xref: /illumos-gate/usr/src/uts/i86pc/os/mp_startup.c (revision 447b1e1fca22e4de5e04623965fbb1460857930c)
1 /*
2  * CDDL HEADER START
3  *
4  * The contents of this file are subject to the terms of the
5  * Common Development and Distribution License (the "License").
6  * You may not use this file except in compliance with the License.
7  *
8  * You can obtain a copy of the license at usr/src/OPENSOLARIS.LICENSE
9  * or http://www.opensolaris.org/os/licensing.
10  * See the License for the specific language governing permissions
11  * and limitations under the License.
12  *
13  * When distributing Covered Code, include this CDDL HEADER in each
14  * file and include the License file at usr/src/OPENSOLARIS.LICENSE.
15  * If applicable, add the following below this CDDL HEADER, with the
16  * fields enclosed by brackets "[]" replaced with your own identifying
17  * information: Portions Copyright [yyyy] [name of copyright owner]
18  *
19  * CDDL HEADER END
20  */
21 
22 /*
23  * Copyright (c) 1992, 2010, Oracle and/or its affiliates. All rights reserved.
24  */
25 /*
26  * Copyright (c) 2010, Intel Corporation.
27  * All rights reserved.
28  */
29 /*
30  * Copyright 2015 Joyent, Inc.
31  * Copyright 2013 Nexenta Systems, Inc.  All rights reserved.
32  */
33 
34 #include <sys/types.h>
35 #include <sys/thread.h>
36 #include <sys/cpuvar.h>
37 #include <sys/cpu.h>
38 #include <sys/t_lock.h>
39 #include <sys/param.h>
40 #include <sys/proc.h>
41 #include <sys/disp.h>
42 #include <sys/class.h>
43 #include <sys/cmn_err.h>
44 #include <sys/debug.h>
45 #include <sys/note.h>
46 #include <sys/asm_linkage.h>
47 #include <sys/x_call.h>
48 #include <sys/systm.h>
49 #include <sys/var.h>
50 #include <sys/vtrace.h>
51 #include <vm/hat.h>
52 #include <vm/as.h>
53 #include <vm/seg_kmem.h>
54 #include <vm/seg_kp.h>
55 #include <sys/segments.h>
56 #include <sys/kmem.h>
57 #include <sys/stack.h>
58 #include <sys/smp_impldefs.h>
59 #include <sys/x86_archext.h>
60 #include <sys/machsystm.h>
61 #include <sys/traptrace.h>
62 #include <sys/clock.h>
63 #include <sys/cpc_impl.h>
64 #include <sys/pg.h>
65 #include <sys/cmt.h>
66 #include <sys/dtrace.h>
67 #include <sys/archsystm.h>
68 #include <sys/fp.h>
69 #include <sys/reboot.h>
70 #include <sys/kdi_machimpl.h>
71 #include <vm/hat_i86.h>
72 #include <vm/vm_dep.h>
73 #include <sys/memnode.h>
74 #include <sys/pci_cfgspace.h>
75 #include <sys/mach_mmu.h>
76 #include <sys/sysmacros.h>
77 #if defined(__xpv)
78 #include <sys/hypervisor.h>
79 #endif
80 #include <sys/cpu_module.h>
81 #include <sys/ontrap.h>
82 
83 struct cpu	cpus[1];			/* CPU data */
84 struct cpu	*cpu[NCPU] = {&cpus[0]};	/* pointers to all CPUs */
85 struct cpu	*cpu_free_list;			/* list for released CPUs */
86 cpu_core_t	cpu_core[NCPU];			/* cpu_core structures */
87 
88 #define	cpu_next_free	cpu_prev
89 
90 /*
91  * Useful for disabling MP bring-up on a MP capable system.
92  */
93 int use_mp = 1;
94 
95 /*
96  * to be set by a PSM to indicate what cpus
97  * are sitting around on the system.
98  */
99 cpuset_t mp_cpus;
100 
101 /*
102  * This variable is used by the hat layer to decide whether or not
103  * critical sections are needed to prevent race conditions.  For sun4m,
104  * this variable is set once enough MP initialization has been done in
105  * order to allow cross calls.
106  */
107 int flushes_require_xcalls;
108 
109 cpuset_t cpu_ready_set;		/* initialized in startup() */
110 
111 static void mp_startup_boot(void);
112 static void mp_startup_hotplug(void);
113 
114 static void cpu_sep_enable(void);
115 static void cpu_sep_disable(void);
116 static void cpu_asysc_enable(void);
117 static void cpu_asysc_disable(void);
118 
119 /*
120  * Init CPU info - get CPU type info for processor_info system call.
121  */
122 void
123 init_cpu_info(struct cpu *cp)
124 {
125 	processor_info_t *pi = &cp->cpu_type_info;
126 
127 	/*
128 	 * Get clock-frequency property for the CPU.
129 	 */
130 	pi->pi_clock = cpu_freq;
131 
132 	/*
133 	 * Current frequency in Hz.
134 	 */
135 	cp->cpu_curr_clock = cpu_freq_hz;
136 
137 	/*
138 	 * Supported frequencies.
139 	 */
140 	if (cp->cpu_supp_freqs == NULL) {
141 		cpu_set_supp_freqs(cp, NULL);
142 	}
143 
144 	(void) strcpy(pi->pi_processor_type, "i386");
145 	if (fpu_exists)
146 		(void) strcpy(pi->pi_fputypes, "i387 compatible");
147 
148 	cp->cpu_idstr = kmem_zalloc(CPU_IDSTRLEN, KM_SLEEP);
149 	cp->cpu_brandstr = kmem_zalloc(CPU_IDSTRLEN, KM_SLEEP);
150 
151 	/*
152 	 * If called for the BSP, cp is equal to current CPU.
153 	 * For non-BSPs, cpuid info of cp is not ready yet, so use cpuid info
154 	 * of current CPU as default values for cpu_idstr and cpu_brandstr.
155 	 * They will be corrected in mp_startup_common() after cpuid_pass1()
156 	 * has been invoked on target CPU.
157 	 */
158 	(void) cpuid_getidstr(CPU, cp->cpu_idstr, CPU_IDSTRLEN);
159 	(void) cpuid_getbrandstr(CPU, cp->cpu_brandstr, CPU_IDSTRLEN);
160 }
161 
162 /*
163  * Configure syscall support on this CPU.
164  */
165 /*ARGSUSED*/
166 void
167 init_cpu_syscall(struct cpu *cp)
168 {
169 	kpreempt_disable();
170 
171 #if defined(__amd64)
172 	if (is_x86_feature(x86_featureset, X86FSET_MSR) &&
173 	    is_x86_feature(x86_featureset, X86FSET_ASYSC)) {
174 		uint64_t flags;
175 
176 #if !defined(__lint)
177 		/*
178 		 * The syscall instruction imposes a certain ordering on
179 		 * segment selectors, so we double-check that ordering
180 		 * here.
181 		 */
182 		ASSERT(KDS_SEL == KCS_SEL + 8);
183 		ASSERT(UDS_SEL == U32CS_SEL + 8);
184 		ASSERT(UCS_SEL == U32CS_SEL + 16);
185 #endif
186 		/*
187 		 * Turn syscall/sysret extensions on.
188 		 */
189 		cpu_asysc_enable();
190 
191 		/*
192 		 * Program the magic registers ..
193 		 */
194 		wrmsr(MSR_AMD_STAR,
195 		    ((uint64_t)(U32CS_SEL << 16 | KCS_SEL)) << 32);
196 		wrmsr(MSR_AMD_LSTAR, (uint64_t)(uintptr_t)sys_syscall);
197 		wrmsr(MSR_AMD_CSTAR, (uint64_t)(uintptr_t)sys_syscall32);
198 
199 		/*
200 		 * This list of flags is masked off the incoming
201 		 * %rfl when we enter the kernel.
202 		 */
203 		flags = PS_IE | PS_T;
204 		if (is_x86_feature(x86_featureset, X86FSET_SMAP) == B_TRUE)
205 			flags |= PS_ACHK;
206 		wrmsr(MSR_AMD_SFMASK, flags);
207 	}
208 #endif
209 
210 	/*
211 	 * On 32-bit kernels, we use sysenter/sysexit because it's too
212 	 * hard to use syscall/sysret, and it is more portable anyway.
213 	 *
214 	 * On 64-bit kernels on Nocona machines, the 32-bit syscall
215 	 * variant isn't available to 32-bit applications, but sysenter is.
216 	 */
217 	if (is_x86_feature(x86_featureset, X86FSET_MSR) &&
218 	    is_x86_feature(x86_featureset, X86FSET_SEP)) {
219 
220 #if !defined(__lint)
221 		/*
222 		 * The sysenter instruction imposes a certain ordering on
223 		 * segment selectors, so we double-check that ordering
224 		 * here. See "sysenter" in Intel document 245471-012, "IA-32
225 		 * Intel Architecture Software Developer's Manual Volume 2:
226 		 * Instruction Set Reference"
227 		 */
228 		ASSERT(KDS_SEL == KCS_SEL + 8);
229 
230 		ASSERT32(UCS_SEL == ((KCS_SEL + 16) | 3));
231 		ASSERT32(UDS_SEL == UCS_SEL + 8);
232 
233 		ASSERT64(U32CS_SEL == ((KCS_SEL + 16) | 3));
234 		ASSERT64(UDS_SEL == U32CS_SEL + 8);
235 #endif
236 
237 		cpu_sep_enable();
238 
239 		/*
240 		 * resume() sets this value to the base of the threads stack
241 		 * via a context handler.
242 		 */
243 		wrmsr(MSR_INTC_SEP_ESP, 0);
244 		wrmsr(MSR_INTC_SEP_EIP, (uint64_t)(uintptr_t)sys_sysenter);
245 	}
246 
247 	kpreempt_enable();
248 }
249 
250 /*
251  * Multiprocessor initialization.
252  *
253  * Allocate and initialize the cpu structure, TRAPTRACE buffer, and the
254  * startup and idle threads for the specified CPU.
