xref: /freebsd/sys/x86/x86/cpu_machdep.c (revision 031beb4e239bfce798af17f5fe8dba8bcaf13d99)
1 /*-
2  * Copyright (c) 2003 Peter Wemm.
3  * Copyright (c) 1992 Terrence R. Lambert.
4  * Copyright (c) 1982, 1987, 1990 The Regents of the University of California.
5  * All rights reserved.
6  *
7  * This code is derived from software contributed to Berkeley by
8  * William Jolitz.
9  *
10  * Redistribution and use in source and binary forms, with or without
11  * modification, are permitted provided that the following conditions
12  * are met:
13  * 1. Redistributions of source code must retain the above copyright
14  *    notice, this list of conditions and the following disclaimer.
15  * 2. Redistributions in binary form must reproduce the above copyright
16  *    notice, this list of conditions and the following disclaimer in the
17  *    documentation and/or other materials provided with the distribution.
18  * 3. All advertising materials mentioning features or use of this software
19  *    must display the following acknowledgement:
20  *	This product includes software developed by the University of
21  *	California, Berkeley and its contributors.
22  * 4. Neither the name of the University nor the names of its contributors
23  *    may be used to endorse or promote products derived from this software
24  *    without specific prior written permission.
25  *
26  * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
27  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
28  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
29  * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
30  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
31  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
32  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
33  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
34  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
35  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
36  * SUCH DAMAGE.
37  *
38  *	from: @(#)machdep.c	7.4 (Berkeley) 6/3/91
39  */
40 
41 #include <sys/cdefs.h>
42 #include "opt_acpi.h"
43 #include "opt_atpic.h"
44 #include "opt_cpu.h"
45 #include "opt_ddb.h"
46 #include "opt_inet.h"
47 #include "opt_isa.h"
48 #include "opt_kdb.h"
49 #include "opt_kstack_pages.h"
50 #include "opt_maxmem.h"
51 #include "opt_platform.h"
52 #include "opt_sched.h"
53 #ifdef __i386__
54 #include "opt_apic.h"
55 #endif
56 
57 #include <sys/param.h>
58 #include <sys/proc.h>
59 #include <sys/systm.h>
60 #include <sys/bus.h>
61 #include <sys/cpu.h>
62 #include <sys/domainset.h>
63 #include <sys/kdb.h>
64 #include <sys/kernel.h>
65 #include <sys/ktr.h>
66 #include <sys/lock.h>
67 #include <sys/malloc.h>
68 #include <sys/mutex.h>
69 #include <sys/pcpu.h>
70 #include <sys/rwlock.h>
71 #include <sys/sched.h>
72 #include <sys/smp.h>
73 #include <sys/sysctl.h>
74 
75 #include <machine/clock.h>
76 #include <machine/cpu.h>
77 #include <machine/cpufunc.h>
78 #include <machine/cputypes.h>
79 #include <machine/specialreg.h>
80 #include <machine/md_var.h>
81 #include <machine/tss.h>
82 #ifdef SMP
83 #include <machine/smp.h>
84 #endif
85 #ifdef CPU_ELAN
86 #include <machine/elan_mmcr.h>
87 #endif
88 #include <x86/acpica_machdep.h>
89 #include <x86/ifunc.h>
90 
91 #include <vm/vm.h>
92 #include <vm/vm_extern.h>
93 #include <vm/vm_kern.h>
94 #include <vm/vm_page.h>
95 #include <vm/vm_map.h>
96 #include <vm/vm_object.h>
97 #include <vm/vm_pager.h>
98 #include <vm/vm_param.h>
99 
100 #include <isa/isareg.h>
101 
102 #include <contrib/dev/acpica/include/acpi.h>
103 
104 #define	STATE_RUNNING	0x0
105 #define	STATE_MWAIT	0x1
106 #define	STATE_SLEEPING	0x2
107 
108 #ifdef SMP
109 static u_int	cpu_reset_proxyid;
110 static volatile u_int	cpu_reset_proxy_active;
111 #endif
112 
113 char bootmethod[16];
114 SYSCTL_STRING(_machdep, OID_AUTO, bootmethod, CTLFLAG_RD, bootmethod, 0,
115     "System firmware boot method");
116 
117 struct msr_op_arg {
118 	u_int msr;
119 	int op;
120 	uint64_t arg1;
121 	uint64_t *res;
122 };
123 
124 static void
125 x86_msr_op_one(void *argp)
126 {
127 	struct msr_op_arg *a;
128 	uint64_t v;
129 
130 	a = argp;
131 	switch (a->op) {
132 	case MSR_OP_ANDNOT:
133 		v = rdmsr(a->msr);
134 		v &= ~a->arg1;
135 		wrmsr(a->msr, v);
136 		break;
137 	case MSR_OP_OR:
138 		v = rdmsr(a->msr);
139 		v |= a->arg1;
140 		wrmsr(a->msr, v);
141 		break;
142 	case MSR_OP_WRITE:
143 		wrmsr(a->msr, a->arg1);
144 		break;
145 	case MSR_OP_READ:
146 		v = rdmsr(a->msr);
147 		*a->res = v;
148 		break;
149 	}
150 }
151 
152 #define	MSR_OP_EXMODE_MASK	0xf0000000
153 #define	MSR_OP_OP_MASK		0x000000ff
154 #define	MSR_OP_GET_CPUID(x)	(((x) & ~MSR_OP_EXMODE_MASK) >> 8)
155 
156 void
157 x86_msr_op(u_int msr, u_int op, uint64_t arg1, uint64_t *res)
158 {
159 	struct thread *td;
160 	struct msr_op_arg a;
161 	cpuset_t set;
162 	u_int exmode;
163 	int bound_cpu, cpu, i, is_bound;
164 
165 	a.op = op & MSR_OP_OP_MASK;
166 	MPASS(a.op == MSR_OP_ANDNOT || a.op == MSR_OP_OR ||
167 	    a.op == MSR_OP_WRITE || a.op == MSR_OP_READ);
168 	exmode = op & MSR_OP_EXMODE_MASK;
169 	MPASS(exmode == MSR_OP_LOCAL || exmode == MSR_OP_SCHED_ALL ||
170 	    exmode == MSR_OP_SCHED_ONE || exmode == MSR_OP_RENDEZVOUS_ALL ||
171 	    exmode == MSR_OP_RENDEZVOUS_ONE);
172 	a.msr = msr;
173 	a.arg1 = arg1;
174 	a.res = res;
175 	switch (exmode) {
176 	case MSR_OP_LOCAL:
177 		x86_msr_op_one(&a);
178 		break;
179 	case MSR_OP_SCHED_ALL:
180 		td = curthread;
181 		thread_lock(td);
182 		is_bound = sched_is_bound(td);
183 		bound_cpu = td->td_oncpu;
184 		CPU_FOREACH(i) {
185 			sched_bind(td, i);
186 			x86_msr_op_one(&a);
187 		}
188 		if (is_bound)
189 			sched_bind(td, bound_cpu);
190 		else
191 			sched_unbind(td);
192 		thread_unlock(td);
193 		break;
194 	case MSR_OP_SCHED_ONE:
195 		td = curthread;
196 		cpu = MSR_OP_GET_CPUID(op);
197 		thread_lock(td);
198 		is_bound = sched_is_bound(td);
199 		bound_cpu = td->td_oncpu;
200 		if (!is_bound || bound_cpu != cpu)
201 			sched_bind(td, cpu);
202 		x86_msr_op_one(&a);
203 		if (is_bound) {
204 			if (bound_cpu != cpu)
205 				sched_bind(td, bound_cpu);
206 		} else {
207 			sched_unbind(td);
208 		}
209 		thread_unlock(td);
210 		break;
211 	case MSR_OP_RENDEZVOUS_ALL:
212 		smp_rendezvous(smp_no_rendezvous_barrier, x86_msr_op_one,
213 		    smp_no_rendezvous_barrier, &a);
214 		break;
215 	case MSR_OP_RENDEZVOUS_ONE:
216 		cpu = MSR_OP_GET_CPUID(op);
217 		CPU_SETOF(cpu, &set);
218 		smp_rendezvous_cpus(set, smp_no_rendezvous_barrier,
219 		    x86_msr_op_one, smp_no_rendezvous_barrier, &a);
220 		break;
221 	}
222 }
223 
224 /*
225  * Automatically initialized per CPU errata in cpu_idle_tun below.
