds initial support for providing processor cache information to userspace through sysfs interface. This is based on already existing implementations(x86, ia64, s390 and powerpc) and hence the interface is intended to be fully compatible. The main purpose of this generic support is to avoid further code duplication to support new architectures and also to unify all the existing different implementations. This implementation maintains the hierarchy of cache objects which reflects the system's cache topology. Cache devices are instantiated as needed as CPUs come online. The cache information is replicated per-cpu even if they are shared. A per-cpu array of cache information maintained is used mainly for sysfs-related book keeping. It also implements the shared_cpu_map attribute, which is essential for enabling both kernel and user-space to discover the system's overall cache topology. This patch also add the missing ABI documentation for the cacheinfo sysfs interface already, which is well defined and widely used. Signed-off-by: Sudeep Holla <sudeep.holla@arm.com> Reviewed-by: Stephen Boyd <sboyd@codeaurora.org> Tested-by: Stephen Boyd <sboyd@codeaurora.org> Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org> Cc: linux-api@vger.kernel.org Cc: linux390@de.ibm.com Cc: linux-arm-kernel@lists.infradead.org Cc: linux-ia64@vger.kernel.org Cc: linuxppc-dev@lists.ozlabs.org Cc: linux-s390@vger.kernel.org Cc: x86@kernel.org Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2014-09-30 14:48:25 +01:00
drivers: base: support cpu cache information interface to userspace via sysfs This patch adds initial support for providing processor cache information to userspace through sysfs interface. This is based on already existing implementations(x86, ia64, s390 and powerpc) and hence the interface is intended to be fully compatible. The main purpose of this generic support is to avoid further code duplication to support new architectures and also to unify all the existing different implementations. This implementation maintains the hierarchy of cache objects which reflects the system's cache topology. Cache devices are instantiated as needed as CPUs come online. The cache information is replicated per-cpu even if they are shared. A per-cpu array of cache information maintained is used mainly for sysfs-related book keeping. It also implements the shared_cpu_map attribute, which is essential for enabling both kernel and user-space to discover the system's overall cache topology. This patch also add the missing ABI documentation for the cacheinfo sysfs interface already, which is well defined and widely used. Signed-off-by: Sudeep Holla <sudeep.holla@arm.com> Reviewed-by: Stephen Boyd <sboyd@codeaurora.org> Tested-by: Stephen Boyd <sboyd@codeaurora.org> Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org> Cc: linux-api@vger.kernel.org Cc: linux390@de.ibm.com Cc: linux-arm-kernel@lists.infradead.org Cc: linux-ia64@vger.kernel.org Cc: linuxppc-dev@lists.ozlabs.org Cc: linux-s390@vger.kernel.org Cc: x86@kernel.org Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2014-09-30 14:48:25 +01:00
drivers: base: support cpu cache information interface to userspace via sysfs This patch adds initial support for providing processor cache information to userspace through sysfs interface. This is based on already existing implementations(x86, ia64, s390 and powerpc) and hence the interface is intended to be fully compatible. The main purpose of this generic support is to avoid further code duplication to support new architectures and also to unify all the existing different implementations. This implementation maintains the hierarchy of cache objects which reflects the system's cache topology. Cache devices are instantiated as needed as CPUs come online. The cache information is replicated per-cpu even if they are shared. A per-cpu array of cache information maintained is used mainly for sysfs-related book keeping. It also implements the shared_cpu_map attribute, which is essential for enabling both kernel and user-space to discover the system's overall cache topology. This patch also add the missing ABI documentation for the cacheinfo sysfs interface already, which is well defined and widely used. Signed-off-by: Sudeep Holla <sudeep.holla@arm.com> Reviewed-by: Stephen Boyd <sboyd@codeaurora.org> Tested-by: Stephen Boyd <sboyd@codeaurora.org> Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org> Cc: linux-api@vger.kernel.org Cc: linux390@de.ibm.com Cc: linux-arm-kernel@lists.infradead.org Cc: linux-ia64@vger.kernel.org Cc: linuxppc-dev@lists.ozlabs.org Cc: linux-s390@vger.kernel.org Cc: x86@kernel.org Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2014-09-30 14:48:25 +01:00
drivers core: Use sysfs_emit and sysfs_emit_at for show(device *...) functions Convert the various sprintf fmaily calls in sysfs device show functions to sysfs_emit and sysfs_emit_at for PAGE_SIZE buffer safety. Done with: $ spatch -sp-file sysfs_emit_dev.cocci --in-place --max-width=80 . And cocci script: $ cat sysfs_emit_dev.cocci @@ identifier d_show; identifier dev, attr, buf; @@ ssize_t d_show(struct device *dev, struct device_attribute *attr, char *buf) { <... return - sprintf(buf, + sysfs_emit(buf, ...); ...> } @@ identifier d_show; identifier dev, attr, buf; @@ ssize_t d_show(struct device *dev, struct device_attribute *attr, char *buf) { <... return - snprintf(buf, PAGE_SIZE, + sysfs_emit(buf, ...); ...> } @@ identifier d_show; identifier dev, attr, buf; @@ ssize_t d_show(struct device *dev, struct device_attribute *attr, char *buf) { <... return - scnprintf(buf, PAGE_SIZE, + sysfs_emit(buf, ...); ...> } @@ identifier d_show; identifier dev, attr, buf; expression chr; @@ ssize_t d_show(struct device *dev, struct device_attribute *attr, char *buf) { <... return - strcpy(buf, chr); + sysfs_emit(buf, chr); ...> } @@ identifier d_show; identifier dev, attr, buf; identifier len; @@ ssize_t d_show(struct device *dev, struct device_attribute *attr, char *buf) { <... len = - sprintf(buf, + sysfs_emit(buf, ...); ...> return len; } @@ identifier d_show; identifier dev, attr, buf; identifier len; @@ ssize_t d_show(struct device *dev, struct device_attribute *attr, char *buf) { <... len = - snprintf(buf, PAGE_SIZE, + sysfs_emit(buf, ...); ...> return len; } @@ identifier d_show; identifier dev, attr, buf; identifier len; @@ ssize_t d_show(struct device *dev, struct device_attribute *attr, char *buf) { <... len = - scnprintf(buf, PAGE_SIZE, + sysfs_emit(buf, ...); ...> return len; } @@ identifier d_show; identifier dev, attr, buf; identifier len; @@ ssize_t d_show(struct device *dev, struct device_attribute *attr, char *buf) { <... - len += scnprintf(buf + len, PAGE_SIZE - len, + len += sysfs_emit_at(buf, len, ...); ...> return len; } @@ identifier d_show; identifier dev, attr, buf; expression chr; @@ ssize_t d_show(struct device *dev, struct device_attribute *attr, char *buf) { ... - strcpy(buf, chr); - return strlen(buf); + return sysfs_emit(buf, chr); } Signed-off-by: Joe Perches <joe@perches.com> Link: https://lore.kernel.org/r/3d033c33056d88bbe34d4ddb62afd05ee166ab9a.1600285923.git.joe@perches.com Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2020-09-16 13:40:39 -07:00
