From: hch@infradead.org (Christoph Hellwig)
Subject: [PATCH 0/5 v2] Fix NVMe driver support on Power with 32-bit DMA
Date: Sat, 3 Oct 2015 01:19:52 -0700 [thread overview]
Message-ID: <20151003081952.GC24025@infradead.org> (raw)
In-Reply-To: <1443819066.27295.19.camel@kernel.crashing.org>
On Sat, Oct 03, 2015@06:51:06AM +1000, Benjamin Herrenschmidt wrote:
> On Fri, 2015-10-02@13:09 -0700, Nishanth Aravamudan wrote:
>
> > 1) add a generic dma_get_page_shift implementation that just returns
> > PAGE_SHIFT
>
> So you chose to return the granularity of the iommu to the driver
> rather than providing a way for the driver to request a specific
> alignment for DMA mappings. Any specific reason ?
At least for NVMe that's the way to go - it allows to set a page set in
the device which should fit the IOMMU page size.
WARNING: multiple messages have this Message-ID (diff)
From: Christoph Hellwig <hch@infradead.org>
To: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Cc: Nishanth Aravamudan <nacc@linux.vnet.ibm.com>,
Matthew Wilcox <willy@linux.intel.com>,
Keith Busch <keith.busch@intel.com>,
Paul Mackerras <paulus@samba.org>,
Michael Ellerman <mpe@ellerman.id.au>,
Alexey Kardashevskiy <aik@ozlabs.ru>,
David Gibson <david@gibson.dropbear.id.au>,
Christoph Hellwig <hch@infradead.org>,
linux-nvme@lists.infradead.org, linux-kernel@vger.kernel.org,
linuxppc-dev@lists.ozlabs.org
Subject: Re: [PATCH 0/5 v2] Fix NVMe driver support on Power with 32-bit DMA
Date: Sat, 3 Oct 2015 01:19:52 -0700 [thread overview]
Message-ID: <20151003081952.GC24025@infradead.org> (raw)
In-Reply-To: <1443819066.27295.19.camel@kernel.crashing.org>
On Sat, Oct 03, 2015 at 06:51:06AM +1000, Benjamin Herrenschmidt wrote:
> On Fri, 2015-10-02 at 13:09 -0700, Nishanth Aravamudan wrote:
>
> > 1) add a generic dma_get_page_shift implementation that just returns
> > PAGE_SHIFT
>
> So you chose to return the granularity of the iommu to the driver
> rather than providing a way for the driver to request a specific
> alignment for DMA mappings. Any specific reason ?
At least for NVMe that's the way to go - it allows to set a page set in
the device which should fit the IOMMU page size.
next prev parent reply other threads:[~2015-10-03 8:19 UTC|newest]
Thread overview: 84+ messages / expand[flat|nested] mbox.gz Atom feed top
2015-10-02 17:16 [PATCH 0/2] Fix NVMe driver support on Power with 32-bit DMA Nishanth Aravamudan
2015-10-02 17:16 ` Nishanth Aravamudan
2015-10-02 17:18 ` [PATCH 1/2] powerpc/iommu: expose IOMMU page shift Nishanth Aravamudan
2015-10-02 17:18 ` Nishanth Aravamudan
2015-10-02 17:23 ` [PATCH 2/2] drivers/nvme: default to the IOMMU page size on Power Nishanth Aravamudan
2015-10-02 17:23 ` Nishanth Aravamudan
2015-10-02 17:25 ` Christoph Hellwig
2015-10-02 17:25 ` Christoph Hellwig
2015-10-02 17:39 ` Nishanth Aravamudan
2015-10-02 17:39 ` Nishanth Aravamudan
2015-10-02 17:41 ` Christoph Hellwig
2015-10-02 17:41 ` Christoph Hellwig
2015-10-02 18:57 ` kbuild test robot
2015-10-02 18:57 ` kbuild test robot
2015-10-06 3:19 ` [PATCH 1/2] powerpc/iommu: expose IOMMU page shift David Gibson
2015-10-06 3:19 ` David Gibson
2015-10-12 16:03 ` Nishanth Aravamudan
