1/* 2 * 3 * Intel Management Engine Interface (Intel MEI) Linux driver 4 * Copyright (c) 2003-2011, Intel Corporation. 5 * 6 * This program is free software; you can redistribute it and/or modify it 7 * under the terms and conditions of the GNU General Public License, 8 * version 2, as published by the Free Software Foundation. 9 * 10 * This program is distributed in the hope it will be useful, but WITHOUT 11 * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or 12 * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License for 13 * more details. 14 * 15 */ 16#include <linux/kernel.h> 17#include <linux/module.h> 18#include <linux/moduleparam.h> 19#include <linux/device.h> 20#include <linux/pci.h> 21#include <linux/sched.h> 22#include <linux/watchdog.h> 23 24#include "mei_dev.h" 25#include "hw.h" 26#include "interface.h" 27#include "mei.h" 28 29static const u8 mei_start_wd_params[] = { 0x02, 0x12, 0x13, 0x10 }; 30static const u8 mei_stop_wd_params[] = { 0x02, 0x02, 0x14, 0x10 }; 31 32const u8 mei_wd_state_independence_msg[3][4] = { 33 {0x05, 0x02, 0x51, 0x10}, 34 {0x05, 0x02, 0x52, 0x10}, 35 {0x07, 0x02, 0x01, 0x10} 36}; 37 38/* 39 * AMT Watchdog Device 40 */ 41#define INTEL_AMT_WATCHDOG_ID "INTCAMT" 42 43/* UUIDs for AMT F/W clients */ 44const uuid_le mei_wd_guid = UUID_LE(0x05B79A6F, 0x4628, 0x4D7F, 0x89, 45 0x9D, 0xA9, 0x15, 0x14, 0xCB, 46 0x32, 0xAB); 47 48void mei_wd_set_start_timeout(struct mei_device *dev, u16 timeout) 49{ 50 dev_dbg(&dev->pdev->dev, "timeout=%d.\n", timeout); 51 memcpy(dev->wd_data, mei_start_wd_params, MEI_WD_PARAMS_SIZE); 52 memcpy(dev->wd_data + MEI_WD_PARAMS_SIZE, 53 &timeout, sizeof(u16)); 54} 55 56/** 57 * host_init_wd - mei initialization wd. 58 * 59 * @dev: the device structure 60 */ 61bool mei_wd_host_init(struct mei_device *dev) 62{ 63 bool ret = false; 64 65 mei_cl_init(&dev->wd_cl, dev); 66 67 /* look for WD client and connect to it */ 68 dev->wd_cl.state = MEI_FILE_DISCONNECTED; 69 dev->wd_timeout = AMT_WD_DEFAULT_TIMEOUT; 70 71 /* find ME WD client */ 72 mei_find_me_client_update_filext(dev, &dev->wd_cl, 73 &mei_wd_guid, MEI_WD_HOST_CLIENT_ID); 74 75 dev_dbg(&dev->pdev->dev, "check wd_cl\n"); 76 if (MEI_FILE_CONNECTING == dev->wd_cl.state) { 77 if (!mei_connect(dev, &dev->wd_cl)) { 78 dev_dbg(&dev->pdev->dev, "Failed to connect to WD client\n"); 79 dev->wd_cl.state = MEI_FILE_DISCONNECTED; 80 dev->wd_cl.host_client_id = 0; 81 ret = false; 82 goto end; 83 } else { 84 dev->wd_cl.timer_count = CONNECT_TIMEOUT; 85 } 86 } else { 87 dev_dbg(&dev->pdev->dev, "Failed to find WD client\n"); 88 ret = false; 89 goto end; 90 } 91 92end: 93 return ret; 94} 95 96/** 97 * mei_wd_send - sends watch dog message to fw. 98 * 99 * @dev: the device structure 100 * 101 * returns 0 if success, 102 * -EIO when message send fails 103 * -EINVAL when invalid message is to be sent 104 */ 105int mei_wd_send(struct mei_device *dev) 106{ 107 struct mei_msg_hdr *mei_hdr; 108 109 mei_hdr = (struct mei_msg_hdr *) &dev->wr_msg_buf[0]; 110 mei_hdr->host_addr = dev->wd_cl.host_client_id; 111 mei_hdr->me_addr = dev->wd_cl.me_client_id; 112 mei_hdr->msg_complete = 1; 113 mei_hdr->reserved = 0; 114 115 if (!memcmp(dev->wd_data, mei_start_wd_params, MEI_WD_PARAMS_SIZE)) 116 mei_hdr->length = MEI_START_WD_DATA_SIZE; 