255  * Parameter boot is true for boot time operations and is false for CPU
256  * DR operations.
257  */
258 static struct cpu *
259 mp_cpu_configure_common(int cpun, boolean_t boot)
260 {
261 	struct cpu *cp;
262 	kthread_id_t tp;
263 	caddr_t	sp;
264 	proc_t *procp;
265 #if !defined(__xpv)
266 	extern int idle_cpu_prefer_mwait;
267 	extern void cpu_idle_mwait();
268 #endif
269 	extern void idle();
270 	extern void cpu_idle();
271 
272 #ifdef TRAPTRACE
273 	trap_trace_ctl_t *ttc = &trap_trace_ctl[cpun];
274 #endif
275 
276 	ASSERT(MUTEX_HELD(&cpu_lock));
277 	ASSERT(cpun < NCPU && cpu[cpun] == NULL);
278 
279 	if (cpu_free_list == NULL) {
280 		cp = kmem_zalloc(sizeof (*cp), KM_SLEEP);
281 	} else {
282 		cp = cpu_free_list;
283 		cpu_free_list = cp->cpu_next_free;
284 	}
285 
286 	cp->cpu_m.mcpu_istamp = cpun << 16;
287 
288 	/* Create per CPU specific threads in the process p0. */
289 	procp = &p0;
290 
291 	/*
292 	 * Initialize the dispatcher first.
293 	 */
294 	disp_cpu_init(cp);
295 
296 	cpu_vm_data_init(cp);
297 
298 	/*
299 	 * Allocate and initialize the startup thread for this CPU.
300 	 * Interrupt and process switch stacks get allocated later
301 	 * when the CPU starts running.
302 	 */
303 	tp = thread_create(NULL, 0, NULL, NULL, 0, procp,
304 	    TS_STOPPED, maxclsyspri);
305 
306 	/*
307 	 * Set state to TS_ONPROC since this thread will start running
308 	 * as soon as the CPU comes online.
309 	 *
310 	 * All the other fields of the thread structure are setup by
311 	 * thread_create().
312 	 */
313 	THREAD_ONPROC(tp, cp);
314 	tp->t_preempt = 1;
315 	tp->t_bound_cpu = cp;
316 	tp->t_affinitycnt = 1;
317 	tp->t_cpu = cp;
318 	tp->t_disp_queue = cp->cpu_disp;
319 
320 	/*
321 	 * Setup thread to start in mp_startup_common.
322 	 */
323 	sp = tp->t_stk;
324 	tp->t_sp = (uintptr_t)(sp - MINFRAME);
325 #if defined(__amd64)
326 	tp->t_sp -= STACK_ENTRY_ALIGN;		/* fake a call */
327 #endif
328 	/*
329 	 * Setup thread start entry point for boot or hotplug.
330 	 */
331 	if (boot) {
332 		tp->t_pc = (uintptr_t)mp_startup_boot;
333 	} else {
334 		tp->t_pc = (uintptr_t)mp_startup_hotplug;
335 	}
336 
337 	cp->cpu_id = cpun;
338 	cp->cpu_self = cp;
339 	cp->cpu_thread = tp;
340 	cp->cpu_lwp = NULL;
341 	cp->cpu_dispthread = tp;
342 	cp->cpu_dispatch_pri = DISP_PRIO(tp);
343 
344 	/*
345 	 * cpu_base_spl must be set explicitly here to prevent any blocking
346 	 * operations in mp_startup_common from causing the spl of the cpu
347 	 * to drop to 0 (allowing device interrupts before we're ready) in
348 	 * resume().
349 	 * cpu_base_spl MUST remain at LOCK_LEVEL until the cpu is CPU_READY.
350 	 * As an extra bit of security on DEBUG kernels, this is enforced with
351 	 * an assertion in mp_startup_common() -- before cpu_base_spl is set
352 	 * to its proper value.
353 	 */
354 	cp->cpu_base_spl = ipltospl(LOCK_LEVEL);
355 
356 	/*
357 	 * Now, initialize per-CPU idle thread for this CPU.
358 	 */
359 	tp = thread_create(NULL, PAGESIZE, idle, NULL, 0, procp, TS_ONPROC, -1);
360 
361 	cp->cpu_idle_thread = tp;
362 
363 	tp->t_preempt = 1;
364 	tp->t_bound_cpu = cp;
365 	tp->t_affinitycnt = 1;
366 	tp->t_cpu = cp;
367 	tp->t_disp_queue = cp->cpu_disp;
368 
369 	/*
370 	 * Bootstrap the CPU's PG data
371 	 */
372 	pg_cpu_bootstrap(cp);
373 
374 	/*
375 	 * Perform CPC initialization on the new CPU.
376 	 */
377 	kcpc_hw_init(cp);
378 
379 	/*
380 	 * Allocate virtual addresses for cpu_caddr1 and cpu_caddr2
381 	 * for each CPU.
382 	 */
383 	setup_vaddr_for_ppcopy(cp);
384 
385 	/*
386 	 * Allocate page for new GDT and initialize from current GDT.
387 	 */
388 #if !defined(__lint)
389 	ASSERT((sizeof (*cp->cpu_gdt) * NGDT) <= PAGESIZE);
390 #endif
391 	cp->cpu_gdt = kmem_zalloc(PAGESIZE, KM_SLEEP);
392 	bcopy(CPU->cpu_gdt, cp->cpu_gdt, (sizeof (*cp->cpu_gdt) * NGDT));
393 
394 #if defined(__i386)
395 	/*
396 	 * setup kernel %gs.
397 	 */
398 	set_usegd(&cp->cpu_gdt[GDT_GS], cp, sizeof (struct cpu) -1, SDT_MEMRWA,
399 	    SEL_KPL, 0, 1);
400 #endif
401 
402 	/*
403 	 * If we have more than one node, each cpu gets a copy of IDT
404 	 * local to its node. If this is a Pentium box, we use cpu 0's
405 	 * IDT. cpu 0's IDT has been made read-only to workaround the
406 	 * cmpxchgl register bug
407 	 */
408 	if (system_hardware.hd_nodes && x86_type != X86_TYPE_P5) {
409 #if !defined(__lint)
410 		ASSERT((sizeof (*CPU->cpu_idt) * NIDT) <= PAGESIZE);
411 #endif
412 		cp->cpu_idt = kmem_zalloc(PAGESIZE, KM_SLEEP);
413 		bcopy(CPU->cpu_idt, cp->cpu_idt, PAGESIZE);
414 	} else {
415 		cp->cpu_idt = CPU->cpu_idt;
416 	}
417 
418 	/*
419 	 * alloc space for cpuid info
420 	 */
421 	cpuid_alloc_space(cp);
422 #if !defined(__xpv)
423 	if (is_x86_feature(x86_featureset, X86FSET_MWAIT) &&
424 	    idle_cpu_prefer_mwait) {
425 		cp->cpu_m.mcpu_mwait = cpuid_mwait_alloc(cp);
426 		cp->cpu_m.mcpu_idle_cpu = cpu_idle_mwait;
427 	} else
428 #endif
429 		cp->cpu_m.mcpu_idle_cpu = cpu_idle;
430 
431 	init_cpu_info(cp);
432 
433 	/*
434 	 * alloc space for ucode_info
435 	 */
436 	ucode_alloc_space(cp);
437 	xc_init_cpu(cp);
438 	hat_cpu_online(cp);
439 
440 #ifdef TRAPTRACE
441 	/*
442 	 * If this is a TRAPTRACE kernel, allocate TRAPTRACE buffers
443 	 */
444 	ttc->ttc_first = (uintptr_t)kmem_zalloc(trap_trace_bufsize, KM_SLEEP);
445 	ttc->ttc_next = ttc->ttc_first;
446 	ttc->ttc_limit = ttc->ttc_first + trap_trace_bufsize;
447 #endif
448 
449 	/*
450 	 * Record that we have another CPU.
451 	 */
452 	/*
453 	 * Initialize the interrupt threads for this CPU
454 	 */
455 	cpu_intr_alloc(cp, NINTR_THREADS);
456 
457 	cp->cpu_flags = CPU_OFFLINE | CPU_QUIESCED | CPU_POWEROFF;
458 	cpu_set_state(cp);
459 
460 	/*
461 	 * Add CPU to list of available CPUs.  It'll be on the active list
462 	 * after mp_startup_common().
463 	 */
464 	cpu_add_unit(cp);
465 
466 	return (cp);
467 }
468 
469 /*
470  * Undo what was done in mp_cpu_configure_common
471  */
472 static void
473 mp_cpu_unconfigure_common(struct cpu *cp, int error)
474 {
475 	ASSERT(MUTEX_HELD(&cpu_lock));
476 
477 	/*
478 	 * Remove the CPU from the list of available CPUs.
479 	 */
480 	cpu_del_unit(cp->cpu_id);
481 
482 	if (error == ETIMEDOUT) {
483 		/*
484 		 * The cpu was started, but never *seemed* to run any
485 		 * code in the kernel; it's probably off spinning in its
486 		 * own private world, though with potential references to
487 		 * our kmem-allocated IDTs and GDTs (for example).
488 		 *
489 		 * Worse still, it may actually wake up some time later,
490 		 * so rather than guess what it might or might not do, we
491 		 * leave the fundamental data structures intact.
492 		 */
493 		cp->cpu_flags = 0;
494 		return;
495 	}
496 
497 	/*
498 	 * At this point, the only threads bound to this CPU should
499 	 * special per-cpu threads: it's idle thread, it's pause threads,
500 	 * and it's interrupt threads.  Clean these up.
501 	 */
502 	cpu_destroy_bound_threads(cp);
503 	cp->cpu_idle_thread = NULL;
504 
505 	/*
506 	 * Free the interrupt stack.
