xref: /freebsd/sys/dev/acpica/acpi_cpu.c (revision 9a46a1439c46045ecb33684d8fbdb1a841ccb425)
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 #include "opt_acpi.h"
30 #include <sys/param.h>
31 #include <sys/bus.h>
32 #include <sys/cpu.h>
33 #include <sys/kernel.h>
34 #include <sys/malloc.h>
35 #include <sys/module.h>
36 #include <sys/pcpu.h>
37 #include <sys/power.h>
38 #include <sys/proc.h>
39 #include <sys/sched.h>
40 #include <sys/sbuf.h>
41 #include <sys/smp.h>
42 
43 #include <dev/pci/pcivar.h>
44 #include <machine/atomic.h>
45 #include <machine/bus.h>
46 #if defined(__amd64__) || defined(__i386__)
47 #include <machine/clock.h>
48 #include <machine/specialreg.h>
49 #include <machine/md_var.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     bool		 do_mwait;
74     uint32_t		 mwait_hint;
75     bool		 mwait_hw_coord;
76     bool		 mwait_bm_avoidance;
77 };
78 #define MAX_CX_STATES	 8
79 
80 struct acpi_cpu_softc {
81     device_t		 cpu_dev;
82     ACPI_HANDLE		 cpu_handle;
83     struct pcpu		*cpu_pcpu;
84     uint32_t		 cpu_acpi_id;	/* ACPI processor id */
85     uint32_t		 cpu_p_blk;	/* ACPI P_BLK location */
86     uint32_t		 cpu_p_blk_len;	/* P_BLK length (must be 6). */
87     struct acpi_cx	 cpu_cx_states[MAX_CX_STATES];
88     int			 cpu_cx_count;	/* Number of valid Cx states. */
89     int			 cpu_prev_sleep;/* Last idle sleep duration. */
90     int			 cpu_features;	/* Child driver supported features. */
91     /* Runtime state. */
92     int			 cpu_non_c2;	/* Index of lowest non-C2 state. */
93     int			 cpu_non_c3;	/* Index of lowest non-C3 state. */
94     u_int		 cpu_cx_stats[MAX_CX_STATES];/* Cx usage history. */
95     uint64_t		 cpu_cx_duration[MAX_CX_STATES];/* Cx cumulative sleep */
96     /* Values for sysctl. */
97     struct sysctl_ctx_list cpu_sysctl_ctx;
98     struct sysctl_oid	*cpu_sysctl_tree;
99     int			 cpu_cx_lowest;
100     int			 cpu_cx_lowest_lim;
101     int			 cpu_disable_idle; /* Disable entry to idle function */
102     char 		 cpu_cx_supported[64];
103 };
104 
105 struct acpi_cpu_device {
106     struct resource_list	ad_rl;
107 };
108 
109 #define CPU_GET_REG(reg, width) 					\
110     (bus_space_read_ ## width(rman_get_bustag((reg)), 			\
111 		      rman_get_bushandle((reg)), 0))
112 #define CPU_SET_REG(reg, width, val)					\
113     (bus_space_write_ ## width(rman_get_bustag((reg)), 			\
114 		       rman_get_bushandle((reg)), 0, (val)))
115 
116 #define ACPI_NOTIFY_CX_STATES	0x81	/* _CST changed. */
117 
118 #define CPU_QUIRK_NO_C3		(1<<0)	/* C3-type states are not usable. */
119 #define CPU_QUIRK_NO_BM_CTRL	(1<<2)	/* No bus mastering control. */
120 
121 #define PCI_VENDOR_INTEL	0x8086
122 #define PCI_DEVICE_82371AB_3	0x7113	/* PIIX4 chipset for quirks. */
123 #define PCI_REVISION_A_STEP	0
124 #define PCI_REVISION_B_STEP	1
125 #define PCI_REVISION_4E		2
126 #define PCI_REVISION_4M		3
127 #define PIIX4_DEVACTB_REG	0x58
128 #define PIIX4_BRLD_EN_IRQ0	(1<<0)
129 #define PIIX4_BRLD_EN_IRQ	(1<<1)
130 #define PIIX4_BRLD_EN_IRQ8	(1<<5)
131 #define PIIX4_STOP_BREAK_MASK	(PIIX4_BRLD_EN_IRQ0 | PIIX4_BRLD_EN_IRQ | PIIX4_BRLD_EN_IRQ8)
132 #define PIIX4_PCNTRL_BST_EN	(1<<10)
133 
134 #define	CST_FFH_VENDOR_INTEL	1
135 #define	CST_FFH_VENDOR_AMD	2
136 #define	CST_FFH_INTEL_CL_C1IO	1
137 #define	CST_FFH_INTEL_CL_MWAIT	2
138 #define	CST_FFH_MWAIT_HW_COORD	0x0001
139 #define	CST_FFH_MWAIT_BM_AVOID	0x0002
140 
141 #define	CPUDEV_DEVICE_ID	"ACPI0007"
142 
143 /* Platform hardware resource information. */
144 static uint32_t		 cpu_smi_cmd;	/* Value to write to SMI_CMD. */
145 static uint8_t		 cpu_cst_cnt;	/* Indicate we are _CST aware. */
146 static int		 cpu_quirks;	/* Indicate any hardware bugs. */
147 
148 /* Values for sysctl. */
149 static struct sysctl_ctx_list cpu_sysctl_ctx;
150 static struct sysctl_oid *cpu_sysctl_tree;
151 static int		 cpu_cx_generic;
152 static int		 cpu_cx_lowest_lim;
153 #if defined(__i386__) || defined(__amd64__)
154 static bool		 cppc_notify;
155 #endif
156 
157 static struct acpi_cpu_softc **cpu_softc;
158 ACPI_SERIAL_DECL(cpu, "ACPI CPU");
159 
160 static int	acpi_cpu_probe(device_t dev);
161 static int	acpi_cpu_attach(device_t dev);
162 static int	acpi_cpu_suspend(device_t dev);
163 static int	acpi_cpu_resume(device_t dev);
164 static int	acpi_pcpu_get_id(device_t dev, uint32_t acpi_id,
165 		    u_int *cpu_id);
166 static void	acpi_cpu_madt_handler(ACPI_SUBTABLE_HEADER *entry, void *arg);
167 static bool	acpi_cpu_enabled_in_madt(uint32_t acpi_id);
168 static struct resource_list *acpi_cpu_get_rlist(device_t dev, device_t child);
169 static device_t	acpi_cpu_add_child(device_t dev, u_int order, const char *name,
170 		    int unit);
171 static int	acpi_cpu_read_ivar(device_t dev, device_t child, int index,
172 		    uintptr_t *result);
173 static int	acpi_cpu_shutdown(device_t dev);
174 static void	acpi_cpu_cx_probe(struct acpi_cpu_softc *sc);
175 static void	acpi_cpu_generic_cx_probe(struct acpi_cpu_softc *sc);
176 static int	acpi_cpu_cx_cst(struct acpi_cpu_softc *sc);
177 static void	acpi_cpu_startup(void *arg);
178 static void	acpi_cpu_startup_cx(struct acpi_cpu_softc *sc);
179 static void	acpi_cpu_cx_list(struct acpi_cpu_softc *sc);
180 #if defined(__i386__) || defined(__amd64__)
181 static void	acpi_cpu_idle(sbintime_t sbt);
182 #endif
183 static void	acpi_cpu_notify(ACPI_HANDLE h, UINT32 notify, void *context);
184 static void	acpi_cpu_quirks(void);
185 static void	acpi_cpu_quirks_piix4(void);
186 static int	acpi_cpu_usage_sysctl(SYSCTL_HANDLER_ARGS);
187 static int	acpi_cpu_usage_counters_sysctl(SYSCTL_HANDLER_ARGS);
188 static int	acpi_cpu_duration_counters_sysctl(SYSCTL_HANDLER_ARGS);
189 static int	acpi_cpu_set_cx_lowest(struct acpi_cpu_softc *sc);
190 static int	acpi_cpu_cx_lowest_sysctl(SYSCTL_HANDLER_ARGS);
191 static int	acpi_cpu_global_cx_lowest_sysctl(SYSCTL_HANDLER_ARGS);
192 #if defined(__i386__) || defined(__amd64__)
193 static int	acpi_cpu_method_sysctl(SYSCTL_HANDLER_ARGS);
194 #endif
195 
196 static device_method_t acpi_cpu_methods[] = {
197     /* Device interface */
198     DEVMETHOD(device_probe,	acpi_cpu_probe),
199     DEVMETHOD(device_attach,	acpi_cpu_attach),
200     DEVMETHOD(device_detach,	bus_generic_detach),
201     DEVMETHOD(device_shutdown,	acpi_cpu_shutdown),
202     DEVMETHOD(device_suspend,	acpi_cpu_suspend),
203     DEVMETHOD(device_resume,	acpi_cpu_resume),
204 
205     /* Bus interface */
206     DEVMETHOD(bus_add_child,	acpi_cpu_add_child),
207     DEVMETHOD(bus_read_ivar,	acpi_cpu_read_ivar),
208     DEVMETHOD(bus_get_resource_list, acpi_cpu_get_rlist),
209     DEVMETHOD(bus_get_resource,	bus_generic_rl_get_resource),
210     DEVMETHOD(bus_set_resource,	bus_generic_rl_set_resource),
211     DEVMETHOD(bus_alloc_resource, bus_generic_rl_alloc_resource),
212     DEVMETHOD(bus_release_resource, bus_generic_rl_release_resource),
213     DEVMETHOD(bus_activate_resource, bus_generic_activate_resource),
