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 * mei_fw_status2str - convert fw status registers to printable string
59 *
60 * @fw_status: firmware status
61 * @buf: string buffer at minimal size MEI_FW_STATUS_STR_SZ
62 * @len: buffer len must be >= MEI_FW_STATUS_STR_SZ
63 *
64 * Return: number of bytes written or -EINVAL if buffer is to small
65 */
mei_fw_status2str(struct mei_fw_status * fw_status,char * buf,size_t len)66 ssize_t mei_fw_status2str(struct mei_fw_status *fw_status,
67 char *buf, size_t len)
68 {
69 ssize_t cnt = 0;
70 int i;
71
72 buf[0] = '\0';
73
74 if (len < MEI_FW_STATUS_STR_SZ)
75 return -EINVAL;
76
77 for (i = 0; i < fw_status->count; i++)
78 cnt += scnprintf(buf + cnt, len - cnt, "%08X ",
79 fw_status->status[i]);
80
81 /* drop last space */
82 buf[cnt] = '\0';
83 return cnt;
84 }
85 EXPORT_SYMBOL_GPL(mei_fw_status2str);
86
87 /**
88 * mei_cancel_work - Cancel mei background jobs
89 *
90 * @dev: the device structure
91 */
mei_cancel_work(struct mei_device * dev)92 void mei_cancel_work(struct mei_device *dev)
93 {
94 cancel_work_sync(&dev->init_work);
95 cancel_work_sync(&dev->reset_work);
96
97 cancel_delayed_work(&dev->timer_work);
98 }
99 EXPORT_SYMBOL_GPL(mei_cancel_work);
100
101 /**
102 * mei_reset - resets host and fw.
103 *
104 * @dev: the device structure
105 *
106 * Return: 0 on success or < 0 if the reset hasn't succeeded
107 */
mei_reset(struct mei_device * dev)108 int mei_reset(struct mei_device *dev)
109 {
110 enum mei_dev_state state = dev->dev_state;
111 bool interrupts_enabled;
112 int ret;
113
114 if (state != MEI_DEV_INITIALIZING &&
115 state != MEI_DEV_DISABLED &&
116 state != MEI_DEV_POWER_DOWN &&
117 state != MEI_DEV_POWER_UP) {
118 char fw_sts_str[MEI_FW_STATUS_STR_SZ];
119
120 mei_fw_status_str(dev, fw_sts_str, MEI_FW_STATUS_STR_SZ);
121 dev_warn(dev->dev, "unexpected reset: dev_state = %s fw status = %s\n",
122 mei_dev_state_str(state), fw_sts_str);
123 }
124
125 /* we're already in reset, cancel the init timer
126 * if the reset was called due the hbm protocol error
127 * we need to call it before hw start
128 * so the hbm watchdog won't kick in
129 */
130 mei_hbm_idle(dev);
131
132 /* enter reset flow */
133 interrupts_enabled = state != MEI_DEV_POWER_DOWN;
134 dev->dev_state = MEI_DEV_RESETTING;
135
136 dev->reset_count++;
137 if (dev->reset_count > MEI_MAX_CONSEC_RESET) {
138 dev_err(dev->dev, "reset: reached maximal consecutive resets: disabling the device\n");
139 dev->dev_state = MEI_DEV_DISABLED;
140 return -ENODEV;
141 }
142
143 ret = mei_hw_reset(dev, interrupts_enabled);
144 /* fall through and remove the sw state even if hw reset has failed */
145
146 /* no need to clean up software state in case of power up */
147 if (state != MEI_DEV_INITIALIZING &&
148 state != MEI_DEV_POWER_UP) {
149
150 /* remove all waiting requests */
151 mei_cl_all_write_clear(dev);
152
153 mei_cl_all_disconnect(dev);
154
155 /* wake up all readers and writers so they can be interrupted */
156 mei_cl_all_wakeup(dev);
157
158 /* remove entry if already in list */
159 dev_dbg(dev->dev, "remove iamthif and wd from the file list.\n");
160 mei_cl_unlink(&dev->wd_cl);
161 mei_cl_unlink(&dev->iamthif_cl);
162 mei_amthif_reset_params(dev);
163 }
164
165 mei_hbm_reset(dev);
166
167 dev->rd_msg_hdr = 0;
168 dev->wd_pending = false;
169
170 if (ret) {
171 dev_err(dev->dev, "hw_reset failed ret = %d\n", ret);
172 return ret;
173 }
174
175 if (state == MEI_DEV_POWER_DOWN) {
176 dev_dbg(dev->dev, "powering down: end of reset\n");
177 dev->dev_state = MEI_DEV_DISABLED;
178 return 0;
179 }
180
181 ret = mei_hw_start(dev);
182 if (ret) {
183 dev_err(dev->dev, "hw_start failed ret = %d\n", ret);
184 return ret;
185 }
186
187 dev_dbg(dev->dev, "link is established start sending messages.\n");
188
189 dev->dev_state = MEI_DEV_INIT_CLIENTS;
190 ret = mei_hbm_start_req(dev);
191 if (ret) {
192 dev_err(dev->dev, "hbm_start failed ret = %d\n", ret);
193 dev->dev_state = MEI_DEV_RESETTING;
194 return ret;
195 }
196
197 return 0;
198 }
199 EXPORT_SYMBOL_GPL(mei_reset);
200
201 /**
202 * mei_start - initializes host and fw to start work.
