1 // SPDX-License-Identifier: GPL-2.0
3 * Copyright (c) 2012-2019, Intel Corporation. All rights reserved.
4 * Intel Management Engine Interface (Intel MEI) Linux driver
7 #include <linux/export.h>
8 #include <linux/sched.h>
9 #include <linux/wait.h>
10 #include <linux/delay.h>
12 #include <linux/mei.h>
18 const char *mei_dev_state_str(int state)
20 #define MEI_DEV_STATE(state) case MEI_DEV_##state: return #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);
36 const char *mei_pg_state_str(enum mei_pg_state state)
38 #define MEI_PG_STATE(state) case MEI_PG_##state: return #state
49 * mei_fw_status2str - convert fw status registers to printable string
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
55 * Return: number of bytes written or -EINVAL if buffer is to small
57 ssize_t mei_fw_status2str(struct mei_fw_status *fw_status,
58 char *buf, size_t len)
65 if (len < MEI_FW_STATUS_STR_SZ)
68 for (i = 0; i < fw_status->count; i++)
69 cnt += scnprintf(buf + cnt, len - cnt, "%08X ",
70 fw_status->status[i]);
76 EXPORT_SYMBOL_GPL(mei_fw_status2str);
79 * mei_cancel_work - Cancel mei background jobs
81 * @dev: the device structure
83 void mei_cancel_work(struct mei_device *dev)
85 cancel_work_sync(&dev->reset_work);
86 cancel_work_sync(&dev->bus_rescan_work);
88 cancel_delayed_work_sync(&dev->timer_work);
90 EXPORT_SYMBOL_GPL(mei_cancel_work);
93 * mei_reset - resets host and fw.
95 * @dev: the device structure
97 * Return: 0 on success or < 0 if the reset hasn't succeeded
99 int mei_reset(struct mei_device *dev)
101 enum mei_dev_state state = dev->dev_state;
102 bool interrupts_enabled;
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];
111 mei_fw_status_str(dev, fw_sts_str, MEI_FW_STATUS_STR_SZ);
112 dev_warn(dev->dev, "unexpected reset: dev_state = %s fw status = %s\n",
113 mei_dev_state_str(state), fw_sts_str);
116 mei_clear_interrupts(dev);
118 /* we're already in reset, cancel the init timer
119 * if the reset was called due the hbm protocol error
120 * we need to call it before hw start
121 * so the hbm watchdog won't kick in
125 /* enter reset flow */
126 interrupts_enabled = state != MEI_DEV_POWER_DOWN;
127 mei_set_devstate(dev, MEI_DEV_RESETTING);
130 if (dev->reset_count > MEI_MAX_CONSEC_RESET) {
131 dev_err(dev->dev, "reset: reached maximal consecutive resets: disabling the device\n");
132 mei_set_devstate(dev, MEI_DEV_DISABLED);
136 ret = mei_hw_reset(dev, interrupts_enabled);
137 /* fall through and remove the sw state even if hw reset has failed */
139 /* no need to clean up software state in case of power up */
140 if (state != MEI_DEV_INITIALIZING && state != MEI_DEV_POWER_UP)
141 mei_cl_all_disconnect(dev);
145 memset(dev->rd_msg_hdr, 0, sizeof(dev->rd_msg_hdr));
148 dev_err(dev->dev, "hw_reset failed ret = %d\n", ret);
152 if (state == MEI_DEV_POWER_DOWN) {
153 dev_dbg(dev->dev, "powering down: end of reset\n");
154 mei_set_devstate(dev, MEI_DEV_DISABLED);
158 ret = mei_hw_start(dev);
160 dev_err(dev->dev, "hw_start failed ret = %d\n", ret);
164 if (dev->dev_state != MEI_DEV_RESETTING) {
165 dev_dbg(dev->dev, "wrong state = %d on link start\n", dev->dev_state);
169 dev_dbg(dev->dev, "link is established start sending messages.\n");
171 mei_set_devstate(dev, MEI_DEV_INIT_CLIENTS);
172 ret = mei_hbm_start_req(dev);
174 dev_err(dev->dev, "hbm_start failed ret = %d\n", ret);
175 mei_set_devstate(dev, MEI_DEV_RESETTING);
181 EXPORT_SYMBOL_GPL(mei_reset);
184 * mei_start - initializes host and fw to start work.
186 * @dev: the device structure
188 * Return: 0 on success, <0 on failure.
