Bilddatei hpwdt.c   Sprache: C

// SPDX-License-Identifier: GPL-2.0-only
/*
 * HPE WatchDog Driver
 * based on
 *
 * SoftDog 0.05: A Software Watchdog Device
 *
 * (c) Copyright 2018 Hewlett Packard Enterprise Development LP
 * Thomas Mingarelli <thomas.mingarelli@hpe.com>
 */

#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt

#include <linux/device.h>
#include <linux/io.h>
#include <linux/kernel.h>
#include <linux/module.h>
#include <linux/moduleparam.h>
#include <linux/pci.h>
#include <linux/pci_ids.h>
#include <linux/types.h>
#include <linux/watchdog.h>
#ifdef CONFIG_HPWDT_NMI_DECODING
#include <asm/nmi.h>
#endif
#include <linux/crash_dump.h>

#define HPWDT_VERSION   "2.0.4"
#define SECS_TO_TICKS(secs)  ((secs) * 1000 / 128)
#define TICKS_TO_SECS(ticks)  ((ticks) * 128 / 1000)
#define HPWDT_MAX_TICKS   65535
#define HPWDT_MAX_TIMER   TICKS_TO_SECS(HPWDT_MAX_TICKS)
#define DEFAULT_MARGIN   30
#define PRETIMEOUT_SEC   9

static unsigned int soft_margin = DEFAULT_MARGIN; /* in seconds */
static bool nowayout = WATCHDOG_NOWAYOUT;
static bool pretimeout = IS_ENABLED(CONFIG_HPWDT_NMI_DECODING);
static int kdumptimeout = -1;

static void __iomem *pci_mem_addr;  /* the PCI-memory address */
static unsigned long __iomem *hpwdt_nmistat;
static unsigned long __iomem *hpwdt_timer_reg;
static unsigned long __iomem *hpwdt_timer_con;

static const struct pci_device_id hpwdt_devices[] = {
 { PCI_DEVICE(PCI_VENDOR_ID_COMPAQ, 0xB203) }, /* iLO2 */
 { PCI_DEVICE(PCI_VENDOR_ID_HP, 0x3306) }, /* iLO3 */
 { PCI_DEVICE(PCI_VENDOR_ID_HP_3PAR, 0x0389) }, /* PCtrl */
 {0},   /* terminate list */
};
MODULE_DEVICE_TABLE(pci, hpwdt_devices);

static const struct pci_device_id hpwdt_blacklist[] = {
 { PCI_DEVICE_SUB(PCI_VENDOR_ID_HP, 0x3306, PCI_VENDOR_ID_HP, 0x1979) }, /* auxilary iLO */
 { PCI_DEVICE_SUB(PCI_VENDOR_ID_HP, 0x3306, PCI_VENDOR_ID_HP_3PAR, 0x0289) },  /* CL */
 {0},   /* terminate list */
};

static struct watchdog_device hpwdt_dev;
/*
 * Watchdog operations
 */
static int hpwdt_hw_is_running(void)
{
 return ioread8(hpwdt_timer_con) & 0x01;
}

static int hpwdt_start(struct watchdog_device *wdd)
{
 int control = 0x81 | (pretimeout ? 0x4 : 0);
 int reload = SECS_TO_TICKS(min(wdd->timeout, wdd->max_hw_heartbeat_ms/1000));

 dev_dbg(wdd->parent, "start watchdog 0x%08x:0x%08x:0x%02x\n", wdd->timeout, reload, control);
 iowrite16(reload, hpwdt_timer_reg);
 iowrite8(control, hpwdt_timer_con);

 return 0;
}

static void hpwdt_stop(void)
{
 unsigned long data;

 pr_debug("stop watchdog\n");

 data = ioread8(hpwdt_timer_con);
 data &= 0xFE;
 iowrite8(data, hpwdt_timer_con);
}

static int hpwdt_stop_core(struct watchdog_device *wdd)
{
 hpwdt_stop();

