xref: /freebsd/sys/dev/acpica/acpi_thermal.c (revision 724b4bfdf1306e4f2c451b6d146fe0fe0353b2c8)
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 
28 #include <sys/cdefs.h>
29 __FBSDID("$FreeBSD$");
30 
31 #include "opt_acpi.h"
32 #include <sys/param.h>
33 #include <sys/kernel.h>
34 #include <sys/bus.h>
35 #include <sys/cpu.h>
36 #include <sys/kthread.h>
37 #include <sys/malloc.h>
38 #include <sys/module.h>
39 #include <sys/proc.h>
40 #include <sys/reboot.h>
41 #include <sys/sysctl.h>
42 #include <sys/unistd.h>
43 #include <sys/power.h>
44 
45 #include "cpufreq_if.h"
46 
47 #include <contrib/dev/acpica/include/acpi.h>
48 #include <contrib/dev/acpica/include/accommon.h>
49 
50 #include <dev/acpica/acpivar.h>
51 
52 /* Hooks for the ACPI CA debugging infrastructure */
53 #define _COMPONENT	ACPI_THERMAL
54 ACPI_MODULE_NAME("THERMAL")
55 
56 #define TZ_ZEROC	2732
57 #define TZ_KELVTOC(x)	(((x) - TZ_ZEROC) / 10), abs(((x) - TZ_ZEROC) % 10)
58 
59 #define TZ_NOTIFY_TEMPERATURE	0x80 /* Temperature changed. */
60 #define TZ_NOTIFY_LEVELS	0x81 /* Cooling levels changed. */
61 #define TZ_NOTIFY_DEVICES	0x82 /* Device lists changed. */
62 #define TZ_NOTIFY_CRITICAL	0xcc /* Fake notify that _CRT/_HOT reached. */
63 
64 /* Check for temperature changes every 10 seconds by default */
65 #define TZ_POLLRATE	10
66 
67 /* Make sure the reported temperature is valid for this number of polls. */
68 #define TZ_VALIDCHECKS	3
69 
70 /* Notify the user we will be shutting down in one more poll cycle. */
71 #define TZ_NOTIFYCOUNT	(TZ_VALIDCHECKS - 1)
72 
73 /* ACPI spec defines this */
74 #define TZ_NUMLEVELS	10
75 struct acpi_tz_zone {
76     int		ac[TZ_NUMLEVELS];
77     ACPI_BUFFER	al[TZ_NUMLEVELS];
78     int		crt;
79     int		hot;
80     ACPI_BUFFER	psl;
81     int		psv;
82     int		tc1;
83     int		tc2;
84     int		tsp;
85     int		tzp;
86 };
87 
88 struct acpi_tz_softc {
89     device_t			tz_dev;
90     ACPI_HANDLE			tz_handle;	/*Thermal zone handle*/
91     int				tz_temperature;	/*Current temperature*/
92     int				tz_active;	/*Current active cooling*/
93 #define TZ_ACTIVE_NONE		-1
94 #define TZ_ACTIVE_UNKNOWN	-2
95     int				tz_requested;	/*Minimum active cooling*/
96     int				tz_thflags;	/*Current temp-related flags*/
97 #define TZ_THFLAG_NONE		0
98 #define TZ_THFLAG_PSV		(1<<0)
99 #define TZ_THFLAG_HOT		(1<<2)
100 #define TZ_THFLAG_CRT		(1<<3)
101     int				tz_flags;
102 #define TZ_FLAG_NO_SCP		(1<<0)		/*No _SCP method*/
103 #define TZ_FLAG_GETPROFILE	(1<<1)		/*Get power_profile in timeout*/
104 #define TZ_FLAG_GETSETTINGS	(1<<2)		/*Get devs/setpoints*/
105     struct timespec		tz_cooling_started;
106 					/*Current cooling starting time*/
107 
108     struct sysctl_ctx_list	tz_sysctl_ctx;
109     struct sysctl_oid		*tz_sysctl_tree;
110     eventhandler_tag		tz_event;
111 
112     struct acpi_tz_zone 	tz_zone;	/*Thermal zone parameters*/
113     int				tz_validchecks;
114 
115     /* passive cooling */
116     struct proc			*tz_cooling_proc;
117     int				tz_cooling_proc_running;
118     int				tz_cooling_enabled;
119     int				tz_cooling_active;
120     int				tz_cooling_updated;
121     int				tz_cooling_saved_freq;
122 };
123 
124 #define	TZ_ACTIVE_LEVEL(act)	((act) >= 0 ? (act) : TZ_NUMLEVELS)
125 
126 #define CPUFREQ_MAX_LEVELS	64 /* XXX cpufreq should export this */
127 
128 static int	acpi_tz_probe(device_t dev);
129 static int	acpi_tz_attach(device_t dev);
130 static int	acpi_tz_establish(struct acpi_tz_softc *sc);
131 static void	acpi_tz_monitor(void *Context);
132 static void	acpi_tz_switch_cooler_off(ACPI_OBJECT *obj, void *arg);
133 static void	acpi_tz_switch_cooler_on(ACPI_OBJECT *obj, void *arg);
134 static void	acpi_tz_getparam(struct acpi_tz_softc *sc, char *node,
135 				 int *data);
136 static void	acpi_tz_sanity(struct acpi_tz_softc *sc, int *val, char *what);
137 static int	acpi_tz_active_sysctl(SYSCTL_HANDLER_ARGS);
138 static int	acpi_tz_cooling_sysctl(SYSCTL_HANDLER_ARGS);
139 static int	acpi_tz_temp_sysctl(SYSCTL_HANDLER_ARGS);
140 static int	acpi_tz_passive_sysctl(SYSCTL_HANDLER_ARGS);
141 static void	acpi_tz_notify_handler(ACPI_HANDLE h, UINT32 notify,
142 				       void *context);
143 static void	acpi_tz_signal(struct acpi_tz_softc *sc, int flags);
144 static void	acpi_tz_timeout(struct acpi_tz_softc *sc, int flags);
145 static void	acpi_tz_power_profile(void *arg);
146 static void	acpi_tz_thread(void *arg);
147 static int	acpi_tz_cooling_is_available(struct acpi_tz_softc *sc);
148 static int	acpi_tz_cooling_thread_start(struct acpi_tz_softc *sc);
149 
150 static device_method_t acpi_tz_methods[] = {
151     /* Device interface */
152     DEVMETHOD(device_probe,	acpi_tz_probe),
