1/*
2 *
3 * Intel Management Engine Interface (Intel MEI) Linux driver
4 * Copyright (c) 2003-2011, 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#include <linux/kernel.h>
17#include <linux/module.h>
18#include <linux/moduleparam.h>
19#include <linux/device.h>
20#include <linux/pci.h>
21#include <linux/sched.h>
22#include <linux/watchdog.h>
23
24#include "mei_dev.h"
25#include "hw.h"
26#include "interface.h"
27#include "mei.h"
28
29static const u8 mei_start_wd_params[] = { 0x02, 0x12, 0x13, 0x10 };
30static const u8 mei_stop_wd_params[] = { 0x02, 0x02, 0x14, 0x10 };
31
32const u8 mei_wd_state_independence_msg[3][4] = {
33	{0x05, 0x02, 0x51, 0x10},
34	{0x05, 0x02, 0x52, 0x10},
35	{0x07, 0x02, 0x01, 0x10}
36};
37
38/*
39 * AMT Watchdog Device
40 */
41#define INTEL_AMT_WATCHDOG_ID "INTCAMT"
42
43/* UUIDs for AMT F/W clients */
44const uuid_le mei_wd_guid = UUID_LE(0x05B79A6F, 0x4628, 0x4D7F, 0x89,
45						0x9D, 0xA9, 0x15, 0x14, 0xCB,
46						0x32, 0xAB);
47
48void mei_wd_set_start_timeout(struct mei_device *dev, u16 timeout)
49{
50	dev_dbg(&dev->pdev->dev, "timeout=%d.\n", timeout);
51	memcpy(dev->wd_data, mei_start_wd_params, MEI_WD_PARAMS_SIZE);
52	memcpy(dev->wd_data + MEI_WD_PARAMS_SIZE,
53			&timeout, sizeof(u16));
54}
55
56/**
57 * host_init_wd - mei initialization wd.
58 *
59 * @dev: the device structure
60 */
61bool mei_wd_host_init(struct mei_device *dev)
62{
63	bool ret = false;
64
65	mei_cl_init(&dev->wd_cl, dev);
66
67	/* look for WD client and connect to it */
68	dev->wd_cl.state = MEI_FILE_DISCONNECTED;
69	dev->wd_timeout = AMT_WD_DEFAULT_TIMEOUT;
70
71	/* find ME WD client */
72	mei_find_me_client_update_filext(dev, &dev->wd_cl,
73				&mei_wd_guid, MEI_WD_HOST_CLIENT_ID);
74
75	dev_dbg(&dev->pdev->dev, "check wd_cl\n");
76	if (MEI_FILE_CONNECTING == dev->wd_cl.state) {
77		if (!mei_connect(dev, &dev->wd_cl)) {
78			dev_dbg(&dev->pdev->dev, "Failed to connect to WD client\n");
79			dev->wd_cl.state = MEI_FILE_DISCONNECTED;
80			dev->wd_cl.host_client_id = 0;
81			ret = false;
82			goto end;
83		} else {
84			dev->wd_cl.timer_count = CONNECT_TIMEOUT;
85		}
86	} else {
87		dev_dbg(&dev->pdev->dev, "Failed to find WD client\n");
88		ret = false;
89		goto end;
90	}
91
92end:
93	return ret;
94}
95
96/**
97 * mei_wd_send - sends watch dog message to fw.
98 *
99 * @dev: the device structure
100 *
101 * returns 0 if success,
102 *	-EIO when message send fails
103 *	-EINVAL when invalid message is to be sent
104 */
105int mei_wd_send(struct mei_device *dev)
106{
107	struct mei_msg_hdr *mei_hdr;
108
109	mei_hdr = (struct mei_msg_hdr *) &dev->wr_msg_buf[0];
110	mei_hdr->host_addr = dev->wd_cl.host_client_id;
111	mei_hdr->me_addr = dev->wd_cl.me_client_id;
112	mei_hdr->msg_complete = 1;
113	mei_hdr->reserved = 0;
114
115	if (!memcmp(dev->wd_data, mei_start_wd_params, MEI_WD_PARAMS_SIZE))
116		mei_hdr->length = MEI_START_WD_DATA_SIZE;
117	else if (!memcmp(dev->wd_data, mei_stop_wd_params, MEI_WD_PARAMS_SIZE))
118		mei_hdr->length = MEI_WD_PARAMS_SIZE;
119	else
120		return -EINVAL;
121
122	if (mei_write_message(dev, mei_hdr, dev->wd_data, mei_hdr->length))
123		return 0;
124	return -EIO;
125}
126
127/**
128 * mei_wd_stop - sends watchdog stop message to fw.
