summaryrefslogtreecommitdiff
path: root/arch/sh/kernel/smp.c
blob: 65924d9ec24598f81e995bee85bf4cb135b1d84b (plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
274
275
276
277
278
279
280
281
282
283
284
285
286
287
288
289
290
291
292
293
294
295
296
297
298
299
300
301
302
303
304
305
306
307
308
309
310
311
312
313
314
315
316
317
318
319
320
321
322
323
324
325
326
327
328
329
330
331
332
333
334
335
336
337
338
339
340
341
342
343
344
345
346
347
348
349
350
351
352
353
354
355
356
357
358
359
360
361
362
363
364
365
366
367
368
369
370
371
372
373
374
375
376
377
378
379
380
381
382
383
384
385
386
387
388
389
390
391
392
393
394
395
396
397
398
399
400
401
402
403
404
405
406
407
408
409
410
411
412
413
414
415
416
417
418
419
420
421
422
423
424
425
426
427
428
429
430
431
432
433
434
435
436
437
438
439
440
441
442
443
444
445
446
447
448
449
450
451
452
453
454
455
456
457
458
459
460
461
462
463
464
465
466
467
468
469
470
471
// SPDX-License-Identifier: GPL-2.0
/*
 * arch/sh/kernel/smp.c
 *
 * SMP support for the SuperH processors.
 *
 * Copyright (C) 2002 - 2010 Paul Mundt
 * Copyright (C) 2006 - 2007 Akio Idehara
 */
#include <linux/err.h>
#include <linux/cache.h>
#include <linux/cpumask.h>
#include <linux/delay.h>
#include <linux/init.h>
#include <linux/spinlock.h>
#include <linux/mm.h>
#include <linux/module.h>
#include <linux/cpu.h>
#include <linux/interrupt.h>
#include <linux/sched/mm.h>
#include <linux/sched/hotplug.h>
#include <linux/atomic.h>
#include <linux/clockchips.h>
#include <asm/processor.h>
#include <asm/mmu_context.h>
#include <asm/smp.h>
#include <asm/cacheflush.h>
#include <asm/sections.h>
#include <asm/setup.h>

int __cpu_number_map[NR_CPUS];		/* Map physical to logical */
int __cpu_logical_map[NR_CPUS];		/* Map logical to physical */

struct plat_smp_ops *mp_ops = NULL;

/* State of each CPU */
DEFINE_PER_CPU(int, cpu_state) = { 0 };

void register_smp_ops(struct plat_smp_ops *ops)
{
	if (mp_ops)
		printk(KERN_WARNING "Overriding previously set SMP ops\n");

	mp_ops = ops;
}

static inline void smp_store_cpu_info(unsigned int cpu)
{
	struct sh_cpuinfo *c = cpu_data + cpu;

	memcpy(c, &boot_cpu_data, sizeof(struct sh_cpuinfo));

	c->loops_per_jiffy = loops_per_jiffy;
}

void __init smp_prepare_cpus(unsigned int max_cpus)
{
	unsigned int cpu = smp_processor_id();

	init_new_context(current, &init_mm);
	current_thread_info()->cpu = cpu;
	mp_ops->prepare_cpus(max_cpus);

#ifndef CONFIG_HOTPLUG_CPU
	init_cpu_present(cpu_possible_mask);
#endif
}

void __init smp_prepare_boot_cpu(void)
{
	unsigned int cpu = smp_processor_id();

	__cpu_number_map[0] = cpu;
	__cpu_logical_map[0] = cpu;

	set_cpu_online(cpu, true);
	set_cpu_possible(cpu, true);

	per_cpu(cpu_state, cpu) = CPU_ONLINE;
}

#ifdef CONFIG_HOTPLUG_CPU
void native_cpu_die(unsigned int cpu)
{
	unsigned int i;

	for (i = 0; i < 10; i++) {
		smp_rmb();
		if (per_cpu(cpu_state, cpu) == CPU_DEAD) {
			if (system_state == SYSTEM_RUNNING)
				pr_info("CPU %u is now offline\n", cpu);

			return;
		}

		msleep(100);
	}

	pr_err("CPU %u didn't die...\n", cpu);
}

int native_cpu_disable(unsigned int cpu)
{
	return cpu == 0 ? -EPERM : 0;
}

void play_dead_common(void)
{
	idle_task_exit();
	irq_ctx_exit(raw_smp_processor_id());
	mb();

	__this_cpu_write(cpu_state, CPU_DEAD);
	local_irq_disable();
}

void native_play_dead(void)
{
	play_dead_common();
}

int __cpu_disable(void)
{
	unsigned int cpu = smp_processor_id();
	int ret;

	ret = mp_ops->cpu_disable(cpu);
	if (ret)
		return ret;

