From: Christoph Hellwig <hch@lst.de>
To: Catalin Marinas <catalin.marinas@arm.com>
Cc: tony@atomide.com, joro@8bytes.org, will.deacon@arm.com,
linux@armlinux.org.uk, iommu@lists.linux-foundation.org,
linux-kernel@vger.kernel.org,
Nicolin Chen <nicoleotsuka@gmail.com>,
robin.murphy@arm.com, Christoph Hellwig <hch@lst.de>,
linux-arm-kernel@lists.infradead.org, m.szyprowski@samsung.com
Subject: Re: [PATCH v2 RFC/RFT 1/5] ARM: dma-mapping: Add fallback normal page allocations
Date: Thu, 2 May 2019 15:26:10 +0200 [thread overview]
Message-ID: <20190502132610.GA3107@lst.de> (raw)
In-Reply-To: <20190430152421.GE29799@arrakis.emea.arm.com>
On Tue, Apr 30, 2019 at 04:24:21PM +0100, Catalin Marinas wrote:
> My reading of the arm32 __dma_alloc() is that if the conditions are
> right for the CMA allocator (allows blocking) and there is a default CMA
> area or a per-device one, the call ends up in cma_alloc() without any
> fallback if such allocation fails. Whether this is on purpose, I'm not
> entirely sure. There are a couple of arm32 SoCs which call
> dma_declare_contiguous() or dma_contiguous_reserve_area() and a few DT
> files describing a specific CMA range (e.g. arch/arm/boot/dts/sun5i.dtsi
> with a comment that address must be kept in the lower 256MB).
>
> If ZONE_DMA is set up correctly so that cma_alloc() is (or can be made)
> interchangeable with alloc_pages(GFP_DMA) from a device DMA capability
> perspective , I think it should be fine to have such fallback.
Indeed. I missed arm32 being different from everyone else, but we
already addresses that in another thread. Sorry for misleading
everyone.
WARNING: multiple messages have this Message-ID (diff)
From: Christoph Hellwig <hch@lst.de>
To: Catalin Marinas <catalin.marinas@arm.com>
Cc: tony@atomide.com, will.deacon@arm.com, linux@armlinux.org.uk,
iommu@lists.linux-foundation.org, linux-kernel@vger.kernel.org,
Nicolin Chen <nicoleotsuka@gmail.com>,
robin.murphy@arm.com, Christoph Hellwig <hch@lst.de>,
linux-arm-kernel@lists.infradead.org
Subject: Re: [PATCH v2 RFC/RFT 1/5] ARM: dma-mapping: Add fallback normal page allocations
Date: Thu, 2 May 2019 15:26:10 +0200 [thread overview]
Message-ID: <20190502132610.GA3107@lst.de> (raw)
Message-ID: <20190502132610.NSYaziH1A_hpBg-R3ws_JQ-wu2R387hYFrDWKcPN8Ac@z> (raw)
In-Reply-To: <20190430152421.GE29799@arrakis.emea.arm.com>
On Tue, Apr 30, 2019 at 04:24:21PM +0100, Catalin Marinas wrote:
> My reading of the arm32 __dma_alloc() is that if the conditions are
> right for the CMA allocator (allows blocking) and there is a default CMA
> area or a per-device one, the call ends up in cma_alloc() without any
> fallback if such allocation fails. Whether this is on purpose, I'm not
> entirely sure. There are a couple of arm32 SoCs which call
> dma_declare_contiguous() or dma_contiguous_reserve_area() and a few DT
> files describing a specific CMA range (e.g. arch/arm/boot/dts/sun5i.dtsi
> with a comment that address must be kept in the lower 256MB).
>
> If ZONE_DMA is set up correctly so that cma_alloc() is (or can be made)
> interchangeable with alloc_pages(GFP_DMA) from a device DMA capability
> perspective , I think it should be fine to have such fallback.
Indeed. I missed arm32 being different from everyone else, but we
already addresses that in another thread. Sorry for misleading
everyone.
