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
17 #include <linux/export.h>
18 #include <linux/sched.h>
19 #include <linux/wait.h>
20 #include <linux/delay.h>
21
22 #include <linux/mei.h>
23
24 #include "mei_dev.h"
25 #include "hbm.h"
26 #include "client.h"
27
mei_dev_state_str(int state)28 const char *mei_dev_state_str(int state)
29 {
30 #define MEI_DEV_STATE(state) case MEI_DEV_##state: return #state
31 switch (state) {
32 MEI_DEV_STATE(INITIALIZING);
33 MEI_DEV_STATE(INIT_CLIENTS);
34 MEI_DEV_STATE(ENABLED);
35 MEI_DEV_STATE(RESETTING);
36 MEI_DEV_STATE(DISABLED);
37 MEI_DEV_STATE(POWER_DOWN);
38 MEI_DEV_STATE(POWER_UP);
39 default:
40 return "unknown";
41 }
42 #undef MEI_DEV_STATE
43 }
44
mei_pg_state_str(enum mei_pg_state state)45 const char *mei_pg_state_str(enum mei_pg_state state)
46 {
47 #define MEI_PG_STATE(state) case MEI_PG_##state: return #state
48 switch (state) {
49 MEI_PG_STATE(OFF);
50 MEI_PG_STATE(ON);
51 default:
52 return "unknown";
53 }
54 #undef MEI_PG_STATE
55 }
56
57
58 /**
59 * mei_cancel_work - Cancel mei background jobs
60 *
61 * @dev: the device structure
62 */
mei_cancel_work(struct mei_device * dev)63 void mei_cancel_work(struct mei_device *dev)
64 {
65 cancel_work_sync(&dev->init_work);
66 cancel_work_sync(&dev->reset_work);
67
68 cancel_delayed_work(&dev->timer_work);
69 }
70 EXPORT_SYMBOL_GPL(mei_cancel_work);
71
72 /**
73 * mei_reset - resets host and fw.
74 *
75 * @dev: the device structure
76 *
77 * Return: 0 on success or < 0 if the reset hasn't succeeded
78 */
mei_reset(struct mei_device * dev)79 int mei_reset(struct mei_device *dev)
80 {
81 enum mei_dev_state state = dev->dev_state;
82 bool interrupts_enabled;
83 int ret;
84
85 if (state != MEI_DEV_INITIALIZING &&
86 state != MEI_DEV_DISABLED &&
87 state != MEI_DEV_POWER_DOWN &&
88 state != MEI_DEV_POWER_UP) {
89 struct mei_fw_status fw_status;
90
91 mei_fw_status(dev, &fw_status);
92 dev_warn(dev->dev,
93 "unexpected reset: dev_state = %s " FW_STS_FMT "\n",
94 mei_dev_state_str(state), FW_STS_PRM(fw_status));
95 }
96
97 /* we're already in reset, cancel the init timer
98 * if the reset was called due the hbm protocol error
99 * we need to call it before hw start
100 * so the hbm watchdog won't kick in
101 */
102 mei_hbm_idle(dev);
103
104 /* enter reset flow */
105 interrupts_enabled = state != MEI_DEV_POWER_DOWN;
106 dev->dev_state = MEI_DEV_RESETTING;
107
108 dev->reset_count++;
109 if (dev->reset_count > MEI_MAX_CONSEC_RESET) {
110 dev_err(dev->dev, "reset: reached maximal consecutive resets: disabling the device\n");
111 dev->dev_state = MEI_DEV_DISABLED;
112 return -ENODEV;
113 }
114
115 ret = mei_hw_reset(dev, interrupts_enabled);
116 /* fall through and remove the sw state even if hw reset has failed */
117
118 /* no need to clean up software state in case of power up */
119 if (state != MEI_DEV_INITIALIZING &&
120 state != MEI_DEV_POWER_UP) {
121
122 /* remove all waiting requests */
123 mei_cl_all_write_clear(dev);
124
125 mei_cl_all_disconnect(dev);
126
127 /* wake up all readers and writers so they can be interrupted */
128 mei_cl_all_wakeup(dev);
129
130 /* remove entry if already in list */
131 dev_dbg(dev->dev, "remove iamthif and wd from the file list.\n");
132 mei_cl_unlink(&dev->wd_cl);
133 mei_cl_unlink(&dev->iamthif_cl);
134 mei_amthif_reset_params(dev);
135 }
136
137 mei_hbm_reset(dev);
138
139 dev->rd_msg_hdr = 0;
140 dev->wd_pending = false;
141
142 if (ret) {
143 dev_err(dev->dev, "hw_reset failed ret = %d\n", ret);
144 return ret;
145 }
146
147 if (state == MEI_DEV_POWER_DOWN) {
148 dev_dbg(dev->dev, "powering down: end of reset\n");
149 dev->dev_state = MEI_DEV_DISABLED;
150 return 0;
151 }
152
153 ret = mei_hw_start(dev);
154 if (ret) {
155 dev_err(dev->dev, "hw_start failed ret = %d\n", ret);
156 return ret;
157 }
158
159 dev_dbg(dev->dev, "link is established start sending messages.\n");
160
161 dev->dev_state = MEI_DEV_INIT_CLIENTS;
162 ret = mei_hbm_start_req(dev);
163 if (ret) {
164 dev_err(dev->dev, "hbm_start failed ret = %d\n", ret);
165 dev->dev_state = MEI_DEV_RESETTING;
166 return ret;
167 }
168
169 return 0;
170 }
171 EXPORT_SYMBOL_GPL(mei_reset);
172
173 /**
174 * mei_start - initializes host and fw to start work.