153     DEVMETHOD(device_attach,	acpi_tz_attach),
154 
155     {0, 0}
156 };
157 
158 static driver_t acpi_tz_driver = {
159     "acpi_tz",
160     acpi_tz_methods,
161     sizeof(struct acpi_tz_softc),
162 };
163 
164 static devclass_t acpi_tz_devclass;
165 DRIVER_MODULE(acpi_tz, acpi, acpi_tz_driver, acpi_tz_devclass, 0, 0);
166 MODULE_DEPEND(acpi_tz, acpi, 1, 1, 1);
167 
168 static struct sysctl_ctx_list	acpi_tz_sysctl_ctx;
169 static struct sysctl_oid	*acpi_tz_sysctl_tree;
170 
171 /* Minimum cooling run time */
172 static int			acpi_tz_min_runtime;
173 static int			acpi_tz_polling_rate = TZ_POLLRATE;
174 static int			acpi_tz_override;
175 
176 /* Timezone polling thread */
177 static struct proc		*acpi_tz_proc;
178 ACPI_LOCK_DECL(thermal, "ACPI thermal zone");
179 
180 static int			acpi_tz_cooling_unit = -1;
181 
182 static int
183 acpi_tz_probe(device_t dev)
184 {
185     int		result;
186 
187     if (acpi_get_type(dev) == ACPI_TYPE_THERMAL && !acpi_disabled("thermal")) {
188 	device_set_desc(dev, "Thermal Zone");
189 	result = -10;
190     } else
191 	result = ENXIO;
192     return (result);
193 }
194 
195 static int
196 acpi_tz_attach(device_t dev)
197 {
198     struct acpi_tz_softc	*sc;
199     struct acpi_softc		*acpi_sc;
200     int				error;
201     char			oidname[8];
202 
203     ACPI_FUNCTION_TRACE((char *)(uintptr_t)__func__);
204 
205     sc = device_get_softc(dev);
206     sc->tz_dev = dev;
207     sc->tz_handle = acpi_get_handle(dev);
208     sc->tz_requested = TZ_ACTIVE_NONE;
209     sc->tz_active = TZ_ACTIVE_UNKNOWN;
210     sc->tz_thflags = TZ_THFLAG_NONE;
211     sc->tz_cooling_proc = NULL;
212     sc->tz_cooling_proc_running = FALSE;
213     sc->tz_cooling_active = FALSE;
214     sc->tz_cooling_updated = FALSE;
215     sc->tz_cooling_enabled = FALSE;
216 
217     /*
218      * Parse the current state of the thermal zone and build control
219      * structures.  We don't need to worry about interference with the
220      * control thread since we haven't fully attached this device yet.
221      */
222     if ((error = acpi_tz_establish(sc)) != 0)
223 	return (error);
224 
225     /*
226      * Register for any Notify events sent to this zone.
227      */
228     AcpiInstallNotifyHandler(sc->tz_handle, ACPI_DEVICE_NOTIFY,
229 			     acpi_tz_notify_handler, sc);
230 
231     /*
232      * Create our sysctl nodes.
233      *
234      * XXX we need a mechanism for adding nodes under ACPI.
235      */
236     if (device_get_unit(dev) == 0) {
237 	acpi_sc = acpi_device_get_parent_softc(dev);
238 	sysctl_ctx_init(&acpi_tz_sysctl_ctx);
239 	acpi_tz_sysctl_tree = SYSCTL_ADD_NODE(&acpi_tz_sysctl_ctx,
240 			      SYSCTL_CHILDREN(acpi_sc->acpi_sysctl_tree),
241 			      OID_AUTO, "thermal", CTLFLAG_RD, 0, "");
242 	SYSCTL_ADD_INT(&acpi_tz_sysctl_ctx,
243 		       SYSCTL_CHILDREN(acpi_tz_sysctl_tree),
244 		       OID_AUTO, "min_runtime", CTLFLAG_RW,
245 		       &acpi_tz_min_runtime, 0,
246 		       "minimum cooling run time in sec");
247 	SYSCTL_ADD_INT(&acpi_tz_sysctl_ctx,
248 		       SYSCTL_CHILDREN(acpi_tz_sysctl_tree),
249 		       OID_AUTO, "polling_rate", CTLFLAG_RW,
250 		       &acpi_tz_polling_rate, 0, "monitor polling interval in seconds");
251 	SYSCTL_ADD_INT(&acpi_tz_sysctl_ctx,
252 		       SYSCTL_CHILDREN(acpi_tz_sysctl_tree), OID_AUTO,
253 		       "user_override", CTLFLAG_RW, &acpi_tz_override, 0,
254 		       "allow override of thermal settings");
255     }
256     sysctl_ctx_init(&sc->tz_sysctl_ctx);
257     sprintf(oidname, "tz%d", device_get_unit(dev));
258     sc->tz_sysctl_tree = SYSCTL_ADD_NODE(&sc->tz_sysctl_ctx,
259 					 SYSCTL_CHILDREN(acpi_tz_sysctl_tree),
260 					 OID_AUTO, oidname, CTLFLAG_RD, 0, "");
261     SYSCTL_ADD_PROC(&sc->tz_sysctl_ctx, SYSCTL_CHILDREN(sc->tz_sysctl_tree),
262 		    OID_AUTO, "temperature", CTLTYPE_INT | CTLFLAG_RD,
263 		    &sc->tz_temperature, 0, sysctl_handle_int,
264 		    "IK", "current thermal zone temperature");
265     SYSCTL_ADD_PROC(&sc->tz_sysctl_ctx, SYSCTL_CHILDREN(sc->tz_sysctl_tree),
266 		    OID_AUTO, "active", CTLTYPE_INT | CTLFLAG_RW,
267 		    sc, 0, acpi_tz_active_sysctl, "I", "cooling is active");
268     SYSCTL_ADD_PROC(&sc->tz_sysctl_ctx, SYSCTL_CHILDREN(sc->tz_sysctl_tree),
269 		    OID_AUTO, "passive_cooling", CTLTYPE_INT | CTLFLAG_RW,
270 		    sc, 0, acpi_tz_cooling_sysctl, "I",
271 		    "enable passive (speed reduction) cooling");
272 
273     SYSCTL_ADD_INT(&sc->tz_sysctl_ctx, SYSCTL_CHILDREN(sc->tz_sysctl_tree),
274 		   OID_AUTO, "thermal_flags", CTLFLAG_RD,
275 		   &sc->tz_thflags, 0, "thermal zone flags");
276     SYSCTL_ADD_PROC(&sc->tz_sysctl_ctx, SYSCTL_CHILDREN(sc->tz_sysctl_tree),
