Commit 5c87cffe authored by Christoph Hellwig's avatar Christoph Hellwig Committed by Marek Szyprowski
Browse files

iommu: generalize the batched sync after map interface 



For the upcoming IOVA-based DMA API we want to batch the
ops->iotlb_sync_map() call after mapping multiple IOVAs from
dma-iommu without having a scatterlist. Improve the API.

Add a wrapper for the map_sync as iommu_sync_map() so that callers
don't need to poke into the methods directly.

Formalize __iommu_map() into iommu_map_nosync() which requires the
caller to call iommu_sync_map() after all maps are completed.

Refactor the existing sanity checks from all the different layers
into iommu_map_nosync().

Signed-off-by: default avatarChristoph Hellwig <hch@lst.de>
Acked-by: default avatarWill Deacon <will@kernel.org>
Tested-by: default avatarJens Axboe <axboe@kernel.dk>
Reviewed-by: default avatarJason Gunthorpe <jgg@nvidia.com>
Reviewed-by: default avatarLuis Chamberlain <mcgrof@kernel.org>
Signed-off-by: default avatarLeon Romanovsky <leonro@nvidia.com>
Signed-off-by: default avatarMarek Szyprowski <m.szyprowski@samsung.com>
parent ca2c2e4a

drivers/iommu/iommu.c

+29 −36
Original line number Diff line number Diff line
@@ -2440,7 +2440,7 @@ static size_t iommu_pgsize(struct iommu_domain *domain, unsigned long iova, 
	return pgsize;

}



static int __iommu_map(struct iommu_domain *domain, unsigned long iova,

int iommu_map_nosync(struct iommu_domain *domain, unsigned long iova,

		phys_addr_t paddr, size_t size, int prot, gfp_t gfp)

{

	const struct iommu_domain_ops *ops = domain->ops;
@@ -2450,12 +2450,19 @@ static int __iommu_map(struct iommu_domain *domain, unsigned long iova, 
	phys_addr_t orig_paddr = paddr;

	int ret = 0;



	might_sleep_if(gfpflags_allow_blocking(gfp));



	if (unlikely(!(domain->type & __IOMMU_DOMAIN_PAGING)))

		return -EINVAL;



	if (WARN_ON(!ops->map_pages || domain->pgsize_bitmap == 0UL))

		return -ENODEV;



	/* Discourage passing strange GFP flags */

	if (WARN_ON_ONCE(gfp & (__GFP_COMP | __GFP_DMA | __GFP_DMA32 |

				__GFP_HIGHMEM)))

		return -EINVAL;



	/* find out the minimum page size supported */

	min_pagesz = 1 << __ffs(domain->pgsize_bitmap);
@@ -2503,30 +2510,26 @@ static int __iommu_map(struct iommu_domain *domain, unsigned long iova, 
	return ret;

}



int iommu_map(struct iommu_domain *domain, unsigned long iova,

	      phys_addr_t paddr, size_t size, int prot, gfp_t gfp)

int iommu_sync_map(struct iommu_domain *domain, unsigned long iova, size_t size)

{

	const struct iommu_domain_ops *ops = domain->ops;

	int ret;



	might_sleep_if(gfpflags_allow_blocking(gfp));

	if (!ops->iotlb_sync_map)

		return 0;

	return ops->iotlb_sync_map(domain, iova, size);

}



	/* Discourage passing strange GFP flags */

	if (WARN_ON_ONCE(gfp & (__GFP_COMP | __GFP_DMA | __GFP_DMA32 |

				__GFP_HIGHMEM)))

		return -EINVAL;

int iommu_map(struct iommu_domain *domain, unsigned long iova,

	      phys_addr_t paddr, size_t size, int prot, gfp_t gfp)

{

	int ret;



	ret = __iommu_map(domain, iova, paddr, size, prot, gfp);

	if (ret == 0 && ops->iotlb_sync_map) {

		ret = ops->iotlb_sync_map(domain, iova, size);

	ret = iommu_map_nosync(domain, iova, paddr, size, prot, gfp);

	if (ret)

			goto out_err;

	}



		return ret;



out_err:

	/* undo mappings already done */

	ret = iommu_sync_map(domain, iova, size);

	if (ret)

		iommu_unmap(domain, iova, size);



	return ret;
@@ -2627,26 +2630,17 @@ ssize_t iommu_map_sg(struct iommu_domain *domain, unsigned long iova, 
		     struct scatterlist *sg, unsigned int nents, int prot,

		     gfp_t gfp)

{

	const struct iommu_domain_ops *ops = domain->ops;

	size_t len = 0, mapped = 0;

	phys_addr_t start;

	unsigned int i = 0;

	int ret;



	might_sleep_if(gfpflags_allow_blocking(gfp));



	/* Discourage passing strange GFP flags */

	if (WARN_ON_ONCE(gfp & (__GFP_COMP | __GFP_DMA | __GFP_DMA32 |

				__GFP_HIGHMEM)))

		return -EINVAL;



	while (i <= nents) {

		phys_addr_t s_phys = sg_phys(sg);



		if (len && s_phys != start + len) {

			ret = __iommu_map(domain, iova + mapped, start,

			ret = iommu_map_nosync(domain, iova + mapped, start,

					len, prot, gfp);



			if (ret)

				goto out_err;
@@ -2669,11 +2663,10 @@ ssize_t iommu_map_sg(struct iommu_domain *domain, unsigned long iova, 
			sg = sg_next(sg);

	}



	if (ops->iotlb_sync_map) {

		ret = ops->iotlb_sync_map(domain, iova, mapped);

	ret = iommu_sync_map(domain, iova, mapped);

	if (ret)

		goto out_err;

	}



	return mapped;



out_err:

include/linux/iommu.h

+4 −0
Original line number Diff line number Diff line
@@ -872,6 +872,10 @@ extern struct iommu_domain *iommu_get_domain_for_dev(struct device *dev); 
extern struct iommu_domain *iommu_get_dma_domain(struct device *dev);

extern int iommu_map(struct iommu_domain *domain, unsigned long iova,

		     phys_addr_t paddr, size_t size, int prot, gfp_t gfp);

int iommu_map_nosync(struct iommu_domain *domain, unsigned long iova,

		phys_addr_t paddr, size_t size, int prot, gfp_t gfp);

int iommu_sync_map(struct iommu_domain *domain, unsigned long iova,

		size_t size);

extern size_t iommu_unmap(struct iommu_domain *domain, unsigned long iova,

			  size_t size);

extern size_t iommu_unmap_fast(struct iommu_domain *domain,