Converting the cpu hotplug locking to a percpu rwsem unearthed hidden lock
ordering problems.
There is a wide range of locks involved in this: kprobe_mutex,
jump_label_mutex, ftrace_lock, text_mutex, event_mutex, module_mutex,
func_hash->regex_lock and a gazillion of lock order permutations with
nested get_online_cpus() calls.
Some of those permutations are potential deadlocks even with the current
nesting hotplug locking scheme, but they can't be discovered by lockdep.
The conversion of the hotplug locking to a percpu rwsem requires to prevent
nested locking, so it's required to take the hotplug rwsem early in the
call chain and establish a proper lock order.
After quite some analysis and going down the wrong road severa times the
following lock order has been chosen:
kprobe_mutex -> cpus_rwsem -> jump_label_mutex -> text_mutex
For kprobes which hook on an ftrace function trace point, it's required to
drop cpus_rwsem before calling into the ftrace code to avoid a deadlock on
the func_hash->regex_lock.
[ Steven: Ftrace interaction fixes ]
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Acked-by: Ingo Molnar <mingo@kernel.org>
Acked-by: Masami Hiramatsu <mhiramat@kernel.org>
Cc: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Sebastian Siewior <bigeasy@linutronix.de>
Link: http://lkml.kernel.org/r/20170524081549.104864779@linutronix.de
The conversion of the hotplug locking to a percpu rwsem unearthed lock
ordering issues all over the place.
The jump_label code has two issues:
1) Nested get_online_cpus() invocations
2) Ordering problems vs. the cpus rwsem and the jump_label_mutex
To cure these, the following lock order has been established;
cpus_rwsem -> jump_label_lock -> text_mutex
Even if not all architectures need protection against CPU hotplug, taking
cpus_rwsem before jump_label_lock is now mandatory in code pathes which
actually modify code and therefor need text_mutex protection.
Move the get_online_cpus() invocations into the core jump label code and
establish the proper lock order where required.
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Acked-by: Ingo Molnar <mingo@kernel.org>
Acked-by: "David S. Miller" <davem@davemloft.net>
Cc: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
Cc: Chris Metcalf <cmetcalf@mellanox.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Sebastian Siewior <bigeasy@linutronix.de>
Cc: Steven Rostedt <rostedt@goodmis.org>
Cc: Jason Baron <jbaron@akamai.com>
Cc: Ralf Baechle <ralf@linux-mips.org>
Link: http://lkml.kernel.org/r/20170524081549.025830817@linutronix.de
perf, tracing, kprobes and jump_labels have a gazillion of ways to create
dependency lock chains. Some of those involve nested invocations of
get_online_cpus().
The conversion of the hotplug locking to a percpu rwsem requires to avoid
such nested calls. sys_perf_event_open() protects most of the syscall logic
against cpu hotplug. This causes nested calls and lock inversions versus
ftrace and kprobes in various interesting ways.
It's impossible to move the hotplug locking to the outer end of all call
chains in the involved facilities, so the hotplug protection in
sys_perf_event_open() needs to be solved differently.
Introduce 'pmus_mutex' which protects a perf private online cpumask. This
mutex is taken when the mask is updated in the cpu hotplug callbacks and
can be taken in sys_perf_event_open() to protect the swhash setup/teardown
code and when the final judgement about a valid event has to be made.
[ tglx: Produced changelog and fixed the swhash interaction ]
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Acked-by: Ingo Molnar <mingo@kernel.org>
Cc: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
Cc: Sebastian Siewior <bigeasy@linutronix.de>
Cc: Steven Rostedt <rostedt@goodmis.org>
Cc: Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
Cc: Masami Hiramatsu <mhiramat@kernel.org>
Link: http://lkml.kernel.org/r/20170524081548.930941109@linutronix.de
Converting the hotplug locking, i.e. get_online_cpus(), to a percpu rwsem
unearthed a circular lock dependency which was hidden from lockdep due to
the lockdep annotation of get_online_cpus() which prevents lockdep from
creating full dependency chains.
