xref: /openbmc/linux/arch/powerpc/kernel/smp.c (revision e5c86679)
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/mm.h>
23 #include <linux/sched/topology.h>
24 #include <linux/smp.h>
25 #include <linux/interrupt.h>
26 #include <linux/delay.h>
27 #include <linux/init.h>
28 #include <linux/spinlock.h>
29 #include <linux/cache.h>
30 #include <linux/err.h>
31 #include <linux/device.h>
32 #include <linux/cpu.h>
33 #include <linux/notifier.h>
34 #include <linux/topology.h>
35 #include <linux/profile.h>
36 
37 #include <asm/ptrace.h>
38 #include <linux/atomic.h>
39 #include <asm/irq.h>
40 #include <asm/hw_irq.h>
41 #include <asm/kvm_ppc.h>
42 #include <asm/page.h>
43 #include <asm/pgtable.h>
44 #include <asm/prom.h>
45 #include <asm/smp.h>
46 #include <asm/time.h>
47 #include <asm/machdep.h>
48 #include <asm/cputhreads.h>
49 #include <asm/cputable.h>
50 #include <asm/mpic.h>
51 #include <asm/vdso_datapage.h>
52 #ifdef CONFIG_PPC64
53 #include <asm/paca.h>
54 #endif
55 #include <asm/vdso.h>
56 #include <asm/debug.h>
57 #include <asm/kexec.h>
58 #include <asm/asm-prototypes.h>
59 #include <asm/cpu_has_feature.h>
60 
61 #ifdef DEBUG
62 #include <asm/udbg.h>
63 #define DBG(fmt...) udbg_printf(fmt)
64 #else
65 #define DBG(fmt...)
66 #endif
67 
68 #ifdef CONFIG_HOTPLUG_CPU
69 /* State of each CPU during hotplug phases */
70 static DEFINE_PER_CPU(int, cpu_state) = { 0 };
71 #endif
72 
73 struct thread_info *secondary_ti;
74 
75 DEFINE_PER_CPU(cpumask_var_t, cpu_sibling_map);
76 DEFINE_PER_CPU(cpumask_var_t, cpu_core_map);
77 
78 EXPORT_PER_CPU_SYMBOL(cpu_sibling_map);
79 EXPORT_PER_CPU_SYMBOL(cpu_core_map);
80 
81 /* SMP operations for this machine */
82 struct smp_ops_t *smp_ops;
83 
84 /* Can't be static due to PowerMac hackery */
85 volatile unsigned int cpu_callin_map[NR_CPUS];
86 
87 int smt_enabled_at_boot = 1;
88 
89 static void (*crash_ipi_function_ptr)(struct pt_regs *) = NULL;
90 
91 /*
92  * Returns 1 if the specified cpu should be brought up during boot.
93  * Used to inhibit booting threads if they've been disabled or
94  * limited on the command line
95  */
96 int smp_generic_cpu_bootable(unsigned int nr)
97 {
98 	/* Special case - we inhibit secondary thread startup
99 	 * during boot if the user requests it.
