From d541ae55d538265861ef729a64d2d816d34ef1e2 Mon Sep 17 00:00:00 2001 From: Christoph Hellwig Date: Mon, 18 Oct 2021 13:08:07 +0200 Subject: [PATCH] dma-direct: factor out a helper for DMA_ATTR_NO_KERNEL_MAPPING allocations Split the code for DMA_ATTR_NO_KERNEL_MAPPING allocations into a separate helper to make dma_direct_alloc a little more readable. Signed-off-by: Christoph Hellwig Reviewed-by: Robin Murphy Acked-by: David Rientjes --- kernel/dma/direct.c | 31 ++++++++++++++++++++----------- 1 file changed, 20 insertions(+), 11 deletions(-) diff --git a/kernel/dma/direct.c b/kernel/dma/direct.c index 3d1718d..0110466 100644 --- a/kernel/dma/direct.c +++ b/kernel/dma/direct.c @@ -168,6 +168,24 @@ static void *dma_direct_alloc_from_pool(struct device *dev, size_t size, return ret; } +static void *dma_direct_alloc_no_mapping(struct device *dev, size_t size, + dma_addr_t *dma_handle, gfp_t gfp) +{ + struct page *page; + + page = __dma_direct_alloc_pages(dev, size, gfp & ~__GFP_ZERO); + if (!page) + return NULL; + + /* remove any dirty cache lines on the kernel alias */ + if (!PageHighMem(page)) + arch_dma_prep_coherent(page, size); + + /* return the page pointer as the opaque cookie */ + *dma_handle = phys_to_dma_direct(dev, page_to_phys(page)); + return page; +} + void *dma_direct_alloc(struct device *dev, size_t size, dma_addr_t *dma_handle, gfp_t gfp, unsigned long attrs) { @@ -180,17 +198,8 @@ void *dma_direct_alloc(struct device *dev, size_t size, gfp |= __GFP_NOWARN; if ((attrs & DMA_ATTR_NO_KERNEL_MAPPING) && - !force_dma_unencrypted(dev) && !is_swiotlb_for_alloc(dev)) { - page = __dma_direct_alloc_pages(dev, size, gfp & ~__GFP_ZERO); - if (!page) - return NULL; - /* remove any dirty cache lines on the kernel alias */ - if (!PageHighMem(page)) - arch_dma_prep_coherent(page, size); - *dma_handle = phys_to_dma_direct(dev, page_to_phys(page)); - /* return the page pointer as the opaque cookie */ - return page; - } + !force_dma_unencrypted(dev) && !is_swiotlb_for_alloc(dev)) + return dma_direct_alloc_no_mapping(dev, size, dma_handle, gfp); if (!IS_ENABLED(CONFIG_ARCH_HAS_DMA_SET_UNCACHED) && !IS_ENABLED(CONFIG_DMA_DIRECT_REMAP) && -- 2.7.4