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