100 	 */
101 	if (system_state == SYSTEM_BOOTING && cpu_has_feature(CPU_FTR_SMT)) {
102 		if (!smt_enabled_at_boot && cpu_thread_in_core(nr) != 0)
103 			return 0;
104 		if (smt_enabled_at_boot
105 		    && cpu_thread_in_core(nr) >= smt_enabled_at_boot)
106 			return 0;
107 	}
108 
109 	return 1;
110 }
111 
112 
113 #ifdef CONFIG_PPC64
114 int smp_generic_kick_cpu(int nr)
115 {
116 	BUG_ON(nr < 0 || nr >= NR_CPUS);
117 
118 	/*
119 	 * The processor is currently spinning, waiting for the
120 	 * cpu_start field to become non-zero After we set cpu_start,
121 	 * the processor will continue on to secondary_start
122 	 */
123 	if (!paca[nr].cpu_start) {
124 		paca[nr].cpu_start = 1;
125 		smp_mb();
126 		return 0;
127 	}
128 
129 #ifdef CONFIG_HOTPLUG_CPU
130 	/*
131 	 * Ok it's not there, so it might be soft-unplugged, let's
132 	 * try to bring it back
133 	 */
134 	generic_set_cpu_up(nr);
135 	smp_wmb();
136 	smp_send_reschedule(nr);
137 #endif /* CONFIG_HOTPLUG_CPU */
138 
139 	return 0;
140 }
141 #endif /* CONFIG_PPC64 */
142 
143 static irqreturn_t call_function_action(int irq, void *data)
144 {
145 	generic_smp_call_function_interrupt();
146 	return IRQ_HANDLED;
147 }
148 
149 static irqreturn_t reschedule_action(int irq, void *data)
150 {
151 	scheduler_ipi();
152 	return IRQ_HANDLED;
153 }
154 
155 static irqreturn_t tick_broadcast_ipi_action(int irq, void *data)
156 {
157 	tick_broadcast_ipi_handler();
158 	return IRQ_HANDLED;
159 }
160 
161 static irqreturn_t debug_ipi_action(int irq, void *data)
162 {
163 	if (crash_ipi_function_ptr) {
164 		crash_ipi_function_ptr(get_irq_regs());
165 		return IRQ_HANDLED;
166 	}
167 
168 #ifdef CONFIG_DEBUGGER
169 	debugger_ipi(get_irq_regs());
170 #endif /* CONFIG_DEBUGGER */
171 
172 	return IRQ_HANDLED;
173 }
174 
175 static irq_handler_t smp_ipi_action[] = {
176 	[PPC_MSG_CALL_FUNCTION] =  call_function_action,
177 	[PPC_MSG_RESCHEDULE] = reschedule_action,
178 	[PPC_MSG_TICK_BROADCAST] = tick_broadcast_ipi_action,
179 	[PPC_MSG_DEBUGGER_BREAK] = debug_ipi_action,
180 };
181 
182 const char *smp_ipi_name[] = {
183 	[PPC_MSG_CALL_FUNCTION] =  "ipi call function",
184 	[PPC_MSG_RESCHEDULE] = "ipi reschedule",
185 	[PPC_MSG_TICK_BROADCAST] = "ipi tick-broadcast",
186 	[PPC_MSG_DEBUGGER_BREAK] = "ipi debugger",
187 };
188 
189 /* optional function to request ipi, for controllers with >= 4 ipis */
190 int smp_request_message_ipi(int virq, int msg)
191 {
192 	int err;
193 
194 	if (msg < 0 || msg > PPC_MSG_DEBUGGER_BREAK) {
195 		return -EINVAL;
196 	}
197 #if !defined(CONFIG_DEBUGGER) && !defined(CONFIG_KEXEC_CORE)
198 	if (msg == PPC_MSG_DEBUGGER_BREAK) {
199 		return 1;
200 	}
201 #endif
202 	err = request_irq(virq, smp_ipi_action[msg],
203 			  IRQF_PERCPU | IRQF_NO_THREAD | IRQF_NO_SUSPEND,
204 			  smp_ipi_name[msg], NULL);
205 	WARN(err < 0, "unable to request_irq %d for %s (rc %d)\n",
206 		virq, smp_ipi_name[msg], err);
207 
208 	return err;
209 }
210 
211 #ifdef CONFIG_PPC_SMP_MUXED_IPI
212 struct cpu_messages {
213 	long messages;			/* current messages */
214 	unsigned long data;		/* data for cause ipi */
215 };
216 static DEFINE_PER_CPU_SHARED_ALIGNED(struct cpu_messages, ipi_message);
217 
218 void smp_muxed_ipi_set_data(int cpu, unsigned long data)
219 {
220 	struct cpu_messages *info = &per_cpu(ipi_message, cpu);
221 
222 	info->data = data;
223 }
224 
225 void smp_muxed_ipi_set_message(int cpu, int msg)
226 {
227 	struct cpu_messages *info = &per_cpu(ipi_message, cpu);
228 	char *message = (char *)&info->messages;
229 
230 	/*
231 	 * Order previous accesses before accesses in the IPI handler.
