Skip to content

Commit

Permalink
cpufreq/amd-pstate: Replace all AMD_CPPC_* macros with masks
Browse files Browse the repository at this point in the history
Bitfield masks are easier to follow and less error prone.

Reviewed-by: Dhananjay Ugwekar <dhananjay.ugwekar@amd.com>
Reviewed-by: Gautham R. Shenoy <gautham.shenoy@amd.com>
Signed-off-by: Mario Limonciello <mario.limonciello@amd.com>
  • Loading branch information
Mario Limonciello committed Mar 6, 2025
1 parent c630458 commit b4cc466
Show file tree
Hide file tree
Showing 4 changed files with 25 additions and 24 deletions.
20 changes: 11 additions & 9 deletions arch/x86/include/asm/msr-index.h
Original file line number Diff line number Diff line change
Expand Up @@ -701,15 +701,17 @@
#define MSR_AMD_CPPC_REQ 0xc00102b3
#define MSR_AMD_CPPC_STATUS 0xc00102b4

#define AMD_CPPC_LOWEST_PERF(x) (((x) >> 0) & 0xff)
#define AMD_CPPC_LOWNONLIN_PERF(x) (((x) >> 8) & 0xff)
#define AMD_CPPC_NOMINAL_PERF(x) (((x) >> 16) & 0xff)
#define AMD_CPPC_HIGHEST_PERF(x) (((x) >> 24) & 0xff)

#define AMD_CPPC_MAX_PERF(x) (((x) & 0xff) << 0)
#define AMD_CPPC_MIN_PERF(x) (((x) & 0xff) << 8)
#define AMD_CPPC_DES_PERF(x) (((x) & 0xff) << 16)
#define AMD_CPPC_ENERGY_PERF_PREF(x) (((x) & 0xff) << 24)
/* Masks for use with MSR_AMD_CPPC_CAP1 */
#define AMD_CPPC_LOWEST_PERF_MASK GENMASK(7, 0)
#define AMD_CPPC_LOWNONLIN_PERF_MASK GENMASK(15, 8)
#define AMD_CPPC_NOMINAL_PERF_MASK GENMASK(23, 16)
#define AMD_CPPC_HIGHEST_PERF_MASK GENMASK(31, 24)

/* Masks for use with MSR_AMD_CPPC_REQ */
#define AMD_CPPC_MAX_PERF_MASK GENMASK(7, 0)
#define AMD_CPPC_MIN_PERF_MASK GENMASK(15, 8)
#define AMD_CPPC_DES_PERF_MASK GENMASK(23, 16)
#define AMD_CPPC_EPP_PERF_MASK GENMASK(31, 24)

/* AMD Performance Counter Global Status and Control MSRs */
#define MSR_AMD64_PERF_CNTR_GLOBAL_STATUS 0xc0000300
Expand Down
4 changes: 3 additions & 1 deletion arch/x86/kernel/acpi/cppc.c
Original file line number Diff line number Diff line change
Expand Up @@ -4,6 +4,8 @@
* Copyright (c) 2016, Intel Corporation.
*/

#include <linux/bitfield.h>

#include <acpi/cppc_acpi.h>
#include <asm/msr.h>
#include <asm/processor.h>
Expand Down Expand Up @@ -149,7 +151,7 @@ int amd_get_highest_perf(unsigned int cpu, u32 *highest_perf)
if (ret)
goto out;

val = AMD_CPPC_HIGHEST_PERF(val);
val = FIELD_GET(AMD_CPPC_HIGHEST_PERF_MASK, val);
} else {
ret = cppc_get_highest_perf(cpu, &val);
if (ret)
Expand Down
9 changes: 5 additions & 4 deletions drivers/cpufreq/amd-pstate-ut.c
Original file line number Diff line number Diff line change
Expand Up @@ -22,6 +22,7 @@

#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt

#include <linux/bitfield.h>
#include <linux/kernel.h>
#include <linux/module.h>
#include <linux/moduleparam.h>
Expand Down Expand Up @@ -142,10 +143,10 @@ static int amd_pstate_ut_check_perf(u32 index)
return ret;
}

highest_perf = AMD_CPPC_HIGHEST_PERF(cap1);
nominal_perf = AMD_CPPC_NOMINAL_PERF(cap1);
lowest_nonlinear_perf = AMD_CPPC_LOWNONLIN_PERF(cap1);
lowest_perf = AMD_CPPC_LOWEST_PERF(cap1);
highest_perf = FIELD_GET(AMD_CPPC_HIGHEST_PERF_MASK, cap1);
nominal_perf = FIELD_GET(AMD_CPPC_NOMINAL_PERF_MASK, cap1);
lowest_nonlinear_perf = FIELD_GET(AMD_CPPC_LOWNONLIN_PERF_MASK, cap1);
lowest_perf = FIELD_GET(AMD_CPPC_LOWEST_PERF_MASK, cap1);
}

cur_perf = READ_ONCE(cpudata->perf);
Expand Down
16 changes: 6 additions & 10 deletions drivers/cpufreq/amd-pstate.c
Original file line number Diff line number Diff line change
Expand Up @@ -89,11 +89,6 @@ static bool cppc_enabled;
static bool amd_pstate_prefcore = true;
static struct quirk_entry *quirks;

#define AMD_CPPC_MAX_PERF_MASK GENMASK(7, 0)
#define AMD_CPPC_MIN_PERF_MASK GENMASK(15, 8)
#define AMD_CPPC_DES_PERF_MASK GENMASK(23, 16)
#define AMD_CPPC_EPP_PERF_MASK GENMASK(31, 24)

/*
* AMD Energy Preference Performance (EPP)
* The EPP is used in the CCLK DPM controller to drive
Expand Down Expand Up @@ -439,12 +434,13 @@ static int msr_init_perf(struct amd_cpudata *cpudata)

perf.highest_perf = numerator;
perf.max_limit_perf = numerator;
perf.min_limit_perf = AMD_CPPC_LOWEST_PERF(cap1);
perf.nominal_perf = AMD_CPPC_NOMINAL_PERF(cap1);
perf.lowest_nonlinear_perf = AMD_CPPC_LOWNONLIN_PERF(cap1);
perf.lowest_perf = AMD_CPPC_LOWEST_PERF(cap1);
perf.min_limit_perf = FIELD_GET(AMD_CPPC_LOWEST_PERF_MASK, cap1);
perf.nominal_perf = FIELD_GET(AMD_CPPC_NOMINAL_PERF_MASK, cap1);
perf.lowest_nonlinear_perf = FIELD_GET(AMD_CPPC_LOWNONLIN_PERF_MASK, cap1);
perf.lowest_perf = FIELD_GET(AMD_CPPC_LOWEST_PERF_MASK, cap1);
WRITE_ONCE(cpudata->perf, perf);
WRITE_ONCE(cpudata->prefcore_ranking, AMD_CPPC_HIGHEST_PERF(cap1));
WRITE_ONCE(cpudata->prefcore_ranking, FIELD_GET(AMD_CPPC_HIGHEST_PERF_MASK, cap1));

return 0;
}

Expand Down

0 comments on commit b4cc466

Please sign in to comment.