CPU0 CPU1
---- ----
lock((&wfc.work));
lock(cpu_hotplug_lock.rw_sem);
lock((&wfc.work));
lock(cpu_hotplug_lock.rw_sem);
This dependency is established via acpi_processor_start() which calls into
the work queue code. And the work queue code establishes the reverse
dependency.
This is not a problem of get_online_cpus() recursion, it's a possible
deadlock undetected by lockdep so far.
The cure is to use cpu_hotplug_disable() instead of get_online_cpus() to
protect the probing from acpi_processor_start().
There is a side effect to this: cpu_hotplug_disable() makes a concurrent
cpu hotplug attempt via the sysfs interfaces fail with -EBUSY, but that
probing usually happens during the boot process where no interaction is
possible. Any later invocations are infrequent enough and concurrent
hotplug attempts are so unlikely that the danger of user space visible
regressions is very close to zero. Anyway, thats preferrable over a real
deadlock.
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Acked-by: Ingo Molnar <mingo@kernel.org>
Acked-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
Cc: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Sebastian Siewior <bigeasy@linutronix.de>
Cc: Steven Rostedt <rostedt@goodmis.org>
Cc: linux-acpi@vger.kernel.org
Cc: Len Brown <lenb@kernel.org>
Link: http://lkml.kernel.org/r/20170524081548.851588594@linutronix.de
pci_call_probe() can called recursively when a physcial function is probed
and the probing creates virtual functions, which are populated via
pci_bus_add_device() which in turn can end up calling pci_call_probe()
again.
The code has an interesting way to prevent recursing into the workqueue
code. That's accomplished by a check whether the current task runs already
on the numa node which is associated with the device.
While that works to prevent the recursion into the workqueue code, it's
racy versus normal execution as there is no guarantee that the node does
not vanish after the check.
There is another issue with this code. It dereferences cpumask_of_node()
unconditionally without checking whether the node is available.
Make the detection reliable by:
- Mark a probed device as 'is_probed' in pci_call_probe()
- Check in pci_call_probe for a virtual function. If it's a virtual
function and the associated physical function device is marked
'is_probed' then this is a recursive call, so the call can be invoked in
the calling context.
- Add a check whether the node is online before dereferencing it.
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Acked-by: Ingo Molnar <mingo@kernel.org>
Acked-by: Bjorn Helgaas <bhelgaas@google.com>
Cc: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: linux-pci@vger.kernel.org
Cc: Sebastian Siewior <bigeasy@linutronix.de>
Cc: Steven Rostedt <rostedt@goodmis.org>
Link: http://lkml.kernel.org/r/20170524081548.771457199@linutronix.de
Converting the hotplug locking, i.e. get_online_cpus(), to a percpu rwsem
unearthed a circular lock dependency which was hidden from lockdep due to
the lockdep annotation of get_online_cpus() which prevents lockdep from
creating full dependency chains. There are several variants of this. And
example is:
Chain exists of:
cpu_hotplug_lock.rw_sem --> drm_global_mutex --> &item->mutex
CPU0 CPU1
---- ----
lock(&item->mutex);
lock(drm_global_mutex);
lock(&item->mutex);
lock(cpu_hotplug_lock.rw_sem);
because there are dependencies through workqueues. The call chain is:
get_online_cpus
apply_workqueue_attrs
__alloc_workqueue_key
ttm_mem_global_init
ast_ttm_mem_global_init
drm_global_item_ref
ast_mm_init
ast_driver_load
drm_dev_register
drm_get_pci_dev
ast_pci_probe
local_pci_probe
work_for_cpu_fn
process_one_work
worker_thread
This is not a problem of get_online_cpus() recursion, it's a possible
deadlock undetected by lockdep so far.
The cure is to use cpu_hotplug_disable() instead of get_online_cpus() to
protect the PCI probing.
There is a side effect to this: cpu_hotplug_disable() makes a concurrent
cpu hotplug attempt via the sysfs interfaces fail with -EBUSY, but PCI
probing usually happens during the boot process where no interaction is
possible. Any later invocations are infrequent enough and concurrent
hotplug attempts are so unlikely that the danger of user space visible
regressions is very close to zero. Anyway, thats preferrable over a real
deadlock.
