1 /*
2  * Copyright (c) 1996, by Steve Passe
3  * All rights reserved.
4  *
5  * Redistribution and use in source and binary forms, with or without
6  * modification, are permitted provided that the following conditions
7  * are met:
8  * 1. Redistributions of source code must retain the above copyright
9  *    notice, this list of conditions and the following disclaimer.
10  * 2. The name of the developer may NOT be used to endorse or promote products
11  *    derived from this software without specific prior written permission.
12  *
13  * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
14  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
15  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
16  * ARE DISCLAIMED.  IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
17  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
18  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
19  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
20  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
21  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
22  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
23  * SUCH DAMAGE.
24  *
25  * $FreeBSD: src/sys/i386/i386/mp_machdep.c,v 1.115.2.15 2003/03/14 21:22:35 jhb Exp $
26  */
27 
28 #include "opt_cpu.h"
29 
30 #include <sys/param.h>
31 #include <sys/systm.h>
32 #include <sys/kernel.h>
33 #include <sys/sysctl.h>
34 #include <sys/malloc.h>
35 #include <sys/memrange.h>
36 #include <sys/cons.h>	/* cngetc() */
37 #include <sys/machintr.h>
38 
39 #include <sys/mplock2.h>
40 
41 #include <vm/vm.h>
42 #include <vm/vm_param.h>
43 #include <vm/pmap.h>
44 #include <vm/vm_kern.h>
45 #include <vm/vm_extern.h>
46 #include <sys/lock.h>
47 #include <vm/vm_map.h>
48 #include <sys/user.h>
49 #ifdef GPROF
50 #include <sys/gmon.h>
51 #endif
52 
53 #include <machine/smp.h>
54 #include <machine_base/apic/apicreg.h>
55 #include <machine/atomic.h>
56 #include <machine/cpufunc.h>
57 #include <machine/cputypes.h>
58 #include <machine_base/apic/lapic.h>
59 #include <machine_base/apic/ioapic.h>
60 #include <machine/psl.h>
61 #include <machine/segments.h>
62 #include <machine/tss.h>
63 #include <machine/specialreg.h>
64 #include <machine/globaldata.h>
65 #include <machine/pmap_inval.h>
66 
67 #include <machine/md_var.h>		/* setidt() */
68 #include <machine_base/icu/icu.h>	/* IPIs */
69 #include <machine_base/icu/icu_var.h>
70 #include <machine_base/apic/ioapic_abi.h>
71 #include <machine/intr_machdep.h>	/* IPIs */
72 
73 #define WARMBOOT_TARGET		0
74 #define WARMBOOT_OFF		(KERNBASE + 0x0467)
75 #define WARMBOOT_SEG		(KERNBASE + 0x0469)
76 
77 #define CMOS_REG		(0x70)
78 #define CMOS_DATA		(0x71)
79 #define BIOS_RESET		(0x0f)
80 #define BIOS_WARM		(0x0a)
81 
82 /*
83  * this code MUST be enabled here and in mpboot.s.
84  * it follows the very early stages of AP boot by placing values in CMOS ram.
85  * it NORMALLY will never be needed and thus the primitive method for enabling.
86  *
87  */
88 #if defined(CHECK_POINTS)
89 #define CHECK_READ(A)	 (outb(CMOS_REG, (A)), inb(CMOS_DATA))
90 #define CHECK_WRITE(A,D) (outb(CMOS_REG, (A)), outb(CMOS_DATA, (D)))
91 
92 #define CHECK_INIT(D);				\
93 	CHECK_WRITE(0x34, (D));			\
94 	CHECK_WRITE(0x35, (D));			\
95 	CHECK_WRITE(0x36, (D));			\
96 	CHECK_WRITE(0x37, (D));			\
97 	CHECK_WRITE(0x38, (D));			\
98 	CHECK_WRITE(0x39, (D));
99 
100 #define CHECK_PRINT(S);				\
101 	kprintf("%s: %d, %d, %d, %d, %d, %d\n",	\
102 	   (S),					\
103 	   CHECK_READ(0x34),			\
104 	   CHECK_READ(0x35),			\
105 	   CHECK_READ(0x36),			\
106 	   CHECK_READ(0x37),			\
107 	   CHECK_READ(0x38),			\
108 	   CHECK_READ(0x39));
109 
110 #else				/* CHECK_POINTS */
111 
112 #define CHECK_INIT(D)
113 #define CHECK_PRINT(S)
114 
115 #endif				/* CHECK_POINTS */
116 
117 /*
118  * Values to send to the POST hardware.
119  */
120 #define MP_BOOTADDRESS_POST	0x10
121 #define MP_PROBE_POST		0x11
122 #define MPTABLE_PASS1_POST	0x12
123 
124 #define MP_START_POST		0x13
125 #define MP_ENABLE_POST		0x14
126 #define MPTABLE_PASS2_POST	0x15
127 
128 #define START_ALL_APS_POST	0x16
129 #define INSTALL_AP_TRAMP_POST	0x17
130 #define START_AP_POST		0x18
131 
132 #define MP_ANNOUNCE_POST	0x19
133 
134 /** XXX FIXME: where does this really belong, isa.h/isa.c perhaps? */
135 int	current_postcode;
136 
137 /** XXX FIXME: what system files declare these??? */
138 extern struct region_descriptor r_gdt;
139 
140 extern int nkpt;
141 extern int naps;
142 
143 int64_t tsc0_offset;
144 extern int64_t tsc_offsets[];
145 
146 /* AP uses this during bootstrap.  Do not staticize.  */
147 char *bootSTK;
148 static int bootAP;
149 
150 struct pcb stoppcbs[MAXCPU];
151 
152 extern inthand_t IDTVEC(fast_syscall), IDTVEC(fast_syscall32);
153 
154 /*
155  * Local data and functions.
156  */
157 
158 static u_int	boot_address;
159 static int	mp_finish;
160 static int	mp_finish_lapic;
161 
162 static int	start_all_aps(u_int boot_addr);
163 #if 0
164 static void	install_ap_tramp(u_int boot_addr);
165 #endif
166 static int	start_ap(struct mdglobaldata *gd, u_int boot_addr, int smibest);
167 static int	smitest(void);
168 static void	mp_bsp_simple_setup(void);
169 
170 static cpumask_t smp_startup_mask = 1;	/* which cpus have been started */
171 static cpumask_t smp_lapic_mask = 1;	/* which cpus have lapic been inited */
172 cpumask_t smp_active_mask = 1;	/* which cpus are ready for IPIs etc? */
173 SYSCTL_INT(_machdep, OID_AUTO, smp_active, CTLFLAG_RD, &smp_active_mask, 0, "");
174 static u_int	bootMP_size;
175 
176 /* Local data for detecting CPU TOPOLOGY */
177 static int core_bits = 0;
178 static int logical_CPU_bits = 0;
179 
180 
181 /*
182  * Calculate usable address in base memory for AP trampoline code.
