xref: /dflybsd-src/sys/dev/acpica/acpi_thermal.c (revision 10cf3bfcde2ee9c50d77a153397b93d8026b03e1)
1 /*-
2  * Copyright (c) 2000, 2001 Michael Smith
3  * Copyright (c) 2000 BSDi
4  * All rights reserved.
5  *
6  * Redistribution and use in source and binary forms, with or without
7  * modification, are permitted provided that the following conditions
8  * are met:
9  * 1. Redistributions of source code must retain the above copyright
10  *    notice, this list of conditions and the following disclaimer.
11  * 2. Redistributions in binary form must reproduce the above copyright
12  *    notice, this list of conditions and the following disclaimer in the
13  *    documentation and/or other materials provided with the distribution.
14  *
15  * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
16  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
17  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
18  * ARE DISCLAIMED.  IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
19  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
20  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
21  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
22  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
23  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
24  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
25  * SUCH DAMAGE.
26  *
27  * $FreeBSD: head/sys/dev/acpica/acpi_thermal.c 255077 2013-08-30 19:21:12Z dumbbell $
28  */
29 
30 #include "opt_acpi.h"
31 #include <sys/param.h>
32 #include <sys/kernel.h>
33 #include <sys/bus.h>
34 #include <sys/kthread.h>
35 #include <sys/malloc.h>
36 #include <sys/module.h>
37 #include <sys/proc.h>
38 #include <sys/reboot.h>
39 #include <sys/sysctl.h>
40 #include <sys/unistd.h>
41 #include <sys/power.h>
42 #include <sys/sensors.h>
43 
44 #include <sys/mplock2.h>
45 
46 #include "acpi.h"
47 #include "accommon.h"
48 
49 #include <dev/acpica/acpivar.h>
50 
51 /* Hooks for the ACPICA debugging infrastructure */
52 #define _COMPONENT	ACPI_THERMAL
53 ACPI_MODULE_NAME("THERMAL")
54 
55 #define TZ_ZEROC	2732
56 #define TZ_KELVTOC(x)	(((x) - TZ_ZEROC) / 10), abs(((x) - TZ_ZEROC) % 10)
57 
58 #define TZ_NOTIFY_TEMPERATURE	0x80 /* Temperature changed. */
59 #define TZ_NOTIFY_LEVELS	0x81 /* Cooling levels changed. */
60 #define TZ_NOTIFY_DEVICES	0x82 /* Device lists changed. */
61 #define TZ_NOTIFY_CRITICAL	0xcc /* Fake notify that _CRT/_HOT reached. */
62 
63 /* Check for temperature changes every 10 seconds by default */
64 #define TZ_POLLRATE	10
65 
66 /* Make sure the reported temperature is valid for this number of polls. */
67 #define TZ_VALIDCHECKS	3
68 
69 /* Notify the user we will be shutting down in one more poll cycle. */
70 #define TZ_NOTIFYCOUNT	(TZ_VALIDCHECKS - 1)
71 
72 /* ACPI spec defines this */
73 #define TZ_NUMLEVELS	10
74 struct acpi_tz_zone {
75     int		ac[TZ_NUMLEVELS];
76     ACPI_BUFFER	al[TZ_NUMLEVELS];
77     int		crt;
78     int		hot;
79     ACPI_BUFFER	psl;
80     int		psv;
81     int		tc1;
82     int		tc2;
83     int		tsp;
84     int		tzp;
85 };
86 
87 struct acpi_tz_softc {
88     device_t			tz_dev;
89     ACPI_HANDLE			tz_handle;	/*Thermal zone handle*/
90     int				tz_temperature;	/*Current temperature*/
91     int				tz_active;	/*Current active cooling*/
92 #define TZ_ACTIVE_NONE		-1
93 #define TZ_ACTIVE_UNKNOWN	-2
94     int				tz_requested;	/*Minimum active cooling*/
95     int				tz_thflags;	/*Current temp-related flags*/
96 #define TZ_THFLAG_NONE		0
97 #define TZ_THFLAG_PSV		(1<<0)
98 #define TZ_THFLAG_HOT		(1<<2)
99 #define TZ_THFLAG_CRT		(1<<3)
100     int				tz_flags;
101 #define TZ_FLAG_NO_SCP		(1<<0)		/*No _SCP method*/
102 #define TZ_FLAG_GETPROFILE	(1<<1)		/*Get power_profile in timeout*/
103 #define TZ_FLAG_GETSETTINGS	(1<<2)		/*Get devs/setpoints*/
104     struct timespec		tz_cooling_started;
105 					/*Current cooling starting time*/
106 
107     struct sysctl_ctx_list	tz_sysctl_ctx;
108     struct sysctl_oid		*tz_sysctl_tree;
109     eventhandler_tag		tz_event;
110 
111     struct acpi_tz_zone 	tz_zone;	/*Thermal zone parameters*/
112     time_t			tz_error_time;	/*Lookup error timestamp*/
113     int				tz_validchecks;
114     int				tz_insane_tmp_notified;
115 
116     /* passive cooling */
117     struct thread		*tz_cooling_proc;
118     int				tz_cooling_proc_running;
119     int				tz_cooling_enabled;
120     int				tz_cooling_active;
121     int				tz_cooling_updated;
122     int				tz_cooling_saved_freq;
123     /* sensors(9) related */
124     struct ksensordev		sensordev;
125     struct ksensor		sensor;
126 };
127 
128 /* silence errors after X seconds, try again after Y seconds */
129 #define TZ_SILENCE_ERROR	(acpi_tz_polling_rate * 2 + 1)
130 #define TZ_RETRY_ERROR		7200
131 
132 #define	TZ_ACTIVE_LEVEL(act)	((act) >= 0 ? (act) : TZ_NUMLEVELS)
133 
134 #define CPUFREQ_MAX_LEVELS	64 /* XXX cpufreq should export this */
135 
136 static int	acpi_tz_probe(device_t dev);
137 static int	acpi_tz_attach(device_t dev);
138 static int	acpi_tz_establish(struct acpi_tz_softc *sc);
139 static void	acpi_tz_monitor(void *Context);
140 static void	acpi_tz_switch_cooler_off(ACPI_OBJECT *obj, void *arg);
141 static void	acpi_tz_switch_cooler_on(ACPI_OBJECT *obj, void *arg);
142 static void	acpi_tz_getparam(struct acpi_tz_softc *sc, char *node,
143 				 int *data);
