From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from mgamail.intel.com (mgamail.intel.com [192.198.163.19]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id CB3641A291; Thu, 9 May 2024 14:47:00 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=192.198.163.19 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1715266022; cv=none; b=gQlvuQGf4MtndP7j5d7v+ELT4B/d8YGxv8uK2by/avkkqGG0+G8YD1l9fL149kFAu/PAx3pBJVcAJbbRrtpzs0q+1PIxYrrsPh+FTh1KnYwRilYPX7SX74IpBYxZuKBO5tx68uVVlIoyCSsYrUwJ0vFwey7ktMGCkKGJJitdJ3Q= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1715266022; c=relaxed/simple; bh=44nu8TQxim7F3121JfCwQxg3SRkVOTAgI+q5yLgxXI8=; h=From:To:Cc:Subject:Date:Message-ID:MIME-Version; b=rcAzPGLKLtB3ogsUbKpT/Ow82wHgtF2urIXwNbv/hSrbZ+xxOOuQA4xcwMsrH0ch3yI2fvvjfW2Es9Wwip9Pgj8wKjWaq4HX0mSfdjGY9NexIbGrMaSJvTAa9KJgGnOCp8NTvv4PdThOw+0RmsX7T/vvEXTfu15+w1N7/fLs/QM= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=intel.com; spf=pass smtp.mailfrom=intel.com; dkim=pass (2048-bit key) header.d=intel.com header.i=@intel.com header.b=P0lEfVc/; arc=none smtp.client-ip=192.198.163.19 Authentication-Results: smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=intel.com Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=intel.com Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=intel.com header.i=@intel.com header.b="P0lEfVc/" DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=intel.com; i=@intel.com; q=dns/txt; s=Intel; t=1715266021; x=1746802021; h=from:to:cc:subject:date:message-id:mime-version: content-transfer-encoding; bh=44nu8TQxim7F3121JfCwQxg3SRkVOTAgI+q5yLgxXI8=; b=P0lEfVc/s//qXkMO627xZy+p0BBx7WJJJ0g4j6v0EFv3W2VbF6eHhIqx xqf4bVWpl2+dQGB9kzC8of36SZ3ocUOcgrkqs78j/q0d8euETfOJYKBh0 1XiVEgnxyoKmM5BB/x+37ZQh+PqRGPrWie5WGK//2hq6PrRNYLr18HZ0d AyCCEcYG8NxqyChLZrNMQal3svf63oZ04gYHfo6F4XafrJ5yobh+RLf5f A7DMdf3NzJmKlJaAOqWkO64qC8SCEXs/RalcWxjvUrTwEJfyO4qum/3zC cxqi3Zr/WIY/QyAKiaLwHlCIX+CXgHLv3MSO4QuuI3AplMmU4aUzMDpb2 A==; X-CSE-ConnectionGUID: CbB/oyKlTlq2wMwVOZKbKQ== X-CSE-MsgGUID: js4hFtT2R7um2Kt/2su+7A== X-IronPort-AV: E=McAfee;i="6600,9927,11067"; a="11052035" X-IronPort-AV: E=Sophos;i="6.08,148,1712646000"; d="scan'208";a="11052035" Received: from orviesa004.jf.intel.com ([10.64.159.144]) by fmvoesa113.fm.intel.com with ESMTP/TLS/ECDHE-RSA-AES256-GCM-SHA384; 09 May 2024 07:47:00 -0700 X-CSE-ConnectionGUID: tiVKl2c0RcGZ8zyTSJAfAw== X-CSE-MsgGUID: WSHUraYDR+CfMCbB9uynSw== X-ExtLoop1: 1 X-IronPort-AV: E=Sophos;i="6.08,148,1712646000"; d="scan'208";a="34119686" Received: from newjersey.igk.intel.com ([10.102.20.203]) by orviesa004.jf.intel.com with ESMTP; 09 May 2024 07:46:56 -0700 From: Alexander Lobakin To: Christoph Hellwig Cc: Alexander Lobakin , Eric Dumazet , Jakub Kicinski , Marek Szyprowski , Steven Price , Robin Murphy , Joerg Roedel , Will Deacon , "Rafael J. Wysocki" , Magnus Karlsson , nex.sw.ncis.osdt.itp.upstreaming@intel.com, bpf@vger.kernel.org, netdev@vger.kernel.org, iommu@lists.linux.dev, linux-kernel@vger.kernel.org Subject: [PATCH] dma: fix DMA sync for drivers not calling dma_set_mask*() Date: Thu, 9 May 2024 16:46:16 +0200 Message-ID: <20240509144616.938519-1-aleksander.lobakin@intel.com> X-Mailer: git-send-email 2.45.0 Precedence: bulk X-Mailing-List: bpf@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Transfer-Encoding: 8bit There are several reports that the DMA sync shortcut broke non-coherent devices. dev->dma_need_sync is false after the &device allocation and if a driver didn't call dma_set_mask*(), it will still be false even if the device is not DMA-coherent and thus needs synchronizing. Due to historical reasons, there's still a lot of drivers not calling it. Invert the boolean, so that the sync will be performed by default and the shortcut will be enabled only when calling dma_set_mask*(). Reported-by: Marek Szyprowski Closes: https://lore.kernel.org/lkml/46160534-5003-4809-a408-6b3a3f4921e9@samsung.com Reported-by: Steven Price Closes: https://lore.kernel.org/lkml/010686f5-3049-46a1-8230-7752a1b433ff@arm.com Fixes: 32ba8b823252 ("dma: avoid redundant