drm/amd/display: Add tracing to dc

[Why]
Tracing is a useful and cheap debug functionality

[How]
This creates a new trace system amdgpu_dm, currently with
three trace events

amdgpu_dc_rreg and amdgpu_dc_wreg report the address and value
of any dc register reads and writes

amdgpu_dc_performance requires at least one of those two to be
enabled.  It counts the register reads and writes since the
last entry

v2: Don't check for NULL before kfree
Signed-off-by: David Francis <David.Francis@amd.com>
Reviewed-by: Harry Wentland <Harry.Wentland@amd.com>
Acked-by: Leo Li <sunpeng.li@amd.com>
Signed-off-by: Alex Deucher <alexander.deucher@amd.com>

drivers/gpu/drm/amd/display/amdgpu_dm/amdgpu_dm.c

@@ -23,6 +23,9 @@
  *
  */
 
+/* The caprices of the preprocessor require that this be declared right here */
+#define CREATE_TRACE_POINTS
+
 #include "dm_services_types.h"
 #include "dc.h"
 #include "dc/inc/core_types.h"

drivers/gpu/drm/amd/display/amdgpu_dm/amdgpu_dm_trace.h

+/*
+ * Copyright 2018 Advanced Micro Devices, Inc.
+ *
+ * Permission is hereby granted, free of charge, to any person obtaining a
+ * copy of this software and associated documentation files (the "Software"),
+ * to deal in the Software without restriction, including without limitation
+ * the rights to use, copy, modify, merge, publish, distribute, sublicense,
+ * and/or sell copies of the Software, and to permit persons to whom the
+ * Software is furnished to do so, subject to the following conditions:
+ *
+ * The above copyright notice and this permission notice shall be included in
+ * all copies or substantial portions of the Software.
+ *
+ * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+ * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+ * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT.  IN NO EVENT SHALL
+ * THE COPYRIGHT HOLDER(S) OR AUTHOR(S) BE LIABLE FOR ANY CLAIM, DAMAGES OR
+ * OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE,
+ * ARISING FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR
+ * OTHER DEALINGS IN THE SOFTWARE.
+ *
+ * Authors: AMD
+ *
+ */
+
+#undef TRACE_SYSTEM
+#define TRACE_SYSTEM amdgpu_dm
+
+#if !defined(_AMDGPU_DM_TRACE_H) || defined(TRACE_HEADER_MULTI_READ)
+#define _AMDGPU_DM_TRACE_H_
+
+#include <linux/tracepoint.h>
+
+TRACE_EVENT(amdgpu_dc_rreg,
+	TP_PROTO(unsigned long *read_count, uint32_t reg, uint32_t value),
+	TP_ARGS(read_count, reg, value),
+	TP_STRUCT__entry(
+			__field(uint32_t, reg)
+			__field(uint32_t, value)
+		),
+	TP_fast_assign(
+			__entry->reg = reg;
+			__entry->value = value;
+			*read_count = *read_count + 1;
+		),
+	TP_printk("reg=0x%08lx, value=0x%08lx",
+			(unsigned long)__entry->reg,
+			(unsigned long)__entry->value)
+);
+
+TRACE_EVENT(amdgpu_dc_wreg,
+	TP_PROTO(unsigned long *write_count, uint32_t reg, uint32_t value),
+	TP_ARGS(write_count, reg, value),
+	TP_STRUCT__entry(
+			__field(uint32_t, reg)
+			__field(uint32_t, value)
+		),
+	TP_fast_assign(
+			__entry->reg = reg;
+			__entry->value = value;
+			*write_count = *write_count + 1;
+		),
+	TP_printk("reg=0x%08lx, value=0x%08lx",
+			(unsigned long)__entry->reg,
+			(unsigned long)__entry->value)
+);
+
+
+TRACE_EVENT(amdgpu_dc_performance,
+	TP_PROTO(unsigned long read_count, unsigned long write_count,
+		unsigned long *last_read, unsigned long *last_write,
+		const char *func, unsigned int line),
+	TP_ARGS(read_count, write_count, last_read, last_write, func, line),
+	TP_STRUCT__entry(
+			__field(uint32_t, reads)
+			__field(uint32_t, writes)
+			__field(uint32_t, read_delta)
+			__field(uint32_t, write_delta)
+			__string(func, func)
+			__field(uint32_t, line)
+			),
+	TP_fast_assign(
+			__entry->reads = read_count;
+			__entry->writes = write_count;
+			__entry->read_delta = read_count - *last_read;
+			__entry->write_delta = write_count - *last_write;
+			__assign_str(func, func);
+			__entry->line = line;
+			*last_read = read_count;
+			*last_write = write_count;
+			),
+	TP_printk("%s:%d reads=%08ld (%08ld total), writes=%08ld (%08ld total)",
+			__get_str(func), __entry->line,
+			(unsigned long)__entry->read_delta,
+			(unsigned long)__entry->reads,
+			(unsigned long)__entry->write_delta,
+			(unsigned long)__entry->writes)
+);
+#endif /* _AMDGPU_DM_TRACE_H_ */
+
+#undef TRACE_INCLUDE_PATH
+#define TRACE_INCLUDE_PATH .
+#define TRACE_INCLUDE_FILE amdgpu_dm_trace
+#include <trace/define_trace.h>

