blob: 02c2db08114ad66e42876d5e1f2b80c402ec9a84 [file] [log] [blame]
Linus Torvalds1da177e2005-04-16 15:20:36 -07001/*
2 * linux/arch/alpha/kernel/smp.c
3 *
4 * 2001-07-09 Phil Ezolt (Phillip.Ezolt@compaq.com)
5 * Renamed modified smp_call_function to smp_call_function_on_cpu()
6 * Created an function that conforms to the old calling convention
7 * of smp_call_function().
8 *
9 * This is helpful for DCPI.
10 *
11 */
12
13#include <linux/errno.h>
14#include <linux/kernel.h>
15#include <linux/kernel_stat.h>
16#include <linux/module.h>
17#include <linux/sched.h>
18#include <linux/mm.h>
19#include <linux/threads.h>
20#include <linux/smp.h>
21#include <linux/smp_lock.h>
22#include <linux/interrupt.h>
23#include <linux/init.h>
24#include <linux/delay.h>
25#include <linux/spinlock.h>
26#include <linux/irq.h>
27#include <linux/cache.h>
28#include <linux/profile.h>
29#include <linux/bitops.h>
30
31#include <asm/hwrpb.h>
32#include <asm/ptrace.h>
33#include <asm/atomic.h>
34
35#include <asm/io.h>
36#include <asm/irq.h>
37#include <asm/pgtable.h>
38#include <asm/pgalloc.h>
39#include <asm/mmu_context.h>
40#include <asm/tlbflush.h>
41
42#include "proto.h"
43#include "irq_impl.h"
44
45
46#define DEBUG_SMP 0
47#if DEBUG_SMP
48#define DBGS(args) printk args
49#else
50#define DBGS(args)
51#endif
52
53/* A collection of per-processor data. */
54struct cpuinfo_alpha cpu_data[NR_CPUS];
55
56/* A collection of single bit ipi messages. */
57static struct {
58 unsigned long bits ____cacheline_aligned;
59} ipi_data[NR_CPUS] __cacheline_aligned;
60
61enum ipi_message_type {
62 IPI_RESCHEDULE,
63 IPI_CALL_FUNC,
64 IPI_CPU_STOP,
65};
66
67/* Set to a secondary's cpuid when it comes online. */
68static int smp_secondary_alive __initdata = 0;
69
70/* Which cpus ids came online. */
71cpumask_t cpu_present_mask;
72cpumask_t cpu_online_map;
73
74EXPORT_SYMBOL(cpu_online_map);
75
Linus Torvalds1da177e2005-04-16 15:20:36 -070076int smp_num_probed; /* Internal processor count */
77int smp_num_cpus = 1; /* Number that came online. */
78
79extern void calibrate_delay(void);
80
81
82
83/*
84 * Called by both boot and secondaries to move global data into
85 * per-processor storage.
86 */
87static inline void __init
88smp_store_cpu_info(int cpuid)
89{
90 cpu_data[cpuid].loops_per_jiffy = loops_per_jiffy;
91 cpu_data[cpuid].last_asn = ASN_FIRST_VERSION;
92 cpu_data[cpuid].need_new_asn = 0;
93 cpu_data[cpuid].asn_lock = 0;
94}
95
96/*
97 * Ideally sets up per-cpu profiling hooks. Doesn't do much now...
98 */
99static inline void __init
100smp_setup_percpu_timer(int cpuid)
101{
102 cpu_data[cpuid].prof_counter = 1;
103 cpu_data[cpuid].prof_multiplier = 1;
104}
105
106static void __init
107wait_boot_cpu_to_stop(int cpuid)
108{
109 unsigned long stop = jiffies + 10*HZ;
110
111 while (time_before(jiffies, stop)) {
112 if (!smp_secondary_alive)
113 return;
114 barrier();
115 }
116
117 printk("wait_boot_cpu_to_stop: FAILED on CPU %d, hanging now\n", cpuid);
118 for (;;)
119 barrier();
120}
121
122/*
123 * Where secondaries begin a life of C.
