And new pages_pin_count field to struct drm_gem_shmem_object that will
determine whether pages are evictable by memory shrinker. The pages will
be evictable only when pages_pin_count=0. This patch prepares code for
addition of the memory shrinker that will utilize the new field.
Signed-off-by: Dmitry Osipenko <dmitry.osipenko@xxxxxxxxxxxxx>
---
drivers/gpu/drm/drm_gem_shmem_helper.c | 7 +++++++
include/drm/drm_gem_shmem_helper.h | 9 +++++++++
2 files changed, 16 insertions(+)
diff --git a/drivers/gpu/drm/drm_gem_shmem_helper.c b/drivers/gpu/drm/drm_gem_shmem_helper.c
index 4da9c9c39b9a..81d61791f874 100644
--- a/drivers/gpu/drm/drm_gem_shmem_helper.c
+++ b/drivers/gpu/drm/drm_gem_shmem_helper.c
@@ -277,6 +277,8 @@ static int drm_gem_shmem_pin_locked(struct drm_gem_shmem_object *shmem)
drm_WARN_ON(obj->dev, obj->import_attach);
ret = drm_gem_shmem_get_pages(shmem);
+ if (!ret)
+ shmem->pages_pin_count++;
return ret;
}
@@ -289,7 +291,12 @@ static void drm_gem_shmem_unpin_locked(struct drm_gem_shmem_object *shmem)
drm_WARN_ON(obj->dev, obj->import_attach);
+ if (drm_WARN_ON_ONCE(obj->dev, !shmem->pages_pin_count))
+ return;
+
drm_gem_shmem_put_pages(shmem);
+
+ shmem->pages_pin_count--;
}
/**
diff --git a/include/drm/drm_gem_shmem_helper.h b/include/drm/drm_gem_shmem_helper.h
index 20ddcd799df9..7d823c9fc480 100644
--- a/include/drm/drm_gem_shmem_helper.h
+++ b/include/drm/drm_gem_shmem_helper.h
@@ -39,6 +39,15 @@ struct drm_gem_shmem_object {
*/
unsigned int pages_use_count;
+ /**
+ * @pages_pin_count:
+ *
+ * Reference count on the pinned pages table.
+ * The pages allowed to be evicted by memory shrinker
+ * only when the count is zero.
+ */
+ unsigned int pages_pin_count;
+
/**
* @madv: State for madvise
*
--
2.39.2
