From patchwork Thu Oct 17 17:43:33 2013 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Stefano Stabellini X-Patchwork-Id: 3062601 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 [198.145.19.201]) by patchwork1.web.kernel.org (Postfix) with ESMTP id 8FECA9F3E2 for ; Thu, 17 Oct 2013 18:05:57 +0000 (UTC) Received: from mail.kernel.org (localhost [127.0.0.1]) by mail.kernel.org (Postfix) with ESMTP id 82541204D2 for ; Thu, 17 Oct 2013 18:05:56 +0000 (UTC) Received: from casper.infradead.org (casper.infradead.org [85.118.1.10]) (using TLSv1 with cipher DHE-RSA-AES256-SHA (256/256 bits)) (No client certificate requested) by mail.kernel.org (Postfix) with ESMTPS id CFEFA20489 for ; Thu, 17 Oct 2013 18:05:51 +0000 (UTC) Received: from merlin.infradead.org ([2001:4978:20e::2]) by casper.infradead.org with esmtps (Exim 4.80.1 #2 (Red Hat Linux)) id 1VWrxD-0002K0-Pl; Thu, 17 Oct 2013 18:05:47 +0000 Received: from localhost ([::1] helo=merlin.infradead.org) by merlin.infradead.org with esmtp (Exim 4.80.1 #2 (Red Hat Linux)) id 1VWrxB-0006Et-8D; Thu, 17 Oct 2013 18:05:45 +0000 Received: from smtp.citrix.com ([66.165.176.89]) by merlin.infradead.org with esmtps (Exim 4.80.1 #2 (Red Hat Linux)) id 1VWrx7-0006Dl-AE for linux-arm-kernel@lists.infradead.org; Thu, 17 Oct 2013 18:05:42 +0000 X-IronPort-AV: E=Sophos;i="4.93,515,1378857600"; d="scan'208";a="64695223" Received: from accessns.citrite.net (HELO FTLPEX01CL03.citrite.net) ([10.9.154.239]) by FTLPIPO01.CITRIX.COM with ESMTP; 17 Oct 2013 18:05:19 +0000 Received: from ukmail1.uk.xensource.com (10.80.16.128) by smtprelay.citrix.com (10.13.107.80) with Microsoft SMTP Server id 14.2.342.4; Thu, 17 Oct 2013 14:05:18 -0400 Received: from kaball.uk.xensource.com ([10.80.2.59]) by ukmail1.uk.xensource.com with esmtp (Exim 4.69) (envelope-from ) id 1VWrcf-0005Gf-40; Thu, 17 Oct 2013 18:44:33 +0100 From: Stefano Stabellini To: Subject: [PATCH v8 18/19] swiotlb-xen: no need to do execute two bus_to_phys translations in a row Date: Thu, 17 Oct 2013 18:43:33 +0100 Message-ID: <1382031814-8782-18-git-send-email-stefano.stabellini@eu.citrix.com> X-Mailer: git-send-email 1.7.9.5 In-Reply-To: References: MIME-Version: 1.0 X-DLP: MIA2 X-CRM114-Version: 20100106-BlameMichelson ( TRE 0.8.0 (BSD) ) MR-646709E3 X-CRM114-CacheID: sfid-20131017_140541_484895_19873FB2 X-CRM114-Status: GOOD ( 10.52 ) X-Spam-Score: -7.3 (-------) Cc: Ian.Campbell@citrix.com, Stefano Stabellini , linux-kernel@vger.kernel.org, linux-arm-kernel@lists.infradead.org, konrad.wilk@oracle.com X-BeenThere: linux-arm-kernel@lists.infradead.org X-Mailman-Version: 2.1.15 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Sender: "linux-arm-kernel" Errors-To: linux-arm-kernel-bounces+patchwork-linux-arm=patchwork.kernel.org@lists.infradead.org X-Spam-Status: No, score=-4.6 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 xen_unmap_single calls xen_bus_to_phys, then passes dev_addr to is_xen_swiotlb_buffer that calls xen_bus_to_phys again. xen_bus_to_phys is potentially a slow operation that might involve walking a tree. We can avoid calling xen_bus_to_phys twice by removing the is_xen_swiotlb_buffer call and doing the check directly in xen_unmap_single using the physical address. Signed-off-by: Stefano Stabellini --- drivers/xen/swiotlb-xen.c | 4 ++-- 1 files changed, 2 insertions(+), 2 deletions(-) diff --git a/drivers/xen/swiotlb-xen.c b/drivers/xen/swiotlb-xen.c index 4d50058..6d9ca61 100644 --- a/drivers/xen/swiotlb-xen.c +++ b/drivers/xen/swiotlb-xen.c @@ -426,8 +426,8 @@ static void xen_unmap_single(struct device *hwdev, dma_addr_t dev_addr, xen_dma_unmap_page(hwdev, paddr, size, dir, attrs); - /* NOTE: We use dev_addr here, not paddr! */ - if (is_xen_swiotlb_buffer(dev_addr)) { + if (paddr >= virt_to_phys(xen_io_tlb_start) && + paddr < virt_to_phys(xen_io_tlb_end)) { swiotlb_tbl_unmap_single(hwdev, paddr, size, dir); return; }