From patchwork Sat Jul 25 02:38:06 2015 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Dan Williams X-Patchwork-Id: 6863951 Return-Path: X-Original-To: patchwork-linux-arm@patchwork.kernel.org Delivered-To: patchwork-parsemail@patchwork1.web.kernel.org Received: from mail.kernel.org (mail.kernel.org [198.145.29.136]) by patchwork1.web.kernel.org (Postfix) with ESMTP id 87A809F1D4 for ; Sat, 25 Jul 2015 02:46:49 +0000 (UTC) Received: from mail.kernel.org (localhost [127.0.0.1]) by mail.kernel.org (Postfix) with ESMTP id 85BB6205EA for ; Sat, 25 Jul 2015 02:46:48 +0000 (UTC) Received: from bombadil.infradead.org (bombadil.infradead.org [198.137.202.9]) (using TLSv1.2 with cipher AES128-GCM-SHA256 (128/128 bits)) (No client certificate requested) by mail.kernel.org (Postfix) with ESMTPS id 8CD0C205DC for ; Sat, 25 Jul 2015 02:46:47 +0000 (UTC) Received: from localhost ([127.0.0.1] helo=bombadil.infradead.org) by bombadil.infradead.org with esmtp (Exim 4.80.1 #2 (Red Hat Linux)) id 1ZIpRr-0000Yc-7D; Sat, 25 Jul 2015 02:44:27 +0000 Received: from mga11.intel.com ([192.55.52.93]) by bombadil.infradead.org with esmtp (Exim 4.80.1 #2 (Red Hat Linux)) id 1ZIpRe-0000OF-J5 for linux-arm-kernel@lists.infradead.org; Sat, 25 Jul 2015 02:44:16 +0000 Received: from orsmga002.jf.intel.com ([10.7.209.21]) by fmsmga102.fm.intel.com with ESMTP; 24 Jul 2015 19:43:54 -0700 X-ExtLoop1: 1 X-IronPort-AV: E=Sophos;i="5.15,542,1432623600"; d="scan'208";a="770837212" Received: from dwillia2-desk3.jf.intel.com (HELO dwillia2-desk3.amr.corp.intel.com) ([10.54.39.11]) by orsmga002.jf.intel.com with ESMTP; 24 Jul 2015 19:43:52 -0700 Subject: [PATCH v2 02/25] mm, x86: Remove region_is_ram() call from ioremap From: Dan Williams To: tglx@linutronix.de, mingo@kernel.org, hpa@zytor.com Date: Fri, 24 Jul 2015 22:38:06 -0400 Message-ID: <20150725023806.8664.68687.stgit@dwillia2-desk3.amr.corp.intel.com> In-Reply-To: <20150725023649.8664.59145.stgit@dwillia2-desk3.amr.corp.intel.com> References: <20150725023649.8664.59145.stgit@dwillia2-desk3.amr.corp.intel.com> User-Agent: StGit/0.17.1-8-g92dd MIME-Version: 1.0 X-CRM114-Version: 20100106-BlameMichelson ( TRE 0.8.0 (BSD) ) MR-646709E3 X-CRM114-CacheID: sfid-20150724_194414_791607_1A863ADF X-CRM114-Status: GOOD ( 17.91 ) X-Spam-Score: -8.1 (--------) X-BeenThere: linux-arm-kernel@lists.infradead.org X-Mailman-Version: 2.1.20 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Cc: linux-arch@vger.kernel.org, toshi.kani@hp.com, linux-nvdimm@lists.01.org, "Luis R. Rodriguez" , linux-kernel@vger.kernel.org, Mike Travis , Roland Dreier , Ingo Molnar , Borislav Petkov , rmk+kernel@arm.linux.org.uk, hch@lst.de, linux-arm-kernel@lists.infradead.org Sender: "linux-arm-kernel" Errors-To: linux-arm-kernel-bounces+patchwork-linux-arm=patchwork.kernel.org@lists.infradead.org X-Spam-Status: No, score=-5.4 required=5.0 tests=BAYES_00, RCVD_IN_DNSWL_MED, RP_MATCHES_RCVD, UNPARSEABLE_RELAY autolearn=unavailable version=3.3.1 X-Spam-Checker-Version: SpamAssassin 3.3.1 (2010-03-16) on mail.kernel.org X-Virus-Scanned: ClamAV using ClamSMTP From: Toshi Kani __ioremap_caller() calls region_is_ram() to walk through the iomem_resource table to check if a target range is in RAM, which was added to improve the lookup performance over page_is_ram() (commit 906e36c5c717 "x86: use optimized ioresource lookup in ioremap function"). page_is_ram() was no longer used when this change was added, though. __ioremap_caller() then calls walk_system_ram_range(), which had replaced page_is_ram() to improve the lookup performance (commit c81c8a1eeede "x86, ioremap: Speed up check for RAM pages"). Since both checks walk through the same iomem_resource table for the same purpose, there is no need to call the two functions. Furthermore, region_is_ram() always returns with -1, which makes walk_system_ram_range() as the only check being used at this point. Therefore, this patch changes __ioremap_caller() to call walk_system_ram_range() only. Note, removing the call to region_is_ram() is also necessary to fix bugs in region_is_ram(). walk_system_ram_range() requires RAM ranges be page-aligned in the iomem_resource table to work properly. This restriction has allowed multiple ioremaps to RAM (setup_data) which are page-unaligned. Using fixed region_is_ram() will cause these callers to start failing. After all ioremap callers to setup_data are converted, __ioremap_caller() may call region_is_ram() instead to remove this restriction. Signed-off-by: Toshi Kani Cc: Roland Dreier Cc: Mike Travis Cc: Luis R. Rodriguez Cc: Thomas Gleixner Cc: H. Peter Anvin Cc: Ingo Molnar Cc: Borislav Petkov Signed-off-by: Dan Williams --- arch/x86/mm/ioremap.c | 24 ++++++------------------ 1 file changed, 6 insertions(+), 18 deletions(-) diff --git a/arch/x86/mm/ioremap.c b/arch/x86/mm/ioremap.c index c13f7fdca142..12b1eaeab6b9 100644 --- a/arch/x86/mm/ioremap.c +++ b/arch/x86/mm/ioremap.c @@ -92,7 +92,6 @@ static void __iomem *__ioremap_caller(resource_size_t phys_addr, 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; @@ -115,26 +114,15 @@ static void __iomem *__ioremap_caller(resource_size_t phys_addr, /* * Don't allow anybody to remap normal RAM that we're using.. */ - /* 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, + 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) { - WARN_ONCE(1, "ioremap on RAM at %pa - %pa\n", + WARN_ONCE(1, "ioremap on RAM at %pa - %pa\n", &phys_addr, &last_addr); - return NULL; - } + return NULL; } + /* * Mappings have to be page-aligned */