Merge branch 'rcu/next' of git://git.kernel.org/pub/scm/linux/kernel/git/paulmck...
[deliverable/linux.git] / arch / ia64 / kernel / process.c
1 /*
2 * Architecture-specific setup.
3 *
4 * Copyright (C) 1998-2003 Hewlett-Packard Co
5 * David Mosberger-Tang <davidm@hpl.hp.com>
6 * 04/11/17 Ashok Raj <ashok.raj@intel.com> Added CPU Hotplug Support
7 *
8 * 2005-10-07 Keith Owens <kaos@sgi.com>
9 * Add notify_die() hooks.
10 */
11 #include <linux/cpu.h>
12 #include <linux/pm.h>
13 #include <linux/elf.h>
14 #include <linux/errno.h>
15 #include <linux/kallsyms.h>
16 #include <linux/kernel.h>
17 #include <linux/mm.h>
18 #include <linux/slab.h>
19 #include <linux/module.h>
20 #include <linux/notifier.h>
21 #include <linux/personality.h>
22 #include <linux/sched.h>
23 #include <linux/stddef.h>
24 #include <linux/thread_info.h>
25 #include <linux/unistd.h>
26 #include <linux/efi.h>
27 #include <linux/interrupt.h>
28 #include <linux/delay.h>
29 #include <linux/kdebug.h>
30 #include <linux/utsname.h>
31 #include <linux/tracehook.h>
32 #include <linux/rcupdate.h>
33
34 #include <asm/cpu.h>
35 #include <asm/delay.h>
36 #include <asm/elf.h>
37 #include <asm/irq.h>
38 #include <asm/kexec.h>
39 #include <asm/pgalloc.h>
40 #include <asm/processor.h>
41 #include <asm/sal.h>
42 #include <asm/switch_to.h>
43 #include <asm/tlbflush.h>
44 #include <asm/uaccess.h>
45 #include <asm/unwind.h>
46 #include <asm/user.h>
47
48 #include "entry.h"
49
50 #ifdef CONFIG_PERFMON
51 # include <asm/perfmon.h>
52 #endif
53
54 #include "sigframe.h"
55
56 void (*ia64_mark_idle)(int);
57
58 unsigned long boot_option_idle_override = IDLE_NO_OVERRIDE;
59 EXPORT_SYMBOL(boot_option_idle_override);
60 void (*pm_power_off) (void);
61 EXPORT_SYMBOL(pm_power_off);
62
63 void
64 ia64_do_show_stack (struct unw_frame_info *info, void *arg)
65 {
66 unsigned long ip, sp, bsp;
67 char buf[128]; /* don't make it so big that it overflows the stack! */
68
69 printk("\nCall Trace:\n");
70 do {
71 unw_get_ip(info, &ip);
72 if (ip == 0)
73 break;
74
75 unw_get_sp(info, &sp);
76 unw_get_bsp(info, &bsp);
77 snprintf(buf, sizeof(buf),
78 " [<%016lx>] %%s\n"
79 " sp=%016lx bsp=%016lx\n",
80 ip, sp, bsp);
81 print_symbol(buf, ip);
82 } while (unw_unwind(info) >= 0);
83 }
84
85 void
86 show_stack (struct task_struct *task, unsigned long *sp)
87 {
88 if (!task)
89 unw_init_running(ia64_do_show_stack, NULL);
90 else {
91 struct unw_frame_info info;
92
93 unw_init_from_blocked_task(&info, task);
94 ia64_do_show_stack(&info, NULL);
95 }
96 }
97
98 void
99 dump_stack (void)
100 {
101 show_stack(NULL, NULL);
102 }
103
104 EXPORT_SYMBOL(dump_stack);
105
106 void
107 show_regs (struct pt_regs *regs)
108 {
109 unsigned long ip = regs->cr_iip + ia64_psr(regs)->ri;
110
111 print_modules();
112 printk("\nPid: %d, CPU %d, comm: %20s\n", task_pid_nr(current),
