cpufreq: amd-pstate: Add trace for AMD P-State module

Add trace event to monitor the performance value changes which is
controlled by cpu governors.

Signed-off-by: Huang Rui <ray.huang@amd.com>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>

diff --git a/drivers/cpufreq/Makefile b/drivers/cpufreq/Makefile
index c8d307010922c6a042a541446d5055122acc3c0d..285de70af87749781b4c717f7247c4ce981b4899 100644 (file)
--- a/drivers/cpufreq/Makefile
+++ b/drivers/cpufreq/Makefile
@@ -17,6 +17,10 @@ obj-$(CONFIG_CPU_FREQ_GOV_ATTR_SET)  += cpufreq_governor_attr_set.o
 obj-$(CONFIG_CPUFREQ_DT)               += cpufreq-dt.o
 obj-$(CONFIG_CPUFREQ_DT_PLATDEV)       += cpufreq-dt-platdev.o
 
+# Traces
+CFLAGS_amd-pstate-trace.o               := -I$(src)
+amd_pstate-y                           := amd-pstate.o amd-pstate-trace.o
+
 ##################################################################################
 # x86 drivers.
 # Link order matters. K8 is preferred to ACPI because of firmware bugs in early
@@ -25,7 +29,7 @@ obj-$(CONFIG_CPUFREQ_DT_PLATDEV)      += cpufreq-dt-platdev.o
 # speedstep-* is preferred over p4-clockmod.
 
 obj-$(CONFIG_X86_ACPI_CPUFREQ)         += acpi-cpufreq.o
-obj-$(CONFIG_X86_AMD_PSTATE)           += amd-pstate.o
+obj-$(CONFIG_X86_AMD_PSTATE)           += amd_pstate.o
 obj-$(CONFIG_X86_POWERNOW_K8)          += powernow-k8.o
 obj-$(CONFIG_X86_PCC_CPUFREQ)          += pcc-cpufreq.o
 obj-$(CONFIG_X86_POWERNOW_K6)          += powernow-k6.o

diff --git a/drivers/cpufreq/amd-pstate-trace.c b/drivers/cpufreq/amd-pstate-trace.c
new file mode 100644 (file)
index 0000000..891b696
--- /dev/null
+++ b/drivers/cpufreq/amd-pstate-trace.c
@@ -0,0 +1,2 @@
+#define CREATE_TRACE_POINTS
+#include "amd-pstate-trace.h"

diff --git a/drivers/cpufreq/amd-pstate-trace.h b/drivers/cpufreq/amd-pstate-trace.h
new file mode 100644 (file)
index 0000000..6475059
--- /dev/null
+++ b/drivers/cpufreq/amd-pstate-trace.h
@@ -0,0 +1,77 @@
+/* SPDX-License-Identifier: GPL-2.0 */
+/*
+ * amd-pstate-trace.h - AMD Processor P-state Frequency Driver Tracer
+ *
+ * Copyright (C) 2021 Advanced Micro Devices, Inc. All Rights Reserved.
+ *
+ * Author: Huang Rui <ray.huang@amd.com>
+ */
+
+#if !defined(_AMD_PSTATE_TRACE_H) || defined(TRACE_HEADER_MULTI_READ)
+#define _AMD_PSTATE_TRACE_H
+
+#include <linux/cpufreq.h>
+#include <linux/tracepoint.h>
+#include <linux/trace_events.h>
+
+#undef TRACE_SYSTEM
+#define TRACE_SYSTEM amd_cpu
+
+#undef TRACE_INCLUDE_FILE
+#define TRACE_INCLUDE_FILE amd-pstate-trace
+
+#define TPS(x)  tracepoint_string(x)
+
+TRACE_EVENT(amd_pstate_perf,
+
+       TP_PROTO(unsigned long min_perf,
+                unsigned long target_perf,
+                unsigned long capacity,
+                unsigned int cpu_id,
+                bool changed,
+                bool fast_switch
+                ),
+
+       TP_ARGS(min_perf,
+               target_perf,
+               capacity,
+               cpu_id,
+               changed,
+               fast_switch
+               ),
+
+       TP_STRUCT__entry(
+               __field(unsigned long, min_perf)
+               __field(unsigned long, target_perf)
+               __field(unsigned long, capacity)
+               __field(unsigned int, cpu_id)
+               __field(bool, changed)
+               __field(bool, fast_switch)
+               ),
+
+       TP_fast_assign(
+               __entry->min_perf = min_perf;
+               __entry->target_perf = target_perf;
+               __entry->capacity = capacity;
+               __entry->cpu_id = cpu_id;
+               __entry->changed = changed;
+               __entry->fast_switch = fast_switch;
+               ),
+
+       TP_printk("amd_min_perf=%lu amd_des_perf=%lu amd_max_perf=%lu cpu_id=%u changed=%s fast_switch=%s",
+                 (unsigned long)__entry->min_perf,
+                 (unsigned long)__entry->target_perf,
+                 (unsigned long)__entry->capacity,
+                 (unsigned int)__entry->cpu_id,
+                 (__entry->changed) ? "true" : "false",
+                 (__entry->fast_switch) ? "true" : "false"
+                )
+);
+
+#endif /* _AMD_PSTATE_TRACE_H */
+
+/* This part must be outside protection */
+#undef TRACE_INCLUDE_PATH
+#define TRACE_INCLUDE_PATH .
+
+#include <trace/define_trace.h>

diff --git a/drivers/cpufreq/amd-pstate.c b/drivers/cpufreq/amd-pstate.c
index cc62f7484007c47784f0d1b390c9cfd443d2f453..63efd5de98a20d37bf827fb4be506d1a7755533b 100644 (file)
--- a/drivers/cpufreq/amd-pstate.c
+++ b/drivers/cpufreq/amd-pstate.c
@@ -44,6 +44,7 @@
 #include <asm/processor.h>
 #include <asm/cpufeature.h>
 #include <asm/cpu_device_id.h>
+#include "amd-pstate-trace.h"
 
 #define AMD_PSTATE_TRANSITION_LATENCY  0x20000
 #define AMD_PSTATE_TRANSITION_DELAY    500
@@ -220,6 +221,9 @@ static void amd_pstate_update(struct amd_cpudata *cpudata, u32 min_perf,
        value &= ~AMD_CPPC_MAX_PERF(~0L);
        value |= AMD_CPPC_MAX_PERF(max_perf);
 
+       trace_amd_pstate_perf(min_perf, des_perf, max_perf,
+                             cpudata->cpu, (value != prev), fast_switch);
+
        if (value == prev)
                return;