Linux 2.6.31.8
[linux/fpc-iii.git] / arch / ia64 / kernel / process.c
blob5d7c0e5b9e76f150b20269cb9ba9e2497062209a
1 /*
2 * Architecture-specific setup.
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
8 * 2005-10-07 Keith Owens <kaos@sgi.com>
9 * Add notify_die() hooks.
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/module.h>
19 #include <linux/notifier.h>
20 #include <linux/personality.h>
21 #include <linux/sched.h>
22 #include <linux/slab.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>
33 #include <asm/cpu.h>
34 #include <asm/delay.h>
35 #include <asm/elf.h>
36 #include <asm/ia32.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/tlbflush.h>
43 #include <asm/uaccess.h>
44 #include <asm/unwind.h>
45 #include <asm/user.h>
47 #include "entry.h"
49 #ifdef CONFIG_PERFMON
50 # include <asm/perfmon.h>
51 #endif
53 #include "sigframe.h"
55 void (*ia64_mark_idle)(int);
57 unsigned long boot_option_idle_override = 0;
58 EXPORT_SYMBOL(boot_option_idle_override);
59 unsigned long idle_halt;
60 EXPORT_SYMBOL(idle_halt);
61 unsigned long idle_nomwait;
62 EXPORT_SYMBOL(idle_nomwait);
64 void
65 ia64_do_show_stack (struct unw_frame_info *info, void *arg)
67 unsigned long ip, sp, bsp;
68 char buf[128]; /* don't make it so big that it overflows the stack! */
70 printk("\nCall Trace:\n");
71 do {
72 unw_get_ip(info, &ip);
73 if (ip == 0)
74 break;
76 unw_get_sp(info, &sp);
77 unw_get_bsp(info, &bsp);
78 snprintf(buf, sizeof(buf),
79 " [<%016lx>] %%s\n"
80 " sp=%016lx bsp=%016lx\n",
81 ip, sp, bsp);
82 print_symbol(buf, ip);
83 } while (unw_unwind(info) >= 0);
86 void
87 show_stack (struct task_struct *task, unsigned long *sp)
89 if (!task)
90 unw_init_running(ia64_do_show_stack, NULL);
91 else {
92 struct unw_frame_info info;
94 unw_init_from_blocked_task(&info, task);
95 ia64_do_show_stack(&info, NULL);
99 void
100 dump_stack (void)
102 show_stack(NULL, NULL);
105 EXPORT_SYMBOL(dump_stack);
107 void
108 show_regs (struct pt_regs *regs)
110 unsigned long ip = regs->cr_iip + ia64_psr(regs)->ri;
112 print_modules();
113 printk("\nPid: %d, CPU %d, comm: %20s\n", task_pid_nr(current),
114 smp_processor_id(), current->comm);
115 printk("psr : %016lx ifs : %016lx ip : [<%016lx>] %s (%s)\n",
116 regs->cr_ipsr, regs->cr_ifs, ip, print_tainted(),
117 init_utsname()->release);
118 print_symbol("ip is at %s\n", ip);
119 printk("unat: %016lx pfs : %016lx rsc : %016lx\n",
120 regs->ar_unat, regs->ar_pfs, regs->ar_rsc);
121 printk("rnat: %016lx bsps: %016lx pr : %016lx\n",
122 regs->ar_rnat, regs->ar_bspstore, regs->pr);
123 printk("ldrs: %016lx ccv : %016lx fpsr: %016lx\n",
124 regs->loadrs, regs->ar_ccv, regs->ar_fpsr);
125 printk("csd : %016lx ssd : %016lx\n", regs->ar_csd, regs->ar_ssd);
126 printk("b0 : %016lx b6 : %016lx b7 : %016lx\n", regs->b0, regs->b6, regs->b7);
127 printk("f6 : %05lx%016lx f7 : %05lx%016lx\n",
128 regs->f6.u.bits[1], regs->f6.u.bits[0],
129 regs->f7.u.bits[1], regs->f7.u.bits[0]);
130 printk("f8 : %05lx%016lx f9 : %05lx%016lx\n",