214     DEVMETHOD(bus_deactivate_resource, bus_generic_deactivate_resource),
215     DEVMETHOD(bus_setup_intr,	bus_generic_setup_intr),
216     DEVMETHOD(bus_teardown_intr, bus_generic_teardown_intr),
217 
218     DEVMETHOD_END
219 };
220 
221 static driver_t acpi_cpu_driver = {
222     "cpu",
223     acpi_cpu_methods,
224     sizeof(struct acpi_cpu_softc),
225 };
226 
227 DRIVER_MODULE(cpu, acpi, acpi_cpu_driver, 0, 0);
228 MODULE_DEPEND(cpu, acpi, 1, 1, 1);
229 
230 static int
acpi_cpu_probe(device_t dev)231 acpi_cpu_probe(device_t dev)
232 {
233     static char		   *cpudev_ids[] = { CPUDEV_DEVICE_ID, NULL };
234     int			   acpi_id, cpu_id;
235     ACPI_BUFFER		   buf;
236     ACPI_HANDLE		   handle;
237     ACPI_OBJECT		   *obj;
238     ACPI_STATUS		   status;
239     ACPI_OBJECT_TYPE	   type;
240 
241     if (acpi_disabled("cpu"))
242 	return (ENXIO);
243     type = acpi_get_type(dev);
244     if (type != ACPI_TYPE_PROCESSOR && type != ACPI_TYPE_DEVICE)
245 	return (ENXIO);
246     if (type == ACPI_TYPE_DEVICE &&
247 	ACPI_ID_PROBE(device_get_parent(dev), dev, cpudev_ids, NULL) >= 0)
248 	return (ENXIO);
249 
250     handle = acpi_get_handle(dev);
251     if (cpu_softc == NULL)
252 	cpu_softc = malloc(sizeof(struct acpi_cpu_softc *) *
253 	    (mp_maxid + 1), M_TEMP /* XXX */, M_WAITOK | M_ZERO);
254 
255     if (type == ACPI_TYPE_PROCESSOR) {
256 	/* Get our Processor object. */
257 	buf.Pointer = NULL;
258 	buf.Length = ACPI_ALLOCATE_BUFFER;
259 	status = AcpiEvaluateObject(handle, NULL, NULL, &buf);
260 	if (ACPI_FAILURE(status)) {
261 	    device_printf(dev, "probe failed to get Processor obj - %s\n",
262 		AcpiFormatException(status));
263 	    return (ENXIO);
264 	}
265 	obj = (ACPI_OBJECT *)buf.Pointer;
266 	if (obj->Type != ACPI_TYPE_PROCESSOR) {
267 	    device_printf(dev, "Processor object has bad type %d\n",
268 		obj->Type);
269 	    AcpiOsFree(obj);
270 	    return (ENXIO);
271 	}
272 
273 	/*
274 	 * Find the processor associated with our unit.  We could use the
275 	 * ProcId as a key, however, some boxes do not have the same values
276 	 * in their Processor object as the ProcId values in the MADT.
277 	 */
278 	acpi_id = obj->Processor.ProcId;
279 	AcpiOsFree(obj);
280     } else {
281 	status = acpi_GetInteger(handle, "_UID", &acpi_id);
282 	if (ACPI_FAILURE(status)) {
283 	    device_printf(dev, "Device object has bad value - %s\n",
284 		AcpiFormatException(status));
285 	    return (ENXIO);
286 	}
287     }
288     if (acpi_pcpu_get_id(dev, acpi_id, &cpu_id) != 0) {
289 	if (bootverbose && (type != ACPI_TYPE_PROCESSOR || acpi_id != 255) &&
290 	    acpi_cpu_enabled_in_madt(acpi_id))
291 	    printf("ACPI: Processor %s (ACPI ID %u) enabled but not online, "
292 		"ignored\n", acpi_name(handle), acpi_id);
293 	return (ENXIO);
294     }
295 
296     if (device_set_unit(dev, cpu_id) != 0)
297 	return (ENXIO);
298 
299     device_set_desc(dev, "ACPI CPU");
300 
301     if (!bootverbose && device_get_unit(dev) != 0) {
302 	    device_quiet(dev);
303 	    device_quiet_children(dev);
304     }
305 
306     return (BUS_PROBE_DEFAULT);
307 }
308 
309 static int
acpi_cpu_attach(device_t dev)310 acpi_cpu_attach(device_t dev)
311 {
312     ACPI_BUFFER		   buf;
313     ACPI_OBJECT		   arg, *obj;
314     ACPI_OBJECT_LIST	   arglist;
315     struct pcpu		   *pcpu_data;
316     struct acpi_cpu_softc *sc;
317     struct acpi_softc	  *acpi_sc;
318     ACPI_STATUS		   status;
319     int			   cpu_id, drv_count, i;
320     driver_t 		  **drivers;
321     uint32_t		   cap_set[3];
322 
323     /* UUID needed by _OSC evaluation */
324     static uint8_t cpu_oscuuid[16] = { 0x16, 0xA6, 0x77, 0x40, 0x0C, 0x29,
325 				       0xBE, 0x47, 0x9E, 0xBD, 0xD8, 0x70,
326 				       0x58, 0x71, 0x39, 0x53 };
327 
328     ACPI_FUNCTION_TRACE((char *)(uintptr_t)__func__);
329 
330     sc = device_get_softc(dev);
331     sc->cpu_dev = dev;
332     sc->cpu_handle = acpi_get_handle(dev);
333     cpu_id = device_get_unit(dev);
334     cpu_softc[cpu_id] = sc;
335     pcpu_data = pcpu_find(cpu_id);
336     pcpu_data->pc_device = dev;
337     sc->cpu_pcpu = pcpu_data;
338     cpu_smi_cmd = AcpiGbl_FADT.SmiCommand;
339     cpu_cst_cnt = AcpiGbl_FADT.CstControl;
340 
341     if (acpi_get_type(dev) == ACPI_TYPE_PROCESSOR) {
342 	buf.Pointer = NULL;
343 	buf.Length = ACPI_ALLOCATE_BUFFER;
344 	status = AcpiEvaluateObject(sc->cpu_handle, NULL, NULL, &buf);
345 	if (ACPI_FAILURE(status)) {
346 	    device_printf(dev, "attach failed to get Processor obj - %s\n",
347 		AcpiFormatException(status));
348 	    return (ENXIO);
349 	}
350 	obj = (ACPI_OBJECT *)buf.Pointer;
351 	sc->cpu_p_blk = obj->Processor.PblkAddress;
352 	sc->cpu_p_blk_len = obj->Processor.PblkLength;
353 	sc->cpu_acpi_id = obj->Processor.ProcId;
354 	AcpiOsFree(obj);
355     } else {
356 	KASSERT(acpi_get_type(dev) == ACPI_TYPE_DEVICE,
357 	    ("Unexpected ACPI object"));
358 	status = acpi_GetInteger(sc->cpu_handle, "_UID", &sc->cpu_acpi_id);
359 	if (ACPI_FAILURE(status)) {
360 	    device_printf(dev, "Device object has bad value - %s\n",
361 		AcpiFormatException(status));
362 	    return (ENXIO);
363 	}
364 	sc->cpu_p_blk = 0;
365 	sc->cpu_p_blk_len = 0;
366     }
367     ACPI_DEBUG_PRINT((ACPI_DB_INFO, "acpi_cpu%d: P_BLK at %#x/%d\n",
368 		     device_get_unit(dev), sc->cpu_p_blk, sc->cpu_p_blk_len));
369 
370     /*
371      * If this is the first cpu we attach, create and initialize the generic
372      * resources that will be used by all acpi cpu devices.
373      */
374     if (device_get_unit(dev) == 0) {
375 	/* Assume we won't be using generic Cx mode by default */
376 	cpu_cx_generic = FALSE;
377 
378 	/* Install hw.acpi.cpu sysctl tree */
379 	acpi_sc = acpi_device_get_parent_softc(dev);
380 	sysctl_ctx_init(&cpu_sysctl_ctx);
381 	cpu_sysctl_tree = SYSCTL_ADD_NODE(&cpu_sysctl_ctx,
382 	    SYSCTL_CHILDREN(acpi_sc->acpi_sysctl_tree), OID_AUTO, "cpu",
383 	    CTLFLAG_RD | CTLFLAG_MPSAFE, 0, "node for CPU children");
384 
385 #if defined(__i386__) || defined(__amd64__)
386 	/* Add sysctl handler to control registering for CPPC notifications */
387 	cppc_notify = 1;
388 	SYSCTL_ADD_BOOL(&cpu_sysctl_ctx, SYSCTL_CHILDREN(cpu_sysctl_tree),
389 	    OID_AUTO, "cppc_notify", CTLFLAG_RDTUN | CTLFLAG_MPSAFE,
390 	    &cppc_notify, 0, "Register for CPPC Notifications");
391 #endif
392     }
393 
394     /*
395      * Before calling any CPU methods, collect child driver feature hints
396      * and notify ACPI of them.  We support unified SMP power control
397      * so advertise this ourselves.  Note this is not the same as independent
398      * SMP control where each CPU can have different settings.
399      */
400     sc->cpu_features = ACPI_CAP_SMP_SAME | ACPI_CAP_SMP_SAME_C3 |
401       ACPI_CAP_C1_IO_HALT;
402 
403 #if defined(__i386__) || defined(__amd64__)
404     /*
405      * Ask for MWAIT modes if not disabled and interrupts work
406      * reasonable with MWAIT.
