From: Dan Malek <dan@mvista•com>
To: mgreer@mvista•com
Cc: linuxppc-dev@lists•linuxppc.org
Subject: Re: CONFIG_HIGHMEM on PPC
Date: Thu, 25 Jan 2001 01:04:27 -0500 [thread overview]
Message-ID: <3A6FC1EB.1CC0B893@mvista.com> (raw)
In-Reply-To: 3A6E224E.C0305107@mvista.com
"Mark A. Greer" wrote:
> Has anyone tried CONFIG_HIGHMEM on PPC lately?
I think it is broken and I have also stumbled into a fix for it.
When HIGHMEM is used, memory pages are mapped to virtual addresses
that are not 1:1 mapped. Our simple virt_to_phys macros won't work
with HIGHMEM pages. The 4xx and 8xx processor (and in my test
kernel all processors) map the virt_to_phys to the 'iopa' function
in arch/ppc/mm/init.c. This way the actual page table entry is
tracked down for a virtual address.
Change your virt_to_phys, virt_to_bus macros in include/asm-ppc/io.h
to call 'iopa' (and do the PCI_DRAM_OFFSET adjustment as necessary)
and let me know what happens. I'm working on the reverse, using
the mm_ptov() but I don't have it done yet. If you are using the
reverse (bus_to_virt, etc.) functions, let me know and I'll try to
find a quick hack.
I would like to know who works on APUS as well. In making these
VM changes, I certainly broke the APUS code (because I stole from
there and made it all common :-). I would like to work with someone
to straighten this out as I have no way to test it.
Thanks.
-- Dan
** Sent via the linuxppc-dev mail list. See http://lists.linuxppc.org/
next prev parent reply other threads:[~2001-01-25 6:04 UTC|newest]
Thread overview: 17+ messages / expand[flat|nested] mbox.gz Atom feed top
2001-01-24 0:31 CONFIG_HIGHMEM on PPC Mark A. Greer
2001-01-25 6:04 ` Dan Malek [this message]
2001-01-25 6:44 ` HTTP daemon required Srinivas Rao.M
2001-01-25 9:25 ` CONFIG_HIGHMEM on PPC Roman Zippel
2001-01-25 17:08 ` Dan Malek
2001-01-25 18:37 ` Roman Zippel
2001-01-25 19:47 ` Dan Malek
2001-01-25 19:59 ` David Edelsohn
2001-01-25 21:36 ` Roman Zippel
2001-01-25 21:51 ` Gabriel Paubert
2001-01-25 22:35 ` Roman Zippel
2001-01-25 22:39 ` David Edelsohn
2001-01-26 3:05 ` Frank Rowand
2001-01-25 19:28 ` Gabriel Paubert
2001-01-25 20:07 ` Dan Malek
2001-01-25 21:40 ` Gabriel Paubert
2001-01-25 21:46 ` David Edelsohn
Reply instructions:
You may reply publicly to this message via plain-text email
using any one of the following methods:
* Save the following mbox file, import it into your mail client,
and reply-to-all from there: mbox
Avoid top-posting and favor interleaved quoting:
https://en.wikipedia.org/wiki/Posting_style#Interleaved_style
* Reply using the --to, --cc, and --in-reply-to
switches of git-send-email(1):
git send-email \
--in-reply-to=3A6FC1EB.1CC0B893@mvista.com \
--to=dan@mvista$(echo .)com \
--cc=linuxppc-dev@lists$(echo .)linuxppc.org \
--cc=mgreer@mvista$(echo .)com \
/path/to/YOUR_REPLY
https://kernel.org/pub/software/scm/git/docs/git-send-email.html
Be sure your reply has a Subject: header at the top and a blank line
before the message body.
This is a public inbox, see mirroring instructions
for how to clone and mirror all data and code used for this inbox