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1 /* SMP support routines.
2  *
3  * Copyright (C) 2006-2008 Panasonic Corporation
4  * All Rights Reserved.
5  *
6  * This program is free software; you can redistribute it and/or
7  * modify it under the terms of the GNU General Public License
8  * version 2 as published by the Free Software Foundation.
9  *
10  * This program is distributed in the hope that it will be useful,
11  * but WITHOUT ANY WARRANTY; without even the implied warranty of
12  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
13  * GNU General Public License for more details.
14  */
15 
16 #include <linux/interrupt.h>
17 #include <linux/spinlock.h>
18 #include <linux/init.h>
19 #include <linux/jiffies.h>
20 #include <linux/cpumask.h>
21 #include <linux/err.h>
22 #include <linux/kernel.h>
23 #include <linux/delay.h>
24 #include <linux/sched.h>
25 #include <linux/profile.h>
26 #include <linux/smp.h>
27 #include <linux/cpu.h>
28 #include <asm/tlbflush.h>
29 #include <asm/bitops.h>
30 #include <asm/processor.h>
31 #include <asm/bug.h>
32 #include <asm/exceptions.h>
33 #include <asm/hardirq.h>
34 #include <asm/fpu.h>
35 #include <asm/mmu_context.h>
36 #include <asm/thread_info.h>
37 #include <asm/cpu-regs.h>
38 #include <asm/intctl-regs.h>
39 #include "internal.h"
40 
41 #ifdef CONFIG_HOTPLUG_CPU
42 #include <asm/cacheflush.h>
43 
44 static unsigned long sleep_mode[NR_CPUS];
45 
46 static void run_sleep_cpu(unsigned int cpu);
47 static void run_wakeup_cpu(unsigned int cpu);
48 #endif /* CONFIG_HOTPLUG_CPU */
49 
50 /*
51  * Debug Message function
52  */
53 
54 #undef DEBUG_SMP
55 #ifdef DEBUG_SMP
56 #define Dprintk(fmt, ...) printk(KERN_DEBUG fmt, ##__VA_ARGS__)
57 #else
58 #define Dprintk(fmt, ...) no_printk(KERN_DEBUG fmt, ##__VA_ARGS__)
59 #endif
60 
61 /* timeout value in msec for smp_nmi_call_function. zero is no timeout. */
62 #define	CALL_FUNCTION_NMI_IPI_TIMEOUT	0
63 
64 /*
65  * Structure and data for smp_nmi_call_function().
66  */
67 struct nmi_call_data_struct {
68 	smp_call_func_t	func;
69 	void		*info;
70 	cpumask_t	started;
71 	cpumask_t	finished;
72 	int		wait;
73 	char		size_alignment[0]
74 	__attribute__ ((__aligned__(SMP_CACHE_BYTES)));
75 } __attribute__ ((__aligned__(SMP_CACHE_BYTES)));
76 
77 static DEFINE_SPINLOCK(smp_nmi_call_lock);
78 static struct nmi_call_data_struct *nmi_call_data;
79 
80 /*
81  * Data structures and variables
82  */
83 static cpumask_t cpu_callin_map;	/* Bitmask of callin CPUs */
84 static cpumask_t cpu_callout_map;	/* Bitmask of callout CPUs */
85 cpumask_t cpu_boot_map;			/* Bitmask of boot APs */
86 unsigned long start_stack[NR_CPUS - 1];
87 
88 /*
89  * Per CPU parameters
90  */
91 struct mn10300_cpuinfo cpu_data[NR_CPUS] __cacheline_aligned;
92 
93 static int cpucount;			/* The count of boot CPUs */
94 static cpumask_t smp_commenced_mask;
95 cpumask_t cpu_initialized __initdata = CPU_MASK_NONE;
96 
97 /*
98  * Function Prototypes
99  */
100 static int do_boot_cpu(int);
101 static void smp_show_cpu_info(int cpu_id);
102 static void smp_callin(void);
103 static void smp_online(void);
104 static void smp_store_cpu_info(int);
105 static void smp_cpu_init(void);
106 static void smp_tune_scheduling(void);
107 static void send_IPI_mask(const cpumask_t *cpumask, int irq);
108 static void init_ipi(void);
109 
110 /*
111  * IPI Initialization interrupt definitions
112  */
113 static void mn10300_ipi_disable(unsigned int irq);
114 static void mn10300_ipi_enable(unsigned int irq);
115 static void mn10300_ipi_chip_disable(struct irq_data *d);
116 static void mn10300_ipi_chip_enable(struct irq_data *d);
117 static void mn10300_ipi_ack(struct irq_data *d);
118 static void mn10300_ipi_nop(struct irq_data *d);
119 
120 static struct irq_chip mn10300_ipi_type = {
121 	.name		= "cpu_ipi",
122 	.irq_disable	= mn10300_ipi_chip_disable,
123 	.irq_enable	= mn10300_ipi_chip_enable,
124 	.irq_ack	= mn10300_ipi_ack,
125 	.irq_eoi	= mn10300_ipi_nop
126 };
127 
128 static irqreturn_t smp_reschedule_interrupt(int irq, void *dev_id);
129 static irqreturn_t smp_call_function_interrupt(int irq, void *dev_id);
130 
131 static struct irqaction reschedule_ipi = {
132 	.handler	= smp_reschedule_interrupt,
133 	.flags		= IRQF_NOBALANCING,
134 	.name		= "smp reschedule IPI"
135 };
136 static struct irqaction call_function_ipi = {
137 	.handler	= smp_call_function_interrupt,