129 *
130 * @dev: the device structure
131 * @preserve: indicate if to keep the timeout value
132 *
133 * returns 0 if success,
134 *	-EIO when message send fails
135 *	-EINVAL when invalid message is to be sent
136 */
137int mei_wd_stop(struct mei_device *dev, bool preserve)
138{
139	int ret;
140	u16 wd_timeout = dev->wd_timeout;
141
142	cancel_delayed_work(&dev->timer_work);
143	if (dev->wd_cl.state != MEI_FILE_CONNECTED || !dev->wd_timeout)
144		return 0;
145
146	dev->wd_timeout = 0;
147	dev->wd_due_counter = 0;
148	memcpy(dev->wd_data, mei_stop_wd_params, MEI_WD_PARAMS_SIZE);
149	dev->stop = true;
150
151	ret = mei_flow_ctrl_creds(dev, &dev->wd_cl);
152	if (ret < 0)
153		goto out;
154
155	if (ret && dev->mei_host_buffer_is_empty) {
156		ret = 0;
157		dev->mei_host_buffer_is_empty = false;
158
159		if (!mei_wd_send(dev)) {
160			ret = mei_flow_ctrl_reduce(dev, &dev->wd_cl);
161			if (ret)
162				goto out;
163		} else {
164			dev_dbg(&dev->pdev->dev, "send stop WD failed\n");
165		}
166
167		dev->wd_pending = false;
168	} else {
169		dev->wd_pending = true;
170	}
171	dev->wd_stopped = false;
172	mutex_unlock(&dev->device_lock);
173
174	ret = wait_event_interruptible_timeout(dev->wait_stop_wd,
175					dev->wd_stopped, 10 * HZ);
176	mutex_lock(&dev->device_lock);
177	if (dev->wd_stopped) {
178		dev_dbg(&dev->pdev->dev, "stop wd complete ret=%d.\n", ret);
179		ret = 0;
180	} else {
181		if (!ret)
182			ret = -ETIMEDOUT;
183		dev_warn(&dev->pdev->dev,
184			"stop wd failed to complete ret=%d.\n", ret);
185	}
186
187	if (preserve)
188		dev->wd_timeout = wd_timeout;
189
190out:
191	return ret;
192}
193
194/*
195 * mei_wd_ops_start - wd start command from the watchdog core.
196 *
197 * @wd_dev - watchdog device struct
198 *
199 * returns 0 if success, negative errno code for failure
200 */
201static int mei_wd_ops_start(struct watchdog_device *wd_dev)
202{
203	int err = -ENODEV;
204	struct mei_device *dev;
205
206	dev = pci_get_drvdata(mei_device);
207	if (!dev)
208		return -ENODEV;
209
210	mutex_lock(&dev->device_lock);
211
212	if (dev->mei_state != MEI_ENABLED) {
213		dev_dbg(&dev->pdev->dev, "mei_state != MEI_ENABLED  mei_state= %d\n",
214		    dev->mei_state);
215		goto end_unlock;
216	}
217
218	if (dev->wd_cl.state != MEI_FILE_CONNECTED)	{
219		dev_dbg(&dev->pdev->dev, "MEI Driver is not connected to Watchdog Client\n");
220		goto end_unlock;
221	}
222
223	mei_wd_set_start_timeout(dev, dev->wd_timeout);
224
225	err = 0;
226end_unlock:
227	mutex_unlock(&dev->device_lock);
228	return err;
229}
230
231/*
232 * mei_wd_ops_stop -  wd stop command from the watchdog core.
233 *
234 * @wd_dev - watchdog device struct
235 *
236 * returns 0 if success, negative errno code for failure
237 */
238static int mei_wd_ops_stop(struct watchdog_device *wd_dev)
239{
240	struct mei_device *dev;
241	dev = pci_get_drvdata(mei_device);
242
243	if (!dev)
244		return -ENODEV;
245
246	mutex_lock(&dev->device_lock);
247	mei_wd_stop(dev, false);
248	mutex_unlock(&dev->device_lock);
249
250	return 0;
251}
252
253/*
254 * mei_wd_ops_ping - wd ping command from the watchdog core.
