[PATCH 1/4] add is_buffer_dma_capable helper function

From: FUJITA Tomonori
Date: Tue Sep 09 2008 - 12:10:51 EST

is_buffer_dma_capable helper function is to see if a memory region is
DMA-capable or not. The arugments are the dma_mask (or
coherent_dma_mask) of a device and the address and size of a memory

Signed-off-by: FUJITA Tomonori <fujita.tomonori@xxxxxxxxxxxxx>
Cc: Tony Luck <tony.luck@xxxxxxxxx>
Cc: Joerg Roedel <joerg.roedel@xxxxxxx>
include/linux/dma-mapping.h | 5 +++++
1 files changed, 5 insertions(+), 0 deletions(-)

diff --git a/include/linux/dma-mapping.h b/include/linux/dma-mapping.h
index 952e0f8..6ed50c1 100644
--- a/include/linux/dma-mapping.h
+++ b/include/linux/dma-mapping.h
@@ -48,6 +48,11 @@ static inline int is_device_dma_capable(struct device *dev)
return dev->dma_mask != NULL && *dev->dma_mask != DMA_MASK_NONE;

+static inline int is_buffer_dma_capable(u64 mask, dma_addr_t addr, size_t size)
+ return addr + size <= mask;
#include <asm/dma-mapping.h>

To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@xxxxxxxxxxxxxxx
More majordomo info at http://vger.kernel.org/majordomo-info.html
Please read the FAQ at http://www.tux.org/lkml/