xref: /freebsd/sys/dev/acpica/acpi_cpu.c (revision c6ec7d31830ab1c80edae95ad5e4b9dba10c47ac)
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(void);
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_set_cx_lowest(struct acpi_cpu_softc *sc);
176 static int	acpi_cpu_cx_lowest_sysctl(SYSCTL_HANDLER_ARGS);
177 static int	acpi_cpu_global_cx_lowest_sysctl(SYSCTL_HANDLER_ARGS);
178 
179 static device_method_t acpi_cpu_methods[] = {
180     /* Device interface */
181     DEVMETHOD(device_probe,	acpi_cpu_probe),
182     DEVMETHOD(device_attach,	acpi_cpu_attach),
183     DEVMETHOD(device_detach,	bus_generic_detach),
184     DEVMETHOD(device_shutdown,	acpi_cpu_shutdown),
185     DEVMETHOD(device_suspend,	acpi_cpu_suspend),
186     DEVMETHOD(device_resume,	acpi_cpu_resume),
187 
188     /* Bus interface */
189     DEVMETHOD(bus_add_child,	acpi_cpu_add_child),
190     DEVMETHOD(bus_read_ivar,	acpi_cpu_read_ivar),
191     DEVMETHOD(bus_get_resource_list, acpi_cpu_get_rlist),
192     DEVMETHOD(bus_get_resource,	bus_generic_rl_get_resource),
193     DEVMETHOD(bus_set_resource,	bus_generic_rl_set_resource),
194     DEVMETHOD(bus_alloc_resource, bus_generic_rl_alloc_resource),
195     DEVMETHOD(bus_release_resource, bus_generic_rl_release_resource),
196     DEVMETHOD(bus_activate_resource, bus_generic_activate_resource),
197     DEVMETHOD(bus_deactivate_resource, bus_generic_deactivate_resource),
198     DEVMETHOD(bus_setup_intr,	bus_generic_setup_intr),
199     DEVMETHOD(bus_teardown_intr, bus_generic_teardown_intr),
200 
201     DEVMETHOD_END
202 };
203 
204 static driver_t acpi_cpu_driver = {
205     "cpu",
206     acpi_cpu_methods,
207     sizeof(struct acpi_cpu_softc),
208 };
209 
210 static devclass_t acpi_cpu_devclass;
211 DRIVER_MODULE(cpu, acpi, acpi_cpu_driver, acpi_cpu_devclass, 0, 0);
212 MODULE_DEPEND(cpu, acpi, 1, 1, 1);
213 
214 static int
215 acpi_cpu_probe(device_t dev)
216 {
217     int			   acpi_id, cpu_id;
218     ACPI_BUFFER		   buf;
219     ACPI_HANDLE		   handle;
220     ACPI_OBJECT		   *obj;
221     ACPI_STATUS		   status;
222 
223     if (acpi_disabled("cpu") || acpi_get_type(dev) != ACPI_TYPE_PROCESSOR)
224 	return (ENXIO);
225 
226     handle = acpi_get_handle(dev);
227     if (cpu_softc == NULL)
228 	cpu_softc = malloc(sizeof(struct acpi_cpu_softc *) *
229 	    (mp_maxid + 1), M_TEMP /* XXX */, M_WAITOK | M_ZERO);
230 
231     /* Get our Processor object. */
232     buf.Pointer = NULL;
233     buf.Length = ACPI_ALLOCATE_BUFFER;
234     status = AcpiEvaluateObject(handle, NULL, NULL, &buf);
235     if (ACPI_FAILURE(status)) {
236 	device_printf(dev, "probe failed to get Processor obj - %s\n",
237 		      AcpiFormatException(status));
238 	return (ENXIO);
239     }
240     obj = (ACPI_OBJECT *)buf.Pointer;
241     if (obj->Type != ACPI_TYPE_PROCESSOR) {
242 	device_printf(dev, "Processor object has bad type %d\n", obj->Type);
243 	AcpiOsFree(obj);
244 	return (ENXIO);
245     }
246 
247     /*
248      * Find the processor associated with our unit.  We could use the
249      * ProcId as a key, however, some boxes do not have the same values
250      * in their Processor object as the ProcId values in the MADT.
251      */
252     acpi_id = obj->Processor.ProcId;
253     AcpiOsFree(obj);
254     if (acpi_pcpu_get_id(dev, &acpi_id, &cpu_id) != 0)
255 	return (ENXIO);
256 
257     /*
258      * Check if we already probed this processor.  We scan the bus twice
259      * so it's possible we've already seen this one.
260      */
261     if (cpu_softc[cpu_id] != NULL)
262 	return (ENXIO);
263 
264     /* Mark this processor as in-use and save our derived id for attach. */
265     cpu_softc[cpu_id] = (void *)1;
266     acpi_set_private(dev, (void*)(intptr_t)cpu_id);
267     device_set_desc(dev, "ACPI CPU");
268 
269     return (0);
270 }
271 
272 static int
273 acpi_cpu_attach(device_t dev)
274 {
275     ACPI_BUFFER		   buf;
276     ACPI_OBJECT		   arg[4], *obj;
277     ACPI_OBJECT_LIST	   arglist;
278     struct pcpu		   *pcpu_data;
279     struct acpi_cpu_softc *sc;
280     struct acpi_softc	  *acpi_sc;
281     ACPI_STATUS		   status;
282     u_int		   features;
283     int			   cpu_id, drv_count, i;
284     driver_t 		  **drivers;
285     uint32_t		   cap_set[3];
286 
287     /* UUID needed by _OSC evaluation */
288     static uint8_t cpu_oscuuid[16] = { 0x16, 0xA6, 0x77, 0x40, 0x0C, 0x29,
289 				       0xBE, 0x47, 0x9E, 0xBD, 0xD8, 0x70,
290 				       0x58, 0x71, 0x39, 0x53 };
291 
292     ACPI_FUNCTION_TRACE((char *)(uintptr_t)__func__);
293 
294     sc = device_get_softc(dev);
295     sc->cpu_dev = dev;
296     sc->cpu_handle = acpi_get_handle(dev);
297     cpu_id = (int)(intptr_t)acpi_get_private(dev);
298     cpu_softc[cpu_id] = sc;
299     pcpu_data = pcpu_find(cpu_id);
300     pcpu_data->pc_device = dev;
301     sc->cpu_pcpu = pcpu_data;
302     cpu_smi_cmd = AcpiGbl_FADT.SmiCommand;
303     cpu_cst_cnt = AcpiGbl_FADT.CstControl;
304 
305     buf.Pointer = NULL;
306     buf.Length = ACPI_ALLOCATE_BUFFER;
307     status = AcpiEvaluateObject(sc->cpu_handle, NULL, NULL, &buf);
308     if (ACPI_FAILURE(status)) {
309 	device_printf(dev, "attach failed to get Processor obj - %s\n",
310 		      AcpiFormatException(status));
311 	return (ENXIO);
312     }
313     obj = (ACPI_OBJECT *)buf.Pointer;
314     sc->cpu_p_blk = obj->Processor.PblkAddress;
315     sc->cpu_p_blk_len = obj->Processor.PblkLength;
316     sc->cpu_acpi_id = obj->Processor.ProcId;
317     AcpiOsFree(obj);
318     ACPI_DEBUG_PRINT((ACPI_DB_INFO, "acpi_cpu%d: P_BLK at %#x/%d\n",
319 		     device_get_unit(dev), sc->cpu_p_blk, sc->cpu_p_blk_len));
320 
321     /*
322      * If this is the first cpu we attach, create and initialize the generic
323      * resources that will be used by all acpi cpu devices.