183  */
184 u_int
185 mp_bootaddress(u_int basemem)
186 {
187 	POSTCODE(MP_BOOTADDRESS_POST);
188 
189 	bootMP_size = mptramp_end - mptramp_start;
190 	boot_address = trunc_page(basemem * 1024); /* round down to 4k boundary */
191 	if (((basemem * 1024) - boot_address) < bootMP_size)
192 		boot_address -= PAGE_SIZE;	/* not enough, lower by 4k */
193 	/* 3 levels of page table pages */
194 	mptramp_pagetables = boot_address - (PAGE_SIZE * 3);
195 
196 	return mptramp_pagetables;
197 }
198 
199 /*
200  * Print various information about the SMP system hardware and setup.
201  */
202 void
203 mp_announce(void)
204 {
205 	int     x;
206 
207 	POSTCODE(MP_ANNOUNCE_POST);
208 
209 	kprintf("DragonFly/MP: Multiprocessor motherboard\n");
210 	kprintf(" cpu0 (BSP): apic id: %2d\n", CPUID_TO_APICID(0));
211 	for (x = 1; x <= naps; ++x)
212 		kprintf(" cpu%d (AP):  apic id: %2d\n", x, CPUID_TO_APICID(x));
213 
214 	if (!ioapic_enable)
215 		kprintf(" Warning: APIC I/O disabled\n");
216 }
217 
218 /*
219  * AP cpu's call this to sync up protected mode.
220  *
221  * WARNING! %gs is not set up on entry.  This routine sets up %gs.
222  */
223 void
224 init_secondary(void)
225 {
226 	int	gsel_tss;
227 	int	x, myid = bootAP;
228 	u_int64_t msr, cr0;
229 	struct mdglobaldata *md;
230 	struct privatespace *ps;
231 
232 	ps = &CPU_prvspace[myid];
233 
234 	gdt_segs[GPROC0_SEL].ssd_base =
235 		(long) &ps->mdglobaldata.gd_common_tss;
236 	ps->mdglobaldata.mi.gd_prvspace = ps;
237 
238 	/* We fill the 32-bit segment descriptors */
239 	for (x = 0; x < NGDT; x++) {
240 		if (x != GPROC0_SEL && x != (GPROC0_SEL + 1))
241 			ssdtosd(&gdt_segs[x], &gdt[myid * NGDT + x]);
242 	}
243 	/* And now a 64-bit one */
244 	ssdtosyssd(&gdt_segs[GPROC0_SEL],
245 	    (struct system_segment_descriptor *)&gdt[myid * NGDT + GPROC0_SEL]);
246 
247 	r_gdt.rd_limit = NGDT * sizeof(gdt[0]) - 1;
248 	r_gdt.rd_base = (long) &gdt[myid * NGDT];
249 	lgdt(&r_gdt);			/* does magic intra-segment return */
250 
251 	/* lgdt() destroys the GSBASE value, so we load GSBASE after lgdt() */
252 	wrmsr(MSR_FSBASE, 0);		/* User value */
253 	wrmsr(MSR_GSBASE, (u_int64_t)ps);
254 	wrmsr(MSR_KGSBASE, 0);		/* XXX User value while we're in the kernel */
255 
256 	lidt(&r_idt_arr[mdcpu->mi.gd_cpuid]);
257 
258 #if 0
259 	lldt(_default_ldt);
260 	mdcpu->gd_currentldt = _default_ldt;
261 #endif
262 
263 	gsel_tss = GSEL(GPROC0_SEL, SEL_KPL);
264 	gdt[myid * NGDT + GPROC0_SEL].sd_type = SDT_SYSTSS;
265 
266 	md = mdcpu;	/* loaded through %gs:0 (mdglobaldata.mi.gd_prvspace)*/
267 
268 	md->gd_common_tss.tss_rsp0 = 0;	/* not used until after switch */
269 #if 0 /* JG XXX */
270 	md->gd_common_tss.tss_ioopt = (sizeof md->gd_common_tss) << 16;
271 #endif
272 	md->gd_tss_gdt = &gdt[myid * NGDT + GPROC0_SEL];
273 	md->gd_common_tssd = *md->gd_tss_gdt;
274 
275 	/* double fault stack */
276 	md->gd_common_tss.tss_ist1 =
277 		(long)&md->mi.gd_prvspace->idlestack[
278 			sizeof(md->mi.gd_prvspace->idlestack)];
279 
280 	ltr(gsel_tss);
281 
282 	/*
283 	 * Set to a known state:
284 	 * Set by mpboot.s: CR0_PG, CR0_PE
285 	 * Set by cpu_setregs: CR0_NE, CR0_MP, CR0_TS, CR0_WP, CR0_AM
286 	 */
287 	cr0 = rcr0();
288 	cr0 &= ~(CR0_CD | CR0_NW | CR0_EM);
289 	load_cr0(cr0);
290 
291 	/* Set up the fast syscall stuff */
292 	msr = rdmsr(MSR_EFER) | EFER_SCE;
293 	wrmsr(MSR_EFER, msr);
294 	wrmsr(MSR_LSTAR, (u_int64_t)IDTVEC(fast_syscall));
295 	wrmsr(MSR_CSTAR, (u_int64_t)IDTVEC(fast_syscall32));
296 	msr = ((u_int64_t)GSEL(GCODE_SEL, SEL_KPL) << 32) |
297 	      ((u_int64_t)GSEL(GUCODE32_SEL, SEL_UPL) << 48);
298 	wrmsr(MSR_STAR, msr);
299 	wrmsr(MSR_SF_MASK, PSL_NT|PSL_T|PSL_I|PSL_C|PSL_D|PSL_IOPL);
300 
301 	pmap_set_opt();		/* PSE/4MB pages, etc */
302 #if JGXXX
303 	/* Initialize the PAT MSR. */
304 	pmap_init_pat();
305 #endif
306 
307 	/* set up CPU registers and state */
308 	cpu_setregs();
309 
310 	/* set up SSE/NX registers */
311 	initializecpu();
312 
313 	/* set up FPU state on the AP */
314 	npxinit(__INITIAL_FPUCW__);
315 
316 	/* disable the APIC, just to be SURE */
317 	lapic->svr &= ~APIC_SVR_ENABLE;
318 }
319 
320 /*******************************************************************
321  * local functions and data
322  */
323 
324 /*
325  * Start the SMP system
326  */
327 static void
328 mp_start_aps(void *dummy __unused)
329 {
330 	if (lapic_enable) {
331 		/* start each Application Processor */
332 		start_all_aps(boot_address);
333 	} else {
334 		mp_bsp_simple_setup();
335 	}
336 }
337 SYSINIT(startaps, SI_BOOT2_START_APS, SI_ORDER_FIRST, mp_start_aps, NULL)
338 
339 /*
340  * start each AP in our list
341  */
342 static int
343 start_all_aps(u_int boot_addr)
344 {
345 	vm_offset_t va = boot_address + KERNBASE;
346 	u_int64_t *pt4, *pt3, *pt2;
347 	int     x, i, pg;
348 	int	shift;
349 	int	smicount;
350 	int	smibest;
351 	int	smilast;
352 	u_char  mpbiosreason;
353 	u_long  mpbioswarmvec;
354 	struct mdglobaldata *gd;
355 	struct privatespace *ps;
356 
357 	POSTCODE(START_ALL_APS_POST);
358 
