[RFC 3/3] drm/i915/gt: Export device and per-process runtimes via procfs

[Chris Wilson]

Register with /proc/gpu to provide the client runtimes for generic
top-like overview, e.g. gnome-system-monitor can use this information to
show the per-process multi-GPU usage.

Signed-off-by: Chris Wilson <chris at chris-wilson.co.uk>
---
 drivers/gpu/drm/i915/Makefile            |  1 +
 drivers/gpu/drm/i915/gt/intel_gt.c       |  5 ++
 drivers/gpu/drm/i915/gt/intel_gt_proc.c  | 66 ++++++++++++++++++++++++
 drivers/gpu/drm/i915/gt/intel_gt_proc.h  | 14 +++++
 drivers/gpu/drm/i915/gt/intel_gt_types.h |  3 ++
 5 files changed, 89 insertions(+)
 create mode 100644 drivers/gpu/drm/i915/gt/intel_gt_proc.c
 create mode 100644 drivers/gpu/drm/i915/gt/intel_gt_proc.h

diff --git a/drivers/gpu/drm/i915/Makefile b/drivers/gpu/drm/i915/Makefile
index ce01634d4ea7..16171f65f5d1 100644
--- a/drivers/gpu/drm/i915/Makefile
+++ b/drivers/gpu/drm/i915/Makefile
@@ -104,6 +104,7 @@ gt-y += \
 	gt/intel_gt_irq.o \
 	gt/intel_gt_pm.o \
 	gt/intel_gt_pm_irq.o \
+	gt/intel_gt_proc.o \
 	gt/intel_gt_requests.o \
 	gt/intel_gtt.o \
 	gt/intel_llc.o \
diff --git a/drivers/gpu/drm/i915/gt/intel_gt.c b/drivers/gpu/drm/i915/gt/intel_gt.c
index ca76f93bc03d..72199c13330d 100644
--- a/drivers/gpu/drm/i915/gt/intel_gt.c
+++ b/drivers/gpu/drm/i915/gt/intel_gt.c
@@ -12,6 +12,7 @@
 #include "intel_gt_buffer_pool.h"
 #include "intel_gt_clock_utils.h"
 #include "intel_gt_pm.h"
+#include "intel_gt_proc.h"
 #include "intel_gt_requests.h"
 #include "intel_mocs.h"
 #include "intel_rc6.h"
@@ -373,6 +374,8 @@ void intel_gt_driver_register(struct intel_gt *gt)
 	intel_rps_driver_register(&gt->rps);
 
 	debugfs_gt_register(gt);
+
+	intel_gt_driver_register__proc(gt);
 }
 
 static int intel_gt_init_scratch(struct intel_gt *gt, unsigned int size)
@@ -656,6 +659,8 @@ void intel_gt_driver_unregister(struct intel_gt *gt)
 {
 	intel_wakeref_t wakeref;
 
+	intel_gt_driver_unregister__proc(gt);
+
 	intel_rps_driver_unregister(&gt->rps);
 
 	/*
diff --git a/drivers/gpu/drm/i915/gt/intel_gt_proc.c b/drivers/gpu/drm/i915/gt/intel_gt_proc.c
new file mode 100644
index 000000000000..42db22326c7c
--- /dev/null
+++ b/drivers/gpu/drm/i915/gt/intel_gt_proc.c
@@ -0,0 +1,66 @@
+// SPDX-License-Identifier: MIT
+/*
+ * Copyright © 2020 Intel Corporation
+ */
+
+#include <linux/proc_gpu.h>
+
+#include "i915_drm_client.h"
+#include "i915_drv.h"
+#include "intel_gt.h"
+#include "intel_gt_pm.h"
+#include "intel_gt_proc.h"
+
+static void proc_runtime_pid(struct intel_gt *gt,
+			     struct pid *pid,
+			     struct proc_gpu_runtime *rt)
+{
+	struct i915_drm_clients *clients = &gt->i915->clients;
+
+	BUILD_BUG_ON(MAX_ENGINE_CLASS >= ARRAY_SIZE(rt->channel));
+
+	rt->device = i915_drm_clients_get_runtime(clients, pid, rt->channel);
+	rt->nchannel = MAX_ENGINE_CLASS + 1;
+}
+
+static void proc_runtime_device(struct intel_gt *gt,
+				struct pid *pid,
+				struct proc_gpu_runtime *rt)
+{
+	struct intel_engine_cs *engine;
+	enum intel_engine_id id;
+	ktime_t dummy;
+
+	rt->nchannel = 0;
+	for_each_engine(engine, gt, id) {
+		rt->channel[rt->nchannel++] =
+			intel_engine_get_busy_time(engine, &dummy);
+		if (rt->nchannel == ARRAY_SIZE(rt->channel))
+			break;
+	}
+	rt->device = intel_gt_get_awake_time(gt);
+}
+
+static void proc_runtime(struct proc_gpu *pg,
+			 struct pid *pid,
+			 struct proc_gpu_runtime *rt)
+{
+	struct intel_gt *gt = container_of(pg, typeof(*gt), proc);
+
+	strscpy(rt->name, dev_name(gt->i915->drm.dev), sizeof(rt->name));
+	if (pid)
+		proc_runtime_pid(gt, pid, rt);
+	else
+		proc_runtime_device(gt, pid, rt);
+}
+
+void intel_gt_driver_register__proc(struct intel_gt *gt)
+{
+	gt->proc.fn = proc_runtime;
+	proc_gpu_register(&gt->proc);
+}
+
+void intel_gt_driver_unregister__proc(struct intel_gt *gt)
+{
+	proc_gpu_unregister(&gt->proc);
+}
diff --git a/drivers/gpu/drm/i915/gt/intel_gt_proc.h b/drivers/gpu/drm/i915/gt/intel_gt_proc.h
new file mode 100644
index 000000000000..7a9bff0fb020
--- /dev/null
+++ b/drivers/gpu/drm/i915/gt/intel_gt_proc.h
@@ -0,0 +1,14 @@
+/* SPDX-License-Identifier: MIT */
+/*
+ * Copyright © 2020 Intel Corporation
+ */
+
+#ifndef INTEL_GT_PROC_H
+#define INTEL_GT_PROC_H
+
+struct intel_gt;
+
+void intel_gt_driver_register__proc(struct intel_gt *gt);
+void intel_gt_driver_unregister__proc(struct intel_gt *gt);
+
+#endif /* INTEL_GT_PROC_H */
diff --git a/drivers/gpu/drm/i915/gt/intel_gt_types.h b/drivers/gpu/drm/i915/gt/intel_gt_types.h
index 626af37c7790..3fc6d9741764 100644
--- a/drivers/gpu/drm/i915/gt/intel_gt_types.h
+++ b/drivers/gpu/drm/i915/gt/intel_gt_types.h
@@ -10,6 +10,7 @@
 #include <linux/list.h>
 #include <linux/mutex.h>
 #include <linux/notifier.h>
+#include <linux/proc_gpu.h>
 #include <linux/spinlock.h>
 #include <linux/types.h>
 
@@ -135,6 +136,8 @@ struct intel_gt {
 
 	struct i915_vma *scratch;
 
+	struct proc_gpu proc;
+
 	struct intel_gt_info {
 		intel_engine_mask_t engine_mask;
 		u8 num_engines;
-- 
2.20.1