| .. | .. |
|---|
| 1 | +// SPDX-License-Identifier: GPL-2.0+ |
|---|
| 1 | 2 | /* |
|---|
| 2 | 3 | * watchdog_core.c |
|---|
| 3 | 4 | * |
|---|
| .. | .. |
|---|
| 15 | 16 | * Rusty Lynch <rusty@linux.co.intel.com> |
|---|
| 16 | 17 | * Satyam Sharma <satyam@infradead.org> |
|---|
| 17 | 18 | * Randy Dunlap <randy.dunlap@oracle.com> |
|---|
| 18 | | - * |
|---|
| 19 | | - * This program is free software; you can redistribute it and/or |
|---|
| 20 | | - * modify it under the terms of the GNU General Public License |
|---|
| 21 | | - * as published by the Free Software Foundation; either version |
|---|
| 22 | | - * 2 of the License, or (at your option) any later version. |
|---|
| 23 | 19 | * |
|---|
| 24 | 20 | * Neither Alan Cox, CymruNet Ltd., Wim Van Sebroeck nor Iguana vzw. |
|---|
| 25 | 21 | * admit liability nor provide warranty for any of this software. |
|---|
| .. | .. |
|---|
| 43 | 39 | |
|---|
| 44 | 40 | static DEFINE_IDA(watchdog_ida); |
|---|
| 45 | 41 | |
|---|
| 42 | +static int stop_on_reboot = -1; |
|---|
| 43 | +module_param(stop_on_reboot, int, 0444); |
|---|
| 44 | +MODULE_PARM_DESC(stop_on_reboot, "Stop watchdogs on reboot (0=keep watching, 1=stop)"); |
|---|
| 45 | + |
|---|
| 46 | 46 | /* |
|---|
| 47 | 47 | * Deferred Registration infrastructure. |
|---|
| 48 | 48 | * |
|---|
| .. | .. |
|---|
| 60 | 60 | static LIST_HEAD(wtd_deferred_reg_list); |
|---|
| 61 | 61 | static bool wtd_deferred_reg_done; |
|---|
| 62 | 62 | |
|---|
| 63 | | -static int watchdog_deferred_registration_add(struct watchdog_device *wdd) |
|---|
| 63 | +static void watchdog_deferred_registration_add(struct watchdog_device *wdd) |
|---|
| 64 | 64 | { |
|---|
| 65 | 65 | list_add_tail(&wdd->deferred, |
|---|
| 66 | 66 | &wtd_deferred_reg_list); |
|---|
| 67 | | - return 0; |
|---|
| 68 | 67 | } |
|---|
| 69 | 68 | |
|---|
| 70 | 69 | static void watchdog_deferred_registration_del(struct watchdog_device *wdd) |
|---|
| .. | .. |
|---|
| 105 | 104 | * timeout module parameter (if it is valid value) or the timeout-sec property |
|---|
| 106 | 105 | * (only if it is a valid value and the timeout_parm is out of bounds). |
|---|
| 107 | 106 | * If none of them are valid then we keep the old value (which should normally |
|---|
| 108 | | - * be the default timeout value). |
|---|
| 107 | + * be the default timeout value). Note that for the module parameter, '0' means |
|---|
| 108 | + * 'use default' while it is an invalid value for the timeout-sec property. |
|---|
| 109 | + * It should simply be dropped if you want to use the default value then. |
|---|
| 109 | 110 | * |
|---|
| 110 | | - * A zero is returned on success and -EINVAL for failure. |
|---|
| 111 | + * A zero is returned on success or -EINVAL if all provided values are out of |
|---|
| 112 | + * bounds. |
|---|
| 111 | 113 | */ |
|---|
| 112 | 114 | int watchdog_init_timeout(struct watchdog_device *wdd, |
|---|
| 113 | 115 | unsigned int timeout_parm, struct device *dev) |
|---|
| 114 | 116 | { |
|---|
| 117 | + const char *dev_str = wdd->parent ? dev_name(wdd->parent) : |
|---|
| 118 | + (const char *)wdd->info->identity; |
|---|
| 115 | 119 | unsigned int t = 0; |
|---|
| 116 | 120 | int ret = 0; |
|---|
| 117 | 121 | |
|---|
| 118 | 122 | watchdog_check_min_max_timeout(wdd); |
|---|
| 119 | 123 | |
|---|
| 120 | | - /* try to get the timeout module parameter first */ |
|---|
