From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S932676AbbHGQgW (ORCPT ); Fri, 7 Aug 2015 12:36:22 -0400 Received: from smtp02.citrix.com ([66.165.176.63]:2800 "EHLO SMTP02.CITRIX.COM" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S932628AbbHGQgQ (ORCPT ); Fri, 7 Aug 2015 12:36:16 -0400 X-IronPort-AV: E=Sophos;i="5.15,630,1432598400"; d="scan'208";a="292471244" From: Julien Grall To: CC: , , , Julien Grall , Russell King , 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 Content-Type: text/plain X-DLP: MIA1 Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org 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; } -- 2.1.4