117 else if (!memcmp(dev->wd_data, mei_stop_wd_params, MEI_WD_PARAMS_SIZE)) 118 mei_hdr->length = MEI_WD_PARAMS_SIZE; 119 else 120 return -EINVAL; 121 122 if (mei_write_message(dev, mei_hdr, dev->wd_data, mei_hdr->length)) 123 return 0; 124 return -EIO; 125} 126 127/** 128 * mei_wd_stop - sends watchdog stop message to fw. 129 * 130 * @dev: the device structure 131 * @preserve: indicate if to keep the timeout value 132 * 133 * returns 0 if success, 134 * -EIO when message send fails 135 * -EINVAL when invalid message is to be sent 136 */ 137int mei_wd_stop(struct mei_device *dev, bool preserve) 138{ 139 int ret; 140 u16 wd_timeout = dev->wd_timeout; 141 142 cancel_delayed_work(&dev->timer_work); 143 if (dev->wd_cl.state != MEI_FILE_CONNECTED || !dev->wd_timeout) 144 return 0; 145 146 dev->wd_timeout = 0; 147 dev->wd_due_counter = 0; 148 memcpy(dev->wd_data, mei_stop_wd_params, MEI_WD_PARAMS_SIZE); 149 dev->stop = true; 150 151 ret = mei_flow_ctrl_creds(dev, &dev->wd_cl); 152 if (ret < 0) 153 goto out; 154 155 if (ret && dev->mei_host_buffer_is_empty) { 156 ret = 0; 157 dev->mei_host_buffer_is_empty = false; 158 159 if (!mei_wd_send(dev)) { 160 ret = mei_flow_ctrl_reduce(dev, &dev->wd_cl); 161 if (ret) 162 goto out; 163 } else { 164 dev_dbg(&dev->pdev->dev, "send stop WD failed\n"); 165 } 166 167 dev->wd_pending = false; 168 } else { 169 dev->wd_pending = true; 170 } 171 dev->wd_stopped = false; 172 mutex_unlock(&dev->device_lock); 173 174 ret = wait_event_interruptible_timeout(dev->wait_stop_wd, 175 dev->wd_stopped, 10 * HZ); 176 mutex_lock(&dev->device_lock); 177 if (dev->wd_stopped) { 178 dev_dbg(&dev->pdev->dev, "stop wd complete ret=%d.\n", ret); 179 ret = 0; 180 } else { 181 if (!ret) 182 ret = -ETIMEDOUT; 183 dev_warn(&dev->pdev->dev, 184 "stop wd failed to complete ret=%d.\n", ret); 185 } 186 187 if (preserve) 188 dev->wd_timeout = wd_timeout; 189 190out: 191 return ret; 192} 193 194/* 195 * mei_wd_ops_start - wd start command from the watchdog core. 196 * 197 * @wd_dev - watchdog device struct 198 * 199 * returns 0 if success, negative errno code for failure 200 */ 201static int mei_wd_ops_start(struct watchdog_device *wd_dev) 202{ 203 int err = -ENODEV; 204 struct mei_device *dev; 205 206 dev = pci_get_drvdata(mei_device); 207 if (!dev) 208 return -ENODEV; 209 210 mutex_lock(&dev->device_lock); 211 212 if (dev->mei_state != MEI_ENABLED) { 213 dev_dbg(&dev->pdev->dev, "mei_state != MEI_ENABLED mei_state= %d\n", 214 dev->mei_state); 215 goto end_unlock; 216 } 217 218 if (dev->wd_cl.state != MEI_FILE_CONNECTED) { 219 dev_dbg(&dev->pdev->dev, "MEI Driver is not connected to Watchdog Client\n"); 220 goto end_unlock; 221 } 222 223 mei_wd_set_start_timeout(dev, dev->wd_timeout); 224 225 err = 0; 226end_unlock: 227 mutex_unlock(&dev->device_lock); 228 return err; 229} 230 231/* 232 * mei_wd_ops_stop - wd stop command from the watchdog core. 233 * 234 * @wd_dev - watchdog device struct 235 * 236 * returns 0 if success, negative errno code for failure 237 */ 238static int mei_wd_ops_stop(struct watchdog_device *wd_dev) 239{ 240 struct mei_device *dev; 241 dev = pci_get_drvdata(mei_device); 242 243 if (!dev) 244 return -ENODEV; 245 246 mutex_lock(&dev->device_lock); 247 mei_wd_stop(dev, false); 248 mutex_unlock(&dev->device_lock); 