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Commit 58188afe authored by Robin Murphy's avatar Robin Murphy Committed by Will Deacon
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iommu/arm-smmu-v3: Remove io-pgtable spinlock 



As for SMMUv2, take advantage of io-pgtable's newfound tolerance for
concurrency. Unfortunately in this case the command queue lock remains a
point of serialisation for the unmap path, but there may be a little
more we can do to ameliorate that in future.

Signed-off-by: default avatarRobin Murphy <robin.murphy@arm.com>
Signed-off-by: default avatarWill Deacon <will.deacon@arm.com>
parent 523d7423

drivers/iommu/arm-smmu-v3.c

+6 −27
Original line number Diff line number Diff line
@@ -646,7 +646,6 @@ struct arm_smmu_domain { 
	struct mutex			init_mutex; /* Protects smmu pointer */



	struct io_pgtable_ops		*pgtbl_ops;

	spinlock_t			pgtbl_lock;



	enum arm_smmu_domain_stage	stage;

	union {
@@ -1414,7 +1413,6 @@ static struct iommu_domain *arm_smmu_domain_alloc(unsigned type) 
	}



	mutex_init(&smmu_domain->init_mutex);

	spin_lock_init(&smmu_domain->pgtbl_lock);

	return &smmu_domain->domain;

}
@@ -1686,44 +1684,29 @@ static int arm_smmu_attach_dev(struct iommu_domain *domain, struct device *dev) 
static int arm_smmu_map(struct iommu_domain *domain, unsigned long iova,

			phys_addr_t paddr, size_t size, int prot)

{

	int ret;

	unsigned long flags;

	struct arm_smmu_domain *smmu_domain = to_smmu_domain(domain);

	struct io_pgtable_ops *ops = smmu_domain->pgtbl_ops;

	struct io_pgtable_ops *ops = to_smmu_domain(domain)->pgtbl_ops;



	if (!ops)

		return -ENODEV;



	spin_lock_irqsave(&smmu_domain->pgtbl_lock, flags);

	ret = ops->map(ops, iova, paddr, size, prot);

	spin_unlock_irqrestore(&smmu_domain->pgtbl_lock, flags);

	return ret;

	return ops->map(ops, iova, paddr, size, prot);

}



static size_t

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

{

	size_t ret;

	unsigned long flags;

	struct arm_smmu_domain *smmu_domain = to_smmu_domain(domain);

	struct io_pgtable_ops *ops = smmu_domain->pgtbl_ops;

	struct io_pgtable_ops *ops = to_smmu_domain(domain)->pgtbl_ops;



	if (!ops)

		return 0;



	spin_lock_irqsave(&smmu_domain->pgtbl_lock, flags);

	ret = ops->unmap(ops, iova, size);

	spin_unlock_irqrestore(&smmu_domain->pgtbl_lock, flags);

	return ret;

	return ops->unmap(ops, iova, size);

}



static phys_addr_t

arm_smmu_iova_to_phys(struct iommu_domain *domain, dma_addr_t iova)

{

	phys_addr_t ret;

	unsigned long flags;

	struct arm_smmu_domain *smmu_domain = to_smmu_domain(domain);

	struct io_pgtable_ops *ops = smmu_domain->pgtbl_ops;

	struct io_pgtable_ops *ops = to_smmu_domain(domain)->pgtbl_ops;



	if (domain->type == IOMMU_DOMAIN_IDENTITY)

		return iova;
@@ -1731,11 +1714,7 @@ arm_smmu_iova_to_phys(struct iommu_domain *domain, dma_addr_t iova) 
	if (!ops)

		return 0;



	spin_lock_irqsave(&smmu_domain->pgtbl_lock, flags);

	ret = ops->iova_to_phys(ops, iova);

	spin_unlock_irqrestore(&smmu_domain->pgtbl_lock, flags);



	return ret;

	return ops->iova_to_phys(ops, iova);

}



static struct platform_driver arm_smmu_driver;