131 regs->f8.u.bits[1], regs->f8.u.bits[0],
132 regs->f9.u.bits[1], regs->f9.u.bits[0]);
133 printk("f10 : %05lx%016lx f11 : %05lx%016lx\n",
134 regs->f10.u.bits[1], regs->f10.u.bits[0],
135 regs->f11.u.bits[1], regs->f11.u.bits[0]);
137 printk("r1 : %016lx r2 : %016lx r3 : %016lx\n", regs->r1, regs->r2, regs->r3);
138 printk("r8 : %016lx r9 : %016lx r10 : %016lx\n", regs->r8, regs->r9, regs->r10);
139 printk("r11 : %016lx r12 : %016lx r13 : %016lx\n", regs->r11, regs->r12, regs->r13);
140 printk("r14 : %016lx r15 : %016lx r16 : %016lx\n", regs->r14, regs->r15, regs->r16);
141 printk("r17 : %016lx r18 : %016lx r19 : %016lx\n", regs->r17, regs->r18, regs->r19);
142 printk("r20 : %016lx r21 : %016lx r22 : %016lx\n", regs->r20, regs->r21, regs->r22);
143 printk("r23 : %016lx r24 : %016lx r25 : %016lx\n", regs->r23, regs->r24, regs->r25);
144 printk("r26 : %016lx r27 : %016lx r28 : %016lx\n", regs->r26, regs->r27, regs->r28);
145 printk("r29 : %016lx r30 : %016lx r31 : %016lx\n", regs->r29, regs->r30, regs->r31);
147 if (user_mode(regs)) {
148 /* print the stacked registers */
149 unsigned long val, *bsp, ndirty;
150 int i, sof, is_nat = 0;
152 sof = regs->cr_ifs & 0x7f; /* size of frame */
153 ndirty = (regs->loadrs >> 19);
154 bsp = ia64_rse_skip_regs((unsigned long *) regs->ar_bspstore, ndirty);
155 for (i = 0; i < sof; ++i) {
156 get_user(val, (unsigned long __user *) ia64_rse_skip_regs(bsp, i));
157 printk("r%-3u:%c%016lx%s", 32 + i, is_nat ? '*' : ' ', val,
158 ((i == sof - 1) || (i % 3) == 2) ? "\n" : " ");
160 } else
161 show_stack(NULL, NULL);
164 void
165 do_notify_resume_user(sigset_t *unused, struct sigscratch *scr, long in_syscall)
167 if (fsys_mode(current, &scr->pt)) {
169 * defer signal-handling etc. until we return to
170 * privilege-level 0.
172 if (!ia64_psr(&scr->pt)->lp)
173 ia64_psr(&scr->pt)->lp = 1;
174 return;
177 #ifdef CONFIG_PERFMON
178 if (current->thread.pfm_needs_checking)
180 * Note: pfm_handle_work() allow us to call it with interrupts
181 * disabled, and may enable interrupts within the function.
183 pfm_handle_work();
184 #endif
186 /* deal with pending signal delivery */
187 if (test_thread_flag(TIF_SIGPENDING)) {
188 local_irq_enable(); /* force interrupt enable */
189 ia64_do_signal(scr, in_syscall);
192 if (test_thread_flag(TIF_NOTIFY_RESUME)) {
193 clear_thread_flag(TIF_NOTIFY_RESUME);
194 tracehook_notify_resume(&scr->pt);
197 /* copy user rbs to kernel rbs */
198 if (unlikely(test_thread_flag(TIF_RESTORE_RSE))) {
199 local_irq_enable(); /* force interrupt enable */
200 ia64_sync_krbs();
203 local_irq_disable(); /* force interrupt disable */
206 static int pal_halt = 1;
207 static int can_do_pal_halt = 1;
209 static int __init nohalt_setup(char * str)
211 pal_halt = can_do_pal_halt = 0;
212 return 1;
214 __setup("nohalt", nohalt_setup);
216 void
217 update_pal_halt_status(int status)
219 can_do_pal_halt = pal_halt && status;
223 * We use this if we don't have any better idle routine..
