xref: /openbmc/linux/arch/sh/kernel/smp.c (revision b6dcefde)
1 /*
2  * arch/sh/kernel/smp.c
3  *
4  * SMP support for the SuperH processors.
5  *
6  * Copyright (C) 2002 - 2008 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 <asm/atomic.h>
24 #include <asm/processor.h>
25 #include <asm/system.h>
26 #include <asm/mmu_context.h>
27 #include <asm/smp.h>
28 #include <asm/cacheflush.h>
29 #include <asm/sections.h>
30 
31 int __cpu_number_map[NR_CPUS];		/* Map physical to logical */
32 int __cpu_logical_map[NR_CPUS];		/* Map logical to physical */
33 
34 static inline void __init smp_store_cpu_info(unsigned int cpu)
35 {
36 	struct sh_cpuinfo *c = cpu_data + cpu;
37 
38 	memcpy(c, &boot_cpu_data, sizeof(struct sh_cpuinfo));
39 
40 	c->loops_per_jiffy = loops_per_jiffy;
41 }
42 
43 void __init smp_prepare_cpus(unsigned int max_cpus)
44 {
45 	unsigned int cpu = smp_processor_id();
46 
47 	init_new_context(current, &init_mm);
48 	current_thread_info()->cpu = cpu;
49 	plat_prepare_cpus(max_cpus);
50 
51 #ifndef CONFIG_HOTPLUG_CPU
52 	init_cpu_present(&cpu_possible_map);
53 #endif
54 }
55 
56 void __devinit smp_prepare_boot_cpu(void)
57 {
58 	unsigned int cpu = smp_processor_id();
59 
60 	__cpu_number_map[0] = cpu;
61 	__cpu_logical_map[0] = cpu;
62 
63 	set_cpu_online(cpu, true);
64 	set_cpu_possible(cpu, true);
65 }
66 
67 asmlinkage void __cpuinit start_secondary(void)
68 {
69 	unsigned int cpu;
70 	struct mm_struct *mm = &init_mm;
71 
72 	atomic_inc(&mm->mm_count);
73 	atomic_inc(&mm->mm_users);
74 	current->active_mm = mm;
75 	BUG_ON(current->mm);
76 	enter_lazy_tlb(mm, current);
77 
78 	per_cpu_trap_init();
79 
80 	preempt_disable();
81 
82 	notify_cpu_starting(smp_processor_id());
83 
84 	local_irq_enable();
85 
86 	cpu = smp_processor_id();
87 
88 	/* Enable local timers */
89 	local_timer_setup(cpu);
90 	calibrate_delay();
91 
92 	smp_store_cpu_info(cpu);
93 
94 	cpu_set(cpu, cpu_online_map);
95 
96 	cpu_idle();
97 }
98 
99 extern struct {
100 	unsigned long sp;
101 	unsigned long bss_start;
102 	unsigned long bss_end;
103 	void *start_kernel_fn;
104 	void *cpu_init_fn;
105 	void *thread_info;
106 } stack_start;
107 
108 int __cpuinit __cpu_up(unsigned int cpu)
109 {
110 	struct task_struct *tsk;
111 	unsigned long timeout;
112 
113 	tsk = fork_idle(cpu);
114 	if (IS_ERR(tsk)) {
115 		printk(KERN_ERR "Failed forking idle task for cpu %d\n", cpu);
116 		return PTR_ERR(tsk);
117 	}
118 
119 	/* Fill in data in head.S for secondary cpus */
120 	stack_start.sp = tsk->thread.sp;
121 	stack_start.thread_info = tsk->stack;
122 	stack_start.bss_start = 0; /* don't clear bss for secondary cpus */
123 	stack_start.start_kernel_fn = start_secondary;
124 
125 	flush_icache_range((unsigned long)&stack_start,
126 			   (unsigned long)&stack_start + sizeof(stack_start));
127 	wmb();
128 
129 	plat_start_cpu(cpu, (unsigned long)_stext);
130 
131 	timeout = jiffies + HZ;
132 	while (time_before(jiffies, timeout)) {
133 		if (cpu_online(cpu))
134 			break;
135 
136 		udelay(10);
137 	}
138 