249 250 return 0; 251} 252 253/* 254 * mei_wd_ops_ping - wd ping command from the watchdog core. 255 * 256 * @wd_dev - watchdog device struct 257 * 258 * returns 0 if success, negative errno code for failure 259 */ 260static int mei_wd_ops_ping(struct watchdog_device *wd_dev) 261{ 262 int ret = 0; 263 struct mei_device *dev; 264 dev = pci_get_drvdata(mei_device); 265 266 if (!dev) 267 return -ENODEV; 268 269 mutex_lock(&dev->device_lock); 270 271 if (dev->wd_cl.state != MEI_FILE_CONNECTED) { 272 dev_dbg(&dev->pdev->dev, "wd is not connected.\n"); 273 ret = -ENODEV; 274 goto end; 275 } 276 277 /* Check if we can send the ping to HW*/ 278 if (dev->mei_host_buffer_is_empty && 279 mei_flow_ctrl_creds(dev, &dev->wd_cl) > 0) { 280 281 dev->mei_host_buffer_is_empty = false; 282 dev_dbg(&dev->pdev->dev, "sending watchdog ping\n"); 283 284 if (mei_wd_send(dev)) { 285 dev_dbg(&dev->pdev->dev, "wd send failed.\n"); 286 ret = -EIO; 287 goto end; 288 } 289 290 if (mei_flow_ctrl_reduce(dev, &dev->wd_cl)) { 291 dev_dbg(&dev->pdev->dev, "mei_flow_ctrl_reduce() failed.\n"); 292 ret = -EIO; 293 goto end; 294 } 295 296 } else { 297 dev->wd_pending = true; 298 } 299 300end: 301 mutex_unlock(&dev->device_lock); 302 return ret; 303} 304 305/* 306 * mei_wd_ops_set_timeout - wd set timeout command from the watchdog core. 307 * 308 * @wd_dev - watchdog device struct 309 * @timeout - timeout value to set 310 * 311 * returns 0 if success, negative errno code for failure 312 */ 313static int mei_wd_ops_set_timeout(struct watchdog_device *wd_dev, unsigned int timeout) 314{ 315 struct mei_device *dev; 316 dev = pci_get_drvdata(mei_device); 317 318 if (!dev) 319 return -ENODEV; 320 321 /* Check Timeout value */ 322 if (timeout < AMT_WD_MIN_TIMEOUT || timeout > AMT_WD_MAX_TIMEOUT) 323 return -EINVAL; 324 325 mutex_lock(&dev->device_lock); 326 327 dev->wd_timeout = timeout; 328 mei_wd_set_start_timeout(dev, dev->wd_timeout); 329 330 mutex_unlock(&dev->device_lock); 331 332 return 0; 333} 334 335/* 336 * Watchdog Device structs 337 */ 338static const struct watchdog_ops wd_ops = { 339 .owner = THIS_MODULE, 340 .start = mei_wd_ops_start, 341 .stop = mei_wd_ops_stop, 342 .ping = mei_wd_ops_ping, 343 .set_timeout = mei_wd_ops_set_timeout, 344}; 345static const struct watchdog_info wd_info = { 346 .identity = INTEL_AMT_WATCHDOG_ID, 347 .options = WDIOF_KEEPALIVEPING, 348}; 349 350struct watchdog_device amt_wd_dev = { 351 .info = &wd_info, 352 .ops = &wd_ops, 353 .timeout = AMT_WD_DEFAULT_TIMEOUT, 354 .min_timeout = AMT_WD_MIN_TIMEOUT, 355 .max_timeout = AMT_WD_MAX_TIMEOUT, 356}; 357 358 359void mei_watchdog_register(struct mei_device *dev) 360{ 361 dev_dbg(&dev->pdev->dev, "dev->wd_timeout =%d.\n", dev->wd_timeout); 362 363 dev->wd_due_counter = !!dev->wd_timeout; 364 365 if (watchdog_register_device(&amt_wd_dev)) { 366 dev_err(&dev->pdev->dev, "unable to register watchdog device.\n"); 367 dev->wd_interface_reg = false; 368 } else { 369 dev_dbg(&dev->pdev->dev, "successfully register watchdog interface.\n"); 370 dev->wd_interface_reg = true; 371 } 372} 373 374void mei_watchdog_unregister(struct mei_device *dev) 375{ 376 if (dev->wd_interface_reg) 377 watchdog_unregister_device(&amt_wd_dev); 378 dev->wd_interface_reg = false; 379} 380 381