 return 0;
}

static void hpwdt_ping_ticks(int val)
{
 val = min(val, HPWDT_MAX_TICKS);
 iowrite16(val, hpwdt_timer_reg);
}

static int hpwdt_ping(struct watchdog_device *wdd)
{
 int reload = SECS_TO_TICKS(min(wdd->timeout, wdd->max_hw_heartbeat_ms/1000));

 dev_dbg(wdd->parent, "ping watchdog 0x%08x:0x%08x\n", wdd->timeout, reload);
 hpwdt_ping_ticks(reload);

 return 0;
}

static unsigned int hpwdt_gettimeleft(struct watchdog_device *wdd)
{
 return TICKS_TO_SECS(ioread16(hpwdt_timer_reg));
}

static int hpwdt_settimeout(struct watchdog_device *wdd, unsigned int val)
{
 dev_dbg(wdd->parent, "set_timeout = %d\n", val);

 wdd->timeout = val;
 if (val <= wdd->pretimeout) {
  dev_dbg(wdd->parent, "pretimeout < timeout. Setting to zero\n");
  wdd->pretimeout = 0;
  pretimeout = false;
  if (watchdog_active(wdd))
   hpwdt_start(wdd);
 }
 hpwdt_ping(wdd);

 return 0;
}

#ifdef CONFIG_HPWDT_NMI_DECODING
static int hpwdt_set_pretimeout(struct watchdog_device *wdd, unsigned int req)
{
 unsigned int val = 0;

 dev_dbg(wdd->parent, "set_pretimeout = %d\n", req);
 if (req) {
  val = PRETIMEOUT_SEC;
  if (val >= wdd->timeout)
   return -EINVAL;
 }

 if (val != req)
  dev_dbg(wdd->parent, "Rounding pretimeout to: %d\n", val);

 wdd->pretimeout = val;
 pretimeout = !!val;

 if (watchdog_active(wdd))
  hpwdt_start(wdd);

 return 0;
}

static int hpwdt_my_nmi(void)
{
 return ioread8(hpwdt_nmistat) & 0x6;
}

/*
 * NMI Handler
 */
static int hpwdt_pretimeout(unsigned int ulReason, struct pt_regs *regs)
{
 unsigned int mynmi = hpwdt_my_nmi();
 static char panic_msg[] =
  "00: An NMI occurred. Depending on your system the reason "
  "for the NMI is logged in any one of the following resources:\n"
  "1. Integrated Management Log (IML)\n"
  "2. OA Syslog\n"
  "3. OA Forward Progress Log\n"
  "4. iLO Event Log";

 if (ulReason == NMI_UNKNOWN && !mynmi)
  return NMI_DONE;

 if (kdumptimeout < 0)
  hpwdt_stop();
 else if (kdumptimeout == 0)
  ;
 else {
  unsigned int val = max((unsigned int)kdumptimeout, hpwdt_dev.timeout);
  hpwdt_ping_ticks(SECS_TO_TICKS(val));
 }

 hex_byte_pack(panic_msg, mynmi);
 nmi_panic(regs, panic_msg);

 return NMI_HANDLED;
}
#endif /* CONFIG_HPWDT_NMI_DECODING */


static const struct watchdog_info ident = {
 .options = WDIOF_PRETIMEOUT    |
     WDIOF_SETTIMEOUT    |
     WDIOF_KEEPALIVEPING |
     WDIOF_MAGICCLOSE,
 .identity = "HPE iLO2+ HW Watchdog Timer",
};

