This patch adds a simple implementation of mmap to dma_noop_ops.
Cc: Joerg Roedel <jroe...@suse.de>
Cc: Christian Borntraeger <borntrae...@de.ibm.com>
Reported-by: Benjamin Gaignard <benjamin.gaign...@linaro.org>
Tested-by: Benjamin Gaignard <benjamin.gaign...@linaro.org>
Tested-by: Andras Szemzo <s...@esh.hu>
Tested-by: Alexandre TORGUE <alexandre.tor...@st.com>
Signed-off-by: Vladimir Murzin <vladimir.mur...@arm.com>
---
lib/dma-noop.c | 24 ++++++++++++++++++++++++
1 file changed, 24 insertions(+)
diff --git a/lib/dma-noop.c b/lib/dma-noop.c
index 1f60c8a..4b43d15 100644
--- a/lib/dma-noop.c
+++ b/lib/dma-noop.c
@@ -67,6 +67,29 @@ 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 (dma_mmap_from_coherent(dev, vma, cpu_addr, size, &ret))
+ return ret;
+
+ 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,
@@ -74,6 +97,7 @@ 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
