From: Christoph Hellwig <hch@lst.de>
To: Christophe LEROY <christophe.leroy@c-s.fr>
Cc: Christoph Hellwig <hch@lst.de>,
iommu@lists.linux-foundation.org, Chris Zankel <chris@zankel.net>,
Michal Simek <monstr@monstr.eu>,
linux-ia64@vger.kernel.org, linux-mips@linux-mips.org,
linux-sh@vger.kernel.org, linuxppc-dev@lists.ozlabs.org,
linux-xtensa@linux-xtensa.org, x86@kernel.org,
linux-kernel@vger.kernel.org, David Howells <dhowells@redhat.com>,
Max Filippov <jcmvbkbc@gmail.com>,
Guan Xuetao <gxt@mprc.pku.edu.cn>,
Robin Murphy <robin.murphy@arm.com>,
Marek Szyprowski <m.szyprowski@samsung.com>
Subject: Re: [PATCH 07/11] powerpc: make dma_cache_sync a no-op
Date: Tue, 3 Oct 2017 13:43:30 +0200 [thread overview]
Message-ID: <20171003114330.GA24592@lst.de> (raw)
In-Reply-To: <670a0571-1a36-51a3-db52-64bc61184c35@c-s.fr>
On Tue, Oct 03, 2017 at 01:24:57PM +0200, Christophe LEROY wrote:
>> powerpc does not implement DMA_ATTR_NON_CONSISTENT allocations, so it
>> doesn't make any sense to do any work in dma_cache_sync given that it
>> must be a no-op when dma_alloc_attrs returns coherent memory.
> What about arch/powerpc/mm/dma-noncoherent.c ?
>
> Powerpc 8xx doesn't have coherent memory.
It doesn't implement the DMA_ATTR_NON_CONSISTENT interface either,
so if it really doesn't have a way to provide dma coherent allocation
(although the code in __dma_alloc_coherent suggests it does provide
dma coherent allocations) I have no idea how it could ever have
worked.
next prev parent reply other threads:[~2017-10-03 11:43 UTC|newest]
Thread overview: 23+ messages / expand[flat|nested] mbox.gz Atom feed top
2017-10-03 10:43 refactor dma_cache_sync V2 Christoph Hellwig
2017-10-03 10:43 ` [PATCH 01/11] floppy: consolidate the dummy fd_cacheflush definition Christoph Hellwig
2017-10-03 10:43 ` [PATCH 02/11] x86: make dma_cache_sync a no-op Christoph Hellwig
2017-10-03 16:02 ` David Laight
2017-10-03 20:27 ` Thomas Gleixner
2017-10-03 10:43 ` [PATCH 03/11] frv: " Christoph Hellwig
2017-10-03 10:43 ` [PATCH 04/11] ia64: " Christoph Hellwig
2017-10-04 8:59 ` David Laight
2017-10-04 9:06 ` 'Christoph Hellwig'
2017-10-03 10:43 ` [PATCH 05/11] microblaze: " Christoph Hellwig
2017-10-03 10:43 ` [PATCH 06/11] mn10300: " Christoph Hellwig
2017-10-03 10:43 ` [PATCH 07/11] powerpc: " Christoph Hellwig
2017-10-03 11:24 ` Christophe LEROY
2017-10-03 11:43 ` Robin Murphy
2017-10-03 11:43 ` Christoph Hellwig [this message]
2017-10-04 8:29 ` Christophe LEROY
2017-10-03 10:43 ` [PATCH 08/11] unicore32: " Christoph Hellwig
2017-10-03 10:43 ` [PATCH 09/11] xtensa: " Christoph Hellwig
2017-10-03 10:43 ` [PATCH 10/11] sh: " Christoph Hellwig
2017-10-03 10:43 ` [PATCH 11/11] dma-mapping: turn dma_cache_sync into a dma_map_ops method Christoph Hellwig
2017-10-03 11:49 ` refactor dma_cache_sync V2 Robin Murphy
2017-10-16 12:44 ` Christoph Hellwig
2017-10-19 15:02 ` Christoph Hellwig
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