[RFC 11/12] drm/i915: Wire up with drm controller GPU time query

[Tvrtko Ursulin <tvrtko.ursulin@xxxxxxxxxxxxxxx>]

From: Tvrtko Ursulin <tvrtko.ursulin@xxxxxxxxx>

Implement the drm_cgroup_ops->active_time_us callback.

Signed-off-by: Tvrtko Ursulin <tvrtko.ursulin@xxxxxxxxx>
---
 drivers/gpu/drm/i915/i915_driver.c     | 10 ++++
 drivers/gpu/drm/i915/i915_drm_client.c | 76 ++++++++++++++++++++++----
 drivers/gpu/drm/i915/i915_drm_client.h |  2 +
 3 files changed, 78 insertions(+), 10 deletions(-)

diff --git a/drivers/gpu/drm/i915/i915_driver.c b/drivers/gpu/drm/i915/i915_driver.c
index c1e427ba57ae..50935cdb3a93 100644
--- a/drivers/gpu/drm/i915/i915_driver.c
+++ b/drivers/gpu/drm/i915/i915_driver.c
@@ -1897,6 +1897,12 @@ static const struct drm_ioctl_desc i915_ioctls[] = {
 	DRM_IOCTL_DEF_DRV(I915_GEM_VM_DESTROY, i915_gem_vm_destroy_ioctl, DRM_RENDER_ALLOW),
 };
 
+#ifdef CONFIG_CGROUP_DRM
+static const struct drm_cgroup_ops i915_drm_cgroup_ops = {
+	.active_time_us = i915_drm_cgroup_get_active_time_us,
+};
+#endif
+
 /*
  * Interface history:
  *
@@ -1925,6 +1931,10 @@ static const struct drm_driver i915_drm_driver = {
 	.lastclose = i915_driver_lastclose,
 	.postclose = i915_driver_postclose,
 
+#ifdef CONFIG_CGROUP_DRM
+	.cg_ops = &i915_drm_cgroup_ops,
+#endif
+
 	.prime_handle_to_fd = drm_gem_prime_handle_to_fd,
 	.prime_fd_to_handle = drm_gem_prime_fd_to_handle,
 	.gem_prime_import = i915_gem_prime_import,
diff --git a/drivers/gpu/drm/i915/i915_drm_client.c b/drivers/gpu/drm/i915/i915_drm_client.c
index b09d1d386574..c9754cb0277f 100644
--- a/drivers/gpu/drm/i915/i915_drm_client.c
+++ b/drivers/gpu/drm/i915/i915_drm_client.c
@@ -75,7 +75,7 @@ void i915_drm_clients_fini(struct i915_drm_clients *clients)
 	xa_destroy(&clients->xarray);
 }
 
-#ifdef CONFIG_PROC_FS
+#if defined(CONFIG_PROC_FS) || defined(CONFIG_CGROUP_DRM)
 static const char * const uabi_class_names[] = {
 	[I915_ENGINE_CLASS_RENDER] = "render",
 	[I915_ENGINE_CLASS_COPY] = "copy",
@@ -100,22 +100,78 @@ static u64 busy_add(struct i915_gem_context *ctx, unsigned int class)
 	return total;
 }
 
-static void
-show_client_class(struct seq_file *m,
-		  struct i915_drm_client *client,
-		  unsigned int class)
+static u64 get_class_active_ns(struct i915_drm_client *client,
+			       unsigned int class,
+			       unsigned int *capacity)
 {
-	const struct list_head *list = &client->ctx_list;
-	u64 total = atomic64_read(&client->past_runtime[class]);
-	const unsigned int capacity =
-		client->clients->i915->engine_uabi_class_count[class];
 	struct i915_gem_context *ctx;
+	u64 total;
+
+	*capacity =
+	    client->clients->i915->engine_uabi_class_count[class];
+	if (!*capacity)
+		return 0;
+
+	total = atomic64_read(&client->past_runtime[class]);
 
 	rcu_read_lock();
-	list_for_each_entry_rcu(ctx, list, client_link)
+	list_for_each_entry_rcu(ctx, &client->ctx_list, client_link)
 		total += busy_add(ctx, class);
 	rcu_read_unlock();
 
+	return total;
+}
+#endif
+
+#ifdef CONFIG_CGROUP_DRM
+static bool supports_stats(struct drm_i915_private *i915)
+{
+	if (GRAPHICS_VER(i915) < 8)
+		return false;
+
+	/* temporary... */
+	if (intel_uc_uses_guc_submission(&to_gt(i915)->uc))
+		return false;
+
+	return true;
+}
+
+u64 i915_drm_cgroup_get_active_time_us(struct drm_file *file)
+{
+	struct drm_i915_file_private *fpriv = file->driver_priv;
+	struct i915_drm_client *client = fpriv->client;
+	unsigned int i;
+	u64 busy = 0;
+
+	if (!supports_stats(client->clients->i915))
+		return 0;
+
+	for (i = 0; i < ARRAY_SIZE(uabi_class_names); i++) {
+		unsigned int capacity;
+		u64 b;
+
+		b = get_class_active_ns(client, i, &capacity);
+		if (capacity) {
+			b = DIV_ROUND_UP_ULL(b, capacity * 1000);
+			busy += b;
+		}
+	}
+
+	return busy;
+}
+#endif
+
+#ifdef CONFIG_PROC_FS
+static void
+show_client_class(struct seq_file *m,
+		  struct i915_drm_client *client,
+		  unsigned int class)
+{
+	unsigned int capacity;
+	u64 total;
+
+	total = get_class_active_ns(client, class, &capacity);
+
 	if (capacity)
 		seq_printf(m, "drm-engine-%s:\t%llu ns\n",
 			   uabi_class_names[class], total);
diff --git a/drivers/gpu/drm/i915/i915_drm_client.h b/drivers/gpu/drm/i915/i915_drm_client.h
index 69496af996d9..c8439eaa89be 100644
--- a/drivers/gpu/drm/i915/i915_drm_client.h
+++ b/drivers/gpu/drm/i915/i915_drm_client.h
@@ -65,4 +65,6 @@ void i915_drm_client_fdinfo(struct seq_file *m, struct file *f);
 
 void i915_drm_clients_fini(struct i915_drm_clients *clients);
 
+u64 i915_drm_cgroup_get_active_time_us(struct drm_file *file);
+
 #endif /* !__I915_DRM_CLIENT_H__ */
-- 
2.34.1