mei: replace callback structures used as list head by list_head
[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_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  */
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         mei_clear_interrupts(dev);
126
127         mei_synchronize_irq(dev);
128
129         /* we're already in reset, cancel the init timer
130          * if the reset was called due the hbm protocol error
131          * we need to call it before hw start
132          * so the hbm watchdog won't kick in
133          */
134         mei_hbm_idle(dev);
135
136         /* enter reset flow */
137         interrupts_enabled = state != MEI_DEV_POWER_DOWN;
138         dev->dev_state = MEI_DEV_RESETTING;
139
140         dev->reset_count++;
141         if (dev->reset_count > MEI_MAX_CONSEC_RESET) {
142                 dev_err(dev->dev, "reset: reached maximal consecutive resets: disabling the device\n");
143                 dev->dev_state = MEI_DEV_DISABLED;
144                 return -ENODEV;
145         }
146
147         ret = mei_hw_reset(dev, interrupts_enabled);
148         /* fall through and remove the sw state even if hw reset has failed */
149
150         /* no need to clean up software state in case of power up */
151         if (state != MEI_DEV_INITIALIZING &&
152             state != MEI_DEV_POWER_UP) {
153
154                 /* remove all waiting requests */
155                 mei_cl_all_disconnect(dev);
156
157                 /* remove entry if already in list */
158                 dev_dbg(dev->dev, "remove iamthif from the file list.\n");
159                 mei_cl_unlink(&dev->iamthif_cl);
160                 mei_amthif_reset_params(dev);
161         }
162
163         mei_hbm_reset(dev);
164
165         dev->rd_msg_hdr = 0;
166
167         if (ret) {
168                 dev_err(dev->dev, "hw_reset failed ret = %d\n", ret);
169                 return ret;
170         }
171
172         if (state == MEI_DEV_POWER_DOWN) {
173                 dev_dbg(dev->dev, "powering down: end of reset\n");
174                 dev->dev_state = MEI_DEV_DISABLED;
175                 return 0;
176         }
177
178         ret = mei_hw_start(dev);
179         if (ret) {
180                 dev_err(dev->dev, "hw_start failed ret = %d\n", ret);
181                 return ret;
182         }
183
184         dev_dbg(dev->dev, "link is established start sending messages.\n");
185
186         dev->dev_state = MEI_DEV_INIT_CLIENTS;
187         ret = mei_hbm_start_req(dev);
188         if (ret) {
189                 dev_err(dev->dev, "hbm_start failed ret = %d\n", ret);
190                 dev->dev_state = MEI_DEV_RESETTING;
191                 return ret;
192         }
193
194         return 0;
195 }
196 EXPORT_SYMBOL_GPL(mei_reset);
197
198 /**
199  * mei_start - initializes host and fw to start work.
200  *
201  * @dev: the device structure
202  *
203  * Return: 0 on success, <0 on failure.
204  */
205 int mei_start(struct mei_device *dev)
206 {
207         int ret;
208
209         mutex_lock(&dev->device_lock);
210
211         /* acknowledge interrupt and stop interrupts */
212         mei_clear_interrupts(dev);
213
214         mei_hw_config(dev);
215
216         dev_dbg(dev->dev, "reset in start the mei device.\n");
217
218         dev->reset_count = 0;
219         do {
220                 dev->dev_state = MEI_DEV_INITIALIZING;
221                 ret = mei_reset(dev);
222
223                 if (ret == -ENODEV || dev->dev_state == MEI_DEV_DISABLED) {
224                         dev_err(dev->dev, "reset failed ret = %d", ret);
225                         goto err;
226                 }
227         } while (ret);
228
229         /* we cannot start the device w/o hbm start message completed */
230         if (dev->dev_state == MEI_DEV_DISABLED) {
231                 dev_err(dev->dev, "reset failed");
232                 goto err;
233         }
234
235         if (mei_hbm_start_wait(dev)) {
236                 dev_err(dev->dev, "HBM haven't started");
237                 goto err;
238         }
239
240         if (!mei_host_is_ready(dev)) {
241                 dev_err(dev->dev, "host is not ready.\n");
242                 goto err;
243         }
244
245         if (!mei_hw_is_ready(dev)) {
246                 dev_err(dev->dev, "ME is not ready.\n");
247                 goto err;
248         }
249
250         if (!mei_hbm_version_is_supported(dev)) {
251                 dev_dbg(dev->dev, "MEI start failed.\n");
252                 goto err;
253         }
254
255         dev_dbg(dev->dev, "link layer has been established.\n");
256
257         mutex_unlock(&dev->device_lock);
258         return 0;
259 err:
260         dev_err(dev->dev, "link layer initialization failed.\n");
261         dev->dev_state = MEI_DEV_DISABLED;
262         mutex_unlock(&dev->device_lock);
