Merge branch 'for-33' of git://repo.or.cz/linux-kbuild
[linux-2.6-block.git] / arch / parisc / kernel / smp.c
CommitLineData
1da177e4
LT
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**
7022672e 11** Thanks to John Curry and Ullas Ponnadi. I learned a lot from their work.
1da177e4
LT
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*/
1da177e4
LT
19#include <linux/types.h>
20#include <linux/spinlock.h>
21#include <linux/slab.h>
22
23#include <linux/kernel.h>
24#include <linux/module.h>
25#include <linux/sched.h>
26#include <linux/init.h>
27#include <linux/interrupt.h>
28#include <linux/smp.h>
29#include <linux/kernel_stat.h>
30#include <linux/mm.h>
4e950f6f 31#include <linux/err.h>
1da177e4
LT
32#include <linux/delay.h>
33#include <linux/bitops.h>
d75f054a 34#include <linux/ftrace.h>
1da177e4
LT
35
36#include <asm/system.h>
37#include <asm/atomic.h>
38#include <asm/current.h>
39#include <asm/delay.h>
1b2425e3 40#include <asm/tlbflush.h>
1da177e4
LT
41
42#include <asm/io.h>
43#include <asm/irq.h> /* for CPU_IRQ_REGION and friends */
44#include <asm/mmu_context.h>
45#include <asm/page.h>
46#include <asm/pgtable.h>
47#include <asm/pgalloc.h>
48#include <asm/processor.h>
49#include <asm/ptrace.h>
50#include <asm/unistd.h>
51#include <asm/cacheflush.h>
52
5492a0f0
KM
53#undef DEBUG_SMP
54#ifdef DEBUG_SMP
55static int smp_debug_lvl = 0;
56#define smp_debug(lvl, printargs...) \
57 if (lvl >= smp_debug_lvl) \
58 printk(printargs);
59#else
ef017beb 60#define smp_debug(lvl, ...) do { } while(0)
5492a0f0 61#endif /* DEBUG_SMP */
1da177e4 62
1da177e4
LT
63volatile struct task_struct *smp_init_current_idle_task;
64
ef017beb
HD
65/* track which CPU is booting */
66static volatile int cpu_now_booting __cpuinitdata;
1da177e4 67
ef017beb 68static int parisc_max_cpus __cpuinitdata = 1;
1da177e4 69
6ad6c424 70static DEFINE_PER_CPU(spinlock_t, ipi_lock);
1da177e4 71
1da177e4
LT
72enum ipi_message_type {
73 IPI_NOP=0,
74 IPI_RESCHEDULE=1,
75 IPI_CALL_FUNC,
dbcf4787 76 IPI_CALL_FUNC_SINGLE,
1da177e4
LT
77 IPI_CPU_START,
78 IPI_CPU_STOP,
79 IPI_CPU_TEST
80};
81
82
83/********** SMP inter processor interrupt and communication routines */
84
85#undef PER_CPU_IRQ_REGION
86#ifdef PER_CPU_IRQ_REGION
87/* XXX REVISIT Ignore for now.
88** *May* need this "hook" to register IPI handler
89** once we have perCPU ExtIntr switch tables.
90*/
91static void
92ipi_init(int cpuid)
93{
1da177e4
LT
94#error verify IRQ_OFFSET(IPI_IRQ) is ipi_interrupt() in new IRQ region
95
96 if(cpu_online(cpuid) )
97 {
98 switch_to_idle_task(current);
99 }
100
101 return;
102}
103#endif
104
105
106/*
107** Yoink this CPU from the runnable list...