124 */
125void __init
126smp_callin(void)
127{
128 int cpuid = hard_smp_processor_id();
129
130 if (cpu_test_and_set(cpuid, cpu_online_map)) {
131 printk("??, cpu 0x%x already present??\n", cpuid);
132 BUG();
133 }
134
135 /* Turn on machine checks. */
136 wrmces(7);
137
138 /* Set trap vectors. */
139 trap_init();
140
141 /* Set interrupt vector. */
142 wrent(entInt, 0);
143
144 /* Get our local ticker going. */
145 smp_setup_percpu_timer(cpuid);
146
147 /* Call platform-specific callin, if specified */
148 if (alpha_mv.smp_callin) alpha_mv.smp_callin();
149
150 /* All kernel threads share the same mm context. */
151 atomic_inc(&init_mm.mm_count);
152 current->active_mm = &init_mm;
153
154 /* Must have completely accurate bogos. */
155 local_irq_enable();
156
157 /* Wait boot CPU to stop with irq enabled before running
158 calibrate_delay. */
159 wait_boot_cpu_to_stop(cpuid);
160 mb();
161 calibrate_delay();
162
163 smp_store_cpu_info(cpuid);
164 /* Allow master to continue only after we written loops_per_jiffy. */
165 wmb();
166 smp_secondary_alive = 1;
167
168 DBGS(("smp_callin: commencing CPU %d current %p active_mm %p\n",
169 cpuid, current, current->active_mm));
170
171 /* Do nothing. */
172 cpu_idle();
173}
174
175/* Wait until hwrpb->txrdy is clear for cpu. Return -1 on timeout. */
176static int __init
177wait_for_txrdy (unsigned long cpumask)
178{
179 unsigned long timeout;
180
181 if (!(hwrpb->txrdy & cpumask))
182 return 0;
183
184 timeout = jiffies + 10*HZ;
185 while (time_before(jiffies, timeout)) {
186 if (!(hwrpb->txrdy & cpumask))
187 return 0;
188 udelay(10);
189 barrier();
190 }
191
192 return -1;
193}
194
195/*
196 * Send a message to a secondary's console. "START" is one such
197 * interesting message. ;-)
198 */
199static void __init
200send_secondary_console_msg(char *str, int cpuid)
201{
202 struct percpu_struct *cpu;
203 register char *cp1, *cp2;
204 unsigned long cpumask;
205 size_t len;
206
207 cpu = (struct percpu_struct *)
208 ((char*)hwrpb
209 + hwrpb->processor_offset
210 + cpuid * hwrpb->processor_size);
211
212 cpumask = (1UL << cpuid);
213 if (wait_for_txrdy(cpumask))
214 goto timeout;
215
216 cp2 = str;
217 len = strlen(cp2);
218 *(unsigned int *)&cpu->ipc_buffer[0] = len;
219 cp1 = (char *) &cpu->ipc_buffer[1];
220 memcpy(cp1, cp2, len);
221
222 /* atomic test and set */
223 wmb();
224 set_bit(cpuid, &hwrpb->rxrdy);
225
226 if (wait_for_txrdy(cpumask))
227 goto timeout;
228 return;
229
230 timeout:
231 printk("Processor %x not ready\n", cpuid);
232}
233
234/*
235 * A secondary console wants to send a message. Receive it.