507 	 */
508 	segkp_release(segkp,
509 	    cp->cpu_intr_stack - (INTR_STACK_SIZE - SA(MINFRAME)));
510 	cp->cpu_intr_stack = NULL;
511 
512 #ifdef TRAPTRACE
513 	/*
514 	 * Discard the trap trace buffer
515 	 */
516 	{
517 		trap_trace_ctl_t *ttc = &trap_trace_ctl[cp->cpu_id];
518 
519 		kmem_free((void *)ttc->ttc_first, trap_trace_bufsize);
520 		ttc->ttc_first = NULL;
521 	}
522 #endif
523 
524 	hat_cpu_offline(cp);
525 
526 	ucode_free_space(cp);
527 
528 	/* Free CPU ID string and brand string. */
529 	if (cp->cpu_idstr) {
530 		kmem_free(cp->cpu_idstr, CPU_IDSTRLEN);
531 		cp->cpu_idstr = NULL;
532 	}
533 	if (cp->cpu_brandstr) {
534 		kmem_free(cp->cpu_brandstr, CPU_IDSTRLEN);
535 		cp->cpu_brandstr = NULL;
536 	}
537 
538 #if !defined(__xpv)
539 	if (cp->cpu_m.mcpu_mwait != NULL) {
540 		cpuid_mwait_free(cp);
541 		cp->cpu_m.mcpu_mwait = NULL;
542 	}
543 #endif
544 	cpuid_free_space(cp);
545 
546 	if (cp->cpu_idt != CPU->cpu_idt)
547 		kmem_free(cp->cpu_idt, PAGESIZE);
548 	cp->cpu_idt = NULL;
549 
550 	kmem_free(cp->cpu_gdt, PAGESIZE);
551 	cp->cpu_gdt = NULL;
552 
553 	if (cp->cpu_supp_freqs != NULL) {
554 		size_t len = strlen(cp->cpu_supp_freqs) + 1;
555 		kmem_free(cp->cpu_supp_freqs, len);
556 		cp->cpu_supp_freqs = NULL;
557 	}
558 
559 	teardown_vaddr_for_ppcopy(cp);
560 
561 	kcpc_hw_fini(cp);
562 
563 	cp->cpu_dispthread = NULL;
564 	cp->cpu_thread = NULL;	/* discarded by cpu_destroy_bound_threads() */
565 
566 	cpu_vm_data_destroy(cp);
567 
568 	xc_fini_cpu(cp);
569 	disp_cpu_fini(cp);
570 
571 	ASSERT(cp != CPU0);
572 	bzero(cp, sizeof (*cp));
573 	cp->cpu_next_free = cpu_free_list;
574 	cpu_free_list = cp;
575 }
576 
577 /*
578  * Apply workarounds for known errata, and warn about those that are absent.
579  *
580  * System vendors occasionally create configurations which contain different
581  * revisions of the CPUs that are almost but not exactly the same.  At the
582  * time of writing, this meant that their clock rates were the same, their
583  * feature sets were the same, but the required workaround were -not-
584  * necessarily the same.  So, this routine is invoked on -every- CPU soon
585  * after starting to make sure that the resulting system contains the most
586  * pessimal set of workarounds needed to cope with *any* of the CPUs in the
587  * system.
588  *
589  * workaround_errata is invoked early in mlsetup() for CPU 0, and in
590  * mp_startup_common() for all slave CPUs. Slaves process workaround_errata
591  * prior to acknowledging their readiness to the master, so this routine will
592  * never be executed by multiple CPUs in parallel, thus making updates to
593  * global data safe.
594  *
595  * These workarounds are based on Rev 3.57 of the Revision Guide for
596  * AMD Athlon(tm) 64 and AMD Opteron(tm) Processors, August 2005.
597  */
598 
599 #if defined(OPTERON_ERRATUM_88)
600 int opteron_erratum_88;		/* if non-zero -> at least one cpu has it */
601 #endif
602 
603 #if defined(OPTERON_ERRATUM_91)
604 int opteron_erratum_91;		/* if non-zero -> at least one cpu has it */
605 #endif
606 
607 #if defined(OPTERON_ERRATUM_93)
608 int opteron_erratum_93;		/* if non-zero -> at least one cpu has it */
609 #endif
610 
611 #if defined(OPTERON_ERRATUM_95)
612 int opteron_erratum_95;		/* if non-zero -> at least one cpu has it */
613 #endif
614 
615 #if defined(OPTERON_ERRATUM_100)
616 int opteron_erratum_100;	/* if non-zero -> at least one cpu has it */
617 #endif
618 
619 #if defined(OPTERON_ERRATUM_108)
620 int opteron_erratum_108;	/* if non-zero -> at least one cpu has it */
621 #endif
622 
623 #if defined(OPTERON_ERRATUM_109)
624 int opteron_erratum_109;	/* if non-zero -> at least one cpu has it */
625 #endif
626 
627 #if defined(OPTERON_ERRATUM_121)
628 int opteron_erratum_121;	/* if non-zero -> at least one cpu has it */
629 #endif
630 
631 #if defined(OPTERON_ERRATUM_122)
632 int opteron_erratum_122;	/* if non-zero -> at least one cpu has it */
633 #endif
634 
635 #if defined(OPTERON_ERRATUM_123)
636 int opteron_erratum_123;	/* if non-zero -> at least one cpu has it */
637 #endif
638 
639 #if defined(OPTERON_ERRATUM_131)
640 int opteron_erratum_131;	/* if non-zero -> at least one cpu has it */
641 #endif
642 
643 #if defined(OPTERON_WORKAROUND_6336786)
644 int opteron_workaround_6336786;	/* non-zero -> WA relevant and applied */
645 int opteron_workaround_6336786_UP = 0;	/* Not needed for UP */
646 #endif
647 
648 #if defined(OPTERON_WORKAROUND_6323525)
649 int opteron_workaround_6323525;	/* if non-zero -> at least one cpu has it */
650 #endif
651 
652 #if defined(OPTERON_ERRATUM_298)
653 int opteron_erratum_298;
654 #endif
655 
656 #if defined(OPTERON_ERRATUM_721)
657 int opteron_erratum_721;
658 #endif
659 
660 static void
661 workaround_warning(cpu_t *cp, uint_t erratum)
662 {
663 	cmn_err(CE_WARN, "cpu%d: no workaround for erratum %u",
664 	    cp->cpu_id, erratum);
665 }
666 
667 static void
668 workaround_applied(uint_t erratum)
669 {
670 	if (erratum > 1000000)
671 		cmn_err(CE_CONT, "?workaround applied for cpu issue #%d\n",
672 		    erratum);
673 	else
674 		cmn_err(CE_CONT, "?workaround applied for cpu erratum #%d\n",
675 		    erratum);
676 }
677 
678 static void
679 msr_warning(cpu_t *cp, const char *rw, uint_t msr, int error)
680 {
681 	cmn_err(CE_WARN, "cpu%d: couldn't %smsr 0x%x, error %d",
682 	    cp->cpu_id, rw, msr, error);
683 }
684 
685 /*
686  * Determine the number of nodes in a Hammer / Greyhound / Griffin family
687  * system.
688  */
689 static uint_t
690 opteron_get_nnodes(void)
691 {
692 	static uint_t nnodes = 0;
693 
694 	if (nnodes == 0) {
695 #ifdef	DEBUG
696 		uint_t family;
697 
698 		/*
699 		 * This routine uses a PCI config space based mechanism
700 		 * for retrieving the number of nodes in the system.
701 		 * Device 24, function 0, offset 0x60 as used here is not
702 		 * AMD processor architectural, and may not work on processor
703 		 * families other than those listed below.
704 		 *
705 		 * Callers of this routine must ensure that we're running on
706 		 * a processor which supports this mechanism.
707 		 * The assertion below is meant to catch calls on unsupported
708 		 * processors.
709 		 */
710 		family = cpuid_getfamily(CPU);
711 		ASSERT(family == 0xf || family == 0x10 || family == 0x11);
712 #endif	/* DEBUG */
713 
714 		/*
715 		 * Obtain the number of nodes in the system from
716 		 * bits [6:4] of the Node ID register on node 0.
717 		 *
718 		 * The actual node count is NodeID[6:4] + 1
719 		 *
720 		 * The Node ID register is accessed via function 0,
721 		 * offset 0x60. Node 0 is device 24.
722 		 */
723 		nnodes = ((pci_getl_func(0, 24, 0, 0x60) & 0x70) >> 4) + 1;
724 	}
725 	return (nnodes);
726 }
727 
728 uint_t
729 do_erratum_298(struct cpu *cpu)
730 {
731 	static int	osvwrc = -3;
732 	extern int	osvw_opteron_erratum(cpu_t *, uint_t);
733 
734 	/*
735 	 * L2 Eviction May Occur During Processor Operation To Set
736 	 * Accessed or Dirty Bit.
737 	 */
738 	if (osvwrc == -3) {
739 		osvwrc = osvw_opteron_erratum(cpu, 298);
740 	} else {
741 		/* osvw return codes should be consistent for all cpus */
742 		ASSERT(osvwrc == osvw_opteron_erratum(cpu, 298));
743 	}
744 
745 	switch (osvwrc) {
746 	case 0:		/* erratum is not present: do nothing */
747 		break;
748 	case 1:		/* erratum is present: BIOS workaround applied */
749 		/*
750 		 * check if workaround is actually in place and issue warning
751 		 * if not.
