From: Arnd Bergmann <arnd@arndb.de>
To: Marek Szyprowski <m.szyprowski@samsung.com>
Cc: linux-arm-kernel@lists.infradead.org,
linux-samsung-soc@vger.kernel.org, linux-media@vger.kernel.org,
Kyungmin Park <kyungmin.park@samsung.com>,
Andrzej Pietrasiwiecz <andrzej.p@samsung.com>,
Sylwester Nawrocki <s.nawrocki@samsung.com>,
Kukjin Kim <kgene.kim@samsung.com>
Subject: Re: [PATCH 4/7] v4l: videobuf2: add IOMMU based DMA memory allocator
Date: Mon, 18 Apr 2011 16:15:48 +0200 [thread overview]
Message-ID: <201104181615.49009.arnd@arndb.de> (raw)
In-Reply-To: <1303118804-5575-5-git-send-email-m.szyprowski@samsung.com>
On Monday 18 April 2011, Marek Szyprowski wrote:
> From: Andrzej Pietrasiewicz <andrzej.p@samsung.com>
>
> This patch adds new videobuf2 memory allocator dedicated to devices that
> supports IOMMU DMA mappings. A device with IOMMU module and a driver
> with include/iommu.h compatible interface is required. This allocator
> aquires memory with standard alloc_page() call and doesn't suffer from
> memory fragmentation issues. The allocator support following page sizes:
> 4KiB, 64KiB, 1MiB and 16MiB to reduce iommu translation overhead.
My feeling is that this is not the right abstraction. Why can't you
just implement the regular dma-mapping.h interfaces for your IOMMU
so that the videobuf code can use the existing allocators?
Arnd
WARNING: multiple messages have this Message-ID (diff)
From: arnd@arndb.de (Arnd Bergmann)
To: linux-arm-kernel@lists.infradead.org
Subject: [PATCH 4/7] v4l: videobuf2: add IOMMU based DMA memory allocator
Date: Mon, 18 Apr 2011 16:15:48 +0200 [thread overview]
Message-ID: <201104181615.49009.arnd@arndb.de> (raw)
In-Reply-To: <1303118804-5575-5-git-send-email-m.szyprowski@samsung.com>
On Monday 18 April 2011, Marek Szyprowski wrote:
> From: Andrzej Pietrasiewicz <andrzej.p@samsung.com>
>
> This patch adds new videobuf2 memory allocator dedicated to devices that
> supports IOMMU DMA mappings. A device with IOMMU module and a driver
> with include/iommu.h compatible interface is required. This allocator
> aquires memory with standard alloc_page() call and doesn't suffer from
> memory fragmentation issues. The allocator support following page sizes:
> 4KiB, 64KiB, 1MiB and 16MiB to reduce iommu translation overhead.
My feeling is that this is not the right abstraction. Why can't you
just implement the regular dma-mapping.h interfaces for your IOMMU
so that the videobuf code can use the existing allocators?
Arnd
next prev parent reply other threads:[~2011-04-18 14:15 UTC|newest]
Thread overview: 66+ messages / expand[flat|nested] mbox.gz Atom feed top
2011-04-18 9:26 [RFC/PATCH v3 0/7] Samsung IOMMU videobuf2 allocator and s5p-fimc update Marek Szyprowski
2011-04-18 9:26 ` Marek Szyprowski
2011-04-18 9:26 ` [PATCH 1/7] ARM: EXYNOS4: power domains: fixes and code cleanup Marek Szyprowski
2011-04-18 9:26 ` Marek Szyprowski
2011-04-18 9:26 ` [PATCH 2/7] ARM: Samsung: update/rewrite Samsung SYSMMU (IOMMU) driver Marek Szyprowski
2011-04-18 9:26 ` Marek Szyprowski
2011-04-18 14:12 ` Arnd Bergmann
