Merge branch 'for-upstream/hdlcd' of git://linux-arm.org/linux-ld into drm-fixes
[deliverable/linux.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>
ec2e0f98 34#include <linux/cpu.h>
1da177e4 35
60063497 36#include <linux/atomic.h>
1da177e4
LT
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 64/* track which CPU is booting */
60ffef06 65static volatile int cpu_now_booting;
1da177e4 66
60ffef06 67static int parisc_max_cpus = 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,
75 IPI_CPU_START,
76 IPI_CPU_STOP,
77 IPI_CPU_TEST
78};
79
80
81/********** SMP inter processor interrupt and communication routines */
82
83#undef PER_CPU_IRQ_REGION
84#ifdef PER_CPU_IRQ_REGION
85/* XXX REVISIT Ignore for now.
86** *May* need this "hook" to register IPI handler
87** once we have perCPU ExtIntr switch tables.
88*/
89static void
90ipi_init(int cpuid)
91{
1da177e4
LT
92#error verify IRQ_OFFSET(IPI_IRQ) is ipi_interrupt() in new IRQ region
93
94 if(cpu_online(cpuid) )
95 {
96 switch_to_idle_task(current);
97 }
98
99 return;
100}
101#endif
102
103
104/*
105** Yoink this CPU from the runnable list...
106**
107*/
108static void
109halt_processor(void)
110{
1da177e4
LT
111 /* REVISIT : redirect I/O Interrupts to another CPU? */
112 /* REVISIT : does PM *know* this CPU isn't available? */
9bc181d8 113 set_cpu_online(smp_processor_id(), false);
1da177e4
LT
114 local_irq_disable();
115 for (;;)
116 ;
1da177e4
LT
117}
118
119
d75f054a 120irqreturn_t __irq_entry
c7753f18 121ipi_interrupt(int irq, void *dev_id)
1da177e4
LT
122{
123 int this_cpu = smp_processor_id();
ef017beb 124 struct cpuinfo_parisc *p = &per_cpu(cpu_data, this_cpu);
1da177e4
LT
125 unsigned long ops;
126 unsigned long flags;
127
1da177e4 128 for (;;) {
3c97b5e9
KM
129 spinlock_t *lock = &per_cpu(ipi_lock, this_cpu);
130 spin_lock_irqsave(lock, flags);
1da177e4
LT
131 ops = p->pending_ipi;
132 p->pending_ipi = 0;
3c97b5e9 133 spin_unlock_irqrestore(lock, flags);
1da177e4
LT
134
135 mb(); /* Order bit clearing and data access. */
136
137 if (!ops)
138 break;
139
140 while (ops) {
141 unsigned long which = ffz(~ops);
142
d911aed8
JB
143 ops &= ~(1 << which);
144
1da177e4 145 switch (which) {
d911aed8 146 case IPI_NOP:
5492a0f0 147 smp_debug(100, KERN_DEBUG "CPU%d IPI_NOP\n", this_cpu);
d911aed8
JB
148 break;
149
1da177e4 150 case IPI_RESCHEDULE:
5492a0f0 151 smp_debug(100, KERN_DEBUG "CPU%d IPI_RESCHEDULE\n", this_cpu);
cd85d551 152 inc_irq_stat(irq_resched_count);
184748cc 153 scheduler_ipi();
1da177e4
LT
154 break;
155
156 case IPI_CALL_FUNC:
5492a0f0 157 smp_debug(100, KERN_DEBUG "CPU%d IPI_CALL_FUNC\n", this_cpu);
dbcf4787
JA
158 generic_smp_call_function_interrupt();
159 break;
160
1da177e4 161 case IPI_CPU_START:
5492a0f0 162 smp_debug(100, KERN_DEBUG "CPU%d IPI_CPU_START\n", this_cpu);
1da177e4
LT
163 break;
164
165 case IPI_CPU_STOP:
5492a0f0 166 smp_debug(100, KERN_DEBUG "CPU%d IPI_CPU_STOP\n", this_cpu);
1da177e4 167 halt_processor();
1da177e4
LT
168 break;
169
170 case IPI_CPU_TEST:
5492a0f0 171 smp_debug(100, KERN_DEBUG "CPU%d is alive!\n", this_cpu);
1da177e4
LT
172 break;
173
174 default:
175 printk(KERN_CRIT "Unknown IPI num on CPU%d: %lu\n",
176 this_cpu, which);
1da177e4
LT
177 return IRQ_NONE;
178 } /* Switch */
7085689e
JB
179 /* let in any pending interrupts */
180 local_irq_enable();
181 local_irq_disable();
1da177e4
LT
182 } /* while (ops) */
183 }
184 return IRQ_HANDLED;
185}
186
187
188static inline void
189ipi_send(int cpu, enum ipi_message_type op)
190{
