linux-stable.git/drivers/cpufreq, branch v5.11.4

cpufreq: intel_pstate: Get per-CPU max freq via MSR_HWP_CAPABILITIES if available

2021-03-04T11:15:38+00:00

commit 6f67e060083a84a4cc364eab6ae40c717165fb0c upstream.

Currently, when turbo is disabled (either by BIOS or by the user),
the intel_pstate driver reads the max non-turbo frequency from the
package-wide MSR_PLATFORM_INFO(0xce) register.

However, on asymmetric platforms it is possible in theory that small
and big core with HWP enabled might have different max non-turbo CPU
frequency, because MSR_HWP_CAPABILITIES is per-CPU scope according
to Intel Software Developer Manual.

The turbo max freq is already per-CPU in current code, so make
similar change to the max non-turbo frequency as well.

Reported-by: Wendy Wang 
Signed-off-by: Chen Yu 
[ rjw: Subject and changelog edits ]
Cc: 4.18+  # 4.18+: a45ee4d4e13b: cpufreq: intel_pstate: Change intel_pstate_get_hwp_max() argument
Signed-off-by: Rafael J. Wysocki 
Signed-off-by: Greg Kroah-Hartman

cpufreq: intel_pstate: Change intel_pstate_get_hwp_max() argument

2021-03-04T11:15:38+00:00

commit a45ee4d4e13b0e35a8ec7ea0bf9267243d57b302 upstream.

All of the callers of intel_pstate_get_hwp_max() access the struct
cpudata object that corresponds to the given CPU already and the
function itself needs to access that object (in order to update
hwp_cap_cached), so modify the code to pass a struct cpudata pointer
to it instead of the CPU number.

Signed-off-by: Rafael J. Wysocki 
Tested-by: Chen Yu 
Signed-off-by: Greg Kroah-Hartman

cpufreq: qcom-hw: drop devm_xxx() calls from init/exit hooks

2021-03-04T11:15:38+00:00

commit 67fc209b527d023db4d087c68e44e9790aa089ef upstream.

Commit f17b3e44320b ("cpufreq: qcom-hw: Use
devm_platform_ioremap_resource() to simplify code") introduces
a regression on platforms using the driver, by failing to initialise
a policy, when one is created post hotplug.

When all the CPUs of a policy are hoptplugged out, the call to .exit()
and later to devm_iounmap() does not release the memory region that was
requested during devm_platform_ioremap_resource().  Therefore,
a subsequent call to .init() will result in the following error, which
will prevent a new policy to be initialised:

[ 3395.915416] CPU4: shutdown
[ 3395.938185] psci: CPU4 killed (polled 0 ms)
[ 3399.071424] CPU5: shutdown
[ 3399.094316] psci: CPU5 killed (polled 0 ms)
[ 3402.139358] CPU6: shutdown
[ 3402.161705] psci: CPU6 killed (polled 0 ms)
[ 3404.742939] CPU7: shutdown
[ 3404.765592] psci: CPU7 killed (polled 0 ms)
[ 3411.492274] Detected VIPT I-cache on CPU4
[ 3411.492337] GICv3: CPU4: found redistributor 400 region 0:0x0000000017ae0000
[ 3411.492448] CPU4: Booted secondary processor 0x0000000400 [0x516f802d]
[ 3411.503654] qcom-cpufreq-hw 17d43000.cpufreq: can't request region for resource [mem 0x17d45800-0x17d46bff]

With that being said, the original code was tricky and skipping memory
region request intentionally to hide this issue.  The true cause is that
those devm_xxx() device managed functions shouldn't be used for cpufreq
init/exit hooks, because &pdev->dev is alive across the hooks and will
not trigger auto resource free-up.  Let's drop the use of device managed
functions and manually allocate/free resources, so that the issue can be
fixed properly.

Cc: v5.10+  # v5.10+
Fixes: f17b3e44320b ("cpufreq: qcom-hw: Use devm_platform_ioremap_resource() to simplify code")
Suggested-by: Bjorn Andersson 
Signed-off-by: Shawn Guo 
Signed-off-by: Viresh Kumar 
Signed-off-by: Greg Kroah-Hartman

cpufreq: ACPI: Set cpuinfo.max_freq directly if max boost is known

2021-03-04T11:15:17+00:00

commit 538b0188da4653b9f4511a114f014354fb6fb7a5 upstream.

Commit 3c55e94c0ade ("cpufreq: ACPI: Extend frequency tables to cover
boost frequencies") attempted to address a performance issue involving
acpi-cpufreq, the schedutil governor and scale-invariance on x86 by
extending the frequency tables created by acpi-cpufreq to cover the
entire range of "turbo" (or "boost") frequencies, but that caused
frequencies reported via /proc/cpuinfo and the scaling_cur_freq
attribute in sysfs to change which may confuse users and monitoring
tools.

