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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 <linux/profile.h>
25
26#include <asm/processor.h>
27#include <asm/mmu_context.h>
28#include <asm/smp.h>
29#include <asm/cacheflush.h>
30#include <asm/sections.h>
31#include <asm/setup.h>
32
33int __cpu_number_map[NR_CPUS]; /* Map physical to logical */
34int __cpu_logical_map[NR_CPUS]; /* Map logical to physical */
35
36struct plat_smp_ops *mp_ops = NULL;
37
38/* State of each CPU */
39DEFINE_PER_CPU(int, cpu_state) = { 0 };
40
41void register_smp_ops(struct plat_smp_ops *ops)
42{
43 if (mp_ops)
44 printk(KERN_WARNING "Overriding previously set SMP ops\n");
45
46 mp_ops = ops;
47}
48
49static inline void smp_store_cpu_info(unsigned int cpu)
50{
51 struct sh_cpuinfo *c = cpu_data + cpu;
52
53 memcpy(c, &boot_cpu_data, sizeof(struct sh_cpuinfo));
54
55 c->loops_per_jiffy = loops_per_jiffy;
56}
57
58void __init smp_prepare_cpus(unsigned int max_cpus)
59{
60 unsigned int cpu = smp_processor_id();
61
62 init_new_context(current, &init_mm);
63 current_thread_info()->cpu = cpu;
64 mp_ops->prepare_cpus(max_cpus);
65
66#ifndef CONFIG_HOTPLUG_CPU
67 init_cpu_present(cpu_possible_mask);
68#endif
69}
70
71void __init smp_prepare_boot_cpu(void)
72{
73 unsigned int cpu = smp_processor_id();
74
75 __cpu_number_map[0] = cpu;
76 __cpu_logical_map[0] = cpu;
77
78 set_cpu_online(cpu, true);
79 set_cpu_possible(cpu, true);
80
81 per_cpu(cpu_state, cpu) = CPU_ONLINE;
82}
83
84#ifdef CONFIG_HOTPLUG_CPU
85void native_cpu_die(unsigned int cpu)
86{
87 unsigned int i;
88
89 for (i = 0; i < 10; i++) {
90 smp_rmb();
91 if (per_cpu(cpu_state, cpu) == CPU_DEAD) {
92 if (system_state == SYSTEM_RUNNING)
93 pr_info("CPU %u is now offline\n", cpu);
94
95 return;
96 }
97
98 msleep(100);
99 }
100
101 pr_err("CPU %u didn't die...\n", cpu);
102}
103
104int native_cpu_disable(unsigned int cpu)
105{
106 return cpu == 0 ? -EPERM : 0;
107}
108
109void play_dead_common(void)
110{
111 idle_task_exit();
112 irq_ctx_exit(raw_smp_processor_id());
113 mb();
114
115 __this_cpu_write(cpu_state, CPU_DEAD);
116 local_irq_disable();
117}
118
119void native_play_dead(void)
120{
121 play_dead_common();
122}
123
124int __cpu_disable(void)
125{
126 unsigned int cpu = smp_processor_id();
127 int ret;
128
129 ret = mp_ops->cpu_disable(cpu);
130 if (ret)
131 return ret;
132
133 /*
134 * Take this CPU offline. Once we clear this, we can't return,
135 * and we must not schedule until we're ready to give up the cpu.
136 */
137 set_cpu_online(cpu, false);
138
139 /*
140 * OK - migrate IRQs away from this CPU
141 */
142 migrate_irqs();
143
144 /*
145 * Flush user cache and TLB mappings, and then remove this CPU
146 * from the vm mask set of all processes.
