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Commit 6d515ec7 authored by Sudarshan Rajagopalan's avatar Sudarshan Rajagopalan
Browse files

iommu: arm-smmu: fix check for need for preallocate memory 



commit b312b4f0 ("iommu: arm-smmu: Preallocate memory for map
only on failure") had the following two errors:

  1. The return code we checking when map_sg fails and we preallocte
     is wrong. The check should be for 0 and not -ENOMEM.
     So the preallocate is never happening when map_sg fails.

  2. map_sg could've have mapped certain elements in sglist and later
     had got failed. With proper check, we are trying to call map_sg
     on the same size again, which would leave to double map of
     previously mapped elements in sglist.

Fix this by returning the actual ret code from arm_lpae_map_sg()
and check it against -ENOMEM if we need to preallocate or not.
Also, unmap any partial iovas that was mapped previously.

Change-Id: Ifee7c0bed6b9cf1c35ebb4a03d51a1a80ab0ed58
Signed-off-by: default avatarSudarshan Rajagopalan <sudaraja@codeaurora.org>
parent 4cb71ce2

drivers/iommu/arm-smmu.c

+9 −3
Original line number Diff line number Diff line
@@ -3256,8 +3256,13 @@ static size_t arm_smmu_map_sg(struct iommu_domain *domain, unsigned long iova, 
				  prot, &size);

		spin_unlock_irqrestore(&smmu_domain->cb_lock, flags);





		if (ret == -ENOMEM) {

			/* unmap any partially mapped iova */

			if (size) {

				arm_smmu_secure_domain_unlock(smmu_domain);

				arm_smmu_unmap(domain, iova, size);

				arm_smmu_secure_domain_lock(smmu_domain);

			}

			arm_smmu_prealloc_memory(smmu_domain,

						 batch_size, &nonsecure_pool);

			spin_lock_irqsave(&smmu_domain->cb_lock, flags);
@@ -3272,8 +3277,8 @@ static size_t arm_smmu_map_sg(struct iommu_domain *domain, unsigned long iova, 
							 &nonsecure_pool);

		}



		/* Returns 0 on error */

		if (!ret) {

		/* Returns -ve val on error */

		if (ret < 0) {

			size_to_unmap = iova + size - __saved_iova_start;

			goto out;

		}
@@ -3281,6 +3286,7 @@ static size_t arm_smmu_map_sg(struct iommu_domain *domain, unsigned long iova, 
		iova += batch_size;

		idx_start = idx_end;

		sg_start = sg_end;

		size = 0;

	}



out:

drivers/iommu/io-pgtable-arm.c

+3 −2
Original line number Diff line number Diff line
@@ -634,7 +634,8 @@ static int arm_lpae_map_sg(struct io_pgtable_ops *ops, unsigned long iova, 
	arm_lpae_iopte prot;

	struct scatterlist *s;

	size_t mapped = 0;

	int i, ret;

	int i;

	int ret = -EINVAL;

	unsigned int min_pagesz;

	struct io_pgtable_cfg *cfg = &data->iop.cfg;

	struct map_state ms;
@@ -705,7 +706,7 @@ static int arm_lpae_map_sg(struct io_pgtable_ops *ops, unsigned long iova, 
out_err:

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

	*size = mapped;

	return 0;

	return ret;

}



static void __arm_lpae_free_pgtable(struct arm_lpae_io_pgtable *data, int lvl,

drivers/iommu/io-pgtable.h

+2 −2
Original line number Diff line number Diff line
@@ -154,8 +154,8 @@ struct io_pgtable_cfg { 
 *

 * @map:		Map a physically contiguous memory region.

 * @map_sg:		Map a scatterlist.  Returns the number of bytes mapped,

 *			or 0 on failure.  The size parameter contains the size

 *			of the partial mapping in case of failure.

 *			or -ve val on failure.  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.

 * @is_iova_coherent:	Checks coherency of given IOVA. Returns True if coherent