xref: /linux/arch/powerpc/kernel/smp.c (revision 0883c2c06fb5bcf5b9e008270827e63c09a88c1e)
1 /*
2  * SMP support for ppc.
3  *
4  * Written by Cort Dougan (cort@cs.nmt.edu) borrowing a great
5  * deal of code from the sparc and intel versions.
6  *
7  * Copyright (C) 1999 Cort Dougan <cort@cs.nmt.edu>
8  *
9  * PowerPC-64 Support added by Dave Engebretsen, Peter Bergner, and
10  * Mike Corrigan {engebret|bergner|mikec}@us.ibm.com
11  *
12  *      This program is free software; you can redistribute it and/or
13  *      modify it under the terms of the GNU General Public License
14  *      as published by the Free Software Foundation; either version
15  *      2 of the License, or (at your option) any later version.
16  */
17 
18 #undef DEBUG
19 
20 #include <linux/kernel.h>
21 #include <linux/export.h>
22 #include <linux/sched.h>
23 #include <linux/smp.h>
24 #include <linux/interrupt.h>
25 #include <linux/delay.h>
26 #include <linux/init.h>
27 #include <linux/spinlock.h>
28 #include <linux/cache.h>
29 #include <linux/err.h>
30 #include <linux/device.h>
31 #include <linux/cpu.h>
32 #include <linux/notifier.h>
33 #include <linux/topology.h>
34 #include <linux/profile.h>
35 
36 #include <asm/ptrace.h>
37 #include <linux/atomic.h>
38 #include <asm/irq.h>
39 #include <asm/hw_irq.h>
40 #include <asm/kvm_ppc.h>
41 #include <asm/page.h>
42 #include <asm/pgtable.h>
43 #include <asm/prom.h>
44 #include <asm/smp.h>
45 #include <asm/time.h>
46 #include <asm/machdep.h>
47 #include <asm/cputhreads.h>
48 #include <asm/cputable.h>
49 #include <asm/mpic.h>
50 #include <asm/vdso_datapage.h>
51 #ifdef CONFIG_PPC64
52 #include <asm/paca.h>
53 #endif
54 #include <asm/vdso.h>
55 #include <asm/debug.h>
56 #include <asm/kexec.h>
57 #include <asm/asm-prototypes.h>
58 
59 #ifdef DEBUG
60 #include <asm/udbg.h>
61 #define DBG(fmt...) udbg_printf(fmt)
62 #else
63 #define DBG(fmt...)
64 #endif
65 
66 #ifdef CONFIG_HOTPLUG_CPU
67 /* State of each CPU during hotplug phases */
68 static DEFINE_PER_CPU(int, cpu_state) = { 0 };
69 #endif
70 
71 struct thread_info *secondary_ti;
72 
73 DEFINE_PER_CPU(cpumask_var_t, cpu_sibling_map);
74 DEFINE_PER_CPU(cpumask_var_t, cpu_core_map);
75 
76 EXPORT_PER_CPU_SYMBOL(cpu_sibling_map);
77 EXPORT_PER_CPU_SYMBOL(cpu_core_map);
78 
79 /* SMP operations for this machine */
80 struct smp_ops_t *smp_ops;
81 
82 /* Can't be static due to PowerMac hackery */
83 volatile unsigned int cpu_callin_map[NR_CPUS];
84 
85 int smt_enabled_at_boot = 1;
86 
87 static void (*crash_ipi_function_ptr)(struct pt_regs *) = NULL;
88 
89 /*
90  * Returns 1 if the specified cpu should be brought up during boot.
91  * Used to inhibit booting threads if they've been disabled or
92  * limited on the command line
93  */
94 int smp_generic_cpu_bootable(unsigned int nr)
95 {
96 	/* Special case - we inhibit secondary thread startup
97 	 * during boot if the user requests it.
