All of lore.kernel.org
 help / color / mirror / Atom feed
From: benh@kernel.crashing.org (Benjamin Herrenschmidt)
To: linux-arm-kernel@lists.infradead.org
Subject: [Linaro-mm-sig] [RFC] ARM DMA mapping TODO, v1
Date: Sat, 30 Apr 2011 08:53:40 +1000	[thread overview]
Message-ID: <1304117620.2513.268.camel@pasglop> (raw)
In-Reply-To: <4DBAA9B4.3070306@vmware.com>

On Fri, 2011-04-29 at 14:06 +0200, Thomas Hellstrom wrote:
> I think Jerome has mentioned at one point that the Radeon graphics
> cards support non-coherent mappings.

If the card is PCI/PCI-X/PCIe then coherency is not its business, it's
the business of the host bridge. However, on PCIe at least, the card can
indeed set a "no snoop" attribute on DMA transactions to request "no
coherency". At least the systems have the latitude to just ignore that
bit (like we do on all ppc afaik) :-)

> Fwiw, the PowerVR SGX MMU also supports this mode of operation,
> although  it being functional I guess depends on the system
> implementation.

Right, it's not a GPU thing, it's really a system design thing.

Cheers,
Ben.

WARNING: multiple messages have this Message-ID (diff)
From: Benjamin Herrenschmidt <benh@kernel.crashing.org>
To: Thomas Hellstrom <thellstrom@vmware.com>
Cc: Arnd Bergmann <arnd@arndb.de>,
	linaro-mm-sig@lists.linaro.org,
	Russell King - ARM Linux <linux@arm.linux.org.uk>,
	linux-kernel@vger.kernel.org,
	linux-arm-kernel@lists.infradead.org
Subject: Re: [Linaro-mm-sig] [RFC] ARM DMA mapping TODO, v1
Date: Sat, 30 Apr 2011 08:53:40 +1000	[thread overview]
Message-ID: <1304117620.2513.268.camel@pasglop> (raw)
In-Reply-To: <4DBAA9B4.3070306@vmware.com>

On Fri, 2011-04-29 at 14:06 +0200, Thomas Hellstrom wrote:
> I think Jerome has mentioned at one point that the Radeon graphics
> cards support non-coherent mappings.

If the card is PCI/PCI-X/PCIe then coherency is not its business, it's
the business of the host bridge. However, on PCIe at least, the card can
indeed set a "no snoop" attribute on DMA transactions to request "no
coherency". At least the systems have the latitude to just ignore that
bit (like we do on all ppc afaik) :-)

> Fwiw, the PowerVR SGX MMU also supports this mode of operation,
> although  it being functional I guess depends on the system
> implementation.

Right, it's not a GPU thing, it's really a system design thing.

Cheers,
Ben.



  parent reply	other threads:[~2011-04-29 22:53 UTC|newest]

