From 58b0440663ec11372befb8ead0ee7099d8878590 Mon Sep 17 00:00:00 2001 From: Christoph Hellwig Date: Tue, 11 Sep 2018 08:55:28 +0200 Subject: dma-mapping: consolidate the dma mmap implementations The only functional differences (modulo a few missing fixes in the arch code) is that architectures without coherent caches need a hook to convert a virtual or dma address into a pfn, given that we don't have the kernel linear mapping available for the otherwise easy virt_to_page call. As a side effect we can support mmap of the per-device coherent area even on architectures not providing the callback, and we make previous dangerous default methods dma_common_mmap actually save for non-coherent architectures by rejecting it without the right helper. In addition to that we need a hook so that some architectures can override the protection bits when mmaping a dma coherent allocations. Signed-off-by: Christoph Hellwig Acked-by: Paul Burton # MIPS parts --- kernel/dma/mapping.c | 32 +++++++++++++++++++++----------- 1 file changed, 21 insertions(+), 11 deletions(-) (limited to 'kernel/dma/mapping.c') diff --git a/kernel/dma/mapping.c b/kernel/dma/mapping.c index 3540cb399bd2..42fd73aca305 100644 --- a/kernel/dma/mapping.c +++ b/kernel/dma/mapping.c @@ -7,7 +7,7 @@ */ #include -#include +#include #include #include #include @@ -220,27 +220,37 @@ EXPORT_SYMBOL(dma_common_get_sgtable); * Create userspace mapping for the DMA-coherent memory. */ int dma_common_mmap(struct device *dev, struct vm_area_struct *vma, - void *cpu_addr, dma_addr_t dma_addr, size_t size) + void *cpu_addr, dma_addr_t dma_addr, size_t size, + unsigned long attrs) { - int ret = -ENXIO; #ifndef CONFIG_ARCH_NO_COHERENT_DMA_MMAP unsigned long user_count = vma_pages(vma); unsigned long count = PAGE_ALIGN(size) >> PAGE_SHIFT; unsigned long off = vma->vm_pgoff; + unsigned long pfn; + int ret = -ENXIO; - vma->vm_page_prot = pgprot_noncached(vma->vm_page_prot); + vma->vm_page_prot = arch_dma_mmap_pgprot(dev, vma->vm_page_prot, attrs); if (dma_mmap_from_dev_coherent(dev, vma, cpu_addr, size, &ret)) return ret; - if (off < count && user_count <= (count - off)) - ret = remap_pfn_range(vma, vma->vm_start, - page_to_pfn(virt_to_page(cpu_addr)) + off, - user_count << PAGE_SHIFT, - vma->vm_page_prot); -#endif /* !CONFIG_ARCH_NO_COHERENT_DMA_MMAP */ + if (off >= count || user_count > count - off) + return -ENXIO; + + if (!dev_is_dma_coherent(dev)) { + if (!IS_ENABLED(CONFIG_ARCH_HAS_DMA_COHERENT_TO_PFN)) + return -ENXIO; + pfn = arch_dma_coherent_to_pfn(dev, cpu_addr, dma_addr); + } else { + pfn = page_to_pfn(virt_to_page(cpu_addr)); + } - return ret; + return remap_pfn_range(vma, vma->vm_start, pfn + vma->vm_pgoff, + user_count << PAGE_SHIFT, vma->vm_page_prot); +#else + return -ENXIO; +#endif /* !CONFIG_ARCH_NO_COHERENT_DMA_MMAP */ } EXPORT_SYMBOL(dma_common_mmap); -- cgit v1.2.3