From d98849aff87911013aadb730138ab728b52fc547 Mon Sep 17 00:00:00 2001 From: Christoph Hellwig Date: Fri, 14 Jun 2019 16:17:27 +0200 Subject: dma-direct: handle DMA_ATTR_NO_KERNEL_MAPPING in common code DMA_ATTR_NO_KERNEL_MAPPING is generally implemented by allocating normal cacheable pages or CMA memory, and then returning the page pointer as the opaque handle. Lift that code from the xtensa and generic dma remapping implementations into the generic dma-direct code so that we don't even call arch_dma_alloc for these allocations. Signed-off-by: Christoph Hellwig --- kernel/dma/direct.c | 14 ++++++++++++++ kernel/dma/remap.c | 13 ++----------- 2 files changed, 16 insertions(+), 11 deletions(-) (limited to 'kernel/dma') diff --git a/kernel/dma/direct.c b/kernel/dma/direct.c index fc354f4f490b..b90e1aede743 100644 --- a/kernel/dma/direct.c +++ b/kernel/dma/direct.c @@ -138,6 +138,14 @@ void *dma_direct_alloc_pages(struct device *dev, size_t size, if (!page) return NULL; + if (attrs & DMA_ATTR_NO_KERNEL_MAPPING) { + /* 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 */ + return page; + } + if (PageHighMem(page)) { /* * Depending on the cma= arguments and per-arch setup @@ -178,6 +186,12 @@ void dma_direct_free_pages(struct device *dev, size_t size, void *cpu_addr, { unsigned int page_order = get_order(size); + if (attrs & DMA_ATTR_NO_KERNEL_MAPPING) { + /* cpu_addr is a struct page cookie, not a kernel address */ + __dma_direct_free_pages(dev, size, cpu_addr); + return; + } + if (force_dma_unencrypted()) set_memory_encrypted((unsigned long)cpu_addr, 1 << page_order); diff --git a/kernel/dma/remap.c b/kernel/dma/remap.c index 0207e3764d52..a594aec07882 100644 --- a/kernel/dma/remap.c +++ b/kernel/dma/remap.c @@ -202,8 +202,7 @@ void *arch_dma_alloc(struct device *dev, size_t size, dma_addr_t *dma_handle, size = PAGE_ALIGN(size); - if (!gfpflags_allow_blocking(flags) && - !(attrs & DMA_ATTR_NO_KERNEL_MAPPING)) { + if (!gfpflags_allow_blocking(flags)) { ret = dma_alloc_from_pool(size, &page, flags); if (!ret) return NULL; @@ -217,11 +216,6 @@ void *arch_dma_alloc(struct device *dev, size_t size, dma_addr_t *dma_handle, /* remove any dirty cache lines on the kernel alias */ arch_dma_prep_coherent(page, size); - if (attrs & DMA_ATTR_NO_KERNEL_MAPPING) { - ret = page; /* opaque cookie */ - goto done; - } - /* create a coherent mapping */ ret = dma_common_contiguous_remap(page, size, VM_USERMAP, arch_dma_mmap_pgprot(dev, PAGE_KERNEL, attrs), @@ -240,10 +234,7 @@ done: void arch_dma_free(struct device *dev, size_t size, void *vaddr, dma_addr_t dma_handle, unsigned long attrs) { - if (attrs & DMA_ATTR_NO_KERNEL_MAPPING) { - /* vaddr is a struct page cookie, not a kernel address */ - __dma_direct_free_pages(dev, size, vaddr); - } else if (!dma_free_from_pool(vaddr, PAGE_ALIGN(size))) { + if (!dma_free_from_pool(vaddr, PAGE_ALIGN(size))) { phys_addr_t phys = dma_to_phys(dev, dma_handle); struct page *page = pfn_to_page(__phys_to_pfn(phys)); -- cgit v1.2.3