407      */
408     if (!acpi_disabled("mwait") && cpu_mwait_usable())
409 	sc->cpu_features |= ACPI_CAP_SMP_C1_NATIVE | ACPI_CAP_SMP_C3_NATIVE;
410 
411     /*
412      * Work around a lingering SMM bug which leads to freezes when handling
413      * CPPC notifications. Tell the SMM we will handle any CPPC notifications.
414      */
415     if ((cpu_power_eax & CPUTPM1_HWP_NOTIFICATION) && cppc_notify)
416 	    sc->cpu_features |= ACPI_CAP_INTR_CPPC;
417 #endif
418 
419     if (devclass_get_drivers(device_get_devclass(dev), &drivers,
420 	&drv_count) == 0) {
421 	for (i = 0; i < drv_count; i++) {
422 	    u_int features = 0;
423 
424 	    if (ACPI_GET_FEATURES(drivers[i], &features) == 0)
425 		sc->cpu_features |= features;
426 	}
427 	free(drivers, M_TEMP);
428     }
429 
430     /*
431      * CPU capabilities are specified in
432      * Intel Processor Vendor-Specific ACPI Interface Specification.
433      */
434     if (sc->cpu_features) {
435 	cap_set[1] = sc->cpu_features;
436 	status = acpi_EvaluateOSC(sc->cpu_handle, cpu_oscuuid, 1, 2, cap_set,
437 	    cap_set, false);
438 	if (ACPI_SUCCESS(status)) {
439 	    if (cap_set[0] != 0)
440 		device_printf(dev, "_OSC returned status %#x\n", cap_set[0]);
441 	}
442 	else {
443 	    arglist.Pointer = &arg;
444 	    arglist.Count = 1;
445 	    arg.Type = ACPI_TYPE_BUFFER;
446 	    arg.Buffer.Length = sizeof(cap_set);
447 	    arg.Buffer.Pointer = (uint8_t *)cap_set;
448 	    cap_set[0] = 1; /* revision */
449 	    cap_set[1] = 1; /* number of capabilities integers */
450 	    cap_set[2] = sc->cpu_features;
451 	    AcpiEvaluateObject(sc->cpu_handle, "_PDC", &arglist, NULL);
452 	}
453     }
454 
455     /* Probe for Cx state support. */
456     acpi_cpu_cx_probe(sc);
457 
458     return (0);
459 }
460 
461 static void
acpi_cpu_postattach(void * unused __unused)462 acpi_cpu_postattach(void *unused __unused)
463 {
464     struct acpi_cpu_softc *sc;
465     int attached = 0, i;
466 
467     if (cpu_softc == NULL)
468 	return;
469 
470     bus_topo_lock();
471     CPU_FOREACH(i) {
472 	if ((sc = cpu_softc[i]) != NULL)
473 		bus_identify_children(sc->cpu_dev);
474     }
475     CPU_FOREACH(i) {
476 	if ((sc = cpu_softc[i]) != NULL) {
477 		bus_attach_children(sc->cpu_dev);
478 		attached = 1;
479 	}
480     }
481     bus_topo_unlock();
482 
483     if (attached) {
484 #ifdef EARLY_AP_STARTUP
485 	acpi_cpu_startup(NULL);
486 #else
487 	/* Queue post cpu-probing task handler */
488 	AcpiOsExecute(OSL_NOTIFY_HANDLER, acpi_cpu_startup, NULL);
489 #endif
490     }
491 }
492 
493 SYSINIT(acpi_cpu, SI_SUB_CONFIGURE, SI_ORDER_MIDDLE,
494     acpi_cpu_postattach, NULL);
495 
496 static void
disable_idle(struct acpi_cpu_softc * sc)497 disable_idle(struct acpi_cpu_softc *sc)
498 {
499     cpuset_t cpuset;
500 
501     CPU_SETOF(sc->cpu_pcpu->pc_cpuid, &cpuset);
502     sc->cpu_disable_idle = TRUE;
503 
504     /*
505      * Ensure that the CPU is not in idle state or in acpi_cpu_idle().
506      * Note that this code depends on the fact that the rendezvous IPI
507      * can not penetrate context where interrupts are disabled and acpi_cpu_idle
508      * is called and executed in such a context with interrupts being re-enabled
509      * right before return.
510      */
511     smp_rendezvous_cpus(cpuset, smp_no_rendezvous_barrier, NULL,
512 	smp_no_rendezvous_barrier, NULL);
513 }
514 
515 static void
enable_idle(struct acpi_cpu_softc * sc)516 enable_idle(struct acpi_cpu_softc *sc)
517 {
518 
519     if (sc->cpu_cx_count > sc->cpu_non_c3 + 1 &&
520 	(cpu_quirks & CPU_QUIRK_NO_BM_CTRL) == 0)
521 	    AcpiWriteBitRegister(ACPI_BITREG_BUS_MASTER_RLD, 1);
522     sc->cpu_disable_idle = FALSE;
523 }
524 
525 #if defined(__i386__) || defined(__amd64__)
526 static int
is_idle_disabled(struct acpi_cpu_softc * sc)527 is_idle_disabled(struct acpi_cpu_softc *sc)
528 {
529 
530     return (sc->cpu_disable_idle);
531 }
532 #endif
533 
534 /*
535  * Disable any entry to the idle function during suspend and re-enable it
536  * during resume.
537  */
538 static int
acpi_cpu_suspend(device_t dev)539 acpi_cpu_suspend(device_t dev)
540 {
541     int error;
542 
543     error = bus_generic_suspend(dev);
544     if (error)
545 	return (error);
546     disable_idle(device_get_softc(dev));
547     return (0);
548 }
549 
550 static int
acpi_cpu_resume(device_t dev)551 acpi_cpu_resume(device_t dev)
552 {
553 
554     enable_idle(device_get_softc(dev));
555     return (bus_generic_resume(dev));
556 }
557 
558 /*
559  * Find the processor associated with a given ACPI ID.
560  */
561 static int
acpi_pcpu_get_id(device_t dev,uint32_t acpi_id,u_int * cpu_id)562 acpi_pcpu_get_id(device_t dev, uint32_t acpi_id, u_int *cpu_id)
563 {
564     struct pcpu	*pc;
565     u_int	 i;
566 
567     CPU_FOREACH(i) {
568 	pc = pcpu_find(i);
569 	if (pc->pc_acpi_id == acpi_id) {
570 	    *cpu_id = pc->pc_cpuid;
571 	    return (0);
572 	}
573     }
574 
575     /*
576      * If pc_acpi_id for CPU 0 is not initialized (e.g. a non-APIC
577      * UP box) use the ACPI ID from the first processor we find.
578      */
579     if (mp_ncpus == 1) {
580 	pc = pcpu_find(0);
581 	if (pc->pc_acpi_id == 0xffffffff)
582 	    pc->pc_acpi_id = acpi_id;
583 	*cpu_id = 0;
584 	return (0);
585     }
586 
587     return (ESRCH);
588 }
589 
590 struct acpi_cpu_madt_check {
591     uint32_t	acpi_id;
592     bool	enabled;
593 };
594 
595 static void
acpi_cpu_madt_handler(ACPI_SUBTABLE_HEADER * entry,void * arg)596 acpi_cpu_madt_handler(ACPI_SUBTABLE_HEADER *entry, void *arg)
597 {
598     struct acpi_cpu_madt_check *check = arg;
599     uint32_t id, flags;
600 
601     switch (entry->Type) {
602     case ACPI_MADT_TYPE_LOCAL_APIC:
603 	id = ((ACPI_MADT_LOCAL_APIC *)entry)->ProcessorId;
604 	flags = ((ACPI_MADT_LOCAL_APIC *)entry)->LapicFlags;
605 	break;
606     case ACPI_MADT_TYPE_LOCAL_X2APIC:
607 	id = ((ACPI_MADT_LOCAL_X2APIC *)entry)->Uid;
608 	flags = ((ACPI_MADT_LOCAL_X2APIC *)entry)->LapicFlags;
609 	break;
610     case ACPI_MADT_TYPE_GENERIC_INTERRUPT:
611 	id = ((ACPI_MADT_GENERIC_INTERRUPT *)entry)->Uid;
612 	flags = ((ACPI_MADT_GENERIC_INTERRUPT *)entry)->Flags;
613 	break;
614     case ACPI_MADT_TYPE_RINTC:
615 	id = ((ACPI_MADT_RINTC *)entry)->Uid;
616 	flags = ((ACPI_MADT_RINTC *)entry)->Flags;
617 	break;
618     default:
619 	return;
620     }
621     if (id == check->acpi_id && (flags & ACPI_MADT_ENABLED) != 0)
622 	check->enabled = true;
623 }
624 
625 static bool
acpi_cpu_enabled_in_madt(uint32_t acpi_id)626 acpi_cpu_enabled_in_madt(uint32_t acpi_id)
627 {
628     static ACPI_TABLE_MADT *madt;
629     struct acpi_cpu_madt_check check = {
630 	.acpi_id = acpi_id,
631     };
632     ACPI_TABLE_HEADER *hdr;
633 
634     if (madt == NULL) {
635 	if (ACPI_FAILURE(AcpiGetTable(ACPI_SIG_MADT, 1, &hdr)))
636 	    return (false);
637 	madt = (ACPI_TABLE_MADT *)hdr;
638 	/* Retain the table reference for subsequent processor probes. */
639     }
640 
641     acpi_walk_subtables(madt + 1,
642 	(char *)madt + madt->Header.Length, acpi_cpu_madt_handler, &check);
643     return (check.enabled);
644 }
645 
646 static struct resource_list *
acpi_cpu_get_rlist(device_t dev,device_t child)647 acpi_cpu_get_rlist(device_t dev, device_t child)
648 {
649     struct acpi_cpu_device *ad;
650 
651     ad = device_get_ivars(child);
652     if (ad == NULL)
653 	return (NULL);
654     return (&ad->ad_rl);
655 }
656 
657 static device_t
acpi_cpu_add_child(device_t dev,u_int order,const char * name,int unit)658 acpi_cpu_add_child(device_t dev, u_int order, const char *name, int unit)
659 {
660     struct acpi_cpu_device *ad;
661     device_t child;
662 
663     if ((ad = malloc(sizeof(*ad), M_TEMP, M_NOWAIT | M_ZERO)) == NULL)
664 	return (NULL);
665 
666     resource_list_init(&ad->ad_rl);
667 
668     child = device_add_child_ordered(dev, order, name, unit);
669     if (child != NULL)
670 	device_set_ivars(child, ad);
671     else
672 	free(ad, M_TEMP);
673     return (child);
674 }
675 
676 static int
acpi_cpu_read_ivar(device_t dev,device_t child,int index,uintptr_t * result)677 acpi_cpu_read_ivar(device_t dev, device_t child, int index, uintptr_t *result)
678 {
679     struct acpi_cpu_softc *sc;
680 
681     sc = device_get_softc(dev);
682     switch (index) {
683     case ACPI_IVAR_HANDLE:
684 	*result = (uintptr_t)sc->cpu_handle;
685 	break;
686     case CPU_IVAR_PCPU:
687 	*result = (uintptr_t)sc->cpu_pcpu;
688 	break;
689 #if defined(__amd64__) || defined(__i386__)
690     case CPU_IVAR_NOMINAL_MHZ:
691 	if (tsc_is_invariant) {
692 	    *result = (uintptr_t)(atomic_load_acq_64(&tsc_freq) / 1000000);
693 	    break;
694 	}
695 	/* FALLTHROUGH */
696 #endif
697     default:
698 	return (ENOENT);
699     }
700     return (0);
701 }
702 
703 static int
acpi_cpu_shutdown(device_t dev)704 acpi_cpu_shutdown(device_t dev)
705 {
706     ACPI_FUNCTION_TRACE((char *)(uintptr_t)__func__);
707 
708     /* Allow children to shutdown first. */
709     bus_generic_shutdown(dev);
710 
711     /*
712      * Disable any entry to the idle function.
