On 04/02/16 09:30, ankitprasad.r.sha...@intel.com wrote:
From: Chris Wilson <ch...@chris-wilson.co.uk>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 <ch...@chris-wilson.co.uk> Signed-off-by: Ankitprasad Sharma <ankitprasad.r.sha...@intel.com> --- drivers/gpu/drm/i915/i915_drv.h | 17 +++++++++++++++++ 1 file changed, 17 insertions(+) diff --git a/drivers/gpu/drm/i915/i915_drv.h b/drivers/gpu/drm/i915/i915_drv.h index 65a2cd0..e4c25c6 100644 --- a/drivers/gpu/drm/i915/i915_drv.h +++ b/drivers/gpu/drm/i915/i915_drv.h @@ -2947,6 +2947,23 @@ 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) {
Reviewed-by: Tvrtko Ursulin <tvrtko.ursu...@intel.com> Regards, Tvrtko _______________________________________________ Intel-gfx mailing list Intel-gfx@lists.freedesktop.org https://lists.freedesktop.org/mailman/listinfo/intel-gfx