144 static void	acpi_tz_sanity(struct acpi_tz_softc *sc, int *val, char *what);
145 static int	acpi_tz_active_sysctl(SYSCTL_HANDLER_ARGS);
146 static int	acpi_tz_cooling_sysctl(SYSCTL_HANDLER_ARGS);
147 static int	acpi_tz_temp_sysctl(SYSCTL_HANDLER_ARGS);
148 static int	acpi_tz_passive_sysctl(SYSCTL_HANDLER_ARGS);
149 static void	acpi_tz_notify_handler(ACPI_HANDLE h, UINT32 notify,
150 				       void *context);
151 static void	acpi_tz_signal(struct acpi_tz_softc *sc, int flags);
152 static void	acpi_tz_timeout(struct acpi_tz_softc *sc, int flags);
153 static void	acpi_tz_power_profile(void *arg);
154 static void	acpi_tz_thread(void *arg);
155 static int	acpi_tz_cooling_is_available(struct acpi_tz_softc *sc);
156 static int	acpi_tz_cooling_thread_start(struct acpi_tz_softc *sc);
157 
158 static device_method_t acpi_tz_methods[] = {
159     /* Device interface */
160     DEVMETHOD(device_probe,	acpi_tz_probe),
161     DEVMETHOD(device_attach,	acpi_tz_attach),
162 
163     DEVMETHOD_END
164 };
165 
166 static driver_t acpi_tz_driver = {
167     "acpi_tz",
168     acpi_tz_methods,
169     sizeof(struct acpi_tz_softc),
170 };
171 
172 static char *acpi_tz_tmp_name = "_TMP";
173 
174 static devclass_t acpi_tz_devclass;
175 DRIVER_MODULE(acpi_tz, acpi, acpi_tz_driver, acpi_tz_devclass, NULL, NULL);
176 MODULE_DEPEND(acpi_tz, acpi, 1, 1, 1);
177 
178 static struct sysctl_ctx_list	acpi_tz_sysctl_ctx;
179 static struct sysctl_oid	*acpi_tz_sysctl_tree;
180 
181 /* Minimum cooling run time */
182 static int			acpi_tz_min_runtime;
183 static int			acpi_tz_polling_rate = TZ_POLLRATE;
184 static int			acpi_tz_override;
185 
186 /* Timezone polling thread */
187 static struct thread		*acpi_tz_td;
188 ACPI_LOCK_DECL(thermal, "ACPI thermal zone");
189 
190 static int			acpi_tz_cooling_unit = -1;
191 
192 static int
193 acpi_tz_probe(device_t dev)
194 {
195     int		result;
196 
197     if (acpi_get_type(dev) == ACPI_TYPE_THERMAL && !acpi_disabled("thermal")) {
198 	device_set_desc(dev, "Thermal Zone");
199 	result = -10;
200     } else
201 	result = ENXIO;
202     return (result);
203 }
204 
205 static int
206 acpi_tz_attach(device_t dev)
207 {
208     struct acpi_tz_softc	*sc;
209     struct acpi_softc		*acpi_sc;
210     int				error;
211     char			oidname[8];
212 
213     ACPI_FUNCTION_TRACE((char *)(uintptr_t)__func__);
214     if (device_get_unit(dev) == 0)
215 	ACPI_LOCK_INIT(thermal, "acpitz");
216 
217     sc = device_get_softc(dev);
218     sc->tz_dev = dev;
219     sc->tz_handle = acpi_get_handle(dev);
220     sc->tz_requested = TZ_ACTIVE_NONE;
221     sc->tz_active = TZ_ACTIVE_UNKNOWN;
222     sc->tz_thflags = TZ_THFLAG_NONE;
223     sc->tz_cooling_proc = NULL;
224     sc->tz_cooling_proc_running = FALSE;
225     sc->tz_cooling_active = FALSE;
226     sc->tz_cooling_updated = FALSE;
227     sc->tz_cooling_enabled = FALSE;
228 
229     /*
230      * Parse the current state of the thermal zone and build control
231      * structures.  We don't need to worry about interference with the
232      * control thread since we haven't fully attached this device yet.
233      */
234     if ((error = acpi_tz_establish(sc)) != 0)
235 	return (error);
236 
237     /*
238      * Register for any Notify events sent to this zone.
239      */
240     AcpiInstallNotifyHandler(sc->tz_handle, ACPI_DEVICE_NOTIFY,
241 			     acpi_tz_notify_handler, sc);
242 
243     /*
244      * Create our sysctl nodes.
245      *
246      * XXX we need a mechanism for adding nodes under ACPI.
247      */
248     if (device_get_unit(dev) == 0) {
249 	acpi_sc = acpi_device_get_parent_softc(dev);
250 	sysctl_ctx_init(&acpi_tz_sysctl_ctx);
251 	acpi_tz_sysctl_tree = SYSCTL_ADD_NODE(&acpi_tz_sysctl_ctx,
252 			      SYSCTL_CHILDREN(acpi_sc->acpi_sysctl_tree),
253 			      OID_AUTO, "thermal", CTLFLAG_RD, 0, "");
254 	SYSCTL_ADD_INT(&acpi_tz_sysctl_ctx,
255 		       SYSCTL_CHILDREN(acpi_tz_sysctl_tree),
256 		       OID_AUTO, "min_runtime", CTLFLAG_RW,
257 		       &acpi_tz_min_runtime, 0,
258 		       "minimum cooling run time in sec");
259 	SYSCTL_ADD_INT(&acpi_tz_sysctl_ctx,
260 		       SYSCTL_CHILDREN(acpi_tz_sysctl_tree),
261 		       OID_AUTO, "polling_rate", CTLFLAG_RW,
262 		       &acpi_tz_polling_rate, 0, "monitor polling interval in seconds");
263 	SYSCTL_ADD_INT(&acpi_tz_sysctl_ctx,
264 		       SYSCTL_CHILDREN(acpi_tz_sysctl_tree), OID_AUTO,
265 		       "user_override", CTLFLAG_RW, &acpi_tz_override, 0,
266 		       "allow override of thermal settings");
267     }
268     sysctl_ctx_init(&sc->tz_sysctl_ctx);
269     ksprintf(oidname, "tz%d", device_get_unit(dev));
270     sc->tz_sysctl_tree = SYSCTL_ADD_NODE(&sc->tz_sysctl_ctx,
271 					 SYSCTL_CHILDREN(acpi_tz_sysctl_tree),
272 					 OID_AUTO, oidname, CTLFLAG_RD, 0, "");
273     SYSCTL_ADD_PROC(&sc->tz_sysctl_ctx, SYSCTL_CHILDREN(sc->tz_sysctl_tree),
274 		    OID_AUTO, "temperature", CTLTYPE_INT | CTLFLAG_RD,
275 		    &sc->tz_temperature, 0, sysctl_handle_int,
276 		    "IK", "current thermal zone temperature");
277     SYSCTL_ADD_PROC(&sc->tz_sysctl_ctx, SYSCTL_CHILDREN(sc->tz_sysctl_tree),
278 		    OID_AUTO, "active", CTLTYPE_INT | CTLFLAG_RW,
279 		    sc, 0, acpi_tz_active_sysctl, "I", "cooling is active");
280     SYSCTL_ADD_PROC(&sc->tz_sysctl_ctx, SYSCTL_CHILDREN(sc->tz_sysctl_tree),
281 		    OID_AUTO, "passive_cooling", CTLTYPE_INT | CTLFLAG_RW,
