xref: /openbmc/linux/arch/ia64/kernel/smpboot.c (revision 82e6fdd6)
1 /*
2  * SMP boot-related support
3  *
4  * Copyright (C) 1998-2003, 2005 Hewlett-Packard Co
5  *	David Mosberger-Tang <davidm@hpl.hp.com>
6  * Copyright (C) 2001, 2004-2005 Intel Corp
7  * 	Rohit Seth <rohit.seth@intel.com>
8  * 	Suresh Siddha <suresh.b.siddha@intel.com>
9  * 	Gordon Jin <gordon.jin@intel.com>
10  *	Ashok Raj  <ashok.raj@intel.com>
11  *
12  * 01/05/16 Rohit Seth <rohit.seth@intel.com>	Moved SMP booting functions from smp.c to here.
13  * 01/04/27 David Mosberger <davidm@hpl.hp.com>	Added ITC synching code.
14  * 02/07/31 David Mosberger <davidm@hpl.hp.com>	Switch over to hotplug-CPU boot-sequence.
15  *						smp_boot_cpus()/smp_commence() is replaced by
16  *						smp_prepare_cpus()/__cpu_up()/smp_cpus_done().
17  * 04/06/21 Ashok Raj		<ashok.raj@intel.com> Added CPU Hotplug Support
18  * 04/12/26 Jin Gordon <gordon.jin@intel.com>
19  * 04/12/26 Rohit Seth <rohit.seth@intel.com>
20  *						Add multi-threading and multi-core detection
21  * 05/01/30 Suresh Siddha <suresh.b.siddha@intel.com>
22  *						Setup cpu_sibling_map and cpu_core_map
23  */
24 
25 #include <linux/module.h>
26 #include <linux/acpi.h>
27 #include <linux/bootmem.h>
28 #include <linux/cpu.h>
29 #include <linux/delay.h>
30 #include <linux/init.h>
31 #include <linux/interrupt.h>
32 #include <linux/irq.h>
33 #include <linux/kernel.h>
34 #include <linux/kernel_stat.h>
35 #include <linux/mm.h>
36 #include <linux/notifier.h>
37 #include <linux/smp.h>
38 #include <linux/spinlock.h>
39 #include <linux/efi.h>
40 #include <linux/percpu.h>
41 #include <linux/bitops.h>
42 
43 #include <linux/atomic.h>
44 #include <asm/cache.h>
45 #include <asm/current.h>
46 #include <asm/delay.h>
47 #include <asm/io.h>
48 #include <asm/irq.h>
49 #include <asm/machvec.h>
50 #include <asm/mca.h>
51 #include <asm/page.h>
52 #include <asm/pgalloc.h>
53 #include <asm/pgtable.h>
54 #include <asm/processor.h>
55 #include <asm/ptrace.h>
56 #include <asm/sal.h>
57 #include <asm/tlbflush.h>
58 #include <asm/unistd.h>
59 #include <asm/sn/arch.h>
60 
61 #define SMP_DEBUG 0
62 
63 #if SMP_DEBUG
64 #define Dprintk(x...)  printk(x)
65 #else
66 #define Dprintk(x...)
67 #endif
68 
69 #ifdef CONFIG_HOTPLUG_CPU
70 #ifdef CONFIG_PERMIT_BSP_REMOVE
71 #define bsp_remove_ok	1
72 #else
73 #define bsp_remove_ok	0
74 #endif
75 
76 /*
77  * Global array allocated for NR_CPUS at boot time
78  */
79 struct sal_to_os_boot sal_boot_rendez_state[NR_CPUS];
80 
81 /*
82  * start_ap in head.S uses this to store current booting cpu
83  * info.