359 	/* install the AP 1st level boot code */
360 	pmap_kenter(va, boot_address);
361 	cpu_invlpg((void *)va);		/* JG XXX */
362 	bcopy(mptramp_start, (void *)va, bootMP_size);
363 
364 	/* Locate the page tables, they'll be below the trampoline */
365 	pt4 = (u_int64_t *)(uintptr_t)(mptramp_pagetables + KERNBASE);
366 	pt3 = pt4 + (PAGE_SIZE) / sizeof(u_int64_t);
367 	pt2 = pt3 + (PAGE_SIZE) / sizeof(u_int64_t);
368 
369 	/* Create the initial 1GB replicated page tables */
370 	for (i = 0; i < 512; i++) {
371 		/* Each slot of the level 4 pages points to the same level 3 page */
372 		pt4[i] = (u_int64_t)(uintptr_t)(mptramp_pagetables + PAGE_SIZE);
373 		pt4[i] |= PG_V | PG_RW | PG_U;
374 
375 		/* Each slot of the level 3 pages points to the same level 2 page */
376 		pt3[i] = (u_int64_t)(uintptr_t)(mptramp_pagetables + (2 * PAGE_SIZE));
377 		pt3[i] |= PG_V | PG_RW | PG_U;
378 
379 		/* The level 2 page slots are mapped with 2MB pages for 1GB. */
380 		pt2[i] = i * (2 * 1024 * 1024);
381 		pt2[i] |= PG_V | PG_RW | PG_PS | PG_U;
382 	}
383 
384 	/* save the current value of the warm-start vector */
385 	mpbioswarmvec = *((u_int32_t *) WARMBOOT_OFF);
386 	outb(CMOS_REG, BIOS_RESET);
387 	mpbiosreason = inb(CMOS_DATA);
388 
389 	/* setup a vector to our boot code */
390 	*((volatile u_short *) WARMBOOT_OFF) = WARMBOOT_TARGET;
391 	*((volatile u_short *) WARMBOOT_SEG) = (boot_address >> 4);
392 	outb(CMOS_REG, BIOS_RESET);
393 	outb(CMOS_DATA, BIOS_WARM);	/* 'warm-start' */
394 
395 	/*
396 	 * If we have a TSC we can figure out the SMI interrupt rate.
397 	 * The SMI does not necessarily use a constant rate.  Spend
398 	 * up to 250ms trying to figure it out.
399 	 */
400 	smibest = 0;
401 	if (cpu_feature & CPUID_TSC) {
402 		set_apic_timer(275000);
403 		smilast = read_apic_timer();
404 		for (x = 0; x < 20 && read_apic_timer(); ++x) {
405 			smicount = smitest();
406 			if (smibest == 0 || smilast - smicount < smibest)
407 				smibest = smilast - smicount;
408 			smilast = smicount;
409 		}
410 		if (smibest > 250000)
411 			smibest = 0;
412 		if (smibest) {
413 			smibest = smibest * (int64_t)1000000 /
414 				  get_apic_timer_frequency();
415 		}
416 	}
417 	if (smibest)
418 		kprintf("SMI Frequency (worst case): %d Hz (%d us)\n",
419 			1000000 / smibest, smibest);
420 
421 	/* start each AP */
422 	for (x = 1; x <= naps; ++x) {
423 
424 		/* This is a bit verbose, it will go away soon.  */
425 
426 		/* first page of AP's private space */
427 		pg = x * x86_64_btop(sizeof(struct privatespace));
428 
429 		/* allocate new private data page(s) */
430 		gd = (struct mdglobaldata *)kmem_alloc(&kernel_map,
431 				MDGLOBALDATA_BASEALLOC_SIZE);
432 
433 		gd = &CPU_prvspace[x].mdglobaldata;	/* official location */
434 		bzero(gd, sizeof(*gd));
435 		gd->mi.gd_prvspace = ps = &CPU_prvspace[x];
436 
437 		/* prime data page for it to use */
438 		mi_gdinit(&gd->mi, x);
439 		cpu_gdinit(gd, x);
440 		gd->mi.gd_ipiq = (void *)kmem_alloc(&kernel_map, sizeof(lwkt_ipiq) * (naps + 1));
441 		bzero(gd->mi.gd_ipiq, sizeof(lwkt_ipiq) * (naps + 1));
442 
443 		/* setup a vector to our boot code */
444 		*((volatile u_short *) WARMBOOT_OFF) = WARMBOOT_TARGET;
445 		*((volatile u_short *) WARMBOOT_SEG) = (boot_addr >> 4);
446 		outb(CMOS_REG, BIOS_RESET);
447 		outb(CMOS_DATA, BIOS_WARM);	/* 'warm-start' */
448 
449 		/*
450 		 * Setup the AP boot stack
451 		 */
452 		bootSTK = &ps->idlestack[UPAGES*PAGE_SIZE/2];
453 		bootAP = x;
454 
455 		/* attempt to start the Application Processor */
456 		CHECK_INIT(99);	/* setup checkpoints */
457 		if (!start_ap(gd, boot_addr, smibest)) {
458 			kprintf("\nAP #%d (PHY# %d) failed!\n",
459 				x, CPUID_TO_APICID(x));
460 			CHECK_PRINT("trace");	/* show checkpoints */
461 			/* better panic as the AP may be running loose */
462 			kprintf("panic y/n? [y] ");
463 			if (cngetc() != 'n')
464 				panic("bye-bye");
465 		}
466 		CHECK_PRINT("trace");		/* show checkpoints */
467 	}
468 
469 	/* set ncpus to 1 + highest logical cpu.  Not all may have come up */
470 	ncpus = x;
471 
472 	/* ncpus2 -- ncpus rounded down to the nearest power of 2 */
473 	for (shift = 0; (1 << shift) <= ncpus; ++shift)
474 		;
475 	--shift;
476 	ncpus2_shift = shift;
477 	ncpus2 = 1 << shift;
478 	ncpus2_mask = ncpus2 - 1;
479 
480 	/* ncpus_fit -- ncpus rounded up to the nearest power of 2 */
481 	if ((1 << shift) < ncpus)
482 		++shift;
483 	ncpus_fit = 1 << shift;
484 	ncpus_fit_mask = ncpus_fit - 1;
485 
486 	/* build our map of 'other' CPUs */
487 	mycpu->gd_other_cpus = smp_startup_mask & ~CPUMASK(mycpu->gd_cpuid);
488 	mycpu->gd_ipiq = (void *)kmem_alloc(&kernel_map, sizeof(lwkt_ipiq) * ncpus);
489 	bzero(mycpu->gd_ipiq, sizeof(lwkt_ipiq) * ncpus);
490 
491 	/* restore the warmstart vector */
492 	*(u_long *) WARMBOOT_OFF = mpbioswarmvec;
493 	outb(CMOS_REG, BIOS_RESET);
494 	outb(CMOS_DATA, mpbiosreason);
495 
496 	/*
497 	 * NOTE!  The idlestack for the BSP was setup by locore.  Finish
498 	 * up, clean out the P==V mapping we did earlier.