282 		    sc, 0, acpi_tz_cooling_sysctl, "I",
283 		    "enable passive (speed reduction) cooling");
284 
285     SYSCTL_ADD_INT(&sc->tz_sysctl_ctx, SYSCTL_CHILDREN(sc->tz_sysctl_tree),
286 		   OID_AUTO, "thermal_flags", CTLFLAG_RD,
287 		   &sc->tz_thflags, 0, "thermal zone flags");
288     SYSCTL_ADD_PROC(&sc->tz_sysctl_ctx, SYSCTL_CHILDREN(sc->tz_sysctl_tree),
289 		    OID_AUTO, "_PSV", CTLTYPE_INT | CTLFLAG_RW,
290 		    sc, offsetof(struct acpi_tz_softc, tz_zone.psv),
291 		    acpi_tz_temp_sysctl, "IK", "passive cooling temp setpoint");
292     SYSCTL_ADD_PROC(&sc->tz_sysctl_ctx, SYSCTL_CHILDREN(sc->tz_sysctl_tree),
293 		    OID_AUTO, "_HOT", CTLTYPE_INT | CTLFLAG_RW,
294 		    sc, offsetof(struct acpi_tz_softc, tz_zone.hot),
295 		    acpi_tz_temp_sysctl, "IK",
296 		    "too hot temp setpoint (suspend now)");
297     SYSCTL_ADD_PROC(&sc->tz_sysctl_ctx, SYSCTL_CHILDREN(sc->tz_sysctl_tree),
298 		    OID_AUTO, "_CRT", CTLTYPE_INT | CTLFLAG_RW,
299 		    sc, offsetof(struct acpi_tz_softc, tz_zone.crt),
300 		    acpi_tz_temp_sysctl, "IK",
301 		    "critical temp setpoint (shutdown now)");
302     SYSCTL_ADD_PROC(&sc->tz_sysctl_ctx, SYSCTL_CHILDREN(sc->tz_sysctl_tree),
303 		    OID_AUTO, "_ACx", CTLTYPE_INT | CTLFLAG_RD,
304 		    &sc->tz_zone.ac, sizeof(sc->tz_zone.ac),
305 		    sysctl_handle_opaque, "IK", "");
306     SYSCTL_ADD_PROC(&sc->tz_sysctl_ctx, SYSCTL_CHILDREN(sc->tz_sysctl_tree),
307 		    OID_AUTO, "_TC1", CTLTYPE_INT | CTLFLAG_RW,
308 		    sc, offsetof(struct acpi_tz_softc, tz_zone.tc1),
309 		    acpi_tz_passive_sysctl, "I",
310 		    "thermal constant 1 for passive cooling");
311     SYSCTL_ADD_PROC(&sc->tz_sysctl_ctx, SYSCTL_CHILDREN(sc->tz_sysctl_tree),
312 		    OID_AUTO, "_TC2", CTLTYPE_INT | CTLFLAG_RW,
313 		    sc, offsetof(struct acpi_tz_softc, tz_zone.tc2),
314 		    acpi_tz_passive_sysctl, "I",
315 		    "thermal constant 2 for passive cooling");
316     SYSCTL_ADD_PROC(&sc->tz_sysctl_ctx, SYSCTL_CHILDREN(sc->tz_sysctl_tree),
317 		    OID_AUTO, "_TSP", CTLTYPE_INT | CTLFLAG_RW,
318 		    sc, offsetof(struct acpi_tz_softc, tz_zone.tsp),
319 		    acpi_tz_passive_sysctl, "I",
320 		    "thermal sampling period for passive cooling");
321 
322     /*
323      * Create thread to service all of the thermal zones.  Register
324      * our power profile event handler.
325      */
326     sc->tz_event = EVENTHANDLER_REGISTER(power_profile_change,
327 	acpi_tz_power_profile, sc, 0);
328     if (acpi_tz_td == NULL) {
329 	error = kthread_create(acpi_tz_thread, NULL, &acpi_tz_td,
330 	    "acpi_thermal");
331 	if (error != 0) {
332 	    device_printf(sc->tz_dev, "could not create thread - %d", error);
333 	    goto out;
334 	}
335     }
336 
337     /*
338      * Create a thread to handle passive cooling for 1st zone which
339      * has _PSV, _TSP, _TC1 and _TC2.  Users can enable it for other
340      * zones manually for now.
341      *
342      * XXX We enable only one zone to avoid multiple zones conflict
343      * with each other since cpufreq currently sets all CPUs to the
344      * given frequency whereas it's possible for different thermal
345      * zones to specify independent settings for multiple CPUs.
346      */
347     if (acpi_tz_cooling_unit < 0 && acpi_tz_cooling_is_available(sc))
348 	sc->tz_cooling_enabled = TRUE;
349     if (sc->tz_cooling_enabled) {
350 	error = acpi_tz_cooling_thread_start(sc);
351 	if (error != 0) {
352 	    sc->tz_cooling_enabled = FALSE;
353 	    goto out;
354 	}
355 	acpi_tz_cooling_unit = device_get_unit(dev);
356     }
357 
358     /*
359      * Flag the event handler for a manual invocation by our timeout.
360      * We defer it like this so that the rest of the subsystem has time
361      * to come up.  Don't bother evaluating/printing the temperature at
362      * this point; on many systems it'll be bogus until the EC is running.
363      */
364     sc->tz_flags |= TZ_FLAG_GETPROFILE;
365 
366     /* Attach sensors(9). */
367     strlcpy(sc->sensordev.xname, device_get_nameunit(sc->tz_dev),
368         sizeof(sc->sensordev.xname));
369 
370     sc->sensor.type = SENSOR_TEMP;
371     sensor_attach(&sc->sensordev, &sc->sensor);
372 
373     sensordev_install(&sc->sensordev);
374 
375 out:
376     if (error != 0) {
377 	EVENTHANDLER_DEREGISTER(power_profile_change, sc->tz_event);
378 	AcpiRemoveNotifyHandler(sc->tz_handle, ACPI_DEVICE_NOTIFY,
379 	    acpi_tz_notify_handler);
380 	sysctl_ctx_free(&sc->tz_sysctl_ctx);
381     }
382     return_VALUE (error);
383 }
384 
385 /*
386  * Parse the current state of this thermal zone and set up to use it.
387  *
388  * Note that we may have previous state, which will have to be discarded.
389  */
390 static int
391 acpi_tz_establish(struct acpi_tz_softc *sc)
392 {
393     ACPI_OBJECT	*obj;
394     int		i;
395     char	nbuf[8];
396 
397     ACPI_FUNCTION_TRACE((char *)(uintptr_t)__func__);
398 
399     /* Erase any existing state. */
400     for (i = 0; i < TZ_NUMLEVELS; i++)
401 	if (sc->tz_zone.al[i].Pointer != NULL)
402 	    AcpiOsFree(sc->tz_zone.al[i].Pointer);
403     if (sc->tz_zone.psl.Pointer != NULL)
404 	AcpiOsFree(sc->tz_zone.psl.Pointer);
405 
406     /*
407      * XXX: We initialize only ACPI_BUFFER to avoid race condition
408      * with passive cooling thread which refers psv, tc1, tc2 and tsp.
