diff options
author | Christoph Hellwig <hch@lst.de> | 2021-01-28 16:53:22 +0300 |
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committer | Christoph Hellwig <hch@lst.de> | 2021-03-15 12:02:31 +0300 |
commit | eedb0b12d091a21909b5e84d9f3e5e649305bd12 (patch) | |
tree | 82524abc75941a66dedc9f476cd576eebc7ba225 /kernel/dma | |
parent | 1e28eed17697bcf343c6743f0028cc3b5dd88bf0 (diff) | |
download | linux-eedb0b12d091a21909b5e84d9f3e5e649305bd12.tar.xz |
dma-mapping: add a dma_mmap_pages helper
Add a helper to map memory allocated using dma_alloc_pages into
a user address space, similar to the dma_alloc_attrs function for
coherent allocations.
Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Tomasz Figa <tfiga@chromium.org>
Tested-by: Ricardo Ribalda <ribalda@chromium.org>
Diffstat (limited to 'kernel/dma')
-rw-r--r-- | kernel/dma/mapping.c | 13 |
1 files changed, 13 insertions, 0 deletions
diff --git a/kernel/dma/mapping.c b/kernel/dma/mapping.c index b6a633679933..9ce86c77651c 100644 --- a/kernel/dma/mapping.c +++ b/kernel/dma/mapping.c @@ -517,6 +517,19 @@ void dma_free_pages(struct device *dev, size_t size, struct page *page, } EXPORT_SYMBOL_GPL(dma_free_pages); +int dma_mmap_pages(struct device *dev, struct vm_area_struct *vma, + size_t size, struct page *page) +{ + unsigned long count = PAGE_ALIGN(size) >> PAGE_SHIFT; + + if (vma->vm_pgoff >= count || vma_pages(vma) > count - vma->vm_pgoff) + return -ENXIO; + return remap_pfn_range(vma, vma->vm_start, + page_to_pfn(page) + vma->vm_pgoff, + vma_pages(vma) << PAGE_SHIFT, vma->vm_page_prot); +} +EXPORT_SYMBOL_GPL(dma_mmap_pages); + int dma_supported(struct device *dev, u64 mask) { const struct dma_map_ops *ops = get_dma_ops(dev); |