175 *
176 * @dev: the device structure
177 *
178 * Return: 0 on success, <0 on failure.
179 */
mei_start(struct mei_device * dev)180 int mei_start(struct mei_device *dev)
181 {
182 int ret;
183
184 mutex_lock(&dev->device_lock);
185
186 /* acknowledge interrupt and stop interrupts */
187 mei_clear_interrupts(dev);
188
189 mei_hw_config(dev);
190
191 dev_dbg(dev->dev, "reset in start the mei device.\n");
192
193 dev->reset_count = 0;
194 do {
195 dev->dev_state = MEI_DEV_INITIALIZING;
196 ret = mei_reset(dev);
197
198 if (ret == -ENODEV || dev->dev_state == MEI_DEV_DISABLED) {
199 dev_err(dev->dev, "reset failed ret = %d", ret);
200 goto err;
201 }
202 } while (ret);
203
204 /* we cannot start the device w/o hbm start message completed */
205 if (dev->dev_state == MEI_DEV_DISABLED) {
206 dev_err(dev->dev, "reset failed");
207 goto err;
208 }
209
210 if (mei_hbm_start_wait(dev)) {
211 dev_err(dev->dev, "HBM haven't started");
212 goto err;
213 }
214
215 if (!mei_host_is_ready(dev)) {
216 dev_err(dev->dev, "host is not ready.\n");
217 goto err;
218 }
219
220 if (!mei_hw_is_ready(dev)) {
221 dev_err(dev->dev, "ME is not ready.\n");
222 goto err;
223 }
224
225 if (!mei_hbm_version_is_supported(dev)) {
226 dev_dbg(dev->dev, "MEI start failed.\n");
227 goto err;
228 }
229
230 dev_dbg(dev->dev, "link layer has been established.\n");
231
232 mutex_unlock(&dev->device_lock);
233 return 0;
234 err:
235 dev_err(dev->dev, "link layer initialization failed.\n");
236 dev->dev_state = MEI_DEV_DISABLED;
237 mutex_unlock(&dev->device_lock);
238 return -ENODEV;
239 }
240 EXPORT_SYMBOL_GPL(mei_start);
241
242 /**
243 * mei_restart - restart device after suspend
244 *
245 * @dev: the device structure
246 *
247 * Return: 0 on success or -ENODEV if the restart hasn't succeeded
248 */
mei_restart(struct mei_device * dev)249 int mei_restart(struct mei_device *dev)
250 {
251 int err;
252
253 mutex_lock(&dev->device_lock);
254
255 mei_clear_interrupts(dev);
256
257 dev->dev_state = MEI_DEV_POWER_UP;
258 dev->reset_count = 0;
259
260 err = mei_reset(dev);
261
262 mutex_unlock(&dev->device_lock);
263
264 if (err == -ENODEV || dev->dev_state == MEI_DEV_DISABLED) {
265 dev_err(dev->dev, "device disabled = %d\n", err);
266 return -ENODEV;
267 }
268
269 /* try to start again */
270 if (err)
271 schedule_work(&dev->reset_work);
272
273
274 return 0;
275 }
276 EXPORT_SYMBOL_GPL(mei_restart);
277
mei_reset_work(struct work_struct * work)278 static void mei_reset_work(struct work_struct *work)
279 {
280 struct mei_device *dev =
281 container_of(work, struct mei_device, reset_work);
282 int ret;
283
284 mutex_lock(&dev->device_lock);
285
286 ret = mei_reset(dev);
287
288 mutex_unlock(&dev->device_lock);
289
290 if (dev->dev_state == MEI_DEV_DISABLED) {
291 dev_err(dev->dev, "device disabled = %d\n", ret);
292 return;
293 }
294
295 /* retry reset in case of failure */
296 if (ret)
297 schedule_work(&dev->reset_work);
298 }
299
mei_stop(struct mei_device * dev)300 void mei_stop(struct mei_device *dev)