409      */
410     bzero(sc->tz_zone.ac, sizeof(sc->tz_zone.ac));
411     bzero(sc->tz_zone.al, sizeof(sc->tz_zone.al));
412     bzero(&sc->tz_zone.psl, sizeof(sc->tz_zone.psl));
413 
414     /* Evaluate thermal zone parameters. */
415     for (i = 0; i < TZ_NUMLEVELS; i++) {
416 	ksprintf(nbuf, "_AC%d", i);
417 	acpi_tz_getparam(sc, nbuf, &sc->tz_zone.ac[i]);
418 	ksprintf(nbuf, "_AL%d", i);
419 	sc->tz_zone.al[i].Length = ACPI_ALLOCATE_BUFFER;
420 	sc->tz_zone.al[i].Pointer = NULL;
421 	AcpiEvaluateObject(sc->tz_handle, nbuf, NULL, &sc->tz_zone.al[i]);
422 	obj = (ACPI_OBJECT *)sc->tz_zone.al[i].Pointer;
423 	if (obj != NULL) {
424 	    /* Should be a package containing a list of power objects */
425 	    if (obj->Type != ACPI_TYPE_PACKAGE) {
426 		device_printf(sc->tz_dev, "%s has unknown type %d, rejecting\n",
427 			      nbuf, obj->Type);
428 		return_VALUE (ENXIO);
429 	    }
430 	}
431     }
432     acpi_tz_getparam(sc, "_CRT", &sc->tz_zone.crt);
433     acpi_tz_getparam(sc, "_HOT", &sc->tz_zone.hot);
434     sc->tz_zone.psl.Length = ACPI_ALLOCATE_BUFFER;
435     sc->tz_zone.psl.Pointer = NULL;
436     AcpiEvaluateObject(sc->tz_handle, "_PSL", NULL, &sc->tz_zone.psl);
437     acpi_tz_getparam(sc, "_PSV", &sc->tz_zone.psv);
438     acpi_tz_getparam(sc, "_TC1", &sc->tz_zone.tc1);
439     acpi_tz_getparam(sc, "_TC2", &sc->tz_zone.tc2);
440     acpi_tz_getparam(sc, "_TSP", &sc->tz_zone.tsp);
441     acpi_tz_getparam(sc, "_TZP", &sc->tz_zone.tzp);
442 
443     /*
444      * Sanity-check the values we've been given.
445      *
446      * XXX what do we do about systems that give us the same value for
447      *     more than one of these setpoints?
448      */
449     acpi_tz_sanity(sc, &sc->tz_zone.crt, "_CRT");
450     acpi_tz_sanity(sc, &sc->tz_zone.hot, "_HOT");
451     acpi_tz_sanity(sc, &sc->tz_zone.psv, "_PSV");
452     for (i = 0; i < TZ_NUMLEVELS; i++)
453 	acpi_tz_sanity(sc, &sc->tz_zone.ac[i], "_ACx");
454 
455     return_VALUE (0);
456 }
457 
458 static char *aclevel_string[] = {
459     "NONE", "_AC0", "_AC1", "_AC2", "_AC3", "_AC4",
460     "_AC5", "_AC6", "_AC7", "_AC8", "_AC9"
461 };
462 
463 static __inline const char *
464 acpi_tz_aclevel_string(int active)
465 {
466     if (active < -1 || active >= TZ_NUMLEVELS)
467 	return (aclevel_string[0]);
468 
469     return (aclevel_string[active + 1]);
470 }
471 
472 /*
473  * Get the current temperature.
474  */
475 static int
476 acpi_tz_get_temperature(struct acpi_tz_softc *sc)
477 {
478     int		temp;
479     ACPI_STATUS	status;
480 
481     ACPI_FUNCTION_NAME ("acpi_tz_get_temperature");
482 
483     /*
484      * Silence lookup errors after 10 seconds, then retry every two hours.
485      */
486     if (sc->tz_error_time &&
487 	time_uptime - sc->tz_error_time > TZ_SILENCE_ERROR) {
488 	    if (time_uptime - sc->tz_error_time < TZ_RETRY_ERROR)
489 		return (FALSE);
490 	sc->tz_error_time = time_uptime - TZ_SILENCE_ERROR;
491     }
492 
493     /* Evaluate the thermal zone's _TMP method. */
494     status = acpi_GetInteger(sc->tz_handle, acpi_tz_tmp_name, &temp);
495     if (ACPI_FAILURE(status)) {
496 	ACPI_VPRINT(sc->tz_dev, acpi_device_get_parent_softc(sc->tz_dev),
497 	    "error fetching current temperature -- %s\n",
498 	     AcpiFormatException(status));
499 	if (sc->tz_error_time == 0)
500 	    sc->tz_error_time = time_uptime;
501 	return (FALSE);
502     }
503 
504     /* Check it for validity. */
505     acpi_tz_sanity(sc, &temp, acpi_tz_tmp_name);
506     if (temp == -1) {
507 	if (sc->tz_error_time == 0)
508 	    sc->tz_error_time = time_uptime;
509 	return (FALSE);
510     }
511 
512     ACPI_DEBUG_PRINT((ACPI_DB_VALUES, "got %d.%dC\n", TZ_KELVTOC(temp)));
513     sc->tz_temperature = temp;
514     sc->tz_error_time = 0;
515     /* Update sensor */
516     if(sc->tz_temperature == -1)
517         sc->sensor.flags &= ~SENSOR_FINVALID;
518     sc->sensor.value = sc->tz_temperature * 100000 - 50000;
519     return (TRUE);
520 }
521 
522 /*
523  * Evaluate the condition of a thermal zone, take appropriate actions.
524  */
525 static void
526 acpi_tz_monitor(void *Context)
527 {
528     struct acpi_tz_softc *sc;
529     struct	timespec curtime;
530     int		temp;
531     int		i;
532     int		newactive, newflags;
533 
534     ACPI_FUNCTION_TRACE((char *)(uintptr_t)__func__);
535 
536     sc = (struct acpi_tz_softc *)Context;
537 
538     /* Get the current temperature. */
539     if (!acpi_tz_get_temperature(sc)) {
540 	/* XXX disable zone? go to max cooling? */
541 	return_VOID;
542     }
543     temp = sc->tz_temperature;
544 
545     /*
546      * Work out what we ought to be doing right now.
547      *
548      * Note that the _ACx levels sort from hot to cold.
549      */
550     newactive = TZ_ACTIVE_NONE;
551     for (i = TZ_NUMLEVELS - 1; i >= 0; i--) {
552 	if (sc->tz_zone.ac[i] != -1 && temp >= sc->tz_zone.ac[i])
553 	    newactive = i;
554     }
555 
556     /*
557      * We are going to get _ACx level down (colder side), but give a guaranteed
558      * minimum cooling run time if requested.
