xref: /freebsd/sys/dev/acpica/acpi_cpu.c (revision 2a2234c0f41da33b8cfc938e46b54a8234b64135)
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 #include <machine/specialreg.h>
51 #include <machine/md_var.h>
52 #endif
53 #include <sys/rman.h>
54 
55 #include <contrib/dev/acpica/include/acpi.h>
56 #include <contrib/dev/acpica/include/accommon.h>
57 
58 #include <dev/acpica/acpivar.h>
59 
60 /*
61  * Support for ACPI Processor devices, including C[1-3] sleep states.
62  */
63 
64 /* Hooks for the ACPI CA debugging infrastructure */
65 #define _COMPONENT	ACPI_PROCESSOR
66 ACPI_MODULE_NAME("PROCESSOR")
67 
68 struct acpi_cx {
69     struct resource	*p_lvlx;	/* Register to read to enter state. */
70     uint32_t		 type;		/* C1-3 (C4 and up treated as C3). */
71     uint32_t		 trans_lat;	/* Transition latency (usec). */
72     uint32_t		 power;		/* Power consumed (mW). */
73     int			 res_type;	/* Resource type for p_lvlx. */
74     int			 res_rid;	/* Resource ID for p_lvlx. */
75     bool		 do_mwait;
76     uint32_t		 mwait_hint;
77     bool		 mwait_hw_coord;
78     bool		 mwait_bm_avoidance;
79 };
80 #define MAX_CX_STATES	 8
81 
82 struct acpi_cpu_softc {
83     device_t		 cpu_dev;
84     ACPI_HANDLE		 cpu_handle;
85     struct pcpu		*cpu_pcpu;
86     uint32_t		 cpu_acpi_id;	/* ACPI processor id */
87     uint32_t		 cpu_p_blk;	/* ACPI P_BLK location */
88     uint32_t		 cpu_p_blk_len;	/* P_BLK length (must be 6). */
89     struct acpi_cx	 cpu_cx_states[MAX_CX_STATES];
90     int			 cpu_cx_count;	/* Number of valid Cx states. */
91     int			 cpu_prev_sleep;/* Last idle sleep duration. */
92     int			 cpu_features;	/* Child driver supported features. */
93     /* Runtime state. */
94     int			 cpu_non_c2;	/* Index of lowest non-C2 state. */
95     int			 cpu_non_c3;	/* Index of lowest non-C3 state. */
96     u_int		 cpu_cx_stats[MAX_CX_STATES];/* Cx usage history. */
97     /* Values for sysctl. */
98     struct sysctl_ctx_list cpu_sysctl_ctx;
99     struct sysctl_oid	*cpu_sysctl_tree;
100     int			 cpu_cx_lowest;
101     int			 cpu_cx_lowest_lim;
102     int			 cpu_disable_idle; /* Disable entry to idle function */
103     char 		 cpu_cx_supported[64];
104 };
105 
106 struct acpi_cpu_device {
107     struct resource_list	ad_rl;
108 };
109 
110 #define CPU_GET_REG(reg, width) 					\
111     (bus_space_read_ ## width(rman_get_bustag((reg)), 			\
112 		      rman_get_bushandle((reg)), 0))
113 #define CPU_SET_REG(reg, width, val)					\
114     (bus_space_write_ ## width(rman_get_bustag((reg)), 			\
115 		       rman_get_bushandle((reg)), 0, (val)))
116 
117 #define PM_USEC(x)	 ((x) >> 2)	/* ~4 clocks per usec (3.57955 Mhz) */
118 
119 #define ACPI_NOTIFY_CX_STATES	0x81	/* _CST changed. */
120 
121 #define CPU_QUIRK_NO_C3		(1<<0)	/* C3-type states are not usable. */
122 #define CPU_QUIRK_NO_BM_CTRL	(1<<2)	/* No bus mastering control. */
123 
124 #define PCI_VENDOR_INTEL	0x8086
125 #define PCI_DEVICE_82371AB_3	0x7113	/* PIIX4 chipset for quirks. */
126 #define PCI_REVISION_A_STEP	0
127 #define PCI_REVISION_B_STEP	1
128 #define PCI_REVISION_4E		2
129 #define PCI_REVISION_4M		3
130 #define PIIX4_DEVACTB_REG	0x58
131 #define PIIX4_BRLD_EN_IRQ0	(1<<0)
132 #define PIIX4_BRLD_EN_IRQ	(1<<1)
133 #define PIIX4_BRLD_EN_IRQ8	(1<<5)
134 #define PIIX4_STOP_BREAK_MASK	(PIIX4_BRLD_EN_IRQ0 | PIIX4_BRLD_EN_IRQ | PIIX4_BRLD_EN_IRQ8)
135 #define PIIX4_PCNTRL_BST_EN	(1<<10)
136 
137 #define	CST_FFH_VENDOR_INTEL	1
138 #define	CST_FFH_INTEL_CL_C1IO	1
139 #define	CST_FFH_INTEL_CL_MWAIT	2
140 #define	CST_FFH_MWAIT_HW_COORD	0x0001
141 #define	CST_FFH_MWAIT_BM_AVOID	0x0002
142 
143 #define	CPUDEV_DEVICE_ID	"ACPI0007"
144 
145 /* Allow users to ignore processor orders in MADT. */
146 static int cpu_unordered;
147 SYSCTL_INT(_debug_acpi, OID_AUTO, cpu_unordered, CTLFLAG_RDTUN,
148     &cpu_unordered, 0,
149     "Do not use the MADT to match ACPI Processor objects to CPUs.");
150 
151 /* Knob to disable acpi_cpu devices */
152 bool acpi_cpu_disabled = false;
153 
154 /* Platform hardware resource information. */
155 static uint32_t		 cpu_smi_cmd;	/* Value to write to SMI_CMD. */
156 static uint8_t		 cpu_cst_cnt;	/* Indicate we are _CST aware. */
157 static int		 cpu_quirks;	/* Indicate any hardware bugs. */
158 
159 /* Values for sysctl. */
160 static struct sysctl_ctx_list cpu_sysctl_ctx;
161 static struct sysctl_oid *cpu_sysctl_tree;
162 static int		 cpu_cx_generic;
163 static int		 cpu_cx_lowest_lim;
164 
165 static device_t		*cpu_devices;
166 static int		 cpu_ndevices;
167 static struct acpi_cpu_softc **cpu_softc;
168 ACPI_SERIAL_DECL(cpu, "ACPI CPU");
169 
170 static int	acpi_cpu_probe(device_t dev);
171 static int	acpi_cpu_attach(device_t dev);
172 static int	acpi_cpu_suspend(device_t dev);
173 static int	acpi_cpu_resume(device_t dev);
174 static int	acpi_pcpu_get_id(device_t dev, uint32_t *acpi_id,
175 		    uint32_t *cpu_id);
176 static struct resource_list *acpi_cpu_get_rlist(device_t dev, device_t child);
177 static device_t	acpi_cpu_add_child(device_t dev, u_int order, const char *name,
178 		    int unit);
179 static int	acpi_cpu_read_ivar(device_t dev, device_t child, int index,
180 		    uintptr_t *result);
181 static int	acpi_cpu_shutdown(device_t dev);
182 static void	acpi_cpu_cx_probe(struct acpi_cpu_softc *sc);
183 static void	acpi_cpu_generic_cx_probe(struct acpi_cpu_softc *sc);
184 static int	acpi_cpu_cx_cst(struct acpi_cpu_softc *sc);
185 static void	acpi_cpu_startup(void *arg);
186 static void	acpi_cpu_startup_cx(struct acpi_cpu_softc *sc);
187 static void	acpi_cpu_cx_list(struct acpi_cpu_softc *sc);
188 #if defined(__i386__) || defined(__amd64__)
189 static void	acpi_cpu_idle(sbintime_t sbt);
190 #endif
191 static void	acpi_cpu_notify(ACPI_HANDLE h, UINT32 notify, void *context);
192 static void	acpi_cpu_quirks(void);
193 static void	acpi_cpu_quirks_piix4(void);
194 static int	acpi_cpu_usage_sysctl(SYSCTL_HANDLER_ARGS);
195 static int	acpi_cpu_usage_counters_sysctl(SYSCTL_HANDLER_ARGS);
196 static int	acpi_cpu_set_cx_lowest(struct acpi_cpu_softc *sc);
197 static int	acpi_cpu_cx_lowest_sysctl(SYSCTL_HANDLER_ARGS);
198 static int	acpi_cpu_global_cx_lowest_sysctl(SYSCTL_HANDLER_ARGS);
199 #if defined(__i386__) || defined(__amd64__)
200 static int	acpi_cpu_method_sysctl(SYSCTL_HANDLER_ARGS);
201 #endif
202 
203 static device_method_t acpi_cpu_methods[] = {
