x86/amd-iommu: Dump illegal command on ILLEGAL_COMMAND_ERROR

This patch adds code to dump the command which caused an
ILLEGAL_COMMAND_ERROR raised by the IOMMU hardware.
Signed-off-by: NJoerg Roedel <joerg.roedel@amd.com>

arch/x86/kernel/amd_iommu.c

@@ -147,6 +147,15 @@ static void dump_dte_entry(u16 devid)
 			amd_iommu_dev_table[devid].data[i]);
 }
 
+static void dump_command(unsigned long phys_addr)
+{
+	struct iommu_cmd *cmd = phys_to_virt(phys_addr);
+	int i;
+
+	for (i = 0; i < 4; ++i)
+		pr_err("AMD-Vi: CMD[%d]: %08x\n", i, cmd->data[i]);
+}
+
 static void iommu_print_event(void *__evt)
 {
 	u32 *event = __evt;
@@ -186,6 +195,7 @@ static void iommu_print_event(void *__evt)
 		break;
 	case EVENT_TYPE_ILL_CMD:
 		printk("ILLEGAL_COMMAND_ERROR address=0x%016llx]\n", address);
+		dump_command(address);
 		break;
 	case EVENT_TYPE_CMD_HARD_ERR:
 		printk("COMMAND_HARDWARE_ERROR address=0x%016llx "