559      */
560     if (acpi_tz_min_runtime > 0 && sc->tz_active != TZ_ACTIVE_NONE &&
561 	sc->tz_active != TZ_ACTIVE_UNKNOWN &&
562 	(newactive == TZ_ACTIVE_NONE || newactive > sc->tz_active)) {
563 
564 	getnanotime(&curtime);
565 	timespecsub(&curtime, &sc->tz_cooling_started);
566 	if (curtime.tv_sec < acpi_tz_min_runtime)
567 	    newactive = sc->tz_active;
568     }
569 
570     /* Handle user override of active mode */
571     if (sc->tz_requested != TZ_ACTIVE_NONE && (newactive == TZ_ACTIVE_NONE
572         || sc->tz_requested < newactive))
573 	newactive = sc->tz_requested;
574 
575     /* update temperature-related flags */
576     newflags = TZ_THFLAG_NONE;
577     if (sc->tz_zone.psv != -1 && temp >= sc->tz_zone.psv)
578 	newflags |= TZ_THFLAG_PSV;
579     if (sc->tz_zone.hot != -1 && temp >= sc->tz_zone.hot)
580 	newflags |= TZ_THFLAG_HOT;
581     if (sc->tz_zone.crt != -1 && temp >= sc->tz_zone.crt)
582 	newflags |= TZ_THFLAG_CRT;
583 
584     /* If the active cooling state has changed, we have to switch things. */
585     if (sc->tz_active == TZ_ACTIVE_UNKNOWN) {
586 	/*
587 	 * We don't know which cooling device is on or off,
588 	 * so stop them all, because we now know which
589 	 * should be on (if any).
590 	 */
591 	for (i = 0; i < TZ_NUMLEVELS; i++) {
592 	    if (sc->tz_zone.al[i].Pointer != NULL) {
593 		acpi_ForeachPackageObject(
594 		    (ACPI_OBJECT *)sc->tz_zone.al[i].Pointer,
595 		    acpi_tz_switch_cooler_off, sc);
596 	    }
597 	}
598 	/* now we know that all devices are off */
599 	sc->tz_active = TZ_ACTIVE_NONE;
600     }
601 
602     if (newactive != sc->tz_active) {
603 	/* Turn off unneeded cooling devices that are on, if any are */
604 	for (i = TZ_ACTIVE_LEVEL(sc->tz_active);
605 	     i < TZ_ACTIVE_LEVEL(newactive); i++) {
606 	    acpi_ForeachPackageObject(
607 		(ACPI_OBJECT *)sc->tz_zone.al[i].Pointer,
608 		acpi_tz_switch_cooler_off, sc);
609 	}
610 	/* Turn on cooling devices that are required, if any are */
611 	for (i = TZ_ACTIVE_LEVEL(sc->tz_active) - 1;
612 	     i >= TZ_ACTIVE_LEVEL(newactive); i--) {
613 	    acpi_ForeachPackageObject(
614 		(ACPI_OBJECT *)sc->tz_zone.al[i].Pointer,
615 		acpi_tz_switch_cooler_on, sc);
616 	}
617 
618 	ACPI_VPRINT(sc->tz_dev, acpi_device_get_parent_softc(sc->tz_dev),
619 		    "switched from %s to %s: %d.%dC\n",
620 		    acpi_tz_aclevel_string(sc->tz_active),
621 		    acpi_tz_aclevel_string(newactive), TZ_KELVTOC(temp));
622 	sc->tz_active = newactive;
623 	getnanotime(&sc->tz_cooling_started);
624     }
625 
626     /* XXX (de)activate any passive cooling that may be required. */
627 
628     /*
629      * If the temperature is at _HOT or _CRT, increment our event count.
630      * If it has occurred enough times, shutdown the system.  This is
631      * needed because some systems will report an invalid high temperature
632      * for one poll cycle.  It is suspected this is due to the embedded
633      * controller timing out.  A typical value is 138C for one cycle on
634      * a system that is otherwise 65C.
635      *
636      * If we're almost at that threshold, notify the user through devd(8).
637      */
638     if ((newflags & (TZ_THFLAG_HOT | TZ_THFLAG_CRT)) != 0) {
639 	sc->tz_validchecks++;
640 	if (sc->tz_validchecks == TZ_VALIDCHECKS) {
641 	    device_printf(sc->tz_dev,
642 		"WARNING - current temperature (%d.%dC) exceeds safe limits\n",
643 		TZ_KELVTOC(sc->tz_temperature));
644 	    shutdown_nice(RB_POWEROFF);
645 	} else if (sc->tz_validchecks == TZ_NOTIFYCOUNT)
646 	    acpi_UserNotify("Thermal", sc->tz_handle, TZ_NOTIFY_CRITICAL);
647     } else {
648 	sc->tz_validchecks = 0;
649     }
650     sc->tz_thflags = newflags;
651 
652     return_VOID;
653 }
654 
655 /*
656  * Given an object, verify that it's a reference to a device of some sort,
657  * and try to switch it off.
658  */
659 static void
660 acpi_tz_switch_cooler_off(ACPI_OBJECT *obj, void *arg)
661 {
662     ACPI_HANDLE			cooler;
663 
664     ACPI_FUNCTION_TRACE((char *)(uintptr_t)__func__);
665 
666     cooler = acpi_GetReference(NULL, obj);
667     if (cooler == NULL) {
668 	ACPI_DEBUG_PRINT((ACPI_DB_OBJECTS, "can't get handle\n"));
669 	return_VOID;
670     }
671 
672     ACPI_DEBUG_PRINT((ACPI_DB_OBJECTS, "called to turn %s off\n",
673 		     acpi_name(cooler)));
674     acpi_pwr_switch_consumer(cooler, ACPI_STATE_D3);
675 
676     return_VOID;
677 }
678 
679 /*
680  * Given an object, verify that it's a reference to a device of some sort,
681  * and try to switch it on.
682  *
683  * XXX replication of off/on function code is bad.
684  */
685 static void
686 acpi_tz_switch_cooler_on(ACPI_OBJECT *obj, void *arg)
687 {
688     struct acpi_tz_softc	*sc = (struct acpi_tz_softc *)arg;
689     ACPI_HANDLE			cooler;
690     ACPI_STATUS			status;
691 
692     ACPI_FUNCTION_TRACE((char *)(uintptr_t)__func__);
693 
694     cooler = acpi_GetReference(NULL, obj);
695     if (cooler == NULL) {
696 	ACPI_DEBUG_PRINT((ACPI_DB_OBJECTS, "can't get handle\n"));
697 	return_VOID;
698     }
699 
700     ACPI_DEBUG_PRINT((ACPI_DB_OBJECTS, "called to turn %s on\n",
701 		     acpi_name(cooler)));
702     status = acpi_pwr_switch_consumer(cooler, ACPI_STATE_D0);
703     if (ACPI_FAILURE(status)) {
704 	ACPI_VPRINT(sc->tz_dev, acpi_device_get_parent_softc(sc->tz_dev),
705 		    "failed to activate %s - %s\n", acpi_name(cooler),
706 		    AcpiFormatException(status));
707     }
708 
709     return_VOID;
710 }
711 
712 /*
713  * Read/debug-print a parameter, default it to -1.
