From: Robin Murphy <robin.murphy@arm.com>
To: Christoph Hellwig <hch@lst.de>
Cc: x86@kernel.org, Tom Lendacky <thomas.lendacky@amd.com>,
Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>,
linux-kernel@vger.kernel.org, Muli Ben-Yehuda <mulix@mulix.org>,
iommu@lists.linux-foundation.org,
David Woodhouse <dwmw2@infradead.org>,
Will Deacon <will.deacon@arm.com>,
Catalin Marinas <catalin.marinas@arm.com>
Subject: Re: [PATCH 12/14] dma-direct: handle the memory encryption bit in common code
Date: Mon, 19 Mar 2018 15:37:20 +0000 [thread overview]
Message-ID: <5316b479-7e75-d62f-6b17-b6bece55187c@arm.com> (raw)
In-Reply-To: <20180319152442.GA27915@lst.de>
On 19/03/18 15:24, Christoph Hellwig wrote:
> On Mon, Mar 19, 2018 at 03:19:04PM +0000, Robin Murphy wrote:
>> As a heads-up, I've just realised there's now a silent (but build-breaking)
>> conflict with the current arm64 queue brewing here, as we've unfortunately
>> had to reintroduce ARCH_HAS_PHYS_TO_DMA as a means of being safe against an
>> ugly architectural corner case - currently commit 1f85b42a691c ("arm64:
>> Revert L1_CACHE_SHIFT back to 6 (64-byte cache line size)") in -next.
>
> Please revert that arm64 commit. This condition should be handled
> in common code as it is not arm specific. And next time please CC
> the iommu list and dma-mapping maintainers before doing such a change.
There didn't seem enough justification to clutter up core SWIOTLB code
with the ability to force bouncing on a per-device basis, but if you
think there are real potential users out there then fair enough. For
arm64, it's extremely unlikely that anyone will ever build a
sufficiently wacky system to actually hit this code path; we really only
implemented it for peace of mind per the letter of the architecture.
Robin.
WARNING: multiple messages have this Message-ID (diff)
From: Robin Murphy <robin.murphy-5wv7dgnIgG8@public.gmane.org>
To: Christoph Hellwig <hch-jcswGhMUV9g@public.gmane.org>
Cc: Tom Lendacky <thomas.lendacky-5C7GfCeVMHo@public.gmane.org>,
Konrad Rzeszutek Wilk
<konrad.wilk-QHcLZuEGTsvQT0dZR+AlfA@public.gmane.org>,
Catalin Marinas <catalin.marinas-5wv7dgnIgG8@public.gmane.org>,
x86-DgEjT+Ai2ygdnm+yROfE0A@public.gmane.org,
Will Deacon <will.deacon-5wv7dgnIgG8@public.gmane.org>,
linux-kernel-u79uwXL29TY76Z2rM5mHXA@public.gmane.org,
Muli Ben-Yehuda <mulix-BzGcCpaT2IbYtjvyW6yDsg@public.gmane.org>,
iommu-cunTk1MwBs9QetFLy7KEm3xJsTq8ys+cHZ5vskTnxNA@public.gmane.org,
David Woodhouse <dwmw2-wEGCiKHe2LqWVfeAwA7xHQ@public.gmane.org>
Subject: Re: [PATCH 12/14] dma-direct: handle the memory encryption bit in common code
Date: Mon, 19 Mar 2018 15:37:20 +0000 [thread overview]
Message-ID: <5316b479-7e75-d62f-6b17-b6bece55187c@arm.com> (raw)
In-Reply-To: <20180319152442.GA27915-jcswGhMUV9g@public.gmane.org>
On 19/03/18 15:24, Christoph Hellwig wrote:
> On Mon, Mar 19, 2018 at 03:19:04PM +0000, Robin Murphy wrote:
>> As a heads-up, I've just realised there's now a silent (but build-breaking)
>> conflict with the current arm64 queue brewing here, as we've unfortunately
>> had to reintroduce ARCH_HAS_PHYS_TO_DMA as a means of being safe against an
>> ugly architectural corner case - currently commit 1f85b42a691c ("arm64:
>> Revert L1_CACHE_SHIFT back to 6 (64-byte cache line size)") in -next.
>
> Please revert that arm64 commit. This condition should be handled
> in common code as it is not arm specific. And next time please CC
> the iommu list and dma-mapping maintainers before doing such a change.
