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[ Upstream commit 46770be0cf94149ca48be87719bda1d951066644 ]
The cpufreq core heavily depends on the availability of the struct
device for CPUs and if they aren't available at the time cpufreq driver
is registered, we will never succeed in making cpufreq work.
This happens due to following sequence of events:
- cpufreq_register_driver()
- subsys_interface_register()
- return 0; //successful registration of driver
... at a later point of time
- register_cpu();
- device_register();
- bus_probe_device();
- sif->add_dev();
- cpufreq_add_dev();
- get_cpu_device(); //FAILS
- per_cpu(cpu_sys_devices, num) = &cpu->dev; //used by get_cpu_device()
- return 0; //CPU registered successfully
Because the per-cpu variable cpu_sys_devices is set only after the CPU
device is regsitered, cpufreq will never be able to get it when
cpufreq_add_dev() is called.
This patch avoids this failure by making sure device structure of at
least CPU0 is available when the cpufreq driver is registered, else
return -EPROBE_DEFER.
Reported-by: Bjorn Andersson <bjorn.andersson@linaro.org>
Co-developed-by: Amit Kucheria <amit.kucheria@linaro.org>
Signed-off-by: Viresh Kumar <viresh.kumar@linaro.org>
Tested-by: Amit Kucheria <amit.kucheria@linaro.org>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>
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commit e6e8df07268c1f75dd9215536e2ce4587b70f977 upstream.
Add NULL checks to show() and store() in cpufreq.c to avoid attempts
to invoke a NULL callback.
Though some interfaces of cpufreq are set as read-only, users can
still get write permission using chmod which can lead to a kernel
crash, as follows:
chmod +w /sys/devices/system/cpu/cpu0/cpufreq/scaling_cur_freq
echo 1 > /sys/devices/system/cpu/cpu0/cpufreq/scaling_cur_freq
This bug was found in linux 4.19.
Signed-off-by: Kai Shen <shenkai8@huawei.com>
Reported-by: Feilong Lin <linfeilong@huawei.com>
Reviewed-by: Feilong Lin <linfeilong@huawei.com>
Acked-by: Viresh Kumar <viresh.kumar@linaro.org>
[ rjw: Subject & changelog ]
Cc: All applicable <stable@vger.kernel.org>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
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commit 703cbaa601ff3fb554d1246c336ba727cc083ea0 upstream.
cpufreq_resume can be called even without preceding cpufreq_suspend.
This can happen in following scenario:
suspend_devices_and_enter
--> dpm_suspend_start
--> dpm_prepare
--> device_prepare : this function errors out
--> dpm_suspend: this is skipped due to dpm_prepare failure
this means cpufreq_suspend is skipped over
--> goto Recover_platform, due to previous error
--> goto Resume_devices
--> dpm_resume_end
--> dpm_resume
--> cpufreq_resume
In case schedutil is used as frequency governor, cpufreq_resume will
eventually call sugov_start, which does following:
memset(sg_cpu, 0, sizeof(*sg_cpu));
....
This effectively erases function pointer for frequency update, causing
crash later on. The function pointer would have been set correctly if
subsequent cpufreq_add_update_util_hook runs successfully, but that
function returns earlier because cpufreq_suspend was not called:
if (WARN_ON(per_cpu(cpufreq_update_util_data, cpu)))
return;
The fix is to check cpufreq_suspended first, if it's false, that means
cpufreq_suspend was not called in the first place, so do not resume
cpufreq.
Signed-off-by: Bo Yan <byan@nvidia.com>
Acked-by: Viresh Kumar <viresh.kumar@linaro.org>
[ rjw: Dropped printing a message ]
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
Signed-off-by: Lee Jones <lee.jones@linaro.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
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commit 65650b35133ff20f0c9ef0abd5c3c66dbce3ae57 upstream.
It is incorrect to set the cpufreq syscore shutdown callback pointer
to cpufreq_suspend(), because that function cannot be run in the
syscore stage of system shutdown for two reasons: (a) it may attempt
to carry out actions depending on devices that have already been shut
down at that point and (b) the RCU synchronization carried out by it
may not be able to make progress then.
The latter issue has been present since commit 45975c7d21a1 ("rcu:
Define RCU-sched API in terms of RCU for Tree RCU PREEMPT builds"),
but the former one has been there since commit 90de2a4aa9f3 ("cpufreq:
suspend cpufreq governors on shutdown") regardless.
