Valery Ushakov <u...@stderr.spb.ru> writes:
> On Fri, Oct 04, 2024 at 18:58:39 +0000, Van Ly wrote: > >> => http://sdf.org/~van.ly/art/bus-dma-9-copyedit.jpeg > > I don't think so. "Exclusive" here means that the given flag is > mutually exclusive with another flag. It doesn't make sense to > combine nocache and prefetchable exclusive and that's what the > highlighted sentences say. > I haven't made the cognitive effort. The indenting in the presentation and separation distance of tokens had my eyes wanting to group them that way on skim reading, perhaps an xor flag demonstration gets the intended point across succinctly 1 BUS_DMA_NOCACHE This flag is a hint to machine- 2 dependent code. If possible, map the 3 memory uncached. This flag may be 4 useful in the case that the memory 5 cache causes unexpected behavior of the 6 device. 7 8 Exclusive with BUS_DMA_PREFETCHABLE. 9 BUS_DMA_PREFETCHABLE 10 This flag is a hint to machine- 11 dependent code. If possible, map the 12 memory prefetchable/write-combining. 13 14 Exclusive with BUS_DMA_NOCACHE. -- vl
