Merge remote-tracking branch 'spi/topic/rspi' into spi-pdata
[deliverable/linux.git] / arch / parisc / kernel / smp.c
1 /*
2 ** SMP Support
3 **
4 ** Copyright (C) 1999 Walt Drummond <drummond@valinux.com>
5 ** Copyright (C) 1999 David Mosberger-Tang <davidm@hpl.hp.com>
6 ** Copyright (C) 2001,2004 Grant Grundler <grundler@parisc-linux.org>
7 **
8 ** Lots of stuff stolen from arch/alpha/kernel/smp.c
9 ** ...and then parisc stole from arch/ia64/kernel/smp.c. Thanks David! :^)
10 **
11 ** Thanks to John Curry and Ullas Ponnadi. I learned a lot from their work.
12 ** -grant (1/12/2001)
13 **
14 ** This program is free software; you can redistribute it and/or modify
15 ** it under the terms of the GNU General Public License as published by
16 ** the Free Software Foundation; either version 2 of the License, or
17 ** (at your option) any later version.
18 */
19 #include <linux/types.h>
20 #include <linux/spinlock.h>
21
22 #include <linux/kernel.h>
23 #include <linux/module.h>
24 #include <linux/sched.h>
25 #include <linux/init.h>
26 #include <linux/interrupt.h>
27 #include <linux/smp.h>
28 #include <linux/kernel_stat.h>
29 #include <linux/mm.h>
30 #include <linux/err.h>
31 #include <linux/delay.h>
32 #include <linux/bitops.h>
33 #include <linux/ftrace.h>
34 #include <linux/cpu.h>
35
36 #include <linux/atomic.h>
37 #include <asm/current.h>
38 #include <asm/delay.h>
39 #include <asm/tlbflush.h>
40
41 #include <asm/io.h>
42 #include <asm/irq.h> /* for CPU_IRQ_REGION and friends */
43 #include <asm/mmu_context.h>
44 #include <asm/page.h>
45 #include <asm/pgtable.h>
46 #include <asm/pgalloc.h>
47 #include <asm/processor.h>
48 #include <asm/ptrace.h>
49 #include <asm/unistd.h>
50 #include <asm/cacheflush.h>
51
52 #undef DEBUG_SMP
53 #ifdef DEBUG_SMP
54 static int smp_debug_lvl = 0;
55 #define smp_debug(lvl, printargs...) \
56 if (lvl >= smp_debug_lvl) \
57 printk(printargs);
58 #else
59 #define smp_debug(lvl, ...) do { } while(0)
60 #endif /* DEBUG_SMP */
61
62 volatile struct task_struct *smp_init_current_idle_task;
63
64 /* track which CPU is booting */
65 static volatile int cpu_now_booting;
66
67 static int parisc_max_cpus = 1;
68
69 static DEFINE_PER_CPU(spinlock_t, ipi_lock);
70
71 enum ipi_message_type {
72 IPI_NOP=0,
73 IPI_RESCHEDULE=1,
74 IPI_CALL_FUNC,
75 IPI_CALL_FUNC_SINGLE,
76 IPI_CPU_START,
77 IPI_CPU_STOP,
78 IPI_CPU_TEST
79 };
80
81
82 /********** SMP inter processor interrupt and communication routines */
83
84 #undef PER_CPU_IRQ_REGION
85 #ifdef PER_CPU_IRQ_REGION
86 /* XXX REVISIT Ignore for now.
87 ** *May* need this "hook" to register IPI handler
88 ** once we have perCPU ExtIntr switch tables.
89 */
90 static void
91 ipi_init(int cpuid)
92 {
93 #error verify IRQ_OFFSET(IPI_IRQ) is ipi_interrupt() in new IRQ region
94
95 if(cpu_online(cpuid) )
96 {
97 switch_to_idle_task(current);
98 }
99
100 return;
101 }
102 #endif
103
104
105 /*
106 ** Yoink this CPU from the runnable list...