Thread overview: 198+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2011-04-21 19:29 [RFC] ARM DMA mapping TODO, v1 Arnd Bergmann
2011-04-21 19:29 ` Arnd Bergmann
2011-04-21 20:09 ` [Linaro-mm-sig] " Jesse Barnes
2011-04-21 20:09   ` Jesse Barnes
2011-04-21 21:52   ` Zach Pfeffer
2011-04-21 21:52     ` Zach Pfeffer
2011-04-22  0:34     ` KyongHo Cho
2011-04-22  0:34       ` KyongHo Cho
2011-04-26 14:29       ` Arnd Bergmann
2011-04-26 14:29         ` Arnd Bergmann
2011-04-26 14:28     ` Arnd Bergmann
2011-04-26 14:28       ` Arnd Bergmann
2011-04-26 14:26   ` Arnd Bergmann
2011-04-26 14:26     ` Arnd Bergmann
2011-04-26 15:39     ` Jesse Barnes
2011-04-26 15:39       ` Jesse Barnes
2011-04-27  7:35 ` Russell King - ARM Linux
2011-04-27  7:35   ` Russell King - ARM Linux
2011-04-27  8:56   ` Arnd Bergmann
2011-04-27  8:56     ` Arnd Bergmann
2011-04-27  9:09     ` Russell King - ARM Linux
2011-04-27  9:09       ` Russell King - ARM Linux
2011-04-27 11:02       ` Arnd Bergmann
2011-04-27 11:02         ` Arnd Bergmann
2011-04-27 16:16         ` [Linaro-mm-sig] " Alex Deucher
2011-04-27 16:16           ` Alex Deucher
2011-04-27 17:44           ` Anca Emanuel
2011-04-27 17:44             ` Anca Emanuel
2011-04-27 20:27             ` Russell King - ARM Linux
2011-04-27 20:27               ` Russell King - ARM Linux
2011-04-27 20:16         ` Russell King - ARM Linux
2011-04-27 20:16           ` Russell King - ARM Linux
2011-04-27 20:21           ` Arnd Bergmann
2011-04-27 20:21             ` Arnd Bergmann
2011-04-27 20:26             ` Russell King - ARM Linux
2011-04-27 20:26               ` Russell King - ARM Linux
2011-04-27 20:48               ` Arnd Bergmann
2011-04-27 20:48                 ` Arnd Bergmann
2011-04-27 21:41               ` Benjamin Herrenschmidt
2011-04-27 21:41                 ` Benjamin Herrenschmidt
2011-04-28  9:30                 ` Russell King - ARM Linux
2011-04-28  9:30                   ` Russell King - ARM Linux
2011-04-28 21:07                   ` Benjamin Herrenschmidt
2011-04-28 21:07                     ` Benjamin Herrenschmidt
2011-04-29 11:26                     ` Arnd Bergmann
2011-04-29 11:26                       ` Arnd Bergmann
2011-04-29 11:47                       ` Benjamin Herrenschmidt
2011-04-29 11:47                         ` Benjamin Herrenschmidt
2011-04-29 11:56                       ` Alan Cox
2011-04-29 11:56                         ` Alan Cox
2011-04-29 22:51                         ` Benjamin Herrenschmidt
2011-04-29 22:51                           ` Benjamin Herrenschmidt
2011-04-29 12:06                       ` [Linaro-mm-sig] " Thomas Hellstrom
2011-04-29 12:06                         ` Thomas Hellstrom
2011-04-29 13:34                         ` Jerome Glisse
2011-04-29 13:34                           ` Jerome Glisse
2011-04-29 22:55                           ` Benjamin Herrenschmidt
2011-04-29 22:55                             ` Benjamin Herrenschmidt
2011-04-29 22:53                         ` Benjamin Herrenschmidt [this message]
2011-04-29 22:53                           ` Benjamin Herrenschmidt
2011-04-27 10:51     ` Marek Szyprowski
2011-04-27 10:51       ` Marek Szyprowski
2011-04-27 21:37   ` Benjamin Herrenschmidt
2011-04-27 21:37     ` Benjamin Herrenschmidt
2011-04-28  6:40     ` [Linaro-mm-sig] " Arnd Bergmann
2011-04-28  6:40       ` Arnd Bergmann
2011-04-28  6:46       ` FUJITA Tomonori
2011-04-28  6:46         ` FUJITA Tomonori
2011-04-28  9:37     ` Russell King - ARM Linux
