James Bottomley wrote: > On Thu, 2008-04-17 at 16:44 +0200, Andi Kleen wrote: >>> For drivers that can alter their descriptor types, we have this >>> function: >>> >>> dma_get_required_mask() >> Are you sure we have it? It seems to be in drivers/base/platform.c >> conditional on ARCH_HAS_DMA_GET_REQUIRED_MASK, but according to my >> grep no architecture ever sets that flag. > > Yes ... positive. That's the default and correct implementation based > on the largest addressable physical memory. Ok but still the whole thing is completely useless right now. >> I don't think it would be very hard to implement on x86 at least, >> mind you. Just nobody seems to have done it so far. > > Really, only machines with IOMMUs that want to restrict this need > implement it. I don't think so. For once in the scenario described by the original poster it makes some sense even without IOMMU. -Andi -- To unsubscribe from this list: send the line "unsubscribe linux-scsi" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
