arch/i386/kernel/reboot_fixups.c

   1 /*
   2  * linux/arch/i386/kernel/reboot_fixups.c
   3  *
   4  * This is a good place to put board specific reboot fixups.
   5  *
   6  * List of supported fixups:
   7  * geode-gx1/cs5530a - Jaya Kumar <jayalk@intworks.biz>
   8  * geode-gx/lx/cs5536 - Andres Salomon <dilinger@debian.org>
   9  *
  10  */
  11
  12 #include <asm/delay.h>
  13 #include <linux/pci.h>
  14 #include <asm/reboot_fixups.h>
  15 #include <asm/msr.h>
  16
  17 static void cs5530a_warm_reset(struct pci_dev *dev)
  18 {
  19         /* writing 1 to the reset control register, 0x44 causes the
  20         cs5530a to perform a system warm reset */
  21         pci_write_config_byte(dev, 0x44, 0x1);
  22         udelay(50); /* shouldn't get here but be safe and spin-a-while */
  23         return;
  24 }
  25
  26 static void cs5536_warm_reset(struct pci_dev *dev)
  27 {
  28         /*
  29          * 6.6.2.12 Soft Reset (DIVIL_SOFT_RESET)
  30          * writing 1 to the LSB of this MSR causes a hard reset.
  31          */
  32         wrmsrl(0x51400017, 1ULL);
  33         udelay(50); /* shouldn't get here but be safe and spin a while */
  34 }
  35
  36 struct device_fixup {
  37         unsigned int vendor;
  38         unsigned int device;
  39         void (*reboot_fixup)(struct pci_dev *);
  40 };
  41
  42 static struct device_fixup fixups_table[] = {
  43 { PCI_VENDOR_ID_CYRIX, PCI_DEVICE_ID_CYRIX_5530_LEGACY, cs5530a_warm_reset },
  44 { PCI_VENDOR_ID_AMD, PCI_DEVICE_ID_AMD_CS5536_ISA, cs5536_warm_reset },
  45 };
  46
  47 /*
  48  * we see if any fixup is available for our current hardware. if there
  49  * is a fixup, we call it and we expect to never return from it. if we
  50  * do return, we keep looking and then eventually fall back to the
  51  * standard mach_reboot on return.
  52  */
  53 void mach_reboot_fixups(void)
  54 {
  55         struct device_fixup *cur;
  56         struct pci_dev *dev;
  57         int i;
  58
  59         for (i=0; i < ARRAY_SIZE(fixups_table); i++) {
  60                 cur = &(fixups_table[i]);
  61                 dev = pci_get_device(cur->vendor, cur->device, NULL);
  62                 if (!dev)
  63                         continue;
  64
  65                 cur->reboot_fixup(dev);
  66         }
  67 }
  68