For this reason, revert the part of commit 3c55e94c0ade adding the
extra entry to the frequency table and use the observation that
in principle cpuinfo.max_freq need not be equal to the maximum
frequency listed in the frequency table for the given policy.

Namely, modify cpufreq_frequency_table_cpuinfo() to allow cpufreq
drivers to set their own cpuinfo.max_freq above that frequency and
change  acpi-cpufreq to set cpuinfo.max_freq to the maximum boost
frequency found via CPPC.

This should be sufficient to let all of the cpufreq subsystem know
the real maximum frequency of the CPU without changing frequency
reporting.

Link: https://bugzilla.kernel.org/show_bug.cgi?id=211305
Fixes: 3c55e94c0ade ("cpufreq: ACPI: Extend frequency tables to cover boost frequencies")
Reported-by: Matt McDonald 
Tested-by: Matt McDonald 
Signed-off-by: Rafael J. Wysocki 
Tested-by: Giovanni Gherdovich 
Tested-by: Michael Larabel 
Cc: 5.11+  # 5.11+
Signed-off-by: Greg Kroah-Hartman

cpufreq: brcmstb-avs-cpufreq: Fix resource leaks in ->remove()

2021-03-04T11:13:41+00:00

[ Upstream commit 3657f729b6fb5f2c0bf693742de2dcd49c572aa1 ]

If 'cpufreq_unregister_driver()' fails, just WARN and continue, so that
other resources are freed.

Fixes: de322e085995 ("cpufreq: brcmstb-avs-cpufreq: AVS CPUfreq driver for Broadcom STB SoCs")
Signed-off-by: Christophe JAILLET 
[ Viresh: Updated Subject ]
Signed-off-by: Viresh Kumar 
Signed-off-by: Sasha Levin

cpufreq: brcmstb-avs-cpufreq: Free resources in error path

2021-03-04T11:13:41+00:00

[ Upstream commit 05f456286fd489558c72a4711d22a5612c965685 ]

If 'cpufreq_register_driver()' fails, we must release the resources
allocated in 'brcm_avs_prepare_init()' as already done in the remove
function.

To do that, introduce a new function 'brcm_avs_prepare_uninit()' in order
to avoid code duplication. This also makes the code more readable (IMHO).

Fixes: de322e085995 ("cpufreq: brcmstb-avs-cpufreq: AVS CPUfreq driver for Broadcom STB SoCs")
Signed-off-by: Christophe JAILLET 
[ Viresh: Updated Subject ]
Signed-off-by: Viresh Kumar 
Signed-off-by: Sasha Levin

cpufreq: ACPI: Update arch scale-invariance max perf ratio if CPPC is not there

2021-02-08T12:45:51+00:00

If the maximum performance level taken for computing the
arch_max_freq_ratio value used in the x86 scale-invariance code is
higher than the one corresponding to the cpuinfo.max_freq value
coming from the acpi_cpufreq driver, the scale-invariant utilization
falls below 100% even if the CPU runs at cpuinfo.max_freq or slightly
faster, which causes the schedutil governor to select a frequency
below cpuinfo.max_freq.  That frequency corresponds to a frequency
table entry below the maximum performance level necessary to get to
the "boost" range of CPU frequencies which prevents "boost"
frequencies from being used in some workloads.

While this issue is related to scale-invariance, it may be amplified
by commit db865272d9c4 ("cpufreq: Avoid configuring old governors as
default with intel_pstate") from the 5.10 development cycle which
made it extremely easy to default to schedutil even if the preferred
driver is acpi_cpufreq as long as intel_pstate is built too, because
the mere presence of the latter effectively removes the ondemand
governor from the defaults.  Distro kernels are likely to include
both intel_pstate and acpi_cpufreq on x86, so their users who cannot
use intel_pstate or choose to use acpi_cpufreq may easily be
affectecd by this issue.

If CPPC is available, it can be used to address this issue by
extending the frequency tables created by acpi_cpufreq to cover the
entire available frequency range (including "boost" frequencies) for
each CPU, but if CPPC is not there, acpi_cpufreq has no idea what
the maximum "boost" frequency is and the frequency tables created by
it cannot be extended in a meaningful way, so in that case make it
ask the arch scale-invariance code to to use the "nominal" performance
level for CPU utilization scaling in order to avoid the issue at hand.

Fixes: db865272d9c4 ("cpufreq: Avoid configuring old governors as default with intel_pstate")
Signed-off-by: Rafael J. Wysocki 
Reviewed-by: Giovanni Gherdovich 
Acked-by: Peter Zijlstra (Intel)

cpufreq: ACPI: Extend frequency tables to cover boost frequencies

2021-02-08T12:45:51+00:00

A severe performance regression on AMD EPYC processors when using
the schedutil scaling governor was discovered by Phoronix.com and
attributed to the following commits:

  41ea667227ba ("x86, sched: Calculate frequency invariance for AMD
  systems")

  976df7e5730e ("x86, sched: Use midpoint of max_boost and max_P for
  frequency invariance on AMD EPYC")

The source of the problem is that the maximum performance level taken
for computing the arch_max_freq_ratio value used in the x86 scale-
invariance code is higher than the one corresponding to the
cpuinfo.max_freq value coming from the acpi_cpufreq driver.

