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authorKyle McMartin <kyle@redhat.com>2009-02-04 14:29:19 -0800
committerIngo Molnar <mingo@elte.hu>2009-02-05 16:48:38 +0100
commit0cd5c3c80a0ebd68c08312fa7d8c13149cc61c4c (patch)
tree4dc6093ee08e668a182b38bd13cd85436555c4b6
parentb534816b552d35bbd3c60702139ed5c7da2f55c2 (diff)
downloadop-kernel-dev-0cd5c3c80a0ebd68c08312fa7d8c13149cc61c4c.zip
op-kernel-dev-0cd5c3c80a0ebd68c08312fa7d8c13149cc61c4c.tar.gz
x86: disable intel_iommu support by default
Due to recurring issues with DMAR support on certain platforms. There's a number of filesystem corruption incidents reported: https://bugzilla.redhat.com/show_bug.cgi?id=479996 http://bugzilla.kernel.org/show_bug.cgi?id=12578 Provide a Kconfig option to change whether it is enabled by default. If disabled, it can still be reenabled by passing intel_iommu=on to the kernel. Keep the .config option off by default. Signed-off-by: Kyle McMartin <kyle@redhat.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Acked-By: David Woodhouse <David.Woodhouse@intel.com> Signed-off-by: Ingo Molnar <mingo@elte.hu>
-rw-r--r--Documentation/kernel-parameters.txt2
-rw-r--r--arch/x86/Kconfig11
-rw-r--r--drivers/pci/intel-iommu.c14
3 files changed, 24 insertions, 3 deletions
diff --git a/Documentation/kernel-parameters.txt b/Documentation/kernel-parameters.txt
index d8362cf..b182626 100644
--- a/Documentation/kernel-parameters.txt
+++ b/Documentation/kernel-parameters.txt
@@ -937,6 +937,8 @@ and is between 256 and 4096 characters. It is defined in the file
intel_iommu= [DMAR] Intel IOMMU driver (DMAR) option
+ on
+ Enable intel iommu driver.
off
Disable intel iommu driver.
igfx_off [Default Off]
diff --git a/arch/x86/Kconfig b/arch/x86/Kconfig
index 73f7fe8..9c39095 100644
--- a/arch/x86/Kconfig
+++ b/arch/x86/Kconfig
@@ -1802,6 +1802,17 @@ config DMAR
and include PCI device scope covered by these DMA
remapping devices.
+config DMAR_DEFAULT_ON
+ def_bool n
+ prompt "Enable DMA Remapping Devices by default"
+ depends on DMAR
+ help
+ Selecting this option will enable a DMAR device at boot time if
+ one is found. If this option is not selected, DMAR support can
+ be enabled by passing intel_iommu=on to the kernel. It is
+ recommended you say N here while the DMAR code remains
+ experimental.
+
config DMAR_GFX_WA
def_bool y
prompt "Support for Graphics workaround"
diff --git a/drivers/pci/intel-iommu.c b/drivers/pci/intel-iommu.c
index 3dfecb2..f4b7c79 100644
--- a/drivers/pci/intel-iommu.c
+++ b/drivers/pci/intel-iommu.c
@@ -268,7 +268,12 @@ static long list_size;
static void domain_remove_dev_info(struct dmar_domain *domain);
-int dmar_disabled;
+#ifdef CONFIG_DMAR_DEFAULT_ON
+int dmar_disabled = 0;
+#else
+int dmar_disabled = 1;
+#endif /*CONFIG_DMAR_DEFAULT_ON*/
+
static int __initdata dmar_map_gfx = 1;
static int dmar_forcedac;
static int intel_iommu_strict;
@@ -284,9 +289,12 @@ static int __init intel_iommu_setup(char *str)
if (!str)
return -EINVAL;
while (*str) {
- if (!strncmp(str, "off", 3)) {
+ if (!strncmp(str, "on", 2)) {
+ dmar_disabled = 0;
+ printk(KERN_INFO "Intel-IOMMU: enabled\n");
+ } else if (!strncmp(str, "off", 3)) {
dmar_disabled = 1;
- printk(KERN_INFO"Intel-IOMMU: disabled\n");
+ printk(KERN_INFO "Intel-IOMMU: disabled\n");
} else if (!strncmp(str, "igfx_off", 8)) {
dmar_map_gfx = 0;
printk(KERN_INFO
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