Commit c8c68c38b5 ("cpufreq: amd-pstate: initialize core precision
boost state") sets per-policy boost flag to false when boost fail.
However, this boost flag will be set to reverse value in
store_local_boost() and cpufreq_boost_trigger_state() in cpufreq.c. This
will cause the per-policy boost flag set to true when fail to set boost.
Remove the extra assignment in amd_pstate_set_boost() and keep all
operations on per-policy boost flag outside of set_boost() to fix this
problem.
Fixes: c8c68c38b5 ("cpufreq: amd-pstate: initialize core precision boost state")
Signed-off-by: Lifeng Zheng <zhenglifeng1@huawei.com>
Reviewed-by: Mario Limonciello <mario.limonciello@amd.com>
Link: https://lore.kernel.org/r/20250110091949.3610770-1-zhenglifeng1@huawei.com
Signed-off-by: Mario Limonciello <mario.limonciello@amd.com>
The previous approach introduced roundoff errors during division when
calculating the boost ratio. This, in turn, affected the maximum
frequency calculation, often resulting in reporting lower frequency
values.
For example, on the Glinda SoC based board with the following
parameters:
max_perf = 208
nominal_perf = 100
nominal_freq = 2600 MHz
The Linux kernel previously calculated the frequency as:
freq = ((max_perf * 1024 / nominal_perf) * nominal_freq) / 1024
freq = 5405 MHz // Integer arithmetic.
With the updated formula:
freq = (max_perf * nominal_freq) / nominal_perf
freq = 5408 MHz
This change ensures more accurate frequency calculations by eliminating
unnecessary shifts and divisions, thereby improving precision.
Signed-off-by: Naresh Solanki <naresh.solanki@9elements.com>
[ML: trim the changelog from commit message]
Reviewed-by: Mario Limonciello <mario.limonciello@amd.com>
Link: https://lore.kernel.org/r/20241219201833.2750998-1-naresh.solanki@9elements.com
Signed-off-by: Mario Limonciello <mario.limonciello@amd.com>
Currently boost_state is cached for every processor in cpudata structure
and driver boost state is set for every processor.
Both of these aren't necessary as the driver only needs to set once and
the policy stores whether boost is enabled.
Move the driver boost setting to registration and adjust all references
to cached value to pull from the policy instead.
Reviewed-by: Gautham R. Shenoy <gautham.shenoy@amd.com>
Link: https://lore.kernel.org/r/20241209185248.16301-16-mario.limonciello@amd.com
Signed-off-by: Mario Limonciello <mario.limonciello@amd.com>
For MSR systems the EPP value is in the same register as perf targets
and so divding them into two separate MSR writes is wasteful.
In msr_update_perf(), update both EPP and perf values in one write to
MSR_AMD_CPPC_REQ, and cache them if successful.
To accomplish this plumb the EPP value into the update_perf call and
modify all its callers to check the return value.
As this unifies calls, ensure that the MSR write is necessary before
flushing a write out. Also drop the comparison from the passive flow
tracing.
Reviewed-by: Gautham R. Shenoy <gautham.shenoy@amd.com>
Link: https://lore.kernel.org/r/20241209185248.16301-13-mario.limonciello@amd.com
Signed-off-by: Mario Limonciello <mario.limonciello@amd.com>
The limit updating code in amd_pstate_epp_update_limit() should not
only apply to EPP updates. Move it to amd_pstate_update_min_max_limit()
so other callers can benefit as well.
With this move it's not necessary to have clamp_t calls anymore because
the verify callback is called when setting limits.
Reviewed-by: Gautham R. Shenoy <gautham.shenoy@amd.com>
Link: https://lore.kernel.org/r/20241209185248.16301-11-mario.limonciello@amd.com
Signed-off-by: Mario Limonciello <mario.limonciello@amd.com>
MSR and shared memory based systems have different mechanisms to get and
set the epp value. Split those mechanisms into different functions and
assign them appropriately to the static calls at boot time. This eliminates
the need for the "if(cpu_feature_enabled(X86_FEATURE_CPPC))" checks at
runtime.
Also, propagate the error code from rdmsrl_on_cpu() and cppc_get_epp_perf()
to *_get_epp()'s caller, instead of returning -EIO unconditionally.
Signed-off-by: Dhananjay Ugwekar <Dhananjay.Ugwekar@amd.com>
Reviewed-by: Mario Limonciello <mario.limonciello@amd.com>
Reviewed-by: Gautham R. Shenoy <gautham.shenoy@amd.com>
Link: https://lore.kernel.org/r/20241204144842.164178-2-Dhananjay.Ugwekar@amd.com
Signed-off-by: Mario Limonciello <mario.limonciello@amd.com>
commit ad4caad58d ("cpufreq: amd-pstate: Merge
amd_pstate_highest_perf_set() into amd_get_boost_ratio_numerator()")
changed the semantics for highest perf and commit 18d9b52271
("cpufreq/amd-pstate: Use nominal perf for limits when boost is disabled")
worked around those semantic changes.
