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Commit 4d7cdd9e authored by Rohit Vaswani's avatar Rohit Vaswani Committed by Patrick Daly
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iommu/arm-smmu: Check the return type of map_sg and take appropriate action 



We cannot call unmap directly if the map_sg fails partially as the tlb
invalidate functions need to enable/prepare clocks, which require
non-atomic context. Let map_sg return the failure and handle this when
we are out of the atomic context.

Change-Id: I6401c1e281850aeda27e32524cae34324045f762
Signed-off-by: default avatarRohit Vaswani <rvaswani@codeaurora.org>
Signed-off-by: default avatarPatrick Daly <pdaly@codeaurora.org>
parent daab041f

drivers/iommu/arm-smmu.c

+6 −1
Original line number Diff line number Diff line
@@ -1606,6 +1606,7 @@ static size_t arm_smmu_map_sg(struct iommu_domain *domain, unsigned long iova, 
			   struct scatterlist *sg, unsigned int nents, int prot)

{

	int ret;

	size_t size;

	unsigned long flags;

	struct arm_smmu_domain *smmu_domain = to_smmu_domain(domain);

	struct io_pgtable_ops *ops = smmu_domain->pgtbl_ops;
@@ -1614,8 +1615,12 @@ static size_t arm_smmu_map_sg(struct iommu_domain *domain, unsigned long iova, 
		return -ENODEV;



	spin_lock_irqsave(&smmu_domain->pgtbl_lock, flags);

	ret = ops->map_sg(ops, iova, sg, nents, prot);

	ret = ops->map_sg(ops, iova, sg, nents, prot, &size);

	spin_unlock_irqrestore(&smmu_domain->pgtbl_lock, flags);



	if (!ret)

		arm_smmu_unmap(domain, iova, size);



	return ret;

}

drivers/iommu/io-pgtable-arm.c

+4 −6
Original line number Diff line number Diff line
@@ -407,7 +407,7 @@ static int arm_lpae_map(struct io_pgtable_ops *ops, unsigned long iova, 


static int arm_lpae_map_sg(struct io_pgtable_ops *ops, unsigned long iova,

			   struct scatterlist *sg, unsigned int nents,

			   int iommu_prot)

			   int iommu_prot, size_t *size)

{

	struct arm_lpae_io_pgtable *data = io_pgtable_ops_to_data(ops);

	arm_lpae_iopte *ptep = data->pgd;
@@ -420,7 +420,7 @@ static int arm_lpae_map_sg(struct io_pgtable_ops *ops, unsigned long iova, 


	/* If no access, then nothing to do */

	if (!(iommu_prot & (IOMMU_READ | IOMMU_WRITE)))

		return 0;

		goto out_err;



	prot = arm_lpae_prot_to_pte(data, iommu_prot);
@@ -457,10 +457,8 @@ static int arm_lpae_map_sg(struct io_pgtable_ops *ops, unsigned long iova, 
	return mapped;



out_err:

	/* undo mappings already done */

	if (mapped)

		ops->unmap(ops, iova, mapped);



	/* Return the size of the partial mapping so that they can be undone */

	*size = mapped;

	return 0;

}

drivers/iommu/io-pgtable.h

+4 −1
Original line number Diff line number Diff line
@@ -105,6 +105,8 @@ struct io_pgtable_cfg { 
 * struct io_pgtable_ops - Page table manipulation API for IOMMU drivers.

 *

 * @map:          Map a physically contiguous memory region.

 * @map_sg:	  Map a scatterlist. The size parameter contains the size

 *		  of the partial mapping in case of failure.

 * @unmap:        Unmap a physically contiguous memory region.

 * @iova_to_phys: Translate iova to physical address.

 *
@@ -115,7 +117,8 @@ struct io_pgtable_ops { 
	int (*map)(struct io_pgtable_ops *ops, unsigned long iova,

		   phys_addr_t paddr, size_t size, int prot);

	int (*map_sg)(struct io_pgtable_ops *ops, unsigned long iova,

		      struct scatterlist *sg, unsigned int nents, int prot);

		      struct scatterlist *sg, unsigned int nents,

		      int prot, size_t *size);

	int (*unmap)(struct io_pgtable_ops *ops, unsigned long iova,

		     size_t size);

	phys_addr_t (*iova_to_phys)(struct io_pgtable_ops *ops,