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Acked-by: Ingo Molnar <mingo@kernel.org>
Acked-by: Bjorn Helgaas <bhelgaas@google.com>
Cc: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: linux-pci@vger.kernel.org
Cc: Sebastian Siewior <bigeasy@linutronix.de>
Cc: Steven Rostedt <rostedt@goodmis.org>
Link: http://lkml.kernel.org/r/20170524081548.691198590@linutronix.de
If intel_snb_check_microcode() is invoked via
microcode_init -> perf_check_microcode -> intel_snb_check_microcode
then get_online_cpus() is invoked nested. This works with the current
implementation of get_online_cpus() but prevents converting it to a percpu
rwsem.
intel_snb_check_microcode() is also invoked from intel_sandybridge_quirk()
unprotected.
Drop get_online_cpus() from intel_snb_check_microcode() and add it to
intel_sandybridge_quirk() so both call sites are protected.
Convert *_online_cpus() to the new interfaces while at it.
Signed-off-by: Sebastian Andrzej Siewior <bigeasy@linutronix.de>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Acked-by: Ingo Molnar <mingo@kernel.org>
Acked-by: Borislav Petkov <bp@suse.de>
Cc: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Steven Rostedt <rostedt@goodmis.org>
Cc: Borislav Petkov <bp@alien8.de>
Link: http://lkml.kernel.org/r/20170524081548.594862191@linutronix.de
The only caller is the microcode update, which cannot be modular.
Drop the export.
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Acked-by: Ingo Molnar <mingo@kernel.org>
Acked-by: Borislav Petkov <bp@suse.de>
Cc: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Sebastian Siewior <bigeasy@linutronix.de>
Cc: Steven Rostedt <rostedt@goodmis.org>
Cc: Borislav Petkov <bp@alien8.de>
Link: http://lkml.kernel.org/r/20170524081548.515204988@linutronix.de
takedown_cpu() is a cpu hotplug function invoking stop_machine(). The cpu
hotplug machinery holds the hotplug lock for write.
stop_machine() invokes get_online_cpus() as well. This is correct, but
prevents the conversion of the hotplug locking to a percpu rwsem.
Use stop_machine_cpuslocked() to avoid the nested call.
Signed-off-by: Sebastian Andrzej Siewior <bigeasy@linutronix.de>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Tested-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
Acked-by: Ingo Molnar <mingo@kernel.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Steven Rostedt <rostedt@goodmis.org>
Link: http://lkml.kernel.org/r/20170524081548.423292433@linutronix.de
set_subcores_per_core() holds get_online_cpus() while invoking stop_machine().
stop_machine() invokes get_online_cpus() as well. This is correct, but
prevents the conversion of the hotplug locking to a percpu rwsem.
Use stop_machine_cpuslocked() to avoid the nested call. Convert
*_online_cpus() to the new interfaces while at it.
Signed-off-by: Sebastian Andrzej Siewior <bigeasy@linutronix.de>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Acked-by: Ingo Molnar <mingo@kernel.org>
Cc: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Cc: Steven Rostedt <rostedt@goodmis.org>
Cc: Michael Ellerman <mpe@ellerman.id.au>
Cc: linuxppc-dev@lists.ozlabs.org
Link: http://lkml.kernel.org/r/20170524081548.331016542@linutronix.de
stp_work_fn() holds get_online_cpus() while invoking stop_machine().
stop_machine() invokes get_online_cpus() as well. This is correct, but
prevents the conversion of the hotplug locking to a percpu rwsem.
Use stop_machine_cpuslocked() to avoid the nested call. Convert
*_online_cpus() to the new interfaces while at it.
