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1// SPDX-License-Identifier: GPL-2.0
2/*
3 * Copyright (c) 2012-2022, Intel Corporation. All rights reserved.
4 * Intel Management Engine Interface (Intel MEI) Linux driver
5 */
6
7#include <linux/export.h>
8#include <linux/sched.h>
9#include <linux/wait.h>
10#include <linux/delay.h>
11
12#include <linux/mei.h>
13
14#include "mei_dev.h"
15#include "hbm.h"
16#include "client.h"
17
18const char *mei_dev_state_str(int state)
19{
20#define MEI_DEV_STATE(state) case MEI_DEV_##state: return #state
21 switch (state) {
22 MEI_DEV_STATE(INITIALIZING);
23 MEI_DEV_STATE(INIT_CLIENTS);
24 MEI_DEV_STATE(ENABLED);
25 MEI_DEV_STATE(RESETTING);
26 MEI_DEV_STATE(DISABLED);
27 MEI_DEV_STATE(POWERING_DOWN);
28 MEI_DEV_STATE(POWER_DOWN);
29 MEI_DEV_STATE(POWER_UP);
30 default:
31 return "unknown";
32 }
33#undef MEI_DEV_STATE
34}
35
36const char *mei_pg_state_str(enum mei_pg_state state)
37{
38#define MEI_PG_STATE(state) case MEI_PG_##state: return #state
39 switch (state) {
40 MEI_PG_STATE(OFF);
41 MEI_PG_STATE(ON);
42 default:
43 return "unknown";
44 }
45#undef MEI_PG_STATE
46}
47
48/**
49 * mei_fw_status2str - convert fw status registers to printable string
50 *
51 * @fw_status: firmware status
52 * @buf: string buffer at minimal size MEI_FW_STATUS_STR_SZ
53 * @len: buffer len must be >= MEI_FW_STATUS_STR_SZ
54 *
55 * Return: number of bytes written or -EINVAL if buffer is to small
56 */
57ssize_t mei_fw_status2str(struct mei_fw_status *fw_status,
58 char *buf, size_t len)
59{
60 ssize_t cnt = 0;
61 int i;
62
63 buf[0] = '\0';
64
65 if (len < MEI_FW_STATUS_STR_SZ)
66 return -EINVAL;
67
68 for (i = 0; i < fw_status->count; i++)
69 cnt += scnprintf(buf + cnt, len - cnt, "%08X ",
70 fw_status->status[i]);
71
72 /* drop last space */
73 buf[cnt] = '\0';
74 return cnt;
75}
76EXPORT_SYMBOL_GPL(mei_fw_status2str);
77
78/**
79 * mei_cancel_work - Cancel mei background jobs
80 *
81 * @dev: the device structure
82 */
83void mei_cancel_work(struct mei_device *dev)
84{
85 cancel_work_sync(&dev->reset_work);
86 cancel_work_sync(&dev->bus_rescan_work);
87
88 cancel_delayed_work_sync(&dev->timer_work);
89}
90EXPORT_SYMBOL_GPL(mei_cancel_work);
91
92/**
93 * mei_reset - resets host and fw.