324      */
325     if (device_get_unit(dev) == 0) {
326 	/* Assume we won't be using generic Cx mode by default */
327 	cpu_cx_generic = FALSE;
328 
329 	/* Install hw.acpi.cpu sysctl tree */
330 	acpi_sc = acpi_device_get_parent_softc(dev);
331 	sysctl_ctx_init(&cpu_sysctl_ctx);
332 	cpu_sysctl_tree = SYSCTL_ADD_NODE(&cpu_sysctl_ctx,
333 	    SYSCTL_CHILDREN(acpi_sc->acpi_sysctl_tree), OID_AUTO, "cpu",
334 	    CTLFLAG_RD, 0, "node for CPU children");
335 
336 	/* Queue post cpu-probing task handler */
337 	AcpiOsExecute(OSL_NOTIFY_HANDLER, acpi_cpu_startup, NULL);
338     }
339 
340     /*
341      * Before calling any CPU methods, collect child driver feature hints
342      * and notify ACPI of them.  We support unified SMP power control
343      * so advertise this ourselves.  Note this is not the same as independent
344      * SMP control where each CPU can have different settings.
345      */
346     sc->cpu_features = ACPI_CAP_SMP_SAME | ACPI_CAP_SMP_SAME_C3;
347     if (devclass_get_drivers(acpi_cpu_devclass, &drivers, &drv_count) == 0) {
348 	for (i = 0; i < drv_count; i++) {
349 	    if (ACPI_GET_FEATURES(drivers[i], &features) == 0)
350 		sc->cpu_features |= features;
351 	}
352 	free(drivers, M_TEMP);
353     }
354 
355     /*
356      * CPU capabilities are specified in
357      * Intel Processor Vendor-Specific ACPI Interface Specification.
358      */
359     if (sc->cpu_features) {
360 	arglist.Pointer = arg;
361 	arglist.Count = 4;
362 	arg[0].Type = ACPI_TYPE_BUFFER;
363 	arg[0].Buffer.Length = sizeof(cpu_oscuuid);
364 	arg[0].Buffer.Pointer = cpu_oscuuid;	/* UUID */
365 	arg[1].Type = ACPI_TYPE_INTEGER;
366 	arg[1].Integer.Value = 1;		/* revision */
367 	arg[2].Type = ACPI_TYPE_INTEGER;
368 	arg[2].Integer.Value = 1;		/* count */
369 	arg[3].Type = ACPI_TYPE_BUFFER;
370 	arg[3].Buffer.Length = sizeof(cap_set);	/* Capabilities buffer */
371 	arg[3].Buffer.Pointer = (uint8_t *)cap_set;
372 	cap_set[0] = 0;				/* status */
373 	cap_set[1] = sc->cpu_features;
374 	status = AcpiEvaluateObject(sc->cpu_handle, "_OSC", &arglist, NULL);
375 	if (ACPI_SUCCESS(status)) {
376 	    if (cap_set[0] != 0)
377 		device_printf(dev, "_OSC returned status %#x\n", cap_set[0]);
378 	}
379 	else {
380 	    arglist.Pointer = arg;
381 	    arglist.Count = 1;
382 	    arg[0].Type = ACPI_TYPE_BUFFER;
383 	    arg[0].Buffer.Length = sizeof(cap_set);
384 	    arg[0].Buffer.Pointer = (uint8_t *)cap_set;
385 	    cap_set[0] = 1; /* revision */
386 	    cap_set[1] = 1; /* number of capabilities integers */
387 	    cap_set[2] = sc->cpu_features;
388 	    AcpiEvaluateObject(sc->cpu_handle, "_PDC", &arglist, NULL);
389 	}
390     }
391 
392     /* Probe for Cx state support. */
393     acpi_cpu_cx_probe(sc);
394 
395     return (0);
396 }
397 
398 static void
399 acpi_cpu_postattach(void *unused __unused)
400 {
401     device_t *devices;
402     int err;
403     int i, n;
404 
405     err = devclass_get_devices(acpi_cpu_devclass, &devices, &n);
406     if (err != 0) {
407 	printf("devclass_get_devices(acpi_cpu_devclass) failed\n");
408 	return;
409     }
410     for (i = 0; i < n; i++)
411 	bus_generic_probe(devices[i]);
412     for (i = 0; i < n; i++)
413 	bus_generic_attach(devices[i]);
414     free(devices, M_TEMP);
415 }
416 
417 SYSINIT(acpi_cpu, SI_SUB_CONFIGURE, SI_ORDER_MIDDLE,
418     acpi_cpu_postattach, NULL);
419 
420 static void
421 disable_idle(struct acpi_cpu_softc *sc)
422 {
423     cpuset_t cpuset;
424 
425     CPU_SETOF(sc->cpu_pcpu->pc_cpuid, &cpuset);
426     sc->cpu_disable_idle = TRUE;
427 
428     /*
429      * Ensure that the CPU is not in idle state or in acpi_cpu_idle().
430      * Note that this code depends on the fact that the rendezvous IPI
431      * can not penetrate context where interrupts are disabled and acpi_cpu_idle
432      * is called and executed in such a context with interrupts being re-enabled
433      * right before return.