499 	 */
500 	pmap_set_opt();
501 
502 	/*
503 	 * Wait all APs to finish initializing LAPIC
504 	 */
505 	mp_finish_lapic = 1;
506 	if (bootverbose)
507 		kprintf("SMP: Waiting APs LAPIC initialization\n");
508 	if (cpu_feature & CPUID_TSC)
509 		tsc0_offset = rdtsc();
510 	tsc_offsets[0] = 0;
511 	rel_mplock();
512 	while (smp_lapic_mask != smp_startup_mask) {
513 		cpu_lfence();
514 		if (cpu_feature & CPUID_TSC)
515 			tsc0_offset = rdtsc();
516 	}
517 	while (try_mplock() == 0)
518 		;
519 
520 	/* number of APs actually started */
521 	return ncpus - 1;
522 }
523 
524 
525 /*
526  * load the 1st level AP boot code into base memory.
527  */
528 
529 /* targets for relocation */
530 extern void bigJump(void);
531 extern void bootCodeSeg(void);
532 extern void bootDataSeg(void);
533 extern void MPentry(void);
534 extern u_int MP_GDT;
535 extern u_int mp_gdtbase;
536 
537 #if 0
538 
539 static void
540 install_ap_tramp(u_int boot_addr)
541 {
542 	int     x;
543 	int     size = *(int *) ((u_long) & bootMP_size);
544 	u_char *src = (u_char *) ((u_long) bootMP);
545 	u_char *dst = (u_char *) boot_addr + KERNBASE;
546 	u_int   boot_base = (u_int) bootMP;
547 	u_int8_t *dst8;
548 	u_int16_t *dst16;
549 	u_int32_t *dst32;
550 
551 	POSTCODE(INSTALL_AP_TRAMP_POST);
552 
553 	for (x = 0; x < size; ++x)
554 		*dst++ = *src++;
555 
556 	/*
557 	 * modify addresses in code we just moved to basemem. unfortunately we
558 	 * need fairly detailed info about mpboot.s for this to work.  changes
559 	 * to mpboot.s might require changes here.
560 	 */
561 
562 	/* boot code is located in KERNEL space */
563 	dst = (u_char *) boot_addr + KERNBASE;
564 
565 	/* modify the lgdt arg */
566 	dst32 = (u_int32_t *) (dst + ((u_int) & mp_gdtbase - boot_base));
567 	*dst32 = boot_addr + ((u_int) & MP_GDT - boot_base);
568 
569 	/* modify the ljmp target for MPentry() */
570 	dst32 = (u_int32_t *) (dst + ((u_int) bigJump - boot_base) + 1);
571 	*dst32 = ((u_int) MPentry - KERNBASE);
572 
573 	/* modify the target for boot code segment */
574 	dst16 = (u_int16_t *) (dst + ((u_int) bootCodeSeg - boot_base));
575 	dst8 = (u_int8_t *) (dst16 + 1);
576 	*dst16 = (u_int) boot_addr & 0xffff;
577 	*dst8 = ((u_int) boot_addr >> 16) & 0xff;
578 
579 	/* modify the target for boot data segment */
580 	dst16 = (u_int16_t *) (dst + ((u_int) bootDataSeg - boot_base));
581 	dst8 = (u_int8_t *) (dst16 + 1);
582 	*dst16 = (u_int) boot_addr & 0xffff;
583 	*dst8 = ((u_int) boot_addr >> 16) & 0xff;
584 }
585 
586 #endif
587 
588 /*
589  * This function starts the AP (application processor) identified
590  * by the APIC ID 'physicalCpu'.  It does quite a "song and dance"
591  * to accomplish this.  This is necessary because of the nuances
592  * of the different hardware we might encounter.  It ain't pretty,
593  * but it seems to work.
594  *
595  * NOTE: eventually an AP gets to ap_init(), which is called just
596  * before the AP goes into the LWKT scheduler's idle loop.
597  */
598 static int
599 start_ap(struct mdglobaldata *gd, u_int boot_addr, int smibest)
600 {
601 	int     physical_cpu;
602 	int     vector;
603 	u_long  icr_lo, icr_hi;
604 
605 	POSTCODE(START_AP_POST);
606 
607 	/* get the PHYSICAL APIC ID# */
608 	physical_cpu = CPUID_TO_APICID(gd->mi.gd_cpuid);
609 
610 	/* calculate the vector */
611 	vector = (boot_addr >> 12) & 0xff;
612 
613 	/* We don't want anything interfering */
614 	cpu_disable_intr();
615 
616 	/* Make sure the target cpu sees everything */
617 	wbinvd();
618 
619 	/*
620 	 * Try to detect when a SMI has occurred, wait up to 200ms.
621 	 *
622 	 * If a SMI occurs during an AP reset but before we issue
623 	 * the STARTUP command, the AP may brick.  To work around
624 	 * this problem we hold off doing the AP startup until
625 	 * after we have detected the SMI.  Hopefully another SMI
626 	 * will not occur before we finish the AP startup.
