[v10,03/11] drm/gem: Add evict() callback to drm_gem_object_funcs

Message ID 20230108210445.3948344-4-dmitry.osipenko@collabora.com
State New
Headers
Series Add generic memory shrinker to VirtIO-GPU and Panfrost DRM drivers |

Commit Message

Dmitry Osipenko Jan. 8, 2023, 9:04 p.m. UTC
  Add new common evict() callback to drm_gem_object_funcs and corresponding
drm_gem_object_evict() helper. This is a first step on a way to providing
common GEM-shrinker API for DRM drivers.

Suggested-by: Thomas Zimmermann <tzimmermann@suse.de>
Signed-off-by: Dmitry Osipenko <dmitry.osipenko@collabora.com>
---
 drivers/gpu/drm/drm_gem.c | 16 ++++++++++++++++
 include/drm/drm_gem.h     | 12 ++++++++++++
 2 files changed, 28 insertions(+)
  

Comments

Thomas Zimmermann Feb. 17, 2023, 12:23 p.m. UTC | #1
Hi

Am 08.01.23 um 22:04 schrieb Dmitry Osipenko:
> Add new common evict() callback to drm_gem_object_funcs and corresponding
> drm_gem_object_evict() helper. This is a first step on a way to providing
> common GEM-shrinker API for DRM drivers.
> 
> Suggested-by: Thomas Zimmermann <tzimmermann@suse.de>
> Signed-off-by: Dmitry Osipenko <dmitry.osipenko@collabora.com>

Reviewed-by: Thomas Zimmermann <tzimmermann@suse.de>

with my comments below addressed.

> ---
>   drivers/gpu/drm/drm_gem.c | 16 ++++++++++++++++
>   include/drm/drm_gem.h     | 12 ++++++++++++
>   2 files changed, 28 insertions(+)
> 
> diff --git a/drivers/gpu/drm/drm_gem.c b/drivers/gpu/drm/drm_gem.c
> index c6bca5ac6e0f..dbb48fc9dff3 100644
> --- a/drivers/gpu/drm/drm_gem.c
> +++ b/drivers/gpu/drm/drm_gem.c
> @@ -1471,3 +1471,19 @@ drm_gem_lru_scan(struct drm_gem_lru *lru,
>   	return freed;
>   }
>   EXPORT_SYMBOL(drm_gem_lru_scan);
> +
> +/**
> + * drm_gem_object_evict - helper to evict backing pages for a GEM object
> + * @obj: obj in question
> + */
> +bool

Please use int and return an errno code.

No newline here, please.

> +drm_gem_object_evict(struct drm_gem_object *obj)
> +{
> +	dma_resv_assert_held(obj->resv);
> +
> +	if (obj->funcs->evict)
> +		return obj->funcs->evict(obj);
> +
> +	return false;
> +}
> +EXPORT_SYMBOL(drm_gem_object_evict);
> diff --git a/include/drm/drm_gem.h b/include/drm/drm_gem.h
> index f1f00fc2dba6..8e5c22f25691 100644
> --- a/include/drm/drm_gem.h
> +++ b/include/drm/drm_gem.h
> @@ -172,6 +172,16 @@ struct drm_gem_object_funcs {
>   	 * This is optional but necessary for mmap support.
>   	 */
>   	const struct vm_operations_struct *vm_ops;
> +
> +	/**
> +	 * @evict:
> +	 *
> +	 * Evicts gem object out from memory. Used by the drm_gem_object_evict()
> +	 * helper. Returns true on success, false otherwise.
> +	 *
> +	 * This callback is optional.
> +	 */
> +	bool (*evict)(struct drm_gem_object *obj);

This should be declared between mmap and evict.

Again, please use int and return an errno code.

>   };
>   
>   /**
> @@ -481,4 +491,6 @@ unsigned long drm_gem_lru_scan(struct drm_gem_lru *lru,
>   			       unsigned long *remaining,
>   			       bool (*shrink)(struct drm_gem_object *obj));
>   
> +bool drm_gem_object_evict(struct drm_gem_object *obj);

drm_gem_evict() should be the correct name; like drm_gem_vmap() and 
drm_gem_pin(), etc.

Best regards
Thomas

> +
>   #endif /* __DRM_GEM_H__ */

-- 
Thomas Zimmermann
Graphics Driver Developer
SUSE Software Solutions Germany GmbH
Maxfeldstr. 5, 90409 Nürnberg, Germany
(HRB 36809, AG Nürnberg)
Geschäftsführer: Ivo Totev
  

Patch

diff --git a/drivers/gpu/drm/drm_gem.c b/drivers/gpu/drm/drm_gem.c
index c6bca5ac6e0f..dbb48fc9dff3 100644
--- a/drivers/gpu/drm/drm_gem.c
+++ b/drivers/gpu/drm/drm_gem.c
@@ -1471,3 +1471,19 @@  drm_gem_lru_scan(struct drm_gem_lru *lru,
 	return freed;
 }
 EXPORT_SYMBOL(drm_gem_lru_scan);
+
+/**
+ * drm_gem_object_evict - helper to evict backing pages for a GEM object
+ * @obj: obj in question
+ */
+bool
+drm_gem_object_evict(struct drm_gem_object *obj)
+{
+	dma_resv_assert_held(obj->resv);
+
+	if (obj->funcs->evict)
+		return obj->funcs->evict(obj);
+
+	return false;
+}
+EXPORT_SYMBOL(drm_gem_object_evict);
diff --git a/include/drm/drm_gem.h b/include/drm/drm_gem.h
index f1f00fc2dba6..8e5c22f25691 100644
--- a/include/drm/drm_gem.h
+++ b/include/drm/drm_gem.h
@@ -172,6 +172,16 @@  struct drm_gem_object_funcs {
 	 * This is optional but necessary for mmap support.
 	 */
 	const struct vm_operations_struct *vm_ops;
+
+	/**
+	 * @evict:
+	 *
+	 * Evicts gem object out from memory. Used by the drm_gem_object_evict()
+	 * helper. Returns true on success, false otherwise.
+	 *
+	 * This callback is optional.
+	 */
+	bool (*evict)(struct drm_gem_object *obj);
 };
 
 /**
@@ -481,4 +491,6 @@  unsigned long drm_gem_lru_scan(struct drm_gem_lru *lru,
 			       unsigned long *remaining,
 			       bool (*shrink)(struct drm_gem_object *obj));
 
+bool drm_gem_object_evict(struct drm_gem_object *obj);
+
 #endif /* __DRM_GEM_H__ */