Messages in this thread Patch in this message | | | From | Vladimir Murzin <> | Subject | [PATCH v4 2/7] dma: Add simple dma_noop_mmap | Date | Mon, 24 Apr 2017 11:16:52 +0100 |
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This patch adds a simple implementation of mmap to dma_noop_ops.
Cc: Joerg Roedel <jroedel@suse.de> Cc: Christian Borntraeger <borntraeger@de.ibm.com> Reported-by: Benjamin Gaignard <benjamin.gaignard@linaro.org> Tested-by: Benjamin Gaignard <benjamin.gaignard@linaro.org> Tested-by: Andras Szemzo <sza@esh.hu> Tested-by: Alexandre TORGUE <alexandre.torgue@st.com> Signed-off-by: Vladimir Murzin <vladimir.murzin@arm.com> --- lib/dma-noop.c | 21 +++++++++++++++++++++ 1 file changed, 21 insertions(+)
diff --git a/lib/dma-noop.c b/lib/dma-noop.c index ff4ef5e..0acc3f6 100644 --- a/lib/dma-noop.c +++ b/lib/dma-noop.c @@ -66,6 +66,26 @@ static int dma_noop_supported(struct device *dev, u64 mask) return 1; } +static int dma_noop_mmap(struct device *dev, struct vm_area_struct *vma, + void *cpu_addr, dma_addr_t dma_addr, size_t size, + unsigned long attrs) +{ + unsigned long user_count = vma_pages(vma); + unsigned long count = PAGE_ALIGN(size) >> PAGE_SHIFT; + unsigned long pfn = page_to_pfn(virt_to_page(cpu_addr)); + unsigned long off = vma->vm_pgoff; + int ret = -ENXIO; + + if (off < count && user_count <= (count - off)) { + ret = remap_pfn_range(vma, vma->vm_start, + pfn + off, + user_count << PAGE_SHIFT, + vma->vm_page_prot); + } + + return ret; +} + const struct dma_map_ops dma_noop_ops = { .alloc = dma_noop_alloc, .free = dma_noop_free, @@ -73,6 +93,7 @@ const struct dma_map_ops dma_noop_ops = { .map_sg = dma_noop_map_sg, .mapping_error = dma_noop_mapping_error, .dma_supported = dma_noop_supported, + .mmap = dma_noop_mmap, }; EXPORT_SYMBOL(dma_noop_ops); -- 2.0.0
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