arch/i386/kernel/quirks.c

   1 /*
   2  * This file contains work-arounds for x86 and x86_64 platform bugs.
   3  */
   4 #include <linux/pci.h>
   5 #include <linux/irq.h>
   6 #include <asm/pci-direct.h>
   7 #include <asm/genapic.h>
   8 #include <asm/cpu.h>
   9
  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)
  12 {
  13         u8 config, rev;
  14         u32 word;
  15
  16         /* BIOS may enable hardware IRQ balancing for
  17          * E7520/E7320/E7525(revision ID 0x9 and below)
  18          * based platforms.
  19          * For those platforms, make sure that the genapic is set to 'flat'
  20          */
  21         pci_read_config_byte(dev, PCI_CLASS_REVISION, &rev);
  22         if (rev > 0x9)
  23                 return;
  24
  25         /* enable access to config space*/
  26         pci_read_config_byte(dev, 0xf4, &config);
  27         pci_write_config_byte(dev, 0xf4, config|0x2);
  28
  29         /* read xTPR register */
  30         raw_pci_ops->read(0, 0, 0x40, 0x4c, 2, &word);
  31
  32         if (!(word & (1 << 13))) {
  33 #ifdef CONFIG_X86_64
  34                 if (genapic !=  &apic_flat)
  35                         panic("APIC mode must be flat on this system\n");
  36 #elif defined(CONFIG_X86_GENERICARCH)
  37                 if (genapic != &apic_default)
  38                         panic("APIC mode must be default(flat) on this system. Use apic=default\n");
  39 #endif
  40         }
  41
  42         /* put back the original value for config space*/
  43         if (!(config & 0x2))
  44                 pci_write_config_byte(dev, 0xf4, config);
  45 }
  46
  47 void __init quirk_intel_irqbalance(void)
  48 {
  49         u8 config, rev;
  50         u32 word;
  51
  52         /* BIOS may enable hardware IRQ balancing for
  53          * E7520/E7320/E7525(revision ID 0x9 and below)
  54          * based platforms.
  55          * Disable SW irqbalance/affinity on those platforms.
  56          */
  57         rev = read_pci_config_byte(0, 0, 0, PCI_CLASS_REVISION);
  58         if (rev > 0x9)
  59                 return;
  60
  61         printk(KERN_INFO "Intel E7520/7320/7525 detected.");
  62
  63         /* enable access to config space */
  64         config = read_pci_config_byte(0, 0, 0, 0xf4);
  65         write_pci_config_byte(0, 0, 0, 0xf4, config|0x2);
  66
  67         /* read xTPR register */
  68         word = read_pci_config_16(0, 0, 0x40, 0x4c);
  69
  70         if (!(word & (1 << 13))) {
  71                 printk(KERN_INFO "Disabling irq balancing and affinity\n");
  72 #ifdef CONFIG_IRQBALANCE
  73                 irqbalance_disable("");
  74 #endif
  75                 noirqdebug_setup("");
  76 #ifdef CONFIG_PROC_FS
  77                 no_irq_affinity = 1;
  78 #endif
  79 #ifdef CONFIG_HOTPLUG_CPU
  80                 printk(KERN_INFO "Disabling cpu hotplug control\n");
  81                 enable_cpu_hotplug = 0;
  82 #endif
  83 #ifdef CONFIG_X86_64
  84                 /* force the genapic selection to flat mode so that
  85                  * interrupts can be redirected to more than one CPU.
  86                  */
  87                 genapic_force = &apic_flat;
  88 #endif
  89         }
  90
  91         /* put back the original value for config space */
  92         if (!(config & 0x2))
  93                 write_pci_config_byte(0, 0, 0, 0xf4, config);
  94 }
  95 DECLARE_PCI_FIXUP_FINAL(PCI_VENDOR_ID_INTEL,   PCI_DEVICE_ID_INTEL_E7320_MCH,  verify_quirk_intel_irqbalance);
  96 DECLARE_PCI_FIXUP_FINAL(PCI_VENDOR_ID_INTEL,   PCI_DEVICE_ID_INTEL_E7525_MCH,  verify_quirk_intel_irqbalance);
  97 DECLARE_PCI_FIXUP_FINAL(PCI_VENDOR_ID_INTEL,   PCI_DEVICE_ID_INTEL_E7520_MCH,  verify_quirk_intel_irqbalance);
  98
  99 #endif