138 	.flags		= IRQF_NOBALANCING,
139 	.name		= "smp call function IPI"
140 };
141 
142 #if !defined(CONFIG_GENERIC_CLOCKEVENTS) || defined(CONFIG_GENERIC_CLOCKEVENTS_BROADCAST)
143 static irqreturn_t smp_ipi_timer_interrupt(int irq, void *dev_id);
144 static struct irqaction local_timer_ipi = {
145 	.handler	= smp_ipi_timer_interrupt,
146 	.flags		= IRQF_NOBALANCING,
147 	.name		= "smp local timer IPI"
148 };
149 #endif
150 
151 /**
152  * init_ipi - Initialise the IPI mechanism
153  */
init_ipi(void)154 static void init_ipi(void)
155 {
156 	unsigned long flags;
157 	u16 tmp16;
158 
159 	/* set up the reschedule IPI */
160 	irq_set_chip_and_handler(RESCHEDULE_IPI, &mn10300_ipi_type,
161 				 handle_percpu_irq);
162 	setup_irq(RESCHEDULE_IPI, &reschedule_ipi);
163 	set_intr_level(RESCHEDULE_IPI, RESCHEDULE_GxICR_LV);
164 	mn10300_ipi_enable(RESCHEDULE_IPI);
165 
166 	/* set up the call function IPI */
167 	irq_set_chip_and_handler(CALL_FUNC_SINGLE_IPI, &mn10300_ipi_type,
168 				 handle_percpu_irq);
169 	setup_irq(CALL_FUNC_SINGLE_IPI, &call_function_ipi);
170 	set_intr_level(CALL_FUNC_SINGLE_IPI, CALL_FUNCTION_GxICR_LV);
171 	mn10300_ipi_enable(CALL_FUNC_SINGLE_IPI);
172 
173 	/* set up the local timer IPI */
174 #if !defined(CONFIG_GENERIC_CLOCKEVENTS) || \
175     defined(CONFIG_GENERIC_CLOCKEVENTS_BROADCAST)
176 	irq_set_chip_and_handler(LOCAL_TIMER_IPI, &mn10300_ipi_type,
177 				 handle_percpu_irq);
178 	setup_irq(LOCAL_TIMER_IPI, &local_timer_ipi);
179 	set_intr_level(LOCAL_TIMER_IPI, LOCAL_TIMER_GxICR_LV);
180 	mn10300_ipi_enable(LOCAL_TIMER_IPI);
181 #endif
182 
183 #ifdef CONFIG_MN10300_CACHE_ENABLED
184 	/* set up the cache flush IPI */
185 	irq_set_chip(FLUSH_CACHE_IPI, &mn10300_ipi_type);
186 	flags = arch_local_cli_save();
187 	__set_intr_stub(NUM2EXCEP_IRQ_LEVEL(FLUSH_CACHE_GxICR_LV),
188 			mn10300_low_ipi_handler);
189 	GxICR(FLUSH_CACHE_IPI) = FLUSH_CACHE_GxICR_LV | GxICR_DETECT;
190 	mn10300_ipi_enable(FLUSH_CACHE_IPI);
191 	arch_local_irq_restore(flags);
192 #endif
193 
194 	/* set up the NMI call function IPI */
195 	irq_set_chip(CALL_FUNCTION_NMI_IPI, &mn10300_ipi_type);
196 	flags = arch_local_cli_save();
197 	GxICR(CALL_FUNCTION_NMI_IPI) = GxICR_NMI | GxICR_ENABLE | GxICR_DETECT;
198 	tmp16 = GxICR(CALL_FUNCTION_NMI_IPI);
199 	arch_local_irq_restore(flags);
200 
201 	/* set up the SMP boot IPI */
202 	flags = arch_local_cli_save();
203 	__set_intr_stub(NUM2EXCEP_IRQ_LEVEL(SMP_BOOT_GxICR_LV),
204 			mn10300_low_ipi_handler);
205 	arch_local_irq_restore(flags);
206 
207 #ifdef CONFIG_KERNEL_DEBUGGER
208 	irq_set_chip(DEBUGGER_NMI_IPI, &mn10300_ipi_type);
209 #endif
210 }
211 
212 /**
213  * mn10300_ipi_shutdown - Shut down handling of an IPI
214  * @irq: The IPI to be shut down.
215  */
mn10300_ipi_shutdown(unsigned int irq)216 static void mn10300_ipi_shutdown(unsigned int irq)
217 {
218 	unsigned long flags;
219 	u16 tmp;
220 
221 	flags = arch_local_cli_save();
222 
223 	tmp = GxICR(irq);
224 	GxICR(irq) = (tmp & GxICR_LEVEL) | GxICR_DETECT;
225 	tmp = GxICR(irq);
226 
227 	arch_local_irq_restore(flags);
228 }
229 
230 /**
231  * mn10300_ipi_enable - Enable an IPI
232  * @irq: The IPI to be enabled.
233  */
mn10300_ipi_enable(unsigned int irq)234 static void mn10300_ipi_enable(unsigned int irq)
235 {
236 	unsigned long flags;
237 	u16 tmp;
238 
239 	flags = arch_local_cli_save();
240 
241 	tmp = GxICR(irq);
242 	GxICR(irq) = (tmp & GxICR_LEVEL) | GxICR_ENABLE;
243 	tmp = GxICR(irq);
244 
245 	arch_local_irq_restore(flags);
246 }
247 
mn10300_ipi_chip_enable(struct irq_data * d)248 static void mn10300_ipi_chip_enable(struct irq_data *d)
249 {
250 	mn10300_ipi_enable(d->irq);
251 }
252 
253 /**
254  * mn10300_ipi_disable - Disable an IPI
255  * @irq: The IPI to be disabled.
256  */
mn10300_ipi_disable(unsigned int irq)257 static void mn10300_ipi_disable(unsigned int irq)
258 {
259 	unsigned long flags;
260 	u16 tmp;
261 
262 	flags = arch_local_cli_save();
263 
264 	tmp = GxICR(irq);
265 	GxICR(irq) = tmp & GxICR_LEVEL;
266 	tmp = GxICR(irq);
267 
268 	arch_local_irq_restore(flags);
269 }
270 
mn10300_ipi_chip_disable(struct irq_data * d)271 static void mn10300_ipi_chip_disable(struct irq_data *d)
272 {
273 	mn10300_ipi_disable(d->irq);
274 }
275 
276 
277 /**
278  * mn10300_ipi_ack - Acknowledge an IPI interrupt in the PIC
279  * @irq: The IPI to be acknowledged.
