From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mail-pa0-f45.google.com (mail-pa0-f45.google.com [209.85.220.45]) by kanga.kvack.org (Postfix) with ESMTP id 356D56B0037 for ; Fri, 29 Aug 2014 15:16:52 -0400 (EDT) Received: by mail-pa0-f45.google.com with SMTP id bj1so7090985pad.32 for ; Fri, 29 Aug 2014 12:16:51 -0700 (PDT) Received: from relay.sgi.com (relay1.sgi.com. [192.48.180.66]) by mx.google.com with ESMTP id go4si787265pbb.210.2014.08.29.12.16.50 for ; Fri, 29 Aug 2014 12:16:51 -0700 (PDT) Message-Id: <20140829191647.744730085@asylum.americas.sgi.com> References: <20140829191647.364032240@asylum.americas.sgi.com> Date: Fri, 29 Aug 2014 14:16:49 -0500 From: Mike Travis Subject: [PATCH 2/2] x86: Use optimized ioresource lookup in ioremap function Content-Disposition: inline; filename=use-get-resource-type Sender: owner-linux-mm@kvack.org List-ID: To: mingo@redhat.com, tglx@linutronix.de, hpa@zytor.com Cc: akpm@linux-foundation.org, msalter@redhat.com, dyoung@redhat.com, riel@redhat.com, peterz@infradead.org, mgorman@suse.de, linux-kernel@vger.kernel.org, x86@kernel.org, linux-mm@kvack.org, Alex Thorlton This patch uses the optimized ioresource lookup, "region_is_ram", for the ioremap function. If the region is not found, it falls back to the "page_is_ram" function. If it is found and it is RAM, then the usual warning message is issued, and the ioremap operation is aborted. Otherwise, the ioremap operation continues. Signed-off-by: Mike Travis Acked-by: Alex Thorlton Reviewed-by: Cliff Wickman --- v2: slight rearrangement of code --- arch/x86/mm/ioremap.c | 20 ++++++++++++++++---- 1 file changed, 16 insertions(+), 4 deletions(-) --- linux.orig/arch/x86/mm/ioremap.c +++ linux/arch/x86/mm/ioremap.c @@ -86,6 +86,7 @@ static void __iomem *__ioremap_caller(re pgprot_t prot; int retval; void __iomem *ret_addr; + int ram_region; /* Don't allow wraparound or zero size */ last_addr = phys_addr + size - 1; @@ -108,12 +109,23 @@ static void __iomem *__ioremap_caller(re /* * Don't allow anybody to remap normal RAM that we're using.. */ - pfn = phys_addr >> PAGE_SHIFT; - last_pfn = last_addr >> PAGE_SHIFT; - if (walk_system_ram_range(pfn, last_pfn - pfn + 1, NULL, - __ioremap_check_ram) == 1) + /* First check if whole region can be identified as RAM or not */ + ram_region = region_is_ram(phys_addr, size); + if (ram_region > 0) { + WARN_ONCE(1, "ioremap on RAM at 0x%lx - 0x%lx\n", + (unsigned long int)phys_addr, + (unsigned long int)last_addr); return NULL; + } + /* If could not be identified(-1), check page by page */ + if (ram_region < 0) { + pfn = phys_addr >> PAGE_SHIFT; + last_pfn = last_addr >> PAGE_SHIFT; + if (walk_system_ram_range(pfn, last_pfn - pfn + 1, NULL, + __ioremap_check_ram) == 1) + return NULL; + } /* * Mappings have to be page-aligned */ -- -- To unsubscribe, send a message with 'unsubscribe linux-mm' in the body to majordomo@kvack.org. For more info on Linux MM, see: http://www.linux-mm.org/ . Don't email: email@kvack.org