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authorRobin Murphy <robin.murphy@arm.com>2017-06-22 18:53:57 +0300
committerWill Deacon <will.deacon@arm.com>2017-06-23 19:58:01 +0300
commit58188afeb727e0f73706f1460707bd3ba6ccc221 (patch)
tree9fca03971c4a362fdd9476509f6e36b9c8069ca7 /drivers/iommu
parent523d7423e21bfe78452a640878d1de189ac45d91 (diff)
downloadlinux-58188afeb727e0f73706f1460707bd3ba6ccc221.tar.xz
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: Robin Murphy <robin.murphy@arm.com> Signed-off-by: Will Deacon <will.deacon@arm.com>
Diffstat (limited to 'drivers/iommu')
-rw-r--r--drivers/iommu/arm-smmu-v3.c33
1 files changed, 6 insertions, 27 deletions
diff --git a/drivers/iommu/arm-smmu-v3.c b/drivers/iommu/arm-smmu-v3.c
index d50c8d4b9af9..884b1a49a52a 100644
--- a/drivers/iommu/arm-smmu-v3.c
+++ b/drivers/iommu/arm-smmu-v3.c
@@ -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 @@ out_unlock:
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;