diff options
Diffstat (limited to 'drivers/watchdog/intel_scu_watchdog.c')
| -rw-r--r-- | drivers/watchdog/intel_scu_watchdog.c | 533 |
1 files changed, 0 insertions, 533 deletions
diff --git a/drivers/watchdog/intel_scu_watchdog.c b/drivers/watchdog/intel_scu_watchdog.c deleted file mode 100644 index 804e35940983..000000000000 --- a/drivers/watchdog/intel_scu_watchdog.c +++ /dev/null @@ -1,533 +0,0 @@ -// SPDX-License-Identifier: GPL-2.0-only -/* - * Intel_SCU 0.2: An Intel SCU IOH Based Watchdog Device - * for Intel part #(s): - * - AF82MP20 PCH - * - * Copyright (C) 2009-2010 Intel Corporation. All rights reserved. - */ - -#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt - -#include <linux/compiler.h> -#include <linux/kernel.h> -#include <linux/moduleparam.h> -#include <linux/types.h> -#include <linux/miscdevice.h> -#include <linux/watchdog.h> -#include <linux/fs.h> -#include <linux/notifier.h> -#include <linux/reboot.h> -#include <linux/init.h> -#include <linux/jiffies.h> -#include <linux/uaccess.h> -#include <linux/slab.h> -#include <linux/io.h> -#include <linux/interrupt.h> -#include <linux/delay.h> -#include <linux/sched.h> -#include <linux/signal.h> -#include <linux/sfi.h> -#include <asm/irq.h> -#include <linux/atomic.h> -#include <asm/intel_scu_ipc.h> -#include <asm/apb_timer.h> -#include <asm/intel-mid.h> - -#include "intel_scu_watchdog.h" - -/* Bounds number of times we will retry loading time count */ -/* This retry is a work around for a silicon bug. */ -#define MAX_RETRY 16 - -#define IPC_SET_WATCHDOG_TIMER 0xF8 - -static int timer_margin = DEFAULT_SOFT_TO_HARD_MARGIN; -module_param(timer_margin, int, 0); -MODULE_PARM_DESC(timer_margin, - "Watchdog timer margin" - "Time between interrupt and resetting the system" - "The range is from 1 to 160" - "This is the time for all keep alives to arrive"); - -static int timer_set = DEFAULT_TIME; -module_param(timer_set, int, 0); -MODULE_PARM_DESC(timer_set, - "Default Watchdog timer setting" - "Complete cycle time" - "The range is from 1 to 170" - "This is the time for all keep alives to arrive"); - -/* After watchdog device is closed, check force_boot. If: - * force_boot == 0, then force boot on next watchdog interrupt after close, - * force_boot == 1, then force boot immediately when device is closed. - */ -static int force_boot; -module_param(force_boot, int, 0); -MODULE_PARM_DESC(force_boot, - "A value of 1 means that the driver will reboot" - "the system immediately if the /dev/watchdog device is closed" - "A value of 0 means that when /dev/watchdog device is closed" - "the watchdog timer will be refreshed for one more interval" - "of length: timer_set. At the end of this interval, the" - "watchdog timer will reset the system." - ); - -/* there is only one device in the system now; this can be made into - * an array in the future if we have more than one device */ - -static struct intel_scu_watchdog_dev watchdog_device; - -/* Forces restart, if force_reboot is set */ -static void watchdog_fire(void) -{ - if (force_boot) { - pr_crit("Initiating system reboot\n"); - emergency_restart(); - pr_crit("Reboot didn't ?????\n"); - } - - else { - pr_crit("Immediate Reboot Disabled\n"); - pr_crit("System will reset when watchdog timer times out!