From: Roland Dreier <rdreier@cisco.com>
To: vb <vb@vsbe.com>
Cc: linuxppc-embedded@ozlabs.org
Subject: Re: mmap and ppc460gt
Date: Tue, 26 Aug 2008 20:24:18 -0700 [thread overview]
Message-ID: <ada3akri1i5.fsf@cisco.com> (raw)
In-Reply-To: <f608b67d0808261926p67e27770mb7c64cc14015b9ab@mail.gmail.com> (vb@vsbe.com's message of "Tue, 26 Aug 2008 19:26:58 -0700")
> I don't seem to be able to port this to ppc460gt: on this architecture
> the PCI register space can be mapped only to 36 bit address ranges
> with nonzero top nibbles. But mmap() (at least the one I have in
> 2.6.25) accepts only 32 bit values for addresses, hence there is no
> way to map PCI space into user space.
In the past I've been able to use mmap64() on ppc440 to get at 36-bit
addresses. As far as I know this should still work.
Also you should be able to get at the BAR of a PCI device by using
mmap() on a resource file under /sys/devices, eg something like
/sys/devices/pci0000:00/0000:00:04.0/0000:0b:00.0/resource0
(where the bus numbers obviously depend on your system and the resource
number depends on what BAR your device has registers in)
- R.
next prev parent reply other threads:[~2008-08-27 3:24 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 [this message]
2008-08-27 8:13 ` Arnd Bergmann
2008-08-27 23:13 ` vb
2008-08-28 0:11 ` Roland Dreier
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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