Fix that by dropping cpufreq_syscore_ops altogether and making
device_shutdown() call cpufreq_suspend() directly before shutting
down devices, which is along the lines of what system-wide power
management does.
Fixes: 45975c7d21a1 ("rcu: Define RCU-sched API in terms of RCU for Tree RCU PREEMPT builds")
Fixes: 90de2a4aa9f3 ("cpufreq: suspend cpufreq governors on shutdown")
Reported-by: Ville Syrjälä <ville.syrjala@linux.intel.com>
Tested-by: Ville Syrjälä <ville.syrjala@linux.intel.com>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
Acked-by: Viresh Kumar <viresh.kumar@linaro.org>
Cc: 4.0+ <stable@vger.kernel.org> # 4.0+
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
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[ Upstream commit 9a4f26cc98d81b67ecc23b890c28e2df324e29f3 ]
Currently the error return path from kobject_init_and_add() is not
followed by a call to kobject_put() - which means we are leaking
the kobject.
Fix it by adding a call to kobject_put() in the error path of
kobject_init_and_add().
Signed-off-by: Tobin C. Harding <tobin@kernel.org>
Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Tobin C. Harding <tobin@kernel.org>
Cc: Vincent Guittot <vincent.guittot@linaro.org>
Cc: Viresh Kumar <viresh.kumar@linaro.org>
Link: http://lkml.kernel.org/r/20190430001144.24890-1-tobin@kernel.org
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>
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commit 625c85a62cb7d3c79f6e16de3cfa972033658250 upstream.
The cpufreq_global_kobject is created using kobject_create_and_add()
helper, which assigns the kobj_type as dynamic_kobj_ktype and show/store
routines are set to kobj_attr_show() and kobj_attr_store().
These routines pass struct kobj_attribute as an argument to the
show/store callbacks. But all the cpufreq files created using the
cpufreq_global_kobject expect the argument to be of type struct
attribute. Things work fine currently as no one accesses the "attr"
argument. We may not see issues even if the argument is used, as struct
kobj_attribute has struct attribute as its first element and so they
will both get same address.
But this is logically incorrect and we should rather use struct
kobj_attribute instead of struct global_attr in the cpufreq core and
drivers and the show/store callbacks should take struct kobj_attribute
as argument instead.
This bug is caught using CFI CLANG builds in android kernel which
catches mismatch in function prototypes for such callbacks.
Reported-by: Donghee Han <dh.han@samsung.com>
Reported-by: Sangkyu Kim <skwith.kim@samsung.com>
Signed-off-by: Viresh Kumar <viresh.kumar@linaro.org>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
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[ Upstream commit 2f66196208c98b3d1b4294edffb2c5a8197be899 ]
cpuinfo_cur_freq gets current CPU frequency as detected by hardware
while scaling_cur_freq last known CPU frequency. Some platforms may not
allow checking the CPU frequency of an offline CPU or the associated
resources may have been released via cpufreq_exit when the CPU gets
offlined, in which case the policy would have been invalidated already.
If we attempt to get current frequency from the hardware, it may result
in hang or crash.
For example on Juno, I see:
Unable to handle kernel NULL pointer dereference at virtual address 0000000000000188
[0000000000000188] pgd=0000000000000000
Internal error: Oops: 96000004 [#1] PREEMPT SMP
Modules linked in:
CPU: 5 PID: 4202 Comm: cat Not tainted 4.20.0-08251-ga0f2c0318a15-dirty #87
Hardware name: ARM LTD ARM Juno Development Platform/ARM Juno Development Platform
pstate: 40000005 (nZcv daif -PAN -UAO)
pc : scmi_cpufreq_get_rate+0x34/0xb0
lr : scmi_cpufreq_get_rate+0x34/0xb0
Call trace:
scmi_cpufreq_get_rate+0x34/0xb0
__cpufreq_get+0x34/0xc0
show_cpuinfo_cur_freq+0x24/0x78
show+0x40/0x60
sysfs_kf_seq_show+0xc0/0x148
kernfs_seq_show+0x44/0x50
seq_read+0xd4/0x480
kernfs_fop_read+0x15c/0x208
__vfs_read+0x60/0x188
vfs_read+0x94/0x150
ksys_read+0x6c/0xd8
__arm64_sys_read+0x24/0x30
el0_svc_common+0x78/0x100
el0_svc_handler+0x38/0x78
el0_svc+0x8/0xc
---[ end trace 3d1024e58f77f6b2 ]---
So fix the issue by checking if the policy is invalid early in
__cpufreq_get before attempting to get the current frequency.
Signed-off-by: Sudeep Holla <sudeep.holla@arm.com>
Acked-by: Viresh Kumar <viresh.kumar@linaro.org>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>
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commit 7fb1327ee9b92fca27662f9b9d60c7c3376d6c69 upstream.