There didn't seem enough justification to clutter up core SWIOTLB code
with the ability to force bouncing on a per-device basis, but if you
think there are real potential users out there then fair enough. For
arm64, it's extremely unlikely that anyone will ever build a
sufficiently wacky system to actually hit this code path; we really only
implemented it for peace of mind per the letter of the architecture.
Robin.
next prev parent reply other threads:[~2018-03-19 15:37 UTC|newest]
Thread overview: 91+ messages / expand[flat|nested] mbox.gz Atom feed top
2018-03-19 10:38 use generic dma-direct and swiotlb code for x86 V3 Christoph Hellwig
2018-03-19 10:38 ` Christoph Hellwig
2018-03-19 10:38 ` [PATCH 01/14] x86: remove X86_PPRO_FENCE Christoph Hellwig
2018-03-19 10:38 ` Christoph Hellwig
2018-03-20 11:04 ` [tip:x86/pti] x86/cpu: Remove the CONFIG_X86_PPRO_FENCE=y quirk tip-bot for Christoph Hellwig
2018-03-20 12:51 ` Peter Zijlstra
2018-03-19 10:38 ` [PATCH 02/14] x86: remove dma_alloc_coherent_mask Christoph Hellwig
2018-03-19 10:38 ` Christoph Hellwig
2018-03-23 19:48 ` [tip:x86/dma] x86/dma: Remove dma_alloc_coherent_mask() tip-bot for Christoph Hellwig
2018-03-19 10:38 ` [PATCH 03/14] x86: use dma-direct Christoph Hellwig
2018-03-19 10:38 ` Christoph Hellwig
2018-03-23 19:49 ` [tip:x86/dma] x86/dma: Use DMA-direct (CONFIG_DMA_DIRECT_OPS=y) tip-bot for Christoph Hellwig
2018-03-19 10:38 ` [PATCH 04/14] x86: use generic swiotlb_ops Christoph Hellwig
2018-03-19 10:38 ` Christoph Hellwig
2018-03-23 19:49 ` [tip:x86/dma] x86/dma: Use " tip-bot for Christoph Hellwig
2018-03-19 10:38 ` [PATCH 05/14] x86/amd_gart: look at coherent_dma_mask instead of GFP_DMA Christoph Hellwig
2018-03-19 10:38 ` Christoph Hellwig
2018-03-23 19:50 ` [tip:x86/dma] x86/dma/amd_gart: Look at dev->coherent_dma_mask " tip-bot for Christoph Hellwig
2018-03-19 10:38 ` [PATCH 06/14] x86/amd_gart: use dma_direct_{alloc,free} Christoph Hellwig
2018-03-19 10:38 ` Christoph Hellwig
2018-03-23 19:50 ` [tip:x86/dma] x86/dma/amd_gart: Use dma_direct_{alloc,free}() tip-bot for Christoph Hellwig
2018-03-19 10:38 ` [PATCH 07/14] iommu/amd_iommu: use dma_direct_{alloc,free} Christoph Hellwig
2018-03-19 10:38 ` Christoph Hellwig
2018-03-23 19:51 ` [tip:x86/dma] iommu/amd_iommu: Use CONFIG_DMA_DIRECT_OPS=y and dma_direct_{alloc,free}() tip-bot for Christoph Hellwig
2018-03-19 10:38 ` [PATCH 08/14] iommu/intel-iommu: cleanup intel_{alloc,free}_coherent Christoph Hellwig
2018-03-19 10:38 ` Christoph Hellwig
2018-03-23 19:51 ` [tip:x86/dma] iommu/intel-iommu: Enable CONFIG_DMA_DIRECT_OPS=y and clean up intel_{alloc,free}_coherent() tip-bot for Christoph Hellwig
2018-03-19 10:38 ` [PATCH 09/14] x86: remove dma_alloc_coherent_gfp_flags Christoph Hellwig
2018-03-19 10:38 ` Christoph Hellwig
2018-03-23 19:52 ` [tip:x86/dma] x86/dma: Remove dma_alloc_coherent_gfp_flags() tip-bot for Christoph Hellwig
2018-03-19 10:38 ` [PATCH 10/14] set_memory.h: provide set_memory_{en,de}crypted stubs Christoph Hellwig
2018-03-19 10:38 ` Christoph Hellwig
2018-03-19 14:21 ` Tom Lendacky
