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authorJames Bottomley <James.Bottomley@SteelEye.com>2007-10-16 04:23:55 -0400
committerLinus Torvalds <torvalds@woody.linux-foundation.org>2007-10-16 12:42:50 -0400
commit32e8f70230c0c417490787b3f48b6ed6c48e7ec9 (patch)
tree54ef9f6c8960ab2a9634d0d82d69d6049bc6f3fb /include/linux/dma-mapping.h
parent64da82efae0d7b5f7c478021840fd329f76d965d (diff)
introduce DMA_MASK_NONE as a signal for unable to do DMA
Some devices are incapable of DMA and need to be recognised as such. Introduce a NONE dma mask to facilitate this plus an inline function: is_device_dma_capable() to check this. Signed-off-by: James Bottomley <James.Bottomley@SteelEye.com> Cc: Andi Kleen <andi@firstfloor.org> Cc: Alan Cox <alan@lxorguk.ukuu.org.uk> Cc: Tejun Heo <htejun@gmail.com> Cc: Natalie Protasevich <protasnb@gmail.com> Cc: Jeff Garzik <jgarzik@pobox.com> Cc: Dominik Brodowski <linux@dominikbrodowski.net> Cc: Russell King <rmk@arm.linux.org.uk> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Diffstat (limited to 'include/linux/dma-mapping.h')
-rw-r--r--include/linux/dma-mapping.h7
1 files changed, 7 insertions, 0 deletions
diff --git a/include/linux/dma-mapping.h b/include/linux/dma-mapping.h
index 2dc21cbeb304..0ebfafbd338c 100644
--- a/include/linux/dma-mapping.h
+++ b/include/linux/dma-mapping.h
@@ -24,6 +24,8 @@ enum dma_data_direction {
24#define DMA_28BIT_MASK 0x000000000fffffffULL 24#define DMA_28BIT_MASK 0x000000000fffffffULL
25#define DMA_24BIT_MASK 0x0000000000ffffffULL 25#define DMA_24BIT_MASK 0x0000000000ffffffULL
26 26
27#define DMA_MASK_NONE 0x0ULL
28
27static inline int valid_dma_direction(int dma_direction) 29static inline int valid_dma_direction(int dma_direction)
28{ 30{
29 return ((dma_direction == DMA_BIDIRECTIONAL) || 31 return ((dma_direction == DMA_BIDIRECTIONAL) ||
@@ -31,6 +33,11 @@ static inline int valid_dma_direction(int dma_direction)
31 (dma_direction == DMA_FROM_DEVICE)); 33 (dma_direction == DMA_FROM_DEVICE));
32} 34}
33 35
36static inline int is_device_dma_capable(struct device *dev)
37{
38 return dev->dma_mask != NULL && *dev->dma_mask != DMA_MASK_NONE;
39}
40
34#ifdef CONFIG_HAS_DMA 41#ifdef CONFIG_HAS_DMA
35#include <asm/dma-mapping.h> 42#include <asm/dma-mapping.h>
36#else 43#else