xref: /openbmc/linux/drivers/misc/mei/init.c (revision e23feb16)
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/pci.h>
19 #include <linux/sched.h>
20 #include <linux/wait.h>
21 #include <linux/delay.h>
22 
23 #include <linux/mei.h>
24 
25 #include "mei_dev.h"
26 #include "hbm.h"
27 #include "client.h"
28 
29 const char *mei_dev_state_str(int state)
30 {
31 #define MEI_DEV_STATE(state) case MEI_DEV_##state: return #state
32 	switch (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);
40 	default:
41 		return "unknown";
42 	}
43 #undef MEI_DEV_STATE
44 }
45 
46 void mei_device_init(struct mei_device *dev)
47 {
48 	/* setup our list array */
49 	INIT_LIST_HEAD(&dev->file_list);
50 	INIT_LIST_HEAD(&dev->device_list);
51 	mutex_init(&dev->device_lock);
52 	init_waitqueue_head(&dev->wait_hw_ready);
53 	init_waitqueue_head(&dev->wait_recvd_msg);
54 	init_waitqueue_head(&dev->wait_stop_wd);
55 	dev->dev_state = MEI_DEV_INITIALIZING;
56 
57 	mei_io_list_init(&dev->read_list);
58 	mei_io_list_init(&dev->write_list);
59 	mei_io_list_init(&dev->write_waiting_list);
60 	mei_io_list_init(&dev->ctrl_wr_list);
61 	mei_io_list_init(&dev->ctrl_rd_list);
62 
63 	INIT_DELAYED_WORK(&dev->timer_work, mei_timer);
64 	INIT_WORK(&dev->init_work, mei_host_client_init);
65 
66 	INIT_LIST_HEAD(&dev->wd_cl.link);
67 	INIT_LIST_HEAD(&dev->iamthif_cl.link);
68 	mei_io_list_init(&dev->amthif_cmd_list);
69 	mei_io_list_init(&dev->amthif_rd_complete_list);
70 
71 }
72 EXPORT_SYMBOL_GPL(mei_device_init);
73 
74 /**
75  * mei_start - initializes host and fw to start work.
76  *
77  * @dev: the device structure
78  *
79  * returns 0 on success, <0 on failure.
80  */
81 int mei_start(struct mei_device *dev)
82 {
83 	mutex_lock(&dev->device_lock);
84 
85 	/* acknowledge interrupt and stop interupts */
86 	mei_clear_interrupts(dev);
87 
88 	mei_hw_config(dev);
89 
90 	dev_dbg(&dev->pdev->dev, "reset in start the mei device.\n");
91 
92 	mei_reset(dev, 1);
93 
94 	if (mei_hbm_start_wait(dev)) {
95 		dev_err(&dev->pdev->dev, "HBM haven't started");
96 		goto err;
97 	}
98 
99 	if (!mei_host_is_ready(dev)) {
100 		dev_err(&dev->pdev->dev, "host is not ready.\n");
101 		goto err;
102 	}
103 
104 	if (!mei_hw_is_ready(dev)) {
105 		dev_err(&dev->pdev->dev, "ME is not ready.\n");
106 		goto err;
107 	}
108 
109 	if (!mei_hbm_version_is_supported(dev)) {
110 		dev_dbg(&dev->pdev->dev, "MEI start failed.\n");
111 		goto err;
112 	}
113 
114 	dev_dbg(&dev->pdev->dev, "link layer has been established.\n");
115 
116 	mutex_unlock(&dev->device_lock);
117 	return 0;
118 err:
119 	dev_err(&dev->pdev->dev, "link layer initialization failed.\n");
120 	dev->dev_state = MEI_DEV_DISABLED;
121 	mutex_unlock(&dev->device_lock);
122 	return -ENODEV;
123 }
124 EXPORT_SYMBOL_GPL(mei_start);
125 
126 /**
127  * mei_reset - resets host and fw.
128  *
129  * @dev: the device structure
130  * @interrupts_enabled: if interrupt should be enabled after reset.