713      */
714     disable_idle(device_get_softc(dev));
715 
716     /*
717      * CPU devices are not truly detached and remain referenced,
718      * so their resources are not freed.
719      */
720 
721     return_VALUE (0);
722 }
723 
724 static void
acpi_cpu_cx_probe(struct acpi_cpu_softc * sc)725 acpi_cpu_cx_probe(struct acpi_cpu_softc *sc)
726 {
727     ACPI_FUNCTION_TRACE((char *)(uintptr_t)__func__);
728 
729     /* Use initial sleep value of 1 sec. to start with lowest idle state. */
730     sc->cpu_prev_sleep = 1000000;
731     sc->cpu_cx_lowest = 0;
732     sc->cpu_cx_lowest_lim = 0;
733 
734     /*
735      * Check for the ACPI 2.0 _CST sleep states object. If we can't find
736      * any, we'll revert to generic FADT/P_BLK Cx control method which will
737      * be handled by acpi_cpu_startup. We need to defer to after having
738      * probed all the cpus in the system before probing for generic Cx
739      * states as we may already have found cpus with valid _CST packages
740      */
741     if (!cpu_cx_generic && acpi_cpu_cx_cst(sc) != 0) {
742 	/*
743 	 * We were unable to find a _CST package for this cpu or there
744 	 * was an error parsing it. Switch back to generic mode.
745 	 */
746 	cpu_cx_generic = TRUE;
747 	if (bootverbose)
748 	    device_printf(sc->cpu_dev, "switching to generic Cx mode\n");
749     }
750 
751     /*
752      * TODO: _CSD Package should be checked here.
753      */
754 }
755 
756 static void
acpi_cpu_generic_cx_probe(struct acpi_cpu_softc * sc)757 acpi_cpu_generic_cx_probe(struct acpi_cpu_softc *sc)
758 {
759     ACPI_GENERIC_ADDRESS	 gas;
760     struct acpi_cx		*cx_ptr;
761 
762     sc->cpu_cx_count = 0;
763     cx_ptr = sc->cpu_cx_states;
764 
765     /* Use initial sleep value of 1 sec. to start with lowest idle state. */
766     sc->cpu_prev_sleep = 1000000;
767 
768     /* C1 has been required since just after ACPI 1.0 */
769     cx_ptr->type = ACPI_STATE_C1;
770     cx_ptr->trans_lat = 0;
771     cx_ptr++;
772     sc->cpu_non_c2 = sc->cpu_cx_count;
773     sc->cpu_non_c3 = sc->cpu_cx_count;
774     sc->cpu_cx_count++;
775 
776     /*
777      * The spec says P_BLK must be 6 bytes long.  However, some systems
778      * use it to indicate a fractional set of features present so we
779      * take 5 as C2.  Some may also have a value of 7 to indicate
780      * another C3 but most use _CST for this (as required) and having
781      * "only" C1-C3 is not a hardship.
782      */
783     if (sc->cpu_p_blk_len < 5)
784 	return;
785 
786     /* Validate and allocate resources for C2 (P_LVL2). */
787     gas.SpaceId = ACPI_ADR_SPACE_SYSTEM_IO;
788     gas.BitWidth = 8;
789     if (AcpiGbl_FADT.C2Latency <= 100) {
790 	gas.Address = sc->cpu_p_blk + 4;
791 	cx_ptr->res_rid = 0;
792 	acpi_bus_alloc_gas(sc->cpu_dev, &cx_ptr->res_type, cx_ptr->res_rid,
793 	    &gas, &cx_ptr->p_lvlx, RF_SHAREABLE);
794 	if (cx_ptr->p_lvlx != NULL) {
795 	    cx_ptr->type = ACPI_STATE_C2;
796 	    cx_ptr->trans_lat = AcpiGbl_FADT.C2Latency;
797 	    cx_ptr++;
798 	    sc->cpu_non_c3 = sc->cpu_cx_count;
799 	    sc->cpu_cx_count++;
800 	}
801     }
802     if (sc->cpu_p_blk_len < 6)
803 	return;
804 
805     /* Validate and allocate resources for C3 (P_LVL3). */
806     if (AcpiGbl_FADT.C3Latency <= 1000 && !(cpu_quirks & CPU_QUIRK_NO_C3)) {
807 	gas.Address = sc->cpu_p_blk + 5;
808 	cx_ptr->res_rid = 1;
809 	acpi_bus_alloc_gas(sc->cpu_dev, &cx_ptr->res_type, cx_ptr->res_rid,
810 	    &gas, &cx_ptr->p_lvlx, RF_SHAREABLE);
811 	if (cx_ptr->p_lvlx != NULL) {
812 	    cx_ptr->type = ACPI_STATE_C3;
813 	    cx_ptr->trans_lat = AcpiGbl_FADT.C3Latency;
814 	    cx_ptr++;
815 	    sc->cpu_cx_count++;
816 	}
817     }
818 }
819 
820 #if defined(__i386__) || defined(__amd64__)
821 static void
acpi_cpu_cx_cst_mwait(struct acpi_cx * cx_ptr,uint64_t address,int accsize)822 acpi_cpu_cx_cst_mwait(struct acpi_cx *cx_ptr, uint64_t address, int accsize)
823 {
824 
825 	cx_ptr->do_mwait = true;
826 	cx_ptr->mwait_hint = address & 0xffffffff;
827 	cx_ptr->mwait_hw_coord = (accsize & CST_FFH_MWAIT_HW_COORD) != 0;
828 	cx_ptr->mwait_bm_avoidance = (accsize & CST_FFH_MWAIT_BM_AVOID) != 0;
829 }
830 #endif
831 
832 static void
acpi_cpu_cx_cst_free_plvlx(device_t cpu_dev,struct acpi_cx * cx_ptr)833 acpi_cpu_cx_cst_free_plvlx(device_t cpu_dev, struct acpi_cx *cx_ptr)
834 {
835 
836 	if (cx_ptr->p_lvlx == NULL)
837 		return;
838 	bus_release_resource(cpu_dev, cx_ptr->res_type, cx_ptr->res_rid,
839 	    cx_ptr->p_lvlx);
840 	cx_ptr->p_lvlx = NULL;
841 }
842 
843 /*
844  * Parse a _CST package and set up its Cx states.  Since the _CST object
845  * can change dynamically, our notify handler may call this function
846  * to clean up and probe the new _CST package.
