Messages in this thread Patch in this message | | | Date | Fri, 10 Oct 2008 09:46:33 -0700 | From | Yinghai Lu <> | Subject | Re: [PATCH] pci: print out DMA mask info |
| |
Matthew Wilcox wrote: > > By the way, commit 8f286c33f1e838d631f4a3260b33efce4bc5973c is a really > bad idea. It is very helpful to see which bitmasks are used by real > devices, and which ones aren't. It should be reverted, IMO. >
why? did you point to wrong commit?
commit 8f286c33f1e838d631f4a3260b33efce4bc5973c Author: Andrew Morton <akpm@linux-foundation.org> Date: Thu Oct 18 03:05:07 2007 -0700
stop using DMA_xxBIT_MASK
Now that we have DMA_BIT_MASK(), these macros are pointless.
Cc: Jeremy Fitzhardinge <jeremy@goop.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
diff --git a/include/linux/dma-mapping.h b/include/linux/dma-mapping.h index 29b0285..101a2d4 100644 --- a/include/linux/dma-mapping.h +++ b/include/linux/dma-mapping.h @@ -13,9 +13,15 @@ enum dma_data_direction { DMA_NONE = 3, }; -#define DMA_BIT_MASK(n) ((1ULL<<(n))-1) +#define DMA_BIT_MASK(n) (((n) == 64) ? ~0ULL : ((1ULL<<(n))-1)) -#define DMA_64BIT_MASK (~0ULL) +/* + * NOTE: do not use the below macros in new code and do not add new definitions + * here. + * + * Instead, just open-code DMA_BIT_MASK(n) within your driver + */ +#define DMA_64BIT_MASK DMA_BIT_MASK(64) #define DMA_48BIT_MASK DMA_BIT_MASK(48) #define DMA_47BIT_MASK DMA_BIT_MASK(47) #define DMA_40BIT_MASK DMA_BIT_MASK(40)
| |