From mboxrd@z Thu Jan 1 00:00:00 1970 From: Christoph Hellwig Subject: [PATCH 26/33] dma-direct: add support for CMA allocation Date: Wed, 10 Jan 2018 09:00:20 +0100 Message-ID: <20180110080027.13879-27-hch@lst.de> References: <20180110080027.13879-1-hch@lst.de> Return-path: In-Reply-To: <20180110080027.13879-1-hch@lst.de> Sender: linux-m68k-owner@vger.kernel.org List-Id: linux-m68k@vger.kernel.org To: iommu@lists.linux-foundation.org Cc: Konrad Rzeszutek Wilk , linux-alpha@vger.kernel.org, linux-snps-arc@lists.infradead.org, linux-arm-kernel@lists.infradead.org, linux-c6x-dev@linux-c6x.org, linux-cris-kernel@axis.com, linux-hexagon@vger.kernel.org, linux-ia64@vger.kernel.org, linux-m68k@lists.linux-m68k.org, linux-metag@vger.kernel.org, Michal Simek , linux-mips@linux-mips.org, linux-parisc@vger.kernel.org, linuxppc-dev@lists.ozlabs.org, patches@groups.riscv.org, linux-s390@vger.kernel.org, linux-sh@vger.kernel.org, sparclinux@vger.kernel.org, Guan Xuetao , x86@kernel.org, linux-arch@vger.kernel.org, linux-kernel@vger.kernel.org Try the CMA allocator for coherent allocations if supported. Roughly modelled after the x86 code. Signed-off-by: Christoph Hellwig --- lib/dma-direct.c | 24 ++++++++++++++++++------ 1 file changed, 18 insertions(+), 6 deletions(-) diff --git a/lib/dma-direct.c b/lib/dma-direct.c index 32fd4d9e4c47..a9ae98be7af3 100644 --- a/lib/dma-direct.c +++ b/lib/dma-direct.c @@ -7,6 +7,7 @@ #include #include #include +#include #include #define DIRECT_MAPPING_ERROR 0 @@ -29,19 +30,30 @@ check_addr(struct device *dev, dma_addr_t dma_addr, size_t size, static void *dma_direct_alloc(struct device *dev, size_t size, dma_addr_t *dma_handle, gfp_t gfp, unsigned long attrs) { - void *ret; + unsigned int count = PAGE_ALIGN(size) >> PAGE_SHIFT; + int page_order = get_order(size); + struct page *page = NULL; - ret = (void *)__get_free_pages(gfp, get_order(size)); - if (ret) - *dma_handle = phys_to_dma(dev, virt_to_phys(ret)); + /* CMA can be used only in the context which permits sleeping */ + if (gfpflags_allow_blocking(gfp)) + page = dma_alloc_from_contiguous(dev, count, page_order, gfp); + if (!page) + page = alloc_pages(gfp, page_order); + if (!page) + return NULL; - return ret; + *dma_handle = phys_to_dma(dev, page_to_phys(page)); + memset(page_address(page), 0, size); + return page_address(page); } static void dma_direct_free(struct device *dev, size_t size, void *cpu_addr, dma_addr_t dma_addr, unsigned long attrs) { - free_pages((unsigned long)cpu_addr, get_order(size)); + unsigned int count = PAGE_ALIGN(size) >> PAGE_SHIFT; + + if (!dma_release_from_contiguous(dev, virt_to_page(cpu_addr), count)) + free_pages((unsigned long)cpu_addr, get_order(size)); } static dma_addr_t dma_direct_map_page(struct device *dev, struct page *page, -- 2.14.2