3 * Intel Management Engine Interface (Intel MEI) Linux driver
4 * Copyright (c) 2003-2012, Intel Corporation.
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.
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
17 #include <linux/export.h>
18 #include <linux/sched.h>
19 #include <linux/wait.h>
20 #include <linux/delay.h>
22 #include <linux/mei.h>
28 const char *mei_dev_state_str(int state)
30 #define MEI_DEV_STATE(state) case MEI_DEV_##state: return #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);
45 const char *mei_pg_state_str(enum mei_pg_state state)
47 #define MEI_PG_STATE(state) case MEI_PG_##state: return #state
58 * mei_fw_status2str - convert fw status registers to printable string
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
64 * Return: number of bytes written or -EINVAL if buffer is to small
66 ssize_t mei_fw_status2str(struct mei_fw_status *fw_status,
67 char *buf, size_t len)
74 if (len < MEI_FW_STATUS_STR_SZ)
77 for (i = 0; i < fw_status->count; i++)
78 cnt += scnprintf(buf + cnt, len - cnt, "%08X ",
79 fw_status->status[i]);
85 EXPORT_SYMBOL_GPL(mei_fw_status2str);
88 * mei_cancel_work - Cancel mei background jobs
90 * @dev: the device structure
92 void mei_cancel_work(struct mei_device *dev)
94 cancel_work_sync(&dev->reset_work);
95 cancel_work_sync(&dev->bus_rescan_work);
97 cancel_delayed_work_sync(&dev->timer_work);
99 EXPORT_SYMBOL_GPL(mei_cancel_work);
102 * mei_reset - resets host and fw.
104 * @dev: the device structure
106 * Return: 0 on success or < 0 if the reset hasn't succeeded
108 int mei_reset(struct mei_device *dev)
110 enum mei_dev_state state = dev->dev_state;
111 bool interrupts_enabled;
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];
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);
125 mei_clear_interrupts(dev);
127 /* we're already in reset, cancel the init timer
128 * if the reset was called due the hbm protocol error
129 * we need to call it before hw start
130 * so the hbm watchdog won't kick in
134 /* enter reset flow */
135 interrupts_enabled = state != MEI_DEV_POWER_DOWN;
136 dev->dev_state = MEI_DEV_RESETTING;
139 if (dev->reset_count > MEI_MAX_CONSEC_RESET) {
140 dev_err(dev->dev, "reset: reached maximal consecutive resets: disabling the device\n");
141 dev->dev_state = MEI_DEV_DISABLED;
145 ret = mei_hw_reset(dev, interrupts_enabled);
146 /* fall through and remove the sw state even if hw reset has failed */
148 /* no need to clean up software state in case of power up */
149 if (state != MEI_DEV_INITIALIZING &&
150 state != MEI_DEV_POWER_UP) {
152 /* remove all waiting requests */
153 mei_cl_all_disconnect(dev);
155 /* remove entry if already in list */
156 dev_dbg(dev->dev, "remove iamthif from the file list.\n");
157 mei_cl_unlink(&dev->iamthif_cl);
158 mei_amthif_reset_params(dev);
166 dev_err(dev->dev, "hw_reset failed ret = %d\n", ret);
170 if (state == MEI_DEV_POWER_DOWN) {
171 dev_dbg(dev->dev, "powering down: end of reset\n");
172 dev->dev_state = MEI_DEV_DISABLED;
176 ret = mei_hw_start(dev);
178 dev_err(dev->dev, "hw_start failed ret = %d\n", ret);
182 dev_dbg(dev->dev, "link is established start sending messages.\n");
184 dev->dev_state = MEI_DEV_INIT_CLIENTS;
185 ret = mei_hbm_start_req(dev);
187 dev_err(dev->dev, "hbm_start failed ret = %d\n", ret);
188 dev->dev_state = MEI_DEV_RESETTING;
194 EXPORT_SYMBOL_GPL(mei_reset);
197 * mei_start - initializes host and fw to start work.
199 * @dev: the device structure
201 * Return: 0 on success, <0 on failure.
