From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1755586AbYBNQ5A (ORCPT ); Thu, 14 Feb 2008 11:57:00 -0500 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1751358AbYBNQ4s (ORCPT ); Thu, 14 Feb 2008 11:56:48 -0500 Received: from smtp-out03.alice-dsl.net ([88.44.63.5]:16624 "EHLO smtp-out03.alice-dsl.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751232AbYBNQ4r (ORCPT ); Thu, 14 Feb 2008 11:56:47 -0500 Date: Thu, 14 Feb 2008 17:56:45 +0100 From: Andi Kleen To: Ingo Molnar , tglx@linutronix.de, linux-kernel@vger.kernel.org, torvalds@osdl.org Subject: [PATCH] Fix direct mapping alias regressin in ioremap v2 Message-ID: <20080214165645.GA26748@basil.nowhere.org> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline User-Agent: Mutt/1.5.13 (2006-08-11) X-OriginalArrivalTime: 14 Feb 2008 16:50:23.0267 (UTC) FILETIME=[B0EC2F30:01C86F29] Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Fix direct mapping alias regressin in ioremap v2 [This fixes the general ioremap bug I mentioned earlier. It was fortunately easier to fix that I thought first.] set_memory_*/cpa is not currently able to resolve ioremap addresses to their direct mapping aliases. However uncached ioremap still needs to fix up the direct mapping to be uncached when the direct mapping happens to overlap the remapped area. Otherwise there would be a cached mapping to the uncached ioremap area and that is not allowed in the x86 architecture. Do this explicitely in ioremap() by passing the direct mapping address to cpa and ignoring the error if the address wasn't in the direct mapping. I also fixed a minor bug I noticed -- need to pass in size + offset, not just size. v2: Improve description Fix bug noticed by Ingo of __va() wrapping on 32bit Signed-off-by: Andi Kleen Index: linux/arch/x86/mm/ioremap.c =================================================================== --- linux.orig/arch/x86/mm/ioremap.c +++ linux/arch/x86/mm/ioremap.c @@ -104,6 +104,7 @@ static void __iomem *__ioremap(unsigned unsigned long pfn, offset, last_addr, vaddr; struct vm_struct *area; pgprot_t prot; + int err; /* Don't allow wraparound or zero size */ last_addr = phys_addr + size - 1; @@ -156,9 +157,16 @@ static void __iomem *__ioremap(unsigned return NULL; } - if (ioremap_change_attr(vaddr, size, mode) < 0) { - vunmap(area->addr); - return NULL; + /* Fix up the direct mapping for the new cache attributes */ + if ((phys_addr + size + offset) >> PAGE_SHIFT <= max_pfn_mapped) { + err = ioremap_change_attr((unsigned long)__va(phys_addr), + size + offset, mode); + if (err == -EINVAL) { + /* Original address was partly unmapped. Ignore. */ + } else if (err < 0) { + vunmap(area->addr); + return NULL; + } } return (void __iomem *) (vaddr + offset);