236 */
237static void
238recv_secondary_console_msg(void)
239{
240 int mycpu, i, cnt;
241 unsigned long txrdy = hwrpb->txrdy;
242 char *cp1, *cp2, buf[80];
243 struct percpu_struct *cpu;
244
245 DBGS(("recv_secondary_console_msg: TXRDY 0x%lx.\n", txrdy));
246
247 mycpu = hard_smp_processor_id();
248
249 for (i = 0; i < NR_CPUS; i++) {
250 if (!(txrdy & (1UL << i)))
251 continue;
252
253 DBGS(("recv_secondary_console_msg: "
254 "TXRDY contains CPU %d.\n", i));
255
256 cpu = (struct percpu_struct *)
257 ((char*)hwrpb
258 + hwrpb->processor_offset
259 + i * hwrpb->processor_size);
260
261 DBGS(("recv_secondary_console_msg: on %d from %d"
262 " HALT_REASON 0x%lx FLAGS 0x%lx\n",
263 mycpu, i, cpu->halt_reason, cpu->flags));
264
265 cnt = cpu->ipc_buffer[0] >> 32;
266 if (cnt <= 0 || cnt >= 80)
267 strcpy(buf, "<<< BOGUS MSG >>>");
268 else {
269 cp1 = (char *) &cpu->ipc_buffer[11];
270 cp2 = buf;
271 strcpy(cp2, cp1);
272
273 while ((cp2 = strchr(cp2, '\r')) != 0) {
274 *cp2 = ' ';
275 if (cp2[1] == '\n')
276 cp2[1] = ' ';
277 }
278 }
279
280 DBGS((KERN_INFO "recv_secondary_console_msg: on %d "
281 "message is '%s'\n", mycpu, buf));
282 }
283
284 hwrpb->txrdy = 0;
285}
286
287/*
288 * Convince the console to have a secondary cpu begin execution.
289 */
290static int __init
291secondary_cpu_start(int cpuid, struct task_struct *idle)
292{
293 struct percpu_struct *cpu;
294 struct pcb_struct *hwpcb, *ipcb;
295 unsigned long timeout;
296
297 cpu = (struct percpu_struct *)
298 ((char*)hwrpb
299 + hwrpb->processor_offset
300 + cpuid * hwrpb->processor_size);
301 hwpcb = (struct pcb_struct *) cpu->hwpcb;
Al Viro37bfbaf2006-01-12 01:05:36 -0800302 ipcb = &task_thread_info(idle)->pcb;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700303
304 /* Initialize the CPU's HWPCB to something just good enough for
305 us to get started. Immediately after starting, we'll swpctx
306 to the target idle task's pcb. Reuse the stack in the mean
307 time. Precalculate the target PCBB. */
308 hwpcb->ksp = (unsigned long)ipcb + sizeof(union thread_union) - 16;
309 hwpcb->usp = 0;
310 hwpcb->ptbr = ipcb->ptbr;
311 hwpcb->pcc = 0;
312 hwpcb->asn = 0;
313 hwpcb->unique = virt_to_phys(ipcb);
314 hwpcb->flags = ipcb->flags;
315 hwpcb->res1 = hwpcb->res2 = 0;
316
317#if 0
318 DBGS(("KSP 0x%lx PTBR 0x%lx VPTBR 0x%lx UNIQUE 0x%lx\n",
319 hwpcb->ksp, hwpcb->ptbr, hwrpb->vptb, hwpcb->unique));
320#endif
321 DBGS(("Starting secondary cpu %d: state 0x%lx pal_flags 0x%lx\n",
322 cpuid, idle->state, ipcb->flags));
323
324 /* Setup HWRPB fields that SRM uses to activate secondary CPU */
325 hwrpb->CPU_restart = __smp_callin;
326 hwrpb->CPU_restart_data = (unsigned long) __smp_callin;
327
328 /* Recalculate and update the HWRPB checksum */
329 hwrpb_update_checksum(hwrpb);
330
331 /*
332 * Send a "start" command to the specified processor.
333 */
334
335 /* SRM III 3.4.1.3 */
336 cpu->flags |= 0x22; /* turn on Context Valid and Restart Capable */
337 cpu->flags &= ~1; /* turn off Bootstrap In Progress */
338 wmb();
339
340 send_secondary_console_msg("START\r\n", cpuid);
341
342 /* Wait 10 seconds for an ACK from the console. */
343 timeout = jiffies + 10*HZ;
344 while (time_before(jiffies, timeout)) {
345 if (cpu->flags & 1)
346 goto started;
347 udelay(10);
348 barrier();
349 }
350 printk(KERN_ERR "SMP: Processor %d failed to start.\n", cpuid);
351 return -1;
352
353 started:
354 DBGS(("secondary_cpu_start: SUCCESS for CPU %d!!!\n", cpuid));
355 return 0;
356}
357
358/*
359 * Bring one cpu online.
