From mboxrd@z Thu Jan 1 00:00:00 1970 Received: with ECARTIS (v1.0.0; list linux-mips); Wed, 25 Sep 2013 14:58:45 +0200 (CEST) Received: from mms3.broadcom.com ([216.31.210.19]:4627 "EHLO mms3.broadcom.com" rhost-flags-OK-OK-OK-OK) by eddie.linux-mips.org with ESMTP id S6816233Ab3IYM6l5H404 (ORCPT ); Wed, 25 Sep 2013 14:58:41 +0200 Received: from [10.9.208.57] by mms3.broadcom.com with ESMTP (Broadcom SMTP Relay (Email Firewall v6.5)); Wed, 25 Sep 2013 05:47:44 -0700 X-Server-Uuid: B86B6450-0931-4310-942E-F00ED04CA7AF Received: from IRVEXCHSMTP1.corp.ad.broadcom.com (10.9.207.51) by IRVEXCHCAS08.corp.ad.broadcom.com (10.9.208.57) with Microsoft SMTP Server (TLS) id 14.1.438.0; Wed, 25 Sep 2013 05:56:27 -0700 Received: from mail-irva-13.broadcom.com (10.10.10.20) by IRVEXCHSMTP1.corp.ad.broadcom.com (10.9.207.51) with Microsoft SMTP Server id 14.1.438.0; Wed, 25 Sep 2013 05:56:27 -0700 Received: from netl-snoppy.ban.broadcom.com ( netl-snoppy.ban.broadcom.com [10.132.128.129]) by mail-irva-13.broadcom.com (Postfix) with ESMTP id 76781246A4; Wed, 25 Sep 2013 05:56:26 -0700 (PDT) From: "Jayachandran C" To: ralf@linux-mips.org cc: linux-mips@linux-mips.org, "Jayachandran C" Subject: [PATCH] MIPS: mm: Move some checks out of 'for' loop in DMA operations Date: Wed, 25 Sep 2013 18:31:05 +0530 Message-ID: <1380114065-9761-1-git-send-email-jchandra@broadcom.com> X-Mailer: git-send-email 1.7.9.5 MIME-Version: 1.0 X-WSS-ID: 7E5C04E52L888359311-04-01 Content-Type: text/plain Content-Transfer-Encoding: 7bit Return-Path: X-Envelope-To: <"|/home/ecartis/ecartis -s linux-mips"> (uid 0) X-Orcpt: rfc822;linux-mips@linux-mips.org Original-Recipient: rfc822;linux-mips@linux-mips.org X-archive-position: 37971 X-ecartis-version: Ecartis v1.0.0 Sender: linux-mips-bounce@linux-mips.org Errors-to: linux-mips-bounce@linux-mips.org X-original-sender: jchandra@broadcom.com Precedence: bulk List-help: List-unsubscribe: List-software: Ecartis version 1.0.0 List-Id: linux-mips X-List-ID: linux-mips List-subscribe: List-owner: List-post: List-archive: X-list: linux-mips The check cpu_needs_post_dma_flush() in mips_dma_sync_sg_for_cpu() and the check !plat_device_is_coherent() in mips_dma_sync_sg_for_device() can be moved outside the for loop. As a side effect, this also avoids a GCC bug that caused kernel compile to fail with the error: arch/mips/mm/dma-default.c: In function 'mips_dma_sync_sg_for_cpu': arch/mips/mm/dma-default.c:316:1: internal compiler error: in add_insn_before, at emit-rtl.c:3852 This gcc failure is seen in Code Sourcery toolchains [e.g. gcc version 4.7.2 (Sourcery CodeBench Lite 2012.09-99)] after commit "MIPS: Optimize current_cpu_type() for better code." --- arch/mips/mm/dma-default.c | 12 ++++-------- 1 file changed, 4 insertions(+), 8 deletions(-) diff --git a/arch/mips/mm/dma-default.c b/arch/mips/mm/dma-default.c index e45e4b0..2e94185 100644 --- a/arch/mips/mm/dma-default.c +++ b/arch/mips/mm/dma-default.c @@ -307,12 +307,10 @@ static void mips_dma_sync_sg_for_cpu(struct device *dev, { int i; - /* Make sure that gcc doesn't leave the empty loop body. */ - for (i = 0; i < nelems; i++, sg++) { - if (cpu_needs_post_dma_flush(dev)) + if (cpu_needs_post_dma_flush(dev)) + for (i = 0; i < nelems; i++, sg++) __dma_sync(sg_page(sg), sg->offset, sg->length, direction); - } } static void mips_dma_sync_sg_for_device(struct device *dev, @@ -320,12 +318,10 @@ static void mips_dma_sync_sg_for_device(struct device *dev, { int i; - /* Make sure that gcc doesn't leave the empty loop body. */ - for (i = 0; i < nelems; i++, sg++) { - if (!plat_device_is_coherent(dev)) + if (!plat_device_is_coherent(dev)) + for (i = 0; i < nelems; i++, sg++) __dma_sync(sg_page(sg), sg->offset, sg->length, direction); - } } int mips_dma_mapping_error(struct device *dev, dma_addr_t dma_addr) -- 1.7.9.5