ia64/linux-2.6.18-xen.hg

view drivers/macintosh/windfarm_core.c @ 893:f994bfe9b93b

linux/blktap2: reduce TLB flush scope

c/s 885 added very coarse TLB flushing. Since these flushes always
follow single page updates, single page flushes (when available) are
sufficient.

Signed-off-by: Jan Beulich <jbeulich@novell.com>
author Keir Fraser <keir.fraser@citrix.com>
date Thu Jun 04 10:32:57 2009 +0100 (2009-06-04)
parents 831230e53067
children
line source
1 /*
2 * Windfarm PowerMac thermal control. Core
3 *
4 * (c) Copyright 2005 Benjamin Herrenschmidt, IBM Corp.
5 * <benh@kernel.crashing.org>
6 *
7 * Released under the term of the GNU GPL v2.
8 *
9 * This core code tracks the list of sensors & controls, register
10 * clients, and holds the kernel thread used for control.
11 *
12 * TODO:
13 *
14 * Add some information about sensor/control type and data format to
15 * sensors/controls, and have the sysfs attribute stuff be moved
16 * generically here instead of hard coded in the platform specific
17 * driver as it us currently
18 *
19 * This however requires solving some annoying lifetime issues with
20 * sysfs which doesn't seem to have lifetime rules for struct attribute,
21 * I may have to create full features kobjects for every sensor/control
22 * instead which is a bit of an overkill imho
23 */
25 #include <linux/types.h>
26 #include <linux/errno.h>
27 #include <linux/kernel.h>
28 #include <linux/init.h>
29 #include <linux/spinlock.h>
30 #include <linux/smp_lock.h>
31 #include <linux/kthread.h>
32 #include <linux/jiffies.h>
33 #include <linux/reboot.h>
34 #include <linux/device.h>
35 #include <linux/platform_device.h>
36 #include <linux/mutex.h>
38 #include <asm/prom.h>
40 #include "windfarm.h"
42 #define VERSION "0.2"
44 #undef DEBUG
46 #ifdef DEBUG
47 #define DBG(args...) printk(args)
48 #else
49 #define DBG(args...) do { } while(0)
50 #endif
52 static LIST_HEAD(wf_controls);
53 static LIST_HEAD(wf_sensors);
54 static DEFINE_MUTEX(wf_lock);
55 static BLOCKING_NOTIFIER_HEAD(wf_client_list);
56 static int wf_client_count;
57 static unsigned int wf_overtemp;
58 static unsigned int wf_overtemp_counter;
59 struct task_struct *wf_thread;
61 static struct platform_device wf_platform_device = {
62 .name = "windfarm",
63 };
65 /*
66 * Utilities & tick thread
67 */
69 static inline void wf_notify(int event, void *param)
70 {
71 blocking_notifier_call_chain(&wf_client_list, event, param);
72 }
74 int wf_critical_overtemp(void)
75 {
76 static char * critical_overtemp_path = "/sbin/critical_overtemp";
77 char *argv[] = { critical_overtemp_path, NULL };
78 static char *envp[] = { "HOME=/",
79 "TERM=linux",
80 "PATH=/sbin:/usr/sbin:/bin:/usr/bin",
81 NULL };
83 return call_usermodehelper(critical_overtemp_path, argv, envp, 0);
84 }
85 EXPORT_SYMBOL_GPL(wf_critical_overtemp);
87 static int wf_thread_func(void *data)
88 {
89 unsigned long next, delay;
91 next = jiffies;
93 DBG("wf: thread started\n");
95 while(!kthread_should_stop()) {
96 try_to_freeze();
98 if (time_after_eq(jiffies, next)) {
99 wf_notify(WF_EVENT_TICK, NULL);
100 if (wf_overtemp) {
101 wf_overtemp_counter++;
