From mboxrd@z Thu Jan 1 00:00:00 1970 From: Christoph Hellwig Subject: [PATCH 1/3] hexagon: remove the sync_single_for_cpu DMA operation Date: Thu, 19 Jul 2018 05:56:33 -0700 Message-ID: <20180719125635.824-2-hch@lst.de> References: <20180719125635.824-1-hch@lst.de> Return-path: DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=infradead.org; s=bombadil.20170209; h=References:In-Reply-To:Message-Id: Date:Subject:Cc:To:From:Sender:Reply-To:MIME-Version:Content-Type: Content-Transfer-Encoding:Content-ID:Content-Description:Resent-Date: Resent-From:Resent-Sender:Resent-To:Resent-Cc:Resent-Message-ID:List-Id: List-Help:List-Unsubscribe:List-Subscribe:List-Post:List-Owner:List-Archive; bh=aqD8eDnO2LcHaLjon8E2opomA3Ye3ujWt8xxAKkGCT0=; b=eln+POS1V/c2QXRI8XjOmLnXZ XIaGRGTrFhLLdnXyWsAHJ4oE3BC/FFHjgheSni7qkYDkjfFxw+VwXQzNKVsTr8/l3RKwdE0m87xOA uk28zpqxNIpaS3PnoCCcXU85RomOLl5YlBPetvmF3VerULuP439zKP2aHJbSbgNf/Gt+5WX42kifM QHoMkH96a2LPA+em4c0faVrHJMtITgzrh20GIwos4F5OK3nn/f3/MuotXajs6mZrVSrZMwIZTw7JR Ig+xRuF0tpQZY+gHirDIAIeYZKV6olM59qfyBxwl1k6xZqcNVlJw0Z/pHPEDPyK1LfAYwmzbxMthV In-Reply-To: <20180719125635.824-1-hch@lst.de> Sender: linux-kernel-owner@vger.kernel.org List-ID: MIME-Version: 1.0 Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit To: Richard Kuo Cc: linux-hexagon@vger.kernel.org, iommu@lists.linux-foundation.org, linux-kernel@vger.kernel.org hexagon does all the required cache maintainance at dma map time, and none at unmap time. It thus has to implement sync_single_for_device to match the map cace for buffer reuse, but there is no point in doing another invalidation in the sync_single_cpu_case, which in terms of cache maintainance is equivalent to the unmap case. Signed-off-by: Christoph Hellwig --- arch/hexagon/kernel/dma.c | 8 -------- 1 file changed, 8 deletions(-) diff --git a/arch/hexagon/kernel/dma.c b/arch/hexagon/kernel/dma.c index 77459df34e2e..d2b717f352f4 100644 --- a/arch/hexagon/kernel/dma.c +++ b/arch/hexagon/kernel/dma.c @@ -181,13 +181,6 @@ static dma_addr_t hexagon_map_page(struct device *dev, struct page *page, return bus; } -static void hexagon_sync_single_for_cpu(struct device *dev, - dma_addr_t dma_handle, size_t size, - enum dma_data_direction dir) -{ - dma_sync(dma_addr_to_virt(dma_handle), size, dir); -} - static void hexagon_sync_single_for_device(struct device *dev, dma_addr_t dma_handle, size_t size, enum dma_data_direction dir) @@ -205,7 +198,6 @@ const struct dma_map_ops hexagon_dma_ops = { .free = hexagon_free_coherent, .map_sg = hexagon_map_sg, .map_page = hexagon_map_page, - .sync_single_for_cpu = hexagon_sync_single_for_cpu, .sync_single_for_device = hexagon_sync_single_for_device, .mapping_error = hexagon_mapping_error, }; -- 2.18.0