360 */
361static int __init
362smp_boot_one_cpu(int cpuid)
363{
364 struct task_struct *idle;
365 unsigned long timeout;
366
367 /* Cook up an idler for this guy. Note that the address we
368 give to kernel_thread is irrelevant -- it's going to start
369 where HWRPB.CPU_restart says to start. But this gets all
370 the other task-y sort of data structures set up like we
371 wish. We can't use kernel_thread since we must avoid
372 rescheduling the child. */
373 idle = fork_idle(cpuid);
374 if (IS_ERR(idle))
375 panic("failed fork for CPU %d", cpuid);
376
377 DBGS(("smp_boot_one_cpu: CPU %d state 0x%lx flags 0x%lx\n",
378 cpuid, idle->state, idle->flags));
379
380 /* Signal the secondary to wait a moment. */
381 smp_secondary_alive = -1;
382
383 /* Whirrr, whirrr, whirrrrrrrrr... */
384 if (secondary_cpu_start(cpuid, idle))
385 return -1;
386
387 /* Notify the secondary CPU it can run calibrate_delay. */
388 mb();
389 smp_secondary_alive = 0;
390
391 /* We've been acked by the console; wait one second for
392 the task to start up for real. */
393 timeout = jiffies + 1*HZ;
394 while (time_before(jiffies, timeout)) {
395 if (smp_secondary_alive == 1)
396 goto alive;
397 udelay(10);
398 barrier();
399 }
400
401 /* We failed to boot the CPU. */
402
403 printk(KERN_ERR "SMP: Processor %d is stuck.\n", cpuid);
404 return -1;
405
406 alive:
407 /* Another "Red Snapper". */
408 return 0;
409}
410
411/*
412 * Called from setup_arch. Detect an SMP system and which processors
413 * are present.
414 */
415void __init
416setup_smp(void)
417{
418 struct percpu_struct *cpubase, *cpu;
419 unsigned long i;
420
421 if (boot_cpuid != 0) {
422 printk(KERN_WARNING "SMP: Booting off cpu %d instead of 0?\n",
423 boot_cpuid);
424 }
425
426 if (hwrpb->nr_processors > 1) {
427 int boot_cpu_palrev;
428
429 DBGS(("setup_smp: nr_processors %ld\n",
430 hwrpb->nr_processors));
431
432 cpubase = (struct percpu_struct *)
433 ((char*)hwrpb + hwrpb->processor_offset);
434 boot_cpu_palrev = cpubase->pal_revision;
435
436 for (i = 0; i < hwrpb->nr_processors; i++) {
437 cpu = (struct percpu_struct *)
438 ((char *)cpubase + i*hwrpb->processor_size);
439 if ((cpu->flags & 0x1cc) == 0x1cc) {
440 smp_num_probed++;
441 /* Assume here that "whami" == index */
Ivan Kokshaysky328c2a82006-02-08 11:55:06 +0300442 cpu_set(i, cpu_possible_map);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700443 cpu->pal_revision = boot_cpu_palrev;
444 }
445
446 DBGS(("setup_smp: CPU %d: flags 0x%lx type 0x%lx\n",
447 i, cpu->flags, cpu->type));
448 DBGS(("setup_smp: CPU %d: PAL rev 0x%lx\n",
449 i, cpu->pal_revision));
450 }
451 } else {
452 smp_num_probed = 1;
Ivan Kokshaysky328c2a82006-02-08 11:55:06 +0300453 cpu_set(boot_cpuid, cpu_possible_map);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700454 }
455 cpu_present_mask = cpumask_of_cpu(boot_cpuid);
456
457 printk(KERN_INFO "SMP: %d CPUs probed -- cpu_present_mask = %lx\n",
Ivan Kokshaysky328c2a82006-02-08 11:55:06 +0300458 smp_num_probed, cpu_possible_map.bits[0]);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700459}
460
461/*
462 * Called by smp_init prepare the secondaries
