From 49962ef977aa9c6e5c001d9f4fc38bd1aa047102 Mon Sep 17 00:00:00 2001
From: Suresh Siddha <suresh.b.siddha@intel.com>
Date: Thu, 10 Jul 2008 11:16:51 -0700
Subject: [PATCH] --- yaml --- r: 112651 b: refs/heads/master c:
 1cb11583a6c4ceda7426eb36f7bf0419da8dfbc2 h: refs/heads/master i:   112649:
 63b2091d3810eb268e49d6e83330d325d7f9e482   112647:
 e47a853aaa39d141edbb693d9e97e95aa2483454 v: v3

---
 [refs]                   |  2 +-
 trunk/drivers/pci/dmar.c | 25 +++++++++++++++++++++++++
 2 files changed, 26 insertions(+), 1 deletion(-)

diff --git a/[refs] b/[refs]
index ac42f560ce2e..9ab05ac1b9d0 100644
--- a/[refs]
+++ b/[refs]
@@ -1,2 +1,2 @@
 ---
-refs/heads/master: 32e1d0a0651004f5fe47f85a2a5c725ad579a90c
+refs/heads/master: 1cb11583a6c4ceda7426eb36f7bf0419da8dfbc2
diff --git a/trunk/drivers/pci/dmar.c b/trunk/drivers/pci/dmar.c
index 23a119e6485e..bd2c01674f5e 100644
--- a/trunk/drivers/pci/dmar.c
+++ b/trunk/drivers/pci/dmar.c
@@ -457,6 +457,31 @@ void __init detect_intel_iommu(void)
 
 #ifdef CONFIG_DMAR
 	{
+		struct acpi_table_dmar *dmar;
+		/*
+		 * for now we will disable dma-remapping when interrupt
+		 * remapping is enabled.
+		 * When support for queued invalidation for IOTLB invalidation
+		 * is added, we will not need this any more.
+		 */
+		dmar = (struct acpi_table_dmar *) dmar_tbl;
+		if (ret && cpu_has_x2apic && dmar->flags & 0x1) {
+			printk(KERN_INFO
+			       "Queued invalidation will be enabled to support "
+			       "x2apic and Intr-remapping.\n");
+			printk(KERN_INFO
+			       "Disabling IOMMU detection, because of missing "
+			       "queued invalidation support for IOTLB "
+			       "invalidation\n");
+			printk(KERN_INFO
+			       "Use \"nox2apic\", if you want to use Intel "
+			       " IOMMU for DMA-remapping and don't care about "
+			       " x2apic support\n");
+
+			dmar_disabled = 1;
+			return;
+		}
+
 		if (ret && !no_iommu && !iommu_detected && !swiotlb &&
 		    !dmar_disabled)
 			iommu_detected = 1;