84  */
85 struct sal_to_os_boot *sal_state_for_booting_cpu = &sal_boot_rendez_state[0];
86 
87 #define set_brendez_area(x) (sal_state_for_booting_cpu = &sal_boot_rendez_state[(x)]);
88 
89 #else
90 #define set_brendez_area(x)
91 #endif
92 
93 
94 /*
95  * ITC synchronization related stuff:
96  */
97 #define MASTER	(0)
98 #define SLAVE	(SMP_CACHE_BYTES/8)
99 
100 #define NUM_ROUNDS	64	/* magic value */
101 #define NUM_ITERS	5	/* likewise */
102 
103 static DEFINE_SPINLOCK(itc_sync_lock);
104 static volatile unsigned long go[SLAVE + 1];
105 
106 #define DEBUG_ITC_SYNC	0
107 
108 extern void start_ap (void);
109 extern unsigned long ia64_iobase;
110 
111 struct task_struct *task_for_booting_cpu;
112 
113 /*
114  * State for each CPU
115  */
116 DEFINE_PER_CPU(int, cpu_state);
117 
118 cpumask_t cpu_core_map[NR_CPUS] __cacheline_aligned;
119 EXPORT_SYMBOL(cpu_core_map);
120 DEFINE_PER_CPU_SHARED_ALIGNED(cpumask_t, cpu_sibling_map);
121 EXPORT_PER_CPU_SYMBOL(cpu_sibling_map);
122 
123 int smp_num_siblings = 1;
124 
125 /* which logical CPU number maps to which CPU (physical APIC ID) */
126 volatile int ia64_cpu_to_sapicid[NR_CPUS];
127 EXPORT_SYMBOL(ia64_cpu_to_sapicid);
128 
129 static cpumask_t cpu_callin_map;
130 
131 struct smp_boot_data smp_boot_data __initdata;
132 
133 unsigned long ap_wakeup_vector = -1; /* External Int use to wakeup APs */
134 
135 char __initdata no_int_routing;
136 
137 unsigned char smp_int_redirect; /* are INT and IPI redirectable by the chipset? */
138 
139 #ifdef CONFIG_FORCE_CPEI_RETARGET
140 #define CPEI_OVERRIDE_DEFAULT	(1)
141 #else
142 #define CPEI_OVERRIDE_DEFAULT	(0)
143 #endif
144 
145 unsigned int force_cpei_retarget = CPEI_OVERRIDE_DEFAULT;
146 
147 static int __init
148 cmdl_force_cpei(char *str)
149 {
150 	int value=0;
151 
152 	get_option (&str, &value);
153 	force_cpei_retarget = value;
154 
155 	return 1;
156 }
157 
158 __setup("force_cpei=", cmdl_force_cpei);
159 
160 static int __init
161 nointroute (char *str)
162 {
163 	no_int_routing = 1;
164 	printk ("no_int_routing on\n");
165 	return 1;
166 }
167 
168 __setup("nointroute", nointroute);
169 
170 static void fix_b0_for_bsp(void)
171 {
172 #ifdef CONFIG_HOTPLUG_CPU
173 	int cpuid;
174 	static int fix_bsp_b0 = 1;
175 
176 	cpuid = smp_processor_id();
177 
178 	/*
179 	 * Cache the b0 value on the first AP that comes up
180 	 */
181 	if (!(fix_bsp_b0 && cpuid))
182 		return;
183 
184 	sal_boot_rendez_state[0].br[0] = sal_boot_rendez_state[cpuid].br[0];
185 	printk ("Fixed BSP b0 value from CPU %d\n", cpuid);
186 
187 	fix_bsp_b0 = 0;
188 #endif
189 }
190 
191 void
192 sync_master (void *arg)
193 {
194 	unsigned long flags, i;
195 
196 	go[MASTER] = 0;
197 
198 	local_irq_save(flags);
199 	{
200 		for (i = 0; i < NUM_ROUNDS*NUM_ITERS; ++i) {
201 			while (!go[MASTER])
202 				cpu_relax();
203 			go[MASTER] = 0;
204 			go[SLAVE] = ia64_get_itc();
205 		}
206 	}
207 	local_irq_restore(flags);
208 }
209 
210 /*
211  * Return the number of cycles by which our itc differs from the itc on the master
212  * (time-keeper) CPU.  A positive number indicates our itc is ahead of the master,
213  * negative that it is behind.
