From: Benjamin Herrenschmidt <benh@kernel.crashing.org>
To: Geert Uytterhoeven <geert@linux-m68k.org>
Cc: Kars de Jong <jongk@linux-m68k.org>,
Richard Zidlicky <rz@linux-m68k.org>,
Russell King <rmk@arm.linux.org.uk>,
Linux/m68k kernel mailing list <linux-m68k@lists.linux-m68k.org>,
Linux Frame Buffer Device Development
<linux-fbdev-devel@lists.sourceforge.net>
Subject: Re: Re: Usage of readb() and friends...
Date: Wed, 03 Mar 2004 09:50:13 +1100 [thread overview]
Message-ID: <1078267813.21578.201.camel@gaston> (raw)
In-Reply-To: <Pine.GSO.4.58.0403021313400.9959@waterleaf.sonytel.be>
On Tue, 2004-03-02 at 23:15, Geert Uytterhoeven wrote:
> On Tue, 2 Mar 2004, Kars de Jong wrote:
> > Which reminds me: drivers/video/fbmem.c at least seems to treat the
> > return value of ioremap() as a virtual address, since it calls
> > copy_{to,from}_user on it directly...
>
> You're right. And the trouble there is that you can't easily find out which
> ioremap() variant was used...
And... it's illegal to call copy_to/from_user on the return of
ioremap anyway. Not only for semantic reasons, but also for practical
reasons, for example, ioremap returns non cacheable space on PPC,
and copy_to/from_user uses "cache hints" to speed up the copy.
Ben.
-------------------------------------------------------
SF.Net is sponsored by: Speed Start Your Linux Apps Now.
Build and deploy apps & Web services for Linux with
a free DVD software kit from IBM. Click Now!
http://ads.osdn.com/?ad_id=1356&alloc_id=3438&op=click
next prev parent reply other threads:[~2004-03-02 23:14 UTC|newest]
Thread overview: 11+ messages / expand[flat|nested] mbox.gz Atom feed top
[not found] <1076450411.4250.65.camel@kars.perseus.home>
[not found] ` <Pine.GSO.4.58.0402111105230.19627@waterleaf.sonytel.be>
[not found] ` <1076535969.4035.104.camel@kars.perseus.home>
[not found] ` <20040225101534.GA1103@linux-m68k.org>
[not found] ` <20040301175850.L24955@flint.arm.linux.org.uk>
[not found] ` <20040301181727.GA2379@linux-m68k.org>
[not found] ` <Pine.GSO.4.58.0403020939250.9959@waterleaf.sonytel.be>
[not found] ` <1078225776.1321.71.camel@laptop.locamation.com>
2004-03-02 12:15 ` Usage of readb() and friends Geert Uytterhoeven
2004-03-02 17:42 ` James Simmons
2004-03-02 22:50 ` Benjamin Herrenschmidt [this message]
2004-03-02 23:36 ` James Simmons
2004-03-02 23:49 ` Benjamin Herrenschmidt
2004-03-03 19:15 ` [Linux-fbdev-devel] " James Simmons
2004-03-03 22:42 ` Richard Smith
2004-03-03 23:10 ` James Simmons
2004-03-03 23:22 ` Richard Smith
2004-03-03 23:33 ` James Simmons
2004-03-04 0:14 ` Richard Smith
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=1078267813.21578.201.camel@gaston \
--to=benh@kernel.crashing.org \
--cc=geert@linux-m68k.org \
--cc=jongk@linux-m68k.org \
--cc=linux-fbdev-devel@lists.sourceforge.net \
--cc=linux-m68k@lists.linux-m68k.org \
--cc=rmk@arm.linux.org.uk \
--cc=rz@linux-m68k.org \
/path/to/YOUR_REPLY
https://kernel.org/pub/software/scm/git/docs/git-send-email.html
* If your mail client supports setting the In-Reply-To header
via mailto: links, try the mailto: link
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;
as well as URLs for NNTP newsgroup(s).