Kernel CPU stats are stored in cputime_t which is an architecture
defined type, and hence a bit opaque and requiring accessors and mutators
for any operation.
Converting them to nsecs simplifies the code and is one step toward
the removal of cputime_t in the core code.
Signed-off-by: Frederic Weisbecker <fweisbec@gmail.com>
Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Cc: Paul Mackerras <paulus@samba.org>
Cc: Michael Ellerman <mpe@ellerman.id.au>
Cc: Heiko Carstens <heiko.carstens@de.ibm.com>
Cc: Martin Schwidefsky <schwidefsky@de.ibm.com>
Cc: Tony Luck <tony.luck@intel.com>
Cc: Fenghua Yu <fenghua.yu@intel.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Rik van Riel <riel@redhat.com>
Cc: Stanislaw Gruszka <sgruszka@redhat.com>
Cc: Wanpeng Li <wanpeng.li@hotmail.com>
Link: http://lkml.kernel.org/r/1485832191-26889-4-git-send-email-fweisbec@gmail.com
Signed-off-by: Ingo Molnar <mingo@kernel.org>
[colona: minor conflict as 527b0a76f41d ("sched/cpuacct: Avoid %lld seq_printf
warning") is missing from v4.9]
Signed-off-by: Ivan Delalande <colona@arista.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
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commit c7d1f119c48f64bebf0fa1e326af577c6152fe30 upstream.
If the policy limits are updated via cpufreq_update_policy() and
subsequently via sysfs, the limits stored in user_policy may be
set incorrectly.
For example, if both min and max are set via sysfs to the maximum
available frequency, user_policy.min and user_policy.max will also
be the maximum. If a policy notifier triggered by
cpufreq_update_policy() lowers both the min and the max at this
point, that change is not reflected by the user_policy limits, so
if the max is updated again via sysfs to the same lower value,
then user_policy.max will be lower than user_policy.min which
shouldn't happen. In particular, if one of the policy CPUs is
then taken offline and back online, cpufreq_set_policy() will
fail for it due to a failing limits check.
To prevent that from happening, initialize the min and max fields
of the new_policy object to the ones stored in user_policy that
were previously set via sysfs.
Signed-off-by: Kevin Wangtao <kevin.wangtao@hisilicon.com>
Acked-by: Viresh Kumar <viresh.kumar@linaro.org>
[ rjw: Subject & changelog ]
Cc: All applicable <stable@vger.kernel.org>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
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[ Upstream commit b24b6478e65f140610ab1ffaadc7bc6bf0be8aad ]
Ideally the de-allocation of resources should happen in the exact
opposite order in which they were allocated. It helps maintain the code
in long term, even if nothing really breaks with incorrect ordering.
That wasn't followed in cpufreq_online() and it has some
inconsistencies. For example, the symlinks were created from within
the locked region while they are removed only after putting the locks.
Also ->exit() should have been called only after the symlinks are
removed and the lock is dropped, as that was the case when ->init()
was first called.
Signed-off-by: Viresh Kumar <viresh.kumar@linaro.org>
[ rjw: Subject ]
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
Signed-off-by: Sasha Levin <alexander.levin@microsoft.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
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[ Upstream commit 2f0ba790df51721794c11abc7a076d407392f648 ]
The cpufreq core only tries to create symbolic links from CPU
directories in sysfs to policy directories in cpufreq_add_dev(),
either when a given CPU is registered or when the cpufreq driver
is registered, whichever happens first. That is not sufficient,
however, because cpufreq_add_dev() may be called for an offline CPU
whose policy object has not been created yet and, quite obviously,
the symbolic cannot be added in that case.