2015-10-12 16:03 ` Nishanth Aravamudan
2015-10-12 21:10 ` Nishanth Aravamudan
2015-10-12 21:10 ` Nishanth Aravamudan
2015-10-02 20:09 ` [PATCH 0/5 v2] Fix NVMe driver support on Power with 32-bit DMA Nishanth Aravamudan
2015-10-02 20:09 ` Nishanth Aravamudan
2015-10-02 20:11 ` [PATCH 1/5 v2] dma-mapping: add generic dma_get_page_shift API Nishanth Aravamudan
2015-10-02 20:11 ` Nishanth Aravamudan
2015-10-02 20:16 ` [PATCH 2/5 v2] powerpc/dma-mapping: override dma_get_page_shift Nishanth Aravamudan
2015-10-02 20:16 ` Nishanth Aravamudan
2015-10-02 20:19 ` [PATCH 3/5 v2] powerpc/dma: implement per-platform dma_get_page_shift Nishanth Aravamudan
2015-10-02 20:19 ` Nishanth Aravamudan
2015-10-02 20:21 ` [PATCH 4/5 v2] pseries/iommu: implement DDW-aware dma_get_page_shift Nishanth Aravamudan
2015-10-02 20:21 ` Nishanth Aravamudan
2015-10-02 20:30 ` [PATCH 5/5 v2] drivers/nvme: default to the IOMMU page size Nishanth Aravamudan
2015-10-02 20:30 ` Nishanth Aravamudan
2015-10-02 20:43 ` kbuild test robot
2015-10-02 20:43 ` kbuild test robot
2015-10-02 20:33 ` [PATCH 4/5 v2] pseries/iommu: implement DDW-aware dma_get_page_shift kbuild test robot
2015-10-02 20:33 ` kbuild test robot
2015-10-06 3:39 ` Michael Ellerman
2015-10-06 3:39 ` Michael Ellerman
2015-10-07 13:56 ` [kbuild-all] " Fengguang Wu
2015-10-07 13:56 ` Fengguang Wu
2015-10-08 0:11 ` Michael Ellerman
2015-10-08 0:11 ` Michael Ellerman
2015-10-08 1:06 ` Fengguang Wu
2015-10-08 1:06 ` Fengguang Wu
2015-10-08 1:16 ` Fengguang Wu
2015-10-08 1:16 ` Fengguang Wu
2015-10-08 4:06 ` Michael Ellerman
2015-10-08 4:06 ` Michael Ellerman
2015-10-11 14:22 ` Fengguang Wu
2015-10-11 14:22 ` Fengguang Wu
2015-10-12 2:51 ` Michael Ellerman
2015-10-12 2:51 ` Michael Ellerman
2015-10-08 7:46 ` Christoph Hellwig
2015-10-08 7:46 ` Christoph Hellwig
2015-10-11 14:19 ` testing email patches Fengguang Wu
2015-10-11 14:19 ` Fengguang Wu
2015-10-06 3:43 ` [PATCH 1/5 v2] dma-mapping: add generic dma_get_page_shift API Michael Ellerman
2015-10-06 3:43 ` Michael Ellerman
2015-10-06 9:51 ` Christoph Hellwig
2015-10-06 9:51 ` Christoph Hellwig
2015-10-12 16:04 ` Nishanth Aravamudan
2015-10-12 16:04 ` Nishanth Aravamudan
2015-10-12 21:06 ` Nishanth Aravamudan
2015-10-12 21:06 ` Nishanth Aravamudan
2015-10-14 15:39 ` Nishanth Aravamudan
2015-10-14 15:39 ` Nishanth Aravamudan
2015-10-14 15:42 ` Christoph Hellwig
2015-10-14 15:42 ` Christoph Hellwig
2015-10-15 22:52 ` Nishanth Aravamudan
2015-10-15 22:52 ` Nishanth Aravamudan
2015-10-15 22:52 ` Nishanth Aravamudan
2015-10-19 17:56 ` Nishanth Aravamudan
2015-10-19 17:56 ` Nishanth Aravamudan
2015-10-19 17:56 ` Nishanth Aravamudan
2015-10-02 20:51 ` [PATCH 0/5 v2] Fix NVMe driver support on Power with 32-bit DMA Benjamin Herrenschmidt
2015-10-02 20:51 ` Benjamin Herrenschmidt
2015-10-02 21:04 ` Nishanth Aravamudan
2015-10-02 21:04 ` Nishanth Aravamudan
2015-10-02 21:35 ` Benjamin Herrenschmidt
2015-10-02 21:35 ` Benjamin Herrenschmidt
2015-10-02 21:48 ` Nishanth Aravamudan
2015-10-02 21:48 ` Nishanth Aravamudan
2015-10-03 8:19 ` Christoph Hellwig [this message]
2015-10-03 8:19 ` Christoph Hellwig
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