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