tjh.dev
Linux kernel mirror (for testing)
git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git
kernel
os
linux
1/*
2 * Intel MIC Platform Software Stack (MPSS)
3 *
4 * Copyright(c) 2015 Intel Corporation.
5 *
6 * This program is free software; you can redistribute it and/or modify
7 * it under the terms of the GNU General Public License, version 2, as
8 * published by the Free Software Foundation.
9 *
10 * This program is distributed in the hope that it will be useful, but
11 * WITHOUT ANY WARRANTY; without even the implied warranty of
12 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
13 * General Public License for more details.
14 *
15 * The full GNU General Public License is included in this distribution in
16 * the file called "COPYING".
17 *
18 * Intel MIC COSM Client Driver
19 *
20 */
21#include <linux/module.h>
22#include <linux/delay.h>
23#include <linux/reboot.h>
24#include <linux/kthread.h>
25#include "../cosm/cosm_main.h"
26
27#define COSM_SCIF_MAX_RETRIES 10
28#define COSM_HEARTBEAT_SEND_MSEC (COSM_HEARTBEAT_SEND_SEC * MSEC_PER_SEC)
29
30static struct task_struct *client_thread;
31static scif_epd_t client_epd;
32static struct scif_peer_dev *client_spdev;
33
34/*
35 * Reboot notifier: receives shutdown status from the OS and communicates it
36 * back to the COSM process on the host
37 */
38static int cosm_reboot_event(struct notifier_block *this, unsigned long event,
39 void *ptr)
40{
41 struct cosm_msg msg = { .id = COSM_MSG_SHUTDOWN_STATUS };
42 int rc;
43
44 event = (event == SYS_RESTART) ? SYSTEM_RESTART : event;
45 dev_info(&client_spdev->dev, "%s %d received event %ld\n",
46 __func__, __LINE__, event);
47
48 msg.shutdown_status = event;
49 rc = scif_send(client_epd, &msg, sizeof(msg), SCIF_SEND_BLOCK);
50 if (rc < 0)
51 dev_err(&client_spdev->dev, "%s %d scif_send rc %d\n",
52 __func__, __LINE__, rc);
53
54 return NOTIFY_DONE;
55}
56
57static struct notifier_block cosm_reboot = {
58 .notifier_call = cosm_reboot_event,
59};
60
61/* Set system time from timespec value received from the host */
62static void cosm_set_time(struct cosm_msg *msg)
63{
64 int rc = do_settimeofday64(&msg->timespec);
65
66 if (rc)
67 dev_err(&client_spdev->dev, "%s: %d settimeofday rc %d\n",
68 __func__, __LINE__, rc);
69}
70
71/* COSM client receive message processing */
72static void cosm_client_recv(void)
73{
74 struct cosm_msg msg;
75 int rc;
76
77 while (1) {
78 rc = scif_recv(client_epd, &msg, sizeof(msg), 0);
79 if (!rc) {
80 return;
81 } else if (rc < 0) {
82 dev_err(&client_spdev->dev, "%s: %d rc %d\n",
83 __func__, __LINE__, rc);
84 return;
85 }
86
87 dev_dbg(&client_spdev->dev, "%s: %d rc %d id 0x%llx\n",
88 __func__, __LINE__, rc, msg.id);
89
90 switch (msg.id) {
91 case COSM_MSG_SYNC_TIME:
92 cosm_set_time(&msg);
93 break;
94 case COSM_MSG_SHUTDOWN:
95 orderly_poweroff(true);
96 break;
97 default:
98 dev_err(&client_spdev->dev, "%s: %d unknown id %lld\n",
99 __func__, __LINE__, msg.id);
100 break;
101 }
102 }
103}
104
105/* Initiate connection to the COSM server on the host */
106static int cosm_scif_connect(void)
107{
108 struct scif_port_id port_id;
109 int i, rc;
110
111 client_epd = scif_open();
112 if (!client_epd) {
113 dev_err(&client_spdev->dev, "%s %d scif_open failed\n",
114 __func__, __LINE__);
115 return -ENOMEM;
116 }
117
118 port_id.node = 0;
119 port_id.port = SCIF_COSM_LISTEN_PORT;
120
121 for (i = 0; i < COSM_SCIF_MAX_RETRIES; i++) {
122 rc = scif_connect(client_epd, &port_id);
123 if (rc < 0)
124 msleep(1000);
125 else
126 break;
127 }
128
129 if (rc < 0) {
