From mboxrd@z Thu Jan 1 00:00:00 1970 From: vladimir.murzin@arm.com (Vladimir Murzin) Date: Tue, 10 Jan 2017 14:18:41 +0000 Subject: [RFC PATCH v4 1/5] dma: Add simple dma_noop_mmap In-Reply-To: <1484057925-23586-1-git-send-email-vladimir.murzin@arm.com> References: <1484057925-23586-1-git-send-email-vladimir.murzin@arm.com> Message-ID: <1484057925-23586-2-git-send-email-vladimir.murzin@arm.com> To: linux-arm-kernel@lists.infradead.org List-Id: linux-arm-kernel.lists.infradead.org This patch adds a simple implementation of mmap to dma_noop_ops. Cc: Christian Borntraeger Signed-off-by: Vladimir Murzin --- lib/dma-noop.c | 21 +++++++++++++++++++++ 1 file changed, 21 insertions(+) diff --git a/lib/dma-noop.c b/lib/dma-noop.c index 3d766e7..96638a1 100644 --- a/lib/dma-noop.c +++ b/lib/dma-noop.c @@ -64,6 +64,26 @@ 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; +} + struct dma_map_ops dma_noop_ops = { .alloc = dma_noop_alloc, .free = dma_noop_free, @@ -71,6 +91,7 @@ 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