190 int mei_start(struct mei_device *dev)
194 mutex_lock(&dev->device_lock);
196 /* acknowledge interrupt and stop interrupts */
197 mei_clear_interrupts(dev);
199 ret = mei_hw_config(dev);
203 dev_dbg(dev->dev, "reset in start the mei device.\n");
205 dev->reset_count = 0;
207 mei_set_devstate(dev, MEI_DEV_INITIALIZING);
208 ret = mei_reset(dev);
210 if (ret == -ENODEV || dev->dev_state == MEI_DEV_DISABLED) {
211 dev_err(dev->dev, "reset failed ret = %d", ret);
216 if (mei_hbm_start_wait(dev)) {
217 dev_err(dev->dev, "HBM haven't started");
221 if (!mei_host_is_ready(dev)) {
222 dev_err(dev->dev, "host is not ready.\n");
226 if (!mei_hw_is_ready(dev)) {
227 dev_err(dev->dev, "ME is not ready.\n");
231 if (!mei_hbm_version_is_supported(dev)) {
232 dev_dbg(dev->dev, "MEI start failed.\n");
236 dev_dbg(dev->dev, "link layer has been established.\n");
238 mutex_unlock(&dev->device_lock);
241 dev_err(dev->dev, "link layer initialization failed.\n");
242 mei_set_devstate(dev, MEI_DEV_DISABLED);
243 mutex_unlock(&dev->device_lock);
246 EXPORT_SYMBOL_GPL(mei_start);
249 * mei_restart - restart device after suspend
251 * @dev: the device structure
253 * Return: 0 on success or -ENODEV if the restart hasn't succeeded
255 int mei_restart(struct mei_device *dev)
259 mutex_lock(&dev->device_lock);
261 mei_set_devstate(dev, MEI_DEV_POWER_UP);
262 dev->reset_count = 0;
264 err = mei_reset(dev);
266 mutex_unlock(&dev->device_lock);
268 if (err == -ENODEV || dev->dev_state == MEI_DEV_DISABLED) {
269 dev_err(dev->dev, "device disabled = %d\n", err);
273 /* try to start again */
275 schedule_work(&dev->reset_work);
280 EXPORT_SYMBOL_GPL(mei_restart);
282 static void mei_reset_work(struct work_struct *work)
284 struct mei_device *dev =
285 container_of(work, struct mei_device, reset_work);
288 mei_clear_interrupts(dev);
289 mei_synchronize_irq(dev);
291 mutex_lock(&dev->device_lock);
293 ret = mei_reset(dev);
295 mutex_unlock(&dev->device_lock);
297 if (dev->dev_state == MEI_DEV_DISABLED) {
298 dev_err(dev->dev, "device disabled = %d\n", ret);
302 /* retry reset in case of failure */
304 schedule_work(&dev->reset_work);
307 void mei_stop(struct mei_device *dev)
309 dev_dbg(dev->dev, "stopping the device.\n");
311 mutex_lock(&dev->device_lock);
312 mei_set_devstate(dev, MEI_DEV_POWERING_DOWN);
313 mutex_unlock(&dev->device_lock);
314 mei_cl_bus_remove_devices(dev);
315 mutex_lock(&dev->device_lock);
316 mei_set_devstate(dev, MEI_DEV_POWER_DOWN);
317 mutex_unlock(&dev->device_lock);
319 mei_cancel_work(dev);
321 mei_clear_interrupts(dev);
322 mei_synchronize_irq(dev);
324 mutex_lock(&dev->device_lock);
327 /* move device to disabled state unconditionally */
328 mei_set_devstate(dev, MEI_DEV_DISABLED);
330 mutex_unlock(&dev->device_lock);
332 EXPORT_SYMBOL_GPL(mei_stop);
335 * mei_write_is_idle - check if the write queues are idle
337 * @dev: the device structure
339 * Return: true of there is no pending write
341 bool mei_write_is_idle(struct mei_device *dev)
343 bool idle = (dev->dev_state == MEI_DEV_ENABLED &&
344 list_empty(&dev->ctrl_wr_list) &&
345 list_empty(&dev->write_list) &&
346 list_empty(&dev->write_waiting_list));
348 dev_dbg(dev->dev, "write pg: is idle[%d] state=%s ctrl=%01d write=%01d wwait=%01d\n",
350 mei_dev_state_str(dev->dev_state),
351 list_empty(&dev->ctrl_wr_list),
352 list_empty(&dev->write_list),
353 list_empty(&dev->write_waiting_list));
357 EXPORT_SYMBOL_GPL(mei_write_is_idle);
360 * mei_device_init -- initialize mei_device structure
362 * @dev: the mei device
363 * @device: the device structure
364 * @hw_ops: hw operations
366 void mei_device_init(struct mei_device *dev,
367 struct device *device,
368 const struct mei_hw_ops *hw_ops)
370 /* setup our list array */
371 INIT_LIST_HEAD(&dev->file_list);
372 INIT_LIST_HEAD(&dev->device_list);
373 INIT_LIST_HEAD(&dev->me_clients);
374 mutex_init(&dev->device_lock);
375 init_rwsem(&dev->me_clients_rwsem);
376 mutex_init(&dev->cl_bus_lock);
377 init_waitqueue_head(&dev->wait_hw_ready);
378 init_waitqueue_head(&dev->wait_pg);
379 init_waitqueue_head(&dev->wait_hbm_start);
380 dev->dev_state = MEI_DEV_INITIALIZING;
381 dev->reset_count = 0;
383 INIT_LIST_HEAD(&dev->write_list);
384 INIT_LIST_HEAD(&dev->write_waiting_list);
385 INIT_LIST_HEAD(&dev->ctrl_wr_list);
386 INIT_LIST_HEAD(&dev->ctrl_rd_list);
387 dev->tx_queue_limit = MEI_TX_QUEUE_LIMIT_DEFAULT;
389 INIT_DELAYED_WORK(&dev->timer_work, mei_timer);
390 INIT_WORK(&dev->reset_work, mei_reset_work);
391 INIT_WORK(&dev->bus_rescan_work, mei_cl_bus_rescan_work);
393 bitmap_zero(dev->host_clients_map, MEI_CLIENTS_MAX);
394 dev->open_handle_count = 0;
397 * Reserving the first client ID
398 * 0: Reserved for MEI Bus Message communications
400 bitmap_set(dev->host_clients_map, 0, 1);
402 dev->pg_event = MEI_PG_EVENT_IDLE;
406 EXPORT_SYMBOL_GPL(mei_device_init);