From 274b3f7bf34415eed106e479e4815e897ce5d763 Mon Sep 17 00:00:00 2001 From: Christoph Hellwig Date: Wed, 22 Jul 2020 16:33:43 +0200 Subject: [PATCH] dma-contiguous: cleanup dma_alloc_contiguous Split out a cma_alloc_aligned helper to deal with the "interesting" calling conventions for cma_alloc, which then allows to the main function to be written straight forward. This also takes advantage of the fact that NULL dev arguments have been gone from the DMA API for a while. Signed-off-by: Christoph Hellwig Reviewed-by: Nicolin Chen Reviewed-by: Barry Song --- kernel/dma/contiguous.c | 31 ++++++++++++++----------------- 1 file changed, 14 insertions(+), 17 deletions(-) diff --git a/kernel/dma/contiguous.c b/kernel/dma/contiguous.c index 15bc5026c485..cff7e60968b9 100644 --- a/kernel/dma/contiguous.c +++ b/kernel/dma/contiguous.c @@ -215,6 +215,13 @@ bool dma_release_from_contiguous(struct device *dev, struct page *pages, return cma_release(dev_get_cma_area(dev), pages, count); } +static struct page *cma_alloc_aligned(struct cma *cma, size_t size, gfp_t gfp) +{ + unsigned int align = min(get_order(size), CONFIG_CMA_ALIGNMENT); + + return cma_alloc(cma, size >> PAGE_SHIFT, align, gfp & __GFP_NOWARN); +} + /** * dma_alloc_contiguous() - allocate contiguous pages * @dev: Pointer to device for which the allocation is performed. @@ -231,24 +238,14 @@ bool dma_release_from_contiguous(struct device *dev, struct page *pages, */ struct page *dma_alloc_contiguous(struct device *dev, size_t size, gfp_t gfp) { - size_t count = size >> PAGE_SHIFT; - struct page *page = NULL; - struct cma *cma = NULL; - - if (dev && dev->cma_area) - cma = dev->cma_area; - else if (count > 1) - cma = dma_contiguous_default_area; - /* CMA can be used only in the context which permits sleeping */ - if (cma && gfpflags_allow_blocking(gfp)) { - size_t align = get_order(size); - size_t cma_align = min_t(size_t, align, CONFIG_CMA_ALIGNMENT); - - page = cma_alloc(cma, count, cma_align, gfp & __GFP_NOWARN); - } - - return page; + if (!gfpflags_allow_blocking(gfp)) + return NULL; + if (dev->cma_area) + return cma_alloc_aligned(dev->cma_area, size, gfp); + if (size <= PAGE_SIZE || !dma_contiguous_default_area) + return NULL; + return cma_alloc_aligned(dma_contiguous_default_area, size, gfp); } /**