847  */
848 static int
acpi_cpu_cx_cst(struct acpi_cpu_softc * sc)849 acpi_cpu_cx_cst(struct acpi_cpu_softc *sc)
850 {
851     struct	 acpi_cx *cx_ptr;
852     ACPI_STATUS	 status;
853     ACPI_BUFFER	 buf;
854     ACPI_OBJECT	*top;
855     ACPI_OBJECT	*pkg;
856     uint32_t	 count;
857     int		 i;
858 #if defined(__i386__) || defined(__amd64__)
859     uint64_t	 address;
860     int		 vendor, class, accsize;
861 #endif
862 
863     ACPI_FUNCTION_TRACE((char *)(uintptr_t)__func__);
864 
865     buf.Pointer = NULL;
866     buf.Length = ACPI_ALLOCATE_BUFFER;
867     status = AcpiEvaluateObject(sc->cpu_handle, "_CST", NULL, &buf);
868     if (ACPI_FAILURE(status))
869 	return (ENXIO);
870 
871     /* _CST is a package with a count and at least one Cx package. */
872     top = (ACPI_OBJECT *)buf.Pointer;
873     if (!ACPI_PKG_VALID(top, 2) || acpi_PkgInt32(top, 0, &count) != 0) {
874 	device_printf(sc->cpu_dev, "invalid _CST package\n");
875 	AcpiOsFree(buf.Pointer);
876 	return (ENXIO);
877     }
878     if (count != top->Package.Count - 1) {
879 	device_printf(sc->cpu_dev, "invalid _CST state count (%d != %d)\n",
880 	       count, top->Package.Count - 1);
881 	count = top->Package.Count - 1;
882     }
883     if (count > MAX_CX_STATES) {
884 	device_printf(sc->cpu_dev, "_CST has too many states (%d)\n", count);
885 	count = MAX_CX_STATES;
886     }
887 
888     sc->cpu_non_c2 = 0;
889     sc->cpu_non_c3 = 0;
890     sc->cpu_cx_count = 0;
891     cx_ptr = sc->cpu_cx_states;
892 
893     /*
894      * C1 has been required since just after ACPI 1.0.
895      * Reserve the first slot for it.
896      */
897     cx_ptr->type = ACPI_STATE_C0;
898     cx_ptr++;
899     sc->cpu_cx_count++;
900 
901     /* Set up all valid states. */
902     for (i = 0; i < count; i++) {
903 	pkg = &top->Package.Elements[i + 1];
904 	if (!ACPI_PKG_VALID(pkg, 4) ||
905 	    acpi_PkgInt32(pkg, 1, &cx_ptr->type) != 0 ||
906 	    acpi_PkgInt32(pkg, 2, &cx_ptr->trans_lat) != 0 ||
907 	    acpi_PkgInt32(pkg, 3, &cx_ptr->power) != 0) {
908 	    device_printf(sc->cpu_dev, "skipping invalid Cx state package\n");
909 	    continue;
910 	}
911 
912 	/* Validate the state to see if we should use it. */
913 	switch (cx_ptr->type) {
914 	case ACPI_STATE_C1:
915 	    acpi_cpu_cx_cst_free_plvlx(sc->cpu_dev, cx_ptr);
916 #if defined(__i386__) || defined(__amd64__)
917 	    if (acpi_PkgFFH_IntelCpu(pkg, 0, &vendor, &class, &address,
918 	      &accsize) == 0 &&
919 		(vendor == CST_FFH_VENDOR_INTEL || vendor == CST_FFH_VENDOR_AMD)) {
920 		if (class == CST_FFH_INTEL_CL_C1IO) {
921 		    /* C1 I/O then Halt */
922 		    cx_ptr->res_rid = sc->cpu_cx_count;
923 		    bus_set_resource(sc->cpu_dev, SYS_RES_IOPORT,
924 		      cx_ptr->res_rid, address, 1);
925 		    cx_ptr->p_lvlx = bus_alloc_resource_any(sc->cpu_dev,
926 		      SYS_RES_IOPORT, &cx_ptr->res_rid, RF_ACTIVE |
927 		      RF_SHAREABLE);
928 		    if (cx_ptr->p_lvlx == NULL) {
929 			bus_delete_resource(sc->cpu_dev, SYS_RES_IOPORT,
930 			  cx_ptr->res_rid);
931 			device_printf(sc->cpu_dev,
932 			  "C1 I/O failed to allocate port %d, "
933 			  "degrading to C1 Halt", (int)address);
934 		    }
935 		} else if (class == CST_FFH_INTEL_CL_MWAIT) {
936 		    if (vendor == CST_FFH_VENDOR_INTEL ||
937 			(vendor == CST_FFH_VENDOR_AMD && cpu_mon_mwait_edx != 0))
938 		        acpi_cpu_cx_cst_mwait(cx_ptr, address, accsize);
939 		}
940 	    }
941 #endif
942 	    if (sc->cpu_cx_states[0].type == ACPI_STATE_C0) {
943 		/* This is the first C1 state.  Use the reserved slot. */
944 		sc->cpu_cx_states[0] = *cx_ptr;
945 	    } else {
946 		sc->cpu_non_c2 = sc->cpu_cx_count;
947 		sc->cpu_non_c3 = sc->cpu_cx_count;
948 		cx_ptr++;
949 		sc->cpu_cx_count++;
950 	    }
951 	    continue;
952 	case ACPI_STATE_C2:
953 	    sc->cpu_non_c3 = sc->cpu_cx_count;
954 	    break;
955 	case ACPI_STATE_C3:
956 	default:
957 	    if ((cpu_quirks & CPU_QUIRK_NO_C3) != 0) {
958 		ACPI_DEBUG_PRINT((ACPI_DB_INFO,
959 				 "acpi_cpu%d: C3[%d] not available.\n",
960 				 device_get_unit(sc->cpu_dev), i));
961 		continue;
962 	    }
963 	    break;
964 	}
965 
966 	/* Free up any previous register. */
967 	acpi_cpu_cx_cst_free_plvlx(sc->cpu_dev, cx_ptr);
968 
969 	/* Allocate the control register for C2 or C3. */
970 #if defined(__i386__) || defined(__amd64__)
971 	if (acpi_PkgFFH_IntelCpu(pkg, 0, &vendor, &class, &address,
972 	  &accsize) == 0 && vendor == CST_FFH_VENDOR_INTEL &&
973 	  class == CST_FFH_INTEL_CL_MWAIT) {
974 	    /* Native C State Instruction use (mwait) */
975 	    acpi_cpu_cx_cst_mwait(cx_ptr, address, accsize);
976 	    ACPI_DEBUG_PRINT((ACPI_DB_INFO,
977 	      "acpi_cpu%d: Got C%d/mwait - %d latency\n",
978 	      device_get_unit(sc->cpu_dev), cx_ptr->type, cx_ptr->trans_lat));
979 	    cx_ptr++;
980 	    sc->cpu_cx_count++;
981 	} else
982 #endif
983 	{
984 	    cx_ptr->res_rid = sc->cpu_cx_count;
985 	    acpi_PkgGas(sc->cpu_dev, pkg, 0, &cx_ptr->res_type,
986 		cx_ptr->res_rid, &cx_ptr->p_lvlx, RF_SHAREABLE);
987 	    if (cx_ptr->p_lvlx) {
988 		cx_ptr->do_mwait = false;
989 		ACPI_DEBUG_PRINT((ACPI_DB_INFO,
990 		     "acpi_cpu%d: Got C%d - %d latency\n",
991 		     device_get_unit(sc->cpu_dev), cx_ptr->type,
992 		     cx_ptr->trans_lat));
993 		cx_ptr++;
994 		sc->cpu_cx_count++;
995 	    }
996 	}
997     }
998     AcpiOsFree(buf.Pointer);
999 
1000     /* If C1 state was not found, we need one now. */
1001     cx_ptr = sc->cpu_cx_states;
1002     if (cx_ptr->type == ACPI_STATE_C0) {
1003 	cx_ptr->type = ACPI_STATE_C1;
1004 	cx_ptr->trans_lat = 0;
1005     }
1006 
1007     return (0);
1008 }
1009 
1010 /*
1011  * Call this *after* all CPUs have been attached.
1012  */
1013 static void
acpi_cpu_startup(void * arg)1014 acpi_cpu_startup(void *arg)
1015 {
1016     struct acpi_cpu_softc *sc;
1017     int i;
1018 
1019     /*
1020      * Setup any quirks that might necessary now that we have probed
1021      * all the CPUs
1022      */
1023     acpi_cpu_quirks();
1024 
1025     if (cpu_cx_generic) {
1026 	/*
1027 	 * We are using generic Cx mode, probe for available Cx states
1028 	 * for all processors.
1029 	 */
1030 	CPU_FOREACH(i) {
1031 	    if ((sc = cpu_softc[i]) != NULL)
1032 		acpi_cpu_generic_cx_probe(sc);
1033 	}
1034     } else {
1035 	/*
1036 	 * We are using _CST mode, remove C3 state if necessary.
1037 	 * As we now know for sure that we will be using _CST mode
1038 	 * install our notify handler.
