From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1754352AbbALSRI (ORCPT ); Mon, 12 Jan 2015 13:17:08 -0500 Received: from youngberry.canonical.com ([91.189.89.112]:57667 "EHLO youngberry.canonical.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1753692AbbALSG0 (ORCPT ); Mon, 12 Jan 2015 13:06:26 -0500 From: Luis Henriques To: linux-kernel@vger.kernel.org, stable@vger.kernel.org, kernel-team@lists.ubuntu.com Cc: Stefano Stabellini , Luis Henriques Subject: [PATCH 3.16.y-ckt 081/216] swiotlb-xen: remove BUG_ON in xen_bus_to_phys Date: Mon, 12 Jan 2015 18:03:18 +0000 Message-Id: <1421085933-32536-82-git-send-email-luis.henriques@canonical.com> X-Mailer: git-send-email 2.1.4 In-Reply-To: <1421085933-32536-1-git-send-email-luis.henriques@canonical.com> References: <1421085933-32536-1-git-send-email-luis.henriques@canonical.com> X-Extended-Stable: 3.16 Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org 3.16.7-ckt4 -stable review patch. If anyone has any objections, please let me know. ------------------ From: Stefano Stabellini commit c884227eaae9936f8ecbde6e1387bccdab5f4e90 upstream. On x86 truncation cannot occur because config XEN depends on X86_64 || (X86_32 && X86_PAE). On ARM truncation can occur without CONFIG_ARM_LPAE, when the dma operation involves foreign grants. However in that case the physical address returned by xen_bus_to_phys is actually invalid (there is no mfn to pfn tracking for foreign grants on ARM) and it is not used. Signed-off-by: Stefano Stabellini Reviewed-by: Catalin Marinas Acked-by: Konrad Rzeszutek Wilk Signed-off-by: Luis Henriques --- drivers/xen/swiotlb-xen.c | 2 -- 1 file changed, 2 deletions(-) diff --git a/drivers/xen/swiotlb-xen.c b/drivers/xen/swiotlb-xen.c index bc6fb0d24ad5..f21282da9876 100644 --- a/drivers/xen/swiotlb-xen.c +++ b/drivers/xen/swiotlb-xen.c @@ -96,8 +96,6 @@ static inline phys_addr_t xen_bus_to_phys(dma_addr_t baddr) dma_addr_t dma = (dma_addr_t)pfn << PAGE_SHIFT; phys_addr_t paddr = dma; - BUG_ON(paddr != dma); /* truncation has occurred, should never happen */ - paddr |= baddr & ~PAGE_MASK; return paddr; -- 2.1.4