1// SPDX-License-Identifier: GPL-2.0
2/*
3 * arch/sh/kernel/smp.c
4 *
5 * SMP support for the SuperH processors.
6 *
7 * Copyright (C) 2002 - 2010 Paul Mundt
8 * Copyright (C) 2006 - 2007 Akio Idehara
9 */
10#include <linux/err.h>
11#include <linux/cache.h>
12#include <linux/cpumask.h>
13#include <linux/delay.h>
14#include <linux/init.h>
15#include <linux/spinlock.h>
16#include <linux/mm.h>
17#include <linux/module.h>
18#include <linux/cpu.h>
19#include <linux/interrupt.h>
20#include <linux/sched/mm.h>
21#include <linux/sched/hotplug.h>
22#include <linux/atomic.h>
23#include <linux/clockchips.h>
24#include <asm/processor.h>
25#include <asm/mmu_context.h>
26#include <asm/smp.h>
27#include <asm/cacheflush.h>
28#include <asm/sections.h>
29#include <asm/setup.h>
30
31int __cpu_number_map[NR_CPUS];		/* Map physical to logical */
32int __cpu_logical_map[NR_CPUS];		/* Map logical to physical */
33
34struct plat_smp_ops *mp_ops = NULL;
35
36/* State of each CPU */
37DEFINE_PER_CPU(int, cpu_state) = { 0 };
38
39void register_smp_ops(struct plat_smp_ops *ops)
40{
41	if (mp_ops)
42		printk(KERN_WARNING "Overriding previously set SMP ops\n");
43
44	mp_ops = ops;
45}
46
47static inline void smp_store_cpu_info(unsigned int cpu)
48{
49	struct sh_cpuinfo *c = cpu_data + cpu;
50
51	memcpy(c, &boot_cpu_data, sizeof(struct sh_cpuinfo));
52
53	c->loops_per_jiffy = loops_per_jiffy;
54}
55
56void __init smp_prepare_cpus(unsigned int max_cpus)
57{
58	unsigned int cpu = smp_processor_id();
59
60	init_new_context(current, &init_mm);
61	current_thread_info()->cpu = cpu;
62	mp_ops->prepare_cpus(max_cpus);
63
64#ifndef CONFIG_HOTPLUG_CPU
65	init_cpu_present(cpu_possible_mask);
66#endif
67}
68
69void __init smp_prepare_boot_cpu(void)
70{
71	unsigned int cpu = smp_processor_id();
72
73	__cpu_number_map[0] = cpu;
74	__cpu_logical_map[0] = cpu;
75
76	set_cpu_online(cpu, true);
77	set_cpu_possible(cpu, true);
78
79	per_cpu(cpu_state, cpu) = CPU_ONLINE;
80}
81
82#ifdef CONFIG_HOTPLUG_CPU
83void native_cpu_die(unsigned int cpu)
84{
85	unsigned int i;
86
87	for (i = 0; i < 10; i++) {
88		smp_rmb();
89		if (per_cpu(cpu_state, cpu) == CPU_DEAD) {
90			if (system_state == SYSTEM_RUNNING)
91				pr_info("CPU %u is now offline\n", cpu);
92
93			return;
94		}
95
96		msleep(100);
97	}
98
99	pr_err("CPU %u didn't die...\n", cpu);
100}
101
102int native_cpu_disable(unsigned int cpu)
103{
104	return cpu == 0 ? -EPERM : 0;
105}
106
107void play_dead_common(void)
108{
109	idle_task_exit();
110	irq_ctx_exit(raw_smp_processor_id());
111	mb();
112
113	__this_cpu_write(cpu_state, CPU_DEAD);
114	local_irq_disable();
115}
116
117void native_play_dead(void)
118{
119	play_dead_common();
120}
121
122int __cpu_disable(void)
123{
124	unsigned int cpu = smp_processor_id();
125	int ret;
126
127	ret = mp_ops->cpu_disable(cpu);
128	if (ret)
129		return ret;
130
131	/*
132	 * Take this CPU offline.  Once we clear this, we can't return,
133	 * and we must not schedule until we're ready to give up the cpu.
134	 */
135	set_cpu_online(cpu, false);
136
137	/*
138	 * OK - migrate IRQs away from this CPU
139	 */
140	migrate_irqs();
141
142	/*
143	 * Flush user cache and TLB mappings, and then remove this CPU
144	 * from the vm mask set of all processes.