1039 	 */
1040 	CPU_FOREACH(i) {
1041 	    if ((sc = cpu_softc[i]) == NULL)
1042 		continue;
1043 	    if (cpu_quirks & CPU_QUIRK_NO_C3) {
1044 		sc->cpu_cx_count = min(sc->cpu_cx_count, sc->cpu_non_c3 + 1);
1045 	    }
1046 	    AcpiInstallNotifyHandler(sc->cpu_handle, ACPI_DEVICE_NOTIFY,
1047 		acpi_cpu_notify, sc);
1048 	}
1049     }
1050 
1051     /* Perform Cx final initialization. */
1052     CPU_FOREACH(i) {
1053 	if ((sc = cpu_softc[i]) != NULL)
1054 	    acpi_cpu_startup_cx(sc);
1055     }
1056 
1057     /* Add a sysctl handler to handle global Cx lowest setting */
1058     SYSCTL_ADD_PROC(&cpu_sysctl_ctx, SYSCTL_CHILDREN(cpu_sysctl_tree),
1059 	OID_AUTO, "cx_lowest", CTLTYPE_STRING | CTLFLAG_RW | CTLFLAG_MPSAFE,
1060 	NULL, 0, acpi_cpu_global_cx_lowest_sysctl, "A",
1061 	"Global lowest Cx sleep state to use");
1062 
1063     /* Take over idling from cpu_idle_default(). */
1064     cpu_cx_lowest_lim = 0;
1065     CPU_FOREACH(i) {
1066 	if ((sc = cpu_softc[i]) != NULL)
1067 	    enable_idle(sc);
1068     }
1069 #if defined(__i386__) || defined(__amd64__)
1070     cpu_idle_hook = acpi_cpu_idle;
1071 #endif
1072 }
1073 
1074 static void
acpi_cpu_cx_list(struct acpi_cpu_softc * sc)1075 acpi_cpu_cx_list(struct acpi_cpu_softc *sc)
1076 {
1077     struct sbuf sb;
1078     int i;
1079 
1080     /*
1081      * Set up the list of Cx states
1082      */
1083     sbuf_new(&sb, sc->cpu_cx_supported, sizeof(sc->cpu_cx_supported),
1084 	SBUF_FIXEDLEN);
1085     for (i = 0; i < sc->cpu_cx_count; i++)
1086 	sbuf_printf(&sb, "C%d/%d/%d ", i + 1, sc->cpu_cx_states[i].type,
1087 	    sc->cpu_cx_states[i].trans_lat);
1088     sbuf_trim(&sb);
1089     sbuf_finish(&sb);
1090 }
1091 
1092 static void
acpi_cpu_startup_cx(struct acpi_cpu_softc * sc)1093 acpi_cpu_startup_cx(struct acpi_cpu_softc *sc)
1094 {
1095     acpi_cpu_cx_list(sc);
1096 
1097     SYSCTL_ADD_STRING(&sc->cpu_sysctl_ctx,
1098 		      SYSCTL_CHILDREN(device_get_sysctl_tree(sc->cpu_dev)),
1099 		      OID_AUTO, "cx_supported", CTLFLAG_RD,
1100 		      sc->cpu_cx_supported, 0,
1101 		      "Cx/microsecond values for supported Cx states");
1102     SYSCTL_ADD_PROC(&sc->cpu_sysctl_ctx,
1103         SYSCTL_CHILDREN(device_get_sysctl_tree(sc->cpu_dev)), OID_AUTO,
1104 	"cx_lowest", CTLTYPE_STRING | CTLFLAG_RW | CTLFLAG_MPSAFE,
1105 	(void *)sc, 0, acpi_cpu_cx_lowest_sysctl, "A",
1106 	"lowest Cx sleep state to use");
1107     SYSCTL_ADD_PROC(&sc->cpu_sysctl_ctx,
1108         SYSCTL_CHILDREN(device_get_sysctl_tree(sc->cpu_dev)), OID_AUTO,
1109 	"cx_usage", CTLTYPE_STRING | CTLFLAG_RD | CTLFLAG_MPSAFE,
1110 	(void *)sc, 0, acpi_cpu_usage_sysctl, "A",
1111 	"percent usage for each Cx state");
1112     SYSCTL_ADD_PROC(&sc->cpu_sysctl_ctx,
1113         SYSCTL_CHILDREN(device_get_sysctl_tree(sc->cpu_dev)), OID_AUTO,
1114 	"cx_usage_counters", CTLTYPE_STRING | CTLFLAG_RD | CTLFLAG_MPSAFE,
1115 	(void *)sc, 0, acpi_cpu_usage_counters_sysctl, "A",
1116 	"Cx sleep state counters");
1117     SYSCTL_ADD_PROC(&sc->cpu_sysctl_ctx,
1118         SYSCTL_CHILDREN(device_get_sysctl_tree(sc->cpu_dev)), OID_AUTO,
1119 	"cx_duration_counters", CTLTYPE_STRING | CTLFLAG_RD | CTLFLAG_MPSAFE,
1120 	(void *)sc, 0, acpi_cpu_duration_counters_sysctl, "A",
1121 	"Cx sleep duration cumulative time");
1122 
1123 #if defined(__i386__) || defined(__amd64__)
1124     SYSCTL_ADD_PROC(&sc->cpu_sysctl_ctx,
1125         SYSCTL_CHILDREN(device_get_sysctl_tree(sc->cpu_dev)), OID_AUTO,
1126 	"cx_method", CTLTYPE_STRING | CTLFLAG_RD | CTLFLAG_MPSAFE,
1127 	(void *)sc, 0, acpi_cpu_method_sysctl, "A", "Cx entrance methods");
1128 #endif
1129 
1130     /* Signal platform that we can handle _CST notification. */
1131     if (!cpu_cx_generic && cpu_cst_cnt != 0) {
1132 	ACPI_LOCK(acpi);
1133 	AcpiOsWritePort(cpu_smi_cmd, cpu_cst_cnt, 8);
1134 	ACPI_UNLOCK(acpi);
1135     }
1136 }
1137 
1138 #if defined(__i386__) || defined(__amd64__)
1139 /*
1140  * Idle the CPU in the lowest state possible.  This function is called with
1141  * interrupts disabled.  Note that once it re-enables interrupts, a task
1142  * switch can occur so do not access shared data (i.e. the softc) after
1143  * interrupts are re-enabled.
1144  */
1145 static void
acpi_cpu_idle(sbintime_t sbt)1146 acpi_cpu_idle(sbintime_t sbt)
1147 {
1148     struct	acpi_cpu_softc *sc;
1149     struct	acpi_cx *cx_next;
1150     uint64_t	start_ticks, end_ticks;
1151     uint32_t	start_time, end_time;
1152     ACPI_STATUS	status;
1153     int		bm_active, cx_next_idx, i, us;
1154 
1155     /*
1156      * Look up our CPU id to get our softc.  If it's NULL, we'll use C1
1157      * since there is no ACPI processor object for this CPU.  This occurs
1158      * for logical CPUs in the HTT case.
1159      */
1160     sc = cpu_softc[PCPU_GET(cpuid)];
1161     if (sc == NULL) {
1162 	acpi_cpu_c1();
1163 	return;
1164     }
1165 
1166     /* If disabled, take the safe path. */
1167     if (is_idle_disabled(sc)) {
1168 	acpi_cpu_c1();
1169 	return;
1170     }
1171 
1172     /* Find the lowest state that has small enough latency. */
1173     us = sc->cpu_prev_sleep;
1174     if (sbt >= 0 && us > (sbt >> 12))
1175 	us = (sbt >> 12);
1176     cx_next_idx = 0;
1177     if (cpu_disable_c2_sleep)
1178 	i = min(sc->cpu_cx_lowest, sc->cpu_non_c2);
1179     else if (cpu_disable_c3_sleep)
1180 	i = min(sc->cpu_cx_lowest, sc->cpu_non_c3);
1181     else
1182 	i = sc->cpu_cx_lowest;
1183     for (; i >= 0; i--) {
1184 	if (sc->cpu_cx_states[i].trans_lat * 3 <= us) {
1185 	    cx_next_idx = i;
1186 	    break;
1187 	}
1188     }
1189 
1190     /*
1191      * Check for bus master activity.  If there was activity, clear
1192      * the bit and use the lowest non-C3 state.  Note that the USB
1193      * driver polling for new devices keeps this bit set all the
1194      * time if USB is loaded.
1195      */
1196     cx_next = &sc->cpu_cx_states[cx_next_idx];
1197     if ((cpu_quirks & CPU_QUIRK_NO_BM_CTRL) == 0 &&
1198 	cx_next_idx > sc->cpu_non_c3 &&
1199 	(!cx_next->do_mwait || cx_next->mwait_bm_avoidance)) {
1200 	status = AcpiReadBitRegister(ACPI_BITREG_BUS_MASTER_STATUS, &bm_active);
1201 	if (ACPI_SUCCESS(status) && bm_active != 0) {
1202 	    AcpiWriteBitRegister(ACPI_BITREG_BUS_MASTER_STATUS, 1);
1203 	    cx_next_idx = sc->cpu_non_c3;
1204 	    cx_next = &sc->cpu_cx_states[cx_next_idx];
1205 	}
1206     }
1207 
1208     /* Select the next state and update statistics. */
1209     sc->cpu_cx_stats[cx_next_idx]++;
1210     KASSERT(cx_next->type != ACPI_STATE_C0, ("acpi_cpu_idle: C0 sleep"));
1211 
1212     /*
1213      * Execute HLT (or equivalent) and wait for an interrupt.  We can't
1214      * precisely calculate the time spent in C1 since the place we wake up
1215      * is an ISR.  Assume we slept no more then half of quantum, unless
1216      * we are called inside critical section, delaying context switch.
