diff --git a/drivers/gpu/drm/i915/i915_scatterlist.c b/drivers/gpu/drm/i915/i915_scatterlist.c index 69e9e6c3135e..4a6712dca838 100644 --- a/drivers/gpu/drm/i915/i915_scatterlist.c +++ b/drivers/gpu/drm/i915/i915_scatterlist.c @@ -6,6 +6,9 @@ #include "i915_scatterlist.h" +#include "i915_buddy.h" +#include "i915_ttm_buddy_manager.h" + #include #include @@ -104,6 +107,83 @@ struct sg_table *i915_sg_from_mm_node(const struct drm_mm_node *node, return st; } +/** + * i915_sg_from_buddy_resource - Create an sg_table from a struct + * i915_buddy_block list + * @res: The struct i915_ttm_buddy_resource. + * @region_start: An offset to add to the dma addresses of the sg list. + * + * Create a struct sg_table, initializing it from struct i915_buddy_block list, + * taking a maximum segment length into account, splitting into segments + * if necessary. + * + * Return: A pointer to a kmalloced struct sg_table on success, negative + * error code cast to an error pointer on failure. + */ +struct sg_table *i915_sg_from_buddy_resource(struct ttm_resource *res, + u64 region_start) +{ + struct i915_ttm_buddy_resource *bman_res = to_ttm_buddy_resource(res); + const u64 size = res->num_pages << PAGE_SHIFT; + const u64 max_segment = rounddown(UINT_MAX, PAGE_SIZE); + struct i915_buddy_mm *mm = bman_res->mm; + struct list_head *blocks = &bman_res->blocks; + struct i915_buddy_block *block; + struct scatterlist *sg; + struct sg_table *st; + resource_size_t prev_end; + + GEM_BUG_ON(list_empty(blocks)); + + st = kmalloc(sizeof(*st), GFP_KERNEL); + if (!st) + return ERR_PTR(-ENOMEM); + + if (sg_alloc_table(st, res->num_pages, GFP_KERNEL)) { + kfree(st); + return ERR_PTR(-ENOMEM); + } + + sg = st->sgl; + st->nents = 0; + prev_end = (resource_size_t)-1; + + list_for_each_entry(block, blocks, link) { + u64 block_size, offset; + + block_size = min_t(u64, size, i915_buddy_block_size(mm, block)); + offset = i915_buddy_block_offset(block); + + while (block_size) { + u64 len; + + if (offset != prev_end || sg->length >= max_segment) { + if (st->nents) + sg = __sg_next(sg); + + sg_dma_address(sg) = region_start + offset; + sg_dma_len(sg) = 0; + sg->length = 0; + st->nents++; + } + + len = min(block_size, max_segment - sg->length); + sg->length += len; + sg_dma_len(sg) += len; + + offset += len; + block_size -= len; + + prev_end = offset; + } + } + + sg_mark_end(sg); + i915_sg_trim(st); + + return st; +} + #if IS_ENABLED(CONFIG_DRM_I915_SELFTEST) #include "selftests/scatterlist.c" #endif diff --git a/drivers/gpu/drm/i915/i915_scatterlist.h b/drivers/gpu/drm/i915/i915_scatterlist.h index 5acca45ea981..b8bd5925b03f 100644 --- a/drivers/gpu/drm/i915/i915_scatterlist.h +++ b/drivers/gpu/drm/i915/i915_scatterlist.h @@ -14,6 +14,7 @@ #include "i915_gem.h" struct drm_mm_node; +struct ttm_resource; /* * Optimised SGL iterator for GEM objects @@ -145,4 +146,8 @@ bool i915_sg_trim(struct sg_table *orig_st); struct sg_table *i915_sg_from_mm_node(const struct drm_mm_node *node, u64 region_start); + +struct sg_table *i915_sg_from_buddy_resource(struct ttm_resource *res, + u64 region_start); + #endif