xref: /openbmc/linux/arch/ia64/kernel/process.c (revision 9d749629)
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 			void (*idle)(void);
295 #ifdef CONFIG_SMP
296 			min_xtp();
297 #endif
298 			rmb();
299 			if (mark_idle)
300 				(*mark_idle)(1);
301 
302 			if (!idle)
303 				idle = default_idle;
304 			(*idle)();
305 			if (mark_idle)
306 				(*mark_idle)(0);
307 #ifdef CONFIG_SMP
308 			normal_xtp();
309 #endif
310 		}
311 		rcu_idle_exit();
312 		schedule_preempt_disabled();
313 		check_pgt_cache();
314 		if (cpu_is_offline(cpu))
315 			play_dead();
316 	}
317 }
318 
319 void
320 ia64_save_extra (struct task_struct *task)
321 {
322 #ifdef CONFIG_PERFMON
323 	unsigned long info;
324 #endif
325 
326 	if ((task->thread.flags & IA64_THREAD_DBG_VALID) != 0)
327 		ia64_save_debug_regs(&task->thread.dbr[0]);
328 
329 #ifdef CONFIG_PERFMON
330 	if ((task->thread.flags & IA64_THREAD_PM_VALID) != 0)
331 		pfm_save_regs(task);
332 
333 	info = __get_cpu_var(pfm_syst_info);
334 	if (info & PFM_CPUINFO_SYST_WIDE)
335 		pfm_syst_wide_update_task(task, info, 0);
336 #endif
337 }
338 
339 void
340 ia64_load_extra (struct task_struct *task)
341 {
342 #ifdef CONFIG_PERFMON
343 	unsigned long info;
344 #endif
345 
346 	if ((task->thread.flags & IA64_THREAD_DBG_VALID) != 0)
347 		ia64_load_debug_regs(&task->thread.dbr[0]);
348 
349 #ifdef CONFIG_PERFMON
350 	if ((task->thread.flags & IA64_THREAD_PM_VALID) != 0)
351 		pfm_load_regs(task);
352 
353 	info = __get_cpu_var(pfm_syst_info);
354 	if (info & PFM_CPUINFO_SYST_WIDE)
355 		pfm_syst_wide_update_task(task, info, 1);
356 #endif
357 }
358 
359 /*
360  * Copy the state of an ia-64 thread.
361  *
362  * We get here through the following  call chain:
363  *
364  *	from user-level:	from kernel:
365  *
366  *	<clone syscall>	        <some kernel call frames>
367  *	sys_clone		   :
368  *	do_fork			do_fork
369  *	copy_thread		copy_thread
370  *
371  * This means that the stack layout is as follows:
372  *
373  *	+---------------------+ (highest addr)
374  *	|   struct pt_regs    |
375  *	+---------------------+
376  *	| struct switch_stack |
377  *	+---------------------+
378  *	|                     |
379  *	|    memory stack     |
380  *	|                     | <-- sp (lowest addr)
381  *	+---------------------+
382  *
383  * Observe that we copy the unat values that are in pt_regs and switch_stack.  Spilling an
384  * integer to address X causes bit N in ar.unat to be set to the NaT bit of the register,
385  * with N=(X & 0x1ff)/8.  Thus, copying the unat value preserves the NaT bits ONLY if the
386  * pt_regs structure in the parent is congruent to that of the child, modulo 512.  Since
387  * the stack is page aligned and the page size is at least 4KB, this is always the case,
388  * so there is nothing to worry about.