145	 */
146	flush_cache_all();
147#ifdef CONFIG_MMU
148	local_flush_tlb_all();
149#endif
150
151	clear_tasks_mm_cpumask(cpu);
152
153	return 0;
154}
155#else /* ... !CONFIG_HOTPLUG_CPU */
156int native_cpu_disable(unsigned int cpu)
157{
158	return -ENOSYS;
159}
160
161void native_cpu_die(unsigned int cpu)
162{
163	/* We said "no" in __cpu_disable */
164	BUG();
165}
166
167void native_play_dead(void)
168{
169	BUG();
170}
171#endif
172
173asmlinkage void start_secondary(void)
174{
175	unsigned int cpu = smp_processor_id();
176	struct mm_struct *mm = &init_mm;
177
178	enable_mmu();
179	mmgrab(mm);
180	mmget(mm);
181	current->active_mm = mm;
182#ifdef CONFIG_MMU
183	enter_lazy_tlb(mm, current);
184	local_flush_tlb_all();
185#endif
186
187	per_cpu_trap_init();
188
189	notify_cpu_starting(cpu);
190
191	local_irq_enable();
192
193	calibrate_delay();
194
195	smp_store_cpu_info(cpu);
196
197	set_cpu_online(cpu, true);
198	per_cpu(cpu_state, cpu) = CPU_ONLINE;
199
200	cpu_startup_entry(CPUHP_AP_ONLINE_IDLE);
201}
202
203extern struct {
204	unsigned long sp;
205	unsigned long bss_start;
206	unsigned long bss_end;
207	void *start_kernel_fn;
208	void *cpu_init_fn;
209	void *thread_info;
210} stack_start;
211
212int __cpu_up(unsigned int cpu, struct task_struct *tsk)
213{
214	unsigned long timeout;
215
216	per_cpu(cpu_state, cpu) = CPU_UP_PREPARE;
217
218	/* Fill in data in head.S for secondary cpus */
219	stack_start.sp = tsk->thread.sp;
220	stack_start.thread_info = tsk->stack;
221	stack_start.bss_start = 0; /* don't clear bss for secondary cpus */
222	stack_start.start_kernel_fn = start_secondary;
223
224	flush_icache_range((unsigned long)&stack_start,
225			   (unsigned long)&stack_start + sizeof(stack_start));
226	wmb();
227
228	mp_ops->start_cpu(cpu, (unsigned long)_stext);
229
230	timeout = jiffies + HZ;
231	while (time_before(jiffies, timeout)) {
232		if (cpu_online(cpu))
233			break;
234
235		udelay(10);
236		barrier();
237	}
238
239	if (cpu_online(cpu))
240		return 0;
241
242	return -ENOENT;
243}
244
245void __init smp_cpus_done(unsigned int max_cpus)
246{
247	unsigned long bogosum = 0;
248	int cpu;
249
250	for_each_online_cpu(cpu)
251		bogosum += cpu_data[cpu].loops_per_jiffy;
252
253	printk(KERN_INFO "SMP: Total of %d processors activated "
254	       "(%lu.%02lu BogoMIPS).\n", num_online_cpus(),
255	       bogosum / (500000/HZ),
256	       (bogosum / (5000/HZ)) % 100);
257}
258
259void arch_smp_send_reschedule(int cpu)
260{
261	mp_ops->send_ipi(cpu, SMP_MSG_RESCHEDULE);
262}
263
264void smp_send_stop(void)
265{
266	smp_call_function(stop_this_cpu, 0, 0);
267}
268
269void arch_send_call_function_ipi_mask(const struct cpumask *mask)
270{
271	int cpu;
272
273	for_each_cpu(cpu, mask)
274		mp_ops->send_ipi(cpu, SMP_MSG_FUNCTION);
275}
276
277void arch_send_call_function_single_ipi(int cpu)
278{
279	mp_ops->send_ipi(cpu, SMP_MSG_FUNCTION_SINGLE);
280}
281
282#ifdef CONFIG_GENERIC_CLOCKEVENTS_BROADCAST
283void tick_broadcast(const struct cpumask *mask)
284{
285	int cpu;
286
287	for_each_cpu(cpu, mask)
288		mp_ops->send_ipi(cpu, SMP_MSG_TIMER);
289}
290
291static void ipi_timer(void)
292{
293	irq_enter();
294	tick_receive_broadcast();
295	irq_exit();
296}
297#endif
298
299void smp_message_recv(unsigned int msg)
300{
301	switch (msg) {
302	case SMP_MSG_FUNCTION:
303		generic_smp_call_function_interrupt();
304		break;
305	case SMP_MSG_RESCHEDULE:
306		scheduler_ipi();
307		break;
308	case SMP_MSG_FUNCTION_SINGLE:
309		generic_smp_call_function_single_interrupt();
310		break;
311#ifdef CONFIG_GENERIC_CLOCKEVENTS_BROADCAST
312	case SMP_MSG_TIMER:
313		ipi_timer();
314		break;
315#endif
316	default:
317		printk(KERN_WARNING "SMP %d: %s(): unknown IPI %d\n",
318		       smp_processor_id(), __func__, msg);
319		break;
320	}
321}
322
323/* Not really SMP stuff ... */
324int setup_profiling_timer(unsigned int multiplier)
325{
326	return 0;
327}
328
329#ifdef CONFIG_MMU
330
331static void flush_tlb_all_ipi(void *info)
332{
333	local_flush_tlb_all();
334}
335
336void flush_tlb_all(void)
337{
338	on_each_cpu(flush_tlb_all_ipi, 0, 1);
339}
340
341static void flush_tlb_mm_ipi(void *mm)
342{
343	local_flush_tlb_mm((struct mm_struct *)mm);
344}
345
346/*
347 * The following tlb flush calls are invoked when old translations are
348 * being torn down, or pte attributes are changing. For single threaded
349 * address spaces, a new context is obtained on the current cpu, and tlb
350 * context on other cpus are invalidated to force a new context allocation
351 * at switch_mm time, should the mm ever be used on other cpus. For
352 * multithreaded address spaces, intercpu interrupts have to be sent.