204     /* Device interface */
205     DEVMETHOD(device_probe,	acpi_cpu_probe),
206     DEVMETHOD(device_attach,	acpi_cpu_attach),
207     DEVMETHOD(device_detach,	bus_generic_detach),
208     DEVMETHOD(device_shutdown,	acpi_cpu_shutdown),
209     DEVMETHOD(device_suspend,	acpi_cpu_suspend),
210     DEVMETHOD(device_resume,	acpi_cpu_resume),
211 
212     /* Bus interface */
213     DEVMETHOD(bus_add_child,	acpi_cpu_add_child),
214     DEVMETHOD(bus_read_ivar,	acpi_cpu_read_ivar),
215     DEVMETHOD(bus_get_resource_list, acpi_cpu_get_rlist),
216     DEVMETHOD(bus_get_resource,	bus_generic_rl_get_resource),
217     DEVMETHOD(bus_set_resource,	bus_generic_rl_set_resource),
218     DEVMETHOD(bus_alloc_resource, bus_generic_rl_alloc_resource),
219     DEVMETHOD(bus_release_resource, bus_generic_rl_release_resource),
220     DEVMETHOD(bus_activate_resource, bus_generic_activate_resource),
221     DEVMETHOD(bus_deactivate_resource, bus_generic_deactivate_resource),
222     DEVMETHOD(bus_setup_intr,	bus_generic_setup_intr),
223     DEVMETHOD(bus_teardown_intr, bus_generic_teardown_intr),
224 
225     DEVMETHOD_END
226 };
227 
228 static driver_t acpi_cpu_driver = {
229     "cpu",
230     acpi_cpu_methods,
231     sizeof(struct acpi_cpu_softc),
232 };
233 
234 static devclass_t acpi_cpu_devclass;
235 DRIVER_MODULE(cpu, acpi, acpi_cpu_driver, acpi_cpu_devclass, 0, 0);
236 MODULE_DEPEND(cpu, acpi, 1, 1, 1);
237 
238 static int
239 acpi_cpu_probe(device_t dev)
240 {
241     static char		   *cpudev_ids[] = { CPUDEV_DEVICE_ID, NULL };
242     int			   acpi_id, cpu_id;
243     ACPI_BUFFER		   buf;
244     ACPI_HANDLE		   handle;
245     ACPI_OBJECT		   *obj;
246     ACPI_STATUS		   status;
247     ACPI_OBJECT_TYPE	   type;
248 
249     if (acpi_disabled("cpu") || acpi_cpu_disabled)
250 	return (ENXIO);
251     type = acpi_get_type(dev);
252     if (type != ACPI_TYPE_PROCESSOR && type != ACPI_TYPE_DEVICE)
253 	return (ENXIO);
254     if (type == ACPI_TYPE_DEVICE &&
255 	ACPI_ID_PROBE(device_get_parent(dev), dev, cpudev_ids) == NULL)
256 	return (ENXIO);
257 
258     handle = acpi_get_handle(dev);
259     if (cpu_softc == NULL)
260 	cpu_softc = malloc(sizeof(struct acpi_cpu_softc *) *
261 	    (mp_maxid + 1), M_TEMP /* XXX */, M_WAITOK | M_ZERO);
262 
263     if (type == ACPI_TYPE_PROCESSOR) {
264 	/* Get our Processor object. */
265 	buf.Pointer = NULL;
266 	buf.Length = ACPI_ALLOCATE_BUFFER;
267 	status = AcpiEvaluateObject(handle, NULL, NULL, &buf);
268 	if (ACPI_FAILURE(status)) {
269 	    device_printf(dev, "probe failed to get Processor obj - %s\n",
270 		AcpiFormatException(status));
271 	    return (ENXIO);
272 	}
273 	obj = (ACPI_OBJECT *)buf.Pointer;
274 	if (obj->Type != ACPI_TYPE_PROCESSOR) {
275 	    device_printf(dev, "Processor object has bad type %d\n",
276 		obj->Type);
277 	    AcpiOsFree(obj);
278 	    return (ENXIO);
279 	}
280 
281 	/*
282 	 * Find the processor associated with our unit.  We could use the
283 	 * ProcId as a key, however, some boxes do not have the same values
284 	 * in their Processor object as the ProcId values in the MADT.
285 	 */
286 	acpi_id = obj->Processor.ProcId;
287 	AcpiOsFree(obj);
288     } else {
289 	status = acpi_GetInteger(handle, "_UID", &acpi_id);
290 	if (ACPI_FAILURE(status)) {
291 	    device_printf(dev, "Device object has bad value - %s\n",
292 		AcpiFormatException(status));
293 	    return (ENXIO);
294 	}
295     }
296     if (acpi_pcpu_get_id(dev, &acpi_id, &cpu_id) != 0)
297 	return (ENXIO);
298 
299     /*
300      * Check if we already probed this processor.  We scan the bus twice
301      * so it's possible we've already seen this one.
302      */
303     if (cpu_softc[cpu_id] != NULL)
304 	return (ENXIO);
305 
306     /* Mark this processor as in-use and save our derived id for attach. */
307     cpu_softc[cpu_id] = (void *)1;
308     acpi_set_private(dev, (void*)(intptr_t)cpu_id);
309     device_set_desc(dev, "ACPI CPU");
310 
311     return (0);
312 }
313 
314 static int
315 acpi_cpu_attach(device_t dev)
316 {
317     ACPI_BUFFER		   buf;
318     ACPI_OBJECT		   arg, *obj;
319     ACPI_OBJECT_LIST	   arglist;
320     struct pcpu		   *pcpu_data;
321     struct acpi_cpu_softc *sc;
322     struct acpi_softc	  *acpi_sc;
323     ACPI_STATUS		   status;
324     u_int		   features;
325     int			   cpu_id, drv_count, i;
326     driver_t 		  **drivers;
327     uint32_t		   cap_set[3];
328 
329     /* UUID needed by _OSC evaluation */
330     static uint8_t cpu_oscuuid[16] = { 0x16, 0xA6, 0x77, 0x40, 0x0C, 0x29,
331 				       0xBE, 0x47, 0x9E, 0xBD, 0xD8, 0x70,
332 				       0x58, 0x71, 0x39, 0x53 };
333 
334     ACPI_FUNCTION_TRACE((char *)(uintptr_t)__func__);
335 
336     sc = device_get_softc(dev);
337     sc->cpu_dev = dev;
338     sc->cpu_handle = acpi_get_handle(dev);
339     cpu_id = (int)(intptr_t)acpi_get_private(dev);
340     cpu_softc[cpu_id] = sc;
341     pcpu_data = pcpu_find(cpu_id);
342     pcpu_data->pc_device = dev;
343     sc->cpu_pcpu = pcpu_data;
344     cpu_smi_cmd = AcpiGbl_FADT.SmiCommand;
345     cpu_cst_cnt = AcpiGbl_FADT.CstControl;
346 
347     if (acpi_get_type(dev) == ACPI_TYPE_PROCESSOR) {
348 	buf.Pointer = NULL;
349 	buf.Length = ACPI_ALLOCATE_BUFFER;
350 	status = AcpiEvaluateObject(sc->cpu_handle, NULL, NULL, &buf);
351 	if (ACPI_FAILURE(status)) {
352 	    device_printf(dev, "attach failed to get Processor obj - %s\n",
353 		AcpiFormatException(status));
354 	    return (ENXIO);
355 	}
356 	obj = (ACPI_OBJECT *)buf.Pointer;
357 	sc->cpu_p_blk = obj->Processor.PblkAddress;
358 	sc->cpu_p_blk_len = obj->Processor.PblkLength;
359 	sc->cpu_acpi_id = obj->Processor.ProcId;
360 	AcpiOsFree(obj);
361     } else {
362 	KASSERT(acpi_get_type(dev) == ACPI_TYPE_DEVICE,
363 	    ("Unexpected ACPI object"));
364 	status = acpi_GetInteger(sc->cpu_handle, "_UID", &sc->cpu_acpi_id);
365 	if (ACPI_FAILURE(status)) {
366 	    device_printf(dev, "Device object has bad value - %s\n",
367 		AcpiFormatException(status));
368 	    return (ENXIO);
369 	}
370 	sc->cpu_p_blk = 0;
371 	sc->cpu_p_blk_len = 0;
372     }
373     ACPI_DEBUG_PRINT((ACPI_DB_INFO, "acpi_cpu%d: P_BLK at %#x/%d\n",
374 		     device_get_unit(dev), sc->cpu_p_blk, sc->cpu_p_blk_len));
375 
376     /*
377      * If this is the first cpu we attach, create and initialize the generic
378      * resources that will be used by all acpi cpu devices.
