| Author | Tokens | Token Proportion | Commits | Commit Proportion |
|---|---|---|---|---|
| Donald Johnson | 1612 | 97.05% | 1 | 10.00% |
| Joe Perches | 36 | 2.17% | 1 | 10.00% |
| Arnd Bergmann | 5 | 0.30% | 1 | 10.00% |
| Kuppuswamy Sathyanarayanan | 2 | 0.12% | 2 | 20.00% |
| Thomas Gleixner | 2 | 0.12% | 1 | 10.00% |
| Kirill Smelkov | 1 | 0.06% | 1 | 10.00% |
| Christoph Hellwig | 1 | 0.06% | 1 | 10.00% |
| Colin Ian King | 1 | 0.06% | 1 | 10.00% |
| Arun Sharma | 1 | 0.06% | 1 | 10.00% |
| Total | 1661 | 10 |
// 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);
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