From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org Received: from bombadil.infradead.org (bombadil.infradead.org [198.137.202.133]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.lore.kernel.org (Postfix) with ESMTPS id 8483DC77B75 for ; Wed, 19 Apr 2023 14:23:04 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=lists.infradead.org; s=bombadil.20210309; h=Sender:Content-Type: Content-Transfer-Encoding:List-Subscribe:List-Help:List-Post:List-Archive: List-Unsubscribe:List-Id:Mime-Version:Message-ID:To:From:CC:In-Reply-To: Subject:Date:Reply-To:Content-ID:Content-Description:Resent-Date:Resent-From: Resent-Sender:Resent-To:Resent-Cc:Resent-Message-ID:References:List-Owner; bh=MjFC0BTU66MeqTC1XkNYpQ/jmCpcyOswYh1HDWcPYu0=; b=BJZGVqUQBJBTkGitWFHwLQzEtp Zlu6FJz5fv2wmwvnyS003I7f4iecghqwbYvXrZJg/NTNjF13sKfxRaAcJru+3gT1qwDnZXYFrDoN4 5fMITh0hzRVUFj1QpucVbJL9K7/A+ootB9WOkPULNH4ZOhvPlm29yBdIQselIWIS/zK12zPnUHoEp BMUiNVk6Dki61lR+aRaXDlBdP8SzoC04Qfe6bcFx7fR4sGhNx7gl46SZq0wJsG2XVmY4x8nrnqSL7 zTLsgz5Aq/CfW2xHBMeimiYkYcaN78LrSfjk5W/OsgCyiVcou/2R9NMnMRJBPoqAJaGf1NfdieWNJ mrGH0MTA==; Received: from localhost ([::1] helo=bombadil.infradead.org) by bombadil.infradead.org with esmtp (Exim 4.96 #2 (Red Hat Linux)) id 1pp8i6-005e90-2c; Wed, 19 Apr 2023 14:23:02 +0000 Received: from mail-pf1-x431.google.com ([2607:f8b0:4864:20::431]) by bombadil.infradead.org with esmtps (Exim 4.96 #2 (Red Hat Linux)) id 1pp8hz-005dzZ-14 for linux-snps-arc@lists.infradead.org; Wed, 19 Apr 2023 14:22:57 +0000 Received: by mail-pf1-x431.google.com with SMTP id d2e1a72fcca58-63b62d2f729so2471202b3a.1 for ; Wed, 19 Apr 2023 07:22:52 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=dabbelt-com.20221208.gappssmtp.com; s=20221208; t=1681914172; x=1684506172; h=content-transfer-encoding:mime-version:message-id:to:from:cc :in-reply-to:subject:date:from:to:cc:subject:date:message-id :reply-to; bh=IvT99d3vu2s9u2HdXHuOsCskK0/5VChFq+aBcaoQwKM=; b=eJ51Lyhme8n3XB+0k6fcBFov9PY8/EUmTR8+nuSaGr7xBsijqIoLjwhsLzVxYH/nx0 wauVowtfzqnaLMg0Md06tjLXI3lWkSGzsXedNOsMpQwkDCNvEtBTyQ19M/Yyo6D06BSV XNjXn0CGdLZl3nFWqDjNax+yB6CXLq01SwKNwyDS36uGnLYxQFXzNQuK/+7hScqPlZwX z+agJw/VCIGMUixwVDzm2XMnLSn8GR3DsnMXY+jrQCfbr9O1Le1uXDKTi2rYkt7oJ2Ce tyNNGrxSj0L54sdbIeiSTDtndMc3YiWnjyxMJLeRw/TsNRHsyFeDM9KNzzDNKUVPs4Et pKOQ== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20221208; t=1681914172; x=1684506172; h=content-transfer-encoding:mime-version:message-id:to:from:cc :in-reply-to:subject:date:x-gm-message-state:from:to:cc:subject:date :message-id:reply-to; bh=IvT99d3vu2s9u2HdXHuOsCskK0/5VChFq+aBcaoQwKM=; b=jqIjN7qIt11DuQaSHf2RTWDkGUBP4Je1eUaKCLYBCu9H3BrSnQZ+QumiHLKluepxIZ pCTlJcrLpQHR+6ZIDelQWFFUO9W2v7xeV5KO2xs3E9ULa2ZxfIonu9fQnoYTNckfAsKu 62cKkuX3mVLHudMPesiZQVn+Ev6/ANKc9Q/VgCZdN5flpTXvyd98CALx9zQRmxwujc0W qSn1BL2LYp0M01wpY2VhE2fLs2lU8dpgZzLPFttyiHFilCbe57tsIPzInOJAbgk5XMzM JxVyd6iTrOb64uWx9fqafyM7jdLHWt6K8LYkrVSc3XLfAryaUNNeCG8lMn9oeI/emHRM xbCQ== X-Gm-Message-State: AAQBX9fu5urpXMDlcW+7ESLosivQtJKIdTho/C8V4zaAzAQOQ535TeDu nxMzXU+TqyADN57lrGU88ORYPw== X-Google-Smtp-Source: AKy350YgrN7zbaEKFT5DU1qrct74Wsi9a0WokbCy4dVCW0VXg9H7v3lPwT87yJxbljWHRWpRpF5B0Q== X-Received: by 2002:a05:6a00:130a:b0:63b:859f:f094 with SMTP id j10-20020a056a00130a00b0063b859ff094mr4002975pfu.20.1681914171995; Wed, 19 Apr 2023 07:22:51 -0700 (PDT) Received: from localhost ([135.180.227.0]) by smtp.gmail.com with ESMTPSA id d2-20020a63d642000000b005140ce70582sm10431557pgj.44.2023.04.19.07.22.51 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Wed, 19 Apr 2023 07:22:51 -0700 (PDT) Date: Wed, 19 Apr 2023 07:22:51 -0700 (PDT) X-Google-Original-Date: Wed, 19 Apr 2023 07:22:44 PDT (-0700) Subject: Re: [PATCH 09/21] riscv: dma-mapping: skip invalidation before bidirectional DMA In-Reply-To: <20230327121317.4081816-10-arnd@kernel.org> CC: linux-kernel@vger.kernel.org, Arnd Bergmann , vgupta@kernel.org, linux@armlinux.org.uk, neil.armstrong@linaro.org, linus.walleij@linaro.org, Catalin Marinas , Will Deacon , guoren@kernel.org, bcain@quicinc.com, geert@linux-m68k.org, monstr@monstr.eu, tsbogend@alpha.franken.de, dinguyen@kernel.org, shorne@gmail.com, deller@gmx.de, mpe@ellerman.id.au, christophe.leroy@csgroup.eu, Paul Walmsley , dalias@libc.org, glaubitz@physik.fu-berlin.de, davem@davemloft.net, jcmvbkbc@gmail.com, Christoph Hellwig , robin.murphy@arm.com, prabhakar.mahadev-lad.rj@bp.renesas.com, Conor Dooley , linux-snps-arc@lists.infradead.org, linux-arm-kernel@lists.infradead.org, linux-oxnas@groups.io, linux-csky@vger.kernel.org, linux-hexagon@vger.kernel.org, linux-m68k@lists.linux-m68k.org, linux-mips@vger.kernel.org, linux-openrisc@vger.kernel.org, linux-parisc@vger.kernel.org, linuxppc-dev@lists.ozlabs.org, linux-riscv@lists.infradead.org, linux-sh@vger.kernel.org, sparclinux@vger.kernel.org, linux-xtensa@linux-xtensa.org From: Palmer Dabbelt To: arnd@kernel.org Message-ID: Mime-Version: 1.0 (MHng) X-CRM114-Version: 20100106-BlameMichelson ( TRE 0.8.0 (BSD) ) MR-646709E3 X-CRM114-CacheID: sfid-20230419_072255_373582_F6D2567A X-CRM114-Status: GOOD ( 19.66 ) X-BeenThere: linux-snps-arc@lists.infradead.org X-Mailman-Version: 2.1.34 Precedence: list List-Id: Linux on Synopsys ARC Processors List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Content-Transfer-Encoding: 7bit Content-Type: text/plain; charset="us-ascii"; Format="flowed" Sender: "linux-snps-arc" Errors-To: linux-snps-arc-bounces+linux-snps-arc=archiver.kernel.org@lists.infradead.org On Mon, 27 Mar 2023 05:13:05 PDT (-0700), arnd@kernel.org wrote: > From: Arnd Bergmann > > For a DMA_BIDIRECTIONAL transfer, the caches have to be cleaned > first to let the device see data written by the CPU, and invalidated > after the transfer to let the CPU see data written by the device. > > riscv also invalidates the caches before the transfer, which does > not appear to serve any purpose. > > Signed-off-by: Arnd Bergmann > --- > arch/riscv/mm/dma-noncoherent.c | 2 +- > 1 file changed, 1 insertion(+), 1 deletion(-) > > diff --git a/arch/riscv/mm/dma-noncoherent.c b/arch/riscv/mm/dma-noncoherent.c > index 640f4c496d26..69c80b2155a1 100644 > --- a/arch/riscv/mm/dma-noncoherent.c > +++ b/arch/riscv/mm/dma-noncoherent.c > @@ -25,7 +25,7 @@ void arch_sync_dma_for_device(phys_addr_t paddr, size_t size, > ALT_CMO_OP(clean, vaddr, size, riscv_cbom_block_size); > break; > case DMA_BIDIRECTIONAL: > - ALT_CMO_OP(flush, vaddr, size, riscv_cbom_block_size); > + ALT_CMO_OP(clean, vaddr, size, riscv_cbom_block_size); > break; > default: > break; Acked-by: Palmer Dabbelt _______________________________________________ linux-snps-arc mailing list linux-snps-arc@lists.infradead.org http://lists.infradead.org/mailman/listinfo/linux-snps-arc