From mboxrd@z Thu Jan 1 00:00:00 1970 From: Christoph Hellwig Subject: [PATCH 1/7] dma-direct: add support for dma_coherent_default_memory Date: Mon, 12 Jul 2021 08:16:58 +0200 Message-ID: <20210712061704.4162464-2-hch@lst.de> References: <20210712061704.4162464-1-hch@lst.de> Mime-Version: 1.0 Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit Return-path: DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=infradead.org; s=casper.20170209; h=Content-Transfer-Encoding:MIME-Version: References:In-Reply-To:Message-Id:Date:Subject:Cc:To:From:Sender:Reply-To: Content-Type:Content-ID:Content-Description; bh=beM8fTJDPaLnKCeeGRk85GXcYvQNxhia1GMUUJGaUo8=; b=o2m4AAjPPOwEANBCECmW+IDLQl SCrxeIXMJkPAWxGKoQyPE70bdBKQSCgOmWgN+J+2z2C4uenkIrHK+Q83i4EmI5CQl40G1ULfC4Gpb mkjxKHO7+/C0hS3oWTqoKT6gSDjZPh1abW0pQvLE+2RuAw0HWddRWHZVc1c8vxGtnBltpXK2U671e CQwkjrxAwl+C6LUTMG5tR+NIjMa84o2lwVGH0/qoztBh2mloJD1mqMyrLRablFbBGeJdJOVqoDByD flvW0aCcJ3xtq7srGwc/1O20Gnol6iCihR5ual04IxxLfH95hYVP6MtMCiTySMvL1PO93JPVqg82t /UWUkW3Q==; In-Reply-To: <20210712061704.4162464-1-hch-jcswGhMUV9g@public.gmane.org> List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Errors-To: iommu-bounces-cunTk1MwBs9QetFLy7KEm3xJsTq8ys+cHZ5vskTnxNA@public.gmane.org Sender: "iommu" To: iommu-cunTk1MwBs9QetFLy7KEm3xJsTq8ys+cHZ5vskTnxNA@public.gmane.org, Russell King , Brian Cain Cc: linux-hexagon-u79uwXL29TY76Z2rM5mHXA@public.gmane.org, Vladimir Murzin , Dillon Min , linux-kernel-u79uwXL29TY76Z2rM5mHXA@public.gmane.org, linux-arm-kernel-IAPFreCvJWM7uuMidbF8XUB+6BGkLq7r@public.gmane.org Add an option to allocate uncached memory for dma_alloc_coherent from the global dma_coherent_default_memory. This will allow to move arm-nommu (and eventually other platforms) to use generic code for allocating uncached memory from a pre-populated pool. Note that this is a different pool from the one that platforms that can remap at runtime use for GFP_ATOMIC allocations for now, although there might be opportunities to eventually end up with a common codebase for the two use cases. Signed-off-by: Christoph Hellwig Tested-by: Dillon Min --- kernel/dma/Kconfig | 4 ++++ kernel/dma/direct.c | 15 +++++++++++++++ 2 files changed, 19 insertions(+) diff --git a/kernel/dma/Kconfig b/kernel/dma/Kconfig index 77b405508743..725cfd51762b 100644 --- a/kernel/dma/Kconfig +++ b/kernel/dma/Kconfig @@ -93,6 +93,10 @@ config DMA_COHERENT_POOL select GENERIC_ALLOCATOR bool +config DMA_GLOBAL_POOL + select DMA_DECLARE_COHERENT + bool + config DMA_REMAP bool depends on MMU diff --git a/kernel/dma/direct.c b/kernel/dma/direct.c index f737e3347059..d1d0258ed6d0 100644 --- a/kernel/dma/direct.c +++ b/kernel/dma/direct.c @@ -156,9 +156,14 @@ void *dma_direct_alloc(struct device *dev, size_t size, if (!IS_ENABLED(CONFIG_ARCH_HAS_DMA_SET_UNCACHED) && !IS_ENABLED(CONFIG_DMA_DIRECT_REMAP) && + !IS_ENABLED(CONFIG_DMA_GLOBAL_POOL) && !dev_is_dma_coherent(dev)) return arch_dma_alloc(dev, size, dma_handle, gfp, attrs); + if (IS_ENABLED(CONFIG_DMA_GLOBAL_POOL) && + !dev_is_dma_coherent(dev)) + return dma_alloc_from_global_coherent(dev, size, dma_handle); + /* * Remapping or decrypting memory may block. If either is required and * we can't block, allocate the memory from the atomic pools. @@ -255,11 +260,19 @@ void dma_direct_free(struct device *dev, size_t size, if (!IS_ENABLED(CONFIG_ARCH_HAS_DMA_SET_UNCACHED) && !IS_ENABLED(CONFIG_DMA_DIRECT_REMAP) && + !IS_ENABLED(CONFIG_DMA_GLOBAL_POOL) && !dev_is_dma_coherent(dev)) { arch_dma_free(dev, size, cpu_addr, dma_addr, attrs); return; } + if (IS_ENABLED(CONFIG_DMA_GLOBAL_POOL) && + !dev_is_dma_coherent(dev)) { + if (!dma_release_from_global_coherent(page_order, cpu_addr)) + WARN_ON_ONCE(1); + return; + } + /* If cpu_addr is not from an atomic pool, dma_free_from_pool() fails */ if (IS_ENABLED(CONFIG_DMA_COHERENT_POOL) && dma_free_from_pool(dev, cpu_addr, PAGE_ALIGN(size))) @@ -462,6 +475,8 @@ int dma_direct_mmap(struct device *dev, struct vm_area_struct *vma, if (dma_mmap_from_dev_coherent(dev, vma, cpu_addr, size, &ret)) return ret; + if (dma_mmap_from_global_coherent(vma, cpu_addr, size, &ret)) + return ret; if (vma->vm_pgoff >= count || user_count > count - vma->vm_pgoff) return -ENXIO; -- 2.30.2