Signed-off-by: Sebastian Andrzej Siewior <bigeasy@linutronix.de>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Acked-by: Ingo Molnar <mingo@kernel.org>
Acked-by: Heiko Carstens <heiko.carstens@de.ibm.com>
Cc: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
Cc: linux-s390@vger.kernel.org
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Steven Rostedt <rostedt@goodmis.org>
Cc: David Hildenbrand <dahi@linux.vnet.ibm.com>
Cc: Martin Schwidefsky <schwidefsky@de.ibm.com>
Link: http://lkml.kernel.org/r/20170524081548.250203087@linutronix.de
arch_hw_breakpoint_init() holds get_online_cpus() while registerring the
hotplug callbacks.
cpuhp_setup_state() invokes get_online_cpus() as well. This is correct, but
prevents the conversion of the hotplug locking to a percpu rwsem.
Use cpuhp_setup_state_cpuslocked() to avoid the nested call. Convert
*_online_cpus() to the new interfaces while at it.
Signed-off-by: Sebastian Andrzej Siewior <bigeasy@linutronix.de>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Acked-by: Ingo Molnar <mingo@kernel.org>
Acked-by: Mark Rutland <mark.rutland@arm.com>
Cc: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Will Deacon <will.deacon@arm.com>
Cc: Steven Rostedt <rostedt@goodmis.org>
Cc: Russell King <linux@armlinux.org.uk>
Cc: linux-arm-kernel@lists.infradead.org
Link: http://lkml.kernel.org/r/20170524081548.170940729@linutronix.de
intel_cqm_init() holds get_online_cpus() while registerring the hotplug
callbacks.
cpuhp_setup_state() invokes get_online_cpus() as well. This is correct, but
prevents the conversion of the hotplug locking to a percpu rwsem.
Use cpuhp_setup_state_cpuslocked() to avoid the nested call. Convert
*_online_cpus() to the new interfaces while at it.
Signed-off-by: Sebastian Andrzej Siewior <bigeasy@linutronix.de>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Acked-by: Ingo Molnar <mingo@kernel.org>
Cc: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
Cc: Fenghua Yu <fenghua.yu@intel.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Steven Rostedt <rostedt@goodmis.org>
Link: http://lkml.kernel.org/r/20170524081548.075604046@linutronix.de
etm_probe4() holds get_online_cpus() while invoking
cpuhp_setup_state_nocalls().
cpuhp_setup_state_nocalls() invokes get_online_cpus() as well. This is
correct, but prevents the conversion of the hotplug locking to a percpu
rwsem.
Use cpuhp_setup_state_nocalls_cpuslocked() to avoid the nested
call. Convert *_online_cpus() to the new interfaces while at it.
Signed-off-by: Sebastian Andrzej Siewior <bigeasy@linutronix.de>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Acked-by: Ingo Molnar <mingo@kernel.org>
Acked-by: Mathieu Poirier <mathieu.poirier@linaro.org>
Cc: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Steven Rostedt <rostedt@goodmis.org>
Cc: linux-arm-kernel@lists.infradead.org
Link: http://lkml.kernel.org/r/20170524081547.983493849@linutronix.de
etm_probe() holds get_online_cpus() while invoking
cpuhp_setup_state_nocalls().
cpuhp_setup_state_nocalls() invokes get_online_cpus() as well. This is
correct, but prevents the conversion of the hotplug locking to a percpu
rwsem.
Use cpuhp_setup_state_nocalls_cpuslocked() to avoid the nested
call. Convert *_online_cpus() to the new interfaces while at it.
Signed-off-by: Sebastian Andrzej Siewior <bigeasy@linutronix.de>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Acked-by: Ingo Molnar <mingo@kernel.org>
Acked-by: Mathieu Poirier <mathieu.poirier@linaro.org>
Cc: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Steven Rostedt <rostedt@goodmis.org>
Cc: linux-arm-kernel@lists.infradead.org
Link: http://lkml.kernel.org/r/20170524081547.889092478@linutronix.de
kvmppc_alloc_host_rm_ops() holds get_online_cpus() while invoking
cpuhp_setup_state_nocalls().
cpuhp_setup_state_nocalls() invokes get_online_cpus() as well. This is
correct, but prevents the conversion of the hotplug locking to a percpu
rwsem.
Use cpuhp_setup_state_nocalls_cpuslocked() to avoid the nested
call. Convert *_online_cpus() to the new interfaces while at it.