130 dev_err(&client_spdev->dev, "%s %d scif_connect rc %d\n",
131 __func__, __LINE__, rc);
132 scif_close(client_epd);
133 client_epd = NULL;
134 }
135 return rc < 0 ? rc : 0;
136}
137
138/* Close host SCIF connection */
139static void cosm_scif_connect_exit(void)
140{
141 if (client_epd) {
142 scif_close(client_epd);
143 client_epd = NULL;
144 }
145}
146
147/*
148 * COSM SCIF client thread function: waits for messages from the host and sends
149 * a heartbeat to the host
150 */
151static int cosm_scif_client(void *unused)
152{
153 struct cosm_msg msg = { .id = COSM_MSG_HEARTBEAT };
154 struct scif_pollepd pollepd;
155 int rc;
156
157 allow_signal(SIGKILL);
158
159 while (!kthread_should_stop()) {
160 pollepd.epd = client_epd;
161 pollepd.events = POLLIN;
162
163 rc = scif_poll(&pollepd, 1, COSM_HEARTBEAT_SEND_MSEC);
164 if (rc < 0) {
165 if (-EINTR != rc)
166 dev_err(&client_spdev->dev,
167 "%s %d scif_poll rc %d\n",
168 __func__, __LINE__, rc);
169 continue;
170 }
171
172 if (pollepd.revents & POLLIN)
173 cosm_client_recv();
174
175 msg.id = COSM_MSG_HEARTBEAT;
176 rc = scif_send(client_epd, &msg, sizeof(msg), SCIF_SEND_BLOCK);
177 if (rc < 0)
178 dev_err(&client_spdev->dev, "%s %d scif_send rc %d\n",
179 __func__, __LINE__, rc);
180 }
181
182 dev_dbg(&client_spdev->dev, "%s %d Client thread stopped\n",
183 __func__, __LINE__);
184 return 0;
185}
186
187static void cosm_scif_probe(struct scif_peer_dev *spdev)
188{
189 int rc;
190
191 dev_dbg(&spdev->dev, "%s %d: dnode %d\n",
192 __func__, __LINE__, spdev->dnode);
193
194 /* We are only interested in the host with spdev->dnode == 0 */
195 if (spdev->dnode)
196 return;
197
198 client_spdev = spdev;
199 rc = cosm_scif_connect();
200 if (rc)
201 goto exit;
202
203 rc = register_reboot_notifier(&cosm_reboot);
204 if (rc) {
205 dev_err(&spdev->dev,
206 "reboot notifier registration failed rc %d\n", rc);
207 goto connect_exit;
208 }
209
210 client_thread = kthread_run(cosm_scif_client, NULL, "cosm_client");
211 if (IS_ERR(client_thread)) {
212 rc = PTR_ERR(client_thread);
213 dev_err(&spdev->dev, "%s %d kthread_run rc %d\n",
214 __func__, __LINE__, rc);
215 goto unreg_reboot;
216 }
217 return;
218unreg_reboot:
219 unregister_reboot_notifier(&cosm_reboot);
220connect_exit:
221 cosm_scif_connect_exit();
222exit:
223 client_spdev = NULL;
224}
225
226static void cosm_scif_remove(struct scif_peer_dev *spdev)
227{
228 int rc;
229
230 dev_dbg(&spdev->dev, "%s %d: dnode %d\n",
231 __func__, __LINE__, spdev->dnode);
232
233 if (spdev->dnode)
234 return;
235
236 if (!IS_ERR_OR_NULL(client_thread)) {
237 rc = send_sig(SIGKILL, client_thread, 0);
238 if (rc) {
239 pr_err("%s %d send_sig rc %d\n",
240 __func__, __LINE__, rc);
241 return;
242 }
243 kthread_stop(client_thread);
244 }
245 unregister_reboot_notifier(&cosm_reboot);
246 cosm_scif_connect_exit();
247 client_spdev = NULL;
248}
249
250static struct scif_client scif_client_cosm = {
251 .name = KBUILD_MODNAME,
252 .probe = cosm_scif_probe,
253 .remove = cosm_scif_remove,
254};
255
256static int __init cosm_client_init(void)
257{
258 int rc = scif_client_register(&scif_client_cosm);
259
260 if (rc)
261 pr_err("scif_client_register failed rc %d\n", rc);
262 return rc;
263}
264
265static void __exit cosm_client_exit(void)
266{
267 scif_client_unregister(&scif_client_cosm);
268}
269
270module_init(cosm_client_init);
271module_exit(cosm_client_exit);
272
273MODULE_AUTHOR("Intel Corporation");
274MODULE_DESCRIPTION("Intel(R) MIC card OS state management client driver");
275MODULE_LICENSE("GPL v2");