752 		 */
753 		if (((rdmsr(MSR_AMD_HWCR) & AMD_HWCR_TLBCACHEDIS) == 0) ||
754 		    ((rdmsr(MSR_AMD_BU_CFG) & AMD_BU_CFG_E298) == 0)) {
755 #if defined(OPTERON_ERRATUM_298)
756 			opteron_erratum_298++;
757 #else
758 			workaround_warning(cpu, 298);
759 			return (1);
760 #endif
761 		}
762 		break;
763 	case -1:	/* cannot determine via osvw: check cpuid */
764 		if ((cpuid_opteron_erratum(cpu, 298) > 0) &&
765 		    (((rdmsr(MSR_AMD_HWCR) & AMD_HWCR_TLBCACHEDIS) == 0) ||
766 		    ((rdmsr(MSR_AMD_BU_CFG) & AMD_BU_CFG_E298) == 0))) {
767 #if defined(OPTERON_ERRATUM_298)
768 			opteron_erratum_298++;
769 #else
770 			workaround_warning(cpu, 298);
771 			return (1);
772 #endif
773 		}
774 		break;
775 	}
776 	return (0);
777 }
778 
779 uint_t
780 workaround_errata(struct cpu *cpu)
781 {
782 	uint_t missing = 0;
783 
784 	ASSERT(cpu == CPU);
785 
786 	/*LINTED*/
787 	if (cpuid_opteron_erratum(cpu, 88) > 0) {
788 		/*
789 		 * SWAPGS May Fail To Read Correct GS Base
790 		 */
791 #if defined(OPTERON_ERRATUM_88)
792 		/*
793 		 * The workaround is an mfence in the relevant assembler code
794 		 */
795 		opteron_erratum_88++;
796 #else
797 		workaround_warning(cpu, 88);
798 		missing++;
799 #endif
800 	}
801 
802 	if (cpuid_opteron_erratum(cpu, 91) > 0) {
803 		/*
804 		 * Software Prefetches May Report A Page Fault
805 		 */
806 #if defined(OPTERON_ERRATUM_91)
807 		/*
808 		 * fix is in trap.c
809 		 */
810 		opteron_erratum_91++;
811 #else
812 		workaround_warning(cpu, 91);
813 		missing++;
814 #endif
815 	}
816 
817 	if (cpuid_opteron_erratum(cpu, 93) > 0) {
818 		/*
819 		 * RSM Auto-Halt Restart Returns to Incorrect RIP
820 		 */
821 #if defined(OPTERON_ERRATUM_93)
822 		/*
823 		 * fix is in trap.c
824 		 */
825 		opteron_erratum_93++;
826 #else
827 		workaround_warning(cpu, 93);
828 		missing++;
829 #endif
830 	}
831 
832 	/*LINTED*/
833 	if (cpuid_opteron_erratum(cpu, 95) > 0) {
834 		/*
835 		 * RET Instruction May Return to Incorrect EIP
836 		 */
837 #if defined(OPTERON_ERRATUM_95)
838 #if defined(_LP64)
839 		/*
840 		 * Workaround this by ensuring that 32-bit user code and
841 		 * 64-bit kernel code never occupy the same address
842 		 * range mod 4G.
843 		 */
844 		if (_userlimit32 > 0xc0000000ul)
845 			*(uintptr_t *)&_userlimit32 = 0xc0000000ul;
846 
847 		/*LINTED*/
848 		ASSERT((uint32_t)COREHEAP_BASE == 0xc0000000u);
849 		opteron_erratum_95++;
850 #endif	/* _LP64 */
851 #else
852 		workaround_warning(cpu, 95);
853 		missing++;
854 #endif
855 	}
856 
857 	if (cpuid_opteron_erratum(cpu, 100) > 0) {
858 		/*
859 		 * Compatibility Mode Branches Transfer to Illegal Address
860 		 */
861 #if defined(OPTERON_ERRATUM_100)
862 		/*
863 		 * fix is in trap.c
864 		 */
865 		opteron_erratum_100++;
866 #else
867 		workaround_warning(cpu, 100);
868 		missing++;
869 #endif
870 	}
871 
872 	/*LINTED*/
873 	if (cpuid_opteron_erratum(cpu, 108) > 0) {
874 		/*
875 		 * CPUID Instruction May Return Incorrect Model Number In
876 		 * Some Processors
877 		 */
878 #if defined(OPTERON_ERRATUM_108)
879 		/*
880 		 * (Our cpuid-handling code corrects the model number on
881 		 * those processors)
882 		 */
883 #else
884 		workaround_warning(cpu, 108);
885 		missing++;
886 #endif
887 	}
888 
889 	/*LINTED*/
890 	if (cpuid_opteron_erratum(cpu, 109) > 0) do {
891 		/*
892 		 * Certain Reverse REP MOVS May Produce Unpredictable Behavior
893 		 */
894 #if defined(OPTERON_ERRATUM_109)
895 		/*
896 		 * The "workaround" is to print a warning to upgrade the BIOS
897 		 */
898 		uint64_t value;
899 		const uint_t msr = MSR_AMD_PATCHLEVEL;
900 		int err;
901 
902 		if ((err = checked_rdmsr(msr, &value)) != 0) {
903 			msr_warning(cpu, "rd", msr, err);
904 			workaround_warning(cpu, 109);
905 			missing++;
906 		}
907 		if (value == 0)
908 			opteron_erratum_109++;
909 #else
910 		workaround_warning(cpu, 109);
911 		missing++;
912 #endif
913 	/*CONSTANTCONDITION*/
914 	} while (0);
915 
916 	/*LINTED*/
917 	if (cpuid_opteron_erratum(cpu, 121) > 0) {
918 		/*
919 		 * Sequential Execution Across Non_Canonical Boundary Caused
920 		 * Processor Hang
921 		 */
922 #if defined(OPTERON_ERRATUM_121)
923 #if defined(_LP64)
924 		/*
925 		 * Erratum 121 is only present in long (64 bit) mode.
926 		 * Workaround is to include the page immediately before the
927 		 * va hole to eliminate the possibility of system hangs due to
928 		 * sequential execution across the va hole boundary.
929 		 */
930 		if (opteron_erratum_121)
931 			opteron_erratum_121++;
932 		else {
933 			if (hole_start) {
934 				hole_start -= PAGESIZE;
935 			} else {
936 				/*
937 				 * hole_start not yet initialized by
938 				 * mmu_init. Initialize hole_start
939 				 * with value to be subtracted.
940 				 */
941 				hole_start = PAGESIZE;
942 			}
943 			opteron_erratum_121++;
944 		}
945 #endif	/* _LP64 */
946 #else
947 		workaround_warning(cpu, 121);
948 		missing++;
949 #endif
950 	}
951 
952 	/*LINTED*/
953 	if (cpuid_opteron_erratum(cpu, 122) > 0) do {
954 		/*
955 		 * TLB Flush Filter May Cause Coherency Problem in
956 		 * Multiprocessor Systems
957 		 */
958 #if defined(OPTERON_ERRATUM_122)
959 		uint64_t value;
960 		const uint_t msr = MSR_AMD_HWCR;
961 		int error;
962 
963 		/*
964 		 * Erratum 122 is only present in MP configurations (multi-core
965 		 * or multi-processor).
966 		 */
967 #if defined(__xpv)
968 		if (!DOMAIN_IS_INITDOMAIN(xen_info))
969 			break;
970 		if (!opteron_erratum_122 && xpv_nr_phys_cpus() == 1)
971 			break;
972 #else
973 		if (!opteron_erratum_122 && opteron_get_nnodes() == 1 &&
974 		    cpuid_get_ncpu_per_chip(cpu) == 1)
975 			break;
976 #endif
977 		/* disable TLB Flush Filter */
978 
979 		if ((error = checked_rdmsr(msr, &value)) != 0) {
980 			msr_warning(cpu, "rd", msr, error);
981 			workaround_warning(cpu, 122);
982 			missing++;
983 		} else {
984 			value |= (uint64_t)AMD_HWCR_FFDIS;
985 			if ((error = checked_wrmsr(msr, value)) != 0) {
986 				msr_warning(cpu, "wr", msr, error);
987 				workaround_warning(cpu, 122);
988 				missing++;
989 			}
990 		}
991 		opteron_erratum_122++;
992 #else
993 		workaround_warning(cpu, 122);
994 		missing++;
995 #endif
996 	/*CONSTANTCONDITION*/
997 	} while (0);
998 
999 	/*LINTED*/
1000 	if (cpuid_opteron_erratum(cpu, 123) > 0) do {
1001 		/*
1002 		 * Bypassed Reads May Cause Data Corruption of System Hang in
1003 		 * Dual Core Processors
1004 		 */
1005 #if defined(OPTERON_ERRATUM_123)
1006 		uint64_t value;
1007 		const uint_t msr = MSR_AMD_PATCHLEVEL;
1008 		int err;
1009 
1010 		/*
1011 		 * Erratum 123 applies only to multi-core cpus.
1012 		 */
1013 		if (cpuid_get_ncpu_per_chip(cpu) < 2)
1014 			break;
1015 #if defined(__xpv)
1016 		if (!DOMAIN_IS_INITDOMAIN(xen_info))
1017 			break;
1018 #endif
1019 		/*
1020 		 * The "workaround" is to print a warning to upgrade the BIOS
1021 		 */
1022 		if ((err = checked_rdmsr(msr, &value)) != 0) {
1023 			msr_warning(cpu, "rd", msr, err);
1024 			workaround_warning(cpu, 123);
1025 			missing++;
1026 		}
1027 		if (value == 0)
1028 			opteron_erratum_123++;
1029 #else
1030 		workaround_warning(cpu, 123);
1031 		missing++;
1032 
1033 #endif
1034 	/*CONSTANTCONDITION*/
1035 	} while (0);
1036 
1037 	/*LINTED*/
1038 	if (cpuid_opteron_erratum(cpu, 131) > 0) do {
1039 		/*
1040 		 * Multiprocessor Systems with Four or More Cores May Deadlock
1041 		 * Waiting for a Probe Response
1042 		 */
1043 #if defined(OPTERON_ERRATUM_131)
1044 		uint64_t nbcfg;
1045 		const uint_t msr = MSR_AMD_NB_CFG;
1046 		const uint64_t wabits =
1047 		    AMD_NB_CFG_SRQ_HEARTBEAT | AMD_NB_CFG_SRQ_SPR;
1048 		int error;
1049 
1050 		/*
1051 		 * Erratum 131 applies to any system with four or more cores.
1052 		 */
1053 		if (opteron_erratum_131)
1054 			break;
1055 #if defined(__xpv)
1056 		if (!DOMAIN_IS_INITDOMAIN(xen_info))
1057 			break;
1058 		if (xpv_nr_phys_cpus() < 4)
1059 			break;
1060 #else
1061 		if (opteron_get_nnodes() * cpuid_get_ncpu_per_chip(cpu) < 4)
1062 			break;
1063 #endif
1064 		/*
1065 		 * Print a warning if neither of the workarounds for
1066 		 * erratum 131 is present.
