locking, x86, iommu: Annotate iommu->register_lock as raw

The iommu->register_lock can be taken in atomic context and therefore
must not 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>
diff --git a/drivers/iommu/intr_remapping.c b/drivers/iommu/intr_remapping.c
index 1a89d4a..b2443f1 100644
--- a/drivers/iommu/intr_remapping.c
+++ b/drivers/iommu/intr_remapping.c
@@ -409,7 +409,7 @@
 
 	addr = virt_to_phys((void *)iommu->ir_table->base);
 
-	spin_lock_irqsave(&iommu->register_lock, flags);
+	raw_spin_lock_irqsave(&iommu->register_lock, flags);
 
 	dmar_writeq(iommu->reg + DMAR_IRTA_REG,
 		    (addr) | IR_X2APIC_MODE(mode) | INTR_REMAP_TABLE_REG_SIZE);
@@ -420,7 +420,7 @@
 
 	IOMMU_WAIT_OP(iommu, DMAR_GSTS_REG,
 		      readl, (sts & DMA_GSTS_IRTPS), sts);
-	spin_unlock_irqrestore(&iommu->register_lock, flags);
+	raw_spin_unlock_irqrestore(&iommu->register_lock, flags);
 
 	/*
 	 * global invalidation of interrupt entry cache before enabling
@@ -428,7 +428,7 @@
 	 */
 	qi_global_iec(iommu);
 
-	spin_lock_irqsave(&iommu->register_lock, flags);
+	raw_spin_lock_irqsave(&iommu->register_lock, flags);
 
 	/* Enable interrupt-remapping */
 	iommu->gcmd |= DMA_GCMD_IRE;
@@ -437,7 +437,7 @@
 	IOMMU_WAIT_OP(iommu, DMAR_GSTS_REG,
 		      readl, (sts & DMA_GSTS_IRES), sts);
 
-	spin_unlock_irqrestore(&iommu->register_lock, flags);
+	raw_spin_unlock_irqrestore(&iommu->register_lock, flags);
 }
 
 
@@ -485,7 +485,7 @@
 	 */
 	qi_global_iec(iommu);
 
-	spin_lock_irqsave(&iommu->register_lock, flags);
+	raw_spin_lock_irqsave(&iommu->register_lock, flags);
 
 	sts = dmar_readq(iommu->reg + DMAR_GSTS_REG);
 	if (!(sts & DMA_GSTS_IRES))
@@ -498,7 +498,7 @@
 		      readl, !(sts & DMA_GSTS_IRES), sts);
 
 end:
-	spin_unlock_irqrestore(&iommu->register_lock, flags);
+	raw_spin_unlock_irqrestore(&iommu->register_lock, flags);
 }
 
 int __init intr_remapping_supported(void)