98 	 */
99 	if (system_state == SYSTEM_BOOTING && cpu_has_feature(CPU_FTR_SMT)) {
100 		if (!smt_enabled_at_boot && cpu_thread_in_core(nr) != 0)
101 			return 0;
102 		if (smt_enabled_at_boot
103 		    && cpu_thread_in_core(nr) >= smt_enabled_at_boot)
104 			return 0;
105 	}
106 
107 	return 1;
108 }
109 
110 
111 #ifdef CONFIG_PPC64
112 int smp_generic_kick_cpu(int nr)
113 {
114 	BUG_ON(nr < 0 || nr >= NR_CPUS);
115 
116 	/*
117 	 * The processor is currently spinning, waiting for the
118 	 * cpu_start field to become non-zero After we set cpu_start,
119 	 * the processor will continue on to secondary_start
120 	 */
121 	if (!paca[nr].cpu_start) {
122 		paca[nr].cpu_start = 1;
123 		smp_mb();
124 		return 0;
125 	}
126 
127 #ifdef CONFIG_HOTPLUG_CPU
128 	/*
129 	 * Ok it's not there, so it might be soft-unplugged, let's
130 	 * try to bring it back
131 	 */
132 	generic_set_cpu_up(nr);
133 	smp_wmb();
134 	smp_send_reschedule(nr);
135 #endif /* CONFIG_HOTPLUG_CPU */
136 
137 	return 0;
138 }
139 #endif /* CONFIG_PPC64 */
140 
141 static irqreturn_t call_function_action(int irq, void *data)
142 {
143 	generic_smp_call_function_interrupt();
144 	return IRQ_HANDLED;
145 }
146 
147 static irqreturn_t reschedule_action(int irq, void *data)
148 {
149 	scheduler_ipi();
150 	return IRQ_HANDLED;
151 }
152 
153 static irqreturn_t tick_broadcast_ipi_action(int irq, void *data)
154 {
155 	tick_broadcast_ipi_handler();
156 	return IRQ_HANDLED;
157 }
158 
159 static irqreturn_t debug_ipi_action(int irq, void *data)
160 {
161 	if (crash_ipi_function_ptr) {
162 		crash_ipi_function_ptr(get_irq_regs());
163 		return IRQ_HANDLED;
164 	}
165 
166 #ifdef CONFIG_DEBUGGER
167 	debugger_ipi(get_irq_regs());
168 #endif /* CONFIG_DEBUGGER */
169 
170 	return IRQ_HANDLED;
171 }
172 
173 static irq_handler_t smp_ipi_action[] = {
174 	[PPC_MSG_CALL_FUNCTION] =  call_function_action,
175 	[PPC_MSG_RESCHEDULE] = reschedule_action,
176 	[PPC_MSG_TICK_BROADCAST] = tick_broadcast_ipi_action,
177 	[PPC_MSG_DEBUGGER_BREAK] = debug_ipi_action,
178 };
179 
180 const char *smp_ipi_name[] = {
181 	[PPC_MSG_CALL_FUNCTION] =  "ipi call function",
182 	[PPC_MSG_RESCHEDULE] = "ipi reschedule",
183 	[PPC_MSG_TICK_BROADCAST] = "ipi tick-broadcast",
184 	[PPC_MSG_DEBUGGER_BREAK] = "ipi debugger",
185 };
186 
187 /* optional function to request ipi, for controllers with >= 4 ipis */
188 int smp_request_message_ipi(int virq, int msg)
189 {
190 	int err;
191 
192 	if (msg < 0 || msg > PPC_MSG_DEBUGGER_BREAK) {
193 		return -EINVAL;
194 	}
195 #if !defined(CONFIG_DEBUGGER) && !defined(CONFIG_KEXEC)
196 	if (msg == PPC_MSG_DEBUGGER_BREAK) {
197 		return 1;
198 	}
199 #endif
200 	err = request_irq(virq, smp_ipi_action[msg],
201 			  IRQF_PERCPU | IRQF_NO_THREAD | IRQF_NO_SUSPEND,
202 			  smp_ipi_name[msg], NULL);
203 	WARN(err < 0, "unable to request_irq %d for %s (rc %d)\n",
204 		virq, smp_ipi_name[msg], err);
205 
206 	return err;
207 }
208 
209 #ifdef CONFIG_PPC_SMP_MUXED_IPI
210 struct cpu_messages {
211 	long messages;			/* current messages */
212 	unsigned long data;		/* data for cause ipi */
213 };
214 static DEFINE_PER_CPU_SHARED_ALIGNED(struct cpu_messages, ipi_message);
215 
216 void smp_muxed_ipi_set_data(int cpu, unsigned long data)
217 {
218 	struct cpu_messages *info = &per_cpu(ipi_message, cpu);
219 
220 	info->data = data;
221 }
222 
223 void smp_muxed_ipi_set_message(int cpu, int msg)
224 {
225 	struct cpu_messages *info = &per_cpu(ipi_message, cpu);
226 	char *message = (char *)&info->messages;
227 
228 	/*
229 	 * Order previous accesses before accesses in the IPI handler.