214  */
215 static inline long
216 get_delta (long *rt, long *master)
217 {
218 	unsigned long best_t0 = 0, best_t1 = ~0UL, best_tm = 0;
219 	unsigned long tcenter, t0, t1, tm;
220 	long i;
221 
222 	for (i = 0; i < NUM_ITERS; ++i) {
223 		t0 = ia64_get_itc();
224 		go[MASTER] = 1;
225 		while (!(tm = go[SLAVE]))
226 			cpu_relax();
227 		go[SLAVE] = 0;
228 		t1 = ia64_get_itc();
229 
230 		if (t1 - t0 < best_t1 - best_t0)
231 			best_t0 = t0, best_t1 = t1, best_tm = tm;
232 	}
233 
234 	*rt = best_t1 - best_t0;
235 	*master = best_tm - best_t0;
236 
237 	/* average best_t0 and best_t1 without overflow: */
238 	tcenter = (best_t0/2 + best_t1/2);
239 	if (best_t0 % 2 + best_t1 % 2 == 2)
240 		++tcenter;
241 	return tcenter - best_tm;
242 }
243 
244 /*
245  * Synchronize ar.itc of the current (slave) CPU with the ar.itc of the MASTER CPU
246  * (normally the time-keeper CPU).  We use a closed loop to eliminate the possibility of
247  * unaccounted-for errors (such as getting a machine check in the middle of a calibration
248  * step).  The basic idea is for the slave to ask the master what itc value it has and to
249  * read its own itc before and after the master responds.  Each iteration gives us three
250  * timestamps:
251  *
252  *	slave		master
253  *
254  *	t0 ---\
255  *             ---\
256  *		   --->
257  *			tm
258  *		   /---
259  *	       /---
260  *	t1 <---
261  *
262  *
263  * The goal is to adjust the slave's ar.itc such that tm falls exactly half-way between t0
264  * and t1.  If we achieve this, the clocks are synchronized provided the interconnect
265  * between the slave and the master is symmetric.  Even if the interconnect were
266  * asymmetric, we would still know that the synchronization error is smaller than the
267  * roundtrip latency (t0 - t1).
268  *
269  * When the interconnect is quiet and symmetric, this lets us synchronize the itc to
270  * within one or two cycles.  However, we can only *guarantee* that the synchronization is
271  * accurate to within a round-trip time, which is typically in the range of several
272  * hundred cycles (e.g., ~500 cycles).  In practice, this means that the itc's are usually
273  * almost perfectly synchronized, but we shouldn't assume that the accuracy is much better
274  * than half a micro second or so.
275  */
276 void
277 ia64_sync_itc (unsigned int master)
278 {
279 	long i, delta, adj, adjust_latency = 0, done = 0;
280 	unsigned long flags, rt, master_time_stamp, bound;
281 #if DEBUG_ITC_SYNC
282 	struct {
283 		long rt;	/* roundtrip time */
284 		long master;	/* master's timestamp */
285 		long diff;	/* difference between midpoint and master's timestamp */
286 		long lat;	/* estimate of itc adjustment latency */
287 	} t[NUM_ROUNDS];
288 #endif
289 
290 	/*
291 	 * Make sure local timer ticks are disabled while we sync.  If
292 	 * they were enabled, we'd have to worry about nasty issues
293 	 * like setting the ITC ahead of (or a long time before) the
294 	 * next scheduled tick.