Fix that by making cpufreq_online() attempt to add symbolic links to
policy objects for the CPUs in the related_cpus mask of every new
policy object created by it.
The cpufreq_driver_lock locking around the for_each_cpu() loop
in cpufreq_online() is dropped, because it is not necessary and the
code is somewhat simpler without it. Moreover, failures to create
a symbolic link will not be regarded as hard errors any more and
the CPUs without those links will not be taken offline automatically,
but that should not be problematic in practice.
Reported-and-tested-by: Prashanth Prakash <pprakash@codeaurora.org>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
Signed-off-by: Sasha Levin <alexander.levin@verizon.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
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[ Upstream commit f451014692ae34e587b00de6745e16661cf734d8 ]
If new_policy is set in cpufreq_online(), the policy object has just
been created and its real_cpus mask has been zeroed on allocation,
and the driver's ->init() callback should not touch it.
It doesn't need to be cleared again, so don't do that.
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
Acked-by: Viresh Kumar <viresh.kumar@linaro.org>
Signed-off-by: Sasha Levin <alexander.levin@verizon.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
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commit 6c77003677d5f1ce15f26d24360cb66c0bc07bb3 upstream.
For a driver that does not set the CPUFREQ_STICKY flag, if all of the
->init() calls fail, cpufreq_register_driver() should return an error.
This will prevent the driver from loading.
Fixes: ce1bcfe94db8 (cpufreq: check cpufreq_policy_list instead of scanning policies for all CPUs)
Signed-off-by: David Arcari <darcari@redhat.com>
Acked-by: Viresh Kumar <viresh.kumar@linaro.org>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
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commit c4a3fa261b16858416f1fd7db03a33d7ef5fc0b3 upstream.
There is a report that after commit 27622b061eb4 ("cpufreq: Convert
to hotplug state machine"), the normal CPU offline/online cycle
fails on some platforms.
According to the ftrace result, this problem was triggered on
platforms using acpi-cpufreq as the default cpufreq driver,
and due to the lack of some ACPI freq method (eg. _PCT),
cpufreq_online() failed and returned a negative value, so the CPU
hotplug state machine rolled back the CPU online process. Actually,
from the user's perspective, the failure of cpufreq_online() should
not prevent that CPU from being brought up, although cpufreq might
not work on that CPU.
BTW, during system startup cpufreq_online() is not invoked via CPU
online but by the cpufreq device creation process, so the APs can be
brought up even though cpufreq_online() fails in that stage.
This patch ignores the return value of cpufreq_online/offline() and
lets the cpufreq framework deal with the failure. cpufreq_online()
itself will do a proper rollback in that case and if _PCT is missing,
the ACPI cpufreq driver will print a warning if the corresponding
debug options have been enabled.
Bugzilla: https://bugzilla.kernel.org/show_bug.cgi?id=194581
Fixes: 27622b061eb4 ("cpufreq: Convert to hotplug state machine")
Reported-and-tested-by: Tomasz Maciej Nowak <tmn505@gmail.com>
Signed-off-by: Chen Yu <yu.c.chen@intel.com>
Acked-by: Viresh Kumar <viresh.kumar@linaro.org>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
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commit ff010472fb75670cb5c08671e820eeea3af59c87 upstream.
On CPU online the cpufreq core restores the previous governor (or
the previous "policy" setting for ->setpolicy drivers), but it does
not restore the min/max limits at the same time, which is confusing,
inconsistent and real pain for users who set the limits and then
suspend/resume the system (using full suspend), in which case the
limits are reset on all CPUs except for the boot one.
Fix this by making cpufreq_online() restore the limits when an inactive
policy is brought online.
The commit log and patch are inspired from Rafael's earlier work.
Reported-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
Signed-off-by: Viresh Kumar <viresh.kumar@linaro.org>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
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commit 9b4f603e7a9f4282aec451063ffbbb8bb410dcd9 upstream.
There is a missing newline in show_cpuinfo_cur_freq(), so add it,
but while at it clean that function up somewhat too.
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
Acked-by: Viresh Kumar <viresh.kumar@linaro.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
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git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip
Pull CPU hotplug updates from Thomas Gleixner:
"Yet another batch of cpu hotplug core updates and conversions:
- Provide core infrastructure for multi instance drivers so the
drivers do not have to keep custom lists.