113 smp_processor_id(), current->comm);
114 printk("psr : %016lx ifs : %016lx ip : [<%016lx>] %s (%s)\n",
115 regs->cr_ipsr, regs->cr_ifs, ip, print_tainted(),
116 init_utsname()->release);
117 print_symbol("ip is at %s\n", ip);
118 printk("unat: %016lx pfs : %016lx rsc : %016lx\n",
119 regs->ar_unat, regs->ar_pfs, regs->ar_rsc);
120 printk("rnat: %016lx bsps: %016lx pr : %016lx\n",
121 regs->ar_rnat, regs->ar_bspstore, regs->pr);
122 printk("ldrs: %016lx ccv : %016lx fpsr: %016lx\n",
123 regs->loadrs, regs->ar_ccv, regs->ar_fpsr);
124 printk("csd : %016lx ssd : %016lx\n", regs->ar_csd, regs->ar_ssd);
125 printk("b0 : %016lx b6 : %016lx b7 : %016lx\n", regs->b0, regs->b6, regs->b7);
126 printk("f6 : %05lx%016lx f7 : %05lx%016lx\n",
127 regs->f6.u.bits[1], regs->f6.u.bits[0],
128 regs->f7.u.bits[1], regs->f7.u.bits[0]);
129 printk("f8 : %05lx%016lx f9 : %05lx%016lx\n",
130 regs->f8.u.bits[1], regs->f8.u.bits[0],
131 regs->f9.u.bits[1], regs->f9.u.bits[0]);
132 printk("f10 : %05lx%016lx f11 : %05lx%016lx\n",
133 regs->f10.u.bits[1], regs->f10.u.bits[0],
134 regs->f11.u.bits[1], regs->f11.u.bits[0]);
135
136 printk("r1 : %016lx r2 : %016lx r3 : %016lx\n", regs->r1, regs->r2, regs->r3);
137 printk("r8 : %016lx r9 : %016lx r10 : %016lx\n", regs->r8, regs->r9, regs->r10);
138 printk("r11 : %016lx r12 : %016lx r13 : %016lx\n", regs->r11, regs->r12, regs->r13);
139 printk("r14 : %016lx r15 : %016lx r16 : %016lx\n", regs->r14, regs->r15, regs->r16);
140 printk("r17 : %016lx r18 : %016lx r19 : %016lx\n", regs->r17, regs->r18, regs->r19);
141 printk("r20 : %016lx r21 : %016lx r22 : %016lx\n", regs->r20, regs->r21, regs->r22);
142 printk("r23 : %016lx r24 : %016lx r25 : %016lx\n", regs->r23, regs->r24, regs->r25);
143 printk("r26 : %016lx r27 : %016lx r28 : %016lx\n", regs->r26, regs->r27, regs->r28);
144 printk("r29 : %016lx r30 : %016lx r31 : %016lx\n", regs->r29, regs->r30, regs->r31);
145
146 if (user_mode(regs)) {
147 /* print the stacked registers */
148 unsigned long val, *bsp, ndirty;
149 int i, sof, is_nat = 0;
150
151 sof = regs->cr_ifs & 0x7f; /* size of frame */
152 ndirty = (regs->loadrs >> 19);
153 bsp = ia64_rse_skip_regs((unsigned long *) regs->ar_bspstore, ndirty);
154 for (i = 0; i < sof; ++i) {
155 get_user(val, (unsigned long __user *) ia64_rse_skip_regs(bsp, i));
156 printk("r%-3u:%c%016lx%s", 32 + i, is_nat ? '*' : ' ', val,
157 ((i == sof - 1) || (i % 3) == 2) ? "\n" : " ");
158 }
159 } else
160 show_stack(NULL, NULL);
161 }
162
163 /* local support for deprecated console_print */
164 void
165 console_print(const char *s)
166 {
167 printk(KERN_EMERG "%s", s);
168 }
169
170 void
171 do_notify_resume_user(sigset_t *unused, struct sigscratch *scr, long in_syscall)
172 {
173 if (fsys_mode(current, &scr->pt)) {
174 /*
175 * defer signal-handling etc. until we return to
176 * privilege-level 0.
