1/*
2 * arch/sh/kernel/smp.c
3 *
4 * SMP support for the SuperH processors.
5 *
6 * Copyright (C) 2002 - 2010 Paul Mundt
7 * Copyright (C) 2006 - 2007 Akio Idehara
8 *
9 * This file is subject to the terms and conditions of the GNU General Public
10 * License.  See the file "COPYING" in the main directory of this archive
11 * for more details.
12 */
13#include <linux/err.h>
14#include <linux/cache.h>
15#include <linux/cpumask.h>
16#include <linux/delay.h>
17#include <linux/init.h>
18#include <linux/spinlock.h>
19#include <linux/mm.h>
20#include <linux/module.h>
21#include <linux/cpu.h>
22#include <linux/interrupt.h>
23#include <linux/sched.h>
24#include <linux/atomic.h>
25#include <asm/processor.h>
26#include <asm/mmu_context.h>
27#include <asm/smp.h>
28#include <asm/cacheflush.h>
29#include <asm/sections.h>
30#include <asm/setup.h>
31
32int __cpu_number_map[NR_CPUS];		/* Map physical to logical */
33int __cpu_logical_map[NR_CPUS];		/* Map logical to physical */
34
35struct plat_smp_ops *mp_ops = NULL;
36
37/* State of each CPU */
38DEFINE_PER_CPU(int, cpu_state) = { 0 };
39
40void register_smp_ops(struct plat_smp_ops *ops)
41{
42	if (mp_ops)
43		printk(KERN_WARNING "Overriding previously set SMP ops\n");
44
45	mp_ops = ops;
46}
47
48static inline void smp_store_cpu_info(unsigned int cpu)
49{
50	struct sh_cpuinfo *c = cpu_data + cpu;
51
52	memcpy(c, &boot_cpu_data, sizeof(struct sh_cpuinfo));
53
54	c->loops_per_jiffy = loops_per_jiffy;
55}
56
57void __init smp_prepare_cpus(unsigned int max_cpus)
58{
59	unsigned int cpu = smp_processor_id();
60
61	init_new_context(current, &init_mm);
62	current_thread_info()->cpu = cpu;
63	mp_ops->prepare_cpus(max_cpus);
64
65#ifndef CONFIG_HOTPLUG_CPU
66	init_cpu_present(cpu_possible_mask);
67#endif
68}
69
70void __init smp_prepare_boot_cpu(void)
71{
72	unsigned int cpu = smp_processor_id();
73
74	__cpu_number_map[0] = cpu;
75	__cpu_logical_map[0] = cpu;
76
77	set_cpu_online(cpu, true);
78	set_cpu_possible(cpu, true);
79
80	per_cpu(cpu_state, cpu) = CPU_ONLINE;
81}
82
83#ifdef CONFIG_HOTPLUG_CPU
84void native_cpu_die(unsigned int cpu)
85{
86	unsigned int i;
87
88	for (i = 0; i < 10; i++) {
89		smp_rmb();
90		if (per_cpu(cpu_state, cpu) == CPU_DEAD) {
91			if (system_state == SYSTEM_RUNNING)
92				pr_info("CPU %u is now offline\n", cpu);
93
94			return;
95		}
96
97		msleep(100);
98	}
99
100	pr_err("CPU %u didn't die...\n", cpu);
101}
102
103int native_cpu_disable(unsigned int cpu)
104{
105	return cpu == 0 ? -EPERM : 0;
106}
107
108void play_dead_common(void)
109{
110	idle_task_exit();
111	irq_ctx_exit(raw_smp_processor_id());
112	mb();
113
114	__this_cpu_write(cpu_state, CPU_DEAD);
115	local_irq_disable();
116}
117
118void native_play_dead(void)
119{
120	play_dead_common();
121}
122
123int __cpu_disable(void)
124{
125	unsigned int cpu = smp_processor_id();
126	int ret;
127
128	ret = mp_ops->cpu_disable(cpu);
129	if (ret)
130		return ret;
131
132	/*
133	 * Take this CPU offline.  Once we clear this, we can't return,
134	 * and we must not schedule until we're ready to give up the cpu.
135	 */
136	set_cpu_online(cpu, false);
137
138	/*
139	 * OK - migrate IRQs away from this CPU
140	 */
141	migrate_irqs();
142
143	/*
144	 * Stop the local timer for this CPU.
145	 */
146	local_timer_stop(cpu);
147
148	/*
149	 * Flush user cache and TLB mappings, and then remove this CPU
150	 * from the vm mask set of all processes.
