From: Roland Dreier <rdreier@cisco.com>
To: vb <vb@vsbe.com>
Cc: Arnd Bergmann <arnd@arndb.de>, linuxppc-embedded@ozlabs.org
Subject: Re: mmap and ppc460gt
Date: Wed, 27 Aug 2008 17:11:14 -0700 [thread overview]
Message-ID: <adawsi2j8wt.fsf@cisco.com> (raw)
In-Reply-To: <f608b67d0808271613g2092b287o44c3418fb7d33499@mail.gmail.com> (vb@vsbe.com's message of "Wed, 27 Aug 2008 16:13:52 -0700")
> The problem now is that that PCI register space gets mapped with
> caching enabled (by looking at the TLB contents), so I still can't
> control the device. I did some search and indeed UIO device driver
> came up, I'll read the article. I was wondering though if there is a
> simpler way to modify cache attributes of a region. mmap() doesn't
> seem to provide an interface for that, is there some other function to
> call to configure 'cache inhibit' attribute for a region?
The issue would be related to phys_mem_access_prot() not doing the right
thing in this case. In fact it looks like the arch/powerpc
page_is_ram() implementation has the same bug that I fixed a long time
ago for arch/ppc in 8b150478 ("[PATCH] ppc: make phys_mem_access_prot()
work with pfns instead of addresses"). I'll send a patch a little later
that you can try out.
- R.
next prev parent reply other threads:[~2008-08-28 0:21 UTC|newest]
Thread overview: 11+ messages / expand[flat|nested] mbox.gz Atom feed top
2008-08-27 2:26 mmap and ppc460gt vb
2008-08-27 3:24 ` Roland Dreier
2008-08-27 8:13 ` Arnd Bergmann
2008-08-27 23:13 ` vb
2008-08-28 0:11 ` Roland Dreier [this message]
2008-08-28 0:21 ` vb
2008-08-28 3:12 ` Roland Dreier
2008-08-28 3:47 ` vb
2008-08-28 10:36 ` Josh Boyer
2008-08-30 3:39 ` [PATCH] powerpc: Avoid integer overflow in page_is_ram() Roland Dreier
2008-09-01 0:27 ` Benjamin Herrenschmidt
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