255 *
256 * @wd_dev - watchdog device struct
257 *
258 * returns 0 if success, negative errno code for failure
259 */
260static int mei_wd_ops_ping(struct watchdog_device *wd_dev)
261{
262	int ret = 0;
263	struct mei_device *dev;
264	dev = pci_get_drvdata(mei_device);
265
266	if (!dev)
267		return -ENODEV;
268
269	mutex_lock(&dev->device_lock);
270
271	if (dev->wd_cl.state != MEI_FILE_CONNECTED) {
272		dev_dbg(&dev->pdev->dev, "wd is not connected.\n");
273		ret = -ENODEV;
274		goto end;
275	}
276
277	/* Check if we can send the ping to HW*/
278	if (dev->mei_host_buffer_is_empty &&
279		mei_flow_ctrl_creds(dev, &dev->wd_cl) > 0) {
280
281		dev->mei_host_buffer_is_empty = false;
282		dev_dbg(&dev->pdev->dev, "sending watchdog ping\n");
283
284		if (mei_wd_send(dev)) {
285			dev_dbg(&dev->pdev->dev, "wd send failed.\n");
286			ret = -EIO;
287			goto end;
288		}
289
290		if (mei_flow_ctrl_reduce(dev, &dev->wd_cl)) {
291			dev_dbg(&dev->pdev->dev, "mei_flow_ctrl_reduce() failed.\n");
292			ret = -EIO;
293			goto end;
294		}
295
296	} else {
297		dev->wd_pending = true;
298	}
299
300end:
301	mutex_unlock(&dev->device_lock);
302	return ret;
303}
304
305/*
306 * mei_wd_ops_set_timeout - wd set timeout command from the watchdog core.
307 *
308 * @wd_dev - watchdog device struct
309 * @timeout - timeout value to set
310 *
311 * returns 0 if success, negative errno code for failure
312 */
313static int mei_wd_ops_set_timeout(struct watchdog_device *wd_dev, unsigned int timeout)
314{
315	struct mei_device *dev;
316	dev = pci_get_drvdata(mei_device);
317
318	if (!dev)
319		return -ENODEV;
320
321	/* Check Timeout value */
322	if (timeout < AMT_WD_MIN_TIMEOUT || timeout > AMT_WD_MAX_TIMEOUT)
323		return -EINVAL;
324
325	mutex_lock(&dev->device_lock);
326
327	dev->wd_timeout = timeout;
328	mei_wd_set_start_timeout(dev, dev->wd_timeout);
329
330	mutex_unlock(&dev->device_lock);
331
332	return 0;
333}
334
335/*
336 * Watchdog Device structs
337 */
338static const struct watchdog_ops wd_ops = {
339		.owner = THIS_MODULE,
340		.start = mei_wd_ops_start,
341		.stop = mei_wd_ops_stop,
342		.ping = mei_wd_ops_ping,
343		.set_timeout = mei_wd_ops_set_timeout,
344};
345static const struct watchdog_info wd_info = {
346		.identity = INTEL_AMT_WATCHDOG_ID,
347		.options = WDIOF_KEEPALIVEPING,
348};
349
350struct watchdog_device amt_wd_dev = {
351		.info = &wd_info,
352		.ops = &wd_ops,
353		.timeout = AMT_WD_DEFAULT_TIMEOUT,
354		.min_timeout = AMT_WD_MIN_TIMEOUT,
355		.max_timeout = AMT_WD_MAX_TIMEOUT,
356};
357
358
359void  mei_watchdog_register(struct mei_device *dev)
360{
361	dev_dbg(&dev->pdev->dev, "dev->wd_timeout =%d.\n", dev->wd_timeout);
362
363	dev->wd_due_counter = !!dev->wd_timeout;
364
365	if (watchdog_register_device(&amt_wd_dev)) {
366		dev_err(&dev->pdev->dev, "unable to register watchdog device.\n");
367		dev->wd_interface_reg = false;
368	} else {
369		dev_dbg(&dev->pdev->dev, "successfully register watchdog interface.\n");
370		dev->wd_interface_reg = true;
371	}
372}
373
374void mei_watchdog_unregister(struct mei_device *dev)
375{
376	if (dev->wd_interface_reg)
377		watchdog_unregister_device(&amt_wd_dev);
378	dev->wd_interface_reg = false;
379}
380
381