iommu/amd: WARN when __[attach|detach]_device are called with irqs enabled

These functions rely on being called with IRQs disabled. Add
a WARN_ON to detect early when its not.
Signed-off-by: Joerg Roedel <jroedel@suse.de>

drivers/iommu/amd_iommu.c

@@ -2030,6 +2030,12 @@ static int __attach_device(struct iommu_dev_data *dev_data,
 {
 	int ret;
 
+	/*
+	 * Must be called with IRQs disabled. Warn here to detect early
+	 * when its not.
+	 */
+	WARN_ON(!irqs_disabled());
+
 	/* lock domain */
 	spin_lock(&domain->lock);
 
@@ -2190,6 +2196,12 @@ static void __detach_device(struct iommu_dev_data *dev_data)
 {
 	struct protection_domain *domain;
 
+	/*
+	 * Must be called with IRQs disabled. Warn here to detect early
+	 * when its not.
+	 */
+	WARN_ON(!irqs_disabled());
+
 	if (WARN_ON(!dev_data->domain))
 		return;