LXR linux/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
   7#if defined(CONFIG_X86_IO_APIC) && defined(CONFIG_SMP) && defined(CONFIG_PCI)
   8
   9static void __devinit quirk_intel_irqbalance(struct pci_dev *dev)
  10{
  11        u8 config, rev;
  12        u32 word;
  13
  14        /* BIOS may enable hardware IRQ balancing for
  15         * E7520/E7320/E7525(revision ID 0x9 and below)
  16         * based platforms.
  17         * Disable SW irqbalance/affinity on those platforms.
  18         */
  19        pci_read_config_byte(dev, PCI_CLASS_REVISION, &rev);
  20        if (rev > 0x9)
  21                return;
  22
  23        /* enable access to config space*/
  24        pci_read_config_byte(dev, 0xf4, &config);
  25        pci_write_config_byte(dev, 0xf4, config|0x2);
  26
  27        /* read xTPR register */
  28        raw_pci_ops->read(0, 0, 0x40, 0x4c, 2, &word);
  29
  30        if (!(word & (1 << 13))) {
  31                printk(KERN_INFO "Intel E7520/7320/7525 detected. "
  32                        "Disabling irq balancing and affinity\n");
  33#ifdef CONFIG_IRQBALANCE
  34                irqbalance_disable("");
  35#endif
  36                noirqdebug_setup("");
  37#ifdef CONFIG_PROC_FS
  38                no_irq_affinity = 1;
  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}
  46DECLARE_PCI_FIXUP_FINAL(PCI_VENDOR_ID_INTEL,    PCI_DEVICE_ID_INTEL_E7320_MCH,  quirk_intel_irqbalance);
  47DECLARE_PCI_FIXUP_FINAL(PCI_VENDOR_ID_INTEL,    PCI_DEVICE_ID_INTEL_E7525_MCH,  quirk_intel_irqbalance);
  48DECLARE_PCI_FIXUP_FINAL(PCI_VENDOR_ID_INTEL,    PCI_DEVICE_ID_INTEL_E7520_MCH,  quirk_intel_irqbalance);
  49#endif
  50