drivers: base: support cpu cache information interface to userspace via sysfs This patch adds initial support for providing processor cache information to userspace through sysfs interface. This is based on already existing implementations(x86, ia64, s390 and powerpc) and hence the interface is intended to be fully compatible. The main purpose of this generic support is to avoid further code duplication to support new architectures and also to unify all the existing different implementations. This implementation maintains the hierarchy of cache objects which reflects the system's cache topology. Cache devices are instantiated as needed as CPUs come online. The cache information is replicated per-cpu even if they are shared. A per-cpu array of cache information maintained is used mainly for sysfs-related book keeping. It also implements the shared_cpu_map attribute, which is essential for enabling both kernel and user-space to discover the system's overall cache topology. This patch also add the missing ABI documentation for the cacheinfo sysfs interface already, which is well defined and widely used. Signed-off-by: Sudeep Holla <sudeep.holla@arm.com> Reviewed-by: Stephen Boyd <sboyd@codeaurora.org> Tested-by: Stephen Boyd <sboyd@codeaurora.org> Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org> Cc: linux-api@vger.kernel.org Cc: linux390@de.ibm.com Cc: linux-arm-kernel@lists.infradead.org Cc: linux-ia64@vger.kernel.org Cc: linuxppc-dev@lists.ozlabs.org Cc: linux-s390@vger.kernel.org Cc: x86@kernel.org Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2014-09-30 14:48:25 +01:00
drivers: base: support cpu cache information interface to userspace via sysfs This patch adds initial support for providing processor cache information to userspace through sysfs interface. This is based on already existing implementations(x86, ia64, s390 and powerpc) and hence the interface is intended to be fully compatible. The main purpose of this generic support is to avoid further code duplication to support new architectures and also to unify all the existing different implementations. This implementation maintains the hierarchy of cache objects which reflects the system's cache topology. Cache devices are instantiated as needed as CPUs come online. The cache information is replicated per-cpu even if they are shared. A per-cpu array of cache information maintained is used mainly for sysfs-related book keeping. It also implements the shared_cpu_map attribute, which is essential for enabling both kernel and user-space to discover the system's overall cache topology. This patch also add the missing ABI documentation for the cacheinfo sysfs interface already, which is well defined and widely used. Signed-off-by: Sudeep Holla <sudeep.holla@arm.com> Reviewed-by: Stephen Boyd <sboyd@codeaurora.org> Tested-by: Stephen Boyd <sboyd@codeaurora.org> Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org> Cc: linux-api@vger.kernel.org Cc: linux390@de.ibm.com Cc: linux-arm-kernel@lists.infradead.org Cc: linux-ia64@vger.kernel.org Cc: linuxppc-dev@lists.ozlabs.org Cc: linux-s390@vger.kernel.org Cc: x86@kernel.org Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2014-09-30 14:48:25 +01:00
drivers: base: support cpu cache information interface to userspace via sysfs This patch adds initial support for providing processor cache information to userspace through sysfs interface. This is based on already existing implementations(x86, ia64, s390 and powerpc) and hence the interface is intended to be fully compatible. The main purpose of this generic support is to avoid further code duplication to support new architectures and also to unify all the existing different implementations. This implementation maintains the hierarchy of cache objects which reflects the system's cache topology. Cache devices are instantiated as needed as CPUs come online. The cache information is replicated per-cpu even if they are shared. A per-cpu array of cache information maintained is used mainly for sysfs-related book keeping. It also implements the shared_cpu_map attribute, which is essential for enabling both kernel and user-space to discover the system's overall cache topology. This patch also add the missing ABI documentation for the cacheinfo sysfs interface already, which is well defined and widely used. Signed-off-by: Sudeep Holla <sudeep.holla@arm.com> Reviewed-by: Stephen Boyd <sboyd@codeaurora.org> Tested-by: Stephen Boyd <sboyd@codeaurora.org> Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org> Cc: linux-api@vger.kernel.org Cc: linux390@de.ibm.com Cc: linux-arm-kernel@lists.infradead.org Cc: linux-ia64@vger.kernel.org Cc: linuxppc-dev@lists.ozlabs.org Cc: linux-s390@vger.kernel.org Cc: x86@kernel.org Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2014-09-30 14:48:25 +01:00
drivers: base: support cpu cache information interface to userspace via sysfs This patch adds initial support for providing processor cache information to userspace through sysfs interface. This is based on already existing implementations(x86, ia64, s390 and powerpc) and hence the interface is intended to be fully compatible. The main purpose of this generic support is to avoid further code duplication to support new architectures and also to unify all the existing different implementations. This implementation maintains the hierarchy of cache objects which reflects the system's cache topology. Cache devices are instantiated as needed as CPUs come online. The cache information is replicated per-cpu even if they are shared. A per-cpu array of cache information maintained is used mainly for sysfs-related book keeping. It also implements the shared_cpu_map attribute, which is essential for enabling both kernel and user-space to discover the system's overall cache topology. This patch also add the missing ABI documentation for the cacheinfo sysfs interface already, which is well defined and widely used. Signed-off-by: Sudeep Holla <sudeep.holla@arm.com> Reviewed-by: Stephen Boyd <sboyd@codeaurora.org> Tested-by: Stephen Boyd <sboyd@codeaurora.org> Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org> Cc: linux-api@vger.kernel.org Cc: linux390@de.ibm.com Cc: linux-arm-kernel@lists.infradead.org Cc: linux-ia64@vger.kernel.org Cc: linuxppc-dev@lists.ozlabs.org Cc: linux-s390@vger.kernel.org Cc: x86@kernel.org Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2014-09-30 14:48:25 +01:00