230 	 */
231 	smp_mb();
232 	message[msg] = 1;
233 }
234 
235 void smp_muxed_ipi_message_pass(int cpu, int msg)
236 {
237 	struct cpu_messages *info = &per_cpu(ipi_message, cpu);
238 
239 	smp_muxed_ipi_set_message(cpu, msg);
240 	/*
241 	 * cause_ipi functions are required to include a full barrier
242 	 * before doing whatever causes the IPI.
243 	 */
244 	smp_ops->cause_ipi(cpu, info->data);
245 }
246 
247 #ifdef __BIG_ENDIAN__
248 #define IPI_MESSAGE(A) (1uL << ((BITS_PER_LONG - 8) - 8 * (A)))
249 #else
250 #define IPI_MESSAGE(A) (1uL << (8 * (A)))
251 #endif
252 
253 irqreturn_t smp_ipi_demux(void)
254 {
255 	struct cpu_messages *info = this_cpu_ptr(&ipi_message);
256 	unsigned long all;
257 
258 	mb();	/* order any irq clear */
259 
260 	do {
261 		all = xchg(&info->messages, 0);
262 #if defined(CONFIG_KVM_XICS) && defined(CONFIG_KVM_BOOK3S_HV_POSSIBLE)
263 		/*
264 		 * Must check for PPC_MSG_RM_HOST_ACTION messages
265 		 * before PPC_MSG_CALL_FUNCTION messages because when
266 		 * a VM is destroyed, we call kick_all_cpus_sync()
267 		 * to ensure that any pending PPC_MSG_RM_HOST_ACTION
268 		 * messages have completed before we free any VCPUs.
269 		 */
270 		if (all & IPI_MESSAGE(PPC_MSG_RM_HOST_ACTION))
271 			kvmppc_xics_ipi_action();
272 #endif
273 		if (all & IPI_MESSAGE(PPC_MSG_CALL_FUNCTION))
274 			generic_smp_call_function_interrupt();
275 		if (all & IPI_MESSAGE(PPC_MSG_RESCHEDULE))
276 			scheduler_ipi();
277 		if (all & IPI_MESSAGE(PPC_MSG_TICK_BROADCAST))
278 			tick_broadcast_ipi_handler();
279 		if (all & IPI_MESSAGE(PPC_MSG_DEBUGGER_BREAK))
280 			debug_ipi_action(0, NULL);
281 	} while (info->messages);
282 
283 	return IRQ_HANDLED;
284 }
285 #endif /* CONFIG_PPC_SMP_MUXED_IPI */
286 
287 static inline void do_message_pass(int cpu, int msg)
288 {
289 	if (smp_ops->message_pass)
290 		smp_ops->message_pass(cpu, msg);
291 #ifdef CONFIG_PPC_SMP_MUXED_IPI
292 	else
293 		smp_muxed_ipi_message_pass(cpu, msg);
294 #endif
295 }
296 
297 void smp_send_reschedule(int cpu)
298 {
299 	if (likely(smp_ops))
300 		do_message_pass(cpu, PPC_MSG_RESCHEDULE);
301 }
302 EXPORT_SYMBOL_GPL(smp_send_reschedule);
303 
304 void arch_send_call_function_single_ipi(int cpu)
305 {
306 	do_message_pass(cpu, PPC_MSG_CALL_FUNCTION);
307 }
308 
