The quotes symbol in
"EEE "link partner ability 1
should be at the end of the register name
"EEE link partner ability 1"
Signed-off-by: Marek Behún <kabel@kernel.org>
Reviewed-by: Andrew Lunn <andrew@lunn.ch>
Signed-off-by: David S. Miller <davem@davemloft.net>
Add record for TI Industrial Communication Subsystem - Gigabit (ICSSG)
Ethernet driver.
Also add Roger and myself as maintainer.
Signed-off-by: MD Danish Anwar <danishanwar@ti.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Add an "unmovable" flag for mappings that cannot be migrated under any
circumstance. KVM will use the flag for its upcoming GUEST_MEMFD support,
which will not support compaction/migration, at least not in the
foreseeable future.
Test AS_UNMOVABLE under folio lock as already done for the async
compaction/dirty folio case, as the mapping can be removed by truncation
while compaction is running. To avoid having to lock every folio with a
mapping, assume/require that unmovable mappings are also unevictable, and
have mapping_set_unmovable() also set AS_UNEVICTABLE.
Cc: Matthew Wilcox <willy@infradead.org>
Co-developed-by: Vlastimil Babka <vbabka@suse.cz>
Signed-off-by: Vlastimil Babka <vbabka@suse.cz>
Signed-off-by: Sean Christopherson <seanjc@google.com>
Message-Id: <20231027182217.3615211-15-seanjc@google.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
In confidential computing usages, whether a page is private or shared is
necessary information for KVM to perform operations like page fault
handling, page zapping etc. There are other potential use cases for
per-page memory attributes, e.g. to make memory read-only (or no-exec,
or exec-only, etc.) without having to modify memslots.
Introduce the KVM_SET_MEMORY_ATTRIBUTES ioctl, advertised by
KVM_CAP_MEMORY_ATTRIBUTES, to allow userspace to set the per-page memory
attributes to a guest memory range.
Use an xarray to store the per-page attributes internally, with a naive,
not fully optimized implementation, i.e. prioritize correctness over
performance for the initial implementation.
Use bit 3 for the PRIVATE attribute so that KVM can use bits 0-2 for RWX
attributes/protections in the future, e.g. to give userspace fine-grained
control over read, write, and execute protections for guest memory.
Provide arch hooks for handling attribute changes before and after common
code sets the new attributes, e.g. x86 will use the "pre" hook to zap all
relevant mappings, and the "post" hook to track whether or not hugepages
can be used to map the range.
To simplify the implementation wrap the entire sequence with
kvm_mmu_invalidate_{begin,end}() even though the operation isn't strictly
guaranteed to be an invalidation. For the initial use case, x86 *will*
always invalidate memory, and preventing arch code from creating new
mappings while the attributes are in flux makes it much easier to reason
about the correctness of consuming attributes.
It's possible that future usages may not require an invalidation, e.g.
if KVM ends up supporting RWX protections and userspace grants _more_
protections, but again opt for simplicity and punt optimizations to
if/when they are needed.
Suggested-by: Sean Christopherson <seanjc@google.com>
Link: https://lore.kernel.org/all/Y2WB48kD0J4VGynX@google.com
Cc: Fuad Tabba <tabba@google.com>
Cc: Xu Yilun <yilun.xu@intel.com>
Cc: Mickaël Salaün <mic@digikod.net>
Signed-off-by: Chao Peng <chao.p.peng@linux.intel.com>
Co-developed-by: Sean Christopherson <seanjc@google.com>
Signed-off-by: Sean Christopherson <seanjc@google.com>
Message-Id: <20231027182217.3615211-14-seanjc@google.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Drop the .on_unlock() mmu_notifer hook now that it's no longer used for
notifying arch code that memory has been reclaimed. Adding .on_unlock()
and invoking it *after* dropping mmu_lock was a terrible idea, as doing so
resulted in .on_lock() and .on_unlock() having divergent and asymmetric
behavior, and set future developers up for failure, i.e. all but asked for
bugs where KVM relied on using .on_unlock() to try to run a callback while
holding mmu_lock.
Opportunistically add a lockdep assertion in kvm_mmu_invalidate_end() to
guard against future bugs of this nature.
Reported-by: Isaku Yamahata <isaku.yamahata@intel.com>
Link: https://lore.kernel.org/all/20230802203119.GB2021422@ls.amr.corp.intel.com
Signed-off-by: Sean Christopherson <seanjc@google.com>
Reviewed-by: Paolo Bonzini <pbonzini@redhat.com>
Reviewed-by: Fuad Tabba <tabba@google.com>
Tested-by: Fuad Tabba <tabba@google.com>
Message-Id: <20231027182217.3615211-12-seanjc@google.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Handle AMD SEV's kvm_arch_guest_memory_reclaimed() hook by having
__kvm_handle_hva_range() return whether or not an overlapping memslot
was found, i.e. mmu_lock was acquired. Using the .on_unlock() hook
works, but kvm_arch_guest_memory_reclaimed() needs to run after dropping
mmu_lock, which makes .on_lock() and .on_unlock() asymmetrical.
Use a small struct to return the tuple of the notifier-specific return,
plus whether or not overlap was found. Because the iteration helpers are
__always_inlined, practically speaking, the struct will never actually be
returned from a function call (not to mention the size of the struct will
be two bytes in practice).
Signed-off-by: Sean Christopherson <seanjc@google.com>
Reviewed-by: Paolo Bonzini <pbonzini@redhat.com>
Reviewed-by: Fuad Tabba <tabba@google.com>
Tested-by: Fuad Tabba <tabba@google.com>
Message-Id: <20231027182217.3615211-11-seanjc@google.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Add a new KVM exit type to allow userspace to handle memory faults that
KVM cannot resolve, but that userspace *may* be able to handle (without
terminating the guest).
KVM will initially use KVM_EXIT_MEMORY_FAULT to report implicit
conversions between private and shared memory. With guest private memory,
there will be two kind of memory conversions:
- explicit conversion: happens when the guest explicitly calls into KVM
to map a range (as private or shared)
- implicit conversion: happens when the guest attempts to access a gfn
that is configured in the "wrong" state (private vs. shared)
On x86 (first architecture to support guest private memory), explicit
conversions will be reported via KVM_EXIT_HYPERCALL+KVM_HC_MAP_GPA_RANGE,
but reporting KVM_EXIT_HYPERCALL for implicit conversions is undesriable
as there is (obviously) no hypercall, and there is no guarantee that the
guest actually intends to convert between private and shared, i.e. what
KVM thinks is an implicit conversion "request" could actually be the
result of a guest code bug.
