p71924506
/
linux_old1
1
0
Fork 0
Code Issues Pull Requests Projects Releases Wiki Activity

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>
This commit is contained in:
Robin Murphy 2017-06-22 16:53:57 +01:00 committed by Will Deacon
parent 523d7423e2
commit 58188afeb7
1 changed files with 6 additions and 27 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

33
drivers/iommu/arm-smmu-v3.c
View File

@ -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;