[PATCH 10/36] drm/gem: add _locked suffix to drm_object_put

[PATCH 10/36] drm/gem: add _locked suffix to drm_object_put

[Emil Velikov]

From: Emil Velikov <emil.velikov@collabora.com>

Vast majority of DRM (core and drivers) are struct_mutex free.

As such we have only a handful of cases where the locked helper should
be used. Make that stand out a little bit better.

Done via the following script:

__from=drm_gem_object_put
__to=drm_gem_object_put_locked

for __file in $(git grep --name-only --word-regexp $__from); do
  sed -i  "s/\<$__from\>/$__to/g" $__file;
done

Cc: Rob Clark <robdclark@gmail.com>
Cc: Sean Paul <sean@poorly.run>
Cc: linux-arm-msm@vger.kernel.org
Signed-off-by: Emil Velikov <emil.velikov@collabora.com>
---
 drivers/gpu/drm/drm_gem.c                 | 6 +++---
 drivers/gpu/drm/msm/adreno/a5xx_debugfs.c | 4 ++--
 drivers/gpu/drm/msm/msm_drv.c             | 2 +-
 drivers/gpu/drm/msm/msm_gem.c             | 6 +++---
 drivers/gpu/drm/msm/msm_gem_submit.c      | 2 +-
 drivers/gpu/drm/msm/msm_gpu.c             | 2 +-
 include/drm/drm_gem.h                     | 4 ++--
 7 files changed, 13 insertions(+), 13 deletions(-)

diff --git a/drivers/gpu/drm/drm_gem.c b/drivers/gpu/drm/drm_gem.c
index 599d5ff53b73..f21327ebc562 100644
--- a/drivers/gpu/drm/drm_gem.c
+++ b/drivers/gpu/drm/drm_gem.c
@@ -983,7 +983,7 @@ drm_gem_object_free(struct kref *kref)
 EXPORT_SYMBOL(drm_gem_object_free);
 
 /**
- * drm_gem_object_put - release a GEM buffer object reference
+ * drm_gem_object_put_locked - release a GEM buffer object reference
  * @obj: GEM buffer object
  *
  * This releases a reference to @obj. Callers must hold the
@@ -994,7 +994,7 @@ EXPORT_SYMBOL(drm_gem_object_free);
  * drm_gem_object_put_unlocked() instead.
  */
 void
-drm_gem_object_put(struct drm_gem_object *obj)
+drm_gem_object_put_locked(struct drm_gem_object *obj)
 {
 	if (obj) {
 		WARN_ON(!mutex_is_locked(&obj->dev->struct_mutex));
@@ -1002,7 +1002,7 @@ drm_gem_object_put(struct drm_gem_object *obj)
 		kref_put(&obj->refcount, drm_gem_object_free);
 	}
 }
-EXPORT_SYMBOL(drm_gem_object_put);
+EXPORT_SYMBOL(drm_gem_object_put_locked);
 
 /**
  * drm_gem_vm_open - vma->ops->open implementation for GEM
diff --git a/drivers/gpu/drm/msm/adreno/a5xx_debugfs.c b/drivers/gpu/drm/msm/adreno/a5xx_debugfs.c
index 8cae2ca4af6b..68eddac7771c 100644
--- a/drivers/gpu/drm/msm/adreno/a5xx_debugfs.c
+++ b/drivers/gpu/drm/msm/adreno/a5xx_debugfs.c
@@ -124,13 +124,13 @@ reset_set(void *data, u64 val)
 
 	if (a5xx_gpu->pm4_bo) {
 		msm_gem_unpin_iova(a5xx_gpu->pm4_bo, gpu->aspace);
-		drm_gem_object_put(a5xx_gpu->pm4_bo);
+		drm_gem_object_put_locked(a5xx_gpu->pm4_bo);
 		a5xx_gpu->pm4_bo = NULL;
 	}
 
 	if (a5xx_gpu->pfp_bo) {
 		msm_gem_unpin_iova(a5xx_gpu->pfp_bo, gpu->aspace);
-		drm_gem_object_put(a5xx_gpu->pfp_bo);
+		drm_gem_object_put_locked(a5xx_gpu->pfp_bo);
 		a5xx_gpu->pfp_bo = NULL;
 	}
 
