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| author | Chris Wilson <chris@chris-wilson.co.uk> | 2016-06-10 11:53:00 +0300 |
|---|---|---|
| committer | Tvrtko Ursulin <tvrtko.ursulin@intel.com> | 2016-06-13 12:03:55 +0300 |
| commit | 341be1cd61826a8a143c2fc4cf3e418d1d5efc02 (patch) | |
| tree | 80d0517df8b1c3435afa0972110657e4a65068ca | |
| parent | d6473f566417a507b9ea5b0fc44ff26d930d0e5d (diff) | |
| download | linux-341be1cd61826a8a143c2fc4cf3e418d1d5efc02.tar.xz | |
drm/i915: Introduce i915_gem_object_get_dma_address()
This utility function is a companion to i915_gem_object_get_page() that
uses the same cached iterator for the scatterlist to perform fast
sequential lookup of the dma address associated with any page within the
object.
Signed-off-by: Chris Wilson <chris@chris-wilson.co.uk>
Signed-off-by: Ankitprasad Sharma <ankitprasad.r.sharma@intel.com>
Reviewed-by: Tvrtko Ursulin <tvrtko.ursulin@intel.com>
Signed-off-by: Tvrtko Ursulin <tvrtko.ursulin@intel.com>
| -rw-r--r-- | drivers/gpu/drm/i915/i915_drv.h | 17 |
1 files changed, 17 insertions, 0 deletions
diff --git a/drivers/gpu/drm/i915/i915_drv.h b/drivers/gpu/drm/i915/i915_drv.h index 53d9e3fab489..0349c5fe946c 100644 --- a/drivers/gpu/drm/i915/i915_drv.h +++ b/drivers/gpu/drm/i915/i915_drv.h @@ -3118,6 +3118,23 @@ static inline int __sg_page_count(struct scatterlist *sg) struct page * i915_gem_object_get_dirty_page(struct drm_i915_gem_object *obj, int n); +static inline dma_addr_t +i915_gem_object_get_dma_address(struct drm_i915_gem_object *obj, int n) +{ + if (n < obj->get_page.last) { + obj->get_page.sg = obj->pages->sgl; + obj->get_page.last = 0; + } + + while (obj->get_page.last + __sg_page_count(obj->get_page.sg) <= n) { + obj->get_page.last += __sg_page_count(obj->get_page.sg++); + if (unlikely(sg_is_chain(obj->get_page.sg))) + obj->get_page.sg = sg_chain_ptr(obj->get_page.sg); + } + + return sg_dma_address(obj->get_page.sg) + ((n - obj->get_page.last) << PAGE_SHIFT); +} + static inline struct page * i915_gem_object_get_page(struct drm_i915_gem_object *obj, int n) { |