Signed-off-by: Sebastian Andrzej Siewior <bigeasy@linutronix.de>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Acked-by: Ingo Molnar <mingo@kernel.org>
Cc: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
Cc: kvm@vger.kernel.org
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Cc: Steven Rostedt <rostedt@goodmis.org>
Cc: kvm-ppc@vger.kernel.org
Cc: Michael Ellerman <mpe@ellerman.id.au>
Cc: linuxppc-dev@lists.ozlabs.org
Cc: Alexander Graf <agraf@suse.com>
Link: http://lkml.kernel.org/r/20170524081547.809616236@linutronix.de
cpufreq holds get_online_cpus() while invoking cpuhp_setup_state_nocalls()
to make subsys_interface_register() and the registration of hotplug calls
atomic versus cpu hotplug.
cpuhp_setup_state_nocalls() invokes get_online_cpus() as well. This is
correct, but prevents the conversion of the hotplug locking to a percpu
rwsem.
Use cpuhp_setup/remove_state_nocalls_cpuslocked() to avoid the nested
call. Convert *_online_cpus() to the new interfaces while at it.
Signed-off-by: Sebastian Andrzej Siewior <bigeasy@linutronix.de>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Tested-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
Acked-by: Ingo Molnar <mingo@kernel.org>
Acked-by: "Rafael J. Wysocki" <rafael.j.wysocki@intel.com>
Acked-by: Viresh Kumar <viresh.kumar@linaro.org>
Cc: linux-pm@vger.kernel.org
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Steven Rostedt <rostedt@goodmis.org>
Link: http://lkml.kernel.org/r/20170524081547.731628408@linutronix.de
mtrr_save_state() is invoked from native_cpu_up() which is in the context
of a CPU hotplug operation and therefor calling get_online_cpus() is
pointless.
While this works in the current get_online_cpus() implementation it
prevents from converting the hotplug locking to percpu rwsems.
Remove it.
Signed-off-by: Sebastian Andrzej Siewior <bigeasy@linutronix.de>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Tested-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
Acked-by: Ingo Molnar <mingo@kernel.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Steven Rostedt <rostedt@goodmis.org>
Link: http://lkml.kernel.org/r/20170524081547.651378834@linutronix.de
pcrypt_init_padata()
cpus_read_lock()
padata_alloc_possible()
padata_alloc()
cpus_read_lock()
The nested call to cpus_read_lock() works with the current implementation,
but prevents the conversion to a percpu rwsem.
The other caller of padata_alloc_possible() is pcrypt_init_padata() which
calls from a cpus_read_lock() protected region as well.
Remove the cpus_read_lock() call in padata_alloc() and document the
calling convention.
Signed-off-by: Sebastian Andrzej Siewior <bigeasy@linutronix.de>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Tested-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
Acked-by: Ingo Molnar <mingo@kernel.org>
Cc: Steffen Klassert <steffen.klassert@secunet.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Steven Rostedt <rostedt@goodmis.org>
Cc: linux-crypto@vger.kernel.org
Link: http://lkml.kernel.org/r/20170524081547.571278910@linutronix.de
No users outside of padata.c
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Tested-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
Acked-by: Ingo Molnar <mingo@kernel.org>
Cc: Steffen Klassert <steffen.klassert@secunet.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Sebastian Siewior <bigeasy@linutronix.de>
Cc: Steven Rostedt <rostedt@goodmis.org>
Cc: linux-crypto@vger.kernel.org
Link: http://lkml.kernel.org/r/20170524081547.491457256@linutronix.de
Some call sites of stop_machine() are within a get_online_cpus() protected
region.
stop_machine() calls get_online_cpus() as well, which is possible in the
current implementation but prevents converting the hotplug locking to a
percpu rwsem.
Provide stop_machine_cpuslocked() to avoid nested calls to get_online_cpus().