232 	 */
233 	smp_mb();
234 	message[msg] = 1;
235 }
236 
237 void smp_muxed_ipi_message_pass(int cpu, int msg)
238 {
239 	struct cpu_messages *info = &per_cpu(ipi_message, cpu);
240 
241 	smp_muxed_ipi_set_message(cpu, msg);
242 	/*
243 	 * cause_ipi functions are required to include a full barrier
244 	 * before doing whatever causes the IPI.
245 	 */
246 	smp_ops->cause_ipi(cpu, info->data);
247 }
248 
249 #ifdef __BIG_ENDIAN__
250 #define IPI_MESSAGE(A) (1uL << ((BITS_PER_LONG - 8) - 8 * (A)))
251 #else
252 #define IPI_MESSAGE(A) (1uL << (8 * (A)))
253 #endif
254 
255 irqreturn_t smp_ipi_demux(void)
256 {
257 	struct cpu_messages *info = this_cpu_ptr(&ipi_message);
258 	unsigned long all;
259 
260 	mb();	/* order any irq clear */
261 
262 	do {
263 		all = xchg(&info->messages, 0);
264 #if defined(CONFIG_KVM_XICS) && defined(CONFIG_KVM_BOOK3S_HV_POSSIBLE)
265 		/*
266 		 * Must check for PPC_MSG_RM_HOST_ACTION messages
267 		 * before PPC_MSG_CALL_FUNCTION messages because when
268 		 * a VM is destroyed, we call kick_all_cpus_sync()
269 		 * to ensure that any pending PPC_MSG_RM_HOST_ACTION
270 		 * messages have completed before we free any VCPUs.
271 		 */
272 		if (all & IPI_MESSAGE(PPC_MSG_RM_HOST_ACTION))
273 			kvmppc_xics_ipi_action();
274 #endif
275 		if (all & IPI_MESSAGE(PPC_MSG_CALL_FUNCTION))
276 			generic_smp_call_function_interrupt();
277 		if (all & IPI_MESSAGE(PPC_MSG_RESCHEDULE))
278 			scheduler_ipi();
279 		if (all & IPI_MESSAGE(PPC_MSG_TICK_BROADCAST))
280 			tick_broadcast_ipi_handler();
281 		if (all & IPI_MESSAGE(PPC_MSG_DEBUGGER_BREAK))
282 			debug_ipi_action(0, NULL);
283 	} while (info->messages);
284 
285 	return IRQ_HANDLED;
286 }
287 #endif /* CONFIG_PPC_SMP_MUXED_IPI */
288 
289 static inline void do_message_pass(int cpu, int msg)
290 {
291 	if (smp_ops->message_pass)
292 		smp_ops->message_pass(cpu, msg);
293 #ifdef CONFIG_PPC_SMP_MUXED_IPI
294 	else
295 		smp_muxed_ipi_message_pass(cpu, msg);
296 #endif
297 }
298 
299 void smp_send_reschedule(int cpu)
300 {
301 	if (likely(smp_ops))
302 		do_message_pass(cpu, PPC_MSG_RESCHEDULE);
303 }
304 EXPORT_SYMBOL_GPL(smp_send_reschedule);
305 
306 void arch_send_call_function_single_ipi(int cpu)
307 {
308 	do_message_pass(cpu, PPC_MSG_CALL_FUNCTION);
309 }
310 