309 void arch_send_call_function_ipi_mask(const struct cpumask *mask)
310 {
311 	unsigned int cpu;
312 
313 	for_each_cpu(cpu, mask)
314 		do_message_pass(cpu, PPC_MSG_CALL_FUNCTION);
315 }
316 
317 #ifdef CONFIG_GENERIC_CLOCKEVENTS_BROADCAST
318 void tick_broadcast(const struct cpumask *mask)
319 {
320 	unsigned int cpu;
321 
322 	for_each_cpu(cpu, mask)
323 		do_message_pass(cpu, PPC_MSG_TICK_BROADCAST);
324 }
325 #endif
326 
327 #if defined(CONFIG_DEBUGGER) || defined(CONFIG_KEXEC)
328 void smp_send_debugger_break(void)
329 {
330 	int cpu;
331 	int me = raw_smp_processor_id();
332 
333 	if (unlikely(!smp_ops))
334 		return;
335 
336 	for_each_online_cpu(cpu)
337 		if (cpu != me)
338 			do_message_pass(cpu, PPC_MSG_DEBUGGER_BREAK);
339 }
340 #endif
341 
342 #ifdef CONFIG_KEXEC
343 void crash_send_ipi(void (*crash_ipi_callback)(struct pt_regs *))
344 {
345 	crash_ipi_function_ptr = crash_ipi_callback;
346 	if (crash_ipi_callback) {
347 		mb();
348 		smp_send_debugger_break();
349 	}
350 }
351 #endif
352 
353 static void stop_this_cpu(void *dummy)
354 {
355 	/* Remove this CPU */
356 	set_cpu_online(smp_processor_id(), false);
357 
358 	local_irq_disable();
359 	while (1)
360 		;
361 }
362 
363 void smp_send_stop(void)
364 {
365 	smp_call_function(stop_this_cpu, NULL, 0);
366 }
367 
368 struct thread_info *current_set[NR_CPUS];
369 
370 static void smp_store_cpu_info(int id)
371 {
372 	per_cpu(cpu_pvr, id) = mfspr(SPRN_PVR);
373 #ifdef CONFIG_PPC_FSL_BOOK3E
374 	per_cpu(next_tlbcam_idx, id)
375 		= (mfspr(SPRN_TLB1CFG) & TLBnCFG_N_ENTRY) - 1;
376 #endif
377 }
378 
379 void __init smp_prepare_cpus(unsigned int max_cpus)
380 {
381 	unsigned int cpu;
382 
383 	DBG("smp_prepare_cpus\n");
384 
385 	/*
386 	 * setup_cpu may need to be called on the boot cpu. We havent
387 	 * spun any cpus up but lets be paranoid.
388 	 */
389 	BUG_ON(boot_cpuid != smp_processor_id());
390 
391 	/* Fixup boot cpu */
392 	smp_store_cpu_info(boot_cpuid);
393 	cpu_callin_map[boot_cpuid] = 1;
394 
395 	for_each_possible_cpu(cpu) {
396 		zalloc_cpumask_var_node(&per_cpu(cpu_sibling_map, cpu),
397 					GFP_KERNEL, cpu_to_node(cpu));
398 		zalloc_cpumask_var_node(&per_cpu(cpu_core_map, cpu),
399 					GFP_KERNEL, cpu_to_node(cpu));
400 		/*
401 		 * numa_node_id() works after this.
