From mboxrd@z Thu Jan 1 00:00:00 1970 Received: with ECARTIS (v1.0.0; list linux-mips); Fri, 08 May 2009 09:56:04 +0100 (BST) Received: from [222.92.8.141] ([222.92.8.141]:57867 "EHLO lemote.com" rhost-flags-FAIL-FAIL-OK-OK) by ftp.linux-mips.org with ESMTP id S20023943AbZEHIz6 (ORCPT ); Fri, 8 May 2009 09:55:58 +0100 Received: from localhost (localhost [127.0.0.1]) by lemote.com (Postfix) with ESMTP id 26EFB34121; Fri, 8 May 2009 16:51:36 +0800 (CST) X-Virus-Scanned: Debian amavisd-new at lemote.com Received: from lemote.com ([127.0.0.1]) by localhost (www.lemote.com [127.0.0.1]) (amavisd-new, port 10024) with ESMTP id VJYmakHlR+aN; Fri, 8 May 2009 16:51:30 +0800 (CST) Received: from [172.16.1.226] (unknown [222.92.8.142]) by lemote.com (Postfix) with ESMTP id BF71C34120; Fri, 8 May 2009 16:51:30 +0800 (CST) Subject: Re: [PATCH 3/3] MIPS: handle write_combine in pci_mmap_page_range From: yanh Reply-To: yanh@lemote.com To: Zhang Le Cc: linux-mips@linux-mips.org In-Reply-To: References: Content-Type: text/plain; charset="UTF-8" Date: Fri, 08 May 2009 16:54:47 +0800 Message-Id: <1241772887.9177.139.camel@localhost.localdomain> Mime-Version: 1.0 X-Mailer: Evolution 2.24.1 (2.24.1-2.fc10) Content-Transfer-Encoding: 8bit Return-Path: X-Envelope-To: <"|/home/ecartis/ecartis -s linux-mips"> (uid 0) X-Orcpt: rfc822;linux-mips@linux-mips.org Original-Recipient: rfc822;linux-mips@linux-mips.org X-archive-position: 22667 X-ecartis-version: Ecartis v1.0.0 Sender: linux-mips-bounce@linux-mips.org Errors-to: linux-mips-bounce@linux-mips.org X-original-sender: yanh@lemote.com Precedence: bulk X-list: linux-mips 在 2009-05-08五的 14:30 +0800，Zhang Le写道： > Signed-off-by: Zhang Le > --- > arch/mips/pci/pci.c | 8 ++++++-- > 1 files changed, 6 insertions(+), 2 deletions(-) > > diff --git a/arch/mips/pci/pci.c b/arch/mips/pci/pci.c > index b0eb9e7..4ca53ef 100644 > --- a/arch/mips/pci/pci.c > +++ b/arch/mips/pci/pci.c > @@ -346,10 +346,14 @@ int pci_mmap_page_range(struct pci_dev *dev, struct vm_area_struct *vma, > return -EINVAL; > > /* > - * Ignore write-combine; for now only return uncached mappings. > + * For write-combine, return uncached accelerated mappings if CPU > + * supports; otherwise, return uncached mappings. > */ > prot = pgprot_val(vma->vm_page_prot); > - prot = (prot & ~_CACHE_MASK) | _CACHE_UNCACHED; > + if (write_combine && cpu_has_uncached_accelerated) > + prot = (prot & ~_CACHE_MASK) | _CACHE_UNCACHED_ACCELERATED; > + else > + prot = (prot & ~_CACHE_MASK) | _CACHE_UNCACHED; > vma->vm_page_prot = __pgprot(prot); This should be definietely wrong for MMIOs. uncache accelleration should only be enabled for addresses which have no side effect when doing write combine such as video memory. > > return remap_pfn_range(vma, vma->vm_start, vma->vm_pgoff,