From: David Howells <dhowells@redhat.com>
To: Mike Frysinger <vapier.adi@gmail.com>
Cc: dhowells@redhat.com, Bernd Schmidt <bernds_cb1@t-online.de>,
uclinux-dist-devel@blackfin.uclinux.org,
linux-kernel@vger.kernel.org
Subject: Re: [Uclinux-dist-devel] [PATCH v2] NOMMU: add support for Memory Protection Units (MPU)
Date: Wed, 15 Jul 2009 13:25:42 +0100 [thread overview]
Message-ID: <3751.1247660742@redhat.com> (raw)
In-Reply-To: <8bd0f97a0907150455l59a86540l655604579ab70b4f@mail.gmail.com>
Mike Frysinger <vapier.adi@gmail.com> wrote:
> yes, you can see page_rwx_mask in our mmu.h's mm_context_t. this is
> what the protect_page/update_protections operate on. we have a global
> current_rwx_mask that gets updated during context changes and the CPLB
> miss handler uses that to keep things simple.
Interesting.
Since FRV does not really allow separate execute permissions (it has a very
few separate static I and D protection/mapping registers and a shared TLB), I
could do it with just pairs of bits.
Also, how do you deal with mappable devices that lie outside of RAM? I'm
guessing from the code that you don't cover those with the bitmap, but rather
just grant userspace RW access.
David
next prev parent reply other threads:[~2009-07-15 12:27 UTC|newest]
Thread overview: 18+ messages / expand[flat|nested] mbox.gz Atom feed top
2009-07-14 14:22 [PATCH] NOMMU: add support for Memory Protection Units (MPU) Mike Frysinger
2009-07-14 16:14 ` Johannes Weiner
2009-07-14 16:19 ` Mike Frysinger
2009-07-14 17:14 ` [PATCH v2] " Mike Frysinger
2009-07-14 17:22 ` David Howells
2009-07-14 21:59 ` Bernd Schmidt
2009-07-15 10:31 ` David Howells
2009-07-15 11:18 ` [Uclinux-dist-devel] " Mike Frysinger
2009-07-15 10:37 ` David Howells
2009-07-15 11:12 ` [Uclinux-dist-devel] " Mike Frysinger
2009-07-15 11:45 ` David Howells
2009-07-15 11:55 ` Mike Frysinger
2009-07-15 12:25 ` David Howells [this message]
2009-07-15 12:52 ` Mike Frysinger
2009-07-15 9:24 ` Paul Mundt
2009-09-14 3:52 ` Mike Frysinger
2009-09-16 10:09 ` David Howells
2009-09-16 13:57 ` [PATCH] " Mike Frysinger
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