402 		 */
403 		if (cpu_present(cpu)) {
404 			set_cpu_numa_node(cpu, numa_cpu_lookup_table[cpu]);
405 			set_cpu_numa_mem(cpu,
406 				local_memory_node(numa_cpu_lookup_table[cpu]));
407 		}
408 	}
409 
410 	cpumask_set_cpu(boot_cpuid, cpu_sibling_mask(boot_cpuid));
411 	cpumask_set_cpu(boot_cpuid, cpu_core_mask(boot_cpuid));
412 
413 	if (smp_ops && smp_ops->probe)
414 		smp_ops->probe();
415 }
416 
417 void smp_prepare_boot_cpu(void)
418 {
419 	BUG_ON(smp_processor_id() != boot_cpuid);
420 #ifdef CONFIG_PPC64
421 	paca[boot_cpuid].__current = current;
422 #endif
423 	set_numa_node(numa_cpu_lookup_table[boot_cpuid]);
424 	current_set[boot_cpuid] = task_thread_info(current);
425 }
426 
427 #ifdef CONFIG_HOTPLUG_CPU
428 
429 int generic_cpu_disable(void)
430 {
431 	unsigned int cpu = smp_processor_id();
432 
433 	if (cpu == boot_cpuid)
434 		return -EBUSY;
435 
436 	set_cpu_online(cpu, false);
437 #ifdef CONFIG_PPC64
438 	vdso_data->processorCount--;
439 #endif
440 	migrate_irqs();
441 	return 0;
442 }
443 
444 void generic_cpu_die(unsigned int cpu)
445 {
446 	int i;
447 
448 	for (i = 0; i < 100; i++) {
449 		smp_rmb();
450 		if (is_cpu_dead(cpu))
451 			return;
452 		msleep(100);
453 	}
454 	printk(KERN_ERR "CPU%d didn't die...\n", cpu);
455 }
456 
457 void generic_set_cpu_dead(unsigned int cpu)
458 {
459 	per_cpu(cpu_state, cpu) = CPU_DEAD;
460 }
461 
462 /*
463  * The cpu_state should be set to CPU_UP_PREPARE in kick_cpu(), otherwise
464  * the cpu_state is always CPU_DEAD after calling generic_set_cpu_dead(),
465  * which makes the delay in generic_cpu_die() not happen.
466  */
467 void generic_set_cpu_up(unsigned int cpu)
468 {
469 	per_cpu(cpu_state, cpu) = CPU_UP_PREPARE;
470 }
471 
472 int generic_check_cpu_restart(unsigned int cpu)
473 {
474 	return per_cpu(cpu_state, cpu) == CPU_UP_PREPARE;
475 }
476 
477 int is_cpu_dead(unsigned int cpu)
478 {
479 	return per_cpu(cpu_state, cpu) == CPU_DEAD;
480 }
481 
482 static bool secondaries_inhibited(void)
483 {
484 	return kvm_hv_mode_active();
485 }
486 
487 #else /* HOTPLUG_CPU */
488 
489 #define secondaries_inhibited()		0
490 
491 #endif
492 
493 static void cpu_idle_thread_init(unsigned int cpu, struct task_struct *idle)
494 {
495 	struct thread_info *ti = task_thread_info(idle);
496 
497 #ifdef CONFIG_PPC64
498 	paca[cpu].__current = idle;
499 	paca[cpu].kstack = (unsigned long)ti + THREAD_SIZE - STACK_FRAME_OVERHEAD;
500 #endif
501 	ti->cpu = cpu;
502 	secondary_ti = current_set[cpu] = ti;
503 }
504 
505 int __cpu_up(unsigned int cpu, struct task_struct *tidle)
506 {
507 	int rc, c;
508 
509 	/*
510 	 * Don't allow secondary threads to come online if inhibited
511 	 */
512 	if (threads_per_core > 1 && secondaries_inhibited() &&
513 	    cpu_thread_in_subcore(cpu))
514 		return -EBUSY;
515 
516 	if (smp_ops == NULL ||
517 	    (smp_ops->cpu_bootable && !smp_ops->cpu_bootable(cpu)))
518 		return -EINVAL;
519 
520 	cpu_idle_thread_init(cpu, tidle);
521 
522 	/* Make sure callin-map entry is 0 (can be leftover a CPU
523 	 * hotplug
524 	 */
525 	cpu_callin_map[cpu] = 0;
526 
527 	/* The information for processor bringup must
528 	 * be written out to main store before we release
529 	 * the processor.