102 /* 10 seconds overtemp, notify userland */
103 if (wf_overtemp_counter > 10)
104 wf_critical_overtemp();
105 /* 30 seconds, shutdown */
106 if (wf_overtemp_counter > 30) {
107 printk(KERN_ERR "windfarm: Overtemp "
108 "for more than 30"
109 " seconds, shutting down\n");
110 machine_power_off();
111 }
112 }
113 next += HZ;
114 }
116 delay = next - jiffies;
117 if (delay <= HZ)
118 schedule_timeout_interruptible(delay);
120 /* there should be no signal, but oh well */
121 if (signal_pending(current)) {
122 printk(KERN_WARNING "windfarm: thread got sigl !\n");
123 break;
124 }
125 }
127 DBG("wf: thread stopped\n");
129 return 0;
130 }
132 static void wf_start_thread(void)
133 {
134 wf_thread = kthread_run(wf_thread_func, NULL, "kwindfarm");
135 if (IS_ERR(wf_thread)) {
136 printk(KERN_ERR "windfarm: failed to create thread,err %ld\n",
137 PTR_ERR(wf_thread));
138 wf_thread = NULL;
139 }
140 }
143 static void wf_stop_thread(void)
144 {
145 if (wf_thread)
146 kthread_stop(wf_thread);
147 wf_thread = NULL;
148 }
150 /*
151 * Controls
152 */
154 static void wf_control_release(struct kref *kref)
155 {
156 struct wf_control *ct = container_of(kref, struct wf_control, ref);
158 DBG("wf: Deleting control %s\n", ct->name);
160 if (ct->ops && ct->ops->release)
161 ct->ops->release(ct);
162 else
163 kfree(ct);
164 }
166 static ssize_t wf_show_control(struct device *dev,
167 struct device_attribute *attr, char *buf)
168 {
169 struct wf_control *ctrl = container_of(attr, struct wf_control, attr);
170 s32 val = 0;
171 int err;
173 err = ctrl->ops->get_value(ctrl, &val);
174 if (err < 0)
175 return err;
176 return sprintf(buf, "%d\n", val);
177 }
179 /* This is really only for debugging... */
180 static ssize_t wf_store_control(struct device *dev,
181 struct device_attribute *attr,
182 const char *buf, size_t count)
183 {
184 struct wf_control *ctrl = container_of(attr, struct wf_control, attr);
185 int val;
186 int err;
187 char *endp;
189 val = simple_strtoul(buf, &endp, 0);
190 while (endp < buf + count && (*endp == ' ' || *endp == '\n'))
191 ++endp;
192 if (endp - buf < count)
193 return -EINVAL;
194 err = ctrl->ops->set_value(ctrl, val);
195 if (err < 0)
196 return err;
197 return count;
198 }
200 int wf_register_control(struct wf_control *new_ct)
201 {
202 struct wf_control *ct;
204 mutex_lock(&wf_lock);
205 list_for_each_entry(ct, &wf_controls, link) {
206 if (!strcmp(ct->name, new_ct->name)) {
207 printk(KERN_WARNING "windfarm: trying to register"
208 " duplicate control %s\n", ct->name);
209 mutex_unlock(&wf_lock);
210 return -EEXIST;
211 }
212 }
213 kref_init(&new_ct->ref);
214 list_add(&new_ct->link, &wf_controls);
216 new_ct->attr.attr.name = new_ct->name;
217 new_ct->attr.attr.owner = THIS_MODULE;
218 new_ct->attr.attr.mode = 0644;
219 new_ct->attr.show = wf_show_control;
220 new_ct->attr.store = wf_store_control;
221 device_create_file(&wf_platform_device.dev, &new_ct->attr);
223 DBG("wf: Registered control %s\n", new_ct->name);
225 wf_notify(WF_EVENT_NEW_CONTROL, new_ct);
226 mutex_unlock(&wf_lock);
228 return 0;
229 }
230 EXPORT_SYMBOL_GPL(wf_register_control);
