From patchwork Mon Mar 27 12:13:16 2023 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Arnd Bergmann X-Patchwork-Id: 13189215 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 56031C77B6D for ; Mon, 27 Mar 2023 12:18:59 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S232877AbjC0MS6 (ORCPT ); Mon, 27 Mar 2023 08:18:58 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:34158 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S231932AbjC0MSR (ORCPT ); Mon, 27 Mar 2023 08:18:17 -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 6FF465FEE; Mon, 27 Mar 2023 05:16:54 -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 C939EB80B7E; Mon, 27 Mar 2023 12:16:52 +0000 (UTC) Received: by smtp.kernel.org (Postfix) with ESMTPSA id 501AFC433EF; Mon, 27 Mar 2023 12:16:43 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1679919411; bh=Rv4KYy6sKfgGeqiWLGkVJXsqyPpN0yobcAkWx6hOhRA=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=seVtQRQNuB5GWBdC8cr5KZ0W+Dgkdso6D+FfC2lHsM55FW+HCEqGCdYrQFb6Hvnnl bXHyqMcd3DyyV7hi1FueJFrSKcIZT1GcdjqwY+W+kWsNdEnWRPJylqhRRg5RsHevq7 WBFUd0m9uRKlCn7LN+gS0Oo+KRc8tPOfbCxZQI64X7AW5W6Ofpjnb7fmDoiT4RacVw vk4b1z+FUEyiJWAWMcn0G5UR2lUKTJzFuBhtLP8MwNCX/APqFQwsqhZT0tSSdZGUwv DnaR/fiB4vNkK6jouFd9Zrn6qoIastoqdb9WZidfdEvnyO6j1MKTBI641v/Mfj9Cpi 1m6kthf5XYK2Q== 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 20/21] ARM: dma-mapping: split out arch_dma_mark_clean() helper Date: Mon, 27 Mar 2023 14:13:16 +0200 Message-Id: <20230327121317.4081816-21-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-parisc@vger.kernel.org From: Arnd Bergmann The arm version of the arch_sync_dma_for_cpu() function annotates pages as PG_dcache_clean after a DMA, but no other architecture does this here. On ia64, the same thing is done in arch_sync_dma_for_cpu(), so it makes sense to use the same hook in order to have identical arch_sync_dma_for_cpu() semantics as all other architectures. Splitting this out has multiple effects: - for dma-direct, this now gets called after arch_sync_dma_for_cpu() for DMA_FROM_DEVICE mappings, but not for DMA_BIDIRECTIONAL. While it would not be harmful to keep doing it for bidirectional mappings, those are apparently not used in any callers that care about the flag. - Since arm has its own dma-iommu abstraction, this now also needs to call the same function, so the calls are added there to mirror the dma-direct version. - Like dma-direct, the dma-iommu version now marks the dcache clean for both coherent and noncoherent devices after a DMA, but it only does this for DMA_FROM_DEVICE, not DMA_BIDIRECTIONAL. [ HELP NEEDED: can anyone confirm that it is a correct assumption on arm that a cache-coherent device writing to a page always results in it being in a PG_dcache_clean state like on ia64, or can a device write directly into the dcache?] Signed-off-by: Arnd Bergmann --- arch/arm/Kconfig | 1 + arch/arm/mm/dma-mapping.c | 71 +++++++++++++++++++++++---------------- 2 files changed, 43 insertions(+), 29 deletions(-) diff --git a/arch/arm/Kconfig b/arch/arm/Kconfig index e24a9820e12f..125d58c54ab1 100644 --- a/arch/arm/Kconfig +++ b/arch/arm/Kconfig @@ -7,6 +7,7 @@ config ARM select ARCH_HAS_BINFMT_FLAT select ARCH_HAS_CURRENT_STACK_POINTER select ARCH_HAS_DEBUG_VIRTUAL if MMU + select ARCH_HAS_DMA_MARK_CLEAN if MMU select ARCH_HAS_DMA_WRITE_COMBINE if !ARM_DMA_MEM_BUFFERABLE select ARCH_HAS_ELF_RANDOMIZE select ARCH_HAS_FORTIFY_SOURCE diff --git a/arch/arm/mm/dma-mapping.c