Merge branch 'for-v4.1-rc1' of git://git.linaro.org/people/mszyprowski/linux-dma-mapping
Pull DMA-mapping updates from Marek Szyprowski:
"This contains two patches, which clarify abiguity in the dma-mapping
api"
* 'for-v4.1-rc1' of git://git.linaro.org/people/mszyprowski/linux-dma-mapping:
include/dma-mapping: Clarify output of dma_map_sg
asm/dma-mapping-common: Clarify output of dma_map_sg_attrs
diff --git a/include/asm-generic/dma-mapping-common.h b/include/asm-generic/dma-mapping-common.h
index 3378dcf..940d5ec 100644
--- a/include/asm-generic/dma-mapping-common.h
+++ b/include/asm-generic/dma-mapping-common.h
@@ -39,6 +39,10 @@
debug_dma_unmap_page(dev, addr, size, dir, true);
}
+/*
+ * dma_maps_sg_attrs returns 0 on error and > 0 on success.
+ * It should never return a value < 0.
+ */
static inline int dma_map_sg_attrs(struct device *dev, struct scatterlist *sg,
int nents, enum dma_data_direction dir,
struct dma_attrs *attrs)
@@ -51,6 +55,7 @@
kmemcheck_mark_initialized(sg_virt(s), s->length);
BUG_ON(!valid_dma_direction(dir));
ents = ops->map_sg(dev, sg, nents, dir, attrs);
+ BUG_ON(ents < 0);
debug_dma_map_sg(dev, sg, nents, ents, dir);
return ents;
diff --git a/include/linux/dma-mapping.h b/include/linux/dma-mapping.h
index c3007cb..ac07ff0 100644
--- a/include/linux/dma-mapping.h
+++ b/include/linux/dma-mapping.h
@@ -34,6 +34,10 @@
void (*unmap_page)(struct device *dev, dma_addr_t dma_handle,
size_t size, enum dma_data_direction dir,
struct dma_attrs *attrs);
+ /*
+ * map_sg returns 0 on error and a value > 0 on success.
+ * It should never return a value < 0.
+ */
int (*map_sg)(struct device *dev, struct scatterlist *sg,
int nents, enum dma_data_direction dir,
struct dma_attrs *attrs);