drivers/gpu/drm/amd/display/dc/core/dc.c

@@ -224,6 +224,17 @@ static bool create_links(
 	return false;
 }
 
+static struct dc_perf_trace *dc_perf_trace_create(void)
+{
+	return kzalloc(sizeof(struct dc_perf_trace), GFP_KERNEL);
+}
+
+static void dc_perf_trace_destroy(struct dc_perf_trace **perf_trace)
+{
+	kfree(*perf_trace);
+	*perf_trace = NULL;
+}
+
 /**
  *****************************************************************************
  *  Function: dc_stream_adjust_vmin_vmax
@@ -585,6 +596,8 @@ static void destruct(struct dc *dc)
 	if (dc->ctx->created_bios)
 		dal_bios_parser_destroy(&dc->ctx->dc_bios);
 
+	dc_perf_trace_destroy(&dc->ctx->perf_trace);
+
 	kfree(dc->ctx);
 	dc->ctx = NULL;
 
@@ -708,6 +721,12 @@ static bool construct(struct dc *dc,
 		goto fail;
 	}
 
+	dc_ctx->perf_trace = dc_perf_trace_create();
+	if (!dc_ctx->perf_trace) {
+		ASSERT_CRITICAL(false);
+		goto fail;
+	}
+
 	/* Create GPIO service */
 	dc_ctx->gpio_service = dal_gpio_service_create(
 			dc_version,

drivers/gpu/drm/amd/display/dc/dc_types.h

@@ -73,10 +73,18 @@ struct hw_asic_id {
 	void *atombios_base_address;
 };
 
+struct dc_perf_trace {
+	unsigned long read_count;
+	unsigned long write_count;
+	unsigned long last_entry_read;
+	unsigned long last_entry_write;
+};
+
 struct dc_context {
 	struct dc *dc;
 
 	void *driver_context; /* e.g. amdgpu_device */
+	struct dc_perf_trace *perf_trace;
 	void *cgs_device;
 
 	enum dce_environment dce_environment;

drivers/gpu/drm/amd/display/dc/dcn10/dcn10_cm_common.c

@@ -324,7 +324,7 @@ bool cm_helper_translate_curve_to_hw_format(
 	if (output_tf == NULL || lut_params == NULL || output_tf->type == TF_TYPE_BYPASS)
 		return false;
 
-	PERF_TRACE();
+	PERF_TRACE_CTX(output_tf->ctx);
 
 	corner_points = lut_params->corner_points;
 	rgb_resulted = lut_params->rgb_resulted;
@@ -513,7 +513,7 @@ bool cm_helper_translate_curve_to_degamma_hw_format(
 	if (output_tf == NULL || lut_params == NULL || output_tf->type == TF_TYPE_BYPASS)
 		return false;
 
-	PERF_TRACE();
+	PERF_TRACE_CTX(output_tf->ctx);
 
 	corner_points = lut_params->corner_points;
 	rgb_resulted = lut_params->rgb_resulted;

drivers/gpu/drm/amd/display/dc/dm_services.h

@@ -31,6 +31,8 @@
 
 #define __DM_SERVICES_H__
 
+#include "amdgpu_dm_trace.h"
+
 /* TODO: remove when DC is complete. */
 #include "dm_services_types.h"
 #include "logger_interface.h"
@@ -70,6 +72,7 @@ static inline uint32_t dm_read_reg_func(
 	}
 #endif
 	value = cgs_read_register(ctx->cgs_device, address);
+	trace_amdgpu_dc_rreg(&ctx->perf_trace->read_count, address, value);
 
 	return value;
 }
@@ -90,6 +93,7 @@ static inline void dm_write_reg_func(
 	}
 #endif
 	cgs_write_register(ctx->cgs_device, address, value);
+	trace_amdgpu_dc_wreg(&ctx->perf_trace->write_count, address, value);
 }
 
 static inline uint32_t dm_read_index_reg(
@@ -351,8 +355,12 @@ unsigned long long dm_get_elapse_time_in_ns(struct dc_context *ctx,
 /*
  * performance tracing
  */
-void dm_perf_trace_timestamp(const char *func_name, unsigned int line);
-#define PERF_TRACE()	dm_perf_trace_timestamp(__func__, __LINE__)
+#define PERF_TRACE()	trace_amdgpu_dc_performance(CTX->perf_trace->read_count,\
+		CTX->perf_trace->write_count, &CTX->perf_trace->last_entry_read,\
+		&CTX->perf_trace->last_entry_write, __func__, __LINE__)
+#define PERF_TRACE_CTX(__CTX)	trace_amdgpu_dc_performance(__CTX->perf_trace->read_count,\
+		__CTX->perf_trace->write_count, &__CTX->perf_trace->last_entry_read,\
+		&__CTX->perf_trace->last_entry_write, __func__, __LINE__)
 
 
 /*