147 */
148 flush_cache_all();
149#ifdef CONFIG_MMU
150 local_flush_tlb_all();
151#endif
152
153 clear_tasks_mm_cpumask(cpu);
154
155 return 0;
156}
157#else /* ... !CONFIG_HOTPLUG_CPU */
158int native_cpu_disable(unsigned int cpu)
159{
160 return -ENOSYS;
161}
162
163void native_cpu_die(unsigned int cpu)
164{
165 /* We said "no" in __cpu_disable */
166 BUG();
167}
168
169void native_play_dead(void)
170{
171 BUG();
172}
173#endif
174
175static asmlinkage void start_secondary(void)
176{
177 unsigned int cpu = smp_processor_id();
178 struct mm_struct *mm = &init_mm;
179
180 enable_mmu();
181 mmgrab(mm);
182 mmget(mm);
183 current->active_mm = mm;
184#ifdef CONFIG_MMU
185 enter_lazy_tlb(mm, current);
186 local_flush_tlb_all();
187#endif
188
189 per_cpu_trap_init();
190
191 notify_cpu_starting(cpu);
192
193 local_irq_enable();
194
195 calibrate_delay();
196
197 smp_store_cpu_info(cpu);
198
199 set_cpu_online(cpu, true);
200 per_cpu(cpu_state, cpu) = CPU_ONLINE;
201
202 cpu_startup_entry(CPUHP_AP_ONLINE_IDLE);
203}
204
205extern struct {
206 unsigned long sp;
207 unsigned long bss_start;
208 unsigned long bss_end;
209 void *start_kernel_fn;
210 void *cpu_init_fn;
211 void *thread_info;
212} stack_start;
213
214int __cpu_up(unsigned int cpu, struct task_struct *tsk)
215{
216 unsigned long timeout;
217
218 per_cpu(cpu_state, cpu) = CPU_UP_PREPARE;
219
220 /* Fill in data in head.S for secondary cpus */
221 stack_start.sp = tsk->thread.sp;
222 stack_start.thread_info = tsk->stack;
223 stack_start.bss_start = 0; /* don't clear bss for secondary cpus */
224 stack_start.start_kernel_fn = start_secondary;
225
226 flush_icache_range((unsigned long)&stack_start,
227 (unsigned long)&stack_start + sizeof(stack_start));
228 wmb();
229
230 mp_ops->start_cpu(cpu, (unsigned long)_stext);
231
232 timeout = jiffies + HZ;
233 while (time_before(jiffies, timeout)) {
234 if (cpu_online(cpu))
235 break;
236
237 udelay(10);
238 barrier();
239 }
240
241 if (cpu_online(cpu))
242 return 0;
243
244 return -ENOENT;
245}
246
247void __init smp_cpus_done(unsigned int max_cpus)
248{
249 unsigned long bogosum = 0;
250 int cpu;
251
252 for_each_online_cpu(cpu)
253 bogosum += cpu_data[cpu].loops_per_jiffy;
254
255 printk(KERN_INFO "SMP: Total of %d processors activated "
256 "(%lu.%02lu BogoMIPS).\n", num_online_cpus(),
257 bogosum / (500000/HZ),
258 (bogosum / (5000/HZ)) % 100);
259}
260
261void arch_smp_send_reschedule(int cpu)
262{
263 mp_ops->send_ipi(cpu, SMP_MSG_RESCHEDULE);
264}
265
266void smp_send_stop(void)
267{
268 smp_call_function(stop_this_cpu, 0, 0);
269}
270
271void arch_send_call_function_ipi_mask(const struct cpumask *mask)
272{
273 int cpu;
274
275 for_each_cpu(cpu, mask)
276 mp_ops->send_ipi(cpu, SMP_MSG_FUNCTION);
277}
278
279void arch_send_call_function_single_ipi(int cpu)
280{
281 mp_ops->send_ipi(cpu, SMP_MSG_FUNCTION_SINGLE);
282}
283
284#ifdef CONFIG_GENERIC_CLOCKEVENTS_BROADCAST
285void tick_broadcast(const struct cpumask *mask)
286{
287 int cpu;
288
289 for_each_cpu(cpu, mask)
290 mp_ops->send_ipi(cpu, SMP_MSG_TIMER);
291}
292
293static void ipi_timer(void)
294{
295 irq_enter();
296 tick_receive_broadcast();
297 irq_exit();
298}
299#endif
300
301void smp_message_recv(unsigned int msg)
302{
303 switch (msg) {
304 case SMP_MSG_FUNCTION:
305 generic_smp_call_function_interrupt();
306 break;
307 case SMP_MSG_RESCHEDULE:
308 scheduler_ipi();
309 break;
310 case SMP_MSG_FUNCTION_SINGLE:
311 generic_smp_call_function_single_interrupt();
312 break;
313#ifdef CONFIG_GENERIC_CLOCKEVENTS_BROADCAST
314 case SMP_MSG_TIMER:
315 ipi_timer();
316 break;
317#endif
318 default:
319 printk(KERN_WARNING "SMP %d: %s(): unknown IPI %d\n",
320 smp_processor_id(), __func__, msg);
321 break;
322 }
323}
324
325#ifdef CONFIG_PROFILING
326/* Not really SMP stuff ... */
327int setup_profiling_timer(unsigned int multiplier)
328{
329 return 0;
330}
331#endif
332
333#ifdef CONFIG_MMU
334
335static void flush_tlb_all_ipi(void *info)
336{
337 local_flush_tlb_all();
338}
339
340void flush_tlb_all(void)
341{
342 on_each_cpu(flush_tlb_all_ipi, 0, 1);
343}
344
345static void flush_tlb_mm_ipi(void *mm)
346{
347 local_flush_tlb_mm((struct mm_struct *)mm);
348}
349
350/*
351 * The following tlb flush calls are invoked when old translations are
352 * being torn down, or pte attributes are changing. For single threaded
353 * address spaces, a new context is obtained on the current cpu, and tlb
354 * context on other cpus are invalidated to force a new context allocation
355 * at switch_mm time, should the mm ever be used on other cpus. For
356 * multithreaded address spaces, intercpu interrupts have to be sent.