225 void
226 default_idle (void)
228 local_irq_enable();
229 while (!need_resched()) {
230 if (can_do_pal_halt) {
231 local_irq_disable();
232 if (!need_resched()) {
233 safe_halt();
235 local_irq_enable();
236 } else
237 cpu_relax();
241 #ifdef CONFIG_HOTPLUG_CPU
242 /* We don't actually take CPU down, just spin without interrupts. */
243 static inline void play_dead(void)
245 unsigned int this_cpu = smp_processor_id();
247 /* Ack it */
248 __get_cpu_var(cpu_state) = CPU_DEAD;
250 max_xtp();
251 local_irq_disable();
252 idle_task_exit();
253 ia64_jump_to_sal(&sal_boot_rendez_state[this_cpu]);
255 * The above is a point of no-return, the processor is
256 * expected to be in SAL loop now.
258 BUG();
260 #else
261 static inline void play_dead(void)
263 BUG();
265 #endif /* CONFIG_HOTPLUG_CPU */
267 static void do_nothing(void *unused)
272 * cpu_idle_wait - Used to ensure that all the CPUs discard old value of
273 * pm_idle and update to new pm_idle value. Required while changing pm_idle
274 * handler on SMP systems.
276 * Caller must have changed pm_idle to the new value before the call. Old
277 * pm_idle value will not be used by any CPU after the return of this function.
279 void cpu_idle_wait(void)
281 smp_mb();
282 /* kick all the CPUs so that they exit out of pm_idle */
283 smp_call_function(do_nothing, NULL, 1);
285 EXPORT_SYMBOL_GPL(cpu_idle_wait);
287 void __attribute__((noreturn))
288 cpu_idle (void)
290 void (*mark_idle)(int) = ia64_mark_idle;
291 int cpu = smp_processor_id();
293 /* endless idle loop with no priority at all */
294 while (1) {
295 if (can_do_pal_halt) {
296 current_thread_info()->status &= ~TS_POLLING;
298 * TS_POLLING-cleared state must be visible before we
299 * test NEED_RESCHED:
301 smp_mb();
302 } else {
303 current_thread_info()->status |= TS_POLLING;
306 if (!need_resched()) {
307 void (*idle)(void);
308 #ifdef CONFIG_SMP
309 min_xtp();
310 #endif
311 rmb();
312 if (mark_idle)
313 (*mark_idle)(1);
315 idle = pm_idle;
316 if (!idle)
317 idle = default_idle;
318 (*idle)();
319 if (mark_idle)
320 (*mark_idle)(0);
321 #ifdef CONFIG_SMP
322 normal_xtp();
323 #endif
325 preempt_enable_no_resched();
326 schedule();
327 preempt_disable();
328 check_pgt_cache();
329 if (cpu_is_offline(cpu))
330 play_dead();
334 void
335 ia64_save_extra (struct task_struct *task)
337 #ifdef CONFIG_PERFMON
338 unsigned long info;
339 #endif
341 if ((task->thread.flags & IA64_THREAD_DBG_VALID) != 0)
342 ia64_save_debug_regs(&task->thread.dbr[0]);
344 #ifdef CONFIG_PERFMON
345 if ((task->thread.flags & IA64_THREAD_PM_VALID) != 0)
346 pfm_save_regs(task);
348 info = __get_cpu_var(pfm_syst_info);
349 if (info & PFM_CPUINFO_SYST_WIDE)
350 pfm_syst_wide_update_task(task, info, 0);
351 #endif
353 #ifdef CONFIG_IA32_SUPPORT
354 if (IS_IA32_PROCESS(task_pt_regs(task)))
355 ia32_save_state(task);
356 #endif
359 void
360 ia64_load_extra (struct task_struct *task)
362 #ifdef CONFIG_PERFMON
363 unsigned long info;
364 #endif
366 if ((task->thread.flags & IA64_THREAD_DBG_VALID) != 0)
367 ia64_load_debug_regs(&task->thread.dbr[0]);
369 #ifdef CONFIG_PERFMON
370 if ((task->thread.flags & IA64_THREAD_PM_VALID) != 0)
371 pfm_load_regs(task);
373 info = __get_cpu_var(pfm_syst_info);
374 if (info & PFM_CPUINFO_SYST_WIDE)
375 pfm_syst_wide_update_task(task, info, 1);
376 #endif
378 #ifdef CONFIG_IA32_SUPPORT
379 if (IS_IA32_PROCESS(task_pt_regs(task)))
380 ia32_load_state(task);
381 #endif
385 * Copy the state of an ia-64 thread.