295 	 */
296 	BUG_ON((ia64_get_itv() & (1 << 16)) == 0);
297 
298 	go[MASTER] = 1;
299 
300 	if (smp_call_function_single(master, sync_master, NULL, 0) < 0) {
301 		printk(KERN_ERR "sync_itc: failed to get attention of CPU %u!\n", master);
302 		return;
303 	}
304 
305 	while (go[MASTER])
306 		cpu_relax();	/* wait for master to be ready */
307 
308 	spin_lock_irqsave(&itc_sync_lock, flags);
309 	{
310 		for (i = 0; i < NUM_ROUNDS; ++i) {
311 			delta = get_delta(&rt, &master_time_stamp);
312 			if (delta == 0) {
313 				done = 1;	/* let's lock on to this... */
314 				bound = rt;
315 			}
316 
317 			if (!done) {
318 				if (i > 0) {
319 					adjust_latency += -delta;
320 					adj = -delta + adjust_latency/4;
321 				} else
322 					adj = -delta;
323 
324 				ia64_set_itc(ia64_get_itc() + adj);
325 			}
326 #if DEBUG_ITC_SYNC
327 			t[i].rt = rt;
328 			t[i].master = master_time_stamp;
329 			t[i].diff = delta;
330 			t[i].lat = adjust_latency/4;
331 #endif
332 		}
333 	}
334 	spin_unlock_irqrestore(&itc_sync_lock, flags);
335 
336 #if DEBUG_ITC_SYNC
337 	for (i = 0; i < NUM_ROUNDS; ++i)
338 		printk("rt=%5ld master=%5ld diff=%5ld adjlat=%5ld\n",
339 		       t[i].rt, t[i].master, t[i].diff, t[i].lat);
340 #endif
341 
342 	printk(KERN_INFO "CPU %d: synchronized ITC with CPU %u (last diff %ld cycles, "
343 	       "maxerr %lu cycles)\n", smp_processor_id(), master, delta, rt);
344 }
345 
346 /*
347  * Ideally sets up per-cpu profiling hooks.  Doesn't do much now...
348  */
349 static inline void smp_setup_percpu_timer(void)
350 {
351 }
352 
353 static void
354 smp_callin (void)
355 {
356 	int cpuid, phys_id, itc_master;
357 	struct cpuinfo_ia64 *last_cpuinfo, *this_cpuinfo;
358 	extern void ia64_init_itm(void);
359 	extern volatile int time_keeper_id;
360 
361 #ifdef CONFIG_PERFMON
362 	extern void pfm_init_percpu(void);
363 #endif
364 
365 	cpuid = smp_processor_id();
366 	phys_id = hard_smp_processor_id();
367 	itc_master = time_keeper_id;
368 
369 	if (cpu_online(cpuid)) {
370 		printk(KERN_ERR "huh, phys CPU#0x%x, CPU#0x%x already present??\n",
371 		       phys_id, cpuid);
372 		BUG();
373 	}
374 
375 	fix_b0_for_bsp();
376 
377 	/*
378 	 * numa_node_id() works after this.
379 	 */
380 	set_numa_node(cpu_to_node_map[cpuid]);
381 	set_numa_mem(local_memory_node(cpu_to_node_map[cpuid]));
382 
383 	spin_lock(&vector_lock);
384 	/* Setup the per cpu irq handling data structures */
385 	__setup_vector_irq(cpuid);
386 	notify_cpu_starting(cpuid);
387 	set_cpu_online(cpuid, true);
388 	per_cpu(cpu_state, cpuid) = CPU_ONLINE;
389 	spin_unlock(&vector_lock);
390 
391 	smp_setup_percpu_timer();
392 
393 	ia64_mca_cmc_vector_setup();	/* Setup vector on AP */
394 
395 #ifdef CONFIG_PERFMON
396 	pfm_init_percpu();
397 #endif
398 
399 	local_irq_enable();
400 
401 	if (!(sal_platform_features & IA64_SAL_PLATFORM_FEATURE_ITC_DRIFT)) {
402 		/*
403 		 * Synchronize the ITC with the BP.  Need to do this after irqs are
404 		 * enabled because ia64_sync_itc() calls smp_call_function_single(), which
405 		 * calls spin_unlock_bh(), which calls spin_unlock_bh(), which calls
406 		 * local_bh_enable(), which bugs out if irqs are not enabled...
407 		 */
408 		Dprintk("Going to syncup ITC with ITC Master.\n");
409 		ia64_sync_itc(itc_master);
410 	}
411 
412 	/*
413 	 * Get our bogomips.
414 	 */
415 	ia64_init_itm();
416 
417 	/*
418 	 * Delay calibration can be skipped if new processor is identical to the
419 	 * previous processor.
