[PATCH v3] Prevent devices with RMRRs from being placed into SI Domain during startup

[Tom Mingarelli <thomas.mingarelli@hp.com>]

This patch is to prevent devices that have RMRRs associated with them 
from getting placed into the SI Domain during init. We don't put USB devices
into this category, however. This fixes the issue where the RMRR info
for devices being placed in and out of the SI Domain gets lost.

Signed-off-by: Thomas Mingarelli <thomas.mingarelli@hp.com>
----
PATCH v1: https://lkml.org/lkml/2012/6/15/204
PATCH v2: https://lkml.org/lkml/2012/9/18/354

drivers/iommu/intel-iommu.c |   33 +++++++++++++++++++++++++++++++++
1 files changed, 33 insertions(+), 0 deletions(-)

diff -up ./drivers/iommu/intel-iommu.c.ORIG ./drivers/iommu/intel-iommu.c
--- ./drivers/iommu/intel-iommu.c.ORIG	2012-10-16 09:34:23.148089944 -0500
+++ ./drivers/iommu/intel-iommu.c	2012-10-16 09:56:56.905932861 -0500
@@ -2320,8 +2320,41 @@ static int domain_add_dev_info(struct dm
 	return 0;
 }
 
+static bool device_has_rmrr(struct pci_dev *dev)
+{
+	struct dmar_rmrr_unit *rmrr;
+	int i;
+
+	for_each_rmrr_units(rmrr) {
+		for (i = 0; i < rmrr->devices_cnt; i++) {
+			/*
+			 * Here we are just concerned with checking each device
+			 * that has an RMRR associated with it and not allow it
+			 * to be placed into the SI Domain during startup.
+			*/
+			if (rmrr->devices[i] == dev)
+				return true;
+		}
+	}
+	return false;
+}
+
 static int iommu_should_identity_map(struct pci_dev *pdev, int startup)
 {
+
+	if (startup) {
+		/*
+		 * This is where we will refuse any device that has an
+		 * RMRR associated with it and is not a USB device and
+		 * NOT allow it to be placed into the SI Domain. We
+		 * only do this on startup. We don't need a separate bit
+		 * for this because it could be ANY device.
+		*/
+		if (device_has_rmrr(pdev) &&
+			(pdev->class >> 8) != PCI_CLASS_SERIAL_USB)
+				return 0;
+	}
+
 	if ((iommu_identity_mapping & IDENTMAP_AZALIA) && IS_AZALIA(pdev))
 		return 1;