94 *
95 * @dev: the device structure
96 *
97 * Return: 0 on success or < 0 if the reset hasn't succeeded
98 */
99int mei_reset(struct mei_device *dev)
100{
101 enum mei_dev_state state = dev->dev_state;
102 bool interrupts_enabled;
103 int ret;
104
105 if (state != MEI_DEV_INITIALIZING &&
106 state != MEI_DEV_DISABLED &&
107 state != MEI_DEV_POWER_DOWN &&
108 state != MEI_DEV_POWER_UP) {
109 char fw_sts_str[MEI_FW_STATUS_STR_SZ];
110
111 mei_fw_status_str(dev, fw_sts_str, MEI_FW_STATUS_STR_SZ);
112 if (kind_is_gsc(dev) || kind_is_gscfi(dev)) {
113 dev_dbg(&dev->dev, "unexpected reset: dev_state = %s fw status = %s\n",
114 mei_dev_state_str(state), fw_sts_str);
115 } else {
116 dev_warn(&dev->dev, "unexpected reset: dev_state = %s fw status = %s\n",
117 mei_dev_state_str(state), fw_sts_str);
118 }
119 }
120
121 mei_clear_interrupts(dev);
122
123 /* we're already in reset, cancel the init timer
124 * if the reset was called due the hbm protocol error
125 * we need to call it before hw start
126 * so the hbm watchdog won't kick in
127 */
128 mei_hbm_idle(dev);
129
130 /* enter reset flow */
131 interrupts_enabled = state != MEI_DEV_POWER_DOWN;
132 mei_set_devstate(dev, MEI_DEV_RESETTING);
133
134 dev->reset_count++;
135 if (dev->reset_count > MEI_MAX_CONSEC_RESET) {
136 dev_err(&dev->dev, "reset: reached maximal consecutive resets: disabling the device\n");
137 mei_set_devstate(dev, MEI_DEV_DISABLED);
138 return -ENODEV;
139 }
140
141 ret = mei_hw_reset(dev, interrupts_enabled);
142 /* fall through and remove the sw state even if hw reset has failed */
143
144 /* no need to clean up software state in case of power up */
145 if (state != MEI_DEV_INITIALIZING && state != MEI_DEV_POWER_UP)
146 mei_cl_all_disconnect(dev);
147
148 mei_hbm_reset(dev);
149
150 /* clean stale FW version */
151 dev->fw_ver_received = 0;
152
153 memset(dev->rd_msg_hdr, 0, sizeof(dev->rd_msg_hdr));
154
155 if (ret) {
156 dev_err(&dev->dev, "hw_reset failed ret = %d\n", ret);
157 return ret;
158 }
159
160 if (state == MEI_DEV_POWER_DOWN) {
161 dev_dbg(&dev->dev, "powering down: end of reset\n");
162 mei_set_devstate(dev, MEI_DEV_DISABLED);
163 return 0;
164 }
165
166 ret = mei_hw_start(dev);
167 if (ret) {
168 char fw_sts_str[MEI_FW_STATUS_STR_SZ];
169
170 mei_fw_status_str(dev, fw_sts_str, MEI_FW_STATUS_STR_SZ);
171 dev_err(&dev->dev, "hw_start failed ret = %d fw status = %s\n", ret, fw_sts_str);
172 return ret;
173 }
174
175 if (dev->dev_state != MEI_DEV_RESETTING) {
176 dev_dbg(&dev->dev, "wrong state = %d on link start\n", dev->dev_state);
177 return 0;
178 }
179
180 dev_dbg(&dev->dev, "link is established start sending messages.\n");
181
182 mei_set_devstate(dev, 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 mei_set_devstate(dev, MEI_DEV_RESETTING);
187 return ret;
188 }
189
190 return 0;
191}
192EXPORT_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 */
201int 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 ret = mei_hw_config(dev);
211 if (ret)
212 goto err;
213
214 dev_dbg(&dev->dev, "reset in start the mei device.\n");
