On 28.10.2015 [09:57:48 +1100], Julian Calaby wrote: > Hi Nishanth, > > On Wed, Oct 28, 2015 at 9:20 AM, Nishanth Aravamudan > <nacc@xxxxxxxxxxxxxxxxxx> wrote: > > On 26.10.2015 [18:27:46 -0700], David Miller wrote: > >> From: Nishanth Aravamudan <nacc@xxxxxxxxxxxxxxxxxx> > >> Date: Fri, 23 Oct 2015 13:54:20 -0700 > >> > >> > 1) add a generic dma_get_page_shift implementation that just returns > >> > PAGE_SHIFT > >> > >> I won't object to this patch series, but if I had implemented this I > >> would have required the architectures to implement this explicitly, > >> one-by-one. I think it is less error prone and more likely to end > >> up with all the architectures setting this correctly. > > > > Well, looks like I should spin up a v4 anyways for the powerpc changes. > > So, to make sure I understand your point, should I make the generic > > dma_get_page_shift a compile-error kind of thing? It will only fail on > > architectures that actually build the NVME driver (as the only caller). > > But I'm not sure how exactly to achieve that, if you could give a bit > > more detail I'd appreciate it! > > He's suggesting that you _don't_ put a generic implementation in > /include/linux/dma-mapping.h and instead add it to _every_ > architecture. Ah, I see! Well, I don't know much about the DMA internals of most architectures -- and my approach kept things functionally the same everywhere (using PAGE_SHIFT) except: a) Power, where I know it doesn't work as-is and b) sparc, where the code implied that a different value than PAGE_SHIFT should be used. Thanks, Nish -- To unsubscribe from this list: send the line "unsubscribe sparclinux" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
