arch/x86/kernel/reboot_fixups_32.c

   1 // SPDX-License-Identifier: GPL-2.0
   2 /*
   3  * This is a good place to put board specific reboot fixups.
   4  *
   5  * List of supported fixups:
   6  * geode-gx1/cs5530a - Jaya Kumar <jayalk@intworks.biz>
   7  * geode-gx/lx/cs5536 - Andres Salomon <dilinger@debian.org>
   8  *
   9  */
  10
  11 #include <asm/delay.h>
  12 #include <linux/pci.h>
  13 #include <linux/interrupt.h>
  14 #include <asm/reboot_fixups.h>
  15 #include <asm/msr.h>
  16 #include <linux/cs5535.h>
  17
  18 static void cs5530a_warm_reset(struct pci_dev *dev)
  19 {
  20         /* writing 1 to the reset control register, 0x44 causes the
  21         cs5530a to perform a system warm reset */
  22         pci_write_config_byte(dev, 0x44, 0x1);
  23         udelay(50); /* shouldn't get here but be safe and spin-a-while */
  24         return;
  25 }
  26
  27 static void cs5536_warm_reset(struct pci_dev *dev)
  28 {
  29         /* writing 1 to the LSB of this MSR causes a hard reset */
  30         wrmsrl(MSR_DIVIL_SOFT_RESET, 1ULL);
  31         udelay(50); /* shouldn't get here but be safe and spin a while */
  32 }
  33
  34 static void rdc321x_reset(struct pci_dev *dev)
  35 {
  36         unsigned i;
  37         /* Voluntary reset the watchdog timer */
  38         outl(0x80003840, 0xCF8);
  39         /* Generate a CPU reset on next tick */
  40         i = inl(0xCFC);
  41         /* Use the minimum timer resolution */
  42         i |= 0x1600;
  43         outl(i, 0xCFC);
  44         outb(1, 0x92);
  45 }
  46
  47 static void ce4100_reset(struct pci_dev *dev)
  48 {
  49         int i;
  50
  51         for (i = 0; i < 10; i++) {
  52                 outb(0x2, 0xcf9);
  53                 udelay(50);
  54         }
  55 }
  56
  57 struct device_fixup {
  58         unsigned int vendor;
  59         unsigned int device;
  60         void (*reboot_fixup)(struct pci_dev *);
  61 };
  62
  63 /*
  64  * PCI ids solely used for fixups_table go here
  65  */
  66 #define PCI_DEVICE_ID_INTEL_CE4100      0x0708
  67
  68 static const struct device_fixup fixups_table[] = {
  69 { PCI_VENDOR_ID_CYRIX, PCI_DEVICE_ID_CYRIX_5530_LEGACY, cs5530a_warm_reset },
  70 { PCI_VENDOR_ID_AMD, PCI_DEVICE_ID_AMD_CS5536_ISA, cs5536_warm_reset },
  71 { PCI_VENDOR_ID_NS, PCI_DEVICE_ID_NS_SC1100_BRIDGE, cs5530a_warm_reset },
  72 { PCI_VENDOR_ID_RDC, PCI_DEVICE_ID_RDC_R6030, rdc321x_reset },
  73 { PCI_VENDOR_ID_INTEL, PCI_DEVICE_ID_INTEL_CE4100, ce4100_reset },
  74 };
  75
  76 /*
  77  * we see if any fixup is available for our current hardware. if there
  78  * is a fixup, we call it and we expect to never return from it. if we
  79  * do return, we keep looking and then eventually fall back to the
  80  * standard mach_reboot on return.
  81  */
  82 void mach_reboot_fixups(void)
  83 {
  84         const struct device_fixup *cur;
  85         struct pci_dev *dev;
  86         int i;
  87
  88         /* we can be called from sysrq-B code. In such a case it is
  89          * prohibited to dig PCI */
  90         if (in_interrupt())
  91                 return;
  92
  93         for (i=0; i < ARRAY_SIZE(fixups_table); i++) {
  94                 cur = &(fixups_table[i]);
  95                 dev = pci_get_device(cur->vendor, cur->device, NULL);
  96                 if (!dev)
  97                         continue;
  98
  99                 cur->reboot_fixup(dev);
 100                 pci_dev_put(dev);
 101         }
 102 }
 103