226  */
227 bool mwait_cpustop_broken = false;
228 SYSCTL_BOOL(_machdep, OID_AUTO, mwait_cpustop_broken, CTLFLAG_RDTUN,
229     &mwait_cpustop_broken, 0,
230     "Can not reliably wake MONITOR/MWAIT cpus without interrupts");
231 
232 /*
233  * Flush the D-cache for non-DMA I/O so that the I-cache can
234  * be made coherent later.
235  */
236 void
237 cpu_flush_dcache(void *ptr, size_t len)
238 {
239 	/* Not applicable */
240 }
241 
242 void
243 acpi_cpu_c1(void)
244 {
245 
246 	__asm __volatile("sti; hlt");
247 }
248 
249 /*
250  * Use mwait to pause execution while waiting for an interrupt or
251  * another thread to signal that there is more work.
252  *
253  * NOTE: Interrupts will cause a wakeup; however, this function does
254  * not enable interrupt handling. The caller is responsible to enable
255  * interrupts.
256  */
257 void
258 acpi_cpu_idle_mwait(uint32_t mwait_hint)
259 {
260 	int *state;
261 	uint64_t v;
262 
263 	/*
264 	 * A comment in Linux patch claims that 'CPUs run faster with
265 	 * speculation protection disabled. All CPU threads in a core
266 	 * must disable speculation protection for it to be
267 	 * disabled. Disable it while we are idle so the other
268 	 * hyperthread can run fast.'
269 	 *
270 	 * XXXKIB.  Software coordination mode should be supported,
271 	 * but all Intel CPUs provide hardware coordination.
272 	 */
273 
274 	state = &PCPU_PTR(monitorbuf)->idle_state;
275 	KASSERT(atomic_load_int(state) == STATE_SLEEPING,
276 	    ("cpu_mwait_cx: wrong monitorbuf state"));
277 	atomic_store_int(state, STATE_MWAIT);
278 	if (PCPU_GET(ibpb_set) || hw_ssb_active) {
279 		v = rdmsr(MSR_IA32_SPEC_CTRL);
280 		wrmsr(MSR_IA32_SPEC_CTRL, v & ~(IA32_SPEC_CTRL_IBRS |
281 		    IA32_SPEC_CTRL_STIBP | IA32_SPEC_CTRL_SSBD));
282 	} else {
283 		v = 0;
284 	}
285 	cpu_monitor(state, 0, 0);
286 	if (atomic_load_int(state) == STATE_MWAIT)
287 		cpu_mwait(MWAIT_INTRBREAK, mwait_hint);
288 
289 	/*
290 	 * SSB cannot be disabled while we sleep, or rather, if it was
291 	 * disabled, the sysctl thread will bind to our cpu to tweak
292 	 * MSR.
293 	 */
294 	if (v != 0)
295 		wrmsr(MSR_IA32_SPEC_CTRL, v);
296 
297 	/*
298 	 * We should exit on any event that interrupts mwait, because
299 	 * that event might be a wanted interrupt.
300 	 */
301 	atomic_store_int(state, STATE_RUNNING);
302 }
303 
304 /* Get current clock frequency for the given cpu id. */
305 int
306 cpu_est_clockrate(int cpu_id, uint64_t *rate)
307 {
308 	uint64_t tsc1, tsc2;
309 	uint64_t acnt, mcnt, perf;
310 	register_t reg;
311 
312 	if (pcpu_find(cpu_id) == NULL || rate == NULL)
313 		return (EINVAL);
314 #ifdef __i386__
315 	if ((cpu_feature & CPUID_TSC) == 0)
316 		return (EOPNOTSUPP);
317 #endif
318 
319 	/*
320 	 * If TSC is P-state invariant and APERF/MPERF MSRs do not exist,
321 	 * DELAY(9) based logic fails.
322 	 */
323 	if (tsc_is_invariant && !tsc_perf_stat)
324 		return (EOPNOTSUPP);
325 
326 #ifdef SMP
327 	if (smp_cpus > 1) {
328 		/* Schedule ourselves on the indicated cpu. */
329 		thread_lock(curthread);
330 		sched_bind(curthread, cpu_id);
331 		thread_unlock(curthread);
332 	}
333 #endif
334 
335 	/* Calibrate by measuring a short delay. */
336 	reg = intr_disable();
337 	if (tsc_is_invariant) {
338 		wrmsr(MSR_MPERF, 0);
339 		wrmsr(MSR_APERF, 0);
340 		tsc1 = rdtsc();
341 		DELAY(1000);
342 		mcnt = rdmsr(MSR_MPERF);
343 		acnt = rdmsr(MSR_APERF);
344 		tsc2 = rdtsc();
345 		intr_restore(reg);
346 		perf = 1000 * acnt / mcnt;
347 		*rate = (tsc2 - tsc1) * perf;
348 	} else {
349 		tsc1 = rdtsc();
350 		DELAY(1000);
351 		tsc2 = rdtsc();
352 		intr_restore(reg);
353 		*rate = (tsc2 - tsc1) * 1000;
354 	}
355 
356 #ifdef SMP
357 	if (smp_cpus > 1) {
358 		thread_lock(curthread);
359 		sched_unbind(curthread);
360 		thread_unlock(curthread);
361 	}
362 #endif
363 
364 	return (0);
365 }
366 
367 /*
368  * Shutdown the CPU as much as possible
369  */
370 void
371 cpu_halt(void)
372 {
373 	for (;;)
374 		halt();
375 }
376 
377 static void
378 cpu_reset_real(void)
379 {
380 	struct region_descriptor null_idt;
381 	int b;
382 
383 	disable_intr();
384 #ifdef CPU_ELAN
385 	if (elan_mmcr != NULL)
386 		elan_mmcr->RESCFG = 1;
387 #endif
388 #ifdef __i386__
389 	if (cpu == CPU_GEODE1100) {
390 		/* Attempt Geode's own reset */
391 		outl(0xcf8, 0x80009044ul);
392 		outl(0xcfc, 0xf);
393 	}
394 #endif
395 #if !defined(BROKEN_KEYBOARD_RESET)
396 	/*
397 	 * Attempt to do a CPU reset via the keyboard controller,
398 	 * do not turn off GateA20, as any machine that fails
399 	 * to do the reset here would then end up in no man's land.
400 	 */
401 	outb(IO_KBD + 4, 0xFE);
402 	DELAY(500000);	/* wait 0.5 sec to see if that did it */
403 #endif
404 
405 	/*
406 	 * Attempt to force a reset via the Reset Control register at
407 	 * I/O port 0xcf9.  Bit 2 forces a system reset when it
408 	 * transitions from 0 to 1.  Bit 1 selects the type of reset
409 	 * to attempt: 0 selects a "soft" reset, and 1 selects a
410 	 * "hard" reset.  We try a "hard" reset.  The first write sets
411 	 * bit 1 to select a "hard" reset and clears bit 2.  The
412 	 * second write forces a 0 -> 1 transition in bit 2 to trigger
413 	 * a reset.
414 	 */
415 	outb(0xcf9, 0x2);
416 	outb(0xcf9, 0x6);
417 	DELAY(500000);  /* wait 0.5 sec to see if that did it */
418 
419 	/*
420 	 * Attempt to force a reset via the Fast A20 and Init register
421 	 * at I/O port 0x92.  Bit 1 serves as an alternate A20 gate.
422 	 * Bit 0 asserts INIT# when set to 1.  We are careful to only
423 	 * preserve bit 1 while setting bit 0.  We also must clear bit
424 	 * 0 before setting it if it isn't already clear.
