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/pci.h>
19 #include <linux/sched.h>
20 #include <linux/wait.h>
21 #include <linux/delay.h>
23 #include <linux/mei.h>
29 const char *mei_dev_state_str(int state)
31 #define MEI_DEV_STATE(state) case MEI_DEV_##state: return #state
33 MEI_DEV_STATE(INITIALIZING);
34 MEI_DEV_STATE(INIT_CLIENTS);
35 MEI_DEV_STATE(ENABLED);
36 MEI_DEV_STATE(RESETTING);
37 MEI_DEV_STATE(DISABLED);
38 MEI_DEV_STATE(POWER_DOWN);
39 MEI_DEV_STATE(POWER_UP);
48 * mei_cancel_work. Cancel mei background jobs
50 * @dev: the device structure
52 * returns 0 on success or < 0 if the reset hasn't succeeded
54 void mei_cancel_work(struct mei_device *dev)
56 cancel_work_sync(&dev->init_work);
57 cancel_work_sync(&dev->reset_work);
59 cancel_delayed_work(&dev->timer_work);
61 EXPORT_SYMBOL_GPL(mei_cancel_work);
64 * mei_reset - resets host and fw.
66 * @dev: the device structure
68 int mei_reset(struct mei_device *dev)
70 enum mei_dev_state state = dev->dev_state;
71 bool interrupts_enabled;
74 if (state != MEI_DEV_INITIALIZING &&
75 state != MEI_DEV_DISABLED &&
76 state != MEI_DEV_POWER_DOWN &&
77 state != MEI_DEV_POWER_UP)
78 dev_warn(&dev->pdev->dev, "unexpected reset: dev_state = %s\n",
79 mei_dev_state_str(state));
81 /* we're already in reset, cancel the init timer
82 * if the reset was called due the hbm protocol error
83 * we need to call it before hw start
84 * so the hbm watchdog won't kick in
88 /* enter reset flow */
89 interrupts_enabled = state != MEI_DEV_POWER_DOWN;
90 dev->dev_state = MEI_DEV_RESETTING;
93 if (dev->reset_count > MEI_MAX_CONSEC_RESET) {
94 dev_err(&dev->pdev->dev, "reset: reached maximal consecutive resets: disabling the device\n");
95 dev->dev_state = MEI_DEV_DISABLED;
99 ret = mei_hw_reset(dev, interrupts_enabled);
100 /* fall through and remove the sw state even if hw reset has failed */
102 /* no need to clean up software state in case of power up */
103 if (state != MEI_DEV_INITIALIZING &&
104 state != MEI_DEV_POWER_UP) {
106 /* remove all waiting requests */
107 mei_cl_all_write_clear(dev);
109 mei_cl_all_disconnect(dev);
111 /* wake up all readers and writers so they can be interrupted */
112 mei_cl_all_wakeup(dev);
114 /* remove entry if already in list */
115 dev_dbg(&dev->pdev->dev, "remove iamthif and wd from the file list.\n");
116 mei_cl_unlink(&dev->wd_cl);
117 mei_cl_unlink(&dev->iamthif_cl);
118 mei_amthif_reset_params(dev);
122 dev->me_clients_num = 0;
124 dev->wd_pending = false;
127 dev_err(&dev->pdev->dev, "hw_reset failed ret = %d\n", ret);
131 if (state == MEI_DEV_POWER_DOWN) {
132 dev_dbg(&dev->pdev->dev, "powering down: end of reset\n");
133 dev->dev_state = MEI_DEV_DISABLED;
137 ret = mei_hw_start(dev);
139 dev_err(&dev->pdev->dev, "hw_start failed ret = %d\n", ret);
143 dev_dbg(&dev->pdev->dev, "link is established start sending messages.\n");
145 dev->dev_state = MEI_DEV_INIT_CLIENTS;
146 ret = mei_hbm_start_req(dev);
148 dev_err(&dev->pdev->dev, "hbm_start failed ret = %d\n", ret);
149 dev->dev_state = MEI_DEV_RESETTING;
155 EXPORT_SYMBOL_GPL(mei_reset);
158 * mei_start - initializes host and fw to start work.
160 * @dev: the device structure
162 * returns 0 on success, <0 on failure.
