Commit 341be1cd authored by Chris Wilson's avatar Chris Wilson Committed by Tvrtko Ursulin

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: default avatarChris Wilson <chris@chris-wilson.co.uk>
Signed-off-by: default avatarAnkitprasad Sharma <ankitprasad.r.sharma@intel.com>
Reviewed-by: default avatarTvrtko Ursulin <tvrtko.ursulin@intel.com>
Signed-off-by: default avatarTvrtko Ursulin <tvrtko.ursulin@intel.com>
parent d6473f56
...@@ -3118,6 +3118,23 @@ static inline int __sg_page_count(struct scatterlist *sg) ...@@ -3118,6 +3118,23 @@ static inline int __sg_page_count(struct scatterlist *sg)
struct page * struct page *
i915_gem_object_get_dirty_page(struct drm_i915_gem_object *obj, int n); 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 * static inline struct page *
i915_gem_object_get_page(struct drm_i915_gem_object *obj, int n) i915_gem_object_get_page(struct drm_i915_gem_object *obj, int n)
{ {
......
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