drivers: base: support cpu cache information interface to userspace via sysfs This patch adds initial support for providing processor cache information to userspace through sysfs interface. This is based on already existing implementations(x86, ia64, s390 and powerpc) and hence the interface is intended to be fully compatible. The main purpose of this generic support is to avoid further code duplication to support new architectures and also to unify all the existing different implementations. This implementation maintains the hierarchy of cache objects which reflects the system's cache topology. Cache devices are instantiated as needed as CPUs come online. The cache information is replicated per-cpu even if they are shared. A per-cpu array of cache information maintained is used mainly for sysfs-related book keeping. It also implements the shared_cpu_map attribute, which is essential for enabling both kernel and user-space to discover the system's overall cache topology. This patch also add the missing ABI documentation for the cacheinfo sysfs interface already, which is well defined and widely used. Signed-off-by: Sudeep Holla <sudeep.holla@arm.com> Reviewed-by: Stephen Boyd <sboyd@codeaurora.org> Tested-by: Stephen Boyd <sboyd@codeaurora.org> Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org> Cc: linux-api@vger.kernel.org Cc: linux390@de.ibm.com Cc: linux-arm-kernel@lists.infradead.org Cc: linux-ia64@vger.kernel.org Cc: linuxppc-dev@lists.ozlabs.org Cc: linux-s390@vger.kernel.org Cc: x86@kernel.org Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2014-09-30 14:48:25 +01:00
drivers: base: support cpu cache information interface to userspace via sysfs This patch adds initial support for providing processor cache information to userspace through sysfs interface. This is based on already existing implementations(x86, ia64, s390 and powerpc) and hence the interface is intended to be fully compatible. The main purpose of this generic support is to avoid further code duplication to support new architectures and also to unify all the existing different implementations. This implementation maintains the hierarchy of cache objects which reflects the system's cache topology. Cache devices are instantiated as needed as CPUs come online. The cache information is replicated per-cpu even if they are shared. A per-cpu array of cache information maintained is used mainly for sysfs-related book keeping. It also implements the shared_cpu_map attribute, which is essential for enabling both kernel and user-space to discover the system's overall cache topology. This patch also add the missing ABI documentation for the cacheinfo sysfs interface already, which is well defined and widely used. Signed-off-by: Sudeep Holla <sudeep.holla@arm.com> Reviewed-by: Stephen Boyd <sboyd@codeaurora.org> Tested-by: Stephen Boyd <sboyd@codeaurora.org> Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org> Cc: linux-api@vger.kernel.org Cc: linux390@de.ibm.com Cc: linux-arm-kernel@lists.infradead.org Cc: linux-ia64@vger.kernel.org Cc: linuxppc-dev@lists.ozlabs.org Cc: linux-s390@vger.kernel.org Cc: x86@kernel.org Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2014-09-30 14:48:25 +01:00
drivers: base: support cpu cache information interface to userspace via sysfs This patch adds initial support for providing processor cache information to userspace through sysfs interface. This is based on already existing implementations(x86, ia64, s390 and powerpc) and hence the interface is intended to be fully compatible. The main purpose of this generic support is to avoid further code duplication to support new architectures and also to unify all the existing different implementations. This implementation maintains the hierarchy of cache objects which reflects the system's cache topology. Cache devices are instantiated as needed as CPUs come online. The cache information is replicated per-cpu even if they are shared. A per-cpu array of cache information maintained is used mainly for sysfs-related book keeping. It also implements the shared_cpu_map attribute, which is essential for enabling both kernel and user-space to discover the system's overall cache topology. This patch also add the missing ABI documentation for the cacheinfo sysfs interface already, which is well defined and widely used. Signed-off-by: Sudeep Holla <sudeep.holla@arm.com> Reviewed-by: Stephen Boyd <sboyd@codeaurora.org> Tested-by: Stephen Boyd <sboyd@codeaurora.org> Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org> Cc: linux-api@vger.kernel.org Cc: linux390@de.ibm.com Cc: linux-arm-kernel@lists.infradead.org Cc: linux-ia64@vger.kernel.org Cc: linuxppc-dev@lists.ozlabs.org Cc: linux-s390@vger.kernel.org Cc: x86@kernel.org Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2014-09-30 14:48:25 +01:00
drivers: base: support cpu cache information interface to userspace via sysfs This patch adds initial support for providing processor cache information to userspace through sysfs interface. This is based on already existing implementations(x86, ia64, s390 and powerpc) and hence the interface is intended to be fully compatible. The main purpose of this generic support is to avoid further code duplication to support new architectures and also to unify all the existing different implementations. This implementation maintains the hierarchy of cache objects which reflects the system's cache topology. Cache devices are instantiated as needed as CPUs come online. The cache information is replicated per-cpu even if they are shared. A per-cpu array of cache information maintained is used mainly for sysfs-related book keeping. It also implements the shared_cpu_map attribute, which is essential for enabling both kernel and user-space to discover the system's overall cache topology. This patch also add the missing ABI documentation for the cacheinfo sysfs interface already, which is well defined and widely used. Signed-off-by: Sudeep Holla <sudeep.holla@arm.com> Reviewed-by: Stephen Boyd <sboyd@codeaurora.org> Tested-by: Stephen Boyd <sboyd@codeaurora.org> Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org> Cc: linux-api@vger.kernel.org Cc: linux390@de.ibm.com Cc: linux-arm-kernel@lists.infradead.org Cc: linux-ia64@vger.kernel.org Cc: linuxppc-dev@lists.ozlabs.org Cc: linux-s390@vger.kernel.org Cc: x86@kernel.org Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2014-09-30 14:48:25 +01:00