139 	if (cpu_online(cpu))
140 		return 0;
141 
142 	return -ENOENT;
143 }
144 
145 void __init smp_cpus_done(unsigned int max_cpus)
146 {
147 	unsigned long bogosum = 0;
148 	int cpu;
149 
150 	for_each_online_cpu(cpu)
151 		bogosum += cpu_data[cpu].loops_per_jiffy;
152 
153 	printk(KERN_INFO "SMP: Total of %d processors activated "
154 	       "(%lu.%02lu BogoMIPS).\n", num_online_cpus(),
155 	       bogosum / (500000/HZ),
156 	       (bogosum / (5000/HZ)) % 100);
157 }
158 
159 void smp_send_reschedule(int cpu)
160 {
161 	plat_send_ipi(cpu, SMP_MSG_RESCHEDULE);
162 }
163 
164 static void stop_this_cpu(void *unused)
165 {
166 	cpu_clear(smp_processor_id(), cpu_online_map);
167 	local_irq_disable();
168 
169 	for (;;)
170 		cpu_relax();
171 }
172 
173 void smp_send_stop(void)
174 {
175 	smp_call_function(stop_this_cpu, 0, 0);
176 }
177 
178 void arch_send_call_function_ipi_mask(const struct cpumask *mask)
179 {
180 	int cpu;
181 
182 	for_each_cpu(cpu, mask)
183 		plat_send_ipi(cpu, SMP_MSG_FUNCTION);
184 }
185 
186 void arch_send_call_function_single_ipi(int cpu)
187 {
188 	plat_send_ipi(cpu, SMP_MSG_FUNCTION_SINGLE);
189 }
190 
191 void smp_timer_broadcast(const struct cpumask *mask)
192 {
193 	int cpu;
194 
195 	for_each_cpu(cpu, mask)
196 		plat_send_ipi(cpu, SMP_MSG_TIMER);
197 }
198 
199 static void ipi_timer(void)
200 {
201 	irq_enter();
202 	local_timer_interrupt();
203 	irq_exit();
204 }
205 
206 void smp_message_recv(unsigned int msg)
207 {
208 	switch (msg) {
209 	case SMP_MSG_FUNCTION:
210 		generic_smp_call_function_interrupt();
211 		break;
212 	case SMP_MSG_RESCHEDULE:
213 		break;
214 	case SMP_MSG_FUNCTION_SINGLE:
215 		generic_smp_call_function_single_interrupt();
216 		break;
217 	case SMP_MSG_TIMER:
218 		ipi_timer();
219 		break;
220 	default:
221 		printk(KERN_WARNING "SMP %d: %s(): unknown IPI %d\n",
222 		       smp_processor_id(), __func__, msg);
223 		break;
224 	}
225 }
226 
227 /* Not really SMP stuff ... */
228 int setup_profiling_timer(unsigned int multiplier)
229 {
230 	return 0;
231 }
232 
233 static void flush_tlb_all_ipi(void *info)
234 {
235 	local_flush_tlb_all();
236 }
237 
238 void flush_tlb_all(void)
239 {
240 	on_each_cpu(flush_tlb_all_ipi, 0, 1);
241 }
242 
243 static void flush_tlb_mm_ipi(void *mm)
244 {
245 	local_flush_tlb_mm((struct mm_struct *)mm);
246 }
247 
248 /*
249  * The following tlb flush calls are invoked when old translations are
250  * being torn down, or pte attributes are changing. For single threaded
251  * address spaces, a new context is obtained on the current cpu, and tlb
252  * context on other cpus are invalidated to force a new context allocation
253  * at switch_mm time, should the mm ever be used on other cpus. For
254  * multithreaded address spaces, intercpu interrupts have to be sent.
255  * Another case where intercpu interrupts are required is when the target
256  * mm might be active on another cpu (eg debuggers doing the flushes on
257  * behalf of debugees, kswapd stealing pages from another process etc).
258  * Kanoj 07/00.