357 * Another case where intercpu interrupts are required is when the target
358 * mm might be active on another cpu (eg debuggers doing the flushes on
359 * behalf of debugees, kswapd stealing pages from another process etc).
360 * Kanoj 07/00.
361 */
362void flush_tlb_mm(struct mm_struct *mm)
363{
364 preempt_disable();
365
366 if ((atomic_read(&mm->mm_users) != 1) || (current->mm != mm)) {
367 smp_call_function(flush_tlb_mm_ipi, (void *)mm, 1);
368 } else {
369 int i;
370 for_each_online_cpu(i)
371 if (smp_processor_id() != i)
372 cpu_context(i, mm) = 0;
373 }
374 local_flush_tlb_mm(mm);
375
376 preempt_enable();
377}
378
379struct flush_tlb_data {
380 struct vm_area_struct *vma;
381 unsigned long addr1;
382 unsigned long addr2;
383};
384
385static void flush_tlb_range_ipi(void *info)
386{
387 struct flush_tlb_data *fd = (struct flush_tlb_data *)info;
388
389 local_flush_tlb_range(fd->vma, fd->addr1, fd->addr2);
390}
391
392void flush_tlb_range(struct vm_area_struct *vma,
393 unsigned long start, unsigned long end)
394{
395 struct mm_struct *mm = vma->vm_mm;
396
397 preempt_disable();
398 if ((atomic_read(&mm->mm_users) != 1) || (current->mm != mm)) {
399 struct flush_tlb_data fd;
400
401 fd.vma = vma;
402 fd.addr1 = start;
403 fd.addr2 = end;
404 smp_call_function(flush_tlb_range_ipi, (void *)&fd, 1);
405 } else {
406 int i;
407 for_each_online_cpu(i)
408 if (smp_processor_id() != i)
409 cpu_context(i, mm) = 0;
410 }
411 local_flush_tlb_range(vma, start, end);
412 preempt_enable();
413}
414
415static void flush_tlb_kernel_range_ipi(void *info)
416{
417 struct flush_tlb_data *fd = (struct flush_tlb_data *)info;
418
419 local_flush_tlb_kernel_range(fd->addr1, fd->addr2);
420}
421
422void flush_tlb_kernel_range(unsigned long start, unsigned long end)
423{
424 struct flush_tlb_data fd;
425
426 fd.addr1 = start;
427 fd.addr2 = end;
428 on_each_cpu(flush_tlb_kernel_range_ipi, (void *)&fd, 1);
429}
430
431static void flush_tlb_page_ipi(void *info)
432{
433 struct flush_tlb_data *fd = (struct flush_tlb_data *)info;
434
435 local_flush_tlb_page(fd->vma, fd->addr1);
436}
437
438void flush_tlb_page(struct vm_area_struct *vma, unsigned long page)
439{
440 preempt_disable();
441 if ((atomic_read(&vma->vm_mm->mm_users) != 1) ||
442 (current->mm != vma->vm_mm)) {
443 struct flush_tlb_data fd;
444
445 fd.vma = vma;
446 fd.addr1 = page;
447 smp_call_function(flush_tlb_page_ipi, (void *)&fd, 1);
448 } else {
449 int i;
450 for_each_online_cpu(i)
451 if (smp_processor_id() != i)
452 cpu_context(i, vma->vm_mm) = 0;
453 }
454 local_flush_tlb_page(vma, page);
455 preempt_enable();
456}
457
458static void flush_tlb_one_ipi(void *info)
459{
460 struct flush_tlb_data *fd = (struct flush_tlb_data *)info;
461 local_flush_tlb_one(fd->addr1, fd->addr2);
462}
463
464void flush_tlb_one(unsigned long asid, unsigned long vaddr)
465{
466 struct flush_tlb_data fd;
467
468 fd.addr1 = asid;
469 fd.addr2 = vaddr;
470
471 smp_call_function(flush_tlb_one_ipi, (void *)&fd, 1);
472 local_flush_tlb_one(asid, vaddr);
473}
474
475#endif