diff --git a/drivers/gpu/drm/msm/msm_drv.c b/drivers/gpu/drm/msm/msm_drv.c
index 29295dee2a2e..6baed5b43ea3 100644
--- a/drivers/gpu/drm/msm/msm_drv.c
+++ b/drivers/gpu/drm/msm/msm_drv.c
@@ -932,7 +932,7 @@ static int msm_ioctl_gem_madvise(struct drm_device *dev, void *data,
 		ret = 0;
 	}
 
-	drm_gem_object_put(obj);
+	drm_gem_object_put_locked(obj);
 
 unlock:
 	mutex_unlock(&dev->struct_mutex);
diff --git a/drivers/gpu/drm/msm/msm_gem.c b/drivers/gpu/drm/msm/msm_gem.c
index 5a6a79fbc9d6..8696c405f709 100644
--- a/drivers/gpu/drm/msm/msm_gem.c
+++ b/drivers/gpu/drm/msm/msm_gem.c
@@ -879,7 +879,7 @@ void msm_gem_describe_objects(struct list_head *list, struct seq_file *m)
 }
 #endif
 
-/* don't call directly!  Use drm_gem_object_put() and friends */
+/* don't call directly!  Use drm_gem_object_put_locked() and friends */
 void msm_gem_free_object(struct drm_gem_object *obj)
 {
 	struct msm_gem_object *msm_obj = to_msm_bo(obj);
@@ -1183,7 +1183,7 @@ static void *_msm_gem_kernel_new(struct drm_device *dev, uint32_t size,
 	return vaddr;
 err:
 	if (locked)
-		drm_gem_object_put(obj);
+		drm_gem_object_put_locked(obj);
 	else
 		drm_gem_object_put_unlocked(obj);
 
@@ -1215,7 +1215,7 @@ void msm_gem_kernel_put(struct drm_gem_object *bo,
 	msm_gem_unpin_iova(bo, aspace);
 
 	if (locked)
-		drm_gem_object_put(bo);
+		drm_gem_object_put_locked(bo);
 	else
 		drm_gem_object_put_unlocked(bo);
 }
diff --git a/drivers/gpu/drm/msm/msm_gem_submit.c b/drivers/gpu/drm/msm/msm_gem_submit.c
index 385d4965a8d0..8f450a245cfb 100644
--- a/drivers/gpu/drm/msm/msm_gem_submit.c
+++ b/drivers/gpu/drm/msm/msm_gem_submit.c
@@ -387,7 +387,7 @@ static void submit_cleanup(struct msm_gem_submit *submit)
 		struct msm_gem_object *msm_obj = submit->bos[i].obj;
 		submit_unlock_unpin_bo(submit, i, false);
 		list_del_init(&msm_obj->submit_entry);
-		drm_gem_object_put(&msm_obj->base);
+		drm_gem_object_put_locked(&msm_obj->base);
 	}
 }
 
diff --git a/drivers/gpu/drm/msm/msm_gpu.c b/drivers/gpu/drm/msm/msm_gpu.c
index 615c5cda5389..86a68f96c48d 100644
--- a/drivers/gpu/drm/msm/msm_gpu.c
+++ b/drivers/gpu/drm/msm/msm_gpu.c
@@ -694,7 +694,7 @@ static void retire_submit(struct msm_gpu *gpu, struct msm_ringbuffer *ring,
 		/* move to inactive: */
 		msm_gem_move_to_inactive(&msm_obj->base);
 		msm_gem_unpin_iova(&msm_obj->base, submit->aspace);
-		drm_gem_object_put(&msm_obj->base);
+		drm_gem_object_put_locked(&msm_obj->base);
 	}
 
 	pm_runtime_mark_last_busy(&gpu->pdev->dev);
diff --git a/include/drm/drm_gem.h b/include/drm/drm_gem.h
index 7c877bea7b3a..0f22f3320dcb 100644
--- a/include/drm/drm_gem.h
+++ b/include/drm/drm_gem.h
@@ -187,7 +187,7 @@ struct drm_gem_object {
 	 *
 	 * Reference count of this object
 	 *
-	 * Please use drm_gem_object_get() to acquire and drm_gem_object_put()
+	 * Please use drm_gem_object_get() to acquire and drm_gem_object_put_locked()
 	 * or drm_gem_object_put_unlocked() to release a reference to a GEM
 	 * buffer object.
 	 */
@@ -376,7 +376,7 @@ drm_gem_object_put_unlocked(struct drm_gem_object *obj)
 	kref_put(&obj->refcount, drm_gem_object_free);
 }
 
