159 lines
5.2 KiB
Diff
159 lines
5.2 KiB
Diff
From acf3f432287638044e472501a1d5969abee15043 Mon Sep 17 00:00:00 2001
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From: Mario Limonciello <mario.limonciello@amd.com>
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Date: Thu, 5 Dec 2024 16:28:45 -0600
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Subject: cpufreq/amd-pstate: Check if CPPC request has changed before writing
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to the MSR or shared memory
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Move the common MSR field formatting code to msr_update_perf() from
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its callers.
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Ensure that the MSR write is necessary before flushing a write out.
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Also drop the comparison from the passive flow tracing.
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Signed-off-by: Mario Limonciello <mario.limonciello@amd.com>
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---
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drivers/cpufreq/amd-pstate-trace.h | 7 +----
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drivers/cpufreq/amd-pstate.c | 47 +++++++++++-------------------
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2 files changed, 18 insertions(+), 36 deletions(-)
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--- a/drivers/cpufreq/amd-pstate-trace.h
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+++ b/drivers/cpufreq/amd-pstate-trace.h
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@@ -32,7 +32,6 @@ TRACE_EVENT(amd_pstate_perf,
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u64 aperf,
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u64 tsc,
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unsigned int cpu_id,
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- bool changed,
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bool fast_switch
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),
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@@ -44,7 +43,6 @@ TRACE_EVENT(amd_pstate_perf,
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aperf,
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tsc,
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cpu_id,
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- changed,
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fast_switch
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),
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@@ -57,7 +55,6 @@ TRACE_EVENT(amd_pstate_perf,
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__field(unsigned long long, aperf)
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__field(unsigned long long, tsc)
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__field(unsigned int, cpu_id)
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- __field(bool, changed)
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__field(bool, fast_switch)
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),
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@@ -70,11 +67,10 @@ TRACE_EVENT(amd_pstate_perf,
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__entry->aperf = aperf;
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__entry->tsc = tsc;
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__entry->cpu_id = cpu_id;
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- __entry->changed = changed;
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__entry->fast_switch = fast_switch;
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),
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- TP_printk("amd_min_perf=%lu amd_des_perf=%lu amd_max_perf=%lu freq=%llu mperf=%llu aperf=%llu tsc=%llu cpu_id=%u changed=%s fast_switch=%s",
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+ TP_printk("amd_min_perf=%lu amd_des_perf=%lu amd_max_perf=%lu freq=%llu mperf=%llu aperf=%llu tsc=%llu cpu_id=%u fast_switch=%s",
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(unsigned long)__entry->min_perf,
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(unsigned long)__entry->target_perf,
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(unsigned long)__entry->capacity,
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@@ -83,7 +79,6 @@ TRACE_EVENT(amd_pstate_perf,
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(unsigned long long)__entry->aperf,
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(unsigned long long)__entry->tsc,
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(unsigned int)__entry->cpu_id,
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- (__entry->changed) ? "true" : "false",
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(__entry->fast_switch) ? "true" : "false"
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)
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);
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--- a/drivers/cpufreq/amd-pstate.c
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+++ b/drivers/cpufreq/amd-pstate.c
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@@ -254,15 +254,26 @@ static s16 shmem_get_epp(struct amd_cpud
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static int msr_update_perf(struct amd_cpudata *cpudata, u32 min_perf,
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u32 des_perf, u32 max_perf, u32 epp, bool fast_switch)
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{
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- u64 value;
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+ u64 value, prev;
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+
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+ value = prev = READ_ONCE(cpudata->cppc_req_cached);
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+
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+ value &= ~(AMD_PSTATE_MAX_PERF_MASK | AMD_PSTATE_MIN_PERF_MASK |
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+ AMD_PSTATE_DES_PERF_MASK | AMD_PSTATE_EPP_PERF_MASK);
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+ value |= FIELD_PREP(AMD_PSTATE_MAX_PERF_MASK, max_perf);