KVM_EXIT_MEMORY_FAULT will be used to report memory faults that appear to
be implicit conversions.
Note! To allow for future possibilities where KVM reports
KVM_EXIT_MEMORY_FAULT and fills run->memory_fault on _any_ unresolved
fault, KVM returns "-EFAULT" (-1 with errno == EFAULT from userspace's
perspective), not '0'! Due to historical baggage within KVM, exiting to
userspace with '0' from deep callstacks, e.g. in emulation paths, is
infeasible as doing so would require a near-complete overhaul of KVM,
whereas KVM already propagates -errno return codes to userspace even when
the -errno originated in a low level helper.
Report the gpa+size instead of a single gfn even though the initial usage
is expected to always report single pages. It's entirely possible, likely
even, that KVM will someday support sub-page granularity faults, e.g.
Intel's sub-page protection feature allows for additional protections at
128-byte granularity.
Link: https://lore.kernel.org/all/20230908222905.1321305-5-amoorthy@google.com
Link: https://lore.kernel.org/all/ZQ3AmLO2SYv3DszH@google.com
Cc: Anish Moorthy <amoorthy@google.com>
Cc: David Matlack <dmatlack@google.com>
Suggested-by: Sean Christopherson <seanjc@google.com>
Co-developed-by: Yu Zhang <yu.c.zhang@linux.intel.com>
Signed-off-by: Yu Zhang <yu.c.zhang@linux.intel.com>
Signed-off-by: Chao Peng <chao.p.peng@linux.intel.com>
Co-developed-by: Sean Christopherson <seanjc@google.com>
Signed-off-by: Sean Christopherson <seanjc@google.com>
Reviewed-by: Paolo Bonzini <pbonzini@redhat.com>
Message-Id: <20231027182217.3615211-10-seanjc@google.com>
Reviewed-by: Fuad Tabba <tabba@google.com>
Tested-by: Fuad Tabba <tabba@google.com>
Reviewed-by: Xiaoyao Li <xiaoyao.li@intel.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Introduce a "version 2" of KVM_SET_USER_MEMORY_REGION so that additional
information can be supplied without setting userspace up to fail. The
padding in the new kvm_userspace_memory_region2 structure will be used to
pass a file descriptor in addition to the userspace_addr, i.e. allow
userspace to point at a file descriptor and map memory into a guest that
is NOT mapped into host userspace.
Alternatively, KVM could simply add "struct kvm_userspace_memory_region2"
without a new ioctl(), but as Paolo pointed out, adding a new ioctl()
makes detection of bad flags a bit more robust, e.g. if the new fd field
is guarded only by a flag and not a new ioctl(), then a userspace bug
(setting a "bad" flag) would generate out-of-bounds access instead of an
-EINVAL error.
Cc: Jarkko Sakkinen <jarkko@kernel.org>
Reviewed-by: Paolo Bonzini <pbonzini@redhat.com>
Reviewed-by: Xiaoyao Li <xiaoyao.li@intel.com>
Signed-off-by: Sean Christopherson <seanjc@google.com>
Reviewed-by: Fuad Tabba <tabba@google.com>
Tested-by: Fuad Tabba <tabba@google.com>
Message-Id: <20231027182217.3615211-9-seanjc@google.com>
Acked-by: Kai Huang <kai.huang@intel.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Convert KVM_ARCH_WANT_MMU_NOTIFIER into a Kconfig and select it where
appropriate to effectively maintain existing behavior. Using a proper
Kconfig will simplify building more functionality on top of KVM's
mmu_notifier infrastructure.
Add a forward declaration of kvm_gfn_range to kvm_types.h so that
including arch/powerpc/include/asm/kvm_ppc.h's with CONFIG_KVM=n doesn't
generate warnings due to kvm_gfn_range being undeclared. PPC defines
hooks for PR vs. HV without guarding them via #ifdeffery, e.g.
bool (*unmap_gfn_range)(struct kvm *kvm, struct kvm_gfn_range *range);
bool (*age_gfn)(struct kvm *kvm, struct kvm_gfn_range *range);
bool (*test_age_gfn)(struct kvm *kvm, struct kvm_gfn_range *range);
bool (*set_spte_gfn)(struct kvm *kvm, struct kvm_gfn_range *range);
Alternatively, PPC could forward declare kvm_gfn_range, but there's no
good reason not to define it in common KVM.
Acked-by: Anup Patel <anup@brainfault.org>
Signed-off-by: Sean Christopherson <seanjc@google.com>
Reviewed-by: Paolo Bonzini <pbonzini@redhat.com>
Reviewed-by: Fuad Tabba <tabba@google.com>
Tested-by: Fuad Tabba <tabba@google.com>
Message-Id: <20231027182217.3615211-8-seanjc@google.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Advertise that KVM's MMU is synchronized with the primary MMU for all
flavors of PPC KVM support, i.e. advertise that the MMU is synchronized
when CONFIG_KVM_BOOK3S_HV_POSSIBLE=y but the VM is not using hypervisor
mode (a.k.a. PR VMs). PR VMs, via kvm_unmap_gfn_range_pr(), do the right
thing for mmu_notifier invalidation events, and more tellingly, KVM
returns '1' for KVM_CAP_SYNC_MMU when CONFIG_KVM_BOOK3S_HV_POSSIBLE=n
and CONFIG_KVM_BOOK3S_PR_POSSIBLE=y, i.e. KVM already advertises a
synchronized MMU for PR VMs, just not when CONFIG_KVM_BOOK3S_HV_POSSIBLE=y.
Suggested-by: Paolo Bonzini <pbonzini@redhat.com>
Signed-off-by: Sean Christopherson <seanjc@google.com>
Message-Id: <20231027182217.3615211-7-seanjc@google.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Assert that both KVM_ARCH_WANT_MMU_NOTIFIER and CONFIG_MMU_NOTIFIER are
defined when KVM is enabled, and return '1' unconditionally for the
CONFIG_KVM_BOOK3S_HV_POSSIBLE=n path. All flavors of PPC support for KVM
select MMU_NOTIFIER, and KVM_ARCH_WANT_MMU_NOTIFIER is unconditionally
defined by arch/powerpc/include/asm/kvm_host.h.