108**
109*/
110static void
111halt_processor(void)
112{
1da177e4
LT
113 /* REVISIT : redirect I/O Interrupts to another CPU? */
114 /* REVISIT : does PM *know* this CPU isn't available? */
9bc181d8 115 set_cpu_online(smp_processor_id(), false);
1da177e4
LT
116 local_irq_disable();
117 for (;;)
118 ;
1da177e4
LT
119}
120
121
d75f054a 122irqreturn_t __irq_entry
c7753f18 123ipi_interrupt(int irq, void *dev_id)
1da177e4
LT
124{
125 int this_cpu = smp_processor_id();
ef017beb 126 struct cpuinfo_parisc *p = &per_cpu(cpu_data, this_cpu);
1da177e4
LT
127 unsigned long ops;
128 unsigned long flags;
129
130 /* Count this now; we may make a call that never returns. */
131 p->ipi_count++;
132
133 mb(); /* Order interrupt and bit testing. */
134
135 for (;;) {
3c97b5e9
KM
136 spinlock_t *lock = &per_cpu(ipi_lock, this_cpu);
137 spin_lock_irqsave(lock, flags);
1da177e4
LT
138 ops = p->pending_ipi;
139 p->pending_ipi = 0;
3c97b5e9 140 spin_unlock_irqrestore(lock, flags);
1da177e4
LT
141
142 mb(); /* Order bit clearing and data access. */
143
144 if (!ops)
145 break;
146
147 while (ops) {
148 unsigned long which = ffz(~ops);
149
d911aed8
JB
150 ops &= ~(1 << which);
151
1da177e4 152 switch (which) {
d911aed8 153 case IPI_NOP:
5492a0f0 154 smp_debug(100, KERN_DEBUG "CPU%d IPI_NOP\n", this_cpu);
d911aed8
JB
155 break;
156
1da177e4 157 case IPI_RESCHEDULE:
5492a0f0 158 smp_debug(100, KERN_DEBUG "CPU%d IPI_RESCHEDULE\n", this_cpu);
1da177e4
LT
159 /*
160 * Reschedule callback. Everything to be
161 * done is done by the interrupt return path.
162 */
163 break;
164
165 case IPI_CALL_FUNC:
5492a0f0 166 smp_debug(100, KERN_DEBUG "CPU%d IPI_CALL_FUNC\n", this_cpu);
dbcf4787
JA
167 generic_smp_call_function_interrupt();
168 break;
169
170 case IPI_CALL_FUNC_SINGLE:
171 smp_debug(100, KERN_DEBUG "CPU%d IPI_CALL_FUNC_SINGLE\n", this_cpu);
172 generic_smp_call_function_single_interrupt();
1da177e4
LT
173 break;
174
175 case IPI_CPU_START:
5492a0f0 176 smp_debug(100, KERN_DEBUG "CPU%d IPI_CPU_START\n", this_cpu);
1da177e4
LT
177 break;
178
179 case IPI_CPU_STOP:
5492a0f0 180 smp_debug(100, KERN_DEBUG "CPU%d IPI_CPU_STOP\n", this_cpu);
1da177e4 181 halt_processor();
1da177e4
LT
182 break;
183
184 case IPI_CPU_TEST:
5492a0f0 185 smp_debug(100, KERN_DEBUG "CPU%d is alive!\n", this_cpu);
1da177e4
LT
186 break;
187
188 default:
189 printk(KERN_CRIT "Unknown IPI num on CPU%d: %lu\n",
190 this_cpu, which);
1da177e4
LT
191 return IRQ_NONE;
192 } /* Switch */
7085689e
JB
193 /* let in any pending interrupts */
194 local_irq_enable();
195 local_irq_disable();
1da177e4
LT
196 } /* while (ops) */
197 }
198 return IRQ_HANDLED;
199}
200
201
202static inline void
203ipi_send(int cpu, enum ipi_message_type op)
204{
ef017beb 205 struct cpuinfo_parisc *p = &per_cpu(cpu_data, cpu);
3c97b5e9 206 spinlock_t *lock = &per_cpu(ipi_lock, cpu);
1da177e4
LT
207 unsigned long flags;
208
3c97b5e9 209 spin_lock_irqsave(lock, flags);
1da177e4 210 p->pending_ipi |= 1 << op;
ef017beb 211 gsc_writel(IPI_IRQ - CPU_IRQ_BASE, p->hpa);
3c97b5e9 212 spin_unlock_irqrestore(lock, flags);
1da177e4
LT
213}
214
dbcf4787 215static void
91887a36 216send_IPI_mask(const struct cpumask *mask, enum ipi_message_type op)
dbcf4787
JA
217{
218 int cpu;
219
91887a36 220 for_each_cpu(cpu, mask)
dbcf4787
JA
221 ipi_send(cpu, op);
222}
1da177e4
LT
223
224static inline void
225send_IPI_single(int dest_cpu, enum ipi_message_type op)
226{
7f2347a4 227 BUG_ON(dest_cpu == NO_PROC_ID);
1da177e4
LT
228
229 ipi_send(dest_cpu, op);
230}
231
232static inline void
233send_IPI_allbutself(enum ipi_message_type op)
234{
235 int i;
236
394e3902
AM
237 for_each_online_cpu(i) {
238 if (i != smp_processor_id())
1da177e4
LT
239 send_IPI_single(i, op);
240 }
241}
242
243
244inline void
245smp_send_stop(void) { send_IPI_allbutself(IPI_CPU_STOP); }
246
247static inline void
248smp_send_start(void) { send_IPI_allbutself(IPI_CPU_START); }
249
250void
251smp_send_reschedule(int cpu) { send_IPI_single(cpu, IPI_RESCHEDULE); }
252
d911aed8
JB
253void
254smp_send_all_nop(void)
255{
256 send_IPI_allbutself(IPI_NOP);
257}
258
91887a36 259void arch_send_call_function_ipi_mask(const struct cpumask *mask)
1da177e4 260{
dbcf4787 261 send_IPI_mask(mask, IPI_CALL_FUNC);
1da177e4
LT
262}
263
dbcf4787
JA
264void arch_send_call_function_single_ipi(int cpu)
265{
266 send_IPI_single(cpu, IPI_CALL_FUNC_SINGLE);
267}
1da177e4
LT
268
269/*
270 * Flush all other CPU's tlb and then mine. Do this with on_each_cpu()
271 * as we want to ensure all TLB's flushed before proceeding.
