From: Robin Murphy <robin.murphy@arm.com>
To: Keith Busch <kbusch@kernel.org>, Christoph Hellwig <hch@lst.de>
Cc: nvdimm@lists.linux.dev, linux-rdma@vger.kernel.org,
John Hubbard <jhubbard@nvidia.com>,
linux-kernel@vger.kernel.org,
Matthew Wilcox <willy@infradead.org>,
Ming Lei <ming.lei@redhat.com>,
linux-block@vger.kernel.org, linux-mm@kvack.org,
dri-devel@lists.freedesktop.org, Jason Gunthorpe <jgg@nvidia.com>,
netdev@vger.kernel.org, Joao Martins <joao.m.martins@oracle.com>,
Logan Gunthorpe <logang@deltatee.com>
Subject: Re: Phyr Starter
Date: Thu, 20 Jan 2022 17:54:30 +0000 [thread overview]
Message-ID: <744d247c-bbb5-80aa-f774-c65791cb0766@arm.com> (raw)
In-Reply-To: <20220120152736.GB383746@dhcp-10-100-145-180.wdc.com>
On 2022-01-20 15:27, Keith Busch wrote:
> On Thu, Jan 20, 2022 at 02:56:02PM +0100, Christoph Hellwig wrote:
>> - on the input side to dma mapping the bio_vecs (or phyrs) are chained
>> as bios or whatever the containing structure is. These already exist
>> and have infrastructure at least in the block layer
>> - on the output side I plan for two options:
>>
>> 1) we have a sane IOMMU and everyting will be coalesced into a
>> single dma_range. This requires setting the block layer
>> merge boundary to match the IOMMU page size, but that is
>> a very good thing to do anyway.
>
> It doesn't look like IOMMU page sizes are exported, or even necessarily
> consistently sized on at least one arch (power).
FWIW POWER does its own thing separate from the IOMMU API. For all the
regular IOMMU API players, page sizes are published in the iommu_domain
that the common iommu-dma layer operates on. In fact it already uses
them to pick chunk sizes for composing large buffer allocations.
Robin.
next prev parent reply other threads:[~2022-01-20 17:54 UTC|newest]
Thread overview: 36+ messages / expand[flat|nested] mbox.gz Atom feed top
2022-01-10 19:34 Phyr Starter Matthew Wilcox
2022-01-11 0:41 ` Jason Gunthorpe
2022-01-11 4:32 ` Matthew Wilcox
2022-01-11 15:01 ` Jason Gunthorpe
2022-01-11 18:33 ` Matthew Wilcox
2022-01-11 20:21 ` Jason Gunthorpe
2022-01-11 21:25 ` Matthew Wilcox
2022-01-11 22:09 ` Logan Gunthorpe
2022-01-11 22:57 ` Jason Gunthorpe
2022-01-11 23:02 ` Logan Gunthorpe
2022-01-11 22:53 ` Jason Gunthorpe
2022-01-11 22:57 ` Logan Gunthorpe
2022-01-11 23:02 ` Jason Gunthorpe
2022-01-11 23:08 ` Logan Gunthorpe
2022-01-12 18:37 ` Matthew Wilcox
2022-01-12 19:08 ` Jason Gunthorpe
2022-01-20 14:03 ` Christoph Hellwig
2022-01-20 17:17 ` Jason Gunthorpe
2022-01-20 14:00 ` Christoph Hellwig
2022-01-11 9:05 ` Daniel Vetter
2022-01-11 20:26 ` Jason Gunthorpe
2022-01-20 14:09 ` Christoph Hellwig
2022-01-20 13:56 ` Christoph Hellwig
2022-01-20 15:27 ` Keith Busch
2022-01-20 15:28 ` Christoph Hellwig
2022-01-20 17:54 ` Robin Murphy [this message]
2022-01-11 8:17 ` John Hubbard
2022-01-11 14:01 ` Matthew Wilcox
2022-01-11 15:02 ` Jason Gunthorpe
2022-01-11 17:31 ` Logan Gunthorpe
2022-01-20 14:12 ` Christoph Hellwig
2022-01-20 21:35 ` John Hubbard
2022-01-11 11:40 ` Thomas Zimmermann
2022-01-11 13:56 ` Matthew Wilcox
2022-01-11 14:10 ` Thomas Zimmermann
2022-01-20 13:39 ` Christoph Hellwig
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