434      */
435     smp_rendezvous_cpus(cpuset, smp_no_rendevous_barrier, NULL,
436 	smp_no_rendevous_barrier, NULL);
437 }
438 
439 static void
440 enable_idle(struct acpi_cpu_softc *sc)
441 {
442 
443     sc->cpu_disable_idle = FALSE;
444 }
445 
446 static int
447 is_idle_disabled(struct acpi_cpu_softc *sc)
448 {
449 
450     return (sc->cpu_disable_idle);
451 }
452 
453 /*
454  * Disable any entry to the idle function during suspend and re-enable it
455  * during resume.
456  */
457 static int
458 acpi_cpu_suspend(device_t dev)
459 {
460     int error;
461 
462     error = bus_generic_suspend(dev);
463     if (error)
464 	return (error);
465     disable_idle(device_get_softc(dev));
466     return (0);
467 }
468 
469 static int
470 acpi_cpu_resume(device_t dev)
471 {
472 
473     enable_idle(device_get_softc(dev));
474     return (bus_generic_resume(dev));
475 }
476 
477 /*
478  * Find the processor associated with a given ACPI ID.  By default,
479  * use the MADT to map ACPI IDs to APIC IDs and use that to locate a
480  * processor.  Some systems have inconsistent ASL and MADT however.
481  * For these systems the cpu_unordered tunable can be set in which
482  * case we assume that Processor objects are listed in the same order
483  * in both the MADT and ASL.
484  */
485 static int
486 acpi_pcpu_get_id(device_t dev, uint32_t *acpi_id, uint32_t *cpu_id)
487 {
488     struct pcpu	*pc;
489     uint32_t	 i, idx;
490 
491     KASSERT(acpi_id != NULL, ("Null acpi_id"));
492     KASSERT(cpu_id != NULL, ("Null cpu_id"));
493     idx = device_get_unit(dev);
494 
495     /*
496      * If pc_acpi_id for CPU 0 is not initialized (e.g. a non-APIC
497      * UP box) use the ACPI ID from the first processor we find.
498      */
499     if (idx == 0 && mp_ncpus == 1) {
500 	pc = pcpu_find(0);
501 	if (pc->pc_acpi_id == 0xffffffff)
502 	    pc->pc_acpi_id = *acpi_id;
503 	*cpu_id = 0;
504 	return (0);
505     }
506 
507     CPU_FOREACH(i) {
508 	pc = pcpu_find(i);
509 	KASSERT(pc != NULL, ("no pcpu data for %d", i));
510 	if (cpu_unordered) {
511 	    if (idx-- == 0) {
512 		/*
513 		 * If pc_acpi_id doesn't match the ACPI ID from the
514 		 * ASL, prefer the MADT-derived value.
515 		 */
516 		if (pc->pc_acpi_id != *acpi_id)
517 		    *acpi_id = pc->pc_acpi_id;
518 		*cpu_id = pc->pc_cpuid;
519 		return (0);
520 	    }
521 	} else {
522 	    if (pc->pc_acpi_id == *acpi_id) {
523 		if (bootverbose)
524 		    device_printf(dev,
525 			"Processor %s (ACPI ID %u) -> APIC ID %d\n",
526 			acpi_name(acpi_get_handle(dev)), *acpi_id,
527 			pc->pc_cpuid);
528 		*cpu_id = pc->pc_cpuid;
529 		return (0);
530 	    }
531 	}
532     }
533 
534     if (bootverbose)
535 	printf("ACPI: Processor %s (ACPI ID %u) ignored\n",
536 	    acpi_name(acpi_get_handle(dev)), *acpi_id);
537 
538     return (ESRCH);
539 }
540 
541 static struct resource_list *
542 acpi_cpu_get_rlist(device_t dev, device_t child)
543 {
544     struct acpi_cpu_device *ad;
545 
546     ad = device_get_ivars(child);
547     if (ad == NULL)
548 	return (NULL);
549     return (&ad->ad_rl);
550 }
551 
552 static device_t
553 acpi_cpu_add_child(device_t dev, u_int order, const char *name, int unit)
554 {
555     struct acpi_cpu_device *ad;
556     device_t child;
557 
558     if ((ad = malloc(sizeof(*ad), M_TEMP, M_NOWAIT | M_ZERO)) == NULL)
559 	return (NULL);
560 
561     resource_list_init(&ad->ad_rl);
562 
563     child = device_add_child_ordered(dev, order, name, unit);
564     if (child != NULL)
565 	device_set_ivars(child, ad);
566     else
567 	free(ad, M_TEMP);
568     return (child);
569 }
570 
571 static int
572 acpi_cpu_read_ivar(device_t dev, device_t child, int index, uintptr_t *result)
573 {
574     struct acpi_cpu_softc *sc;
575 
576     sc = device_get_softc(dev);
577     switch (index) {
578     case ACPI_IVAR_HANDLE:
579 	*result = (uintptr_t)sc->cpu_handle;
580 	break;
581     case CPU_IVAR_PCPU:
582 	*result = (uintptr_t)sc->cpu_pcpu;
583 	break;
584 #if defined(__amd64__) || defined(__i386__)
585     case CPU_IVAR_NOMINAL_MHZ:
586 	if (tsc_is_invariant) {
587 	    *result = (uintptr_t)(atomic_load_acq_64(&tsc_freq) / 1000000);
588 	    break;
589 	}
590 	/* FALLTHROUGH */
591 #endif
592     default:
593 	return (ENOENT);
594     }
595     return (0);
596 }
597 
598 static int
599 acpi_cpu_shutdown(device_t dev)
600 {
601     ACPI_FUNCTION_TRACE((char *)(uintptr_t)__func__);
602 
603     /* Allow children to shutdown first. */
604     bus_generic_shutdown(dev);
605 
606     /*
607      * Disable any entry to the idle function.
608      */
609     disable_idle(device_get_softc(dev));
610 
611     /*
612      * CPU devices are not truely detached and remain referenced,
613      * so their resources are not freed.
614      */
615 
616     return_VALUE (0);
617 }
618 
619 static void
620 acpi_cpu_cx_probe(struct acpi_cpu_softc *sc)
621 {
622     ACPI_FUNCTION_TRACE((char *)(uintptr_t)__func__);
623 
624     /* Use initial sleep value of 1 sec. to start with lowest idle state. */
625     sc->cpu_prev_sleep = 1000000;
626     sc->cpu_cx_lowest = 0;
627     sc->cpu_cx_lowest_lim = 0;
628 
629     /*
630      * Check for the ACPI 2.0 _CST sleep states object. If we can't find
631      * any, we'll revert to generic FADT/P_BLK Cx control method which will
632      * be handled by acpi_cpu_startup. We need to defer to after having
633      * probed all the cpus in the system before probing for generic Cx
634      * states as we may already have found cpus with valid _CST packages
635      */
636     if (!cpu_cx_generic && acpi_cpu_cx_cst(sc) != 0) {
637 	/*
638 	 * We were unable to find a _CST package for this cpu or there
639 	 * was an error parsing it. Switch back to generic mode.