389  */
390 int
391 copy_thread(unsigned long clone_flags,
392 	     unsigned long user_stack_base, unsigned long user_stack_size,
393 	     struct task_struct *p)
394 {
395 	extern char ia64_ret_from_clone;
396 	struct switch_stack *child_stack, *stack;
397 	unsigned long rbs, child_rbs, rbs_size;
398 	struct pt_regs *child_ptregs;
399 	struct pt_regs *regs = current_pt_regs();
400 	int retval = 0;
401 
402 	child_ptregs = (struct pt_regs *) ((unsigned long) p + IA64_STK_OFFSET) - 1;
403 	child_stack = (struct switch_stack *) child_ptregs - 1;
404 
405 	rbs = (unsigned long) current + IA64_RBS_OFFSET;
406 	child_rbs = (unsigned long) p + IA64_RBS_OFFSET;
407 
408 	/* copy parts of thread_struct: */
409 	p->thread.ksp = (unsigned long) child_stack - 16;
410 
411 	/*
412 	 * NOTE: The calling convention considers all floating point
413 	 * registers in the high partition (fph) to be scratch.  Since
414 	 * the only way to get to this point is through a system call,
415 	 * we know that the values in fph are all dead.  Hence, there
416 	 * is no need to inherit the fph state from the parent to the
417 	 * child and all we have to do is to make sure that
418 	 * IA64_THREAD_FPH_VALID is cleared in the child.
419 	 *
420 	 * XXX We could push this optimization a bit further by
421 	 * clearing IA64_THREAD_FPH_VALID on ANY system call.
422 	 * However, it's not clear this is worth doing.  Also, it
423 	 * would be a slight deviation from the normal Linux system
424 	 * call behavior where scratch registers are preserved across
425 	 * system calls (unless used by the system call itself).
426 	 */
427 #	define THREAD_FLAGS_TO_CLEAR	(IA64_THREAD_FPH_VALID | IA64_THREAD_DBG_VALID \
428 					 | IA64_THREAD_PM_VALID)
429 #	define THREAD_FLAGS_TO_SET	0
430 	p->thread.flags = ((current->thread.flags & ~THREAD_FLAGS_TO_CLEAR)
431 			   | THREAD_FLAGS_TO_SET);
432 
433 	ia64_drop_fpu(p);	/* don't pick up stale state from a CPU's fph */
434 
435 	if (unlikely(p->flags & PF_KTHREAD)) {
436 		if (unlikely(!user_stack_base)) {
437 			/* fork_idle() called us */
438 			return 0;
439 		}
440 		memset(child_stack, 0, sizeof(*child_ptregs) + sizeof(*child_stack));
441 		child_stack->r4 = user_stack_base;	/* payload */
442 		child_stack->r5 = user_stack_size;	/* argument */
443 		/*
444 		 * Preserve PSR bits, except for bits 32-34 and 37-45,
445 		 * which we can't read.
446 		 */
447 		child_ptregs->cr_ipsr = ia64_getreg(_IA64_REG_PSR) | IA64_PSR_BN;
448 		/* mark as valid, empty frame */
449 		child_ptregs->cr_ifs = 1UL << 63;
450 		child_stack->ar_fpsr = child_ptregs->ar_fpsr
451 			= ia64_getreg(_IA64_REG_AR_FPSR);
452 		child_stack->pr = (1 << PRED_KERNEL_STACK);
453 		child_stack->ar_bspstore = child_rbs;
454 		child_stack->b0 = (unsigned long) &ia64_ret_from_clone;
455 
456 		/* stop some PSR bits from being inherited.
457 		 * the psr.up/psr.pp bits must be cleared on fork but inherited on execve()
458 		 * therefore we must specify them explicitly here and not include them in
459 		 * IA64_PSR_BITS_TO_CLEAR.