530 	 */
531 	smp_mb();
532 
533 	/* wake up cpus */
534 	DBG("smp: kicking cpu %d\n", cpu);
535 	rc = smp_ops->kick_cpu(cpu);
536 	if (rc) {
537 		pr_err("smp: failed starting cpu %d (rc %d)\n", cpu, rc);
538 		return rc;
539 	}
540 
541 	/*
542 	 * wait to see if the cpu made a callin (is actually up).
543 	 * use this value that I found through experimentation.
544 	 * -- Cort
545 	 */
546 	if (system_state < SYSTEM_RUNNING)
547 		for (c = 50000; c && !cpu_callin_map[cpu]; c--)
548 			udelay(100);
549 #ifdef CONFIG_HOTPLUG_CPU
550 	else
551 		/*
552 		 * CPUs can take much longer to come up in the
553 		 * hotplug case.  Wait five seconds.
554 		 */
555 		for (c = 5000; c && !cpu_callin_map[cpu]; c--)
556 			msleep(1);
557 #endif
558 
559 	if (!cpu_callin_map[cpu]) {
560 		printk(KERN_ERR "Processor %u is stuck.\n", cpu);
561 		return -ENOENT;
562 	}
563 
564 	DBG("Processor %u found.\n", cpu);
565 
566 	if (smp_ops->give_timebase)
567 		smp_ops->give_timebase();
568 
569 	/* Wait until cpu puts itself in the online & active maps */
570 	while (!cpu_online(cpu))
571 		cpu_relax();
572 
573 	return 0;
574 }
575 
576 /* Return the value of the reg property corresponding to the given
577  * logical cpu.
578  */
579 int cpu_to_core_id(int cpu)
580 {
581 	struct device_node *np;
582 	const __be32 *reg;
583 	int id = -1;
584 
585 	np = of_get_cpu_node(cpu, NULL);
586 	if (!np)
587 		goto out;
588 
589 	reg = of_get_property(np, "reg", NULL);
590 	if (!reg)
591 		goto out;
592 
593 	id = be32_to_cpup(reg);
594 out:
595 	of_node_put(np);
596 	return id;
597 }
598 EXPORT_SYMBOL_GPL(cpu_to_core_id);
599 
600 /* Helper routines for cpu to core mapping */
601 int cpu_core_index_of_thread(int cpu)
602 {
603 	return cpu >> threads_shift;
604 }
605 EXPORT_SYMBOL_GPL(cpu_core_index_of_thread);
606 
607 int cpu_first_thread_of_core(int core)
608 {
609 	return core << threads_shift;
610 }
611 EXPORT_SYMBOL_GPL(cpu_first_thread_of_core);
612 
613 static void traverse_siblings_chip_id(int cpu, bool add, int chipid)
614 {
615 	const struct cpumask *mask;
616 	struct device_node *np;
617 	int i, plen;
618 	const __be32 *prop;
619 
620 	mask = add ? cpu_online_mask : cpu_present_mask;
621 	for_each_cpu(i, mask) {
622 		np = of_get_cpu_node(i, NULL);
623 		if (!np)
624 			continue;
625 		prop = of_get_property(np, "ibm,chip-id", &plen);
626 		if (prop && plen == sizeof(int) &&
627 		    of_read_number(prop, 1) == chipid) {
628 			if (add) {
629 				cpumask_set_cpu(cpu, cpu_core_mask(i));
630 				cpumask_set_cpu(i, cpu_core_mask(cpu));
631 			} else {
632 				cpumask_clear_cpu(cpu, cpu_core_mask(i));
633 				cpumask_clear_cpu(i, cpu_core_mask(cpu));
634 			}
635 		}
636 		of_node_put(np);
637 	}
638 }
639 
640 /* Must be called when no change can occur to cpu_present_mask,
641  * i.e. during cpu online or offline.