107 **
108 */
109 static void
110 halt_processor(void)
111 {
112 /* REVISIT : redirect I/O Interrupts to another CPU? */
113 /* REVISIT : does PM *know* this CPU isn't available? */
114 set_cpu_online(smp_processor_id(), false);
115 local_irq_disable();
116 for (;;)
117 ;
118 }
119
120
121 irqreturn_t __irq_entry
122 ipi_interrupt(int irq, void *dev_id)
123 {
124 int this_cpu = smp_processor_id();
125 struct cpuinfo_parisc *p = &per_cpu(cpu_data, this_cpu);
126 unsigned long ops;
127 unsigned long flags;
128
129 /* Count this now; we may make a call that never returns. */
130 inc_irq_stat(irq_call_count);
131
132 mb(); /* Order interrupt and bit testing. */
133
134 for (;;) {
135 spinlock_t *lock = &per_cpu(ipi_lock, this_cpu);
136 spin_lock_irqsave(lock, flags);
137 ops = p->pending_ipi;
138 p->pending_ipi = 0;
139 spin_unlock_irqrestore(lock, flags);
140
141 mb(); /* Order bit clearing and data access. */
142
143 if (!ops)
144 break;
145
146 while (ops) {
147 unsigned long which = ffz(~ops);
148
149 ops &= ~(1 << which);
150
151 switch (which) {
152 case IPI_NOP:
153 smp_debug(100, KERN_DEBUG "CPU%d IPI_NOP\n", this_cpu);
154 break;
155
156 case IPI_RESCHEDULE:
157 smp_debug(100, KERN_DEBUG "CPU%d IPI_RESCHEDULE\n", this_cpu);
158 inc_irq_stat(irq_resched_count);
159 scheduler_ipi();
160 break;
161
162 case IPI_CALL_FUNC:
163 smp_debug(100, KERN_DEBUG "CPU%d IPI_CALL_FUNC\n", this_cpu);
164 generic_smp_call_function_interrupt();
165 break;
166
167 case IPI_CALL_FUNC_SINGLE:
168 smp_debug(100, KERN_DEBUG "CPU%d IPI_CALL_FUNC_SINGLE\n", this_cpu);
169 generic_smp_call_function_single_interrupt();
170 break;
171
172 case IPI_CPU_START:
173 smp_debug(100, KERN_DEBUG "CPU%d IPI_CPU_START\n", this_cpu);
174 break;
175
176 case IPI_CPU_STOP:
177 smp_debug(100, KERN_DEBUG "CPU%d IPI_CPU_STOP\n", this_cpu);
178 halt_processor();
179 break;
180
181 case IPI_CPU_TEST:
182 smp_debug(100, KERN_DEBUG "CPU%d is alive!\n", this_cpu);
183 break;
184
185 default:
186 printk(KERN_CRIT "Unknown IPI num on CPU%d: %lu\n",
187 this_cpu, which);
188 return IRQ_NONE;
189 } /* Switch */
190 /* let in any pending interrupts */
191 local_irq_enable();
192 local_irq_disable();
193 } /* while (ops) */
194 }
195 return IRQ_HANDLED;
196 }
197
198
199 static inline void
200 ipi_send(int cpu, enum ipi_message_type op)
201 {
202 struct cpuinfo_parisc *p = &per_cpu(cpu_data, cpu);
203 spinlock_t *lock = &per_cpu(ipi_lock, cpu);
204 unsigned long flags;
205
206 spin_lock_irqsave(lock, flags);
207 p->pending_ipi |= 1 << op;
208 gsc_writel(IPI_IRQ - CPU_IRQ_BASE, p->hpa);
209 spin_unlock_irqrestore(lock, flags);
210 }
211
212 static void
213 send_IPI_mask(const struct cpumask *mask, enum ipi_message_type op)
214 {
215 int cpu;
216
217 for_each_cpu(cpu, mask)
218 ipi_send(cpu, op);
219 }
220
221 static inline void
222 send_IPI_single(int dest_cpu, enum ipi_message_type op)
223 {
224 BUG_ON(dest_cpu == NO_PROC_ID);
225
226 ipi_send(dest_cpu, op);
227 }
228
229 static inline void
230 send_IPI_allbutself(enum ipi_message_type op)
231 {
232 int i;
233
234 for_each_online_cpu(i) {
235 if (i != smp_processor_id())
236 send_IPI_single(i, op);
237 }
238 }
239
240
241 inline void
242 smp_send_stop(void) { send_IPI_allbutself(IPI_CPU_STOP); }
243
244 static inline void
245 smp_send_start(void) { send_IPI_allbutself(IPI_CPU_START); }
246
247 void
248 smp_send_reschedule(int cpu) { send_IPI_single(cpu, IPI_RESCHEDULE); }
249
250 void
251 smp_send_all_nop(void)
252 {
253 send_IPI_allbutself(IPI_NOP);
254 }
255
256 void arch_send_call_function_ipi_mask(const struct cpumask *mask)
257 {
258 send_IPI_mask(mask, IPI_CALL_FUNC);
259 }
260
261 void arch_send_call_function_single_ipi(int cpu)
262 {
263 send_IPI_single(cpu, IPI_CALL_FUNC_SINGLE);
264 }
265
266 /*
267 * Called by secondaries to update state and initialize CPU registers.
268 */
269 static void __init
270 smp_cpu_init(int cpunum)
271 {
272 extern int init_per_cpu(int); /* arch/parisc/kernel/processor.c */
273 extern void init_IRQ(void); /* arch/parisc/kernel/irq.c */
274 extern void start_cpu_itimer(void); /* arch/parisc/kernel/time.c */
275
276 /* Set modes and Enable floating point coprocessor */
277 (void) init_per_cpu(cpunum);
278
279 disable_sr_hashing();
280
281 mb();
282
283 /* Well, support 2.4 linux scheme as well. */
284 if (cpu_online(cpunum)) {
285 extern void machine_halt(void); /* arch/parisc.../process.c */
286
287 printk(KERN_CRIT "CPU#%d already initialized!\n", cpunum);
288 machine_halt();
289 }
290
291 notify_cpu_starting(cpunum);
292
293 set_cpu_online(cpunum, true);
294
295 /* Initialise the idle task for this CPU */
296 atomic_inc(&init_mm.mm_count);
297 current->active_mm = &init_mm;
298 BUG_ON(current->mm);
299 enter_lazy_tlb(&init_mm, current);
300
301 init_IRQ(); /* make sure no IRQs are enabled or pending */
302 start_cpu_itimer();
303 }
304
305
306 /*
307 * Slaves start using C here. Indirectly called from smp_slave_stext.
