Add a GPU frequency tracepoint at the DRM subsystem level
The implementation includes:
- DRM-level tracepoint exposed at
/sys/kernel/debug/tracing/events/power/gpu_frequency/
- CONFIG_DRM_GPU_FREQUENCY_TRACE Kconfig option (default=n)
The tracepoint follows kernel tracing and provides kHz frequency
values with GPU identification for power analysis and
performance monitoring tools.
The tracepoint is only active when CONFIG_DRM_GPU_FREQUENCY_TRACE=y
and can be integrated by GPU drivers for frequency reporting.
Signed-off-by: S Sebinraj <s.sebin...@intel.com>
---
drivers/gpu/drm/Kconfig | 11 ++++++
drivers/gpu/drm/Makefile | 1 +
drivers/gpu/drm/drm_gpu_frequency_trace.c | 16 ++++++++
drivers/gpu/drm/drm_gpu_frequency_trace.h | 47 +++++++++++++++++++++++
4 files changed, 75 insertions(+)
create mode 100644 drivers/gpu/drm/drm_gpu_frequency_trace.c
create mode 100644 drivers/gpu/drm/drm_gpu_frequency_trace.h
diff --git a/drivers/gpu/drm/Kconfig b/drivers/gpu/drm/Kconfig
index f7ea8e895c0c..975cc7b2581d 100644
--- a/drivers/gpu/drm/Kconfig
+++ b/drivers/gpu/drm/Kconfig
@@ -53,6 +53,17 @@ config DRM_DRAW
bool
depends on DRM
+config DRM_GPU_FREQUENCY_TRACE
+ bool "Enable GPU frequency tracepoints"
+ depends on DRM && TRACEPOINTS
+ default n
+ help
+ Enable GPU frequency tracepoints in the power trace subsystem.
+ This provides kernel tracing support for GPU frequency changes
+ that will be exposed at
/sys/kernel/debug/tracing/events/power/gpu_frequency/.
+
+ If unsure, say N.
+
config DRM_PANIC
bool "Display a user-friendly message when a kernel panic occurs"
depends on DRM
diff --git a/drivers/gpu/drm/Makefile b/drivers/gpu/drm/Makefile
index 4dafbdc8f86a..12c81b6a750d 100644
--- a/drivers/gpu/drm/Makefile
+++ b/drivers/gpu/drm/Makefile
@@ -77,6 +77,7 @@ drm-$(CONFIG_DRM_CLIENT) += \
drm_client.o \
drm_client_event.o \
drm_client_modeset.o
+drm-$(CONFIG_DRM_GPU_FREQUENCY_TRACE) += drm_gpu_frequency_trace.o
drm-$(CONFIG_DRM_LIB_RANDOM) += lib/drm_random.o
drm-$(CONFIG_COMPAT) += drm_ioc32.o
drm-$(CONFIG_DRM_PANEL) += drm_panel.o
diff --git a/drivers/gpu/drm/drm_gpu_frequency_trace.c
b/drivers/gpu/drm/drm_gpu_frequency_trace.c
new file mode 100644
index 000000000000..b5fa5134226d
--- /dev/null
+++ b/drivers/gpu/drm/drm_gpu_frequency_trace.c
@@ -0,0 +1,16 @@
+// SPDX-License-Identifier: GPL-2.0
+/*
+ * GPU frequency trace points for DRM subsystem
+ *
+ * This provides GPU frequency tracing support that will be exposed at:
+ * /sys/kernel/debug/tracing/events/power/gpu_frequency/
+ */
+
+#ifdef CONFIG_DRM_GPU_FREQUENCY_TRACE
+
+#define CREATE_TRACE_POINTS
+#include "drm_gpu_frequency_trace.h"
+
+EXPORT_TRACEPOINT_SYMBOL_GPL(gpu_frequency);
+
+#endif /* CONFIG_DRM_GPU_FREQUENCY_TRACE */
diff --git a/drivers/gpu/drm/drm_gpu_frequency_trace.h
b/drivers/gpu/drm/drm_gpu_frequency_trace.h
new file mode 100644
index 000000000000..cf6337847b3a
--- /dev/null
+++ b/drivers/gpu/drm/drm_gpu_frequency_trace.h
@@ -0,0 +1,47 @@
+/* SPDX-License-Identifier: GPL-2.0 */
+#if !defined(_GPU_FREQUENCY_TRACE_H) || defined(TRACE_HEADER_MULTI_READ)
+#define _GPU_FREQUENCY_TRACE_H
+
+#include <linux/tracepoint.h>
+
+#ifdef CONFIG_DRM_GPU_FREQUENCY_TRACE
+
+#undef TRACE_SYSTEM
+#define TRACE_SYSTEM power
+#define TRACE_INCLUDE_FILE drm_gpu_frequency_trace
+
+/*
+ * Tracepoint for GPU frequency changes
+ * This tracepoint is exposed at
/sys/kernel/debug/tracing/events/power/gpu_frequency
+ *
+ * location: /sys/kernel/debug/tracing/events/power/gpu_frequency
+ * format: {unsigned int state, unsigned int gpu_id}
+ * where state holds the frequency(in KHz) and the gpu_id holds the GPU clock
domain.
+ */
+TRACE_EVENT(gpu_frequency,
+ TP_PROTO(unsigned int state, unsigned int gpu_id),
+ TP_ARGS(state, gpu_id),
+ TP_STRUCT__entry(
+ __field(unsigned int, state)
+ __field(unsigned int, gpu_id)
+ ),
+ TP_fast_assign(
+ __entry->state = state;
+ __entry->gpu_id = gpu_id;
+ ),
+ TP_printk("state=%u gpu_id=%u", __entry->state, __entry->gpu_id)
+);
+
+#else /* !CONFIG_DRM_GPU_FREQUENCY_TRACE */
+
+static inline void trace_gpu_frequency(unsigned int state, unsigned int
gpu_id) { }
+
+#endif /* CONFIG_DRM_GPU_FREQUENCY_TRACE */
+
+#endif /* _GPU_FREQUENCY_TRACE_H */
+
+#ifdef CONFIG_DRM_GPU_FREQUENCY_TRACE
+#undef TRACE_INCLUDE_PATH
+#define TRACE_INCLUDE_PATH ../../drivers/gpu/drm
+#include <trace/define_trace.h>
+#endif
--
2.34.1