640 	 */
641 	cpu_cx_generic = TRUE;
642 	if (bootverbose)
643 	    device_printf(sc->cpu_dev, "switching to generic Cx mode\n");
644     }
645 
646     /*
647      * TODO: _CSD Package should be checked here.
648      */
649 }
650 
651 static void
652 acpi_cpu_generic_cx_probe(struct acpi_cpu_softc *sc)
653 {
654     ACPI_GENERIC_ADDRESS	 gas;
655     struct acpi_cx		*cx_ptr;
656 
657     sc->cpu_cx_count = 0;
658     cx_ptr = sc->cpu_cx_states;
659 
660     /* Use initial sleep value of 1 sec. to start with lowest idle state. */
661     sc->cpu_prev_sleep = 1000000;
662 
663     /* C1 has been required since just after ACPI 1.0 */
664     cx_ptr->type = ACPI_STATE_C1;
665     cx_ptr->trans_lat = 0;
666     cx_ptr++;
667     sc->cpu_non_c3 = sc->cpu_cx_count;
668     sc->cpu_cx_count++;
669 
670     /*
671      * The spec says P_BLK must be 6 bytes long.  However, some systems
672      * use it to indicate a fractional set of features present so we
673      * take 5 as C2.  Some may also have a value of 7 to indicate
674      * another C3 but most use _CST for this (as required) and having
675      * "only" C1-C3 is not a hardship.
676      */
677     if (sc->cpu_p_blk_len < 5)
678 	return;
679 
680     /* Validate and allocate resources for C2 (P_LVL2). */
681     gas.SpaceId = ACPI_ADR_SPACE_SYSTEM_IO;
682     gas.BitWidth = 8;
683     if (AcpiGbl_FADT.C2Latency <= 100) {
684 	gas.Address = sc->cpu_p_blk + 4;
685 	cx_ptr->res_rid = 0;
686 	acpi_bus_alloc_gas(sc->cpu_dev, &cx_ptr->res_type, &cx_ptr->res_rid,
687 	    &gas, &cx_ptr->p_lvlx, RF_SHAREABLE);
688 	if (cx_ptr->p_lvlx != NULL) {
689 	    cx_ptr->type = ACPI_STATE_C2;
690 	    cx_ptr->trans_lat = AcpiGbl_FADT.C2Latency;
691 	    cx_ptr++;
692 	    sc->cpu_non_c3 = sc->cpu_cx_count;
693 	    sc->cpu_cx_count++;
694 	}
695     }
696     if (sc->cpu_p_blk_len < 6)
697 	return;
698 
699     /* Validate and allocate resources for C3 (P_LVL3). */
700     if (AcpiGbl_FADT.C3Latency <= 1000 && !(cpu_quirks & CPU_QUIRK_NO_C3)) {
701 	gas.Address = sc->cpu_p_blk + 5;
702 	cx_ptr->res_rid = 1;
703 	acpi_bus_alloc_gas(sc->cpu_dev, &cx_ptr->res_type, &cx_ptr->res_rid,
704 	    &gas, &cx_ptr->p_lvlx, RF_SHAREABLE);
705 	if (cx_ptr->p_lvlx != NULL) {
706 	    cx_ptr->type = ACPI_STATE_C3;
707 	    cx_ptr->trans_lat = AcpiGbl_FADT.C3Latency;
708 	    cx_ptr++;
709 	    sc->cpu_cx_count++;
710 	    cpu_can_deep_sleep = 1;
711 	}
712     }
713 }
714 
715 /*
716  * Parse a _CST package and set up its Cx states.  Since the _CST object
717  * can change dynamically, our notify handler may call this function
718  * to clean up and probe the new _CST package.
719  */
720 static int
721 acpi_cpu_cx_cst(struct acpi_cpu_softc *sc)
722 {
723     struct	 acpi_cx *cx_ptr;
724     ACPI_STATUS	 status;
725     ACPI_BUFFER	 buf;
726     ACPI_OBJECT	*top;
727     ACPI_OBJECT	*pkg;
728     uint32_t	 count;
729     int		 i;
730 
731     ACPI_FUNCTION_TRACE((char *)(uintptr_t)__func__);
732 
733     buf.Pointer = NULL;
734     buf.Length = ACPI_ALLOCATE_BUFFER;
735     status = AcpiEvaluateObject(sc->cpu_handle, "_CST", NULL, &buf);
736     if (ACPI_FAILURE(status))
737 	return (ENXIO);
738 
739     /* _CST is a package with a count and at least one Cx package. */
740     top = (ACPI_OBJECT *)buf.Pointer;
741     if (!ACPI_PKG_VALID(top, 2) || acpi_PkgInt32(top, 0, &count) != 0) {
742 	device_printf(sc->cpu_dev, "invalid _CST package\n");
743 	AcpiOsFree(buf.Pointer);
744 	return (ENXIO);
745     }
746     if (count != top->Package.Count - 1) {
747 	device_printf(sc->cpu_dev, "invalid _CST state count (%d != %d)\n",
748 	       count, top->Package.Count - 1);
749 	count = top->Package.Count - 1;
750     }
751     if (count > MAX_CX_STATES) {
752 	device_printf(sc->cpu_dev, "_CST has too many states (%d)\n", count);
753 	count = MAX_CX_STATES;
754     }
755 
756     sc->cpu_non_c3 = 0;
757     sc->cpu_cx_count = 0;
758     cx_ptr = sc->cpu_cx_states;
759 
760     /*
761      * C1 has been required since just after ACPI 1.0.
762      * Reserve the first slot for it.
