diff options
| -rw-r--r-- | arch/i386/kernel/quirks.c | 33 |
1 files changed, 29 insertions, 4 deletions
diff --git a/arch/i386/kernel/quirks.c b/arch/i386/kernel/quirks.c index a01320a7b63..34874c398b4 100644 --- a/arch/i386/kernel/quirks.c +++ b/arch/i386/kernel/quirks.c @@ -10,13 +10,38 @@ #if defined(CONFIG_X86_IO_APIC) && defined(CONFIG_SMP) && defined(CONFIG_PCI) static void __devinit verify_quirk_intel_irqbalance(struct pci_dev *dev) { + u8 config, rev; + u32 word; + + /* BIOS may enable hardware IRQ balancing for + * E7520/E7320/E7525(revision ID 0x9 and below) + * based platforms. + * For those platforms, make sure that the genapic is set to 'flat' + */ + pci_read_config_byte(dev, PCI_CLASS_REVISION, &rev); + if (rev > 0x9) + return; + + /* enable access to config space*/ + pci_read_config_byte(dev, 0xf4, &config); + pci_write_config_byte(dev, 0xf4, config|0x2); + + /* read xTPR register */ + raw_pci_ops->read(0, 0, 0x40, 0x4c, 2, &word); + + if (!(word & (1 << 13))) { #ifdef CONFIG_X86_64 - if (genapic != &apic_flat) - panic("APIC mode must be flat on this system\n"); + if (genapic != &apic_flat) + panic("APIC mode must be flat on this system\n"); #elif defined(CONFIG_X86_GENERICARCH) - if (genapic != &apic_default) - panic("APIC mode must be default(flat) on this system. Use apic=default\n"); + if (genapic != &apic_default) + panic("APIC mode must be default(flat) on this system. Use apic=default\n"); #endif + } + + /* put back the original value for config space*/ + if (!(config & 0x2)) + pci_write_config_byte(dev, 0xf4, config); } void __init quirk_intel_irqbalance(void) |