263         return -ENODEV;
264 }
265 EXPORT_SYMBOL_GPL(mei_start);
266
267 /**
268  * mei_restart - restart device after suspend
269  *
270  * @dev: the device structure
271  *
272  * Return: 0 on success or -ENODEV if the restart hasn't succeeded
273  */
274 int mei_restart(struct mei_device *dev)
275 {
276         int err;
277
278         mutex_lock(&dev->device_lock);
279
280         dev->dev_state = MEI_DEV_POWER_UP;
281         dev->reset_count = 0;
282
283         err = mei_reset(dev);
284
285         mutex_unlock(&dev->device_lock);
286
287         if (err == -ENODEV || dev->dev_state == MEI_DEV_DISABLED) {
288                 dev_err(dev->dev, "device disabled = %d\n", err);
289                 return -ENODEV;
290         }
291
292         /* try to start again */
293         if (err)
294                 schedule_work(&dev->reset_work);
295
296
297         return 0;
298 }
299 EXPORT_SYMBOL_GPL(mei_restart);
300
301 static void mei_reset_work(struct work_struct *work)
302 {
303         struct mei_device *dev =
304                 container_of(work, struct mei_device,  reset_work);
305         int ret;
306
307         mutex_lock(&dev->device_lock);
308
309         ret = mei_reset(dev);
310
311         mutex_unlock(&dev->device_lock);
312
313         if (dev->dev_state == MEI_DEV_DISABLED) {
314                 dev_err(dev->dev, "device disabled = %d\n", ret);
315                 return;
316         }
317
318         /* retry reset in case of failure */
319         if (ret)
320                 schedule_work(&dev->reset_work);
321 }
322
323 void mei_stop(struct mei_device *dev)
324 {
325         dev_dbg(dev->dev, "stopping the device.\n");
326
327         mei_cl_bus_remove_devices(dev);
328
329         mei_cancel_work(dev);
330
331         mutex_lock(&dev->device_lock);
332
333         dev->dev_state = MEI_DEV_POWER_DOWN;
334         mei_reset(dev);
335         /* move device to disabled state unconditionally */
336         dev->dev_state = MEI_DEV_DISABLED;
337
338         mutex_unlock(&dev->device_lock);
339 }
340 EXPORT_SYMBOL_GPL(mei_stop);
341
342 /**
343  * mei_write_is_idle - check if the write queues are idle
344  *
345  * @dev: the device structure
346  *
347  * Return: true of there is no pending write
348  */
349 bool mei_write_is_idle(struct mei_device *dev)
350 {
351         bool idle = (dev->dev_state == MEI_DEV_ENABLED &&
352                 list_empty(&dev->ctrl_wr_list) &&
353                 list_empty(&dev->write_list)   &&
354                 list_empty(&dev->write_waiting_list));
355
356         dev_dbg(dev->dev, "write pg: is idle[%d] state=%s ctrl=%01d write=%01d wwait=%01d\n",
357                 idle,
358                 mei_dev_state_str(dev->dev_state),
359                 list_empty(&dev->ctrl_wr_list),
360                 list_empty(&dev->write_list),
361                 list_empty(&dev->write_waiting_list));
362
363         return idle;
364 }
365 EXPORT_SYMBOL_GPL(mei_write_is_idle);
366
367 /**
368  * mei_device_init  -- initialize mei_device structure
369  *
370  * @dev: the mei device
371  * @device: the device structure
372  * @hw_ops: hw operations
373  */
374 void mei_device_init(struct mei_device *dev,
375                      struct device *device,
376                      const struct mei_hw_ops *hw_ops)
377 {
378         /* setup our list array */
379         INIT_LIST_HEAD(&dev->file_list);
380         INIT_LIST_HEAD(&dev->device_list);
381         INIT_LIST_HEAD(&dev->me_clients);
382         mutex_init(&dev->device_lock);
383         init_rwsem(&dev->me_clients_rwsem);
384         mutex_init(&dev->cl_bus_lock);
385         init_waitqueue_head(&dev->wait_hw_ready);
386         init_waitqueue_head(&dev->wait_pg);
387         init_waitqueue_head(&dev->wait_hbm_start);
388         dev->dev_state = MEI_DEV_INITIALIZING;
389         dev->reset_count = 0;
390
391         INIT_LIST_HEAD(&dev->write_list);
392         INIT_LIST_HEAD(&dev->write_waiting_list);
393         INIT_LIST_HEAD(&dev->ctrl_wr_list);
394         INIT_LIST_HEAD(&dev->ctrl_rd_list);
395
396         INIT_DELAYED_WORK(&dev->timer_work, mei_timer);
397         INIT_WORK(&dev->reset_work, mei_reset_work);
398         INIT_WORK(&dev->bus_rescan_work, mei_cl_bus_rescan_work);
399
400         INIT_LIST_HEAD(&dev->iamthif_cl.link);
401         INIT_LIST_HEAD(&dev->amthif_cmd_list);
402
403         bitmap_zero(dev->host_clients_map, MEI_CLIENTS_MAX);
404         dev->open_handle_count = 0;
405
406         /*
407          * Reserving the first client ID
408          * 0: Reserved for MEI Bus Message communications
409          */
410         bitmap_set(dev->host_clients_map, 0, 1);
411
412         dev->pg_event = MEI_PG_EVENT_IDLE;
413         dev->ops      = hw_ops;
414         dev->dev      = device;
415 }
416 EXPORT_SYMBOL_GPL(mei_device_init);
417