763      */
764     cx_ptr->type = ACPI_STATE_C0;
765     cx_ptr++;
766     sc->cpu_cx_count++;
767 
768     /* Set up all valid states. */
769     for (i = 0; i < count; i++) {
770 	pkg = &top->Package.Elements[i + 1];
771 	if (!ACPI_PKG_VALID(pkg, 4) ||
772 	    acpi_PkgInt32(pkg, 1, &cx_ptr->type) != 0 ||
773 	    acpi_PkgInt32(pkg, 2, &cx_ptr->trans_lat) != 0 ||
774 	    acpi_PkgInt32(pkg, 3, &cx_ptr->power) != 0) {
775 
776 	    device_printf(sc->cpu_dev, "skipping invalid Cx state package\n");
777 	    continue;
778 	}
779 
780 	/* Validate the state to see if we should use it. */
781 	switch (cx_ptr->type) {
782 	case ACPI_STATE_C1:
783 	    if (sc->cpu_cx_states[0].type == ACPI_STATE_C0) {
784 		/* This is the first C1 state.  Use the reserved slot. */
785 		sc->cpu_cx_states[0] = *cx_ptr;
786 	    } else {
787 		sc->cpu_non_c3 = sc->cpu_cx_count;
788 		cx_ptr++;
789 		sc->cpu_cx_count++;
790 	    }
791 	    continue;
792 	case ACPI_STATE_C2:
793 	    sc->cpu_non_c3 = sc->cpu_cx_count;
794 	    break;
795 	case ACPI_STATE_C3:
796 	default:
797 	    if ((cpu_quirks & CPU_QUIRK_NO_C3) != 0) {
798 		ACPI_DEBUG_PRINT((ACPI_DB_INFO,
799 				 "acpi_cpu%d: C3[%d] not available.\n",
800 				 device_get_unit(sc->cpu_dev), i));
801 		continue;
802 	    } else
803 		cpu_can_deep_sleep = 1;
804 	    break;
805 	}
806 
807 	/* Free up any previous register. */
808 	if (cx_ptr->p_lvlx != NULL) {
809 	    bus_release_resource(sc->cpu_dev, cx_ptr->res_type, cx_ptr->res_rid,
810 	        cx_ptr->p_lvlx);
811 	    cx_ptr->p_lvlx = NULL;
812 	}
813 
814 	/* Allocate the control register for C2 or C3. */
815 	cx_ptr->res_rid = sc->cpu_cx_count;
816 	acpi_PkgGas(sc->cpu_dev, pkg, 0, &cx_ptr->res_type, &cx_ptr->res_rid,
817 	    &cx_ptr->p_lvlx, RF_SHAREABLE);
818 	if (cx_ptr->p_lvlx) {
819 	    ACPI_DEBUG_PRINT((ACPI_DB_INFO,
820 			     "acpi_cpu%d: Got C%d - %d latency\n",
821 			     device_get_unit(sc->cpu_dev), cx_ptr->type,
822 			     cx_ptr->trans_lat));
823 	    cx_ptr++;
824 	    sc->cpu_cx_count++;
825 	}
826     }
827     AcpiOsFree(buf.Pointer);
828 
829     /* If C1 state was not found, we need one now. */
830     cx_ptr = sc->cpu_cx_states;
831     if (cx_ptr->type == ACPI_STATE_C0) {
832 	cx_ptr->type = ACPI_STATE_C1;
833 	cx_ptr->trans_lat = 0;
834     }
835 
836     return (0);
837 }
838 
839 /*
840  * Call this *after* all CPUs have been attached.
841  */
842 static void
843 acpi_cpu_startup(void *arg)
844 {
845     struct acpi_cpu_softc *sc;
846     int i;
847 
848     /* Get set of CPU devices */
849     devclass_get_devices(acpi_cpu_devclass, &cpu_devices, &cpu_ndevices);
850 
851     /*
852      * Setup any quirks that might necessary now that we have probed
853      * all the CPUs
854      */
855     acpi_cpu_quirks();
856 
857     if (cpu_cx_generic) {
858 	/*
859 	 * We are using generic Cx mode, probe for available Cx states
860 	 * for all processors.
861 	 */
862 	for (i = 0; i < cpu_ndevices; i++) {
863 	    sc = device_get_softc(cpu_devices[i]);
864 	    acpi_cpu_generic_cx_probe(sc);
865 	}
866     } else {
867 	/*
868 	 * We are using _CST mode, remove C3 state if necessary.
869 	 * As we now know for sure that we will be using _CST mode
870 	 * install our notify handler.
871 	 */
872 	for (i = 0; i < cpu_ndevices; i++) {
873 	    sc = device_get_softc(cpu_devices[i]);
874 	    if (cpu_quirks & CPU_QUIRK_NO_C3) {
875 		sc->cpu_cx_count = sc->cpu_non_c3 + 1;
876 	    }
877 	    AcpiInstallNotifyHandler(sc->cpu_handle, ACPI_DEVICE_NOTIFY,
878 		acpi_cpu_notify, sc);
879 	}
880     }
881 
882     /* Perform Cx final initialization. */
883     for (i = 0; i < cpu_ndevices; i++) {
884 	sc = device_get_softc(cpu_devices[i]);
885 	acpi_cpu_startup_cx(sc);
886     }
887 
888     /* Add a sysctl handler to handle global Cx lowest setting */
889     SYSCTL_ADD_PROC(&cpu_sysctl_ctx, SYSCTL_CHILDREN(cpu_sysctl_tree),
890 	OID_AUTO, "cx_lowest", CTLTYPE_STRING | CTLFLAG_RW,
891 	NULL, 0, acpi_cpu_global_cx_lowest_sysctl, "A",
892 	"Global lowest Cx sleep state to use");
893 
894     /* Take over idling from cpu_idle_default(). */
895     cpu_cx_lowest_lim = 0;
896     for (i = 0; i < cpu_ndevices; i++) {
897 	sc = device_get_softc(cpu_devices[i]);
898 	enable_idle(sc);
899     }
900     cpu_idle_hook = acpi_cpu_idle;
901 }
902 
903 static void
904 acpi_cpu_cx_list(struct acpi_cpu_softc *sc)
905 {
906     struct sbuf sb;
907     int i;
908 
909     /*
910      * Set up the list of Cx states
911      */
912     sbuf_new(&sb, sc->cpu_cx_supported, sizeof(sc->cpu_cx_supported),
913 	SBUF_FIXEDLEN);
914     for (i = 0; i < sc->cpu_cx_count; i++)
915 	sbuf_printf(&sb, "C%d/%d/%d ", i + 1, sc->cpu_cx_states[i].type,
916 	    sc->cpu_cx_states[i].trans_lat);
917     sbuf_trim(&sb);
918     sbuf_finish(&sb);
919 }
920 
921 static void
922 acpi_cpu_startup_cx(struct acpi_cpu_softc *sc)
923 {
924     acpi_cpu_cx_list(sc);
925 
926     SYSCTL_ADD_STRING(&sc->cpu_sysctl_ctx,
927 		      SYSCTL_CHILDREN(device_get_sysctl_tree(sc->cpu_dev)),
928 		      OID_AUTO, "cx_supported", CTLFLAG_RD,
929 		      sc->cpu_cx_supported, 0,
930 		      "Cx/microsecond values for supported Cx states");
931     SYSCTL_ADD_PROC(&sc->cpu_sysctl_ctx,
932 		    SYSCTL_CHILDREN(device_get_sysctl_tree(sc->cpu_dev)),
933 		    OID_AUTO, "cx_lowest", CTLTYPE_STRING | CTLFLAG_RW,
934 		    (void *)sc, 0, acpi_cpu_cx_lowest_sysctl, "A",
935 		    "lowest Cx sleep state to use");
936     SYSCTL_ADD_PROC(&sc->cpu_sysctl_ctx,
937 		    SYSCTL_CHILDREN(device_get_sysctl_tree(sc->cpu_dev)),
938 		    OID_AUTO, "cx_usage", CTLTYPE_STRING | CTLFLAG_RD,
939 		    (void *)sc, 0, acpi_cpu_usage_sysctl, "A",
940 		    "percent usage for each Cx state");
941 
942     /* Signal platform that we can handle _CST notification. */
943     if (!cpu_cx_generic && cpu_cst_cnt != 0) {
944 	ACPI_LOCK(acpi);
945 	AcpiOsWritePort(cpu_smi_cmd, cpu_cst_cnt, 8);
946 	ACPI_UNLOCK(acpi);
947     }
948 }
949 
950 /*
951  * Idle the CPU in the lowest state possible.  This function is called with
952  * interrupts disabled.  Note that once it re-enables interrupts, a task
953  * switch can occur so do not access shared data (i.e. the softc) after
954  * interrupts are re-enabled.