drivers: base: support cpu cache information interface to userspace via sysfs This patch adds initial support for providing processor cache information to userspace through sysfs interface. This is based on already existing implementations(x86, ia64, s390 and powerpc) and hence the interface is intended to be fully compatible. The main purpose of this generic support is to avoid further code duplication to support new architectures and also to unify all the existing different implementations. This implementation maintains the hierarchy of cache objects which reflects the system's cache topology. Cache devices are instantiated as needed as CPUs come online. The cache information is replicated per-cpu even if they are shared. A per-cpu array of cache information maintained is used mainly for sysfs-related book keeping. It also implements the shared_cpu_map attribute, which is essential for enabling both kernel and user-space to discover the system's overall cache topology. This patch also add the missing ABI documentation for the cacheinfo sysfs interface already, which is well defined and widely used. Signed-off-by: Sudeep Holla <sudeep.holla@arm.com> Reviewed-by: Stephen Boyd <sboyd@codeaurora.org> Tested-by: Stephen Boyd <sboyd@codeaurora.org> Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org> Cc: linux-api@vger.kernel.org Cc: linux390@de.ibm.com Cc: linux-arm-kernel@lists.infradead.org Cc: linux-ia64@vger.kernel.org Cc: linuxppc-dev@lists.ozlabs.org Cc: linux-s390@vger.kernel.org Cc: x86@kernel.org Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2014-09-30 14:48:25 +01:00
drivers: base: support cpu cache information interface to userspace via sysfs This patch adds initial support for providing processor cache information to userspace through sysfs interface. This is based on already existing implementations(x86, ia64, s390 and powerpc) and hence the interface is intended to be fully compatible. The main purpose of this generic support is to avoid further code duplication to support new architectures and also to unify all the existing different implementations. This implementation maintains the hierarchy of cache objects which reflects the system's cache topology. Cache devices are instantiated as needed as CPUs come online. The cache information is replicated per-cpu even if they are shared. A per-cpu array of cache information maintained is used mainly for sysfs-related book keeping. It also implements the shared_cpu_map attribute, which is essential for enabling both kernel and user-space to discover the system's overall cache topology. This patch also add the missing ABI documentation for the cacheinfo sysfs interface already, which is well defined and widely used. Signed-off-by: Sudeep Holla <sudeep.holla@arm.com> Reviewed-by: Stephen Boyd <sboyd@codeaurora.org> Tested-by: Stephen Boyd <sboyd@codeaurora.org> Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org> Cc: linux-api@vger.kernel.org Cc: linux390@de.ibm.com Cc: linux-arm-kernel@lists.infradead.org Cc: linux-ia64@vger.kernel.org Cc: linuxppc-dev@lists.ozlabs.org Cc: linux-s390@vger.kernel.org Cc: x86@kernel.org Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2014-09-30 14:48:25 +01:00
drivers: base: support cpu cache information interface to userspace via sysfs This patch adds initial support for providing processor cache information to userspace through sysfs interface. This is based on already existing implementations(x86, ia64, s390 and powerpc) and hence the interface is intended to be fully compatible. The main purpose of this generic support is to avoid further code duplication to support new architectures and also to unify all the existing different implementations. This implementation maintains the hierarchy of cache objects which reflects the system's cache topology. Cache devices are instantiated as needed as CPUs come online. The cache information is replicated per-cpu even if they are shared. A per-cpu array of cache information maintained is used mainly for sysfs-related book keeping. It also implements the shared_cpu_map attribute, which is essential for enabling both kernel and user-space to discover the system's overall cache topology. This patch also add the missing ABI documentation for the cacheinfo sysfs interface already, which is well defined and widely used. Signed-off-by: Sudeep Holla <sudeep.holla@arm.com> Reviewed-by: Stephen Boyd <sboyd@codeaurora.org> Tested-by: Stephen Boyd <sboyd@codeaurora.org> Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org> Cc: linux-api@vger.kernel.org Cc: linux390@de.ibm.com Cc: linux-arm-kernel@lists.infradead.org Cc: linux-ia64@vger.kernel.org Cc: linuxppc-dev@lists.ozlabs.org Cc: linux-s390@vger.kernel.org Cc: x86@kernel.org Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2014-09-30 14:48:25 +01:00
drivers: base: support cpu cache information interface to userspace via sysfs This patch adds initial support for providing processor cache information to userspace through sysfs interface. This is based on already existing implementations(x86, ia64, s390 and powerpc) and hence the interface is intended to be fully compatible. The main purpose of this generic support is to avoid further code duplication to support new architectures and also to unify all the existing different implementations. This implementation maintains the hierarchy of cache objects which reflects the system's cache topology. Cache devices are instantiated as needed as CPUs come online. The cache information is replicated per-cpu even if they are shared. A per-cpu array of cache information maintained is used mainly for sysfs-related book keeping. It also implements the shared_cpu_map attribute, which is essential for enabling both kernel and user-space to discover the system's overall cache topology. This patch also add the missing ABI documentation for the cacheinfo sysfs interface already, which is well defined and widely used. Signed-off-by: Sudeep Holla <sudeep.holla@arm.com> Reviewed-by: Stephen Boyd <sboyd@codeaurora.org> Tested-by: Stephen Boyd <sboyd@codeaurora.org> Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org> Cc: linux-api@vger.kernel.org Cc: linux390@de.ibm.com Cc: linux-arm-kernel@lists.infradead.org Cc: linux-ia64@vger.kernel.org Cc: linuxppc-dev@lists.ozlabs.org Cc: linux-s390@vger.kernel.org Cc: x86@kernel.org Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2014-09-30 14:48:25 +01:00