425 	 */
426 	b = inb(0x92);
427 	if (b != 0xff) {
428 		if ((b & 0x1) != 0)
429 			outb(0x92, b & 0xfe);
430 		outb(0x92, b | 0x1);
431 		DELAY(500000);  /* wait 0.5 sec to see if that did it */
432 	}
433 
434 	printf("No known reset method worked, attempting CPU shutdown\n");
435 	DELAY(1000000); /* wait 1 sec for printf to complete */
436 
437 	/* Wipe the IDT. */
438 	null_idt.rd_limit = 0;
439 	null_idt.rd_base = 0;
440 	lidt(&null_idt);
441 
442 	/* "good night, sweet prince .... <THUNK!>" */
443 	breakpoint();
444 
445 	/* NOTREACHED */
446 	while(1);
447 }
448 
449 #ifdef SMP
450 static void
451 cpu_reset_proxy(void)
452 {
453 
454 	cpu_reset_proxy_active = 1;
455 	while (cpu_reset_proxy_active == 1)
456 		ia32_pause(); /* Wait for other cpu to see that we've started */
457 
458 	printf("cpu_reset_proxy: Stopped CPU %d\n", cpu_reset_proxyid);
459 	DELAY(1000000);
460 	cpu_reset_real();
461 }
462 #endif
463 
464 void
465 cpu_reset(void)
466 {
467 #ifdef SMP
468 	struct monitorbuf *mb;
469 	cpuset_t map;
470 	u_int cnt;
471 
472 	if (smp_started) {
473 		map = all_cpus;
474 		CPU_CLR(PCPU_GET(cpuid), &map);
475 		CPU_ANDNOT(&map, &map, &stopped_cpus);
476 		if (!CPU_EMPTY(&map)) {
477 			printf("cpu_reset: Stopping other CPUs\n");
478 			stop_cpus(map);
479 		}
480 
481 		if (PCPU_GET(cpuid) != 0) {
482 			cpu_reset_proxyid = PCPU_GET(cpuid);
483 			cpustop_restartfunc = cpu_reset_proxy;
484 			cpu_reset_proxy_active = 0;
485 			printf("cpu_reset: Restarting BSP\n");
486 
487 			/* Restart CPU #0. */
488 			CPU_SETOF(0, &started_cpus);
489 			mb = &pcpu_find(0)->pc_monitorbuf;
490 			atomic_store_int(&mb->stop_state,
491 			    MONITOR_STOPSTATE_RUNNING);
492 
493 			cnt = 0;
494 			while (cpu_reset_proxy_active == 0 && cnt < 10000000) {
495 				ia32_pause();
496 				cnt++;	/* Wait for BSP to announce restart */
497 			}
498 			if (cpu_reset_proxy_active == 0) {
499 				printf("cpu_reset: Failed to restart BSP\n");
500 			} else {
501 				cpu_reset_proxy_active = 2;
502 				while (1)
503 					ia32_pause();
504 				/* NOTREACHED */
505 			}
506 		}
507 	}
508 #endif
509 	cpu_reset_real();
510 	/* NOTREACHED */
511 }
512 
513 bool
514 cpu_mwait_usable(void)
515 {
516 
517 	return ((cpu_feature2 & CPUID2_MON) != 0 && ((cpu_mon_mwait_flags &
518 	    (CPUID5_MON_MWAIT_EXT | CPUID5_MWAIT_INTRBREAK)) ==
519 	    (CPUID5_MON_MWAIT_EXT | CPUID5_MWAIT_INTRBREAK)));
520 }
521 
522 void (*cpu_idle_hook)(sbintime_t) = NULL;	/* ACPI idle hook. */
523 
524 int cpu_amdc1e_bug = 0;			/* AMD C1E APIC workaround required. */
525 
526 static int	idle_mwait = 1;		/* Use MONITOR/MWAIT for short idle. */
527 SYSCTL_INT(_machdep, OID_AUTO, idle_mwait, CTLFLAG_RWTUN, &idle_mwait,
528     0, "Use MONITOR/MWAIT for short idle");
529 
530 static bool
531 cpu_idle_enter(int *statep, int newstate)
532 {
533 	KASSERT(atomic_load_int(statep) == STATE_RUNNING,
534 	    ("%s: state %d", __func__, atomic_load_int(statep)));
535 
536 	/*
537 	 * A fence is needed to prevent reordering of the load in
538 	 * sched_runnable() with this store to the idle state word.  Without it,
539 	 * cpu_idle_wakeup() can observe the state as STATE_RUNNING after having
540 	 * added load to the queue, and elide an IPI.  Then, sched_runnable()
541 	 * can observe tdq_load == 0, so the CPU ends up idling with pending
542 	 * work.  tdq_notify() similarly ensures that a prior update to tdq_load
543 	 * is visible before calling cpu_idle_wakeup().
544 	 */
545 	atomic_store_int(statep, newstate);
546 #if defined(SCHED_ULE) && defined(SMP)
547 	atomic_thread_fence_seq_cst();
548 #endif
549 
550 	/*
551 	 * Since we may be in a critical section from cpu_idle(), if
552 	 * an interrupt fires during that critical section we may have
553 	 * a pending preemption.  If the CPU halts, then that thread
554 	 * may not execute until a later interrupt awakens the CPU.
555 	 * To handle this race, check for a runnable thread after
556 	 * disabling interrupts and immediately return if one is
557 	 * found.  Also, we must absolutely guarentee that hlt is
558 	 * the next instruction after sti.  This ensures that any
559 	 * interrupt that fires after the call to disable_intr() will
560 	 * immediately awaken the CPU from hlt.  Finally, please note
561 	 * that on x86 this works fine because of interrupts enabled only
562 	 * after the instruction following sti takes place, while IF is set
563 	 * to 1 immediately, allowing hlt instruction to acknowledge the
564 	 * interrupt.
565 	 */
566 	disable_intr();
567 	if (sched_runnable()) {
568 		enable_intr();
569 		atomic_store_int(statep, STATE_RUNNING);
570 		return (false);
571 	} else {
572 		return (true);
573 	}
574 }
575 
576 static void
577 cpu_idle_exit(int *statep)
578 {
579 	atomic_store_int(statep, STATE_RUNNING);
580 }
581 
582 static void
583 cpu_idle_acpi(sbintime_t sbt)
584 {
585 	int *state;
586 
587 	state = &PCPU_PTR(monitorbuf)->idle_state;
588 	if (cpu_idle_enter(state, STATE_SLEEPING)) {
589 		if (cpu_idle_hook)
590 			cpu_idle_hook(sbt);
591 		else
592 			acpi_cpu_c1();
593 		cpu_idle_exit(state);
594 	}
595 }
596 
597 static void
598 cpu_idle_hlt(sbintime_t sbt)
599 {
600 	int *state;
601 
602 	state = &PCPU_PTR(monitorbuf)->idle_state;
603 	if (cpu_idle_enter(state, STATE_SLEEPING)) {
604 		acpi_cpu_c1();
605 		atomic_store_int(state, STATE_RUNNING);
606 	}
607 }
608 
609 static void
610 cpu_idle_mwait(sbintime_t sbt)
611 {
612 	int *state;
613 
614 	state = &PCPU_PTR(monitorbuf)->idle_state;
615 	if (cpu_idle_enter(state, STATE_MWAIT)) {
616 		cpu_monitor(state, 0, 0);
617 		if (atomic_load_int(state) == STATE_MWAIT)
618 			__asm __volatile("sti; mwait" : : "a" (MWAIT_C1), "c" (0));
619 		else
620 			enable_intr();
621 		cpu_idle_exit(state);
622 	}
623 }
624 
625 static void
626 cpu_idle_spin(sbintime_t sbt)
627 {
628 	int *state;
629 	int i;
630 
631 	state = &PCPU_PTR(monitorbuf)->idle_state;
632 	atomic_store_int(state, STATE_RUNNING);
633 
634 	/*
635 	 * The sched_runnable() call is racy but as long as there is
636 	 * a loop missing it one time will have just a little impact if any
637 	 * (and it is much better than missing the check at all).