955  */
956 static void
957 acpi_cpu_idle()
958 {
959     struct	acpi_cpu_softc *sc;
960     struct	acpi_cx *cx_next;
961     uint64_t	cputicks;
962     uint32_t	start_time, end_time;
963     int		bm_active, cx_next_idx, i;
964 
965     /*
966      * Look up our CPU id to get our softc.  If it's NULL, we'll use C1
967      * since there is no ACPI processor object for this CPU.  This occurs
968      * for logical CPUs in the HTT case.
969      */
970     sc = cpu_softc[PCPU_GET(cpuid)];
971     if (sc == NULL) {
972 	acpi_cpu_c1();
973 	return;
974     }
975 
976     /* If disabled, take the safe path. */
977     if (is_idle_disabled(sc)) {
978 	acpi_cpu_c1();
979 	return;
980     }
981 
982     /* Find the lowest state that has small enough latency. */
983     cx_next_idx = 0;
984     if (cpu_disable_deep_sleep)
985 	i = min(sc->cpu_cx_lowest, sc->cpu_non_c3);
986     else
987 	i = sc->cpu_cx_lowest;
988     for (; i >= 0; i--) {
989 	if (sc->cpu_cx_states[i].trans_lat * 3 <= sc->cpu_prev_sleep) {
990 	    cx_next_idx = i;
991 	    break;
992 	}
993     }
994 
995     /*
996      * Check for bus master activity.  If there was activity, clear
997      * the bit and use the lowest non-C3 state.  Note that the USB
998      * driver polling for new devices keeps this bit set all the
999      * time if USB is loaded.
1000      */
1001     if ((cpu_quirks & CPU_QUIRK_NO_BM_CTRL) == 0 &&
1002 	cx_next_idx > sc->cpu_non_c3) {
1003 	AcpiReadBitRegister(ACPI_BITREG_BUS_MASTER_STATUS, &bm_active);
1004 	if (bm_active != 0) {
1005 	    AcpiWriteBitRegister(ACPI_BITREG_BUS_MASTER_STATUS, 1);
1006 	    cx_next_idx = sc->cpu_non_c3;
1007 	}
1008     }
1009 
1010     /* Select the next state and update statistics. */
1011     cx_next = &sc->cpu_cx_states[cx_next_idx];
1012     sc->cpu_cx_stats[cx_next_idx]++;
1013     KASSERT(cx_next->type != ACPI_STATE_C0, ("acpi_cpu_idle: C0 sleep"));
1014 
1015     /*
1016      * Execute HLT (or equivalent) and wait for an interrupt.  We can't
1017      * precisely calculate the time spent in C1 since the place we wake up
1018      * is an ISR.  Assume we slept no more then half of quantum, unless
1019      * we are called inside critical section, delaying context switch.
1020      */
1021     if (cx_next->type == ACPI_STATE_C1) {
1022 	cputicks = cpu_ticks();
1023 	acpi_cpu_c1();
1024 	end_time = ((cpu_ticks() - cputicks) << 20) / cpu_tickrate();
1025 	if (curthread->td_critnest == 0)
1026 		end_time = min(end_time, 500000 / hz);
1027 	sc->cpu_prev_sleep = (sc->cpu_prev_sleep * 3 + end_time) / 4;
1028 	return;
1029     }
1030 
1031     /*
1032      * For C3, disable bus master arbitration and enable bus master wake
1033      * if BM control is available, otherwise flush the CPU cache.
1034      */
1035     if (cx_next->type == ACPI_STATE_C3) {
1036 	if ((cpu_quirks & CPU_QUIRK_NO_BM_CTRL) == 0) {
1037 	    AcpiWriteBitRegister(ACPI_BITREG_ARB_DISABLE, 1);
1038 	    AcpiWriteBitRegister(ACPI_BITREG_BUS_MASTER_RLD, 1);
1039 	} else
1040 	    ACPI_FLUSH_CPU_CACHE();
1041     }
1042 
1043     /*
1044      * Read from P_LVLx to enter C2(+), checking time spent asleep.
1045      * Use the ACPI timer for measuring sleep time.  Since we need to
1046      * get the time very close to the CPU start/stop clock logic, this
1047      * is the only reliable time source.
1048      */
1049     if (cx_next->type == ACPI_STATE_C3) {
1050 	AcpiHwRead(&start_time, &AcpiGbl_FADT.XPmTimerBlock);
1051 	cputicks = 0;
1052     } else {
1053 	start_time = 0;
1054 	cputicks = cpu_ticks();
1055     }
1056     CPU_GET_REG(cx_next->p_lvlx, 1);
1057 
1058     /*
1059      * Read the end time twice.  Since it may take an arbitrary time
1060      * to enter the idle state, the first read may be executed before
1061      * the processor has stopped.  Doing it again provides enough
1062      * margin that we are certain to have a correct value.