\n"); - } -} - -static int check_timer_margin(int new_margin) -{ - if ((new_margin < MIN_TIME_CYCLE) || - (new_margin > MAX_TIME - timer_set)) { - pr_debug("value of new_margin %d is out of the range %d to %d\n", - new_margin, MIN_TIME_CYCLE, MAX_TIME - timer_set); - return -EINVAL; - } - return 0; -} - -/* - * IPC operations - */ -static int watchdog_set_ipc(int soft_threshold, int threshold) -{ - u32 *ipc_wbuf; - u8 cbuf[16] = { '\0' }; - int ipc_ret = 0; - - ipc_wbuf = (u32 *)&cbuf; - ipc_wbuf[0] = soft_threshold; - ipc_wbuf[1] = threshold; - - ipc_ret = intel_scu_ipc_command( - IPC_SET_WATCHDOG_TIMER, - 0, - ipc_wbuf, - 2, - NULL, - 0); - - if (ipc_ret != 0) - pr_err("Error setting SCU watchdog timer: %x\n", ipc_ret); - - return ipc_ret; -}; - -/* - * Intel_SCU operations - */ - -/* timer interrupt handler */ -static irqreturn_t watchdog_timer_interrupt(int irq, void *dev_id) -{ - int int_status; - int_status = ioread32(watchdog_device.timer_interrupt_status_addr); - - pr_debug("irq, int_status: %x\n", int_status); - - if (int_status != 0) - return IRQ_NONE; - - /* has the timer been started? If not, then this is spurious */ - if (watchdog_device.timer_started == 0) { - pr_debug("spurious interrupt received\n"); - return IRQ_HANDLED; - } - - /* temporarily disable the timer */ - iowrite32(0x00000002, watchdog_device.timer_control_addr); - - /* set the timer to the threshold */ - iowrite32(watchdog_device.threshold, - watchdog_device.timer_load_count_addr); - - /* allow the timer to run */ - iowrite32(0x00000003, watchdog_device.timer_control_addr); - - return IRQ_HANDLED; -} - -static int intel_scu_keepalive(void) -{ - - /* read eoi register - clears interrupt */ - ioread32(watchdog_device.timer_clear_interrupt_addr); - - /* temporarily disable the timer */ - iowrite32(0x00000002, watchdog_device.timer_control_addr); - - /* set the timer to the soft_threshold */ - iowrite32(watchdog_device.soft_threshold, - watchdog_device.timer_load_count_addr); - - /* allow the timer to run */ - iowrite32(0x00000003, watchdog_device.timer_control_addr); - - return 0; -} - -static int intel_scu_stop(void) -{ - iowrite32(0, watchdog_device.timer_control_addr); - return 0; -} - -static int intel_scu_set_heartbeat(u32 t) -{ - int ipc_ret; - int retry_count; - u32 soft_value; - u32 hw_value; - - watchdog_device.timer_set = t; - watchdog_device.threshold = - timer_margin * watchdog_device.timer_tbl_ptr->freq_hz; - watchdog_device.soft_threshold = - (watchdog_device.timer_set - timer_margin) - * watchdog_device.timer_tbl_ptr->freq_hz; - - pr_debug("set_heartbeat: timer freq is %d\n", - watchdog_device.timer_tbl_ptr->freq_hz); - pr_debug("set_heartbeat: timer_set is %x (hex)\n", - watchdog_device.timer_set); - pr_debug("set_heartbeat: timer_margin is %x (hex)\n", timer_margin); - pr_debug("set_heartbeat: threshold is %x (hex)\n", - watchdog_device.threshold); - pr_debug("set_heartbeat: soft_threshold is %x (hex)\n", - watchdog_device.soft_threshold); - - /* Adjust thresholds by FREQ_ADJUSTMENT factor, to make the */ - /* watchdog timing come out right. */ - watchdog_device.threshold = - watchdog_device.threshold / FREQ_ADJUSTMENT; - watchdog_device.soft_threshold = - watchdog_device.soft_threshold / FREQ_ADJUSTMENT; - - /* temporarily disable the timer */ - iowrite32(0x00000002, watchdog_device.timer_control_addr); - - /* send the threshold and soft_threshold via IPC to the processor */ - ipc_ret = watchdog_set_ipc(watchdog_device.soft_threshold, - watchdog_device.threshold); - - if (ipc_ret != 0) { - /* Make sure the watchdog timer is stopped */ - intel_scu_stop(); - return ipc_ret; - } - - /* Soft Threshold set loop. Early versions of silicon did */ - /* not always set this count correctly. This loop checks */ - /* the value and retries if it was not set correctly. */ - - retry_count = 0; - soft_value = watchdog_device.soft_threshold & 0xFFFF0000; - do { - - /* Make sure timer is stopped */ - intel_scu_stop(); - - if (MAX_RETRY < retry_count++) { - /* Unable to set timer value */ - pr_err("Unable to set timer\n"); - return -ENODEV; - } - - /* set the timer to the soft threshold */ - iowrite32(watchdog_device.soft_threshold, - watchdog_device.timer_load_count_addr); - - /* read count value before starting timer */ - ioread32(watchdog_device.timer_load_count_addr); - - /* Start the timer */ - iowrite32(0x00000003, watchdog_device.timer_control_addr); - - /* read the value the time loaded into its count reg */ - hw_value = ioread32(watchdog_device.timer_load_count_addr); - hw_value = hw_value & 0xFFFF0000; - - - } while (soft_value != hw_value); - - watchdog_device.timer_started = 1; - - return 0; -} - -/* - * /dev/watchdog handling - */ - -static int intel_scu_open(struct inode *inode, struct file *file) -{ - - /* Set flag to indicate that watchdog device is open */ - if (test_and_set_bit(0, &watchdog_device.driver_open)) - return -EBUSY; - - /* Check for reopen of driver. Reopens are not allowed */ - if (watchdog_device.driver_closed) - return -EPERM; - - return stream_open(inode, file); -} - -static int intel_scu_release(struct inode *inode, struct file *file) -{ - /* - * This watchdog should not be closed, after the timer - * is started with the WDIPC_SETTIMEOUT ioctl - * If force_boot is set watchdog_fire() will cause an - * immediate reset. If force_boot is not set, the watchdog - * timer is refreshed for one more interval. At the end - * of that interval, the watchdog timer will reset the system. - */ - - if (!test_and_clear_bit(0, &watchdog_device.driver_open)) { - pr_debug("intel_scu_release, without open\n"); - return -ENOTTY; - } - - if (!watchdog_device.timer_started) { - /* Just close, since timer has not been started */ - pr_debug("closed, without starting timer\n"); - return 0; - } - - pr_crit("Unexpected close of /dev/watchdog!\n"); - - /* Since the timer was started, prevent future reopens */ - watchdog_device.driver_closed = 1; - - /* Refresh the timer for one more interval */ - intel_scu_keepalive(); - - /* Reboot system (if force_boot is set) */ - watchdog_fire(); - - /* We should only reach this point if force_boot is not set */ - return 0; -} - -static ssize_t intel_scu_write(struct file *file, - char const *data, - size_t len, - loff_t *ppos) -{ - - if (watchdog_device.timer_started) - /* Watchdog already started, keep it alive */ - intel_scu_keepalive(); - else - /* Start watchdog with timer value set by init */ - intel_scu_set_heartbeat(watchdog_device.timer_set); - - return len; -} - -static long intel_scu_ioctl(struct file *file, - unsigned int cmd, - unsigned long arg) -{ - void __user *argp = (void __user *)arg; - u32 __user *p = argp; - u32 new_margin; - - - static const struct watchdog_info ident = { - .options = WDIOF_SETTIMEOUT - | WDIOF_KEEPALIVEPING, - .firmware_version = 0, /* @todo Get from SCU via - ipc_get_scu_fw_version()? */ - .identity = "Intel_SCU IOH Watchdog" /* len < 32 */ - }; - - switch (cmd) { - case WDIOC_GETSUPPORT: - return copy_to_user(argp, - &ident, - sizeof(ident)) ? -EFAULT : 0; - case WDIOC_GETSTATUS: - case WDIOC_GETBOOTSTATUS: - return put_user(0, p); - case WDIOC_KEEPALIVE: - intel_scu_keepalive(); - - return 0; - case WDIOC_SETTIMEOUT: - if (get_user(new_margin, p)) - return -EFAULT; - - if (check_timer_margin(new_margin)) - return -EINVAL; - - if (intel_scu_set_heartbeat(new_margin)) - return -EINVAL; - return 0; - case WDIOC_GETTIMEOUT: - return put_user(watchdog_device.soft_threshold, p); - - default: - return -ENOTTY; - } -} - -/* - * Notifier for system down - */ -static int intel_scu_notify_sys(struct notifier_block *this, - unsigned long code, - void *another_unused) -{ - if (code == SYS_DOWN || code == SYS_HALT) - /* Turn off the watchdog timer. */ - intel_scu_stop(); - return