dma: Introduce dma_max_mapping_size()
The function returns the maximum size that can be mapped
using DMA-API functions. The patch also adds the
implementation for direct DMA and a new dma_map_ops pointer
so that other implementations can expose their limit.
Cc: stable@vger.kernel.org
Reviewed-by: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Joerg Roedel <jroedel@suse.de>
Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
diff --git a/include/linux/dma-mapping.h b/include/linux/dma-mapping.h
index f6ded99..5b21f14 100644
--- a/include/linux/dma-mapping.h
+++ b/include/linux/dma-mapping.h
@@ -130,6 +130,7 @@
enum dma_data_direction direction);
int (*dma_supported)(struct device *dev, u64 mask);
u64 (*get_required_mask)(struct device *dev);
+ size_t (*max_mapping_size)(struct device *dev);
};
#define DMA_MAPPING_ERROR (~(dma_addr_t)0)
@@ -257,6 +258,8 @@
}
#endif
+size_t dma_direct_max_mapping_size(struct device *dev);
+
#ifdef CONFIG_HAS_DMA
#include <asm/dma-mapping.h>
@@ -460,6 +463,7 @@
int dma_set_mask(struct device *dev, u64 mask);
int dma_set_coherent_mask(struct device *dev, u64 mask);
u64 dma_get_required_mask(struct device *dev);
+size_t dma_max_mapping_size(struct device *dev);
#else /* CONFIG_HAS_DMA */
static inline dma_addr_t dma_map_page_attrs(struct device *dev,
struct page *page, size_t offset, size_t size,
@@ -561,6 +565,10 @@
{
return 0;
}
+static inline size_t dma_max_mapping_size(struct device *dev)
+{
+ return 0;
+}
#endif /* CONFIG_HAS_DMA */
static inline dma_addr_t dma_map_single_attrs(struct device *dev, void *ptr,