	/*
	 * Take this CPU offline.  Once we clear this, we can't return,
	 * and we must not schedule until we're ready to give up the cpu.
	 */
	set_cpu_online(cpu, false);

	/*
	 * OK - migrate IRQs away from this CPU
	 */
	migrate_irqs();

	/*
	 * Flush user cache and TLB mappings, and then remove this CPU
	 * from the vm mask set of all processes.
	 */
	flush_cache_all();
#ifdef CONFIG_MMU
	local_flush_tlb_all();
#endif

	clear_tasks_mm_cpumask(cpu);

	return 0;
}
#else /* ... !CONFIG_HOTPLUG_CPU */
int native_cpu_disable(unsigned int cpu)
{
	return -ENOSYS;
}

void native_cpu_die(unsigned int cpu)
{
	/* We said "no" in __cpu_disable */
	BUG();
}

void native_play_dead(void)
{
	BUG();
}
#endif

asmlinkage void start_secondary(void)
{
	unsigned int cpu = smp_processor_id();
	struct mm_struct *mm = &init_mm;

	enable_mmu();
	mmgrab(mm);
	mmget(mm);
	current->active_mm = mm;
#ifdef CONFIG_MMU
	enter_lazy_tlb(mm, current);
	local_flush_tlb_all();
#endif

	per_cpu_trap_init();

	notify_cpu_starting(cpu);

	local_irq_enable();

	calibrate_delay();

	smp_store_cpu_info(cpu);

	set_cpu_online(cpu, true);
	per_cpu(cpu_state, cpu) = CPU_ONLINE;

	cpu_startup_entry(CPUHP_AP_ONLINE_IDLE);
}

extern struct {
	unsigned long sp;
	unsigned long bss_start;
	unsigned long bss_end;
	void *start_kernel_fn;
	void *cpu_init_fn;
	void *thread_info;
} stack_start;

int __cpu_up(unsigned int cpu, struct task_struct *tsk)
{
	unsigned long timeout;

	per_cpu(cpu_state, cpu) = CPU_UP_PREPARE;

	/* Fill in data in head.S for secondary cpus */
	stack_start.sp = tsk->thread.sp;
	stack_start.thread_info = tsk->stack;
	stack_start.bss_start = 0; /* don't clear bss for secondary cpus */
	stack_start.start_kernel_fn = start_secondary;

	flush_icache_range((unsigned long)&stack_start,
			   (unsigned long)&stack_start + sizeof(stack_start));
	wmb();

	mp_ops->start_cpu(cpu, (unsigned long)_stext);

	timeout = jiffies + HZ;
	while (time_before(jiffies, timeout)) {
		if (cpu_online(cpu))
			break;

		udelay(10);
		barrier();
	}

	if (cpu_online(cpu))
		return 0;

	return -ENOENT;
}

void __init smp_cpus_done(unsigned int max_cpus)
{
	unsigned long bogosum = 0;
	int cpu;

	for_each_online_cpu(cpu)
		bogosum += cpu_data[cpu].loops_per_jiffy;

	printk(KERN_INFO "SMP: Total of %d processors activated "
	       "(%lu.%02lu BogoMIPS).\n", num_online_cpus(),
	       bogosum / (500000/HZ),
	       (bogosum / (5000/HZ)) % 100);
}

void smp_send_reschedule(int cpu)
{
	mp_ops->send_ipi(cpu, SMP_MSG_RESCHEDULE);
}

void smp_send_stop(void)
{
	smp_call_function(stop_this_cpu, 0, 0);
}

void arch_send_call_function_ipi_mask(const struct cpumask *mask)
{
	int cpu;

	for_each_cpu(cpu, mask)
		mp_ops->send_ipi(cpu, SMP_MSG_FUNCTION);
}

void arch_send_call_function_single_ipi(int cpu)
{
	mp_ops->send_ipi(cpu, SMP_MSG_FUNCTION_SINGLE);
}

#ifdef CONFIG_GENERIC_CLOCKEVENTS_BROADCAST
void tick_broadcast(const struct cpumask *mask)
{
	int cpu;

	for_each_cpu(cpu, mask)
		mp_ops->send_ipi(cpu, SMP_MSG_TIMER);
}

static void ipi_timer(void)
{
	irq_enter();
	tick_receive_broadcast();
	irq_exit();
}
#endif

void smp_message_recv(unsigned int msg)
{
	switch (msg) {
	case SMP_MSG_FUNCTION:
		generic_smp_call_function_interrupt();
		break;
	case SMP_MSG_RESCHEDULE:
		scheduler_ipi();
		break;
	case SMP_MSG_FUNCTION_SINGLE:
		generic_smp_call_function_single_interrupt();
		break;
#ifdef CONFIG_GENERIC_CLOCKEVENTS_BROADCAST
	case SMP_MSG_TIMER:
		ipi_timer();
		break;
#endif
	default:
		printk(KERN_WARNING "SMP %d: %s(): unknown IPI %d\n",
		       smp_processor_id(), __func__, msg);
		break;
	}
}

