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iommu/vt-d: Print x2apic opt out info instead of printing a warning 

BIOS can set up x2apic_opt_out bit on some platforms, for various misguided
reasons like insane SMM code with weird assumptions about what descriptors
look like, or wanting Windows not to enable the IOMMU so that the graphics
driver will take it over for SVM in "driver mode".

A user can either disable the x2apic_opt_out bit in BIOS or by kernel
parameter "no_x2apic_optout". Instead of printing a warning, we just
print information of x2apic opt out.

Signed-off-by: Fenghua Yu <fenghua.yu@intel.com>
Signed-off-by: David Woodhouse <David.Woodhouse@intel.com>
hifive-unleashed-5.1
Fenghua Yu 2015-02-21 13:07:27 -08:00 committed by David Woodhouse
parent 44caf2f37f
commit 68c1b89cf5
1 changed files with 1 additions and 4 deletions
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5
drivers/iommu/intel_irq_remapping.c
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@ -615,10 +615,7 @@ static int __init intel_enable_irq_remapping(void)
eim = !dmar_x2apic_optout();
if (!eim)
printk(KERN_WARNING
"Your BIOS is broken and requested that x2apic be disabled.\n"
"This will slightly decrease performance.\n"
"Use 'intremap=no_x2apic_optout' to override BIOS request.\n");
pr_info("x2apic is disabled because BIOS sets x2apic opt out bit. You can use 'intremap=no_x2apic_optout' to override the BIOS setting.\n");
}
for_each_iommu(iommu, drhd) {