b/arch/arm/mm/dma-mapping.c index cc702cb27ae7..b703cb83d27e 100644 --- a/arch/arm/mm/dma-mapping.c +++ b/arch/arm/mm/dma-mapping.c @@ -665,6 +665,28 @@ static void dma_cache_maint(phys_addr_t paddr, } while (left); } +/* + * Mark the D-cache clean for these pages to avoid extra flushing. + */ +void arch_dma_mark_clean(phys_addr_t paddr, size_t size) +{ + unsigned long pfn = PFN_UP(paddr); + unsigned long off = paddr & (PAGE_SIZE - 1); + size_t left = size; + + if (size < PAGE_SIZE) + return; + + if (off) + left -= PAGE_SIZE - off; + + while (left >= PAGE_SIZE) { + struct page *page = pfn_to_page(pfn++); + set_bit(PG_dcache_clean, &page->flags); + left -= PAGE_SIZE; + } +} + static bool arch_sync_dma_cpu_needs_post_dma_flush(void) { if (IS_ENABLED(CONFIG_CPU_V6) || @@ -715,24 +737,6 @@ void arch_sync_dma_for_cpu(phys_addr_t paddr, size_t size, outer_inv_range(paddr, paddr + size); dma_cache_maint(paddr, size, dmac_inv_range); } - - /* - * Mark the D-cache clean for these pages to avoid extra flushing. - */ - if (dir != DMA_TO_DEVICE && size >= PAGE_SIZE) { - unsigned long pfn = PFN_UP(paddr); - unsigned long off = paddr & (PAGE_SIZE - 1); - size_t left = size; - - if (off) - left -= PAGE_SIZE - off; - - while (left >= PAGE_SIZE) { - struct page *page = pfn_to_page(pfn++); - set_bit(PG_dcache_clean, &page->flags); - left -= PAGE_SIZE; - } - } } #ifdef CONFIG_ARM_DMA_USE_IOMMU @@ -1294,6 +1298,17 @@ static int arm_iommu_map_sg(struct device *dev, struct scatterlist *sg, return -EINVAL; } +static void arm_iommu_sync_dma_for_cpu(phys_addr_t phys, size_t len, + enum dma_data_direction dir, + bool dma_coherent) +{ + if (!dma_coherent) + arch_sync_dma_for_cpu(phys, s->length, dir); + + if (dir == DMA_FROM_DEVICE) + arch_dma_mark_clean(phys, s->length); +} + /** * arm_iommu_unmap_sg - unmap a set of SG buffers mapped by dma_map_sg * @dev: valid struct device pointer @@ -1316,8 +1331,9 @@ static void arm_iommu_unmap_sg(struct device *dev, if (sg_dma_len(s)) __iommu_remove_mapping(dev, sg_dma_address(s), sg_dma_len(s)); - if (!dev->dma_coherent && !(attrs & DMA_ATTR_SKIP_CPU_SYNC)) - arch_sync_dma_for_cpu(sg_phys(s), s->length, dir); + if (!(attrs & DMA_ATTR_SKIP_CPU_SYNC)) + arm_iommu_sync_dma_for_cpu(sg_phys(s), s->length, dir, + dev->dma_coherent); } } @@ -1335,12 +1351,9 @@ static void arm_iommu_sync_sg_for_cpu(struct device *dev, struct scatterlist *s; int i; - if (dev->dma_coherent) - return; - for_each_sg(sg, s, nents, i) - arch_sync_dma_for_cpu(sg_phys(s), s->length, dir); - + arm_iommu_sync_dma_for_cpu(sg_phys(s), s->length, dir, + dev->dma_coherent); } /** @@ -1425,9 +1438,9 @@ static void arm_iommu_unmap_page(struct device *dev, dma_addr_t handle, if (!iova) return; - if (!dev->dma_coherent && !(attrs & DMA_ATTR_SKIP_CPU_SYNC)) { + if (!(attrs & DMA_ATTR_SKIP_CPU_SYNC)) phys = iommu_iova_to_phys(mapping->domain, handle); - arch_sync_dma_for_cpu(phys, size, dir); + arm_iommu_sync_dma_for_cpu(phys, size, dir, dev->dma_coherent); } iommu_unmap(mapping->domain, iova, len); @@ -1497,11 +1510,11 @@ static void arm_iommu_sync_single_for_cpu(struct device *dev, struct dma_iommu_mapping *mapping = to_dma_iommu_mapping(dev); phys_addr_t phys; - if (dev->dma_coherent || !(handle & PAGE_MASK)) + if (!(handle & PAGE_MASK)) return; phys = iommu_iova_to_phys(mapping->domain, handle); - arch_sync_dma_for_cpu(phys, size, dir); + arm_iommu_sync_dma_for_cpu(phys, size, dir, dev->dma_coherent); } static void arm_iommu_sync_single_for_device(struct device *dev,