1067 		 */
1068 		if ((error = checked_rdmsr(msr, &nbcfg)) != 0) {
1069 			msr_warning(cpu, "rd", msr, error);
1070 			workaround_warning(cpu, 131);
1071 			missing++;
1072 		} else if ((nbcfg & wabits) == 0) {
1073 			opteron_erratum_131++;
1074 		} else {
1075 			/* cannot have both workarounds set */
1076 			ASSERT((nbcfg & wabits) != wabits);
1077 		}
1078 #else
1079 		workaround_warning(cpu, 131);
1080 		missing++;
1081 #endif
1082 	/*CONSTANTCONDITION*/
1083 	} while (0);
1084 
1085 	/*
1086 	 * This isn't really an erratum, but for convenience the
1087 	 * detection/workaround code lives here and in cpuid_opteron_erratum.
1088 	 */
1089 	if (cpuid_opteron_erratum(cpu, 6336786) > 0) {
1090 #if defined(OPTERON_WORKAROUND_6336786)
1091 		/*
1092 		 * Disable C1-Clock ramping on multi-core/multi-processor
1093 		 * K8 platforms to guard against TSC drift.
1094 		 */
1095 		if (opteron_workaround_6336786) {
1096 			opteron_workaround_6336786++;
1097 #if defined(__xpv)
1098 		} else if ((DOMAIN_IS_INITDOMAIN(xen_info) &&
1099 		    xpv_nr_phys_cpus() > 1) ||
1100 		    opteron_workaround_6336786_UP) {
1101 			/*
1102 			 * XXPV	Hmm.  We can't walk the Northbridges on
1103 			 *	the hypervisor; so just complain and drive
1104 			 *	on.  This probably needs to be fixed in
1105 			 *	the hypervisor itself.
1106 			 */
1107 			opteron_workaround_6336786++;
1108 			workaround_warning(cpu, 6336786);
1109 #else	/* __xpv */
1110 		} else if ((opteron_get_nnodes() *
1111 		    cpuid_get_ncpu_per_chip(cpu) > 1) ||
1112 		    opteron_workaround_6336786_UP) {
1113 
1114 			uint_t	node, nnodes;
1115 			uint8_t data;
1116 
1117 			nnodes = opteron_get_nnodes();
1118 			for (node = 0; node < nnodes; node++) {
1119 				/*
1120 				 * Clear PMM7[1:0] (function 3, offset 0x87)
1121 				 * Northbridge device is the node id + 24.
1122 				 */
1123 				data = pci_getb_func(0, node + 24, 3, 0x87);
1124 				data &= 0xFC;
1125 				pci_putb_func(0, node + 24, 3, 0x87, data);
1126 			}
1127 			opteron_workaround_6336786++;
1128 #endif	/* __xpv */
1129 		}
1130 #else
1131 		workaround_warning(cpu, 6336786);
1132 		missing++;
1133 #endif
1134 	}
1135 
1136 	/*LINTED*/
1137 	/*
1138 	 * Mutex primitives don't work as expected.
1139 	 */
1140 	if (cpuid_opteron_erratum(cpu, 6323525) > 0) {
1141 #if defined(OPTERON_WORKAROUND_6323525)
1142 		/*
1143 		 * This problem only occurs with 2 or more cores. If bit in
1144 		 * MSR_AMD_BU_CFG set, then not applicable. The workaround
1145 		 * is to patch the semaphone routines with the lfence
1146 		 * instruction to provide necessary load memory barrier with
1147 		 * possible subsequent read-modify-write ops.
1148 		 *
1149 		 * It is too early in boot to call the patch routine so
1150 		 * set erratum variable to be done in startup_end().
1151 		 */
1152 		if (opteron_workaround_6323525) {
1153 			opteron_workaround_6323525++;
1154 #if defined(__xpv)
1155 		} else if (is_x86_feature(x86_featureset, X86FSET_SSE2)) {
1156 			if (DOMAIN_IS_INITDOMAIN(xen_info)) {
1157 				/*
1158 				 * XXPV	Use dom0_msr here when extended
1159 				 *	operations are supported?
1160 				 */
1161 				if (xpv_nr_phys_cpus() > 1)
1162 					opteron_workaround_6323525++;
1163 			} else {
1164 				/*
1165 				 * We have no way to tell how many physical
1166 				 * cpus there are, or even if this processor
1167 				 * has the problem, so enable the workaround
1168 				 * unconditionally (at some performance cost).
1169 				 */
1170 				opteron_workaround_6323525++;
1171 			}
1172 #else	/* __xpv */
1173 		} else if (is_x86_feature(x86_featureset, X86FSET_SSE2) &&
1174 		    ((opteron_get_nnodes() *
1175 		    cpuid_get_ncpu_per_chip(cpu)) > 1)) {
1176 			if ((xrdmsr(MSR_AMD_BU_CFG) & (UINT64_C(1) << 33)) == 0)
1177 				opteron_workaround_6323525++;
1178 #endif	/* __xpv */
1179 		}
1180 #else
1181 		workaround_warning(cpu, 6323525);
1182 		missing++;
1183 #endif
1184 	}
1185 
1186 	missing += do_erratum_298(cpu);
1187 
1188 	if (cpuid_opteron_erratum(cpu, 721) > 0) {
1189 #if defined(OPTERON_ERRATUM_721)
1190 		on_trap_data_t otd;
1191 
1192 		if (!on_trap(&otd, OT_DATA_ACCESS))
1193 			wrmsr(MSR_AMD_DE_CFG,
1194 			    rdmsr(MSR_AMD_DE_CFG) | AMD_DE_CFG_E721);
1195 		no_trap();
1196 
1197 		opteron_erratum_721++;
1198 #else
1199 		workaround_warning(cpu, 721);
1200 		missing++;
1201 #endif
1202 	}
1203 
1204 #ifdef __xpv
1205 	return (0);
1206 #else
1207 	return (missing);
1208 #endif
1209 }
1210 
1211 void
1212 workaround_errata_end()
1213 {
1214 #if defined(OPTERON_ERRATUM_88)
1215 	if (opteron_erratum_88)
1216 		workaround_applied(88);
1217 #endif
1218 #if defined(OPTERON_ERRATUM_91)
1219 	if (opteron_erratum_91)
1220 		workaround_applied(91);
1221 #endif
1222 #if defined(OPTERON_ERRATUM_93)
1223 	if (opteron_erratum_93)
1224 		workaround_applied(93);
1225 #endif
1226 #if defined(OPTERON_ERRATUM_95)
1227 	if (opteron_erratum_95)
1228 		workaround_applied(95);
1229 #endif
1230 #if defined(OPTERON_ERRATUM_100)
1231 	if (opteron_erratum_100)
1232 		workaround_applied(100);
1233 #endif
1234 #if defined(OPTERON_ERRATUM_108)
1235 	if (opteron_erratum_108)
1236 		workaround_applied(108);
1237 #endif
1238 #if defined(OPTERON_ERRATUM_109)
1239 	if (opteron_erratum_109) {
1240 		cmn_err(CE_WARN,
1241 		    "BIOS microcode patch for AMD Athlon(tm) 64/Opteron(tm)"
1242 		    " processor\nerratum 109 was not detected; updating your"
1243 		    " system's BIOS to a version\ncontaining this"
1244 		    " microcode patch is HIGHLY recommended or erroneous"
1245 		    " system\noperation may occur.\n");
1246 	}
1247 #endif
1248 #if defined(OPTERON_ERRATUM_121)
1249 	if (opteron_erratum_121)
1250 		workaround_applied(121);
1251 #endif
1252 #if defined(OPTERON_ERRATUM_122)
1253 	if (opteron_erratum_122)
1254 		workaround_applied(122);
1255 #endif
1256 #if defined(OPTERON_ERRATUM_123)
1257 	if (opteron_erratum_123) {
1258 		cmn_err(CE_WARN,
1259 		    "BIOS microcode patch for AMD Athlon(tm) 64/Opteron(tm)"
1260 		    " processor\nerratum 123 was not detected; updating your"
1261 		    " system's BIOS to a version\ncontaining this"
1262 		    " microcode patch is HIGHLY recommended or erroneous"
1263 		    " system\noperation may occur.\n");
1264 	}
1265 #endif
1266 #if defined(OPTERON_ERRATUM_131)
1267 	if (opteron_erratum_131) {
1268 		cmn_err(CE_WARN,
1269 		    "BIOS microcode patch for AMD Athlon(tm) 64/Opteron(tm)"
1270 		    " processor\nerratum 131 was not detected; updating your"
1271 		    " system's BIOS to a version\ncontaining this"
1272 		    " microcode patch is HIGHLY recommended or erroneous"
1273 		    " system\noperation may occur.\n");
1274 	}
1275 #endif
1276 #if defined(OPTERON_WORKAROUND_6336786)
1277 	if (opteron_workaround_6336786)
1278 		workaround_applied(6336786);
1279 #endif
1280 #if defined(OPTERON_WORKAROUND_6323525)
1281 	if (opteron_workaround_6323525)
1282 		workaround_applied(6323525);
1283 #endif
1284 #if defined(OPTERON_ERRATUM_298)
1285 	if (opteron_erratum_298) {
1286 		cmn_err(CE_WARN,
1287 		    "BIOS microcode patch for AMD 64/Opteron(tm)"
1288 		    " processor\nerratum 298 was not detected; updating your"
1289 		    " system's BIOS to a version\ncontaining this"
1290 		    " microcode patch is HIGHLY recommended or erroneous"
1291 		    " system\noperation may occur.\n");
1292 	}
1293 #endif
1294 #if defined(OPTERON_ERRATUM_721)
1295 	if (opteron_erratum_721)
1296 		workaround_applied(721);
1297 #endif
1298 }
1299 
1300 /*
1301  * The procset_slave and procset_master are used to synchronize
1302  * between the control CPU and the target CPU when starting CPUs.