215
216 dev->reset_count = 0;
217 do {
218 mei_set_devstate(dev, MEI_DEV_INITIALIZING);
219 ret = mei_reset(dev);
220
221 if (ret == -ENODEV || dev->dev_state == MEI_DEV_DISABLED) {
222 dev_err(&dev->dev, "reset failed ret = %d", ret);
223 goto err;
224 }
225 } while (ret);
226
227 if (mei_hbm_start_wait(dev)) {
228 dev_err(&dev->dev, "HBM haven't started");
229 goto err;
230 }
231
232 if (!mei_hbm_version_is_supported(dev)) {
233 dev_dbg(&dev->dev, "MEI start failed.\n");
234 goto err;
235 }
236
237 dev_dbg(&dev->dev, "link layer has been established.\n");
238
239 mutex_unlock(&dev->device_lock);
240 return 0;
241err:
242 dev_err(&dev->dev, "link layer initialization failed.\n");
243 mei_set_devstate(dev, MEI_DEV_DISABLED);
244 mutex_unlock(&dev->device_lock);
245 return -ENODEV;
246}
247EXPORT_SYMBOL_GPL(mei_start);
248
249/**
250 * mei_restart - restart device after suspend
251 *
252 * @dev: the device structure
253 *
254 * Return: 0 on success or -ENODEV if the restart hasn't succeeded
255 */
256int mei_restart(struct mei_device *dev)
257{
258 int err;
259
260 mutex_lock(&dev->device_lock);
261
262 mei_set_devstate(dev, MEI_DEV_POWER_UP);
263 dev->reset_count = 0;
264
265 err = mei_reset(dev);
266
267 mutex_unlock(&dev->device_lock);
268
269 if (err == -ENODEV || dev->dev_state == MEI_DEV_DISABLED) {
270 dev_err(&dev->dev, "device disabled = %d\n", err);
271 return -ENODEV;
272 }
273
274 /* try to start again */
275 if (err)
276 schedule_work(&dev->reset_work);
277
278
279 return 0;
280}
281EXPORT_SYMBOL_GPL(mei_restart);
282
283static void mei_reset_work(struct work_struct *work)
284{
285 struct mei_device *dev =
286 container_of(work, struct mei_device, reset_work);
287 int ret;
288
289 mei_clear_interrupts(dev);
290 mei_synchronize_irq(dev);
291
292 mutex_lock(&dev->device_lock);
293
294 ret = mei_reset(dev);
295
296 mutex_unlock(&dev->device_lock);
297
298 if (dev->dev_state == MEI_DEV_DISABLED) {
299 dev_err(&dev->dev, "device disabled = %d\n", ret);
300 return;
301 }
302
303 /* retry reset in case of failure */
304 if (ret)
305 schedule_work(&dev->reset_work);
306}
307
308void mei_stop(struct mei_device *dev)
309{
310 dev_dbg(&dev->dev, "stopping the device.\n");
311
312 mutex_lock(&dev->device_lock);
313 mei_set_devstate(dev, MEI_DEV_POWERING_DOWN);
314 mutex_unlock(&dev->device_lock);
315 mei_cl_bus_remove_devices(dev);
316 mutex_lock(&dev->device_lock);
317 mei_set_devstate(dev, MEI_DEV_POWER_DOWN);
318 mutex_unlock(&dev->device_lock);
319
320 mei_cancel_work(dev);
321
322 mei_clear_interrupts(dev);
323 mei_synchronize_irq(dev);
324 /* to catch HW-initiated reset */
325 mei_cancel_work(dev);
326
327 mutex_lock(&dev->device_lock);
328
329 mei_reset(dev);
330 /* move device to disabled state unconditionally */
331 mei_set_devstate(dev, MEI_DEV_DISABLED);
332
333 mutex_unlock(&dev->device_lock);
334}
335EXPORT_SYMBOL_GPL(mei_stop);
336
337/**
338 * mei_write_is_idle - check if the write queues are idle
339 *
340 * @dev: the device structure
341 *
342 * Return: true of there is no pending write