Signed-off-by: Sebastian Andrzej Siewior <bigeasy@linutronix.de>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Tested-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
Acked-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
Acked-by: Ingo Molnar <mingo@kernel.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Steven Rostedt <rostedt@goodmis.org>
Link: http://lkml.kernel.org/r/20170524081547.400700852@linutronix.de
Add cpuslocked() variants for the multi instance registration so this can
be called from a cpus_read_lock() protected region.
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Tested-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
Acked-by: Ingo Molnar <mingo@kernel.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Sebastian Siewior <bigeasy@linutronix.de>
Cc: Steven Rostedt <rostedt@goodmis.org>
Link: http://lkml.kernel.org/r/20170524081547.321782217@linutronix.de
Some call sites of cpuhp_setup/remove_state[_nocalls]() are within a
cpus_read locked region.
cpuhp_setup/remove_state[_nocalls]() call cpus_read_lock() as well, which
is possible in the current implementation but prevents converting the
hotplug locking to a percpu rwsem.
Provide locked versions of the interfaces to avoid nested calls to
cpus_read_lock().
Signed-off-by: Sebastian Andrzej Siewior <bigeasy@linutronix.de>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Tested-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
Acked-by: Ingo Molnar <mingo@kernel.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Steven Rostedt <rostedt@goodmis.org>
Link: http://lkml.kernel.org/r/20170524081547.239600868@linutronix.de
Provide a stub function which can be used in places where existing
get_online_cpus() calls are moved to call sites.
This stub is going to be filled by the final conversion of the hotplug
locking mechanism to a percpu rwsem.
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Tested-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
Acked-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
Acked-by: Ingo Molnar <mingo@kernel.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Sebastian Siewior <bigeasy@linutronix.de>
Cc: Steven Rostedt <rostedt@goodmis.org>
Link: http://lkml.kernel.org/r/20170524081547.161282442@linutronix.de
The counting 'rwsem' hackery of get|put_online_cpus() is going to be
replaced by percpu rwsem.
Rename the functions to make it clear that it's locking and not some
refcount style interface. These new functions will be used for the
preparatory patches which make the code ready for the percpu rwsem
conversion.
Rename all instances in the cpu hotplug code while at it.
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Tested-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
Acked-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
Acked-by: Ingo Molnar <mingo@kernel.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Sebastian Siewior <bigeasy@linutronix.de>
Cc: Steven Rostedt <rostedt@goodmis.org>
Link: http://lkml.kernel.org/r/20170524081547.080397752@linutronix.de
Currently only the PCIe driver supports metadata, so we should not claim
integrity support for the other drivers. This prevents nasty crashes
with targets that advertise metadata support on fabrics.
Also use the opportunity to factor out some code into a separate helper
that isn't even compiled if CONFIG_BLK_DEV_INTEGRITY is disabled.
Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Keith Busch <keith.busch@intel.com>
So that we can have more flags for transport-specific behavior.
Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Keith Busch <keith.busch@intel.com>
This is what most of the code already does and gives much more useful
prefixes than the device embedded in the pci_dev.
Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Keith Busch <keith.busch@intel.com>
Identical to the setup on Koelsch.
Signed-off-by: Ulrich Hecht <ulrich.hecht+renesas@gmail.com>
Reviewed-by: Laurent Pinchart <laurent.pinchart@ideasonboard.com>
Signed-off-by: Simon Horman <horms+renesas@verge.net.au>
Several files are used to construct PCM core module, a.k.a snd-pcm.
Although available APIs are described in 'include/sound/pcm.h', some of
them are not exported as symbols in kernel space. Such APIs are just for
module local usage.
This commit adds module local header file and move some function prototypes
into it so that scopes of them are controlled properly and developers
get no confusion from unavailable symbols.
Signed-off-by: Takashi Sakamoto <o-takashi@sakamocchi.jp>
Signed-off-by: Takashi Iwai <tiwai@suse.de>
We currently have three device nodes for the same USB hardware
block, as evident by the reuse of the same reg address multiple
times. Now that the chipidea driver fully supports OTG with the
MSM wrapper we can collapse all these nodes into one USB device
node, reflecting the true nature of the hardware.
