Re: DMA mapping (was Re: [PATCH] cciss 2.6; replaces DMA maskswith kernel defines)

From: Lee Revell
Date: Fri Jun 10 2005 - 18:15:00 EST


On Fri, 2005-06-10 at 22:30 +0100, Matthew Wilcox wrote:
> On Fri, Jun 10, 2005 at 05:17:32PM -0400, Lee Revell wrote:
> > OK, this covers the drivers I know. I didn't make any attempt to check
> > them all.
>
> I know of two others ...
>
> sym2 has:
> #define DMA_DAC_MASK 0x000000ffffffffffULL /* 40-bit */
>
> and aic7xxx has:
> const uint64_t mask_39bit = 0x7FFFFFFFFFULL;

b44 needs 30 bit:

#define B44_DMA_MASK 0x3fffffff

These seem to be all over the place. I guess it saves a tiny bit of
silicon. Don't these all violate the PCI spec?

Should I just add everything from 24 to 63?

Lee

-
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/