From: James.Bottomley@HansenPartnership.com (James Bottomley)
To: linux-arm-kernel@lists.infradead.org
Subject: USB mass storage and ARM cache coherency
Date: Thu, 25 Feb 2010 12:36:25 +0000 [thread overview]
Message-ID: <1267101385.2902.8.camel@mulgrave.site> (raw)
In-Reply-To: <1267045954.23523.1692.camel@pasglop>
On Thu, 2010-02-25 at 08:12 +1100, Benjamin Herrenschmidt wrote:
> On Wed, 2010-02-24 at 08:16 +0100, Oliver Neukum wrote:
> > I don't know. The issue seems quite complex. It would seem better to
> > centralize it as far as practical. Do you have a wrapper drivers could
> > call?
>
> flush_dcache_page() ? :-)
Actually, that can be wrong depending on the implementation. The
problem is incoherency of the kernel page (dirty) with respect to user
space aliases (clean). What has to happen on parisc is that the kernel
alias needs flushing. We can guarantee the userspace aliases to be
clean (and not moved in). We wouldn't want to incur the expense of
flushing the user space pages as well.
> Now, the subsystem might be the one to know whether something is mapped
> into userspace or not (v4l in our case) in which case a wrapper could be
> created.
Right, so it's the responsibility of the API used by the subsystem.
Thus Caitlin's pio_kmap seems the right one ... I don't understand what
the additional problems are.
James
next prev parent reply other threads:[~2010-02-25 12:36 UTC|newest]
Thread overview: 155+ messages / expand[flat|nested] mbox.gz Atom feed top
[not found] <20100129185434.GH19501@one-eyed-alien.net>
[not found] ` <1265045354.25750.52.camel@pc1117.cambridge.arm.com>
2010-02-08 6:55 ` USB mass storage and ARM cache coherency Pavel Machek
2010-02-08 7:33 ` Andreas Mohr
2010-02-08 10:19 ` Catalin Marinas
2010-02-08 9:51 ` Catalin Marinas
2010-02-08 10:03 ` Andy Green
2010-02-17 9:50 ` Sascha Hauer
2010-02-17 9:57 ` Andy Green
2010-02-08 10:52 ` Pavel Machek
2010-02-08 11:28 ` Catalin Marinas
2010-02-16 7:57 ` Shilimkar, Santosh
2010-02-16 8:22 ` Oliver Neukum
2010-02-16 8:55 ` Shilimkar, Santosh
2010-02-16 9:07 ` Oliver Neukum
2010-02-16 9:39 ` Russell King - ARM Linux
2010-02-16 13:32 ` Oliver Neukum
2010-02-16 13:40 ` Shilimkar, Santosh
2010-02-16 13:46 ` Oliver Neukum
2010-02-16 14:12 ` Shilimkar, Santosh
2010-02-16 14:22 ` Oliver Neukum
2010-02-16 14:45 ` Shilimkar, Santosh
2010-02-16 15:44 ` Alan Stern
2010-02-17 8:55 ` Shilimkar, Santosh
2010-02-17 9:10 ` Oliver Neukum
2010-02-17 9:17 ` Shilimkar, Santosh
2010-02-17 17:02 ` Alan Stern
2010-02-17 20:26 ` Russell King - ARM Linux
2010-02-17 20:30 ` Gadiyar, Anand
2010-02-18 6:56 ` Oliver Neukum
2010-02-18 7:14 ` Gadiyar, Anand
2010-02-17 12:29 ` Jamie Lokier
2010-02-17 3:21 ` Ming Lei
2010-02-17 9:05 ` Benjamin Herrenschmidt
2010-02-17 9:15 ` Oliver Neukum
2010-02-17 9:40 ` Benjamin Herrenschmidt
2010-02-17 10:09 ` Oliver Neukum
2010-02-17 10:18 ` Benjamin Herrenschmidt
2010-02-17 10:23 ` Oliver Neukum
2010-02-17 12:15 ` Benjamin Herrenschmidt
2010-02-17 9:55 ` Russell King - ARM Linux
2010-02-17 10:05 ` Benjamin Herrenschmidt
2010-02-17 15:27 ` Catalin Marinas
2010-02-17 20:37 ` Benjamin Herrenschmidt
2010-02-17 20:44 ` Russell King - ARM Linux
2010-02-17 22:31 ` Benjamin Herrenschmidt
2010-02-19 17:15 ` Catalin Marinas
2010-02-19 17:36 ` Catalin Marinas
2010-02-19 20:53 ` Oliver Neukum
2010-02-24 2:48 ` Benjamin Herrenschmidt
2010-02-24 7:16 ` Oliver Neukum
2010-02-24 21:12 ` Benjamin Herrenschmidt
2010-02-25 3:48 ` Oliver Neukum
2010-02-26 0:22 ` Benjamin Herrenschmidt
2010-02-25 12:36 ` James Bottomley [this message]
2010-02-24 2:47 ` Benjamin Herrenschmidt
2010-02-24 16:19 ` Alan Stern
2010-02-24 21:13 ` Benjamin Herrenschmidt
2010-02-24 21:50 ` Alan Stern