1303  */
1304 static cpuset_t procset_slave, procset_master;
1305 
1306 static void
1307 mp_startup_wait(cpuset_t *sp, processorid_t cpuid)
1308 {
1309 	cpuset_t tempset;
1310 
1311 	for (tempset = *sp; !CPU_IN_SET(tempset, cpuid);
1312 	    tempset = *(volatile cpuset_t *)sp) {
1313 		SMT_PAUSE();
1314 	}
1315 	CPUSET_ATOMIC_DEL(*(cpuset_t *)sp, cpuid);
1316 }
1317 
1318 static void
1319 mp_startup_signal(cpuset_t *sp, processorid_t cpuid)
1320 {
1321 	cpuset_t tempset;
1322 
1323 	CPUSET_ATOMIC_ADD(*(cpuset_t *)sp, cpuid);
1324 	for (tempset = *sp; CPU_IN_SET(tempset, cpuid);
1325 	    tempset = *(volatile cpuset_t *)sp) {
1326 		SMT_PAUSE();
1327 	}
1328 }
1329 
1330 int
1331 mp_start_cpu_common(cpu_t *cp, boolean_t boot)
1332 {
1333 	_NOTE(ARGUNUSED(boot));
1334 
1335 	void *ctx;
1336 	int delays;
1337 	int error = 0;
1338 	cpuset_t tempset;
1339 	processorid_t cpuid;
1340 #ifndef __xpv
1341 	extern void cpupm_init(cpu_t *);
1342 #endif
1343 
1344 	ASSERT(cp != NULL);
1345 	cpuid = cp->cpu_id;
1346 	ctx = mach_cpucontext_alloc(cp);
1347 	if (ctx == NULL) {
1348 		cmn_err(CE_WARN,
1349 		    "cpu%d: failed to allocate context", cp->cpu_id);
1350 		return (EAGAIN);
1351 	}
1352 	error = mach_cpu_start(cp, ctx);
1353 	if (error != 0) {
1354 		cmn_err(CE_WARN,
1355 		    "cpu%d: failed to start, error %d", cp->cpu_id, error);
1356 		mach_cpucontext_free(cp, ctx, error);
1357 		return (error);
1358 	}
1359 
1360 	for (delays = 0, tempset = procset_slave; !CPU_IN_SET(tempset, cpuid);
1361 	    delays++) {
1362 		if (delays == 500) {
1363 			/*
1364 			 * After five seconds, things are probably looking
1365 			 * a bit bleak - explain the hang.
1366 			 */
1367 			cmn_err(CE_NOTE, "cpu%d: started, "
1368 			    "but not running in the kernel yet", cpuid);
1369 		} else if (delays > 2000) {
1370 			/*
1371 			 * We waited at least 20 seconds, bail ..
1372 			 */
1373 			error = ETIMEDOUT;
1374 			cmn_err(CE_WARN, "cpu%d: timed out", cpuid);
1375 			mach_cpucontext_free(cp, ctx, error);
1376 			return (error);
1377 		}
1378 
1379 		/*
1380 		 * wait at least 10ms, then check again..
1381 		 */
1382 		delay(USEC_TO_TICK_ROUNDUP(10000));
1383 		tempset = *((volatile cpuset_t *)&procset_slave);
1384 	}
1385 	CPUSET_ATOMIC_DEL(procset_slave, cpuid);
1386 
1387 	mach_cpucontext_free(cp, ctx, 0);
1388 
1389 #ifndef __xpv
1390 	if (tsc_gethrtime_enable)
1391 		tsc_sync_master(cpuid);
1392 #endif
1393 
1394 	if (dtrace_cpu_init != NULL) {
1395 		(*dtrace_cpu_init)(cpuid);
1396 	}
1397 
1398 	/*
1399 	 * During CPU DR operations, the cpu_lock is held by current
1400 	 * (the control) thread. We can't release the cpu_lock here
1401 	 * because that will break the CPU DR logic.
1402 	 * On the other hand, CPUPM and processor group initialization
1403 	 * routines need to access the cpu_lock. So we invoke those
1404 	 * routines here on behalf of mp_startup_common().
1405 	 *
1406 	 * CPUPM and processor group initialization routines depend
1407 	 * on the cpuid probing results. Wait for mp_startup_common()
1408 	 * to signal that cpuid probing is done.
1409 	 */
1410 	mp_startup_wait(&procset_slave, cpuid);
1411 #ifndef __xpv
1412 	cpupm_init(cp);
1413 #endif
1414 	(void) pg_cpu_init(cp, B_FALSE);
1415 	cpu_set_state(cp);
1416 	mp_startup_signal(&procset_master, cpuid);
1417 
1418 	return (0);
1419 }
1420 
1421 /*
1422  * Start a single cpu, assuming that the kernel context is available
1423  * to successfully start another cpu.
1424  *
1425  * (For example, real mode code is mapped into the right place
1426  * in memory and is ready to be run.)
1427  */
1428 int
1429 start_cpu(processorid_t who)
1430 {
1431 	cpu_t *cp;
1432 	int error = 0;
1433 	cpuset_t tempset;
1434 
1435 	ASSERT(who != 0);
1436 
1437 	/*
1438 	 * Check if there's at least a Mbyte of kmem available
1439 	 * before attempting to start the cpu.
1440 	 */
1441 	if (kmem_avail() < 1024 * 1024) {
1442 		/*
1443 		 * Kick off a reap in case that helps us with
1444 		 * later attempts ..
1445 		 */
1446 		kmem_reap();
1447 		return (ENOMEM);
1448 	}
1449 
1450 	/*
1451 	 * First configure cpu.
1452 	 */
1453 	cp = mp_cpu_configure_common(who, B_TRUE);
1454 	ASSERT(cp != NULL);
1455 
1456 	/*
1457 	 * Then start cpu.
1458 	 */
1459 	error = mp_start_cpu_common(cp, B_TRUE);
1460 	if (error != 0) {
1461 		mp_cpu_unconfigure_common(cp, error);
1462 		return (error);
1463 	}
1464 
1465 	mutex_exit(&cpu_lock);
1466 	tempset = cpu_ready_set;
1467 	while (!CPU_IN_SET(tempset, who)) {
1468 		drv_usecwait(1);
1469 		tempset = *((volatile cpuset_t *)&cpu_ready_set);
1470 	}
1471 	mutex_enter(&cpu_lock);
1472 
1473 	return (0);
1474 }
1475 
1476 void
1477 start_other_cpus(int cprboot)
1478 {
1479 	_NOTE(ARGUNUSED(cprboot));
1480 
1481 	uint_t who;
1482 	uint_t bootcpuid = 0;
1483 
1484 	/*
1485 	 * Initialize our own cpu_info.
1486 	 */
1487 	init_cpu_info(CPU);
1488 
1489 	cmn_err(CE_CONT, "?cpu%d: %s\n", CPU->cpu_id, CPU->cpu_idstr);
1490 	cmn_err(CE_CONT, "?cpu%d: %s\n", CPU->cpu_id, CPU->cpu_brandstr);
1491 
1492 	/*
1493 	 * Initialize our syscall handlers
1494 	 */
1495 	init_cpu_syscall(CPU);
1496 
1497 	/*
1498 	 * Take the boot cpu out of the mp_cpus set because we know
1499 	 * it's already running.  Add it to the cpu_ready_set for
1500 	 * precisely the same reason.
1501 	 */
1502 	CPUSET_DEL(mp_cpus, bootcpuid);
1503 	CPUSET_ADD(cpu_ready_set, bootcpuid);
1504 
1505 	/*
1506 	 * skip the rest of this if
1507 	 * . only 1 cpu dectected and system isn't hotplug-capable
1508 	 * . not using MP
1509 	 */
1510 	if ((CPUSET_ISNULL(mp_cpus) && plat_dr_support_cpu() == 0) ||
1511 	    use_mp == 0) {
1512 		if (use_mp == 0)
1513 			cmn_err(CE_CONT, "?***** Not in MP mode\n");
1514 		goto done;
1515 	}
1516 
1517 	/*
1518 	 * perform such initialization as is needed
1519 	 * to be able to take CPUs on- and off-line.
1520 	 */
1521 	cpu_pause_init();
1522 
1523 	xc_init_cpu(CPU);		/* initialize processor crosscalls */
1524 
1525 	if (mach_cpucontext_init() != 0)
1526 		goto done;
1527 
1528 	flushes_require_xcalls = 1;
1529 
1530 	/*
1531 	 * We lock our affinity to the master CPU to ensure that all slave CPUs
1532 	 * do their TSC syncs with the same CPU.
1533 	 */
1534 	affinity_set(CPU_CURRENT);
1535 
1536 	for (who = 0; who < NCPU; who++) {
1537 		if (!CPU_IN_SET(mp_cpus, who))
1538 			continue;
1539 		ASSERT(who != bootcpuid);
1540 
1541 		mutex_enter(&cpu_lock);
1542 		if (start_cpu(who) != 0)
1543 			CPUSET_DEL(mp_cpus, who);
1544 		cpu_state_change_notify(who, CPU_SETUP);
1545 		mutex_exit(&cpu_lock);
1546 	}
1547 
1548 	/* Free the space allocated to hold the microcode file */
1549 	ucode_cleanup();
1550 
1551 	affinity_clear();
1552 
1553 	mach_cpucontext_fini();
1554 
1555 done:
1556 	if (get_hwenv() == HW_NATIVE)
1557 		workaround_errata_end();
1558 	cmi_post_mpstartup();
1559 
1560 	if (use_mp && ncpus != boot_max_ncpus) {
1561 		cmn_err(CE_NOTE,
1562 		    "System detected %d cpus, but "
1563 		    "only %d cpu(s) were enabled during boot.",
1564 		    boot_max_ncpus, ncpus);
1565 		cmn_err(CE_NOTE,
1566 		    "Use \"boot-ncpus\" parameter to enable more CPU(s). "
1567 		    "See eeprom(1M).");
1568 	}
1569 }
1570 
1571 int
1572 mp_cpu_configure(int cpuid)
1573 {
1574 	cpu_t *cp;
1575 
1576 	if (use_mp == 0 || plat_dr_support_cpu() == 0) {
1577 		return (ENOTSUP);
1578 	}
1579 
1580 	cp = cpu_get(cpuid);
1581 	if (cp != NULL) {
1582 		return (EALREADY);
1583 	}
1584 
1585 	/*
1586 	 * Check if there's at least a Mbyte of kmem available
1587 	 * before attempting to start the cpu.