311 void arch_send_call_function_ipi_mask(const struct cpumask *mask)
312 {
313 	unsigned int cpu;
314 
315 	for_each_cpu(cpu, mask)
316 		do_message_pass(cpu, PPC_MSG_CALL_FUNCTION);
317 }
318 
319 #ifdef CONFIG_GENERIC_CLOCKEVENTS_BROADCAST
320 void tick_broadcast(const struct cpumask *mask)
321 {
322 	unsigned int cpu;
323 
324 	for_each_cpu(cpu, mask)
325 		do_message_pass(cpu, PPC_MSG_TICK_BROADCAST);
326 }
327 #endif
328 
329 #if defined(CONFIG_DEBUGGER) || defined(CONFIG_KEXEC_CORE)
330 void smp_send_debugger_break(void)
331 {
332 	int cpu;
333 	int me = raw_smp_processor_id();
334 
335 	if (unlikely(!smp_ops))
336 		return;
337 
338 	for_each_online_cpu(cpu)
339 		if (cpu != me)
340 			do_message_pass(cpu, PPC_MSG_DEBUGGER_BREAK);
341 }
342 #endif
343 
344 #ifdef CONFIG_KEXEC_CORE
345 void crash_send_ipi(void (*crash_ipi_callback)(struct pt_regs *))
346 {
347 	crash_ipi_function_ptr = crash_ipi_callback;
348 	if (crash_ipi_callback) {
349 		mb();
350 		smp_send_debugger_break();
351 	}
352 }
353 #endif
354 
355 static void stop_this_cpu(void *dummy)
356 {
357 	/* Remove this CPU */
358 	set_cpu_online(smp_processor_id(), false);
359 
360 	local_irq_disable();
361 	while (1)
362 		;
363 }
364 
365 void smp_send_stop(void)
366 {
367 	smp_call_function(stop_this_cpu, NULL, 0);
368 }
369 
370 struct thread_info *current_set[NR_CPUS];
371 
372 static void smp_store_cpu_info(int id)
373 {
374 	per_cpu(cpu_pvr, id) = mfspr(SPRN_PVR);
375 #ifdef CONFIG_PPC_FSL_BOOK3E
376 	per_cpu(next_tlbcam_idx, id)
377 		= (mfspr(SPRN_TLB1CFG) & TLBnCFG_N_ENTRY) - 1;
378 #endif
379 }
380 
381 void __init smp_prepare_cpus(unsigned int max_cpus)
382 {
383 	unsigned int cpu;
384 
385 	DBG("smp_prepare_cpus\n");
386 
387 	/*
388 	 * setup_cpu may need to be called on the boot cpu. We havent
389 	 * spun any cpus up but lets be paranoid.
390 	 */
391 	BUG_ON(boot_cpuid != smp_processor_id());
392 
393 	/* Fixup boot cpu */
394 	smp_store_cpu_info(boot_cpuid);
395 	cpu_callin_map[boot_cpuid] = 1;
396 
397 	for_each_possible_cpu(cpu) {
398 		zalloc_cpumask_var_node(&per_cpu(cpu_sibling_map, cpu),
399 					GFP_KERNEL, cpu_to_node(cpu));
400 		zalloc_cpumask_var_node(&per_cpu(cpu_core_map, cpu),
401 					GFP_KERNEL, cpu_to_node(cpu));
402 		/*
403 		 * numa_node_id() works after this.