Effectively dropping use of KVM_ARCH_WANT_MMU_NOTIFIER will simplify a
future cleanup to turn KVM_ARCH_WANT_MMU_NOTIFIER into a Kconfig, i.e.
will allow combining all of the
#if defined(CONFIG_MMU_NOTIFIER) && defined(KVM_ARCH_WANT_MMU_NOTIFIER)
checks into a single
#ifdef CONFIG_KVM_GENERIC_MMU_NOTIFIER
without having to worry about PPC's "bare" usage of
KVM_ARCH_WANT_MMU_NOTIFIER.
Signed-off-by: Sean Christopherson <seanjc@google.com>
Reviewed-by: Paolo Bonzini <pbonzini@redhat.com>
Reviewed-by: Fuad Tabba <tabba@google.com>
Message-Id: <20231027182217.3615211-6-seanjc@google.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Add an assertion that there are no in-progress MMU invalidations when a
VM is being destroyed, with the exception of the scenario where KVM
unregisters its MMU notifier between an .invalidate_range_start() call and
the corresponding .invalidate_range_end().
KVM can't detect unpaired calls from the mmu_notifier due to the above
exception waiver, but the assertion can detect KVM bugs, e.g. such as the
bug that *almost* escaped initial guest_memfd development.
Link: https://lore.kernel.org/all/e397d30c-c6af-e68f-d18e-b4e3739c5389@linux.intel.com
Signed-off-by: Sean Christopherson <seanjc@google.com>
Reviewed-by: Paolo Bonzini <pbonzini@redhat.com>
Reviewed-by: Fuad Tabba <tabba@google.com>
Tested-by: Fuad Tabba <tabba@google.com>
Message-Id: <20231027182217.3615211-5-seanjc@google.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Currently in mmu_notifier invalidate path, hva range is recorded and then
checked against by mmu_invalidate_retry_hva() in the page fault handling
path. However, for the soon-to-be-introduced private memory, a page fault
may not have a hva associated, checking gfn(gpa) makes more sense.
For existing hva based shared memory, gfn is expected to also work. The
only downside is when aliasing multiple gfns to a single hva, the
current algorithm of checking multiple ranges could result in a much
larger range being rejected. Such aliasing should be uncommon, so the
impact is expected small.
Suggested-by: Sean Christopherson <seanjc@google.com>
Cc: Xu Yilun <yilun.xu@intel.com>
Signed-off-by: Chao Peng <chao.p.peng@linux.intel.com>
Reviewed-by: Fuad Tabba <tabba@google.com>
Tested-by: Fuad Tabba <tabba@google.com>
[sean: convert vmx_set_apic_access_page_addr() to gfn-based API]
Signed-off-by: Sean Christopherson <seanjc@google.com>
Reviewed-by: Paolo Bonzini <pbonzini@redhat.com>
Reviewed-by: Xu Yilun <yilun.xu@linux.intel.com>
Message-Id: <20231027182217.3615211-4-seanjc@google.com>
Reviewed-by: Kai Huang <kai.huang@intel.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Move the assertion on the in-progress invalidation count from the primary
MMU's notifier path to KVM's common notification path, i.e. assert that
the count doesn't go negative even when the invalidation is coming from
KVM itself.
Opportunistically convert the assertion to a KVM_BUG_ON(), i.e. kill only
the affected VM, not the entire kernel. A corrupted count is fatal to the
VM, e.g. the non-zero (negative) count will cause mmu_invalidate_retry()
to block any and all attempts to install new mappings. But it's far from
guaranteed that an end() without a start() is fatal or even problematic to
anything other than the target VM, e.g. the underlying bug could simply be
a duplicate call to end(). And it's much more likely that a missed
invalidation, i.e. a potential use-after-free, would manifest as no
notification whatsoever, not an end() without a start().
Signed-off-by: Sean Christopherson <seanjc@google.com>
Reviewed-by: Paolo Bonzini <pbonzini@redhat.com>
Reviewed-by: Fuad Tabba <tabba@google.com>
Tested-by: Fuad Tabba <tabba@google.com>
Message-Id: <20231027182217.3615211-3-seanjc@google.com>
Reviewed-by: Kai Huang <kai.huang@intel.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Rework and rename "struct kvm_hva_range" into "kvm_mmu_notifier_range" so
that the structure can be used to handle notifications that operate on gfn
context, i.e. that aren't tied to a host virtual address. Rename the
handler typedef too (arguably it should always have been gfn_handler_t).
Practically speaking, this is a nop for 64-bit kernels as the only
meaningful change is to store start+end as u64s instead of unsigned longs.
Reviewed-by: Paolo Bonzini <pbonzini@redhat.com>
Reviewed-by: Xiaoyao Li <xiaoyao.li@intel.com>
Signed-off-by: Sean Christopherson <seanjc@google.com>
Reviewed-by: Fuad Tabba <tabba@google.com>
Tested-by: Fuad Tabba <tabba@google.com>
Message-Id: <20231027182217.3615211-2-seanjc@google.com>
Reviewed-by: Kai Huang <kai.huang@intel.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
When running on a many core ARM64 server, errors were
happening in the ISR that looked like corrupted memory. These
corruptions would fix themselves if small delays were inserted
in the ISR. Errors reported by the driver included "i2c_designware
APMC0D0F:00: i2c_dw_xfer_msg: invalid target address" and
"i2c_designware APMC0D0F:00:controller timed out" during
in-band IPMI SSIF stress tests.
The problem was determined to be memory writes in the driver were not
becoming visible to all cores when execution rapidly shifted between
cores, like when a register write immediately triggers an ISR.
Processors with weak memory ordering, like ARM64, make no
guarantees about the order normal memory writes become globally
visible, unless barrier instructions are used to control ordering.
To solve this, regmap accessor functions configured by this driver
were changed to use non-relaxed forms of the low-level register
access functions, which include a barrier on platforms that require
it. This assures memory writes before a controller register access are
visible to all cores. The community concluded defaulting to correct
operation outweighed defaulting to the small performance gains from
using relaxed access functions. Being a low speed device added weight to
this choice of default register access behavior.
Signed-off-by: Jan Bottorff <janb@os.amperecomputing.com>
Acked-by: Jarkko Nikula <jarkko.nikula@linux.intel.com>
Tested-by: Serge Semin <fancer.lancer@gmail.com>
Reviewed-by: Serge Semin <fancer.lancer@gmail.com>
Signed-off-by: Wolfram Sang <wsa@kernel.org>
PTT is an uncore PMU and shouldn't be attached to any task. Block
the usage in pmu::event_init().
