2 * This file contains work-arounds for x86 and x86_64 platform bugs.
6 #include <asm/pci-direct.h>
7 #include <asm/genapic.h>
10 #if defined(CONFIG_X86_IO_APIC) && defined(CONFIG_SMP) && defined(CONFIG_PCI)
11 static void __devinit verify_quirk_intel_irqbalance(struct pci_dev *dev)
14 if (genapic != &apic_flat)
15 panic("APIC mode must be flat on this system\n");
16 #elif defined(CONFIG_X86_GENERICARCH)
17 if (genapic != &apic_default)
18 panic("APIC mode must be default(flat) on this system. Use apic=default\n");
22 void __init quirk_intel_irqbalance(void)
27 /* BIOS may enable hardware IRQ balancing for
28 * E7520/E7320/E7525(revision ID 0x9 and below)
30 * Disable SW irqbalance/affinity on those platforms.
32 rev = read_pci_config_byte(0, 0, 0, PCI_CLASS_REVISION);
36 printk(KERN_INFO "Intel E7520/7320/7525 detected.");
38 /* enable access to config space */
39 config = read_pci_config_byte(0, 0, 0, 0xf4);
40 write_pci_config_byte(0, 0, 0, 0xf4, config|0x2);
42 /* read xTPR register */
43 word = read_pci_config_16(0, 0, 0x40, 0x4c);
45 if (!(word & (1 << 13))) {
46 printk(KERN_INFO "Disabling irq balancing and affinity\n");
47 #ifdef CONFIG_IRQBALANCE
48 irqbalance_disable("");
54 #ifdef CONFIG_HOTPLUG_CPU
55 printk(KERN_INFO "Disabling cpu hotplug control\n");
56 enable_cpu_hotplug = 0;
59 /* force the genapic selection to flat mode so that
60 * interrupts can be redirected to more than one CPU.
62 genapic_force = &apic_flat;
66 /* put back the original value for config space */
68 write_pci_config_byte(0, 0, 0, 0xf4, config);
70 DECLARE_PCI_FIXUP_FINAL(PCI_VENDOR_ID_INTEL, PCI_DEVICE_ID_INTEL_E7320_MCH, verify_quirk_intel_irqbalance);
71 DECLARE_PCI_FIXUP_FINAL(PCI_VENDOR_ID_INTEL, PCI_DEVICE_ID_INTEL_E7525_MCH, verify_quirk_intel_irqbalance);
72 DECLARE_PCI_FIXUP_FINAL(PCI_VENDOR_ID_INTEL, PCI_DEVICE_ID_INTEL_E7520_MCH, verify_quirk_intel_irqbalance);