-void drm_gem_object_put(struct drm_gem_object *obj);
+void drm_gem_object_put_locked(struct drm_gem_object *obj);
 
 int drm_gem_handle_create(struct drm_file *file_priv,
 			  struct drm_gem_object *obj,
-- 
2.25.1

Re: [PATCH 10/36] drm/gem: add _locked suffix to drm_object_put

[Daniel Vetter]

On Thu, May 07, 2020 at 04:07:56PM +0100, Emil Velikov wrote:
> From: Emil Velikov <emil.velikov@collabora.com>
> 
> Vast majority of DRM (core and drivers) are struct_mutex free.
> 
> As such we have only a handful of cases where the locked helper should
> be used. Make that stand out a little bit better.
> 
> Done via the following script:
> 
> __from=drm_gem_object_put
> __to=drm_gem_object_put_locked
> 
> for __file in $(git grep --name-only --word-regexp $__from); do
>   sed -i  "s/\<$__from\>/$__to/g" $__file;
> done
> 
> Cc: Rob Clark <robdclark@gmail.com>
> Cc: Sean Paul <sean@poorly.run>
> Cc: linux-arm-msm@vger.kernel.org
> Signed-off-by: Emil Velikov <emil.velikov@collabora.com>

Since

commit 48e7f18392c66f9b69ebac11c54f1a2e033ced54
Author: Kristian H. Kristensen <hoegsberg@gmail.com>
Date:   Wed Mar 20 10:09:08 2019 -0700

    drm/msm: Implement .gem_free_object_unlocked

msm doesn't need the struct_mutex in the bo_put anymore, the only reason
we had to use the _locked version here is historical accidents I think.

I think you could convert these all to the _unlocked variant and then
entirely drop the _locked version.

Once we have that we could move struct_mutex into each driver (at least
for msm and i915) since it's purely internal, and then wrap it in an
#ifdef CONFIG_DRM_LEGACY to gloriously sunset it all :-)