301 {
302 dev_dbg(dev->dev, "stopping the device.\n");
303
304 mei_cancel_work(dev);
305
306 mei_nfc_host_exit(dev);
307
308 mei_cl_bus_remove_devices(dev);
309
310 mutex_lock(&dev->device_lock);
311
312 mei_wd_stop(dev);
313
314 dev->dev_state = MEI_DEV_POWER_DOWN;
315 mei_reset(dev);
316 /* move device to disabled state unconditionally */
317 dev->dev_state = MEI_DEV_DISABLED;
318
319 mutex_unlock(&dev->device_lock);
320
321 mei_watchdog_unregister(dev);
322 }
323 EXPORT_SYMBOL_GPL(mei_stop);
324
325 /**
326 * mei_write_is_idle - check if the write queues are idle
327 *
328 * @dev: the device structure
329 *
330 * Return: true of there is no pending write
331 */
mei_write_is_idle(struct mei_device * dev)332 bool mei_write_is_idle(struct mei_device *dev)
333 {
334 bool idle = (dev->dev_state == MEI_DEV_ENABLED &&
335 list_empty(&dev->ctrl_wr_list.list) &&
336 list_empty(&dev->write_list.list));
337
338 dev_dbg(dev->dev, "write pg: is idle[%d] state=%s ctrl=%d write=%d\n",
339 idle,
340 mei_dev_state_str(dev->dev_state),
341 list_empty(&dev->ctrl_wr_list.list),
342 list_empty(&dev->write_list.list));
343
344 return idle;
345 }
346 EXPORT_SYMBOL_GPL(mei_write_is_idle);
347
348 /**
349 * mei_device_init -- initialize mei_device structure
350 *
351 * @dev: the mei device
352 * @device: the device structure
353 * @hw_ops: hw operations
354 */
mei_device_init(struct mei_device * dev,struct device * device,const struct mei_hw_ops * hw_ops)355 void mei_device_init(struct mei_device *dev,
356 struct device *device,
357 const struct mei_hw_ops *hw_ops)
358 {
359 /* setup our list array */
360 INIT_LIST_HEAD(&dev->file_list);
361 INIT_LIST_HEAD(&dev->device_list);
362 INIT_LIST_HEAD(&dev->me_clients);
363 mutex_init(&dev->device_lock);
364 init_waitqueue_head(&dev->wait_hw_ready);
365 init_waitqueue_head(&dev->wait_pg);
366 init_waitqueue_head(&dev->wait_hbm_start);
367 init_waitqueue_head(&dev->wait_stop_wd);
368 dev->dev_state = MEI_DEV_INITIALIZING;
369 dev->reset_count = 0;
370
371 mei_io_list_init(&dev->read_list);
372 mei_io_list_init(&dev->write_list);
373 mei_io_list_init(&dev->write_waiting_list);
374 mei_io_list_init(&dev->ctrl_wr_list);
375 mei_io_list_init(&dev->ctrl_rd_list);
376
377 INIT_DELAYED_WORK(&dev->timer_work, mei_timer);
378 INIT_WORK(&dev->init_work, mei_host_client_init);
379 INIT_WORK(&dev->reset_work, mei_reset_work);
380
381 INIT_LIST_HEAD(&dev->wd_cl.link);
382 INIT_LIST_HEAD(&dev->iamthif_cl.link);
383 mei_io_list_init(&dev->amthif_cmd_list);
384 mei_io_list_init(&dev->amthif_rd_complete_list);
385
386 bitmap_zero(dev->host_clients_map, MEI_CLIENTS_MAX);
387 dev->open_handle_count = 0;
388
389 /*
390 * Reserving the first client ID
391 * 0: Reserved for MEI Bus Message communications
392 */
393 bitmap_set(dev->host_clients_map, 0, 1);
394
395 dev->pg_event = MEI_PG_EVENT_IDLE;
396 dev->ops = hw_ops;
397 dev->dev = device;
398 }
399 EXPORT_SYMBOL_GPL(mei_device_init);
400
401