177 */
178 if (!ia64_psr(&scr->pt)->lp)
179 ia64_psr(&scr->pt)->lp = 1;
180 return;
181 }
182
183 #ifdef CONFIG_PERFMON
184 if (current->thread.pfm_needs_checking)
185 /*
186 * Note: pfm_handle_work() allow us to call it with interrupts
187 * disabled, and may enable interrupts within the function.
188 */
189 pfm_handle_work();
190 #endif
191
192 /* deal with pending signal delivery */
193 if (test_thread_flag(TIF_SIGPENDING)) {
194 local_irq_enable(); /* force interrupt enable */
195 ia64_do_signal(scr, in_syscall);
196 }
197
198 if (test_and_clear_thread_flag(TIF_NOTIFY_RESUME)) {
199 local_irq_enable(); /* force interrupt enable */
200 tracehook_notify_resume(&scr->pt);
201 }
202
203 /* copy user rbs to kernel rbs */
204 if (unlikely(test_thread_flag(TIF_RESTORE_RSE))) {
205 local_irq_enable(); /* force interrupt enable */
206 ia64_sync_krbs();
207 }
208
209 local_irq_disable(); /* force interrupt disable */
210 }
211
212 static int pal_halt = 1;
213 static int can_do_pal_halt = 1;
214
215 static int __init nohalt_setup(char * str)
216 {
217 pal_halt = can_do_pal_halt = 0;
218 return 1;
219 }
220 __setup("nohalt", nohalt_setup);
221
222 void
223 update_pal_halt_status(int status)
224 {
225 can_do_pal_halt = pal_halt && status;
226 }
227
228 /*
229 * We use this if we don't have any better idle routine..
230 */
231 void
232 default_idle (void)
233 {
234 local_irq_enable();
235 while (!need_resched()) {
236 if (can_do_pal_halt) {
237 local_irq_disable();
238 if (!need_resched()) {
239 safe_halt();
240 }
241 local_irq_enable();
242 } else
243 cpu_relax();
244 }
245 }
246
247 #ifdef CONFIG_HOTPLUG_CPU
248 /* We don't actually take CPU down, just spin without interrupts. */
249 static inline void play_dead(void)
250 {
251 unsigned int this_cpu = smp_processor_id();
252
253 /* Ack it */
254 __get_cpu_var(cpu_state) = CPU_DEAD;
255
256 max_xtp();
257 local_irq_disable();
258 idle_task_exit();
259 ia64_jump_to_sal(&sal_boot_rendez_state[this_cpu]);
260 /*
261 * The above is a point of no-return, the processor is
262 * expected to be in SAL loop now.
263 */
264 BUG();
265 }
266 #else
267 static inline void play_dead(void)
268 {
269 BUG();
270 }
271 #endif /* CONFIG_HOTPLUG_CPU */
272
273 void __attribute__((noreturn))
274 cpu_idle (void)
275 {
276 void (*mark_idle)(int) = ia64_mark_idle;
277 int cpu = smp_processor_id();
278
279 /* endless idle loop with no priority at all */
280 while (1) {
281 rcu_idle_enter();
282 if (can_do_pal_halt) {
283 current_thread_info()->status &= ~TS_POLLING;
284 /*
285 * TS_POLLING-cleared state must be visible before we
286 * test NEED_RESCHED:
287 */
288 smp_mb();
289 } else {
290 current_thread_info()->status |= TS_POLLING;
291 }
292
293 if (!need_resched()) {
294 #ifdef CONFIG_SMP
295 min_xtp();
296 #endif
297 rmb();
298 if (mark_idle)
299 (*mark_idle)(1);
300
301 default_idle();
302 if (mark_idle)
303 (*mark_idle)(0);
304 #ifdef CONFIG_SMP
305 normal_xtp();
306 #endif
307 }
308 rcu_idle_exit();
309 schedule_preempt_disabled();
310 check_pgt_cache();
311 if (cpu_is_offline(cpu))
312 play_dead();
313 }
314 }
315
316 void
317 ia64_save_extra (struct task_struct *task)
318 {
319 #ifdef CONFIG_PERFMON
320 unsigned long info;
321 #endif
322
323 if ((task->thread.flags & IA64_THREAD_DBG_VALID) != 0)
324 ia64_save_debug_regs(&task->thread.dbr[0]);
325
326 #ifdef CONFIG_PERFMON