627 	 *
628 	 * Retries don't seem to help.  SMIs have a window of opportunity
629 	 * and if USB->legacy keyboard emulation is enabled in the BIOS
630 	 * the interrupt rate can be quite high.
631 	 *
632 	 * NOTE: Don't worry about the L1 cache load, it might bloat
633 	 *	 ldelta a little but ndelta will be so huge when the SMI
634 	 *	 occurs the detection logic will still work fine.
635 	 */
636 	if (smibest) {
637 		set_apic_timer(200000);
638 		smitest();
639 	}
640 
641 	/*
642 	 * first we do an INIT/RESET IPI this INIT IPI might be run, reseting
643 	 * and running the target CPU. OR this INIT IPI might be latched (P5
644 	 * bug), CPU waiting for STARTUP IPI. OR this INIT IPI might be
645 	 * ignored.
646 	 *
647 	 * see apic/apicreg.h for icr bit definitions.
648 	 *
649 	 * TIME CRITICAL CODE, DO NOT DO ANY KPRINTFS IN THE HOT PATH.
650 	 */
651 
652 	/*
653 	 * Setup the address for the target AP.  We can setup
654 	 * icr_hi once and then just trigger operations with
655 	 * icr_lo.
656 	 */
657 	icr_hi = lapic->icr_hi & ~APIC_ID_MASK;
658 	icr_hi |= (physical_cpu << 24);
659 	icr_lo = lapic->icr_lo & 0xfff00000;
660 	lapic->icr_hi = icr_hi;
661 
662 	/*
663 	 * Do an INIT IPI: assert RESET
664 	 *
665 	 * Use edge triggered mode to assert INIT
666 	 */
667 	lapic->icr_lo = icr_lo | 0x00004500;
668 	while (lapic->icr_lo & APIC_DELSTAT_MASK)
669 		 /* spin */ ;
670 
671 	/*
672 	 * The spec calls for a 10ms delay but we may have to use a
673 	 * MUCH lower delay to avoid bricking an AP due to a fast SMI
674 	 * interrupt.  We have other loops here too and dividing by 2
675 	 * doesn't seem to be enough even after subtracting 350us,
676 	 * so we divide by 4.
677 	 *
678 	 * Our minimum delay is 150uS, maximum is 10ms.  If no SMI
679 	 * interrupt was detected we use the full 10ms.
680 	 */
681 	if (smibest == 0)
682 		u_sleep(10000);
683 	else if (smibest < 150 * 4 + 350)
684 		u_sleep(150);
685 	else if ((smibest - 350) / 4 < 10000)
686 		u_sleep((smibest - 350) / 4);
687 	else
688 		u_sleep(10000);
689 
690 	/*
691 	 * Do an INIT IPI: deassert RESET
692 	 *
693 	 * Use level triggered mode to deassert.  It is unclear
694 	 * why we need to do this.
695 	 */
696 	lapic->icr_lo = icr_lo | 0x00008500;
697 	while (lapic->icr_lo & APIC_DELSTAT_MASK)
698 		 /* spin */ ;
699 	u_sleep(150);				/* wait 150us */
700 
701 	/*
702 	 * Next we do a STARTUP IPI: the previous INIT IPI might still be
703 	 * latched, (P5 bug) this 1st STARTUP would then terminate
704 	 * immediately, and the previously started INIT IPI would continue. OR
705 	 * the previous INIT IPI has already run. and this STARTUP IPI will
706 	 * run. OR the previous INIT IPI was ignored. and this STARTUP IPI
707 	 * will run.
708 	 */
709 	lapic->icr_lo = icr_lo | 0x00000600 | vector;
710 	while (lapic->icr_lo & APIC_DELSTAT_MASK)
711 		 /* spin */ ;
712 	u_sleep(200);		/* wait ~200uS */
713 
714 	/*
715 	 * Finally we do a 2nd STARTUP IPI: this 2nd STARTUP IPI should run IF
716 	 * the previous STARTUP IPI was cancelled by a latched INIT IPI. OR
717 	 * this STARTUP IPI will be ignored, as only ONE STARTUP IPI is
718 	 * recognized after hardware RESET or INIT IPI.
719 	 */
720 	lapic->icr_lo = icr_lo | 0x00000600 | vector;
721 	while (lapic->icr_lo & APIC_DELSTAT_MASK)
722 		 /* spin */ ;
723 
724 	/* Resume normal operation */
725 	cpu_enable_intr();
726 
727 	/* wait for it to start, see ap_init() */
728 	set_apic_timer(5000000);/* == 5 seconds */
729 	while (read_apic_timer()) {
730 		if (smp_startup_mask & CPUMASK(gd->mi.gd_cpuid))
731 			return 1;	/* return SUCCESS */
732 	}
733 
734 	return 0;		/* return FAILURE */
735 }
736 
737 static
738 int
739 smitest(void)
740 {
741 	int64_t	ltsc;
742 	int64_t	ntsc;
743 	int64_t	ldelta;
744 	int64_t	ndelta;
745 	int count;
746 
747 	ldelta = 0;
748 	ndelta = 0;
749 	while (read_apic_timer()) {
750 		ltsc = rdtsc();
751 		for (count = 0; count < 100; ++count)
752 			ntsc = rdtsc();	/* force loop to occur */
753 		if (ldelta) {
754 			ndelta = ntsc - ltsc;
755 			if (ldelta > ndelta)
756 				ldelta = ndelta;
757 			if (ndelta > ldelta * 2)
758 				break;
759 		} else {
760 			ldelta = ntsc - ltsc;
761 		}
762 	}
763 	return(read_apic_timer());
764 }
765 
766 /*
767  * Synchronously flush the TLB on all other CPU's.  The current cpu's
768  * TLB is not flushed.  If the caller wishes to flush the current cpu's
769  * TLB the caller must call cpu_invltlb() in addition to smp_invltlb().
770  *
771  * NOTE: If for some reason we were unable to start all cpus we cannot
772  *	 safely use broadcast IPIs.