- Convert custom lists to the new infrastructure. The block-mq custom
list conversion comes through the block tree and makes the diffstat
tip over to more lines removed than added.
- Handle unbalanced hotplug enable/disable calls more gracefully.
- Remove the obsolete CPU_STARTING/DYING notifier support.
- Convert another batch of notifier users.
The relayfs changes which conflicted with the conversion have been
shipped to me by Andrew.
The remaining lot is targeted for 4.10 so that we finally can remove
the rest of the notifiers"
* 'smp-hotplug-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: (46 commits)
cpufreq: Fix up conversion to hotplug state machine
blk/mq: Reserve hotplug states for block multiqueue
x86/apic/uv: Convert to hotplug state machine
s390/mm/pfault: Convert to hotplug state machine
mips/loongson/smp: Convert to hotplug state machine
mips/octeon/smp: Convert to hotplug state machine
fault-injection/cpu: Convert to hotplug state machine
padata: Convert to hotplug state machine
cpufreq: Convert to hotplug state machine
ACPI/processor: Convert to hotplug state machine
virtio scsi: Convert to hotplug state machine
oprofile/timer: Convert to hotplug state machine
block/softirq: Convert to hotplug state machine
lib/irq_poll: Convert to hotplug state machine
x86/microcode: Convert to hotplug state machine
sh/SH-X3 SMP: Convert to hotplug state machine
ia64/mca: Convert to hotplug state machine
ARM/OMAP/wakeupgen: Convert to hotplug state machine
ARM/shmobile: Convert to hotplug state machine
arm64/FP/SIMD: Convert to hotplug state machine
...
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The function cpufreq_register_driver() returns zero on success and since
commit 27622b061eb4 ("cpufreq: Convert to hotplug state machine")
erroneously a positive number. Due to the "if (x) assume_error" construct
all callers assumed an error and as a consequence the cpu freq kworker
crashes with a NULL pointer dereference.
Reset the return value back to zero in the success case.
Fixes: 27622b061eb4 ("cpufreq: Convert to hotplug state machine")
Reported-by: Borislav Petkov <bp@alien8.de>
Reported-and-tested-by: Ingo Molnar <mingo@kernel.org>
Signed-off-by: Sebastian Andrzej Siewior <bigeasy@linutronix.de>
Cc: peterz@infradead.org
Cc: rjw@rjwysocki.net
Link: http://lkml.kernel.org/r/20160920145628.lp2bmq72ip3oiash@linutronix.de
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
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Install the callbacks via the state machine.
Signed-off-by: Sebastian Andrzej Siewior <bigeasy@linutronix.de>
Acked-by: "Rafael J. Wysocki" <rjw@rjwysocki.net>
Cc: linux-pm@vger.kernel.org
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Viresh Kumar <viresh.kumar@linaro.or
Cc: rt@linutronix.de
Link: http://lkml.kernel.org/r/20160906170457.32393-13-bigeasy@linutronix.de
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
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If a cpufreq driver is registered very early in the boot stage (e.g.
registered from postcore_initcall()), then cpufreq core may generate
kernel warnings for it.
In this case, the CPUs are brought online, then the cpufreq driver is
registered, and then the CPU topology devices are registered. However,
by the time cpufreq_add_dev() gets called, the cpu device isn't stored
in the per-cpu variable (cpu_sys_devices,) which is read by
get_cpu_device().
So the cpufreq core fails to get device for the CPU, for which
cpufreq_add_dev() was called in the first place and we will hit a
WARN_ON(!cpu_dev).
Even if we reuse the 'dev' parameter passed to cpufreq_add_dev() to
avoid that warning, there might be other CPUs online that share the
policy with the cpu for which cpufreq_add_dev() is called. Eventually
get_cpu_device() will return NULL for them as well, and we will hit the
same WARN_ON() again.
In order to fix these issues, change cpufreq core to create links to the
policy for a cpu only when cpufreq_add_dev() is called for that CPU.
Reuse the 'real_cpus' mask to track that as well.
Note that cpufreq_remove_dev() already handles removal of the links for
individual CPUs and cpufreq_add_dev() has aligned with that now.
Reported-by: Russell King <rmk+kernel@arm.linux.org.uk>
Tested-by: Russell King <rmk+kernel@arm.linux.org.uk>
Signed-off-by: Viresh Kumar <viresh.kumar@linaro.org>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
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Since cpufreq_policy_alloc() doesn't use its dev variable for
anything useful, drop that variable from there along with the
NULL check against it.