ef017beb 191 struct cpuinfo_parisc *p = &per_cpu(cpu_data, cpu);
3c97b5e9 192 spinlock_t *lock = &per_cpu(ipi_lock, cpu);
1da177e4
LT
193 unsigned long flags;
194
3c97b5e9 195 spin_lock_irqsave(lock, flags);
1da177e4 196 p->pending_ipi |= 1 << op;
ef017beb 197 gsc_writel(IPI_IRQ - CPU_IRQ_BASE, p->hpa);
3c97b5e9 198 spin_unlock_irqrestore(lock, flags);
1da177e4
LT
199}
200
dbcf4787 201static void
91887a36 202send_IPI_mask(const struct cpumask *mask, enum ipi_message_type op)
dbcf4787
JA
203{
204 int cpu;
205
91887a36 206 for_each_cpu(cpu, mask)
dbcf4787
JA
207 ipi_send(cpu, op);
208}
1da177e4
LT
209
210static inline void
211send_IPI_single(int dest_cpu, enum ipi_message_type op)
212{
7f2347a4 213 BUG_ON(dest_cpu == NO_PROC_ID);
1da177e4
LT
214
215 ipi_send(dest_cpu, op);
216}
217
218static inline void
219send_IPI_allbutself(enum ipi_message_type op)
220{
221 int i;
222
394e3902
AM
223 for_each_online_cpu(i) {
224 if (i != smp_processor_id())
1da177e4
LT
225 send_IPI_single(i, op);
226 }
227}
228
229
230inline void
231smp_send_stop(void) { send_IPI_allbutself(IPI_CPU_STOP); }
232
1da177e4
LT
233void
234smp_send_reschedule(int cpu) { send_IPI_single(cpu, IPI_RESCHEDULE); }
235
d911aed8
JB
236void
237smp_send_all_nop(void)
238{
239 send_IPI_allbutself(IPI_NOP);
240}
241
91887a36 242void arch_send_call_function_ipi_mask(const struct cpumask *mask)
1da177e4 243{
dbcf4787 244 send_IPI_mask(mask, IPI_CALL_FUNC);
1da177e4
LT
245}
246
dbcf4787
JA
247void arch_send_call_function_single_ipi(int cpu)
248{
528d8eb2 249 send_IPI_single(cpu, IPI_CALL_FUNC);
dbcf4787 250}
1da177e4 251
1da177e4
LT
252/*
253 * Called by secondaries to update state and initialize CPU registers.
254 */
255static void __init
256smp_cpu_init(int cpunum)
257{
56f335c8 258 extern int init_per_cpu(int); /* arch/parisc/kernel/processor.c */
1da177e4 259 extern void init_IRQ(void); /* arch/parisc/kernel/irq.c */
56f335c8 260 extern void start_cpu_itimer(void); /* arch/parisc/kernel/time.c */
1da177e4
LT
261
262 /* Set modes and Enable floating point coprocessor */
263 (void) init_per_cpu(cpunum);
264
265 disable_sr_hashing();
266
267 mb();
268
269 /* Well, support 2.4 linux scheme as well. */
7ec6118c 270 if (cpu_online(cpunum)) {
1da177e4
LT
271 extern void machine_halt(void); /* arch/parisc.../process.c */
272
273 printk(KERN_CRIT "CPU#%d already initialized!\n", cpunum);
274 machine_halt();
ec2e0f98
SB
275 }
276
277 notify_cpu_starting(cpunum);
278
9bc181d8 279 set_cpu_online(cpunum, true);
1da177e4
LT
280
281 /* Initialise the idle task for this CPU */
282 atomic_inc(&init_mm.mm_count);
283 current->active_mm = &init_mm;
7f2347a4 284 BUG_ON(current->mm);
1da177e4
LT
285 enter_lazy_tlb(&init_mm, current);
286
7022672e 287 init_IRQ(); /* make sure no IRQs are enabled or pending */
56f335c8 288 start_cpu_itimer();
1da177e4
LT
289}
290
291
292/*
293 * Slaves start using C here. Indirectly called from smp_slave_stext.
294 * Do what start_kernel() and main() do for boot strap processor (aka monarch)
295 */
296void __init smp_callin(void)
297{
298 int slave_id = cpu_now_booting;
1da177e4
LT
299
300 smp_cpu_init(slave_id);
5bfb5d69 301 preempt_disable();
1da177e4 302
1da177e4 303 flush_cache_all_local(); /* start with known state */
1b2425e3 304 flush_tlb_all_local(NULL);
1da177e4
LT
305
306 local_irq_enable(); /* Interrupts have been off until now */
307
fc6d73d6 308 cpu_startup_entry(CPUHP_AP_ONLINE_IDLE);
1da177e4
LT
309
310 /* NOTREACHED */
311 panic("smp_callin() AAAAaaaaahhhh....\n");
312}
313
314/*
315 * Bring one cpu online.