232 void wf_unregister_control(struct wf_control *ct)
233 {
234 mutex_lock(&wf_lock);
235 list_del(&ct->link);
236 mutex_unlock(&wf_lock);
238 DBG("wf: Unregistered control %s\n", ct->name);
240 kref_put(&ct->ref, wf_control_release);
241 }
242 EXPORT_SYMBOL_GPL(wf_unregister_control);
244 struct wf_control * wf_find_control(const char *name)
245 {
246 struct wf_control *ct;
248 mutex_lock(&wf_lock);
249 list_for_each_entry(ct, &wf_controls, link) {
250 if (!strcmp(ct->name, name)) {
251 if (wf_get_control(ct))
252 ct = NULL;
253 mutex_unlock(&wf_lock);
254 return ct;
255 }
256 }
257 mutex_unlock(&wf_lock);
258 return NULL;
259 }
260 EXPORT_SYMBOL_GPL(wf_find_control);
262 int wf_get_control(struct wf_control *ct)
263 {
264 if (!try_module_get(ct->ops->owner))
265 return -ENODEV;
266 kref_get(&ct->ref);
267 return 0;
268 }
269 EXPORT_SYMBOL_GPL(wf_get_control);
271 void wf_put_control(struct wf_control *ct)
272 {
273 struct module *mod = ct->ops->owner;
274 kref_put(&ct->ref, wf_control_release);
275 module_put(mod);
276 }
277 EXPORT_SYMBOL_GPL(wf_put_control);
280 /*
281 * Sensors
282 */
285 static void wf_sensor_release(struct kref *kref)
286 {
287 struct wf_sensor *sr = container_of(kref, struct wf_sensor, ref);
289 DBG("wf: Deleting sensor %s\n", sr->name);
291 if (sr->ops && sr->ops->release)
292 sr->ops->release(sr);
293 else
294 kfree(sr);
295 }
297 static ssize_t wf_show_sensor(struct device *dev,
298 struct device_attribute *attr, char *buf)
299 {
300 struct wf_sensor *sens = container_of(attr, struct wf_sensor, attr);
301 s32 val = 0;
302 int err;
304 err = sens->ops->get_value(sens, &val);
305 if (err < 0)
306 return err;
307 return sprintf(buf, "%d.%03d\n", FIX32TOPRINT(val));
308 }
310 int wf_register_sensor(struct wf_sensor *new_sr)
311 {
312 struct wf_sensor *sr;
314 mutex_lock(&wf_lock);
315 list_for_each_entry(sr, &wf_sensors, link) {
316 if (!strcmp(sr->name, new_sr->name)) {
317 printk(KERN_WARNING "windfarm: trying to register"
318 " duplicate sensor %s\n", sr->name);
319 mutex_unlock(&wf_lock);
320 return -EEXIST;
321 }
322 }
323 kref_init(&new_sr->ref);
324 list_add(&new_sr->link, &wf_sensors);
326 new_sr->attr.attr.name = new_sr->name;
327 new_sr->attr.attr.owner = THIS_MODULE;
328 new_sr->attr.attr.mode = 0444;
329 new_sr->attr.show = wf_show_sensor;
330 new_sr->attr.store = NULL;
331 device_create_file(&wf_platform_device.dev, &new_sr->attr);
333 DBG("wf: Registered sensor %s\n", new_sr->name);
335 wf_notify(WF_EVENT_NEW_SENSOR, new_sr);
336 mutex_unlock(&wf_lock);
338 return 0;
339 }
340 EXPORT_SYMBOL_GPL(wf_register_sensor);
342 void wf_unregister_sensor(struct wf_sensor *sr)
343 {
344 mutex_lock(&wf_lock);
345 list_del(&sr->link);
346 mutex_unlock(&wf_lock);
348 DBG("wf: Unregistered sensor %s\n", sr->name);
350 wf_put_sensor(sr);
351 }
352 EXPORT_SYMBOL_GPL(wf_unregister_sensor);
354 struct wf_sensor * wf_find_sensor(const char *name)
355 {
356 struct wf_sensor *sr;
358 mutex_lock(&wf_lock);
359 list_for_each_entry(sr, &wf_sensors, link) {
360 if (!strcmp(sr->name, name)) {
361 if (wf_get_sensor(sr))
362 sr = NULL;
363 mutex_unlock(&wf_lock);