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
Acked-by: Viresh Kumar <viresh.kumar@linaro.org>
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Export cpufreq_driver_resolve_freq() since governors may be compiled as
modules.
Reported-by: Stephen Rothwell <sfr@canb.auug.org.au>
Signed-off-by: Steve Muckle <smuckle@linaro.org>
Acked-by: Viresh Kumar <viresh.kumar@linaro.org>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
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The handlers provided by cpufreq core are sufficient for resolving the
frequency for drivers providing ->target_index(), as the core already
has the frequency table and so ->resolve_freq() isn't required for such
platforms.
This patch disallows drivers with ->target_index() callback to use the
->resolve_freq() callback.
Also, it fixes a potential kernel crash for drivers providing ->target()
but no ->resolve_freq().
Fixes: e3c062360870 "cpufreq: add cpufreq_driver_resolve_freq()"
Signed-off-by: Viresh Kumar <viresh.kumar@linaro.org>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
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Cpufreq governors may need to know what a particular target frequency
maps to in the driver without necessarily wanting to set the frequency.
Support this operation via a new cpufreq API,
cpufreq_driver_resolve_freq(). This API returns the lowest driver
frequency equal or greater than the target frequency
(CPUFREQ_RELATION_L), subject to any policy (min/max) or driver
limitations. The mapping is also cached in the policy so that a
subsequent fast_switch operation can avoid repeating the same lookup.
The API will call a new cpufreq driver callback, resolve_freq(), if it
has been registered by the driver. Otherwise the frequency is resolved
via cpufreq_frequency_table_target(). Rather than require ->target()
style drivers to provide a resolve_freq() callback it is left to the
caller to ensure that the driver implements this callback if necessary
to use cpufreq_driver_resolve_freq().
Suggested-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
Signed-off-by: Steve Muckle <smuckle@linaro.org>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
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Both callers of cpufreq_update_current_freq(), cpufreq_update_policy()
and cpufreq_start_governor(), check cpufreq_suspended before calling
that function, so drop the redundant cpufreq_suspended check from it.
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
Acked-by: Viresh Kumar <viresh.kumar@linaro.org>
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CPU notifications from the firmware coming in when cpufreq is
suspended cause cpufreq_update_current_freq() to return 0 which
triggers the WARN_ON() in cpufreq_update_policy() for no reason.
Avoid that by checking cpufreq_suspended before calling
cpufreq_update_current_freq().
Fixes: c9d9c929e674 (cpufreq: Abort cpufreq_update_current_freq() for cpufreq_suspended set)
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
Acked-by: Viresh Kumar <viresh.kumar@linaro.org>
Cc: 4.6+ <stable@vger.kernel.org> # 4.6+
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This routine can't fail unless the frequency table is invalid and
doesn't contain any valid entries.
Make it return the index and WARN() in case it is used for an invalid
table.
Signed-off-by: Viresh Kumar <viresh.kumar@linaro.org>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
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It is already present as part of the policy and so no need to pass it
from the caller. Also, 'freq_table' is guaranteed to be valid in this
function and so no need to check it.
Signed-off-by: Viresh Kumar <viresh.kumar@linaro.org>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
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The policy already has this pointer set, use it instead.
Signed-off-by: Viresh Kumar <viresh.kumar@linaro.org>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
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Most of the callers of cpufreq_frequency_get_table() already have the
pointer to a valid 'policy' structure and they don't really need to go
through the per-cpu variable first and then a check to validate the
frequency, in order to find the freq-table for the policy.
Directly use the policy->freq_table field instead for them.
Only one user of that API is left after above changes, cpu_cooling.c and
it accesses the freq_table in a racy way as the policy can get freed in
between.
Fix it by using cpufreq_cpu_get() properly.
Since there are no more users of cpufreq_frequency_get_table() left, get
rid of it.
Signed-off-by: Viresh Kumar <viresh.kumar@linaro.org>
Acked-by: Javi Merino <javi.merino@arm.com> (cpu_cooling.c)
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
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The modularity of cpufreq_stats is quite problematic.
First off, the usage of policy notifiers for the initialization
and cleanup in the cpufreq_stats module is inherently racy with
respect to CPU offline/online and the initialization and cleanup
of the cpufreq driver.
