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git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git
kernel
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linux
amd-pstate: Introduce a tracepoint trace_amd_pstate_cppc_req2()
Introduce a new tracepoint trace_amd_pstate_cppc_req2() to track
updates to MSR_AMD_CPPC_REQ2.
Invoke this while changing the Floor Perf.
Reviewed-by: Mario Limonciello <mario.limonciello@amd.com>
Signed-off-by: Gautham R. Shenoy <gautham.shenoy@amd.com>
Signed-off-by: Mario Limonciello (AMD) <superm1@kernel.org>
authored by
Gautham R. Shenoy
and committed by
Mario Limonciello (AMD)
30c63f72
b9f103d0
+46
-3
+35
drivers/cpufreq/amd-pstate-trace.h
+35
drivers/cpufreq/amd-pstate-trace.h
···
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)
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);
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TRACE_EVENT(amd_pstate_cppc_req2,
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+
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TP_PROTO(unsigned int cpu_id,
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u8 floor_perf,
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bool changed,
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int err_code
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),
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+
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TP_ARGS(cpu_id,
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floor_perf,
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changed,
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err_code),
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+
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TP_STRUCT__entry(
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__field(unsigned int, cpu_id)
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__field(u8, floor_perf)
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__field(bool, changed)
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__field(int, err_code)
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),
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+
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TP_fast_assign(
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__entry->cpu_id = cpu_id;
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__entry->floor_perf = floor_perf;
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__entry->changed = changed;
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__entry->err_code = err_code;
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),
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+
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TP_printk("cpu%u: floor_perf=%u, changed=%u (error = %d)",
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__entry->cpu_id,
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__entry->floor_perf,
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__entry->changed,
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__entry->err_code
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)
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);
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#endif /* _AMD_PSTATE_TRACE_H */
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/* This part must be outside protection */
+11
-3
drivers/cpufreq/amd-pstate.c
+11
-3
drivers/cpufreq/amd-pstate.c
···
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{
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struct amd_cpudata *cpudata = policy->driver_data;
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u64 value, prev;
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bool changed;
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int ret;
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if (!cpu_feature_enabled(X86_FEATURE_CPPC_PERF_PRIO))
···
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value = prev = READ_ONCE(cpudata->cppc_req2_cached);
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FIELD_MODIFY(AMD_CPPC_FLOOR_PERF_MASK, &value, perf);
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-
if (value == prev)
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return 0;
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changed = value != prev;
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if (!changed) {
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ret = 0;
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goto out_trace;
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}
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ret = wrmsrq_on_cpu(cpudata->cpu, MSR_AMD_CPPC_REQ2, value);
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if (ret) {
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changed = false;
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pr_err("failed to set CPPC REQ2 value. Error (%d)\n", ret);
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-
return ret;
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goto out_trace;
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}
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WRITE_ONCE(cpudata->cppc_req2_cached, value);
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out_trace:
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if (trace_amd_pstate_cppc_req2_enabled())
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trace_amd_pstate_cppc_req2(cpudata->cpu, perf, changed, ret);
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return ret;
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}
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