164 int mei_start(struct mei_device *dev)
167 mutex_lock(&dev->device_lock);
169 /* acknowledge interrupt and stop interrupts */
170 mei_clear_interrupts(dev);
174 dev_dbg(&dev->pdev->dev, "reset in start the mei device.\n");
176 dev->reset_count = 0;
178 dev->dev_state = MEI_DEV_INITIALIZING;
179 ret = mei_reset(dev);
181 if (ret == -ENODEV || dev->dev_state == MEI_DEV_DISABLED) {
182 dev_err(&dev->pdev->dev, "reset failed ret = %d", ret);
187 /* we cannot start the device w/o hbm start message completed */
188 if (dev->dev_state == MEI_DEV_DISABLED) {
189 dev_err(&dev->pdev->dev, "reset failed");
193 if (mei_hbm_start_wait(dev)) {
194 dev_err(&dev->pdev->dev, "HBM haven't started");
198 if (!mei_host_is_ready(dev)) {
199 dev_err(&dev->pdev->dev, "host is not ready.\n");
203 if (!mei_hw_is_ready(dev)) {
204 dev_err(&dev->pdev->dev, "ME is not ready.\n");
208 if (!mei_hbm_version_is_supported(dev)) {
209 dev_dbg(&dev->pdev->dev, "MEI start failed.\n");
213 dev_dbg(&dev->pdev->dev, "link layer has been established.\n");
215 mutex_unlock(&dev->device_lock);
218 dev_err(&dev->pdev->dev, "link layer initialization failed.\n");
219 dev->dev_state = MEI_DEV_DISABLED;
220 mutex_unlock(&dev->device_lock);
223 EXPORT_SYMBOL_GPL(mei_start);
226 * mei_restart - restart device after suspend
228 * @dev: the device structure
230 * returns 0 on success or -ENODEV if the restart hasn't succeeded
232 int mei_restart(struct mei_device *dev)
236 mutex_lock(&dev->device_lock);
238 mei_clear_interrupts(dev);
240 dev->dev_state = MEI_DEV_POWER_UP;
241 dev->reset_count = 0;
243 err = mei_reset(dev);
245 mutex_unlock(&dev->device_lock);
247 if (err == -ENODEV || dev->dev_state == MEI_DEV_DISABLED) {
248 dev_err(&dev->pdev->dev, "device disabled = %d\n", err);
252 /* try to start again */
254 schedule_work(&dev->reset_work);
259 EXPORT_SYMBOL_GPL(mei_restart);
261 static void mei_reset_work(struct work_struct *work)
263 struct mei_device *dev =
264 container_of(work, struct mei_device, reset_work);
267 mutex_lock(&dev->device_lock);
269 ret = mei_reset(dev);
271 mutex_unlock(&dev->device_lock);
273 if (dev->dev_state == MEI_DEV_DISABLED) {
274 dev_err(&dev->pdev->dev, "device disabled = %d\n", ret);
278 /* retry reset in case of failure */
280 schedule_work(&dev->reset_work);
283 void mei_stop(struct mei_device *dev)
285 dev_dbg(&dev->pdev->dev, "stopping the device.\n");
287 mei_cancel_work(dev);
289 mei_nfc_host_exit(dev);
291 mei_cl_bus_remove_devices(dev);
293 mutex_lock(&dev->device_lock);
297 dev->dev_state = MEI_DEV_POWER_DOWN;
300 mutex_unlock(&dev->device_lock);
302 mei_watchdog_unregister(dev);
304 EXPORT_SYMBOL_GPL(mei_stop);
308 void mei_device_init(struct mei_device *dev)
310 /* setup our list array */
311 INIT_LIST_HEAD(&dev->file_list);
312 INIT_LIST_HEAD(&dev->device_list);
313 mutex_init(&dev->device_lock);
314 init_waitqueue_head(&dev->wait_hw_ready);
315 init_waitqueue_head(&dev->wait_recvd_msg);
316 init_waitqueue_head(&dev->wait_stop_wd);
317 dev->dev_state = MEI_DEV_INITIALIZING;
318 dev->reset_count = 0;
320 mei_io_list_init(&dev->read_list);
321 mei_io_list_init(&dev->write_list);
322 mei_io_list_init(&dev->write_waiting_list);
323 mei_io_list_init(&dev->ctrl_wr_list);
324 mei_io_list_init(&dev->ctrl_rd_list);
326 INIT_DELAYED_WORK(&dev->timer_work, mei_timer);
327 INIT_WORK(&dev->init_work, mei_host_client_init);
328 INIT_WORK(&dev->reset_work, mei_reset_work);
330 INIT_LIST_HEAD(&dev->wd_cl.link);
331 INIT_LIST_HEAD(&dev->iamthif_cl.link);
332 mei_io_list_init(&dev->amthif_cmd_list);
333 mei_io_list_init(&dev->amthif_rd_complete_list);
335 bitmap_zero(dev->host_clients_map, MEI_CLIENTS_MAX);
336 dev->open_handle_count = 0;
339 * Reserving the first client ID
340 * 0: Reserved for MEI Bus Message communications
342 bitmap_set(dev->host_clients_map, 0, 1);
344 EXPORT_SYMBOL_GPL(mei_device_init);