drm/i915: Cleanup i915_gem_request_add_to_client

Commit Message

Tvrtko Ursulin Sept. 27, 2016, 12:07 p.m. UTC

From: Tvrtko Ursulin <[e-mail]>

Several things we can clean up in this function:

 * Request and file passed in cannot be NULL. There is
   a single caller which makes it impossible so change
   that condition to a GEM_BUG_ON instead of a WARN
   with a return code.

 * Same is true for req->file_priv which is always
   zeroed before this function is called.

 * With the above we can remove the error return
   from the function making it void.

 * dev_private local variable was unused.

 * Call site in i915_gem_do_execbuffer can be
   simplified since there is no error handling any
   longer.

Signed-off-by: Tvrtko Ursulin <[e-mail]>
---
 drivers/gpu/drm/i915/i915_gem_execbuffer.c |  7 ++-----
 drivers/gpu/drm/i915/i915_gem_request.c    | 16 +++-------------
 drivers/gpu/drm/i915/i915_gem_request.h    |  4 ++--
 3 files changed, 7 insertions(+), 20 deletions(-)

Comments

Chris Wilson Sept. 27, 2016, 12:19 p.m. UTC | #1

On Tue, Sep 27, 2016 at 01:07:13PM +0100, Tvrtko Ursulin wrote:
> From: Tvrtko Ursulin <[e-mail]>
> 
> Several things we can clean up in this function:
> 
>  * Request and file passed in cannot be NULL. There is
>    a single caller which makes it impossible so change
>    that condition to a GEM_BUG_ON instead of a WARN
>    with a return code.

And move it next to the single caller since this is a specialised
function that is tied to userspace batches.

And the spinlock here is superfluous.
-Chris

Tvrtko Ursulin Sept. 27, 2016, 12:35 p.m. UTC | #2

On 27/09/2016 13:19, Chris Wilson wrote:
> On Tue, Sep 27, 2016 at 01:07:13PM +0100, Tvrtko Ursulin wrote:
>> From: Tvrtko Ursulin <[e-mail]>
>>
>> Several things we can clean up in this function:
>>
>>   * Request and file passed in cannot be NULL. There is
>>     a single caller which makes it impossible so change
>>     that condition to a GEM_BUG_ON instead of a WARN
>>     with a return code.
> And move it next to the single caller since this is a specialised
> function that is tied to userspace batches.

I thought about it, so OK, will do that.

> And the spinlock here is superfluous.

Hm why? There are places which iterate the list.

Regards,

Tvrtko

Patch

diff --git a/drivers/gpu/drm/i915/i915_gem_execbuffer.c b/drivers/gpu/drm/i915/i915_gem_execbuffer.c
index 33c85227643d..67f9fbeb29d0 100644
--- a/drivers/gpu/drm/i915/i915_gem_execbuffer.c
+++ b/drivers/gpu/drm/i915/i915_gem_execbuffer.c
@@ -1824,9 +1824,7 @@  i915_gem_do_execbuffer(struct drm_device *dev, void *data,
 	 */
 	params->request->batch = params->batch;
 
-	ret = i915_gem_request_add_to_client(params->request, file);
-	if (ret)
-		goto err_request;
+	i915_gem_request_add_to_client(params->request, file);
 
 	/*
 	 * Save assorted stuff away to pass through to *_submission().
@@ -1841,8 +1839,7 @@  i915_gem_do_execbuffer(struct drm_device *dev, void *data,
 	params->ctx                     = ctx;
 
 	ret = execbuf_submit(params, args, &eb->vmas);
-err_request:
-	__i915_add_request(params->request, ret == 0);
+	__i915_add_request(params->request, true);
 
 err_batch_unpin:
 	/*
diff --git a/drivers/gpu/drm/i915/i915_gem_request.c b/drivers/gpu/drm/i915/i915_gem_request.c
index 40978bc12ceb..b03f09567da2 100644
--- a/drivers/gpu/drm/i915/i915_gem_request.c
+++ b/drivers/gpu/drm/i915/i915_gem_request.c
@@ -115,29 +115,19 @@  const struct fence_ops i915_fence_ops = {
 	.timeline_value_str = i915_fence_timeline_value_str,
 };
 
-int i915_gem_request_add_to_client(struct drm_i915_gem_request *req,
-				   struct drm_file *file)
+void i915_gem_request_add_to_client(struct drm_i915_gem_request *req,
+				    struct drm_file *file)
 {
-	struct drm_i915_private *dev_private;
 	struct drm_i915_file_private *file_priv;
 
-	WARN_ON(!req || !file || req->file_priv);
+	GEM_BUG_ON(!req || !file || req->file_priv);
 
-	if (!req || !file)
-		return -EINVAL;
-
-	if (req->file_priv)
-		return -EINVAL;
-
-	dev_private = req->i915;
 	file_priv = file->driver_priv;
 
 	spin_lock(&file_priv->mm.lock);
 	req->file_priv = file_priv;
 	list_add_tail(&req->client_list, &file_priv->mm.request_list);
 	spin_unlock(&file_priv->mm.lock);
-
-	return 0;
 }
 
 static inline void
diff --git a/drivers/gpu/drm/i915/i915_gem_request.h b/drivers/gpu/drm/i915/i915_gem_request.h
index 974bd7bcc801..7fa20f342acf 100644
--- a/drivers/gpu/drm/i915/i915_gem_request.h
+++ b/drivers/gpu/drm/i915/i915_gem_request.h
@@ -155,8 +155,8 @@  static inline bool fence_is_i915(struct fence *fence)
 struct drm_i915_gem_request * __must_check
 i915_gem_request_alloc(struct intel_engine_cs *engine,
 		       struct i915_gem_context *ctx);
-int i915_gem_request_add_to_client(struct drm_i915_gem_request *req,
-				   struct drm_file *file);
+void i915_gem_request_add_to_client(struct drm_i915_gem_request *req,
+				    struct drm_file *file);
 void i915_gem_request_retire_upto(struct drm_i915_gem_request *req);
 
 static inline u32