277 		    OID_AUTO, "_PSV", CTLTYPE_INT | CTLFLAG_RW,
278 		    sc, offsetof(struct acpi_tz_softc, tz_zone.psv),
279 		    acpi_tz_temp_sysctl, "IK", "passive cooling temp setpoint");
280     SYSCTL_ADD_PROC(&sc->tz_sysctl_ctx, SYSCTL_CHILDREN(sc->tz_sysctl_tree),
281 		    OID_AUTO, "_HOT", CTLTYPE_INT | CTLFLAG_RW,
282 		    sc, offsetof(struct acpi_tz_softc, tz_zone.hot),
283 		    acpi_tz_temp_sysctl, "IK",
284 		    "too hot temp setpoint (suspend now)");
285     SYSCTL_ADD_PROC(&sc->tz_sysctl_ctx, SYSCTL_CHILDREN(sc->tz_sysctl_tree),
286 		    OID_AUTO, "_CRT", CTLTYPE_INT | CTLFLAG_RW,
287 		    sc, offsetof(struct acpi_tz_softc, tz_zone.crt),
288 		    acpi_tz_temp_sysctl, "IK",
289 		    "critical temp setpoint (shutdown now)");
290     SYSCTL_ADD_PROC(&sc->tz_sysctl_ctx, SYSCTL_CHILDREN(sc->tz_sysctl_tree),
291 		    OID_AUTO, "_ACx", CTLTYPE_INT | CTLFLAG_RD,
292 		    &sc->tz_zone.ac, sizeof(sc->tz_zone.ac),
293 		    sysctl_handle_opaque, "IK", "");
294     SYSCTL_ADD_PROC(&sc->tz_sysctl_ctx, SYSCTL_CHILDREN(sc->tz_sysctl_tree),
295 		    OID_AUTO, "_TC1", CTLTYPE_INT | CTLFLAG_RW,
296 		    sc, offsetof(struct acpi_tz_softc, tz_zone.tc1),
297 		    acpi_tz_passive_sysctl, "I",
298 		    "thermal constant 1 for passive cooling");
299     SYSCTL_ADD_PROC(&sc->tz_sysctl_ctx, SYSCTL_CHILDREN(sc->tz_sysctl_tree),
300 		    OID_AUTO, "_TC2", CTLTYPE_INT | CTLFLAG_RW,
301 		    sc, offsetof(struct acpi_tz_softc, tz_zone.tc2),
302 		    acpi_tz_passive_sysctl, "I",
303 		    "thermal constant 2 for passive cooling");
304     SYSCTL_ADD_PROC(&sc->tz_sysctl_ctx, SYSCTL_CHILDREN(sc->tz_sysctl_tree),
305 		    OID_AUTO, "_TSP", CTLTYPE_INT | CTLFLAG_RW,
306 		    sc, offsetof(struct acpi_tz_softc, tz_zone.tsp),
307 		    acpi_tz_passive_sysctl, "I",
308 		    "thermal sampling period for passive cooling");
309 
310     /*
311      * Create thread to service all of the thermal zones.  Register
312      * our power profile event handler.
313      */
314     sc->tz_event = EVENTHANDLER_REGISTER(power_profile_change,
315 	acpi_tz_power_profile, sc, 0);
316     if (acpi_tz_proc == NULL) {
317 	error = kproc_create(acpi_tz_thread, NULL, &acpi_tz_proc,
318 	    RFHIGHPID, 0, "acpi_thermal");
319 	if (error != 0) {
320 	    device_printf(sc->tz_dev, "could not create thread - %d", error);
321 	    goto out;
322 	}
323     }
324 
325     /*
326      * Create a thread to handle passive cooling for 1st zone which
327      * has _PSV, _TSP, _TC1 and _TC2.  Users can enable it for other
328      * zones manually for now.
329      *
330      * XXX We enable only one zone to avoid multiple zones conflict
331      * with each other since cpufreq currently sets all CPUs to the
332      * given frequency whereas it's possible for different thermal
333      * zones to specify independent settings for multiple CPUs.
334      */
335     if (acpi_tz_cooling_unit < 0 && acpi_tz_cooling_is_available(sc))
336 	sc->tz_cooling_enabled = TRUE;
337     if (sc->tz_cooling_enabled) {
338 	error = acpi_tz_cooling_thread_start(sc);
339 	if (error != 0) {
340 	    sc->tz_cooling_enabled = FALSE;
341 	    goto out;
342 	}
343 	acpi_tz_cooling_unit = device_get_unit(dev);
344     }
345 
346     /*
347      * Flag the event handler for a manual invocation by our timeout.
348      * We defer it like this so that the rest of the subsystem has time
349      * to come up.  Don't bother evaluating/printing the temperature at
350      * this point; on many systems it'll be bogus until the EC is running.
351      */
352     sc->tz_flags |= TZ_FLAG_GETPROFILE;
353 
354 out:
355     if (error != 0) {
356 	EVENTHANDLER_DEREGISTER(power_profile_change, sc->tz_event);
357 	AcpiRemoveNotifyHandler(sc->tz_handle, ACPI_DEVICE_NOTIFY,
358 	    acpi_tz_notify_handler);
359 	sysctl_ctx_free(&sc->tz_sysctl_ctx);
360     }
361     return_VALUE (error);
362 }
363 
364 /*
365  * Parse the current state of this thermal zone and set up to use it.
366  *
367  * Note that we may have previous state, which will have to be discarded.
368  */
369 static int
370 acpi_tz_establish(struct acpi_tz_softc *sc)
371 {
372     ACPI_OBJECT	*obj;
373     int		i;
374     char	nbuf[8];
375 
376     ACPI_FUNCTION_TRACE((char *)(uintptr_t)__func__);
377 
378     /* Erase any existing state. */
379     for (i = 0; i < TZ_NUMLEVELS; i++)
380 	if (sc->tz_zone.al[i].Pointer != NULL)
381 	    AcpiOsFree(sc->tz_zone.al[i].Pointer);
382     if (sc->tz_zone.psl.Pointer != NULL)
383 	AcpiOsFree(sc->tz_zone.psl.Pointer);
384 
385     /*
386      * XXX: We initialize only ACPI_BUFFER to avoid race condition
387      * with passive cooling thread which refers psv, tc1, tc2 and tsp.
