On Mon, May 28, 2012 at 10:19:39AM +0200, Marek Szyprowski wrote: > Hello, > > On Sunday, May 27, 2012 2:35 PM KOSAKI Motohiro wrote: > > > On Thu, May 24, 2012 at 8:28 AM, Paul Mundt <lethal@xxxxxxxxxxxx> wrote: > > > On Thu, May 24, 2012 at 02:26:12PM +0200, Marek Szyprowski wrote: > > >> On Tuesday, May 22, 2012 9:08 AM Minchan Kim wrote: > > >> > Hmm, VM_DMA would become generic flag? > > >> > AFAIU, maybe VM_DMA would be used only on ARM arch. > > >> > > >> Right now yes, it will be used only on ARM architecture, but maybe other architecture will > > >> start using it once it is available. > > >> > > > There's very little about the code in question that is ARM-specific to > > > begin with. I plan to adopt similar changes on SH once the work has > > > settled one way or the other, so we'll probably use the VMA flag there, > > > too. > > > > I don't think VM_DMA is good idea because x86_64 has two dma zones. x86 unaware > > patches make no sense. > > I see no problems to add VM_DMA64 later if x86_64 starts using vmalloc areas for creating > kernel mappings for the dma buffers (I assume that there are 2 dma zones: one 32bit and one > 64bit). Right now x86 and x86_64 don't use vmalloc areas for dma buffers, so I hardly see > how this patch can be considered as 'x86 unaware'. Well they do - kind off. It is usually done by calling vmalloc_32 and then using the DMA API on top of those pages (or sometimes the non-portable virt_to_phys macro). Introducing this and replacing the vmalloc_32 with this seems like a nice step in making those device drivers APIs more portable? -- To unsubscribe, send a message with 'unsubscribe linux-mm' in the body to majordomo@xxxxxxxxx. For more info on Linux MM, see: http://www.linux-mm.org/ . Fight unfair telecom internet charges in Canada: sign http://stopthemeter.ca/ Don't email: <a href=mailto:"dont@xxxxxxxxx";> email@xxxxxxxxx </a>