404 		 */
405 		if (cpu_present(cpu)) {
406 			set_cpu_numa_node(cpu, numa_cpu_lookup_table[cpu]);
407 			set_cpu_numa_mem(cpu,
408 				local_memory_node(numa_cpu_lookup_table[cpu]));
409 		}
410 	}
411 
412 	cpumask_set_cpu(boot_cpuid, cpu_sibling_mask(boot_cpuid));
413 	cpumask_set_cpu(boot_cpuid, cpu_core_mask(boot_cpuid));
414 
415 	if (smp_ops && smp_ops->probe)
416 		smp_ops->probe();
417 }
418 
419 void smp_prepare_boot_cpu(void)
420 {
421 	BUG_ON(smp_processor_id() != boot_cpuid);
422 #ifdef CONFIG_PPC64
423 	paca[boot_cpuid].__current = current;
424 #endif
425 	set_numa_node(numa_cpu_lookup_table[boot_cpuid]);
426 	current_set[boot_cpuid] = task_thread_info(current);
427 }
428 
429 #ifdef CONFIG_HOTPLUG_CPU
430 
431 int generic_cpu_disable(void)
432 {
433 	unsigned int cpu = smp_processor_id();
434 
435 	if (cpu == boot_cpuid)
436 		return -EBUSY;
437 
438 	set_cpu_online(cpu, false);
439 #ifdef CONFIG_PPC64
440 	vdso_data->processorCount--;
441 #endif
442 	migrate_irqs();
443 	return 0;
444 }
445 
446 void generic_cpu_die(unsigned int cpu)
447 {
448 	int i;
449 
450 	for (i = 0; i < 100; i++) {
451 		smp_rmb();
452 		if (is_cpu_dead(cpu))
453 			return;
454 		msleep(100);
455 	}
456 	printk(KERN_ERR "CPU%d didn't die...\n", cpu);
457 }
458 
459 void generic_set_cpu_dead(unsigned int cpu)
460 {
461 	per_cpu(cpu_state, cpu) = CPU_DEAD;
462 }
463 
464 /*
465  * The cpu_state should be set to CPU_UP_PREPARE in kick_cpu(), otherwise
466  * the cpu_state is always CPU_DEAD after calling generic_set_cpu_dead(),
467  * which makes the delay in generic_cpu_die() not happen.
468  */
469 void generic_set_cpu_up(unsigned int cpu)
470 {
471 	per_cpu(cpu_state, cpu) = CPU_UP_PREPARE;
472 }
473 
474 int generic_check_cpu_restart(unsigned int cpu)
475 {
476 	return per_cpu(cpu_state, cpu) == CPU_UP_PREPARE;
477 }
478 
479 int is_cpu_dead(unsigned int cpu)
480 {
481 	return per_cpu(cpu_state, cpu) == CPU_DEAD;
482 }
483 
484 static bool secondaries_inhibited(void)
485 {
486 	return kvm_hv_mode_active();
487 }
488 
489 #else /* HOTPLUG_CPU */
490 
491 #define secondaries_inhibited()		0
492 
493 #endif
494 
495 static void cpu_idle_thread_init(unsigned int cpu, struct task_struct *idle)
496 {
497 	struct thread_info *ti = task_thread_info(idle);
498 
499 #ifdef CONFIG_PPC64
500 	paca[cpu].__current = idle;
501 	paca[cpu].kstack = (unsigned long)ti + THREAD_SIZE - STACK_FRAME_OVERHEAD;
502 #endif
503 	ti->cpu = cpu;
504 	secondary_ti = current_set[cpu] = ti;
505 }
506 
507 int __cpu_up(unsigned int cpu, struct task_struct *tidle)
508 {
509 	int rc, c;
510 
511 	/*
512 	 * Don't allow secondary threads to come online if inhibited
513 	 */
514 	if (threads_per_core > 1 && secondaries_inhibited() &&
515 	    cpu_thread_in_subcore(cpu))
516 		return -EBUSY;
517 
518 	if (smp_ops == NULL ||
519 	    (smp_ops->cpu_bootable && !smp_ops->cpu_bootable(cpu)))
520 		return -EINVAL;
521 
522 	cpu_idle_thread_init(cpu, tidle);
523 
524 	/* Make sure callin-map entry is 0 (can be leftover a CPU
525 	 * hotplug
526 	 */
527 	cpu_callin_map[cpu] = 0;
528 
529 	/* The information for processor bringup must
530 	 * be written out to main store before we release
531 	 * the processor.
