From patchwork Mon Jun 1 19:36:25 2015 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Toshi Kani X-Patchwork-Id: 6524401 Return-Path: X-Original-To: patchwork-linux-nvdimm@patchwork.kernel.org Delivered-To: patchwork-parsemail@patchwork2.web.kernel.org Received: from mail.kernel.org (mail.kernel.org [198.145.29.136]) by patchwork2.web.kernel.org (Postfix) with ESMTP id 7F5D6C0020 for ; Mon, 1 Jun 2015 19:56:18 +0000 (UTC) Received: from mail.kernel.org (localhost [127.0.0.1]) by mail.kernel.org (Postfix) with ESMTP id ACCEA204A9 for ; Mon, 1 Jun 2015 19:56:17 +0000 (UTC) Received: from ml01.01.org (ml01.01.org [198.145.21.10]) (using TLSv1.2 with cipher DHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by mail.kernel.org (Postfix) with ESMTPS id 606EA204A0 for ; Mon, 1 Jun 2015 19:56:16 +0000 (UTC) Received: from ml01.vlan14.01.org (localhost [IPv6:::1]) by ml01.01.org (Postfix) with ESMTP id 535B71827ED; Mon, 1 Jun 2015 12:56:16 -0700 (PDT) X-Original-To: linux-nvdimm@lists.01.org Delivered-To: linux-nvdimm@lists.01.org Received: from g4t3426.houston.hp.com (g4t3426.houston.hp.com [15.201.208.54]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by ml01.01.org (Postfix) with ESMTPS id CC0851827EB for ; Mon, 1 Jun 2015 12:56:15 -0700 (PDT) Received: from g4t3433.houston.hp.com (g4t3433.houston.hp.com [16.210.25.219]) by g4t3426.houston.hp.com (Postfix) with ESMTP id 08ADB83; Mon, 1 Jun 2015 19:56:15 +0000 (UTC) Received: from misato.fc.hp.com (misato.fc.hp.com [16.78.168.61]) by g4t3433.houston.hp.com (Postfix) with ESMTP id 971127A; Mon, 1 Jun 2015 19:56:13 +0000 (UTC) From: Toshi Kani To: bp@alien8.de, hpa@zytor.com, tglx@linutronix.de, mingo@redhat.com, akpm@linux-foundation.org, arnd@arndb.de Subject: [PATCH v12 2/10] x86, mm, pat: Change reserve_memtype() for WT Date: Mon, 1 Jun 2015 13:36:25 -0600 Message-Id: <1433187393-22688-3-git-send-email-toshi.kani@hp.com> X-Mailer: git-send-email 1.9.3 In-Reply-To: <1433187393-22688-1-git-send-email-toshi.kani@hp.com> References: <1433187393-22688-1-git-send-email-toshi.kani@hp.com> Cc: jgross@suse.com, konrad.wilk@oracle.com, linux-nvdimm@lists.01.org, mcgrof@suse.com, x86@kernel.org, linux-kernel@vger.kernel.org, stefan.bader@canonical.com, luto@amacapital.net, linux-mm@kvack.org, hmh@hmh.eng.br, hch@lst.de X-BeenThere: linux-nvdimm@lists.01.org X-Mailman-Version: 2.1.17 Precedence: list List-Id: "Linux-nvdimm developer list." List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , MIME-Version: 1.0 Errors-To: linux-nvdimm-bounces@lists.01.org Sender: "Linux-nvdimm" X-Spam-Status: No, score=-1.9 required=5.0 tests=BAYES_00, T_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 When a RAM range is requested to reserve_memtype(), it calls reserve_ram_pages_type() to verify the requested type. reserve_ram_pages_type() is changed to fail WT and WP requests with -EINVAL since set_page_memtype() is limited to handle three types, WB, WC and UC-. Signed-off-by: Toshi Kani Reviewed-by: Konrad Rzeszutek Wilk Reviewed-by: Thomas Gleixner --- Patch 8/10 enhances set_page_memtype() to support WT. --- arch/x86/mm/pat.c | 10 ++++++++++ 1 file changed, 10 insertions(+) diff --git a/arch/x86/mm/pat.c b/arch/x86/mm/pat.c index 83af01a..56c8b4d 100644 --- a/arch/x86/mm/pat.c +++ b/arch/x86/mm/pat.c @@ -401,6 +401,8 @@ static int pat_pagerange_is_ram(resource_size_t start, resource_size_t end) /* * For RAM pages, we use page flags to mark the pages with appropriate type. + * The page flags are limited to three types, WB, WC and UC-. + * WT and WP requests fail with -EINVAL, and UC gets redirected to UC-. * Here we do two pass: * - Find the memtype of all the pages in the range, look for any conflicts * - In case of no conflicts, set the new memtype for pages in the range @@ -412,6 +414,13 @@ static int reserve_ram_pages_type(u64 start, u64 end, struct page *page; u64 pfn; + if ((req_type == _PAGE_CACHE_MODE_WT) || + (req_type == _PAGE_CACHE_MODE_WP)) { + if (new_type) + *new_type = _PAGE_CACHE_MODE_UC_MINUS; + return -EINVAL; + } + if (req_type == _PAGE_CACHE_MODE_UC) { /* We do not support strong UC */ WARN_ON_ONCE(1); @@ -461,6 +470,7 @@ static int free_ram_pages_type(u64 start, u64 end) * - _PAGE_CACHE_MODE_WC * - _PAGE_CACHE_MODE_UC_MINUS * - _PAGE_CACHE_MODE_UC + * - _PAGE_CACHE_MODE_WT * * If new_type is NULL, function will return an error if it cannot reserve the * region with req_type. If new_type is non-NULL, function will return