xref: /dragonfly/sys/kern/kern_cputimer.c (revision b4f25088) 
1 /*
2  * Copyright (c) 2005 The DragonFly Project.  All rights reserved.
3  *
4  * This code is derived from software contributed to The DragonFly Project
5  * by Matthew Dillon <dillon@backplane.com>
6  *
7  * Redistribution and use in source and binary forms, with or without
8  * modification, are permitted provided that the following conditions
9  * are met:
10  *
11  * 1. Redistributions of source code must retain the above copyright
12  *    notice, this list of conditions and the following disclaimer.
13  * 2. Redistributions in binary form must reproduce the above copyright
14  *    notice, this list of conditions and the following disclaimer in
15  *    the documentation and/or other materials provided with the
16  *    distribution.
17  * 3. Neither the name of The DragonFly Project nor the names of its
18  *    contributors may be used to endorse or promote products derived
19  *    from this software without specific, prior written permission.
20  *
21  * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
22  * ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
23  * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS
24  * FOR A PARTICULAR PURPOSE ARE DISCLAIMED.  IN NO EVENT SHALL THE
25  * COPYRIGHT HOLDERS OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT,
26  * INCIDENTAL, SPECIAL, EXEMPLARY OR CONSEQUENTIAL DAMAGES (INCLUDING,
27  * BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES;
28  * LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED
29  * AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY,
30  * OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT
31  * OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
32  * SUCH DAMAGE.
33  *
34  * $DragonFly: src/sys/kern/kern_cputimer.c,v 1.5 2008/06/05 18:06:32 swildner Exp $
35  */
36 /*
37  * Generic cputimer - access to a reliable, free-running counter.
38  */
39 
40 #include <sys/param.h>
41 #include <sys/kernel.h>
42 #include <sys/systm.h>
43 #include <sys/thread.h>
44 #include <sys/globaldata.h>
45 #include <sys/systimer.h>
46 #include <sys/sysctl.h>
47 #include <sys/thread2.h>
48 
49 static sysclock_t dummy_cputimer_count(void);
50 
51 static struct cputimer dummy_cputimer = {
52     SLIST_ENTRY_INITIALIZER,
53     "dummy",
54     CPUTIMER_PRI_DUMMY,
55     CPUTIMER_DUMMY,
56     dummy_cputimer_count,
57     cputimer_default_fromhz,
58     cputimer_default_fromus,
59     cputimer_default_construct,
60     cputimer_default_destruct,
61     1000000,
62     (1000000LL << 32) / 1000000,
63     (1000000000LL << 32) / 1000000,
64     0
65 };
66 
67 struct cputimer *sys_cputimer = &dummy_cputimer;
68 SLIST_HEAD(, cputimer) cputimerhead = SLIST_HEAD_INITIALIZER(&cputimerhead);
69 
70 /*
71  * Generic cputimer API
72  */
73 void
74 cputimer_select(struct cputimer *timer, int pri)
75 {
76     sysclock_t oldclock;
77 
78     /*
79      * Calculate helper fields
80      */
81     cputimer_set_frequency(timer, timer->freq);
82 
83     /*
84      * Install a new cputimer if its priority allows it.  If timer is
85      * passed as NULL we deinstall the current timer and revert to our
86      * dummy.
87      */
88     if (pri == 0)
89 	pri = timer->pri;
90     if (timer == NULL || pri >= sys_cputimer->pri) {
91 	oldclock = sys_cputimer->count();
92 	sys_cputimer->destruct(sys_cputimer);
93 	sys_cputimer = &dummy_cputimer;
94 	if (timer) {
95 	    sys_cputimer = timer;
96 	    timer->construct(timer, oldclock);
97 	    cputimer_intr_config(timer);
98 	}
99     }
100 }
101 
102 /*
103  * Register a timer.  If the timer has already been registered, do nothing.
104  */
105 void
106 cputimer_register(struct cputimer *timer)
107 {
108     struct cputimer *scan;
109 
110     /*
111      * Initialize dummy_cputimer if the slist is empty, it does not get
112      * registered the normal way.
113      */
114     if (SLIST_EMPTY(&cputimerhead))
115 	SLIST_FIRST(&cputimerhead) = &dummy_cputimer;
116     SLIST_FOREACH(scan, &cputimerhead, next) {
117 	if (scan == timer)
118 	    return;
119     }
120     SLIST_INSERT_HEAD(&cputimerhead, timer, next);
121 }
122 
123 /*
124  * Deregister a timer.  If the timer has already been deregistered, do nothing.
