1 /*
2 *
3 * Intel Management Engine Interface (Intel MEI) Linux driver
4 * Copyright (c) 2003-2012, 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 return mei_write_message(dev, mei_hdr, dev->wd_data, mei_hdr->length);
123 }
124
125 /**
126 * mei_wd_stop - sends watchdog stop message to fw.
127 *
128 * @dev: the device structure
129 * @preserve: indicate if to keep the timeout value
130 *
131 * returns 0 if success,
132 * -EIO when message send fails
133 * -EINVAL when invalid message is to be sent
134 */
mei_wd_stop(struct mei_device * dev,bool preserve)135 int mei_wd_stop(struct mei_device *dev, bool preserve)
136 {
137 int ret;
138 u16 wd_timeout = dev->wd_timeout;
139
140 cancel_delayed_work(&dev->timer_work);
141 if (dev->wd_cl.state != MEI_FILE_CONNECTED || !dev->wd_timeout)
142 return 0;
143
144 dev->wd_timeout = 0;
145 dev->wd_due_counter = 0;
146 memcpy(dev->wd_data, mei_stop_wd_params, MEI_WD_PARAMS_SIZE);
147 dev->stop = true;
148
149 ret = mei_flow_ctrl_creds(dev, &dev->wd_cl);
150 if (ret < 0)
151 goto out;
152
153 if (ret && dev->mei_host_buffer_is_empty) {
154 ret = 0;
155 dev->mei_host_buffer_is_empty = false;
156
157 if (!mei_wd_send(dev)) {
158 ret = mei_flow_ctrl_reduce(dev, &dev->wd_cl);
159 if (ret)
160 goto out;
161 } else {
162 dev_dbg(&dev->pdev->dev, "send stop WD failed\n");
163 }
164
165 dev->wd_pending = false;
166 } else {
167 dev->wd_pending = true;
168 }
169 dev->wd_stopped = false;
170 mutex_unlock(&dev->device_lock);
171
172 ret = wait_event_interruptible_timeout(dev->wait_stop_wd,
173 dev->wd_stopped, 10 * HZ);
174 mutex_lock(&dev->device_lock);
175 if (dev->wd_stopped) {
176 dev_dbg(&dev->pdev->dev, "stop wd complete ret=%d.\n", ret);
177 ret = 0;
178 } else {
179 if (!ret)
180 ret = -ETIMEDOUT;
181 dev_warn(&dev->pdev->dev,
182 "stop wd failed to complete ret=%d.\n", ret);
183 }
184
185 if (preserve)
186 dev->wd_timeout = wd_timeout;
187
188 out:
189 return ret;
190 }
191
192 /*
193 * mei_wd_ops_start - wd start command from the watchdog core.
194 *
195 * @wd_dev - watchdog device struct
196 *
197 * returns 0 if success, negative errno code for failure
198 */
mei_wd_ops_start(struct watchdog_device * wd_dev)199 static int mei_wd_ops_start(struct watchdog_device *wd_dev)
200 {
201 int err = -ENODEV;
202 struct mei_device *dev;
203
204 dev = pci_get_drvdata(mei_device);
205 if (!dev)
206 return -ENODEV;
207
208 mutex_lock(&dev->device_lock);
209
210 if (dev->mei_state != MEI_ENABLED) {
211 dev_dbg(&dev->pdev->dev, "mei_state != MEI_ENABLED mei_state= %d\n",
212 dev->mei_state);
213 goto end_unlock;
214 }
215
216 if (dev->wd_cl.state != MEI_FILE_CONNECTED) {
217 dev_dbg(&dev->pdev->dev, "MEI Driver is not connected to Watchdog Client\n");
218 goto end_unlock;
219 }
220
221 mei_wd_set_start_timeout(dev, dev->wd_timeout);
222
223 err = 0;
224 end_unlock:
225 mutex_unlock(&dev->device_lock);
226 return err;
227 }
228
229 /*
230 * mei_wd_ops_stop - wd stop command from the watchdog core.
231 *
232 * @wd_dev - watchdog device struct
233 *
234 * returns 0 if success, negative errno code for failure
235 */
mei_wd_ops_stop(struct watchdog_device * wd_dev)236 static int mei_wd_ops_stop(struct watchdog_device *wd_dev)
237 {
238 struct mei_device *dev;
239 dev = pci_get_drvdata(mei_device);
240
241 if (!dev)
242 return -ENODEV;
243
244 mutex_lock(&dev->device_lock);
245 mei_wd_stop(dev, false);
246 mutex_unlock(&dev->device_lock);
247
248 return 0;
249 }
250
251 /*
252 * mei_wd_ops_ping - wd ping command from the watchdog core.
