From 3b8f40481513a7b6123def5a02db4cff96ae2198 Mon Sep 17 00:00:00 2001 From: Thomas Gleixner Date: Tue, 19 Jul 2011 17:02:07 +0200 Subject: [PATCH] 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 Signed-off-by: Ingo Molnar --- drivers/iommu/dmar.c | 14 +++++++------- include/linux/intel-iommu.h | 2 +- 2 files changed, 8 insertions(+), 8 deletions(-) diff --git a/drivers/iommu/dmar.c b/drivers/iommu/dmar.c index be4164b3ebe8..388a1189e552 100644 --- a/drivers/iommu/dmar.c +++ b/drivers/iommu/dmar.c @@ -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); diff --git a/include/linux/intel-iommu.h b/include/linux/intel-iommu.h index 19728c462399..8b9b5d365f4e 100644 --- a/include/linux/intel-iommu.h +++ b/include/linux/intel-iommu.h @@ -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 */ -- 2.30.2