379      */
380     if (device_get_unit(dev) == 0) {
381 	/* Assume we won't be using generic Cx mode by default */
382 	cpu_cx_generic = FALSE;
383 
384 	/* Install hw.acpi.cpu sysctl tree */
385 	acpi_sc = acpi_device_get_parent_softc(dev);
386 	sysctl_ctx_init(&cpu_sysctl_ctx);
387 	cpu_sysctl_tree = SYSCTL_ADD_NODE(&cpu_sysctl_ctx,
388 	    SYSCTL_CHILDREN(acpi_sc->acpi_sysctl_tree), OID_AUTO, "cpu",
389 	    CTLFLAG_RD, 0, "node for CPU children");
390     }
391 
392     /*
393      * Before calling any CPU methods, collect child driver feature hints
394      * and notify ACPI of them.  We support unified SMP power control
395      * so advertise this ourselves.  Note this is not the same as independent
396      * SMP control where each CPU can have different settings.
397      */
398     sc->cpu_features = ACPI_CAP_SMP_SAME | ACPI_CAP_SMP_SAME_C3 |
399       ACPI_CAP_C1_IO_HALT;
400 
401 #if defined(__i386__) || defined(__amd64__)
402     /*
403      * Ask for MWAIT modes if not disabled and interrupts work
404      * reasonable with MWAIT.
405      */
406     if (!acpi_disabled("mwait") && cpu_mwait_usable())
407 	sc->cpu_features |= ACPI_CAP_SMP_C1_NATIVE | ACPI_CAP_SMP_C3_NATIVE;
408 #endif
409 
410     if (devclass_get_drivers(acpi_cpu_devclass, &drivers, &drv_count) == 0) {
411 	for (i = 0; i < drv_count; i++) {
412 	    if (ACPI_GET_FEATURES(drivers[i], &features) == 0)
413 		sc->cpu_features |= features;
414 	}
415 	free(drivers, M_TEMP);
416     }
417 
418     /*
419      * CPU capabilities are specified in
420      * Intel Processor Vendor-Specific ACPI Interface Specification.
421      */
422     if (sc->cpu_features) {
423 	cap_set[1] = sc->cpu_features;
424 	status = acpi_EvaluateOSC(sc->cpu_handle, cpu_oscuuid, 1, 2, cap_set,
425 	    cap_set, false);
426 	if (ACPI_SUCCESS(status)) {
427 	    if (cap_set[0] != 0)
428 		device_printf(dev, "_OSC returned status %#x\n", cap_set[0]);
429 	}
430 	else {
431 	    arglist.Pointer = &arg;
432 	    arglist.Count = 1;
433 	    arg.Type = ACPI_TYPE_BUFFER;
434 	    arg.Buffer.Length = sizeof(cap_set);
435 	    arg.Buffer.Pointer = (uint8_t *)cap_set;
436 	    cap_set[0] = 1; /* revision */
437 	    cap_set[1] = 1; /* number of capabilities integers */
438 	    cap_set[2] = sc->cpu_features;
439 	    AcpiEvaluateObject(sc->cpu_handle, "_PDC", &arglist, NULL);
440 	}
441     }
442 
443     /* Probe for Cx state support. */
444     acpi_cpu_cx_probe(sc);
445 
446     return (0);
447 }
448 
449 static void
450 acpi_cpu_postattach(void *unused __unused)
451 {
452     device_t *devices;
453     int err;
454     int i, n;
455     int attached;
456 
457     err = devclass_get_devices(acpi_cpu_devclass, &devices, &n);
458     if (err != 0) {
459 	printf("devclass_get_devices(acpi_cpu_devclass) failed\n");
460 	return;
461     }
462     attached = 0;
463     for (i = 0; i < n; i++)
464 	if (device_is_attached(devices[i]) &&
465 	    device_get_driver(devices[i]) == &acpi_cpu_driver)
466 	    attached = 1;
467     for (i = 0; i < n; i++)
468 	bus_generic_probe(devices[i]);
469     for (i = 0; i < n; i++)
470 	bus_generic_attach(devices[i]);
471     free(devices, M_TEMP);
472 
473     if (attached) {
474 #ifdef EARLY_AP_STARTUP
475 	acpi_cpu_startup(NULL);
476 #else
477 	/* Queue post cpu-probing task handler */
478 	AcpiOsExecute(OSL_NOTIFY_HANDLER, acpi_cpu_startup, NULL);
479 #endif
480     }
481 }
482 
483 SYSINIT(acpi_cpu, SI_SUB_CONFIGURE, SI_ORDER_MIDDLE,
484     acpi_cpu_postattach, NULL);
485 
486 static void
487 disable_idle(struct acpi_cpu_softc *sc)
488 {
489     cpuset_t cpuset;
490 
491     CPU_SETOF(sc->cpu_pcpu->pc_cpuid, &cpuset);
492     sc->cpu_disable_idle = TRUE;
493 
494     /*
495      * Ensure that the CPU is not in idle state or in acpi_cpu_idle().
496      * Note that this code depends on the fact that the rendezvous IPI
497      * can not penetrate context where interrupts are disabled and acpi_cpu_idle
498      * is called and executed in such a context with interrupts being re-enabled
499      * right before return.
500      */
501     smp_rendezvous_cpus(cpuset, smp_no_rendezvous_barrier, NULL,
502 	smp_no_rendezvous_barrier, NULL);
503 }
504 
505 static void
506 enable_idle(struct acpi_cpu_softc *sc)
507 {
508 
509     sc->cpu_disable_idle = FALSE;
510 }
511 
512 #if defined(__i386__) || defined(__amd64__)
513 static int
514 is_idle_disabled(struct acpi_cpu_softc *sc)
515 {
516 
517     return (sc->cpu_disable_idle);
518 }
519 #endif
520 
521 /*
522  * Disable any entry to the idle function during suspend and re-enable it
523  * during resume.
524  */
525 static int
526 acpi_cpu_suspend(device_t dev)
527 {
528     int error;
529 
530     error = bus_generic_suspend(dev);
531     if (error)
532 	return (error);
533     disable_idle(device_get_softc(dev));
534     return (0);
535 }
536 
537 static int
538 acpi_cpu_resume(device_t dev)
539 {
540 
541     enable_idle(device_get_softc(dev));
542     return (bus_generic_resume(dev));
543 }
544 
545 /*
546  * Find the processor associated with a given ACPI ID.  By default,
547  * use the MADT to map ACPI IDs to APIC IDs and use that to locate a
548  * processor.  Some systems have inconsistent ASL and MADT however.
549  * For these systems the cpu_unordered tunable can be set in which
550  * case we assume that Processor objects are listed in the same order
551  * in both the MADT and ASL.
552  */
553 static int
554 acpi_pcpu_get_id(device_t dev, uint32_t *acpi_id, uint32_t *cpu_id)
555 {
556     struct pcpu	*pc;
557     uint32_t	 i, idx;
558 
559     KASSERT(acpi_id != NULL, ("Null acpi_id"));
560     KASSERT(cpu_id != NULL, ("Null cpu_id"));
561     idx = device_get_unit(dev);
562 
563     /*
564      * If pc_acpi_id for CPU 0 is not initialized (e.g. a non-APIC
565      * UP box) use the ACPI ID from the first processor we find.
566      */
567     if (idx == 0 && mp_ncpus == 1) {
568 	pc = pcpu_find(0);
569 	if (pc->pc_acpi_id == 0xffffffff)
570 	    pc->pc_acpi_id = *acpi_id;
571 	*cpu_id = 0;
572 	return (0);
573     }
574 
575     CPU_FOREACH(i) {
576 	pc = pcpu_find(i);
577 	KASSERT(pc != NULL, ("no pcpu data for %d", i));
578 	if (cpu_unordered) {
579 	    if (idx-- == 0) {
580 		/*
581 		 * If pc_acpi_id doesn't match the ACPI ID from the
582 		 * ASL, prefer the MADT-derived value.
