drm/amdgpu: add pmu counters

adding perf event counters

Signed-off-by: Jonathan Kim <Jonathan.Kim@amd.com>
Reviewed-by: Felix Kuehling <Felix.Kuehling@amd.com>
Signed-off-by: Alex Deucher <alexander.deucher@amd.com>

1 files changed, 280 insertions, 0 deletions

diff --git a/drivers/gpu/drm/amd/amdgpu/amdgpu_pmu.c b/drivers/gpu/drm/amd/amdgpu/amdgpu_pmu.c
new file mode 100644
index 000000000000..0e6dba9f60f0
--- /dev/null
+++ b/drivers/gpu/drm/amd/amdgpu/amdgpu_pmu.c
@@ -0,0 +1,280 @@
+/*
+ * Copyright 2019 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.
+ *
+ * Author: Jonathan Kim <jonathan.kim@amd.com>
+ *
+ */
+
+#include <linux/perf_event.h>
+#include <linux/init.h>
+#include "amdgpu.h"
+#include "amdgpu_pmu.h"
+#include "df_v3_6.h"
+
+#define PMU_NAME_SIZE 32
+
+/* record to keep track of pmu entry per pmu type per device */
+struct amdgpu_pmu_entry {
+	struct list_head entry;
+	struct amdgpu_device *adev;
+	struct pmu pmu;
+	unsigned int pmu_perf_type;
+};
+
+static LIST_HEAD(amdgpu_pmu_list);
+
+
+/* initialize perf counter */
+static int amdgpu_perf_event_init(struct perf_event *event)
+{
+	struct hw_perf_event *hwc = &event->hw;
+
+	/* test the event attr type check for PMU enumeration */
+	if (event->attr.type != event->pmu->type)
+		return -ENOENT;
+
+	/* update the hw_perf_event struct with config data */
+	hwc->conf = event->attr.config;
+
+	return 0;
+}
+
+/* start perf counter */
+static void amdgpu_perf_start(struct perf_event *event, int flags)
+{
+	struct hw_perf_event *hwc = &event->hw;
+	struct amdgpu_pmu_entry *pe = container_of(event->pmu,
+						  struct amdgpu_pmu_entry,
+						  pmu);
+
+	if (WARN_ON_ONCE(!(hwc->state & PERF_HES_STOPPED)))
+		return;
+
+	WARN_ON_ONCE(!(hwc->state & PERF_HES_UPTODATE));
+	hwc->state = 0;
+
+	switch (pe->pmu_perf_type) {
+	case PERF_TYPE_AMDGPU_DF:
+		if (!(flags & PERF_EF_RELOAD))
+			pe->adev->df_funcs->pmc_start(pe->adev, hwc->conf, 1);
+
+		pe->adev->df_funcs->pmc_start(pe->adev, hwc->conf, 0);
+		break;
+	default:
+		break;
+	}
+
+	perf_event_update_userpage(event);
+
+}
+
+/* read perf counter */
+static void amdgpu_perf_read(struct perf_event *event)
+{
+	struct hw_perf_event *hwc = &event->hw;
+	struct amdgpu_pmu_entry *pe = container_of(event->pmu,
+						  struct amdgpu_pmu_entry,
+						  pmu);
+
+	u64 count, prev;
+
+	do {
+		prev = local64_read(&hwc->prev_count);
+
+		switch (pe->pmu_perf_type) {
+		case PERF_TYPE_AMDGPU_DF:
+			pe->adev->df_funcs->pmc_get_count(pe->adev, hwc->conf,
+							  &count);
+			break;
+		default:
+			count = 0;
+			break;
+		};
+	} while (local64_cmpxchg(&hwc->prev_count, prev, count) != prev);
+
+	local64_add(count - prev, &event->count);
+}
+
+/* stop perf counter */
+static void amdgpu_perf_stop(struct perf_event *event, int flags)
+{
+	struct hw_perf_event *hwc = &event->hw;
+	struct amdgpu_pmu_entry *pe = container_of(event->pmu,
+						  struct amdgpu_pmu_entry,
+						  pmu);
+
+	if (hwc->state & PERF_HES_UPTODATE)
+		return;
+
+	switch (pe->pmu_perf_type) {
+	case PERF_TYPE_AMDGPU_DF:
+		pe->adev->df_funcs->pmc_stop(pe->adev, hwc->conf, 0);
+		break;
+	default:
+		break;
+	};
+
+	WARN_ON_ONCE(hwc->state & PERF_HES_STOPPED);
+	hwc->state |= PERF_HES_STOPPED;
+
