LXR linux/arch/x86/kernel/reboot_fixups

   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
  18static 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
  27static 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
  34static 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
  47static 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
  57struct 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
  68static 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 */
  82void 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
 104