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->reset_work);
95 cancel_work_sync(&dev->bus_rescan_work);
96
97 cancel_delayed_work_sync(&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_disconnect(dev);
152
153 /* remove entry if already in list */
154 dev_dbg(dev->dev, "remove iamthif from the file list.\n");
155 mei_cl_unlink(&dev->iamthif_cl);
156 mei_amthif_reset_params(dev);
157 }
158
159 mei_hbm_reset(dev);
160
161 dev->rd_msg_hdr = 0;
162
163 if (ret) {
164 dev_err(dev->dev, "hw_reset failed ret = %d\n", ret);
165 return ret;
166 }
167
168 if (state == MEI_DEV_POWER_DOWN) {
169 dev_dbg(dev->dev, "powering down: end of reset\n");
170 dev->dev_state = MEI_DEV_DISABLED;
171 return 0;
172 }
173
174 ret = mei_hw_start(dev);
175 if (ret) {
176 dev_err(dev->dev, "hw_start failed ret = %d\n", ret);
177 return ret;
178 }
179
180 dev_dbg(dev->dev, "link is established start sending messages.\n");
181
182 dev->dev_state = MEI_DEV_INIT_CLIENTS;
183 ret = mei_hbm_start_req(dev);
184 if (ret) {
185 dev_err(dev->dev, "hbm_start failed ret = %d\n", ret);
186 dev->dev_state = MEI_DEV_RESETTING;
187 return ret;
188 }
189
190 return 0;
191 }
192 EXPORT_SYMBOL_GPL(mei_reset);
193
194 /**
195 * mei_start - initializes host and fw to start work.
196 *
197 * @dev: the device structure
198 *
199 * Return: 0 on success, <0 on failure.
200 */
mei_start(struct mei_device * dev)201 int mei_start(struct mei_device *dev)
202 {
203 int ret;
204
205 mutex_lock(&dev->device_lock);
206
207 /* acknowledge interrupt and stop interrupts */
208 mei_clear_interrupts(dev);
209
210 mei_hw_config(dev);
211
212 dev_dbg(dev->dev, "reset in start the mei device.\n");
213
214 dev->reset_count = 0;
215 do {
216 dev->dev_state = MEI_DEV_INITIALIZING;
217 ret = mei_reset(dev);
218
219 if (ret == -ENODEV || dev->dev_state == MEI_DEV_DISABLED) {
220 dev_err(dev->dev, "reset failed ret = %d", ret);
221 goto err;
222 }
223 } while (ret);
224
225 /* we cannot start the device w/o hbm start message completed */
226 if (dev->dev_state == MEI_DEV_DISABLED) {
227 dev_err(dev->dev, "reset failed");
228 goto err;
229 }
230
231 if (mei_hbm_start_wait(dev)) {
232 dev_err(dev->dev, "HBM haven't started");
233 goto err;
234 }
235
236 if (!mei_host_is_ready(dev)) {
237 dev_err(dev->dev, "host is not ready.\n");
238 goto err;
239 }
240
241 if (!mei_hw_is_ready(dev)) {
242 dev_err(dev->dev, "ME is not ready.\n");
243 goto err;
244 }
245
246 if (!mei_hbm_version_is_supported(dev)) {
247 dev_dbg(dev->dev, "MEI start failed.\n");
248 goto err;
249 }
250
251 dev_dbg(dev->dev, "link layer has been established.\n");
252
253 mutex_unlock(&dev->device_lock);
254 return 0;
255 err:
256 dev_err(dev->dev, "link layer initialization failed.\n");
257 dev->dev_state = MEI_DEV_DISABLED;
258 mutex_unlock(&dev->device_lock);
259 return -ENODEV;
260 }
261 EXPORT_SYMBOL_GPL(mei_start);
262
263 /**
264 * mei_restart - restart device after suspend
265 *
266 * @dev: the device structure
267 *
268 * Return: 0 on success or -ENODEV if the restart hasn't succeeded
269 */
mei_restart(struct mei_device * dev)270 int mei_restart(struct mei_device *dev)
271 {
272 int err;
273
274 mutex_lock(&dev->device_lock);
275
276 mei_clear_interrupts(dev);
277
278 dev->dev_state = MEI_DEV_POWER_UP;
279 dev->reset_count = 0;
280
281 err = mei_reset(dev);
282
283 mutex_unlock(&dev->device_lock);
284
285 if (err == -ENODEV || dev->dev_state == MEI_DEV_DISABLED) {
286 dev_err(dev->dev, "device disabled = %d\n", err);
287 return -ENODEV;
288 }
289
290 /* try to start again */
291 if (err)