280  *
281  * Clear the interrupt detection flag for the IPI on the appropriate interrupt
282  * channel in the PIC.
283  */
mn10300_ipi_ack(struct irq_data * d)284 static void mn10300_ipi_ack(struct irq_data *d)
285 {
286 	unsigned int irq = d->irq;
287 	unsigned long flags;
288 	u16 tmp;
289 
290 	flags = arch_local_cli_save();
291 	GxICR_u8(irq) = GxICR_DETECT;
292 	tmp = GxICR(irq);
293 	arch_local_irq_restore(flags);
294 }
295 
296 /**
297  * mn10300_ipi_nop - Dummy IPI action
298  * @irq: The IPI to be acted upon.
299  */
mn10300_ipi_nop(struct irq_data * d)300 static void mn10300_ipi_nop(struct irq_data *d)
301 {
302 }
303 
304 /**
305  * send_IPI_mask - Send IPIs to all CPUs in list
306  * @cpumask: The list of CPUs to target.
307  * @irq: The IPI request to be sent.
308  *
309  * Send the specified IPI to all the CPUs in the list, not waiting for them to
310  * finish before returning.  The caller is responsible for synchronisation if
311  * that is needed.
312  */
send_IPI_mask(const cpumask_t * cpumask,int irq)313 static void send_IPI_mask(const cpumask_t *cpumask, int irq)
314 {
315 	int i;
316 	u16 tmp;
317 
318 	for (i = 0; i < NR_CPUS; i++) {
319 		if (cpumask_test_cpu(i, cpumask)) {
320 			/* send IPI */
321 			tmp = CROSS_GxICR(irq, i);
322 			CROSS_GxICR(irq, i) =
323 				tmp | GxICR_REQUEST | GxICR_DETECT;
324 			tmp = CROSS_GxICR(irq, i); /* flush write buffer */
325 		}
326 	}
327 }
328 
329 /**
330  * send_IPI_self - Send an IPI to this CPU.
331  * @irq: The IPI request to be sent.
332  *
333  * Send the specified IPI to the current CPU.
334  */
send_IPI_self(int irq)335 void send_IPI_self(int irq)
336 {
337 	send_IPI_mask(cpumask_of(smp_processor_id()), irq);
338 }
339 
340 /**
341  * send_IPI_allbutself - Send IPIs to all the other CPUs.
342  * @irq: The IPI request to be sent.
343  *
344  * Send the specified IPI to all CPUs in the system barring the current one,
345  * not waiting for them to finish before returning.  The caller is responsible
346  * for synchronisation if that is needed.
347  */
send_IPI_allbutself(int irq)348 void send_IPI_allbutself(int irq)
349 {
350 	cpumask_t cpumask;
351 
352 	cpumask_copy(&cpumask, cpu_online_mask);
353 	cpumask_clear_cpu(smp_processor_id(), &cpumask);
354 	send_IPI_mask(&cpumask, irq);
355 }
356 
arch_send_call_function_ipi_mask(const struct cpumask * mask)357 void arch_send_call_function_ipi_mask(const struct cpumask *mask)
358 {
359 	BUG();
360 	/*send_IPI_mask(mask, CALL_FUNCTION_IPI);*/
361 }
362 
arch_send_call_function_single_ipi(int cpu)363 void arch_send_call_function_single_ipi(int cpu)
364 {
365 	send_IPI_mask(cpumask_of(cpu), CALL_FUNC_SINGLE_IPI);
366 }
367 
368 /**
369  * smp_send_reschedule - Send reschedule IPI to a CPU
370  * @cpu: The CPU to target.
371  */
smp_send_reschedule(int cpu)372 void smp_send_reschedule(int cpu)
373 {
374 	send_IPI_mask(cpumask_of(cpu), RESCHEDULE_IPI);
375 }
376 
377 /**
378  * smp_nmi_call_function - Send a call function NMI IPI to all CPUs
379  * @func: The function to ask to be run.
380  * @info: The context data to pass to that function.
381  * @wait: If true, wait (atomically) until function is run on all CPUs.
382  *
383  * Send a non-maskable request to all CPUs in the system, requesting them to
384  * run the specified function with the given context data, and, potentially, to
385  * wait for completion of that function on all CPUs.
386  *
387  * Returns 0 if successful, -ETIMEDOUT if we were asked to wait, but hit the
388  * timeout.
389  */
smp_nmi_call_function(smp_call_func_t func,void * info,int wait)390 int smp_nmi_call_function(smp_call_func_t func, void *info, int wait)
391 {
392 	struct nmi_call_data_struct data;
393 	unsigned long flags;
394 	unsigned int cnt;
395 	int cpus, ret = 0;
396 
397 	cpus = num_online_cpus() - 1;
398 	if (cpus < 1)
399 		return 0;
400 
401 	data.func = func;
402 	data.info = info;
403 	cpumask_copy(&data.started, cpu_online_mask);
404 	cpumask_clear_cpu(smp_processor_id(), &data.started);
405 	data.wait = wait;
406 	if (wait)
407 		data.finished = data.started;
408 
409 	spin_lock_irqsave(&smp_nmi_call_lock, flags);
410 	nmi_call_data = &data;
411 	smp_mb();
412 
413 	/* Send a message to all other CPUs and wait for them to respond */
414 	send_IPI_allbutself(CALL_FUNCTION_NMI_IPI);
415 
416 	/* Wait for response */
417 	if (CALL_FUNCTION_NMI_IPI_TIMEOUT > 0) {
418 		for (cnt = 0;
419 		     cnt < CALL_FUNCTION_NMI_IPI_TIMEOUT &&
420 			     !cpumask_empty(&data.started);
421 		     cnt++)
422 			mdelay(1);
423 
424 		if (wait && cnt < CALL_FUNCTION_NMI_IPI_TIMEOUT) {
425 			for (cnt = 0;
426 			     cnt < CALL_FUNCTION_NMI_IPI_TIMEOUT &&
427 				     !cpumask_empty(&data.finished);
428 			     cnt++)
429 				mdelay(1);
430 		}
431 
432 		if (cnt >= CALL_FUNCTION_NMI_IPI_TIMEOUT)
433 			ret = -ETIMEDOUT;
434 
435 	} else {
436 		/* If timeout value is zero, wait until cpumask has been
437 		 * cleared */
438 		while (!cpumask_empty(&data.started))
439 			barrier();
440 		if (wait)
441 			while (!cpumask_empty(&data.finished))
442 				barrier();
443 	}
444 
445 	spin_unlock_irqrestore(&smp_nmi_call_lock, flags);
446 	return ret;
447 }
448 
449 /**
450  * smp_jump_to_debugger - Make other CPUs enter the debugger by sending an IPI
451  *
452  * Send a non-maskable request to all other CPUs in the system, instructing
453  * them to jump into the debugger.  The caller is responsible for checking that
454  * the other CPUs responded to the instruction.