638 	 */
639 	for (i = 0; i < 1000; i++) {
640 		if (sched_runnable())
641 			return;
642 		cpu_spinwait();
643 	}
644 }
645 
646 void (*cpu_idle_fn)(sbintime_t) = cpu_idle_acpi;
647 
648 void
649 cpu_idle(int busy)
650 {
651 	uint64_t msr;
652 	sbintime_t sbt = -1;
653 
654 	CTR1(KTR_SPARE2, "cpu_idle(%d)", busy);
655 
656 	/* If we are busy - try to use fast methods. */
657 	if (busy) {
658 		if ((cpu_feature2 & CPUID2_MON) && idle_mwait) {
659 			cpu_idle_mwait(busy);
660 			goto out;
661 		}
662 	}
663 
664 	/* If we have time - switch timers into idle mode. */
665 	if (!busy) {
666 		critical_enter();
667 		sbt = cpu_idleclock();
668 	}
669 
670 	/* Apply AMD APIC timer C1E workaround. */
671 	if (cpu_amdc1e_bug && cpu_disable_c3_sleep) {
672 		msr = rdmsr(MSR_AMDK8_IPM);
673 		if ((msr & (AMDK8_SMIONCMPHALT | AMDK8_C1EONCMPHALT)) != 0)
674 			wrmsr(MSR_AMDK8_IPM, msr & ~(AMDK8_SMIONCMPHALT |
675 			    AMDK8_C1EONCMPHALT));
676 	}
677 
678 	/* Call main idle method. */
679 	cpu_idle_fn(sbt);
680 
681 	/* Switch timers back into active mode. */
682 	if (!busy) {
683 		cpu_activeclock();
684 		critical_exit();
685 	}
686 out:
687 	CTR1(KTR_SPARE2, "cpu_idle(%d) done", busy);
688 }
689 
690 static int cpu_idle_apl31_workaround;
691 SYSCTL_INT(_machdep, OID_AUTO, idle_apl31, CTLFLAG_RW,
692     &cpu_idle_apl31_workaround, 0,
693     "Apollo Lake APL31 MWAIT bug workaround");
694 
695 int
696 cpu_idle_wakeup(int cpu)
697 {
698 	struct monitorbuf *mb;
699 	int *state;
700 
701 	mb = &pcpu_find(cpu)->pc_monitorbuf;
702 	state = &mb->idle_state;
703 	switch (atomic_load_int(state)) {
704 	case STATE_SLEEPING:
705 		return (0);
706 	case STATE_MWAIT:
707 		atomic_store_int(state, STATE_RUNNING);
708 		return (cpu_idle_apl31_workaround ? 0 : 1);
709 	case STATE_RUNNING:
710 		return (1);
711 	default:
712 		panic("bad monitor state");
713 		return (1);
714 	}
715 }
716 
717 /*
718  * Ordered by speed/power consumption.
719  */
720 static const struct {
721 	void	*id_fn;
722 	const char *id_name;
723 	int	id_cpuid2_flag;
724 } idle_tbl[] = {
725 	{ .id_fn = cpu_idle_spin, .id_name = "spin" },
726 	{ .id_fn = cpu_idle_mwait, .id_name = "mwait",
727 	    .id_cpuid2_flag = CPUID2_MON },
728 	{ .id_fn = cpu_idle_hlt, .id_name = "hlt" },
729 	{ .id_fn = cpu_idle_acpi, .id_name = "acpi" },
730 };
731 
732 static int
733 idle_sysctl_available(SYSCTL_HANDLER_ARGS)
734 {
735 	char *avail, *p;
736 	int error;
737 	int i;
738 
739 	avail = malloc(256, M_TEMP, M_WAITOK);
740 	p = avail;
741 	for (i = 0; i < nitems(idle_tbl); i++) {
742 		if (idle_tbl[i].id_cpuid2_flag != 0 &&
743 		    (cpu_feature2 & idle_tbl[i].id_cpuid2_flag) == 0)
744 			continue;
745 		if (strcmp(idle_tbl[i].id_name, "acpi") == 0 &&
746 		    cpu_idle_hook == NULL)
747 			continue;
748 		p += sprintf(p, "%s%s", p != avail ? ", " : "",
749 		    idle_tbl[i].id_name);
750 	}
751 	error = sysctl_handle_string(oidp, avail, 0, req);
752 	free(avail, M_TEMP);
753 	return (error);
754 }
755 
756 SYSCTL_PROC(_machdep, OID_AUTO, idle_available,
757     CTLTYPE_STRING | CTLFLAG_RD | CTLFLAG_MPSAFE,
758     0, 0, idle_sysctl_available, "A",
759     "list of available idle functions");
760 
761 static bool
762 cpu_idle_selector(const char *new_idle_name)
763 {
764 	int i;
765 
766 	for (i = 0; i < nitems(idle_tbl); i++) {
767 		if (idle_tbl[i].id_cpuid2_flag != 0 &&
768 		    (cpu_feature2 & idle_tbl[i].id_cpuid2_flag) == 0)
769 			continue;
770 		if (strcmp(idle_tbl[i].id_name, "acpi") == 0 &&
771 		    cpu_idle_hook == NULL)
772 			continue;
773 		if (strcmp(idle_tbl[i].id_name, new_idle_name))
774 			continue;
775 		cpu_idle_fn = idle_tbl[i].id_fn;
776 		if (bootverbose)
777 			printf("CPU idle set to %s\n", idle_tbl[i].id_name);
778 		return (true);
779 	}
780 	return (false);
781 }
782 
783 static int
784 cpu_idle_sysctl(SYSCTL_HANDLER_ARGS)
785 {
786 	char buf[16];
787 	const char *p;
788 	int error, i;
789 
790 	p = "unknown";
791 	for (i = 0; i < nitems(idle_tbl); i++) {
792 		if (idle_tbl[i].id_fn == cpu_idle_fn) {
793 			p = idle_tbl[i].id_name;
794 			break;
795 		}
796 	}
797 	strncpy(buf, p, sizeof(buf));
798 	error = sysctl_handle_string(oidp, buf, sizeof(buf), req);
799 	if (error != 0 || req->newptr == NULL)
800 		return (error);
801 	return (cpu_idle_selector(buf) ? 0 : EINVAL);
802 }
803 
804 SYSCTL_PROC(_machdep, OID_AUTO, idle,
805     CTLTYPE_STRING | CTLFLAG_RW | CTLFLAG_MPSAFE,
806     0, 0, cpu_idle_sysctl, "A",
807     "currently selected idle function");
808 
809 static void
810 cpu_idle_tun(void *unused __unused)
811 {
812 	char tunvar[16];
813 
814 	if (TUNABLE_STR_FETCH("machdep.idle", tunvar, sizeof(tunvar)))
815 		cpu_idle_selector(tunvar);
816 	else if (cpu_vendor_id == CPU_VENDOR_AMD &&
817 	    CPUID_TO_FAMILY(cpu_id) == 0x17 && CPUID_TO_MODEL(cpu_id) == 0x1) {
818 		/* Ryzen erratas 1057, 1109. */
819 		cpu_idle_selector("hlt");
820 		idle_mwait = 0;
821 		mwait_cpustop_broken = true;
822 	}
823 
824 	if (cpu_vendor_id == CPU_VENDOR_INTEL &&
825 	    CPUID_TO_FAMILY(cpu_id) == 0x6 && CPUID_TO_MODEL(cpu_id) == 0x5c) {
826 		/*
827 		 * Apollo Lake errata APL31 (public errata APL30).
828 		 * Stores to the armed address range may not trigger
829 		 * MWAIT to resume execution.  OS needs to use
830 		 * interrupts to wake processors from MWAIT-induced
831 		 * sleep states.
832 		 */
833 		cpu_idle_apl31_workaround = 1;
834 		mwait_cpustop_broken = true;
835 	}
836 	TUNABLE_INT_FETCH("machdep.idle_apl31", &cpu_idle_apl31_workaround);
837 }
838 SYSINIT(cpu_idle_tun, SI_SUB_CPU, SI_ORDER_MIDDLE, cpu_idle_tun, NULL);
839 
840 static int panic_on_nmi = 0xff;
841 SYSCTL_INT(_machdep, OID_AUTO, panic_on_nmi, CTLFLAG_RWTUN,
842     &panic_on_nmi, 0,
843     "Panic on NMI: 1 = H/W failure; 2 = unknown; 0xff = all");
844 int nmi_is_broadcast = 1;
845 SYSCTL_INT(_machdep, OID_AUTO, nmi_is_broadcast, CTLFLAG_RWTUN,
846     &nmi_is_broadcast, 0,
847     "Chipset NMI is broadcast");
848 int (*apei_nmi)(void);
849 
850 void
851 nmi_call_kdb(u_int cpu, u_int type, struct trapframe *frame)
852 {
853 	bool claimed = false;
854 
855 #ifdef DEV_ISA
856 	/* machine/parity/power fail/"kitchen sink" faults */
857 	if (isa_nmi(frame->tf_err)) {
858 		claimed = true;
859 		if ((panic_on_nmi & 1) != 0)
860 			panic("NMI indicates hardware failure");
861 	}
862 #endif /* DEV_ISA */
863 
864 	/* ACPI Platform Error Interfaces callback. */
865 	if (apei_nmi != NULL && (*apei_nmi)())
866 		claimed = true;
867 
868 	/*
869 	 * NMIs can be useful for debugging.  They can be hooked up to a
870 	 * pushbutton, usually on an ISA, PCI, or PCIe card.  They can also be
871 	 * generated by an IPMI BMC, either manually or in response to a
872 	 * watchdog timeout.  For example, see the "power diag" command in
873 	 * ports/sysutils/ipmitool.  They can also be generated by a
874 	 * hypervisor; see "bhyvectl --inject-nmi".