583 		 */
584 		if (pc->pc_acpi_id != *acpi_id)
585 		    *acpi_id = pc->pc_acpi_id;
586 		*cpu_id = pc->pc_cpuid;
587 		return (0);
588 	    }
589 	} else {
590 	    if (pc->pc_acpi_id == *acpi_id) {
591 		if (bootverbose)
592 		    device_printf(dev,
593 			"Processor %s (ACPI ID %u) -> APIC ID %d\n",
594 			acpi_name(acpi_get_handle(dev)), *acpi_id,
595 			pc->pc_cpuid);
596 		*cpu_id = pc->pc_cpuid;
597 		return (0);
598 	    }
599 	}
600     }
601 
602     if (bootverbose)
603 	printf("ACPI: Processor %s (ACPI ID %u) ignored\n",
604 	    acpi_name(acpi_get_handle(dev)), *acpi_id);
605 
606     return (ESRCH);
607 }
608 
609 static struct resource_list *
610 acpi_cpu_get_rlist(device_t dev, device_t child)
611 {
612     struct acpi_cpu_device *ad;
613 
614     ad = device_get_ivars(child);
615     if (ad == NULL)
616 	return (NULL);
617     return (&ad->ad_rl);
618 }
619 
620 static device_t
621 acpi_cpu_add_child(device_t dev, u_int order, const char *name, int unit)
622 {
623     struct acpi_cpu_device *ad;
624     device_t child;
625 
626     if ((ad = malloc(sizeof(*ad), M_TEMP, M_NOWAIT | M_ZERO)) == NULL)
627 	return (NULL);
628 
629     resource_list_init(&ad->ad_rl);
630 
631     child = device_add_child_ordered(dev, order, name, unit);
632     if (child != NULL)
633 	device_set_ivars(child, ad);
634     else
635 	free(ad, M_TEMP);
636     return (child);
637 }
638 
639 static int
640 acpi_cpu_read_ivar(device_t dev, device_t child, int index, uintptr_t *result)
641 {
642     struct acpi_cpu_softc *sc;
643 
644     sc = device_get_softc(dev);
645     switch (index) {
646     case ACPI_IVAR_HANDLE:
647 	*result = (uintptr_t)sc->cpu_handle;
648 	break;
649     case CPU_IVAR_PCPU:
650 	*result = (uintptr_t)sc->cpu_pcpu;
651 	break;
652 #if defined(__amd64__) || defined(__i386__)
653     case CPU_IVAR_NOMINAL_MHZ:
654 	if (tsc_is_invariant) {
655 	    *result = (uintptr_t)(atomic_load_acq_64(&tsc_freq) / 1000000);
656 	    break;
657 	}
658 	/* FALLTHROUGH */
659 #endif
660     default:
661 	return (ENOENT);
662     }
663     return (0);
664 }
665 
666 static int
667 acpi_cpu_shutdown(device_t dev)
668 {
669     ACPI_FUNCTION_TRACE((char *)(uintptr_t)__func__);
670 
671     /* Allow children to shutdown first. */
672     bus_generic_shutdown(dev);
673 
674     /*
675      * Disable any entry to the idle function.
676      */
677     disable_idle(device_get_softc(dev));
678 
679     /*
680      * CPU devices are not truly detached and remain referenced,
681      * so their resources are not freed.
682      */
683 
684     return_VALUE (0);
685 }
686 
687 static void
688 acpi_cpu_cx_probe(struct acpi_cpu_softc *sc)
689 {
690     ACPI_FUNCTION_TRACE((char *)(uintptr_t)__func__);
691 
692     /* Use initial sleep value of 1 sec. to start with lowest idle state. */
693     sc->cpu_prev_sleep = 1000000;
694     sc->cpu_cx_lowest = 0;
695     sc->cpu_cx_lowest_lim = 0;
696 
697     /*
698      * Check for the ACPI 2.0 _CST sleep states object. If we can't find
699      * any, we'll revert to generic FADT/P_BLK Cx control method which will
700      * be handled by acpi_cpu_startup. We need to defer to after having
701      * probed all the cpus in the system before probing for generic Cx
702      * states as we may already have found cpus with valid _CST packages
703      */
704     if (!cpu_cx_generic && acpi_cpu_cx_cst(sc) != 0) {
705 	/*
706 	 * We were unable to find a _CST package for this cpu or there
707 	 * was an error parsing it. Switch back to generic mode.
708 	 */
709 	cpu_cx_generic = TRUE;
710 	if (bootverbose)
711 	    device_printf(sc->cpu_dev, "switching to generic Cx mode\n");
712     }
713 
714     /*
715      * TODO: _CSD Package should be checked here.
716      */
717 }
718 
719 static void
720 acpi_cpu_generic_cx_probe(struct acpi_cpu_softc *sc)
721 {
722     ACPI_GENERIC_ADDRESS	 gas;
723     struct acpi_cx		*cx_ptr;
724 
725     sc->cpu_cx_count = 0;
726     cx_ptr = sc->cpu_cx_states;
727 
728     /* Use initial sleep value of 1 sec. to start with lowest idle state. */
729     sc->cpu_prev_sleep = 1000000;
730 
731     /* C1 has been required since just after ACPI 1.0 */
732     cx_ptr->type = ACPI_STATE_C1;
733     cx_ptr->trans_lat = 0;
734     cx_ptr++;
735     sc->cpu_non_c2 = sc->cpu_cx_count;
736     sc->cpu_non_c3 = sc->cpu_cx_count;
737     sc->cpu_cx_count++;
738 
739     /*
740      * The spec says P_BLK must be 6 bytes long.  However, some systems
741      * use it to indicate a fractional set of features present so we
742      * take 5 as C2.  Some may also have a value of 7 to indicate
743      * another C3 but most use _CST for this (as required) and having
744      * "only" C1-C3 is not a hardship.
745      */
746     if (sc->cpu_p_blk_len < 5)
747 	return;
748 
749     /* Validate and allocate resources for C2 (P_LVL2). */
750     gas.SpaceId = ACPI_ADR_SPACE_SYSTEM_IO;
751     gas.BitWidth = 8;
752     if (AcpiGbl_FADT.C2Latency <= 100) {
753 	gas.Address = sc->cpu_p_blk + 4;
754 	cx_ptr->res_rid = 0;
755 	acpi_bus_alloc_gas(sc->cpu_dev, &cx_ptr->res_type, &cx_ptr->res_rid,
756 	    &gas, &cx_ptr->p_lvlx, RF_SHAREABLE);
757 	if (cx_ptr->p_lvlx != NULL) {
758 	    cx_ptr->type = ACPI_STATE_C2;
759 	    cx_ptr->trans_lat = AcpiGbl_FADT.C2Latency;
760 	    cx_ptr++;
761 	    sc->cpu_non_c3 = sc->cpu_cx_count;
762 	    sc->cpu_cx_count++;
763 	}
764     }
765     if (sc->cpu_p_blk_len < 6)
766 	return;
767 
768     /* Validate and allocate resources for C3 (P_LVL3). */
769     if (AcpiGbl_FADT.C3Latency <= 1000 && !(cpu_quirks & CPU_QUIRK_NO_C3)) {
770 	gas.Address = sc->cpu_p_blk + 5;
771 	cx_ptr->res_rid = 1;
772 	acpi_bus_alloc_gas(sc->cpu_dev, &cx_ptr->res_type, &cx_ptr->res_rid,
773 	    &gas, &cx_ptr->p_lvlx, RF_SHAREABLE);
774 	if (cx_ptr->p_lvlx != NULL) {
775 	    cx_ptr->type = ACPI_STATE_C3;
776 	    cx_ptr->trans_lat = AcpiGbl_FADT.C3Latency;
777 	    cx_ptr++;
778 	    sc->cpu_cx_count++;
779 	}
780     }
781 }
782 
783 #if defined(__i386__) || defined(__amd64__)
784 static void
785 acpi_cpu_cx_cst_mwait(struct acpi_cx *cx_ptr, uint64_t address, int accsize)
786 {
787 
788 	cx_ptr->do_mwait = true;
789 	cx_ptr->mwait_hint = address & 0xffffffff;
790 	cx_ptr->mwait_hw_coord = (accsize & CST_FFH_MWAIT_HW_COORD) != 0;
791 	cx_ptr->mwait_bm_avoidance = (accsize & CST_FFH_MWAIT_BM_AVOID) != 0;
792 }
793 #endif
794 
795 static void
796 acpi_cpu_cx_cst_free_plvlx(device_t cpu_dev, struct acpi_cx *cx_ptr)
797 {
798 
799 	if (cx_ptr->p_lvlx == NULL)
800 		return;
801 	bus_release_resource(cpu_dev, cx_ptr->res_type, cx_ptr->res_rid,
802 	    cx_ptr->p_lvlx);
803 	cx_ptr->p_lvlx = NULL;
804 }
805 
806 /*
807  * Parse a _CST package and set up its Cx states.  Since the _CST object
808  * can change dynamically, our notify handler may call this function
809  * to clean up and probe the new _CST package.
