diff options
Diffstat (limited to 'arch/x86/kernel/acpi/cppc.c')
| -rw-r--r-- | arch/x86/kernel/acpi/cppc.c | 172 |
1 files changed, 161 insertions, 11 deletions
diff --git a/arch/x86/kernel/acpi/cppc.c b/arch/x86/kernel/acpi/cppc.c index ff8f25faca3d..956984054bf3 100644 --- a/arch/x86/kernel/acpi/cppc.c +++ b/arch/x86/kernel/acpi/cppc.c @@ -9,6 +9,17 @@ #include <asm/processor.h> #include <asm/topology.h> +#define CPPC_HIGHEST_PERF_PERFORMANCE 196 +#define CPPC_HIGHEST_PERF_PREFCORE 166 + +enum amd_pref_core { + AMD_PREF_CORE_UNKNOWN = 0, + AMD_PREF_CORE_SUPPORTED, + AMD_PREF_CORE_UNSUPPORTED, +}; +static enum amd_pref_core amd_pref_core_detected; +static u64 boost_numerator; + /* Refer to drivers/acpi/cppc_acpi.c for the description of functions */ bool cpc_supported_by_cpu(void) @@ -69,31 +80,30 @@ int cpc_write_ffh(int cpunum, struct cpc_reg *reg, u64 val) static void amd_set_max_freq_ratio(void) { struct cppc_perf_caps perf_caps; - u64 highest_perf, nominal_perf; + u64 numerator, nominal_perf; u64 perf_ratio; int rc; rc = cppc_get_perf_caps(0, &perf_caps); if (rc) { - pr_debug("Could not retrieve perf counters (%d)\n", rc); + pr_warn("Could not retrieve perf counters (%d)\n", rc); return; } - highest_perf = amd_get_highest_perf(); + rc = amd_get_boost_ratio_numerator(0, &numerator); + if (rc) { + pr_warn("Could not retrieve highest performance (%d)\n", rc); + return; + } nominal_perf = perf_caps.nominal_perf; - if (!highest_perf || !nominal_perf) { - pr_debug("Could not retrieve highest or nominal performance\n"); + if (!nominal_perf) { + pr_warn("Could not retrieve nominal performance\n"); return; } - perf_ratio = div_u64(highest_perf * SCHED_CAPACITY_SCALE, nominal_perf); /* midpoint between max_boost and max_P */ - perf_ratio = (perf_ratio + SCHED_CAPACITY_SCALE) >> 1; - if (!perf_ratio) { - pr_debug("Non-zero highest/nominal perf values led to a 0 ratio\n"); - return; - } + perf_ratio = (div_u64(numerator * SCHED_CAPACITY_SCALE, nominal_perf) + SCHED_CAPACITY_SCALE) >> 1; freq_invariance_set_perf_ratio(perf_ratio, false); } @@ -116,3 +126,143 @@ void init_freq_invariance_cppc(void) init_done = true; mutex_unlock(&freq_invariance_lock); } + +/* + * Get the highest performance register value. + * @cpu: CPU from which to get highest performance. + * @highest_perf: Return address for highest performance value. + * + * Return: 0 for success, negative error code otherwise. + */ +int amd_get_highest_perf(unsigned int cpu, u32 *highest_perf) +{ + u64 val; + int ret; + + if (cpu_feature_enabled(X86_FEATURE_CPPC)) { + ret = rdmsrl_safe_on_cpu(cpu, MSR_AMD_CPPC_CAP1, &val); + if (ret) + goto out; + + val = AMD_CPPC_HIGHEST_PERF(val); + } else { + ret = cppc_get_highest_perf(cpu, &val); + if (ret) + goto out; + } + + WRITE_ONCE(*highest_perf, (u32)val); +out: + return ret; +} +EXPORT_SYMBOL_GPL(amd_get_highest_perf); + +/** + * amd_detect_prefcore: Detect if CPUs in the system support preferred cores + * @detected: Output variable for the result of the detection. + * + * Determine whether CPUs in the system support preferred cores. On systems + * that support preferred cores, different highest perf values will be found + * on different cores. On other systems, the highest perf value will be the + * same on all cores. + * + * The result of the detection will be stored in the 'detected' parameter. + * + * Return: 0 for success, negative error code otherwise + */ +int amd_detect_prefcore(bool *detected) +{ + int cpu, count = 0; + u64 highest_perf[2] = {0}; + + if (WARN_ON(!detected)) + return -EINVAL; + + switch (amd_pref_core_detected) { + case AMD_PREF_CORE_SUPPORTED: + *detected = true; + return 0; + case AMD_PREF_CORE_UNSUPPORTED: + *detected = false; + return 0; + default: + break; + } + + for_each_present_cpu(cpu) { + u32 tmp; + int ret; + + ret = amd_get_highest_perf(cpu, &tmp); + if (ret) + return ret; + + if (!count || (count == 1 && tmp != highest_perf[0])) + highest_perf[count++] = tmp; + + if (count == 2) + break; + } + + *detected = (count == 2); + boost_numerator = highest_perf[0]; + + amd_pref_core_detected = *detected ? AMD_PREF_CORE_SUPPORTED : + AMD_PREF_CORE_UNSUPPORTED; + + pr_debug("AMD CPPC preferred core is %ssupported (highest perf: 0x%llx)\n", + *detected ? "" : "un", highest_perf[0]); + + return 0; +} +EXPORT_SYMBOL_GPL(amd_detect_prefcore); + +/** + * amd_get_boost_ratio_numerator: Get the numerator to use for boost ratio calculation + * @cpu: CPU to get numerator for. + * @numerator: Output variable for numerator. + * + * Determine the numerator to use for calculating the boost ratio on + * a CPU. On systems that support preferred cores, this will be a hardcoded + * value. On other systems this will the highest performance register value. + * + * If booting the system with amd-pstate enabled but preferred cores disabled then + * the correct boost numerator will be returned to match hardware capabilities + * even if the preferred cores scheduling hints are not enabled. + * + * Return: 0 for success, negative error code otherwise. + */ +int amd_get_boost_ratio_numerator(unsigned int cpu, u64 *numerator) +{ + bool prefcore; + int ret; + + ret = amd_detect_prefcore(&prefcore); + if (ret) + return ret; + + /* without preferred cores, return the highest perf register value */ + if (!prefcore) { + *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; +} +EXPORT_SYMBOL_GPL(amd_get_boost_ratio_numerator); |