_______________________________________________
iommu mailing list
iommu@lists.linux-foundation.org
https://lists.linuxfoundation.org/mailman/listinfo/iommu
WARNING: multiple messages have this Message-ID (diff)
From: Christoph Hellwig <hch@lst.de>
To: Catalin Marinas <catalin.marinas@arm.com>
Cc: tony@atomide.com, joro@8bytes.org, will.deacon@arm.com,
linux@armlinux.org.uk, iommu@lists.linux-foundation.org,
linux-kernel@vger.kernel.org,
Nicolin Chen <nicoleotsuka@gmail.com>,
robin.murphy@arm.com, Christoph Hellwig <hch@lst.de>,
linux-arm-kernel@lists.infradead.org, m.szyprowski@samsung.com
Subject: Re: [PATCH v2 RFC/RFT 1/5] ARM: dma-mapping: Add fallback normal page allocations
Date: Thu, 2 May 2019 15:26:10 +0200 [thread overview]
Message-ID: <20190502132610.GA3107@lst.de> (raw)
In-Reply-To: <20190430152421.GE29799@arrakis.emea.arm.com>
On Tue, Apr 30, 2019 at 04:24:21PM +0100, Catalin Marinas wrote:
> My reading of the arm32 __dma_alloc() is that if the conditions are
> right for the CMA allocator (allows blocking) and there is a default CMA
> area or a per-device one, the call ends up in cma_alloc() without any
> fallback if such allocation fails. Whether this is on purpose, I'm not
> entirely sure. There are a couple of arm32 SoCs which call
> dma_declare_contiguous() or dma_contiguous_reserve_area() and a few DT
> files describing a specific CMA range (e.g. arch/arm/boot/dts/sun5i.dtsi
> with a comment that address must be kept in the lower 256MB).
>
> If ZONE_DMA is set up correctly so that cma_alloc() is (or can be made)
> interchangeable with alloc_pages(GFP_DMA) from a device DMA capability
> perspective , I think it should be fine to have such fallback.
Indeed. I missed arm32 being different from everyone else, but we
already addresses that in another thread. Sorry for misleading
everyone.
_______________________________________________
linux-arm-kernel mailing list
linux-arm-kernel@lists.infradead.org
http://lists.infradead.org/mailman/listinfo/linux-arm-kernel
WARNING: multiple messages have this Message-ID (diff)
From: Christoph Hellwig <hch@lst.de>
To: Catalin Marinas <catalin.marinas@arm.com>
Cc: Christoph Hellwig <hch@lst.de>,
Nicolin Chen <nicoleotsuka@gmail.com>,
robin.murphy@arm.com, vdumpa@nvidia.com, linux@armlinux.org.uk,
will.deacon@arm.com, joro@8bytes.org, m.szyprowski@samsung.com,
linux-arm-kernel@lists.infradead.org,
linux-kernel@vger.kernel.org, iommu@lists.linux-foundation.org,
tony@atomide.com
Subject: Re: [PATCH v2 RFC/RFT 1/5] ARM: dma-mapping: Add fallback normal page allocations
Date: Thu, 2 May 2019 15:26:10 +0200 [thread overview]
Message-ID: <20190502132610.GA3107@lst.de> (raw)
In-Reply-To: <20190430152421.GE29799@arrakis.emea.arm.com>
On Tue, Apr 30, 2019 at 04:24:21PM +0100, Catalin Marinas wrote:
> My reading of the arm32 __dma_alloc() is that if the conditions are
> right for the CMA allocator (allows blocking) and there is a default CMA
> area or a per-device one, the call ends up in cma_alloc() without any
> fallback if such allocation fails. Whether this is on purpose, I'm not
> entirely sure. There are a couple of arm32 SoCs which call
> dma_declare_contiguous() or dma_contiguous_reserve_area() and a few DT
> files describing a specific CMA range (e.g. arch/arm/boot/dts/sun5i.dtsi
> with a comment that address must be kept in the lower 256MB).
>
> If ZONE_DMA is set up correctly so that cma_alloc() is (or can be made)
> interchangeable with alloc_pages(GFP_DMA) from a device DMA capability
> perspective , I think it should be fine to have such fallback.
Indeed. I missed arm32 being different from everyone else, but we
already addresses that in another thread. Sorry for misleading
everyone.