Signed-off-by: Stephen Boyd <stephen.boyd@linaro.org>
Signed-off-by: Andy Gross <andy.gross@linaro.org>
We currently have three device nodes for the same USB hardware
block, as evident by the reuse of the same reg address multiple
times. Now that the chipidea driver fully supports OTG with the
MSM wrapper we can collapse the three nodes into one USB device
node, reflecting the true nature of the hardware.
Since we're here, we also mark the irq trigger flags correctly,
as IRQ_TYPE_LEVEL_HIGH instead of IRQ_TYPE_NONE.
Cc: Bjorn Andersson <bjorn.andersson@linaro.org>
Cc: Srinivas Kandagatla <srinivas.kandagatla@linaro.org>
Cc: Nicolas Dechesne <nicolas.dechesne@linaro.org>
Cc: John Stultz <john.stultz@linaro.org>
Signed-off-by: Stephen Boyd <stephen.boyd@linaro.org>
Signed-off-by: Andy Gross <andy.gross@linaro.org>
This USB controller has two phys, so add them both underneath the
ULPI bus, but only enable one of them based on the board
configuration. To get OTG to work, we need to add the id and vbus
detection info and also populate the regulators for the vbus
supply.
Signed-off-by: Stephen Boyd <stephen.boyd@linaro.org>
Signed-off-by: Andy Gross <andy.gross@linaro.org>
These regulators are controlled by the SPMI regulator driver
instead of the RPM regulator driver in the downstream android
kernel sources. Let's remove them from the DTS here because
they'll never be used by the RPM regulator driver.
Cc: Bjorn Andersson <bjorn.andersson@linaro.org>
Signed-off-by: Stephen Boyd <stephen.boyd@linaro.org>
Signed-off-by: Andy Gross <andy.gross@linaro.org>
Drop legacy drm_for_each_connector() in favor of the race-free
drm_for_each_connector_iter().
v2: add missing drm_connector_list_iter_end(Daniel Vetter)
Cc: Eric Anholt <eric@anholt.net>
Signed-off-by: Gustavo Padovan <gustavo.padovan@collabora.com>
Reviewed-by: Daniel Vetter <daniel.vetter@ffwll.ch>
Acked-by: Eric Anholt <eric@anholt.net>
Link: http://patchwork.freedesktop.org/patch/msgid/20170512164100.7649-1-gustavo@padovan.org
Drop legacy drm_for_each_connector() in favor of the race-free
drm_for_each_connector_iter().
Cc: Daniel Vetter <daniel.vetter@intel.com>
Cc: Jani Nikula <jani.nikula@linux.intel.com>
Signed-off-by: Gustavo Padovan <gustavo.padovan@collabora.com>
Reviewed-by: Daniel Vetter <daniel.vetter@ffwll.ch>
Link: http://patchwork.freedesktop.org/patch/msgid/20170511191049.28944-4-gustavo@padovan.org
Drop legacy drm_for_each_connector() in favor of the race-free
drm_for_each_connector_iter()
Cc: Mark Yao <mark.yao@rock-chips.com>
Signed-off-by: Gustavo Padovan <gustavo.padovan@collabora.com>
Reviewed-by: Daniel Vetter <daniel.vetter@ffwll.ch>
Reviewed-by: Sean Paul <seanpaul@chromium.org>
Link: http://patchwork.freedesktop.org/patch/msgid/20170515134330.3275-1-gustavo@padovan.org
A bunch of bug fixes:
- Fix display flickering on some chips at high refresh rates
- suspend/resume fix
- hotplug fix
- a couple of segfault fixes for certain cases
* 'drm-fixes-4.12' of git://people.freedesktop.org/~agd5f/linux:
drm/amdgpu: fix null point error when rmmod amdgpu.