810  */
811 static int
812 acpi_cpu_cx_cst(struct acpi_cpu_softc *sc)
813 {
814     struct	 acpi_cx *cx_ptr;
815     ACPI_STATUS	 status;
816     ACPI_BUFFER	 buf;
817     ACPI_OBJECT	*top;
818     ACPI_OBJECT	*pkg;
819     uint32_t	 count;
820     int		 i;
821 #if defined(__i386__) || defined(__amd64__)
822     uint64_t	 address;
823     int		 vendor, class, accsize;
824 #endif
825 
826     ACPI_FUNCTION_TRACE((char *)(uintptr_t)__func__);
827 
828     buf.Pointer = NULL;
829     buf.Length = ACPI_ALLOCATE_BUFFER;
830     status = AcpiEvaluateObject(sc->cpu_handle, "_CST", NULL, &buf);
831     if (ACPI_FAILURE(status))
832 	return (ENXIO);
833 
834     /* _CST is a package with a count and at least one Cx package. */
835     top = (ACPI_OBJECT *)buf.Pointer;
836     if (!ACPI_PKG_VALID(top, 2) || acpi_PkgInt32(top, 0, &count) != 0) {
837 	device_printf(sc->cpu_dev, "invalid _CST package\n");
838 	AcpiOsFree(buf.Pointer);
839 	return (ENXIO);
840     }
841     if (count != top->Package.Count - 1) {
842 	device_printf(sc->cpu_dev, "invalid _CST state count (%d != %d)\n",
843 	       count, top->Package.Count - 1);
844 	count = top->Package.Count - 1;
845     }
846     if (count > MAX_CX_STATES) {
847 	device_printf(sc->cpu_dev, "_CST has too many states (%d)\n", count);
848 	count = MAX_CX_STATES;
849     }
850 
851     sc->cpu_non_c2 = 0;
852     sc->cpu_non_c3 = 0;
853     sc->cpu_cx_count = 0;
854     cx_ptr = sc->cpu_cx_states;
855 
856     /*
857      * C1 has been required since just after ACPI 1.0.
858      * Reserve the first slot for it.
859      */
860     cx_ptr->type = ACPI_STATE_C0;
861     cx_ptr++;
862     sc->cpu_cx_count++;
863 
864     /* Set up all valid states. */
865     for (i = 0; i < count; i++) {
866 	pkg = &top->Package.Elements[i + 1];
867 	if (!ACPI_PKG_VALID(pkg, 4) ||
868 	    acpi_PkgInt32(pkg, 1, &cx_ptr->type) != 0 ||
869 	    acpi_PkgInt32(pkg, 2, &cx_ptr->trans_lat) != 0 ||
870 	    acpi_PkgInt32(pkg, 3, &cx_ptr->power) != 0) {
871 
872 	    device_printf(sc->cpu_dev, "skipping invalid Cx state package\n");
873 	    continue;
874 	}
875 
876 	/* Validate the state to see if we should use it. */
877 	switch (cx_ptr->type) {
878 	case ACPI_STATE_C1:
879 	    acpi_cpu_cx_cst_free_plvlx(sc->cpu_dev, cx_ptr);
880 #if defined(__i386__) || defined(__amd64__)
881 	    if (acpi_PkgFFH_IntelCpu(pkg, 0, &vendor, &class, &address,
882 	      &accsize) == 0 && vendor == CST_FFH_VENDOR_INTEL) {
883 		if (class == CST_FFH_INTEL_CL_C1IO) {
884 		    /* C1 I/O then Halt */
885 		    cx_ptr->res_rid = sc->cpu_cx_count;
886 		    bus_set_resource(sc->cpu_dev, SYS_RES_IOPORT,
887 		      cx_ptr->res_rid, address, 1);
888 		    cx_ptr->p_lvlx = bus_alloc_resource_any(sc->cpu_dev,
889 		      SYS_RES_IOPORT, &cx_ptr->res_rid, RF_ACTIVE |
890 		      RF_SHAREABLE);
891 		    if (cx_ptr->p_lvlx == NULL) {
892 			bus_delete_resource(sc->cpu_dev, SYS_RES_IOPORT,
893 			  cx_ptr->res_rid);
894 			device_printf(sc->cpu_dev,
895 			  "C1 I/O failed to allocate port %d, "
896 			  "degrading to C1 Halt", (int)address);
897 		    }
898 		} else if (class == CST_FFH_INTEL_CL_MWAIT) {
899 		    acpi_cpu_cx_cst_mwait(cx_ptr, address, accsize);
900 		}
901 	    }
902 #endif
903 	    if (sc->cpu_cx_states[0].type == ACPI_STATE_C0) {
904 		/* This is the first C1 state.  Use the reserved slot. */
905 		sc->cpu_cx_states[0] = *cx_ptr;
906 	    } else {
907 		sc->cpu_non_c2 = sc->cpu_cx_count;
908 		sc->cpu_non_c3 = sc->cpu_cx_count;
909 		cx_ptr++;
910 		sc->cpu_cx_count++;
911 	    }
912 	    continue;
913 	case ACPI_STATE_C2:
914 	    sc->cpu_non_c3 = sc->cpu_cx_count;
915 	    break;
916 	case ACPI_STATE_C3:
917 	default:
918 	    if ((cpu_quirks & CPU_QUIRK_NO_C3) != 0) {
919 		ACPI_DEBUG_PRINT((ACPI_DB_INFO,
920 				 "acpi_cpu%d: C3[%d] not available.\n",
921 				 device_get_unit(sc->cpu_dev), i));
922 		continue;
923 	    }
924 	    break;
925 	}
926 
927 	/* Free up any previous register. */
928 	acpi_cpu_cx_cst_free_plvlx(sc->cpu_dev, cx_ptr);
929 
930 	/* Allocate the control register for C2 or C3. */
931 #if defined(__i386__) || defined(__amd64__)
932 	if (acpi_PkgFFH_IntelCpu(pkg, 0, &vendor, &class, &address,
933 	  &accsize) == 0 && vendor == CST_FFH_VENDOR_INTEL &&
934 	  class == CST_FFH_INTEL_CL_MWAIT) {
935 	    /* Native C State Instruction use (mwait) */
936 	    acpi_cpu_cx_cst_mwait(cx_ptr, address, accsize);
937 	    ACPI_DEBUG_PRINT((ACPI_DB_INFO,
938 	      "acpi_cpu%d: Got C%d/mwait - %d latency\n",
939 	      device_get_unit(sc->cpu_dev), cx_ptr->type, cx_ptr->trans_lat));
940 	    cx_ptr++;
941 	    sc->cpu_cx_count++;
942 	} else
943 #endif
944 	{
945 	    cx_ptr->res_rid = sc->cpu_cx_count;
946 	    acpi_PkgGas(sc->cpu_dev, pkg, 0, &cx_ptr->res_type,
947 		&cx_ptr->res_rid, &cx_ptr->p_lvlx, RF_SHAREABLE);
948 	    if (cx_ptr->p_lvlx) {
949 		ACPI_DEBUG_PRINT((ACPI_DB_INFO,
950 		     "acpi_cpu%d: Got C%d - %d latency\n",
951 		     device_get_unit(sc->cpu_dev), cx_ptr->type,
952 		     cx_ptr->trans_lat));
953 		cx_ptr++;
954 		sc->cpu_cx_count++;
955 	    }
956 	}
957     }
958     AcpiOsFree(buf.Pointer);
959 
960     /* If C1 state was not found, we need one now. */
961     cx_ptr = sc->cpu_cx_states;
962     if (cx_ptr->type == ACPI_STATE_C0) {
963 	cx_ptr->type = ACPI_STATE_C1;
964 	cx_ptr->trans_lat = 0;
965     }
966 
967     return (0);
968 }
969 
970 /*
971  * Call this *after* all CPUs have been attached.
972  */
973 static void
974 acpi_cpu_startup(void *arg)
975 {
976     struct acpi_cpu_softc *sc;
977     int i;
978 
979     /* Get set of CPU devices */
980     devclass_get_devices(acpi_cpu_devclass, &cpu_devices, &cpu_ndevices);
981 
982     /*
983      * Setup any quirks that might necessary now that we have probed
984      * all the CPUs
985      */
986     acpi_cpu_quirks();
987 
988     if (cpu_cx_generic) {
989 	/*
990 	 * We are using generic Cx mode, probe for available Cx states
991 	 * for all processors.
992 	 */
993 	for (i = 0; i < cpu_ndevices; i++) {
994 	    sc = device_get_softc(cpu_devices[i]);
995 	    acpi_cpu_generic_cx_probe(sc);
996 	}
997     } else {
998 	/*
999 	 * We are using _CST mode, remove C3 state if necessary.
1000 	 * As we now know for sure that we will be using _CST mode
1001 	 * install our notify handler.
