kevin/linux
1
Fork 0
Code

cpufreq: amd-pstate: Merge amd_pstate_highest_perf_set() into amd_get_boost_ratio_numerator()

Browse Source 
The special case in amd_pstate_highest_perf_set() is the value used
for calculating the boost numerator.  Merge this into
amd_get_boost_ratio_numerator() and then use that to calculate boost
ratio.

This allows dropping more special casing of the highest perf value.

Reviewed-by: Gautham R. Shenoy <gautham.shenoy@amd.com>
Signed-off-by: Mario Limonciello <mario.limonciello@amd.com>
This commit is contained in:
Mario Limonciello 2024-08-26 16:13:56 -05:00
parent 279f838a61
commit ad4caad58d
3 changed files with 28 additions and 43 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

3
Documentation/admin-guide/pm/amd-pstate.rst
View File

@ -251,7 +251,8 @@ performance supported in `AMD CPPC Performance Capability <perf_cap_>`_).
In some ASICs, the highest CPPC performance is not the one in the ``_CPC``
table, so we need to expose it to sysfs. If boost is not active, but
still supported, this maximum frequency will be larger than the one in
``cpuinfo``.
``cpuinfo``. On systems that support preferred core, the driver will have
different values for some cores than others.
This attribute is read-only.
``amd_pstate_lowest_nonlinear_freq``

16
arch/x86/kernel/acpi/cppc.c
View File

@ -9,6 +9,7 @@
#include <asm/processor.h>
#include <asm/topology.h>
#define CPPC_HIGHEST_PERF_PERFORMANCE 196
#define CPPC_HIGHEST_PERF_PREFCORE 166
enum amd_pref_core {
@ -245,6 +246,21 @@ int amd_get_boost_ratio_numerator(unsigned int cpu, u64 *numerator)
*numerator = boost_numerator;
return 0;
}
/*
* For AMD CPUs with Family ID 19H and Model ID range 0x70 to 0x7f,
* the highest performance level is set to 196.
* https://bugzilla.kernel.org/show_bug.cgi?id=218759
*/
if (cpu_feature_enabled(X86_FEATURE_ZEN4)) {
switch (boot_cpu_data.x86_model) {
case 0x70 ... 0x7f:
*numerator = CPPC_HIGHEST_PERF_PERFORMANCE;
return 0;
default:
break;
}
}
*numerator = CPPC_HIGHEST_PERF_PREFCORE;
return 0;

52
drivers/cpufreq/amd-pstate.c
View File

@ -52,8 +52,6 @@
#define AMD_PSTATE_TRANSITION_LATENCY 20000
#define AMD_PSTATE_TRANSITION_DELAY 1000
#define AMD_PSTATE_FAST_CPPC_TRANSITION_DELAY 600
#define CPPC_HIGHEST_PERF_PERFORMANCE 196
#define CPPC_HIGHEST_PERF_DEFAULT 166
#define AMD_CPPC_EPP_PERFORMANCE 0x00
#define AMD_CPPC_EPP_BALANCE_PERFORMANCE 0x80
@ -372,43 +370,17 @@ static inline int amd_pstate_enable(bool enable)
return static_call(amd_pstate_enable)(enable);
}
static u32 amd_pstate_highest_perf_set(struct amd_cpudata *cpudata)
{
struct cpuinfo_x86 *c = &cpu_data(0);
/*
* For AMD CPUs with Family ID 19H and Model ID range 0x70 to 0x7f,
* the highest performance level is set to 196.
* https://bugzilla.kernel.org/show_bug.cgi?id=218759
*/
if (c->x86 == 0x19 && (c->x86_model >= 0x70 && c->x86_model <= 0x7f))
return CPPC_HIGHEST_PERF_PERFORMANCE;
return CPPC_HIGHEST_PERF_DEFAULT;
}
static int pstate_init_perf(struct amd_cpudata *cpudata)
{
u64 cap1;
u32 highest_perf;
int ret = rdmsrl_safe_on_cpu(cpudata->cpu, MSR_AMD_CPPC_CAP1,
&cap1);
if (ret)
return ret;
/* For platforms that do not support the preferred core feature, the
* highest_pef may be configured with 166 or 255, to avoid max frequency
* calculated wrongly. we take the AMD_CPPC_HIGHEST_PERF(cap1) value as
* the default max perf.
*/
if (cpudata->hw_prefcore)
highest_perf = amd_pstate_highest_perf_set(cpudata);
else
highest_perf = AMD_CPPC_HIGHEST_PERF(cap1);
WRITE_ONCE(cpudata->highest_perf, highest_perf);
WRITE_ONCE(cpudata->max_limit_perf, highest_perf);
WRITE_ONCE(cpudata->highest_perf, AMD_CPPC_HIGHEST_PERF(cap1));
WRITE_ONCE(cpudata->max_limit_perf, AMD_CPPC_HIGHEST_PERF(cap1));
WRITE_ONCE(cpudata->nominal_perf, AMD_CPPC_NOMINAL_PERF(cap1));
WRITE_ONCE(cpudata->lowest_nonlinear_perf, AMD_CPPC_LOWNONLIN_PERF(cap1));
WRITE_ONCE(cpudata->lowest_perf, AMD_CPPC_LOWEST_PERF(cap1));
@ -420,19 +392,13 @@ static int pstate_init_perf(struct amd_cpudata *cpudata)
static int cppc_init_perf(struct amd_cpudata *cpudata)
{
struct cppc_perf_caps cppc_perf;
u32 highest_perf;
int ret = cppc_get_perf_caps(cpudata->cpu, &cppc_perf);
if (ret)
return ret;
if (cpudata->hw_prefcore)
highest_perf = amd_pstate_highest_perf_set(cpudata);
else
highest_perf = cppc_perf.highest_perf;
WRITE_ONCE(cpudata->highest_perf, highest_perf);
WRITE_ONCE(cpudata->max_limit_perf, highest_perf);
WRITE_ONCE(cpudata->highest_perf, cppc_perf.highest_perf);
WRITE_ONCE(cpudata->max_limit_perf, cppc_perf.highest_perf);
WRITE_ONCE(cpudata->nominal_perf, cppc_perf.nominal_perf);
WRITE_ONCE(cpudata->lowest_nonlinear_perf,
cppc_perf.lowest_nonlinear_perf);
@ -918,8 +884,8 @@ static u32 amd_pstate_get_transition_latency(unsigned int cpu)
static int amd_pstate_init_freq(struct amd_cpudata *cpudata)
{
int ret;
u32 min_freq;
u32 highest_perf, max_freq;
u32 min_freq, max_freq;
u64 numerator;
u32 nominal_perf, nominal_freq;
u32 lowest_nonlinear_perf, lowest_nonlinear_freq;
u32 boost_ratio, lowest_nonlinear_ratio;
@ -941,8 +907,10 @@ static int amd_pstate_init_freq(struct amd_cpudata *cpudata)
nominal_perf = READ_ONCE(cpudata->nominal_perf);
highest_perf = READ_ONCE(cpudata->highest_perf);
boost_ratio = div_u64(highest_perf << SCHED_CAPACITY_SHIFT, nominal_perf);
ret = amd_get_boost_ratio_numerator(cpudata->cpu, &numerator);
if (ret)
return ret;
boost_ratio = div_u64(numerator << SCHED_CAPACITY_SHIFT, nominal_perf);
max_freq = (nominal_freq * boost_ratio >> SCHED_CAPACITY_SHIFT) * 1000;
lowest_nonlinear_perf = READ_ONCE(cpudata->lowest_nonlinear_perf);