x86/amd-iommu: Use threaded interupt handler

Move the interupt handling for the iommu into the interupt
thread to reduce latencies and prepare interupt handling for
pri handling.
Signed-off-by: NJoerg Roedel <joerg.roedel@amd.com>

arch/x86/include/asm/amd_iommu_proto.h

@@ -23,6 +23,7 @@
 
 extern int amd_iommu_init_dma_ops(void);
 extern int amd_iommu_init_passthrough(void);
+extern irqreturn_t amd_iommu_int_thread(int irq, void *data);
 extern irqreturn_t amd_iommu_int_handler(int irq, void *data);
 extern void amd_iommu_apply_erratum_63(u16 devid);
 extern void amd_iommu_reset_cmd_buffer(struct amd_iommu *iommu);

arch/x86/kernel/amd_iommu.c

@@ -366,7 +366,7 @@ static void iommu_poll_events(struct amd_iommu *iommu)
 	spin_unlock_irqrestore(&iommu->lock, flags);
 }
 
-irqreturn_t amd_iommu_int_handler(int irq, void *data)
+irqreturn_t amd_iommu_int_thread(int irq, void *data)
 {
 	struct amd_iommu *iommu;
 
@@ -376,6 +376,11 @@ irqreturn_t amd_iommu_int_handler(int irq, void *data)
 	return IRQ_HANDLED;
 }
 
+irqreturn_t amd_iommu_int_handler(int irq, void *data)
+{
+	return IRQ_WAKE_THREAD;
+}
+
 /****************************************************************************
  *
  * IOMMU command queuing functions

arch/x86/kernel/amd_iommu_init.c

@@ -1034,10 +1034,11 @@ static int iommu_setup_msi(struct amd_iommu *iommu)
 	if (pci_enable_msi(iommu->dev))
 		return 1;
 
-	r = request_irq(iommu->dev->irq, amd_iommu_int_handler,
-			IRQF_SAMPLE_RANDOM,
-			"AMD-Vi",
-			NULL);
+	r = request_threaded_irq(iommu->dev->irq,
+				 amd_iommu_int_handler,
+				 amd_iommu_int_thread,
+				 0, "AMD-Vi",
+				 iommu->dev);
 
 	if (r) {
 		pci_disable_msi(iommu->dev);