875 	 */
876 
877 #ifdef KDB
878 	if (!claimed && (panic_on_nmi & 2) != 0) {
879 		if (debugger_on_panic) {
880 			printf("NMI/cpu%d ... going to debugger\n", cpu);
881 			claimed = kdb_trap(type, 0, frame);
882 		}
883 	}
884 #endif /* KDB */
885 
886 	if (!claimed && panic_on_nmi != 0)
887 		panic("NMI");
888 }
889 
890 void
891 nmi_handle_intr(u_int type, struct trapframe *frame)
892 {
893 
894 #ifdef SMP
895 	if (nmi_is_broadcast) {
896 		nmi_call_kdb_smp(type, frame);
897 		return;
898 	}
899 #endif
900 	nmi_call_kdb(PCPU_GET(cpuid), type, frame);
901 }
902 
903 static int hw_ibrs_active;
904 int hw_ibrs_ibpb_active;
905 int hw_ibrs_disable = 1;
906 
907 SYSCTL_INT(_hw, OID_AUTO, ibrs_active, CTLFLAG_RD, &hw_ibrs_active, 0,
908     "Indirect Branch Restricted Speculation active");
909 
910 SYSCTL_NODE(_machdep_mitigations, OID_AUTO, ibrs,
911     CTLFLAG_RW | CTLFLAG_MPSAFE, 0,
912     "Indirect Branch Restricted Speculation active");
913 
914 SYSCTL_INT(_machdep_mitigations_ibrs, OID_AUTO, active, CTLFLAG_RD,
915     &hw_ibrs_active, 0, "Indirect Branch Restricted Speculation active");
916 
917 void
918 hw_ibrs_recalculate(bool for_all_cpus)
919 {
920 	if ((cpu_ia32_arch_caps & IA32_ARCH_CAP_IBRS_ALL) != 0) {
921 		x86_msr_op(MSR_IA32_SPEC_CTRL, (for_all_cpus ?
922 		    MSR_OP_RENDEZVOUS_ALL : MSR_OP_LOCAL) |
923 		    (hw_ibrs_disable != 0 ? MSR_OP_ANDNOT : MSR_OP_OR),
924 		    IA32_SPEC_CTRL_IBRS, NULL);
925 		hw_ibrs_active = hw_ibrs_disable == 0;
926 		hw_ibrs_ibpb_active = 0;
927 	} else {
928 		hw_ibrs_active = hw_ibrs_ibpb_active = (cpu_stdext_feature3 &
929 		    CPUID_STDEXT3_IBPB) != 0 && !hw_ibrs_disable;
930 	}
931 }
932 
933 static int
934 hw_ibrs_disable_handler(SYSCTL_HANDLER_ARGS)
935 {
936 	int error, val;
937 
938 	val = hw_ibrs_disable;
939 	error = sysctl_handle_int(oidp, &val, 0, req);
940 	if (error != 0 || req->newptr == NULL)
941 		return (error);
942 	hw_ibrs_disable = val != 0;
943 	hw_ibrs_recalculate(true);
944 	return (0);
945 }
946 SYSCTL_PROC(_hw, OID_AUTO, ibrs_disable, CTLTYPE_INT | CTLFLAG_RWTUN |
947     CTLFLAG_NOFETCH | CTLFLAG_MPSAFE, NULL, 0, hw_ibrs_disable_handler, "I",
948     "Disable Indirect Branch Restricted Speculation");
949 
950 SYSCTL_PROC(_machdep_mitigations_ibrs, OID_AUTO, disable, CTLTYPE_INT |
951     CTLFLAG_RWTUN | CTLFLAG_NOFETCH | CTLFLAG_MPSAFE, NULL, 0,
952     hw_ibrs_disable_handler, "I",
953     "Disable Indirect Branch Restricted Speculation");
954 
955 int hw_ssb_active;
956 int hw_ssb_disable;
957 
958 SYSCTL_INT(_hw, OID_AUTO, spec_store_bypass_disable_active, CTLFLAG_RD,
959     &hw_ssb_active, 0,
960     "Speculative Store Bypass Disable active");
961 
962 SYSCTL_NODE(_machdep_mitigations, OID_AUTO, ssb,
963     CTLFLAG_RW | CTLFLAG_MPSAFE, 0,
964     "Speculative Store Bypass Disable active");
965 
966 SYSCTL_INT(_machdep_mitigations_ssb, OID_AUTO, active, CTLFLAG_RD,
967     &hw_ssb_active, 0, "Speculative Store Bypass Disable active");
968 
969 static void
970 hw_ssb_set(bool enable, bool for_all_cpus)
971 {
972 
973 	if ((cpu_stdext_feature3 & CPUID_STDEXT3_SSBD) == 0) {
974 		hw_ssb_active = 0;
975 		return;
976 	}
977 	hw_ssb_active = enable;
978 	x86_msr_op(MSR_IA32_SPEC_CTRL,
979 	    (enable ? MSR_OP_OR : MSR_OP_ANDNOT) |
980 	    (for_all_cpus ? MSR_OP_SCHED_ALL : MSR_OP_LOCAL),
981 	    IA32_SPEC_CTRL_SSBD, NULL);
982 }
983 
984 void
985 hw_ssb_recalculate(bool all_cpus)
986 {
987 
988 	switch (hw_ssb_disable) {
989 	default:
990 		hw_ssb_disable = 0;
991 		/* FALLTHROUGH */
992 	case 0: /* off */
993 		hw_ssb_set(false, all_cpus);
994 		break;
995 	case 1: /* on */
996 		hw_ssb_set(true, all_cpus);
997 		break;
998 	case 2: /* auto */
999 		hw_ssb_set((cpu_ia32_arch_caps & IA32_ARCH_CAP_SSB_NO) != 0 ?
1000 		    false : true, all_cpus);
1001 		break;
1002 	}
1003 }
1004 
1005 static int
1006 hw_ssb_disable_handler(SYSCTL_HANDLER_ARGS)
1007 {
1008 	int error, val;
1009 
1010 	val = hw_ssb_disable;
1011 	error = sysctl_handle_int(oidp, &val, 0, req);
1012 	if (error != 0 || req->newptr == NULL)
1013 		return (error);
1014 	hw_ssb_disable = val;
1015 	hw_ssb_recalculate(true);
1016 	return (0);
1017 }
1018 SYSCTL_PROC(_hw, OID_AUTO, spec_store_bypass_disable, CTLTYPE_INT |
1019     CTLFLAG_RWTUN | CTLFLAG_NOFETCH | CTLFLAG_MPSAFE, NULL, 0,
1020     hw_ssb_disable_handler, "I",
1021     "Speculative Store Bypass Disable (0 - off, 1 - on, 2 - auto)");
1022 
1023 SYSCTL_PROC(_machdep_mitigations_ssb, OID_AUTO, disable, CTLTYPE_INT |
1024     CTLFLAG_RWTUN | CTLFLAG_NOFETCH | CTLFLAG_MPSAFE, NULL, 0,
1025     hw_ssb_disable_handler, "I",
1026     "Speculative Store Bypass Disable (0 - off, 1 - on, 2 - auto)");
1027 
1028 int hw_mds_disable;
1029 
1030 /*
1031  * Handler for Microarchitectural Data Sampling issues.  Really not a
1032  * pointer to C function: on amd64 the code must not change any CPU
1033  * architectural state except possibly %rflags. Also, it is always
1034  * called with interrupts disabled.