327 if ((task->thread.flags & IA64_THREAD_PM_VALID) != 0)
328 pfm_save_regs(task);
329
330 info = __get_cpu_var(pfm_syst_info);
331 if (info & PFM_CPUINFO_SYST_WIDE)
332 pfm_syst_wide_update_task(task, info, 0);
333 #endif
334 }
335
336 void
337 ia64_load_extra (struct task_struct *task)
338 {
339 #ifdef CONFIG_PERFMON
340 unsigned long info;
341 #endif
342
343 if ((task->thread.flags & IA64_THREAD_DBG_VALID) != 0)
344 ia64_load_debug_regs(&task->thread.dbr[0]);
345
346 #ifdef CONFIG_PERFMON
347 if ((task->thread.flags & IA64_THREAD_PM_VALID) != 0)
348 pfm_load_regs(task);
349
350 info = __get_cpu_var(pfm_syst_info);
351 if (info & PFM_CPUINFO_SYST_WIDE)
352 pfm_syst_wide_update_task(task, info, 1);
353 #endif
354 }
355
356 /*
357 * Copy the state of an ia-64 thread.
358 *
359 * We get here through the following call chain:
360 *
361 * from user-level: from kernel:
362 *
363 * <clone syscall> <some kernel call frames>
364 * sys_clone :
365 * do_fork do_fork
366 * copy_thread copy_thread
367 *
368 * This means that the stack layout is as follows:
369 *
370 * +---------------------+ (highest addr)
371 * | struct pt_regs |
372 * +---------------------+
373 * | struct switch_stack |
374 * +---------------------+
375 * | |
376 * | memory stack |
377 * | | <-- sp (lowest addr)
378 * +---------------------+
379 *
380 * Observe that we copy the unat values that are in pt_regs and switch_stack. Spilling an
381 * integer to address X causes bit N in ar.unat to be set to the NaT bit of the register,
382 * with N=(X & 0x1ff)/8. Thus, copying the unat value preserves the NaT bits ONLY if the
383 * pt_regs structure in the parent is congruent to that of the child, modulo 512. Since
384 * the stack is page aligned and the page size is at least 4KB, this is always the case,
385 * so there is nothing to worry about.
386 */
387 int
388 copy_thread(unsigned long clone_flags,
389 unsigned long user_stack_base, unsigned long user_stack_size,
390 struct task_struct *p)
391 {
392 extern char ia64_ret_from_clone;
393 struct switch_stack *child_stack, *stack;
394 unsigned long rbs, child_rbs, rbs_size;
395 struct pt_regs *child_ptregs;
396 struct pt_regs *regs = current_pt_regs();
397 int retval = 0;
398
399 child_ptregs = (struct pt_regs *) ((unsigned long) p + IA64_STK_OFFSET) - 1;
400 child_stack = (struct switch_stack *) child_ptregs - 1;
401
402 rbs = (unsigned long) current + IA64_RBS_OFFSET;
403 child_rbs = (unsigned long) p + IA64_RBS_OFFSET;
404
405 /* copy parts of thread_struct: */
406 p->thread.ksp = (unsigned long) child_stack - 16;
407
408 /*
409 * NOTE: The calling convention considers all floating point
410 * registers in the high partition (fph) to be scratch. Since
411 * the only way to get to this point is through a system call,
412 * we know that the values in fph are all dead. Hence, there
413 * is no need to inherit the fph state from the parent to the
414 * child and all we have to do is to make sure that
415 * IA64_THREAD_FPH_VALID is cleared in the child.
416 *
417 * XXX We could push this optimization a bit further by
418 * clearing IA64_THREAD_FPH_VALID on ANY system call.
419 * However, it's not clear this is worth doing. Also, it
420 * would be a slight deviation from the normal Linux system
421 * call behavior where scratch registers are preserved across
422 * system calls (unless used by the system call itself).
