drm/i915: Refactor calls to unmap_mapping_range

As we call unmap_mapping_range() twice in identical fashion, refactor
and attempt to explain why we need to call unmap_mapping_range().

Signed-off-by: Chris Wilson <chris@chris-wilson.co.uk>
Signed-off-by: Eric Anholt <eric@anholt.net>
This commit is contained in:
Chris Wilson 2009-07-10 08:18:50 +01:00 committed by Eric Anholt
parent fccdaba431
commit 901782b21e

View File

@ -1252,6 +1252,31 @@ out_free_list:
return ret;
}
/**
* i915_gem_release_mmap - remove physical page mappings
* @obj: obj in question
*
* Preserve the reservation of the mmaping with the DRM core code, but
* relinquish ownership of the pages back to the system.
*
* It is vital that we remove the page mapping if we have mapped a tiled
* object through the GTT and then lose the fence register due to
* resource pressure. Similarly if the object has been moved out of the
* aperture, than pages mapped into userspace must be revoked. Removing the
* mapping will then trigger a page fault on the next user access, allowing
* fixup by i915_gem_fault().
*/
static void
i915_gem_release_mmap(struct drm_gem_object *obj)
{
struct drm_device *dev = obj->dev;
struct drm_i915_gem_object *obj_priv = obj->driver_private;
if (dev->dev_mapping)
unmap_mapping_range(dev->dev_mapping,
obj_priv->mmap_offset, obj->size, 1);
}
static void
i915_gem_free_mmap_offset(struct drm_gem_object *obj)
{
@ -1861,7 +1886,6 @@ i915_gem_object_unbind(struct drm_gem_object *obj)
{
struct drm_device *dev = obj->dev;
struct drm_i915_gem_object *obj_priv = obj->driver_private;
loff_t offset;
int ret = 0;
#if WATCH_BUF
@ -1898,9 +1922,7 @@ i915_gem_object_unbind(struct drm_gem_object *obj)
BUG_ON(obj_priv->active);
/* blow away mappings if mapped through GTT */
offset = ((loff_t) obj->map_list.hash.key) << PAGE_SHIFT;
if (dev->dev_mapping)
unmap_mapping_range(dev->dev_mapping, offset, obj->size, 1);
i915_gem_release_mmap(obj);
if (obj_priv->fence_reg != I915_FENCE_REG_NONE)
i915_gem_clear_fence_reg(obj);
@ -2222,7 +2244,6 @@ try_again:
/* None available, try to steal one or wait for a user to finish */
if (i == dev_priv->num_fence_regs) {
uint32_t seqno = dev_priv->mm.next_gem_seqno;
loff_t offset;
if (avail == 0)
return -ENOSPC;
@ -2274,10 +2295,7 @@ try_again:
* Zap this virtual mapping so we can set up a fence again
* for this object next time we need it.
*/
offset = ((loff_t) reg->obj->map_list.hash.key) << PAGE_SHIFT;
if (dev->dev_mapping)
unmap_mapping_range(dev->dev_mapping, offset,
reg->obj->size, 1);
i915_gem_release_mmap(reg->obj);
old_obj_priv->fence_reg = I915_FENCE_REG_NONE;
}