463 */
464void __init
465smp_prepare_cpus(unsigned int max_cpus)
466{
Linus Torvalds1da177e2005-04-16 15:20:36 -0700467 /* Take care of some initial bookkeeping. */
468 memset(ipi_data, 0, sizeof(ipi_data));
469
470 current_thread_info()->cpu = boot_cpuid;
471
472 smp_store_cpu_info(boot_cpuid);
473 smp_setup_percpu_timer(boot_cpuid);
474
475 /* Nothing to do on a UP box, or when told not to. */
476 if (smp_num_probed == 1 || max_cpus == 0) {
477 cpu_present_mask = cpumask_of_cpu(boot_cpuid);
478 printk(KERN_INFO "SMP mode deactivated.\n");
479 return;
480 }
481
482 printk(KERN_INFO "SMP starting up secondaries.\n");
483
Ivan Kokshaysky328c2a82006-02-08 11:55:06 +0300484 smp_num_cpus = smp_num_probed;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700485}
486
487void __devinit
488smp_prepare_boot_cpu(void)
489{
490 /*
491 * Mark the boot cpu (current cpu) as both present and online
492 */
493 cpu_set(smp_processor_id(), cpu_present_mask);
494 cpu_set(smp_processor_id(), cpu_online_map);
495}
496
497int __devinit
498__cpu_up(unsigned int cpu)
499{
500 smp_boot_one_cpu(cpu);
501
502 return cpu_online(cpu) ? 0 : -ENOSYS;
503}
504
505void __init
506smp_cpus_done(unsigned int max_cpus)
507{
508 int cpu;
509 unsigned long bogosum = 0;
510
511 for(cpu = 0; cpu < NR_CPUS; cpu++)
512 if (cpu_online(cpu))
513 bogosum += cpu_data[cpu].loops_per_jiffy;
514
515 printk(KERN_INFO "SMP: Total of %d processors activated "
516 "(%lu.%02lu BogoMIPS).\n",
517 num_online_cpus(),
518 (bogosum + 2500) / (500000/HZ),
519 ((bogosum + 2500) / (5000/HZ)) % 100);
520}
521
522
523void
524smp_percpu_timer_interrupt(struct pt_regs *regs)
525{
526 int cpu = smp_processor_id();
527 unsigned long user = user_mode(regs);
528 struct cpuinfo_alpha *data = &cpu_data[cpu];
529
530 /* Record kernel PC. */
531 profile_tick(CPU_PROFILING, regs);
532
533 if (!--data->prof_counter) {
534 /* We need to make like a normal interrupt -- otherwise
535 timer interrupts ignore the global interrupt lock,
536 which would be a Bad Thing. */
537 irq_enter();
538
539 update_process_times(user);
540
541 data->prof_counter = data->prof_multiplier;
542
543 irq_exit();
544 }
545}
546
547int __init
548setup_profiling_timer(unsigned int multiplier)
549{
550 return -EINVAL;
551}
552
553
554static void
555send_ipi_message(cpumask_t to_whom, enum ipi_message_type operation)
556{
557 int i;
558
559 mb();
560 for_each_cpu_mask(i, to_whom)
561 set_bit(operation, &ipi_data[i].bits);
562
563 mb();
564 for_each_cpu_mask(i, to_whom)
565 wripir(i);
566}
567
568/* Structure and data for smp_call_function. This is designed to
569 minimize static memory requirements. Plus it looks cleaner. */
570
571struct smp_call_struct {
572 void (*func) (void *info);
573 void *info;
574 long wait;
575 atomic_t unstarted_count;
576 atomic_t unfinished_count;
577};
578
579static struct smp_call_struct *smp_call_function_data;
580
581/* Atomicly drop data into a shared pointer. The pointer is free if
582 it is initially locked. If retry, spin until free. */
583
584static int
585pointer_lock (void *lock, void *data, int retry)
586{
587 void *old, *tmp;
588