292 schedule_work(&dev->reset_work);
293
294
295 return 0;
296 }
297 EXPORT_SYMBOL_GPL(mei_restart);
298
mei_reset_work(struct work_struct * work)299 static void mei_reset_work(struct work_struct *work)
300 {
301 struct mei_device *dev =
302 container_of(work, struct mei_device, reset_work);
303 int ret;
304
305 mutex_lock(&dev->device_lock);
306
307 ret = mei_reset(dev);
308
309 mutex_unlock(&dev->device_lock);
310
311 if (dev->dev_state == MEI_DEV_DISABLED) {
312 dev_err(dev->dev, "device disabled = %d\n", ret);
313 return;
314 }
315
316 /* retry reset in case of failure */
317 if (ret)
318 schedule_work(&dev->reset_work);
319 }
320
mei_stop(struct mei_device * dev)321 void mei_stop(struct mei_device *dev)
322 {
323 dev_dbg(dev->dev, "stopping the device.\n");
324
325 mei_cl_bus_remove_devices(dev);
326
327 mei_cancel_work(dev);
328
329 mutex_lock(&dev->device_lock);
330
331 dev->dev_state = MEI_DEV_POWER_DOWN;
332 mei_reset(dev);
333 /* move device to disabled state unconditionally */
334 dev->dev_state = MEI_DEV_DISABLED;
335
336 mutex_unlock(&dev->device_lock);
337 }
338 EXPORT_SYMBOL_GPL(mei_stop);
339
340 /**
341 * mei_write_is_idle - check if the write queues are idle
342 *
343 * @dev: the device structure
344 *
345 * Return: true of there is no pending write
346 */
mei_write_is_idle(struct mei_device * dev)347 bool mei_write_is_idle(struct mei_device *dev)
348 {
349 bool idle = (dev->dev_state == MEI_DEV_ENABLED &&
350 list_empty(&dev->ctrl_wr_list.list) &&
351 list_empty(&dev->write_list.list) &&
352 list_empty(&dev->write_waiting_list.list));
353
354 dev_dbg(dev->dev, "write pg: is idle[%d] state=%s ctrl=%01d write=%01d wwait=%01d\n",
355 idle,
356 mei_dev_state_str(dev->dev_state),
357 list_empty(&dev->ctrl_wr_list.list),
358 list_empty(&dev->write_list.list),
359 list_empty(&dev->write_waiting_list.list));
360
361 return idle;
362 }
363 EXPORT_SYMBOL_GPL(mei_write_is_idle);
364
365 /**
366 * mei_device_init -- initialize mei_device structure
367 *
368 * @dev: the mei device
369 * @device: the device structure
370 * @hw_ops: hw operations
371 */
mei_device_init(struct mei_device * dev,struct device * device,const struct mei_hw_ops * hw_ops)372 void mei_device_init(struct mei_device *dev,
373 struct device *device,
374 const struct mei_hw_ops *hw_ops)
375 {
376 /* setup our list array */
377 INIT_LIST_HEAD(&dev->file_list);
378 INIT_LIST_HEAD(&dev->device_list);
379 INIT_LIST_HEAD(&dev->me_clients);
380 mutex_init(&dev->device_lock);
381 init_rwsem(&dev->me_clients_rwsem);
382 mutex_init(&dev->cl_bus_lock);
383 init_waitqueue_head(&dev->wait_hw_ready);
384 init_waitqueue_head(&dev->wait_pg);
385 init_waitqueue_head(&dev->wait_hbm_start);
386 dev->dev_state = MEI_DEV_INITIALIZING;
387 dev->reset_count = 0;
388
389 mei_io_list_init(&dev->write_list);
390 mei_io_list_init(&dev->write_waiting_list);
391 mei_io_list_init(&dev->ctrl_wr_list);
392 mei_io_list_init(&dev->ctrl_rd_list);
393
394 INIT_DELAYED_WORK(&dev->timer_work, mei_timer);
395 INIT_WORK(&dev->reset_work, mei_reset_work);
396 INIT_WORK(&dev->bus_rescan_work, mei_cl_bus_rescan_work);
397
398 INIT_LIST_HEAD(&dev->iamthif_cl.link);
399 mei_io_list_init(&dev->amthif_cmd_list);
400
401 bitmap_zero(dev->host_clients_map, MEI_CLIENTS_MAX);
402 dev->open_handle_count = 0;
403
404 /*
405 * Reserving the first client ID
406 * 0: Reserved for MEI Bus Message communications
407 */
408 bitmap_set(dev->host_clients_map, 0, 1);
409
410 dev->pg_event = MEI_PG_EVENT_IDLE;
411 dev->ops = hw_ops;
412 dev->dev = device;
413 }
414 EXPORT_SYMBOL_GPL(mei_device_init);
415
416