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From: James Bottomley <James.Bottomley@HansenPartnership.com>
To: Ingo Molnar <mingo@elte.hu>
Cc: Thomas Gleixner <tglx@linutronix.de>,
	linux-kernel <linux-kernel@vger.kernel.org>,
	"H. Peter Anvin" <hpa@zytor.com>,
	"David S. Miller" <davem@davemloft.net>
Subject: Re: [patch] x86, voyager: fix ioremap_nocache()
Date: Sun, 27 Apr 2008 18:34:20 -0400	[thread overview]
Message-ID: <1209335660.3801.79.camel@localhost.localdomain> (raw)
In-Reply-To: <20080427214837.GA11631@elte.hu>

Here's another piece of the x86 API that's designed to be cached.  The
dma_declare_coherent_memory() usually represents behind bridge memory
that's fully participatory in the coherence model.

Making it uncached damages the utility of this memory because doing
cacheline sized burst cycles when needed to it is far faster than
individual byte/word/quad writes.

Signed-off-by: James Bottomley <James.Bottomley@HansenPartnership.com>

---

diff --git a/arch/x86/kernel/pci-dma.c b/arch/x86/kernel/pci-dma.c
index 388b113..df83ffd 100644
--- a/arch/x86/kernel/pci-dma.c
+++ b/arch/x86/kernel/pci-dma.c
@@ -214,7 +214,7 @@ int dma_declare_coherent_memory(struct device *dev, dma_addr_t bus_addr,
 
 	/* FIXME: this routine just ignores DMA_MEMORY_INCLUDES_CHILDREN */
 
-	mem_base = ioremap(bus_addr, size);
+	mem_base = ioremap_cache(bus_addr, size);
 	if (!mem_base)
 		goto out;
 



  parent reply	other threads:[~2008-04-27 22:34 UTC|newest]

Thread overview: 51+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2008-04-27 20:51 Breakage caused by unreviewed patch in x86 tree James Bottomley
2008-04-27 20:53 ` David Miller
2008-04-27 21:48 ` [patch] x86, voyager: fix ioremap_nocache() Ingo Molnar
2008-04-27 22:05   ` James Bottomley
2008-04-27 22:36     ` Willy Tarreau
2008-04-27 22:41     ` Ingo Molnar
2008-04-27 23:18     ` Ingo Molnar
2008-04-27 23:31       ` David Miller
2008-04-28  0:31         ` Rik van Riel
2008-04-28  0:45           ` Al Viro
2008-04-28  0:52             ` H. Peter Anvin
2008-04-28  9:01         ` Alan Cox
2008-04-28  9:17           ` David Miller
2008-04-28  9:48             ` Adrian Bunk
2008-04-28 11:50             ` Ingo Molnar
2008-04-28  6:10       ` Christoph Hellwig
2008-04-28 16:55         ` H. Peter Anvin
2008-04-27 22:34   ` James Bottomley [this message]
2008-04-27 22:39     ` Jeff Garzik
2008-04-27 22:44       ` H. Peter Anvin
2008-04-27 22:46       ` David Miller
2008-04-27 22:52         ` H. Peter Anvin
2008-04-27 22:58           ` David Miller
2008-04-27 23:04             ` H. Peter Anvin
2008-04-30 20:35               ` Eric W. Biederman
2008-04-27 23:34           ` Jeff Garzik
2008-04-27 23:39             ` H. Peter Anvin
2008-04-27 22:53         ` Jeff Garzik
2008-04-27 22:56           ` H. Peter Anvin
2008-04-27 22:59             ` David Miller
2008-04-27 23:02             ` Jeff Garzik
2008-04-27 23:14               ` Arjan van de Ven
2008-04-27 23:01         ` Arjan van de Ven
2008-04-30 21:44           ` James Bottomley
2008-04-30 22:39             ` H. Peter Anvin
2008-04-27 23:01       ` Thomas Gleixner
2008-04-28 14:10       ` Arjan van de Ven
2008-04-28 14:29         ` James Bottomley
2008-04-28 15:07           ` Arjan van de Ven
2008-04-28 19:59             ` H. Peter Anvin
2008-04-27 22:00 ` Breakage caused by unreviewed patch in x86 tree H. Peter Anvin
2008-04-27 22:10   ` James Bottomley
2008-04-27 22:13     ` H. Peter Anvin
2008-04-27 22:18       ` James Bottomley
2008-04-27 22:31         ` H. Peter Anvin
2008-04-27 22:58 ` Arjan van de Ven
2008-04-27 23:00   ` David Miller
2008-04-27 23:07     ` Arjan van de Ven
2008-04-27 23:03   ` James Bottomley
2008-04-27 23:11     ` Arjan van de Ven
2008-04-27 23:17     ` H. Peter Anvin

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