589 mb();
590 again:
591 /* Compare and swap with zero. */
592 asm volatile (
593 "1: ldq_l %0,%1\n"
594 " mov %3,%2\n"
595 " bne %0,2f\n"
596 " stq_c %2,%1\n"
597 " beq %2,1b\n"
598 "2:"
599 : "=&r"(old), "=m"(*(void **)lock), "=&r"(tmp)
600 : "r"(data)
601 : "memory");
602
603 if (old == 0)
604 return 0;
605 if (! retry)
606 return -EBUSY;
607
608 while (*(void **)lock)
609 barrier();
610 goto again;
611}
612
613void
614handle_ipi(struct pt_regs *regs)
615{
616 int this_cpu = smp_processor_id();
617 unsigned long *pending_ipis = &ipi_data[this_cpu].bits;
618 unsigned long ops;
619
620#if 0
621 DBGS(("handle_ipi: on CPU %d ops 0x%lx PC 0x%lx\n",
622 this_cpu, *pending_ipis, regs->pc));
623#endif
624
625 mb(); /* Order interrupt and bit testing. */
626 while ((ops = xchg(pending_ipis, 0)) != 0) {
627 mb(); /* Order bit clearing and data access. */
628 do {
629 unsigned long which;
630
631 which = ops & -ops;
632 ops &= ~which;
633 which = __ffs(which);
634
635 switch (which) {
636 case IPI_RESCHEDULE:
637 /* Reschedule callback. Everything to be done
638 is done by the interrupt return path. */
639 break;
640
641 case IPI_CALL_FUNC:
642 {
643 struct smp_call_struct *data;
644 void (*func)(void *info);
645 void *info;
646 int wait;
647
648 data = smp_call_function_data;
649 func = data->func;
650 info = data->info;
651 wait = data->wait;
652
653 /* Notify the sending CPU that the data has been
654 received, and execution is about to begin. */
655 mb();
656 atomic_dec (&data->unstarted_count);
657
658 /* At this point the structure may be gone unless
659 wait is true. */
660 (*func)(info);
661
662 /* Notify the sending CPU that the task is done. */
663 mb();
664 if (wait) atomic_dec (&data->unfinished_count);
665 break;
666 }
667
668 case IPI_CPU_STOP:
669 halt();
670
671 default:
672 printk(KERN_CRIT "Unknown IPI on CPU %d: %lu\n",
673 this_cpu, which);
674 break;
675 }
676 } while (ops);
677
678 mb(); /* Order data access and bit testing. */
679 }
680
681 cpu_data[this_cpu].ipi_count++;
682
683 if (hwrpb->txrdy)
684 recv_secondary_console_msg();
685}
686
687void
688smp_send_reschedule(int cpu)
689{
690#ifdef DEBUG_IPI_MSG
691 if (cpu == hard_smp_processor_id())
692 printk(KERN_WARNING
693 "smp_send_reschedule: Sending IPI to self.\n");
694#endif
695 send_ipi_message(cpumask_of_cpu(cpu), IPI_RESCHEDULE);
696}
697
698void
699smp_send_stop(void)
700{
701 cpumask_t to_whom = cpu_possible_map;
702 cpu_clear(smp_processor_id(), to_whom);
703#ifdef DEBUG_IPI_MSG
704 if (hard_smp_processor_id() != boot_cpu_id)
705 printk(KERN_WARNING "smp_send_stop: Not on boot cpu.\n");
706#endif
707 send_ipi_message(to_whom, IPI_CPU_STOP);
708}
709
710/*
711 * Run a function on all other CPUs.
712 * <func> The function to run. This must be fast and non-blocking.
713 * <info> An arbitrary pointer to pass to the function.
714 * <retry> If true, keep retrying until ready.
715 * <wait> If true, wait until function has completed on other CPUs.
716 * [RETURNS] 0 on success, else a negative status code.
717 *
718 * Does not return until remote CPUs are nearly ready to execute <func>
719 * or are or have executed.