drivers: base: support cpu cache information interface to userspace via sysfs This patch adds initial support for providing processor cache information to userspace through sysfs interface. This is based on already existing implementations(x86, ia64, s390 and powerpc) and hence the interface is intended to be fully compatible. The main purpose of this generic support is to avoid further code duplication to support new architectures and also to unify all the existing different implementations. This implementation maintains the hierarchy of cache objects which reflects the system's cache topology. Cache devices are instantiated as needed as CPUs come online. The cache information is replicated per-cpu even if they are shared. A per-cpu array of cache information maintained is used mainly for sysfs-related book keeping. It also implements the shared_cpu_map attribute, which is essential for enabling both kernel and user-space to discover the system's overall cache topology. This patch also add the missing ABI documentation for the cacheinfo sysfs interface already, which is well defined and widely used. Signed-off-by: Sudeep Holla <sudeep.holla@arm.com> Reviewed-by: Stephen Boyd <sboyd@codeaurora.org> Tested-by: Stephen Boyd <sboyd@codeaurora.org> Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org> Cc: linux-api@vger.kernel.org Cc: linux390@de.ibm.com Cc: linux-arm-kernel@lists.infradead.org Cc: linux-ia64@vger.kernel.org Cc: linuxppc-dev@lists.ozlabs.org Cc: linux-s390@vger.kernel.org Cc: x86@kernel.org Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2014-09-30 14:48:25 +01:00
drivers core: Use sysfs_emit and sysfs_emit_at for show(device *...) functions Convert the various sprintf fmaily calls in sysfs device show functions to sysfs_emit and sysfs_emit_at for PAGE_SIZE buffer safety. Done with: $ spatch -sp-file sysfs_emit_dev.cocci --in-place --max-width=80 . And cocci script: $ cat sysfs_emit_dev.cocci @@ identifier d_show; identifier dev, attr, buf; @@ ssize_t d_show(struct device *dev, struct device_attribute *attr, char *buf) { <... return - sprintf(buf, + sysfs_emit(buf, ...); ...> } @@ identifier d_show; identifier dev, attr, buf; @@ ssize_t d_show(struct device *dev, struct device_attribute *attr, char *buf) { <... return - snprintf(buf, PAGE_SIZE, + sysfs_emit(buf, ...); ...> } @@ identifier d_show; identifier dev, attr, buf; @@ ssize_t d_show(struct device *dev, struct device_attribute *attr, char *buf) { <... return - scnprintf(buf, PAGE_SIZE, + sysfs_emit(buf, ...); ...> } @@ identifier d_show; identifier dev, attr, buf; expression chr; @@ ssize_t d_show(struct device *dev, struct device_attribute *attr, char *buf) { <... return - strcpy(buf, chr); + sysfs_emit(buf, chr); ...> } @@ identifier d_show; identifier dev, attr, buf; identifier len; @@ ssize_t d_show(struct device *dev, struct device_attribute *attr, char *buf) { <... len = - sprintf(buf, + sysfs_emit(buf, ...); ...> return len; } @@ identifier d_show; identifier dev, attr, buf; identifier len; @@ ssize_t d_show(struct device *dev, struct device_attribute *attr, char *buf) { <... len = - snprintf(buf, PAGE_SIZE, + sysfs_emit(buf, ...); ...> return len; } @@ identifier d_show; identifier dev, attr, buf; identifier len; @@ ssize_t d_show(struct device *dev, struct device_attribute *attr, char *buf) { <... len = - scnprintf(buf, PAGE_SIZE, + sysfs_emit(buf, ...); ...> return len; } @@ identifier d_show; identifier dev, attr, buf; identifier len; @@ ssize_t d_show(struct device *dev, struct device_attribute *attr, char *buf) { <... - len += scnprintf(buf + len, PAGE_SIZE - len, + len += sysfs_emit_at(buf, len, ...); ...> return len; } @@ identifier d_show; identifier dev, attr, buf; expression chr; @@ ssize_t d_show(struct device *dev, struct device_attribute *attr, char *buf) { ... - strcpy(buf, chr); - return strlen(buf); + return sysfs_emit(buf, chr); } Signed-off-by: Joe Perches <joe@perches.com> Link: https://lore.kernel.org/r/3d033c33056d88bbe34d4ddb62afd05ee166ab9a.1600285923.git.joe@perches.com Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2020-09-16 13:40:39 -07:00
drivers: base: support cpu cache information interface to userspace via sysfs This patch adds initial support for providing processor cache information to userspace through sysfs interface. This is based on already existing implementations(x86, ia64, s390 and powerpc) and hence the interface is intended to be fully compatible. The main purpose of this generic support is to avoid further code duplication to support new architectures and also to unify all the existing different implementations. This implementation maintains the hierarchy of cache objects which reflects the system's cache topology. Cache devices are instantiated as needed as CPUs come online. The cache information is replicated per-cpu even if they are shared. A per-cpu array of cache information maintained is used mainly for sysfs-related book keeping. It also implements the shared_cpu_map attribute, which is essential for enabling both kernel and user-space to discover the system's overall cache topology. This patch also add the missing ABI documentation for the cacheinfo sysfs interface already, which is well defined and widely used. Signed-off-by: Sudeep Holla <sudeep.holla@arm.com> Reviewed-by: Stephen Boyd <sboyd@codeaurora.org> Tested-by: Stephen Boyd <sboyd@codeaurora.org> Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org> Cc: linux-api@vger.kernel.org Cc: linux390@de.ibm.com Cc: linux-arm-kernel@lists.infradead.org Cc: linux-ia64@vger.kernel.org Cc: linuxppc-dev@lists.ozlabs.org Cc: linux-s390@vger.kernel.org Cc: x86@kernel.org Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2014-09-30 14:48:25 +01:00
drivers core: Use sysfs_emit and sysfs_emit_at for show(device *...) functions Convert the various sprintf fmaily calls in sysfs device show functions to sysfs_emit and sysfs_emit_at for PAGE_SIZE buffer safety. Done with: $ spatch -sp-file sysfs_emit_dev.cocci --in-place --max-width=80 . And cocci script: $ cat sysfs_emit_dev.cocci @@ identifier d_show; identifier dev, attr, buf; @@ ssize_t d_show(struct device *dev, struct device_attribute *attr, char *buf) { <... return - sprintf(buf, + sysfs_emit(buf, ...); ...> } @@ identifier d_show; identifier dev, attr, buf; @@ ssize_t d_show(struct device *dev, struct device_attribute *attr, char *buf) { <... return - snprintf(buf, PAGE_SIZE, + sysfs_emit(buf, ...); ...> } @@ identifier d_show; identifier dev, attr, buf; @@ ssize_t d_show(struct device *dev, struct device_attribute *attr, char *buf) { <... return - scnprintf(buf, PAGE_SIZE, + sysfs_emit(buf, ...); ...> } @@ identifier d_show; identifier dev, attr, buf; expression chr; @@ ssize_t d_show(struct device *dev, struct device_attribute *attr, char *buf) { <... return - strcpy(buf, chr); + sysfs_emit(buf, chr); ...> } @@ identifier d_show; identifier dev, attr, buf; identifier len; @@ ssize_t d_show(struct device *dev, struct device_attribute *attr, char *buf) { <... len = - sprintf(buf, + sysfs_emit(buf, ...); ...> return len; } @@ identifier d_show; identifier dev, attr, buf; identifier len; @@ ssize_t d_show(struct device *dev, struct device_attribute *attr, char *buf) { <... len = - snprintf(buf, PAGE_SIZE, + sysfs_emit(buf, ...); ...> return len; } @@ identifier d_show; identifier dev, attr, buf; identifier len; @@ ssize_t d_show(struct device *dev, struct device_attribute *attr, char *buf) { <... len = - scnprintf(buf, PAGE_SIZE, + sysfs_emit(buf, ...); ...> return len; } @@ identifier d_show; identifier dev, attr, buf; identifier len; @@ ssize_t d_show(struct device *dev, struct device_attribute *attr, char *buf) { <... - len += scnprintf(buf + len, PAGE_SIZE - len, + len += sysfs_emit_at(buf, len, ...); ...> return len; } @@ identifier d_show; identifier dev, attr, buf; expression chr; @@ ssize_t d_show(struct device *dev, struct device_attribute *attr, char *buf) { ... - strcpy(buf, chr); - return strlen(buf); + return sysfs_emit(buf, chr); } Signed-off-by: Joe Perches <joe@perches.com> Link: https://lore.kernel.org/r/3d033c33056d88bbe34d4ddb62afd05ee166ab9a.1600285923.git.joe@perches.com Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2020-09-16 13:40:39 -07:00