272 */
273
1da177e4
LT
274void
275smp_flush_tlb_all(void)
276{
15c8b6c1 277 on_each_cpu(flush_tlb_all_local, NULL, 1);
1da177e4
LT
278}
279
1da177e4
LT
280/*
281 * Called by secondaries to update state and initialize CPU registers.
282 */
283static void __init
284smp_cpu_init(int cpunum)
285{
56f335c8 286 extern int init_per_cpu(int); /* arch/parisc/kernel/processor.c */
1da177e4 287 extern void init_IRQ(void); /* arch/parisc/kernel/irq.c */
56f335c8 288 extern void start_cpu_itimer(void); /* arch/parisc/kernel/time.c */
1da177e4
LT
289
290 /* Set modes and Enable floating point coprocessor */
291 (void) init_per_cpu(cpunum);
292
293 disable_sr_hashing();
294
295 mb();
296
297 /* Well, support 2.4 linux scheme as well. */
9bc181d8 298 if (cpu_isset(cpunum, cpu_online_map))
1da177e4
LT
299 {
300 extern void machine_halt(void); /* arch/parisc.../process.c */
301
302 printk(KERN_CRIT "CPU#%d already initialized!\n", cpunum);
303 machine_halt();
304 }
9bc181d8 305 set_cpu_online(cpunum, true);
1da177e4
LT
306
307 /* Initialise the idle task for this CPU */
308 atomic_inc(&init_mm.mm_count);
309 current->active_mm = &init_mm;
7f2347a4 310 BUG_ON(current->mm);
1da177e4
LT
311 enter_lazy_tlb(&init_mm, current);
312
7022672e 313 init_IRQ(); /* make sure no IRQs are enabled or pending */
56f335c8 314 start_cpu_itimer();
1da177e4
LT
315}
316
317
318/*
319 * Slaves start using C here. Indirectly called from smp_slave_stext.
320 * Do what start_kernel() and main() do for boot strap processor (aka monarch)
321 */
322void __init smp_callin(void)
323{
324 int slave_id = cpu_now_booting;
1da177e4
LT
325
326 smp_cpu_init(slave_id);
5bfb5d69 327 preempt_disable();
1da177e4 328
1da177e4 329 flush_cache_all_local(); /* start with known state */
1b2425e3 330 flush_tlb_all_local(NULL);
1da177e4
LT
331
332 local_irq_enable(); /* Interrupts have been off until now */
333
334 cpu_idle(); /* Wait for timer to schedule some work */
335
336 /* NOTREACHED */
337 panic("smp_callin() AAAAaaaaahhhh....\n");
338}
339
340/*
341 * Bring one cpu online.
342 */
8dff980f 343int __cpuinit smp_boot_one_cpu(int cpuid)
1da177e4 344{
ef017beb 345 const struct cpuinfo_parisc *p = &per_cpu(cpu_data, cpuid);
1da177e4
LT
346 struct task_struct *idle;
347 long timeout;
348
349 /*
350 * Create an idle task for this CPU. Note the address wed* give
351 * to kernel_thread is irrelevant -- it's going to start
352 * where OS_BOOT_RENDEVZ vector in SAL says to start. But
353 * this gets all the other task-y sort of data structures set
354 * up like we wish. We need to pull the just created idle task
355 * off the run queue and stuff it into the init_tasks[] array.