387 * We get here through the following call chain:
389 * from user-level: from kernel:
391 * <clone syscall> <some kernel call frames>
392 * sys_clone :
393 * do_fork do_fork
394 * copy_thread copy_thread
396 * This means that the stack layout is as follows:
398 * +---------------------+ (highest addr)
399 * | struct pt_regs |
400 * +---------------------+
401 * | struct switch_stack |
402 * +---------------------+
403 * | |
404 * | memory stack |
405 * | | <-- sp (lowest addr)
406 * +---------------------+
408 * Observe that we copy the unat values that are in pt_regs and switch_stack. Spilling an
409 * integer to address X causes bit N in ar.unat to be set to the NaT bit of the register,
410 * with N=(X & 0x1ff)/8. Thus, copying the unat value preserves the NaT bits ONLY if the
411 * pt_regs structure in the parent is congruent to that of the child, modulo 512. Since
412 * the stack is page aligned and the page size is at least 4KB, this is always the case,
413 * so there is nothing to worry about.
416 copy_thread(unsigned long clone_flags,
417 unsigned long user_stack_base, unsigned long user_stack_size,
418 struct task_struct *p, struct pt_regs *regs)
420 extern char ia64_ret_from_clone, ia32_ret_from_clone;
421 struct switch_stack *child_stack, *stack;
422 unsigned long rbs, child_rbs, rbs_size;
423 struct pt_regs *child_ptregs;
424 int retval = 0;
426 #ifdef CONFIG_SMP
428 * For SMP idle threads, fork_by_hand() calls do_fork with
429 * NULL regs.
431 if (!regs)
432 return 0;
433 #endif
435 stack = ((struct switch_stack *) regs) - 1;
437 child_ptregs = (struct pt_regs *) ((unsigned long) p + IA64_STK_OFFSET) - 1;
438 child_stack = (struct switch_stack *) child_ptregs - 1;
440 /* copy parent's switch_stack & pt_regs to child: */
441 memcpy(child_stack, stack, sizeof(*child_ptregs) + sizeof(*child_stack));
443 rbs = (unsigned long) current + IA64_RBS_OFFSET;
444 child_rbs = (unsigned long) p + IA64_RBS_OFFSET;
445 rbs_size = stack->ar_bspstore - rbs;
447 /* copy the parent's register backing store to the child: */
448 memcpy((void *) child_rbs, (void *) rbs, rbs_size);
450 if (likely(user_mode(child_ptregs))) {
451 if ((clone_flags & CLONE_SETTLS) && !IS_IA32_PROCESS(regs))
452 child_ptregs->r13 = regs->r16; /* see sys_clone2() in entry.S */
453 if (user_stack_base) {
454 child_ptregs->r12 = user_stack_base + user_stack_size - 16;
455 child_ptregs->ar_bspstore = user_stack_base;
456 child_ptregs->ar_rnat = 0;
457 child_ptregs->loadrs = 0;
459 } else {
461 * Note: we simply preserve the relative position of
462 * the stack pointer here. There is no need to
463 * allocate a scratch area here, since that will have
464 * been taken care of by the caller of sys_clone()
465 * already.
467 child_ptregs->r12 = (unsigned long) child_ptregs - 16; /* kernel sp */
468 child_ptregs->r13 = (unsigned long) p; /* set `current' pointer */
470 child_stack->ar_bspstore = child_rbs + rbs_size;
471 if (IS_IA32_PROCESS(regs))
472 child_stack->b0 = (unsigned long) &ia32_ret_from_clone;
473 else
474 child_stack->b0 = (unsigned long) &ia64_ret_from_clone;
476 /* copy parts of thread_struct: */
477 p->thread.ksp = (unsigned long) child_stack - 16;
479 /* stop some PSR bits from being inherited.
480 * the psr.up/psr.pp bits must be cleared on fork but inherited on execve()
481 * therefore we must specify them explicitly here and not include them in
482 * IA64_PSR_BITS_TO_CLEAR.
484 child_ptregs->cr_ipsr = ((child_ptregs->cr_ipsr | IA64_PSR_BITS_TO_SET)
485 & ~(IA64_PSR_BITS_TO_CLEAR | IA64_PSR_PP | IA64_PSR_UP));
488 * NOTE: The calling convention considers all floating point
489 * registers in the high partition (fph) to be scratch. Since
490 * the only way to get to this point is through a system call,
491 * we know that the values in fph are all dead. Hence, there
492 * is no need to inherit the fph state from the parent to the
493 * child and all we have to do is to make sure that
494 * IA64_THREAD_FPH_VALID is cleared in the child.