455  *
456  * The caller should make sure that this CPU's debugger IPI is disabled.
457  */
smp_jump_to_debugger(void)458 void smp_jump_to_debugger(void)
459 {
460 	if (num_online_cpus() > 1)
461 		/* Send a message to all other CPUs */
462 		send_IPI_allbutself(DEBUGGER_NMI_IPI);
463 }
464 
465 /**
466  * stop_this_cpu - Callback to stop a CPU.
467  * @unused: Callback context (ignored).
468  */
stop_this_cpu(void * unused)469 void stop_this_cpu(void *unused)
470 {
471 	static volatile int stopflag;
472 	unsigned long flags;
473 
474 #ifdef CONFIG_GDBSTUB
475 	/* In case of single stepping smp_send_stop by other CPU,
476 	 * clear procindebug to avoid deadlock.
477 	 */
478 	atomic_set(&procindebug[smp_processor_id()], 0);
479 #endif	/* CONFIG_GDBSTUB */
480 
481 	flags = arch_local_cli_save();
482 	set_cpu_online(smp_processor_id(), false);
483 
484 	while (!stopflag)
485 		cpu_relax();
486 
487 	set_cpu_online(smp_processor_id(), true);
488 	arch_local_irq_restore(flags);
489 }
490 
491 /**
492  * smp_send_stop - Send a stop request to all CPUs.
493  */
smp_send_stop(void)494 void smp_send_stop(void)
495 {
496 	smp_nmi_call_function(stop_this_cpu, NULL, 0);
497 }
498 
499 /**
500  * smp_reschedule_interrupt - Reschedule IPI handler
501  * @irq: The interrupt number.
502  * @dev_id: The device ID.
503  *
504  * Returns IRQ_HANDLED to indicate we handled the interrupt successfully.
505  */
smp_reschedule_interrupt(int irq,void * dev_id)506 static irqreturn_t smp_reschedule_interrupt(int irq, void *dev_id)
507 {
508 	scheduler_ipi();
509 	return IRQ_HANDLED;
510 }
511 
512 /**
513  * smp_call_function_interrupt - Call function IPI handler
514  * @irq: The interrupt number.
515  * @dev_id: The device ID.
516  *
517  * Returns IRQ_HANDLED to indicate we handled the interrupt successfully.
518  */
smp_call_function_interrupt(int irq,void * dev_id)519 static irqreturn_t smp_call_function_interrupt(int irq, void *dev_id)
520 {
521 	/* generic_smp_call_function_interrupt(); */
522 	generic_smp_call_function_single_interrupt();
523 	return IRQ_HANDLED;
524 }
525 
526 /**
527  * smp_nmi_call_function_interrupt - Non-maskable call function IPI handler
528  */
smp_nmi_call_function_interrupt(void)529 void smp_nmi_call_function_interrupt(void)
530 {
531 	smp_call_func_t func = nmi_call_data->func;
532 	void *info = nmi_call_data->info;
533 	int wait = nmi_call_data->wait;
534 
535 	/* Notify the initiating CPU that I've grabbed the data and am about to
536 	 * execute the function
537 	 */
538 	smp_mb();
539 	cpumask_clear_cpu(smp_processor_id(), &nmi_call_data->started);
540 	(*func)(info);
541 
542 	if (wait) {
543 		smp_mb();
544 		cpumask_clear_cpu(smp_processor_id(),
545 				  &nmi_call_data->finished);
546 	}
547 }
548 
549 #if !defined(CONFIG_GENERIC_CLOCKEVENTS) || \
550     defined(CONFIG_GENERIC_CLOCKEVENTS_BROADCAST)
551 /**
552  * smp_ipi_timer_interrupt - Local timer IPI handler
553  * @irq: The interrupt number.
554  * @dev_id: The device ID.
555  *
556  * Returns IRQ_HANDLED to indicate we handled the interrupt successfully.
557  */
smp_ipi_timer_interrupt(int irq,void * dev_id)558 static irqreturn_t smp_ipi_timer_interrupt(int irq, void *dev_id)
559 {
560 	return local_timer_interrupt();
561 }
562 #endif
563 
smp_init_cpus(void)564 void __init smp_init_cpus(void)
565 {
566 	int i;
567 	for (i = 0; i < NR_CPUS; i++) {
568 		set_cpu_possible(i, true);
569 		set_cpu_present(i, true);
570 	}
571 }
572 
573 /**
574  * smp_cpu_init - Initialise AP in start_secondary.
575  *
576  * For this Application Processor, set up init_mm, initialise FPU and set
577  * interrupt level 0-6 setting.