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+ value |= FIELD_PREP(AMD_PSTATE_DES_PERF_MASK, des_perf);
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+ value |= FIELD_PREP(AMD_PSTATE_MIN_PERF_MASK, min_perf);
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+ value |= FIELD_PREP(AMD_PSTATE_EPP_PERF_MASK, epp);
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+
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+ if (value == prev)
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+ return 0;
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- value = READ_ONCE(cpudata->cppc_req_cached);
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if (fast_switch) {
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- wrmsrl(MSR_AMD_CPPC_REQ, READ_ONCE(cpudata->cppc_req_cached));
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+ wrmsrl(MSR_AMD_CPPC_REQ, value);
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return 0;
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} else {
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- int ret = wrmsrl_on_cpu(cpudata->cpu, MSR_AMD_CPPC_REQ,
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- READ_ONCE(cpudata->cppc_req_cached));
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+ int ret = wrmsrl_on_cpu(cpudata->cpu, MSR_AMD_CPPC_REQ, value);
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+
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if (ret)
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return ret;
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}
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@@ -558,9 +569,7 @@ static void amd_pstate_update(struct amd
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{
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unsigned long max_freq;
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struct cpufreq_policy *policy = cpufreq_cpu_get(cpudata->cpu);
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- u64 prev = READ_ONCE(cpudata->cppc_req_cached);
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u32 nominal_perf = READ_ONCE(cpudata->nominal_perf);
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- u64 value = prev;
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des_perf = clamp_t(unsigned long, des_perf, min_perf, max_perf);
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@@ -576,27 +585,14 @@ static void amd_pstate_update(struct amd
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if (!cpudata->boost_supported)
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max_perf = min_t(unsigned long, nominal_perf, max_perf);
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- value &= ~(AMD_PSTATE_MAX_PERF_MASK | AMD_PSTATE_MIN_PERF_MASK |
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- AMD_PSTATE_DES_PERF_MASK);
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- value |= FIELD_PREP(AMD_PSTATE_MAX_PERF_MASK, max_perf);
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- value |= FIELD_PREP(AMD_PSTATE_DES_PERF_MASK, des_perf);
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- value |= FIELD_PREP(AMD_PSTATE_MIN_PERF_MASK, min_perf);
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-
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if (trace_amd_pstate_perf_enabled() && amd_pstate_sample(cpudata)) {
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trace_amd_pstate_perf(min_perf, des_perf, max_perf, cpudata->freq,
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cpudata->cur.mperf, cpudata->cur.aperf, cpudata->cur.tsc,
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- cpudata->cpu, (value != prev), fast_switch);
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+ cpudata->cpu, fast_switch);
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}
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- if (value == prev)
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- goto cpufreq_policy_put;
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-
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- WRITE_ONCE(cpudata->cppc_req_cached, value);
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-
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amd_pstate_update_perf(cpudata, min_perf, des_perf, max_perf, 0, fast_switch);
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-cpufreq_policy_put:
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-
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cpufreq_cpu_put(policy);
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}
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@@ -1592,19 +1588,10 @@ static void amd_pstate_epp_cpu_exit(stru
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static int amd_pstate_epp_update_limit(struct cpufreq_policy *policy)
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{
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struct amd_cpudata *cpudata = policy->driver_data;
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- u64 value;
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u32 epp;
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amd_pstate_update_min_max_limit(policy);
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- value = READ_ONCE(cpudata->cppc_req_cached);
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-
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- value &= ~(AMD_PSTATE_MAX_PERF_MASK | AMD_PSTATE_MIN_PERF_MASK |
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- AMD_PSTATE_DES_PERF_MASK | AMD_PSTATE_EPP_PERF_MASK);
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- value |= FIELD_PREP(AMD_PSTATE_MAX_PERF_MASK, cpudata->max_limit_perf);
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- value |= FIELD_PREP(AMD_PSTATE_DES_PERF_MASK, 0);
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- value |= FIELD_PREP(AMD_PSTATE_MIN_PERF_MASK, cpudata->min_limit_perf);
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-
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if (cpudata->policy == CPUFREQ_POLICY_PERFORMANCE)
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epp = 0;
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else
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