drm/amd/powerplay: fix a signedness bugs
drm/amdgpu: fix NULL pointer panic of emit_gds_switch
drm/radeon: Unbreak HPD handling for r600+
drm/amd/powerplay/smu7: disable mclk switching for high refresh rates
drm/amd/powerplay/smu7: add vblank check for mclk switching (v2)
drm/radeon/ci: disable mclk switching for high refresh rates (v2)
drm/amdgpu/ci: disable mclk switching for high refresh rates (v2)
drm/amdgpu: fix fundamental suspend/resume issue
Core Changes:
- Don't drop vblank reference more than once in cases of ww retry (Daniel)
Driver Changes:
- radeon: Fix oops during radeon probe trying to reference wrong device (Lukas)
- qxl: Avoid sleeping while in atomic context on cursor update (Gabriel)
- gma500: Use VBT mode instead of pre-programmed mode for LVDS (Patrik)
Cc: Lukas Wunner <lukas@wunner.de>
Cc: Gabriel Krisman Bertazi <krisman@collabora.co.uk>
Cc: Daniel Vetter <daniel.vetter@ffwll.ch>
Cc: Patrik Jakobsson <patrik.r.jakobsson@gmail.com>
* tag 'drm-misc-fixes-2017-05-25' of git://anongit.freedesktop.org/git/drm-misc:
drm/gma500/psb: Actually use VBT mode when it is found
drm: Fix deadlock retry loop in page_flip_ioctl
drm: qxl: Delay entering atomic context during cursor update
drm/radeon: Fix oops upon driver load on PowerXpress laptops
This patch converts the ds1307 driver to using regmap. It's a rather
big patch and I can test with DS3231 only. With this chip it's
working fine.
I'd appreciate if people with other supported hardware could test as
well.
Signed-off-by: Heiner Kallweit <hkallweit1@gmail.com>
Signed-off-by: Alexandre Belloni <alexandre.belloni@free-electrons.com>
-----BEGIN PGP SIGNATURE-----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=sm+g
-----END PGP SIGNATURE-----
Merge tag 'samsung-fixes-4.12' of git://git.kernel.org/pub/scm/linux/kernel/git/krzk/linux into fixes
Update of maintainers entry for Samsung SoC.
* tag 'samsung-fixes-4.12' of git://git.kernel.org/pub/scm/linux/kernel/git/krzk/linux:
MAINTAINERS: Remove Javier Martinez Canillas as reviewer for Exynos
Signed-off-by: Olof Johansson <olof@lixom.net>
please pull the following:
- Phil provides a fix for the BCM283x (Raspberry Pi) by flagging the first
4KiB of physical memory as a reserved region in order to let the secondary
cores successfully spin until they are brought online
-----BEGIN PGP SIGNATURE-----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=x322
-----END PGP SIGNATURE-----
Merge tag 'arm-soc/for-4.12/devicetree-fixes-2' of http://github.com/Broadcom/stblinux into fixes
This pull request contains Broadcom ARM-based SoCs Device Tree fixes for 4.12,
please pull the following:
- Phil provides a fix for the BCM283x (Raspberry Pi) by flagging the first
4KiB of physical memory as a reserved region in order to let the secondary
cores successfully spin until they are brought online
* tag 'arm-soc/for-4.12/devicetree-fixes-2' of http://github.com/Broadcom/stblinux:
ARM: dts: bcm283x: Reserve first page for firmware
Signed-off-by: Olof Johansson <olof@lixom.net>
Enable some very core config options used on 64bit Rockchip socs.
As built-in driver enable the Rockchip spi driver as well as the
cros-ec-spi and cros-ec keyboard driver, as this may be helpful
in case an initrd does not work as expected and drops the user
into a shell. Another built-in is the fan53555 regulator driver,
as it and its register-compatible cousins Silergy syr827 and syr828
are often used on Rockchip socs as cpu-supply next to regular pmic.
The rest can be enabled as modules and contains the pcie host
controller and its phy, the sucessive approximation adc (saradc)
that gets often used for additional buttons on Rockchip boards
as well as the adc-keys Keyboard driver for these keys.
The cros-ec-pwm also can be a module, as it is normally only used to
drive display backlights as well as the Rockchip thermal controller
that allows to read the cpu and gpu temperatures and affect frequency
scaling if necessary.
Signed-off-by: Heiko Stuebner <heiko@sntech.de>
Signed-off-by: Olof Johansson <olof@lixom.net>