203 *
204 * @dev: the device structure
205 *
206 * Return: 0 on success, <0 on failure.
207 */
mei_start(struct mei_device * dev)208 int mei_start(struct mei_device *dev)
209 {
210 int ret;
211
212 mutex_lock(&dev->device_lock);
213
214 /* acknowledge interrupt and stop interrupts */
215 mei_clear_interrupts(dev);
216
217 mei_hw_config(dev);
218
219 dev_dbg(dev->dev, "reset in start the mei device.\n");
220
221 dev->reset_count = 0;
222 do {
223 dev->dev_state = MEI_DEV_INITIALIZING;
224 ret = mei_reset(dev);
225
226 if (ret == -ENODEV || dev->dev_state == MEI_DEV_DISABLED) {
227 dev_err(dev->dev, "reset failed ret = %d", ret);
228 goto err;
229 }
230 } while (ret);
231
232 /* we cannot start the device w/o hbm start message completed */
233 if (dev->dev_state == MEI_DEV_DISABLED) {
234 dev_err(dev->dev, "reset failed");
235 goto err;
236 }
237
238 if (mei_hbm_start_wait(dev)) {
239 dev_err(dev->dev, "HBM haven't started");
240 goto err;
241 }
242
243 if (!mei_host_is_ready(dev)) {
244 dev_err(dev->dev, "host is not ready.\n");
245 goto err;
246 }
247
248 if (!mei_hw_is_ready(dev)) {
249 dev_err(dev->dev, "ME is not ready.\n");
250 goto err;
251 }
252
253 if (!mei_hbm_version_is_supported(dev)) {
254 dev_dbg(dev->dev, "MEI start failed.\n");
255 goto err;
256 }
257
258 dev_dbg(dev->dev, "link layer has been established.\n");
259
260 mutex_unlock(&dev->device_lock);
261 return 0;
262 err:
263 dev_err(dev->dev, "link layer initialization failed.\n");
264 dev->dev_state = MEI_DEV_DISABLED;
265 mutex_unlock(&dev->device_lock);
266 return -ENODEV;
267 }
268 EXPORT_SYMBOL_GPL(mei_start);
269
270 /**
271 * mei_restart - restart device after suspend
272 *
273 * @dev: the device structure
274 *
275 * Return: 0 on success or -ENODEV if the restart hasn't succeeded
276 */
mei_restart(struct mei_device * dev)277 int mei_restart(struct mei_device *dev)
278 {
279 int err;
280
281 mutex_lock(&dev->device_lock);
282
283 mei_clear_interrupts(dev);
284
285 dev->dev_state = MEI_DEV_POWER_UP;
286 dev->reset_count = 0;
287
288 err = mei_reset(dev);
289
290 mutex_unlock(&dev->device_lock);
291
292 if (err == -ENODEV || dev->dev_state == MEI_DEV_DISABLED) {
293 dev_err(dev->dev, "device disabled = %d\n", err);
294 return -ENODEV;
295 }
296
297 /* try to start again */
298 if (err)
299 schedule_work(&dev->reset_work);
300
301
302 return 0;
303 }
304 EXPORT_SYMBOL_GPL(mei_restart);
305
mei_reset_work(struct work_struct * work)306 static void mei_reset_work(struct work_struct *work)
307 {
308 struct mei_device *dev =
309 container_of(work, struct mei_device, reset_work);
310 int ret;
311
312 mutex_lock(&dev->device_lock);
313
314 ret = mei_reset(dev);
315
316 mutex_unlock(&dev->device_lock);
317
318 if (dev->dev_state == MEI_DEV_DISABLED) {
319 dev_err(dev->dev, "device disabled = %d\n", ret);
320 return;
321 }
322
323 /* retry reset in case of failure */
324 if (ret)
325 schedule_work(&dev->reset_work);
326 }
327
mei_stop(struct mei_device * dev)328 void mei_stop(struct mei_device *dev)
329 {