1035  */
1036 void mds_handler_void(void);
1037 void mds_handler_verw(void);
1038 void mds_handler_ivb(void);
1039 void mds_handler_bdw(void);
1040 void mds_handler_skl_sse(void);
1041 void mds_handler_skl_avx(void);
1042 void mds_handler_skl_avx512(void);
1043 void mds_handler_silvermont(void);
1044 void (*mds_handler)(void) = mds_handler_void;
1045 
1046 static int
1047 sysctl_hw_mds_disable_state_handler(SYSCTL_HANDLER_ARGS)
1048 {
1049 	const char *state;
1050 
1051 	if (mds_handler == mds_handler_void)
1052 		state = "inactive";
1053 	else if (mds_handler == mds_handler_verw)
1054 		state = "VERW";
1055 	else if (mds_handler == mds_handler_ivb)
1056 		state = "software IvyBridge";
1057 	else if (mds_handler == mds_handler_bdw)
1058 		state = "software Broadwell";
1059 	else if (mds_handler == mds_handler_skl_sse)
1060 		state = "software Skylake SSE";
1061 	else if (mds_handler == mds_handler_skl_avx)
1062 		state = "software Skylake AVX";
1063 	else if (mds_handler == mds_handler_skl_avx512)
1064 		state = "software Skylake AVX512";
1065 	else if (mds_handler == mds_handler_silvermont)
1066 		state = "software Silvermont";
1067 	else
1068 		state = "unknown";
1069 	return (SYSCTL_OUT(req, state, strlen(state)));
1070 }
1071 
1072 SYSCTL_PROC(_hw, OID_AUTO, mds_disable_state,
1073     CTLTYPE_STRING | CTLFLAG_RD | CTLFLAG_MPSAFE, NULL, 0,
1074     sysctl_hw_mds_disable_state_handler, "A",
1075     "Microarchitectural Data Sampling Mitigation state");
1076 
1077 SYSCTL_NODE(_machdep_mitigations, OID_AUTO, mds,
1078     CTLFLAG_RW | CTLFLAG_MPSAFE, 0,
1079     "Microarchitectural Data Sampling Mitigation state");
1080 
1081 SYSCTL_PROC(_machdep_mitigations_mds, OID_AUTO, state,
1082     CTLTYPE_STRING | CTLFLAG_RD | CTLFLAG_MPSAFE, NULL, 0,
1083     sysctl_hw_mds_disable_state_handler, "A",
1084     "Microarchitectural Data Sampling Mitigation state");
1085 
1086 _Static_assert(__offsetof(struct pcpu, pc_mds_tmp) % 64 == 0, "MDS AVX512");
1087 
1088 void
1089 hw_mds_recalculate(void)
1090 {
1091 	struct pcpu *pc;
1092 	vm_offset_t b64;
1093 	u_long xcr0;
1094 	int i;
1095 
1096 	/*
1097 	 * Allow user to force VERW variant even if MD_CLEAR is not
1098 	 * reported.  For instance, hypervisor might unknowingly
1099 	 * filter the cap out.
1100 	 * For the similar reasons, and for testing, allow to enable
1101 	 * mitigation even when MDS_NO cap is set.
1102 	 */
1103 	if (cpu_vendor_id != CPU_VENDOR_INTEL || hw_mds_disable == 0 ||
1104 	    ((cpu_ia32_arch_caps & IA32_ARCH_CAP_MDS_NO) != 0 &&
1105 	    hw_mds_disable == 3)) {
1106 		mds_handler = mds_handler_void;
1107 	} else if (((cpu_stdext_feature3 & CPUID_STDEXT3_MD_CLEAR) != 0 &&
1108 	    hw_mds_disable == 3) || hw_mds_disable == 1) {
1109 		mds_handler = mds_handler_verw;
1110 	} else if (CPUID_TO_FAMILY(cpu_id) == 0x6 &&
1111 	    (CPUID_TO_MODEL(cpu_id) == 0x2e || CPUID_TO_MODEL(cpu_id) == 0x1e ||
1112 	    CPUID_TO_MODEL(cpu_id) == 0x1f || CPUID_TO_MODEL(cpu_id) == 0x1a ||
1113 	    CPUID_TO_MODEL(cpu_id) == 0x2f || CPUID_TO_MODEL(cpu_id) == 0x25 ||
1114 	    CPUID_TO_MODEL(cpu_id) == 0x2c || CPUID_TO_MODEL(cpu_id) == 0x2d ||
1115 	    CPUID_TO_MODEL(cpu_id) == 0x2a || CPUID_TO_MODEL(cpu_id) == 0x3e ||
1116 	    CPUID_TO_MODEL(cpu_id) == 0x3a) &&
1117 	    (hw_mds_disable == 2 || hw_mds_disable == 3)) {
1118 		/*
1119 		 * Nehalem, SandyBridge, IvyBridge
1120 		 */
1121 		CPU_FOREACH(i) {
1122 			pc = pcpu_find(i);
1123 			if (pc->pc_mds_buf == NULL) {
1124 				pc->pc_mds_buf = malloc_domainset(672, M_TEMP,
1125 				    DOMAINSET_PREF(pc->pc_domain), M_WAITOK);
1126 				bzero(pc->pc_mds_buf, 16);
1127 			}
1128 		}
1129 		mds_handler = mds_handler_ivb;
1130 	} else if (CPUID_TO_FAMILY(cpu_id) == 0x6 &&
1131 	    (CPUID_TO_MODEL(cpu_id) == 0x3f || CPUID_TO_MODEL(cpu_id) == 0x3c ||
1132 	    CPUID_TO_MODEL(cpu_id) == 0x45 || CPUID_TO_MODEL(cpu_id) == 0x46 ||
1133 	    CPUID_TO_MODEL(cpu_id) == 0x56 || CPUID_TO_MODEL(cpu_id) == 0x4f ||
1134 	    CPUID_TO_MODEL(cpu_id) == 0x47 || CPUID_TO_MODEL(cpu_id) == 0x3d) &&
1135 	    (hw_mds_disable == 2 || hw_mds_disable == 3)) {
1136 		/*
1137 		 * Haswell, Broadwell
1138 		 */
1139 		CPU_FOREACH(i) {
1140 			pc = pcpu_find(i);
1141 			if (pc->pc_mds_buf == NULL) {
1142 				pc->pc_mds_buf = malloc_domainset(1536, M_TEMP,
1143 				    DOMAINSET_PREF(pc->pc_domain), M_WAITOK);
1144 				bzero(pc->pc_mds_buf, 16);
1145 			}
1146 		}
1147 		mds_handler = mds_handler_bdw;
1148 	} else if (CPUID_TO_FAMILY(cpu_id) == 0x6 &&
1149 	    ((CPUID_TO_MODEL(cpu_id) == 0x55 && (cpu_id &
1150 	    CPUID_STEPPING) <= 5) ||
1151 	    CPUID_TO_MODEL(cpu_id) == 0x4e || CPUID_TO_MODEL(cpu_id) == 0x5e ||
1152 	    (CPUID_TO_MODEL(cpu_id) == 0x8e && (cpu_id &
1153 	    CPUID_STEPPING) <= 0xb) ||
1154 	    (CPUID_TO_MODEL(cpu_id) == 0x9e && (cpu_id &
1155 	    CPUID_STEPPING) <= 0xc)) &&
1156 	    (hw_mds_disable == 2 || hw_mds_disable == 3)) {
1157 		/*
1158 		 * Skylake, KabyLake, CoffeeLake, WhiskeyLake,
1159 		 * CascadeLake
1160 		 */
1161 		CPU_FOREACH(i) {
1162 			pc = pcpu_find(i);
1163 			if (pc->pc_mds_buf == NULL) {
1164 				pc->pc_mds_buf = malloc_domainset(6 * 1024,
1165 				    M_TEMP, DOMAINSET_PREF(pc->pc_domain),
1166 				    M_WAITOK);
1167 				b64 = (vm_offset_t)malloc_domainset(64 + 63,
1168 				    M_TEMP, DOMAINSET_PREF(pc->pc_domain),
1169 				    M_WAITOK);
1170 				pc->pc_mds_buf64 = (void *)roundup2(b64, 64);
1171 				bzero(pc->pc_mds_buf64, 64);
1172 			}
1173 		}
1174 		xcr0 = rxcr(0);
1175 		if ((xcr0 & XFEATURE_ENABLED_ZMM_HI256) != 0 &&
1176 		    (cpu_stdext_feature & CPUID_STDEXT_AVX512DQ) != 0)
