Re: [patch] x86, voyager: fix ioremap_nocache()

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From: Arjan van de Ven
Date: Monday, April 28, 2008 - 7:10 am

On Sun, 27 Apr 2008 18:39:24 -0400
Jeff Garzik <jeff@garzik.org> wrote:


this patch patch is likely broken on x86; or rather, anyone who uses it is...
thinking you can find cache coherent memory on a PCI or similar bus that is actually
cachable... keep dreaming. (for now; there's talk about extending PCI)



only if you map ROM's. Anything but ROMs you cannot set IORESOURCE_CACHEABLE
on... since PCI MMIO memory isn't cache coherent per se. (it's cache coherent on
x86 by virtue of being uncachable ;-)
Thankfully Linux doesn't do that.


Can you list one that gets it actually right ?
(cachable pretty much means: "the cpu is the only one changing it AND there is no side effect of 
reading or writing")

-- 
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Messages in current thread:
Breakage caused by unreviewed patch in x86 tree, James Bottomley, (Sun Apr 27, 1:51 pm)
Re: Breakage caused by unreviewed patch in x86 tree, David Miller, (Sun Apr 27, 1:53 pm)
[patch] x86, voyager: fix ioremap_nocache(), Ingo Molnar, (Sun Apr 27, 2:48 pm)
Re: Breakage caused by unreviewed patch in x86 tree, H. Peter Anvin, (Sun Apr 27, 3:00 pm)
Re: [patch] x86, voyager: fix ioremap_nocache(), James Bottomley, (Sun Apr 27, 3:05 pm)
Re: Breakage caused by unreviewed patch in x86 tree, James Bottomley, (Sun Apr 27, 3:10 pm)
Re: Breakage caused by unreviewed patch in x86 tree, H. Peter Anvin, (Sun Apr 27, 3:13 pm)
Re: Breakage caused by unreviewed patch in x86 tree, James Bottomley, (Sun Apr 27, 3:18 pm)
Re: Breakage caused by unreviewed patch in x86 tree, H. Peter Anvin, (Sun Apr 27, 3:31 pm)
Re: [patch] x86, voyager: fix ioremap_nocache(), James Bottomley, (Sun Apr 27, 3:34 pm)
Re: [patch] x86, voyager: fix ioremap_nocache(), Willy Tarreau, (Sun Apr 27, 3:36 pm)
Re: [patch] x86, voyager: fix ioremap_nocache(), Jeff Garzik, (Sun Apr 27, 3:39 pm)
Re: [patch] x86, voyager: fix ioremap_nocache(), Ingo Molnar, (Sun Apr 27, 3:41 pm)
Re: [patch] x86, voyager: fix ioremap_nocache(), H. Peter Anvin, (Sun Apr 27, 3:44 pm)
Re: [patch] x86, voyager: fix ioremap_nocache(), David Miller, (Sun Apr 27, 3:46 pm)
Re: [patch] x86, voyager: fix ioremap_nocache(), H. Peter Anvin, (Sun Apr 27, 3:52 pm)
Re: [patch] x86, voyager: fix ioremap_nocache(), Jeff Garzik, (Sun Apr 27, 3:53 pm)
Re: [patch] x86, voyager: fix ioremap_nocache(), H. Peter Anvin, (Sun Apr 27, 3:56 pm)
Re: Breakage caused by unreviewed patch in x86 tree, Arjan van de Ven, (Sun Apr 27, 3:58 pm)
Re: [patch] x86, voyager: fix ioremap_nocache(), David Miller, (Sun Apr 27, 3:58 pm)
Re: [patch] x86, voyager: fix ioremap_nocache(), David Miller, (Sun Apr 27, 3:59 pm)
Re: Breakage caused by unreviewed patch in x86 tree, David Miller, (Sun Apr 27, 4:00 pm)
Re: [patch] x86, voyager: fix ioremap_nocache(), Arjan van de Ven, (Sun Apr 27, 4:01 pm)
Re: [patch] x86, voyager: fix ioremap_nocache(), Thomas Gleixner, (Sun Apr 27, 4:01 pm)
Re: [patch] x86, voyager: fix ioremap_nocache(), Jeff Garzik, (Sun Apr 27, 4:02 pm)
Re: Breakage caused by unreviewed patch in x86 tree, James Bottomley, (Sun Apr 27, 4:03 pm)
Re: [patch] x86, voyager: fix ioremap_nocache(), H. Peter Anvin, (Sun Apr 27, 4:04 pm)
Re: Breakage caused by unreviewed patch in x86 tree, Arjan van de Ven, (Sun Apr 27, 4:07 pm)
Re: Breakage caused by unreviewed patch in x86 tree, Arjan van de Ven, (Sun Apr 27, 4:11 pm)
Re: [patch] x86, voyager: fix ioremap_nocache(), Arjan van de Ven, (Sun Apr 27, 4:14 pm)
Re: Breakage caused by unreviewed patch in x86 tree, H. Peter Anvin, (Sun Apr 27, 4:17 pm)
Re: [patch] x86, voyager: fix ioremap_nocache(), Ingo Molnar, (Sun Apr 27, 4:18 pm)
Re: [patch] x86, voyager: fix ioremap_nocache(), David Miller, (Sun Apr 27, 4:31 pm)
Re: [patch] x86, voyager: fix ioremap_nocache(), Jeff Garzik, (Sun Apr 27, 4:34 pm)
Re: [patch] x86, voyager: fix ioremap_nocache(), H. Peter Anvin, (Sun Apr 27, 4:39 pm)
Re: [patch] x86, voyager: fix ioremap_nocache(), Rik van Riel, (Sun Apr 27, 5:31 pm)
Re: [patch] x86, voyager: fix ioremap_nocache(), Al Viro, (Sun Apr 27, 5:45 pm)
Re: [patch] x86, voyager: fix ioremap_nocache(), H. Peter Anvin, (Sun Apr 27, 5:52 pm)
Re: [patch] x86, voyager: fix ioremap_nocache(), Christoph Hellwig, (Sun Apr 27, 11:10 pm)
Re: [patch] x86, voyager: fix ioremap_nocache(), Alan Cox, (Mon Apr 28, 2:01 am)
Re: [patch] x86, voyager: fix ioremap_nocache(), David Miller, (Mon Apr 28, 2:17 am)
Re: [patch] x86, voyager: fix ioremap_nocache(), Adrian Bunk, (Mon Apr 28, 2:48 am)
Re: [patch] x86, voyager: fix ioremap_nocache(), Ingo Molnar, (Mon Apr 28, 4:50 am)
Re: [patch] x86, voyager: fix ioremap_nocache(), Arjan van de Ven, (Mon Apr 28, 7:10 am)
Re: [patch] x86, voyager: fix ioremap_nocache(), James Bottomley, (Mon Apr 28, 7:29 am)
Re: [patch] x86, voyager: fix ioremap_nocache(), Arjan van de Ven, (Mon Apr 28, 8:07 am)
Re: [patch] x86, voyager: fix ioremap_nocache(), H. Peter Anvin, (Mon Apr 28, 9:55 am)
Re: [patch] x86, voyager: fix ioremap_nocache(), H. Peter Anvin, (Mon Apr 28, 12:59 pm)
Re: [patch] x86, voyager: fix ioremap_nocache(), Eric W. Biederman, (Wed Apr 30, 1:35 pm)
Re: [patch] x86, voyager: fix ioremap_nocache(), James Bottomley, (Wed Apr 30, 2:44 pm)
Re: [patch] x86, voyager: fix ioremap_nocache(), H. Peter Anvin, (Wed Apr 30, 3:39 pm)