f7c8dfdb6a1254996ac56eebdf8bc760a01dce81
[muen/linux.git] / drivers / misc / mei / init.c
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
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
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  */
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  */
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(&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  */
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  */
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  */
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
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
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  */
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  */
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