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authorJoerg Roedel <jroedel@suse.de>2019-09-25 15:22:56 +0200
committerJoerg Roedel <jroedel@suse.de>2019-09-28 14:43:46 +0200
commit3a11905b69eb026402448c750f97a0eadfa76b08 (patch)
tree64d30ce5111b1080f063adeef861bad127eb6ad3
parentf15d9a992f901d4f22db868adf800844d1cac9f2 (diff)
downloadlinux-3a11905b69eb026402448c750f97a0eadfa76b08.tar.bz2
iommu/amd: Remove amd_iommu_devtable_lock
The lock is not necessary because the device table does not contain shared state that needs protection. Locking is only needed on an individual entry basis, and that needs to happen on the iommu_dev_data level. Fixes: 92d420ec028d ("iommu/amd: Relax locking in dma_ops path") Reviewed-by: Filippo Sironi <sironi@amazon.de> Reviewed-by: Jerry Snitselaar <jsnitsel@redhat.com> Signed-off-by: Joerg Roedel <jroedel@suse.de>
-rw-r--r--drivers/iommu/amd_iommu.c23
1 files changed, 6 insertions, 17 deletions
diff --git a/drivers/iommu/amd_iommu.c b/drivers/iommu/amd_iommu.c
index 042854bbc5bc..37a9c04fc728 100644
--- a/drivers/iommu/amd_iommu.c
+++ b/drivers/iommu/amd_iommu.c
@@ -70,7 +70,6 @@
*/
#define AMD_IOMMU_PGSIZES ((~0xFFFUL) & ~(2ULL << 38))
-static DEFINE_SPINLOCK(amd_iommu_devtable_lock);
static DEFINE_SPINLOCK(pd_bitmap_lock);
/* List of all available dev_data structures */
@@ -2080,10 +2079,11 @@ static void do_detach(struct iommu_dev_data *dev_data)
static int __attach_device(struct iommu_dev_data *dev_data,
struct protection_domain *domain)
{
+ unsigned long flags;
int ret;
/* lock domain */
- spin_lock(&domain->lock);
+ spin_lock_irqsave(&domain->lock, flags);
ret = -EBUSY;
if (dev_data->domain != NULL)
@@ -2097,7 +2097,7 @@ static int __attach_device(struct iommu_dev_data *dev_data,
out_unlock:
/* ready */
- spin_unlock(&domain->lock);
+ spin_unlock_irqrestore(&domain->lock, flags);
return ret;
}
@@ -2181,7 +2181,6 @@ static int attach_device(struct device *dev,
{
struct pci_dev *pdev;
struct iommu_dev_data *dev_data;
- unsigned long flags;
int ret;
dev_data = get_dev_data(dev);
@@ -2209,9 +2208,7 @@ static int attach_device(struct device *dev,
}
skip_ats_check:
- spin_lock_irqsave(&amd_iommu_devtable_lock, flags);
ret = __attach_device(dev_data, domain);
- spin_unlock_irqrestore(&amd_iommu_devtable_lock, flags);
/*
* We might boot into a crash-kernel here. The crashed kernel
@@ -2231,14 +2228,15 @@ skip_ats_check:
static void __detach_device(struct iommu_dev_data *dev_data)
{
struct protection_domain *domain;
+ unsigned long flags;
domain = dev_data->domain;
- spin_lock(&domain->lock);
+ spin_lock_irqsave(&domain->lock, flags);
do_detach(dev_data);
- spin_unlock(&domain->lock);
+ spin_unlock_irqrestore(&domain->lock, flags);
}
/*
@@ -2248,7 +2246,6 @@ static void detach_device(struct device *dev)
{
struct protection_domain *domain;
struct iommu_dev_data *dev_data;
- unsigned long flags;
dev_data = get_dev_data(dev);
domain = dev_data->domain;
@@ -2262,10 +2259,7 @@ static void detach_device(struct device *dev)
if (WARN_ON(!dev_data->domain))
return;
- /* lock device table */
- spin_lock_irqsave(&amd_iommu_devtable_lock, flags);
__detach_device(dev_data);
- spin_unlock_irqrestore(&amd_iommu_devtable_lock, flags);
if (!dev_is_pci(dev))
return;
@@ -2910,9 +2904,6 @@ int __init amd_iommu_init_dma_ops(void)
static void cleanup_domain(struct protection_domain *domain)
{
struct iommu_dev_data *entry;
- unsigned long flags;
-
- spin_lock_irqsave(&amd_iommu_devtable_lock, flags);
while (!list_empty(&domain->dev_list)) {
entry = list_first_entry(&domain->dev_list,
@@ -2920,8 +2911,6 @@ static void cleanup_domain(struct protection_domain *domain)
BUG_ON(!entry->domain);
__detach_device(entry);
}
-
- spin_unlock_irqrestore(&amd_iommu_devtable_lock, flags);
}
static void protection_domain_free(struct protection_domain *domain)