Commit e817ee5f authored by Christoph Hellwig's avatar Christoph Hellwig
Browse files

dma-iommu: implement ->alloc_noncontiguous 



Implement support for allocating a non-contiguous DMA region.

Signed-off-by: default avatarChristoph Hellwig <hch@lst.de>
Reviewed-by: default avatarTomasz Figa <tfiga@chromium.org>
Tested-by: default avatarRicardo Ribalda <ribalda@chromium.org>
parent 8230ce9a

drivers/iommu/dma-iommu.c

+36 −0
Original line number Diff line number Diff line
@@ -708,6 +708,7 @@ static struct page **__iommu_dma_alloc_noncontiguous(struct device *dev, 
		goto out_free_sg;



	sgt->sgl->dma_address = iova;

	sgt->sgl->dma_length = size;

	return pages;



out_free_sg:
@@ -745,6 +746,37 @@ static void *iommu_dma_alloc_remap(struct device *dev, size_t size, 
	return NULL;

}



#ifdef CONFIG_DMA_REMAP

static struct sg_table *iommu_dma_alloc_noncontiguous(struct device *dev,

		size_t size, enum dma_data_direction dir, gfp_t gfp,

		unsigned long attrs)

{

	struct dma_sgt_handle *sh;



	sh = kmalloc(sizeof(*sh), gfp);

	if (!sh)

		return NULL;



	sh->pages = __iommu_dma_alloc_noncontiguous(dev, size, &sh->sgt, gfp,

						    PAGE_KERNEL, attrs);

	if (!sh->pages) {

		kfree(sh);

		return NULL;

	}

	return &sh->sgt;

}



static void iommu_dma_free_noncontiguous(struct device *dev, size_t size,

		struct sg_table *sgt, enum dma_data_direction dir)

{

	struct dma_sgt_handle *sh = sgt_handle(sgt);



	__iommu_dma_unmap(dev, sgt->sgl->dma_address, size);

	__iommu_dma_free_pages(sh->pages, PAGE_ALIGN(size) >> PAGE_SHIFT);

	sg_free_table(&sh->sgt);

}

#endif /* CONFIG_DMA_REMAP */



static void iommu_dma_sync_single_for_cpu(struct device *dev,

		dma_addr_t dma_handle, size_t size, enum dma_data_direction dir)

{
@@ -1261,6 +1293,10 @@ static const struct dma_map_ops iommu_dma_ops = { 
	.free			= iommu_dma_free,

	.alloc_pages		= dma_common_alloc_pages,

	.free_pages		= dma_common_free_pages,

#ifdef CONFIG_DMA_REMAP

	.alloc_noncontiguous	= iommu_dma_alloc_noncontiguous,

	.free_noncontiguous	= iommu_dma_free_noncontiguous,

#endif

	.mmap			= iommu_dma_mmap,

	.get_sgtable		= iommu_dma_get_sgtable,

	.map_page		= iommu_dma_map_page,