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 vger.kernel.org (vger.kernel.org [23.128.96.18]) by smtp.lore.kernel.org (Postfix) with ESMTP id F18C8C77B6D for ; Thu, 30 Mar 2023 13:27:13 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S231972AbjC3N1M (ORCPT ); Thu, 30 Mar 2023 09:27:12 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:60720 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S231822AbjC3N1J (ORCPT ); Thu, 30 Mar 2023 09:27:09 -0400 Received: from mail-il1-x134.google.com (mail-il1-x134.google.com [IPv6:2607:f8b0:4864:20::134]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 6B080BDEF; Thu, 30 Mar 2023 06:26:46 -0700 (PDT) Received: by mail-il1-x134.google.com with SMTP id e6so9776646ilu.9; Thu, 30 Mar 2023 06:26:46 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20210112; t=1680182805; x=1682774805; h=content-transfer-encoding:cc:to:subject:message-id:date:from :in-reply-to:references:mime-version:from:to:cc:subject:date :message-id:reply-to; bh=n2pZnebNGLahNe2yjgjrKsFqnYvTRYd7uF1JoUeedu4=; b=ipMmc4f2rhe9ZxmiesNtaMCdByaDBx7tN+zc7KMJSrXwy2WiELheDph1YzfOyUJK5G 2D9w1lws05LiLD96ktr9W079igf4FZMXTfy1rli6Syf8wtA/xOvdvesIM/xHoHpQ4mp2 kGaQPBqZIeQg75WZRmLC1J0vvz0N+J/wHgPfeNx6CWqljr2xVRlnhMmqStDFXeH9OteD UdDKlBrcDx+IHVgGRnNql6fNqhC8UJ/0zLJcMACiQdKHQjGURJds5lWBs1vyz5ebkPWw 0o6fGsGo2wE6PVztfykuJW8aKjmi0krcntJGszy/82gq0ndxxs4fJ8aJQW98nZewfAkA hgxg== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20210112; t=1680182805; x=1682774805; h=content-transfer-encoding:cc:to:subject:message-id:date:from :in-reply-to:references:mime-version:x-gm-message-state:from:to:cc :subject:date:message-id:reply-to; bh=n2pZnebNGLahNe2yjgjrKsFqnYvTRYd7uF1JoUeedu4=; b=XKsMDayOlwVZ/+/jeS5lmBFAGWD0j4RBR2BY2nyji6WZuy/N3FaKHLkPpqeaWPMqUn txdSh18O2NU16utq/lwzwgwz6rUKdkcXa2qlMQymOBmYC4kqkMXed9jSBvMSDdPiiod+ A6fFy4Nl/uQuMY7iayVLVTYQfi+VgqCvtmdJOwiEv7zl7K7TaBAAFoXizow8b/IX+4jf ga8m21Vt/qrehbiq6t46ECtRixi79KHHi06JGkaEF5lYbie94Jf313PUdpuZI8R7wHI/ EPepXZ1PH2imQByNnwrQ5iLig0ayC5BcZrRK7n7MHVomJSJgP0QgfBN8E4W1mQsLjUrT K/ZQ== X-Gm-Message-State: AAQBX9d+jR2BwKkDtcU459i1tNTLR81oh9wsEQLdmwozA42l3tHgpdiM xDe5DgCBBuRVlvi9zaCfTm8eGSjpDHycrDjd/VE= X-Google-Smtp-Source: AKy350b7GKjd6GbmSD4bjqzZzqd/x8SBG7vY+M0wf9Tl0Xt+rzmxZqELne3/hmMfJjmFaGc7B3VEjdENhXkZ8+X22Co= X-Received: by 2002:a05:6e02:1047:b0:325:dd36:7451 with SMTP id p7-20020a056e02104700b00325dd367451mr11322497ilj.1.1680182805604; Thu, 30 Mar 2023 06:26:45 -0700 (PDT) MIME-Version: 1.0 References: <20230327121317.4081816-1-arnd@kernel.org> <20230327121317.4081816-10-arnd@kernel.org> In-Reply-To: <20230327121317.4081816-10-arnd@kernel.org> From: "Lad, Prabhakar" Date: Thu, 30 Mar 2023 14:26:18 +0100 Message-ID: Subject: Re: [PATCH 09/21] riscv: dma-mapping: skip invalidation before bidirectional DMA To: Arnd Bergmann Cc: linux-kernel@vger.kernel.org, Arnd Bergmann , Vineet Gupta , Russell King , Neil Armstrong , Linus Walleij , Catalin Marinas , Will Deacon , Guo Ren , Brian Cain , Geert Uytterhoeven , Michal Simek , Thomas Bogendoerfer , Dinh Nguyen , Stafford Horne , Helge Deller , Michael Ellerman , Christophe Leroy , Paul Walmsley , Palmer Dabbelt , Rich Felker , John Paul Adrian Glaubitz , "David S. Miller" , Max Filippov , Christoph Hellwig , Robin Murphy , Lad Prabhakar , 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 Content-Type: text/plain; charset="UTF-8" Content-Transfer-Encoding: quoted-printable Precedence: bulk List-ID: X-Mailing-List: linux-sh@vger.kernel.org On Mon, Mar 27, 2023 at 1:16=E2=80=AFPM Arnd Bergmann wro= te: > > 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(-) > Reviewed-by: Lad Prabhakar Cheers, Prabhakar > diff --git a/arch/riscv/mm/dma-noncoherent.c b/arch/riscv/mm/dma-noncoher= ent.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; > -- > 2.39.2 > > > _______________________________________________ > linux-riscv mailing list > linux-riscv@lists.infradead.org > http://lists.infradead.org/mailman/listinfo/linux-riscv