125  */
126 void
127 cputimer_deregister(struct cputimer *timer)
128 {
129     struct cputimer *scan;
130     struct cputimer *best;
131 
132     /*
133      * Locate and remove the timer.  If the timer is our currently active
134      * timer, revert to the dummy timer.
135      */
136     SLIST_FOREACH(scan, &cputimerhead, next) {
137 	    if (timer == scan) {
138 		if (timer == sys_cputimer)
139 		    cputimer_select(&dummy_cputimer, 0x7FFFFFFF);
140 		SLIST_REMOVE(&cputimerhead, timer, cputimer, next);
141 		break;
142 	    }
143     }
144 
145     /*
146      * If sys_cputimer reverted to the dummy, select the best one
147      */
148     if (sys_cputimer == &dummy_cputimer) {
149 	best = NULL;
150 	SLIST_FOREACH(scan, &cputimerhead, next) {
151 	    if (best == NULL || scan->pri > best->pri)
152 		best = scan;
153 	}
154 	if (best)
155 	    cputimer_select(best, 0x7FFFFFFF);
156     }
157 }
158 
159 /*
160  * Calculate usec / tick and nsec / tick, scaled by (1 << 32).
161  *
162  * so e.g. a 3 mhz timer would be 3 usec / tick x (1 << 32),
163  * or 3000 nsec / tick x (1 << 32)
164  */
165 void
166 cputimer_set_frequency(struct cputimer *timer, sysclock_t freq)
167 {
168     timer->freq = freq;
169     timer->freq64_usec = (1000000LL << 32) / freq;
170     timer->freq64_nsec = (1000000000LL << 32) / freq;
171     if (timer == sys_cputimer)
172 	cputimer_intr_config(timer);
173 }
174 
175 sysclock_t
176 cputimer_default_fromhz(int freq)
177 {
178     return(sys_cputimer->freq / freq + 1);
179 }
180 
181 sysclock_t
182 cputimer_default_fromus(int us)
183 {
184     return((int64_t)sys_cputimer->freq * us / 1000000);
185 }
186 
187 /*
188  * Dummy counter implementation
189  */
190 static
191 sysclock_t
192 dummy_cputimer_count(void)
193 {
194     return(++dummy_cputimer.base);
195 }
196 
197 void
198 cputimer_default_construct(struct cputimer *cputimer, sysclock_t oldclock)
199 {
200     cputimer->base = oldclock;
201 }
202 
203 void
204 cputimer_default_destruct(struct cputimer *cputimer)
205 {
206 }
207 
208 /************************************************************************
209  *				SYSCTL SUPPORT				*
210  ************************************************************************
211  *
212  * Note: the ability to change the systimer is not currently enabled
213  * because it will mess up systimer calculations.  You have to live
214  * with what is configured at boot.
215  */
216 static int
217 sysctl_cputimer_reglist(SYSCTL_HANDLER_ARGS)
218 {
219     struct cputimer *scan;
220     int error = 0;
221     int loop = 0;
222 
223     /*
224      * Build a list of available timers
225      */
226     SLIST_FOREACH(scan, &cputimerhead, next) {
227 	if (error == 0 && loop)
228 	    error = SYSCTL_OUT(req, " ", 1);
229 	if (error == 0)
230 	    error = SYSCTL_OUT(req, scan->name, strlen(scan->name));
231 	++loop;
232     }
233     return (error);
234 }
235 
236 static int
237 sysctl_cputimer_name(SYSCTL_HANDLER_ARGS)
238 {
239     int error;
240 
241     error = SYSCTL_OUT(req, sys_cputimer->name, strlen(sys_cputimer->name));
242     return (error);
243 }
244 
245 static int
246 sysctl_cputimer_clock(SYSCTL_HANDLER_ARGS)
247 {
248     sysclock_t clock;
249     int error;
250 
251     clock = sys_cputimer->count();
252     error = SYSCTL_OUT(req, &clock, sizeof(clock));
253     return (error);
254 }
255 
256 static int
257 sysctl_cputimer_freq(SYSCTL_HANDLER_ARGS)
258 {
259     int error;
260 
261     error = SYSCTL_OUT(req, &sys_cputimer->freq, sizeof(sys_cputimer->freq));
262     return (error);
263 }
264 
265 SYSCTL_DECL(_kern_cputimer);
266 SYSCTL_NODE(_kern, OID_AUTO, cputimer, CTLFLAG_RW, NULL, "cputimer");
267 
268 SYSCTL_PROC(_kern_cputimer, OID_AUTO, select, CTLTYPE_STRING|CTLFLAG_RD,
269 	    NULL, 0, sysctl_cputimer_reglist, "A", "");
270 SYSCTL_PROC(_kern_cputimer, OID_AUTO, name, CTLTYPE_STRING|CTLFLAG_RD,