drivers: base: support cpu cache information interface to userspace via sysfs This patch adds initial support for providing processor cache information to userspace through sysfs interface. This is based on already existing implementations(x86, ia64, s390 and powerpc) and hence the interface is intended to be fully compatible. The main purpose of this generic support is to avoid further code duplication to support new architectures and also to unify all the existing different implementations. This implementation maintains the hierarchy of cache objects which reflects the system's cache topology. Cache devices are instantiated as needed as CPUs come online. The cache information is replicated per-cpu even if they are shared. A per-cpu array of cache information maintained is used mainly for sysfs-related book keeping. It also implements the shared_cpu_map attribute, which is essential for enabling both kernel and user-space to discover the system's overall cache topology. This patch also add the missing ABI documentation for the cacheinfo sysfs interface already, which is well defined and widely used. Signed-off-by: Sudeep Holla <sudeep.holla@arm.com> Reviewed-by: Stephen Boyd <sboyd@codeaurora.org> Tested-by: Stephen Boyd <sboyd@codeaurora.org> Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org> Cc: linux-api@vger.kernel.org Cc: linux390@de.ibm.com Cc: linux-arm-kernel@lists.infradead.org Cc: linux-ia64@vger.kernel.org Cc: linuxppc-dev@lists.ozlabs.org Cc: linux-s390@vger.kernel.org Cc: x86@kernel.org Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2014-09-30 14:48:25 +01:00
drivers: base: support cpu cache information interface to userspace via sysfs This patch adds initial support for providing processor cache information to userspace through sysfs interface. This is based on already existing implementations(x86, ia64, s390 and powerpc) and hence the interface is intended to be fully compatible. The main purpose of this generic support is to avoid further code duplication to support new architectures and also to unify all the existing different implementations. This implementation maintains the hierarchy of cache objects which reflects the system's cache topology. Cache devices are instantiated as needed as CPUs come online. The cache information is replicated per-cpu even if they are shared. A per-cpu array of cache information maintained is used mainly for sysfs-related book keeping. It also implements the shared_cpu_map attribute, which is essential for enabling both kernel and user-space to discover the system's overall cache topology. This patch also add the missing ABI documentation for the cacheinfo sysfs interface already, which is well defined and widely used. Signed-off-by: Sudeep Holla <sudeep.holla@arm.com> Reviewed-by: Stephen Boyd <sboyd@codeaurora.org> Tested-by: Stephen Boyd <sboyd@codeaurora.org> Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org> Cc: linux-api@vger.kernel.org Cc: linux390@de.ibm.com Cc: linux-arm-kernel@lists.infradead.org Cc: linux-ia64@vger.kernel.org Cc: linuxppc-dev@lists.ozlabs.org Cc: linux-s390@vger.kernel.org Cc: x86@kernel.org Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2014-09-30 14:48:25 +01:00
drivers: base: support cpu cache information interface to userspace via sysfs This patch adds initial support for providing processor cache information to userspace through sysfs interface. This is based on already existing implementations(x86, ia64, s390 and powerpc) and hence the interface is intended to be fully compatible. The main purpose of this generic support is to avoid further code duplication to support new architectures and also to unify all the existing different implementations. This implementation maintains the hierarchy of cache objects which reflects the system's cache topology. Cache devices are instantiated as needed as CPUs come online. The cache information is replicated per-cpu even if they are shared. A per-cpu array of cache information maintained is used mainly for sysfs-related book keeping. It also implements the shared_cpu_map attribute, which is essential for enabling both kernel and user-space to discover the system's overall cache topology. This patch also add the missing ABI documentation for the cacheinfo sysfs interface already, which is well defined and widely used. Signed-off-by: Sudeep Holla <sudeep.holla@arm.com> Reviewed-by: Stephen Boyd <sboyd@codeaurora.org> Tested-by: Stephen Boyd <sboyd@codeaurora.org> Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org> Cc: linux-api@vger.kernel.org Cc: linux390@de.ibm.com Cc: linux-arm-kernel@lists.infradead.org Cc: linux-ia64@vger.kernel.org Cc: linuxppc-dev@lists.ozlabs.org Cc: linux-s390@vger.kernel.org Cc: x86@kernel.org Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2014-09-30 14:48:25 +01:00
drivers: base: support cpu cache information interface to userspace via sysfs This patch adds initial support for providing processor cache information to userspace through sysfs interface. This is based on already existing implementations(x86, ia64, s390 and powerpc) and hence the interface is intended to be fully compatible. The main purpose of this generic support is to avoid further code duplication to support new architectures and also to unify all the existing different implementations. This implementation maintains the hierarchy of cache objects which reflects the system's cache topology. Cache devices are instantiated as needed as CPUs come online. The cache information is replicated per-cpu even if they are shared. A per-cpu array of cache information maintained is used mainly for sysfs-related book keeping. It also implements the shared_cpu_map attribute, which is essential for enabling both kernel and user-space to discover the system's overall cache topology. This patch also add the missing ABI documentation for the cacheinfo sysfs interface already, which is well defined and widely used. Signed-off-by: Sudeep Holla <sudeep.holla@arm.com> Reviewed-by: Stephen Boyd <sboyd@codeaurora.org> Tested-by: Stephen Boyd <sboyd@codeaurora.org> Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org> Cc: linux-api@vger.kernel.org Cc: linux390@de.ibm.com Cc: linux-arm-kernel@lists.infradead.org Cc: linux-ia64@vger.kernel.org Cc: linuxppc-dev@lists.ozlabs.org Cc: linux-s390@vger.kernel.org Cc: x86@kernel.org Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2014-09-30 14:48:25 +01:00