2011-04-18 14:12 ` Arnd Bergmann
2011-04-19 8:23 ` Marek Szyprowski
2011-04-19 8:23 ` Marek Szyprowski
2011-04-19 12:49 ` Arnd Bergmann
2011-04-19 12:49 ` Arnd Bergmann
2011-04-19 13:50 ` Roedel, Joerg
2011-04-19 13:50 ` Roedel, Joerg
2011-04-19 14:28 ` Arnd Bergmann
2011-04-19 14:28 ` Arnd Bergmann
2011-04-19 14:51 ` Roedel, Joerg
2011-04-19 14:51 ` Roedel, Joerg
2011-04-19 14:03 ` Marek Szyprowski
2011-04-19 14:03 ` Marek Szyprowski
2011-04-19 14:29 ` Arnd Bergmann
2011-04-19 14:29 ` Arnd Bergmann
2011-04-20 14:55 ` Marek Szyprowski
2011-04-20 14:55 ` Marek Szyprowski
2011-04-20 16:07 ` Arnd Bergmann
2011-04-20 16:07 ` Arnd Bergmann
2011-04-21 11:32 ` Marek Szyprowski
2011-04-21 11:32 ` Marek Szyprowski
2011-04-21 12:00 ` Arnd Bergmann
2011-04-21 12:00 ` Arnd Bergmann
2011-04-21 14:03 ` Marek Szyprowski
2011-04-21 14:03 ` Marek Szyprowski
2011-04-21 14:18 ` Arnd Bergmann
2011-04-21 14:18 ` Arnd Bergmann
2011-04-22 7:33 ` Marek Szyprowski
2011-04-22 7:33 ` Marek Szyprowski
2011-04-26 14:10 ` Arnd Bergmann
2011-04-26 14:10 ` Arnd Bergmann
2011-04-26 14:23 ` Marek Szyprowski
2011-04-26 14:23 ` Marek Szyprowski
2011-04-19 15:00 ` Roedel, Joerg
2011-04-19 15:00 ` Roedel, Joerg
2011-04-19 15:37 ` Arnd Bergmann
2011-04-19 15:37 ` Arnd Bergmann
2011-04-18 9:26 ` [PATCH 3/7] v4l: videobuf2: dma-sg: move some generic functions to memops Marek Szyprowski
2011-04-18 9:26 ` Marek Szyprowski
2011-04-18 9:26 ` [PATCH 4/7] v4l: videobuf2: add IOMMU based DMA memory allocator Marek Szyprowski
2011-04-18 9:26 ` Marek Szyprowski
2011-04-18 14:15 ` Arnd Bergmann [this message]
2011-04-18 14:15 ` Arnd Bergmann
2011-04-19 9:02 ` Marek Szyprowski
2011-04-19 9:02 ` Marek Szyprowski
2011-04-19 9:21 ` Russell King - ARM Linux
2011-04-19 9:21 ` Russell King - ARM Linux
2011-04-19 12:00 ` Arnd Bergmann
2011-04-19 12:00 ` Arnd Bergmann
2011-04-18 9:26 ` [PATCH 5/7] v4l: s5p-fimc: add pm_runtime support Marek Szyprowski
2011-04-18 9:26 ` Marek Szyprowski
2011-04-18 9:26 ` [PATCH 6/7] v4l: s5p-fimc: Add support for vb2-dma-iommu allocator Marek Szyprowski
2011-04-18 9:26 ` Marek Szyprowski
2011-04-18 9:26 ` [PATCH 7/7] ARM: EXYNOS4: enable FIMC on Universal_C210 Marek Szyprowski
2011-04-18 9:26 ` Marek Szyprowski
2011-04-18 13:24 ` [RFC/PATCH v3 0/7] Samsung IOMMU videobuf2 allocator and s5p-fimc update Marek Szyprowski
2011-04-18 13:24 ` Marek Szyprowski
-- strict thread matches above, loose matches on Subject: below --
2011-04-05 14:06 [RFC/PATCH v2 " Marek Szyprowski
2011-04-05 14:06 ` [PATCH 4/7] v4l: videobuf2: add IOMMU based DMA memory allocator Marek Szyprowski
2011-04-05 14:06 ` Marek Szyprowski
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=201104181615.49009.arnd@arndb.de \
--to=arnd@arndb.de \
--cc=andrzej.p@samsung.com \
--cc=kgene.kim@samsung.com \
--cc=kyungmin.park@samsung.com \
--cc=linux-arm-kernel@lists.infradead.org \
--cc=linux-media@vger.kernel.org \
--cc=linux-samsung-soc@vger.kernel.org \
--cc=m.szyprowski@samsung.com \
--cc=s.nawrocki@samsung.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.