Signed-off-by: Yicong Yang <yangyicong@hisilicon.com>
Acked-by: Jonathan Cameron <Jonathan.Cameron@huawei.com>
Signed-off-by: Suzuki K Poulose <suzuki.poulose@arm.com>
Link: https://lore.kernel.org/r/20231010084731.30450-5-yangyicong@huawei.com
Handle the trace interrupt in the hardirq context, make sure the irq
core won't threaded it by declaring IRQF_NO_THREAD and userspace won't
balance it by declaring IRQF_NOBALANCING. Otherwise we may violate the
synchronization requirements of the perf core, referenced to the
change of arm-ccn PMU
commit 0811ef7e2f ("bus: arm-ccn: fix PMU interrupt flags").
In the interrupt handler we mainly doing 2 things:
- Copy the data from the local DMA buffer to the AUX buffer
- Commit the data in the AUX buffer
Signed-off-by: Yicong Yang <yangyicong@hisilicon.com>
Acked-by: Jonathan Cameron <Jonathan.Cameron@huawei.com>
[ Fixed commit description to suppress checkpatch warning ]
Signed-off-by: Suzuki K Poulose <suzuki.poulose@arm.com>
Link: https://lore.kernel.org/r/20231010084731.30450-3-yangyicong@huawei.com
When start trace with perf option "-C $cpu" and immediately stop it
with SIGTERM or others, the perf core will invoke pmu::read() while
the driver doesn't implement it. Add a dummy pmu::read() to avoid
any issues.
Fixes: ff0de066b4 ("hwtracing: hisi_ptt: Add trace function support for HiSilicon PCIe Tune and Trace device")
Signed-off-by: Junhao He <hejunhao3@huawei.com>
Signed-off-by: Yicong Yang <yangyicong@hisilicon.com>
Acked-by: Jonathan Cameron <Jonathan.Cameron@huawei.com>
Signed-off-by: Suzuki K Poulose <suzuki.poulose@arm.com>
Link: https://lore.kernel.org/r/20231010084731.30450-6-yangyicong@huawei.com
Partially revert the change in commit 6148652807 ("coresight: Enable
and disable helper devices adjacent to the path") which changed the bare
call from source_ops(csdev)->enable() to coresight_enable_source() for
Perf sessions. It was missed that coresight_enable_source() is
specifically for the sysfs interface, rather than being a generic call.
This interferes with the sysfs reference counting to cause the following
crash:
$ perf record -e cs_etm/@tmc_etr0/ -C 0 &
$ echo 1 > /sys/bus/coresight/devices/tmc_etr0/enable_sink
$ echo 1 > /sys/bus/coresight/devices/etm0/enable_source
$ echo 0 > /sys/bus/coresight/devices/etm0/enable_source
Unable to handle kernel NULL pointer dereference at virtual
address 00000000000001d0
Internal error: Oops: 0000000096000004 [#1] PREEMPT SMP
...
Call trace:
etm4_disable+0x54/0x150 [coresight_etm4x]
coresight_disable_source+0x6c/0x98 [coresight]
coresight_disable+0x74/0x1c0 [coresight]
enable_source_store+0x88/0xa0 [coresight]
dev_attr_store+0x20/0x40
sysfs_kf_write+0x4c/0x68
kernfs_fop_write_iter+0x120/0x1b8
vfs_write+0x2dc/0x3b0
ksys_write+0x70/0x108
__arm64_sys_write+0x24/0x38
invoke_syscall+0x50/0x128
el0_svc_common.constprop.0+0x104/0x130
do_el0_svc+0x40/0xb8
el0_svc+0x2c/0xb8
el0t_64_sync_handler+0xc0/0xc8
el0t_64_sync+0x1a4/0x1a8
Code: d53cd042 91002000 b9402a81 b8626800 (f940ead5)
---[ end trace 0000000000000000 ]---
This commit linked below also fixes the issue, but has unlocked updates
to the mode which could potentially race. So until we come up with a
more complete solution that takes all locking and interaction between
both modes into account, just revert back to the old behavior for Perf.
Reported-by: Junhao He <hejunhao3@huawei.com>
Closes: https://lore.kernel.org/linux-arm-kernel/20230921132904.60996-1-hejunhao3@huawei.com/
Fixes: 6148652807 ("coresight: Enable and disable helper devices adjacent to the path")
Tested-by: Junhao He <hejunhao3@huawei.com>
Signed-off-by: James Clark <james.clark@arm.com>
Signed-off-by: Suzuki K Poulose <suzuki.poulose@arm.com>
Link: https://lore.kernel.org/r/20231006131452.646721-1-james.clark@arm.com
etm4_platform_driver (which lives in ".data" contains a reference to
etm4_remove_platform_dev(). So the latter must not be marked with __exit
which results in the function being discarded for a build with
CONFIG_CORESIGHT_SOURCE_ETM4X=y which in turn makes the remove pointer
contain invalid data.
etm4x_amba_driver referencing etm4_remove_amba() has the same issue.
Drop the __exit annotations for the two affected functions and a third
one that is called by the other two.
For reasons I don't understand this isn't catched by building with
CONFIG_DEBUG_SECTION_MISMATCH=y.
Fixes: c23bc382ef ("coresight: etm4x: Refactor probing routine")
Fixes: 5214b56358 ("coresight: etm4x: Add support for sysreg only devices")
Signed-off-by: Uwe Kleine-König <u.kleine-koenig@pengutronix.de>
Reviewed-by: James Clark <james.clark@arm.com>
Link: https://lore.kernel.org/all/20230929081540.yija47lsj35xtj4v@pengutronix.de/
Link: https://lore.kernel.org/r/20230929081637.2377335-1-u.kleine-koenig@pengutronix.de
Signed-off-by: Suzuki K Poulose <suzuki.poulose@arm.com>
AMD does not have the requirement for a synchronization barrier when
acccessing a certain group of MSRs. Do not incur that unnecessary
penalty there.
There will be a CPUID bit which explicitly states that a MFENCE is not
needed. Once that bit is added to the APM, this will be extended with
it.
While at it, move to processor.h to avoid include hell. Untangling that
file properly is a matter for another day.
Some notes on the performance aspect of why this is relevant, courtesy
of Kishon VijayAbraham <Kishon.VijayAbraham@amd.com>:
On a AMD Zen4 system with 96 cores, a modified ipi-bench[1] on a VM
shows x2AVIC IPI rate is 3% to 4% lower than AVIC IPI rate. The
ipi-bench is modified so that the IPIs are sent between two vCPUs in the
same CCX. This also requires to pin the vCPU to a physical core to
prevent any latencies. This simulates the use case of pinning vCPUs to
the thread of a single CCX to avoid interrupt IPI latency.