NOTIFY_DONE; -} - -/* - * Kernel Interfaces - */ -static const struct file_operations intel_scu_fops = { - .owner = THIS_MODULE, - .llseek = no_llseek, - .write = intel_scu_write, - .unlocked_ioctl = intel_scu_ioctl, - .compat_ioctl = compat_ptr_ioctl, - .open = intel_scu_open, - .release = intel_scu_release, -}; - -static int __init intel_scu_watchdog_init(void) -{ - int ret; - u32 __iomem *tmp_addr; - - /* - * We don't really need to check this as the SFI timer get will fail - * but if we do so we can exit with a clearer reason and no noise. - * - * If it isn't an intel MID device then it doesn't have this watchdog - */ - if (!intel_mid_identify_cpu()) - return -ENODEV; - - /* Check boot parameters to verify that their initial values */ - /* are in range. */ - /* Check value of timer_set boot parameter */ - if ((timer_set < MIN_TIME_CYCLE) || - (timer_set > MAX_TIME - MIN_TIME_CYCLE)) { - pr_err("value of timer_set %x (hex) is out of range from %x to %x (hex)\n", - timer_set, MIN_TIME_CYCLE, MAX_TIME - MIN_TIME_CYCLE); - return -EINVAL; - } - - /* Check value of timer_margin boot parameter */ - if (check_timer_margin(timer_margin)) - return -EINVAL; - - watchdog_device.timer_tbl_ptr = sfi_get_mtmr(sfi_mtimer_num-1); - - if (watchdog_device.timer_tbl_ptr == NULL) { - pr_debug("timer is not available\n"); - return -ENODEV; - } - /* make sure the timer exists */ - if (watchdog_device.timer_tbl_ptr->phys_addr == 0) { - pr_debug("timer %d does not have valid physical memory\n", - sfi_mtimer_num); - return -ENODEV; - } - - if (watchdog_device.timer_tbl_ptr->irq == 0) { - pr_debug("timer %d invalid irq\n", sfi_mtimer_num); - return -ENODEV; - } - - tmp_addr = ioremap(watchdog_device.timer_tbl_ptr->phys_addr, - 20); - - if (tmp_addr == NULL) { - pr_debug("timer unable to ioremap\n"); - return -ENOMEM; - } - - watchdog_device.timer_load_count_addr = tmp_addr++; - watchdog_device.timer_current_value_addr = tmp_addr++; - watchdog_device.timer_control_addr = tmp_addr++; - watchdog_device.timer_clear_interrupt_addr = tmp_addr++; - watchdog_device.timer_interrupt_status_addr = tmp_addr++; - - /* Set the default time values in device structure */ - - watchdog_device.timer_set = timer_set; - watchdog_device.threshold = - timer_margin * watchdog_device.timer_tbl_ptr->freq_hz; - watchdog_device.soft_threshold = - (watchdog_device.timer_set - timer_margin) - * watchdog_device.timer_tbl_ptr->freq_hz; - - - watchdog_device.intel_scu_notifier.notifier_call = - intel_scu_notify_sys; - - ret = register_reboot_notifier(&watchdog_device.intel_scu_notifier); - if (ret) { - pr_err("cannot register notifier %d)\n", ret); - goto register_reboot_error; - } - - watchdog_device.miscdev.minor = WATCHDOG_MINOR; - watchdog_device.miscdev.name = "watchdog"; - watchdog_device.miscdev.fops = &intel_scu_fops; - - ret = misc_register(&watchdog_device.miscdev); - if (ret) { - pr_err("cannot register miscdev %d err =%d\n", - WATCHDOG_MINOR, ret); - goto misc_register_error; - } - - ret = request_irq((unsigned int)watchdog_device.timer_tbl_ptr->irq, - watchdog_timer_interrupt, - IRQF_SHARED, "watchdog", - &watchdog_device.timer_load_count_addr); - if (ret) { - pr_err("error requesting irq %d\n", ret); - goto request_irq_error; - } - /* Make sure timer is disabled before returning */ - intel_scu_stop(); - return 0; - -/* error cleanup */ - -request_irq_error: - misc_deregister(&watchdog_device.miscdev); -misc_register_error: - unregister_reboot_notifier(&watchdog_device.intel_scu_notifier); -register_reboot_error: - intel_scu_stop(); - iounmap(watchdog_device.timer_load_count_addr); - return ret; -} -late_initcall(intel_scu_watchdog_init); |