343 */
344bool mei_write_is_idle(struct mei_device *dev)
345{
346 bool idle = (dev->dev_state == MEI_DEV_ENABLED &&
347 !dev->pg_blocked &&
348 list_empty(&dev->ctrl_wr_list) &&
349 list_empty(&dev->write_list) &&
350 list_empty(&dev->write_waiting_list));
351
352 dev_dbg(&dev->dev, "write pg: is idle[%d] state=%s blocked=%d ctrl=%d write=%d wwait=%d\n",
353 idle,
354 mei_dev_state_str(dev->dev_state),
355 dev->pg_blocked,
356 list_empty(&dev->ctrl_wr_list),
357 list_empty(&dev->write_list),
358 list_empty(&dev->write_waiting_list));
359
360 return idle;
361}
362EXPORT_SYMBOL_GPL(mei_write_is_idle);
363
364/**
365 * mei_device_init - initialize mei_device structure
366 *
367 * @dev: the mei device
368 * @parent: the parent device
369 * @slow_fw: configure longer timeouts as FW is slow
370 * @hw_ops: hw operations
371 */
372void mei_device_init(struct mei_device *dev,
373 struct device *parent,
374 bool slow_fw,
375 const struct mei_hw_ops *hw_ops)
376{
377 /* setup our list array */
378 INIT_LIST_HEAD(&dev->file_list);
379 INIT_LIST_HEAD(&dev->device_list);
380 INIT_LIST_HEAD(&dev->me_clients);
381 mutex_init(&dev->device_lock);
382 init_rwsem(&dev->me_clients_rwsem);
383 mutex_init(&dev->cl_bus_lock);
384 init_waitqueue_head(&dev->wait_hw_ready);
385 init_waitqueue_head(&dev->wait_pg);
386 init_waitqueue_head(&dev->wait_hbm_start);
387 dev->dev_state = MEI_DEV_UNINITIALIZED;
388 init_waitqueue_head(&dev->wait_dev_state);
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 dev->tx_queue_limit = MEI_TX_QUEUE_LIMIT_DEFAULT;
396
397 INIT_DELAYED_WORK(&dev->timer_work, mei_timer);
398 INIT_WORK(&dev->reset_work, mei_reset_work);
399 INIT_WORK(&dev->bus_rescan_work, mei_cl_bus_rescan_work);
400
401 bitmap_zero(dev->host_clients_map, MEI_CLIENTS_MAX);
402 dev->open_handle_count = 0;
403
404 dev->pxp_mode = MEI_DEV_PXP_DEFAULT;
405 dev->gsc_reset_to_pxp = MEI_DEV_RESET_TO_PXP_DEFAULT;
406
407 /*
408 * Reserving the first client ID
409 * 0: Reserved for MEI Bus Message communications
410 */
411 bitmap_set(dev->host_clients_map, 0, 1);
412
413 dev->pg_event = MEI_PG_EVENT_IDLE;
414 dev->ops = hw_ops;
415 dev->parent = parent;
416
417 dev->timeouts.hw_ready = mei_secs_to_jiffies(MEI_HW_READY_TIMEOUT);
418 dev->timeouts.connect = MEI_CONNECT_TIMEOUT;
419 dev->timeouts.client_init = MEI_CLIENTS_INIT_TIMEOUT;
420 dev->timeouts.pgi = mei_secs_to_jiffies(MEI_PGI_TIMEOUT);
421 dev->timeouts.d0i3 = mei_secs_to_jiffies(MEI_D0I3_TIMEOUT);
422 if (slow_fw) {
423 dev->timeouts.cl_connect = mei_secs_to_jiffies(MEI_CL_CONNECT_TIMEOUT_SLOW);
424 dev->timeouts.hbm = mei_secs_to_jiffies(MEI_HBM_TIMEOUT_SLOW);
425 dev->timeouts.mkhi_recv = msecs_to_jiffies(MKHI_RCV_TIMEOUT_SLOW);
426 } else {
427 dev->timeouts.cl_connect = mei_secs_to_jiffies(MEI_CL_CONNECT_TIMEOUT);
428 dev->timeouts.hbm = mei_secs_to_jiffies(MEI_HBM_TIMEOUT);
429 dev->timeouts.mkhi_recv = msecs_to_jiffies(MKHI_RCV_TIMEOUT);
430 }
431 dev->timeouts.link_reset_wait = msecs_to_jiffies(MEI_LINK_RESET_WAIT_TIMEOUT_MSEC);
432}
433EXPORT_SYMBOL_GPL(mei_device_init);