388      */
389     bzero(sc->tz_zone.ac, sizeof(sc->tz_zone.ac));
390     bzero(sc->tz_zone.al, sizeof(sc->tz_zone.al));
391     bzero(&sc->tz_zone.psl, sizeof(sc->tz_zone.psl));
392 
393     /* Evaluate thermal zone parameters. */
394     for (i = 0; i < TZ_NUMLEVELS; i++) {
395 	sprintf(nbuf, "_AC%d", i);
396 	acpi_tz_getparam(sc, nbuf, &sc->tz_zone.ac[i]);
397 	sprintf(nbuf, "_AL%d", i);
398 	sc->tz_zone.al[i].Length = ACPI_ALLOCATE_BUFFER;
399 	sc->tz_zone.al[i].Pointer = NULL;
400 	AcpiEvaluateObject(sc->tz_handle, nbuf, NULL, &sc->tz_zone.al[i]);
401 	obj = (ACPI_OBJECT *)sc->tz_zone.al[i].Pointer;
402 	if (obj != NULL) {
403 	    /* Should be a package containing a list of power objects */
404 	    if (obj->Type != ACPI_TYPE_PACKAGE) {
405 		device_printf(sc->tz_dev, "%s has unknown type %d, rejecting\n",
406 			      nbuf, obj->Type);
407 		return_VALUE (ENXIO);
408 	    }
409 	}
410     }
411     acpi_tz_getparam(sc, "_CRT", &sc->tz_zone.crt);
412     acpi_tz_getparam(sc, "_HOT", &sc->tz_zone.hot);
413     sc->tz_zone.psl.Length = ACPI_ALLOCATE_BUFFER;
414     sc->tz_zone.psl.Pointer = NULL;
415     AcpiEvaluateObject(sc->tz_handle, "_PSL", NULL, &sc->tz_zone.psl);
416     acpi_tz_getparam(sc, "_PSV", &sc->tz_zone.psv);
417     acpi_tz_getparam(sc, "_TC1", &sc->tz_zone.tc1);
418     acpi_tz_getparam(sc, "_TC2", &sc->tz_zone.tc2);
419     acpi_tz_getparam(sc, "_TSP", &sc->tz_zone.tsp);
420     acpi_tz_getparam(sc, "_TZP", &sc->tz_zone.tzp);
421 
422     /*
423      * Sanity-check the values we've been given.
424      *
425      * XXX what do we do about systems that give us the same value for
426      *     more than one of these setpoints?
427      */
428     acpi_tz_sanity(sc, &sc->tz_zone.crt, "_CRT");
429     acpi_tz_sanity(sc, &sc->tz_zone.hot, "_HOT");
430     acpi_tz_sanity(sc, &sc->tz_zone.psv, "_PSV");
431     for (i = 0; i < TZ_NUMLEVELS; i++)
432 	acpi_tz_sanity(sc, &sc->tz_zone.ac[i], "_ACx");
433 
434     return_VALUE (0);
435 }
436 
437 static char *aclevel_string[] = {
438     "NONE", "_AC0", "_AC1", "_AC2", "_AC3", "_AC4",
439     "_AC5", "_AC6", "_AC7", "_AC8", "_AC9"
440 };
441 
442 static __inline const char *
443 acpi_tz_aclevel_string(int active)
444 {
445     if (active < -1 || active >= TZ_NUMLEVELS)
446 	return (aclevel_string[0]);
447 
448     return (aclevel_string[active + 1]);
449 }
450 
451 /*
452  * Get the current temperature.
453  */
454 static int
455 acpi_tz_get_temperature(struct acpi_tz_softc *sc)
456 {
457     int		temp;
458     ACPI_STATUS	status;
459     static char	*tmp_name = "_TMP";
460 
461     ACPI_FUNCTION_NAME ("acpi_tz_get_temperature");
462 
463     /* Evaluate the thermal zone's _TMP method. */
464     status = acpi_GetInteger(sc->tz_handle, tmp_name, &temp);
465     if (ACPI_FAILURE(status)) {
466 	ACPI_VPRINT(sc->tz_dev, acpi_device_get_parent_softc(sc->tz_dev),
467 	    "error fetching current temperature -- %s\n",
468 	     AcpiFormatException(status));
469 	return (FALSE);
470     }
471 
472     /* Check it for validity. */
473     acpi_tz_sanity(sc, &temp, tmp_name);
474     if (temp == -1)
475 	return (FALSE);
476 
477     ACPI_DEBUG_PRINT((ACPI_DB_VALUES, "got %d.%dC\n", TZ_KELVTOC(temp)));
478     sc->tz_temperature = temp;
479     return (TRUE);
480 }
481 
482 /*
483  * Evaluate the condition of a thermal zone, take appropriate actions.
484  */
485 static void
486 acpi_tz_monitor(void *Context)
487 {
488     struct acpi_tz_softc *sc;
489     struct	timespec curtime;
490     int		temp;
491     int		i;
492     int		newactive, newflags;
493 
494     ACPI_FUNCTION_TRACE((char *)(uintptr_t)__func__);
495 
496     sc = (struct acpi_tz_softc *)Context;
497 
498     /* Get the current temperature. */
499     if (!acpi_tz_get_temperature(sc)) {
500 	/* XXX disable zone? go to max cooling? */
501 	return_VOID;
502     }
503     temp = sc->tz_temperature;
504 
505     /*
506      * Work out what we ought to be doing right now.
507      *
508      * Note that the _ACx levels sort from hot to cold.
509      */
510     newactive = TZ_ACTIVE_NONE;
511     for (i = TZ_NUMLEVELS - 1; i >= 0; i--) {
512 	if (sc->tz_zone.ac[i] != -1 && temp >= sc->tz_zone.ac[i]) {
513 	    newactive = i;
514 	    if (sc->tz_active != newactive) {
515 		ACPI_VPRINT(sc->tz_dev,
516 			    acpi_device_get_parent_softc(sc->tz_dev),
517 			    "_AC%d: temperature %d.%d >= setpoint %d.%d\n", i,
518 			    TZ_KELVTOC(temp), TZ_KELVTOC(sc->tz_zone.ac[i]));
519 	    }
520 	}
521     }
522 
523     /*
524      * We are going to get _ACx level down (colder side), but give a guaranteed
525      * minimum cooling run time if requested.
526      */
527     if (acpi_tz_min_runtime > 0 && sc->tz_active != TZ_ACTIVE_NONE &&
528 	sc->tz_active != TZ_ACTIVE_UNKNOWN &&
529 	(newactive == TZ_ACTIVE_NONE || newactive > sc->tz_active)) {
530 
531 	getnanotime(&curtime);
532 	timespecsub(&curtime, &sc->tz_cooling_started);
533 	if (curtime.tv_sec < acpi_tz_min_runtime)
534 	    newactive = sc->tz_active;
535     }
536 
537     /* Handle user override of active mode */
538     if (sc->tz_requested != TZ_ACTIVE_NONE && (newactive == TZ_ACTIVE_NONE
539         || sc->tz_requested < newactive))
540 	newactive = sc->tz_requested;
541 
542     /* update temperature-related flags */
543     newflags = TZ_THFLAG_NONE;
544     if (sc->tz_zone.psv != -1 && temp >= sc->tz_zone.psv)
545 	newflags |= TZ_THFLAG_PSV;
546     if (sc->tz_zone.hot != -1 && temp >= sc->tz_zone.hot)
547 	newflags |= TZ_THFLAG_HOT;
548     if (sc->tz_zone.crt != -1 && temp >= sc->tz_zone.crt)
549 	newflags |= TZ_THFLAG_CRT;
550 
551     /* If the active cooling state has changed, we have to switch things. */
552     if (sc->tz_active == TZ_ACTIVE_UNKNOWN) {
553 	/*
554 	 * We don't know which cooling device is on or off,
555 	 * so stop them all, because we now know which
556 	 * should be on (if any).
557 	 */
558 	for (i = 0; i < TZ_NUMLEVELS; i++) {
559 	    if (sc->tz_zone.al[i].Pointer != NULL) {
560 		acpi_ForeachPackageObject(
561 		    (ACPI_OBJECT *)sc->tz_zone.al[i].Pointer,
562 		    acpi_tz_switch_cooler_off, sc);
563 	    }
564 	}
565 	/* now we know that all devices are off */
566 	sc->tz_active = TZ_ACTIVE_NONE;
567     }
568 
569     if (newactive != sc->tz_active) {
570 	/* Turn off unneeded cooling devices that are on, if any are */
571 	for (i = TZ_ACTIVE_LEVEL(sc->tz_active);
572 	     i < TZ_ACTIVE_LEVEL(newactive); i++) {
573 	    acpi_ForeachPackageObject(
574 		(ACPI_OBJECT *)sc->tz_zone.al[i].Pointer,
575 		acpi_tz_switch_cooler_off, sc);
576 	}
577 	/* Turn on cooling devices that are required, if any are */
578 	for (i = TZ_ACTIVE_LEVEL(sc->tz_active) - 1;
579 	     i >= TZ_ACTIVE_LEVEL(newactive); i--) {
580 	    acpi_ForeachPackageObject(
581 		(ACPI_OBJECT *)sc->tz_zone.al[i].Pointer,
582 		acpi_tz_switch_cooler_on, sc);
583 	}
584 
585 	ACPI_VPRINT(sc->tz_dev, acpi_device_get_parent_softc(sc->tz_dev),
586 		    "switched from %s to %s: %d.%dC\n",
587 		    acpi_tz_aclevel_string(sc->tz_active),
588 		    acpi_tz_aclevel_string(newactive), TZ_KELVTOC(temp));
589 	sc->tz_active = newactive;
590 	getnanotime(&sc->tz_cooling_started);
591     }
592 
593     /* XXX (de)activate any passive cooling that may be required. */
594 
595     /*
596      * If the temperature is at _HOT or _CRT, increment our event count.
597      * If it has occurred enough times, shutdown the system.  This is
598      * needed because some systems will report an invalid high temperature
599      * for one poll cycle.  It is suspected this is due to the embedded
600      * controller timing out.  A typical value is 138C for one cycle on
601      * a system that is otherwise 65C.
602      *
603      * If we're almost at that threshold, notify the user through devd(8).
604      */
605     if ((newflags & (TZ_THFLAG_HOT | TZ_THFLAG_CRT)) != 0) {
606 	sc->tz_validchecks++;
607 	if (sc->tz_validchecks == TZ_VALIDCHECKS) {
608 	    device_printf(sc->tz_dev,
609 		"WARNING - current temperature (%d.%dC) exceeds safe limits\n",
610 		TZ_KELVTOC(sc->tz_temperature));
611 	    shutdown_nice(RB_POWEROFF);
612 	} else if (sc->tz_validchecks == TZ_NOTIFYCOUNT)
613 	    acpi_UserNotify("Thermal", sc->tz_handle, TZ_NOTIFY_CRITICAL);
614     } else {
615 	sc->tz_validchecks = 0;
616     }
617     sc->tz_thflags = newflags;
618 
619     return_VOID;
620 }
621 
622 /*
623  * Given an object, verify that it's a reference to a device of some sort,
624  * and try to switch it off.
625  */
626 static void
627 acpi_tz_switch_cooler_off(ACPI_OBJECT *obj, void *arg)
628 {
629     ACPI_HANDLE			cooler;
630 
631     ACPI_FUNCTION_TRACE((char *)(uintptr_t)__func__);
632 
633     cooler = acpi_GetReference(NULL, obj);
634     if (cooler == NULL) {
635 	ACPI_DEBUG_PRINT((ACPI_DB_OBJECTS, "can't get handle\n"));
636 	return_VOID;
637     }
638 
639     ACPI_DEBUG_PRINT((ACPI_DB_OBJECTS, "called to turn %s off\n",
640 		     acpi_name(cooler)));
641     acpi_pwr_switch_consumer(cooler, ACPI_STATE_D3);
642 
643     return_VOID;
644 }
645 
646 /*
647  * Given an object, verify that it's a reference to a device of some sort,
648  * and try to switch it on.
649  *
650  * XXX replication of off/on function code is bad.
651  */
652 static void
653 acpi_tz_switch_cooler_on(ACPI_OBJECT *obj, void *arg)
654 {
655     struct acpi_tz_softc	*sc = (struct acpi_tz_softc *)arg;
656     ACPI_HANDLE			cooler;
657     ACPI_STATUS			status;
658 
659     ACPI_FUNCTION_TRACE((char *)(uintptr_t)__func__);
660 
661     cooler = acpi_GetReference(NULL, obj);
662     if (cooler == NULL) {
663 	ACPI_DEBUG_PRINT((ACPI_DB_OBJECTS, "can't get handle\n"));
664 	return_VOID;
665     }
666 
667     ACPI_DEBUG_PRINT((ACPI_DB_OBJECTS, "called to turn %s on\n",
668 		     acpi_name(cooler)));
669     status = acpi_pwr_switch_consumer(cooler, ACPI_STATE_D0);
670     if (ACPI_FAILURE(status)) {
671 	ACPI_VPRINT(sc->tz_dev, acpi_device_get_parent_softc(sc->tz_dev),
672 		    "failed to activate %s - %s\n", acpi_name(cooler),
673 		    AcpiFormatException(status));
674     }
675 
676     return_VOID;
677 }
678 
679 /*
680  * Read/debug-print a parameter, default it to -1.
681  */
682 static void
683 acpi_tz_getparam(struct acpi_tz_softc *sc, char *node, int *data)
684 {
685 
686     ACPI_FUNCTION_TRACE((char *)(uintptr_t)__func__);
687 
688     if (ACPI_FAILURE(acpi_GetInteger(sc->tz_handle, node, data))) {
689 	*data = -1;
690     } else {
691 	ACPI_DEBUG_PRINT((ACPI_DB_VALUES, "%s.%s = %d\n",
692 			 acpi_name(sc->tz_handle), node, *data));
693     }
694 
695     return_VOID;
696 }
697 
698 /*
699  * Sanity-check a temperature value.  Assume that setpoints
700  * should be between 0C and 200C.
701  */
702 static void
703 acpi_tz_sanity(struct acpi_tz_softc *sc, int *val, char *what)
704 {
705     if (*val != -1 && (*val < TZ_ZEROC || *val > TZ_ZEROC + 2000)) {
706 	device_printf(sc->tz_dev, "%s value is absurd, ignored (%d.%dC)\n",
707 		      what, TZ_KELVTOC(*val));
708 	*val = -1;
709     }
710 }
711 
712 /*
713  * Respond to a sysctl on the active state node.
714  */
715 static int
716 acpi_tz_active_sysctl(SYSCTL_HANDLER_ARGS)
717 {
718     struct acpi_tz_softc	*sc;
719     int				active;
720     int		 		error;
721 
722     sc = (struct acpi_tz_softc *)oidp->oid_arg1;
723     active = sc->tz_active;
724     error = sysctl_handle_int(oidp, &active, 0, req);
725 
726     /* Error or no new value */
727     if (error != 0 || req->newptr == NULL)
728 	return (error);
729     if (active < -1 || active >= TZ_NUMLEVELS)
730 	return (EINVAL);
731 
732     /* Set new preferred level and re-switch */
733     sc->tz_requested = active;
734     acpi_tz_signal(sc, 0);
735     return (0);
736 }
737 
738 static int
739 acpi_tz_cooling_sysctl(SYSCTL_HANDLER_ARGS)
740 {
741     struct acpi_tz_softc *sc;
742     int enabled, error;
743 
744     sc = (struct acpi_tz_softc *)oidp->oid_arg1;
745     enabled = sc->tz_cooling_enabled;
746     error = sysctl_handle_int(oidp, &enabled, 0, req);
747 
748     /* Error or no new value */
749     if (error != 0 || req->newptr == NULL)
750 	return (error);
751     if (enabled != TRUE && enabled != FALSE)
752 	return (EINVAL);
753 
754     if (enabled) {
755 	if (acpi_tz_cooling_is_available(sc))
756 	    error = acpi_tz_cooling_thread_start(sc);
757 	else
758 	    error = ENODEV;
759 	if (error)
760 	    enabled = FALSE;
761     }
762     sc->tz_cooling_enabled = enabled;
763     return (error);
764 }
765 
766 static int
767 acpi_tz_temp_sysctl(SYSCTL_HANDLER_ARGS)
768 {
769     struct acpi_tz_softc	*sc;
770     int				temp, *temp_ptr;
771     int		 		error;
772 
773     sc = oidp->oid_arg1;
774     temp_ptr = (int *)((uintptr_t)sc + oidp->oid_arg2);
775     temp = *temp_ptr;
776     error = sysctl_handle_int(oidp, &temp, 0, req);
777 
778     /* Error or no new value */
779     if (error != 0 || req->newptr == NULL)
780 	return (error);
781 
782     /* Only allow changing settings if override is set. */
783     if (!acpi_tz_override)
784 	return (EPERM);
785 
786     /* Check user-supplied value for sanity. */
787     acpi_tz_sanity(sc, &temp, "user-supplied temp");
788     if (temp == -1)
789 	return (EINVAL);
790 
791     *temp_ptr = temp;
792     return (0);
793 }
794 
795 static int
796 acpi_tz_passive_sysctl(SYSCTL_HANDLER_ARGS)
797 {
798     struct acpi_tz_softc	*sc;
799     int				val, *val_ptr;
800     int				error;
801 
802     sc = oidp->oid_arg1;
803     val_ptr = (int *)((uintptr_t)sc + oidp->oid_arg2);
804     val = *val_ptr;
805     error = sysctl_handle_int(oidp, &val, 0, req);
806 
807     /* Error or no new value */
808     if (error != 0 || req->newptr == NULL)
809 	return (error);
810 
811     /* Only allow changing settings if override is set. */
812     if (!acpi_tz_override)
813 	return (EPERM);
814 
815     *val_ptr = val;
816     return (0);
817 }
818 
819 static void
820 acpi_tz_notify_handler(ACPI_HANDLE h, UINT32 notify, void *context)
821 {
822     struct acpi_tz_softc	*sc = (struct acpi_tz_softc *)context;
823 
824     ACPI_FUNCTION_TRACE((char *)(uintptr_t)__func__);
825 
826     switch (notify) {
827     case TZ_NOTIFY_TEMPERATURE:
828 	/* Temperature change occurred */
829 	acpi_tz_signal(sc, 0);
830 	break;
831     case TZ_NOTIFY_DEVICES:
832     case TZ_NOTIFY_LEVELS:
833 	/* Zone devices/setpoints changed */
834 	acpi_tz_signal(sc, TZ_FLAG_GETSETTINGS);
835 	break;
836     default:
837 	ACPI_VPRINT(sc->tz_dev, acpi_device_get_parent_softc(sc->tz_dev),
838 		    "unknown Notify event 0x%x\n", notify);
839 	break;
840     }
841 
842     acpi_UserNotify("Thermal", h, notify);
843 
844     return_VOID;
845 }
846 
847 static void
848 acpi_tz_signal(struct acpi_tz_softc *sc, int flags)
849 {
850     ACPI_LOCK(thermal);
851     sc->tz_flags |= flags;
852     ACPI_UNLOCK(thermal);
853     wakeup(&acpi_tz_proc);
854 }
855 
856 /*
857  * Notifies can be generated asynchronously but have also been seen to be
858  * triggered by other thermal methods.  One system generates a notify of
859  * 0x81 when the fan is turned on or off.  Another generates it when _SCP
860  * is called.  To handle these situations, we check the zone via
861  * acpi_tz_monitor() before evaluating changes to setpoints or the cooling
862  * policy.
863  */
864 static void
865 acpi_tz_timeout(struct acpi_tz_softc *sc, int flags)
866 {
867 
868     /* Check the current temperature and take action based on it */
869     acpi_tz_monitor(sc);
870 
871     /* If requested, get the power profile settings. */
872     if (flags & TZ_FLAG_GETPROFILE)
873 	acpi_tz_power_profile(sc);
874 
875     /*
876      * If requested, check for new devices/setpoints.  After finding them,
877      * check if we need to switch fans based on the new values.
878      */
879     if (flags & TZ_FLAG_GETSETTINGS) {
880 	acpi_tz_establish(sc);
881 	acpi_tz_monitor(sc);
882     }
883 
884     /* XXX passive cooling actions? */
885 }
886 
887 /*
888  * System power profile may have changed; fetch and notify the
889  * thermal zone accordingly.
890  *
891  * Since this can be called from an arbitrary eventhandler, it needs
892  * to get the ACPI lock itself.
893  */
894 static void
895 acpi_tz_power_profile(void *arg)
896 {
897     ACPI_STATUS			status;
898     struct acpi_tz_softc	*sc = (struct acpi_tz_softc *)arg;
899     int				state;
900 
901     state = power_profile_get_state();
902     if (state != POWER_PROFILE_PERFORMANCE && state != POWER_PROFILE_ECONOMY)
903 	return;
904 
905     /* check that we haven't decided there's no _SCP method */
906     if ((sc->tz_flags & TZ_FLAG_NO_SCP) == 0) {
907 
908 	/* Call _SCP to set the new profile */
909 	status = acpi_SetInteger(sc->tz_handle, "_SCP",
910 	    (state == POWER_PROFILE_PERFORMANCE) ? 0 : 1);
911 	if (ACPI_FAILURE(status)) {
912 	    if (status != AE_NOT_FOUND)
913 		ACPI_VPRINT(sc->tz_dev,
914 			    acpi_device_get_parent_softc(sc->tz_dev),
915 			    "can't evaluate %s._SCP - %s\n",
916 			    acpi_name(sc->tz_handle),
917 			    AcpiFormatException(status));
918 	    sc->tz_flags |= TZ_FLAG_NO_SCP;
919 	} else {
920 	    /* We have to re-evaluate the entire zone now */
921 	    acpi_tz_signal(sc, TZ_FLAG_GETSETTINGS);
922 	}
923     }
924 }
925 
926 /*
927  * Thermal zone monitor thread.
928  */
929 static void
930 acpi_tz_thread(void *arg)
931 {
932     device_t	*devs;
933     int		devcount, i;
934     int		flags;
935     struct acpi_tz_softc **sc;
936 
937     ACPI_FUNCTION_TRACE((char *)(uintptr_t)__func__);
938 
939     devs = NULL;
940     devcount = 0;
941     sc = NULL;
942 
943     for (;;) {
944 	/* If the number of devices has changed, re-evaluate. */
945 	if (devclass_get_count(acpi_tz_devclass) != devcount) {
946 	    if (devs != NULL) {
947 		free(devs, M_TEMP);
948 		free(sc, M_TEMP);
949 	    }
950 	    devclass_get_devices(acpi_tz_devclass, &devs, &devcount);
951 	    sc = malloc(sizeof(struct acpi_tz_softc *) * devcount, M_TEMP,
952 			M_WAITOK | M_ZERO);
953 	    for (i = 0; i < devcount; i++)
954 		sc[i] = device_get_softc(devs[i]);
955 	}
956 
957 	/* Check for temperature events and act on them. */
958 	for (i = 0; i < devcount; i++) {
959 	    ACPI_LOCK(thermal);
960 	    flags = sc[i]->tz_flags;
961 	    sc[i]->tz_flags &= TZ_FLAG_NO_SCP;
962 	    ACPI_UNLOCK(thermal);
963 	    acpi_tz_timeout(sc[i], flags);
964 	}
965 
966 	/* If more work to do, don't go to sleep yet. */
967 	ACPI_LOCK(thermal);
968 	for (i = 0; i < devcount; i++) {
969 	    if (sc[i]->tz_flags & ~TZ_FLAG_NO_SCP)
970 		break;
971 	}
972 
973 	/*
974 	 * If we have no more work, sleep for a while, setting PDROP so that
975 	 * the mutex will not be reacquired.  Otherwise, drop the mutex and
976 	 * loop to handle more events.
977 	 */
978 	if (i == devcount)
979 	    msleep(&acpi_tz_proc, &thermal_mutex, PZERO | PDROP, "tzpoll",
980 		hz * acpi_tz_polling_rate);
981 	else
982 	    ACPI_UNLOCK(thermal);
983     }
984 }
985 
986 static int
987 acpi_tz_cpufreq_restore(struct acpi_tz_softc *sc)
988 {
989     device_t dev;
990     int error;
991 
992     if (!sc->tz_cooling_updated)
993 	return (0);
994     if ((dev = devclass_get_device(devclass_find("cpufreq"), 0)) == NULL)
995 	return (ENXIO);
996     ACPI_VPRINT(sc->tz_dev, acpi_device_get_parent_softc(sc->tz_dev),
997 	"temperature %d.%dC: resuming previous clock speed (%d MHz)\n",
998 	TZ_KELVTOC(sc->tz_temperature), sc->tz_cooling_saved_freq);
999     error = CPUFREQ_SET(dev, NULL, CPUFREQ_PRIO_KERN);
1000     if (error == 0)
1001 	sc->tz_cooling_updated = FALSE;
1002     return (error);
1003 }
1004 
1005 static int
1006 acpi_tz_cpufreq_update(struct acpi_tz_softc *sc, int req)
1007 {
1008     device_t dev;
1009     struct cf_level *levels;
1010     int num_levels, error, freq, desired_freq, perf, i;
1011 
1012     levels = malloc(CPUFREQ_MAX_LEVELS * sizeof(*levels), M_TEMP, M_NOWAIT);
1013     if (levels == NULL)
1014 	return (ENOMEM);
1015 
1016     /*
1017      * Find the main device, cpufreq0.  We don't yet support independent
1018      * CPU frequency control on SMP.
1019      */
1020     if ((dev = devclass_get_device(devclass_find("cpufreq"), 0)) == NULL) {
1021 	error = ENXIO;
1022 	goto out;
1023     }
1024 
1025     /* Get the current frequency. */
1026     error = CPUFREQ_GET(dev, &levels[0]);
1027     if (error)
1028 	goto out;
1029     freq = levels[0].total_set.freq;
1030 
1031     /* Get the current available frequency levels. */
1032     num_levels = CPUFREQ_MAX_LEVELS;
1033     error = CPUFREQ_LEVELS(dev, levels, &num_levels);
1034     if (error) {
1035 	if (error == E2BIG)
1036 	    printf("cpufreq: need to increase CPUFREQ_MAX_LEVELS\n");
1037 	goto out;
1038     }
1039 
1040     /* Calculate the desired frequency as a percent of the max frequency. */
1041     perf = 100 * freq / levels[0].total_set.freq - req;
1042     if (perf < 0)
1043 	perf = 0;
1044     else if (perf > 100)
1045 	perf = 100;
1046     desired_freq = levels[0].total_set.freq * perf / 100;
1047 
1048     if (desired_freq < freq) {
1049 	/* Find the closest available frequency, rounding down. */
1050 	for (i = 0; i < num_levels; i++)
1051 	    if (levels[i].total_set.freq <= desired_freq)
1052 		break;
1053 
1054 	/* If we didn't find a relevant setting, use the lowest. */
1055 	if (i == num_levels)
1056 	    i--;
1057     } else {
1058 	/* If we didn't decrease frequency yet, don't increase it. */
1059 	if (!sc->tz_cooling_updated) {
1060 	    sc->tz_cooling_active = FALSE;
1061 	    goto out;
1062 	}
1063 
1064 	/* Use saved cpu frequency as maximum value. */
1065 	if (desired_freq > sc->tz_cooling_saved_freq)
1066 	    desired_freq = sc->tz_cooling_saved_freq;
1067 
1068 	/* Find the closest available frequency, rounding up. */
1069 	for (i = num_levels - 1; i >= 0; i--)
1070 	    if (levels[i].total_set.freq >= desired_freq)
1071 		break;
1072 
1073 	/* If we didn't find a relevant setting, use the highest. */
1074 	if (i == -1)
1075 	    i++;
1076 
1077 	/* If we're going to the highest frequency, restore the old setting. */
1078 	if (i == 0 || desired_freq == sc->tz_cooling_saved_freq) {
1079 	    error = acpi_tz_cpufreq_restore(sc);
1080 	    if (error == 0)
1081 		sc->tz_cooling_active = FALSE;
1082 	    goto out;
1083 	}
1084     }
1085 
1086     /* If we are going to a new frequency, activate it. */
1087     if (levels[i].total_set.freq != freq) {
1088 	ACPI_VPRINT(sc->tz_dev, acpi_device_get_parent_softc(sc->tz_dev),
1089 	    "temperature %d.%dC: %screasing clock speed "
1090 	    "from %d MHz to %d MHz\n",
1091 	    TZ_KELVTOC(sc->tz_temperature),
1092 	    (freq > levels[i].total_set.freq) ? "de" : "in",
1093 	    freq, levels[i].total_set.freq);
1094 	error = CPUFREQ_SET(dev, &levels[i], CPUFREQ_PRIO_KERN);
1095 	if (error == 0 && !sc->tz_cooling_updated) {
1096 	    sc->tz_cooling_saved_freq = freq;
1097 	    sc->tz_cooling_updated = TRUE;
1098 	}
1099     }
1100 
1101 out:
1102     if (levels)
1103 	free(levels, M_TEMP);
1104     return (error);
1105 }
1106 
1107 /*
1108  * Passive cooling thread; monitors current temperature according to the
1109  * cooling interval and calculates whether to scale back CPU frequency.
1110  */
1111 static void
1112 acpi_tz_cooling_thread(void *arg)
1113 {
1114     struct acpi_tz_softc *sc;
1115     int error, perf, curr_temp, prev_temp;
1116 
1117     ACPI_FUNCTION_TRACE((char *)(uintptr_t)__func__);
1118 
1119     sc = (struct acpi_tz_softc *)arg;
1120 
1121     prev_temp = sc->tz_temperature;
1122     while (sc->tz_cooling_enabled) {
1123 	if (sc->tz_cooling_active)
1124 	    (void)acpi_tz_get_temperature(sc);
1125 	curr_temp = sc->tz_temperature;
1126 	if (curr_temp >= sc->tz_zone.psv)
1127 	    sc->tz_cooling_active = TRUE;
1128 	if (sc->tz_cooling_active) {
1129 	    perf = sc->tz_zone.tc1 * (curr_temp - prev_temp) +
1130 		   sc->tz_zone.tc2 * (curr_temp - sc->tz_zone.psv);
1131 	    perf /= 10;
1132 
1133 	    if (perf != 0) {
1134 		error = acpi_tz_cpufreq_update(sc, perf);
1135 
1136 		/*
1137 		 * If error and not simply a higher priority setting was
1138 		 * active, disable cooling.
1139 		 */
1140 		if (error != 0 && error != EPERM) {
1141 		    device_printf(sc->tz_dev,
1142 			"failed to set new freq, disabling passive cooling\n");
1143 		    sc->tz_cooling_enabled = FALSE;
1144 		}
1145 	    }
1146 	}
1147 	prev_temp = curr_temp;
1148 	tsleep(&sc->tz_cooling_proc, PZERO, "cooling",
1149 	    hz * sc->tz_zone.tsp / 10);
1150     }
1151     if (sc->tz_cooling_active) {
1152 	acpi_tz_cpufreq_restore(sc);
1153 	sc->tz_cooling_active = FALSE;
1154     }
1155     sc->tz_cooling_proc = NULL;
1156     ACPI_LOCK(thermal);
1157     sc->tz_cooling_proc_running = FALSE;
1158     ACPI_UNLOCK(thermal);
1159     kproc_exit(0);
1160 }
1161 
1162 /*
1163  * TODO: We ignore _PSL (list of cooling devices) since cpufreq enumerates
1164  * all CPUs for us.  However, it's possible in the future _PSL will
1165  * reference non-CPU devices so we may want to support it then.
1166  */
1167 static int
1168 acpi_tz_cooling_is_available(struct acpi_tz_softc *sc)
1169 {
1170     return (sc->tz_zone.tc1 != -1 && sc->tz_zone.tc2 != -1 &&
1171 	sc->tz_zone.tsp != -1 && sc->tz_zone.tsp != 0 &&
1172 	sc->tz_zone.psv != -1);
1173 }
1174 
1175 static int
1176 acpi_tz_cooling_thread_start(struct acpi_tz_softc *sc)
1177 {
1178     int error;
1179 
1180     ACPI_LOCK(thermal);
1181     if (sc->tz_cooling_proc_running) {
1182 	ACPI_UNLOCK(thermal);
1183 	return (0);
1184     }
1185     sc->tz_cooling_proc_running = TRUE;
1186     ACPI_UNLOCK(thermal);
1187     error = 0;
1188     if (sc->tz_cooling_proc == NULL) {
1189 	error = kproc_create(acpi_tz_cooling_thread, sc,
1190 	    &sc->tz_cooling_proc, RFHIGHPID, 0, "acpi_cooling%d",
1191 	    device_get_unit(sc->tz_dev));
1192 	if (error != 0) {
1193 	    device_printf(sc->tz_dev, "could not create thread - %d", error);
1194 	    ACPI_LOCK(thermal);
1195 	    sc->tz_cooling_proc_running = FALSE;
1196 	    ACPI_UNLOCK(thermal);
1197 	}
1198     }
1199     return (error);
1200 }
1201