In order to avoid run-to-run variance (for both x2AVIC and AVIC), the
below configurations are done:
1) Disable Power States in BIOS (to prevent the system from going to
lower power state)
2) Run the system at fixed frequency 2500MHz (to prevent the system
from increasing the frequency when the load is more)
With the above configuration:
*) Performance measured using ipi-bench for AVIC:
Average Latency: 1124.98ns [Time to send IPI from one vCPU to another vCPU]
Cumulative throughput: 42.6759M/s [Total number of IPIs sent in a second from
48 vCPUs simultaneously]
*) Performance measured using ipi-bench for x2AVIC:
Average Latency: 1172.42ns [Time to send IPI from one vCPU to another vCPU]
Cumulative throughput: 40.9432M/s [Total number of IPIs sent in a second from
48 vCPUs simultaneously]
From above, x2AVIC latency is ~4% more than AVIC. However, the expectation is
x2AVIC performance to be better or equivalent to AVIC. Upon analyzing
the perf captures, it is observed significant time is spent in
weak_wrmsr_fence() invoked by x2apic_send_IPI().
With the fix to skip weak_wrmsr_fence()
*) Performance measured using ipi-bench for x2AVIC:
Average Latency: 1117.44ns [Time to send IPI from one vCPU to another vCPU]
Cumulative throughput: 42.9608M/s [Total number of IPIs sent in a second from
48 vCPUs simultaneously]
Comparing the performance of x2AVIC with and without the fix, it can be seen
the performance improves by ~4%.
Performance captured using an unmodified ipi-bench using the 'mesh-ipi' option
with and without weak_wrmsr_fence() on a Zen4 system also showed significant
performance improvement without weak_wrmsr_fence(). The 'mesh-ipi' option ignores
CCX or CCD and just picks random vCPU.
Average throughput (10 iterations) with weak_wrmsr_fence(),
Cumulative throughput: 4933374 IPI/s
Average throughput (10 iterations) without weak_wrmsr_fence(),
Cumulative throughput: 6355156 IPI/s
[1] https://github.com/bytedance/kvm-utils/tree/master/microbenchmark/ipi-bench
Signed-off-by: Borislav Petkov (AMD) <bp@alien8.de>
Link: https://lore.kernel.org/r/20230622095212.20940-1-bp@alien8.de
Jijie Shao says:
====================
There are some bugfix for the HNS3 ethernet driver
There are some bugfix for the HNS3 ethernet driver
---
ChangeLog:
v1 -> v2:
- net: hns3: fix add VLAN fail issue, net: hns3: fix VF reset fail issue
are modified suggested by Paolo
v1: https://lore.kernel.org/all/20231028025917.314305-1-shaojijie@huawei.com/
====================
Signed-off-by: David S. Miller <davem@davemloft.net>
If PF is down, firmware will returns 10 Mbit/s rate and half-duplex mode
when PF queries the port information from firmware.
After imp reset command is executed, PF status changes to down,
and PF will query link status and updates port information
from firmware in a periodic scheduled task.
However, there is a low probability that port information is updated
when PF is down, and then PF link status changes to up.
In this case, PF synchronizes incorrect rate and duplex mode to VF.
This patch fixes it by updating port information before
PF synchronizes the rate and duplex to the VF
when PF changes to up.
Fixes: 18b6e31f8b ("net: hns3: PF add support for pushing link status to VFs")
Signed-off-by: Jijie Shao <shaojijie@huawei.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Currently the reset process in hns3 and firmware watchdog init process is
asynchronous. We think firmware watchdog initialization is completed
before VF clear the interrupt source. However, firmware initialization
may not complete early. So VF will receive multiple reset interrupts
and fail to reset.
So we add delay before VF interrupt source and 5 ms delay
is enough to avoid second reset interrupt.
Fixes: 427900d27d ("net: hns3: fix the timing issue of VF clearing interrupt sources")
Signed-off-by: Jijie Shao <shaojijie@huawei.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
When a VF is calling hns3_init_mac_addr(), get_mac_addr() may
return fail, then the value of mac_addr_temp is not initialized.
Fixes: 76ad4f0ee7 ("net: hns3: Add support of HNS3 Ethernet Driver for hip08 SoC")
Signed-off-by: Yonglong Liu <liuyonglong@huawei.com>
Signed-off-by: Jijie Shao <shaojijie@huawei.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
The hns3 driver define an array of string to show the coalesce
info, but if the kernel adds a new mode or a new state,
out-of-bounds access may occur when coalesce info is read via
debugfs, this patch fix the problem.
Fixes: c99fead7cb ("net: hns3: add debugfs support for interrupt coalesce")
Signed-off-by: Yonglong Liu <liuyonglong@huawei.com>
Signed-off-by: Jijie Shao <shaojijie@huawei.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Currently, the FEC capability bit is default set for device version V2.
It's incorrect for the copper port. Eventhough it doesn't make the nic
work abnormal, but the capability information display in debugfs may
confuse user. So clear it when driver get the port type inforamtion.
Fixes: 433ccce835 ("net: hns3: use FEC capability queried from firmware")
Signed-off-by: Jian Shen <shenjian15@huawei.com>
Signed-off-by: Jijie Shao <shaojijie@huawei.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
In hclgevf_mbx_handler() and hclgevf_get_mbx_resp() functions,
there is a typical store-store and load-load scenario between
received_resp and additional_info. This patch adds barrier
to fix the problem.
Fixes: 4671042f1e ("net: hns3: add match_id to check mailbox response from PF to VF")
Signed-off-by: Yonglong Liu <liuyonglong@huawei.com>
Signed-off-by: Jijie Shao <shaojijie@huawei.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
The hclge_sync_vlan_filter is called in periodic task,
trying to remove VLAN from vlan_del_fail_bmap. It can
be concurrence with VLAN adding operation from user.
So once user failed to delete a VLAN id, and add it
again soon, it may be removed by the periodic task,
which may cause the software configuration being
inconsistent with hardware. So add mutex handling
to avoid this.
user hns3 driver
periodic task
│
add vlan 10 ───── hns3_vlan_rx_add_vid │
│ (suppose success) │
│ │
del vlan 10 ───── hns3_vlan_rx_kill_vid │
│ (suppose fail,add to │
│ vlan_del_fail_bmap) │
│ │
add vlan 10 ───── hns3_vlan_rx_add_vid │
(suppose success) │
foreach vlan_del_fail_bmp
del vlan 10
Fixes: fe4144d47e ("net: hns3: sync VLAN filter entries when kill VLAN ID failed")
Signed-off-by: Jian Shen <shenjian15@huawei.com>
Signed-off-by: Jijie Shao <shaojijie@huawei.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Memory errors don't happen very often, especially fatal ones. However,
in large-scale scenarios such as data centers, that probability
increases with the amount of machines present.