271 	    NULL, 0, sysctl_cputimer_name, "A", "");
272 SYSCTL_PROC(_kern_cputimer, OID_AUTO, clock, CTLTYPE_UINT|CTLFLAG_RD,
273 	    NULL, 0, sysctl_cputimer_clock, "IU", "");
274 SYSCTL_PROC(_kern_cputimer, OID_AUTO, freq, CTLTYPE_INT|CTLFLAG_RD,
275 	    NULL, 0, sysctl_cputimer_freq, "I", "");
276 
277 static struct cputimer_intr *sys_cputimer_intr;
278 static uint32_t cputimer_intr_caps;
279 SLIST_HEAD(, cputimer_intr) cputimer_intr_head =
280 	SLIST_HEAD_INITIALIZER(&cputimer_intr_head);
281 
282 void
283 cputimer_intr_register(struct cputimer_intr *cti)
284 {
285     struct cputimer_intr *scan;
286 
287     SLIST_FOREACH(scan, &cputimer_intr_head, next) {
288 	if (scan == cti)
289 	    return;
290     }
291     cti->config(cti, sys_cputimer);
292     SLIST_INSERT_HEAD(&cputimer_intr_head, cti, next);
293 }
294 
295 void
296 cputimer_intr_deregister(struct cputimer_intr *cti)
297 {
298     KKASSERT(cti != sys_cputimer_intr);
299     SLIST_REMOVE(&cputimer_intr_head, cti, cputimer_intr, next);
300 }
301 
302 int
303 cputimer_intr_select(struct cputimer_intr *cti, int prio)
304 {
305     KKASSERT(cti != NULL);
306 
307     if (prio == 0)
308 	prio = cti->prio;
309 
310     if (sys_cputimer_intr == NULL) {
311 	KKASSERT(cputimer_intr_caps == 0);
312 	sys_cputimer_intr = cti;
313 	return 0;
314     }
315 
316     if ((cti->caps & cputimer_intr_caps) == cputimer_intr_caps) {
317 	if (prio > sys_cputimer_intr->prio) {
318 	    sys_cputimer_intr = cti;
319 	    return 0;
320 	} else {
321 	    return EBUSY;
322 	}
323     } else {
324 	return EOPNOTSUPP;
325     }
326 }
327 
328 void
329 cputimer_intr_default_enable(struct cputimer_intr *cti __unused)
330 {
331 }
332 
333 void
334 cputimer_intr_default_restart(struct cputimer_intr *cti)
335 {
336     cti->reload(cti, 0);
337 }
338 
339 void
340 cputimer_intr_default_config(struct cputimer_intr *cti __unused,
341 			     const struct cputimer *timer __unused)
342 {
343 }
344 
345 void
346 cputimer_intr_default_pmfixup(struct cputimer_intr *cti __unused)
347 {
348 }
349 
350 void
351 cputimer_intr_default_initclock(struct cputimer_intr *cti __unused,
352 				boolean_t selected __unused)
353 {
354 }
355 
356 void
357 cputimer_intr_enable(void)
358 {
359     struct cputimer_intr *cti;
360 
361     SLIST_FOREACH(cti, &cputimer_intr_head, next)
362 	cti->enable(cti);
363 }
364 
365 void
366 cputimer_intr_config(const struct cputimer *timer)
367 {
368     struct cputimer_intr *cti;
369 
370     SLIST_FOREACH(cti, &cputimer_intr_head, next)
371 	cti->config(cti, timer);
372 }
373 
374 void
375 cputimer_intr_pmfixup(void)
376 {
377     struct cputimer_intr *cti;
378 
379     SLIST_FOREACH(cti, &cputimer_intr_head, next)
380 	cti->pmfixup(cti);
381 }
382 
383 void
384 cputimer_intr_reload(sysclock_t reload)
385 {
386     struct cputimer_intr *cti = sys_cputimer_intr;
387 
388     cti->reload(cti, reload);
389 }
390 
391 void
392 cputimer_intr_restart(void)
393 {
394     struct cputimer_intr *cti = sys_cputimer_intr;
395 
396     cti->restart(cti);
397 }
398 
399 int
400 cputimer_intr_select_caps(uint32_t caps)
401 {
402     struct cputimer_intr *cti, *maybe;
403     int error;
404 
405     maybe = NULL;
406     SLIST_FOREACH(cti, &cputimer_intr_head, next) {
407 	if ((cti->caps & caps) == caps) {
408 	    if (maybe == NULL)
409 		maybe = cti;
410 	    else if (cti->prio > maybe->prio)
411 		maybe = cti;
412 	}
413     }
414     if (maybe == NULL)
415 	return ENOENT;
416 
417     cputimer_intr_caps = caps;
418     error = cputimer_intr_select(maybe, CPUTIMER_INTR_PRIO_MAX);
419     KKASSERT(!error);
420 
421     return 0;
422 }
423 
424 static void
425 cputimer_intr_initclocks(void)
426 {
427     struct cputimer_intr *cti, *ncti;
428 
429     /*
430      * An interrupt cputimer may deregister itself,
431      * so use SLIST_FOREACH_MUTABLE here.