423 */
424 # define THREAD_FLAGS_TO_CLEAR (IA64_THREAD_FPH_VALID | IA64_THREAD_DBG_VALID \
425 | IA64_THREAD_PM_VALID)
426 # define THREAD_FLAGS_TO_SET 0
427 p->thread.flags = ((current->thread.flags & ~THREAD_FLAGS_TO_CLEAR)
428 | THREAD_FLAGS_TO_SET);
429
430 ia64_drop_fpu(p); /* don't pick up stale state from a CPU's fph */
431
432 if (unlikely(p->flags & PF_KTHREAD)) {
433 if (unlikely(!user_stack_base)) {
434 /* fork_idle() called us */
435 return 0;
436 }
437 memset(child_stack, 0, sizeof(*child_ptregs) + sizeof(*child_stack));
438 child_stack->r4 = user_stack_base; /* payload */
439 child_stack->r5 = user_stack_size; /* argument */
440 /*
441 * Preserve PSR bits, except for bits 32-34 and 37-45,
442 * which we can't read.
443 */
444 child_ptregs->cr_ipsr = ia64_getreg(_IA64_REG_PSR) | IA64_PSR_BN;
445 /* mark as valid, empty frame */
446 child_ptregs->cr_ifs = 1UL << 63;
447 child_stack->ar_fpsr = child_ptregs->ar_fpsr
448 = ia64_getreg(_IA64_REG_AR_FPSR);
449 child_stack->pr = (1 << PRED_KERNEL_STACK);
450 child_stack->ar_bspstore = child_rbs;
451 child_stack->b0 = (unsigned long) &ia64_ret_from_clone;
452
453 /* stop some PSR bits from being inherited.
454 * the psr.up/psr.pp bits must be cleared on fork but inherited on execve()
455 * therefore we must specify them explicitly here and not include them in
456 * IA64_PSR_BITS_TO_CLEAR.
457 */
458 child_ptregs->cr_ipsr = ((child_ptregs->cr_ipsr | IA64_PSR_BITS_TO_SET)
459 & ~(IA64_PSR_BITS_TO_CLEAR | IA64_PSR_PP | IA64_PSR_UP));
460
461 return 0;
462 }
463 stack = ((struct switch_stack *) regs) - 1;
464 /* copy parent's switch_stack & pt_regs to child: */
465 memcpy(child_stack, stack, sizeof(*child_ptregs) + sizeof(*child_stack));
466
467 /* copy the parent's register backing store to the child: */
468 rbs_size = stack->ar_bspstore - rbs;
469 memcpy((void *) child_rbs, (void *) rbs, rbs_size);
470 if (clone_flags & CLONE_SETTLS)
471 child_ptregs->r13 = regs->r16; /* see sys_clone2() in entry.S */
472 if (user_stack_base) {
473 child_ptregs->r12 = user_stack_base + user_stack_size - 16;
474 child_ptregs->ar_bspstore = user_stack_base;
475 child_ptregs->ar_rnat = 0;
476 child_ptregs->loadrs = 0;
477 }
478 child_stack->ar_bspstore = child_rbs + rbs_size;
479 child_stack->b0 = (unsigned long) &ia64_ret_from_clone;
480
481 /* stop some PSR bits from being inherited.
482 * the psr.up/psr.pp bits must be cleared on fork but inherited on execve()
483 * therefore we must specify them explicitly here and not include them in
484 * IA64_PSR_BITS_TO_CLEAR.