2011-04-28  9:37       ` Russell King - ARM Linux
2011-04-28 10:32       ` [Linaro-mm-sig] " Marek Szyprowski
2011-04-28 10:32         ` Marek Szyprowski
2011-04-28 10:51         ` Russell King - ARM Linux
2011-04-28 10:51           ` Russell King - ARM Linux
2011-04-28 12:28           ` Arnd Bergmann
2011-04-28 12:28             ` Arnd Bergmann
2011-04-28 13:15             ` Russell King - ARM Linux
2011-04-28 13:15               ` Russell King - ARM Linux
2011-04-28 14:29               ` Arnd Bergmann
2011-04-28 14:29                 ` Arnd Bergmann
2011-04-28 14:34                 ` Russell King - ARM Linux
2011-04-28 14:34                   ` Russell King - ARM Linux
2011-04-28 14:39                   ` Arnd Bergmann
2011-04-28 14:39                     ` Arnd Bergmann
2011-04-28 14:58                     ` Russell King - ARM Linux
2011-04-28 14:58                       ` Russell King - ARM Linux
2011-04-28 19:37                   ` Jerome Glisse
2011-04-28 19:37                     ` Jerome Glisse
2011-04-29  0:29                     ` Benjamin Herrenschmidt
2011-04-29  0:29                       ` Benjamin Herrenschmidt
2011-04-29  5:50                       ` Thomas Hellstrom
2011-04-29  5:50                         ` Thomas Hellstrom
2011-04-29  7:35                         ` Benjamin Herrenschmidt
2011-04-29  7:35                           ` Benjamin Herrenschmidt
2011-04-29 10:55                           ` Thomas Hellstrom
2011-04-29 10:55                             ` Thomas Hellstrom
2011-04-29 22:50                             ` Benjamin Herrenschmidt
2011-04-29 22:50                               ` Benjamin Herrenschmidt
2011-04-29 16:27                           ` Jesse Barnes
2011-04-29 16:27                             ` Jesse Barnes
2011-04-29 22:46                             ` Benjamin Herrenschmidt
2011-04-29 22:46                               ` Benjamin Herrenschmidt
2011-04-30  2:45                               ` Jesse Barnes
2011-04-30  2:45                                 ` Jesse Barnes
2011-04-29  7:59                         ` Russell King - ARM Linux
2011-04-29  7:59                           ` Russell King - ARM Linux
2011-04-29 16:32                           ` Jesse Barnes
2011-04-29 16:32                             ` Jesse Barnes
2011-04-29 18:29                             ` Arnd Bergmann
2011-04-29 18:29                               ` Arnd Bergmann
2011-04-29 22:15                               ` Russell King - ARM Linux
2011-04-29 22:15                                 ` Russell King - ARM Linux
2011-05-02  4:42                                 ` David Brown
2011-05-02  4:42                                   ` David Brown
2011-05-02 11:26                                   ` Arnd Bergmann
2011-05-02 11:26                                     ` Arnd Bergmann
2011-04-29 22:37                               ` Benjamin Herrenschmidt
2011-04-29 22:37                                 ` Benjamin Herrenschmidt
2011-04-29 13:42                     ` Joerg Roedel
2011-04-29 13:42                       ` Joerg Roedel
2011-04-29 14:19                       ` Jerome Glisse
2011-04-29 14:19                         ` Jerome Glisse
2011-04-29 15:37                       ` Jordan Crouse
2011-04-29 15:37                         ` Jordan Crouse
2011-04-28 14:38                 ` FUJITA Tomonori
2011-04-28 14:38                   ` FUJITA Tomonori
2011-04-29  0:25               ` Benjamin Herrenschmidt
