[Intel-gfx] [RFC 07/12] drm/i915: Track all user contexts per client

[Tvrtko Ursulin]

From: Tvrtko Ursulin <tvrtko.ursulin at intel.com>

We soon want to start answering questions like how much GPU time is the
context belonging to a client which exited still using.

To enable this we start tracking all context belonging to a client on a
separate list.

Signed-off-by: Tvrtko Ursulin <tvrtko.ursulin at intel.com>
---
 drivers/gpu/drm/i915/gem/i915_gem_context.c       | 8 ++++++++
 drivers/gpu/drm/i915/gem/i915_gem_context_types.h | 3 +++
 drivers/gpu/drm/i915/i915_drm_client.c            | 3 +++
 drivers/gpu/drm/i915/i915_drm_client.h            | 5 +++++
 4 files changed, 19 insertions(+)

diff --git a/drivers/gpu/drm/i915/gem/i915_gem_context.c b/drivers/gpu/drm/i915/gem/i915_gem_context.c
index d99143dca0ab..d3887712f8c3 100644
--- a/drivers/gpu/drm/i915/gem/i915_gem_context.c
+++ b/drivers/gpu/drm/i915/gem/i915_gem_context.c
@@ -319,6 +319,10 @@ static void i915_gem_context_free(struct i915_gem_context *ctx)
 	if (client) {
 		unsigned int i;
 
+		spin_lock(&client->ctx_lock);
+		list_del_rcu(&ctx->client_link);
+		spin_unlock(&client->ctx_lock);
+
 		/* Transfer accumulated runtime to the parent drm client. */
 		BUILD_BUG_ON(ARRAY_SIZE(client->past_runtime) !=
 			     ARRAY_SIZE(ctx->past_runtime));
@@ -952,6 +956,10 @@ static int gem_context_register(struct i915_gem_context *ctx,
 
 	ctx->client = client;
 
+	spin_lock(&client->ctx_lock);
+	list_add_tail_rcu(&ctx->client_link, &client->ctx_list);
+	spin_unlock(&client->ctx_lock);
+
 	return 0;
 
 err:
diff --git a/drivers/gpu/drm/i915/gem/i915_gem_context_types.h b/drivers/gpu/drm/i915/gem/i915_gem_context_types.h
index f0d7441aafc8..255fcc469d9b 100644
--- a/drivers/gpu/drm/i915/gem/i915_gem_context_types.h
+++ b/drivers/gpu/drm/i915/gem/i915_gem_context_types.h
@@ -103,6 +103,9 @@ struct i915_gem_context {
 	/** client: struct i915_drm_client */
 	struct i915_drm_client *client;
 
+	/** link: &drm_client.context_list */
+	struct list_head client_link;
+
 	/**
 	 * @ref: reference count
 	 *
diff --git a/drivers/gpu/drm/i915/i915_drm_client.c b/drivers/gpu/drm/i915/i915_drm_client.c
index a3de02cc3e6b..c9a510c6c6d4 100644
--- a/drivers/gpu/drm/i915/i915_drm_client.c
+++ b/drivers/gpu/drm/i915/i915_drm_client.c
@@ -128,6 +128,9 @@ i915_drm_client_add(struct i915_drm_clients *clients, struct task_struct *task)
 
 	kref_init(&client->kref);
 	mutex_init(&client->update_lock);
+	spin_lock_init(&client->ctx_lock);
+	INIT_LIST_HEAD(&client->ctx_list);
+
 	client->clients = clients;
 
 	ret = mutex_lock_interruptible(&clients->lock);
diff --git a/drivers/gpu/drm/i915/i915_drm_client.h b/drivers/gpu/drm/i915/i915_drm_client.h
index 10752107e8c7..0a9f2c0c12dd 100644
--- a/drivers/gpu/drm/i915/i915_drm_client.h
+++ b/drivers/gpu/drm/i915/i915_drm_client.h
@@ -10,10 +10,12 @@
 #include <linux/device.h>
 #include <linux/kobject.h>
 #include <linux/kref.h>
+#include <linux/list.h>
 #include <linux/mutex.h>
 #include <linux/pid.h>
 #include <linux/rcupdate.h>
 #include <linux/sched.h>
+#include <linux/spinlock.h>
 #include <linux/xarray.h>
 
 #include "gt/intel_engine_types.h"
@@ -38,6 +40,9 @@ struct i915_drm_client {
 	char __rcu *name;
 	bool closed;
 
+	spinlock_t ctx_lock;
+	struct list_head ctx_list;
+
 	struct i915_drm_clients *clients;
 
 	struct kobject *root;
-- 
2.20.1