Cheers, Daniel

> ---
>  drivers/gpu/drm/drm_gem.c                 | 6 +++---
>  drivers/gpu/drm/msm/adreno/a5xx_debugfs.c | 4 ++--
>  drivers/gpu/drm/msm/msm_drv.c             | 2 +-
>  drivers/gpu/drm/msm/msm_gem.c             | 6 +++---
>  drivers/gpu/drm/msm/msm_gem_submit.c      | 2 +-
>  drivers/gpu/drm/msm/msm_gpu.c             | 2 +-
>  include/drm/drm_gem.h                     | 4 ++--
>  7 files changed, 13 insertions(+), 13 deletions(-)
> 
> diff --git a/drivers/gpu/drm/drm_gem.c b/drivers/gpu/drm/drm_gem.c
> index 599d5ff53b73..f21327ebc562 100644
> --- a/drivers/gpu/drm/drm_gem.c
> +++ b/drivers/gpu/drm/drm_gem.c
> @@ -983,7 +983,7 @@ drm_gem_object_free(struct kref *kref)
>  EXPORT_SYMBOL(drm_gem_object_free);
>  
>  /**
> - * drm_gem_object_put - release a GEM buffer object reference
> + * drm_gem_object_put_locked - release a GEM buffer object reference
>   * @obj: GEM buffer object
>   *
>   * This releases a reference to @obj. Callers must hold the
> @@ -994,7 +994,7 @@ EXPORT_SYMBOL(drm_gem_object_free);
>   * drm_gem_object_put_unlocked() instead.
>   */
>  void
> -drm_gem_object_put(struct drm_gem_object *obj)
> +drm_gem_object_put_locked(struct drm_gem_object *obj)
>  {
>  	if (obj) {
>  		WARN_ON(!mutex_is_locked(&obj->dev->struct_mutex));
> @@ -1002,7 +1002,7 @@ drm_gem_object_put(struct drm_gem_object *obj)
>  		kref_put(&obj->refcount, drm_gem_object_free);
>  	}
>  }
> -EXPORT_SYMBOL(drm_gem_object_put);
> +EXPORT_SYMBOL(drm_gem_object_put_locked);
>  
>  /**
>   * drm_gem_vm_open - vma->ops->open implementation for GEM
> diff --git a/drivers/gpu/drm/msm/adreno/a5xx_debugfs.c b/drivers/gpu/drm/msm/adreno/a5xx_debugfs.c
> index 8cae2ca4af6b..68eddac7771c 100644
> --- a/drivers/gpu/drm/msm/adreno/a5xx_debugfs.c
> +++ b/drivers/gpu/drm/msm/adreno/a5xx_debugfs.c
> @@ -124,13 +124,13 @@ reset_set(void *data, u64 val)
>  
>  	if (a5xx_gpu->pm4_bo) {
>  		msm_gem_unpin_iova(a5xx_gpu->pm4_bo, gpu->aspace);
> -		drm_gem_object_put(a5xx_gpu->pm4_bo);
> +		drm_gem_object_put_locked(a5xx_gpu->pm4_bo);
>  		a5xx_gpu->pm4_bo = NULL;
>  	}
>  
>  	if (a5xx_gpu->pfp_bo) {
>  		msm_gem_unpin_iova(a5xx_gpu->pfp_bo, gpu->aspace);
> -		drm_gem_object_put(a5xx_gpu->pfp_bo);
> +		drm_gem_object_put_locked(a5xx_gpu->pfp_bo);
>  		a5xx_gpu->pfp_bo = NULL;
>  	}
>  
> diff --git a/drivers/gpu/drm/msm/msm_drv.c b/drivers/gpu/drm/msm/msm_drv.c
> index 29295dee2a2e..6baed5b43ea3 100644
> --- a/drivers/gpu/drm/msm/msm_drv.c
> +++ b/drivers/gpu/drm/msm/msm_drv.c
> @@ -932,7 +932,7 @@ static int msm_ioctl_gem_madvise(struct drm_device *dev, void *data,
>  		ret = 0;
>  	}
>  
> -	drm_gem_object_put(obj);
> +	drm_gem_object_put_locked(obj);
>  
>  unlock:
>  	mutex_unlock(&dev->struct_mutex);
> diff --git a/drivers/gpu/drm/msm/msm_gem.c b/drivers/gpu/drm/msm/msm_gem.c
> index 5a6a79fbc9d6..8696c405f709 100644
> --- a/drivers/gpu/drm/msm/msm_gem.c
> +++ b/drivers/gpu/drm/msm/msm_gem.c
> @@ -879,7 +879,7 @@ void msm_gem_describe_objects(struct list_head *list, struct seq_file *m)