642  */
643 static struct device_node *cpu_to_l2cache(int cpu)
644 {
645 	struct device_node *np;
646 	struct device_node *cache;
647 
648 	if (!cpu_present(cpu))
649 		return NULL;
650 
651 	np = of_get_cpu_node(cpu, NULL);
652 	if (np == NULL)
653 		return NULL;
654 
655 	cache = of_find_next_cache_node(np);
656 
657 	of_node_put(np);
658 
659 	return cache;
660 }
661 
662 static void traverse_core_siblings(int cpu, bool add)
663 {
664 	struct device_node *l2_cache, *np;
665 	const struct cpumask *mask;
666 	int i, chip, plen;
667 	const __be32 *prop;
668 
669 	/* First see if we have ibm,chip-id properties in cpu nodes */
670 	np = of_get_cpu_node(cpu, NULL);
671 	if (np) {
672 		chip = -1;
673 		prop = of_get_property(np, "ibm,chip-id", &plen);
674 		if (prop && plen == sizeof(int))
675 			chip = of_read_number(prop, 1);
676 		of_node_put(np);
677 		if (chip >= 0) {
678 			traverse_siblings_chip_id(cpu, add, chip);
679 			return;
680 		}
681 	}
682 
683 	l2_cache = cpu_to_l2cache(cpu);
684 	mask = add ? cpu_online_mask : cpu_present_mask;
685 	for_each_cpu(i, mask) {
686 		np = cpu_to_l2cache(i);
687 		if (!np)
688 			continue;
689 		if (np == l2_cache) {
690 			if (add) {
691 				cpumask_set_cpu(cpu, cpu_core_mask(i));
692 				cpumask_set_cpu(i, cpu_core_mask(cpu));
693 			} else {
694 				cpumask_clear_cpu(cpu, cpu_core_mask(i));
695 				cpumask_clear_cpu(i, cpu_core_mask(cpu));
696 			}
697 		}
698 		of_node_put(np);
699 	}
700 	of_node_put(l2_cache);
701 }
702 
703 /* Activate a secondary processor. */
704 void start_secondary(void *unused)
705 {
706 	unsigned int cpu = smp_processor_id();
707 	int i, base;
708 
709 	atomic_inc(&init_mm.mm_count);
710 	current->active_mm = &init_mm;
711 
712 	smp_store_cpu_info(cpu);
713 	set_dec(tb_ticks_per_jiffy);
714 	preempt_disable();
715 	cpu_callin_map[cpu] = 1;
716 
717 	if (smp_ops->setup_cpu)
718 		smp_ops->setup_cpu(cpu);
719 	if (smp_ops->take_timebase)
720 		smp_ops->take_timebase();
721 
722 	secondary_cpu_time_init();
723 
724 #ifdef CONFIG_PPC64
725 	if (system_state == SYSTEM_RUNNING)
726 		vdso_data->processorCount++;
727 
728 	vdso_getcpu_init();
729 #endif
730 	/* Update sibling maps */
731 	base = cpu_first_thread_sibling(cpu);
732 	for (i = 0; i < threads_per_core; i++) {
733 		if (cpu_is_offline(base + i) && (cpu != base + i))
734 			continue;
735 		cpumask_set_cpu(cpu, cpu_sibling_mask(base + i));
736 		cpumask_set_cpu(base + i, cpu_sibling_mask(cpu));
737 
738 		/* cpu_core_map should be a superset of
739 		 * cpu_sibling_map even if we don't have cache
740 		 * information, so update the former here, too.