353 * Another case where intercpu interrupts are required is when the target
354 * mm might be active on another cpu (eg debuggers doing the flushes on
355 * behalf of debugees, kswapd stealing pages from another process etc).
356 * Kanoj 07/00.
357 */
358void flush_tlb_mm(struct mm_struct *mm)
359{
360	preempt_disable();
361
362	if ((atomic_read(&mm->mm_users) != 1) || (current->mm != mm)) {
363		smp_call_function(flush_tlb_mm_ipi, (void *)mm, 1);
364	} else {
365		int i;
366		for_each_online_cpu(i)
367			if (smp_processor_id() != i)
368				cpu_context(i, mm) = 0;
369	}
370	local_flush_tlb_mm(mm);
371
372	preempt_enable();
373}
374
375struct flush_tlb_data {
376	struct vm_area_struct *vma;
377	unsigned long addr1;
378	unsigned long addr2;
379};
380
381static void flush_tlb_range_ipi(void *info)
382{
383	struct flush_tlb_data *fd = (struct flush_tlb_data *)info;
384
385	local_flush_tlb_range(fd->vma, fd->addr1, fd->addr2);
386}
387
388void flush_tlb_range(struct vm_area_struct *vma,
389		     unsigned long start, unsigned long end)
390{
391	struct mm_struct *mm = vma->vm_mm;
392
393	preempt_disable();
394	if ((atomic_read(&mm->mm_users) != 1) || (current->mm != mm)) {
395		struct flush_tlb_data fd;
396
397		fd.vma = vma;
398		fd.addr1 = start;
399		fd.addr2 = end;
400		smp_call_function(flush_tlb_range_ipi, (void *)&fd, 1);
401	} else {
402		int i;
403		for_each_online_cpu(i)
404			if (smp_processor_id() != i)
405				cpu_context(i, mm) = 0;
406	}
407	local_flush_tlb_range(vma, start, end);
408	preempt_enable();
409}
410
411static void flush_tlb_kernel_range_ipi(void *info)
412{
413	struct flush_tlb_data *fd = (struct flush_tlb_data *)info;
414
415	local_flush_tlb_kernel_range(fd->addr1, fd->addr2);
416}
417
418void flush_tlb_kernel_range(unsigned long start, unsigned long end)
419{
420	struct flush_tlb_data fd;
421
422	fd.addr1 = start;
423	fd.addr2 = end;
424	on_each_cpu(flush_tlb_kernel_range_ipi, (void *)&fd, 1);
425}
426
427static void flush_tlb_page_ipi(void *info)
428{
429	struct flush_tlb_data *fd = (struct flush_tlb_data *)info;
430
431	local_flush_tlb_page(fd->vma, fd->addr1);
432}
433
434void flush_tlb_page(struct vm_area_struct *vma, unsigned long page)
435{
436	preempt_disable();
437	if ((atomic_read(&vma->vm_mm->mm_users) != 1) ||
438	    (current->mm != vma->vm_mm)) {
439		struct flush_tlb_data fd;
440
441		fd.vma = vma;
442		fd.addr1 = page;
443		smp_call_function(flush_tlb_page_ipi, (void *)&fd, 1);
444	} else {
445		int i;
446		for_each_online_cpu(i)
447			if (smp_processor_id() != i)
448				cpu_context(i, vma->vm_mm) = 0;
449	}
450	local_flush_tlb_page(vma, page);
451	preempt_enable();
452}
453
454static void flush_tlb_one_ipi(void *info)
455{
456	struct flush_tlb_data *fd = (struct flush_tlb_data *)info;
457	local_flush_tlb_one(fd->addr1, fd->addr2);
458}
459
460void flush_tlb_one(unsigned long asid, unsigned long vaddr)
461{
462	struct flush_tlb_data fd;
463
464	fd.addr1 = asid;
465	fd.addr2 = vaddr;
466
467	smp_call_function(flush_tlb_one_ipi, (void *)&fd, 1);
468	local_flush_tlb_one(asid, vaddr);
469}
470
471#endif
472