714  */
715 static void
716 acpi_tz_getparam(struct acpi_tz_softc *sc, char *node, int *data)
717 {
718 
719     ACPI_FUNCTION_TRACE((char *)(uintptr_t)__func__);
720 
721     if (ACPI_FAILURE(acpi_GetInteger(sc->tz_handle, node, data))) {
722 	*data = -1;
723     } else {
724 	ACPI_DEBUG_PRINT((ACPI_DB_VALUES, "%s.%s = %d\n",
725 			 acpi_name(sc->tz_handle), node, *data));
726     }
727 
728     return_VOID;
729 }
730 
731 /*
732  * Sanity-check a temperature value.  Assume that setpoints
733  * should be between 0C and 200C.
734  */
735 static void
736 acpi_tz_sanity(struct acpi_tz_softc *sc, int *val, char *what)
737 {
738     if (*val != -1 && (*val < TZ_ZEROC || *val > TZ_ZEROC + 2000)) {
739 	/*
740 	 * If the value we are checking is _TMP, warn the user only
741 	 * once. This avoids spamming messages if, for instance, the
742 	 * sensor is broken and always returns an invalid temperature.
743 	 *
744 	 * This is only done for _TMP; other values always emit a
745 	 * warning.
746 	 */
747 	if (what != acpi_tz_tmp_name || !sc->tz_insane_tmp_notified) {
748 	    device_printf(sc->tz_dev, "%s value is absurd, ignored (%d.%dC)\n",
749 			  what, TZ_KELVTOC(*val));
750 
751 	    /* Don't warn the user again if the read value doesn't improve. */
752 	    if (what == acpi_tz_tmp_name)
753 		sc->tz_insane_tmp_notified = 1;
754 	}
755 	*val = -1;
756 	return;
757     }
758 
759     /* This value is correct. Warn if it's incorrect again. */
760     if (what == acpi_tz_tmp_name)
761 	sc->tz_insane_tmp_notified = 0;
762 }
763 
764 /*
765  * Respond to a sysctl on the active state node.
766  */
767 static int
768 acpi_tz_active_sysctl(SYSCTL_HANDLER_ARGS)
769 {
770     struct acpi_tz_softc	*sc;
771     int				active;
772     int		 		error;
773 
774     sc = (struct acpi_tz_softc *)oidp->oid_arg1;
775     active = sc->tz_active;
776     error = sysctl_handle_int(oidp, &active, 0, req);
777 
778     /* Error or no new value */
779     if (error != 0 || req->newptr == NULL)
780 	return (error);
781     if (active < -1 || active >= TZ_NUMLEVELS)
782 	return (EINVAL);
783 
784     /* Set new preferred level and re-switch */
785     sc->tz_requested = active;
786     acpi_tz_signal(sc, 0);
787     return (0);
788 }
789 
790 static int
791 acpi_tz_cooling_sysctl(SYSCTL_HANDLER_ARGS)
792 {
793     struct acpi_tz_softc *sc;
794     int enabled, error;
795 
796     sc = (struct acpi_tz_softc *)oidp->oid_arg1;
797     enabled = sc->tz_cooling_enabled;
798     error = sysctl_handle_int(oidp, &enabled, 0, req);
799 
800     /* Error or no new value */
801     if (error != 0 || req->newptr == NULL)
802 	return (error);
803     if (enabled != TRUE && enabled != FALSE)
804 	return (EINVAL);
805 
806     if (enabled) {
807 	if (acpi_tz_cooling_is_available(sc))
808 	    error = acpi_tz_cooling_thread_start(sc);
809 	else
810 	    error = ENODEV;
811 	if (error)
812 	    enabled = FALSE;
813     }
814     sc->tz_cooling_enabled = enabled;
815     return (error);
816 }
817 
818 static int
819 acpi_tz_temp_sysctl(SYSCTL_HANDLER_ARGS)
820 {
821     struct acpi_tz_softc	*sc;
822     int				temp, *temp_ptr;
823     int		 		error;
824 
825     sc = oidp->oid_arg1;
826     temp_ptr = (int *)((uintptr_t)sc + oidp->oid_arg2);
827     temp = *temp_ptr;
828     error = sysctl_handle_int(oidp, &temp, 0, req);
829 
830     /* Error or no new value */
831     if (error != 0 || req->newptr == NULL)
832 	return (error);
833 
834     /* Only allow changing settings if override is set. */
835     if (!acpi_tz_override)
836 	return (EPERM);
837 
838     /* Check user-supplied value for sanity. */
839     acpi_tz_sanity(sc, &temp, "user-supplied temp");
840     if (temp == -1)
841 	return (EINVAL);
842 
843     *temp_ptr = temp;
844     return (0);
845 }
846 
847 static int
848 acpi_tz_passive_sysctl(SYSCTL_HANDLER_ARGS)
849 {
850     struct acpi_tz_softc	*sc;
851     int				val, *val_ptr;
852     int				error;
853 
854     sc = oidp->oid_arg1;
855     val_ptr = (int *)((uintptr_t)sc + oidp->oid_arg2);
856     val = *val_ptr;
857     error = sysctl_handle_int(oidp, &val, 0, req);
858 
859     /* Error or no new value */
860     if (error != 0 || req->newptr == NULL)
861 	return (error);
862 
863     /* Only allow changing settings if override is set. */
864     if (!acpi_tz_override)
865 	return (EPERM);
866 
867     *val_ptr = val;
868     return (0);
869 }
870 
871 static void
872 acpi_tz_notify_handler(ACPI_HANDLE h, UINT32 notify, void *context)
873 {
874     struct acpi_tz_softc	*sc = (struct acpi_tz_softc *)context;
875 
876     ACPI_FUNCTION_TRACE((char *)(uintptr_t)__func__);
877 
878     switch (notify) {
879     case TZ_NOTIFY_TEMPERATURE:
880 	/* Temperature change occurred */
881 	acpi_tz_signal(sc, 0);
882 	break;
883     case TZ_NOTIFY_DEVICES:
884     case TZ_NOTIFY_LEVELS:
885 	/* Zone devices/setpoints changed */
886 	acpi_tz_signal(sc, TZ_FLAG_GETSETTINGS);
887 	break;
888     default:
889 	ACPI_VPRINT(sc->tz_dev, acpi_device_get_parent_softc(sc->tz_dev),
890 		    "unknown Notify event 0x%x\n", notify);
891 	break;
892     }
893 
894     acpi_UserNotify("Thermal", h, notify);
895 
896     return_VOID;
897 }
898 
899 static void
900 acpi_tz_signal(struct acpi_tz_softc *sc, int flags)
901 {
902     ACPI_LOCK(thermal);
903     sc->tz_flags |= flags;
904     ACPI_UNLOCK(thermal);
905     wakeup(&acpi_tz_td);
906 }
907 
908 /*
909  * Notifies can be generated asynchronously but have also been seen to be
910  * triggered by other thermal methods.  One system generates a notify of
911  * 0x81 when the fan is turned on or off.  Another generates it when _SCP
912  * is called.  To handle these situations, we check the zone via
913  * acpi_tz_monitor() before evaluating changes to setpoints or the cooling
914  * policy.