1177 			mds_handler = mds_handler_skl_avx512;
1178 		else if ((xcr0 & XFEATURE_ENABLED_AVX) != 0 &&
1179 		    (cpu_feature2 & CPUID2_AVX) != 0)
1180 			mds_handler = mds_handler_skl_avx;
1181 		else
1182 			mds_handler = mds_handler_skl_sse;
1183 	} else if (CPUID_TO_FAMILY(cpu_id) == 0x6 &&
1184 	    ((CPUID_TO_MODEL(cpu_id) == 0x37 ||
1185 	    CPUID_TO_MODEL(cpu_id) == 0x4a ||
1186 	    CPUID_TO_MODEL(cpu_id) == 0x4c ||
1187 	    CPUID_TO_MODEL(cpu_id) == 0x4d ||
1188 	    CPUID_TO_MODEL(cpu_id) == 0x5a ||
1189 	    CPUID_TO_MODEL(cpu_id) == 0x5d ||
1190 	    CPUID_TO_MODEL(cpu_id) == 0x6e ||
1191 	    CPUID_TO_MODEL(cpu_id) == 0x65 ||
1192 	    CPUID_TO_MODEL(cpu_id) == 0x75 ||
1193 	    CPUID_TO_MODEL(cpu_id) == 0x1c ||
1194 	    CPUID_TO_MODEL(cpu_id) == 0x26 ||
1195 	    CPUID_TO_MODEL(cpu_id) == 0x27 ||
1196 	    CPUID_TO_MODEL(cpu_id) == 0x35 ||
1197 	    CPUID_TO_MODEL(cpu_id) == 0x36 ||
1198 	    CPUID_TO_MODEL(cpu_id) == 0x7a))) {
1199 		/* Silvermont, Airmont */
1200 		CPU_FOREACH(i) {
1201 			pc = pcpu_find(i);
1202 			if (pc->pc_mds_buf == NULL)
1203 				pc->pc_mds_buf = malloc(256, M_TEMP, M_WAITOK);
1204 		}
1205 		mds_handler = mds_handler_silvermont;
1206 	} else {
1207 		hw_mds_disable = 0;
1208 		mds_handler = mds_handler_void;
1209 	}
1210 }
1211 
1212 static void
1213 hw_mds_recalculate_boot(void *arg __unused)
1214 {
1215 
1216 	hw_mds_recalculate();
1217 }
1218 SYSINIT(mds_recalc, SI_SUB_SMP, SI_ORDER_ANY, hw_mds_recalculate_boot, NULL);
1219 
1220 static int
1221 sysctl_mds_disable_handler(SYSCTL_HANDLER_ARGS)
1222 {
1223 	int error, val;
1224 
1225 	val = hw_mds_disable;
1226 	error = sysctl_handle_int(oidp, &val, 0, req);
1227 	if (error != 0 || req->newptr == NULL)
1228 		return (error);
1229 	if (val < 0 || val > 3)
1230 		return (EINVAL);
1231 	hw_mds_disable = val;
1232 	hw_mds_recalculate();
1233 	return (0);
1234 }
1235 
1236 SYSCTL_PROC(_hw, OID_AUTO, mds_disable, CTLTYPE_INT |
1237     CTLFLAG_RWTUN | CTLFLAG_NOFETCH | CTLFLAG_MPSAFE, NULL, 0,
1238     sysctl_mds_disable_handler, "I",
1239     "Microarchitectural Data Sampling Mitigation "
1240     "(0 - off, 1 - on VERW, 2 - on SW, 3 - on AUTO)");
1241 
1242 SYSCTL_PROC(_machdep_mitigations_mds, OID_AUTO, disable, CTLTYPE_INT |
1243     CTLFLAG_RWTUN | CTLFLAG_NOFETCH | CTLFLAG_MPSAFE, NULL, 0,
1244     sysctl_mds_disable_handler, "I",
1245     "Microarchitectural Data Sampling Mitigation "
1246     "(0 - off, 1 - on VERW, 2 - on SW, 3 - on AUTO)");
1247 
1248 /*
1249  * Intel Transactional Memory Asynchronous Abort Mitigation
1250  * CVE-2019-11135
1251  */
1252 int x86_taa_enable;
1253 int x86_taa_state;
1254 enum {
1255 	TAA_NONE	= 0,	/* No mitigation enabled */
1256 	TAA_TSX_DISABLE	= 1,	/* Disable TSX via MSR */
1257 	TAA_VERW	= 2,	/* Use VERW mitigation */
1258 	TAA_AUTO	= 3,	/* Automatically select the mitigation */
1259 
1260 	/* The states below are not selectable by the operator */
1261 
1262 	TAA_TAA_UC	= 4,	/* Mitigation present in microcode */
1263 	TAA_NOT_PRESENT	= 5	/* TSX is not present */
1264 };
1265 
1266 static void
1267 taa_set(bool enable, bool all)
1268 {
1269 
1270 	x86_msr_op(MSR_IA32_TSX_CTRL,
1271 	    (enable ? MSR_OP_OR : MSR_OP_ANDNOT) |
1272 	    (all ? MSR_OP_RENDEZVOUS_ALL : MSR_OP_LOCAL),
1273 	    IA32_TSX_CTRL_RTM_DISABLE | IA32_TSX_CTRL_TSX_CPUID_CLEAR,
1274 	    NULL);
1275 }
1276 
1277 void
1278 x86_taa_recalculate(void)
1279 {
1280 	static int taa_saved_mds_disable = 0;
1281 	int taa_need = 0, taa_state = 0;
1282 	int mds_disable = 0, need_mds_recalc = 0;
1283 
1284 	/* Check CPUID.07h.EBX.HLE and RTM for the presence of TSX */
1285 	if ((cpu_stdext_feature & CPUID_STDEXT_HLE) == 0 ||
1286 	    (cpu_stdext_feature & CPUID_STDEXT_RTM) == 0) {
1287 		/* TSX is not present */
1288 		x86_taa_state = TAA_NOT_PRESENT;
1289 		return;
1290 	}
1291 
1292 	/* Check to see what mitigation options the CPU gives us */
1293 	if (cpu_ia32_arch_caps & IA32_ARCH_CAP_TAA_NO) {
1294 		/* CPU is not suseptible to TAA */
1295 		taa_need = TAA_TAA_UC;
1296 	} else if (cpu_ia32_arch_caps & IA32_ARCH_CAP_TSX_CTRL) {
1297 		/*
1298 		 * CPU can turn off TSX.  This is the next best option
1299 		 * if TAA_NO hardware mitigation isn't present
1300 		 */
1301 		taa_need = TAA_TSX_DISABLE;
1302 	} else {
1303 		/* No TSX/TAA specific remedies are available. */
1304 		if (x86_taa_enable == TAA_TSX_DISABLE) {
1305 			if (bootverbose)
1306 				printf("TSX control not available\n");
1307 			return;
1308 		} else
1309 			taa_need = TAA_VERW;
1310 	}
1311 
1312 	/* Can we automatically take action, or are we being forced? */
1313 	if (x86_taa_enable == TAA_AUTO)
1314 		taa_state = taa_need;
1315 	else
1316 		taa_state = x86_taa_enable;
1317 
1318 	/* No state change, nothing to do */
1319 	if (taa_state == x86_taa_state) {
1320 		if (bootverbose)
1321 			printf("No TSX change made\n");
1322 		return;
1323 	}
1324 
1325 	/* Does the MSR need to be turned on or off? */
1326 	if (taa_state == TAA_TSX_DISABLE)
1327 		taa_set(true, true);
1328 	else if (x86_taa_state == TAA_TSX_DISABLE)
1329 		taa_set(false, true);
1330 
1331 	/* Does MDS need to be set to turn on VERW? */
1332 	if (taa_state == TAA_VERW) {
1333 		taa_saved_mds_disable = hw_mds_disable;
1334 		mds_disable = hw_mds_disable = 1;
1335 		need_mds_recalc = 1;
1336 	} else if (x86_taa_state == TAA_VERW) {
1337 		mds_disable = hw_mds_disable = taa_saved_mds_disable;
1338 		need_mds_recalc = 1;
1339 	}
1340 	if (need_mds_recalc) {
1341 		hw_mds_recalculate();
1342 		if (mds_disable != hw_mds_disable) {