578  */
smp_cpu_init(void)579 static void __init smp_cpu_init(void)
580 {
581 	unsigned long flags;
582 	int cpu_id = smp_processor_id();
583 	u16 tmp16;
584 
585 	if (test_and_set_bit(cpu_id, &cpu_initialized)) {
586 		printk(KERN_WARNING "CPU#%d already initialized!\n", cpu_id);
587 		for (;;)
588 			local_irq_enable();
589 	}
590 	printk(KERN_INFO "Initializing CPU#%d\n", cpu_id);
591 
592 	atomic_inc(&init_mm.mm_count);
593 	current->active_mm = &init_mm;
594 	BUG_ON(current->mm);
595 
596 	enter_lazy_tlb(&init_mm, current);
597 
598 	/* Force FPU initialization */
599 	clear_using_fpu(current);
600 
601 	GxICR(CALL_FUNC_SINGLE_IPI) = CALL_FUNCTION_GxICR_LV | GxICR_DETECT;
602 	mn10300_ipi_enable(CALL_FUNC_SINGLE_IPI);
603 
604 	GxICR(LOCAL_TIMER_IPI) = LOCAL_TIMER_GxICR_LV | GxICR_DETECT;
605 	mn10300_ipi_enable(LOCAL_TIMER_IPI);
606 
607 	GxICR(RESCHEDULE_IPI) = RESCHEDULE_GxICR_LV | GxICR_DETECT;
608 	mn10300_ipi_enable(RESCHEDULE_IPI);
609 
610 #ifdef CONFIG_MN10300_CACHE_ENABLED
611 	GxICR(FLUSH_CACHE_IPI) = FLUSH_CACHE_GxICR_LV | GxICR_DETECT;
612 	mn10300_ipi_enable(FLUSH_CACHE_IPI);
613 #endif
614 
615 	mn10300_ipi_shutdown(SMP_BOOT_IRQ);
616 
617 	/* Set up the non-maskable call function IPI */
618 	flags = arch_local_cli_save();
619 	GxICR(CALL_FUNCTION_NMI_IPI) = GxICR_NMI | GxICR_ENABLE | GxICR_DETECT;
620 	tmp16 = GxICR(CALL_FUNCTION_NMI_IPI);
621 	arch_local_irq_restore(flags);
622 }
623 
624 /**
625  * smp_prepare_cpu_init - Initialise CPU in startup_secondary
626  *
627  * Set interrupt level 0-6 setting and init ICR of the kernel debugger.
628  */
smp_prepare_cpu_init(void)629 void smp_prepare_cpu_init(void)
630 {
631 	int loop;
632 
633 	/* Set the interrupt vector registers */
634 	IVAR0 = EXCEP_IRQ_LEVEL0;
635 	IVAR1 = EXCEP_IRQ_LEVEL1;
636 	IVAR2 = EXCEP_IRQ_LEVEL2;
637 	IVAR3 = EXCEP_IRQ_LEVEL3;
638 	IVAR4 = EXCEP_IRQ_LEVEL4;
639 	IVAR5 = EXCEP_IRQ_LEVEL5;
640 	IVAR6 = EXCEP_IRQ_LEVEL6;
641 
642 	/* Disable all interrupts and set to priority 6 (lowest) */
643 	for (loop = 0; loop < GxICR_NUM_IRQS; loop++)
644 		GxICR(loop) = GxICR_LEVEL_6 | GxICR_DETECT;
645 
646 #ifdef CONFIG_KERNEL_DEBUGGER
647 	/* initialise the kernel debugger interrupt */
648 	do {
649 		unsigned long flags;
650 		u16 tmp16;
651 
652 		flags = arch_local_cli_save();
653 		GxICR(DEBUGGER_NMI_IPI) = GxICR_NMI | GxICR_ENABLE | GxICR_DETECT;
654 		tmp16 = GxICR(DEBUGGER_NMI_IPI);
655 		arch_local_irq_restore(flags);
656 	} while (0);
657 #endif
658 }
659 
660 /**
661  * start_secondary - Activate a secondary CPU (AP)
662  * @unused: Thread parameter (ignored).
663  */
start_secondary(void * unused)664 int __init start_secondary(void *unused)
665 {
666 	smp_cpu_init();
667 	smp_callin();
668 	while (!cpumask_test_cpu(smp_processor_id(), &smp_commenced_mask))
669 		cpu_relax();
670 
671 	local_flush_tlb();
672 	preempt_disable();
673 	smp_online();
674 
675 #ifdef CONFIG_GENERIC_CLOCKEVENTS
676 	init_clockevents();
677 #endif
678 	cpu_startup_entry(CPUHP_ONLINE);
679 	return 0;
680 }
681 
682 /**
683  * smp_prepare_cpus - Boot up secondary CPUs (APs)
684  * @max_cpus: Maximum number of CPUs to boot.
685  *
686  * Call do_boot_cpu, and boot up APs.
687  */
smp_prepare_cpus(unsigned int max_cpus)688 void __init smp_prepare_cpus(unsigned int max_cpus)
689 {
690 	int phy_id;
691 
692 	/* Setup boot CPU information */
693 	smp_store_cpu_info(0);
694 	smp_tune_scheduling();
695 
696 	init_ipi();
697 
698 	/* If SMP should be disabled, then finish */
699 	if (max_cpus == 0) {
700 		printk(KERN_INFO "SMP mode deactivated.\n");
701 		goto smp_done;
702 	}
703 
704 	/* Boot secondary CPUs (for which phy_id > 0) */
705 	for (phy_id = 0; phy_id < NR_CPUS; phy_id++) {
706 		/* Don't boot primary CPU */
707 		if (max_cpus <= cpucount + 1)
708 			continue;
709 		if (phy_id != 0)
710 			do_boot_cpu(phy_id);
711 		set_cpu_possible(phy_id, true);
712 		smp_show_cpu_info(phy_id);
713 	}
714 
715 smp_done:
716 	Dprintk("Boot done.\n");
717 }
718 
719 /**
720  * smp_store_cpu_info - Save a CPU's information
721  * @cpu: The CPU to save for.
722  *
723  * Save boot_cpu_data and jiffy for the specified CPU.