316 */
60ffef06 317int smp_boot_one_cpu(int cpuid, struct task_struct *idle)
1da177e4 318{
ef017beb 319 const struct cpuinfo_parisc *p = &per_cpu(cpu_data, cpuid);
1da177e4
LT
320 long timeout;
321
40f1f0de 322 task_thread_info(idle)->cpu = cpuid;
1da177e4
LT
323
324 /* Let _start know what logical CPU we're booting
325 ** (offset into init_tasks[],cpu_data[])
326 */
327 cpu_now_booting = cpuid;
328
329 /*
330 ** boot strap code needs to know the task address since
331 ** it also contains the process stack.
332 */
333 smp_init_current_idle_task = idle ;
334 mb();
335
ef017beb 336 printk(KERN_INFO "Releasing cpu %d now, hpa=%lx\n", cpuid, p->hpa);
1da177e4
LT
337
338 /*
339 ** This gets PDC to release the CPU from a very tight loop.
340 **
341 ** From the PA-RISC 2.0 Firmware Architecture Reference Specification:
342 ** "The MEM_RENDEZ vector specifies the location of OS_RENDEZ which
343 ** is executed after receiving the rendezvous signal (an interrupt to
344 ** EIR{0}). MEM_RENDEZ is valid only when it is nonzero and the
345 ** contents of memory are valid."
346 */
ef017beb 347 gsc_writel(TIMER_IRQ - CPU_IRQ_BASE, p->hpa);
1da177e4
LT
348 mb();
349
350 /*
351 * OK, wait a bit for that CPU to finish staggering about.
352 * Slave will set a bit when it reaches smp_cpu_init().
353 * Once the "monarch CPU" sees the bit change, it can move on.
354 */
355 for (timeout = 0; timeout < 10000; timeout++) {
356 if(cpu_online(cpuid)) {
357 /* Which implies Slave has started up */
358 cpu_now_booting = 0;
359 smp_init_current_idle_task = NULL;
360 goto alive ;
361 }
362 udelay(100);
363 barrier();
364 }
1da177e4
LT
365 printk(KERN_CRIT "SMP: CPU:%d is stuck.\n", cpuid);
366 return -1;
367
368alive:
369 /* Remember the Slave data */
5492a0f0 370 smp_debug(100, KERN_DEBUG "SMP: CPU:%d came alive after %ld _us\n",
1da177e4 371 cpuid, timeout * 100);
1da177e4
LT
372 return 0;
373}
374
ef017beb 375void __init smp_prepare_boot_cpu(void)
1da177e4 376{
ef017beb 377 int bootstrap_processor = per_cpu(cpu_data, 0).cpuid;
1da177e4 378
1da177e4 379 /* Setup BSP mappings */
ef017beb 380 printk(KERN_INFO "SMP: bootstrap CPU ID is %d\n", bootstrap_processor);
1da177e4 381
9bc181d8
RR
382 set_cpu_online(bootstrap_processor, true);
383 set_cpu_present(bootstrap_processor, true);
1da177e4
LT
384}
385
386
387
388/*
389** inventory.c:do_inventory() hasn't yet been run and thus we
7022672e 390** don't 'discover' the additional CPUs until later.
1da177e4
LT
391*/
392void __init smp_prepare_cpus(unsigned int max_cpus)
393{
6ad6c424
TG
394 int cpu;
395
396 for_each_possible_cpu(cpu)
397 spin_lock_init(&per_cpu(ipi_lock, cpu));
398
9bc181d8 399 init_cpu_present(cpumask_of(0));
1da177e4
LT
400
401 parisc_max_cpus = max_cpus;
402 if (!max_cpus)
403 printk(KERN_INFO "SMP mode deactivated.\n");
404}
405
406
407void smp_cpus_done(unsigned int cpu_max)
408{
409 return;
410}
411
412
60ffef06 413int __cpu_up(unsigned int cpu, struct task_struct *tidle)
1da177e4
LT
414{
415 if (cpu != 0 && cpu < parisc_max_cpus)
9a134723 416 smp_boot_one_cpu(cpu, tidle);
1da177e4
LT
417
418 return cpu_online(cpu) ? 0 : -ENOSYS;
419}
420
1da177e4
LT
421#ifdef CONFIG_PROC_FS
422int __init
423setup_profiling_timer(unsigned int multiplier)
424{
425 return -EINVAL;
426}
427#endif
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