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

From: Thomas Zimmermann
Date: Fri Feb 17 2023 - 07:23:57 EST


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@xxxxxxx>
Signed-off-by: Dmitry Osipenko <dmitry.osipenko@xxxxxxxxxxxxx>

Reviewed-by: Thomas Zimmermann <tzimmermann@xxxxxxx>

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

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