432      */
433     SLIST_FOREACH_MUTABLE(cti, &cputimer_intr_head, next, ncti) {
434 	boolean_t selected = FALSE;
435 
436 	if (cti == sys_cputimer_intr)
437 	    selected = TRUE;
438 	cti->initclock(cti, selected);
439     }
440 }
441 /* NOTE: Must be SECOND to allow platform initialization to go first */
442 SYSINIT(cputimer_intr, SI_BOOT2_CLOCKREG, SI_ORDER_SECOND,
443 	cputimer_intr_initclocks, NULL)
444 
445 static int
446 sysctl_cputimer_intr_reglist(SYSCTL_HANDLER_ARGS)
447 {
448     struct cputimer_intr *scan;
449     int error = 0;
450     int loop = 0;
451 
452     /*
453      * Build a list of available interrupt cputimers
454      */
455     SLIST_FOREACH(scan, &cputimer_intr_head, next) {
456 	if (error == 0 && loop)
457 	    error = SYSCTL_OUT(req, " ", 1);
458 	if (error == 0)
459 	    error = SYSCTL_OUT(req, scan->name, strlen(scan->name));
460 	++loop;
461     }
462     return (error);
463 }
464 
465 static int
466 sysctl_cputimer_intr_freq(SYSCTL_HANDLER_ARGS)
467 {
468     int error;
469 
470     error = SYSCTL_OUT(req, &sys_cputimer_intr->freq,
471     		       sizeof(sys_cputimer_intr->freq));
472     return (error);
473 }
474 
475 static int
476 sysctl_cputimer_intr_select(SYSCTL_HANDLER_ARGS)
477 {
478     struct cputimer_intr *cti;
479     char name[32];
480     int error;
481 
482     ksnprintf(name, sizeof(name), "%s", sys_cputimer_intr->name);
483     error = sysctl_handle_string(oidp, name, sizeof(name), req);
484     if (error != 0 || req->newptr == NULL)
485 	return error;
486 
487     SLIST_FOREACH(cti, &cputimer_intr_head, next) {
488 	if (strcmp(cti->name, name) == 0)
489 	    break;
490     }
491     if (cti == NULL)
492 	return ENOENT;
493     if (cti == sys_cputimer_intr)
494 	return 0;
495 
496     error = cputimer_intr_select(cti, CPUTIMER_INTR_PRIO_MAX);
497     if (!error)
498 	cputimer_intr_restart();
499     return error;
500 }
501 
502 SYSCTL_NODE(_kern_cputimer, OID_AUTO, intr, CTLFLAG_RW, NULL,
503 	    "interrupt cputimer");
504 
505 SYSCTL_PROC(_kern_cputimer_intr, OID_AUTO, reglist, CTLTYPE_STRING|CTLFLAG_RD,
506 	    NULL, 0, sysctl_cputimer_intr_reglist, "A", "");
507 SYSCTL_PROC(_kern_cputimer_intr, OID_AUTO, freq, CTLTYPE_INT|CTLFLAG_RD,
508 	    NULL, 0, sysctl_cputimer_intr_freq, "I", "");
509 SYSCTL_PROC(_kern_cputimer_intr, OID_AUTO, select, CTLTYPE_STRING|CTLFLAG_RW,
510 	    NULL, 0, sysctl_cputimer_intr_select, "A", "");
511