1002 	 */
1003 	for (i = 0; i < cpu_ndevices; i++) {
1004 	    sc = device_get_softc(cpu_devices[i]);
1005 	    if (cpu_quirks & CPU_QUIRK_NO_C3) {
1006 		sc->cpu_cx_count = min(sc->cpu_cx_count, sc->cpu_non_c3 + 1);
1007 	    }
1008 	    AcpiInstallNotifyHandler(sc->cpu_handle, ACPI_DEVICE_NOTIFY,
1009 		acpi_cpu_notify, sc);
1010 	}
1011     }
1012 
1013     /* Perform Cx final initialization. */
1014     for (i = 0; i < cpu_ndevices; i++) {
1015 	sc = device_get_softc(cpu_devices[i]);
1016 	acpi_cpu_startup_cx(sc);
1017     }
1018 
1019     /* Add a sysctl handler to handle global Cx lowest setting */
1020     SYSCTL_ADD_PROC(&cpu_sysctl_ctx, SYSCTL_CHILDREN(cpu_sysctl_tree),
1021 	OID_AUTO, "cx_lowest", CTLTYPE_STRING | CTLFLAG_RW,
1022 	NULL, 0, acpi_cpu_global_cx_lowest_sysctl, "A",
1023 	"Global lowest Cx sleep state to use");
1024 
1025     /* Take over idling from cpu_idle_default(). */
1026     cpu_cx_lowest_lim = 0;
1027     for (i = 0; i < cpu_ndevices; i++) {
1028 	sc = device_get_softc(cpu_devices[i]);
1029 	enable_idle(sc);
1030     }
1031 #if defined(__i386__) || defined(__amd64__)
1032     cpu_idle_hook = acpi_cpu_idle;
1033 #endif
1034 }
1035 
1036 static void
1037 acpi_cpu_cx_list(struct acpi_cpu_softc *sc)
1038 {
1039     struct sbuf sb;
1040     int i;
1041 
1042     /*
1043      * Set up the list of Cx states
1044      */
1045     sbuf_new(&sb, sc->cpu_cx_supported, sizeof(sc->cpu_cx_supported),
1046 	SBUF_FIXEDLEN);
1047     for (i = 0; i < sc->cpu_cx_count; i++)
1048 	sbuf_printf(&sb, "C%d/%d/%d ", i + 1, sc->cpu_cx_states[i].type,
1049 	    sc->cpu_cx_states[i].trans_lat);
1050     sbuf_trim(&sb);
1051     sbuf_finish(&sb);
1052 }
1053 
1054 static void
1055 acpi_cpu_startup_cx(struct acpi_cpu_softc *sc)
1056 {
1057     acpi_cpu_cx_list(sc);
1058 
1059     SYSCTL_ADD_STRING(&sc->cpu_sysctl_ctx,
1060 		      SYSCTL_CHILDREN(device_get_sysctl_tree(sc->cpu_dev)),
1061 		      OID_AUTO, "cx_supported", CTLFLAG_RD,
1062 		      sc->cpu_cx_supported, 0,
1063 		      "Cx/microsecond values for supported Cx states");
1064     SYSCTL_ADD_PROC(&sc->cpu_sysctl_ctx,
1065 		    SYSCTL_CHILDREN(device_get_sysctl_tree(sc->cpu_dev)),
1066 		    OID_AUTO, "cx_lowest", CTLTYPE_STRING | CTLFLAG_RW,
1067 		    (void *)sc, 0, acpi_cpu_cx_lowest_sysctl, "A",
1068 		    "lowest Cx sleep state to use");
1069     SYSCTL_ADD_PROC(&sc->cpu_sysctl_ctx,
1070 		    SYSCTL_CHILDREN(device_get_sysctl_tree(sc->cpu_dev)),
1071 		    OID_AUTO, "cx_usage", CTLTYPE_STRING | CTLFLAG_RD,
1072 		    (void *)sc, 0, acpi_cpu_usage_sysctl, "A",
1073 		    "percent usage for each Cx state");
1074     SYSCTL_ADD_PROC(&sc->cpu_sysctl_ctx,
1075 		    SYSCTL_CHILDREN(device_get_sysctl_tree(sc->cpu_dev)),
1076 		    OID_AUTO, "cx_usage_counters", CTLTYPE_STRING | CTLFLAG_RD,
1077 		    (void *)sc, 0, acpi_cpu_usage_counters_sysctl, "A",
1078 		    "Cx sleep state counters");
1079 #if defined(__i386__) || defined(__amd64__)
1080     SYSCTL_ADD_PROC(&sc->cpu_sysctl_ctx,
1081 		    SYSCTL_CHILDREN(device_get_sysctl_tree(sc->cpu_dev)),
1082 		    OID_AUTO, "cx_method", CTLTYPE_STRING | CTLFLAG_RD,
1083 		    (void *)sc, 0, acpi_cpu_method_sysctl, "A",
1084 		    "Cx entrance methods");
1085 #endif
1086 
1087     /* Signal platform that we can handle _CST notification. */
1088     if (!cpu_cx_generic && cpu_cst_cnt != 0) {
1089 	ACPI_LOCK(acpi);
1090 	AcpiOsWritePort(cpu_smi_cmd, cpu_cst_cnt, 8);
1091 	ACPI_UNLOCK(acpi);
1092     }
1093 }
1094 
1095 #if defined(__i386__) || defined(__amd64__)
1096 /*
1097  * Idle the CPU in the lowest state possible.  This function is called with
1098  * interrupts disabled.  Note that once it re-enables interrupts, a task
1099  * switch can occur so do not access shared data (i.e. the softc) after
1100  * interrupts are re-enabled.
1101  */
1102 static void
1103 acpi_cpu_idle(sbintime_t sbt)
1104 {
1105     struct	acpi_cpu_softc *sc;
1106     struct	acpi_cx *cx_next;
1107     uint64_t	cputicks;
1108     uint32_t	start_time, end_time;
1109     ACPI_STATUS	status;
1110     int		bm_active, cx_next_idx, i, us;
1111 
1112     /*
1113      * Look up our CPU id to get our softc.  If it's NULL, we'll use C1
1114      * since there is no ACPI processor object for this CPU.  This occurs
1115      * for logical CPUs in the HTT case.
1116      */
1117     sc = cpu_softc[PCPU_GET(cpuid)];
1118     if (sc == NULL) {
1119 	acpi_cpu_c1();
1120 	return;
1121     }
1122 
1123     /* If disabled, take the safe path. */
1124     if (is_idle_disabled(sc)) {
1125 	acpi_cpu_c1();
1126 	return;
1127     }
1128 
1129     /* Find the lowest state that has small enough latency. */
1130     us = sc->cpu_prev_sleep;
1131     if (sbt >= 0 && us > (sbt >> 12))
1132 	us = (sbt >> 12);
1133     cx_next_idx = 0;
1134     if (cpu_disable_c2_sleep)
1135 	i = min(sc->cpu_cx_lowest, sc->cpu_non_c2);
1136     else if (cpu_disable_c3_sleep)
1137 	i = min(sc->cpu_cx_lowest, sc->cpu_non_c3);
1138     else
1139 	i = sc->cpu_cx_lowest;
1140     for (; i >= 0; i--) {
1141 	if (sc->cpu_cx_states[i].trans_lat * 3 <= us) {
1142 	    cx_next_idx = i;
1143 	    break;
1144 	}
1145     }
1146 
1147     /*
1148      * Check for bus master activity.  If there was activity, clear
1149      * the bit and use the lowest non-C3 state.  Note that the USB
1150      * driver polling for new devices keeps this bit set all the
1151      * time if USB is loaded.
1152      */
1153     if ((cpu_quirks & CPU_QUIRK_NO_BM_CTRL) == 0 &&
1154 	cx_next_idx > sc->cpu_non_c3) {
1155 	status = AcpiReadBitRegister(ACPI_BITREG_BUS_MASTER_STATUS, &bm_active);
1156 	if (ACPI_SUCCESS(status) && bm_active != 0) {
1157 	    AcpiWriteBitRegister(ACPI_BITREG_BUS_MASTER_STATUS, 1);
1158 	    cx_next_idx = sc->cpu_non_c3;
1159 	}
1160     }
1161 
1162     /* Select the next state and update statistics. */
1163     cx_next = &sc->cpu_cx_states[cx_next_idx];
1164     sc->cpu_cx_stats[cx_next_idx]++;
1165     KASSERT(cx_next->type != ACPI_STATE_C0, ("acpi_cpu_idle: C0 sleep"));
1166 
1167     /*
1168      * Execute HLT (or equivalent) and wait for an interrupt.  We can't
1169      * precisely calculate the time spent in C1 since the place we wake up
1170      * is an ISR.  Assume we slept no more then half of quantum, unless
1171      * we are called inside critical section, delaying context switch.
1172      */
1173     if (cx_next->type == ACPI_STATE_C1) {
1174 	cputicks = cpu_ticks();
1175 	if (cx_next->p_lvlx != NULL) {
1176 	    /* C1 I/O then Halt */
1177 	    CPU_GET_REG(cx_next->p_lvlx, 1);
1178 	}
1179 	if (cx_next->do_mwait)
1180 	    acpi_cpu_idle_mwait(cx_next->mwait_hint);
1181 	else
1182 	    acpi_cpu_c1();
1183 	end_time = ((cpu_ticks() - cputicks) << 20) / cpu_tickrate();
1184 	if (curthread->td_critnest == 0)
1185 		end_time = min(end_time, 500000 / hz);
1186 	/* acpi_cpu_c1() returns with interrupts enabled. */
1187 	if (cx_next->do_mwait)
1188 	    ACPI_ENABLE_IRQS();
1189 	sc->cpu_prev_sleep = (sc->cpu_prev_sleep * 3 + end_time) / 4;
1190 	return;
1191     }
1192 
1193     /*
1194      * For C3, disable bus master arbitration and enable bus master wake
1195      * if BM control is available, otherwise flush the CPU cache.
