[PATCH v9 03/11] drm/gem: Add evict() callback to drm_gem_object_funcs

[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>
---
 drivers/gpu/drm/drm_gem.c | 15 +++++++++++++++
 include/drm/drm_gem.h     | 12 ++++++++++++
 2 files changed, 27 insertions(+)

diff --git a/drivers/gpu/drm/drm_gem.c b/drivers/gpu/drm/drm_gem.c
index 299bca1390aa..c0510b8080d2 100644
--- a/drivers/gpu/drm/drm_gem.c
+++ b/drivers/gpu/drm/drm_gem.c
@@ -1458,3 +1458,18 @@ 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;
+}
diff --git a/include/drm/drm_gem.h b/include/drm/drm_gem.h
index b46ade812443..add1371453f0 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);
 };
 
 /**
@@ -480,4 +490,6 @@ 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__ */
-- 
2.38.1