Second, fast frequency switching (used by the schedutil governor)
cannot be enabled if any transition notifiers are registered, so
if the cpufreq_stats module (that registers a transition notifier
for updating transition statistics) is loaded, the schedutil governor
cannot use fast frequency switching.
On the other hand, allowing cpufreq_stats to be built as a module
doesn't really add much value. Arguably, there's not much reason
for that code to be modular at all.
For the above reasons, make the cpufreq stats code non-modular,
modify the core to invoke functions provided by that code directly
and drop the notifiers from it.
Make the stats sysfs attributes appear empty if fast frequency
switching is enabled as the statistics will not be updated in that
case anyway (and returning -EBUSY from those attributes breaks
powertop).
While at it, clean up Kconfig help for the CPU_FREQ_STAT and
CPU_FREQ_STAT_DETAILS options.
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
Acked-by: Viresh Kumar <viresh.kumar@linaro.org>
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Use clamp_val() instead of open coding it.
Signed-off-by: Viresh Kumar <viresh.kumar@linaro.org>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
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The sequence got a bit wrong as we are sending CPUFREQ_START
notifications even before we have sent CPUFREQ_CREATE_POLICY.
Fix it.
Signed-off-by: Viresh Kumar <viresh.kumar@linaro.org>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
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The 'initialized' field in struct cpufreq_governor is only used by
the conservative governor (as a usage counter) and the way that
happens is far from straightforward and arguably incorrect.
Namely, the value of 'initialized' is checked by
cpufreq_dbs_governor_init() and cpufreq_dbs_governor_exit() and
the results of those checks are passed (as the second argument) to
the ->init() and ->exit() callbacks in struct dbs_governor. Those
callbacks are only implemented by the ondemand and conservative
governors and ondemand doesn't use their second argument at all.
In turn, the conservative governor uses it to decide whether or not
to either register or unregister a transition notifier.
That whole mechanism is not only unnecessarily convoluted, but also
racy, because the 'initialized' field of struct cpufreq_governor is
updated in cpufreq_init_governor() and cpufreq_exit_governor() under
policy->rwsem which doesn't help if one of these functions is run
twice in parallel for different policies (which isn't impossible in
principle), for example.
Instead of it, add a proper usage counter to the conservative
governor and update it from cs_init() and cs_exit() which is
guaranteed to be non-racy, as those functions are only called
under gov_dbs_data_mutex which is global.
With that in place, drop the 'initialized' field from struct
cpufreq_governor as it is not used any more.
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
Acked-by: Viresh Kumar <viresh.kumar@linaro.org>
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The design of the cpufreq governor API is not very straightforward,
as struct cpufreq_governor provides only one callback to be invoked
from different code paths for different purposes. The purpose it is
invoked for is determined by its second "event" argument, causing it
to act as a "callback multiplexer" of sorts.
Unfortunately, that leads to extra complexity in governors, some of
which implement the ->governor() callback as a switch statement
that simply checks the event argument and invokes a separate function
to handle that specific event.
That extra complexity can be eliminated by replacing the all-purpose
->governor() callback with a family of callbacks to carry out specific
governor operations: initialization and exit, start and stop and policy
limits updates. That also turns out to reduce the code size too, so
do it.
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
Acked-by: Viresh Kumar <viresh.kumar@linaro.org>
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The return value of clamp_val() has to be stored actually.
Fixes: b7898fda5bc7 (cpufreq: Support for fast frequency switching)
Reported-by: Steve Muckle <steve.muckle@linaro.org>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
Acked-by: Viresh Kumar <viresh.kumar@linaro.org>
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The cpufreq_governor() routine is used by the cpufreq core to invoke
the current governor's ->governor() callback with appropriate arguments
and do some housekeeping related to that. Unfortunately, the way it
mixes different governor events in one code path makes it rather hard
to follow the code.
For this reason, split cpufreq_governor() into five simpler functions
that each will handle just one specific governor event and put all of
the code related to the given event into its own function.
This change is a prerequisite for a redesign of the cpufreq governor
API that will be done subsequently.
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
Acked-by: Viresh Kumar <viresh.kumar@linaro.org>
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It is not necessary to check the governor's max_transition_latency
attribute every time cpufreq_governor() runs, so check it only if
the event argument is CPUFREQ_GOV_POLICY_INIT.
