arch/x86/kernel/reboot_fixups_32.c

   1 /*
   2  * This is a good place to put board specific reboot fixups.
   3  *
   4  * List of supported fixups:
   5  * geode-gx1/cs5530a - Jaya Kumar <jayalk@intworks.biz>
   6  * geode-gx/lx/cs5536 - Andres Salomon <dilinger@debian.org>
   7  *
   8  */
   9
  10 #include <asm/delay.h>
  11 #include <linux/pci.h>
  12 #include <linux/interrupt.h>
  13 #include <asm/reboot_fixups.h>
  14 #include <asm/msr.h>
  15 #include <asm/geode.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         /* writing 1 to the LSB of this MSR causes a hard reset */
  29         wrmsrl(MSR_DIVIL_SOFT_RESET, 1ULL);
  30         udelay(50); /* shouldn't get here but be safe and spin a while */
  31 }
  32
  33 struct device_fixup {
  34         unsigned int vendor;
  35         unsigned int device;
  36         void (*reboot_fixup)(struct pci_dev *);
  37 };
  38
  39 static struct device_fixup fixups_table[] = {
  40 { PCI_VENDOR_ID_CYRIX, PCI_DEVICE_ID_CYRIX_5530_LEGACY, cs5530a_warm_reset },
  41 { PCI_VENDOR_ID_AMD, PCI_DEVICE_ID_AMD_CS5536_ISA, cs5536_warm_reset },
  42 { PCI_VENDOR_ID_NS, PCI_DEVICE_ID_NS_SC1100_BRIDGE, cs5530a_warm_reset },
  43 };
  44
  45 /*
  46  * we see if any fixup is available for our current hardware. if there
  47  * is a fixup, we call it and we expect to never return from it. if we
  48  * do return, we keep looking and then eventually fall back to the
  49  * standard mach_reboot on return.
  50  */
  51 void mach_reboot_fixups(void)
  52 {
  53         struct device_fixup *cur;
  54         struct pci_dev *dev;
  55         int i;
  56
  57         /* we can be called from sysrq-B code. In such a case it is
  58          * prohibited to dig PCI */
  59         if (in_interrupt())
  60                 return;
  61
  62         for (i=0; i < ARRAY_SIZE(fixups_table); i++) {
  63                 cur = &(fixups_table[i]);
  64                 dev = pci_get_device(cur->vendor, cur->device, NULL);
  65                 if (!dev)
  66                         continue;
  67
  68                 cur->reboot_fixup(dev);
  69         }
  70 }
  71