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From: Russell King - ARM Linux <linux@arm.linux.org.uk>
To: Arnd Bergmann <arnd@arndb.de>
Cc: Catalin Marinas <catalin.marinas@arm.com>,
	linaro-mm-sig@lists.linaro.org, Valdis.Kletnieks@vt.edu,
	linux-kernel@vger.kernel.org,
	linux-arm-kernel@lists.infradead.org
Subject: Re: [RFC] ARM DMA mapping TODO, v1
Date: Thu, 28 Apr 2011 13:36:16 +0100	[thread overview]
Message-ID: <20110428123616.GI17290@n2100.arm.linux.org.uk> (raw)
In-Reply-To: <201104281412.40991.arnd@arndb.de>

On Thu, Apr 28, 2011 at 02:12:40PM +0200, Arnd Bergmann wrote:
> On Thursday 28 April 2011, Catalin Marinas wrote:
> > On Thu, 2011-04-28 at 01:15 +0100, Valdis.Kletnieks@vt.edu wrote:
> > > On Wed, 27 Apr 2011 12:08:28 BST, Catalin Marinas said:
> > > 
> > > > The current version of the ARM ARM says "unpredictable". But this
> > > > general definition of "unpredictable" does not allow it to deadlock
> > > > (hardware) or have security implications. It is however allowed to
> > > > corrupt data.
> > > 
> > > Not allowed to have security implications, but is allowed to corrupt data.
> > 
> > By security I was referring to TrustZone extensions. IOW, unpredictable
> > in normal (non-secure) world should not cause data corruption in the
> > secure world.
> 
> That definition is rather useless for operating systems that don't use
> Trustzone then, right?

I'm not sure what you're implying.  By running on a device with Trustzone
extensions, Linux is using them whether it knows it or not.

Linux on ARMs evaluation boards runs on the secure size of the Trustzone
dividing line.  Linux on OMAP SoCs runs on the insecure size of that,
and has to make secure monitor calls to manipulate certain registers
(eg, to enable workarounds for errata etc).  As SMC calls are highly
implementation specific, there is and can be no "trustzone" driver.

WARNING: multiple messages have this Message-ID (diff)
From: linux@arm.linux.org.uk (Russell King - ARM Linux)
To: linux-arm-kernel@lists.infradead.org
Subject: [RFC] ARM DMA mapping TODO, v1
Date: Thu, 28 Apr 2011 13:36:16 +0100	[thread overview]
Message-ID: <20110428123616.GI17290@n2100.arm.linux.org.uk> (raw)
In-Reply-To: <201104281412.40991.arnd@arndb.de>

On Thu, Apr 28, 2011 at 02:12:40PM +0200, Arnd Bergmann wrote:
> On Thursday 28 April 2011, Catalin Marinas wrote:
> > On Thu, 2011-04-28 at 01:15 +0100, Valdis.Kletnieks at vt.edu wrote:
> > > On Wed, 27 Apr 2011 12:08:28 BST, Catalin Marinas said:
> > > 
> > > > The current version of the ARM ARM says "unpredictable". But this
> > > > general definition of "unpredictable" does not allow it to deadlock
> > > > (hardware) or have security implications. It is however allowed to
> > > > corrupt data.
> > > 
> > > Not allowed to have security implications, but is allowed to corrupt data.
> > 
> > By security I was referring to TrustZone extensions. IOW, unpredictable
> > in normal (non-secure) world should not cause data corruption in the
> > secure world.
> 
> That definition is rather useless for operating systems that don't use
> Trustzone then, right?

I'm not sure what you're implying.  By running on a device with Trustzone
extensions, Linux is using them whether it knows it or not.

Linux on ARMs evaluation boards runs on the secure size of the Trustzone
dividing line.  Linux on OMAP SoCs runs on the insecure size of that,
and has to make secure monitor calls to manipulate certain registers
(eg, to enable workarounds for errata etc).  As SMC calls are highly
implementation specific, there is and can be no "trustzone" driver.

  reply	other threads:[~2011-04-28 12:36 UTC|newest]

Thread overview: 196+ 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
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
2011-04-28  0:15         ` Valdis.Kletnieks at vt.edu
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 [this message]
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

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