741 		 */
742 		cpumask_set_cpu(cpu, cpu_core_mask(base + i));
743 		cpumask_set_cpu(base + i, cpu_core_mask(cpu));
744 	}
745 	traverse_core_siblings(cpu, true);
746 
747 	set_numa_node(numa_cpu_lookup_table[cpu]);
748 	set_numa_mem(local_memory_node(numa_cpu_lookup_table[cpu]));
749 
750 	smp_wmb();
751 	notify_cpu_starting(cpu);
752 	set_cpu_online(cpu, true);
753 
754 	local_irq_enable();
755 
756 	cpu_startup_entry(CPUHP_AP_ONLINE_IDLE);
757 
758 	BUG();
759 }
760 
761 int setup_profiling_timer(unsigned int multiplier)
762 {
763 	return 0;
764 }
765 
766 #ifdef CONFIG_SCHED_SMT
767 /* cpumask of CPUs with asymetric SMT dependancy */
768 static int powerpc_smt_flags(void)
769 {
770 	int flags = SD_SHARE_CPUCAPACITY | SD_SHARE_PKG_RESOURCES;
771 
772 	if (cpu_has_feature(CPU_FTR_ASYM_SMT)) {
773 		printk_once(KERN_INFO "Enabling Asymmetric SMT scheduling\n");
774 		flags |= SD_ASYM_PACKING;
775 	}
776 	return flags;
777 }
778 #endif
779 
780 static struct sched_domain_topology_level powerpc_topology[] = {
781 #ifdef CONFIG_SCHED_SMT
782 	{ cpu_smt_mask, powerpc_smt_flags, SD_INIT_NAME(SMT) },
783 #endif
784 	{ cpu_cpu_mask, SD_INIT_NAME(DIE) },
785 	{ NULL, },
786 };
787 
788 void __init smp_cpus_done(unsigned int max_cpus)
789 {
790 	cpumask_var_t old_mask;
791 
792 	/* We want the setup_cpu() here to be called from CPU 0, but our
793 	 * init thread may have been "borrowed" by another CPU in the meantime
794 	 * se we pin us down to CPU 0 for a short while
795 	 */
796 	alloc_cpumask_var(&old_mask, GFP_NOWAIT);
797 	cpumask_copy(old_mask, tsk_cpus_allowed(current));
798 	set_cpus_allowed_ptr(current, cpumask_of(boot_cpuid));
799 
800 	if (smp_ops && smp_ops->setup_cpu)
801 		smp_ops->setup_cpu(boot_cpuid);
802 
803 	set_cpus_allowed_ptr(current, old_mask);
804 
805 	free_cpumask_var(old_mask);
806 
807 	if (smp_ops && smp_ops->bringup_done)
808 		smp_ops->bringup_done();
809 
810 	dump_numa_cpu_topology();
811 
812 	set_sched_topology(powerpc_topology);
813 
814 }
815 
816 #ifdef CONFIG_HOTPLUG_CPU
817 int __cpu_disable(void)
818 {
819 	int cpu = smp_processor_id();
820 	int base, i;
821 	int err;
822 
823 	if (!smp_ops->cpu_disable)
824 		return -ENOSYS;
825 
826 	err = smp_ops->cpu_disable();
827 	if (err)
828 		return err;
829 
830 	/* Update sibling maps */
831 	base = cpu_first_thread_sibling(cpu);
832 	for (i = 0; i < threads_per_core; i++) {
833 		cpumask_clear_cpu(cpu, cpu_sibling_mask(base + i));
834 		cpumask_clear_cpu(base + i, cpu_sibling_mask(cpu));
835 		cpumask_clear_cpu(cpu, cpu_core_mask(base + i));
836 		cpumask_clear_cpu(base + i, cpu_core_mask(cpu));
837 	}
838 	traverse_core_siblings(cpu, false);
839 
840 	return 0;
841 }
842 
843 void __cpu_die(unsigned int cpu)
844 {
845 	if (smp_ops->cpu_die)
846 		smp_ops->cpu_die(cpu);
847 }
848 
849 void cpu_die(void)
850 {
851 	if (ppc_md.cpu_die)
852 		ppc_md.cpu_die();
853 
854 	/* If we return, we re-enter start_secondary */
855 	start_secondary_resume();
856 }
857 
858 #endif
859