773  */
774 
775 static cpumask_t smp_invltlb_req;
776 
777 #define SMP_INVLTLB_DEBUG
778 
779 void
780 smp_invltlb(void)
781 {
782 	struct mdglobaldata *md = mdcpu;
783 #ifdef SMP_INVLTLB_DEBUG
784 	long count = 0;
785 	long xcount = 0;
786 #endif
787 
788 	crit_enter_gd(&md->mi);
789 	md->gd_invltlb_ret = 0;
790 	++md->mi.gd_cnt.v_smpinvltlb;
791 	atomic_set_cpumask(&smp_invltlb_req, md->mi.gd_cpumask);
792 #ifdef SMP_INVLTLB_DEBUG
793 again:
794 #endif
795 	if (smp_startup_mask == smp_active_mask) {
796 		all_but_self_ipi(XINVLTLB_OFFSET);
797 	} else {
798 		selected_apic_ipi(smp_active_mask & ~md->mi.gd_cpumask,
799 				  XINVLTLB_OFFSET, APIC_DELMODE_FIXED);
800 	}
801 
802 #ifdef SMP_INVLTLB_DEBUG
803 	if (xcount)
804 		kprintf("smp_invltlb: ipi sent\n");
805 #endif
806 	while ((md->gd_invltlb_ret & smp_active_mask & ~md->mi.gd_cpumask) !=
807 	       (smp_active_mask & ~md->mi.gd_cpumask)) {
808 		cpu_mfence();
809 		cpu_pause();
810 #ifdef SMP_INVLTLB_DEBUG
811 		/* DEBUGGING */
812 		if (++count == 400000000) {
813 			print_backtrace(-1);
814 			kprintf("smp_invltlb: endless loop %08lx %08lx, "
815 				"rflags %016jx retry",
816 			      (long)md->gd_invltlb_ret,
817 			      (long)smp_invltlb_req,
818 			      (intmax_t)read_rflags());
819 			__asm __volatile ("sti");
820 			++xcount;
821 			if (xcount > 2)
822 				lwkt_process_ipiq();
823 			if (xcount > 3) {
824 				int bcpu = BSFCPUMASK(~md->gd_invltlb_ret &
825 						      ~md->mi.gd_cpumask &
826 						      smp_active_mask);
827 				globaldata_t xgd;
828 
829 				kprintf("bcpu %d\n", bcpu);
830 				xgd = globaldata_find(bcpu);
831 				kprintf("thread %p %s\n", xgd->gd_curthread, xgd->gd_curthread->td_comm);
832 			}
833 			if (xcount > 5)
834 				Debugger("giving up");
835 			count = 0;
836 			goto again;
837 		}
838 #endif
839 	}
840 	atomic_clear_cpumask(&smp_invltlb_req, md->mi.gd_cpumask);
841 	crit_exit_gd(&md->mi);
842 }
843 
844 /*
845  * Called from Xinvltlb assembly with interrupts disabled.  We didn't
846  * bother to bump the critical section count or nested interrupt count
847  * so only do very low level operations here.
848  */
849 void
850 smp_invltlb_intr(void)
851 {
852 	struct mdglobaldata *md = mdcpu;
853 	struct mdglobaldata *omd;
854 	cpumask_t mask;
855 	int cpu;
856 
857 	cpu_mfence();
858 	mask = smp_invltlb_req;
859 	cpu_invltlb();
860 	while (mask) {
861 		cpu = BSFCPUMASK(mask);
862 		mask &= ~CPUMASK(cpu);
863 		omd = (struct mdglobaldata *)globaldata_find(cpu);
864 		atomic_set_cpumask(&omd->gd_invltlb_ret, md->mi.gd_cpumask);
865 	}
866 }
867 
868 void
869 cpu_wbinvd_on_all_cpus_callback(void *arg)
870 {
871     wbinvd();
872 }
873 
874 /*
875  * When called the executing CPU will send an IPI to all other CPUs
876  *  requesting that they halt execution.
877  *
878  * Usually (but not necessarily) called with 'other_cpus' as its arg.
879  *
880  *  - Signals all CPUs in map to stop.
881  *  - Waits for each to stop.
882  *
883  * Returns:
884  *  -1: error
885  *   0: NA
886  *   1: ok
887  *
888  * XXX FIXME: this is not MP-safe, needs a lock to prevent multiple CPUs
889  *            from executing at same time.
890  */
891 int
892 stop_cpus(cpumask_t map)
893 {
894 	map &= smp_active_mask;
895 
896 	/* send the Xcpustop IPI to all CPUs in map */
897 	selected_apic_ipi(map, XCPUSTOP_OFFSET, APIC_DELMODE_FIXED);
898 
899 	while ((stopped_cpus & map) != map)
900 		/* spin */ ;
901 
902 	return 1;
903 }
904 
905 
906 /*
907  * Called by a CPU to restart stopped CPUs.
908  *
909  * Usually (but not necessarily) called with 'stopped_cpus' as its arg.
910  *
911  *  - Signals all CPUs in map to restart.
912  *  - Waits for each to restart.
913  *
914  * Returns:
915  *  -1: error
916  *   0: NA
917  *   1: ok
918  */
919 int
920 restart_cpus(cpumask_t map)
921 {
922 	/* signal other cpus to restart */
923 	started_cpus = map & smp_active_mask;
924 
925 	while ((stopped_cpus & map) != 0) /* wait for each to clear its bit */
926 		/* spin */ ;
927 
928 	return 1;
929 }
930 
931 /*
932  * This is called once the mpboot code has gotten us properly relocated
933  * and the MMU turned on, etc.   ap_init() is actually the idle thread,
934  * and when it returns the scheduler will call the real cpu_idle() main
935  * loop for the idlethread.  Interrupts are disabled on entry and should
936  * remain disabled at return.
937  */
938 void
939 ap_init(void)
940 {
941 	int	cpu_id;
942 
943 	/*
944 	 * Adjust smp_startup_mask to signal the BSP that we have started
945 	 * up successfully.  Note that we do not yet hold the BGL.  The BSP
946 	 * is waiting for our signal.
947 	 *
948 	 * We can't set our bit in smp_active_mask yet because we are holding
949 	 * interrupts physically disabled and remote cpus could deadlock
950 	 * trying to send us an IPI.
951 	 */
952 	smp_startup_mask |= CPUMASK(mycpu->gd_cpuid);
953 	cpu_mfence();
954 
955 	/*
956 	 * Interlock for LAPIC initialization.  Wait until mp_finish_lapic is
957 	 * non-zero, then get the MP lock.
958 	 *
959 	 * Note: We are in a critical section.
960 	 *
961 	 * Note: we are the idle thread, we can only spin.
962 	 *
963 	 * Note: The load fence is memory volatile and prevents the compiler
964 	 * from improperly caching mp_finish_lapic, and the cpu from improperly
965 	 * caching it.
966 	 */
967 	while (mp_finish_lapic == 0)
968 		cpu_lfence();
969 	while (try_mplock() == 0)
970 		;
971 
972 	if (cpu_feature & CPUID_TSC) {
973 		/*
974 		 * The BSP is constantly updating tsc0_offset, figure out
975 		 * the relative difference to synchronize ktrdump.