/*
 * Kernel interfaces
 */

static const struct watchdog_ops hpwdt_ops = {
 .owner  = THIS_MODULE,
 .start  = hpwdt_start,
 .stop  = hpwdt_stop_core,
 .ping  = hpwdt_ping,
 .set_timeout = hpwdt_settimeout,
 .get_timeleft = hpwdt_gettimeleft,
#ifdef CONFIG_HPWDT_NMI_DECODING
 .set_pretimeout = hpwdt_set_pretimeout,
#endif
};

static struct watchdog_device hpwdt_dev = {
 .info  = &ident,
 .ops  = &hpwdt_ops,
 .min_timeout = 1,
 .timeout = DEFAULT_MARGIN,
 .pretimeout = PRETIMEOUT_SEC,
 .max_hw_heartbeat_ms = HPWDT_MAX_TIMER * 1000,
};


/*
 * Init & Exit
 */

static int hpwdt_init_nmi_decoding(struct pci_dev *dev)
{
#ifdef CONFIG_HPWDT_NMI_DECODING
 int retval;
 /*
 * Only one function can register for NMI_UNKNOWN
 */
 retval = register_nmi_handler(NMI_UNKNOWN, hpwdt_pretimeout, 0, "hpwdt");
 if (retval)
  goto error;
 retval = register_nmi_handler(NMI_SERR, hpwdt_pretimeout, 0, "hpwdt");
 if (retval)
  goto error1;
 retval = register_nmi_handler(NMI_IO_CHECK, hpwdt_pretimeout, 0, "hpwdt");
 if (retval)
  goto error2;

 dev_info(&dev->dev,
  "HPE Watchdog Timer Driver: NMI decoding initialized\n");

 return 0;

error2:
 unregister_nmi_handler(NMI_SERR, "hpwdt");
error1:
 unregister_nmi_handler(NMI_UNKNOWN, "hpwdt");
error:
 dev_warn(&dev->dev,
  "Unable to register a die notifier (err=%d).\n",
  retval);
 return retval;
#endif /* CONFIG_HPWDT_NMI_DECODING */
 return 0;
}

static void hpwdt_exit_nmi_decoding(void)
{
#ifdef CONFIG_HPWDT_NMI_DECODING
 unregister_nmi_handler(NMI_UNKNOWN, "hpwdt");
 unregister_nmi_handler(NMI_SERR, "hpwdt");
 unregister_nmi_handler(NMI_IO_CHECK, "hpwdt");
#endif
}

static int hpwdt_init_one(struct pci_dev *dev,
     const struct pci_device_id *ent)
{
 int retval;

 /*
 * First let's find out if we are on an iLO2+ server. We will
 * not run on a legacy ASM box.
 * So we only support the G5 ProLiant servers and higher.
 */
 if (dev->subsystem_vendor != PCI_VENDOR_ID_HP &&
     dev->subsystem_vendor != PCI_VENDOR_ID_HP_3PAR) {
  dev_warn(&dev->dev,
   "This server does not have an iLO2+ ASIC.\n");
  return -ENODEV;
 }

 if (pci_match_id(hpwdt_blacklist, dev)) {
  dev_dbg(&dev->dev, "Not supported on this device\n");
  return -ENODEV;
 }

 if (pci_enable_device(dev)) {
  dev_warn(&dev->dev,
   "Not possible to enable PCI Device: 0x%x:0x%x.\n",
   ent->vendor, ent->device);
  return -ENODEV;
 }

 pci_mem_addr = pci_iomap(dev, 1, 0x80);
 if (!pci_mem_addr) {
  dev_warn(&dev->dev,
   "Unable to detect the iLO2+ server memory.\n");
  retval = -ENOMEM;
  goto error_pci_iomap;
 }
 hpwdt_nmistat = pci_mem_addr + 0x6e;
 hpwdt_timer_reg = pci_mem_addr + 0x70;
 hpwdt_timer_con = pci_mem_addr + 0x72;

 /* Have the core update running timer until user space is ready */
 if (hpwdt_hw_is_running()) {
  dev_info(&dev->dev, "timer is running\n");
  set_bit(WDOG_HW_RUNNING, &hpwdt_dev.status);
 }