420 	 */
421 	last_cpuinfo = cpu_data(cpuid - 1);
422 	this_cpuinfo = local_cpu_data;
423 	if (last_cpuinfo->itc_freq != this_cpuinfo->itc_freq ||
424 	    last_cpuinfo->proc_freq != this_cpuinfo->proc_freq ||
425 	    last_cpuinfo->features != this_cpuinfo->features ||
426 	    last_cpuinfo->revision != this_cpuinfo->revision ||
427 	    last_cpuinfo->family != this_cpuinfo->family ||
428 	    last_cpuinfo->archrev != this_cpuinfo->archrev ||
429 	    last_cpuinfo->model != this_cpuinfo->model)
430 		calibrate_delay();
431 	local_cpu_data->loops_per_jiffy = loops_per_jiffy;
432 
433 	/*
434 	 * Allow the master to continue.
435 	 */
436 	cpumask_set_cpu(cpuid, &cpu_callin_map);
437 	Dprintk("Stack on CPU %d at about %p\n",cpuid, &cpuid);
438 }
439 
440 
441 /*
442  * Activate a secondary processor.  head.S calls this.
443  */
444 int
445 start_secondary (void *unused)
446 {
447 	/* Early console may use I/O ports */
448 	ia64_set_kr(IA64_KR_IO_BASE, __pa(ia64_iobase));
449 #ifndef CONFIG_PRINTK_TIME
450 	Dprintk("start_secondary: starting CPU 0x%x\n", hard_smp_processor_id());
451 #endif
452 	efi_map_pal_code();
453 	cpu_init();
454 	preempt_disable();
455 	smp_callin();
456 
457 	cpu_startup_entry(CPUHP_AP_ONLINE_IDLE);
458 	return 0;
459 }
460 
461 static int
462 do_boot_cpu (int sapicid, int cpu, struct task_struct *idle)
463 {
464 	int timeout;
465 
466 	task_for_booting_cpu = idle;
467 	Dprintk("Sending wakeup vector %lu to AP 0x%x/0x%x.\n", ap_wakeup_vector, cpu, sapicid);
468 
469 	set_brendez_area(cpu);
470 	platform_send_ipi(cpu, ap_wakeup_vector, IA64_IPI_DM_INT, 0);
471 
472 	/*
473 	 * Wait 10s total for the AP to start
474 	 */
475 	Dprintk("Waiting on callin_map ...");
476 	for (timeout = 0; timeout < 100000; timeout++) {
477 		if (cpumask_test_cpu(cpu, &cpu_callin_map))
478 			break;  /* It has booted */
479 		barrier(); /* Make sure we re-read cpu_callin_map */
480 		udelay(100);
481 	}
482 	Dprintk("\n");
483 
484 	if (!cpumask_test_cpu(cpu, &cpu_callin_map)) {
485 		printk(KERN_ERR "Processor 0x%x/0x%x is stuck.\n", cpu, sapicid);
486 		ia64_cpu_to_sapicid[cpu] = -1;
487 		set_cpu_online(cpu, false);  /* was set in smp_callin() */
488 		return -EINVAL;
489 	}
490 	return 0;
491 }
492 
493 static int __init
494 decay (char *str)
495 {
496 	int ticks;
497 	get_option (&str, &ticks);
498 	return 1;
499 }
500 
501 __setup("decay=", decay);
502 
503 /*
504  * Initialize the logical CPU number to SAPICID mapping
505  */
506 void __init
507 smp_build_cpu_map (void)
508 {
509 	int sapicid, cpu, i;
510 	int boot_cpu_id = hard_smp_processor_id();
511 
512 	for (cpu = 0; cpu < NR_CPUS; cpu++) {
513 		ia64_cpu_to_sapicid[cpu] = -1;
514 	}
515 
516 	ia64_cpu_to_sapicid[0] = boot_cpu_id;
517 	init_cpu_present(cpumask_of(0));
518 	set_cpu_possible(0, true);
519 	for (cpu = 1, i = 0; i < smp_boot_data.cpu_count; i++) {
520 		sapicid = smp_boot_data.cpu_phys_id[i];
521 		if (sapicid == boot_cpu_id)
522 			continue;
523 		set_cpu_present(cpu, true);
524 		set_cpu_possible(cpu, true);
525 		ia64_cpu_to_sapicid[cpu] = sapicid;
526 		cpu++;
527 	}
528 }
529 
530 /*
531  * Cycle through the APs sending Wakeup IPIs to boot each.
