[ 3.5.y.z extended stable ] Patch "iommu/intel: disable DMAR for g4x integrated gfx" has been added to staging queue

[Herton Ronaldo Krzesinski]

This is a note to let you know that I have just added a patch titled

    iommu/intel: disable DMAR for g4x integrated gfx

to the linux-3.5.y-queue branch of the 3.5.y.z extended stable tree 
which can be found at:

 http://kernel.ubuntu.com/git?p=ubuntu/linux.git;a=shortlog;h=refs/heads/linux-3.5.y-queue

If you, or anyone else, feels it should not be added to this tree, please 
reply to this email.

For more information about the 3.5.y.z tree, see
https://wiki.ubuntu.com/Kernel/Dev/ExtendedStable

Thanks.
-Herton

------

>From 17b58874afd714209b05cdf229740485062afb53 Mon Sep 17 00:00:00 2001
From: Daniel Vetter <daniel.vetter at ffwll.ch>
Date: Sun, 20 Jan 2013 23:50:13 +0100
Subject: [PATCH] iommu/intel: disable DMAR for g4x integrated gfx

commit 9452618e7462181ed9755236803b6719298a13ce upstream.

DMAR support on g4x/gm45 integrated gpus seems to be totally busted.
So don't bother, but instead disable it by default to allow distros to
unconditionally enable DMAR support.

v2: Actually wire up the right quirk entry, spotted by Adam Jackson.

Note that according to intel marketing materials only g45 and gm45
support DMAR/VT-d. So we have reports for all relevant gen4 pci ids by
now. Still, keep all the other gen4 ids in the quirk table in case the
marketing stuff confused me again, which would not be the first time.

Bugzilla: https://bugzilla.kernel.org/show_bug.cgi?id=51921
Bugzilla: https://bugzilla.redhat.com/show_bug.cgi?id=538163
Bugzilla: https://bugzilla.redhat.com/show_bug.cgi?id=538163
Cc: Adam Jackson <ajax at redhat.com>
Cc: David Woodhouse <dwmw2 at infradead.org>
Acked-By: David Woodhouse <David.Woodhouse at intel.com>
Tested-by: stathis <stathis at npcglib.org>
Tested-by: Mihai Moldovan <ionic at ionic.de>
Signed-off-by: Daniel Vetter <daniel.vetter at ffwll.ch>
[ herton: adjust context ]
Signed-off-by: Herton Ronaldo Krzesinski <herton.krzesinski at canonical.com>
---
 drivers/iommu/intel-iommu.c |   21 +++++++++++++++------
 1 file changed, 15 insertions(+), 6 deletions(-)

diff --git a/drivers/iommu/intel-iommu.c b/drivers/iommu/intel-iommu.c
index 92f5912..1f78d86 100644
--- a/drivers/iommu/intel-iommu.c
+++ b/drivers/iommu/intel-iommu.c
@@ -4191,6 +4191,21 @@ static struct iommu_ops intel_iommu_ops = {
 	.pgsize_bitmap	= INTEL_IOMMU_PGSIZES,
 };

+static void quirk_iommu_g4x_gfx(struct pci_dev *dev)
+{
+	/* G4x/GM45 integrated gfx dmar support is totally busted. */
+	printk(KERN_INFO "DMAR: Disabling IOMMU for graphics on this chipset\n");
+	dmar_map_gfx = 0;
+}
+
+DECLARE_PCI_FIXUP_HEADER(PCI_VENDOR_ID_INTEL, 0x2a40, quirk_iommu_g4x_gfx);
+DECLARE_PCI_FIXUP_HEADER(PCI_VENDOR_ID_INTEL, 0x2e00, quirk_iommu_g4x_gfx);
+DECLARE_PCI_FIXUP_HEADER(PCI_VENDOR_ID_INTEL, 0x2e10, quirk_iommu_g4x_gfx);
+DECLARE_PCI_FIXUP_HEADER(PCI_VENDOR_ID_INTEL, 0x2e20, quirk_iommu_g4x_gfx);
+DECLARE_PCI_FIXUP_HEADER(PCI_VENDOR_ID_INTEL, 0x2e30, quirk_iommu_g4x_gfx);
+DECLARE_PCI_FIXUP_HEADER(PCI_VENDOR_ID_INTEL, 0x2e40, quirk_iommu_g4x_gfx);
+DECLARE_PCI_FIXUP_HEADER(PCI_VENDOR_ID_INTEL, 0x2e90, quirk_iommu_g4x_gfx);
+
 static void __devinit quirk_iommu_rwbf(struct pci_dev *dev)
 {
 	/*
@@ -4199,12 +4214,6 @@ static void __devinit quirk_iommu_rwbf(struct pci_dev *dev)
 	 */
 	printk(KERN_INFO "DMAR: Forcing write-buffer flush capability\n");
 	rwbf_quirk = 1;
-
-	/* https://bugzilla.redhat.com/show_bug.cgi?id=538163 */
-	if (dev->revision == 0x07) {
-		printk(KERN_INFO "DMAR: Disabling IOMMU for graphics on this chipset\n");
-		dmar_map_gfx = 0;
-	}
 }

 DECLARE_PCI_FIXUP_HEADER(PCI_VENDOR_ID_INTEL, 0x2a40, quirk_iommu_rwbf);
--
1.7.9.5