From: Christoph Hellwig <hch@lst.de>
To: Linus Torvalds <torvalds@linux-foundation.org>
Cc: linux-arch@vger.kernel.org, linux-ia64@vger.kernel.org,
linux-parisc@vger.kernel.org,
David Woodhouse <dwmw2@infradead.org>,
the arch/x86 maintainers <x86@kernel.org>,
Russell King - ARM Linux <linux@armlinux.org.uk>,
Linux List Kernel Mailing <linux-kernel@vger.kernel.org>,
iommu@lists.linux-foundation.org, linux-alpha@vger.kernel.org,
xen-devel@lists.xenproject.org, robin.murphy@arm.com,
Christoph Hellwig <hch@lst.de>,
linux-arm-kernel@lists.infradead.org
Subject: Re: remove the ->mapping_error method from dma_map_ops V2
Date: Thu, 29 Nov 2018 19:31:32 +0100 [thread overview]
Message-ID: <20181129183132.GA30281@lst.de> (raw)
In-Reply-To: <CAHk-=wi2K7_+dgCbc-sAK9CST5Zh+pOuH7sVT9WW-kqs50HSzQ@mail.gmail.com>
On Thu, Nov 29, 2018 at 09:44:05AM -0800, Linus Torvalds wrote:
> No. Really. If there's no iotlb, then you just mark that one page
> reserved. It simply doesn't get used. It doesn't mean you suddenly
> need a swiotlb.
Sure, we could just skip that page entirely based on dma_to_phys.
> But whatever. It's independent from the patch series under discussion.
> Make dma_mapping_error() at least return a real error (eg -EINVAL, or
> whatever is the common error), and we can maybe do this later.
Ok, I'll do that.
> Or, better yet, plan on removing the single-page dma mappign entirely
> at a later date, and make the issue moot.
What would be the replacement? Build a S/G list for every single page
mapping? Not sure that would create a lot of happy campers..
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next prev parent reply other threads:[~2018-11-29 18:31 UTC|newest]
Thread overview: 53+ messages / expand[flat|nested] mbox.gz Atom feed top
2018-11-22 14:02 remove the ->mapping_error method from dma_map_ops V2 Christoph Hellwig
2018-11-22 14:02 ` [PATCH 01/24] dma-direct: Make DIRECT_MAPPING_ERROR viable for SWIOTLB Christoph Hellwig
2018-11-22 14:02 ` [PATCH 02/24] swiotlb: Skip cache maintenance on map error Christoph Hellwig
2018-11-22 14:02 ` [PATCH 03/24] dma-mapping: provide a generic DMA_MAPPING_ERROR Christoph Hellwig
2018-11-22 14:03 ` [PATCH 04/24] dma-direct: remove the mapping_error dma_map_ops method Christoph Hellwig
2018-11-22 14:03 ` [PATCH 05/24] arm: " Christoph Hellwig
2018-11-22 14:03 ` [PATCH 06/24] powerpc/iommu: " Christoph Hellwig
2018-11-22 14:03 ` [PATCH 07/24] mips/jazz: " Christoph Hellwig
2018-11-22 14:03 ` [PATCH 08/24] s390: " Christoph Hellwig
2018-11-22 14:03 ` [PATCH 09/24] sparc: " Christoph Hellwig
2018-11-22 14:03 ` [PATCH 10/24] parisc/ccio: " Christoph Hellwig
2018-11-22 14:03 ` [PATCH 11/24] parisc/sba_iommu: " Christoph Hellwig
2018-11-22 14:03 ` [PATCH 12/24] arm64: remove the dummy_dma_ops mapping_error method Christoph Hellwig
2018-11-22 14:03 ` [PATCH 13/24] alpha: remove the mapping_error dma_map_ops method Christoph Hellwig
2018-11-22 14:03 ` [PATCH 14/24] ia64/sba_iommu: improve internal map_page users Christoph Hellwig
2018-11-22 14:03 ` [PATCH 15/24] ia64/sba_iommu: remove the mapping_error dma_map_ops method Christoph Hellwig
2018-11-22 14:03 ` [PATCH 16/24] ia64/sn: " Christoph Hellwig
2018-11-22 14:03 ` [PATCH 17/24] x86/amd_gart: " Christoph Hellwig
2018-11-22 14:03 ` [PATCH 18/24] x86/calgary: " Christoph Hellwig
2018-11-22 14:03 ` [PATCH 19/24] iommu: " Christoph Hellwig
2018-11-22 14:03 ` [PATCH 20/24] iommu/intel: small map_page cleanup Christoph Hellwig
2018-11-22 14:03 ` [PATCH 21/24] iommu/vt-d: remove the mapping_error dma_map_ops method Christoph Hellwig
2018-11-22 14:03 ` [PATCH 22/24] iommu/dma-iommu: " Christoph Hellwig
2018-11-22 14:03 ` [PATCH 23/24] xen-swiotlb: " Christoph Hellwig
2018-11-22 14:03 ` [PATCH 24/24] dma-mapping: " Christoph Hellwig
2018-11-22 16:50 ` remove the ->mapping_error method from dma_map_ops V2 Linus Torvalds
2018-11-22 17:07 ` Russell King - ARM Linux
2018-11-22 17:09 ` Linus Torvalds
2018-11-22 17:14 ` Russell King - ARM Linux
2018-11-22 17:52 ` Robin Murphy
2018-11-22 17:55 ` Linus Torvalds
2018-11-22 18:05 ` Russell King - ARM Linux
2018-11-23 6:57 ` Christoph Hellwig
2018-11-23 6:55 ` Christoph Hellwig
2018-11-28 7:41 ` Christoph Hellwig
2018-11-28 16:47 ` Linus Torvalds
2018-11-28 17:45 ` Russell King - ARM Linux
2018-11-28 18:00 ` Linus Torvalds
2018-11-28 18:08 ` Russell King - ARM Linux
2018-11-28 19:23 ` Russell King - ARM Linux
[not found] ` <CAHk-=whcbiSxSUprsKjVPEdN5-+o8WnTGiKxEV-+HbKNDs=iNA@mail.gmail.com>
2018-11-28 19:31 ` Russell King - ARM Linux
2018-11-29 16:23 ` Christoph Hellwig
2018-11-29 17:44 ` Linus Torvalds
2018-11-29 18:31 ` Christoph Hellwig [this message]
2018-11-29 18:53 ` Linus Torvalds
2018-11-29 18:55 ` Christoph Hellwig
2018-11-28 19:27 ` David Miller
2018-11-28 19:47 ` Russell King - ARM Linux
2018-11-28 23:01 ` Shuah Khan
2018-11-23 10:49 ` Joerg Roedel
2018-11-23 11:01 ` Russell King - ARM Linux
2018-11-23 13:03 ` Joerg Roedel
2018-11-23 13:20 ` Russell King - ARM Linux
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