2018-03-19 14:21 ` Tom Lendacky
2018-03-23 19:52 ` [tip:x86/dma] set_memory.h: Provide set_memory_{en,de}crypted() stubs tip-bot for Christoph Hellwig
2018-03-19 10:38 ` [PATCH 11/14] swiotlb: remove swiotlb_set_mem_attributes Christoph Hellwig
2018-03-19 10:38 ` Christoph Hellwig
2018-03-19 14:41 ` Tom Lendacky
2018-03-19 14:41 ` Tom Lendacky
2018-03-23 19:52 ` [tip:x86/dma] dma/swiotlb: Remove swiotlb_set_mem_attributes() tip-bot for Christoph Hellwig
2018-03-19 10:38 ` [PATCH 12/14] dma-direct: handle the memory encryption bit in common code Christoph Hellwig
2018-03-19 10:38 ` Christoph Hellwig
2018-03-19 14:50 ` Tom Lendacky
2018-03-19 14:50 ` Tom Lendacky
2018-03-19 15:19 ` Robin Murphy
2018-03-19 15:19 ` Robin Murphy
2018-03-19 15:24 ` Christoph Hellwig
2018-03-19 15:24 ` Christoph Hellwig
2018-03-19 15:37 ` Robin Murphy [this message]
2018-03-19 15:37 ` Robin Murphy
2018-03-19 15:48 ` Will Deacon
2018-03-19 15:48 ` Will Deacon
2018-03-19 16:03 ` Christoph Hellwig
2018-03-19 16:03 ` Christoph Hellwig
2018-03-19 16:55 ` Will Deacon
2018-03-19 16:55 ` Will Deacon
2018-03-19 18:01 ` Catalin Marinas
2018-03-19 18:01 ` Catalin Marinas
2018-03-19 19:49 ` Christoph Hellwig
2018-03-19 19:49 ` Christoph Hellwig
2018-03-20 16:23 ` Catalin Marinas
2018-03-20 16:23 ` Catalin Marinas
2018-03-23 19:53 ` [tip:x86/dma] dma/direct: Handle " tip-bot for Christoph Hellwig
2018-03-19 10:38 ` [PATCH 13/14] dma-direct: handle force decryption for dma coherent buffers " Christoph Hellwig
2018-03-19 10:38 ` Christoph Hellwig
2018-03-19 14:51 ` Tom Lendacky
2018-03-19 14:51 ` Tom Lendacky
2018-03-23 19:53 ` [tip:x86/dma] dma/direct: Handle force decryption for DMA " tip-bot for Christoph Hellwig
2018-03-19 10:38 ` [PATCH 14/14] swiotlb: remove swiotlb_{alloc,free}_coherent Christoph Hellwig
2018-03-19 10:38 ` Christoph Hellwig
2018-03-23 19:54 ` [tip:x86/dma] dma/swiotlb: Remove swiotlb_{alloc,free}_coherent() tip-bot for Christoph Hellwig
2018-03-19 14:00 ` use generic dma-direct and swiotlb code for x86 V3 Tom Lendacky
2018-03-19 14:00 ` Tom Lendacky
2018-03-19 14:56 ` Thomas Gleixner
2018-03-19 14:56 ` Thomas Gleixner
2018-03-19 15:27 ` Konrad Rzeszutek Wilk
2018-03-19 15:27 ` Konrad Rzeszutek Wilk
2018-03-19 15:28 ` Christoph Hellwig
2018-03-20 8:37 ` Ingo Molnar
2018-03-20 8:37 ` Ingo Molnar
2018-03-20 8:44 ` Christoph Hellwig
2018-03-20 8:44 ` Christoph Hellwig
2018-03-20 9:03 ` Ingo Molnar
2018-03-20 9:03 ` Ingo Molnar
[not found] ` <20180320090351.2qnwcsauhodrqxdj-Re5JQEeQqe8AvxtiuMwx3w@public.gmane.org>
2018-03-20 11:25 ` Konrad Rzeszutek Wilk
2018-03-20 15:16 ` Christoph Hellwig
2018-03-20 15:16 ` Christoph Hellwig
2018-03-21 14:32 ` Konrad Rzeszutek Wilk
2018-03-21 14:32 ` Konrad Rzeszutek Wilk
-- strict thread matches above, loose matches on Subject: below --
2018-03-14 17:51 use generic dma-direct and swiotlb code for x86 V2 Christoph Hellwig
2018-03-14 17:52 ` [PATCH 12/14] dma-direct: handle the memory encryption bit in common code Christoph Hellwig
2018-03-14 17:52 ` Christoph Hellwig
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