Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1755097AbYLSVvf (ORCPT ); Fri, 19 Dec 2008 16:51:35 -0500 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1754236AbYLSVu2 (ORCPT ); Fri, 19 Dec 2008 16:50:28 -0500 Received: from mga01.intel.com ([192.55.52.88]:28552 "EHLO mga01.intel.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1754011AbYLSVuY (ORCPT ); Fri, 19 Dec 2008 16:50:24 -0500 X-ExtLoop1: 1 X-IronPort-AV: E=Sophos;i="4.36,250,1228118400"; d="scan'208";a="416028222" Message-Id: <20081219214837.567076000@intel.com> References: <20081219214725.125171000@intel.com> User-Agent: quilt/0.46-1 Date: Fri, 19 Dec 2008 13:47:30 -0800 From: venkatesh.pallipadi@intel.com To: mingo@elte.hu, tglx@linutronix.de, hpa@zytor.com, akpm@linux-foundation.org, npiggin@suse.de, hugh@veritas.com Cc: arjan@infradead.org, jbarnes@virtuousgeek.org, rdreier@cisco.com, jeremy@goop.org, linux-kernel@vger.kernel.org, Venkatesh Pallipadi , Suresh Siddha Subject: [patch 5/5] x86 PAT: pfnmap documentation update changes Content-Disposition: inline; filename=documentation_updates_comments.patch Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 2180 Lines: 50 Documentation updates as per Randy Dunlap's comments. Signed-off-by: Venkatesh Pallipadi Signed-off-by: Suresh Siddha --- Documentation/x86/pat.txt | 10 +++++----- 1 file changed, 5 insertions(+), 5 deletions(-) Index: linux-2.6/Documentation/x86/pat.txt =================================================================== --- linux-2.6.orig/Documentation/x86/pat.txt 2008-12-19 09:55:04.000000000 -0800 +++ linux-2.6/Documentation/x86/pat.txt 2008-12-19 10:15:46.000000000 -0800 @@ -82,23 +82,23 @@ pci proc | -- | - Advanced APIs for drivers ------------------------- -A. Exporting pages to user with remap_pfn_range, io_remap_pfn_range, +A. Exporting pages to users with remap_pfn_range, io_remap_pfn_range, vm_insert_pfn -Drivers wanting to export some pages to userspace, do it by using mmap +Drivers wanting to export some pages to userspace do it by using mmap interface and a combination of 1) pgprot_noncached() 2) io_remap_pfn_range() or remap_pfn_range() or vm_insert_pfn() -With pat support, a new API pgprot_writecombine is being added. So, driver can +With PAT support, a new API pgprot_writecombine is being added. So, drivers can continue to use the above sequence, with either pgprot_noncached() or pgprot_writecombine() in step 1, followed by step 2. In addition, step 2 internally tracks the region as UC or WC in memtype list in order to ensure no conflicting mapping. -Note that this set of APIs only work with IO (non RAM) regions. If driver -wants to export RAM region, it has to do set_memory_uc() or set_memory_wc() +Note that this set of APIs only works with IO (non RAM) regions. If driver +wants to export a RAM region, it has to do set_memory_uc() or set_memory_wc() as step 0 above and also track the usage of those pages and use set_memory_wb() before the page is freed to free pool. -- -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/