1343 			if (bootverbose)
1344 				printf("Cannot change MDS state for TAA\n");
1345 			/* Don't update our state */
1346 			return;
1347 		}
1348 	}
1349 
1350 	x86_taa_state = taa_state;
1351 	return;
1352 }
1353 
1354 static void
1355 taa_recalculate_boot(void * arg __unused)
1356 {
1357 
1358 	x86_taa_recalculate();
1359 }
1360 SYSINIT(taa_recalc, SI_SUB_SMP, SI_ORDER_ANY, taa_recalculate_boot, NULL);
1361 
1362 SYSCTL_NODE(_machdep_mitigations, OID_AUTO, taa,
1363     CTLFLAG_RW | CTLFLAG_MPSAFE, 0,
1364     "TSX Asynchronous Abort Mitigation");
1365 
1366 static int
1367 sysctl_taa_handler(SYSCTL_HANDLER_ARGS)
1368 {
1369 	int error, val;
1370 
1371 	val = x86_taa_enable;
1372 	error = sysctl_handle_int(oidp, &val, 0, req);
1373 	if (error != 0 || req->newptr == NULL)
1374 		return (error);
1375 	if (val < TAA_NONE || val > TAA_AUTO)
1376 		return (EINVAL);
1377 	x86_taa_enable = val;
1378 	x86_taa_recalculate();
1379 	return (0);
1380 }
1381 
1382 SYSCTL_PROC(_machdep_mitigations_taa, OID_AUTO, enable, CTLTYPE_INT |
1383     CTLFLAG_RWTUN | CTLFLAG_NOFETCH | CTLFLAG_MPSAFE, NULL, 0,
1384     sysctl_taa_handler, "I",
1385     "TAA Mitigation enablement control "
1386     "(0 - off, 1 - disable TSX, 2 - VERW, 3 - on AUTO)");
1387 
1388 static int
1389 sysctl_taa_state_handler(SYSCTL_HANDLER_ARGS)
1390 {
1391 	const char *state;
1392 
1393 	switch (x86_taa_state) {
1394 	case TAA_NONE:
1395 		state = "inactive";
1396 		break;
1397 	case TAA_TSX_DISABLE:
1398 		state = "TSX disabled";
1399 		break;
1400 	case TAA_VERW:
1401 		state = "VERW";
1402 		break;
1403 	case TAA_TAA_UC:
1404 		state = "Mitigated in microcode";
1405 		break;
1406 	case TAA_NOT_PRESENT:
1407 		state = "TSX not present";
1408 		break;
1409 	default:
1410 		state = "unknown";
1411 	}
1412 
1413 	return (SYSCTL_OUT(req, state, strlen(state)));
1414 }
1415 
1416 SYSCTL_PROC(_machdep_mitigations_taa, OID_AUTO, state,
1417     CTLTYPE_STRING | CTLFLAG_RD | CTLFLAG_MPSAFE, NULL, 0,
1418     sysctl_taa_state_handler, "A",
1419     "TAA Mitigation state");
1420 
1421 int __read_frequently cpu_flush_rsb_ctxsw;
1422 SYSCTL_INT(_machdep_mitigations, OID_AUTO, flush_rsb_ctxsw,
1423     CTLFLAG_RW | CTLFLAG_NOFETCH, &cpu_flush_rsb_ctxsw, 0,
1424     "Flush Return Stack Buffer on context switch");
1425 
1426 SYSCTL_NODE(_machdep_mitigations, OID_AUTO, rngds,
1427     CTLFLAG_RW | CTLFLAG_MPSAFE, 0,
1428     "MCU Optimization, disable RDSEED mitigation");
1429 
1430 int x86_rngds_mitg_enable = 1;
1431 void
1432 x86_rngds_mitg_recalculate(bool all_cpus)
1433 {
1434 	if ((cpu_stdext_feature3 & CPUID_STDEXT3_MCUOPT) == 0)
1435 		return;
1436 	x86_msr_op(MSR_IA32_MCU_OPT_CTRL,
1437 	    (x86_rngds_mitg_enable ? MSR_OP_OR : MSR_OP_ANDNOT) |
1438 	    (all_cpus ? MSR_OP_RENDEZVOUS_ALL : MSR_OP_LOCAL),
1439 	    IA32_RNGDS_MITG_DIS, NULL);
1440 }
1441 
1442 static int
1443 sysctl_rngds_mitg_enable_handler(SYSCTL_HANDLER_ARGS)
1444 {
1445 	int error, val;
1446 
1447 	val = x86_rngds_mitg_enable;
1448 	error = sysctl_handle_int(oidp, &val, 0, req);
1449 	if (error != 0 || req->newptr == NULL)
1450 		return (error);
1451 	x86_rngds_mitg_enable = val;
1452 	x86_rngds_mitg_recalculate(true);
1453 	return (0);
1454 }
1455 SYSCTL_PROC(_machdep_mitigations_rngds, OID_AUTO, enable, CTLTYPE_INT |
1456     CTLFLAG_RWTUN | CTLFLAG_NOFETCH | CTLFLAG_MPSAFE, NULL, 0,
1457     sysctl_rngds_mitg_enable_handler, "I",
1458     "MCU Optimization, disabling RDSEED mitigation control "
1459     "(0 - mitigation disabled (RDSEED optimized), 1 - mitigation enabled)");
1460 
1461 static int
1462 sysctl_rngds_state_handler(SYSCTL_HANDLER_ARGS)
1463 {
1464 	const char *state;
1465 
1466 	if ((cpu_stdext_feature3 & CPUID_STDEXT3_MCUOPT) == 0) {
1467 		state = "Not applicable";
1468 	} else if (x86_rngds_mitg_enable == 0) {
1469 		state = "RDSEED not serialized";
1470 	} else {
1471 		state = "Mitigated";
1472 	}
1473 	return (SYSCTL_OUT(req, state, strlen(state)));
1474 }
1475 SYSCTL_PROC(_machdep_mitigations_rngds, OID_AUTO, state,
1476     CTLTYPE_STRING | CTLFLAG_RD | CTLFLAG_MPSAFE, NULL, 0,
1477     sysctl_rngds_state_handler, "A",
1478     "MCU Optimization state");
1479 
1480 /*
1481  * Enable and restore kernel text write permissions.
1482  * Callers must ensure that disable_wp()/restore_wp() are executed
1483  * without rescheduling on the same core.
1484  */
1485 bool
1486 disable_wp(void)
1487 {
1488 	u_int cr0;
1489 
1490 	cr0 = rcr0();
1491 	if ((cr0 & CR0_WP) == 0)
1492 		return (false);
1493 	load_cr0(cr0 & ~CR0_WP);
1494 	return (true);
1495 }
1496 
1497 void
1498 restore_wp(bool old_wp)
1499 {
1500 
1501 	if (old_wp)
1502 		load_cr0(rcr0() | CR0_WP);
1503 }
1504 
1505 bool
1506 acpi_get_fadt_bootflags(uint16_t *flagsp)
1507 {
1508 #ifdef DEV_ACPI
1509 	ACPI_TABLE_FADT *fadt;
1510 	vm_paddr_t physaddr;
1511 
1512 	physaddr = acpi_find_table(ACPI_SIG_FADT);
1513 	if (physaddr == 0)
1514 		return (false);
1515 	fadt = acpi_map_table(physaddr, ACPI_SIG_FADT);
1516 	if (fadt == NULL)
1517 		return (false);
1518 	*flagsp = fadt->BootFlags;
1519 	acpi_unmap_table(fadt);
1520 	return (true);
1521 #else
1522 	return (false);
1523 #endif
1524 }
1525 
1526 DEFINE_IFUNC(, uint64_t, rdtsc_ordered, (void))
1527 {
1528 	bool cpu_is_amd = cpu_vendor_id == CPU_VENDOR_AMD ||
1529 	    cpu_vendor_id == CPU_VENDOR_HYGON;
1530 
1531 	if ((amd_feature & AMDID_RDTSCP) != 0)
1532 		return (rdtscp);
1533 	else if ((cpu_feature & CPUID_SSE2) != 0)
1534 		return (cpu_is_amd ? rdtsc_ordered_mfence :
1535 		    rdtsc_ordered_lfence);
1536 	else
1537 		return (rdtsc);
1538 }
1539