203 int mei_start(struct mei_device *dev)
207 mutex_lock(&dev->device_lock);
209 /* acknowledge interrupt and stop interrupts */
210 mei_clear_interrupts(dev);
214 dev_dbg(dev->dev, "reset in start the mei device.\n");
216 dev->reset_count = 0;
218 dev->dev_state = MEI_DEV_INITIALIZING;
219 ret = mei_reset(dev);
221 if (ret == -ENODEV || dev->dev_state == MEI_DEV_DISABLED) {
222 dev_err(dev->dev, "reset failed ret = %d", ret);
227 /* we cannot start the device w/o hbm start message completed */
228 if (dev->dev_state == MEI_DEV_DISABLED) {
229 dev_err(dev->dev, "reset failed");
233 if (mei_hbm_start_wait(dev)) {
234 dev_err(dev->dev, "HBM haven't started");
238 if (!mei_host_is_ready(dev)) {
239 dev_err(dev->dev, "host is not ready.\n");
243 if (!mei_hw_is_ready(dev)) {
244 dev_err(dev->dev, "ME is not ready.\n");
248 if (!mei_hbm_version_is_supported(dev)) {
249 dev_dbg(dev->dev, "MEI start failed.\n");
253 dev_dbg(dev->dev, "link layer has been established.\n");
255 mutex_unlock(&dev->device_lock);
258 dev_err(dev->dev, "link layer initialization failed.\n");
259 dev->dev_state = MEI_DEV_DISABLED;
260 mutex_unlock(&dev->device_lock);
263 EXPORT_SYMBOL_GPL(mei_start);
266 * mei_restart - restart device after suspend
268 * @dev: the device structure
270 * Return: 0 on success or -ENODEV if the restart hasn't succeeded
272 int mei_restart(struct mei_device *dev)
276 mutex_lock(&dev->device_lock);
278 dev->dev_state = MEI_DEV_POWER_UP;
279 dev->reset_count = 0;
281 err = mei_reset(dev);
283 mutex_unlock(&dev->device_lock);
285 if (err == -ENODEV || dev->dev_state == MEI_DEV_DISABLED) {
286 dev_err(dev->dev, "device disabled = %d\n", err);
290 /* try to start again */
292 schedule_work(&dev->reset_work);
297 EXPORT_SYMBOL_GPL(mei_restart);
299 static void mei_reset_work(struct work_struct *work)
301 struct mei_device *dev =
302 container_of(work, struct mei_device, reset_work);
305 mei_clear_interrupts(dev);
306 mei_synchronize_irq(dev);
308 mutex_lock(&dev->device_lock);
310 ret = mei_reset(dev);
312 mutex_unlock(&dev->device_lock);
314 if (dev->dev_state == MEI_DEV_DISABLED) {
315 dev_err(dev->dev, "device disabled = %d\n", ret);
319 /* retry reset in case of failure */
321 schedule_work(&dev->reset_work);
324 void mei_stop(struct mei_device *dev)
326 dev_dbg(dev->dev, "stopping the device.\n");
328 mei_cl_bus_remove_devices(dev);
330 mei_cancel_work(dev);
332 mei_clear_interrupts(dev);
333 mei_synchronize_irq(dev);
335 mutex_lock(&dev->device_lock);
337 dev->dev_state = MEI_DEV_POWER_DOWN;
339 /* move device to disabled state unconditionally */
340 dev->dev_state = MEI_DEV_DISABLED;
342 mutex_unlock(&dev->device_lock);
344 EXPORT_SYMBOL_GPL(mei_stop);
347 * mei_write_is_idle - check if the write queues are idle
349 * @dev: the device structure
351 * Return: true of there is no pending write
353 bool mei_write_is_idle(struct mei_device *dev)
355 bool idle = (dev->dev_state == MEI_DEV_ENABLED &&
356 list_empty(&dev->ctrl_wr_list) &&
357 list_empty(&dev->write_list) &&
358 list_empty(&dev->write_waiting_list));
360 dev_dbg(dev->dev, "write pg: is idle[%d] state=%s ctrl=%01d write=%01d wwait=%01d\n",
362 mei_dev_state_str(dev->dev_state),
363 list_empty(&dev->ctrl_wr_list),
364 list_empty(&dev->write_list),
365 list_empty(&dev->write_waiting_list));
369 EXPORT_SYMBOL_GPL(mei_write_is_idle);
372 * mei_device_init -- initialize mei_device structure
374 * @dev: the mei device
375 * @device: the device structure
376 * @hw_ops: hw operations
378 void mei_device_init(struct mei_device *dev,
379 struct device *device,
380 const struct mei_hw_ops *hw_ops)
382 /* setup our list array */
383 INIT_LIST_HEAD(&dev->file_list);
384 INIT_LIST_HEAD(&dev->device_list);
385 INIT_LIST_HEAD(&dev->me_clients);
386 mutex_init(&dev->device_lock);
387 init_rwsem(&dev->me_clients_rwsem);
388 mutex_init(&dev->cl_bus_lock);
389 init_waitqueue_head(&dev->wait_hw_ready);
390 init_waitqueue_head(&dev->wait_pg);
391 init_waitqueue_head(&dev->wait_hbm_start);
392 dev->dev_state = MEI_DEV_INITIALIZING;
393 dev->reset_count = 0;
395 INIT_LIST_HEAD(&dev->write_list);
396 INIT_LIST_HEAD(&dev->write_waiting_list);
397 INIT_LIST_HEAD(&dev->ctrl_wr_list);
398 INIT_LIST_HEAD(&dev->ctrl_rd_list);
400 INIT_DELAYED_WORK(&dev->timer_work, mei_timer);
401 INIT_WORK(&dev->reset_work, mei_reset_work);
402 INIT_WORK(&dev->bus_rescan_work, mei_cl_bus_rescan_work);
404 INIT_LIST_HEAD(&dev->iamthif_cl.link);
405 INIT_LIST_HEAD(&dev->amthif_cmd_list);
407 bitmap_zero(dev->host_clients_map, MEI_CLIENTS_MAX);
408 dev->open_handle_count = 0;
411 * Reserving the first client ID
412 * 0: Reserved for MEI Bus Message communications
414 bitmap_set(dev->host_clients_map, 0, 1);
416 dev->pg_event = MEI_PG_EVENT_IDLE;
420 EXPORT_SYMBOL_GPL(mei_device_init);