1196      */
1197     if (cx_next->type == ACPI_STATE_C3 || cx_next->mwait_bm_avoidance) {
1198 	if ((cpu_quirks & CPU_QUIRK_NO_BM_CTRL) == 0) {
1199 	    AcpiWriteBitRegister(ACPI_BITREG_ARB_DISABLE, 1);
1200 	    AcpiWriteBitRegister(ACPI_BITREG_BUS_MASTER_RLD, 1);
1201 	} else
1202 	    ACPI_FLUSH_CPU_CACHE();
1203     }
1204 
1205     /*
1206      * Read from P_LVLx to enter C2(+), checking time spent asleep.
1207      * Use the ACPI timer for measuring sleep time.  Since we need to
1208      * get the time very close to the CPU start/stop clock logic, this
1209      * is the only reliable time source.
1210      */
1211     if (cx_next->type == ACPI_STATE_C3) {
1212 	AcpiGetTimer(&start_time);
1213 	cputicks = 0;
1214     } else {
1215 	start_time = 0;
1216 	cputicks = cpu_ticks();
1217     }
1218     if (cx_next->do_mwait)
1219 	acpi_cpu_idle_mwait(cx_next->mwait_hint);
1220     else
1221 	CPU_GET_REG(cx_next->p_lvlx, 1);
1222 
1223     /*
1224      * Read the end time twice.  Since it may take an arbitrary time
1225      * to enter the idle state, the first read may be executed before
1226      * the processor has stopped.  Doing it again provides enough
1227      * margin that we are certain to have a correct value.
1228      */
1229     AcpiGetTimer(&end_time);
1230     if (cx_next->type == ACPI_STATE_C3) {
1231 	AcpiGetTimer(&end_time);
1232 	AcpiGetTimerDuration(start_time, end_time, &end_time);
1233     } else
1234 	end_time = ((cpu_ticks() - cputicks) << 20) / cpu_tickrate();
1235 
1236     /* Enable bus master arbitration and disable bus master wakeup. */
1237     if ((cx_next->type == ACPI_STATE_C3 || cx_next->mwait_bm_avoidance) &&
1238       (cpu_quirks & CPU_QUIRK_NO_BM_CTRL) == 0) {
1239 	AcpiWriteBitRegister(ACPI_BITREG_ARB_DISABLE, 0);
1240 	AcpiWriteBitRegister(ACPI_BITREG_BUS_MASTER_RLD, 0);
1241     }
1242     ACPI_ENABLE_IRQS();
1243 
1244     sc->cpu_prev_sleep = (sc->cpu_prev_sleep * 3 + PM_USEC(end_time)) / 4;
1245 }
1246 #endif
1247 
1248 /*
1249  * Re-evaluate the _CST object when we are notified that it changed.
1250  */
1251 static void
1252 acpi_cpu_notify(ACPI_HANDLE h, UINT32 notify, void *context)
1253 {
1254     struct acpi_cpu_softc *sc = (struct acpi_cpu_softc *)context;
1255 
1256     if (notify != ACPI_NOTIFY_CX_STATES)
1257 	return;
1258 
1259     /*
1260      * C-state data for target CPU is going to be in flux while we execute
1261      * acpi_cpu_cx_cst, so disable entering acpi_cpu_idle.
1262      * Also, it may happen that multiple ACPI taskqueues may concurrently
1263      * execute notifications for the same CPU.  ACPI_SERIAL is used to
1264      * protect against that.
1265      */
1266     ACPI_SERIAL_BEGIN(cpu);
1267     disable_idle(sc);
1268 
1269     /* Update the list of Cx states. */
1270     acpi_cpu_cx_cst(sc);
1271     acpi_cpu_cx_list(sc);
1272     acpi_cpu_set_cx_lowest(sc);
1273 
1274     enable_idle(sc);
1275     ACPI_SERIAL_END(cpu);
1276 
1277     acpi_UserNotify("PROCESSOR", sc->cpu_handle, notify);
1278 }
1279 
1280 static void
1281 acpi_cpu_quirks(void)
1282 {
1283     ACPI_FUNCTION_TRACE((char *)(uintptr_t)__func__);
1284 
1285     /*
1286      * Bus mastering arbitration control is needed to keep caches coherent
1287      * while sleeping in C3.  If it's not present but a working flush cache
1288      * instruction is present, flush the caches before entering C3 instead.
1289      * Otherwise, just disable C3 completely.
1290      */
1291     if (AcpiGbl_FADT.Pm2ControlBlock == 0 ||
1292 	AcpiGbl_FADT.Pm2ControlLength == 0) {
1293 	if ((AcpiGbl_FADT.Flags & ACPI_FADT_WBINVD) &&
1294 	    (AcpiGbl_FADT.Flags & ACPI_FADT_WBINVD_FLUSH) == 0) {
1295 	    cpu_quirks |= CPU_QUIRK_NO_BM_CTRL;
1296 	    ACPI_DEBUG_PRINT((ACPI_DB_INFO,
1297 		"acpi_cpu: no BM control, using flush cache method\n"));
1298 	} else {
1299 	    cpu_quirks |= CPU_QUIRK_NO_C3;
1300 	    ACPI_DEBUG_PRINT((ACPI_DB_INFO,
1301 		"acpi_cpu: no BM control, C3 not available\n"));
1302 	}
1303     }
1304 
1305     /*
1306      * If we are using generic Cx mode, C3 on multiple CPUs requires using
1307      * the expensive flush cache instruction.
1308      */
1309     if (cpu_cx_generic && mp_ncpus > 1) {
1310 	cpu_quirks |= CPU_QUIRK_NO_BM_CTRL;
1311 	ACPI_DEBUG_PRINT((ACPI_DB_INFO,
1312 	    "acpi_cpu: SMP, using flush cache mode for C3\n"));
1313     }
1314 
1315     /* Look for various quirks of the PIIX4 part. */
1316     acpi_cpu_quirks_piix4();
1317 }
1318 
1319 static void
1320 acpi_cpu_quirks_piix4(void)
1321 {
1322 #ifdef __i386__
1323     device_t acpi_dev;
1324     uint32_t val;
1325     ACPI_STATUS status;
1326 
1327     acpi_dev = pci_find_device(PCI_VENDOR_INTEL, PCI_DEVICE_82371AB_3);
1328     if (acpi_dev != NULL) {
1329 	switch (pci_get_revid(acpi_dev)) {
1330 	/*
1331 	 * Disable C3 support for all PIIX4 chipsets.  Some of these parts
1332 	 * do not report the BMIDE status to the BM status register and
1333 	 * others have a livelock bug if Type-F DMA is enabled.  Linux
1334 	 * works around the BMIDE bug by reading the BM status directly
1335 	 * but we take the simpler approach of disabling C3 for these
1336 	 * parts.
1337 	 *
1338 	 * See erratum #18 ("C3 Power State/BMIDE and Type-F DMA
1339 	 * Livelock") from the January 2002 PIIX4 specification update.
1340 	 * Applies to all PIIX4 models.
1341 	 *
1342 	 * Also, make sure that all interrupts cause a "Stop Break"
1343 	 * event to exit from C2 state.
1344 	 * Also, BRLD_EN_BM (ACPI_BITREG_BUS_MASTER_RLD in ACPI-speak)
1345 	 * should be set to zero, otherwise it causes C2 to short-sleep.
1346 	 * PIIX4 doesn't properly support C3 and bus master activity
1347 	 * need not break out of C2.
