Re: [PATCH 0/5 v3] Fix NVMe driver support on Power with 32-bit DMA

On 29.10.2015 [18:49:55 -0700], David Miller wrote: > From: Nishanth Aravamudan > Date: Thu, 29 Oct 2015 08:57:01 -0700 > > > So, would that imply changing just the NVMe driver code rather than > > adding the dma_page_shift API at all? What about > > architectures that

Re: [PATCH 0/5 v3] Fix NVMe driver support on Power with 32-bit DMA

On Wed, Oct 28, 2015 at 01:59:23PM +, Busch, Keith wrote: > The "new" interface for all the other architectures is the same as the > old one we've been using for the last 5 years. > > I welcome x86 maintainer feedback to confirm virtual and DMA addresses > have the same offset at 4k

Re: [PATCH 0/5 v3] Fix NVMe driver support on Power with 32-bit DMA

On 29.10.2015 [04:55:36 -0700], Christoph Hellwig wrote: > On Wed, Oct 28, 2015 at 01:59:23PM +, Busch, Keith wrote: > > The "new" interface for all the other architectures is the same as the > > old one we've been using for the last 5 years. > > > > I welcome x86 maintainer feedback to

Re: [PATCH 0/5 v3] Fix NVMe driver support on Power with 32-bit DMA

On Thu, Oct 29, 2015 at 08:57:01AM -0700, Nishanth Aravamudan wrote: > On 29.10.2015 [04:55:36 -0700], Christoph Hellwig wrote: > > We had a quick cht about this issue and I think we simply should > > default to a NVMe controler page size of 4k everywhere as that's the > > safe default. This is

Re: [PATCH 0/5 v3] Fix NVMe driver support on Power with 32-bit DMA

From: Nishanth Aravamudan Date: Thu, 29 Oct 2015 08:57:01 -0700 > So, would that imply changing just the NVMe driver code rather than > adding the dma_page_shift API at all? What about > architectures that can support the larger page sizes? There is an > implied

Re: [PATCH 0/5 v3] Fix NVMe driver support on Power with 32-bit DMA

On Tue, Oct 27, 2015 at 05:54:43PM -0700, David Miller wrote: > From: "Busch, Keith" > Date: Tue, 27 Oct 2015 22:36:43 + > > > If you're suggesting to compile-time break architectures that currently > > work just fine with NVMe, let me stop you right there. > >

Re: [PATCH 0/5 v3] Fix NVMe driver support on Power with 32-bit DMA

On 26.10.2015 [18:27:46 -0700], David Miller wrote: > From: Nishanth Aravamudan > 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

Re: [PATCH 0/5 v3] Fix NVMe driver support on Power with 32-bit DMA

Hi Nishanth, On Wed, Oct 28, 2015 at 9:20 AM, Nishanth Aravamudan wrote: > On 26.10.2015 [18:27:46 -0700], David Miller wrote: >> From: Nishanth Aravamudan >> Date: Fri, 23 Oct 2015 13:54:20 -0700 >> >> > 1) add a generic dma_get_page_shift

Re: [PATCH 0/5 v3] Fix NVMe driver support on Power with 32-bit DMA

On 28.10.2015 [09:57:48 +1100], Julian Calaby wrote: > Hi Nishanth, > > On Wed, Oct 28, 2015 at 9:20 AM, Nishanth Aravamudan > wrote: > > On 26.10.2015 [18:27:46 -0700], David Miller wrote: > >> From: Nishanth Aravamudan > >> Date: Fri, 23 Oct

Re: [PATCH 0/5 v3] Fix NVMe driver support on Power with 32-bit DMA

On Wed, 2015-10-28 at 10:43 +1100, Julian Calaby wrote: > Hi Nishanth, > You'll be CCing the maintainers of each architecture on the patches > to > add the functions, so if they do have specific requirements, I'm sure > they'll let you know or provide patches. That sort of accross-all-arch change

Re: [PATCH 0/5 v3] Fix NVMe driver support on Power with 32-bit DMA

Hi Nishanth, On Wed, Oct 28, 2015 at 10:40 AM, Nishanth Aravamudan wrote: > On 28.10.2015 [09:57:48 +1100], Julian Calaby wrote: >> Hi Nishanth, >> >> On Wed, Oct 28, 2015 at 9:20 AM, Nishanth Aravamudan >> wrote: >> > On 26.10.2015 [18:27:46

Re: [PATCH 0/5 v3] Fix NVMe driver support on Power with 32-bit DMA

On Tue, Oct 27, 2015 at 03:20:10PM -0700, Nishanth Aravamudan wrote: > On 26.10.2015 [18:27:46 -0700], David Miller wrote: > > From: Nishanth Aravamudan > > Date: Fri, 23 Oct 2015 13:54:20 -0700 > > > > > 1) add a generic dma_get_page_shift implementation that just

Re: [PATCH 0/5 v3] Fix NVMe driver support on Power with 32-bit DMA

From: Nishanth Aravamudan Date: Tue, 27 Oct 2015 15:20:10 -0700 > 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

Re: [PATCH 0/5 v3] Fix NVMe driver support on Power with 32-bit DMA

From: "Busch, Keith" Date: Tue, 27 Oct 2015 22:36:43 + > If you're suggesting to compile-time break architectures that currently > work just fine with NVMe, let me stop you right there. Silently "working" without the architecture maintainer having to explicity look at

Re: [PATCH 0/5 v3] Fix NVMe driver support on Power with 32-bit DMA

On 27.10.2015 [17:53:22 -0700], David Miller wrote: > From: Nishanth Aravamudan > Date: Tue, 27 Oct 2015 15:20:10 -0700 > > > 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 >

Re: [PATCH 0/5 v3] Fix NVMe driver support on Power with 32-bit DMA

From: Julian Calaby Date: Wed, 28 Oct 2015 10:43:35 +1100 > You'll be CCing the maintainers of each architecture on the patches to > add the functions, so if they do have specific requirements, I'm sure > they'll let you know or provide patches. People miss things,

Re: [PATCH 0/5 v3] Fix NVMe driver support on Power with 32-bit DMA

From: Nishanth Aravamudan 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

Re: [PATCH 0/5 v3] Fix NVMe driver support on Power with 32-bit DMA

[Sorry, subject should have been 0/7!] On 23.10.2015 [13:54:20 -0700], Nishanth Aravamudan wrote: > We received a bug report recently when DDW (64-bit direct DMA on Power) > is not enabled for NVMe devices. In that case, we fall back to 32-bit > DMA via the IOMMU, which is always done via 4K TCEs