496 * XXX We could push this optimization a bit further by
497 * clearing IA64_THREAD_FPH_VALID on ANY system call.
498 * However, it's not clear this is worth doing. Also, it
499 * would be a slight deviation from the normal Linux system
500 * call behavior where scratch registers are preserved across
501 * system calls (unless used by the system call itself).
503 # define THREAD_FLAGS_TO_CLEAR (IA64_THREAD_FPH_VALID | IA64_THREAD_DBG_VALID \
504 | IA64_THREAD_PM_VALID)
505 # define THREAD_FLAGS_TO_SET 0
506 p->thread.flags = ((current->thread.flags & ~THREAD_FLAGS_TO_CLEAR)
507 | THREAD_FLAGS_TO_SET);
508 ia64_drop_fpu(p); /* don't pick up stale state from a CPU's fph */
509 #ifdef CONFIG_IA32_SUPPORT
511 * If we're cloning an IA32 task then save the IA32 extra
512 * state from the current task to the new task
514 if (IS_IA32_PROCESS(task_pt_regs(current))) {
515 ia32_save_state(p);
516 if (clone_flags & CLONE_SETTLS)
517 retval = ia32_clone_tls(p, child_ptregs);
519 /* Copy partially mapped page list */
520 if (!retval)
521 retval = ia32_copy_ia64_partial_page_list(p,
522 clone_flags);
524 #endif
526 #ifdef CONFIG_PERFMON
527 if (current->thread.pfm_context)
528 pfm_inherit(p, child_ptregs);
529 #endif
530 return retval;
533 static void
534 do_copy_task_regs (struct task_struct *task, struct unw_frame_info *info, void *arg)
536 unsigned long mask, sp, nat_bits = 0, ar_rnat, urbs_end, cfm;
537 unsigned long uninitialized_var(ip); /* GCC be quiet */
538 elf_greg_t *dst = arg;
539 struct pt_regs *pt;
540 char nat;
541 int i;
543 memset(dst, 0, sizeof(elf_gregset_t)); /* don't leak any kernel bits to user-level */
545 if (unw_unwind_to_user(info) < 0)
546 return;
548 unw_get_sp(info, &sp);
549 pt = (struct pt_regs *) (sp + 16);
551 urbs_end = ia64_get_user_rbs_end(task, pt, &cfm);
553 if (ia64_sync_user_rbs(task, info->sw, pt->ar_bspstore, urbs_end) < 0)
554 return;
556 ia64_peek(task, info->sw, urbs_end, (long) ia64_rse_rnat_addr((long *) urbs_end),
557 &ar_rnat);
560 * coredump format:
561 * r0-r31
562 * NaT bits (for r0-r31; bit N == 1 iff rN is a NaT)
563 * predicate registers (p0-p63)
564 * b0-b7
565 * ip cfm user-mask
566 * ar.rsc ar.bsp ar.bspstore ar.rnat
567 * ar.ccv ar.unat ar.fpsr ar.pfs ar.lc ar.ec
570 /* r0 is zero */
571 for (i = 1, mask = (1UL << i); i < 32; ++i) {
572 unw_get_gr(info, i, &dst[i], &nat);
573 if (nat)
574 nat_bits |= mask;
575 mask <<= 1;
577 dst[32] = nat_bits;
578 unw_get_pr(info, &dst[33]);
580 for (i = 0; i < 8; ++i)
581 unw_get_br(info, i, &dst[34 + i]);
583 unw_get_rp(info, &ip);
584 dst[42] = ip + ia64_psr(pt)->ri;
585 dst[43] = cfm;
586 dst[44] = pt->cr_ipsr & IA64_PSR_UM;
588 unw_get_ar(info, UNW_AR_RSC, &dst[45]);
590 * For bsp and bspstore, unw_get_ar() would return the kernel
591 * addresses, but we need the user-level addresses instead:
593 dst[46] = urbs_end; /* note: by convention PT_AR_BSP points to the end of the urbs! */
594 dst[47] = pt->ar_bspstore;
595 dst[48] = ar_rnat;
596 unw_get_ar(info, UNW_AR_CCV, &dst[49]);
597 unw_get_ar(info, UNW_AR_UNAT, &dst[50]);
598 unw_get_ar(info, UNW_AR_FPSR, &dst[51]);
599 dst[52] = pt->ar_pfs; /* UNW_AR_PFS is == to pt->cr_ifs for interrupt frames */