915  */
916 static void
917 acpi_tz_timeout(struct acpi_tz_softc *sc, int flags)
918 {
919 
920     /* Check the current temperature and take action based on it */
921     acpi_tz_monitor(sc);
922 
923     /* If requested, get the power profile settings. */
924     if (flags & TZ_FLAG_GETPROFILE)
925 	acpi_tz_power_profile(sc);
926 
927     /*
928      * If requested, check for new devices/setpoints.  After finding them,
929      * check if we need to switch fans based on the new values.
930      */
931     if (flags & TZ_FLAG_GETSETTINGS) {
932 	acpi_tz_establish(sc);
933 	acpi_tz_monitor(sc);
934     }
935 
936     /* XXX passive cooling actions? */
937 }
938 
939 /*
940  * System power profile may have changed; fetch and notify the
941  * thermal zone accordingly.
942  *
943  * Since this can be called from an arbitrary eventhandler, it needs
944  * to get the ACPI lock itself.
945  */
946 static void
947 acpi_tz_power_profile(void *arg)
948 {
949     ACPI_STATUS			status;
950     struct acpi_tz_softc	*sc = (struct acpi_tz_softc *)arg;
951     int				state;
952 
953     state = power_profile_get_state();
954     if (state != POWER_PROFILE_PERFORMANCE && state != POWER_PROFILE_ECONOMY)
955 	return;
956 
957     /* check that we haven't decided there's no _SCP method */
958     if ((sc->tz_flags & TZ_FLAG_NO_SCP) == 0) {
959 
960 	/* Call _SCP to set the new profile */
961 	status = acpi_SetInteger(sc->tz_handle, "_SCP",
962 	    (state == POWER_PROFILE_PERFORMANCE) ? 0 : 1);
963 	if (ACPI_FAILURE(status)) {
964 	    if (status != AE_NOT_FOUND)
965 		ACPI_VPRINT(sc->tz_dev,
966 			    acpi_device_get_parent_softc(sc->tz_dev),
967 			    "can't evaluate %s._SCP - %s\n",
968 			    acpi_name(sc->tz_handle),
969 			    AcpiFormatException(status));
970 	    sc->tz_flags |= TZ_FLAG_NO_SCP;
971 	} else {
972 	    /* We have to re-evaluate the entire zone now */
973 	    acpi_tz_signal(sc, TZ_FLAG_GETSETTINGS);
974 	}
975     }
976 }
977 
978 /*
979  * Thermal zone monitor thread.
980  */
981 static void
982 acpi_tz_thread(void *arg)
983 {
984     device_t	*devs;
985     int		devcount, i;
986     int		flags;
987     struct acpi_tz_softc **sc;
988 
989     ACPI_FUNCTION_TRACE((char *)(uintptr_t)__func__);
990 
991     devs = NULL;
992     devcount = 0;
993     sc = NULL;
994     get_mplock();
995 
996     for (;;) {
997 	/* If the number of devices has changed, re-evaluate. */
998 	if (devclass_get_count(acpi_tz_devclass) != devcount) {
999 	    if (devs != NULL) {
1000 		kfree(devs, M_TEMP);
1001 		kfree(sc, M_TEMP);
1002 	    }
1003 	    devclass_get_devices(acpi_tz_devclass, &devs, &devcount);
1004 	    sc = kmalloc(sizeof(struct acpi_tz_softc *) * devcount, M_TEMP,
1005 			M_WAITOK | M_ZERO);
1006 	    for (i = 0; i < devcount; i++)
1007 		sc[i] = device_get_softc(devs[i]);
1008 	}
1009 
1010 	/* Check for temperature events and act on them. */
1011 	for (i = 0; i < devcount; i++) {
1012 	    ACPI_LOCK(thermal);
1013 	    flags = sc[i]->tz_flags;
1014 	    sc[i]->tz_flags &= TZ_FLAG_NO_SCP;
1015 	    ACPI_UNLOCK(thermal);
1016 	    acpi_tz_timeout(sc[i], flags);
1017 	}
1018 
1019 	/* If more work to do, don't go to sleep yet. */
1020 	ACPI_LOCK(thermal);
1021 	for (i = 0; i < devcount; i++) {
1022 	    if (sc[i]->tz_flags & ~TZ_FLAG_NO_SCP)
1023 		break;
1024 	}
1025 
1026 	/*
1027 	 * Interlocked sleep until signaled or we timeout.
1028 	 */
1029 	if (i == devcount) {
1030 	    tsleep_interlock(&acpi_tz_td, 0);
1031 	    ACPI_UNLOCK(thermal);
1032 	    tsleep(&acpi_tz_td, 0, "tzpoll", hz * acpi_tz_polling_rate);
1033 	} else {
1034 	    ACPI_UNLOCK(thermal);
1035 	}
1036     }
1037     rel_mplock();
1038 }
1039 
1040 #ifdef __FreeBSD__
1041 static int
1042 acpi_tz_cpufreq_restore(struct acpi_tz_softc *sc)
1043 {
1044     device_t dev;
1045     int error;
1046 
1047     if (!sc->tz_cooling_updated)
1048 	return (0);
1049     if ((dev = devclass_get_device(devclass_find("cpufreq"), 0)) == NULL)
1050 	return (ENXIO);
1051     ACPI_VPRINT(sc->tz_dev, acpi_device_get_parent_softc(sc->tz_dev),
1052 	"temperature %d.%dC: resuming previous clock speed (%d MHz)\n",
1053 	TZ_KELVTOC(sc->tz_temperature), sc->tz_cooling_saved_freq);
1054     error = CPUFREQ_SET(dev, NULL, CPUFREQ_PRIO_KERN);
1055     if (error == 0)
1056 	sc->tz_cooling_updated = FALSE;
1057     return (error);
1058 }
1059 
1060 static int
1061 acpi_tz_cpufreq_update(struct acpi_tz_softc *sc, int req)
1062 {
1063     device_t dev;
1064     struct cf_level *levels;
1065     int num_levels, error, freq, desired_freq, perf, i;
1066 
1067     levels = kmalloc(CPUFREQ_MAX_LEVELS * sizeof(*levels), M_TEMP, M_NOWAIT);
1068     if (levels == NULL)
1069 	return (ENOMEM);
1070 
1071     /*
1072      * Find the main device, cpufreq0.  We don't yet support independent
1073      * CPU frequency control on SMP.