| 121 | | - if (!watchdog_timeout_invalid(wdd, timeout_parm) && timeout_parm) { |
|---|
| 122 | | - wdd->timeout = timeout_parm; |
|---|
| 123 | | - return ret; |
|---|
| 124 | | - } |
|---|
| 125 | | - if (timeout_parm) |
|---|
| 124 | + /* check the driver supplied value (likely a module parameter) first */ |
|---|
| 125 | + if (timeout_parm) { |
|---|
| 126 | + if (!watchdog_timeout_invalid(wdd, timeout_parm)) { |
|---|
| 127 | + wdd->timeout = timeout_parm; |
|---|
| 128 | + return 0; |
|---|
| 129 | + } |
|---|
| 130 | + pr_err("%s: driver supplied timeout (%u) out of range\n", |
|---|
| 131 | + dev_str, timeout_parm); |
|---|
| 126 | 132 | ret = -EINVAL; |
|---|
| 133 | + } |
|---|
| 127 | 134 | |
|---|
| 128 | 135 | /* try to get the timeout_sec property */ |
|---|
| 129 | | - if (dev == NULL || dev->of_node == NULL) |
|---|
| 130 | | - return ret; |
|---|
| 131 | | - of_property_read_u32(dev->of_node, "timeout-sec", &t); |
|---|
| 132 | | - if (!watchdog_timeout_invalid(wdd, t) && t) |
|---|
| 133 | | - wdd->timeout = t; |
|---|
| 134 | | - else |
|---|
| 136 | + if (dev && dev->of_node && |
|---|
| 137 | + of_property_read_u32(dev->of_node, "timeout-sec", &t) == 0) { |
|---|
| 138 | + if (t && !watchdog_timeout_invalid(wdd, t)) { |
|---|
| 139 | + wdd->timeout = t; |
|---|
| 140 | + return 0; |
|---|
| 141 | + } |
|---|
| 142 | + pr_err("%s: DT supplied timeout (%u) out of range\n", dev_str, t); |
|---|
| 135 | 143 | ret = -EINVAL; |
|---|
| 144 | + } |
|---|
| 145 | + |
|---|
| 146 | + if (ret < 0 && wdd->timeout) |
|---|
| 147 | + pr_warn("%s: falling back to default timeout (%u)\n", dev_str, |
|---|
| 148 | + wdd->timeout); |
|---|
| 136 | 149 | |
|---|
| 137 | 150 | return ret; |
|---|
| 138 | 151 | } |
|---|
| .. | .. |
|---|
| 245 | 258 | } |
|---|
| 246 | 259 | } |
|---|
| 247 | 260 | |
|---|
| 261 | + /* Module parameter to force watchdog policy on reboot. */ |
|---|
| 262 | + if (stop_on_reboot != -1) { |
|---|
| 263 | + if (stop_on_reboot) |
|---|
| 264 | + set_bit(WDOG_STOP_ON_REBOOT, &wdd->status); |
|---|
| 265 | + else |
|---|
| 266 | + clear_bit(WDOG_STOP_ON_REBOOT, &wdd->status); |
|---|
| 267 | + } |
|---|
| 268 | + |
|---|
| 248 | 269 | if (test_bit(WDOG_STOP_ON_REBOOT, &wdd->status)) { |
|---|
| 249 | 270 | if (!wdd->ops->stop) |
|---|
| 250 | 271 | pr_warn("watchdog%d: stop_on_reboot not supported\n", wdd->id); |
|---|
| .. | .. |
|---|
| 287 | 308 | |
|---|
| 288 | 309 | int watchdog_register_device(struct watchdog_device *wdd) |
|---|
| 289 | 310 | { |
|---|
| 290 | | - int ret; |
|---|
| 311 | + const char *dev_str; |
|---|
| 312 | + int ret = 0; |
|---|
| 291 | 313 | |
|---|
| 292 | 314 | mutex_lock(&wtd_deferred_reg_mutex); |
|---|
| 293 | 315 | if (wtd_deferred_reg_done) |
|---|
| 294 | 316 | ret = __watchdog_register_device(wdd); |
|---|
| 295 | 317 | else |
|---|
| 296 | | - ret = watchdog_deferred_registration_add(wdd); |
|---|
| 318 | + watchdog_deferred_registration_add(wdd); |
|---|
| 297 | 319 | mutex_unlock(&wtd_deferred_reg_mutex); |
|---|
| 320 | + |
|---|
| 321 | + if (ret) { |
|---|
| 322 | + dev_str = wdd->parent ? dev_name(wdd->parent) : |
|---|
| 323 | + (const char *)wdd->info->identity; |
|---|
| 324 | + pr_err("%s: failed to register watchdog device (err = %d)\n", |
|---|
| 325 | + dev_str, ret); |
|---|
| 326 | + } |
|---|
| 327 | + |
|---|
| 298 | 328 | return ret; |
|---|
| 299 | 329 | } |
|---|
| 300 | 330 | EXPORT_SYMBOL_GPL(watchdog_register_device); |
|---|