From: Christoph Hellwig <hch@lst.de>
To: Robin Murphy <robin.murphy@arm.com>
Cc: Dean Luick <dean.luick@cornelisnetworks.com>,
Christoph Hellwig <hch@lst.de>,
Dennis Dalessandro <dennis.dalessandro@cornelisnetworks.com>,
Mauro Carvalho Chehab <mchehab@kernel.org>,
Alexandra Winter <wintera@linux.ibm.com>,
Wenjia Zhang <wenjia@linux.ibm.com>,
Marek Szyprowski <m.szyprowski@samsung.com>,
Jaroslav Kysela <perex@perex.cz>, Takashi Iwai <tiwai@suse.com>,
Russell King <linux@armlinux.org.uk>,
linux-arm-kernel@lists.infradead.org, linux-rdma@vger.kernel.org,
iommu@lists.linux.dev, linux-media@vger.kernel.org,
netdev@vger.kernel.org, linux-s390@vger.kernel.org,
alsa-devel@alsa-project.org
Subject: Re: [PATCH 2/7] RDMA/hfi1: don't pass bogus GFP_ flags to dma_alloc_coherent
Date: Wed, 16 Nov 2022 16:45:07 +0100 [thread overview]
Message-ID: <20221116154507.GB18491@lst.de> (raw)
In-Reply-To: <be8ca3f9-b7f7-5402-0cfc-47b9985e007b@arm.com>
On Wed, Nov 16, 2022 at 03:15:10PM +0000, Robin Murphy wrote:
> Coherent DMA buffers are allocated by a kernel driver or subsystem for the
> use of a device managed by that driver or subsystem, and thus they
> fundamentally belong to the kernel as proxy for the device. Any coherent
> DMA buffer may be mapped to userspace with the dma_mmap_*() interfaces, but
> they're never a "userspace allocation" in that sense.
Exactly. I could not find a place to map the buffers to userspace,
so if it does that without using the proper interfaces we need to fix
that as well. Dean, can you point me to the mmap code?
next prev parent reply other threads:[~2022-11-16 15:45 UTC|newest]
Thread overview: 27+ messages / expand[flat|nested] mbox.gz Atom feed top
2022-11-13 16:35 stop drivers from passing GFP_COMP to dma_alloc_coherent Christoph Hellwig
2022-11-13 16:35 ` [PATCH 1/7] media: videobuf-dma-contig: use dma_mmap_coherent Christoph Hellwig
2022-11-24 14:10 ` Hans Verkuil
2022-11-29 14:00 ` Christoph Hellwig
2022-11-13 16:35 ` [PATCH 2/7] RDMA/hfi1: don't pass bogus GFP_ flags to dma_alloc_coherent Christoph Hellwig
2022-11-15 20:39 ` Jason Gunthorpe
2022-11-16 14:40 ` Dean Luick
2022-11-16 15:15 ` Robin Murphy
2022-11-16 15:45 ` Christoph Hellwig [this message]
2022-11-16 17:49 ` Dean Luick
2022-11-20 20:41 ` Dean Luick
2022-11-16 16:21 ` Dean Luick
2022-11-16 18:37 ` Robin Murphy
2022-11-13 16:35 ` [PATCH 3/7] RDMA/qib: " Christoph Hellwig
2022-11-15 20:40 ` Jason Gunthorpe
2022-11-13 16:35 ` [PATCH 4/7] cnic: " Christoph Hellwig
2022-11-13 16:35 ` [PATCH 5/7] s390/ism: " Christoph Hellwig
2022-11-16 12:39 ` Wenjia Zhang
2022-11-13 16:35 ` [PATCH 6/7] ALSA: memalloc: don't pass bogus GFP_ flags to dma_alloc_* Christoph Hellwig
2022-11-14 9:04 ` Takashi Iwai
2022-11-21 8:37 ` Christoph Hellwig
2022-11-13 16:35 ` [PATCH 7/7] dma-mapping: reject __GFP_COMP in dma_alloc_attrs Christoph Hellwig
2022-11-14 8:11 ` Leon Romanovsky
2022-11-16 6:11 ` Christoph Hellwig
2022-11-16 7:11 ` Leon Romanovsky
2022-11-14 12:16 ` Marek Szyprowski
2022-11-21 8:39 ` stop drivers from passing GFP_COMP to dma_alloc_coherent Christoph Hellwig
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