253 *
254 * @wd_dev - watchdog device struct
255 *
256 * returns 0 if success, negative errno code for failure
257 */
mei_wd_ops_ping(struct watchdog_device * wd_dev)258 static int mei_wd_ops_ping(struct watchdog_device *wd_dev)
259 {
260 int ret = 0;
261 struct mei_device *dev;
262 dev = pci_get_drvdata(mei_device);
263
264 if (!dev)
265 return -ENODEV;
266
267 mutex_lock(&dev->device_lock);
268
269 if (dev->wd_cl.state != MEI_FILE_CONNECTED) {
270 dev_dbg(&dev->pdev->dev, "wd is not connected.\n");
271 ret = -ENODEV;
272 goto end;
273 }
274
275 /* Check if we can send the ping to HW*/
276 if (dev->mei_host_buffer_is_empty &&
277 mei_flow_ctrl_creds(dev, &dev->wd_cl) > 0) {
278
279 dev->mei_host_buffer_is_empty = false;
280 dev_dbg(&dev->pdev->dev, "sending watchdog ping\n");
281
282 if (mei_wd_send(dev)) {
283 dev_dbg(&dev->pdev->dev, "wd send failed.\n");
284 ret = -EIO;
285 goto end;
286 }
287
288 if (mei_flow_ctrl_reduce(dev, &dev->wd_cl)) {
289 dev_dbg(&dev->pdev->dev, "mei_flow_ctrl_reduce() failed.\n");
290 ret = -EIO;
291 goto end;
292 }
293
294 } else {
295 dev->wd_pending = true;
296 }
297
298 end:
299 mutex_unlock(&dev->device_lock);
300 return ret;
301 }
302
303 /*
304 * mei_wd_ops_set_timeout - wd set timeout command from the watchdog core.
305 *
306 * @wd_dev - watchdog device struct
307 * @timeout - timeout value to set
308 *
309 * returns 0 if success, negative errno code for failure
310 */
mei_wd_ops_set_timeout(struct watchdog_device * wd_dev,unsigned int timeout)311 static int mei_wd_ops_set_timeout(struct watchdog_device *wd_dev, unsigned int timeout)
312 {
313 struct mei_device *dev;
314 dev = pci_get_drvdata(mei_device);
315
316 if (!dev)
317 return -ENODEV;
318
319 /* Check Timeout value */
320 if (timeout < AMT_WD_MIN_TIMEOUT || timeout > AMT_WD_MAX_TIMEOUT)
321 return -EINVAL;
322
323 mutex_lock(&dev->device_lock);
324
325 dev->wd_timeout = timeout;
326 wd_dev->timeout = timeout;
327 mei_wd_set_start_timeout(dev, dev->wd_timeout);
328
329 mutex_unlock(&dev->device_lock);
330
331 return 0;
332 }
333
334 /*
335 * Watchdog Device structs
336 */
337 static const struct watchdog_ops wd_ops = {
338 .owner = THIS_MODULE,
339 .start = mei_wd_ops_start,
340 .stop = mei_wd_ops_stop,
341 .ping = mei_wd_ops_ping,
342 .set_timeout = mei_wd_ops_set_timeout,
343 };
344 static const struct watchdog_info wd_info = {
345 .identity = INTEL_AMT_WATCHDOG_ID,
346 .options = WDIOF_KEEPALIVEPING,
347 };
348
349 struct watchdog_device amt_wd_dev = {
350 .info = &wd_info,
351 .ops = &wd_ops,
352 .timeout = AMT_WD_DEFAULT_TIMEOUT,
353 .min_timeout = AMT_WD_MIN_TIMEOUT,
354 .max_timeout = AMT_WD_MAX_TIMEOUT,
355 };
356
357
mei_watchdog_register(struct mei_device * dev)358 void mei_watchdog_register(struct mei_device *dev)
359 {
360 dev_dbg(&dev->pdev->dev, "dev->wd_timeout =%d.\n", dev->wd_timeout);
361
362 dev->wd_due_counter = !!dev->wd_timeout;
363
364 if (watchdog_register_device(&amt_wd_dev)) {
365 dev_err(&dev->pdev->dev, "unable to register watchdog device.\n");
366 dev->wd_interface_reg = false;
367 } else {
368 dev_dbg(&dev->pdev->dev, "successfully register watchdog interface.\n");
369 dev->wd_interface_reg = true;
370 }
371 }
372
mei_watchdog_unregister(struct mei_device * dev)373 void mei_watchdog_unregister(struct mei_device *dev)
374 {
375 if (dev->wd_interface_reg)
376 watchdog_unregister_device(&amt_wd_dev);
377 dev->wd_interface_reg = false;
378 }
379
380