From: Christoph Hellwig <hch@lst.de>
To: Alexey Kardashevskiy <aik@ozlabs.ru>
Cc: linuxppc-dev@lists.ozlabs.org, Christoph Hellwig <hch@lst.de>,
linux-kernel@vger.kernel.org
Subject: Re: [PATCH kernel 0/2] powerpc/dma: Fallback to dma_ops when persistent memory present
Date: Tue, 27 Oct 2020 09:36:47 +0100 [thread overview]
Message-ID: <20201027083647.GA24318@lst.de> (raw)
In-Reply-To: <20201021032026.45030-1-aik@ozlabs.ru>
On Wed, Oct 21, 2020 at 02:20:24PM +1100, Alexey Kardashevskiy wrote:
> This allows mixing direct DMA (to/from RAM) and
> IOMMU (to/from apersistent memory) on the PPC64/pseries
> platform. This was supposed to be a single patch but
> unexpected move of direct DMA functions happened.
>
> This is based on sha1
> 7cf726a59435 Linus Torvalds "Merge tag 'linux-kselftest-kunit-5.10-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/shuah/linux-kselftest".
>
> Please comment. Thanks.
I really don't like your revert. I'm almost ready to kill of
dma-direct.h, and I really want it private in kernel/dma/, as people
keep adding abuses to drivers.
We have two options here:
(1) duplicate the code in arch/powerpc/
(2) add a hook to kernel/dma/
I've not been a fan of (2) in the past, but now that the code is out
of line, and we could make it dependent on a config option only set by
powerpc, I see it as the lesser evil now.
prev parent reply other threads:[~2020-10-27 10:34 UTC|newest]
Thread overview: 4+ messages / expand[flat|nested] mbox.gz Atom feed top
2020-10-21 3:20 [PATCH kernel 0/2] powerpc/dma: Fallback to dma_ops when persistent memory present Alexey Kardashevskiy
2020-10-21 3:20 ` [PATCH kernel 1/2] Revert "dma-mapping: move large parts of <linux/dma-direct.h> to kernel/dma" Alexey Kardashevskiy
2020-10-21 3:20 ` [PATCH kernel 2/2] powerpc/dma: Fallback to dma_ops when persistent memory present Alexey Kardashevskiy
2020-10-27 8:36 ` Christoph Hellwig [this message]
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