724  */
smp_store_cpu_info(int cpu)725 static void __init smp_store_cpu_info(int cpu)
726 {
727 	struct mn10300_cpuinfo *ci = &cpu_data[cpu];
728 
729 	*ci = boot_cpu_data;
730 	ci->loops_per_jiffy = loops_per_jiffy;
731 	ci->type = CPUREV;
732 }
733 
734 /**
735  * smp_tune_scheduling - Set time slice value
736  *
737  * Nothing to do here.
738  */
smp_tune_scheduling(void)739 static void __init smp_tune_scheduling(void)
740 {
741 }
742 
743 /**
744  * do_boot_cpu: Boot up one CPU
745  * @phy_id: Physical ID of CPU to boot.
746  *
747  * Send an IPI to a secondary CPU to boot it.  Returns 0 on success, 1
748  * otherwise.
749  */
do_boot_cpu(int phy_id)750 static int __init do_boot_cpu(int phy_id)
751 {
752 	struct task_struct *idle;
753 	unsigned long send_status, callin_status;
754 	int timeout, cpu_id;
755 
756 	send_status = GxICR_REQUEST;
757 	callin_status = 0;
758 	timeout = 0;
759 	cpu_id = phy_id;
760 
761 	cpucount++;
762 
763 	/* Create idle thread for this CPU */
764 	idle = fork_idle(cpu_id);
765 	if (IS_ERR(idle))
766 		panic("Failed fork for CPU#%d.", cpu_id);
767 
768 	idle->thread.pc = (unsigned long)start_secondary;
769 
770 	printk(KERN_NOTICE "Booting CPU#%d\n", cpu_id);
771 	start_stack[cpu_id - 1] = idle->thread.sp;
772 
773 	task_thread_info(idle)->cpu = cpu_id;
774 
775 	/* Send boot IPI to AP */
776 	send_IPI_mask(cpumask_of(phy_id), SMP_BOOT_IRQ);
777 
778 	Dprintk("Waiting for send to finish...\n");
779 
780 	/* Wait for AP's IPI receive in 100[ms] */
781 	do {
782 		udelay(1000);
783 		send_status =
784 			CROSS_GxICR(SMP_BOOT_IRQ, phy_id) & GxICR_REQUEST;
785 	} while (send_status == GxICR_REQUEST && timeout++ < 100);
786 
787 	Dprintk("Waiting for cpu_callin_map.\n");
788 
789 	if (send_status == 0) {
790 		/* Allow AP to start initializing */
791 		cpumask_set_cpu(cpu_id, &cpu_callout_map);
792 
793 		/* Wait for setting cpu_callin_map */
794 		timeout = 0;
795 		do {
796 			udelay(1000);
797 			callin_status = cpumask_test_cpu(cpu_id,
798 							 &cpu_callin_map);
799 		} while (callin_status == 0 && timeout++ < 5000);
800 
801 		if (callin_status == 0)
802 			Dprintk("Not responding.\n");
803 	} else {
804 		printk(KERN_WARNING "IPI not delivered.\n");
805 	}
806 
807 	if (send_status == GxICR_REQUEST || callin_status == 0) {
808 		cpumask_clear_cpu(cpu_id, &cpu_callout_map);
809 		cpumask_clear_cpu(cpu_id, &cpu_callin_map);
810 		cpumask_clear_cpu(cpu_id, &cpu_initialized);
811 		cpucount--;
812 		return 1;
813 	}
814 	return 0;
815 }
816 
817 /**
818  * smp_show_cpu_info - Show SMP CPU information
819  * @cpu: The CPU of interest.
820  */
smp_show_cpu_info(int cpu)821 static void __init smp_show_cpu_info(int cpu)
822 {
823 	struct mn10300_cpuinfo *ci = &cpu_data[cpu];
824 
825 	printk(KERN_INFO
826 	       "CPU#%d : ioclk speed: %lu.%02luMHz : bogomips : %lu.%02lu\n",
827 	       cpu,
828 	       MN10300_IOCLK / 1000000,
829 	       (MN10300_IOCLK / 10000) % 100,
830 	       ci->loops_per_jiffy / (500000 / HZ),
831 	       (ci->loops_per_jiffy / (5000 / HZ)) % 100);
832 }
833 
834 /**
835  * smp_callin - Set cpu_callin_map of the current CPU ID
836  */
smp_callin(void)837 static void __init smp_callin(void)
838 {
839 	unsigned long timeout;
840 	int cpu;
841 
842 	cpu = smp_processor_id();
843 	timeout = jiffies + (2 * HZ);
844 
845 	if (cpumask_test_cpu(cpu, &cpu_callin_map)) {
846 		printk(KERN_ERR "CPU#%d already present.\n", cpu);
847 		BUG();
848 	}
849 	Dprintk("CPU#%d waiting for CALLOUT\n", cpu);
850 
851 	/* Wait for AP startup 2s total */
852 	while (time_before(jiffies, timeout)) {
853 		if (cpumask_test_cpu(cpu, &cpu_callout_map))
854 			break;
855 		cpu_relax();
856 	}
857 
858 	if (!time_before(jiffies, timeout)) {
859 		printk(KERN_ERR
860 		       "BUG: CPU#%d started up but did not get a callout!\n",
861 		       cpu);
862 		BUG();
863 	}
864 
865 #ifdef CONFIG_CALIBRATE_DELAY
866 	calibrate_delay();		/* Get our bogomips */
867 #endif
868 
869 	/* Save our processor parameters */
870 	smp_store_cpu_info(cpu);
871 
872 	/* Allow the boot processor to continue */
873 	cpumask_set_cpu(cpu, &cpu_callin_map);
874 }
875 
876 /**
877  * smp_online - Set cpu_online_mask
878  */
smp_online(void)879 static void __init smp_online(void)
880 {
881 	int cpu;
882 
883 	cpu = smp_processor_id();
884 
885 	notify_cpu_starting(cpu);
886 
887 	set_cpu_online(cpu, true);
888 
889 	local_irq_enable();
890 }
891 
892 /**
893  * smp_cpus_done -
894  * @max_cpus: Maximum CPU count.