532 	 */
533 	smp_mb();
534 
535 	/* wake up cpus */
536 	DBG("smp: kicking cpu %d\n", cpu);
537 	rc = smp_ops->kick_cpu(cpu);
538 	if (rc) {
539 		pr_err("smp: failed starting cpu %d (rc %d)\n", cpu, rc);
540 		return rc;
541 	}
542 
543 	/*
544 	 * wait to see if the cpu made a callin (is actually up).
545 	 * use this value that I found through experimentation.
546 	 * -- Cort
547 	 */
548 	if (system_state < SYSTEM_RUNNING)
549 		for (c = 50000; c && !cpu_callin_map[cpu]; c--)
550 			udelay(100);
551 #ifdef CONFIG_HOTPLUG_CPU
552 	else
553 		/*
554 		 * CPUs can take much longer to come up in the
555 		 * hotplug case.  Wait five seconds.
556 		 */
557 		for (c = 5000; c && !cpu_callin_map[cpu]; c--)
558 			msleep(1);
559 #endif
560 
561 	if (!cpu_callin_map[cpu]) {
562 		printk(KERN_ERR "Processor %u is stuck.\n", cpu);
563 		return -ENOENT;
564 	}
565 
566 	DBG("Processor %u found.\n", cpu);
567 
568 	if (smp_ops->give_timebase)
569 		smp_ops->give_timebase();
570 
571 	/* Wait until cpu puts itself in the online & active maps */
572 	while (!cpu_online(cpu))
573 		cpu_relax();
574 
575 	return 0;
576 }
577 
578 /* Return the value of the reg property corresponding to the given
579  * logical cpu.
580  */
581 int cpu_to_core_id(int cpu)
582 {
583 	struct device_node *np;
584 	const __be32 *reg;
585 	int id = -1;
586 
587 	np = of_get_cpu_node(cpu, NULL);
588 	if (!np)
589 		goto out;
590 
591 	reg = of_get_property(np, "reg", NULL);
592 	if (!reg)
593 		goto out;
594 
595 	id = be32_to_cpup(reg);
596 out:
597 	of_node_put(np);
598 	return id;
599 }
600 EXPORT_SYMBOL_GPL(cpu_to_core_id);
601 
602 /* Helper routines for cpu to core mapping */
603 int cpu_core_index_of_thread(int cpu)
604 {
605 	return cpu >> threads_shift;
606 }
607 EXPORT_SYMBOL_GPL(cpu_core_index_of_thread);
608 
609 int cpu_first_thread_of_core(int core)
610 {
611 	return core << threads_shift;
612 }
613 EXPORT_SYMBOL_GPL(cpu_first_thread_of_core);
614 
615 static void traverse_siblings_chip_id(int cpu, bool add, int chipid)
616 {
617 	const struct cpumask *mask;
618 	struct device_node *np;
619 	int i, plen;
620 	const __be32 *prop;
621 
622 	mask = add ? cpu_online_mask : cpu_present_mask;
623 	for_each_cpu(i, mask) {
624 		np = of_get_cpu_node(i, NULL);
625 		if (!np)
626 			continue;
627 		prop = of_get_property(np, "ibm,chip-id", &plen);
628 		if (prop && plen == sizeof(int) &&
629 		    of_read_number(prop, 1) == chipid) {
630 			if (add) {
631 				cpumask_set_cpu(cpu, cpu_core_mask(i));
632 				cpumask_set_cpu(i, cpu_core_mask(cpu));
633 			} else {
634 				cpumask_clear_cpu(cpu, cpu_core_mask(i));
635 				cpumask_clear_cpu(i, cpu_core_mask(cpu));
636 			}
637 		}
638 		of_node_put(np);
639 	}
640 }
641 
642 /* Must be called when no change can occur to cpu_present_mask,
643  * i.e. during cpu online or offline.
