On 07/10/2016 10:46, Chris Wilson wrote:We can use the radixtree index of the obj->pages to find the start position of the desired partial range. Signed-off-by: Chris Wilson <chris@xxxxxxxxxxxxxxxxxx> --- drivers/gpu/drm/i915/i915_gem_gtt.c | 38 +++++++++++++++++++++++-------------- 1 file changed, 24 insertions(+), 14 deletions(-) diff --git a/drivers/gpu/drm/i915/i915_gem_gtt.c b/drivers/gpu/drm/i915/i915_gem_gtt.c index 78b692e5b998..7e0c98576e72 100644 --- a/drivers/gpu/drm/i915/i915_gem_gtt.c +++ b/drivers/gpu/drm/i915/i915_gem_gtt.c @@ -3562,35 +3562,45 @@ intel_partial_pages(const struct i915_ggtt_view *view, struct drm_i915_gem_object *obj) { struct sg_table *st; - struct scatterlist *sg; - struct sg_page_iter obj_sg_iter; + struct scatterlist *sg, *iter; + unsigned int count = view->params.partial.size; + unsigned int offset; int ret = -ENOMEM; st = kmalloc(sizeof(*st), GFP_KERNEL); if (!st) goto err_st_alloc; - ret = sg_alloc_table(st, view->params.partial.size, GFP_KERNEL); + ret = sg_alloc_table(st, count, GFP_KERNEL); if (ret) goto err_sg_alloc; + iter = i915_gem_object_get_sg(obj, + view->params.partial.offset, + &offset); + sg = st->sgl; st->nents = 0; - for_each_sg_page(obj->pages->sgl, &obj_sg_iter, obj->pages->nents, - view->params.partial.offset) - { - if (st->nents >= view->params.partial.size) - break; + do { + unsigned int len = + min(iter->length, (count - offset) << PAGE_SHIFT); - sg_set_page(sg, NULL, PAGE_SIZE, 0); - sg_dma_address(sg) = sg_page_iter_dma_address(&obj_sg_iter); - sg_dma_len(sg) = PAGE_SIZE; + sg_set_page(sg, NULL, len, 0); + sg_dma_address(sg) = + sg_dma_address(iter) + (offset << PAGE_SHIFT); + sg_dma_len(sg) = len; - sg = sg_next(sg); st->nents++; - } + count -= len >> PAGE_SHIFT; + if (count == 0) { + sg_mark_end(sg); + return st; + } - return st; + sg = __sg_next(sg); + iter = __sg_next(iter); + offset = 0; + } while (1); err_sg_alloc: kfree(st); Reviewed-by: John Harrison <john.c.harrison@xxxxxxxxx> |
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