720 * You must not call this function with disabled interrupts or from a
721 * hardware interrupt handler or from a bottom half handler.
722 */
723
724int
725smp_call_function_on_cpu (void (*func) (void *info), void *info, int retry,
726 int wait, cpumask_t to_whom)
727{
728 struct smp_call_struct data;
729 unsigned long timeout;
730 int num_cpus_to_call;
731
732 /* Can deadlock when called with interrupts disabled */
733 WARN_ON(irqs_disabled());
734
735 data.func = func;
736 data.info = info;
737 data.wait = wait;
738
739 cpu_clear(smp_processor_id(), to_whom);
740 num_cpus_to_call = cpus_weight(to_whom);
741
742 atomic_set(&data.unstarted_count, num_cpus_to_call);
743 atomic_set(&data.unfinished_count, num_cpus_to_call);
744
745 /* Acquire the smp_call_function_data mutex. */
746 if (pointer_lock(&smp_call_function_data, &data, retry))
747 return -EBUSY;
748
749 /* Send a message to the requested CPUs. */
750 send_ipi_message(to_whom, IPI_CALL_FUNC);
751
752 /* Wait for a minimal response. */
753 timeout = jiffies + HZ;
754 while (atomic_read (&data.unstarted_count) > 0
755 && time_before (jiffies, timeout))
756 barrier();
757
758 /* If there's no response yet, log a message but allow a longer
759 * timeout period -- if we get a response this time, log
760 * a message saying when we got it..
761 */
762 if (atomic_read(&data.unstarted_count) > 0) {
763 long start_time = jiffies;
764 printk(KERN_ERR "%s: initial timeout -- trying long wait\n",
765 __FUNCTION__);
766 timeout = jiffies + 30 * HZ;
767 while (atomic_read(&data.unstarted_count) > 0
768 && time_before(jiffies, timeout))
769 barrier();
770 if (atomic_read(&data.unstarted_count) <= 0) {
771 long delta = jiffies - start_time;
772 printk(KERN_ERR
773 "%s: response %ld.%ld seconds into long wait\n",
774 __FUNCTION__, delta / HZ,
775 (100 * (delta - ((delta / HZ) * HZ))) / HZ);
776 }
777 }
778
779 /* We either got one or timed out -- clear the lock. */
780 mb();
781 smp_call_function_data = NULL;
782
783 /*
784 * If after both the initial and long timeout periods we still don't
785 * have a response, something is very wrong...
786 */
787 BUG_ON(atomic_read (&data.unstarted_count) > 0);
788
789 /* Wait for a complete response, if needed. */
790 if (wait) {
791 while (atomic_read (&data.unfinished_count) > 0)
792 barrier();
793 }
794
795 return 0;
796}
797
798int
799smp_call_function (void (*func) (void *info), void *info, int retry, int wait)
800{
801 return smp_call_function_on_cpu (func, info, retry, wait,
802 cpu_online_map);
803}
804
805static void
806ipi_imb(void *ignored)
807{
808 imb();
809}
810
811void
812smp_imb(void)
813{
814 /* Must wait other processors to flush their icache before continue. */
815 if (on_each_cpu(ipi_imb, NULL, 1, 1))
816 printk(KERN_CRIT "smp_imb: timed out\n");
817}
818
819static void
820ipi_flush_tlb_all(void *ignored)
821{
822 tbia();
823}
824
825void
826flush_tlb_all(void)
827{
828 /* Although we don't have any data to pass, we do want to
829 synchronize with the other processors. */
830 if (on_each_cpu(ipi_flush_tlb_all, NULL, 1, 1)) {
831 printk(KERN_CRIT "flush_tlb_all: timed out\n");
832 }
833}
834
835#define asn_locked() (cpu_data[smp_processor_id()].asn_lock)
836