>  }
>  #endif
>  
> -/* don't call directly!  Use drm_gem_object_put() and friends */
> +/* don't call directly!  Use drm_gem_object_put_locked() and friends */
>  void msm_gem_free_object(struct drm_gem_object *obj)
>  {
>  	struct msm_gem_object *msm_obj = to_msm_bo(obj);
> @@ -1183,7 +1183,7 @@ static void *_msm_gem_kernel_new(struct drm_device *dev, uint32_t size,
>  	return vaddr;
>  err:
>  	if (locked)
> -		drm_gem_object_put(obj);
> +		drm_gem_object_put_locked(obj);
>  	else
>  		drm_gem_object_put_unlocked(obj);
>  
> @@ -1215,7 +1215,7 @@ void msm_gem_kernel_put(struct drm_gem_object *bo,
>  	msm_gem_unpin_iova(bo, aspace);
>  
>  	if (locked)
> -		drm_gem_object_put(bo);
> +		drm_gem_object_put_locked(bo);
>  	else
>  		drm_gem_object_put_unlocked(bo);
>  }
> diff --git a/drivers/gpu/drm/msm/msm_gem_submit.c b/drivers/gpu/drm/msm/msm_gem_submit.c
> index 385d4965a8d0..8f450a245cfb 100644
> --- a/drivers/gpu/drm/msm/msm_gem_submit.c
> +++ b/drivers/gpu/drm/msm/msm_gem_submit.c
> @@ -387,7 +387,7 @@ static void submit_cleanup(struct msm_gem_submit *submit)
>  		struct msm_gem_object *msm_obj = submit->bos[i].obj;
>  		submit_unlock_unpin_bo(submit, i, false);
>  		list_del_init(&msm_obj->submit_entry);
> -		drm_gem_object_put(&msm_obj->base);
> +		drm_gem_object_put_locked(&msm_obj->base);
>  	}
>  }
>  
> diff --git a/drivers/gpu/drm/msm/msm_gpu.c b/drivers/gpu/drm/msm/msm_gpu.c
> index 615c5cda5389..86a68f96c48d 100644
> --- a/drivers/gpu/drm/msm/msm_gpu.c
> +++ b/drivers/gpu/drm/msm/msm_gpu.c
> @@ -694,7 +694,7 @@ static void retire_submit(struct msm_gpu *gpu, struct msm_ringbuffer *ring,
>  		/* move to inactive: */
>  		msm_gem_move_to_inactive(&msm_obj->base);
>  		msm_gem_unpin_iova(&msm_obj->base, submit->aspace);
> -		drm_gem_object_put(&msm_obj->base);
> +		drm_gem_object_put_locked(&msm_obj->base);
>  	}
>  
>  	pm_runtime_mark_last_busy(&gpu->pdev->dev);
> diff --git a/include/drm/drm_gem.h b/include/drm/drm_gem.h
> index 7c877bea7b3a..0f22f3320dcb 100644
> --- a/include/drm/drm_gem.h
> +++ b/include/drm/drm_gem.h
> @@ -187,7 +187,7 @@ struct drm_gem_object {
>  	 *
>  	 * Reference count of this object
>  	 *
> -	 * Please use drm_gem_object_get() to acquire and drm_gem_object_put()
> +	 * Please use drm_gem_object_get() to acquire and drm_gem_object_put_locked()
>  	 * or drm_gem_object_put_unlocked() to release a reference to a GEM
>  	 * buffer object.
>  	 */
> @@ -376,7 +376,7 @@ drm_gem_object_put_unlocked(struct drm_gem_object *obj)
>  	kref_put(&obj->refcount, drm_gem_object_free);
>  }
>  
> -void drm_gem_object_put(struct drm_gem_object *obj);
> +void drm_gem_object_put_locked(struct drm_gem_object *obj);
>  
>  int drm_gem_handle_create(struct drm_file *file_priv,
>  			  struct drm_gem_object *obj,
> -- 
> 2.25.1
> 
> _______________________________________________
> dri-devel mailing list
> dri-devel@lists.freedesktop.org
> https://lists.freedesktop.org/mailman/listinfo/dri-devel