This however is a confusing result and furthermore makes it awkward to
change frequency limits and boost due to the scaling differences. Restore
the boost numerator to highest perf again.
Suggested-by: Dhananjay Ugwekar <Dhananjay.Ugwekar@amd.com>
Reviewed-by: Gautham R. Shenoy <gautham.shenoy@amd.com>
Fixes: ad4caad58d ("cpufreq: amd-pstate: Merge amd_pstate_highest_perf_set() into amd_get_boost_ratio_numerator()")
Link: https://lore.kernel.org/r/20241209185248.16301-2-mario.limonciello@amd.com
Signed-off-by: Mario Limonciello <mario.limonciello@amd.com>
Booting with amd-pstate on 3rd Generation EPYC system incorrectly
enabled ITMT support despite the system not supporting Preferred Core
ranking. amd_pstate_init_prefcore() called during amd_pstate*_cpu_init()
requires "amd_pstate_prefcore" to be set correctly however the preferred
core support is detected only after driver registration which is too
late.
Swap the function calls around to detect preferred core support before
registring the driver via amd_pstate_register_driver(). This ensures
amd_pstate*_cpu_init() sees the correct value of "amd_pstate_prefcore"
considering the platform support.
Fixes: 279f838a61 ("x86/amd: Detect preferred cores in amd_get_boost_ratio_numerator()")
Fixes: ff2653ded4 ("cpufreq/amd-pstate: Move registration after static function call update")
Signed-off-by: K Prateek Nayak <kprateek.nayak@amd.com>
Acked-by: Mario Limonciello <mario.limonciello@amd.com>
Link: https://lore.kernel.org/r/20241210032557.754-1-kprateek.nayak@amd.com
Signed-off-by: Mario Limonciello <mario.limonciello@amd.com>
Pull x86 cpuid updates from Borislav Petkov:
- Add a feature flag which denotes AMD CPUs supporting workload
classification with the purpose of using such hints when making
scheduling decisions
- Determine the boost enumerator for each AMD core based on its type:
efficiency or performance, in the cppc driver
- Add the type of a CPU to the topology CPU descriptor with the goal of
supporting and making decisions based on the type of the respective
core
- Add a feature flag to denote AMD cores which have heterogeneous
topology and enable SD_ASYM_PACKING for those
- Check microcode revisions before disabling PCID on Intel
- Cleanups and fixlets
* tag 'x86_cpu_for_v6.13' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
x86/cpu: Remove redundant CONFIG_NUMA guard around numa_add_cpu()
x86/cpu: Fix FAM5_QUARK_X1000 to use X86_MATCH_VFM()
x86/cpu: Fix formatting of cpuid_bits[] in scattered.c
x86/cpufeatures: Add X86_FEATURE_AMD_WORKLOAD_CLASS feature bit
x86/amd: Use heterogeneous core topology for identifying boost numerator
x86/cpu: Add CPU type to struct cpuinfo_topology
x86/cpu: Enable SD_ASYM_PACKING for PKG domain on AMD
x86/cpufeatures: Add X86_FEATURE_AMD_HETEROGENEOUS_CORES
x86/cpufeatures: Rename X86_FEATURE_FAST_CPPC to have AMD prefix
x86/mm: Don't disable PCID when INVLPG has been fixed by microcode
Currently the default cpufreq driver for all the AMD EPYC servers is
acpi-cpufreq. Going forward, switch to amd-pstate as the default
driver on the AMD EPYC server platforms with CPU family 0x1A or
higher. The default mode will be active mode.
Testing shows that amd-pstate with active mode and performance
governor provides comparable or better performance per-watt against
acpi-cpufreq + performance governor.
Likewise, amd-pstate with active mode and powersave governor with the
energy_performance_preference=power (EPP=255) provides comparable or
better performance per-watt against acpi-cpufreq + schedutil governor
for a wide range of workloads.
Users can still revert to using acpi-cpufreq driver on these platforms
with the "amd_pstate=disable" kernel commandline parameter.
Signed-off-by: Swapnil Sapkal <swapnil.sapkal@amd.com>
Signed-off-by: Gautham R. Shenoy <gautham.shenoy@amd.com>
Reviewed-by: Mario Limonciello <mario.limonciello@amd.com>
Link: https://lore.kernel.org/r/20241021101836.9047-3-gautham.shenoy@amd.com
Signed-off-by: Mario Limonciello <mario.limonciello@amd.com>
The amd-pstate driver sets CPPC_REQ.min_perf to CPPC_REQ.max_perf when
in active mode with performance governor. Typically CPPC_REQ.max_perf
is set to CPPC.highest_perf. This causes frequency throttling on
power-limited platforms which causes performance regressions on
certain classes of workloads.