1074      */
1075     if ((dev = devclass_get_device(devclass_find("cpufreq"), 0)) == NULL) {
1076 	error = ENXIO;
1077 	goto out;
1078     }
1079 
1080     /* Get the current frequency. */
1081     error = CPUFREQ_GET(dev, &levels[0]);
1082     if (error)
1083 	goto out;
1084     freq = levels[0].total_set.freq;
1085 
1086     /* Get the current available frequency levels. */
1087     num_levels = CPUFREQ_MAX_LEVELS;
1088     error = CPUFREQ_LEVELS(dev, levels, &num_levels);
1089     if (error) {
1090 	if (error == E2BIG)
1091 	    printf("cpufreq: need to increase CPUFREQ_MAX_LEVELS\n");
1092 	goto out;
1093     }
1094 
1095     /* Calculate the desired frequency as a percent of the max frequency. */
1096     perf = 100 * freq / levels[0].total_set.freq - req;
1097     if (perf < 0)
1098 	perf = 0;
1099     else if (perf > 100)
1100 	perf = 100;
1101     desired_freq = levels[0].total_set.freq * perf / 100;
1102 
1103     if (desired_freq < freq) {
1104 	/* Find the closest available frequency, rounding down. */
1105 	for (i = 0; i < num_levels; i++)
1106 	    if (levels[i].total_set.freq <= desired_freq)
1107 		break;
1108 
1109 	/* If we didn't find a relevant setting, use the lowest. */
1110 	if (i == num_levels)
1111 	    i--;
1112     } else {
1113 	/* If we didn't decrease frequency yet, don't increase it. */
1114 	if (!sc->tz_cooling_updated) {
1115 	    sc->tz_cooling_active = FALSE;
1116 	    goto out;
1117 	}
1118 
1119 	/* Use saved cpu frequency as maximum value. */
1120 	if (desired_freq > sc->tz_cooling_saved_freq)
1121 	    desired_freq = sc->tz_cooling_saved_freq;
1122 
1123 	/* Find the closest available frequency, rounding up. */
1124 	for (i = num_levels - 1; i >= 0; i--)
1125 	    if (levels[i].total_set.freq >= desired_freq)
1126 		break;
1127 
1128 	/* If we didn't find a relevant setting, use the highest. */
1129 	if (i == -1)
1130 	    i++;
1131 
1132 	/* If we're going to the highest frequency, restore the old setting. */
1133 	if (i == 0 || desired_freq == sc->tz_cooling_saved_freq) {
1134 	    error = acpi_tz_cpufreq_restore(sc);
1135 	    if (error == 0)
1136 		sc->tz_cooling_active = FALSE;
1137 	    goto out;
1138 	}
1139     }
1140 
1141     /* If we are going to a new frequency, activate it. */
1142     if (levels[i].total_set.freq != freq) {
1143 	ACPI_VPRINT(sc->tz_dev, acpi_device_get_parent_softc(sc->tz_dev),
1144 	    "temperature %d.%dC: %screasing clock speed "
1145 	    "from %d MHz to %d MHz\n",
1146 	    TZ_KELVTOC(sc->tz_temperature),
1147 	    (freq > levels[i].total_set.freq) ? "de" : "in",
1148 	    freq, levels[i].total_set.freq);
1149 	error = CPUFREQ_SET(dev, &levels[i], CPUFREQ_PRIO_KERN);
1150 	if (error == 0 && !sc->tz_cooling_updated) {
1151 	    sc->tz_cooling_saved_freq = freq;
1152 	    sc->tz_cooling_updated = TRUE;
1153 	}
1154     }
1155 
1156 out:
1157     if (levels)
1158 	free(levels, M_TEMP);
1159     return (error);
1160 }
1161 #endif
1162 
1163 /*
1164  * Passive cooling thread; monitors current temperature according to the
1165  * cooling interval and calculates whether to scale back CPU frequency.
1166  */
1167 static void
1168 acpi_tz_cooling_thread(void *arg)
1169 {
1170     struct acpi_tz_softc *sc;
1171     int perf, curr_temp, prev_temp;
1172 #ifdef __FreeBSD__
1173     int error;
1174 #endif
1175 
1176     ACPI_FUNCTION_TRACE((char *)(uintptr_t)__func__);
1177 
1178     sc = (struct acpi_tz_softc *)arg;
1179     get_mplock();
1180 
1181     prev_temp = sc->tz_temperature;
1182     while (sc->tz_cooling_enabled) {
1183 	if (sc->tz_cooling_active)
1184 	    (void)acpi_tz_get_temperature(sc);
1185 	curr_temp = sc->tz_temperature;
1186 	if (curr_temp >= sc->tz_zone.psv)
1187 	    sc->tz_cooling_active = TRUE;
1188 	if (sc->tz_cooling_active) {
1189 	    perf = sc->tz_zone.tc1 * (curr_temp - prev_temp) +
1190 		   sc->tz_zone.tc2 * (curr_temp - sc->tz_zone.psv);
1191 	    perf /= 10;
1192 
1193 	    if (perf != 0) {
1194 #ifdef __FreeBSD__
1195 		error = acpi_tz_cpufreq_update(sc, perf);
1196 
1197 		/*
1198 		 * If error and not simply a higher priority setting was
1199 		 * active, disable cooling.
1200 		 */
1201 		if (error != 0 && error != EPERM) {
1202 		    device_printf(sc->tz_dev,
1203 			"failed to set new freq, disabling passive cooling\n");
1204 		    sc->tz_cooling_enabled = FALSE;
1205 		}
1206 #endif
1207 	    }
1208 	}
1209 	prev_temp = curr_temp;
1210 	tsleep(&sc->tz_cooling_proc, 0, "cooling",
1211 	    hz * sc->tz_zone.tsp / 10);
1212     }
1213     if (sc->tz_cooling_active) {
1214 #ifdef __FreeBSD__
1215 	acpi_tz_cpufreq_restore(sc);
1216 #endif
1217 	sc->tz_cooling_active = FALSE;
1218     }
1219     sc->tz_cooling_proc = NULL;
1220     ACPI_LOCK(thermal);
1221     sc->tz_cooling_proc_running = FALSE;
1222     ACPI_UNLOCK(thermal);
1223     rel_mplock();
1224 }
1225 
1226 /*
1227  * TODO: We ignore _PSL (list of cooling devices) since cpufreq enumerates
1228  * all CPUs for us.  However, it's possible in the future _PSL will
1229  * reference non-CPU devices so we may want to support it then.
1230  */
1231 static int
1232 acpi_tz_cooling_is_available(struct acpi_tz_softc *sc)
1233 {
1234     return (sc->tz_zone.tc1 != -1 && sc->tz_zone.tc2 != -1 &&
1235 	sc->tz_zone.tsp != -1 && sc->tz_zone.tsp != 0 &&
1236 	sc->tz_zone.psv != -1);
1237 }
1238 
1239 static int
1240 acpi_tz_cooling_thread_start(struct acpi_tz_softc *sc)
1241 {
1242     int error;
1243 
1244     ACPI_LOCK(thermal);
1245     if (sc->tz_cooling_proc_running) {
1246 	ACPI_UNLOCK(thermal);
1247 	return (0);
1248     }
1249     sc->tz_cooling_proc_running = TRUE;
1250     ACPI_UNLOCK(thermal);
1251     error = 0;
1252     if (sc->tz_cooling_proc == NULL) {
1253 	error = kthread_create(acpi_tz_cooling_thread, sc,
1254 	    &sc->tz_cooling_proc,
1255 	    "acpi_cooling%d", device_get_unit(sc->tz_dev));
1256 	if (error != 0) {
1257 	    device_printf(sc->tz_dev, "could not create thread - %d", error);
1258 	    ACPI_LOCK(thermal);
1259 	    sc->tz_cooling_proc_running = FALSE;
1260 	    ACPI_UNLOCK(thermal);
1261 	}
1262     }
1263     return (error);
1264 }
1265