-- 
Daniel Vetter
Software Engineer, Intel Corporation
http://blog.ffwll.ch

Re: [PATCH 10/36] drm/gem: add _locked suffix to drm_object_put

[Emil Velikov]

On Fri, 8 May 2020 at 07:40, Daniel Vetter <daniel@ffwll.ch> wrote:
>
> On Thu, May 07, 2020 at 04:07:56PM +0100, Emil Velikov wrote:
> > From: Emil Velikov <emil.velikov@collabora.com>
> >
> > Vast majority of DRM (core and drivers) are struct_mutex free.
> >
> > As such we have only a handful of cases where the locked helper should
> > be used. Make that stand out a little bit better.
> >
> > Done via the following script:
> >
> > __from=drm_gem_object_put
> > __to=drm_gem_object_put_locked
> >
> > for __file in $(git grep --name-only --word-regexp $__from); do
> >   sed -i  "s/\<$__from\>/$__to/g" $__file;
> > done
> >
> > Cc: Rob Clark <robdclark@gmail.com>
> > Cc: Sean Paul <sean@poorly.run>
> > Cc: linux-arm-msm@vger.kernel.org
> > Signed-off-by: Emil Velikov <emil.velikov@collabora.com>
>
> Since
>
> commit 48e7f18392c66f9b69ebac11c54f1a2e033ced54
> Author: Kristian H. Kristensen <hoegsberg@gmail.com>
> Date:   Wed Mar 20 10:09:08 2019 -0700
>
>     drm/msm: Implement .gem_free_object_unlocked
>
> msm doesn't need the struct_mutex in the bo_put anymore, the only reason
> we had to use the _locked version here is historical accidents I think.
>
> I think you could convert these all to the _unlocked variant and then
> entirely drop the _locked version.
>
Did not check the msm driver closely, but it makes sense. Let's keep
that as follow-up series?
We're already at 36 patches, plus mixing mostly mechanical and locking
changes doesn't sound wise.

> Once we have that we could move struct_mutex into each driver (at least
> for msm and i915) since it's purely internal, and then wrap it in an
> #ifdef CONFIG_DRM_LEGACY to gloriously sunset it all :-)
>
Indeed, we're nearly there.

-Emil

Re: [PATCH 10/36] drm/gem: add _locked suffix to drm_object_put

[Daniel Vetter]

On Fri, May 08, 2020 at 12:00:40PM +0100, Emil Velikov wrote:
> On Fri, 8 May 2020 at 07:40, Daniel Vetter <daniel@ffwll.ch> wrote:
> >
> > On Thu, May 07, 2020 at 04:07:56PM +0100, Emil Velikov wrote:
> > > From: Emil Velikov <emil.velikov@collabora.com>
> > >
> > > Vast majority of DRM (core and drivers) are struct_mutex free.
> > >
> > > As such we have only a handful of cases where the locked helper should
> > > be used. Make that stand out a little bit better.
> > >
> > > Done via the following script:
> > >
> > > __from=drm_gem_object_put
> > > __to=drm_gem_object_put_locked
> > >
> > > for __file in $(git grep --name-only --word-regexp $__from); do
> > >   sed -i  "s/\<$__from\>/$__to/g" $__file;
> > > done
> > >
> > > Cc: Rob Clark <robdclark@gmail.com>
> > > Cc: Sean Paul <sean@poorly.run>
> > > Cc: linux-arm-msm@vger.kernel.org
> > > Signed-off-by: Emil Velikov <emil.velikov@collabora.com>
> >
> > Since
> >
> > commit 48e7f18392c66f9b69ebac11c54f1a2e033ced54
> > Author: Kristian H. Kristensen <hoegsberg@gmail.com>
> > Date:   Wed Mar 20 10:09:08 2019 -0700
> >
> >     drm/msm: Implement .gem_free_object_unlocked
> >
> > msm doesn't need the struct_mutex in the bo_put anymore, the only reason
> > we had to use the _locked version here is historical accidents I think.
> >
> > I think you could convert these all to the _unlocked variant and then
> > entirely drop the _locked version.
> >
> Did not check the msm driver closely, but it makes sense. Let's keep
> that as follow-up series?
> We're already at 36 patches, plus mixing mostly mechanical and locking
> changes doesn't sound wise.

My idea was to simply throw this patch out, and replace it by an msm patch
to switch over to the unlocked variant.

Well maybe then needs 2nd patch to throw the locked version out.

So feels a bit a detour to touch msm twice, which is why I suggested to do
the more direct route. But if you feel strongly I guess we can go this way
and then follow up with converting msm to unlocked and throwing the
_locked variant out for good too.
-Daniel


> > Once we have that we could move struct_mutex into each driver (at least
> > for msm and i915) since it's purely internal, and then wrap it in an
> > #ifdef CONFIG_DRM_LEGACY to gloriously sunset it all :-)
> >
> Indeed, we're nearly there.
> 
> -Emil

-- 
Daniel Vetter
Software Engineer, Intel Corporation
http://blog.ffwll.ch