532  */
533 void __init
534 smp_prepare_cpus (unsigned int max_cpus)
535 {
536 	int boot_cpu_id = hard_smp_processor_id();
537 
538 	/*
539 	 * Initialize the per-CPU profiling counter/multiplier
540 	 */
541 
542 	smp_setup_percpu_timer();
543 
544 	cpumask_set_cpu(0, &cpu_callin_map);
545 
546 	local_cpu_data->loops_per_jiffy = loops_per_jiffy;
547 	ia64_cpu_to_sapicid[0] = boot_cpu_id;
548 
549 	printk(KERN_INFO "Boot processor id 0x%x/0x%x\n", 0, boot_cpu_id);
550 
551 	current_thread_info()->cpu = 0;
552 
553 	/*
554 	 * If SMP should be disabled, then really disable it!
555 	 */
556 	if (!max_cpus) {
557 		printk(KERN_INFO "SMP mode deactivated.\n");
558 		init_cpu_online(cpumask_of(0));
559 		init_cpu_present(cpumask_of(0));
560 		init_cpu_possible(cpumask_of(0));
561 		return;
562 	}
563 }
564 
565 void smp_prepare_boot_cpu(void)
566 {
567 	set_cpu_online(smp_processor_id(), true);
568 	cpumask_set_cpu(smp_processor_id(), &cpu_callin_map);
569 	set_numa_node(cpu_to_node_map[smp_processor_id()]);
570 	per_cpu(cpu_state, smp_processor_id()) = CPU_ONLINE;
571 }
572 
573 #ifdef CONFIG_HOTPLUG_CPU
574 static inline void
575 clear_cpu_sibling_map(int cpu)
576 {
577 	int i;
578 
579 	for_each_cpu(i, &per_cpu(cpu_sibling_map, cpu))
580 		cpumask_clear_cpu(cpu, &per_cpu(cpu_sibling_map, i));
581 	for_each_cpu(i, &cpu_core_map[cpu])
582 		cpumask_clear_cpu(cpu, &cpu_core_map[i]);
583 
584 	per_cpu(cpu_sibling_map, cpu) = cpu_core_map[cpu] = CPU_MASK_NONE;
585 }
586 
587 static void
588 remove_siblinginfo(int cpu)
589 {
590 	int last = 0;
591 
592 	if (cpu_data(cpu)->threads_per_core == 1 &&
593 	    cpu_data(cpu)->cores_per_socket == 1) {
594 		cpumask_clear_cpu(cpu, &cpu_core_map[cpu]);
595 		cpumask_clear_cpu(cpu, &per_cpu(cpu_sibling_map, cpu));
596 		return;
597 	}
598 
599 	last = (cpumask_weight(&cpu_core_map[cpu]) == 1 ? 1 : 0);
600 
601 	/* remove it from all sibling map's */
602 	clear_cpu_sibling_map(cpu);
603 }
604 
605 extern void fixup_irqs(void);
606 
607 int migrate_platform_irqs(unsigned int cpu)
608 {
609 	int new_cpei_cpu;
610 	struct irq_data *data = NULL;
611 	const struct cpumask *mask;
612 	int 		retval = 0;
613 
614 	/*
615 	 * dont permit CPEI target to removed.
616 	 */
617 	if (cpe_vector > 0 && is_cpu_cpei_target(cpu)) {
618 		printk ("CPU (%d) is CPEI Target\n", cpu);
619 		if (can_cpei_retarget()) {
620 			/*
621 			 * Now re-target the CPEI to a different processor
622 			 */
623 			new_cpei_cpu = cpumask_any(cpu_online_mask);
624 			mask = cpumask_of(new_cpei_cpu);
625 			set_cpei_target_cpu(new_cpei_cpu);
626 			data = irq_get_irq_data(ia64_cpe_irq);
627 			/*
628 			 * Switch for now, immediately, we need to do fake intr
629 			 * as other interrupts, but need to study CPEI behaviour with
630 			 * polling before making changes.