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
Acked-by: Viresh Kumar <viresh.kumar@linaro.org>
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None of the cpufreq governors currently in the tree will ever fail
an invocation of the ->governor() callback with the event argument
equal to CPUFREQ_GOV_LIMITS (unless invoked with incorrect arguments
which doesn't matter anyway) and had it ever failed, the result of
it wouldn't have been very clean.
For this reason, rearrange the code in the core to ignore the return
value of cpufreq_governor() when called with event equal to
CPUFREQ_GOV_LIMITS.
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
Acked-by: Viresh Kumar <viresh.kumar@linaro.org>
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simplified goto out in cpufreq_register_driver for increasing
code readability
Signed-off-by: Pankaj Gupta <pankaj.gupta@spreadtrum.com>
Signed-off-by: Sanjeev Yadav <sanjeev.yadav@spreadtrum.com>
Acked-by: Viresh Kumar <viresh.kumar@linaro.org>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
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None of the cpufreq governors currently in the tree will ever fail
an invocation of the ->governor() callback with the event argument
equal to CPUFREQ_GOV_STOP (unless invoked with incorrect arguments
which doesn't matter anyway) and it is rather difficult to imagine
a valid reason for such a failure.
Accordingly, rearrange the code in the core to make it clear that
this call never fails.
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
Acked-by: Viresh Kumar <viresh.kumar@linaro.org>
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None of the cpufreq governors currently in the tree will ever fail
an invocation of the ->governor() callback with the event argument
equal to CPUFREQ_GOV_POLICY_EXIT (unless invoked with incorrect
arguments which doesn't matter anyway) and it wouldn't really
make sense to fail it, because the caller won't be able to handle
that failure in a meaningful way.
Accordingly, rearrange the code in the core to make it clear that
this call never fails.
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
Acked-by: Viresh Kumar <viresh.kumar@linaro.org>
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* pm-cpufreq-fixes:
intel_pstate: Fix intel_pstate_get()
cpufreq: intel_pstate: Fix HWP on boot CPU after system resume
cpufreq: st: enable selective initialization based on the platform
cpufreq: intel_pstate: Fix processing for turbo activation ratio
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Commit 41cfd64cf49fc "Update frequencies of policy->cpus only from
->set_policy()" changed the way the intel_pstate driver's ->set_policy
callback updates the HWP (hardware-managed P-states) settings.
A side effect of it is that if those settings are modified on the
boot CPU during system suspend and wakeup, they will never be
restored during subsequent system resume.
To address this problem, allow cpufreq drivers that don't provide
->target or ->target_index callbacks to use ->suspend and ->resume
callbacks and add a ->resume callback to intel_pstate to restore
the HWP settings on the CPUs that belong to the given policy.
Fixes: 41cfd64cf49fc "Update frequencies of policy->cpus only from ->set_policy()"
Tested-by: Srinivas Pandruvada <srinivas.pandruvada@linux.intel.com>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
Acked-by: Viresh Kumar <viresh.kumar@linaro.org>
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Since governor operations are generally skipped if cpufreq_suspended
is set, cpufreq_start_governor() should do nothing in that case.
That function is called in the cpufreq_online() path, and may also
be called from cpufreq_offline() in some cases, which are invoked
by the nonboot CPUs disabing/enabling code during system suspend
to RAM and resume. That happens when all devices have been
suspended, so if the cpufreq driver relies on things like I2C to
get the current frequency, it may not be ready to do that then.
To prevent problems from happening for this reason, make
cpufreq_update_current_freq(), which is the only function invoked
by cpufreq_start_governor() that doesn't check cpufreq_suspended
already, return 0 upfront if cpufreq_suspended is set.
Fixes: 3bbf8fe3ae08 (cpufreq: Always update current frequency before startig governor)
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
Acked-by: Viresh Kumar <viresh.kumar@linaro.org>
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Reorganize the code in cpufreq_add_dev() to avoid using the ret
variable and reduce the indentation level in it.
No functional changes.
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
Acked-by: Viresh Kumar <viresh.kumar@linaro.org>
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Merge two switch entries that do the same thing in
cpufreq_cpu_callback().
No functional changes.
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
Acked-by: Viresh Kumar <viresh.kumar@linaro.org>
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