next prev parent reply other threads:[~2019-05-02 13:26 UTC|newest]
Thread overview: 47+ messages / expand[flat|nested] mbox.gz Atom feed top
2019-03-26 23:01 [PATCH v2 RFC/RFT 0/5] Save single pages from CMA area Nicolin Chen
2019-03-26 23:01 ` Nicolin Chen
[not found] ` <20190326230131.16275-1-nicoleotsuka-Re5JQEeQqe8AvxtiuMwx3w@public.gmane.org>
2019-03-26 23:01 ` [PATCH v2 RFC/RFT 1/5] ARM: dma-mapping: Add fallback normal page allocations Nicolin Chen
2019-03-26 23:01 ` Nicolin Chen
2019-03-26 23:01 ` Nicolin Chen
2019-04-24 15:06 ` Christoph Hellwig
2019-04-24 15:06 ` Christoph Hellwig
2019-04-24 15:06 ` Christoph Hellwig
[not found] ` <20190424150638.GA22191-jcswGhMUV9g@public.gmane.org>
2019-04-24 15:08 ` Christoph Hellwig
2019-04-24 15:08 ` Christoph Hellwig
2019-04-24 15:08 ` Christoph Hellwig
2019-04-24 15:08 ` Christoph Hellwig
2019-04-24 18:33 ` Nicolin Chen
2019-04-24 18:33 ` Nicolin Chen
2019-04-24 18:33 ` Nicolin Chen
2019-04-24 19:26 ` Christoph Hellwig
2019-04-24 19:26 ` Christoph Hellwig
2019-04-24 19:26 ` Christoph Hellwig
2019-04-24 19:38 ` Nicolin Chen
2019-04-24 19:38 ` Nicolin Chen
2019-04-24 19:38 ` Nicolin Chen
2019-04-30 15:24 ` Catalin Marinas
2019-04-30 15:24 ` Catalin Marinas
2019-04-30 15:24 ` Catalin Marinas
2019-05-02 13:26 ` Christoph Hellwig [this message]
2019-05-02 13:26 ` Christoph Hellwig
2019-05-02 13:26 ` Christoph Hellwig
2019-05-02 13:26 ` Christoph Hellwig
2019-04-26 20:21 ` Nicolin Chen
2019-04-26 20:21 ` Nicolin Chen
2019-04-26 20:21 ` Nicolin Chen
2019-04-26 20:25 ` Christoph Hellwig
2019-04-26 20:25 ` Christoph Hellwig
2019-04-26 20:25 ` Christoph Hellwig
2019-03-26 23:01 ` [PATCH v2 RFC/RFT 2/5] dma-remap: Run alloc_pages() on failure Nicolin Chen
2019-03-26 23:01 ` Nicolin Chen
2019-03-26 23:01 ` Nicolin Chen
2019-03-26 23:01 ` [PATCH v2 RFC/RFT 3/5] iommu: amd_iommu: Add fallback normal page allocations Nicolin Chen
2019-03-26 23:01 ` Nicolin Chen
2019-03-26 23:01 ` [PATCH v2 RFC/RFT 4/5] arm64: dma-mapping: " Nicolin Chen
2019-03-26 23:01 ` Nicolin Chen
2019-03-26 23:01 ` [PATCH v2 RFC/RFT 5/5] dma-contiguous: Do not allocate a single page from CMA area Nicolin Chen
2019-03-26 23:01 ` Nicolin Chen
2019-03-27 8:08 ` [PATCH v2 RFC/RFT 0/5] Save single pages " Christoph Hellwig
2019-03-27 8:08 ` Christoph Hellwig
2019-03-27 18:42 ` Nicolin Chen
2019-03-27 18:42 ` Nicolin Chen
Reply instructions:
You may reply publicly to this message via plain-text email
using any one of the following methods:
* Save the following mbox file, import it into your mail client,
and reply-to-all from there: mbox
Avoid top-posting and favor interleaved quoting:
https://en.wikipedia.org/wiki/Posting_style#Interleaved_style
* Reply using the --to, --cc, and --in-reply-to
switches of git-send-email(1):
git send-email \
--in-reply-to=20190502132610.GA3107@lst.de \
--to=hch@lst.de \
--cc=catalin.marinas@arm.com \
--cc=iommu@lists.linux-foundation.org \
--cc=joro@8bytes.org \
--cc=linux-arm-kernel@lists.infradead.org \
--cc=linux-kernel@vger.kernel.org \
--cc=linux@armlinux.org.uk \
--cc=m.szyprowski@samsung.com \
--cc=nicoleotsuka@gmail.com \
--cc=robin.murphy@arm.com \
--cc=tony@atomide.com \
--cc=will.deacon@arm.com \
/path/to/YOUR_REPLY
https://kernel.org/pub/software/scm/git/docs/git-send-email.html
* If your mail client supports setting the In-Reply-To header
via mailto: links, try the mailto: link
Be sure your reply has a Subject: header at the top and a blank line
before the message body.
This is an external index of several public inboxes,
see mirroring instructions on how to clone and mirror
all data and code used by this external index.