 /* Initialize NMI Decoding functionality */
 retval = hpwdt_init_nmi_decoding(dev);
 if (retval != 0)
  goto error_init_nmi_decoding;

 watchdog_stop_on_unregister(&hpwdt_dev);
 watchdog_set_nowayout(&hpwdt_dev, nowayout);
 watchdog_init_timeout(&hpwdt_dev, soft_margin, NULL);

 if (is_kdump_kernel()) {
  pretimeout = false;
  kdumptimeout = 0;
 }

 if (pretimeout && hpwdt_dev.timeout <= PRETIMEOUT_SEC) {
  dev_warn(&dev->dev, "timeout <= pretimeout. Setting pretimeout to zero\n");
  pretimeout = false;
 }
 hpwdt_dev.pretimeout = pretimeout ? PRETIMEOUT_SEC : 0;
 kdumptimeout = min(kdumptimeout, HPWDT_MAX_TIMER);

 hpwdt_dev.parent = &dev->dev;
 retval = watchdog_register_device(&hpwdt_dev);
 if (retval < 0)
  goto error_wd_register;

 dev_info(&dev->dev, "HPE Watchdog Timer Driver: Version: %s\n",
    HPWDT_VERSION);
 dev_info(&dev->dev, "timeout: %d seconds (nowayout=%d)\n",
    hpwdt_dev.timeout, nowayout);
 dev_info(&dev->dev, "pretimeout: %s.\n",
    pretimeout ? "on" : "off");
 dev_info(&dev->dev, "kdumptimeout: %d.\n", kdumptimeout);

 return 0;

error_wd_register:
 hpwdt_exit_nmi_decoding();
error_init_nmi_decoding:
 pci_iounmap(dev, pci_mem_addr);
error_pci_iomap:
 pci_disable_device(dev);
 return retval;
}

static void hpwdt_exit(struct pci_dev *dev)
{
 watchdog_unregister_device(&hpwdt_dev);
 hpwdt_exit_nmi_decoding();
 pci_iounmap(dev, pci_mem_addr);
 pci_disable_device(dev);
}

static int hpwdt_suspend(struct device *dev)
{
 if (watchdog_active(&hpwdt_dev))
  hpwdt_stop();

 return 0;
}

static int hpwdt_resume(struct device *dev)
{
 if (watchdog_active(&hpwdt_dev))
  hpwdt_start(&hpwdt_dev);

 return 0;
}

static const struct dev_pm_ops hpwdt_pm_ops = {
 LATE_SYSTEM_SLEEP_PM_OPS(hpwdt_suspend, hpwdt_resume)
};

static struct pci_driver hpwdt_driver = {
 .name = "hpwdt",
 .id_table = hpwdt_devices,
 .probe = hpwdt_init_one,
 .remove = hpwdt_exit,

 .driver = {
  .name = "hpwdt",
  .pm = &hpwdt_pm_ops,
 }
};

MODULE_AUTHOR("Tom Mingarelli");
MODULE_DESCRIPTION("hpe watchdog driver");
MODULE_LICENSE("GPL");
MODULE_VERSION(HPWDT_VERSION);

module_param(soft_margin, int, 0);
MODULE_PARM_DESC(soft_margin, "Watchdog timeout in seconds");

module_param_named(timeout, soft_margin, int, 0);
MODULE_PARM_DESC(timeout, "Alias of soft_margin");

module_param(nowayout, bool, 0);
MODULE_PARM_DESC(nowayout, "Watchdog cannot be stopped once started (default="
  __MODULE_STRING(WATCHDOG_NOWAYOUT) ")");

module_param(kdumptimeout, int, 0444);
MODULE_PARM_DESC(kdumptimeout, "Timeout applied for crash kernel transition in seconds");

#ifdef CONFIG_HPWDT_NMI_DECODING
module_param(pretimeout, bool, 0);
MODULE_PARM_DESC(pretimeout, "Watchdog pretimeout enabled");
#endif

module_pci_driver(hpwdt_driver);