631 			 */
632 			if (data && data->chip) {
633 				data->chip->irq_disable(data);
634 				data->chip->irq_set_affinity(data, mask, false);
635 				data->chip->irq_enable(data);
636 				printk ("Re-targeting CPEI to cpu %d\n", new_cpei_cpu);
637 			}
638 		}
639 		if (!data) {
640 			printk ("Unable to retarget CPEI, offline cpu [%d] failed\n", cpu);
641 			retval = -EBUSY;
642 		}
643 	}
644 	return retval;
645 }
646 
647 /* must be called with cpucontrol mutex held */
648 int __cpu_disable(void)
649 {
650 	int cpu = smp_processor_id();
651 
652 	/*
653 	 * dont permit boot processor for now
654 	 */
655 	if (cpu == 0 && !bsp_remove_ok) {
656 		printk ("Your platform does not support removal of BSP\n");
657 		return (-EBUSY);
658 	}
659 
660 	if (ia64_platform_is("sn2")) {
661 		if (!sn_cpu_disable_allowed(cpu))
662 			return -EBUSY;
663 	}
664 
665 	set_cpu_online(cpu, false);
666 
667 	if (migrate_platform_irqs(cpu)) {
668 		set_cpu_online(cpu, true);
669 		return -EBUSY;
670 	}
671 
672 	remove_siblinginfo(cpu);
673 	fixup_irqs();
674 	local_flush_tlb_all();
675 	cpumask_clear_cpu(cpu, &cpu_callin_map);
676 	return 0;
677 }
678 
679 void __cpu_die(unsigned int cpu)
680 {
681 	unsigned int i;
682 
683 	for (i = 0; i < 100; i++) {
684 		/* They ack this in play_dead by setting CPU_DEAD */
685 		if (per_cpu(cpu_state, cpu) == CPU_DEAD)
686 		{
687 			printk ("CPU %d is now offline\n", cpu);
688 			return;
689 		}
690 		msleep(100);
691 	}
692  	printk(KERN_ERR "CPU %u didn't die...\n", cpu);
693 }
694 #endif /* CONFIG_HOTPLUG_CPU */
695 
696 void
697 smp_cpus_done (unsigned int dummy)
698 {
699 	int cpu;
700 	unsigned long bogosum = 0;
701 
702 	/*
703 	 * Allow the user to impress friends.
704 	 */
705 
706 	for_each_online_cpu(cpu) {
707 		bogosum += cpu_data(cpu)->loops_per_jiffy;
708 	}
709 
710 	printk(KERN_INFO "Total of %d processors activated (%lu.%02lu BogoMIPS).\n",
711 	       (int)num_online_cpus(), bogosum/(500000/HZ), (bogosum/(5000/HZ))%100);
712 }
713 
714 static inline void set_cpu_sibling_map(int cpu)
715 {
716 	int i;
717 
718 	for_each_online_cpu(i) {
719 		if ((cpu_data(cpu)->socket_id == cpu_data(i)->socket_id)) {
720 			cpumask_set_cpu(i, &cpu_core_map[cpu]);
721 			cpumask_set_cpu(cpu, &cpu_core_map[i]);
722 			if (cpu_data(cpu)->core_id == cpu_data(i)->core_id) {
723 				cpumask_set_cpu(i,
724 						&per_cpu(cpu_sibling_map, cpu));
725 				cpumask_set_cpu(cpu,
726 						&per_cpu(cpu_sibling_map, i));
727 			}
728 		}
729 	}
730 }
731 
732 int
733 __cpu_up(unsigned int cpu, struct task_struct *tidle)
734 {
735 	int ret;
736 	int sapicid;
737 
738 	sapicid = ia64_cpu_to_sapicid[cpu];
739 	if (sapicid == -1)
740 		return -EINVAL;
741 
742 	/*
743 	 * Already booted cpu? not valid anymore since we dont
744 	 * do idle loop tightspin anymore.