2010-02-25 20:52 ` Benjamin Herrenschmidt
2010-02-26 16:00 ` Catalin Marinas
2010-02-26 21:36 ` Benjamin Herrenschmidt
2010-02-26 16:25 ` Catalin Marinas
2010-02-26 16:52 ` Alan Stern
2010-02-26 21:51 ` Benjamin Herrenschmidt
2010-02-26 21:00 ` Russell King - ARM Linux
2010-02-28 0:14 ` Benjamin Herrenschmidt
2010-02-28 5:01 ` James Bottomley
2010-03-01 10:39 ` Catalin Marinas
2010-03-01 11:06 ` Russell King - ARM Linux
2010-03-02 12:11 ` FUJITA Tomonori
2010-03-02 17:05 ` Catalin Marinas
2010-03-02 17:47 ` Catalin Marinas
2010-03-02 23:33 ` Benjamin Herrenschmidt
2010-03-03 10:21 ` Catalin Marinas
2010-03-02 23:29 ` Benjamin Herrenschmidt
2010-03-03 3:47 ` FUJITA Tomonori
2010-03-03 5:10 ` Benjamin Herrenschmidt
2010-03-03 5:40 ` James Bottomley
2010-03-03 9:36 ` Russell King - ARM Linux
2010-03-03 10:24 ` James Bottomley
2010-03-03 19:41 ` Russell King - ARM Linux
2010-03-04 2:00 ` Benjamin Herrenschmidt
2010-03-04 8:26 ` James Bottomley
2010-03-04 21:25 ` Benjamin Herrenschmidt
2010-03-03 6:35 ` FUJITA Tomonori
2010-03-03 10:43 ` Catalin Marinas
2010-03-03 10:40 ` Catalin Marinas
2010-03-03 21:54 ` Pavel Machek
2010-03-04 6:54 ` Wolfgang Mües
2010-03-04 9:31 ` Russell King - ARM Linux
2010-03-06 10:56 ` Wolfgang Mües
2010-03-06 11:05 ` Oliver Neukum
2010-03-06 19:44 ` Russell King - ARM Linux
2010-03-04 13:47 ` Catalin Marinas
2010-03-04 13:35 ` Catalin Marinas
2010-03-04 13:51 ` Pavel Machek
2010-03-04 14:21 ` James Bottomley
2010-03-04 14:27 ` Russell King - ARM Linux
2010-03-04 15:25 ` Catalin Marinas
2010-03-04 15:34 ` Russell King - ARM Linux
2010-03-04 21:31 ` Benjamin Herrenschmidt
2010-03-06 10:47 ` James Bottomley
2010-03-06 19:36 ` Russell King - ARM Linux
2010-03-06 21:07 ` Benjamin Herrenschmidt
2010-03-07 5:54 ` James Bottomley
2010-03-08 11:17 ` Catalin Marinas
2010-03-06 21:03 ` Benjamin Herrenschmidt
2010-03-07 3:37 ` James Bottomley
2010-03-08 8:46 ` FUJITA Tomonori
2010-03-09 2:25 ` Benjamin Herrenschmidt
2010-03-04 15:29 ` Catalin Marinas
2010-03-04 15:41 ` Paul Mundt
2010-03-04 16:30 ` Russell King - ARM Linux
2010-03-04 17:34 ` Catalin Marinas
2010-03-04 17:54 ` Russell King - ARM Linux
2010-03-04 18:07 ` Catalin Marinas
2010-03-04 21:37 ` Benjamin Herrenschmidt
2010-03-04 22:11 ` Catalin Marinas
2010-03-05 4:34 ` Benjamin Herrenschmidt
2010-03-05 9:27 ` Catalin Marinas
2010-03-05 1:17 ` Paul Mundt
2010-03-05 4:44 ` Benjamin Herrenschmidt
2010-03-10 3:52 ` Paul Mundt
2010-03-11 21:44 ` Benjamin Herrenschmidt
2010-03-04 21:34 ` Benjamin Herrenschmidt
2010-03-04 21:28 ` Benjamin Herrenschmidt
2010-03-04 21:40 ` Russell King - ARM Linux
2010-03-05 4:31 ` Benjamin Herrenschmidt
2010-03-04 15:35 ` Catalin Marinas
2010-03-07 8:23 ` Pavel Machek
2010-03-08 10:57 ` Catalin Marinas
2010-03-02 23:26 ` Benjamin Herrenschmidt
2010-03-01 10:42 ` Catalin Marinas
2010-03-03 20:24 ` Jamie Lokier
2010-02-26 21:40 ` Benjamin Herrenschmidt
2010-02-26 21:49 ` Russell King - ARM Linux
2010-02-28 0:24 ` Benjamin Herrenschmidt
2010-02-28 19:17 ` Pavel Machek
2010-03-01 11:10 ` Catalin Marinas
2010-03-02 4:11 ` Benjamin Herrenschmidt
2010-02-24 2:39 ` Benjamin Herrenschmidt
2010-02-26 16:44 ` Catalin Marinas
2010-02-26 21:49 ` Benjamin Herrenschmidt
2010-02-26 22:03 ` Russell King - ARM Linux
2010-02-28 0:29 ` Benjamin Herrenschmidt
2010-02-28 23:20 ` Catalin Marinas
2010-02-28 23:17 ` Catalin Marinas
2010-02-17 15:27 ` Catalin Marinas
2010-02-17 15:39 ` Catalin Marinas
2010-02-17 15:40 ` Catalin Marinas
2010-02-17 15:40 ` Catalin Marinas
2010-02-17 16:19 ` Catalin Marinas
2010-02-17 16:19 ` Catalin Marinas
2010-02-16 8:44 ` Russell King - ARM Linux
2010-02-16 8:51 ` Gadiyar, Anand
2010-02-20 7:21 ` Pete Zaitcev
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