Hence, set the CPPC_REQ.min_perf to the CPPC.nominal_perf or
CPPC_REQ.max_perf, whichever is lower of the two.
Fixes: ffa5096a7c ("cpufreq: amd-pstate: implement Pstate EPP support for the AMD processors")
Signed-off-by: Gautham R. Shenoy <gautham.shenoy@amd.com>
Reviewed-by: Mario Limonciello <mario.limonciello@amd.com>
Link: https://lore.kernel.org/r/20241021101836.9047-2-gautham.shenoy@amd.com
Signed-off-by: Mario Limonciello <mario.limonciello@amd.com>
According to the AMD architectural programmer's manual volume 2 [1], in
section "17.6.4.1 CPPC_CAPABILITY_1" lowest_nonlinear_perf is described
as "Reports the most energy efficient performance level (in terms of
performance per watt). Above this threshold, lower performance levels
generally result in increased energy efficiency. Reducing performance
below this threshold does not result in total energy savings for a given
computation, although it reduces instantaneous power consumption". So
lowest_nonlinear_perf is the most power efficient performance level, and
going below that would lead to a worse performance/watt.
Also, setting the minimum frequency to lowest_nonlinear_freq (instead of
lowest_freq) allows the CPU to idle at a higher frequency which leads
to more time being spent in a deeper idle state (as trivial idle tasks
are completed sooner). This has shown a power benefit in some systems,
in other systems, power consumption has increased but so has the
throughput/watt.
Modify the initial policy_data->min set by cpufreq-core to
lowest_nonlinear_freq, in the ->verify() callback. Also set the
cpudata->req[0] to FREQ_QOS_MIN_DEFAULT_VALUE (i.e. 0), so that it also
gets overriden by the check in verify function.
Link: https://www.amd.com/content/dam/amd/en/documents/processor-tech-docs/programmer-references/24593.pdf [1]
Signed-off-by: Dhananjay Ugwekar <Dhananjay.Ugwekar@amd.com>
Reviewed-by: Mario Limonciello <mario.limonciello@amd.com>
Link: https://lore.kernel.org/r/20241017053927.25285-3-Dhananjay.Ugwekar@amd.com
Signed-off-by: Mario Limonciello <mario.limonciello@amd.com>
While switching the driver mode between active and passive, Collaborative
Processor Performance Control (CPPC) is disabled in
amd_pstate_unregister_driver(). But, it is not enabled back while registering
the new driver (passive or active). This leads to the new driver mode not
working correctly, so enable it back in amd_pstate_register_driver().
Fixes: 3ca7bc818d ("cpufreq: amd-pstate: Add guided mode control support via sysfs")
Signed-off-by: Dhananjay Ugwekar <Dhananjay.Ugwekar@amd.com>
Reviewed-by: Mario Limonciello <mario.limonciello@amd.com>
Link: https://lore.kernel.org/r/20241004122303.94283-1-Dhananjay.Ugwekar@amd.com
Signed-off-by: Mario Limonciello <mario.limonciello@amd.com>
Merge the second round of amd-pstate changes for 6.12 from Mario
Limonciello:
"* Move the calculation of the AMD boost numerator outside of
amd-pstate, correcting acpi-cpufreq on systems with preferred cores
* Harden preferred core detection to avoid potential false positives
* Add extra unit test coverage for mode state machine"
* tag 'amd-pstate-v6.12-2024-09-11' of ssh://gitolite.kernel.org/pub/scm/linux/kernel/git/superm1/linux:
cpufreq/amd-pstate-ut: Fix an "Uninitialized variables" issue
cpufreq/amd-pstate-ut: Add test case for mode switches
cpufreq/amd-pstate: Export symbols for changing modes
amd-pstate: Add missing documentation for `amd_pstate_prefcore_ranking`
cpufreq: amd-pstate: Add documentation for `amd_pstate_hw_prefcore`
cpufreq: amd-pstate: Optimize amd_pstate_update_limits()
cpufreq: amd-pstate: Merge amd_pstate_highest_perf_set() into amd_get_boost_ratio_numerator()
x86/amd: Detect preferred cores in amd_get_boost_ratio_numerator()
x86/amd: Move amd_get_highest_perf() out of amd-pstate
ACPI: CPPC: Adjust debug messages in amd_set_max_freq_ratio() to warn
ACPI: CPPC: Drop check for non zero perf ratio
x86/amd: Rename amd_get_highest_perf() to amd_get_boost_ratio_numerator()
ACPI: CPPC: Adjust return code for inline functions in !CONFIG_ACPI_CPPC_LIB
x86/amd: Move amd_get_highest_perf() from amd.c to cppc.c