1348 	 */
1349 	case PCI_REVISION_A_STEP:
1350 	case PCI_REVISION_B_STEP:
1351 	case PCI_REVISION_4E:
1352 	case PCI_REVISION_4M:
1353 	    cpu_quirks |= CPU_QUIRK_NO_C3;
1354 	    ACPI_DEBUG_PRINT((ACPI_DB_INFO,
1355 		"acpi_cpu: working around PIIX4 bug, disabling C3\n"));
1356 
1357 	    val = pci_read_config(acpi_dev, PIIX4_DEVACTB_REG, 4);
1358 	    if ((val & PIIX4_STOP_BREAK_MASK) != PIIX4_STOP_BREAK_MASK) {
1359 		ACPI_DEBUG_PRINT((ACPI_DB_INFO,
1360 		    "acpi_cpu: PIIX4: enabling IRQs to generate Stop Break\n"));
1361 	    	val |= PIIX4_STOP_BREAK_MASK;
1362 		pci_write_config(acpi_dev, PIIX4_DEVACTB_REG, val, 4);
1363 	    }
1364 	    status = AcpiReadBitRegister(ACPI_BITREG_BUS_MASTER_RLD, &val);
1365 	    if (ACPI_SUCCESS(status) && val != 0) {
1366 		ACPI_DEBUG_PRINT((ACPI_DB_INFO,
1367 		    "acpi_cpu: PIIX4: reset BRLD_EN_BM\n"));
1368 		AcpiWriteBitRegister(ACPI_BITREG_BUS_MASTER_RLD, 0);
1369 	    }
1370 	    break;
1371 	default:
1372 	    break;
1373 	}
1374     }
1375 #endif
1376 }
1377 
1378 static int
1379 acpi_cpu_usage_sysctl(SYSCTL_HANDLER_ARGS)
1380 {
1381     struct acpi_cpu_softc *sc;
1382     struct sbuf	 sb;
1383     char	 buf[128];
1384     int		 i;
1385     uintmax_t	 fract, sum, whole;
1386 
1387     sc = (struct acpi_cpu_softc *) arg1;
1388     sum = 0;
1389     for (i = 0; i < sc->cpu_cx_count; i++)
1390 	sum += sc->cpu_cx_stats[i];
1391     sbuf_new(&sb, buf, sizeof(buf), SBUF_FIXEDLEN);
1392     for (i = 0; i < sc->cpu_cx_count; i++) {
1393 	if (sum > 0) {
1394 	    whole = (uintmax_t)sc->cpu_cx_stats[i] * 100;
1395 	    fract = (whole % sum) * 100;
1396 	    sbuf_printf(&sb, "%u.%02u%% ", (u_int)(whole / sum),
1397 		(u_int)(fract / sum));
1398 	} else
1399 	    sbuf_printf(&sb, "0.00%% ");
1400     }
1401     sbuf_printf(&sb, "last %dus", sc->cpu_prev_sleep);
1402     sbuf_trim(&sb);
1403     sbuf_finish(&sb);
1404     sysctl_handle_string(oidp, sbuf_data(&sb), sbuf_len(&sb), req);
1405     sbuf_delete(&sb);
1406 
1407     return (0);
1408 }
1409 
1410 /*
1411  * XXX TODO: actually add support to count each entry/exit
1412  * from the Cx states.
1413  */
1414 static int
1415 acpi_cpu_usage_counters_sysctl(SYSCTL_HANDLER_ARGS)
1416 {
1417     struct acpi_cpu_softc *sc;
1418     struct sbuf	 sb;
1419     char	 buf[128];
1420     int		 i;
1421 
1422     sc = (struct acpi_cpu_softc *) arg1;
1423 
1424     /* Print out the raw counters */
1425     sbuf_new(&sb, buf, sizeof(buf), SBUF_FIXEDLEN);
1426 
1427     for (i = 0; i < sc->cpu_cx_count; i++) {
1428         sbuf_printf(&sb, "%u ", sc->cpu_cx_stats[i]);
1429     }
1430 
1431     sbuf_trim(&sb);
1432     sbuf_finish(&sb);
1433     sysctl_handle_string(oidp, sbuf_data(&sb), sbuf_len(&sb), req);
1434     sbuf_delete(&sb);
1435 
1436     return (0);
1437 }
1438 
1439 #if defined(__i386__) || defined(__amd64__)
1440 static int
1441 acpi_cpu_method_sysctl(SYSCTL_HANDLER_ARGS)
1442 {
1443 	struct acpi_cpu_softc *sc;
1444 	struct acpi_cx *cx;
1445 	struct sbuf sb;
1446 	char buf[128];
1447 	int i;
1448 
1449 	sc = (struct acpi_cpu_softc *)arg1;
1450 	sbuf_new(&sb, buf, sizeof(buf), SBUF_FIXEDLEN);
1451 	for (i = 0; i < sc->cpu_cx_count; i++) {
1452 		cx = &sc->cpu_cx_states[i];
1453 		sbuf_printf(&sb, "C%d/", i + 1);
1454 		if (cx->do_mwait) {
1455 			sbuf_cat(&sb, "mwait");
1456 			if (cx->mwait_hw_coord)
1457 				sbuf_cat(&sb, "/hwc");
1458 			if (cx->mwait_bm_avoidance)
1459 				sbuf_cat(&sb, "/bma");
1460 		} else if (cx->type == ACPI_STATE_C1) {
1461 			sbuf_cat(&sb, "hlt");
1462 		} else {
1463 			sbuf_cat(&sb, "io");
1464 		}
1465 		if (cx->type == ACPI_STATE_C1 && cx->p_lvlx != NULL)
1466 			sbuf_cat(&sb, "/iohlt");
1467 		sbuf_putc(&sb, ' ');
1468 	}
1469 	sbuf_trim(&sb);
1470 	sbuf_finish(&sb);
1471 	sysctl_handle_string(oidp, sbuf_data(&sb), sbuf_len(&sb), req);
1472 	sbuf_delete(&sb);
1473 	return (0);
1474 }
1475 #endif
1476 
1477 static int
1478 acpi_cpu_set_cx_lowest(struct acpi_cpu_softc *sc)
1479 {
1480     int i;
1481 
1482     ACPI_SERIAL_ASSERT(cpu);
1483     sc->cpu_cx_lowest = min(sc->cpu_cx_lowest_lim, sc->cpu_cx_count - 1);
1484 
1485     /* If not disabling, cache the new lowest non-C3 state. */
1486     sc->cpu_non_c3 = 0;
1487     for (i = sc->cpu_cx_lowest; i >= 0; i--) {
1488 	if (sc->cpu_cx_states[i].type < ACPI_STATE_C3) {
1489 	    sc->cpu_non_c3 = i;
1490 	    break;
1491 	}
1492     }
1493 
1494     /* Reset the statistics counters. */
1495     bzero(sc->cpu_cx_stats, sizeof(sc->cpu_cx_stats));
1496     return (0);
1497 }
1498 
1499 static int
1500 acpi_cpu_cx_lowest_sysctl(SYSCTL_HANDLER_ARGS)
1501 {
1502     struct	 acpi_cpu_softc *sc;
1503     char	 state[8];
1504     int		 val, error;
1505 
1506     sc = (struct acpi_cpu_softc *) arg1;
1507     snprintf(state, sizeof(state), "C%d", sc->cpu_cx_lowest_lim + 1);
1508     error = sysctl_handle_string(oidp, state, sizeof(state), req);
1509     if (error != 0 || req->newptr == NULL)
1510 	return (error);
1511     if (strlen(state) < 2 || toupper(state[0]) != 'C')
1512 	return (EINVAL);
1513     if (strcasecmp(state, "Cmax") == 0)
1514 	val = MAX_CX_STATES;
1515     else {
1516 	val = (int) strtol(state + 1, NULL, 10);
1517 	if (val < 1 || val > MAX_CX_STATES)
1518 	    return (EINVAL);
1519     }
1520 
1521     ACPI_SERIAL_BEGIN(cpu);
1522     sc->cpu_cx_lowest_lim = val - 1;
1523     acpi_cpu_set_cx_lowest(sc);
1524     ACPI_SERIAL_END(cpu);
1525 
1526     return (0);
1527 }
1528 
1529 static int
1530 acpi_cpu_global_cx_lowest_sysctl(SYSCTL_HANDLER_ARGS)
1531 {
1532     struct	acpi_cpu_softc *sc;
1533     char	state[8];
1534     int		val, error, i;
1535 
1536     snprintf(state, sizeof(state), "C%d", cpu_cx_lowest_lim + 1);
1537     error = sysctl_handle_string(oidp, state, sizeof(state), req);
1538     if (error != 0 || req->newptr == NULL)
1539 	return (error);
1540     if (strlen(state) < 2 || toupper(state[0]) != 'C')
1541 	return (EINVAL);
1542     if (strcasecmp(state, "Cmax") == 0)
1543 	val = MAX_CX_STATES;
1544     else {
1545 	val = (int) strtol(state + 1, NULL, 10);
1546 	if (val < 1 || val > MAX_CX_STATES)
1547 	    return (EINVAL);
1548     }
1549 
1550     /* Update the new lowest useable Cx state for all CPUs. */
1551     ACPI_SERIAL_BEGIN(cpu);
1552     cpu_cx_lowest_lim = val - 1;
1553     for (i = 0; i < cpu_ndevices; i++) {
1554 	sc = device_get_softc(cpu_devices[i]);
1555 	sc->cpu_cx_lowest_lim = cpu_cx_lowest_lim;
1556 	acpi_cpu_set_cx_lowest(sc);
1557     }
1558     ACPI_SERIAL_END(cpu);
1559 
1560     return (0);
1561 }
1562