iommu/amd: Log IOMMU control register in event log path

Useful for debugging ILLEGAL_DEV_TABLE_ENTRY events as some of the
DTE settings depends on Control register settings.

Signed-off-by: Vasant Hegde <vasant.hegde@amd.com>
Reviewed-by: Jason Gunthorpe <jgg@nvidia.com>
Link: https://lore.kernel.org/r/20250227162320.5805-2-vasant.hegde@amd.com
Signed-off-by: Joerg Roedel <jroedel@suse.de>

drivers/iommu/amd/iommu.c

@@ -868,7 +868,7 @@ static void iommu_print_event(struct amd_iommu *iommu, void *__evt)
 	int type, devid, flags, tag;
 	volatile u32 *event = __evt;
 	int count = 0;
-	u64 address;
+	u64 address, ctrl;
 	u32 pasid;
 
 retry:
@@ -878,6 +878,7 @@ static void iommu_print_event(struct amd_iommu *iommu, void *__evt)
 		  (event[1] & EVENT_DOMID_MASK_LO);
 	flags   = (event[1] >> EVENT_FLAGS_SHIFT) & EVENT_FLAGS_MASK;
 	address = (u64)(((u64)event[3]) << 32) | event[2];
+	ctrl    = readq(iommu->mmio_base + MMIO_CONTROL_OFFSET);
 
 	if (type == 0) {
 		/* Did we hit the erratum? */
@@ -899,6 +900,7 @@ static void iommu_print_event(struct amd_iommu *iommu, void *__evt)
 		dev_err(dev, "Event logged [ILLEGAL_DEV_TABLE_ENTRY device=%04x:%02x:%02x.%x pasid=0x%05x address=0x%llx flags=0x%04x]\n",
 			iommu->pci_seg->id, PCI_BUS_NUM(devid), PCI_SLOT(devid), PCI_FUNC(devid),
 			pasid, address, flags);
+		dev_err(dev, "Control Reg : 0x%llx\n", ctrl);
 		dump_dte_entry(iommu, devid);
 		break;
 	case EVENT_TYPE_DEV_TAB_ERR: