summaryrefslogtreecommitdiff
path: root/include/linux/dma-mapping.h
diff options
context:
space:
mode:
authorChristoph Hellwig <hch@lst.de>2018-11-21 20:52:35 +0300
committerChristoph Hellwig <hch@lst.de>2018-12-06 17:56:36 +0300
commit42ee3cae0ed38b6c04038bf851ea2496da2135bb (patch)
tree6b6b2dd1c60744a356851bfdb0a217e7f9e8b46e /include/linux/dma-mapping.h
parenta1da439cc0d929891f0f7372c9e03530c809068c (diff)
downloadlinux-42ee3cae0ed38b6c04038bf851ea2496da2135bb.tar.xz
dma-mapping: provide a generic DMA_MAPPING_ERROR
Error handling of the dma_map_single and dma_map_page APIs is a little problematic at the moment, in that we use different encodings in the returned dma_addr_t to indicate an error. That means we require an additional indirect call to figure out if a dma mapping call returned an error, and a lot of boilerplate code to implement these semantics. Instead return the maximum addressable value as the error. As long as we don't allow mapping single-byte ranges with single-byte alignment this value can never be a valid return. Additionaly if drivers do not check the return value from the dma_map* routines this values means they will generally not be pointed to actual memory. Once the default value is added here we can start removing the various mapping_error methods and just rely on this generic check. Signed-off-by: Christoph Hellwig <hch@lst.de> Reviewed-by: Robin Murphy <robin.murphy@arm.com> Acked-by: Russell King <rmk+kernel@armlinux.org.uk> Acked-by: Linus Torvalds <torvalds@linux-foundation.org>
Diffstat (limited to 'include/linux/dma-mapping.h')
-rw-r--r--include/linux/dma-mapping.h5
1 files changed, 5 insertions, 0 deletions
diff --git a/include/linux/dma-mapping.h b/include/linux/dma-mapping.h
index 1a0edcde7d14..f89d277cc8ed 100644
--- a/include/linux/dma-mapping.h
+++ b/include/linux/dma-mapping.h
@@ -133,6 +133,8 @@ struct dma_map_ops {
u64 (*get_required_mask)(struct device *dev);
};
+#define DMA_MAPPING_ERROR (~(dma_addr_t)0)
+
extern const struct dma_map_ops dma_direct_ops;
extern const struct dma_map_ops dma_virt_ops;
@@ -581,8 +583,11 @@ static inline int dma_mapping_error(struct device *dev, dma_addr_t dma_addr)
const struct dma_map_ops *ops = get_dma_ops(dev);
debug_dma_mapping_error(dev, dma_addr);
+
if (ops->mapping_error)
return ops->mapping_error(dev, dma_addr);
+ if (dma_addr == DMA_MAPPING_ERROR)
+ return 1;
return 0;
}