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author | Marek Szyprowski <m.szyprowski@samsung.com> | 2020-05-08 16:05:14 +0200 |
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committer | Marek Szyprowski <m.szyprowski@samsung.com> | 2020-09-10 08:17:48 +0200 |
commit | 0552daac2d18fc92c71c94492476b8eb521227e9 (patch) | |
tree | e50576470ca8396e9fa41214044c0a965a13907e /drivers/gpu/drm/drm_prime.c | |
parent | d46e7ae24b81533d21edfa90914d27efa0c5f85d (diff) | |
download | linux-0552daac2d18fc92c71c94492476b8eb521227e9.tar.gz linux-0552daac2d18fc92c71c94492476b8eb521227e9.tar.bz2 linux-0552daac2d18fc92c71c94492476b8eb521227e9.zip |
drm: prime: use sgtable iterators in drm_prime_sg_to_page_addr_arrays()
Replace the current hand-crafted code for extracting pages and DMA
addresses from the given scatterlist by the much more robust
code based on the generic scatterlist iterators and recently
introduced sg_table-based wrappers. The resulting code is simple and
easy to understand, so the comment describing the old code is no
longer needed.
Signed-off-by: Marek Szyprowski <m.szyprowski@samsung.com>
Reviewed-by: Andrzej Hajda <a.hajda@samsung.com>
Reviewed-by: Robin Murphy <robin.murphy@arm.com>
Diffstat (limited to 'drivers/gpu/drm/drm_prime.c')
-rw-r--r-- | drivers/gpu/drm/drm_prime.c | 49 |
1 files changed, 15 insertions, 34 deletions
diff --git a/drivers/gpu/drm/drm_prime.c b/drivers/gpu/drm/drm_prime.c index 4ed5ed1f078c..c5e796d4a489 100644 --- a/drivers/gpu/drm/drm_prime.c +++ b/drivers/gpu/drm/drm_prime.c @@ -990,45 +990,26 @@ EXPORT_SYMBOL(drm_gem_prime_import); int drm_prime_sg_to_page_addr_arrays(struct sg_table *sgt, struct page **pages, dma_addr_t *addrs, int max_entries) { - unsigned count; - struct scatterlist *sg; - struct page *page; - u32 page_len, page_index; - dma_addr_t addr; - u32 dma_len, dma_index; - - /* - * Scatterlist elements contains both pages and DMA addresses, but - * one shoud not assume 1:1 relation between them. The sg->length is - * the size of the physical memory chunk described by the sg->page, - * while sg_dma_len(sg) is the size of the DMA (IO virtual) chunk - * described by the sg_dma_address(sg). - */ - page_index = 0; - dma_index = 0; - for_each_sg(sgt->sgl, sg, sgt->nents, count) { - page_len = sg->length; - page = sg_page(sg); - dma_len = sg_dma_len(sg); - addr = sg_dma_address(sg); - - while (pages && page_len > 0) { - if (WARN_ON(page_index >= max_entries)) + struct sg_dma_page_iter dma_iter; + struct sg_page_iter page_iter; + struct page **p = pages; + dma_addr_t *a = addrs; + + if (pages) { + for_each_sgtable_page(sgt, &page_iter, 0) { + if (WARN_ON(p - pages >= max_entries)) return -1; - pages[page_index] = page; - page++; - page_len -= PAGE_SIZE; - page_index++; + *p++ = sg_page_iter_page(&page_iter); } - while (addrs && dma_len > 0) { - if (WARN_ON(dma_index >= max_entries)) + } + if (addrs) { + for_each_sgtable_dma_page(sgt, &dma_iter, 0) { + if (WARN_ON(a - addrs >= max_entries)) return -1; - addrs[dma_index] = addr; - addr += PAGE_SIZE; - dma_len -= PAGE_SIZE; - dma_index++; + *a++ = sg_page_iter_dma_address(&dma_iter); } } + return 0; } EXPORT_SYMBOL(drm_prime_sg_to_page_addr_arrays); |