895  *
896  * Do nothing.
897  */
smp_cpus_done(unsigned int max_cpus)898 void __init smp_cpus_done(unsigned int max_cpus)
899 {
900 }
901 
902 /*
903  * smp_prepare_boot_cpu - Set up stuff for the boot processor.
904  *
905  * Set up the cpu_online_mask, cpu_callout_map and cpu_callin_map of the boot
906  * processor (CPU 0).
907  */
smp_prepare_boot_cpu(void)908 void smp_prepare_boot_cpu(void)
909 {
910 	cpumask_set_cpu(0, &cpu_callout_map);
911 	cpumask_set_cpu(0, &cpu_callin_map);
912 	current_thread_info()->cpu = 0;
913 }
914 
915 /*
916  * initialize_secondary - Initialise a secondary CPU (Application Processor).
917  *
918  * Set SP register and jump to thread's PC address.
919  */
initialize_secondary(void)920 void initialize_secondary(void)
921 {
922 	asm volatile (
923 		"mov	%0,sp	\n"
924 		"jmp	(%1)	\n"
925 		:
926 		: "a"(current->thread.sp), "a"(current->thread.pc));
927 }
928 
929 /**
930  * __cpu_up - Set smp_commenced_mask for the nominated CPU
931  * @cpu: The target CPU.
932  */
__cpu_up(unsigned int cpu,struct task_struct * tidle)933 int __cpu_up(unsigned int cpu, struct task_struct *tidle)
934 {
935 	int timeout;
936 
937 #ifdef CONFIG_HOTPLUG_CPU
938 	if (sleep_mode[cpu])
939 		run_wakeup_cpu(cpu);
940 #endif /* CONFIG_HOTPLUG_CPU */
941 
942 	cpumask_set_cpu(cpu, &smp_commenced_mask);
943 
944 	/* Wait 5s total for a response */
945 	for (timeout = 0 ; timeout < 5000 ; timeout++) {
946 		if (cpu_online(cpu))
947 			break;
948 		udelay(1000);
949 	}
950 
951 	BUG_ON(!cpu_online(cpu));
952 	return 0;
953 }
954 
955 /**
956  * setup_profiling_timer - Set up the profiling timer
957  * @multiplier - The frequency multiplier to use
958  *
959  * The frequency of the profiling timer can be changed by writing a multiplier
960  * value into /proc/profile.
961  */
setup_profiling_timer(unsigned int multiplier)962 int setup_profiling_timer(unsigned int multiplier)
963 {
964 	return -EINVAL;
965 }
966 
967 /*
968  * CPU hotplug routines
969  */
970 #ifdef CONFIG_HOTPLUG_CPU
971 
972 static DEFINE_PER_CPU(struct cpu, cpu_devices);
973 
topology_init(void)974 static int __init topology_init(void)
975 {
976 	int cpu, ret;
977 
978 	for_each_cpu(cpu) {
979 		ret = register_cpu(&per_cpu(cpu_devices, cpu), cpu, NULL);
980 		if (ret)
981 			printk(KERN_WARNING
982 			       "topology_init: register_cpu %d failed (%d)\n",
983 			       cpu, ret);
984 	}
985 	return 0;
986 }
987 
988 subsys_initcall(topology_init);
989 
__cpu_disable(void)990 int __cpu_disable(void)
991 {
992 	int cpu = smp_processor_id();
993 	if (cpu == 0)
994 		return -EBUSY;
995 
996 	migrate_irqs();
997 	cpumask_clear_cpu(cpu, &mm_cpumask(current->active_mm));
998 	return 0;
999 }
1000 
__cpu_die(unsigned int cpu)1001 void __cpu_die(unsigned int cpu)
1002 {
1003 	run_sleep_cpu(cpu);
1004 }
1005 
1006 #ifdef CONFIG_MN10300_CACHE_ENABLED
hotplug_cpu_disable_cache(void)1007 static inline void hotplug_cpu_disable_cache(void)
1008 {
1009 	int tmp;
1010 	asm volatile(
1011 		"	movhu	(%1),%0	\n"
1012 		"	and	%2,%0	\n"
1013 		"	movhu	%0,(%1)	\n"
1014 		"1:	movhu	(%1),%0	\n"
1015 		"	btst	%3,%0	\n"
1016 		"	bne	1b	\n"
1017 		: "=&r"(tmp)
1018 		: "a"(&CHCTR),
1019 		  "i"(~(CHCTR_ICEN | CHCTR_DCEN)),
1020 		  "i"(CHCTR_ICBUSY | CHCTR_DCBUSY)
1021 		: "memory", "cc");
1022 }
1023 
hotplug_cpu_enable_cache(void)1024 static inline void hotplug_cpu_enable_cache(void)
1025 {
1026 	int tmp;
1027 	asm volatile(
1028 		"movhu	(%1),%0	\n"
1029 		"or	%2,%0	\n"
1030 		"movhu	%0,(%1)	\n"
1031 		: "=&r"(tmp)
1032 		: "a"(&CHCTR),
1033 		  "i"(CHCTR_ICEN | CHCTR_DCEN)
1034 		: "memory", "cc");
1035 }
1036 
hotplug_cpu_invalidate_cache(void)1037 static inline void hotplug_cpu_invalidate_cache(void)
1038 {
1039 	int tmp;
1040 	asm volatile (
1041 		"movhu	(%1),%0	\n"
1042 		"or	%2,%0	\n"
1043 		"movhu	%0,(%1)	\n"
1044 		: "=&r"(tmp)
1045 		: "a"(&CHCTR),
1046 		  "i"(CHCTR_ICINV | CHCTR_DCINV)
1047 		: "cc");
1048 }
1049 
1050 #else /* CONFIG_MN10300_CACHE_ENABLED */
1051 #define hotplug_cpu_disable_cache()	do {} while (0)
1052 #define hotplug_cpu_enable_cache()	do {} while (0)
1053 #define hotplug_cpu_invalidate_cache()	do {} while (0)
1054 #endif /* CONFIG_MN10300_CACHE_ENABLED */
1055 
1056 /**
1057  * hotplug_cpu_nmi_call_function - Call a function on other CPUs for hotplug
1058  * @cpumask: List of target CPUs.