2011-04-29  0:25                 ` Benjamin Herrenschmidt
2011-04-29 11:21                 ` Arnd Bergmann
2011-04-29 11:21                   ` Arnd Bergmann
2011-04-28 10:41   ` Joerg Roedel
2011-04-28 10:41     ` Joerg Roedel
2011-04-28 11:01     ` Russell King - ARM Linux
2011-04-28 11:01       ` Russell King - ARM Linux
2011-04-28 12:25       ` Joerg Roedel
2011-04-28 12:25         ` Joerg Roedel
2011-04-28 12:42         ` Russell King - ARM Linux
2011-04-28 12:42           ` Russell King - ARM Linux
2011-04-28 12:59           ` Joerg Roedel
2011-04-28 12:59             ` Joerg Roedel
2011-04-28 13:02           ` Arnd Bergmann
2011-04-28 13:02             ` Arnd Bergmann
2011-04-28 13:19             ` Russell King - ARM Linux
2011-04-28 13:19               ` Russell King - ARM Linux
2011-04-28 13:56               ` Joerg Roedel
2011-04-28 13:56                 ` Joerg Roedel
2011-04-28 14:30                 ` Russell King - ARM Linux
2011-04-28 14:30                   ` Russell King - ARM Linux
2011-04-27  9:52 ` Catalin Marinas
2011-04-27  9:52   ` Catalin Marinas
2011-04-27 10:43   ` Arnd Bergmann
2011-04-27 10:43     ` Arnd Bergmann
2011-04-27 11:08     ` Catalin Marinas
2011-04-27 11:08       ` Catalin Marinas
2011-04-28  0:15       ` Valdis.Kletnieks at vt.edu
2011-04-28  0:15         ` Valdis.Kletnieks
2011-04-28  8:27         ` Catalin Marinas
2011-04-28  8:27           ` Catalin Marinas
2011-04-28 12:12           ` Arnd Bergmann
2011-04-28 12:12             ` Arnd Bergmann
2011-04-28 12:36             ` Russell King - ARM Linux
2011-04-28 12:36               ` Russell King - ARM Linux
2011-04-28 12:48               ` Arnd Bergmann
2011-04-28 12:48                 ` Arnd Bergmann
2011-05-03 14:45             ` Dave Martin
2011-05-03 14:45               ` Dave Martin
2011-04-29 15:41       ` [Linaro-mm-sig] " Arnd Bergmann
2011-04-29 15:41         ` Arnd Bergmann
2011-04-29 16:42         ` Catalin Marinas
2011-04-29 16:42           ` Catalin Marinas
2011-05-03 15:05     ` [Linaro-mm-sig] " Laurent Pinchart
2011-05-03 15:05       ` Laurent Pinchart
2011-05-03 15:31       ` Arnd Bergmann
2011-05-03 15:31         ` Arnd Bergmann
2011-04-27 14:06   ` FUJITA Tomonori
2011-04-27 14:06     ` FUJITA Tomonori
2011-04-27 14:29     ` Catalin Marinas
2011-04-27 14:29       ` Catalin Marinas
2011-04-27 14:34       ` FUJITA Tomonori
2011-04-27 14:34         ` FUJITA Tomonori
2011-04-27 20:29     ` Russell King - ARM Linux
2011-04-27 20:29       ` Russell King - ARM Linux
2011-04-27 21:45   ` Benjamin Herrenschmidt
2011-04-27 21:45     ` Benjamin Herrenschmidt
2011-04-28  7:24     ` [Linaro-mm-sig] " KyongHo Cho
2011-04-28  7:24       ` KyongHo Cho
2011-04-28  8:31     ` Catalin Marinas
2011-04-28  8:31       ` Catalin Marinas
2011-04-27 21:31 ` Benjamin Herrenschmidt
2011-04-27 21:31   ` Benjamin Herrenschmidt
2011-04-28  9:42   ` Russell King - ARM Linux
2011-04-28  9:42     ` Russell King - ARM Linux
2011-04-28 10:27 ` Joerg Roedel
2011-04-28 10:27   ` Joerg Roedel
2011-04-28 12:15   ` Arnd Bergmann
2011-04-28 12:15     ` Arnd Bergmann
  -- strict thread matches above, loose matches on Subject: below --
2011-05-03 14:35 [Linaro-mm-sig] " Laurent Pinchart
2011-05-03 14:35 ` Laurent Pinchart

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=1304117620.2513.268.camel@pasglop \
    --to=benh@kernel.crashing.org \
    --cc=linux-arm-kernel@lists.infradead.org \
    /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.