1588 	 */
1589 	if (kmem_avail() < 1024 * 1024) {
1590 		/*
1591 		 * Kick off a reap in case that helps us with
1592 		 * later attempts ..
1593 		 */
1594 		kmem_reap();
1595 		return (ENOMEM);
1596 	}
1597 
1598 	cp = mp_cpu_configure_common(cpuid, B_FALSE);
1599 	ASSERT(cp != NULL && cpu_get(cpuid) == cp);
1600 
1601 	return (cp != NULL ? 0 : EAGAIN);
1602 }
1603 
1604 int
1605 mp_cpu_unconfigure(int cpuid)
1606 {
1607 	cpu_t *cp;
1608 
1609 	if (use_mp == 0 || plat_dr_support_cpu() == 0) {
1610 		return (ENOTSUP);
1611 	} else if (cpuid < 0 || cpuid >= max_ncpus) {
1612 		return (EINVAL);
1613 	}
1614 
1615 	cp = cpu_get(cpuid);
1616 	if (cp == NULL) {
1617 		return (ENODEV);
1618 	}
1619 	mp_cpu_unconfigure_common(cp, 0);
1620 
1621 	return (0);
1622 }
1623 
1624 /*
1625  * Startup function for 'other' CPUs (besides boot cpu).
1626  * Called from real_mode_start.
1627  *
1628  * WARNING: until CPU_READY is set, mp_startup_common and routines called by
1629  * mp_startup_common should not call routines (e.g. kmem_free) that could call
1630  * hat_unload which requires CPU_READY to be set.
1631  */
1632 static void
1633 mp_startup_common(boolean_t boot)
1634 {
1635 	cpu_t *cp = CPU;
1636 	uchar_t new_x86_featureset[BT_SIZEOFMAP(NUM_X86_FEATURES)];
1637 	extern void cpu_event_init_cpu(cpu_t *);
1638 
1639 	/*
1640 	 * We need to get TSC on this proc synced (i.e., any delta
1641 	 * from cpu0 accounted for) as soon as we can, because many
1642 	 * many things use gethrtime/pc_gethrestime, including
1643 	 * interrupts, cmn_err, etc.  Before we can do that, we want to
1644 	 * clear TSC if we're on a buggy Sandy/Ivy Bridge CPU, so do that
1645 	 * right away.
1646 	 */
1647 	bzero(new_x86_featureset, BT_SIZEOFMAP(NUM_X86_FEATURES));
1648 	cpuid_pass1(cp, new_x86_featureset);
1649 
1650 	if (boot && get_hwenv() == HW_NATIVE &&
1651 	    cpuid_getvendor(CPU) == X86_VENDOR_Intel &&
1652 	    cpuid_getfamily(CPU) == 6 &&
1653 	    (cpuid_getmodel(CPU) == 0x2d || cpuid_getmodel(CPU) == 0x3e) &&
1654 	    is_x86_feature(new_x86_featureset, X86FSET_TSC)) {
1655 		(void) wrmsr(REG_TSC, 0UL);
1656 	}
1657 
1658 	/* Let the control CPU continue into tsc_sync_master() */
1659 	mp_startup_signal(&procset_slave, cp->cpu_id);
1660 
1661 #ifndef __xpv
1662 	if (tsc_gethrtime_enable)
1663 		tsc_sync_slave();
1664 #endif
1665 
1666 	/*
1667 	 * Once this was done from assembly, but it's safer here; if
1668 	 * it blocks, we need to be able to swtch() to and from, and
1669 	 * since we get here by calling t_pc, we need to do that call
1670 	 * before swtch() overwrites it.
1671 	 */
1672 	(void) (*ap_mlsetup)();
1673 
1674 #ifndef __xpv
1675 	/*
1676 	 * Program this cpu's PAT
1677 	 */
1678 	pat_sync();
1679 #endif
1680 
1681 	/*
1682 	 * Set up TSC_AUX to contain the cpuid for this processor
1683 	 * for the rdtscp instruction.
1684 	 */
1685 	if (is_x86_feature(x86_featureset, X86FSET_TSCP))
1686 		(void) wrmsr(MSR_AMD_TSCAUX, cp->cpu_id);
1687 
1688 	/*
1689 	 * Initialize this CPU's syscall handlers
1690 	 */
1691 	init_cpu_syscall(cp);
1692 
1693 	/*
1694 	 * Enable interrupts with spl set to LOCK_LEVEL. LOCK_LEVEL is the
1695 	 * highest level at which a routine is permitted to block on
1696 	 * an adaptive mutex (allows for cpu poke interrupt in case
1697 	 * the cpu is blocked on a mutex and halts). Setting LOCK_LEVEL blocks
1698 	 * device interrupts that may end up in the hat layer issuing cross
1699 	 * calls before CPU_READY is set.
1700 	 */
1701 	splx(ipltospl(LOCK_LEVEL));
1702 	sti();
1703 
1704 	/*
1705 	 * Do a sanity check to make sure this new CPU is a sane thing
1706 	 * to add to the collection of processors running this system.
1707 	 *
1708 	 * XXX	Clearly this needs to get more sophisticated, if x86
1709 	 * systems start to get built out of heterogenous CPUs; as is
1710 	 * likely to happen once the number of processors in a configuration
1711 	 * gets large enough.
1712 	 */
1713 	if (compare_x86_featureset(x86_featureset, new_x86_featureset) ==
1714 	    B_FALSE) {
1715 		cmn_err(CE_CONT, "cpu%d: featureset\n", cp->cpu_id);
1716 		print_x86_featureset(new_x86_featureset);
1717 		cmn_err(CE_WARN, "cpu%d feature mismatch", cp->cpu_id);
1718 	}
1719 
1720 	/*
1721 	 * We do not support cpus with mixed monitor/mwait support if the
1722 	 * boot cpu supports monitor/mwait.
1723 	 */
1724 	if (is_x86_feature(x86_featureset, X86FSET_MWAIT) !=
1725 	    is_x86_feature(new_x86_featureset, X86FSET_MWAIT))
1726 		panic("unsupported mixed cpu monitor/mwait support detected");
1727 
1728 	/*
1729 	 * We could be more sophisticated here, and just mark the CPU
1730 	 * as "faulted" but at this point we'll opt for the easier
1731 	 * answer of dying horribly.  Provided the boot cpu is ok,
1732 	 * the system can be recovered by booting with use_mp set to zero.
1733 	 */
1734 	if (workaround_errata(cp) != 0)
1735 		panic("critical workaround(s) missing for cpu%d", cp->cpu_id);
1736 
1737 	/*
1738 	 * We can touch cpu_flags here without acquiring the cpu_lock here
1739 	 * because the cpu_lock is held by the control CPU which is running
1740 	 * mp_start_cpu_common().
1741 	 * Need to clear CPU_QUIESCED flag before calling any function which
1742 	 * may cause thread context switching, such as kmem_alloc() etc.
1743 	 * The idle thread checks for CPU_QUIESCED flag and loops for ever if
1744 	 * it's set. So the startup thread may have no chance to switch back
1745 	 * again if it's switched away with CPU_QUIESCED set.
1746 	 */
1747 	cp->cpu_flags &= ~(CPU_POWEROFF | CPU_QUIESCED);
1748 
1749 	/*
1750 	 * Setup this processor for XSAVE.
1751 	 */
1752 	if (fp_save_mech == FP_XSAVE) {
1753 		xsave_setup_msr(cp);
1754 	}
1755 
1756 	cpuid_pass2(cp);
1757 	cpuid_pass3(cp);
1758 	cpuid_pass4(cp, NULL);
1759 
1760 	/*
1761 	 * Correct cpu_idstr and cpu_brandstr on target CPU after
1762 	 * cpuid_pass1() is done.
1763 	 */
1764 	(void) cpuid_getidstr(cp, cp->cpu_idstr, CPU_IDSTRLEN);
1765 	(void) cpuid_getbrandstr(cp, cp->cpu_brandstr, CPU_IDSTRLEN);
1766 
1767 	cp->cpu_flags |= CPU_RUNNING | CPU_READY | CPU_EXISTS;
1768 
1769 	post_startup_cpu_fixups();
1770 
1771 	cpu_event_init_cpu(cp);
1772 
1773 	/*
1774 	 * Enable preemption here so that contention for any locks acquired
1775 	 * later in mp_startup_common may be preempted if the thread owning
1776 	 * those locks is continuously executing on other CPUs (for example,
1777 	 * this CPU must be preemptible to allow other CPUs to pause it during
1778 	 * their startup phases).  It's safe to enable preemption here because
1779 	 * the CPU state is pretty-much fully constructed.
1780 	 */
1781 	curthread->t_preempt = 0;
1782 
1783 	/* The base spl should still be at LOCK LEVEL here */
1784 	ASSERT(cp->cpu_base_spl == ipltospl(LOCK_LEVEL));
1785 	set_base_spl();		/* Restore the spl to its proper value */
1786 
1787 	pghw_physid_create(cp);
1788 	/*
1789 	 * Delegate initialization tasks, which need to access the cpu_lock,
1790 	 * to mp_start_cpu_common() because we can't acquire the cpu_lock here
1791 	 * during CPU DR operations.
1792 	 */
1793 	mp_startup_signal(&procset_slave, cp->cpu_id);
1794 	mp_startup_wait(&procset_master, cp->cpu_id);
1795 	pg_cmt_cpu_startup(cp);
1796 
1797 	if (boot) {
1798 		mutex_enter(&cpu_lock);
1799 		cp->cpu_flags &= ~CPU_OFFLINE;
1800 		cpu_enable_intr(cp);
1801 		cpu_add_active(cp);
1802 		mutex_exit(&cpu_lock);
1803 	}
1804 
1805 	/* Enable interrupts */
1806 	(void) spl0();
1807 
1808 	/*
1809 	 * Fill out cpu_ucode_info.  Update microcode if necessary.