745 	 */
746 	if (cpumask_test_cpu(cpu, &cpu_callin_map))
747 		return -EINVAL;
748 
749 	per_cpu(cpu_state, cpu) = CPU_UP_PREPARE;
750 	/* Processor goes to start_secondary(), sets online flag */
751 	ret = do_boot_cpu(sapicid, cpu, tidle);
752 	if (ret < 0)
753 		return ret;
754 
755 	if (cpu_data(cpu)->threads_per_core == 1 &&
756 	    cpu_data(cpu)->cores_per_socket == 1) {
757 		cpumask_set_cpu(cpu, &per_cpu(cpu_sibling_map, cpu));
758 		cpumask_set_cpu(cpu, &cpu_core_map[cpu]);
759 		return 0;
760 	}
761 
762 	set_cpu_sibling_map(cpu);
763 
764 	return 0;
765 }
766 
767 /*
768  * Assume that CPUs have been discovered by some platform-dependent interface.  For
769  * SoftSDV/Lion, that would be ACPI.
770  *
771  * Setup of the IPI irq handler is done in irq.c:init_IRQ_SMP().
772  */
773 void __init
774 init_smp_config(void)
775 {
776 	struct fptr {
777 		unsigned long fp;
778 		unsigned long gp;
779 	} *ap_startup;
780 	long sal_ret;
781 
782 	/* Tell SAL where to drop the APs.  */
783 	ap_startup = (struct fptr *) start_ap;
784 	sal_ret = ia64_sal_set_vectors(SAL_VECTOR_OS_BOOT_RENDEZ,
785 				       ia64_tpa(ap_startup->fp), ia64_tpa(ap_startup->gp), 0, 0, 0, 0);
786 	if (sal_ret < 0)
787 		printk(KERN_ERR "SMP: Can't set SAL AP Boot Rendezvous: %s\n",
788 		       ia64_sal_strerror(sal_ret));
789 }
790 
791 /*
792  * identify_siblings(cpu) gets called from identify_cpu. This populates the
793  * information related to logical execution units in per_cpu_data structure.
794  */
795 void identify_siblings(struct cpuinfo_ia64 *c)
796 {
797 	long status;
798 	u16 pltid;
799 	pal_logical_to_physical_t info;
800 
801 	status = ia64_pal_logical_to_phys(-1, &info);
802 	if (status != PAL_STATUS_SUCCESS) {
803 		if (status != PAL_STATUS_UNIMPLEMENTED) {
804 			printk(KERN_ERR
805 				"ia64_pal_logical_to_phys failed with %ld\n",
806 				status);
807 			return;
808 		}
809 
810 		info.overview_ppid = 0;
811 		info.overview_cpp  = 1;
812 		info.overview_tpc  = 1;
813 	}
814 
815 	status = ia64_sal_physical_id_info(&pltid);
816 	if (status != PAL_STATUS_SUCCESS) {
817 		if (status != PAL_STATUS_UNIMPLEMENTED)
818 			printk(KERN_ERR
819 				"ia64_sal_pltid failed with %ld\n",
820 				status);
821 		return;
822 	}
823 
824 	c->socket_id =  (pltid << 8) | info.overview_ppid;
825 
826 	if (info.overview_cpp == 1 && info.overview_tpc == 1)
827 		return;
828 
829 	c->cores_per_socket = info.overview_cpp;
830 	c->threads_per_core = info.overview_tpc;
831 	c->num_log = info.overview_num_log;
832 
833 	c->core_id = info.log1_cid;
834 	c->thread_id = info.log1_tid;
835 }
836 
837 /*
838  * returns non zero, if multi-threading is enabled
839  * on at least one physical package. Due to hotplug cpu
840  * and (maxcpus=), all threads may not necessarily be enabled
841  * even though the processor supports multi-threading.
842  */
843 int is_multithreading_enabled(void)
844 {
845 	int i, j;
846 
847 	for_each_present_cpu(i) {
848 		for_each_present_cpu(j) {
849 			if (j == i)
850 				continue;
851 			if ((cpu_data(j)->socket_id == cpu_data(i)->socket_id)) {
852 				if (cpu_data(j)->core_id == cpu_data(i)->core_id)
853 					return 1;
854 			}
855 		}
856 	}
857 	return 0;
858 }
859 EXPORT_SYMBOL_GPL(is_multithreading_enabled);
860