364 return sr;
365 }
366 }
367 mutex_unlock(&wf_lock);
368 return NULL;
369 }
370 EXPORT_SYMBOL_GPL(wf_find_sensor);
372 int wf_get_sensor(struct wf_sensor *sr)
373 {
374 if (!try_module_get(sr->ops->owner))
375 return -ENODEV;
376 kref_get(&sr->ref);
377 return 0;
378 }
379 EXPORT_SYMBOL_GPL(wf_get_sensor);
381 void wf_put_sensor(struct wf_sensor *sr)
382 {
383 struct module *mod = sr->ops->owner;
384 kref_put(&sr->ref, wf_sensor_release);
385 module_put(mod);
386 }
387 EXPORT_SYMBOL_GPL(wf_put_sensor);
390 /*
391 * Client & notification
392 */
394 int wf_register_client(struct notifier_block *nb)
395 {
396 int rc;
397 struct wf_control *ct;
398 struct wf_sensor *sr;
400 mutex_lock(&wf_lock);
401 rc = blocking_notifier_chain_register(&wf_client_list, nb);
402 if (rc != 0)
403 goto bail;
404 wf_client_count++;
405 list_for_each_entry(ct, &wf_controls, link)
406 wf_notify(WF_EVENT_NEW_CONTROL, ct);
407 list_for_each_entry(sr, &wf_sensors, link)
408 wf_notify(WF_EVENT_NEW_SENSOR, sr);
409 if (wf_client_count == 1)
410 wf_start_thread();
411 bail:
412 mutex_unlock(&wf_lock);
413 return rc;
414 }
415 EXPORT_SYMBOL_GPL(wf_register_client);
417 int wf_unregister_client(struct notifier_block *nb)
418 {
419 mutex_lock(&wf_lock);
420 blocking_notifier_chain_unregister(&wf_client_list, nb);
421 wf_client_count++;
422 if (wf_client_count == 0)
423 wf_stop_thread();
424 mutex_unlock(&wf_lock);
426 return 0;
427 }
428 EXPORT_SYMBOL_GPL(wf_unregister_client);
430 void wf_set_overtemp(void)
431 {
432 mutex_lock(&wf_lock);
433 wf_overtemp++;
434 if (wf_overtemp == 1) {
435 printk(KERN_WARNING "windfarm: Overtemp condition detected !\n");
436 wf_overtemp_counter = 0;
437 wf_notify(WF_EVENT_OVERTEMP, NULL);
438 }
439 mutex_unlock(&wf_lock);
440 }
441 EXPORT_SYMBOL_GPL(wf_set_overtemp);
443 void wf_clear_overtemp(void)
444 {
445 mutex_lock(&wf_lock);
446 WARN_ON(wf_overtemp == 0);
447 if (wf_overtemp == 0) {
448 mutex_unlock(&wf_lock);
449 return;
450 }
451 wf_overtemp--;
452 if (wf_overtemp == 0) {
453 printk(KERN_WARNING "windfarm: Overtemp condition cleared !\n");
454 wf_notify(WF_EVENT_NORMALTEMP, NULL);
455 }
456 mutex_unlock(&wf_lock);
457 }
458 EXPORT_SYMBOL_GPL(wf_clear_overtemp);
460 int wf_is_overtemp(void)
461 {
462 return (wf_overtemp != 0);
463 }
464 EXPORT_SYMBOL_GPL(wf_is_overtemp);
466 static int __init windfarm_core_init(void)
467 {
468 DBG("wf: core loaded\n");
470 /* Don't register on old machines that use therm_pm72 for now */
471 if (machine_is_compatible("PowerMac7,2") ||
472 machine_is_compatible("PowerMac7,3") ||
473 machine_is_compatible("RackMac3,1"))
474 return -ENODEV;
475 platform_device_register(&wf_platform_device);
476 return 0;
477 }
479 static void __exit windfarm_core_exit(void)
480 {
481 BUG_ON(wf_client_count != 0);
483 DBG("wf: core unloaded\n");
485 platform_device_unregister(&wf_platform_device);
486 }
489 module_init(windfarm_core_init);
490 module_exit(windfarm_core_exit);
492 MODULE_AUTHOR("Benjamin Herrenschmidt <benh@kernel.crashing.org>");
493 MODULE_DESCRIPTION("Core component of PowerMac thermal control");
494 MODULE_LICENSE("GPL");