drm/vma_manage: Drop has_offset

It's racy, creating mmap offsets is a slowpath, so better to remove it
to avoid drivers doing broken things.

The only user is i915, and it's ok there because everything (well
almost) is protected by dev->struct_mutex in i915-gem.

While at it add a note in the create_mmap_offset kerneldoc that
drivers must release it again. And then I also noticed that
drm_gem_object_release entirely lacks kerneldoc.

Cc: David Herrmann <dh.herrmann@gmail.com>
Signed-off-by: Daniel Vetter <daniel.vetter@intel.com>
Link: http://patchwork.freedesktop.org/patch/msgid/1459330852-27668-14-git-send-email-daniel.vetter@ffwll.ch
This commit is contained in:
Daniel Vetter 2016-03-30 11:40:52 +02:00
parent 0797ac6181
commit f74418a400
3 changed files with 18 additions and 17 deletions

View File

@ -422,6 +422,10 @@ EXPORT_SYMBOL(drm_gem_handle_create);
* @obj: obj in question
*
* This routine frees fake offsets allocated by drm_gem_create_mmap_offset().
*
* Note that drm_gem_object_release() already calls this function, so drivers
* don't have to take care of releasing the mmap offset themselves when freeing
* the GEM object.
*/
void
drm_gem_free_mmap_offset(struct drm_gem_object *obj)
@ -445,6 +449,9 @@ EXPORT_SYMBOL(drm_gem_free_mmap_offset);
* This routine allocates and attaches a fake offset for @obj, in cases where
* the virtual size differs from the physical size (ie. obj->size). Otherwise
* just use drm_gem_create_mmap_offset().
*
* This function is idempotent and handles an already allocated mmap offset
* transparently. Drivers do not need to check for this case.
*/
int
drm_gem_create_mmap_offset_size(struct drm_gem_object *obj, size_t size)
@ -466,6 +473,9 @@ EXPORT_SYMBOL(drm_gem_create_mmap_offset_size);
* structures.
*
* This routine allocates and attaches a fake offset for @obj.
*
* Drivers can call drm_gem_free_mmap_offset() before freeing @obj to release
* the fake offset again.
*/
int drm_gem_create_mmap_offset(struct drm_gem_object *obj)
{
@ -759,6 +769,13 @@ drm_gem_release(struct drm_device *dev, struct drm_file *file_private)
idr_destroy(&file_private->object_idr);
}
/**
* drm_gem_object_release - release GEM buffer object resources
* @obj: GEM buffer object
*
* This releases any structures and resources used by @obj and is the invers of
* drm_gem_object_init().
*/
void
drm_gem_object_release(struct drm_gem_object *obj)
{

View File

@ -2031,9 +2031,6 @@ static int i915_gem_object_create_mmap_offset(struct drm_i915_gem_object *obj)
struct drm_i915_private *dev_priv = obj->base.dev->dev_private;
int ret;
if (drm_vma_node_has_offset(&obj->base.vma_node))
return 0;
dev_priv->mm.shrinker_no_lock_stealing = true;
ret = drm_gem_create_mmap_offset(&obj->base);

View File

@ -175,19 +175,6 @@ static inline unsigned long drm_vma_node_size(struct drm_vma_offset_node *node)
return node->vm_node.size;
}
/**
* drm_vma_node_has_offset() - Check whether node is added to offset manager
* @node: Node to be checked
*
* RETURNS:
* true iff the node was previously allocated an offset and added to
* an vma offset manager.
*/
static inline bool drm_vma_node_has_offset(struct drm_vma_offset_node *node)
{
return drm_mm_node_allocated(&node->vm_node);
}
/**
* drm_vma_node_offset_addr() - Return sanitized offset for user-space mmaps
* @node: Linked offset node
@ -220,7 +207,7 @@ static inline __u64 drm_vma_node_offset_addr(struct drm_vma_offset_node *node)
static inline void drm_vma_node_unmap(struct drm_vma_offset_node *node,
struct address_space *file_mapping)
{
if (drm_vma_node_has_offset(node))
if (drm_mm_node_allocated(&node->vm_node))
unmap_mapping_range(file_mapping,
drm_vma_node_offset_addr(node),
drm_vma_node_size(node) << PAGE_SHIFT, 1);