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locking, x86, iommu: Annotate qi->q_lock as raw 

The qi->q_lock lock can be taken in atomic context and therefore
cannot be preempted on -rt - annotate it.

In mainline this change documents the low level nature of
the lock - otherwise there's no functional difference. Lockdep
and Sparse checking will work as usual.

Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
This commit is contained in:
Thomas Gleixner 2011-07-19 17:02:07 +02:00 committed by Ingo Molnar
parent 96f8e98bfe
commit 3b8f404815
2 changed files with 8 additions and 8 deletions
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14
drivers/iommu/dmar.c
View File

@ -921,11 +921,11 @@ int qi_submit_sync(struct qi_desc *desc, struct intel_iommu *iommu)
restart:
rc = 0;
spin_lock_irqsave(&qi->q_lock, flags);
raw_spin_lock_irqsave(&qi->q_lock, flags);
while (qi->free_cnt < 3) {
spin_unlock_irqrestore(&qi->q_lock, flags);
raw_spin_unlock_irqrestore(&qi->q_lock, flags);
cpu_relax();
spin_lock_irqsave(&qi->q_lock, flags);
raw_spin_lock_irqsave(&qi->q_lock, flags);
}
index = qi->free_head;
@ -965,15 +965,15 @@ restart:
if (rc)
break;
spin_unlock(&qi->q_lock);
raw_spin_unlock(&qi->q_lock);
cpu_relax();
spin_lock(&qi->q_lock);
raw_spin_lock(&qi->q_lock);
}
qi->desc_status[index] = QI_DONE;
reclaim_free_desc(qi);
spin_unlock_irqrestore(&qi->q_lock, flags);
raw_spin_unlock_irqrestore(&qi->q_lock, flags);
if (rc == -EAGAIN)
goto restart;
@ -1159,7 +1159,7 @@ int dmar_enable_qi(struct intel_iommu *iommu)
qi->free_head = qi->free_tail = 0;
qi->free_cnt = QI_LENGTH;
spin_lock_init(&qi->q_lock);
raw_spin_lock_init(&qi->q_lock);
__dmar_enable_qi(iommu);

2
include/linux/intel-iommu.h
View File

@ -271,7 +271,7 @@ struct qi_desc {
};
struct q_inval {
spinlock_t q_lock;
raw_spinlock_t q_lock;
struct qi_desc *desc; /* invalidation queue */
int *desc_status; /* desc status */
int free_head; /* first free entry */