calls for sync operations") Signed-off-by: Alexander Lobakin --- include/linux/device.h | 4 ++-- include/linux/dma-map-ops.h | 4 ++-- include/linux/dma-mapping.h | 2 +- kernel/dma/mapping.c | 10 +++++----- kernel/dma/swiotlb.c | 2 +- 5 files changed, 11 insertions(+), 11 deletions(-) diff --git a/include/linux/device.h b/include/linux/device.h index ed95b829f05b..d4b50accff26 100644 --- a/include/linux/device.h +++ b/include/linux/device.h @@ -691,7 +691,7 @@ struct device_physical_location { * and optionall (if the coherent mask is large enough) also * for dma allocations. This flag is managed by the dma ops * instance from ->dma_supported. - * @dma_need_sync: The device needs performing DMA sync operations. + * @dma_skip_sync: DMA sync operations can be skipped for coherent buffers. * * At the lowest level, every device in a Linux system is represented by an * instance of struct device. The device structure contains the information @@ -805,7 +805,7 @@ struct device { bool dma_ops_bypass : 1; #endif #ifdef CONFIG_DMA_NEED_SYNC - bool dma_need_sync:1; + bool dma_skip_sync:1; #endif }; diff --git a/include/linux/dma-map-ops.h b/include/linux/dma-map-ops.h index 4893cb89cb52..5217b922d29f 100644 --- a/include/linux/dma-map-ops.h +++ b/include/linux/dma-map-ops.h @@ -280,8 +280,8 @@ static inline void dma_reset_need_sync(struct device *dev) { #ifdef CONFIG_DMA_NEED_SYNC /* Reset it only once so that the function can be called on hotpath */ - if (unlikely(!dev->dma_need_sync)) - dev->dma_need_sync = true; + if (unlikely(dev->dma_skip_sync)) + dev->dma_skip_sync = false; #endif } diff --git a/include/linux/dma-mapping.h b/include/linux/dma-mapping.h index eb4e15893b6c..f693aafe221f 100644 --- a/include/linux/dma-mapping.h +++ b/include/linux/dma-mapping.h @@ -295,7 +295,7 @@ bool __dma_need_sync(struct device *dev, dma_addr_t dma_addr); static inline bool dma_dev_need_sync(const struct device *dev) { /* Always call DMA sync operations when debugging is enabled */ - return dev->dma_need_sync || IS_ENABLED(CONFIG_DMA_API_DEBUG); + return !dev->dma_skip_sync || IS_ENABLED(CONFIG_DMA_API_DEBUG); } static inline void dma_sync_single_for_cpu(struct device *dev, dma_addr_t addr, diff --git a/kernel/dma/mapping.c b/kernel/dma/mapping.c index 3524bc92c37f..3f77c3f8d16d 100644 --- a/kernel/dma/mapping.c +++ b/kernel/dma/mapping.c @@ -392,7 +392,7 @@ bool __dma_need_sync(struct device *dev, dma_addr_t dma_addr) if (dma_map_direct(dev, ops)) /* - * dma_need_sync could've been reset on first SWIOTLB buffer + * dma_skip_sync could've been reset on first SWIOTLB buffer * mapping, but @dma_addr is not necessary an SWIOTLB buffer. * In this case, fall back to more granular check. */ @@ -407,20 +407,20 @@ static void dma_setup_need_sync(struct device *dev) if (dma_map_direct(dev, ops) || (ops->flags & DMA_F_CAN_SKIP_SYNC)) /* - * dma_need_sync will be reset to %true on first SWIOTLB buffer + * dma_skip_sync will be reset to %false on first SWIOTLB buffer * mapping, if any. During the device initialization, it's * enough to check only for the DMA coherence. */ - dev->dma_need_sync = !dev_is_dma_coherent(dev); + dev->dma_skip_sync = dev_is_dma_coherent(dev); else if (!ops->sync_single_for_device && !ops->sync_single_for_cpu && !ops->sync_sg_for_device && !ops->sync_sg_for_cpu) /* * Synchronization is not possible when none of DMA sync ops * is set. */ - dev->dma_need_sync = false; + dev->dma_skip_sync = true; else - dev->dma_need_sync = true; + dev->dma_skip_sync = false; } #else /* !CONFIG_DMA_NEED_SYNC */ static inline void dma_setup_need_sync(struct device *dev) { } diff --git a/kernel/dma/swiotlb.c b/kernel/dma/swiotlb.c index ae3e593eaadb..068134697cf1 100644 --- a/kernel/dma/swiotlb.c +++ b/kernel/dma/swiotlb.c @@ -1409,7 +1409,7 @@ phys_addr_t swiotlb_tbl_map_single(struct device *dev, phys_addr_t orig_addr, } /* - * If dma_need_sync wasn't set, reset it on first SWIOTLB buffer + * If dma_skip_sync was set, reset it on first SWIOTLB buffer * mapping to always sync SWIOTLB buffers. */ dma_reset_need_sync(dev); -- 2.45.0