From afc9506c2a8169e871cfafd9b94e0e631ae8f9cb Mon Sep 17 00:00:00 2001 From: Dhananjay Ugwekar Date: Tue, 15 Apr 2025 08:23:09 +0000 Subject: [PATCH 1/4] cpufreq/amd-pstate: Move max_perf limiting in amd_pstate_update Move up the max_perf limiting, so that we clamp the des_perf with the updated max_perf. Signed-off-by: Dhananjay Ugwekar Link: https://lore.kernel.org/r/20250415082308.3341-1-dhananjay.ugwekar@amd.com Signed-off-by: Mario Limonciello --- drivers/cpufreq/amd-pstate.c | 8 ++++---- 1 file changed, 4 insertions(+), 4 deletions(-) diff --git a/drivers/cpufreq/amd-pstate.c b/drivers/cpufreq/amd-pstate.c index b961f3a3b580..12b2736bf62a 100644 --- a/drivers/cpufreq/amd-pstate.c +++ b/drivers/cpufreq/amd-pstate.c @@ -554,6 +554,10 @@ static void amd_pstate_update(struct amd_cpudata *cpudata, u8 min_perf, if (!policy) return; + /* limit the max perf when core performance boost feature is disabled */ + if (!cpudata->boost_supported) + max_perf = min_t(u8, perf.nominal_perf, max_perf); + des_perf = clamp_t(u8, des_perf, min_perf, max_perf); policy->cur = perf_to_freq(perf, cpudata->nominal_freq, des_perf); @@ -563,10 +567,6 @@ static void amd_pstate_update(struct amd_cpudata *cpudata, u8 min_perf, des_perf = 0; } - /* limit the max perf when core performance boost feature is disabled */ - if (!cpudata->boost_supported) - max_perf = min_t(u8, perf.nominal_perf, max_perf); - if (trace_amd_pstate_perf_enabled() && amd_pstate_sample(cpudata)) { trace_amd_pstate_perf(min_perf, des_perf, max_perf, cpudata->freq, cpudata->cur.mperf, cpudata->cur.aperf, cpudata->cur.tsc, From 98b52c6b0b528764b454350a11c53f757304afbc Mon Sep 17 00:00:00 2001 From: Dhananjay Ugwekar Date: Mon, 28 Apr 2025 06:25:21 +0000 Subject: [PATCH 2/4] cpufreq/amd-pstate: Add offline, online and suspend callbacks for amd_pstate_driver Rename and use the existing amd_pstate_epp callbacks for amd_pstate driver as well. Remove the debug print in online callback while at it. These callbacks will be needed to support the "Requested CPU Min Frequency" BIOS option. Reviewed-by: Mario Limonciello Signed-off-by: Dhananjay Ugwekar Link: https://lore.kernel.org/r/20250428062520.4997-2-dhananjay.ugwekar@amd.com Signed-off-by: Mario Limonciello --- drivers/cpufreq/amd-pstate.c | 17 +++++++++-------- 1 file changed, 9 insertions(+), 8 deletions(-) diff --git a/drivers/cpufreq/amd-pstate.c b/drivers/cpufreq/amd-pstate.c index 12b2736bf62a..9a80040e3acf 100644 --- a/drivers/cpufreq/amd-pstate.c +++ b/drivers/cpufreq/amd-pstate.c @@ -1559,19 +1559,17 @@ static int amd_pstate_epp_set_policy(struct cpufreq_policy *policy) return 0; } -static int amd_pstate_epp_cpu_online(struct cpufreq_policy *policy) +static int amd_pstate_cpu_online(struct cpufreq_policy *policy) { - pr_debug("AMD CPU Core %d going online\n", policy->cpu); - return amd_pstate_cppc_enable(policy); } -static int amd_pstate_epp_cpu_offline(struct cpufreq_policy *policy) +static int amd_pstate_cpu_offline(struct cpufreq_policy *policy) { return 0; } -static int amd_pstate_epp_suspend(struct cpufreq_policy *policy) +static int amd_pstate_suspend(struct cpufreq_policy *policy) { struct amd_cpudata *cpudata = policy->driver_data; @@ -1609,6 +1607,9 @@ static struct cpufreq_driver amd_pstate_driver = { .fast_switch = amd_pstate_fast_switch, .init = amd_pstate_cpu_init, .exit = amd_pstate_cpu_exit, + .online = amd_pstate_cpu_online, + .offline = amd_pstate_cpu_offline, + .suspend = amd_pstate_suspend, .set_boost = amd_pstate_set_boost, .update_limits = amd_pstate_update_limits, .name = "amd-pstate", @@ -1621,9 +1622,9 @@ static struct cpufreq_driver amd_pstate_epp_driver = { .setpolicy = amd_pstate_epp_set_policy, .init = amd_pstate_epp_cpu_init, .exit = amd_pstate_epp_cpu_exit, - .offline = amd_pstate_epp_cpu_offline, - .online = amd_pstate_epp_cpu_online, - .suspend = amd_pstate_epp_suspend, + .offline = amd_pstate_cpu_offline, + .online = amd_pstate_cpu_online, + .suspend = amd_pstate_suspend, .resume = amd_pstate_epp_resume, .update_limits = amd_pstate_update_limits, .set_boost = amd_pstate_set_boost, From 608a76b65288698677843d2f22418e03391ef95f Mon Sep 17 00:00:00 2001 From: Dhananjay Ugwekar Date: Mon, 28 Apr 2025 07:16:24 +0000 Subject: [PATCH 3/4] cpufreq/amd-pstate: Add support for the "Requested CPU Min frequency" BIOS option Initialize lower frequency limit to the "Requested CPU Min frequency" BIOS option (if it is set) value as part of the driver->init() callback. The BIOS specified value is passed by the PMFW as min_perf in CPPC_REQ MSR. To ensure that we don't mistake a stale min_perf value in CPPC_REQ value as the "Requested CPU Min frequency" during a kexec wakeup, reset the CPPC_REQ.min_perf value back to the BIOS specified one in the offline, exit and suspend callbacks. amd_pstate_target() and amd_pstate_epp_update_limit() which are invoked as part of the resume() and online() callbacks will take care of restoring the CPPC_REQ back to the correct values. Signed-off-by: Dhananjay Ugwekar Reviewed-by: Mario Limonciello Link: https://lore.kernel.org/r/20250428071623.4309-1-dhananjay.ugwekar@amd.com Signed-off-by: Mario Limonciello --- drivers/cpufreq/amd-pstate.c | 82 ++++++++++++++++++++++++++++++------ drivers/cpufreq/amd-pstate.h | 2 + 2 files changed, 71 insertions(+), 13 deletions(-) diff --git a/drivers/cpufreq/amd-pstate.c b/drivers/cpufreq/amd-pstate.c index 9a80040e3acf..fa4eb5a0a443 100644 --- a/drivers/cpufreq/amd-pstate.c +++ b/drivers/cpufreq/amd-pstate.c @@ -389,7 +389,8 @@ static inline int amd_pstate_cppc_enable(struct cpufreq_policy *policy) static int msr_init_perf(struct amd_cpudata *cpudata) { union perf_cached perf = READ_ONCE(cpudata->perf); - u64 cap1, numerator; + u64 cap1, numerator, cppc_req; + u8 min_perf; int ret = rdmsrl_safe_on_cpu(cpudata->cpu, MSR_AMD_CPPC_CAP1, &cap1); @@ -400,6 +401,22 @@ static int msr_init_perf(struct amd_cpudata *cpudata) if (ret) return ret; + ret = rdmsrl_on_cpu(cpudata->cpu, MSR_AMD_CPPC_REQ, &cppc_req); + if (ret) + return ret; + + WRITE_ONCE(cpudata->cppc_req_cached, cppc_req); + min_perf = FIELD_GET(AMD_CPPC_MIN_PERF_MASK, cppc_req); + + /* + * Clear out the min_perf part to check if the rest of the MSR is 0, if yes, this is an + * indication that the min_perf value is the one specified through the BIOS option + */ + cppc_req &= ~(AMD_CPPC_MIN_PERF_MASK); + + if (!cppc_req) + perf.bios_min_perf = min_perf; + perf.highest_perf = numerator; perf.max_limit_perf = numerator; perf.min_limit_perf = FIELD_GET(AMD_CPPC_LOWEST_PERF_MASK, cap1); @@ -580,20 +597,26 @@ static int amd_pstate_verify(struct cpufreq_policy_data *policy_data) { /* * Initialize lower frequency limit (i.e.policy->min) with - * lowest_nonlinear_frequency which is the most energy efficient - * frequency. Override the initial value set by cpufreq core and - * amd-pstate qos_requests. + * lowest_nonlinear_frequency or the min frequency (if) specified in BIOS, + * Override the initial value set by cpufreq core and amd-pstate qos_requests. */ if (policy_data->min == FREQ_QOS_MIN_DEFAULT_VALUE) { struct cpufreq_policy *policy __free(put_cpufreq_policy) = cpufreq_cpu_get(policy_data->cpu); struct amd_cpudata *cpudata; + union perf_cached perf; if (!policy) return -EINVAL; cpudata = policy->driver_data; - policy_data->min = cpudata->lowest_nonlinear_freq; + perf = READ_ONCE(cpudata->perf); + + if (perf.bios_min_perf) + policy_data->min = perf_to_freq(perf, cpudata->nominal_freq, + perf.bios_min_perf); + else + policy_data->min = cpudata->lowest_nonlinear_freq; } cpufreq_verify_within_cpu_limits(policy_data); @@ -1024,6 +1047,10 @@ static int amd_pstate_cpu_init(struct cpufreq_policy *policy) static void amd_pstate_cpu_exit(struct cpufreq_policy *policy) { struct amd_cpudata *cpudata = policy->driver_data; + union perf_cached perf = READ_ONCE(cpudata->perf); + + /* Reset CPPC_REQ MSR to the BIOS value */ + amd_pstate_update_perf(policy, perf.bios_min_perf, 0U, 0U, 0U, false); freq_qos_remove_request(&cpudata->req[1]); freq_qos_remove_request(&cpudata->req[0]); @@ -1419,7 +1446,6 @@ static int amd_pstate_epp_cpu_init(struct cpufreq_policy *policy) struct amd_cpudata *cpudata; union perf_cached perf; struct device *dev; - u64 value; int ret; /* @@ -1484,12 +1510,6 @@ static int amd_pstate_epp_cpu_init(struct cpufreq_policy *policy) cpudata->epp_default = AMD_CPPC_EPP_BALANCE_PERFORMANCE; } - if (cpu_feature_enabled(X86_FEATURE_CPPC)) { - ret = rdmsrl_on_cpu(cpudata->cpu, MSR_AMD_CPPC_REQ, &value); - if (ret) - return ret; - WRITE_ONCE(cpudata->cppc_req_cached, value); - } ret = amd_pstate_set_epp(policy, cpudata->epp_default); if (ret) return ret; @@ -1509,6 +1529,11 @@ static void amd_pstate_epp_cpu_exit(struct cpufreq_policy *policy) struct amd_cpudata *cpudata = policy->driver_data; if (cpudata) { + union perf_cached perf = READ_ONCE(cpudata->perf); + + /* Reset CPPC_REQ MSR to the BIOS value */ + amd_pstate_update_perf(policy, perf.bios_min_perf, 0U, 0U, 0U, false); + kfree(cpudata); policy->driver_data = NULL; } @@ -1566,12 +1591,31 @@ static int amd_pstate_cpu_online(struct cpufreq_policy *policy) static int amd_pstate_cpu_offline(struct cpufreq_policy *policy) { - return 0; + struct amd_cpudata *cpudata = policy->driver_data; + union perf_cached perf = READ_ONCE(cpudata->perf); + + /* + * Reset CPPC_REQ MSR to the BIOS value, this will allow us to retain the BIOS specified + * min_perf value across kexec reboots. If this CPU is just onlined normally after this, the + * limits, epp and desired perf will get reset to the cached values in cpudata struct + */ + return amd_pstate_update_perf(policy, perf.bios_min_perf, 0U, 0U, 0U, false); } static int amd_pstate_suspend(struct cpufreq_policy *policy) { struct amd_cpudata *cpudata = policy->driver_data; + union perf_cached perf = READ_ONCE(cpudata->perf); + int ret; + + /* + * Reset CPPC_REQ MSR to the BIOS value, this will allow us to retain the BIOS specified + * min_perf value across kexec reboots. If this CPU is just resumed back without kexec, + * the limits, epp and desired perf will get reset to the cached values in cpudata struct + */ + ret = amd_pstate_update_perf(policy, perf.bios_min_perf, 0U, 0U, 0U, false); + if (ret) + return ret; /* invalidate to ensure it's rewritten during resume */ cpudata->cppc_req_cached = 0; @@ -1582,6 +1626,17 @@ static int amd_pstate_suspend(struct cpufreq_policy *policy) return 0; } +static int amd_pstate_resume(struct cpufreq_policy *policy) +{ + struct amd_cpudata *cpudata = policy->driver_data; + union perf_cached perf = READ_ONCE(cpudata->perf); + int cur_perf = freq_to_perf(perf, cpudata->nominal_freq, policy->cur); + + /* Set CPPC_REQ to last sane value until the governor updates it */ + return amd_pstate_update_perf(policy, perf.min_limit_perf, cur_perf, perf.max_limit_perf, + 0U, false); +} + static int amd_pstate_epp_resume(struct cpufreq_policy *policy) { struct amd_cpudata *cpudata = policy->driver_data; @@ -1610,6 +1665,7 @@ static struct cpufreq_driver amd_pstate_driver = { .online = amd_pstate_cpu_online, .offline = amd_pstate_cpu_offline, .suspend = amd_pstate_suspend, + .resume = amd_pstate_resume, .set_boost = amd_pstate_set_boost, .update_limits = amd_pstate_update_limits, .name = "amd-pstate", diff --git a/drivers/cpufreq/amd-pstate.h b/drivers/cpufreq/amd-pstate.h index fbe1c08d3f06..2f7ae364d331 100644 --- a/drivers/cpufreq/amd-pstate.h +++ b/drivers/cpufreq/amd-pstate.h @@ -30,6 +30,7 @@ * @lowest_perf: the absolute lowest performance level of the processor * @min_limit_perf: Cached value of the performance corresponding to policy->min * @max_limit_perf: Cached value of the performance corresponding to policy->max + * @bios_min_perf: Cached perf value corresponding to the "Requested CPU Min Frequency" BIOS option */ union perf_cached { struct { @@ -39,6 +40,7 @@ union perf_cached { u8 lowest_perf; u8 min_limit_perf; u8 max_limit_perf; + u8 bios_min_perf; }; u64 val; }; From d26d16438bc5fd5524121244cc133f9872a63210 Mon Sep 17 00:00:00 2001 From: Swapnil Sapkal Date: Wed, 30 Apr 2025 06:42:06 +0000 Subject: [PATCH 4/4] amd-pstate-ut: Reset amd-pstate driver mode after running selftests In amd-pstate-ut, one of the basic test is to switch between all possible mode combinations. After running this test the mode of the amd-pstate driver is active mode. Store and reset the mode to its original state. Reviewed-by: Gautham R. Shenoy Signed-off-by: Swapnil Sapkal Reviewed-by: Mario Limonciello Link: https://lore.kernel.org/r/20250430064206.7402-1-swapnil.sapkal@amd.com Signed-off-by: Mario Limonciello --- drivers/cpufreq/amd-pstate-ut.c | 19 ++++++++++++------- drivers/cpufreq/amd-pstate.c | 6 ++++++ drivers/cpufreq/amd-pstate.h | 1 + 3 files changed, 19 insertions(+), 7 deletions(-) diff --git a/drivers/cpufreq/amd-pstate-ut.c b/drivers/cpufreq/amd-pstate-ut.c index e671bc7d1550..30835d0e4994 100644 --- a/drivers/cpufreq/amd-pstate-ut.c +++ b/drivers/cpufreq/amd-pstate-ut.c @@ -242,6 +242,8 @@ static int amd_pstate_set_mode(enum amd_pstate_mode mode) static int amd_pstate_ut_check_driver(u32 index) { enum amd_pstate_mode mode1, mode2 = AMD_PSTATE_DISABLE; + enum amd_pstate_mode orig_mode = amd_pstate_get_status(); + int ret; for (mode1 = AMD_PSTATE_DISABLE; mode1 < AMD_PSTATE_MAX; mode1++) { int ret = amd_pstate_set_mode(mode1); @@ -251,16 +253,19 @@ static int amd_pstate_ut_check_driver(u32 index) if (mode1 == mode2) continue; ret = amd_pstate_set_mode(mode2); - if (ret) { - pr_err("%s: failed to update status for %s->%s\n", __func__, - amd_pstate_get_mode_string(mode1), - amd_pstate_get_mode_string(mode2)); - return ret; - } + if (ret) + goto out; } } - return 0; +out: + if (ret) + pr_warn("%s: failed to update status for %s->%s: %d\n", __func__, + amd_pstate_get_mode_string(mode1), + amd_pstate_get_mode_string(mode2), ret); + + amd_pstate_set_mode(orig_mode); + return ret; } static int __init amd_pstate_ut_init(void) diff --git a/drivers/cpufreq/amd-pstate.c b/drivers/cpufreq/amd-pstate.c index fa4eb5a0a443..dee9d84e9f99 100644 --- a/drivers/cpufreq/amd-pstate.c +++ b/drivers/cpufreq/amd-pstate.c @@ -1332,6 +1332,12 @@ static ssize_t amd_pstate_show_status(char *buf) return sysfs_emit(buf, "%s\n", amd_pstate_mode_string[cppc_state]); } +int amd_pstate_get_status(void) +{ + return cppc_state; +} +EXPORT_SYMBOL_GPL(amd_pstate_get_status); + int amd_pstate_update_status(const char *buf, size_t size) { int mode_idx; diff --git a/drivers/cpufreq/amd-pstate.h b/drivers/cpufreq/amd-pstate.h index 2f7ae364d331..cb45fdca27a6 100644 --- a/drivers/cpufreq/amd-pstate.h +++ b/drivers/cpufreq/amd-pstate.h @@ -121,6 +121,7 @@ enum amd_pstate_mode { AMD_PSTATE_MAX, }; const char *amd_pstate_get_mode_string(enum amd_pstate_mode mode); +int amd_pstate_get_status(void); int amd_pstate_update_status(const char *buf, size_t size); #endif /* _LINUX_AMD_PSTATE_H */