When a fatal machine check happens, mce_panic() is called based on the
severity grading of that error. The page containing the error is not
marked as poison.
However, when kexec is enabled, tools like makedumpfile understand when
pages are marked as poison and do not touch them so as not to cause
a fatal machine check exception again while dumping the previous
kernel's memory.
Therefore, mark the page containing the error as poisoned so that the
kexec'ed kernel can avoid accessing the page.
[ bp: Rewrite commit message and comment. ]
Co-developed-by: Youquan Song <youquan.song@intel.com>
Signed-off-by: Youquan Song <youquan.song@intel.com>
Signed-off-by: Zhiquan Li <zhiquan1.li@intel.com>
Signed-off-by: Borislav Petkov (AMD) <bp@alien8.de>
Reviewed-by: Naoya Horiguchi <naoya.horiguchi@nec.com>
Link: https://lore.kernel.org/r/20231014051754.3759099-1-zhiquan1.li@intel.com
Simplify irdma_ieq_check_mpacrc() by using crypto_shash_digest() instead
of an init+update+final sequence. This should also improve performance.
Signed-off-by: Eric Biggers <ebiggers@google.com>
Link: https://lore.kernel.org/r/20231029045756.153943-1-ebiggers@kernel.org
Signed-off-by: Leon Romanovsky <leon@kernel.org>
Simplify siw_qp_prepare_tx() by using crypto_shash_digest() instead of
an init+update+final sequence. This should also improve performance.
Signed-off-by: Eric Biggers <ebiggers@google.com>
Link: https://lore.kernel.org/r/20231029045839.154071-1-ebiggers@kernel.org
Acked-by: Bernard Metzler <bmt@zurich.ibm.com>
Signed-off-by: Leon Romanovsky <leon@kernel.org>
We need all get_partial() related interfaces to return a slab, instead
of returning the freelist (or object).
Use the partial_context.object to return back freelist or object for
now. This patch shouldn't have any functional changes.
Suggested-by: Vlastimil Babka <vbabka@suse.cz>
Signed-off-by: Chengming Zhou <zhouchengming@bytedance.com>
Reviewed-by: Vlastimil Babka <vbabka@suse.cz>
Tested-by: Hyeonggon Yoo <42.hyeyoo@gmail.com>
Reviewed-by: Hyeonggon Yoo <42.hyeyoo@gmail.com>
Signed-off-by: Vlastimil Babka <vbabka@suse.cz>
The get_partial() interface used in ___slab_alloc() may return a single
object in the "kmem_cache_debug(s)" case, in which we will just return
the "freelist" object.
Move this handling up to prepare for later changes.
And the "pfmemalloc_match()" part is not needed for node partial slab,
since we already check this in the get_partial_node().
Signed-off-by: Chengming Zhou <zhouchengming@bytedance.com>
Reviewed-by: Vlastimil Babka <vbabka@suse.cz>
Tested-by: Hyeonggon Yoo <42.hyeyoo@gmail.com>
Reviewed-by: Hyeonggon Yoo <42.hyeyoo@gmail.com>
Signed-off-by: Vlastimil Babka <vbabka@suse.cz>
Rounding up the queue depth to power of two is not a hardware requirement.
In order to optimize the per connection memory usage, removing drivers
implementation which round up to the queue depths to the power of 2.
Implements a mask to maintain backward compatibility with older
library.
Signed-off-by: Chandramohan Akula <chandramohan.akula@broadcom.com>
Signed-off-by: Selvin Xavier <selvin.xavier@broadcom.com>
Link: https://lore.kernel.org/r/1698069803-1787-3-git-send-email-selvin.xavier@broadcom.com
Signed-off-by: Leon Romanovsky <leon@kernel.org>
The queue index wrap around logic is based on power of 2 size depth.
All queues are created with power of 2 depth. This increases the
memory usage by the driver. This change is required for the next
patches that avoids the power of 2 depth requirement for each of
the queues.
Update the function that increments producer index and consumer
index during wrap around. Also, changes the index handling across
multiple functions.
Signed-off-by: Chandramohan Akula <chandramohan.akula@broadcom.com>
Signed-off-by: Selvin Xavier <selvin.xavier@broadcom.com>
Link: https://lore.kernel.org/r/1698069803-1787-2-git-send-email-selvin.xavier@broadcom.com
Signed-off-by: Leon Romanovsky <leon@kernel.org>
Add a default congest control algorithm so that driver won't return
an error when the configured algorithm is invalid.
Fixes: f91696f2f0 ("RDMA/hns: Support congestion control type selection according to the FW")
Signed-off-by: Junxian Huang <huangjunxian6@hisilicon.com>
Link: https://lore.kernel.org/r/20231028093242.670325-1-huangjunxian6@hisilicon.com
Signed-off-by: Leon Romanovsky <leon@kernel.org>
Currently, memdup_user() is utilized at two positions to copy userspace
arrays. This is done without overflow checks.
Use the new wrapper memdup_array_user() to copy the arrays more safely.