485 */
486 child_ptregs->cr_ipsr = ((child_ptregs->cr_ipsr | IA64_PSR_BITS_TO_SET)
487 & ~(IA64_PSR_BITS_TO_CLEAR | IA64_PSR_PP | IA64_PSR_UP));
488
489 #ifdef CONFIG_PERFMON
490 if (current->thread.pfm_context)
491 pfm_inherit(p, child_ptregs);
492 #endif
493 return retval;
494 }
495
496 static void
497 do_copy_task_regs (struct task_struct *task, struct unw_frame_info *info, void *arg)
498 {
499 unsigned long mask, sp, nat_bits = 0, ar_rnat, urbs_end, cfm;
500 unsigned long uninitialized_var(ip); /* GCC be quiet */
501 elf_greg_t *dst = arg;
502 struct pt_regs *pt;
503 char nat;
504 int i;
505
506 memset(dst, 0, sizeof(elf_gregset_t)); /* don't leak any kernel bits to user-level */
507
508 if (unw_unwind_to_user(info) < 0)
509 return;
510
511 unw_get_sp(info, &sp);
512 pt = (struct pt_regs *) (sp + 16);
513
514 urbs_end = ia64_get_user_rbs_end(task, pt, &cfm);
515
516 if (ia64_sync_user_rbs(task, info->sw, pt->ar_bspstore, urbs_end) < 0)
517 return;
518
519 ia64_peek(task, info->sw, urbs_end, (long) ia64_rse_rnat_addr((long *) urbs_end),
520 &ar_rnat);
521
522 /*
523 * coredump format:
524 * r0-r31
525 * NaT bits (for r0-r31; bit N == 1 iff rN is a NaT)
526 * predicate registers (p0-p63)
527 * b0-b7
528 * ip cfm user-mask
529 * ar.rsc ar.bsp ar.bspstore ar.rnat
530 * ar.ccv ar.unat ar.fpsr ar.pfs ar.lc ar.ec
531 */
532
533 /* r0 is zero */
534 for (i = 1, mask = (1UL << i); i < 32; ++i) {
535 unw_get_gr(info, i, &dst[i], &nat);
536 if (nat)
537 nat_bits |= mask;
538 mask <<= 1;
539 }
540 dst[32] = nat_bits;
541 unw_get_pr(info, &dst[33]);
542
543 for (i = 0; i < 8; ++i)
544 unw_get_br(info, i, &dst[34 + i]);
545
546 unw_get_rp(info, &ip);
547 dst[42] = ip + ia64_psr(pt)->ri;
548 dst[43] = cfm;
549 dst[44] = pt->cr_ipsr & IA64_PSR_UM;
550
551 unw_get_ar(info, UNW_AR_RSC, &dst[45]);
552 /*
553 * For bsp and bspstore, unw_get_ar() would return the kernel
554 * addresses, but we need the user-level addresses instead:
555 */
556 dst[46] = urbs_end; /* note: by convention PT_AR_BSP points to the end of the urbs! */
557 dst[47] = pt->ar_bspstore;
558 dst[48] = ar_rnat;
559 unw_get_ar(info, UNW_AR_CCV, &dst[49]);
560 unw_get_ar(info, UNW_AR_UNAT, &dst[50]);
561 unw_get_ar(info, UNW_AR_FPSR, &dst[51]);
562 dst[52] = pt->ar_pfs; /* UNW_AR_PFS is == to pt->cr_ifs for interrupt frames */
563 unw_get_ar(info, UNW_AR_LC, &dst[53]);
564 unw_get_ar(info, UNW_AR_EC, &dst[54]);
565 unw_get_ar(info, UNW_AR_CSD, &dst[55]);
566 unw_get_ar(info, UNW_AR_SSD, &dst[56]);
567 }
568
569 void
570 do_dump_task_fpu (struct task_struct *task, struct unw_frame_info *info, void *arg)
571 {
572 elf_fpreg_t *dst = arg;
573 int i;
574
575 memset(dst, 0, sizeof(elf_fpregset_t)); /* don't leak any "random" bits */
576
577 if (unw_unwind_to_user(info) < 0)
578 return;
579
580 /* f0 is 0.0, f1 is 1.0 */
581
582 for (i = 2; i < 32; ++i)
583 unw_get_fr(info, i, dst + i);
584
585 ia64_flush_fph(task);
586 if ((task->thread.flags & IA64_THREAD_FPH_VALID) != 0)
587 memcpy(dst + 32, task->thread.fph, 96*16);
588 }
589
590 void
591 do_copy_regs (struct unw_frame_info *info, void *arg)
592 {
593 do_copy_task_regs(current, info, arg);
594 }
595
596 void
597 do_dump_fpu (struct unw_frame_info *info, void *arg)
598 {
599 do_dump_task_fpu(current, info, arg);
600 }
601
602 void
603 ia64_elf_core_copy_regs (struct pt_regs *pt, elf_gregset_t dst)
604 {
605 unw_init_running(do_copy_regs, dst);
606 }
607
608 int
609 dump_fpu (struct pt_regs *pt, elf_fpregset_t dst)
610 {
611 unw_init_running(do_dump_fpu, dst);
612 return 1; /* f0-f31 are always valid so we always return 1 */
613 }
614
615 /*
616 * Flush thread state. This is called when a thread does an execve().