600 unw_get_ar(info, UNW_AR_LC, &dst[53]);
601 unw_get_ar(info, UNW_AR_EC, &dst[54]);
602 unw_get_ar(info, UNW_AR_CSD, &dst[55]);
603 unw_get_ar(info, UNW_AR_SSD, &dst[56]);
606 void
607 do_dump_task_fpu (struct task_struct *task, struct unw_frame_info *info, void *arg)
609 elf_fpreg_t *dst = arg;
610 int i;
612 memset(dst, 0, sizeof(elf_fpregset_t)); /* don't leak any "random" bits */
614 if (unw_unwind_to_user(info) < 0)
615 return;
617 /* f0 is 0.0, f1 is 1.0 */
619 for (i = 2; i < 32; ++i)
620 unw_get_fr(info, i, dst + i);
622 ia64_flush_fph(task);
623 if ((task->thread.flags & IA64_THREAD_FPH_VALID) != 0)
624 memcpy(dst + 32, task->thread.fph, 96*16);
627 void
628 do_copy_regs (struct unw_frame_info *info, void *arg)
630 do_copy_task_regs(current, info, arg);
633 void
634 do_dump_fpu (struct unw_frame_info *info, void *arg)
636 do_dump_task_fpu(current, info, arg);
639 void
640 ia64_elf_core_copy_regs (struct pt_regs *pt, elf_gregset_t dst)
642 unw_init_running(do_copy_regs, dst);
646 dump_fpu (struct pt_regs *pt, elf_fpregset_t dst)
648 unw_init_running(do_dump_fpu, dst);
649 return 1; /* f0-f31 are always valid so we always return 1 */
652 long
653 sys_execve (char __user *filename, char __user * __user *argv, char __user * __user *envp,
654 struct pt_regs *regs)
656 char *fname;
657 int error;
659 fname = getname(filename);
660 error = PTR_ERR(fname);
661 if (IS_ERR(fname))
662 goto out;
663 error = do_execve(fname, argv, envp, regs);
664 putname(fname);
665 out:
666 return error;
669 pid_t
670 kernel_thread (int (*fn)(void *), void *arg, unsigned long flags)
672 extern void start_kernel_thread (void);
673 unsigned long *helper_fptr = (unsigned long *) &start_kernel_thread;
674 struct {
675 struct switch_stack sw;
676 struct pt_regs pt;
677 } regs;
679 memset(&regs, 0, sizeof(regs));
680 regs.pt.cr_iip = helper_fptr[0]; /* set entry point (IP) */
681 regs.pt.r1 = helper_fptr[1]; /* set GP */
682 regs.pt.r9 = (unsigned long) fn; /* 1st argument */
683 regs.pt.r11 = (unsigned long) arg; /* 2nd argument */
684 /* Preserve PSR bits, except for bits 32-34 and 37-45, which we can't read. */
685 regs.pt.cr_ipsr = ia64_getreg(_IA64_REG_PSR) | IA64_PSR_BN;
686 regs.pt.cr_ifs = 1UL << 63; /* mark as valid, empty frame */
687 regs.sw.ar_fpsr = regs.pt.ar_fpsr = ia64_getreg(_IA64_REG_AR_FPSR);
688 regs.sw.ar_bspstore = (unsigned long) current + IA64_RBS_OFFSET;
689 regs.sw.pr = (1 << PRED_KERNEL_STACK);
690 return do_fork(flags | CLONE_VM | CLONE_UNTRACED, 0, &regs.pt, 0, NULL, NULL);
692 EXPORT_SYMBOL(kernel_thread);
694 /* This gets called from kernel_thread() via ia64_invoke_thread_helper(). */
696 kernel_thread_helper (int (*fn)(void *), void *arg)
698 #ifdef CONFIG_IA32_SUPPORT
699 if (IS_IA32_PROCESS(task_pt_regs(current))) {
700 /* A kernel thread is always a 64-bit process. */
701 current->thread.map_base = DEFAULT_MAP_BASE;
702 current->thread.task_size = DEFAULT_TASK_SIZE;
703 ia64_set_kr(IA64_KR_IO_BASE, current->thread.old_iob);
704 ia64_set_kr(IA64_KR_TSSD, current->thread.old_k1);
706 #endif
707 return (*fn)(arg);
711 * Flush thread state. This is called when a thread does an execve().