644  */
645 static struct device_node *cpu_to_l2cache(int cpu)
646 {
647 	struct device_node *np;
648 	struct device_node *cache;
649 
650 	if (!cpu_present(cpu))
651 		return NULL;
652 
653 	np = of_get_cpu_node(cpu, NULL);
654 	if (np == NULL)
655 		return NULL;
656 
657 	cache = of_find_next_cache_node(np);
658 
659 	of_node_put(np);
660 
661 	return cache;
662 }
663 
664 static void traverse_core_siblings(int cpu, bool add)
665 {
666 	struct device_node *l2_cache, *np;
667 	const struct cpumask *mask;
668 	int i, chip, plen;
669 	const __be32 *prop;
670 
671 	/* First see if we have ibm,chip-id properties in cpu nodes */
672 	np = of_get_cpu_node(cpu, NULL);
673 	if (np) {
674 		chip = -1;
675 		prop = of_get_property(np, "ibm,chip-id", &plen);
676 		if (prop && plen == sizeof(int))
677 			chip = of_read_number(prop, 1);
678 		of_node_put(np);
679 		if (chip >= 0) {
680 			traverse_siblings_chip_id(cpu, add, chip);
681 			return;
682 		}
683 	}
684 
685 	l2_cache = cpu_to_l2cache(cpu);
686 	mask = add ? cpu_online_mask : cpu_present_mask;
687 	for_each_cpu(i, mask) {
688 		np = cpu_to_l2cache(i);
689 		if (!np)
690 			continue;
691 		if (np == l2_cache) {
692 			if (add) {
693 				cpumask_set_cpu(cpu, cpu_core_mask(i));
694 				cpumask_set_cpu(i, cpu_core_mask(cpu));
695 			} else {
696 				cpumask_clear_cpu(cpu, cpu_core_mask(i));
697 				cpumask_clear_cpu(i, cpu_core_mask(cpu));
698 			}
699 		}
700 		of_node_put(np);
701 	}
702 	of_node_put(l2_cache);
703 }
704 
705 /* Activate a secondary processor. */
706 void start_secondary(void *unused)
707 {
708 	unsigned int cpu = smp_processor_id();
709 	int i, base;
710 
711 	mmgrab(&init_mm);
712 	current->active_mm = &init_mm;
713 
714 	smp_store_cpu_info(cpu);
715 	set_dec(tb_ticks_per_jiffy);
716 	preempt_disable();
717 	cpu_callin_map[cpu] = 1;
718 
719 	if (smp_ops->setup_cpu)
720 		smp_ops->setup_cpu(cpu);
721 	if (smp_ops->take_timebase)
722 		smp_ops->take_timebase();
723 
724 	secondary_cpu_time_init();
725 
726 #ifdef CONFIG_PPC64
727 	if (system_state == SYSTEM_RUNNING)
728 		vdso_data->processorCount++;
729 
730 	vdso_getcpu_init();
731 #endif
732 	/* Update sibling maps */
733 	base = cpu_first_thread_sibling(cpu);
734 	for (i = 0; i < threads_per_core; i++) {
735 		if (cpu_is_offline(base + i) && (cpu != base + i))
736 			continue;
737 		cpumask_set_cpu(cpu, cpu_sibling_mask(base + i));
738 		cpumask_set_cpu(base + i, cpu_sibling_mask(cpu));
739 
740 		/* cpu_core_map should be a superset of
741 		 * cpu_sibling_map even if we don't have cache
742 		 * information, so update the former here, too.