131  */
132 void mei_reset(struct mei_device *dev, int interrupts_enabled)
133 {
134 	bool unexpected;
135 	int ret;
136 
137 	unexpected = (dev->dev_state != MEI_DEV_INITIALIZING &&
138 			dev->dev_state != MEI_DEV_DISABLED &&
139 			dev->dev_state != MEI_DEV_POWER_DOWN &&
140 			dev->dev_state != MEI_DEV_POWER_UP);
141 
142 	ret = mei_hw_reset(dev, interrupts_enabled);
143 	if (ret) {
144 		dev_err(&dev->pdev->dev, "hw reset failed disabling the device\n");
145 		interrupts_enabled = false;
146 		dev->dev_state = MEI_DEV_DISABLED;
147 	}
148 
149 	dev->hbm_state = MEI_HBM_IDLE;
150 
151 	if (dev->dev_state != MEI_DEV_INITIALIZING &&
152 	    dev->dev_state != MEI_DEV_POWER_UP) {
153 		if (dev->dev_state != MEI_DEV_DISABLED &&
154 		    dev->dev_state != MEI_DEV_POWER_DOWN)
155 			dev->dev_state = MEI_DEV_RESETTING;
156 
157 		/* remove all waiting requests */
158 		mei_cl_all_write_clear(dev);
159 
160 		mei_cl_all_disconnect(dev);
161 
162 		/* wake up all readings so they can be interrupted */
163 		mei_cl_all_wakeup(dev);
164 
165 		/* remove entry if already in list */
166 		dev_dbg(&dev->pdev->dev, "remove iamthif and wd from the file list.\n");
167 		mei_cl_unlink(&dev->wd_cl);
168 		if (dev->open_handle_count > 0)
169 			dev->open_handle_count--;
170 		mei_cl_unlink(&dev->iamthif_cl);
171 		if (dev->open_handle_count > 0)
172 			dev->open_handle_count--;
173 
174 		mei_amthif_reset_params(dev);
175 		memset(&dev->wr_ext_msg, 0, sizeof(dev->wr_ext_msg));
176 	}
177 
178 	/* we're already in reset, cancel the init timer */
179 	dev->init_clients_timer = 0;
180 
181 	dev->me_clients_num = 0;
182 	dev->rd_msg_hdr = 0;
183 	dev->wd_pending = false;
184 
185 	if (unexpected)
186 		dev_warn(&dev->pdev->dev, "unexpected reset: dev_state = %s\n",
187 			 mei_dev_state_str(dev->dev_state));
188 
189 	if (!interrupts_enabled) {
190 		dev_dbg(&dev->pdev->dev, "intr not enabled end of reset\n");
191 		return;
192 	}
193 
194 	ret = mei_hw_start(dev);
195 	if (ret) {
196 		dev_err(&dev->pdev->dev, "hw_start failed disabling the device\n");
197 		dev->dev_state = MEI_DEV_DISABLED;
198 		return;
199 	}
200 
201 	dev_dbg(&dev->pdev->dev, "link is established start sending messages.\n");
202 	/* link is established * start sending messages.  */
203 
204 	dev->dev_state = MEI_DEV_INIT_CLIENTS;
205 
206 	mei_hbm_start_req(dev);
207 
208 }
209 EXPORT_SYMBOL_GPL(mei_reset);
210 
211 void mei_stop(struct mei_device *dev)
212 {
213 	dev_dbg(&dev->pdev->dev, "stopping the device.\n");
214 
215 	flush_scheduled_work();
216 
217 	mutex_lock(&dev->device_lock);
218 
219 	cancel_delayed_work(&dev->timer_work);
220 
221 	mei_wd_stop(dev);
222 
223 	mei_nfc_host_exit();
224 
225 	dev->dev_state = MEI_DEV_POWER_DOWN;
226 	mei_reset(dev, 0);
227 
228 	mutex_unlock(&dev->device_lock);
229 
230 	mei_watchdog_unregister(dev);
231 }
232 EXPORT_SYMBOL_GPL(mei_stop);
233 
234 
235 
236