1063      */
1064     AcpiHwRead(&end_time, &AcpiGbl_FADT.XPmTimerBlock);
1065     if (cx_next->type == ACPI_STATE_C3) {
1066 	AcpiHwRead(&end_time, &AcpiGbl_FADT.XPmTimerBlock);
1067 	end_time = acpi_TimerDelta(end_time, start_time);
1068     } else
1069 	end_time = ((cpu_ticks() - cputicks) << 20) / cpu_tickrate();
1070 
1071     /* Enable bus master arbitration and disable bus master wakeup. */
1072     if (cx_next->type == ACPI_STATE_C3 &&
1073 	(cpu_quirks & CPU_QUIRK_NO_BM_CTRL) == 0) {
1074 	AcpiWriteBitRegister(ACPI_BITREG_ARB_DISABLE, 0);
1075 	AcpiWriteBitRegister(ACPI_BITREG_BUS_MASTER_RLD, 0);
1076     }
1077     ACPI_ENABLE_IRQS();
1078 
1079     sc->cpu_prev_sleep = (sc->cpu_prev_sleep * 3 + PM_USEC(end_time)) / 4;
1080 }
1081 
1082 /*
1083  * Re-evaluate the _CST object when we are notified that it changed.
1084  */
1085 static void
1086 acpi_cpu_notify(ACPI_HANDLE h, UINT32 notify, void *context)
1087 {
1088     struct acpi_cpu_softc *sc = (struct acpi_cpu_softc *)context;
1089 
1090     if (notify != ACPI_NOTIFY_CX_STATES)
1091 	return;
1092 
1093     /*
1094      * C-state data for target CPU is going to be in flux while we execute
1095      * acpi_cpu_cx_cst, so disable entering acpi_cpu_idle.
1096      * Also, it may happen that multiple ACPI taskqueues may concurrently
1097      * execute notifications for the same CPU.  ACPI_SERIAL is used to
1098      * protect against that.
1099      */
1100     ACPI_SERIAL_BEGIN(cpu);
1101     disable_idle(sc);
1102 
1103     /* Update the list of Cx states. */
1104     acpi_cpu_cx_cst(sc);
1105     acpi_cpu_cx_list(sc);
1106     acpi_cpu_set_cx_lowest(sc);
1107 
1108     enable_idle(sc);
1109     ACPI_SERIAL_END(cpu);
1110 
1111     acpi_UserNotify("PROCESSOR", sc->cpu_handle, notify);
1112 }
1113 
1114 static int
1115 acpi_cpu_quirks(void)
1116 {
1117     device_t acpi_dev;
1118     uint32_t val;
1119 
1120     ACPI_FUNCTION_TRACE((char *)(uintptr_t)__func__);
1121 
1122     /*
1123      * Bus mastering arbitration control is needed to keep caches coherent
1124      * while sleeping in C3.  If it's not present but a working flush cache
1125      * instruction is present, flush the caches before entering C3 instead.
1126      * Otherwise, just disable C3 completely.
1127      */
1128     if (AcpiGbl_FADT.Pm2ControlBlock == 0 ||
1129 	AcpiGbl_FADT.Pm2ControlLength == 0) {
1130 	if ((AcpiGbl_FADT.Flags & ACPI_FADT_WBINVD) &&
1131 	    (AcpiGbl_FADT.Flags & ACPI_FADT_WBINVD_FLUSH) == 0) {
1132 	    cpu_quirks |= CPU_QUIRK_NO_BM_CTRL;
1133 	    ACPI_DEBUG_PRINT((ACPI_DB_INFO,
1134 		"acpi_cpu: no BM control, using flush cache method\n"));
1135 	} else {
1136 	    cpu_quirks |= CPU_QUIRK_NO_C3;
1137 	    ACPI_DEBUG_PRINT((ACPI_DB_INFO,
1138 		"acpi_cpu: no BM control, C3 not available\n"));
1139 	}
1140     }
1141 
1142     /*
1143      * If we are using generic Cx mode, C3 on multiple CPUs requires using
1144      * the expensive flush cache instruction.
1145      */
1146     if (cpu_cx_generic && mp_ncpus > 1) {
1147 	cpu_quirks |= CPU_QUIRK_NO_BM_CTRL;
1148 	ACPI_DEBUG_PRINT((ACPI_DB_INFO,
1149 	    "acpi_cpu: SMP, using flush cache mode for C3\n"));
1150     }
1151 
1152     /* Look for various quirks of the PIIX4 part. */
1153     acpi_dev = pci_find_device(PCI_VENDOR_INTEL, PCI_DEVICE_82371AB_3);
1154     if (acpi_dev != NULL) {
1155 	switch (pci_get_revid(acpi_dev)) {
1156 	/*
1157 	 * Disable C3 support for all PIIX4 chipsets.  Some of these parts
1158 	 * do not report the BMIDE status to the BM status register and
1159 	 * others have a livelock bug if Type-F DMA is enabled.  Linux
1160 	 * works around the BMIDE bug by reading the BM status directly
1161 	 * but we take the simpler approach of disabling C3 for these
1162 	 * parts.
1163 	 *
1164 	 * See erratum #18 ("C3 Power State/BMIDE and Type-F DMA
1165 	 * Livelock") from the January 2002 PIIX4 specification update.
1166 	 * Applies to all PIIX4 models.
1167 	 *
1168 	 * Also, make sure that all interrupts cause a "Stop Break"
1169 	 * event to exit from C2 state.
1170 	 * Also, BRLD_EN_BM (ACPI_BITREG_BUS_MASTER_RLD in ACPI-speak)
1171 	 * should be set to zero, otherwise it causes C2 to short-sleep.
1172 	 * PIIX4 doesn't properly support C3 and bus master activity
1173 	 * need not break out of C2.