+	if (hwc->state & PERF_HES_UPTODATE)
+		return;
+
+	amdgpu_perf_read(event);
+	hwc->state |= PERF_HES_UPTODATE;
+}
+
+/* add perf counter  */
+static int amdgpu_perf_add(struct perf_event *event, int flags)
+{
+	struct hw_perf_event *hwc = &event->hw;
+	int retval;
+
+	struct amdgpu_pmu_entry *pe = container_of(event->pmu,
+						  struct amdgpu_pmu_entry,
+						  pmu);
+
+	event->hw.state = PERF_HES_UPTODATE | PERF_HES_STOPPED;
+
+	switch (pe->pmu_perf_type) {
+	case PERF_TYPE_AMDGPU_DF:
+		retval = pe->adev->df_funcs->pmc_start(pe->adev, hwc->conf, 1);
+		break;
+	default:
+		return 0;
+	};
+
+	if (retval)
+		return retval;
+
+	if (flags & PERF_EF_START)
+		amdgpu_perf_start(event, PERF_EF_RELOAD);
+
+	return retval;
+
+}
+
+/* delete perf counter  */
+static void amdgpu_perf_del(struct perf_event *event, int flags)
+{
+	struct hw_perf_event *hwc = &event->hw;
+	struct amdgpu_pmu_entry *pe = container_of(event->pmu,
+						  struct amdgpu_pmu_entry,
+						  pmu);
+
+	amdgpu_perf_stop(event, PERF_EF_UPDATE);
+
+	switch (pe->pmu_perf_type) {
+	case PERF_TYPE_AMDGPU_DF:
+		pe->adev->df_funcs->pmc_stop(pe->adev, hwc->conf, 1);
+		break;
+	default:
+		break;
+	};
+
+	perf_event_update_userpage(event);
+}
+
+/* vega20 pmus */
+
+/* init pmu tracking per pmu type */
+static int init_pmu_by_type(struct amdgpu_device *adev,
+		  const struct attribute_group *attr_groups[],
+		  char *pmu_type_name, char *pmu_file_prefix,
+		  unsigned int pmu_perf_type,
+		  unsigned int num_counters)
+{
+	char pmu_name[PMU_NAME_SIZE];
+	struct amdgpu_pmu_entry *pmu_entry;
+	int ret = 0;
+
+	pmu_entry = kzalloc(sizeof(struct amdgpu_pmu_entry), GFP_KERNEL);
+
+	if (!pmu_entry)
+		return -ENOMEM;
+
+	pmu_entry->adev = adev;
+	pmu_entry->pmu = (struct pmu){
+		.event_init = amdgpu_perf_event_init,
+		.add = amdgpu_perf_add,
+		.del = amdgpu_perf_del,
+		.start = amdgpu_perf_start,
+		.stop = amdgpu_perf_stop,
+		.read = amdgpu_perf_read,
+		.task_ctx_nr = perf_invalid_context,
+	};
+
+	pmu_entry->pmu.attr_groups = attr_groups;
+	pmu_entry->pmu_perf_type = pmu_perf_type;
+	snprintf(pmu_name, PMU_NAME_SIZE, "%s_%d",
+				pmu_file_prefix, adev->ddev->primary->index);
+
+	ret = perf_pmu_register(&pmu_entry->pmu, pmu_name, -1);
+
+	if (ret) {
+		kfree(pmu_entry);
+		pr_warn("Error initializing AMDGPU %s PMUs.\n", pmu_type_name);
+		return ret;
+	}
+
+	pr_info("Detected AMDGPU %s Counters. # of Counters = %d.\n",
+			pmu_type_name, num_counters);
+
+	list_add_tail(&pmu_entry->entry, &amdgpu_pmu_list);
+
+	return 0;
+}
+
+/* init amdgpu_pmu */
+int amdgpu_pmu_init(struct amdgpu_device *adev)
+{
+	int ret = 0;
+
+	switch (adev->asic_type) {
+	case CHIP_VEGA20:
+		/* init df */
+		ret = init_pmu_by_type(adev, df_v3_6_attr_groups,
+				       "DF", "amdgpu_df", PERF_TYPE_AMDGPU_DF,
+				       DF_V3_6_MAX_COUNTERS);
+
+		/* other pmu types go here*/
+		break;
+	default:
+		return 0;
+	}
+
+	return 0;
+}
+
+
+/* destroy all pmu data associated with target device */
+void amdgpu_pmu_fini(struct amdgpu_device *adev)
+{
+	struct amdgpu_pmu_entry *pe, *temp;
+
+	list_for_each_entry_safe(pe, temp, &amdgpu_pmu_list, entry) {
+		if (pe->adev == adev) {
+			list_del(&pe->entry);
+			perf_pmu_unregister(&pe->pmu);
+			kfree(pe);
+		}
+	}
+}