Suggested-by: Dave Airlie <airlied@redhat.com>
Signed-off-by: Philipp Stanner <pstanner@redhat.com>
Link: https://lore.kernel.org/r/20231102191308.52046-2-pstanner@redhat.com
Acked-by: Dennis Dalessandro <dennis.dalessandro@cornelisnetworks.com>
Signed-off-by: Leon Romanovsky <leon@kernel.org>
KMSAN reported the following uninit-value access issue:
lo speed is unknown, defaulting to 1000
=====================================================
BUG: KMSAN: uninit-value in ib_get_width_and_speed drivers/infiniband/core/verbs.c:1889 [inline]
BUG: KMSAN: uninit-value in ib_get_eth_speed+0x546/0xaf0 drivers/infiniband/core/verbs.c:1998
ib_get_width_and_speed drivers/infiniband/core/verbs.c:1889 [inline]
ib_get_eth_speed+0x546/0xaf0 drivers/infiniband/core/verbs.c:1998
siw_query_port drivers/infiniband/sw/siw/siw_verbs.c:173 [inline]
siw_get_port_immutable+0x6f/0x120 drivers/infiniband/sw/siw/siw_verbs.c:203
setup_port_data drivers/infiniband/core/device.c:848 [inline]
setup_device drivers/infiniband/core/device.c:1244 [inline]
ib_register_device+0x1589/0x1df0 drivers/infiniband/core/device.c:1383
siw_device_register drivers/infiniband/sw/siw/siw_main.c:72 [inline]
siw_newlink+0x129e/0x13d0 drivers/infiniband/sw/siw/siw_main.c:490
nldev_newlink+0x8fd/0xa60 drivers/infiniband/core/nldev.c:1763
rdma_nl_rcv_skb drivers/infiniband/core/netlink.c:239 [inline]
rdma_nl_rcv+0xe8a/0x1120 drivers/infiniband/core/netlink.c:259
netlink_unicast_kernel net/netlink/af_netlink.c:1342 [inline]
netlink_unicast+0xf4b/0x1230 net/netlink/af_netlink.c:1368
netlink_sendmsg+0x1242/0x1420 net/netlink/af_netlink.c:1910
sock_sendmsg_nosec net/socket.c:730 [inline]
__sock_sendmsg net/socket.c:745 [inline]
____sys_sendmsg+0x997/0xd60 net/socket.c:2588
___sys_sendmsg+0x271/0x3b0 net/socket.c:2642
__sys_sendmsg net/socket.c:2671 [inline]
__do_sys_sendmsg net/socket.c:2680 [inline]
__se_sys_sendmsg net/socket.c:2678 [inline]
__x64_sys_sendmsg+0x2fa/0x4a0 net/socket.c:2678
do_syscall_x64 arch/x86/entry/common.c:51 [inline]
do_syscall_64+0x44/0x110 arch/x86/entry/common.c:82
entry_SYSCALL_64_after_hwframe+0x63/0x6b
Local variable lksettings created at:
ib_get_eth_speed+0x4b/0xaf0 drivers/infiniband/core/verbs.c:1974
siw_query_port drivers/infiniband/sw/siw/siw_verbs.c:173 [inline]
siw_get_port_immutable+0x6f/0x120 drivers/infiniband/sw/siw/siw_verbs.c:203
CPU: 0 PID: 11257 Comm: syz-executor.1 Not tainted 6.6.0-14500-g1c41041124bd #10
Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS 1.16.2-1.fc38 04/01/2014
=====================================================
If __ethtool_get_link_ksettings() fails, `netdev_speed` is set to the
default value, SPEED_1000. In this case, if `lanes` field of struct
ethtool_link_ksettings is not initialized, an uninitialized value is passed
to ib_get_width_and_speed(). This causes the above issue. This patch
resolves the issue by initializing `lanes` to 0.
Fixes: cb06b6b3f6 ("RDMA/core: Get IB width and speed from netdev")
Signed-off-by: Shigeru Yoshida <syoshida@redhat.com>
Link: https://lore.kernel.org/r/20231108143113.1360567-1-syoshida@redhat.com
Signed-off-by: Leon Romanovsky <leon@kernel.org>
Abandon siw private code to pin user pages during user
memory registration, but use ib_umem_get() instead.
This will help maintaining the driver in case of changes
to the memory subsystem.
Signed-off-by: Bernard Metzler <bmt@zurich.ibm.com>
Link: https://lore.kernel.org/r/20231104075643.195186-1-bmt@zurich.ibm.com
Signed-off-by: Leon Romanovsky <leon@kernel.org>
After
0b62f6cb07 ("x86/microcode/32: Move early loading after paging enable"),
the global variable relocated_ramdisk is no longer used anywhere except
for the relocate_initrd() function. Make it a local variable of that
function.
Signed-off-by: Yuntao Wang <ytcoode@gmail.com>
Signed-off-by: Borislav Petkov (AMD) <bp@alien8.de>
Reviewed-by: Baoquan He <bhe@redhat.com>
Link: https://lore.kernel.org/r/20231113034026.130679-1-ytcoode@gmail.com
Don't use kernel-doc markers ("/**") for comments that are not in
kernel-doc format. This prevents multiple kernel-doc warnings:
xen-front-pgdir-shbuf.c:25: warning: This comment starts with '/**', but isn't a kernel-doc comment. Refer Documentation/doc-guide/kernel-doc.rst
* This structure represents the structure of a shared page
xen-front-pgdir-shbuf.c:37: warning: This comment starts with '/**', but isn't a kernel-doc comment. Refer Documentation/doc-guide/kernel-doc.rst
* Shared buffer ops which are differently implemented
xen-front-pgdir-shbuf.c:65: warning: This comment starts with '/**', but isn't a kernel-doc comment. Refer Documentation/doc-guide/kernel-doc.rst
* Get granted reference to the very first page of the
xen-front-pgdir-shbuf.c:85: warning: This comment starts with '/**', but isn't a kernel-doc comment. Refer Documentation/doc-guide/kernel-doc.rst
* Map granted references of the shared buffer.
xen-front-pgdir-shbuf.c:106: warning: This comment starts with '/**', but isn't a kernel-doc comment. Refer Documentation/doc-guide/kernel-doc.rst
* Unmap granted references of the shared buffer.
xen-front-pgdir-shbuf.c:127: warning: This comment starts with '/**', but isn't a kernel-doc comment. Refer Documentation/doc-guide/kernel-doc.rst
* Free all the resources of the shared buffer.
xen-front-pgdir-shbuf.c:154: warning: This comment starts with '/**', but isn't a kernel-doc comment. Refer Documentation/doc-guide/kernel-doc.rst
* Get the number of pages the page directory consumes itself.
xen-front-pgdir-shbuf.c:164: warning: This comment starts with '/**', but isn't a kernel-doc comment. Refer Documentation/doc-guide/kernel-doc.rst
* Calculate the number of grant references needed to share the buffer
xen-front-pgdir-shbuf.c:176: warning: This comment starts with '/**', but isn't a kernel-doc comment. Refer Documentation/doc-guide/kernel-doc.rst
* Calculate the number of grant references needed to share the buffer
xen-front-pgdir-shbuf.c:194: warning: This comment starts with '/**', but isn't a kernel-doc comment. Refer Documentation/doc-guide/kernel-doc.rst
* Unmap the buffer previously mapped with grant references
xen-front-pgdir-shbuf.c:242: warning: This comment starts with '/**', but isn't a kernel-doc comment. Refer Documentation/doc-guide/kernel-doc.rst
* Map the buffer with grant references provided by the backend.