308 * Do what start_kernel() and main() do for boot strap processor (aka monarch)
309 */
310 void __init smp_callin(void)
311 {
312 int slave_id = cpu_now_booting;
313
314 smp_cpu_init(slave_id);
315 preempt_disable();
316
317 flush_cache_all_local(); /* start with known state */
318 flush_tlb_all_local(NULL);
319
320 local_irq_enable(); /* Interrupts have been off until now */
321
322 cpu_startup_entry(CPUHP_ONLINE);
323
324 /* NOTREACHED */
325 panic("smp_callin() AAAAaaaaahhhh....\n");
326 }
327
328 /*
329 * Bring one cpu online.
330 */
331 int smp_boot_one_cpu(int cpuid, struct task_struct *idle)
332 {
333 const struct cpuinfo_parisc *p = &per_cpu(cpu_data, cpuid);
334 long timeout;
335
336 task_thread_info(idle)->cpu = cpuid;
337
338 /* Let _start know what logical CPU we're booting
339 ** (offset into init_tasks[],cpu_data[])
340 */
341 cpu_now_booting = cpuid;
342
343 /*
344 ** boot strap code needs to know the task address since
345 ** it also contains the process stack.
346 */
347 smp_init_current_idle_task = idle ;
348 mb();
349
350 printk(KERN_INFO "Releasing cpu %d now, hpa=%lx\n", cpuid, p->hpa);
351
352 /*
353 ** This gets PDC to release the CPU from a very tight loop.
354 **
355 ** From the PA-RISC 2.0 Firmware Architecture Reference Specification:
356 ** "The MEM_RENDEZ vector specifies the location of OS_RENDEZ which
357 ** is executed after receiving the rendezvous signal (an interrupt to
358 ** EIR{0}). MEM_RENDEZ is valid only when it is nonzero and the
359 ** contents of memory are valid."
360 */
361 gsc_writel(TIMER_IRQ - CPU_IRQ_BASE, p->hpa);
362 mb();
363
364 /*
365 * OK, wait a bit for that CPU to finish staggering about.
366 * Slave will set a bit when it reaches smp_cpu_init().
367 * Once the "monarch CPU" sees the bit change, it can move on.
368 */
369 for (timeout = 0; timeout < 10000; timeout++) {
370 if(cpu_online(cpuid)) {
371 /* Which implies Slave has started up */
372 cpu_now_booting = 0;
373 smp_init_current_idle_task = NULL;
374 goto alive ;
375 }
376 udelay(100);
377 barrier();
378 }
379 printk(KERN_CRIT "SMP: CPU:%d is stuck.\n", cpuid);
380 return -1;
381
382 alive:
383 /* Remember the Slave data */
384 smp_debug(100, KERN_DEBUG "SMP: CPU:%d came alive after %ld _us\n",
385 cpuid, timeout * 100);
386 return 0;
387 }
388
389 void __init smp_prepare_boot_cpu(void)
390 {
391 int bootstrap_processor = per_cpu(cpu_data, 0).cpuid;
392
393 /* Setup BSP mappings */
394 printk(KERN_INFO "SMP: bootstrap CPU ID is %d\n", bootstrap_processor);
395
396 set_cpu_online(bootstrap_processor, true);
397 set_cpu_present(bootstrap_processor, true);
398 }
399
400
401
402 /*
403 ** inventory.c:do_inventory() hasn't yet been run and thus we
404 ** don't 'discover' the additional CPUs until later.
405 */
406 void __init smp_prepare_cpus(unsigned int max_cpus)
407 {
408 int cpu;
409
410 for_each_possible_cpu(cpu)
411 spin_lock_init(&per_cpu(ipi_lock, cpu));
412
413 init_cpu_present(cpumask_of(0));
414
415 parisc_max_cpus = max_cpus;
416 if (!max_cpus)
417 printk(KERN_INFO "SMP mode deactivated.\n");
418 }
419
420
421 void smp_cpus_done(unsigned int cpu_max)
422 {
423 return;
424 }
425
426
427 int __cpu_up(unsigned int cpu, struct task_struct *tidle)
428 {
429 if (cpu != 0 && cpu < parisc_max_cpus)
430 smp_boot_one_cpu(cpu, tidle);
431
432 return cpu_online(cpu) ? 0 : -ENOSYS;
433 }
434
435 #ifdef CONFIG_PROC_FS
436 int __init
437 setup_profiling_timer(unsigned int multiplier)
438 {
439 return -EINVAL;
440 }
441 #endif
This page took 0.055893 seconds and 5 git commands to generate.