1217      */
1218     if (cx_next->type == ACPI_STATE_C1) {
1219 	start_ticks = cpu_ticks();
1220 	if (cx_next->p_lvlx != NULL) {
1221 	    /* C1 I/O then Halt */
1222 	    CPU_GET_REG(cx_next->p_lvlx, 1);
1223 	}
1224 	if (cx_next->do_mwait)
1225 	    acpi_cpu_idle_mwait(cx_next->mwait_hint);
1226 	else
1227 	    acpi_cpu_c1();
1228 	end_ticks = cpu_ticks();
1229 	/* acpi_cpu_c1() returns with interrupts enabled. */
1230 	if (cx_next->do_mwait)
1231 	    ACPI_ENABLE_IRQS();
1232 	end_time = ((end_ticks - start_ticks) << 20) / cpu_tickrate();
1233 	if (!cx_next->do_mwait && curthread->td_critnest == 0)
1234 		end_time = min(end_time, 500000 / hz);
1235 	sc->cpu_prev_sleep = (sc->cpu_prev_sleep * 3 + end_time) / 4;
1236 	sc->cpu_cx_duration[cx_next_idx] += end_time;
1237 	return;
1238     }
1239 
1240     /*
1241      * For C3, disable bus master arbitration if BM control is available.
1242      * CPU may have to wake up to handle it. Otherwise flush the CPU cache.
1243      */
1244     if (cx_next->type == ACPI_STATE_C3) {
1245 	if ((cpu_quirks & CPU_QUIRK_NO_BM_CTRL) == 0)
1246 	    AcpiWriteBitRegister(ACPI_BITREG_ARB_DISABLE, 1);
1247 	else
1248 	    ACPI_FLUSH_CPU_CACHE();
1249     }
1250 
1251     /*
1252      * Read from P_LVLx to enter C2(+), checking time spent asleep.
1253      * Use the ACPI timer for measuring sleep time.  Since we need to
1254      * get the time very close to the CPU start/stop clock logic, this
1255      * is the only reliable time source.
1256      */
1257     if (cx_next->type == ACPI_STATE_C3) {
1258 	AcpiGetTimer(&start_time);
1259 	start_ticks = 0;
1260     } else {
1261 	start_time = 0;
1262 	start_ticks = cpu_ticks();
1263     }
1264     if (cx_next->do_mwait) {
1265 	acpi_cpu_idle_mwait(cx_next->mwait_hint);
1266     } else {
1267 	CPU_GET_REG(cx_next->p_lvlx, 1);
1268 	/*
1269 	 * Read the end time twice.  Since it may take an arbitrary time
1270 	 * to enter the idle state, the first read may be executed before
1271 	 * the processor has stopped.  Doing it again provides enough
1272 	 * margin that we are certain to have a correct value.
1273 	 */
1274 	AcpiGetTimer(&end_time);
1275     }
1276 
1277     if (cx_next->type == ACPI_STATE_C3)
1278 	AcpiGetTimer(&end_time);
1279     else
1280 	end_ticks = cpu_ticks();
1281 
1282     /* Enable bus master arbitration. */
1283     if (cx_next->type == ACPI_STATE_C3 &&
1284       (cpu_quirks & CPU_QUIRK_NO_BM_CTRL) == 0)
1285 	AcpiWriteBitRegister(ACPI_BITREG_ARB_DISABLE, 0);
1286     ACPI_ENABLE_IRQS();
1287 
1288     if (cx_next->type == ACPI_STATE_C3)
1289 	AcpiGetTimerDuration(start_time, end_time, &end_time);
1290     else
1291 	end_time = ((end_ticks - start_ticks) << 20) / cpu_tickrate();
1292     sc->cpu_prev_sleep = (sc->cpu_prev_sleep * 3 + end_time) / 4;
1293     sc->cpu_cx_duration[cx_next_idx] += end_time;
1294 }
1295 #endif
1296 
1297 /*
1298  * Re-evaluate the _CST object when we are notified that it changed.
1299  */
1300 static void
acpi_cpu_notify(ACPI_HANDLE h,UINT32 notify,void * context)1301 acpi_cpu_notify(ACPI_HANDLE h, UINT32 notify, void *context)
1302 {
1303     struct acpi_cpu_softc *sc = (struct acpi_cpu_softc *)context;
1304 
1305     if (notify != ACPI_NOTIFY_CX_STATES)
1306 	return;
1307 
1308     /*
1309      * C-state data for target CPU is going to be in flux while we execute
1310      * acpi_cpu_cx_cst, so disable entering acpi_cpu_idle.
1311      * Also, it may happen that multiple ACPI taskqueues may concurrently
1312      * execute notifications for the same CPU.  ACPI_SERIAL is used to
1313      * protect against that.
1314      */
1315     ACPI_SERIAL_BEGIN(cpu);
1316     disable_idle(sc);
1317 
1318     /* Update the list of Cx states. */
1319     acpi_cpu_cx_cst(sc);
1320     acpi_cpu_cx_list(sc);
1321     acpi_cpu_set_cx_lowest(sc);
1322 
1323     enable_idle(sc);
1324     ACPI_SERIAL_END(cpu);
1325 
1326     acpi_UserNotify("PROCESSOR", sc->cpu_handle, notify);
1327 }
1328 
1329 static void
acpi_cpu_quirks(void)1330 acpi_cpu_quirks(void)
1331 {
1332     ACPI_FUNCTION_TRACE((char *)(uintptr_t)__func__);
1333 
1334     /*
1335      * Bus mastering arbitration control is needed to keep caches coherent
1336      * while sleeping in C3.  If it's not present but a working flush cache
1337      * instruction is present, flush the caches before entering C3 instead.
1338      * Otherwise, just disable C3 completely.
1339      */
1340     if (AcpiGbl_FADT.Pm2ControlBlock == 0 ||
1341 	AcpiGbl_FADT.Pm2ControlLength == 0) {
1342 	if ((AcpiGbl_FADT.Flags & ACPI_FADT_WBINVD) &&
1343 	    (AcpiGbl_FADT.Flags & ACPI_FADT_WBINVD_FLUSH) == 0) {
1344 	    cpu_quirks |= CPU_QUIRK_NO_BM_CTRL;
1345 	    ACPI_DEBUG_PRINT((ACPI_DB_INFO,
1346 		"acpi_cpu: no BM control, using flush cache method\n"));
1347 	} else {
1348 	    cpu_quirks |= CPU_QUIRK_NO_C3;
1349 	    ACPI_DEBUG_PRINT((ACPI_DB_INFO,
1350 		"acpi_cpu: no BM control, C3 not available\n"));
1351 	}
1352     }
1353 
1354     /*
1355      * If we are using generic Cx mode, C3 on multiple CPUs requires using
1356      * the expensive flush cache instruction.
1357      */
1358     if (cpu_cx_generic && mp_ncpus > 1) {
1359 	cpu_quirks |= CPU_QUIRK_NO_BM_CTRL;
1360 	ACPI_DEBUG_PRINT((ACPI_DB_INFO,
1361 	    "acpi_cpu: SMP, using flush cache mode for C3\n"));
1362     }
1363 
1364     /* Look for various quirks of the PIIX4 part. */
1365     acpi_cpu_quirks_piix4();
1366 }
1367 
1368 static void
acpi_cpu_quirks_piix4(void)1369 acpi_cpu_quirks_piix4(void)
1370 {
1371 #ifdef __i386__
1372     device_t acpi_dev;
1373     uint32_t val;
1374     ACPI_STATUS status;
1375 
1376     acpi_dev = pci_find_device(PCI_VENDOR_INTEL, PCI_DEVICE_82371AB_3);
1377     if (acpi_dev != NULL) {
1378 	switch (pci_get_revid(acpi_dev)) {
1379 	/*
1380 	 * Disable C3 support for all PIIX4 chipsets.  Some of these parts
1381 	 * do not report the BMIDE status to the BM status register and
1382 	 * others have a livelock bug if Type-F DMA is enabled.  Linux
1383 	 * works around the BMIDE bug by reading the BM status directly
1384 	 * but we take the simpler approach of disabling C3 for these
1385 	 * parts.
1386 	 *
1387 	 * See erratum #18 ("C3 Power State/BMIDE and Type-F DMA
1388 	 * Livelock") from the January 2002 PIIX4 specification update.
1389 	 * Applies to all PIIX4 models.
1390 	 *
1391 	 * Also, make sure that all interrupts cause a "Stop Break"
1392 	 * event to exit from C2 state.
1393 	 * Also, BRLD_EN_BM (ACPI_BITREG_BUS_MASTER_RLD in ACPI-speak)
1394 	 * should be set to zero, otherwise it causes C2 to short-sleep.
1395 	 * PIIX4 doesn't properly support C3 and bus master activity
1396 	 * need not break out of C2.