151	 */
152	flush_cache_all();
153	local_flush_tlb_all();
154
155	clear_tasks_mm_cpumask(cpu);
156
157	return 0;
158}
159#else /* ... !CONFIG_HOTPLUG_CPU */
160int native_cpu_disable(unsigned int cpu)
161{
162	return -ENOSYS;
163}
164
165void native_cpu_die(unsigned int cpu)
166{
167	/* We said "no" in __cpu_disable */
168	BUG();
169}
170
171void native_play_dead(void)
172{
173	BUG();
174}
175#endif
176
177asmlinkage void start_secondary(void)
178{
179	unsigned int cpu = smp_processor_id();
180	struct mm_struct *mm = &init_mm;
181
182	enable_mmu();
183	atomic_inc(&mm->mm_count);
184	atomic_inc(&mm->mm_users);
185	current->active_mm = mm;
186	enter_lazy_tlb(mm, current);
187	local_flush_tlb_all();
188
189	per_cpu_trap_init();
190
191	preempt_disable();
192
193	notify_cpu_starting(cpu);
194
195	local_irq_enable();
196
197	/* Enable local timers */
198	local_timer_setup(cpu);
199	calibrate_delay();
200
201	smp_store_cpu_info(cpu);
202
203	set_cpu_online(cpu, true);
204	per_cpu(cpu_state, cpu) = CPU_ONLINE;
205
206	cpu_startup_entry(CPUHP_ONLINE);
207}
208
209extern struct {
210	unsigned long sp;
211	unsigned long bss_start;
212	unsigned long bss_end;
213	void *start_kernel_fn;
214	void *cpu_init_fn;
215	void *thread_info;
216} stack_start;
217
218int __cpu_up(unsigned int cpu, struct task_struct *tsk)
219{
220	unsigned long timeout;
221
222	per_cpu(cpu_state, cpu) = CPU_UP_PREPARE;
223
224	/* Fill in data in head.S for secondary cpus */
225	stack_start.sp = tsk->thread.sp;
226	stack_start.thread_info = tsk->stack;
227	stack_start.bss_start = 0; /* don't clear bss for secondary cpus */
228	stack_start.start_kernel_fn = start_secondary;
229
230	flush_icache_range((unsigned long)&stack_start,
231			   (unsigned long)&stack_start + sizeof(stack_start));
232	wmb();
233
234	mp_ops->start_cpu(cpu, (unsigned long)_stext);
235
236	timeout = jiffies + HZ;
237	while (time_before(jiffies, timeout)) {
238		if (cpu_online(cpu))
239			break;
240
241		udelay(10);
242		barrier();
243	}
244
245	if (cpu_online(cpu))
246		return 0;
247
248	return -ENOENT;
249}
250
251void __init smp_cpus_done(unsigned int max_cpus)
252{
253	unsigned long bogosum = 0;
254	int cpu;
255
256	for_each_online_cpu(cpu)
257		bogosum += cpu_data[cpu].loops_per_jiffy;
258
259	printk(KERN_INFO "SMP: Total of %d processors activated "
260	       "(%lu.%02lu BogoMIPS).\n", num_online_cpus(),
261	       bogosum / (500000/HZ),
262	       (bogosum / (5000/HZ)) % 100);
263}
264
265void smp_send_reschedule(int cpu)
266{
267	mp_ops->send_ipi(cpu, SMP_MSG_RESCHEDULE);
268}
269
270void smp_send_stop(void)
271{
272	smp_call_function(stop_this_cpu, 0, 0);
273}
274
275void arch_send_call_function_ipi_mask(const struct cpumask *mask)
276{
277	int cpu;
278
279	for_each_cpu(cpu, mask)
280		mp_ops->send_ipi(cpu, SMP_MSG_FUNCTION);
281}
282
283void arch_send_call_function_single_ipi(int cpu)
284{
285	mp_ops->send_ipi(cpu, SMP_MSG_FUNCTION_SINGLE);
286}
287
288void smp_timer_broadcast(const struct cpumask *mask)
289{
290	int cpu;
291
292	for_each_cpu(cpu, mask)
293		mp_ops->send_ipi(cpu, SMP_MSG_TIMER);
294}
295
296static void ipi_timer(void)
297{
298	irq_enter();
299	local_timer_interrupt();
300	irq_exit();
301}
302
303void smp_message_recv(unsigned int msg)
304{
305	switch (msg) {
306	case SMP_MSG_FUNCTION:
307		generic_smp_call_function_interrupt();
308		break;
309	case SMP_MSG_RESCHEDULE:
310		scheduler_ipi();
311		break;
312	case SMP_MSG_FUNCTION_SINGLE:
313		generic_smp_call_function_single_interrupt();
314		break;
315	case SMP_MSG_TIMER:
316		ipi_timer();
317		break;
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/* Not really SMP stuff ... */
326int setup_profiling_timer(unsigned int multiplier)
327{
328	return 0;
329}
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