356 * Sheesh . . .
357 */
358
359 idle = fork_idle(cpuid);
360 if (IS_ERR(idle))
361 panic("SMP: fork failed for CPU:%d", cpuid);
362
40f1f0de 363 task_thread_info(idle)->cpu = cpuid;
1da177e4
LT
364
365 /* Let _start know what logical CPU we're booting
366 ** (offset into init_tasks[],cpu_data[])
367 */
368 cpu_now_booting = cpuid;
369
370 /*
371 ** boot strap code needs to know the task address since
372 ** it also contains the process stack.
373 */
374 smp_init_current_idle_task = idle ;
375 mb();
376
ef017beb 377 printk(KERN_INFO "Releasing cpu %d now, hpa=%lx\n", cpuid, p->hpa);
1da177e4
LT
378
379 /*
380 ** This gets PDC to release the CPU from a very tight loop.
381 **
382 ** From the PA-RISC 2.0 Firmware Architecture Reference Specification:
383 ** "The MEM_RENDEZ vector specifies the location of OS_RENDEZ which
384 ** is executed after receiving the rendezvous signal (an interrupt to
385 ** EIR{0}). MEM_RENDEZ is valid only when it is nonzero and the
386 ** contents of memory are valid."
387 */
ef017beb 388 gsc_writel(TIMER_IRQ - CPU_IRQ_BASE, p->hpa);
1da177e4
LT
389 mb();
390
391 /*
392 * OK, wait a bit for that CPU to finish staggering about.
393 * Slave will set a bit when it reaches smp_cpu_init().
394 * Once the "monarch CPU" sees the bit change, it can move on.
395 */
396 for (timeout = 0; timeout < 10000; timeout++) {
397 if(cpu_online(cpuid)) {
398 /* Which implies Slave has started up */
399 cpu_now_booting = 0;
400 smp_init_current_idle_task = NULL;
401 goto alive ;
402 }
403 udelay(100);
404 barrier();
405 }
406
407 put_task_struct(idle);
408 idle = NULL;
409
410 printk(KERN_CRIT "SMP: CPU:%d is stuck.\n", cpuid);
411 return -1;
412
413alive:
414 /* Remember the Slave data */
5492a0f0 415 smp_debug(100, KERN_DEBUG "SMP: CPU:%d came alive after %ld _us\n",
1da177e4 416 cpuid, timeout * 100);
1da177e4
LT
417 return 0;
418}
419
ef017beb 420void __init smp_prepare_boot_cpu(void)
1da177e4 421{
ef017beb 422 int bootstrap_processor = per_cpu(cpu_data, 0).cpuid;
1da177e4 423
1da177e4 424 /* Setup BSP mappings */
ef017beb 425 printk(KERN_INFO "SMP: bootstrap CPU ID is %d\n", bootstrap_processor);
1da177e4 426
9bc181d8
RR
427 set_cpu_online(bootstrap_processor, true);
428 set_cpu_present(bootstrap_processor, true);
1da177e4
LT
429}
430
431
432
433/*
434** inventory.c:do_inventory() hasn't yet been run and thus we
7022672e 435** don't 'discover' the additional CPUs until later.
1da177e4
LT
436*/
437void __init smp_prepare_cpus(unsigned int max_cpus)
438{
6ad6c424
TG
439 int cpu;
440
441 for_each_possible_cpu(cpu)
442 spin_lock_init(&per_cpu(ipi_lock, cpu));
443
9bc181d8 444 init_cpu_present(cpumask_of(0));
1da177e4
LT
445
446 parisc_max_cpus = max_cpus;
447 if (!max_cpus)
448 printk(KERN_INFO "SMP mode deactivated.\n");
449}
450
451
452void smp_cpus_done(unsigned int cpu_max)
453{
454 return;
455}
456
457
b282b6f8 458int __cpuinit __cpu_up(unsigned int cpu)
1da177e4
LT
459{
460 if (cpu != 0 && cpu < parisc_max_cpus)
461 smp_boot_one_cpu(cpu);
462
463 return cpu_online(cpu) ? 0 : -ENOSYS;
464}
465
1da177e4
LT
466#ifdef CONFIG_PROC_FS
467int __init
468setup_profiling_timer(unsigned int multiplier)
469{
470 return -EINVAL;
471}
472#endif