From patchwork Mon Mar 27 12:13:09 2023 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Arnd Bergmann X-Patchwork-Id: 13189121 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 E0187C7619A for ; Mon, 27 Mar 2023 12:17:10 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S232785AbjC0MRK (ORCPT ); Mon, 27 Mar 2023 08:17:10 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:33440 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S231970AbjC0MQ3 (ORCPT ); Mon, 27 Mar 2023 08:16:29 -0400 Received: from ams.source.kernel.org (ams.source.kernel.org [IPv6:2604:1380:4601:e00::1]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id DE5A33C2D; Mon, 27 Mar 2023 05:15:52 -0700 (PDT) Received: from smtp.kernel.org (relay.kernel.org [52.25.139.140]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by ams.source.kernel.org (Postfix) with ESMTPS id 96F3BB81151; Mon, 27 Mar 2023 12:15:51 +0000 (UTC) Received: by smtp.kernel.org (Postfix) with ESMTPSA id 3C656C4339B; Mon, 27 Mar 2023 12:15:42 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1679919350; bh=WcyJUuclgspkZHSwVclV5Jksx+zy3hY89ahpztaj0hM=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=gF/2rqKM1LHnyfHfzF1g693XZNfrbHBqd2oKlgoQ2jGFc8xTOws4qsH2njENSW1Si OGeqBCL1Lt3BSCm5fmGZhO1H6HKEoKzetUEYMk3Soh/1yhM8nZtCol16EHntqcT8Er pM+o9uzAgZL1iYBAWUy3z6yGzIeoUU0K+TXymgHYz7EqbCIvcrn8MMo6RRjBuEtKTx 6l+8vcM3FOZ1WkoHQ1Wlf6+gyjrHJP0Ci4xI/sPZptxVi/W3OXZggPcMTH3OeaOXte UVzqZh+or7dDyFm/ogv6Vz88DYJfSiZ34SmQ2duChP+VAO1veqEJjztWBBm3dd9c41 y9Yt0CcmM/sAw== From: Arnd Bergmann To: linux-kernel@vger.kernel.org Cc: 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 Subject: [PATCH 13/21] arc: dma-mapping: skip invalidating before bidirectional DMA Date: Mon, 27 Mar 2023 14:13:09 +0200 Message-Id: <20230327121317.4081816-14-arnd@kernel.org> X-Mailer: git-send-email 2.39.2 In-Reply-To: <20230327121317.4081816-1-arnd@kernel.org> References: <20230327121317.4081816-1-arnd@kernel.org> MIME-Version: 1.0 Precedence: bulk List-ID: X-Mailing-List: linux-mips@vger.kernel.org From: Arnd Bergmann Some architectures that need to invalidate buffers after bidirectional DMA because of speculative prefetching only do a simpler writeback before that DMA, while architectures that don't need to do the second invalidate tend to have a combined writeback+invalidate before the DMA. arc is one of the architectures that does both, which seems unnecessary. Change it to behave like arm/arm64/xtensa instead, and use just a writeback before the DMA when we do the invalidate afterwards. Signed-off-by: Arnd Bergmann Reviewed-by: Vineet Gupta Tested-by: Shahab Vahedi --- arch/arc/mm/dma.c | 4 ++-- 1 file changed, 2 insertions(+), 2 deletions(-) diff --git a/arch/arc/mm/dma.c b/arch/arc/mm/dma.c index 2a7fbbb83b70..ddb96786f765 100644 --- a/arch/arc/mm/dma.c +++ b/arch/arc/mm/dma.c @@ -40,7 +40,7 @@ void arch_dma_prep_coherent(struct page *page, size_t size) * |---------------------------------------------------------------- * TO_DEV | writeback writeback | none none * FROM_DEV | invalidate invalidate | invalidate* invalidate* - * BIDIR | writeback+inv writeback+inv | invalidate invalidate + * BIDIR | writeback writeback | invalidate invalidate * * [*] needed for CPU speculative prefetches * @@ -61,7 +61,7 @@ void arch_sync_dma_for_device(phys_addr_t paddr, size_t size, break; case DMA_BIDIRECTIONAL: - dma_cache_wback_inv(paddr, size); + dma_cache_wback(paddr, size); break; default: