xref: /freebsd/sys/dev/acpica/acpi_cpu.c (revision 0572ccaa4543b0abef8ef81e384c1d04de9f3da1)
1 /*-
2  * Copyright (c) 2003-2005 Nate Lawson (SDG)
3  * Copyright (c) 2001 Michael Smith
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/bus.h>
34 #include <sys/cpu.h>
35 #include <sys/kernel.h>
36 #include <sys/malloc.h>
37 #include <sys/module.h>
38 #include <sys/pcpu.h>
39 #include <sys/power.h>
40 #include <sys/proc.h>
41 #include <sys/sched.h>
42 #include <sys/sbuf.h>
43 #include <sys/smp.h>
44 
45 #include <dev/pci/pcivar.h>
46 #include <machine/atomic.h>
47 #include <machine/bus.h>
48 #if defined(__amd64__) || defined(__i386__)
49 #include <machine/clock.h>
50 #endif
51 #include <sys/rman.h>
52 
53 #include <contrib/dev/acpica/include/acpi.h>
54 #include <contrib/dev/acpica/include/accommon.h>
55 
56 #include <dev/acpica/acpivar.h>
57 
58 /*
59  * Support for ACPI Processor devices, including C[1-3] sleep states.
60  */
61 
62 /* Hooks for the ACPI CA debugging infrastructure */
63 #define _COMPONENT	ACPI_PROCESSOR
64 ACPI_MODULE_NAME("PROCESSOR")
65 
66 struct acpi_cx {
67     struct resource	*p_lvlx;	/* Register to read to enter state. */
68     uint32_t		 type;		/* C1-3 (C4 and up treated as C3). */
69     uint32_t		 trans_lat;	/* Transition latency (usec). */
70     uint32_t		 power;		/* Power consumed (mW). */
71     int			 res_type;	/* Resource type for p_lvlx. */
72     int			 res_rid;	/* Resource ID for p_lvlx. */
73 };
74 #define MAX_CX_STATES	 8
75 
76 struct acpi_cpu_softc {
77     device_t		 cpu_dev;
78     ACPI_HANDLE		 cpu_handle;
79     struct pcpu		*cpu_pcpu;
80     uint32_t		 cpu_acpi_id;	/* ACPI processor id */
81     uint32_t		 cpu_p_blk;	/* ACPI P_BLK location */
82     uint32_t		 cpu_p_blk_len;	/* P_BLK length (must be 6). */
83     struct acpi_cx	 cpu_cx_states[MAX_CX_STATES];
84     int			 cpu_cx_count;	/* Number of valid Cx states. */
85     int			 cpu_prev_sleep;/* Last idle sleep duration. */
86     int			 cpu_features;	/* Child driver supported features. */
87     /* Runtime state. */
88     int			 cpu_non_c3;	/* Index of lowest non-C3 state. */
89     u_int		 cpu_cx_stats[MAX_CX_STATES];/* Cx usage history. */
90     /* Values for sysctl. */
91     struct sysctl_ctx_list cpu_sysctl_ctx;
92     struct sysctl_oid	*cpu_sysctl_tree;
93     int			 cpu_cx_lowest;
94     int			 cpu_cx_lowest_lim;
95     int			 cpu_disable_idle; /* Disable entry to idle function */
96     char 		 cpu_cx_supported[64];
97 };
98 
99 struct acpi_cpu_device {
100     struct resource_list	ad_rl;
101 };
102 
103 #define CPU_GET_REG(reg, width) 					\
104     (bus_space_read_ ## width(rman_get_bustag((reg)), 			\
105 		      rman_get_bushandle((reg)), 0))
106 #define CPU_SET_REG(reg, width, val)					\
107     (bus_space_write_ ## width(rman_get_bustag((reg)), 			\
108 		       rman_get_bushandle((reg)), 0, (val)))
109 
110 #define PM_USEC(x)	 ((x) >> 2)	/* ~4 clocks per usec (3.57955 Mhz) */
111 
112 #define ACPI_NOTIFY_CX_STATES	0x81	/* _CST changed. */
113 
114 #define CPU_QUIRK_NO_C3		(1<<0)	/* C3-type states are not usable. */
115 #define CPU_QUIRK_NO_BM_CTRL	(1<<2)	/* No bus mastering control. */
116 
117 #define PCI_VENDOR_INTEL	0x8086
118 #define PCI_DEVICE_82371AB_3	0x7113	/* PIIX4 chipset for quirks. */
119 #define PCI_REVISION_A_STEP	0
120 #define PCI_REVISION_B_STEP	1
121 #define PCI_REVISION_4E		2
122 #define PCI_REVISION_4M		3
123 #define PIIX4_DEVACTB_REG	0x58
124 #define PIIX4_BRLD_EN_IRQ0	(1<<0)
125 #define PIIX4_BRLD_EN_IRQ	(1<<1)
126 #define PIIX4_BRLD_EN_IRQ8	(1<<5)
127 #define PIIX4_STOP_BREAK_MASK	(PIIX4_BRLD_EN_IRQ0 | PIIX4_BRLD_EN_IRQ | PIIX4_BRLD_EN_IRQ8)
128 #define PIIX4_PCNTRL_BST_EN	(1<<10)
129 
130 /* Allow users to ignore processor orders in MADT. */
131 static int cpu_unordered;
132 TUNABLE_INT("debug.acpi.cpu_unordered", &cpu_unordered);
133 SYSCTL_INT(_debug_acpi, OID_AUTO, cpu_unordered, CTLFLAG_RDTUN,
134     &cpu_unordered, 0,
135     "Do not use the MADT to match ACPI Processor objects to CPUs.");
136 
137 /* Platform hardware resource information. */
138 static uint32_t		 cpu_smi_cmd;	/* Value to write to SMI_CMD. */
139 static uint8_t		 cpu_cst_cnt;	/* Indicate we are _CST aware. */
140 static int		 cpu_quirks;	/* Indicate any hardware bugs. */
141 
142 /* Values for sysctl. */
143 static struct sysctl_ctx_list cpu_sysctl_ctx;
144 static struct sysctl_oid *cpu_sysctl_tree;
145 static int		 cpu_cx_generic;
146 static int		 cpu_cx_lowest_lim;
147 
148 static device_t		*cpu_devices;
149 static int		 cpu_ndevices;
150 static struct acpi_cpu_softc **cpu_softc;
151 ACPI_SERIAL_DECL(cpu, "ACPI CPU");
152 
153 static int	acpi_cpu_probe(device_t dev);
154 static int	acpi_cpu_attach(device_t dev);
155 static int	acpi_cpu_suspend(device_t dev);
156 static int	acpi_cpu_resume(device_t dev);
157 static int	acpi_pcpu_get_id(device_t dev, uint32_t *acpi_id,
158 		    uint32_t *cpu_id);
159 static struct resource_list *acpi_cpu_get_rlist(device_t dev, device_t child);
160 static device_t	acpi_cpu_add_child(device_t dev, u_int order, const char *name,
161 		    int unit);
162 static int	acpi_cpu_read_ivar(device_t dev, device_t child, int index,
163 		    uintptr_t *result);
164 static int	acpi_cpu_shutdown(device_t dev);
165 static void	acpi_cpu_cx_probe(struct acpi_cpu_softc *sc);
166 static void	acpi_cpu_generic_cx_probe(struct acpi_cpu_softc *sc);
167 static int	acpi_cpu_cx_cst(struct acpi_cpu_softc *sc);
168 static void	acpi_cpu_startup(void *arg);
169 static void	acpi_cpu_startup_cx(struct acpi_cpu_softc *sc);
170 static void	acpi_cpu_cx_list(struct acpi_cpu_softc *sc);
171 static void	acpi_cpu_idle(sbintime_t sbt);
172 static void	acpi_cpu_notify(ACPI_HANDLE h, UINT32 notify, void *context);
173 static int	acpi_cpu_quirks(void);
174 static int	acpi_cpu_usage_sysctl(SYSCTL_HANDLER_ARGS);
175 static int	acpi_cpu_usage_counters_sysctl(SYSCTL_HANDLER_ARGS);
176 static int	acpi_cpu_set_cx_lowest(struct acpi_cpu_softc *sc);
177 static int	acpi_cpu_cx_lowest_sysctl(SYSCTL_HANDLER_ARGS);
178 static int	acpi_cpu_global_cx_lowest_sysctl(SYSCTL_HANDLER_ARGS);
179 
180 static device_method_t acpi_cpu_methods[] = {
181     /* Device interface */
182     DEVMETHOD(device_probe,	acpi_cpu_probe),
183     DEVMETHOD(device_attach,	acpi_cpu_attach),
184     DEVMETHOD(device_detach,	bus_generic_detach),
185     DEVMETHOD(device_shutdown,	acpi_cpu_shutdown),
186     DEVMETHOD(device_suspend,	acpi_cpu_suspend),
187     DEVMETHOD(device_resume,	acpi_cpu_resume),
188 
189     /* Bus interface */
190     DEVMETHOD(bus_add_child,	acpi_cpu_add_child),
191     DEVMETHOD(bus_read_ivar,	acpi_cpu_read_ivar),
192     DEVMETHOD(bus_get_resource_list, acpi_cpu_get_rlist),
193     DEVMETHOD(bus_get_resource,	bus_generic_rl_get_resource),
194     DEVMETHOD(bus_set_resource,	bus_generic_rl_set_resource),
195     DEVMETHOD(bus_alloc_resource, bus_generic_rl_alloc_resource),
196     DEVMETHOD(bus_release_resource, bus_generic_rl_release_resource),
197     DEVMETHOD(bus_activate_resource, bus_generic_activate_resource),
198     DEVMETHOD(bus_deactivate_resource, bus_generic_deactivate_resource),
199     DEVMETHOD(bus_setup_intr,	bus_generic_setup_intr),
200     DEVMETHOD(bus_teardown_intr, bus_generic_teardown_intr),
201 
202     DEVMETHOD_END
203 };
204 
205 static driver_t acpi_cpu_driver = {
206     "cpu",
207     acpi_cpu_methods,
208     sizeof(struct acpi_cpu_softc),
209 };
210 
211 static devclass_t acpi_cpu_devclass;
212 DRIVER_MODULE(cpu, acpi, acpi_cpu_driver, acpi_cpu_devclass, 0, 0);
213 MODULE_DEPEND(cpu, acpi, 1, 1, 1);
214 
215 static int
216 acpi_cpu_probe(device_t dev)
217 {
218     int			   acpi_id, cpu_id;
219     ACPI_BUFFER		   buf;
220     ACPI_HANDLE		   handle;
221     ACPI_OBJECT		   *obj;
222     ACPI_STATUS		   status;
223 
224     if (acpi_disabled("cpu") || acpi_get_type(dev) != ACPI_TYPE_PROCESSOR)
225 	return (ENXIO);
226 
227     handle = acpi_get_handle(dev);
228     if (cpu_softc == NULL)
229 	cpu_softc = malloc(sizeof(struct acpi_cpu_softc *) *
230 	    (mp_maxid + 1), M_TEMP /* XXX */, M_WAITOK | M_ZERO);
231 
232     /* Get our Processor object. */
233     buf.Pointer = NULL;
234     buf.Length = ACPI_ALLOCATE_BUFFER;
235     status = AcpiEvaluateObject(handle, NULL, NULL, &buf);
236     if (ACPI_FAILURE(status)) {
237 	device_printf(dev, "probe failed to get Processor obj - %s\n",
238 		      AcpiFormatException(status));
239 	return (ENXIO);
240     }
241     obj = (ACPI_OBJECT *)buf.Pointer;
242     if (obj->Type != ACPI_TYPE_PROCESSOR) {
243 	device_printf(dev, "Processor object has bad type %d\n", obj->Type);
244 	AcpiOsFree(obj);
245 	return (ENXIO);
246     }
247 
248     /*
249      * Find the processor associated with our unit.  We could use the
250      * ProcId as a key, however, some boxes do not have the same values
251      * in their Processor object as the ProcId values in the MADT.
252      */
253     acpi_id = obj->Processor.ProcId;
254     AcpiOsFree(obj);
255     if (acpi_pcpu_get_id(dev, &acpi_id, &cpu_id) != 0)
256 	return (ENXIO);
257 
258     /*
259      * Check if we already probed this processor.  We scan the bus twice
260      * so it's possible we've already seen this one.
261      */
262     if (cpu_softc[cpu_id] != NULL)
263 	return (ENXIO);
264 
265     /* Mark this processor as in-use and save our derived id for attach. */
266     cpu_softc[cpu_id] = (void *)1;
267     acpi_set_private(dev, (void*)(intptr_t)cpu_id);
268     device_set_desc(dev, "ACPI CPU");
269 
270     return (0);
271 }
272 
273 static int
274 acpi_cpu_attach(device_t dev)
275 {
276     ACPI_BUFFER		   buf;
277     ACPI_OBJECT		   arg[4], *obj;
278     ACPI_OBJECT_LIST	   arglist;
279     struct pcpu		   *pcpu_data;
280     struct acpi_cpu_softc *sc;
281     struct acpi_softc	  *acpi_sc;
282     ACPI_STATUS		   status;
283     u_int		   features;
284     int			   cpu_id, drv_count, i;
285     driver_t 		  **drivers;
286     uint32_t		   cap_set[3];
287 
288     /* UUID needed by _OSC evaluation */
289     static uint8_t cpu_oscuuid[16] = { 0x16, 0xA6, 0x77, 0x40, 0x0C, 0x29,
290 				       0xBE, 0x47, 0x9E, 0xBD, 0xD8, 0x70,
291 				       0x58, 0x71, 0x39, 0x53 };
292 
293     ACPI_FUNCTION_TRACE((char *)(uintptr_t)__func__);
294 
295     sc = device_get_softc(dev);
296     sc->cpu_dev = dev;
297     sc->cpu_handle = acpi_get_handle(dev);
298     cpu_id = (int)(intptr_t)acpi_get_private(dev);
299     cpu_softc[cpu_id] = sc;
300     pcpu_data = pcpu_find(cpu_id);
301     pcpu_data->pc_device = dev;
302     sc->cpu_pcpu = pcpu_data;
303     cpu_smi_cmd = AcpiGbl_FADT.SmiCommand;
304     cpu_cst_cnt = AcpiGbl_FADT.CstControl;
305 
306     buf.Pointer = NULL;
307     buf.Length = ACPI_ALLOCATE_BUFFER;
308     status = AcpiEvaluateObject(sc->cpu_handle, NULL, NULL, &buf);
309     if (ACPI_FAILURE(status)) {
310 	device_printf(dev, "attach failed to get Processor obj - %s\n",
311 		      AcpiFormatException(status));
312 	return (ENXIO);
313     }
314     obj = (ACPI_OBJECT *)buf.Pointer;
315     sc->cpu_p_blk = obj->Processor.PblkAddress;
316     sc->cpu_p_blk_len = obj->Processor.PblkLength;
317     sc->cpu_acpi_id = obj->Processor.ProcId;
318     AcpiOsFree(obj);
319     ACPI_DEBUG_PRINT((ACPI_DB_INFO, "acpi_cpu%d: P_BLK at %#x/%d\n",
320 		     device_get_unit(dev), sc->cpu_p_blk, sc->cpu_p_blk_len));
321 
322     /*
323      * If this is the first cpu we attach, create and initialize the generic
324      * resources that will be used by all acpi cpu devices.
325      */
326     if (device_get_unit(dev) == 0) {
327 	/* Assume we won't be using generic Cx mode by default */
328 	cpu_cx_generic = FALSE;
329 
330 	/* Install hw.acpi.cpu sysctl tree */
331 	acpi_sc = acpi_device_get_parent_softc(dev);
332 	sysctl_ctx_init(&cpu_sysctl_ctx);
333 	cpu_sysctl_tree = SYSCTL_ADD_NODE(&cpu_sysctl_ctx,
334 	    SYSCTL_CHILDREN(acpi_sc->acpi_sysctl_tree), OID_AUTO, "cpu",
335 	    CTLFLAG_RD, 0, "node for CPU children");
336 
337 	/* Queue post cpu-probing task handler */
338 	AcpiOsExecute(OSL_NOTIFY_HANDLER, acpi_cpu_startup, NULL);
339     }
340 
341     /*
342      * Before calling any CPU methods, collect child driver feature hints
343      * and notify ACPI of them.  We support unified SMP power control
344      * so advertise this ourselves.  Note this is not the same as independent
345      * SMP control where each CPU can have different settings.
346      */
347     sc->cpu_features = ACPI_CAP_SMP_SAME | ACPI_CAP_SMP_SAME_C3;
348     if (devclass_get_drivers(acpi_cpu_devclass, &drivers, &drv_count) == 0) {
349 	for (i = 0; i < drv_count; i++) {
350 	    if (ACPI_GET_FEATURES(drivers[i], &features) == 0)
351 		sc->cpu_features |= features;
352 	}
353 	free(drivers, M_TEMP);
354     }
355 
356     /*
357      * CPU capabilities are specified in
358      * Intel Processor Vendor-Specific ACPI Interface Specification.
359      */
360     if (sc->cpu_features) {
361 	arglist.Pointer = arg;
362 	arglist.Count = 4;
363 	arg[0].Type = ACPI_TYPE_BUFFER;
364 	arg[0].Buffer.Length = sizeof(cpu_oscuuid);
365 	arg[0].Buffer.Pointer = cpu_oscuuid;	/* UUID */
366 	arg[1].Type = ACPI_TYPE_INTEGER;
367 	arg[1].Integer.Value = 1;		/* revision */
368 	arg[2].Type = ACPI_TYPE_INTEGER;
369 	arg[2].Integer.Value = 1;		/* count */
370 	arg[3].Type = ACPI_TYPE_BUFFER;
371 	arg[3].Buffer.Length = sizeof(cap_set);	/* Capabilities buffer */
372 	arg[3].Buffer.Pointer = (uint8_t *)cap_set;
373 	cap_set[0] = 0;				/* status */
374 	cap_set[1] = sc->cpu_features;
375 	status = AcpiEvaluateObject(sc->cpu_handle, "_OSC", &arglist, NULL);
376 	if (ACPI_SUCCESS(status)) {
377 	    if (cap_set[0] != 0)
378 		device_printf(dev, "_OSC returned status %#x\n", cap_set[0]);
379 	}
380 	else {
381 	    arglist.Pointer = arg;
382 	    arglist.Count = 1;
383 	    arg[0].Type = ACPI_TYPE_BUFFER;
384 	    arg[0].Buffer.Length = sizeof(cap_set);
385 	    arg[0].Buffer.Pointer = (uint8_t *)cap_set;
386 	    cap_set[0] = 1; /* revision */
387 	    cap_set[1] = 1; /* number of capabilities integers */
388 	    cap_set[2] = sc->cpu_features;
389 	    AcpiEvaluateObject(sc->cpu_handle, "_PDC", &arglist, NULL);
390 	}
391     }
392 
393     /* Probe for Cx state support. */
394     acpi_cpu_cx_probe(sc);
395 
396     return (0);
397 }
398 
399 static void
400 acpi_cpu_postattach(void *unused __unused)
401 {
402     device_t *devices;
403     int err;
404     int i, n;
405 
406     err = devclass_get_devices(acpi_cpu_devclass, &devices, &n);
407     if (err != 0) {
408 	printf("devclass_get_devices(acpi_cpu_devclass) failed\n");
409 	return;
410     }
411     for (i = 0; i < n; i++)
412 	bus_generic_probe(devices[i]);
413     for (i = 0; i < n; i++)
414 	bus_generic_attach(devices[i]);
415     free(devices, M_TEMP);
416 }
417 
418 SYSINIT(acpi_cpu, SI_SUB_CONFIGURE, SI_ORDER_MIDDLE,
419     acpi_cpu_postattach, NULL);
420 
421 static void
422 disable_idle(struct acpi_cpu_softc *sc)
423 {
424     cpuset_t cpuset;
425 
426     CPU_SETOF(sc->cpu_pcpu->pc_cpuid, &cpuset);
427     sc->cpu_disable_idle = TRUE;
428 
429     /*
430      * Ensure that the CPU is not in idle state or in acpi_cpu_idle().
431      * Note that this code depends on the fact that the rendezvous IPI
432      * can not penetrate context where interrupts are disabled and acpi_cpu_idle
433      * is called and executed in such a context with interrupts being re-enabled
434      * right before return.
435      */
436     smp_rendezvous_cpus(cpuset, smp_no_rendevous_barrier, NULL,
437 	smp_no_rendevous_barrier, NULL);
438 }
439 
440 static void
441 enable_idle(struct acpi_cpu_softc *sc)
442 {
443 
444     sc->cpu_disable_idle = FALSE;
445 }
446 
447 static int
448 is_idle_disabled(struct acpi_cpu_softc *sc)
449 {
450 
451     return (sc->cpu_disable_idle);
452 }
453 
454 /*
455  * Disable any entry to the idle function during suspend and re-enable it
456  * during resume.
457  */
458 static int
459 acpi_cpu_suspend(device_t dev)
460 {
461     int error;
462 
463     error = bus_generic_suspend(dev);
464     if (error)
465 	return (error);
466     disable_idle(device_get_softc(dev));
467     return (0);
468 }
469 
470 static int
471 acpi_cpu_resume(device_t dev)
472 {
473 
474     enable_idle(device_get_softc(dev));
475     return (bus_generic_resume(dev));
476 }
477 
478 /*
479  * Find the processor associated with a given ACPI ID.  By default,
480  * use the MADT to map ACPI IDs to APIC IDs and use that to locate a
481  * processor.  Some systems have inconsistent ASL and MADT however.
482  * For these systems the cpu_unordered tunable can be set in which
483  * case we assume that Processor objects are listed in the same order
484  * in both the MADT and ASL.
485  */
486 static int
487 acpi_pcpu_get_id(device_t dev, uint32_t *acpi_id, uint32_t *cpu_id)
488 {
489     struct pcpu	*pc;
490     uint32_t	 i, idx;
491 
492     KASSERT(acpi_id != NULL, ("Null acpi_id"));
493     KASSERT(cpu_id != NULL, ("Null cpu_id"));
494     idx = device_get_unit(dev);
495 
496     /*
497      * If pc_acpi_id for CPU 0 is not initialized (e.g. a non-APIC
498      * UP box) use the ACPI ID from the first processor we find.
499      */
500     if (idx == 0 && mp_ncpus == 1) {
501 	pc = pcpu_find(0);
502 	if (pc->pc_acpi_id == 0xffffffff)
503 	    pc->pc_acpi_id = *acpi_id;
504 	*cpu_id = 0;
505 	return (0);
506     }
507 
508     CPU_FOREACH(i) {
509 	pc = pcpu_find(i);
510 	KASSERT(pc != NULL, ("no pcpu data for %d", i));
511 	if (cpu_unordered) {
512 	    if (idx-- == 0) {
513 		/*
514 		 * If pc_acpi_id doesn't match the ACPI ID from the
515 		 * ASL, prefer the MADT-derived value.
516 		 */
517 		if (pc->pc_acpi_id != *acpi_id)
518 		    *acpi_id = pc->pc_acpi_id;
519 		*cpu_id = pc->pc_cpuid;
520 		return (0);
521 	    }
522 	} else {
523 	    if (pc->pc_acpi_id == *acpi_id) {
524 		if (bootverbose)
525 		    device_printf(dev,
526 			"Processor %s (ACPI ID %u) -> APIC ID %d\n",
527 			acpi_name(acpi_get_handle(dev)), *acpi_id,
528 			pc->pc_cpuid);
529 		*cpu_id = pc->pc_cpuid;
530 		return (0);
531 	    }
532 	}
533     }
534 
535     if (bootverbose)
536 	printf("ACPI: Processor %s (ACPI ID %u) ignored\n",
537 	    acpi_name(acpi_get_handle(dev)), *acpi_id);
538 
539     return (ESRCH);
540 }
541 
542 static struct resource_list *
543 acpi_cpu_get_rlist(device_t dev, device_t child)
544 {
545     struct acpi_cpu_device *ad;
546 
547     ad = device_get_ivars(child);
548     if (ad == NULL)
549 	return (NULL);
550     return (&ad->ad_rl);
551 }
552 
553 static device_t
554 acpi_cpu_add_child(device_t dev, u_int order, const char *name, int unit)
555 {
556     struct acpi_cpu_device *ad;
557     device_t child;
558 
559     if ((ad = malloc(sizeof(*ad), M_TEMP, M_NOWAIT | M_ZERO)) == NULL)
560 	return (NULL);
561 
562     resource_list_init(&ad->ad_rl);
563 
564     child = device_add_child_ordered(dev, order, name, unit);
565     if (child != NULL)
566 	device_set_ivars(child, ad);
567     else
568 	free(ad, M_TEMP);
569     return (child);
570 }
571 
572 static int
573 acpi_cpu_read_ivar(device_t dev, device_t child, int index, uintptr_t *result)
574 {
575     struct acpi_cpu_softc *sc;
576 
577     sc = device_get_softc(dev);
578     switch (index) {
579     case ACPI_IVAR_HANDLE:
580 	*result = (uintptr_t)sc->cpu_handle;
581 	break;
582     case CPU_IVAR_PCPU:
583 	*result = (uintptr_t)sc->cpu_pcpu;
584 	break;
585 #if defined(__amd64__) || defined(__i386__)
586     case CPU_IVAR_NOMINAL_MHZ:
587 	if (tsc_is_invariant) {
588 	    *result = (uintptr_t)(atomic_load_acq_64(&tsc_freq) / 1000000);
589 	    break;
590 	}
591 	/* FALLTHROUGH */
592 #endif
593     default:
594 	return (ENOENT);
595     }
596     return (0);
597 }
598 
599 static int
600 acpi_cpu_shutdown(device_t dev)
601 {
602     ACPI_FUNCTION_TRACE((char *)(uintptr_t)__func__);
603 
604     /* Allow children to shutdown first. */
605     bus_generic_shutdown(dev);
606 
607     /*
608      * Disable any entry to the idle function.
609      */
610     disable_idle(device_get_softc(dev));
611 
612     /*
613      * CPU devices are not truely detached and remain referenced,
614      * so their resources are not freed.
615      */
616 
617     return_VALUE (0);
618 }
619 
620 static void
621 acpi_cpu_cx_probe(struct acpi_cpu_softc *sc)
622 {
623     ACPI_FUNCTION_TRACE((char *)(uintptr_t)__func__);
624 
625     /* Use initial sleep value of 1 sec. to start with lowest idle state. */
626     sc->cpu_prev_sleep = 1000000;
627     sc->cpu_cx_lowest = 0;
628     sc->cpu_cx_lowest_lim = 0;
629 
630     /*
631      * Check for the ACPI 2.0 _CST sleep states object. If we can't find
632      * any, we'll revert to generic FADT/P_BLK Cx control method which will
633      * be handled by acpi_cpu_startup. We need to defer to after having
634      * probed all the cpus in the system before probing for generic Cx
635      * states as we may already have found cpus with valid _CST packages
636      */
637     if (!cpu_cx_generic && acpi_cpu_cx_cst(sc) != 0) {
638 	/*
639 	 * We were unable to find a _CST package for this cpu or there
640 	 * was an error parsing it. Switch back to generic mode.
641 	 */
642 	cpu_cx_generic = TRUE;
643 	if (bootverbose)
644 	    device_printf(sc->cpu_dev, "switching to generic Cx mode\n");
645     }
646 
647     /*
648      * TODO: _CSD Package should be checked here.
649      */
650 }
651 
652 static void
653 acpi_cpu_generic_cx_probe(struct acpi_cpu_softc *sc)
654 {
655     ACPI_GENERIC_ADDRESS	 gas;
656     struct acpi_cx		*cx_ptr;
657 
658     sc->cpu_cx_count = 0;
659     cx_ptr = sc->cpu_cx_states;
660 
661     /* Use initial sleep value of 1 sec. to start with lowest idle state. */
662     sc->cpu_prev_sleep = 1000000;
663 
664     /* C1 has been required since just after ACPI 1.0 */
665     cx_ptr->type = ACPI_STATE_C1;
666     cx_ptr->trans_lat = 0;
667     cx_ptr++;
668     sc->cpu_non_c3 = sc->cpu_cx_count;
669     sc->cpu_cx_count++;
670 
671     /*
672      * The spec says P_BLK must be 6 bytes long.  However, some systems
673      * use it to indicate a fractional set of features present so we
674      * take 5 as C2.  Some may also have a value of 7 to indicate
675      * another C3 but most use _CST for this (as required) and having
676      * "only" C1-C3 is not a hardship.
677      */
678     if (sc->cpu_p_blk_len < 5)
679 	return;
680 
681     /* Validate and allocate resources for C2 (P_LVL2). */
682     gas.SpaceId = ACPI_ADR_SPACE_SYSTEM_IO;
683     gas.BitWidth = 8;
684     if (AcpiGbl_FADT.C2Latency <= 100) {
685 	gas.Address = sc->cpu_p_blk + 4;
686 	cx_ptr->res_rid = 0;
687 	acpi_bus_alloc_gas(sc->cpu_dev, &cx_ptr->res_type, &cx_ptr->res_rid,
688 	    &gas, &cx_ptr->p_lvlx, RF_SHAREABLE);
689 	if (cx_ptr->p_lvlx != NULL) {
690 	    cx_ptr->type = ACPI_STATE_C2;
691 	    cx_ptr->trans_lat = AcpiGbl_FADT.C2Latency;
692 	    cx_ptr++;
693 	    sc->cpu_non_c3 = sc->cpu_cx_count;
694 	    sc->cpu_cx_count++;
695 	}
696     }
697     if (sc->cpu_p_blk_len < 6)
698 	return;
699 
700     /* Validate and allocate resources for C3 (P_LVL3). */
701     if (AcpiGbl_FADT.C3Latency <= 1000 && !(cpu_quirks & CPU_QUIRK_NO_C3)) {
702 	gas.Address = sc->cpu_p_blk + 5;
703 	cx_ptr->res_rid = 1;
704 	acpi_bus_alloc_gas(sc->cpu_dev, &cx_ptr->res_type, &cx_ptr->res_rid,
705 	    &gas, &cx_ptr->p_lvlx, RF_SHAREABLE);
706 	if (cx_ptr->p_lvlx != NULL) {
707 	    cx_ptr->type = ACPI_STATE_C3;
708 	    cx_ptr->trans_lat = AcpiGbl_FADT.C3Latency;
709 	    cx_ptr++;
710 	    sc->cpu_cx_count++;
711 	    cpu_can_deep_sleep = 1;
712 	}
713     }
714 }
715 
716 /*
717  * Parse a _CST package and set up its Cx states.  Since the _CST object
718  * can change dynamically, our notify handler may call this function
719  * to clean up and probe the new _CST package.
720  */
721 static int
722 acpi_cpu_cx_cst(struct acpi_cpu_softc *sc)
723 {
724     struct	 acpi_cx *cx_ptr;
725     ACPI_STATUS	 status;
726     ACPI_BUFFER	 buf;
727     ACPI_OBJECT	*top;
728     ACPI_OBJECT	*pkg;
729     uint32_t	 count;
730     int		 i;
731 
732     ACPI_FUNCTION_TRACE((char *)(uintptr_t)__func__);
733 
734     buf.Pointer = NULL;
735     buf.Length = ACPI_ALLOCATE_BUFFER;
736     status = AcpiEvaluateObject(sc->cpu_handle, "_CST", NULL, &buf);
737     if (ACPI_FAILURE(status))
738 	return (ENXIO);
739 
740     /* _CST is a package with a count and at least one Cx package. */
741     top = (ACPI_OBJECT *)buf.Pointer;
742     if (!ACPI_PKG_VALID(top, 2) || acpi_PkgInt32(top, 0, &count) != 0) {
743 	device_printf(sc->cpu_dev, "invalid _CST package\n");
744 	AcpiOsFree(buf.Pointer);
745 	return (ENXIO);
746     }
747     if (count != top->Package.Count - 1) {
748 	device_printf(sc->cpu_dev, "invalid _CST state count (%d != %d)\n",
749 	       count, top->Package.Count - 1);
750 	count = top->Package.Count - 1;
751     }
752     if (count > MAX_CX_STATES) {
753 	device_printf(sc->cpu_dev, "_CST has too many states (%d)\n", count);
754 	count = MAX_CX_STATES;
755     }
756 
757     sc->cpu_non_c3 = 0;
758     sc->cpu_cx_count = 0;
759     cx_ptr = sc->cpu_cx_states;
760 
761     /*
762      * C1 has been required since just after ACPI 1.0.
763      * Reserve the first slot for it.
764      */
765     cx_ptr->type = ACPI_STATE_C0;
766     cx_ptr++;
767     sc->cpu_cx_count++;
768 
769     /* Set up all valid states. */
770     for (i = 0; i < count; i++) {
771 	pkg = &top->Package.Elements[i + 1];
772 	if (!ACPI_PKG_VALID(pkg, 4) ||
773 	    acpi_PkgInt32(pkg, 1, &cx_ptr->type) != 0 ||
774 	    acpi_PkgInt32(pkg, 2, &cx_ptr->trans_lat) != 0 ||
775 	    acpi_PkgInt32(pkg, 3, &cx_ptr->power) != 0) {
776 
777 	    device_printf(sc->cpu_dev, "skipping invalid Cx state package\n");
778 	    continue;
779 	}
780 
781 	/* Validate the state to see if we should use it. */
782 	switch (cx_ptr->type) {
783 	case ACPI_STATE_C1:
784 	    if (sc->cpu_cx_states[0].type == ACPI_STATE_C0) {
785 		/* This is the first C1 state.  Use the reserved slot. */
786 		sc->cpu_cx_states[0] = *cx_ptr;
787 	    } else {
788 		sc->cpu_non_c3 = sc->cpu_cx_count;
789 		cx_ptr++;
790 		sc->cpu_cx_count++;
791 	    }
792 	    continue;
793 	case ACPI_STATE_C2:
794 	    sc->cpu_non_c3 = sc->cpu_cx_count;
795 	    break;
796 	case ACPI_STATE_C3:
797 	default:
798 	    if ((cpu_quirks & CPU_QUIRK_NO_C3) != 0) {
799 		ACPI_DEBUG_PRINT((ACPI_DB_INFO,
800 				 "acpi_cpu%d: C3[%d] not available.\n",
801 				 device_get_unit(sc->cpu_dev), i));
802 		continue;
803 	    } else
804 		cpu_can_deep_sleep = 1;
805 	    break;
806 	}
807 
808 	/* Free up any previous register. */
809 	if (cx_ptr->p_lvlx != NULL) {
810 	    bus_release_resource(sc->cpu_dev, cx_ptr->res_type, cx_ptr->res_rid,
811 	        cx_ptr->p_lvlx);
812 	    cx_ptr->p_lvlx = NULL;
813 	}
814 
815 	/* Allocate the control register for C2 or C3. */
816 	cx_ptr->res_rid = sc->cpu_cx_count;
817 	acpi_PkgGas(sc->cpu_dev, pkg, 0, &cx_ptr->res_type, &cx_ptr->res_rid,
818 	    &cx_ptr->p_lvlx, RF_SHAREABLE);
819 	if (cx_ptr->p_lvlx) {
820 	    ACPI_DEBUG_PRINT((ACPI_DB_INFO,
821 			     "acpi_cpu%d: Got C%d - %d latency\n",
822 			     device_get_unit(sc->cpu_dev), cx_ptr->type,
823 			     cx_ptr->trans_lat));
824 	    cx_ptr++;
825 	    sc->cpu_cx_count++;
826 	}
827     }
828     AcpiOsFree(buf.Pointer);
829 
830     /* If C1 state was not found, we need one now. */
831     cx_ptr = sc->cpu_cx_states;
832     if (cx_ptr->type == ACPI_STATE_C0) {
833 	cx_ptr->type = ACPI_STATE_C1;
834 	cx_ptr->trans_lat = 0;
835     }
836 
837     return (0);
838 }
839 
840 /*
841  * Call this *after* all CPUs have been attached.
842  */
843 static void
844 acpi_cpu_startup(void *arg)
845 {
846     struct acpi_cpu_softc *sc;
847     int i;
848 
849     /* Get set of CPU devices */
850     devclass_get_devices(acpi_cpu_devclass, &cpu_devices, &cpu_ndevices);
851 
852     /*
853      * Setup any quirks that might necessary now that we have probed
854      * all the CPUs
855      */
856     acpi_cpu_quirks();
857 
858     if (cpu_cx_generic) {
859 	/*
860 	 * We are using generic Cx mode, probe for available Cx states
861 	 * for all processors.
862 	 */
863 	for (i = 0; i < cpu_ndevices; i++) {
864 	    sc = device_get_softc(cpu_devices[i]);
865 	    acpi_cpu_generic_cx_probe(sc);
866 	}
867     } else {
868 	/*
869 	 * We are using _CST mode, remove C3 state if necessary.
870 	 * As we now know for sure that we will be using _CST mode
871 	 * install our notify handler.
872 	 */
873 	for (i = 0; i < cpu_ndevices; i++) {
874 	    sc = device_get_softc(cpu_devices[i]);
875 	    if (cpu_quirks & CPU_QUIRK_NO_C3) {
876 		sc->cpu_cx_count = sc->cpu_non_c3 + 1;
877 	    }
878 	    AcpiInstallNotifyHandler(sc->cpu_handle, ACPI_DEVICE_NOTIFY,
879 		acpi_cpu_notify, sc);
880 	}
881     }
882 
883     /* Perform Cx final initialization. */
884     for (i = 0; i < cpu_ndevices; i++) {
885 	sc = device_get_softc(cpu_devices[i]);
886 	acpi_cpu_startup_cx(sc);
887     }
888 
889     /* Add a sysctl handler to handle global Cx lowest setting */
890     SYSCTL_ADD_PROC(&cpu_sysctl_ctx, SYSCTL_CHILDREN(cpu_sysctl_tree),
891 	OID_AUTO, "cx_lowest", CTLTYPE_STRING | CTLFLAG_RW,
892 	NULL, 0, acpi_cpu_global_cx_lowest_sysctl, "A",
893 	"Global lowest Cx sleep state to use");
894 
895     /* Take over idling from cpu_idle_default(). */
896     cpu_cx_lowest_lim = 0;
897     for (i = 0; i < cpu_ndevices; i++) {
898 	sc = device_get_softc(cpu_devices[i]);
899 	enable_idle(sc);
900     }
901     cpu_idle_hook = acpi_cpu_idle;
902 }
903 
904 static void
905 acpi_cpu_cx_list(struct acpi_cpu_softc *sc)
906 {
907     struct sbuf sb;
908     int i;
909 
910     /*
911      * Set up the list of Cx states
912      */
913     sbuf_new(&sb, sc->cpu_cx_supported, sizeof(sc->cpu_cx_supported),
914 	SBUF_FIXEDLEN);
915     for (i = 0; i < sc->cpu_cx_count; i++)
916 	sbuf_printf(&sb, "C%d/%d/%d ", i + 1, sc->cpu_cx_states[i].type,
917 	    sc->cpu_cx_states[i].trans_lat);
918     sbuf_trim(&sb);
919     sbuf_finish(&sb);
920 }
921 
922 static void
923 acpi_cpu_startup_cx(struct acpi_cpu_softc *sc)
924 {
925     acpi_cpu_cx_list(sc);
926 
927     SYSCTL_ADD_STRING(&sc->cpu_sysctl_ctx,
928 		      SYSCTL_CHILDREN(device_get_sysctl_tree(sc->cpu_dev)),
929 		      OID_AUTO, "cx_supported", CTLFLAG_RD,
930 		      sc->cpu_cx_supported, 0,
931 		      "Cx/microsecond values for supported Cx states");
932     SYSCTL_ADD_PROC(&sc->cpu_sysctl_ctx,
933 		    SYSCTL_CHILDREN(device_get_sysctl_tree(sc->cpu_dev)),
934 		    OID_AUTO, "cx_lowest", CTLTYPE_STRING | CTLFLAG_RW,
935 		    (void *)sc, 0, acpi_cpu_cx_lowest_sysctl, "A",
936 		    "lowest Cx sleep state to use");
937     SYSCTL_ADD_PROC(&sc->cpu_sysctl_ctx,
938 		    SYSCTL_CHILDREN(device_get_sysctl_tree(sc->cpu_dev)),
939 		    OID_AUTO, "cx_usage", CTLTYPE_STRING | CTLFLAG_RD,
940 		    (void *)sc, 0, acpi_cpu_usage_sysctl, "A",
941 		    "percent usage for each Cx state");
942     SYSCTL_ADD_PROC(&sc->cpu_sysctl_ctx,
943 		    SYSCTL_CHILDREN(device_get_sysctl_tree(sc->cpu_dev)),
944 		    OID_AUTO, "cx_usage_counters", CTLTYPE_STRING | CTLFLAG_RD,
945 		    (void *)sc, 0, acpi_cpu_usage_counters_sysctl, "A",
946 		    "Cx sleep state counters");
947 
948     /* Signal platform that we can handle _CST notification. */
949     if (!cpu_cx_generic && cpu_cst_cnt != 0) {
950 	ACPI_LOCK(acpi);
951 	AcpiOsWritePort(cpu_smi_cmd, cpu_cst_cnt, 8);
952 	ACPI_UNLOCK(acpi);
953     }
954 }
955 
956 /*
957  * Idle the CPU in the lowest state possible.  This function is called with
958  * interrupts disabled.  Note that once it re-enables interrupts, a task
959  * switch can occur so do not access shared data (i.e. the softc) after
960  * interrupts are re-enabled.
961  */
962 static void
963 acpi_cpu_idle(sbintime_t sbt)
964 {
965     struct	acpi_cpu_softc *sc;
966     struct	acpi_cx *cx_next;
967     uint64_t	cputicks;
968     uint32_t	start_time, end_time;
969     int		bm_active, cx_next_idx, i, us;
970 
971     /*
972      * Look up our CPU id to get our softc.  If it's NULL, we'll use C1
973      * since there is no ACPI processor object for this CPU.  This occurs
974      * for logical CPUs in the HTT case.
975      */
976     sc = cpu_softc[PCPU_GET(cpuid)];
977     if (sc == NULL) {
978 	acpi_cpu_c1();
979 	return;
980     }
981 
982     /* If disabled, take the safe path. */
983     if (is_idle_disabled(sc)) {
984 	acpi_cpu_c1();
985 	return;
986     }
987 
988     /* Find the lowest state that has small enough latency. */
989     us = sc->cpu_prev_sleep;
990     if (sbt >= 0 && us > (sbt >> 12))
991 	us = (sbt >> 12);
992     cx_next_idx = 0;
993     if (cpu_disable_deep_sleep)
994 	i = min(sc->cpu_cx_lowest, sc->cpu_non_c3);
995     else
996 	i = sc->cpu_cx_lowest;
997     for (; i >= 0; i--) {
998 	if (sc->cpu_cx_states[i].trans_lat * 3 <= us) {
999 	    cx_next_idx = i;
1000 	    break;
1001 	}
1002     }
1003 
1004     /*
1005      * Check for bus master activity.  If there was activity, clear
1006      * the bit and use the lowest non-C3 state.  Note that the USB
1007      * driver polling for new devices keeps this bit set all the
1008      * time if USB is loaded.
1009      */
1010     if ((cpu_quirks & CPU_QUIRK_NO_BM_CTRL) == 0 &&
1011 	cx_next_idx > sc->cpu_non_c3) {
1012 	AcpiReadBitRegister(ACPI_BITREG_BUS_MASTER_STATUS, &bm_active);
1013 	if (bm_active != 0) {
1014 	    AcpiWriteBitRegister(ACPI_BITREG_BUS_MASTER_STATUS, 1);
1015 	    cx_next_idx = sc->cpu_non_c3;
1016 	}
1017     }
1018 
1019     /* Select the next state and update statistics. */
1020     cx_next = &sc->cpu_cx_states[cx_next_idx];
1021     sc->cpu_cx_stats[cx_next_idx]++;
1022     KASSERT(cx_next->type != ACPI_STATE_C0, ("acpi_cpu_idle: C0 sleep"));
1023 
1024     /*
1025      * Execute HLT (or equivalent) and wait for an interrupt.  We can't
1026      * precisely calculate the time spent in C1 since the place we wake up
1027      * is an ISR.  Assume we slept no more then half of quantum, unless
1028      * we are called inside critical section, delaying context switch.
1029      */
1030     if (cx_next->type == ACPI_STATE_C1) {
1031 	cputicks = cpu_ticks();
1032 	acpi_cpu_c1();
1033 	end_time = ((cpu_ticks() - cputicks) << 20) / cpu_tickrate();
1034 	if (curthread->td_critnest == 0)
1035 		end_time = min(end_time, 500000 / hz);
1036 	sc->cpu_prev_sleep = (sc->cpu_prev_sleep * 3 + end_time) / 4;
1037 	return;
1038     }
1039 
1040     /*
1041      * For C3, disable bus master arbitration and enable bus master wake
1042      * if BM control is available, otherwise flush the CPU cache.
1043      */
1044     if (cx_next->type == ACPI_STATE_C3) {
1045 	if ((cpu_quirks & CPU_QUIRK_NO_BM_CTRL) == 0) {
1046 	    AcpiWriteBitRegister(ACPI_BITREG_ARB_DISABLE, 1);
1047 	    AcpiWriteBitRegister(ACPI_BITREG_BUS_MASTER_RLD, 1);
1048 	} else
1049 	    ACPI_FLUSH_CPU_CACHE();
1050     }
1051 
1052     /*
1053      * Read from P_LVLx to enter C2(+), checking time spent asleep.
1054      * Use the ACPI timer for measuring sleep time.  Since we need to
1055      * get the time very close to the CPU start/stop clock logic, this
1056      * is the only reliable time source.
1057      */
1058     if (cx_next->type == ACPI_STATE_C3) {
1059 	AcpiHwRead(&start_time, &AcpiGbl_FADT.XPmTimerBlock);
1060 	cputicks = 0;
1061     } else {
1062 	start_time = 0;
1063 	cputicks = cpu_ticks();
1064     }
1065     CPU_GET_REG(cx_next->p_lvlx, 1);
1066 
1067     /*
1068      * Read the end time twice.  Since it may take an arbitrary time
1069      * to enter the idle state, the first read may be executed before
1070      * the processor has stopped.  Doing it again provides enough
1071      * margin that we are certain to have a correct value.
1072      */
1073     AcpiHwRead(&end_time, &AcpiGbl_FADT.XPmTimerBlock);
1074     if (cx_next->type == ACPI_STATE_C3) {
1075 	AcpiHwRead(&end_time, &AcpiGbl_FADT.XPmTimerBlock);
1076 	end_time = acpi_TimerDelta(end_time, start_time);
1077     } else
1078 	end_time = ((cpu_ticks() - cputicks) << 20) / cpu_tickrate();
1079 
1080     /* Enable bus master arbitration and disable bus master wakeup. */
1081     if (cx_next->type == ACPI_STATE_C3 &&
1082 	(cpu_quirks & CPU_QUIRK_NO_BM_CTRL) == 0) {
1083 	AcpiWriteBitRegister(ACPI_BITREG_ARB_DISABLE, 0);
1084 	AcpiWriteBitRegister(ACPI_BITREG_BUS_MASTER_RLD, 0);
1085     }
1086     ACPI_ENABLE_IRQS();
1087 
1088     sc->cpu_prev_sleep = (sc->cpu_prev_sleep * 3 + PM_USEC(end_time)) / 4;
1089 }
1090 
1091 /*
1092  * Re-evaluate the _CST object when we are notified that it changed.
1093  */
1094 static void
1095 acpi_cpu_notify(ACPI_HANDLE h, UINT32 notify, void *context)
1096 {
1097     struct acpi_cpu_softc *sc = (struct acpi_cpu_softc *)context;
1098 
1099     if (notify != ACPI_NOTIFY_CX_STATES)
1100 	return;
1101 
1102     /*
1103      * C-state data for target CPU is going to be in flux while we execute
1104      * acpi_cpu_cx_cst, so disable entering acpi_cpu_idle.
1105      * Also, it may happen that multiple ACPI taskqueues may concurrently
1106      * execute notifications for the same CPU.  ACPI_SERIAL is used to
1107      * protect against that.
1108      */
1109     ACPI_SERIAL_BEGIN(cpu);
1110     disable_idle(sc);
1111 
1112     /* Update the list of Cx states. */
1113     acpi_cpu_cx_cst(sc);
1114     acpi_cpu_cx_list(sc);
1115     acpi_cpu_set_cx_lowest(sc);
1116 
1117     enable_idle(sc);
1118     ACPI_SERIAL_END(cpu);
1119 
1120     acpi_UserNotify("PROCESSOR", sc->cpu_handle, notify);
1121 }
1122 
1123 static int
1124 acpi_cpu_quirks(void)
1125 {
1126     device_t acpi_dev;
1127     uint32_t val;
1128 
1129     ACPI_FUNCTION_TRACE((char *)(uintptr_t)__func__);
1130 
1131     /*
1132      * Bus mastering arbitration control is needed to keep caches coherent
1133      * while sleeping in C3.  If it's not present but a working flush cache
1134      * instruction is present, flush the caches before entering C3 instead.
1135      * Otherwise, just disable C3 completely.
1136      */
1137     if (AcpiGbl_FADT.Pm2ControlBlock == 0 ||
1138 	AcpiGbl_FADT.Pm2ControlLength == 0) {
1139 	if ((AcpiGbl_FADT.Flags & ACPI_FADT_WBINVD) &&
1140 	    (AcpiGbl_FADT.Flags & ACPI_FADT_WBINVD_FLUSH) == 0) {
1141 	    cpu_quirks |= CPU_QUIRK_NO_BM_CTRL;
1142 	    ACPI_DEBUG_PRINT((ACPI_DB_INFO,
1143 		"acpi_cpu: no BM control, using flush cache method\n"));
1144 	} else {
1145 	    cpu_quirks |= CPU_QUIRK_NO_C3;
1146 	    ACPI_DEBUG_PRINT((ACPI_DB_INFO,
1147 		"acpi_cpu: no BM control, C3 not available\n"));
1148 	}
1149     }
1150 
1151     /*
1152      * If we are using generic Cx mode, C3 on multiple CPUs requires using
1153      * the expensive flush cache instruction.
1154      */
1155     if (cpu_cx_generic && mp_ncpus > 1) {
1156 	cpu_quirks |= CPU_QUIRK_NO_BM_CTRL;
1157 	ACPI_DEBUG_PRINT((ACPI_DB_INFO,
1158 	    "acpi_cpu: SMP, using flush cache mode for C3\n"));
1159     }
1160 
1161     /* Look for various quirks of the PIIX4 part. */
1162     acpi_dev = pci_find_device(PCI_VENDOR_INTEL, PCI_DEVICE_82371AB_3);
1163     if (acpi_dev != NULL) {
1164 	switch (pci_get_revid(acpi_dev)) {
1165 	/*
1166 	 * Disable C3 support for all PIIX4 chipsets.  Some of these parts
1167 	 * do not report the BMIDE status to the BM status register and
1168 	 * others have a livelock bug if Type-F DMA is enabled.  Linux
1169 	 * works around the BMIDE bug by reading the BM status directly
1170 	 * but we take the simpler approach of disabling C3 for these
1171 	 * parts.
1172 	 *
1173 	 * See erratum #18 ("C3 Power State/BMIDE and Type-F DMA
1174 	 * Livelock") from the January 2002 PIIX4 specification update.
1175 	 * Applies to all PIIX4 models.
1176 	 *
1177 	 * Also, make sure that all interrupts cause a "Stop Break"
1178 	 * event to exit from C2 state.
1179 	 * Also, BRLD_EN_BM (ACPI_BITREG_BUS_MASTER_RLD in ACPI-speak)
1180 	 * should be set to zero, otherwise it causes C2 to short-sleep.
1181 	 * PIIX4 doesn't properly support C3 and bus master activity
1182 	 * need not break out of C2.
1183 	 */
1184 	case PCI_REVISION_A_STEP:
1185 	case PCI_REVISION_B_STEP:
1186 	case PCI_REVISION_4E:
1187 	case PCI_REVISION_4M:
1188 	    cpu_quirks |= CPU_QUIRK_NO_C3;
1189 	    ACPI_DEBUG_PRINT((ACPI_DB_INFO,
1190 		"acpi_cpu: working around PIIX4 bug, disabling C3\n"));
1191 
1192 	    val = pci_read_config(acpi_dev, PIIX4_DEVACTB_REG, 4);
1193 	    if ((val & PIIX4_STOP_BREAK_MASK) != PIIX4_STOP_BREAK_MASK) {
1194 		ACPI_DEBUG_PRINT((ACPI_DB_INFO,
1195 		    "acpi_cpu: PIIX4: enabling IRQs to generate Stop Break\n"));
1196 	    	val |= PIIX4_STOP_BREAK_MASK;
1197 		pci_write_config(acpi_dev, PIIX4_DEVACTB_REG, val, 4);
1198 	    }
1199 	    AcpiReadBitRegister(ACPI_BITREG_BUS_MASTER_RLD, &val);
1200 	    if (val) {
1201 		ACPI_DEBUG_PRINT((ACPI_DB_INFO,
1202 		    "acpi_cpu: PIIX4: reset BRLD_EN_BM\n"));
1203 		AcpiWriteBitRegister(ACPI_BITREG_BUS_MASTER_RLD, 0);
1204 	    }
1205 	    break;
1206 	default:
1207 	    break;
1208 	}
1209     }
1210 
1211     return (0);
1212 }
1213 
1214 static int
1215 acpi_cpu_usage_sysctl(SYSCTL_HANDLER_ARGS)
1216 {
1217     struct acpi_cpu_softc *sc;
1218     struct sbuf	 sb;
1219     char	 buf[128];
1220     int		 i;
1221     uintmax_t	 fract, sum, whole;
1222 
1223     sc = (struct acpi_cpu_softc *) arg1;
1224     sum = 0;
1225     for (i = 0; i < sc->cpu_cx_count; i++)
1226 	sum += sc->cpu_cx_stats[i];
1227     sbuf_new(&sb, buf, sizeof(buf), SBUF_FIXEDLEN);
1228     for (i = 0; i < sc->cpu_cx_count; i++) {
1229 	if (sum > 0) {
1230 	    whole = (uintmax_t)sc->cpu_cx_stats[i] * 100;
1231 	    fract = (whole % sum) * 100;
1232 	    sbuf_printf(&sb, "%u.%02u%% ", (u_int)(whole / sum),
1233 		(u_int)(fract / sum));
1234 	} else
1235 	    sbuf_printf(&sb, "0.00%% ");
1236     }
1237     sbuf_printf(&sb, "last %dus", sc->cpu_prev_sleep);
1238     sbuf_trim(&sb);
1239     sbuf_finish(&sb);
1240     sysctl_handle_string(oidp, sbuf_data(&sb), sbuf_len(&sb), req);
1241     sbuf_delete(&sb);
1242 
1243     return (0);
1244 }
1245 
1246 /*
1247  * XXX TODO: actually add support to count each entry/exit
1248  * from the Cx states.
1249  */
1250 static int
1251 acpi_cpu_usage_counters_sysctl(SYSCTL_HANDLER_ARGS)
1252 {
1253     struct acpi_cpu_softc *sc;
1254     struct sbuf	 sb;
1255     char	 buf[128];
1256     int		 i;
1257 
1258     sc = (struct acpi_cpu_softc *) arg1;
1259 
1260     /* Print out the raw counters */
1261     sbuf_new(&sb, buf, sizeof(buf), SBUF_FIXEDLEN);
1262 
1263     for (i = 0; i < sc->cpu_cx_count; i++) {
1264         sbuf_printf(&sb, "%u ", sc->cpu_cx_stats[i]);
1265     }
1266 
1267     sbuf_trim(&sb);
1268     sbuf_finish(&sb);
1269     sysctl_handle_string(oidp, sbuf_data(&sb), sbuf_len(&sb), req);
1270     sbuf_delete(&sb);
1271 
1272     return (0);
1273 }
1274 
1275 static int
1276 acpi_cpu_set_cx_lowest(struct acpi_cpu_softc *sc)
1277 {
1278     int i;
1279 
1280     ACPI_SERIAL_ASSERT(cpu);
1281     sc->cpu_cx_lowest = min(sc->cpu_cx_lowest_lim, sc->cpu_cx_count - 1);
1282 
1283     /* If not disabling, cache the new lowest non-C3 state. */
1284     sc->cpu_non_c3 = 0;
1285     for (i = sc->cpu_cx_lowest; i >= 0; i--) {
1286 	if (sc->cpu_cx_states[i].type < ACPI_STATE_C3) {
1287 	    sc->cpu_non_c3 = i;
1288 	    break;
1289 	}
1290     }
1291 
1292     /* Reset the statistics counters. */
1293     bzero(sc->cpu_cx_stats, sizeof(sc->cpu_cx_stats));
1294     return (0);
1295 }
1296 
1297 static int
1298 acpi_cpu_cx_lowest_sysctl(SYSCTL_HANDLER_ARGS)
1299 {
1300     struct	 acpi_cpu_softc *sc;
1301     char	 state[8];
1302     int		 val, error;
1303 
1304     sc = (struct acpi_cpu_softc *) arg1;
1305     snprintf(state, sizeof(state), "C%d", sc->cpu_cx_lowest_lim + 1);
1306     error = sysctl_handle_string(oidp, state, sizeof(state), req);
1307     if (error != 0 || req->newptr == NULL)
1308 	return (error);
1309     if (strlen(state) < 2 || toupper(state[0]) != 'C')
1310 	return (EINVAL);
1311     if (strcasecmp(state, "Cmax") == 0)
1312 	val = MAX_CX_STATES;
1313     else {
1314 	val = (int) strtol(state + 1, NULL, 10);
1315 	if (val < 1 || val > MAX_CX_STATES)
1316 	    return (EINVAL);
1317     }
1318 
1319     ACPI_SERIAL_BEGIN(cpu);
1320     sc->cpu_cx_lowest_lim = val - 1;
1321     acpi_cpu_set_cx_lowest(sc);
1322     ACPI_SERIAL_END(cpu);
1323 
1324     return (0);
1325 }
1326 
1327 static int
1328 acpi_cpu_global_cx_lowest_sysctl(SYSCTL_HANDLER_ARGS)
1329 {
1330     struct	acpi_cpu_softc *sc;
1331     char	state[8];
1332     int		val, error, i;
1333 
1334     snprintf(state, sizeof(state), "C%d", cpu_cx_lowest_lim + 1);
1335     error = sysctl_handle_string(oidp, state, sizeof(state), req);
1336     if (error != 0 || req->newptr == NULL)
1337 	return (error);
1338     if (strlen(state) < 2 || toupper(state[0]) != 'C')
1339 	return (EINVAL);
1340     if (strcasecmp(state, "Cmax") == 0)
1341 	val = MAX_CX_STATES;
1342     else {
1343 	val = (int) strtol(state + 1, NULL, 10);
1344 	if (val < 1 || val > MAX_CX_STATES)
1345 	    return (EINVAL);
1346     }
1347 
1348     /* Update the new lowest useable Cx state for all CPUs. */
1349     ACPI_SERIAL_BEGIN(cpu);
1350     cpu_cx_lowest_lim = val - 1;
1351     for (i = 0; i < cpu_ndevices; i++) {
1352 	sc = device_get_softc(cpu_devices[i]);
1353 	sc->cpu_cx_lowest_lim = cpu_cx_lowest_lim;
1354 	acpi_cpu_set_cx_lowest(sc);
1355     }
1356     ACPI_SERIAL_END(cpu);
1357 
1358     return (0);
1359 }
1360