drivers: base: support cpu cache information interface to userspace via sysfs This patch adds initial support for providing processor cache information to userspace through sysfs interface. This is based on already existing implementations(x86, ia64, s390 and powerpc) and hence the interface is intended to be fully compatible. The main purpose of this generic support is to avoid further code duplication to support new architectures and also to unify all the existing different implementations. This implementation maintains the hierarchy of cache objects which reflects the system's cache topology. Cache devices are instantiated as needed as CPUs come online. The cache information is replicated per-cpu even if they are shared. A per-cpu array of cache information maintained is used mainly for sysfs-related book keeping. It also implements the shared_cpu_map attribute, which is essential for enabling both kernel and user-space to discover the system's overall cache topology. This patch also add the missing ABI documentation for the cacheinfo sysfs interface already, which is well defined and widely used. Signed-off-by: Sudeep Holla <sudeep.holla@arm.com> Reviewed-by: Stephen Boyd <sboyd@codeaurora.org> Tested-by: Stephen Boyd <sboyd@codeaurora.org> Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org> Cc: linux-api@vger.kernel.org Cc: linux390@de.ibm.com Cc: linux-arm-kernel@lists.infradead.org Cc: linux-ia64@vger.kernel.org Cc: linuxppc-dev@lists.ozlabs.org Cc: linux-s390@vger.kernel.org Cc: x86@kernel.org Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2014-09-30 14:48:25 +01:00
drivers: base: support cpu cache information interface to userspace via sysfs This patch adds initial support for providing processor cache information to userspace through sysfs interface. This is based on already existing implementations(x86, ia64, s390 and powerpc) and hence the interface is intended to be fully compatible. The main purpose of this generic support is to avoid further code duplication to support new architectures and also to unify all the existing different implementations. This implementation maintains the hierarchy of cache objects which reflects the system's cache topology. Cache devices are instantiated as needed as CPUs come online. The cache information is replicated per-cpu even if they are shared. A per-cpu array of cache information maintained is used mainly for sysfs-related book keeping. It also implements the shared_cpu_map attribute, which is essential for enabling both kernel and user-space to discover the system's overall cache topology. This patch also add the missing ABI documentation for the cacheinfo sysfs interface already, which is well defined and widely used. Signed-off-by: Sudeep Holla <sudeep.holla@arm.com> Reviewed-by: Stephen Boyd <sboyd@codeaurora.org> Tested-by: Stephen Boyd <sboyd@codeaurora.org> Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org> Cc: linux-api@vger.kernel.org Cc: linux390@de.ibm.com Cc: linux-arm-kernel@lists.infradead.org Cc: linux-ia64@vger.kernel.org Cc: linuxppc-dev@lists.ozlabs.org Cc: linux-s390@vger.kernel.org Cc: x86@kernel.org Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2014-09-30 14:48:25 +01:00
drivers: base: support cpu cache information interface to userspace via sysfs This patch adds initial support for providing processor cache information to userspace through sysfs interface. This is based on already existing implementations(x86, ia64, s390 and powerpc) and hence the interface is intended to be fully compatible. The main purpose of this generic support is to avoid further code duplication to support new architectures and also to unify all the existing different implementations. This implementation maintains the hierarchy of cache objects which reflects the system's cache topology. Cache devices are instantiated as needed as CPUs come online. The cache information is replicated per-cpu even if they are shared. A per-cpu array of cache information maintained is used mainly for sysfs-related book keeping. It also implements the shared_cpu_map attribute, which is essential for enabling both kernel and user-space to discover the system's overall cache topology. This patch also add the missing ABI documentation for the cacheinfo sysfs interface already, which is well defined and widely used. Signed-off-by: Sudeep Holla <sudeep.holla@arm.com> Reviewed-by: Stephen Boyd <sboyd@codeaurora.org> Tested-by: Stephen Boyd <sboyd@codeaurora.org> Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org> Cc: linux-api@vger.kernel.org Cc: linux390@de.ibm.com Cc: linux-arm-kernel@lists.infradead.org Cc: linux-ia64@vger.kernel.org Cc: linuxppc-dev@lists.ozlabs.org Cc: linux-s390@vger.kernel.org Cc: x86@kernel.org Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2014-09-30 14:48:25 +01:00
drivers: base: support cpu cache information interface to userspace via sysfs This patch adds initial support for providing processor cache information to userspace through sysfs interface. This is based on already existing implementations(x86, ia64, s390 and powerpc) and hence the interface is intended to be fully compatible. The main purpose of this generic support is to avoid further code duplication to support new architectures and also to unify all the existing different implementations. This implementation maintains the hierarchy of cache objects which reflects the system's cache topology. Cache devices are instantiated as needed as CPUs come online. The cache information is replicated per-cpu even if they are shared. A per-cpu array of cache information maintained is used mainly for sysfs-related book keeping. It also implements the shared_cpu_map attribute, which is essential for enabling both kernel and user-space to discover the system's overall cache topology. This patch also add the missing ABI documentation for the cacheinfo sysfs interface already, which is well defined and widely used. Signed-off-by: Sudeep Holla <sudeep.holla@arm.com> Reviewed-by: Stephen Boyd <sboyd@codeaurora.org> Tested-by: Stephen Boyd <sboyd@codeaurora.org> Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org> Cc: linux-api@vger.kernel.org Cc: linux390@de.ibm.com Cc: linux-arm-kernel@lists.infradead.org Cc: linux-ia64@vger.kernel.org Cc: linuxppc-dev@lists.ozlabs.org Cc: linux-s390@vger.kernel.org Cc: x86@kernel.org Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2014-09-30 14:48:25 +01:00
