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From: catalin.marinas@arm•com (Catalin Marinas)
To: linux-arm-kernel@lists•infradead.org
Subject: [PATCH 1/2] arm64: Implement custom mmap functions for dma mapping
Date: Thu, 13 Mar 2014 17:49:15 +0000	[thread overview]
Message-ID: <20140313174915.GN30339@arm.com> (raw)
In-Reply-To: <1394732716-11507-1-git-send-email-lauraa@codeaurora.org>

On Thu, Mar 13, 2014 at 05:45:15PM +0000, Laura Abbott wrote:
> +/* vma->vm_page_prot must be set appropriately before calling this function */
> +static int __dma_common_mmap(struct device *dev, struct vm_area_struct *vma,
> +			     void *cpu_addr, dma_addr_t dma_addr, size_t size)
> +{
> +	int ret = -ENXIO;
> +	unsigned long nr_vma_pages = (vma->vm_end - vma->vm_start) >>
> +					PAGE_SHIFT;
> +	unsigned long nr_pages = PAGE_ALIGN(size) >> PAGE_SHIFT;
> +	unsigned long pfn = dma_to_phys(dev, dma_addr) >> PAGE_SHIFT;
> +	unsigned long off = vma->vm_pgoff;
> +
> +	if (dma_mmap_from_coherent(dev, vma, cpu_addr, size, &ret))
> +		return ret;
> +
> +	if (off < nr_pages && nr_vma_pages <= (nr_pages - off)) {
> +		ret = remap_pfn_range(vma, vma->vm_start,
> +				      pfn + off,
> +				      vma->vm_end - vma->vm_start,
> +				      vma->vm_page_prot);
> +	}
> +
> +	return ret;
> +}
> +
> +static int arm64_swiotlb_mmap_noncoherent(struct device *dev,
> +		struct vm_area_struct *vma,
> +		void *cpu_addr, dma_addr_t dma_addr, size_t size,
> +		struct dma_attrs *attrs)
> +{
> +	/* Just use whatever page_prot attributes were specified */
> +	return __dma_common_mmap(dev, vma, cpu_addr, dma_addr, size);
> +}
> +
> +static int arm64_swiotlb_mmap_coherent(struct device *dev,
> +		struct vm_area_struct *vma,
> +		void *cpu_addr, dma_addr_t dma_addr, size_t size,
> +		struct dma_attrs *attrs)
> +{
> +	vma->vm_page_prot = pgprot_dmacoherent(vma->vm_page_prot);
> +	return __dma_common_mmap(dev, vma, cpu_addr, dma_addr, size);
> +}

So I think we got the naming the other way around. The
noncoherent_dma_ops assume that the DMA is non-coherent and therefore
must change the pgprot.

-- 
Catalin

  reply	other threads:[~2014-03-13 17:49 UTC|newest]

Thread overview: 18+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2014-03-05 20:46 Query on patch to be upstream ? Ritesh Harjani
2014-03-11 12:15 ` Catalin Marinas
2014-03-11 18:04   ` Laura Abbott
2014-03-11 18:26     ` Catalin Marinas
2014-03-12 18:20       ` Laura Abbott
2014-03-13 17:45         ` [PATCH 1/2] arm64: Implement custom mmap functions for dma mapping Laura Abbott
2014-03-13 17:49           ` Catalin Marinas [this message]
2014-03-14  1:53             ` Laura Abbott
2014-03-13 17:45         ` [PATCH 2/2] arm64: Support DMA_ATTR_WRITE_COMBINE Laura Abbott
2014-03-13 17:52           ` Catalin Marinas
2014-03-14  2:02             ` Laura Abbott
2014-03-14 19:52           ` [PATCHv2 1/3] arm64: Implement custom mmap functions for dma mapping Laura Abbott
2014-03-24 10:33             ` Catalin Marinas
     [not found]             ` <CALk7dXr3cZSkQ6dTUyCjUDStOd6=ghGN9-iO5RQiTfHCciGxLg@mail.gmail.com>
2014-03-28 10:37               ` Catalin Marinas
2014-03-14 19:52           ` [PATCHv2 2/3] arm64: Support DMA_ATTR_WRITE_COMBINE Laura Abbott
2014-03-14 20:24             ` Rob Herring
2014-03-14 23:07               ` Catalin Marinas
2014-03-14 19:52           ` [PATCHv2 3/3] arm64: Use arm64 coherent APIs for non-coherent freeing Laura Abbott

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