From: Christoph Hellwig <hch@lst.de>
To: Robin Murphy <robin.murphy@arm.com>
Cc: "Christoph Hellwig" <hch@lst.de>,
iommu@lists.linux-foundation.org, linux-arch@vger.kernel.org,
linux-mips@linux-mips.org, "Michal Simek" <monstr@monstr.eu>,
linux-ia64@vger.kernel.org,
"Christian König" <ckoenig.leichtzumerken@gmail.com>,
x86@kernel.org, linux-kernel@vger.kernel.org,
"Konrad Rzeszutek Wilk" <konrad@darnok.org>,
"Guan Xuetao" <gxt@mprc.pku.edu.cn>,
linuxppc-dev@lists.ozlabs.org,
linux-arm-kernel@lists.infradead.org
Subject: Re: [PATCH 21/22] arm64: replace ZONE_DMA with ZONE_DMA32
Date: Wed, 10 Jan 2018 16:55:17 +0100 [thread overview]
Message-ID: <20180110155517.GA18774@lst.de> (raw)
In-Reply-To: <0371cef8-d980-96da-9cb5-3609c39be18a@arm.com>
On Wed, Jan 10, 2018 at 12:58:14PM +0000, Robin Murphy wrote:
> On 10/01/18 08:09, Christoph Hellwig wrote:
>> arm64 uses ZONE_DMA for allocations below 32-bits. These days we
>> name the zone for that ZONE_DMA32, which will allow to use the
>> dma-direct and generic swiotlb code as-is, so rename it.
>
> I do wonder if we could also "upgrade" GFP_DMA to GFP_DMA32 somehow when
> !ZONE_DMA - there are almost certainly arm64 drivers out there using a
> combination of GFP_DMA and streaming mappings which will no longer get the
> guaranteed 32-bit addresses they expect after this. I'm not sure quite how
> feasible that is, though :/
I can't find anything obvious in the tree. The alternative would be
to keep ZONE_DMA and set ARCH_ZONE_DMA_BITS.
> That said, I do agree that this is an appropriate change (the legacy of
> GFP_DMA is obviously horrible), so, provided we get plenty of time to find
> and fix the fallout when it lands:
>
> Reviewed-by: Robin Murphy <robin.murphy@arm.com>
I was hoping to get this into 4.15. What would be proper time to
fix the fallout?
next prev parent reply other threads:[~2018-01-10 15:55 UTC|newest]
Thread overview: 45+ messages / expand[flat|nested] mbox.gz Atom feed top
2018-01-10 8:09 consolidate swiotlb dma_map implementations Christoph Hellwig
2018-01-10 8:09 ` [PATCH 01/22] swiotlb: suppress warning when __GFP_NOWARN is set Christoph Hellwig
2018-01-10 8:09 ` [PATCH 02/22] arm64: rename swiotlb_dma_ops Christoph Hellwig
2018-01-10 12:13 ` Robin Murphy
2018-01-10 8:09 ` [PATCH 03/22] ia64: " Christoph Hellwig
2018-01-12 13:24 ` Konrad Rzeszutek Wilk
2018-01-10 8:09 ` [PATCH 04/22] powerpc: " Christoph Hellwig
2018-01-12 13:25 ` Konrad Rzeszutek Wilk
2018-01-10 8:09 ` [PATCH 05/22] x86: " Christoph Hellwig
2018-01-12 13:25 ` Konrad Rzeszutek Wilk
2018-01-10 8:09 ` [PATCH 06/22] swiotlb: rename swiotlb_free to swiotlb_exit Christoph Hellwig
2018-01-12 13:39 ` Konrad Rzeszutek Wilk
2018-01-10 8:09 ` [PATCH 07/22] swiotlb: add common swiotlb_map_ops Christoph Hellwig
2018-01-10 8:09 ` [PATCH 08/22] swiotlb: wire up ->dma_supported in swiotlb_dma_ops Christoph Hellwig
2018-01-10 12:16 ` Robin Murphy
2018-01-10 15:35 ` Christoph Hellwig
2018-01-10 17:23 ` Robin Murphy
2018-01-10 8:09 ` [PATCH 09/22] swiotlb: refactor coherent buffer freeing Christoph Hellwig
2018-01-10 8:09 ` [PATCH 10/22] swiotlb: refactor coherent buffer allocation Christoph Hellwig
2018-01-10 12:22 ` Robin Murphy
2018-01-10 15:46 ` Christoph Hellwig
2018-01-10 17:02 ` Robin Murphy
2018-01-15 9:10 ` Christoph Hellwig
2018-01-10 8:09 ` [PATCH 11/22] swiotlb: remove various exports Christoph Hellwig
2018-01-10 8:09 ` [PATCH 12/22] ia64: replace ZONE_DMA with ZONE_DMA32 Christoph Hellwig
2018-01-10 8:09 ` [PATCH 13/22] ia64: use generic swiotlb_ops Christoph Hellwig
2018-01-10 8:09 ` [PATCH 14/22] ia64: clean up swiotlb support Christoph Hellwig
2018-01-10 8:09 ` [PATCH 15/22] ia64: remove an ifdef around the content of pci-dma.c Christoph Hellwig
2018-01-10 8:09 ` [PATCH 16/22] unicore32: use generic swiotlb_ops Christoph Hellwig
2018-01-10 8:09 ` [PATCH 17/22] tile: replace ZONE_DMA with ZONE_DMA32 Christoph Hellwig
2018-01-10 8:09 ` [PATCH 18/22] tile: use generic swiotlb_ops Christoph Hellwig
2018-01-10 8:09 ` [PATCH 19/22] mips/netlogic: remove swiotlb support Christoph Hellwig
2018-01-10 8:09 ` [PATCH 20/22] mips: use swiotlb_{alloc,free} Christoph Hellwig
2018-01-10 8:09 ` [PATCH 21/22] arm64: replace ZONE_DMA with ZONE_DMA32 Christoph Hellwig
2018-01-10 12:58 ` Robin Murphy
2018-01-10 15:55 ` Christoph Hellwig [this message]
2018-01-10 15:55 ` Christoph Hellwig
2018-01-10 17:10 ` Robin Murphy
2018-01-10 8:09 ` [PATCH 22/22] arm64: use swiotlb_alloc and swiotlb_free Christoph Hellwig
2018-01-10 13:16 ` Robin Murphy
2018-01-10 8:23 ` consolidate swiotlb dma_map implementations Christian König
2018-01-16 7:53 ` Christoph Hellwig
2018-01-16 8:22 ` Christian König
2018-01-16 8:28 ` Christoph Hellwig
2018-01-16 8:52 ` Christian König
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