976 		 */
977 		tsc_offsets[mycpu->gd_cpuid] = rdtsc() - tsc0_offset;
978 	}
979 
980 	/* BSP may have changed PTD while we're waiting for the lock */
981 	cpu_invltlb();
982 
983 	/* Build our map of 'other' CPUs. */
984 	mycpu->gd_other_cpus = smp_startup_mask & ~CPUMASK(mycpu->gd_cpuid);
985 
986 	/* A quick check from sanity claus */
987 	cpu_id = APICID_TO_CPUID((lapic->id & 0xff000000) >> 24);
988 	if (mycpu->gd_cpuid != cpu_id) {
989 		kprintf("SMP: assigned cpuid = %d\n", mycpu->gd_cpuid);
990 		kprintf("SMP: actual cpuid = %d lapicid %d\n",
991 			cpu_id, (lapic->id & 0xff000000) >> 24);
992 #if JGXXX
993 		kprintf("PTD[MPPTDI] = %p\n", (void *)PTD[MPPTDI]);
994 #endif
995 		panic("cpuid mismatch! boom!!");
996 	}
997 
998 	/* Initialize AP's local APIC for irq's */
999 	lapic_init(FALSE);
1000 
1001 	/* LAPIC initialization is done */
1002 	smp_lapic_mask |= CPUMASK(mycpu->gd_cpuid);
1003 	cpu_mfence();
1004 
1005 	/* Let BSP move onto the next initialization stage */
1006 	rel_mplock();
1007 
1008 	/*
1009 	 * Interlock for finalization.  Wait until mp_finish is non-zero,
1010 	 * then get the MP lock.
1011 	 *
1012 	 * Note: We are in a critical section.
1013 	 *
1014 	 * Note: we are the idle thread, we can only spin.
1015 	 *
1016 	 * Note: The load fence is memory volatile and prevents the compiler
1017 	 * from improperly caching mp_finish, and the cpu from improperly
1018 	 * caching it.
1019 	 */
1020 	while (mp_finish == 0)
1021 		cpu_lfence();
1022 	while (try_mplock() == 0)
1023 		;
1024 
1025 	/* BSP may have changed PTD while we're waiting for the lock */
1026 	cpu_invltlb();
1027 
1028 	/* Set memory range attributes for this CPU to match the BSP */
1029 	mem_range_AP_init();
1030 
1031 	/*
1032 	 * Once we go active we must process any IPIQ messages that may
1033 	 * have been queued, because no actual IPI will occur until we
1034 	 * set our bit in the smp_active_mask.  If we don't the IPI
1035 	 * message interlock could be left set which would also prevent
1036 	 * further IPIs.
1037 	 *
1038 	 * The idle loop doesn't expect the BGL to be held and while
1039 	 * lwkt_switch() normally cleans things up this is a special case
1040 	 * because we returning almost directly into the idle loop.
1041 	 *
1042 	 * The idle thread is never placed on the runq, make sure
1043 	 * nothing we've done put it there.
1044 	 */
1045 	KKASSERT(get_mplock_count(curthread) == 1);
1046 	smp_active_mask |= CPUMASK(mycpu->gd_cpuid);
1047 
1048 	/*
1049 	 * Enable interrupts here.  idle_restore will also do it, but
1050 	 * doing it here lets us clean up any strays that got posted to
1051 	 * the CPU during the AP boot while we are still in a critical
1052 	 * section.
1053 	 */
1054 	__asm __volatile("sti; pause; pause"::);
1055 	bzero(mdcpu->gd_ipending, sizeof(mdcpu->gd_ipending));
1056 
1057 	initclocks_pcpu();	/* clock interrupts (via IPIs) */
1058 	lwkt_process_ipiq();
1059 
1060 	/*
1061 	 * Releasing the mp lock lets the BSP finish up the SMP init
1062 	 */
1063 	rel_mplock();
1064 	KKASSERT((curthread->td_flags & TDF_RUNQ) == 0);
1065 }
1066 
1067 /*
1068  * Get SMP fully working before we start initializing devices.
1069  */
1070 static
1071 void
1072 ap_finish(void)
1073 {
1074 	mp_finish = 1;
1075 	if (bootverbose)
1076 		kprintf("Finish MP startup\n");
1077 	rel_mplock();
1078 	while (smp_active_mask != smp_startup_mask)
1079 		cpu_lfence();
1080 	while (try_mplock() == 0)
1081 		;
1082 	if (bootverbose) {
1083 		kprintf("Active CPU Mask: %016jx\n",
1084 			(uintmax_t)smp_active_mask);
1085 	}
1086 }
1087 
1088 SYSINIT(finishsmp, SI_BOOT2_FINISH_SMP, SI_ORDER_FIRST, ap_finish, NULL)
1089 
1090 void
1091 cpu_send_ipiq(int dcpu)
1092 {
1093         if (CPUMASK(dcpu) & smp_active_mask)
1094                 single_apic_ipi(dcpu, XIPIQ_OFFSET, APIC_DELMODE_FIXED);
1095 }
1096 
1097 #if 0	/* single_apic_ipi_passive() not working yet */
1098 /*
1099  * Returns 0 on failure, 1 on success
1100  */
1101 int
1102 cpu_send_ipiq_passive(int dcpu)
1103 {
1104         int r = 0;
1105         if (CPUMASK(dcpu) & smp_active_mask) {
1106                 r = single_apic_ipi_passive(dcpu, XIPIQ_OFFSET,
1107                                         APIC_DELMODE_FIXED);
1108         }
1109 	return(r);
1110 }
1111 #endif
1112 
1113 static void
1114 mp_bsp_simple_setup(void)
1115 {
1116 	/* build our map of 'other' CPUs */
1117 	mycpu->gd_other_cpus = smp_startup_mask & ~CPUMASK(mycpu->gd_cpuid);
1118 	mycpu->gd_ipiq = (void *)kmem_alloc(&kernel_map, sizeof(lwkt_ipiq) * ncpus);
1119 	bzero(mycpu->gd_ipiq, sizeof(lwkt_ipiq) * ncpus);
1120 
1121 	pmap_set_opt();
1122 
1123 	if (cpu_feature & CPUID_TSC)
1124 		tsc0_offset = rdtsc();
1125 }
1126 
1127 
1128 /*