xen-front-pgdir-shbuf.c:324: warning: This comment starts with '/**', but isn't a kernel-doc comment. Refer Documentation/doc-guide/kernel-doc.rst
* Fill page directory with grant references to the pages of the
xen-front-pgdir-shbuf.c:354: warning: This comment starts with '/**', but isn't a kernel-doc comment. Refer Documentation/doc-guide/kernel-doc.rst
* Fill page directory with grant references to the pages of the
xen-front-pgdir-shbuf.c:393: warning: This comment starts with '/**', but isn't a kernel-doc comment. Refer Documentation/doc-guide/kernel-doc.rst
* Grant references to the frontend's buffer pages.
xen-front-pgdir-shbuf.c:422: warning: This comment starts with '/**', but isn't a kernel-doc comment. Refer Documentation/doc-guide/kernel-doc.rst
* Grant all the references needed to share the buffer.
xen-front-pgdir-shbuf.c:470: warning: This comment starts with '/**', but isn't a kernel-doc comment. Refer Documentation/doc-guide/kernel-doc.rst
* Allocate all required structures to mange shared buffer.
xen-front-pgdir-shbuf.c:510: warning: This comment starts with '/**', but isn't a kernel-doc comment. Refer Documentation/doc-guide/kernel-doc.rst
* Allocate a new instance of a shared buffer.
Signed-off-by: Randy Dunlap <rdunlap@infradead.org>
Reported-by: kernel test robot <lkp@intel.com>
Closes: lore.kernel.org/r/202311060203.yQrpPZhm-lkp@intel.com
Acked-by: Juergen Gross <jgross@suse.com>
Cc: Juergen Gross <jgross@suse.com>
Cc: Stefano Stabellini <sstabellini@kernel.org>
Cc: Oleksandr Tyshchenko <oleksandr_tyshchenko@epam.com>
Cc: xen-devel@lists.xenproject.org
Link: https://lore.kernel.org/r/20231106055631.21520-1-rdunlap@infradead.org
Signed-off-by: Juergen Gross <jgross@suse.com>
The Processor capability bits notify ACPI of the OS capabilities, and
so ACPI can adjust the return of other Processor methods taking the OS
capabilities into account.
When Linux is running as a Xen dom0, the hypervisor is the entity
in charge of processor power management, and hence Xen needs to make
sure the capabilities reported by _OSC/_PDC match the capabilities of
the driver in Xen.
Introduce a small helper to sanitize the buffer when running as Xen
dom0.
When Xen supports HWP, this serves as the equivalent of commit
a21211672c ("ACPI / processor: Request native thermal interrupt
handling via _OSC") to avoid SMM crashes. Xen will set bit
ACPI_PROC_CAP_COLLAB_PROC_PERF (bit 12) in the capability bits and the
_OSC/_PDC call will apply it.
[ jandryuk: Mention Xen HWP's need. Support _OSC & _PDC ]
Signed-off-by: Roger Pau Monné <roger.pau@citrix.com>
Cc: stable@vger.kernel.org
Signed-off-by: Jason Andryuk <jandryuk@gmail.com>
Reviewed-by: Michal Wilczynski <michal.wilczynski@intel.com>
Reviewed-by: Juergen Gross <jgross@suse.com>
Link: https://lore.kernel.org/r/20231108212517.72279-1-jandryuk@gmail.com
Signed-off-by: Juergen Gross <jgross@suse.com>
xen_send_IPI_one() is being used by cpuhp_report_idle_dead() after
it calls rcu_report_dead(), meaning that any RCU usage by
xen_send_IPI_one() is a bad idea.
Unfortunately xen_send_IPI_one() is using notify_remote_via_irq()
today, which is using irq_get_chip_data() via info_for_irq(). And
irq_get_chip_data() in turn is using a maple-tree lookup requiring
RCU.
Avoid this problem by caching the ipi event channels in another
percpu variable, allowing the use notify_remote_via_evtchn() in
xen_send_IPI_one().
Fixes: 721255b982 ("genirq: Use a maple tree for interrupt descriptor management")
Reported-by: David Woodhouse <dwmw@amazon.co.uk>
Signed-off-by: Juergen Gross <jgross@suse.com>
Tested-by: David Woodhouse <dwmw@amazon.co.uk>
Acked-by: Stefano Stabellini <sstabellini@kernel.org>
Signed-off-by: Juergen Gross <jgross@suse.com>
The cros_ec_sensor_ring_median function currently uses an inefficient
sorting algorithm (> O(n)) to find the median of an array. This patch
replaces the sorting approach with the quickselect algorithm, which
achieves an average time complexity of O(n).
The algorithm employs the median-of-three rule to select the pivot,
mitigating worst-case scenarios and reducing the expected number of
necessary comparisons. This strategy enhances the algorithm's
efficiency and ensures a more balanced partitioning.
In the worst case, the runtime of quickselect could regress to O(n^2).
To address this, alternative algorithms like median-of-medians that
can guarantee O(n) even in the worst case. However, due to higher
overhead and increased complexity of implementation, quickselect
remains a pragmatic choice for our use case.
Signed-off-by: Kuan-Wei Chiu <visitorckw@gmail.com>
Link: https://lore.kernel.org/r/20231110165314.1559285-1-visitorckw@gmail.com
Signed-off-by: Tzung-Bi Shih <tzungbi@kernel.org>
I was recently reminded by someone who was unable to reach my old
email address that I really should update the kernel's .mailmap
so that people looking for me in old commits can reach my current
email.
Signed-off-by: Paul Moore <paul@paul-moore.com>
As the kernel test robot helpfully reminded us, all of the lsm_id
instances defined inside the various LSMs should be marked as static.
The one exception is Landlock which uses its lsm_id variable across
multiple source files with an extern declaration in a header file.
Reported-by: kernel test robot <lkp@intel.com>
Suggested-by: Casey Schaufler <casey@schaufler-ca.com>
Reviewed-by: Casey Schaufler <casey@schaufler-ca.com>
Signed-off-by: Paul Moore <paul@paul-moore.com>
As suggested by the kernel test robot, memdup_user() is a better
option than the combo of kmalloc()/copy_from_user().
Reported-by: kernel test robot <lkp@intel.com>
Closes: https://lore.kernel.org/oe-kbuild-all/202310270805.2ArE52i5-lkp@intel.com/
Acked-by: Casey Schaufler <casey@schaufler-ca.com>
Signed-off-by: Paul Moore <paul@paul-moore.com>
Using the size of a void pointer is much cleaner than
BITS_PER_LONG / 8.
Acked-by: Casey Schaufler <casey@schaufler-ca.com>
Signed-off-by: Paul Moore <paul@paul-moore.com>
