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
29 static const u8 mei_start_wd_params[] = { 0x02, 0x12, 0x13, 0x10 };
30 static const u8 mei_stop_wd_params[] = { 0x02, 0x02, 0x14, 0x10 };
31
32 const 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 */
44 const uuid_le mei_wd_guid = UUID_LE(0x05B79A6F, 0x4628, 0x4D7F, 0x89,
45 0x9D, 0xA9, 0x15, 0x14, 0xCB,
46 0x32, 0xAB);
47
mei_wd_set_start_timeout(struct mei_device * dev,u16 timeout)48 void 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 */
mei_wd_host_init(struct mei_device * dev)61 bool 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
92 end:
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 */
mei_wd_send(struct mei_device * dev)105 int 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 */
mei_wd_stop(struct mei_device * dev,bool preserve)137 int 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
190 out:
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 */
mei_wd_ops_start(struct watchdog_device * wd_dev)201 static 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;
226 end_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 */
mei_wd_ops_stop(struct watchdog_device * wd_dev)238 static 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 */
mei_wd_ops_ping(struct watchdog_device * wd_dev)260 static 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
300 end:
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 */
mei_wd_ops_set_timeout(struct watchdog_device * wd_dev,unsigned int timeout)313 static 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 */
338 static 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 };
345 static const struct watchdog_info wd_info = {
346 .identity = INTEL_AMT_WATCHDOG_ID,
347 .options = WDIOF_KEEPALIVEPING,
348 };
349
350 struct 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
mei_watchdog_register(struct mei_device * dev)359 void 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
mei_watchdog_unregister(struct mei_device * dev)374 void 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