743 		 */
744 		cpumask_set_cpu(cpu, cpu_core_mask(base + i));
745 		cpumask_set_cpu(base + i, cpu_core_mask(cpu));
746 	}
747 	traverse_core_siblings(cpu, true);
748 
749 	set_numa_node(numa_cpu_lookup_table[cpu]);
750 	set_numa_mem(local_memory_node(numa_cpu_lookup_table[cpu]));
751 
752 	smp_wmb();
753 	notify_cpu_starting(cpu);
754 	set_cpu_online(cpu, true);
755 
756 	local_irq_enable();
757 
758 	cpu_startup_entry(CPUHP_AP_ONLINE_IDLE);
759 
760 	BUG();
761 }
762 
763 int setup_profiling_timer(unsigned int multiplier)
764 {
765 	return 0;
766 }
767 
768 #ifdef CONFIG_SCHED_SMT
769 /* cpumask of CPUs with asymetric SMT dependancy */
770 static int powerpc_smt_flags(void)
771 {
772 	int flags = SD_SHARE_CPUCAPACITY | SD_SHARE_PKG_RESOURCES;
773 
774 	if (cpu_has_feature(CPU_FTR_ASYM_SMT)) {
775 		printk_once(KERN_INFO "Enabling Asymmetric SMT scheduling\n");
776 		flags |= SD_ASYM_PACKING;
777 	}
778 	return flags;
779 }
780 #endif
781 
782 static struct sched_domain_topology_level powerpc_topology[] = {
783 #ifdef CONFIG_SCHED_SMT
784 	{ cpu_smt_mask, powerpc_smt_flags, SD_INIT_NAME(SMT) },
785 #endif
786 	{ cpu_cpu_mask, SD_INIT_NAME(DIE) },
787 	{ NULL, },
788 };
789 
790 void __init smp_cpus_done(unsigned int max_cpus)
791 {
792 	cpumask_var_t old_mask;
793 
794 	/* We want the setup_cpu() here to be called from CPU 0, but our
795 	 * init thread may have been "borrowed" by another CPU in the meantime
796 	 * se we pin us down to CPU 0 for a short while
797 	 */
798 	alloc_cpumask_var(&old_mask, GFP_NOWAIT);
799 	cpumask_copy(old_mask, &current->cpus_allowed);
800 	set_cpus_allowed_ptr(current, cpumask_of(boot_cpuid));
801 
802 	if (smp_ops && smp_ops->setup_cpu)
803 		smp_ops->setup_cpu(boot_cpuid);
804 
805 	set_cpus_allowed_ptr(current, old_mask);
806 
807 	free_cpumask_var(old_mask);
808 
809 	if (smp_ops && smp_ops->bringup_done)
810 		smp_ops->bringup_done();
811 
812 	dump_numa_cpu_topology();
813 
814 	set_sched_topology(powerpc_topology);
815 
816 }
817 
818 #ifdef CONFIG_HOTPLUG_CPU
819 int __cpu_disable(void)
820 {
821 	int cpu = smp_processor_id();
822 	int base, i;
823 	int err;
824 
825 	if (!smp_ops->cpu_disable)
826 		return -ENOSYS;
827 
828 	err = smp_ops->cpu_disable();
829 	if (err)
830 		return err;
831 
832 	/* Update sibling maps */
833 	base = cpu_first_thread_sibling(cpu);
834 	for (i = 0; i < threads_per_core && base + i < nr_cpu_ids; i++) {
835 		cpumask_clear_cpu(cpu, cpu_sibling_mask(base + i));
836 		cpumask_clear_cpu(base + i, cpu_sibling_mask(cpu));
837 		cpumask_clear_cpu(cpu, cpu_core_mask(base + i));
838 		cpumask_clear_cpu(base + i, cpu_core_mask(cpu));
839 	}
840 	traverse_core_siblings(cpu, false);
841 
842 	return 0;
843 }
844 
845 void __cpu_die(unsigned int cpu)
846 {
847 	if (smp_ops->cpu_die)
848 		smp_ops->cpu_die(cpu);
849 }
850 
851 void cpu_die(void)
852 {
853 	if (ppc_md.cpu_die)
854 		ppc_md.cpu_die();
855 
856 	/* If we return, we re-enter start_secondary */
857 	start_secondary_resume();
858 }
859 
860 #endif
861