From patchwork Fri Aug 7 16:34:36 2015 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Julien Grall X-Patchwork-Id: 6971451 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 B92EA9F46B for ; Fri, 7 Aug 2015 16:38:56 +0000 (UTC) Received: from mail.kernel.org (localhost [127.0.0.1]) by mail.kernel.org (Postfix) with ESMTP id DE7C42041D for ; Fri, 7 Aug 2015 16:38:55 +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 77C50202D1 for ; Fri, 7 Aug 2015 16:38:54 +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 1ZNkdo-0004t9-LD; Fri, 07 Aug 2015 16:37:08 +0000 Received: from smtp02.citrix.com ([66.165.176.63]) by bombadil.infradead.org with esmtps (Exim 4.80.1 #2 (Red Hat Linux)) id 1ZNkdL-0004Pc-3r for linux-arm-kernel@lists.infradead.org; Fri, 07 Aug 2015 16:36:41 +0000 X-IronPort-AV: E=Sophos;i="5.15,630,1432598400"; d="scan'208";a="292471244" From: Julien Grall To: Subject: [PATCH v3 3/9] arm/xen: implement correctly pfn_to_mfn Date: Fri, 7 Aug 2015 17:34:36 +0100 Message-ID: <1438965282-19103-4-git-send-email-julien.grall@citrix.com> X-Mailer: git-send-email 2.1.4 In-Reply-To: <1438965282-19103-1-git-send-email-julien.grall@citrix.com> References: <1438965282-19103-1-git-send-email-julien.grall@citrix.com> MIME-Version: 1.0 X-DLP: MIA1 X-CRM114-Version: 20100106-BlameMichelson ( TRE 0.8.0 (BSD) ) MR-646709E3 X-CRM114-CacheID: sfid-20150807_093639_529055_E67D65C2 X-CRM114-Status: UNSURE ( 9.91 ) X-CRM114-Notice: Please train this message. X-Spam-Score: -4.3 (----) 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: Russell King , ian.campbell@citrix.com, stefano.stabellini@eu.citrix.com, linux-kernel@vger.kernel.org, Julien Grall , 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=-4.3 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 After the commit introducing convertion between DMA and guest addresses, all the callers of pfn_to_mfn are expecting to get a GFN (Guest Frame Number). On ARM, all the guests are auto-translated so the GFN is equal to the Linux PFN (Pseudo-physical Frame Number). The current implementation may return an MFN if the caller is passing a PFN associated to a mapped foreign grant. In pratice, I haven't seen the problem on running guest but we should fix it for the sake of correctness. Correct the implementation by always returning the pfn passed in parameter. A follow-up patch will take care to rename pfn_to_mfn to a suitable name. Signed-off-by: Julien Grall Reviewed-by: Stefano Stabellini --- Cc: Russell King Cc: linux-arm-kernel@lists.infradead.org Changes in v3: - Typoes in the commit message - Add Stefano's reviewed-by --- arch/arm/include/asm/xen/page.h | 8 -------- 1 file changed, 8 deletions(-) diff --git a/arch/arm/include/asm/xen/page.h b/arch/arm/include/asm/xen/page.h index 5f76a9e..911d62b 100644 --- a/arch/arm/include/asm/xen/page.h +++ b/arch/arm/include/asm/xen/page.h @@ -36,14 +36,6 @@ extern struct rb_root phys_to_mach; static inline unsigned long pfn_to_mfn(unsigned long pfn) { - unsigned long mfn; - - if (phys_to_mach.rb_node != NULL) { - mfn = __pfn_to_mfn(pfn); - if (mfn != INVALID_P2M_ENTRY) - return mfn; - } - return pfn; }