330 dev_dbg(dev->dev, "stopping the device.\n");
331
332 mei_cl_bus_remove_devices(dev);
333
334 mei_cancel_work(dev);
335
336 mutex_lock(&dev->device_lock);
337
338 mei_wd_stop(dev);
339
340 dev->dev_state = MEI_DEV_POWER_DOWN;
341 mei_reset(dev);
342 /* move device to disabled state unconditionally */
343 dev->dev_state = MEI_DEV_DISABLED;
344
345 mutex_unlock(&dev->device_lock);
346
347 mei_watchdog_unregister(dev);
348 }
349 EXPORT_SYMBOL_GPL(mei_stop);
350
351 /**
352 * mei_write_is_idle - check if the write queues are idle
353 *
354 * @dev: the device structure
355 *
356 * Return: true of there is no pending write
357 */
mei_write_is_idle(struct mei_device * dev)358 bool mei_write_is_idle(struct mei_device *dev)
359 {
360 bool idle = (dev->dev_state == MEI_DEV_ENABLED &&
361 list_empty(&dev->ctrl_wr_list.list) &&
362 list_empty(&dev->write_list.list) &&
363 list_empty(&dev->write_waiting_list.list));
364
365 dev_dbg(dev->dev, "write pg: is idle[%d] state=%s ctrl=%01d write=%01d wwait=%01d\n",
366 idle,
367 mei_dev_state_str(dev->dev_state),
368 list_empty(&dev->ctrl_wr_list.list),
369 list_empty(&dev->write_list.list),
370 list_empty(&dev->write_waiting_list.list));
371
372 return idle;
373 }
374 EXPORT_SYMBOL_GPL(mei_write_is_idle);
375
376 /**
377 * mei_device_init -- initialize mei_device structure
378 *
379 * @dev: the mei device
380 * @device: the device structure
381 * @hw_ops: hw operations
382 */
mei_device_init(struct mei_device * dev,struct device * device,const struct mei_hw_ops * hw_ops)383 void mei_device_init(struct mei_device *dev,
384 struct device *device,
385 const struct mei_hw_ops *hw_ops)
386 {
387 /* setup our list array */
388 INIT_LIST_HEAD(&dev->file_list);
389 INIT_LIST_HEAD(&dev->device_list);
390 INIT_LIST_HEAD(&dev->me_clients);
391 mutex_init(&dev->device_lock);
392 init_rwsem(&dev->me_clients_rwsem);
393 mutex_init(&dev->cl_bus_lock);
394 init_waitqueue_head(&dev->wait_hw_ready);
395 init_waitqueue_head(&dev->wait_pg);
396 init_waitqueue_head(&dev->wait_hbm_start);
397 init_waitqueue_head(&dev->wait_stop_wd);
398 dev->dev_state = MEI_DEV_INITIALIZING;
399 dev->reset_count = 0;
400
401 mei_io_list_init(&dev->write_list);
402 mei_io_list_init(&dev->write_waiting_list);
403 mei_io_list_init(&dev->ctrl_wr_list);
404 mei_io_list_init(&dev->ctrl_rd_list);
405
406 INIT_DELAYED_WORK(&dev->timer_work, mei_timer);
407 INIT_WORK(&dev->init_work, mei_host_client_init);
408 INIT_WORK(&dev->reset_work, mei_reset_work);
409
410 INIT_LIST_HEAD(&dev->wd_cl.link);
411 INIT_LIST_HEAD(&dev->iamthif_cl.link);
412 mei_io_list_init(&dev->amthif_cmd_list);
413 mei_io_list_init(&dev->amthif_rd_complete_list);
414
415 bitmap_zero(dev->host_clients_map, MEI_CLIENTS_MAX);
416 dev->open_handle_count = 0;
417
418 /*
419 * Reserving the first client ID
420 * 0: Reserved for MEI Bus Message communications
421 */
422 bitmap_set(dev->host_clients_map, 0, 1);
423
424 dev->pg_event = MEI_PG_EVENT_IDLE;
425 dev->ops = hw_ops;
426 dev->dev = device;
427 }
428 EXPORT_SYMBOL_GPL(mei_device_init);
429
430