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| author | Sebastian Andrzej Siewior <bigeasy@linutronix.de> | 2018-03-22 18:22:41 +0300 |
|---|---|---|
| committer | Joerg Roedel <jroedel@suse.de> | 2018-03-29 11:38:17 +0300 |
| commit | 2cd1083d79a0a8c223af430ca97884c28a1e2fc0 (patch) | |
| tree | 02b576c3fd3c6c9726cd6cab987f96acf2d68aa7 /drivers | |
| parent | 993ca6e063a69a0c65ca42ed449b6bc1b3844151 (diff) | |
| download | linux-2cd1083d79a0a8c223af430ca97884c28a1e2fc0.tar.xz | |
iommu/amd: Make amd_iommu_devtable_lock a spin_lock
Before commit 0bb6e243d7fb ("iommu/amd: Support IOMMU_DOMAIN_DMA type
allocation") amd_iommu_devtable_lock had a read_lock() user but now
there are none. In fact, after the mentioned commit we had only
write_lock() user of the lock. Since there is no reason to keep it as
writer lock, change its type to a spin_lock.
I *think* that we might even be able to remove the lock because all its
current user seem to have their own protection.
Signed-off-by: Sebastian Andrzej Siewior <bigeasy@linutronix.de>
Signed-off-by: Joerg Roedel <jroedel@suse.de>
Diffstat (limited to 'drivers')
| -rw-r--r-- | drivers/iommu/amd_iommu.c | 14 |
1 files changed, 7 insertions, 7 deletions
diff --git a/drivers/iommu/amd_iommu.c b/drivers/iommu/amd_iommu.c index c493d345b3ef..23e26a4b708e 100644 --- a/drivers/iommu/amd_iommu.c +++ b/drivers/iommu/amd_iommu.c @@ -80,7 +80,7 @@ */ #define AMD_IOMMU_PGSIZES ((~0xFFFUL) & ~(2ULL << 38)) -static DEFINE_RWLOCK(amd_iommu_devtable_lock); +static DEFINE_SPINLOCK(amd_iommu_devtable_lock); static DEFINE_SPINLOCK(pd_bitmap_lock); static DEFINE_SPINLOCK(iommu_table_lock); @@ -2097,9 +2097,9 @@ static int attach_device(struct device *dev, } skip_ats_check: - write_lock_irqsave(&amd_iommu_devtable_lock, flags); + spin_lock_irqsave(&amd_iommu_devtable_lock, flags); ret = __attach_device(dev_data, domain); - write_unlock_irqrestore(&amd_iommu_devtable_lock, flags); + spin_unlock_irqrestore(&amd_iommu_devtable_lock, flags); /* * We might boot into a crash-kernel here. The crashed kernel @@ -2149,9 +2149,9 @@ static void detach_device(struct device *dev) domain = dev_data->domain; /* lock device table */ - write_lock_irqsave(&amd_iommu_devtable_lock, flags); + spin_lock_irqsave(&amd_iommu_devtable_lock, flags); __detach_device(dev_data); - write_unlock_irqrestore(&amd_iommu_devtable_lock, flags); + spin_unlock_irqrestore(&amd_iommu_devtable_lock, flags); if (!dev_is_pci(dev)) return; @@ -2814,7 +2814,7 @@ static void cleanup_domain(struct protection_domain *domain) struct iommu_dev_data *entry; unsigned long flags; - write_lock_irqsave(&amd_iommu_devtable_lock, flags); + spin_lock_irqsave(&amd_iommu_devtable_lock, flags); while (!list_empty(&domain->dev_list)) { entry = list_first_entry(&domain->dev_list, @@ -2822,7 +2822,7 @@ static void cleanup_domain(struct protection_domain *domain) __detach_device(entry); } - write_unlock_irqrestore(&amd_iommu_devtable_lock, flags); + spin_unlock_irqrestore(&amd_iommu_devtable_lock, flags); } static void protection_domain_free(struct protection_domain *domain) |