1174 	 */
1175 	case PCI_REVISION_A_STEP:
1176 	case PCI_REVISION_B_STEP:
1177 	case PCI_REVISION_4E:
1178 	case PCI_REVISION_4M:
1179 	    cpu_quirks |= CPU_QUIRK_NO_C3;
1180 	    ACPI_DEBUG_PRINT((ACPI_DB_INFO,
1181 		"acpi_cpu: working around PIIX4 bug, disabling C3\n"));
1182 
1183 	    val = pci_read_config(acpi_dev, PIIX4_DEVACTB_REG, 4);
1184 	    if ((val & PIIX4_STOP_BREAK_MASK) != PIIX4_STOP_BREAK_MASK) {
1185 		ACPI_DEBUG_PRINT((ACPI_DB_INFO,
1186 		    "acpi_cpu: PIIX4: enabling IRQs to generate Stop Break\n"));
1187 	    	val |= PIIX4_STOP_BREAK_MASK;
1188 		pci_write_config(acpi_dev, PIIX4_DEVACTB_REG, val, 4);
1189 	    }
1190 	    AcpiReadBitRegister(ACPI_BITREG_BUS_MASTER_RLD, &val);
1191 	    if (val) {
1192 		ACPI_DEBUG_PRINT((ACPI_DB_INFO,
1193 		    "acpi_cpu: PIIX4: reset BRLD_EN_BM\n"));
1194 		AcpiWriteBitRegister(ACPI_BITREG_BUS_MASTER_RLD, 0);
1195 	    }
1196 	    break;
1197 	default:
1198 	    break;
1199 	}
1200     }
1201 
1202     return (0);
1203 }
1204 
1205 static int
1206 acpi_cpu_usage_sysctl(SYSCTL_HANDLER_ARGS)
1207 {
1208     struct acpi_cpu_softc *sc;
1209     struct sbuf	 sb;
1210     char	 buf[128];
1211     int		 i;
1212     uintmax_t	 fract, sum, whole;
1213 
1214     sc = (struct acpi_cpu_softc *) arg1;
1215     sum = 0;
1216     for (i = 0; i < sc->cpu_cx_count; i++)
1217 	sum += sc->cpu_cx_stats[i];
1218     sbuf_new(&sb, buf, sizeof(buf), SBUF_FIXEDLEN);
1219     for (i = 0; i < sc->cpu_cx_count; i++) {
1220 	if (sum > 0) {
1221 	    whole = (uintmax_t)sc->cpu_cx_stats[i] * 100;
1222 	    fract = (whole % sum) * 100;
1223 	    sbuf_printf(&sb, "%u.%02u%% ", (u_int)(whole / sum),
1224 		(u_int)(fract / sum));
1225 	} else
1226 	    sbuf_printf(&sb, "0.00%% ");
1227     }
1228     sbuf_printf(&sb, "last %dus", sc->cpu_prev_sleep);
1229     sbuf_trim(&sb);
1230     sbuf_finish(&sb);
1231     sysctl_handle_string(oidp, sbuf_data(&sb), sbuf_len(&sb), req);
1232     sbuf_delete(&sb);
1233 
1234     return (0);
1235 }
1236 
1237 static int
1238 acpi_cpu_set_cx_lowest(struct acpi_cpu_softc *sc)
1239 {
1240     int i;
1241 
1242     ACPI_SERIAL_ASSERT(cpu);
1243     sc->cpu_cx_lowest = min(sc->cpu_cx_lowest_lim, sc->cpu_cx_count - 1);
1244 
1245     /* If not disabling, cache the new lowest non-C3 state. */
1246     sc->cpu_non_c3 = 0;
1247     for (i = sc->cpu_cx_lowest; i >= 0; i--) {
1248 	if (sc->cpu_cx_states[i].type < ACPI_STATE_C3) {
1249 	    sc->cpu_non_c3 = i;
1250 	    break;
1251 	}
1252     }
1253 
1254     /* Reset the statistics counters. */
1255     bzero(sc->cpu_cx_stats, sizeof(sc->cpu_cx_stats));
1256     return (0);
1257 }
1258 
1259 static int
1260 acpi_cpu_cx_lowest_sysctl(SYSCTL_HANDLER_ARGS)
1261 {
1262     struct	 acpi_cpu_softc *sc;
1263     char	 state[8];
1264     int		 val, error;
1265 
1266     sc = (struct acpi_cpu_softc *) arg1;
1267     snprintf(state, sizeof(state), "C%d", sc->cpu_cx_lowest_lim + 1);
1268     error = sysctl_handle_string(oidp, state, sizeof(state), req);
1269     if (error != 0 || req->newptr == NULL)
1270 	return (error);
1271     if (strlen(state) < 2 || toupper(state[0]) != 'C')
1272 	return (EINVAL);
1273     if (strcasecmp(state, "Cmax") == 0)
1274 	val = MAX_CX_STATES;
1275     else {
1276 	val = (int) strtol(state + 1, NULL, 10);
1277 	if (val < 1 || val > MAX_CX_STATES)
1278 	    return (EINVAL);
1279     }
1280 
1281     ACPI_SERIAL_BEGIN(cpu);
1282     sc->cpu_cx_lowest_lim = val - 1;
1283     acpi_cpu_set_cx_lowest(sc);
1284     ACPI_SERIAL_END(cpu);
1285 
1286     return (0);
1287 }
1288 
1289 static int
1290 acpi_cpu_global_cx_lowest_sysctl(SYSCTL_HANDLER_ARGS)
1291 {
1292     struct	acpi_cpu_softc *sc;
1293     char	state[8];
1294     int		val, error, i;
1295 
1296     snprintf(state, sizeof(state), "C%d", cpu_cx_lowest_lim + 1);
1297     error = sysctl_handle_string(oidp, state, sizeof(state), req);
1298     if (error != 0 || req->newptr == NULL)
1299 	return (error);
1300     if (strlen(state) < 2 || toupper(state[0]) != 'C')
1301 	return (EINVAL);
1302     if (strcasecmp(state, "Cmax") == 0)
1303 	val = MAX_CX_STATES;
1304     else {
1305 	val = (int) strtol(state + 1, NULL, 10);
1306 	if (val < 1 || val > MAX_CX_STATES)
1307 	    return (EINVAL);
1308     }
1309 
1310     /* Update the new lowest useable Cx state for all CPUs. */
1311     ACPI_SERIAL_BEGIN(cpu);
1312     cpu_cx_lowest_lim = val - 1;
1313     for (i = 0; i < cpu_ndevices; i++) {
1314 	sc = device_get_softc(cpu_devices[i]);
1315 	sc->cpu_cx_lowest_lim = cpu_cx_lowest_lim;
1316 	acpi_cpu_set_cx_lowest(sc);
1317     }
1318     ACPI_SERIAL_END(cpu);
1319 
1320     return (0);
1321 }
1322