713 void
714 flush_thread (void)
716 /* drop floating-point and debug-register state if it exists: */
717 current->thread.flags &= ~(IA64_THREAD_FPH_VALID | IA64_THREAD_DBG_VALID);
718 ia64_drop_fpu(current);
719 #ifdef CONFIG_IA32_SUPPORT
720 if (IS_IA32_PROCESS(task_pt_regs(current))) {
721 ia32_drop_ia64_partial_page_list(current);
722 current->thread.task_size = IA32_PAGE_OFFSET;
723 set_fs(USER_DS);
724 memset(current->thread.tls_array, 0, sizeof(current->thread.tls_array));
726 #endif
730 * Clean up state associated with current thread. This is called when
731 * the thread calls exit().
733 void
734 exit_thread (void)
737 ia64_drop_fpu(current);
738 #ifdef CONFIG_PERFMON
739 /* if needed, stop monitoring and flush state to perfmon context */
740 if (current->thread.pfm_context)
741 pfm_exit_thread(current);
743 /* free debug register resources */
744 if (current->thread.flags & IA64_THREAD_DBG_VALID)
745 pfm_release_debug_registers(current);
746 #endif
747 if (IS_IA32_PROCESS(task_pt_regs(current)))
748 ia32_drop_ia64_partial_page_list(current);
751 unsigned long
752 get_wchan (struct task_struct *p)
754 struct unw_frame_info info;
755 unsigned long ip;
756 int count = 0;
758 if (!p || p == current || p->state == TASK_RUNNING)
759 return 0;
762 * Note: p may not be a blocked task (it could be current or
763 * another process running on some other CPU. Rather than
764 * trying to determine if p is really blocked, we just assume
765 * it's blocked and rely on the unwind routines to fail
766 * gracefully if the process wasn't really blocked after all.
767 * --davidm 99/12/15
769 unw_init_from_blocked_task(&info, p);
770 do {
771 if (p->state == TASK_RUNNING)
772 return 0;
773 if (unw_unwind(&info) < 0)
774 return 0;
775 unw_get_ip(&info, &ip);
776 if (!in_sched_functions(ip))
777 return ip;
778 } while (count++ < 16);
779 return 0;
782 void
783 cpu_halt (void)
785 pal_power_mgmt_info_u_t power_info[8];
786 unsigned long min_power;
787 int i, min_power_state;
789 if (ia64_pal_halt_info(power_info) != 0)
790 return;
792 min_power_state = 0;
793 min_power = power_info[0].pal_power_mgmt_info_s.power_consumption;
794 for (i = 1; i < 8; ++i)
795 if (power_info[i].pal_power_mgmt_info_s.im
796 && power_info[i].pal_power_mgmt_info_s.power_consumption < min_power) {
797 min_power = power_info[i].pal_power_mgmt_info_s.power_consumption;
798 min_power_state = i;
801 while (1)
802 ia64_pal_halt(min_power_state);
805 void machine_shutdown(void)
807 #ifdef CONFIG_HOTPLUG_CPU
808 int cpu;
810 for_each_online_cpu(cpu) {
811 if (cpu != smp_processor_id())
812 cpu_down(cpu);
814 #endif
815 #ifdef CONFIG_KEXEC
816 kexec_disable_iosapic();
817 #endif
820 void
821 machine_restart (char *restart_cmd)
823 (void) notify_die(DIE_MACHINE_RESTART, restart_cmd, NULL, 0, 0, 0);
824 (*efi.reset_system)(EFI_RESET_WARM, 0, 0, NULL);
827 void
828 machine_halt (void)
830 (void) notify_die(DIE_MACHINE_HALT, "", NULL, 0, 0, 0);
831 cpu_halt();
834 void
835 machine_power_off (void)
837 if (pm_power_off)
838 pm_power_off();
839 machine_halt();