1129  * CPU TOPOLOGY DETECTION FUNCTIONS
1130  */
1131 
1132 /* Detect intel topology using CPUID
1133  * Ref: http://www.intel.com/Assets/PDF/appnote/241618.pdf, pg 41
1134  */
1135 static void
1136 detect_intel_topology(int count_htt_cores)
1137 {
1138 	int shift = 0;
1139 	int ecx_index = 0;
1140 	int core_plus_logical_bits = 0;
1141 	int cores_per_package;
1142 	int logical_per_package;
1143 	int logical_per_core;
1144 	unsigned int p[4];
1145 
1146 	if (cpu_high >= 0xb) {
1147 		goto FUNC_B;
1148 
1149 	} else if (cpu_high >= 0x4) {
1150 		goto FUNC_4;
1151 
1152 	} else {
1153 		core_bits = 0;
1154 		for (shift = 0; (1 << shift) < count_htt_cores; ++shift)
1155 			;
1156 		logical_CPU_bits = 1 << shift;
1157 		return;
1158 	}
1159 
1160 FUNC_B:
1161 	cpuid_count(0xb, FUNC_B_THREAD_LEVEL, p);
1162 
1163 	/* if 0xb not supported - fallback to 0x4 */
1164 	if (p[1] == 0 || (FUNC_B_TYPE(p[2]) != FUNC_B_THREAD_TYPE)) {
1165 		goto FUNC_4;
1166 	}
1167 
1168 	logical_CPU_bits = FUNC_B_BITS_SHIFT_NEXT_LEVEL(p[0]);
1169 
1170 	ecx_index = FUNC_B_THREAD_LEVEL + 1;
1171 	do {
1172 		cpuid_count(0xb, ecx_index, p);
1173 
1174 		/* Check for the Core type in the implemented sub leaves. */
1175 		if (FUNC_B_TYPE(p[2]) == FUNC_B_CORE_TYPE) {
1176 			core_plus_logical_bits = FUNC_B_BITS_SHIFT_NEXT_LEVEL(p[0]);
1177 			break;
1178 		}
1179 
1180 		ecx_index++;
1181 
1182 	} while (FUNC_B_TYPE(p[2]) != FUNC_B_INVALID_TYPE);
1183 
1184 	core_bits = core_plus_logical_bits - logical_CPU_bits;
1185 
1186 	return;
1187 
1188 FUNC_4:
1189 	cpuid_count(0x4, 0, p);
1190 	cores_per_package = FUNC_4_MAX_CORE_NO(p[0]) + 1;
1191 
1192 	logical_per_package = count_htt_cores;
1193 	logical_per_core = logical_per_package / cores_per_package;
1194 
1195 	for (shift = 0; (1 << shift) < logical_per_core; ++shift)
1196 		;
1197 	logical_CPU_bits = shift;
1198 
1199 	for (shift = 0; (1 << shift) < cores_per_package; ++shift)
1200 		;
1201 	core_bits = shift;
1202 
1203 	return;
1204 }
1205 
1206 /* Detect AMD topology using CPUID
1207  * Ref: http://support.amd.com/us/Embedded_TechDocs/25481.pdf, last page
1208  */
1209 static void
1210 detect_amd_topology(int count_htt_cores)
1211 {
1212 	int shift = 0;
1213 	if ((cpu_feature & CPUID_HTT)
1214 			&& (amd_feature2 & AMDID2_CMP)) {
1215 
1216 		if (cpu_procinfo2 & AMDID_COREID_SIZE) {
1217 			core_bits = (cpu_procinfo2 & AMDID_COREID_SIZE)
1218 			    >> AMDID_COREID_SIZE_SHIFT;
1219 		} else {
1220 			core_bits = (cpu_procinfo2 & AMDID_CMP_CORES) + 1;
1221 			for (shift = 0; (1 << shift) < core_bits; ++shift)
1222 				;
1223 			core_bits = shift;
1224 		}
1225 
1226 		logical_CPU_bits = count_htt_cores >> core_bits;
1227 		for (shift = 0; (1 << shift) < logical_CPU_bits; ++shift)
1228 			;
1229 		logical_CPU_bits = shift;
1230 	} else {
1231 		for (shift = 0; (1 << shift) < count_htt_cores; ++shift)
1232 			;
1233 		core_bits = shift;
1234 		logical_CPU_bits = 0;
1235 	}
1236 }
1237 
1238 /* Calculate
1239  * - logical_CPU_bits
1240  * - core_bits
1241  * With the values above (for AMD or INTEL) we are able to generally
1242  * detect the CPU topology (number of cores for each level):
1243  * Ref: http://wiki.osdev.org/Detecting_CPU_Topology_(80x86)
1244  * Ref: http://www.multicoreinfo.com/research/papers/whitepapers/Intel-detect-topology.pdf
1245  */
1246 void
1247 detect_cpu_topology(void)
1248 {
1249 	static int topology_detected = 0;
1250 	int count = 0;
1251 
1252 	if (topology_detected) {
1253 		goto OUT;
1254 	}
1255 
1256 	if ((cpu_feature & CPUID_HTT) == 0) {
1257 		core_bits = 0;
1258 		logical_CPU_bits = 0;
1259 		goto OUT;
1260 	} else {
1261 		count = (cpu_procinfo & CPUID_HTT_CORES)
1262 		    >> CPUID_HTT_CORE_SHIFT;
1263 	}
1264 
1265 	if (cpu_vendor_id == CPU_VENDOR_INTEL) {
1266 		detect_intel_topology(count);
1267 	} else if (cpu_vendor_id == CPU_VENDOR_AMD) {
1268 		detect_amd_topology(count);
1269 	}
1270 
1271 OUT:
1272 	if (bootverbose)
1273 		kprintf("BITS within APICID: logical_CPU_bits: %d; core_bits: %d\n",
1274 		    logical_CPU_bits, core_bits);
1275 
1276 	topology_detected = 1;
1277 }
1278 
1279 /* Interface functions to calculate chip_ID,
1280  * core_number and logical_number
1281  * Ref: http://wiki.osdev.org/Detecting_CPU_Topology_(80x86)
1282  */
1283 int
1284 get_chip_ID(int cpuid)
1285 {
1286 	return get_apicid_from_cpuid(cpuid) >>
1287 	    (logical_CPU_bits + core_bits);
1288 }
1289 
1290 int
1291 get_core_number_within_chip(int cpuid)
1292 {
1293 	return (get_apicid_from_cpuid(cpuid) >> logical_CPU_bits) &
1294 	    ( (1 << core_bits) -1);
1295 }
1296 
1297 int
1298 get_logical_CPU_number_within_core(int cpuid)
1299 {
1300 	return get_apicid_from_cpuid(cpuid) &
1301 	    ( (1 << logical_CPU_bits) -1);
1302 }
1303