This effectively causes the scale-invariant utilization to fall below
100% even if the CPU runs at cpuinfo.max_freq or slightly faster, so
the schedutil governor selects a frequency below cpuinfo.max_freq
then.  That frequency corresponds to a frequency table entry below
the maximum performance level necessary to get to the "boost" range
of CPU frequencies.

However, if the cpuinfo.max_freq value coming from acpi_cpufreq was
higher, the schedutil governor would select higher frequencies which
in turn would allow acpi_cpufreq to set more adequate performance
levels and to get to the "boost" range of CPU frequencies more often.

This issue affects any systems where acpi_cpufreq is used and the
"boost" (or "turbo") frequencies are enabled, not just AMD EPYC.
Moreover, commit db865272d9c4 ("cpufreq: Avoid configuring old
governors as default with intel_pstate") from the 5.10 development
cycle made it extremely easy to default to schedutil even if the
preferred driver is acpi_cpufreq as long as intel_pstate is built
too, because the mere presence of the latter effectively removes the
ondemand governor from the defaults.  Distro kernels are likely to
include both intel_pstate and acpi_cpufreq on x86, so their users
who cannot use intel_pstate or choose to use acpi_cpufreq may
easily be affectecd by this issue.

To address this issue, extend the frequency table constructed by
acpi_cpufreq for each CPU to cover the entire range of available
frequencies (including the "boost" ones) if CPPC is available and
indicates that "boost" (or "turbo") frequencies are enabled.  That
causes cpuinfo.max_freq to become the maximum "boost" frequency of
the given CPU (instead of the maximum frequency returned by the ACPI
_PSS object that corresponds to the "nominal" performance level).

Fixes: 41ea667227ba ("x86, sched: Calculate frequency invariance for AMD systems")
Fixes: 976df7e5730e ("x86, sched: Use midpoint of max_boost and max_P for frequency invariance on AMD EPYC")
Fixes: db865272d9c4 ("cpufreq: Avoid configuring old governors as default with intel_pstate")
Link: https://www.phoronix.com/scan.php?page=article&item=linux511-amd-schedutil&num=1
Link: https://lore.kernel.org/linux-pm/20210203135321.12253-2-ggherdovich@suse.cz/
Reported-by: Michael Larabel 
Diagnosed-by: Giovanni Gherdovich 
Signed-off-by: Rafael J. Wysocki 
Tested-by: Giovanni Gherdovich 
Reviewed-by: Giovanni Gherdovich 
Tested-by: Michael Larabel

cpufreq: intel_pstate: remove obsolete functions

2021-01-07T17:22:46+00:00

percent_fp() was used in intel_pstate_pid_reset(), which was removed in
commit 9d0ef7af1f2d ("cpufreq: intel_pstate: Do not use PID-based P-state
selection") and hence, percent_fp() is unused since then.

percent_ext_fp() was last used in intel_pstate_update_perf_limits(), which
was refactored in commit 1a4fe38add8b ("cpufreq: intel_pstate: Remove
max/min fractions to limit performance"), and hence, percent_ext_fp() is
unused since then.

make CC=clang W=1 points us those unused functions:

drivers/cpufreq/intel_pstate.c:79:23: warning: unused function 'percent_fp' [-Wunused-function]
static inline int32_t percent_fp(int percent)
                      ^

drivers/cpufreq/intel_pstate.c:94:23: warning: unused function 'percent_ext_fp' [-Wunused-function]
static inline int32_t percent_ext_fp(int percent)
                      ^

Remove those obsolete functions.

Signed-off-by: Lukas Bulwahn 
Reviewed-by: Nathan Chancellor 
Signed-off-by: Rafael J. Wysocki

cpufreq: powernow-k8: pass policy rather than use cpufreq_cpu_get()

2021-01-07T16:37:33+00:00

Currently there is an unlikely case where cpufreq_cpu_get() returns a
NULL policy and this will cause a NULL pointer dereference later on.

Fix this by passing the policy to transition_frequency_fidvid() from
the caller and hence eliminating the need for the cpufreq_cpu_get()
and cpufreq_cpu_put().

Thanks to Viresh Kumar for suggesting the fix.

Addresses-Coverity: ("Dereference null return")
Fixes: b43a7ffbf33b ("cpufreq: Notify all policy->cpus in cpufreq_notify_transition()")
Suggested-by: Viresh Kumar 
Signed-off-by: Colin Ian King 
Acked-by: Viresh Kumar 
Signed-off-by: Rafael J. Wysocki