/* Not really SMP stuff ... */
int setup_profiling_timer(unsigned int multiplier)
{
	return 0;
}

#ifdef CONFIG_MMU

static void flush_tlb_all_ipi(void *info)
{
	local_flush_tlb_all();
}

void flush_tlb_all(void)
{
	on_each_cpu(flush_tlb_all_ipi, 0, 1);
}

static void flush_tlb_mm_ipi(void *mm)
{
	local_flush_tlb_mm((struct mm_struct *)mm);
}

/*
 * The following tlb flush calls are invoked when old translations are
 * being torn down, or pte attributes are changing. For single threaded
 * address spaces, a new context is obtained on the current cpu, and tlb
 * context on other cpus are invalidated to force a new context allocation
 * at switch_mm time, should the mm ever be used on other cpus. For
 * multithreaded address spaces, intercpu interrupts have to be sent.
 * Another case where intercpu interrupts are required is when the target
 * mm might be active on another cpu (eg debuggers doing the flushes on
 * behalf of debugees, kswapd stealing pages from another process etc).
 * Kanoj 07/00.
 */
void flush_tlb_mm(struct mm_struct *mm)
{
	preempt_disable();

	if ((atomic_read(&mm->mm_users) != 1) || (current->mm != mm)) {
		smp_call_function(flush_tlb_mm_ipi, (void *)mm, 1);
	} else {
		int i;
		for_each_online_cpu(i)
			if (smp_processor_id() != i)
				cpu_context(i, mm) = 0;
	}
	local_flush_tlb_mm(mm);

	preempt_enable();
}

struct flush_tlb_data {
	struct vm_area_struct *vma;
	unsigned long addr1;
	unsigned long addr2;
};

static void flush_tlb_range_ipi(void *info)
{
	struct flush_tlb_data *fd = (struct flush_tlb_data *)info;

	local_flush_tlb_range(fd->vma, fd->addr1, fd->addr2);
}

void flush_tlb_range(struct vm_area_struct *vma,
		     unsigned long start, unsigned long end)
{
	struct mm_struct *mm = vma->vm_mm;

	preempt_disable();
	if ((atomic_read(&mm->mm_users) != 1) || (current->mm != mm)) {
		struct flush_tlb_data fd;

		fd.vma = vma;
		fd.addr1 = start;
		fd.addr2 = end;
		smp_call_function(flush_tlb_range_ipi, (void *)&fd, 1);
	} else {
		int i;
		for_each_online_cpu(i)
			if (smp_processor_id() != i)
				cpu_context(i, mm) = 0;
	}
	local_flush_tlb_range(vma, start, end);
	preempt_enable();
}

static void flush_tlb_kernel_range_ipi(void *info)
{
	struct flush_tlb_data *fd = (struct flush_tlb_data *)info;

	local_flush_tlb_kernel_range(fd->addr1, fd->addr2);
}

void flush_tlb_kernel_range(unsigned long start, unsigned long end)
{
	struct flush_tlb_data fd;

	fd.addr1 = start;
	fd.addr2 = end;
	on_each_cpu(flush_tlb_kernel_range_ipi, (void *)&fd, 1);
}

static void flush_tlb_page_ipi(void *info)
{
	struct flush_tlb_data *fd = (struct flush_tlb_data *)info;

	local_flush_tlb_page(fd->vma, fd->addr1);
}

void flush_tlb_page(struct vm_area_struct *vma, unsigned long page)
{
	preempt_disable();
	if ((atomic_read(&vma->vm_mm->mm_users) != 1) ||
	    (current->mm != vma->vm_mm)) {
		struct flush_tlb_data fd;

		fd.vma = vma;
		fd.addr1 = page;
		smp_call_function(flush_tlb_page_ipi, (void *)&fd, 1);
	} else {
		int i;
		for_each_online_cpu(i)
			if (smp_processor_id() != i)
				cpu_context(i, vma->vm_mm) = 0;
	}
	local_flush_tlb_page(vma, page);
	preempt_enable();
}

static void flush_tlb_one_ipi(void *info)
{
	struct flush_tlb_data *fd = (struct flush_tlb_data *)info;
	local_flush_tlb_one(fd->addr1, fd->addr2);
}

void flush_tlb_one(unsigned long asid, unsigned long vaddr)
{
	struct flush_tlb_data fd;

	fd.addr1 = asid;
	fd.addr2 = vaddr;

	smp_call_function(flush_tlb_one_ipi, (void *)&fd, 1);
	local_flush_tlb_one(asid, vaddr);
}

#endif