1810 	 */
1811 	ucode_check(cp);
1812 
1813 #ifndef __xpv
1814 	{
1815 		/*
1816 		 * Set up the CPU module for this CPU.  This can't be done
1817 		 * before this CPU is made CPU_READY, because we may (in
1818 		 * heterogeneous systems) need to go load another CPU module.
1819 		 * The act of attempting to load a module may trigger a
1820 		 * cross-call, which will ASSERT unless this cpu is CPU_READY.
1821 		 */
1822 		cmi_hdl_t hdl;
1823 
1824 		if ((hdl = cmi_init(CMI_HDL_NATIVE, cmi_ntv_hwchipid(CPU),
1825 		    cmi_ntv_hwcoreid(CPU), cmi_ntv_hwstrandid(CPU))) != NULL) {
1826 			if (is_x86_feature(x86_featureset, X86FSET_MCA))
1827 				cmi_mca_init(hdl);
1828 			cp->cpu_m.mcpu_cmi_hdl = hdl;
1829 		}
1830 	}
1831 #endif /* __xpv */
1832 
1833 	if (boothowto & RB_DEBUG)
1834 		kdi_cpu_init();
1835 
1836 	/*
1837 	 * Setting the bit in cpu_ready_set must be the last operation in
1838 	 * processor initialization; the boot CPU will continue to boot once
1839 	 * it sees this bit set for all active CPUs.
1840 	 */
1841 	CPUSET_ATOMIC_ADD(cpu_ready_set, cp->cpu_id);
1842 
1843 	(void) mach_cpu_create_device_node(cp, NULL);
1844 
1845 	cmn_err(CE_CONT, "?cpu%d: %s\n", cp->cpu_id, cp->cpu_idstr);
1846 	cmn_err(CE_CONT, "?cpu%d: %s\n", cp->cpu_id, cp->cpu_brandstr);
1847 	cmn_err(CE_CONT, "?cpu%d initialization complete - online\n",
1848 	    cp->cpu_id);
1849 
1850 	/*
1851 	 * Now we are done with the startup thread, so free it up.
1852 	 */
1853 	thread_exit();
1854 	panic("mp_startup: cannot return");
1855 	/*NOTREACHED*/
1856 }
1857 
1858 /*
1859  * Startup function for 'other' CPUs at boot time (besides boot cpu).
1860  */
1861 static void
1862 mp_startup_boot(void)
1863 {
1864 	mp_startup_common(B_TRUE);
1865 }
1866 
1867 /*
1868  * Startup function for hotplug CPUs at runtime.
1869  */
1870 void
1871 mp_startup_hotplug(void)
1872 {
1873 	mp_startup_common(B_FALSE);
1874 }
1875 
1876 /*
1877  * Start CPU on user request.
1878  */
1879 /* ARGSUSED */
1880 int
1881 mp_cpu_start(struct cpu *cp)
1882 {
1883 	ASSERT(MUTEX_HELD(&cpu_lock));
1884 	return (0);
1885 }
1886 
1887 /*
1888  * Stop CPU on user request.
1889  */
1890 int
1891 mp_cpu_stop(struct cpu *cp)
1892 {
1893 	extern int cbe_psm_timer_mode;
1894 	ASSERT(MUTEX_HELD(&cpu_lock));
1895 
1896 #ifdef __xpv
1897 	/*
1898 	 * We can't offline vcpu0.
1899 	 */
1900 	if (cp->cpu_id == 0)
1901 		return (EBUSY);
1902 #endif
1903 
1904 	/*
1905 	 * If TIMER_PERIODIC mode is used, CPU0 is the one running it;
1906 	 * can't stop it.  (This is true only for machines with no TSC.)
1907 	 */
1908 
1909 	if ((cbe_psm_timer_mode == TIMER_PERIODIC) && (cp->cpu_id == 0))
1910 		return (EBUSY);
1911 
1912 	return (0);
1913 }
1914 
1915 /*
1916  * Take the specified CPU out of participation in interrupts.
1917  */
1918 int
1919 cpu_disable_intr(struct cpu *cp)
1920 {
1921 	if (psm_disable_intr(cp->cpu_id) != DDI_SUCCESS)
1922 		return (EBUSY);
1923 
1924 	cp->cpu_flags &= ~CPU_ENABLE;
1925 	return (0);
1926 }
1927 
1928 /*
1929  * Allow the specified CPU to participate in interrupts.
1930  */
1931 void
1932 cpu_enable_intr(struct cpu *cp)
1933 {
1934 	ASSERT(MUTEX_HELD(&cpu_lock));
1935 	cp->cpu_flags |= CPU_ENABLE;
1936 	psm_enable_intr(cp->cpu_id);
1937 }
1938 
1939 void
1940 mp_cpu_faulted_enter(struct cpu *cp)
1941 {
1942 #ifdef __xpv
1943 	_NOTE(ARGUNUSED(cp));
1944 #else
1945 	cmi_hdl_t hdl = cp->cpu_m.mcpu_cmi_hdl;
1946 
1947 	if (hdl != NULL) {
1948 		cmi_hdl_hold(hdl);
1949 	} else {
1950 		hdl = cmi_hdl_lookup(CMI_HDL_NATIVE, cmi_ntv_hwchipid(cp),
1951 		    cmi_ntv_hwcoreid(cp), cmi_ntv_hwstrandid(cp));
1952 	}
1953 	if (hdl != NULL) {
1954 		cmi_faulted_enter(hdl);
1955 		cmi_hdl_rele(hdl);
1956 	}
1957 #endif
1958 }
1959 
1960 void
1961 mp_cpu_faulted_exit(struct cpu *cp)
1962 {
1963 #ifdef __xpv
1964 	_NOTE(ARGUNUSED(cp));
1965 #else
1966 	cmi_hdl_t hdl = cp->cpu_m.mcpu_cmi_hdl;
1967 
1968 	if (hdl != NULL) {
1969 		cmi_hdl_hold(hdl);
1970 	} else {
1971 		hdl = cmi_hdl_lookup(CMI_HDL_NATIVE, cmi_ntv_hwchipid(cp),
1972 		    cmi_ntv_hwcoreid(cp), cmi_ntv_hwstrandid(cp));
1973 	}
1974 	if (hdl != NULL) {
1975 		cmi_faulted_exit(hdl);
1976 		cmi_hdl_rele(hdl);
1977 	}
1978 #endif
1979 }
1980 
1981 /*
1982  * The following two routines are used as context operators on threads belonging
1983  * to processes with a private LDT (see sysi86).  Due to the rarity of such
1984  * processes, these routines are currently written for best code readability and
1985  * organization rather than speed.  We could avoid checking x86_featureset at
1986  * every context switch by installing different context ops, depending on
1987  * x86_featureset, at LDT creation time -- one for each combination of fast
1988  * syscall features.
1989  */
1990 
1991 /*ARGSUSED*/
1992 void
1993 cpu_fast_syscall_disable(void *arg)
1994 {
1995 	if (is_x86_feature(x86_featureset, X86FSET_MSR) &&
1996 	    is_x86_feature(x86_featureset, X86FSET_SEP))
1997 		cpu_sep_disable();
1998 	if (is_x86_feature(x86_featureset, X86FSET_MSR) &&
1999 	    is_x86_feature(x86_featureset, X86FSET_ASYSC))
2000 		cpu_asysc_disable();
2001 }
2002 
2003 /*ARGSUSED*/
2004 void
2005 cpu_fast_syscall_enable(void *arg)
2006 {
2007 	if (is_x86_feature(x86_featureset, X86FSET_MSR) &&
2008 	    is_x86_feature(x86_featureset, X86FSET_SEP))
2009 		cpu_sep_enable();
2010 	if (is_x86_feature(x86_featureset, X86FSET_MSR) &&
2011 	    is_x86_feature(x86_featureset, X86FSET_ASYSC))
2012 		cpu_asysc_enable();
2013 }
2014 
2015 static void
2016 cpu_sep_enable(void)
2017 {
2018 	ASSERT(is_x86_feature(x86_featureset, X86FSET_SEP));
2019 	ASSERT(curthread->t_preempt || getpil() >= LOCK_LEVEL);
2020 
2021 	wrmsr(MSR_INTC_SEP_CS, (uint64_t)(uintptr_t)KCS_SEL);
2022 }
2023 
2024 static void
2025 cpu_sep_disable(void)
2026 {
2027 	ASSERT(is_x86_feature(x86_featureset, X86FSET_SEP));
2028 	ASSERT(curthread->t_preempt || getpil() >= LOCK_LEVEL);
2029 
2030 	/*
2031 	 * Setting the SYSENTER_CS_MSR register to 0 causes software executing
2032 	 * the sysenter or sysexit instruction to trigger a #gp fault.
2033 	 */
2034 	wrmsr(MSR_INTC_SEP_CS, 0);
2035 }
2036 
2037 static void
2038 cpu_asysc_enable(void)
2039 {
2040 	ASSERT(is_x86_feature(x86_featureset, X86FSET_ASYSC));
2041 	ASSERT(curthread->t_preempt || getpil() >= LOCK_LEVEL);
2042 
2043 	wrmsr(MSR_AMD_EFER, rdmsr(MSR_AMD_EFER) |
2044 	    (uint64_t)(uintptr_t)AMD_EFER_SCE);
2045 }
2046 
2047 static void
2048 cpu_asysc_disable(void)
2049 {
2050 	ASSERT(is_x86_feature(x86_featureset, X86FSET_ASYSC));
2051 	ASSERT(curthread->t_preempt || getpil() >= LOCK_LEVEL);
2052 
2053 	/*
2054 	 * Turn off the SCE (syscall enable) bit in the EFER register. Software
2055 	 * executing syscall or sysret with this bit off will incur a #ud trap.
2056 	 */
2057 	wrmsr(MSR_AMD_EFER, rdmsr(MSR_AMD_EFER) &
2058 	    ~((uint64_t)(uintptr_t)AMD_EFER_SCE));
2059 }
2060