1397 	 */
1398 	case PCI_REVISION_A_STEP:
1399 	case PCI_REVISION_B_STEP:
1400 	case PCI_REVISION_4E:
1401 	case PCI_REVISION_4M:
1402 	    cpu_quirks |= CPU_QUIRK_NO_C3;
1403 	    ACPI_DEBUG_PRINT((ACPI_DB_INFO,
1404 		"acpi_cpu: working around PIIX4 bug, disabling C3\n"));
1405 
1406 	    val = pci_read_config(acpi_dev, PIIX4_DEVACTB_REG, 4);
1407 	    if ((val & PIIX4_STOP_BREAK_MASK) != PIIX4_STOP_BREAK_MASK) {
1408 		ACPI_DEBUG_PRINT((ACPI_DB_INFO,
1409 		    "acpi_cpu: PIIX4: enabling IRQs to generate Stop Break\n"));
1410 	    	val |= PIIX4_STOP_BREAK_MASK;
1411 		pci_write_config(acpi_dev, PIIX4_DEVACTB_REG, val, 4);
1412 	    }
1413 	    status = AcpiReadBitRegister(ACPI_BITREG_BUS_MASTER_RLD, &val);
1414 	    if (ACPI_SUCCESS(status) && val != 0) {
1415 		ACPI_DEBUG_PRINT((ACPI_DB_INFO,
1416 		    "acpi_cpu: PIIX4: reset BRLD_EN_BM\n"));
1417 		AcpiWriteBitRegister(ACPI_BITREG_BUS_MASTER_RLD, 0);
1418 	    }
1419 	    break;
1420 	default:
1421 	    break;
1422 	}
1423     }
1424 #endif
1425 }
1426 
1427 static int
acpi_cpu_usage_sysctl(SYSCTL_HANDLER_ARGS)1428 acpi_cpu_usage_sysctl(SYSCTL_HANDLER_ARGS)
1429 {
1430 	struct acpi_cpu_softc *sc = (struct acpi_cpu_softc *)arg1;
1431 	struct sbuf	 sb;
1432 	char		 buf[128];
1433 	int		 error, i;
1434 	uintmax_t	 fract, sum, whole;
1435 
1436 	sbuf_new_for_sysctl(&sb, buf, sizeof(buf), req);
1437 	sum = 0;
1438 	for (i = 0; i < sc->cpu_cx_count; i++)
1439 		sum += sc->cpu_cx_stats[i];
1440 	for (i = 0; i < sc->cpu_cx_count; i++) {
1441 		if (sum > 0) {
1442 			whole = (uintmax_t)sc->cpu_cx_stats[i] * 100;
1443 			fract = (whole % sum) * 100;
1444 			sbuf_printf(&sb, "%u.%02u%% ", (u_int)(whole / sum),
1445 			    (u_int)(fract / sum));
1446 		} else
1447 			sbuf_printf(&sb, "0.00%% ");
1448 	}
1449 	sbuf_printf(&sb, "last %dus", sc->cpu_prev_sleep);
1450 	error = sbuf_finish(&sb);
1451 	sbuf_delete(&sb);
1452 	return (error);
1453 }
1454 
1455 /*
1456  * XXX TODO: actually add support to count each entry/exit
1457  * from the Cx states.
1458  */
1459 static int
acpi_cpu_usage_counters_sysctl(SYSCTL_HANDLER_ARGS)1460 acpi_cpu_usage_counters_sysctl(SYSCTL_HANDLER_ARGS)
1461 {
1462 	struct acpi_cpu_softc *sc = (struct acpi_cpu_softc *)arg1;
1463 	struct sbuf	 sb;
1464 	char		 buf[128];
1465 	int		 error, i;
1466 
1467 	sbuf_new_for_sysctl(&sb, buf, sizeof(buf), req);
1468 	for (i = 0; i < sc->cpu_cx_count; i++) {
1469 		if (i > 0)
1470 			sbuf_putc(&sb, ' ');
1471 		sbuf_printf(&sb, "%u", sc->cpu_cx_stats[i]);
1472 	}
1473 	error = sbuf_finish(&sb);
1474 	sbuf_delete(&sb);
1475 	return (error);
1476 }
1477 
1478 static int
acpi_cpu_duration_counters_sysctl(SYSCTL_HANDLER_ARGS)1479 acpi_cpu_duration_counters_sysctl(SYSCTL_HANDLER_ARGS)
1480 {
1481 	struct acpi_cpu_softc *sc = (struct acpi_cpu_softc *)arg1;
1482 	struct sbuf	 sb;
1483 	char		 buf[128];
1484 	int		 error, i;
1485 
1486 	sbuf_new_for_sysctl(&sb, buf, sizeof(buf), req);
1487 	for (i = 0; i < sc->cpu_cx_count; i++) {
1488 		if (i > 0)
1489 			sbuf_putc(&sb, ' ');
1490 		sbuf_printf(&sb, "%ju", (uintmax_t) sc->cpu_cx_duration[i]);
1491 	}
1492 	error = sbuf_finish(&sb);
1493 	sbuf_delete(&sb);
1494 	return (error);
1495 }
1496 
1497 
1498 #if defined(__i386__) || defined(__amd64__)
1499 static int
acpi_cpu_method_sysctl(SYSCTL_HANDLER_ARGS)1500 acpi_cpu_method_sysctl(SYSCTL_HANDLER_ARGS)
1501 {
1502 	struct acpi_cpu_softc *sc = (struct acpi_cpu_softc *)arg1;
1503 	struct acpi_cx *cx;
1504 	struct sbuf sb;
1505 	char buf[128];
1506 	int error, i;
1507 
1508 	sbuf_new_for_sysctl(&sb, buf, sizeof(buf), req);
1509 	for (i = 0; i < sc->cpu_cx_count; i++) {
1510 		cx = &sc->cpu_cx_states[i];
1511 		if (i > 0)
1512 			sbuf_putc(&sb, ' ');
1513 		sbuf_printf(&sb, "C%d/", i + 1);
1514 		if (cx->do_mwait) {
1515 			sbuf_cat(&sb, "mwait");
1516 			if (cx->mwait_hw_coord)
1517 				sbuf_cat(&sb, "/hwc");
1518 			if (cx->mwait_bm_avoidance)
1519 				sbuf_cat(&sb, "/bma");
1520 		} else if (cx->type == ACPI_STATE_C1) {
1521 			sbuf_cat(&sb, "hlt");
1522 		} else {
1523 			sbuf_cat(&sb, "io");
1524 		}
1525 		if (cx->type == ACPI_STATE_C1 && cx->p_lvlx != NULL)
1526 			sbuf_cat(&sb, "/iohlt");
1527 	}
1528 	error = sbuf_finish(&sb);
1529 	sbuf_delete(&sb);
1530 	return (error);
1531 }
1532 #endif
1533 
1534 static int
acpi_cpu_set_cx_lowest(struct acpi_cpu_softc * sc)1535 acpi_cpu_set_cx_lowest(struct acpi_cpu_softc *sc)
1536 {
1537     int i;
1538 
1539     ACPI_SERIAL_ASSERT(cpu);
1540     sc->cpu_cx_lowest = min(sc->cpu_cx_lowest_lim, sc->cpu_cx_count - 1);
1541 
1542     /* If not disabling, cache the new lowest non-C3 state. */
1543     sc->cpu_non_c3 = 0;
1544     for (i = sc->cpu_cx_lowest; i >= 0; i--) {
1545 	if (sc->cpu_cx_states[i].type < ACPI_STATE_C3) {
1546 	    sc->cpu_non_c3 = i;
1547 	    break;
1548 	}
1549     }
1550 
1551     /* Reset the statistics counters. */
1552     bzero(sc->cpu_cx_stats, sizeof(sc->cpu_cx_stats));
1553     return (0);
1554 }
1555 
1556 static int
acpi_cpu_cx_lowest_sysctl(SYSCTL_HANDLER_ARGS)1557 acpi_cpu_cx_lowest_sysctl(SYSCTL_HANDLER_ARGS)
1558 {
1559     struct	 acpi_cpu_softc *sc;
1560     char	 state[8];
1561     int		 val, error;
1562 
1563     sc = (struct acpi_cpu_softc *) arg1;
1564     snprintf(state, sizeof(state), "C%d", sc->cpu_cx_lowest_lim + 1);
1565     error = sysctl_handle_string(oidp, state, sizeof(state), req);
1566     if (error != 0 || req->newptr == NULL)
1567 	return (error);
1568     if (strlen(state) < 2 || toupper(state[0]) != 'C')
1569 	return (EINVAL);
1570     if (strcasecmp(state, "Cmax") == 0)
1571 	val = MAX_CX_STATES;
1572     else {
1573 	val = (int) strtol(state + 1, NULL, 10);
1574 	if (val < 1 || val > MAX_CX_STATES)
1575 	    return (EINVAL);
1576     }
1577 
1578     ACPI_SERIAL_BEGIN(cpu);
1579     sc->cpu_cx_lowest_lim = val - 1;
1580     acpi_cpu_set_cx_lowest(sc);
1581     ACPI_SERIAL_END(cpu);
1582 
1583     return (0);
1584 }
1585 
1586 static int
acpi_cpu_global_cx_lowest_sysctl(SYSCTL_HANDLER_ARGS)1587 acpi_cpu_global_cx_lowest_sysctl(SYSCTL_HANDLER_ARGS)
1588 {
1589     struct	acpi_cpu_softc *sc;
1590     char	state[8];
1591     int		val, error, i;
1592 
1593     snprintf(state, sizeof(state), "C%d", cpu_cx_lowest_lim + 1);
1594     error = sysctl_handle_string(oidp, state, sizeof(state), req);
1595     if (error != 0 || req->newptr == NULL)
1596 	return (error);
1597     if (strlen(state) < 2 || toupper(state[0]) != 'C')
1598 	return (EINVAL);
1599     if (strcasecmp(state, "Cmax") == 0)
1600 	val = MAX_CX_STATES;
1601     else {
1602 	val = (int) strtol(state + 1, NULL, 10);
1603 	if (val < 1 || val > MAX_CX_STATES)
1604 	    return (EINVAL);
1605     }
1606 
1607     /* Update the new lowest useable Cx state for all CPUs. */
1608     ACPI_SERIAL_BEGIN(cpu);
1609     cpu_cx_lowest_lim = val - 1;
1610     CPU_FOREACH(i) {
1611 	if ((sc = cpu_softc[i]) == NULL)
1612 	    continue;
1613 	sc->cpu_cx_lowest_lim = cpu_cx_lowest_lim;
1614 	acpi_cpu_set_cx_lowest(sc);
1615     }
1616     ACPI_SERIAL_END(cpu);
1617 
1618     return (0);
1619 }
1620