837static void
838ipi_flush_tlb_mm(void *x)
839{
840 struct mm_struct *mm = (struct mm_struct *) x;
841 if (mm == current->active_mm && !asn_locked())
842 flush_tlb_current(mm);
843 else
844 flush_tlb_other(mm);
845}
846
847void
848flush_tlb_mm(struct mm_struct *mm)
849{
850 preempt_disable();
851
852 if (mm == current->active_mm) {
853 flush_tlb_current(mm);
854 if (atomic_read(&mm->mm_users) <= 1) {
855 int cpu, this_cpu = smp_processor_id();
856 for (cpu = 0; cpu < NR_CPUS; cpu++) {
857 if (!cpu_online(cpu) || cpu == this_cpu)
858 continue;
859 if (mm->context[cpu])
860 mm->context[cpu] = 0;
861 }
862 preempt_enable();
863 return;
864 }
865 }
866
867 if (smp_call_function(ipi_flush_tlb_mm, mm, 1, 1)) {
868 printk(KERN_CRIT "flush_tlb_mm: timed out\n");
869 }
870
871 preempt_enable();
872}
873
874struct flush_tlb_page_struct {
875 struct vm_area_struct *vma;
876 struct mm_struct *mm;
877 unsigned long addr;
878};
879
880static void
881ipi_flush_tlb_page(void *x)
882{
883 struct flush_tlb_page_struct *data = (struct flush_tlb_page_struct *)x;
884 struct mm_struct * mm = data->mm;
885
886 if (mm == current->active_mm && !asn_locked())
887 flush_tlb_current_page(mm, data->vma, data->addr);
888 else
889 flush_tlb_other(mm);
890}
891
892void
893flush_tlb_page(struct vm_area_struct *vma, unsigned long addr)
894{
895 struct flush_tlb_page_struct data;
896 struct mm_struct *mm = vma->vm_mm;
897
898 preempt_disable();
899
900 if (mm == current->active_mm) {
901 flush_tlb_current_page(mm, vma, addr);
902 if (atomic_read(&mm->mm_users) <= 1) {
903 int cpu, this_cpu = smp_processor_id();
904 for (cpu = 0; cpu < NR_CPUS; cpu++) {
905 if (!cpu_online(cpu) || cpu == this_cpu)
906 continue;
907 if (mm->context[cpu])
908 mm->context[cpu] = 0;
909 }
910 preempt_enable();
911 return;
912 }
913 }
914
915 data.vma = vma;
916 data.mm = mm;
917 data.addr = addr;
918
919 if (smp_call_function(ipi_flush_tlb_page, &data, 1, 1)) {
920 printk(KERN_CRIT "flush_tlb_page: timed out\n");
921 }
922
923 preempt_enable();
924}
925
926void
927flush_tlb_range(struct vm_area_struct *vma, unsigned long start, unsigned long end)
928{
929 /* On the Alpha we always flush the whole user tlb. */
930 flush_tlb_mm(vma->vm_mm);
931}
932
933static void
934ipi_flush_icache_page(void *x)
935{
936 struct mm_struct *mm = (struct mm_struct *) x;
937 if (mm == current->active_mm && !asn_locked())
938 __load_new_mm_context(mm);
939 else
940 flush_tlb_other(mm);
941}
942
943void
944flush_icache_user_range(struct vm_area_struct *vma, struct page *page,
945 unsigned long addr, int len)
946{
947 struct mm_struct *mm = vma->vm_mm;
948
949 if ((vma->vm_flags & VM_EXEC) == 0)
950 return;
951
952 preempt_disable();
953
954 if (mm == current->active_mm) {
955 __load_new_mm_context(mm);
956 if (atomic_read(&mm->mm_users) <= 1) {
957 int cpu, this_cpu = smp_processor_id();
958 for (cpu = 0; cpu < NR_CPUS; cpu++) {
959 if (!cpu_online(cpu) || cpu == this_cpu)
960 continue;
961 if (mm->context[cpu])
962 mm->context[cpu] = 0;
963 }
964 preempt_enable();
965 return;
966 }
967 }
968
969 if (smp_call_function(ipi_flush_icache_page, mm, 1, 1)) {
970 printk(KERN_CRIT "flush_icache_page: timed out\n");
971 }
972
973 preempt_enable();
974}