korg/linux
0
0
Fork 0
mirror of https://mirrors.bfsu.edu.cn/git/linux.git synced 2024-12-11 21:14:07 +08:00
Code Issues Packages Projects Releases Wiki Activity

drm/i915: Introduce i915_gem_object_finish_gtt()

Browse Source 
Like its siblings finish_gpu(), this function clears the object from the
GTT domain forcing it to be trigger a domain invalidation should we ever
need to use via the GTT again.

Note that the most important side-effect of finishing the GTT domain
(aside from clearing the tracking read/write domains) is that it imposes
an memory barrier so that all accesses are complete before it returns,
which is important if you intend to be modifying translation tables
shortly afterwards. The second most important side-effect is that it
tears down the GTT mappings forcing a page-fault and invalidation on
next user access to the object.

Signed-off-by: Chris Wilson <chris@chris-wilson.co.uk>
Reviewed-by: Daniel Vetter <daniel.vetter@ffwll.ch>
This commit is contained in:
Chris Wilson 2011-04-13 22:06:03 +01:00 committed by Keith Packard
parent a8198eea15
commit b5ffc9bc38
1 changed files with 25 additions and 2 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

27
drivers/gpu/drm/i915/i915_gem.c
View File

@ -2149,6 +2149,30 @@ i915_gem_object_wait_rendering(struct drm_i915_gem_object *obj)
return 0;
}
static void i915_gem_object_finish_gtt(struct drm_i915_gem_object *obj)
{
u32 old_write_domain, old_read_domains;
if ((obj->base.read_domains & I915_GEM_DOMAIN_GTT) == 0)
return;
/* Act a barrier for all accesses through the GTT */
mb();
/* Force a pagefault for domain tracking on next user access */
i915_gem_release_mmap(obj);
old_read_domains = obj->base.read_domains;
old_write_domain = obj->base.write_domain;
obj->base.read_domains &= ~I915_GEM_DOMAIN_GTT;
obj->base.write_domain &= ~I915_GEM_DOMAIN_GTT;
trace_i915_gem_object_change_domain(obj,
old_read_domains,
old_write_domain);
}
/**
* Unbinds an object from the GTT aperture.
*/
@ -2173,8 +2197,7 @@ i915_gem_object_unbind(struct drm_i915_gem_object *obj)
* cause memory corruption through use-after-free.
*/
/* blow away mappings if mapped through GTT */
i915_gem_release_mmap(obj);
i915_gem_object_finish_gtt(obj);
/* Move the object to the CPU domain to ensure that
* any possible CPU writes while it's not in the GTT