259  */
260 
261 void flush_tlb_mm(struct mm_struct *mm)
262 {
263 	preempt_disable();
264 
265 	if ((atomic_read(&mm->mm_users) != 1) || (current->mm != mm)) {
266 		smp_call_function(flush_tlb_mm_ipi, (void *)mm, 1);
267 	} else {
268 		int i;
269 		for (i = 0; i < num_online_cpus(); i++)
270 			if (smp_processor_id() != i)
271 				cpu_context(i, mm) = 0;
272 	}
273 	local_flush_tlb_mm(mm);
274 
275 	preempt_enable();
276 }
277 
278 struct flush_tlb_data {
279 	struct vm_area_struct *vma;
280 	unsigned long addr1;
281 	unsigned long addr2;
282 };
283 
284 static void flush_tlb_range_ipi(void *info)
285 {
286 	struct flush_tlb_data *fd = (struct flush_tlb_data *)info;
287 
288 	local_flush_tlb_range(fd->vma, fd->addr1, fd->addr2);
289 }
290 
291 void flush_tlb_range(struct vm_area_struct *vma,
292 		     unsigned long start, unsigned long end)
293 {
294 	struct mm_struct *mm = vma->vm_mm;
295 
296 	preempt_disable();
297 	if ((atomic_read(&mm->mm_users) != 1) || (current->mm != mm)) {
298 		struct flush_tlb_data fd;
299 
300 		fd.vma = vma;
301 		fd.addr1 = start;
302 		fd.addr2 = end;
303 		smp_call_function(flush_tlb_range_ipi, (void *)&fd, 1);
304 	} else {
305 		int i;
306 		for (i = 0; i < num_online_cpus(); i++)
307 			if (smp_processor_id() != i)
308 				cpu_context(i, mm) = 0;
309 	}
310 	local_flush_tlb_range(vma, start, end);
311 	preempt_enable();
312 }
313 
314 static void flush_tlb_kernel_range_ipi(void *info)
315 {
316 	struct flush_tlb_data *fd = (struct flush_tlb_data *)info;
317 
318 	local_flush_tlb_kernel_range(fd->addr1, fd->addr2);
319 }
320 
321 void flush_tlb_kernel_range(unsigned long start, unsigned long end)
322 {
323 	struct flush_tlb_data fd;
324 
325 	fd.addr1 = start;
326 	fd.addr2 = end;
327 	on_each_cpu(flush_tlb_kernel_range_ipi, (void *)&fd, 1);
328 }
329 
330 static void flush_tlb_page_ipi(void *info)
331 {
332 	struct flush_tlb_data *fd = (struct flush_tlb_data *)info;
333 
334 	local_flush_tlb_page(fd->vma, fd->addr1);
335 }
336 
337 void flush_tlb_page(struct vm_area_struct *vma, unsigned long page)
338 {
339 	preempt_disable();
340 	if ((atomic_read(&vma->vm_mm->mm_users) != 1) ||
341 	    (current->mm != vma->vm_mm)) {
342 		struct flush_tlb_data fd;
343 
344 		fd.vma = vma;
345 		fd.addr1 = page;
346 		smp_call_function(flush_tlb_page_ipi, (void *)&fd, 1);
347 	} else {
348 		int i;
349 		for (i = 0; i < num_online_cpus(); i++)
350 			if (smp_processor_id() != i)
351 				cpu_context(i, vma->vm_mm) = 0;
352 	}
353 	local_flush_tlb_page(vma, page);
354 	preempt_enable();
355 }
356 
357 static void flush_tlb_one_ipi(void *info)
358 {
359 	struct flush_tlb_data *fd = (struct flush_tlb_data *)info;
360 	local_flush_tlb_one(fd->addr1, fd->addr2);
361 }
362 
363 void flush_tlb_one(unsigned long asid, unsigned long vaddr)
364 {
365 	struct flush_tlb_data fd;
366 
367 	fd.addr1 = asid;
368 	fd.addr2 = vaddr;
369 
370 	smp_call_function(flush_tlb_one_ipi, (void *)&fd, 1);
371 	local_flush_tlb_one(asid, vaddr);
372 }
373