617 */
618 void
619 flush_thread (void)
620 {
621 /* drop floating-point and debug-register state if it exists: */
622 current->thread.flags &= ~(IA64_THREAD_FPH_VALID | IA64_THREAD_DBG_VALID);
623 ia64_drop_fpu(current);
624 }
625
626 /*
627 * Clean up state associated with current thread. This is called when
628 * the thread calls exit().
629 */
630 void
631 exit_thread (void)
632 {
633
634 ia64_drop_fpu(current);
635 #ifdef CONFIG_PERFMON
636 /* if needed, stop monitoring and flush state to perfmon context */
637 if (current->thread.pfm_context)
638 pfm_exit_thread(current);
639
640 /* free debug register resources */
641 if (current->thread.flags & IA64_THREAD_DBG_VALID)
642 pfm_release_debug_registers(current);
643 #endif
644 }
645
646 unsigned long
647 get_wchan (struct task_struct *p)
648 {
649 struct unw_frame_info info;
650 unsigned long ip;
651 int count = 0;
652
653 if (!p || p == current || p->state == TASK_RUNNING)
654 return 0;
655
656 /*
657 * Note: p may not be a blocked task (it could be current or
658 * another process running on some other CPU. Rather than
659 * trying to determine if p is really blocked, we just assume
660 * it's blocked and rely on the unwind routines to fail
661 * gracefully if the process wasn't really blocked after all.
662 * --davidm 99/12/15
663 */
664 unw_init_from_blocked_task(&info, p);
665 do {
666 if (p->state == TASK_RUNNING)
667 return 0;
668 if (unw_unwind(&info) < 0)
669 return 0;
670 unw_get_ip(&info, &ip);
671 if (!in_sched_functions(ip))
672 return ip;
673 } while (count++ < 16);
674 return 0;
675 }
676
677 void
678 cpu_halt (void)
679 {
680 pal_power_mgmt_info_u_t power_info[8];
681 unsigned long min_power;
682 int i, min_power_state;
683
684 if (ia64_pal_halt_info(power_info) != 0)
685 return;
686
687 min_power_state = 0;
688 min_power = power_info[0].pal_power_mgmt_info_s.power_consumption;
689 for (i = 1; i < 8; ++i)
690 if (power_info[i].pal_power_mgmt_info_s.im
691 && power_info[i].pal_power_mgmt_info_s.power_consumption < min_power) {
692 min_power = power_info[i].pal_power_mgmt_info_s.power_consumption;
693 min_power_state = i;
694 }
695
696 while (1)
697 ia64_pal_halt(min_power_state);
698 }
699
700 void machine_shutdown(void)
701 {
702 #ifdef CONFIG_HOTPLUG_CPU
703 int cpu;
704
705 for_each_online_cpu(cpu) {
706 if (cpu != smp_processor_id())
707 cpu_down(cpu);
708 }
709 #endif
710 #ifdef CONFIG_KEXEC
711 kexec_disable_iosapic();
712 #endif
713 }
714
715 void
716 machine_restart (char *restart_cmd)
717 {
718 (void) notify_die(DIE_MACHINE_RESTART, restart_cmd, NULL, 0, 0, 0);
719 (*efi.reset_system)(EFI_RESET_WARM, 0, 0, NULL);
720 }
721
722 void
723 machine_halt (void)
724 {
725 (void) notify_die(DIE_MACHINE_HALT, "", NULL, 0, 0, 0);
726 cpu_halt();
727 }
728
729 void
730 machine_power_off (void)
731 {
732 if (pm_power_off)
733 pm_power_off();
734 machine_halt();
735 }
736
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