drivers: base: support cpu cache information interface to userspace via sysfs This patch adds initial support for providing processor cache information to userspace through sysfs interface. This is based on already existing implementations(x86, ia64, s390 and powerpc) and hence the interface is intended to be fully compatible. The main purpose of this generic support is to avoid further code duplication to support new architectures and also to unify all the existing different implementations. This implementation maintains the hierarchy of cache objects which reflects the system's cache topology. Cache devices are instantiated as needed as CPUs come online. The cache information is replicated per-cpu even if they are shared. A per-cpu array of cache information maintained is used mainly for sysfs-related book keeping. It also implements the shared_cpu_map attribute, which is essential for enabling both kernel and user-space to discover the system's overall cache topology. This patch also add the missing ABI documentation for the cacheinfo sysfs interface already, which is well defined and widely used. Signed-off-by: Sudeep Holla <sudeep.holla@arm.com> Reviewed-by: Stephen Boyd <sboyd@codeaurora.org> Tested-by: Stephen Boyd <sboyd@codeaurora.org> Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org> Cc: linux-api@vger.kernel.org Cc: linux390@de.ibm.com Cc: linux-arm-kernel@lists.infradead.org Cc: linux-ia64@vger.kernel.org Cc: linuxppc-dev@lists.ozlabs.org Cc: linux-s390@vger.kernel.org Cc: x86@kernel.org Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2014-09-30 14:48:25 +01:00
drivers: base: support cpu cache information interface to userspace via sysfs This patch adds initial support for providing processor cache information to userspace through sysfs interface. This is based on already existing implementations(x86, ia64, s390 and powerpc) and hence the interface is intended to be fully compatible. The main purpose of this generic support is to avoid further code duplication to support new architectures and also to unify all the existing different implementations. This implementation maintains the hierarchy of cache objects which reflects the system's cache topology. Cache devices are instantiated as needed as CPUs come online. The cache information is replicated per-cpu even if they are shared. A per-cpu array of cache information maintained is used mainly for sysfs-related book keeping. It also implements the shared_cpu_map attribute, which is essential for enabling both kernel and user-space to discover the system's overall cache topology. This patch also add the missing ABI documentation for the cacheinfo sysfs interface already, which is well defined and widely used. Signed-off-by: Sudeep Holla <sudeep.holla@arm.com> Reviewed-by: Stephen Boyd <sboyd@codeaurora.org> Tested-by: Stephen Boyd <sboyd@codeaurora.org> Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org> Cc: linux-api@vger.kernel.org Cc: linux390@de.ibm.com Cc: linux-arm-kernel@lists.infradead.org Cc: linux-ia64@vger.kernel.org Cc: linuxppc-dev@lists.ozlabs.org Cc: linux-s390@vger.kernel.org Cc: x86@kernel.org Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2014-09-30 14:48:25 +01:00
drivers: base: support cpu cache information interface to userspace via sysfs This patch adds initial support for providing processor cache information to userspace through sysfs interface. This is based on already existing implementations(x86, ia64, s390 and powerpc) and hence the interface is intended to be fully compatible. The main purpose of this generic support is to avoid further code duplication to support new architectures and also to unify all the existing different implementations. This implementation maintains the hierarchy of cache objects which reflects the system's cache topology. Cache devices are instantiated as needed as CPUs come online. The cache information is replicated per-cpu even if they are shared. A per-cpu array of cache information maintained is used mainly for sysfs-related book keeping. It also implements the shared_cpu_map attribute, which is essential for enabling both kernel and user-space to discover the system's overall cache topology. This patch also add the missing ABI documentation for the cacheinfo sysfs interface already, which is well defined and widely used. Signed-off-by: Sudeep Holla <sudeep.holla@arm.com> Reviewed-by: Stephen Boyd <sboyd@codeaurora.org> Tested-by: Stephen Boyd <sboyd@codeaurora.org> Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org> Cc: linux-api@vger.kernel.org Cc: linux390@de.ibm.com Cc: linux-arm-kernel@lists.infradead.org Cc: linux-ia64@vger.kernel.org Cc: linuxppc-dev@lists.ozlabs.org Cc: linux-s390@vger.kernel.org Cc: x86@kernel.org Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2014-09-30 14:48:25 +01:00
drivers: base: support cpu cache information interface to userspace via sysfs This patch adds initial support for providing processor cache information to userspace through sysfs interface. This is based on already existing implementations(x86, ia64, s390 and powerpc) and hence the interface is intended to be fully compatible. The main purpose of this generic support is to avoid further code duplication to support new architectures and also to unify all the existing different implementations. This implementation maintains the hierarchy of cache objects which reflects the system's cache topology. Cache devices are instantiated as needed as CPUs come online. The cache information is replicated per-cpu even if they are shared. A per-cpu array of cache information maintained is used mainly for sysfs-related book keeping. It also implements the shared_cpu_map attribute, which is essential for enabling both kernel and user-space to discover the system's overall cache topology. This patch also add the missing ABI documentation for the cacheinfo sysfs interface already, which is well defined and widely used. Signed-off-by: Sudeep Holla <sudeep.holla@arm.com> Reviewed-by: Stephen Boyd <sboyd@codeaurora.org> Tested-by: Stephen Boyd <sboyd@codeaurora.org> Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org> Cc: linux-api@vger.kernel.org Cc: linux390@de.ibm.com Cc: linux-arm-kernel@lists.infradead.org Cc: linux-ia64@vger.kernel.org Cc: linuxppc-dev@lists.ozlabs.org Cc: linux-s390@vger.kernel.org Cc: x86@kernel.org Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2014-09-30 14:48:25 +01:00