1059  * @func: The function to call on those CPUs.
1060  * @info: The context data for the function to be called.
1061  * @wait: Whether to wait for the calls to complete.
1062  *
1063  * Non-maskably call a function on another CPU for hotplug purposes.
1064  *
1065  * This function must be called with maskable interrupts disabled.
1066  */
hotplug_cpu_nmi_call_function(cpumask_t cpumask,smp_call_func_t func,void * info,int wait)1067 static int hotplug_cpu_nmi_call_function(cpumask_t cpumask,
1068 					 smp_call_func_t func, void *info,
1069 					 int wait)
1070 {
1071 	/*
1072 	 * The address and the size of nmi_call_func_mask_data
1073 	 * need to be aligned on L1_CACHE_BYTES.
1074 	 */
1075 	static struct nmi_call_data_struct nmi_call_func_mask_data
1076 		__cacheline_aligned;
1077 	unsigned long start, end;
1078 
1079 	start = (unsigned long)&nmi_call_func_mask_data;
1080 	end = start + sizeof(struct nmi_call_data_struct);
1081 
1082 	nmi_call_func_mask_data.func = func;
1083 	nmi_call_func_mask_data.info = info;
1084 	nmi_call_func_mask_data.started = cpumask;
1085 	nmi_call_func_mask_data.wait = wait;
1086 	if (wait)
1087 		nmi_call_func_mask_data.finished = cpumask;
1088 
1089 	spin_lock(&smp_nmi_call_lock);
1090 	nmi_call_data = &nmi_call_func_mask_data;
1091 	mn10300_local_dcache_flush_range(start, end);
1092 	smp_wmb();
1093 
1094 	send_IPI_mask(cpumask, CALL_FUNCTION_NMI_IPI);
1095 
1096 	do {
1097 		mn10300_local_dcache_inv_range(start, end);
1098 		barrier();
1099 	} while (!cpumask_empty(&nmi_call_func_mask_data.started));
1100 
1101 	if (wait) {
1102 		do {
1103 			mn10300_local_dcache_inv_range(start, end);
1104 			barrier();
1105 		} while (!cpumask_empty(&nmi_call_func_mask_data.finished));
1106 	}
1107 
1108 	spin_unlock(&smp_nmi_call_lock);
1109 	return 0;
1110 }
1111 
restart_wakeup_cpu(void)1112 static void restart_wakeup_cpu(void)
1113 {
1114 	unsigned int cpu = smp_processor_id();
1115 
1116 	cpumask_set_cpu(cpu, &cpu_callin_map);
1117 	local_flush_tlb();
1118 	set_cpu_online(cpu, true);
1119 	smp_wmb();
1120 }
1121 
prepare_sleep_cpu(void * unused)1122 static void prepare_sleep_cpu(void *unused)
1123 {
1124 	sleep_mode[smp_processor_id()] = 1;
1125 	smp_mb();
1126 	mn10300_local_dcache_flush_inv();
1127 	hotplug_cpu_disable_cache();
1128 	hotplug_cpu_invalidate_cache();
1129 }
1130 
1131 /* when this function called, IE=0, NMID=0. */
sleep_cpu(void * unused)1132 static void sleep_cpu(void *unused)
1133 {
1134 	unsigned int cpu_id = smp_processor_id();
1135 	/*
1136 	 * CALL_FUNCTION_NMI_IPI for wakeup_cpu() shall not be requested,
1137 	 * before this cpu goes in SLEEP mode.
1138 	 */
1139 	do {
1140 		smp_mb();
1141 		__sleep_cpu();
1142 	} while (sleep_mode[cpu_id]);
1143 	restart_wakeup_cpu();
1144 }
1145 
run_sleep_cpu(unsigned int cpu)1146 static void run_sleep_cpu(unsigned int cpu)
1147 {
1148 	unsigned long flags;
1149 	cpumask_t cpumask;
1150 
1151 	cpumask_copy(&cpumask, &cpumask_of(cpu));
1152 	flags = arch_local_cli_save();
1153 	hotplug_cpu_nmi_call_function(cpumask, prepare_sleep_cpu, NULL, 1);
1154 	hotplug_cpu_nmi_call_function(cpumask, sleep_cpu, NULL, 0);
1155 	udelay(1);		/* delay for the cpu to sleep. */
1156 	arch_local_irq_restore(flags);
1157 }
1158 
wakeup_cpu(void)1159 static void wakeup_cpu(void)
1160 {
1161 	hotplug_cpu_invalidate_cache();
1162 	hotplug_cpu_enable_cache();
1163 	smp_mb();
1164 	sleep_mode[smp_processor_id()] = 0;
1165 }
1166 
run_wakeup_cpu(unsigned int cpu)1167 static void run_wakeup_cpu(unsigned int cpu)
1168 {
1169 	unsigned long flags;
1170 
1171 	flags = arch_local_cli_save();
1172 #if NR_CPUS == 2
1173 	mn10300_local_dcache_flush_inv();
1174 #else
1175 	/*
1176 	 * Before waking up the cpu,
1177 	 * all online cpus should stop and flush D-Cache for global data.
1178 	 */
1179 #error not support NR_CPUS > 2, when CONFIG_HOTPLUG_CPU=y.
1180 #endif
1181 	hotplug_cpu_nmi_call_function(cpumask_of(cpu), wakeup_cpu, NULL, 1);
1182 	arch_local_irq_restore(flags);
1183 }
1184 
1185 #endif /* CONFIG_HOTPLUG_CPU */
1186