460 		 */
461 		child_ptregs->cr_ipsr = ((child_ptregs->cr_ipsr | IA64_PSR_BITS_TO_SET)
462 				 & ~(IA64_PSR_BITS_TO_CLEAR | IA64_PSR_PP | IA64_PSR_UP));
463 
464 		return 0;
465 	}
466 	stack = ((struct switch_stack *) regs) - 1;
467 	/* copy parent's switch_stack & pt_regs to child: */
468 	memcpy(child_stack, stack, sizeof(*child_ptregs) + sizeof(*child_stack));
469 
470 	/* copy the parent's register backing store to the child: */
471 	rbs_size = stack->ar_bspstore - rbs;
472 	memcpy((void *) child_rbs, (void *) rbs, rbs_size);
473 	if (clone_flags & CLONE_SETTLS)
474 		child_ptregs->r13 = regs->r16;	/* see sys_clone2() in entry.S */
475 	if (user_stack_base) {
476 		child_ptregs->r12 = user_stack_base + user_stack_size - 16;
477 		child_ptregs->ar_bspstore = user_stack_base;
478 		child_ptregs->ar_rnat = 0;
479 		child_ptregs->loadrs = 0;
480 	}
481 	child_stack->ar_bspstore = child_rbs + rbs_size;
482 	child_stack->b0 = (unsigned long) &ia64_ret_from_clone;
483 
484 	/* stop some PSR bits from being inherited.
485 	 * the psr.up/psr.pp bits must be cleared on fork but inherited on execve()
486 	 * therefore we must specify them explicitly here and not include them in
487 	 * IA64_PSR_BITS_TO_CLEAR.
488 	 */
489 	child_ptregs->cr_ipsr = ((child_ptregs->cr_ipsr | IA64_PSR_BITS_TO_SET)
490 				 & ~(IA64_PSR_BITS_TO_CLEAR | IA64_PSR_PP | IA64_PSR_UP));
491 
492 #ifdef CONFIG_PERFMON
493 	if (current->thread.pfm_context)
494 		pfm_inherit(p, child_ptregs);
495 #endif
496 	return retval;
497 }
498 
499 static void
500 do_copy_task_regs (struct task_struct *task, struct unw_frame_info *info, void *arg)
501 {
502 	unsigned long mask, sp, nat_bits = 0, ar_rnat, urbs_end, cfm;
503 	unsigned long uninitialized_var(ip);	/* GCC be quiet */
504 	elf_greg_t *dst = arg;
505 	struct pt_regs *pt;
506 	char nat;
507 	int i;
508 
509 	memset(dst, 0, sizeof(elf_gregset_t));	/* don't leak any kernel bits to user-level */
510 
511 	if (unw_unwind_to_user(info) < 0)
512 		return;
513 
514 	unw_get_sp(info, &sp);
515 	pt = (struct pt_regs *) (sp + 16);
516 
517 	urbs_end = ia64_get_user_rbs_end(task, pt, &cfm);
518 
519 	if (ia64_sync_user_rbs(task, info->sw, pt->ar_bspstore, urbs_end) < 0)
520 		return;
521 
522 	ia64_peek(task, info->sw, urbs_end, (long) ia64_rse_rnat_addr((long *) urbs_end),
523 		  &ar_rnat);
524 
525 	/*
526 	 * coredump format:
527 	 *	r0-r31
528 	 *	NaT bits (for r0-r31; bit N == 1 iff rN is a NaT)
529 	 *	predicate registers (p0-p63)
530 	 *	b0-b7
531 	 *	ip cfm user-mask
532 	 *	ar.rsc ar.bsp ar.bspstore ar.rnat
533 	 *	ar.ccv ar.unat ar.fpsr ar.pfs ar.lc ar.ec
534 	 */
535 
536 	/* r0 is zero */
537 	for (i = 1, mask = (1UL << i); i < 32; ++i) {
538 		unw_get_gr(info, i, &dst[i], &nat);
539 		if (nat)
540 			nat_bits |= mask;
541 		mask <<= 1;
542 	}
543 	dst[32] = nat_bits;
544 	unw_get_pr(info, &dst[33]);
545 
546 	for (i = 0; i < 8; ++i)
547 		unw_get_br(info, i, &dst[34 + i]);
548 
549 	unw_get_rp(info, &ip);
550 	dst[42] = ip + ia64_psr(pt)->ri;
551 	dst[43] = cfm;
552 	dst[44] = pt->cr_ipsr & IA64_PSR_UM;
553 
554 	unw_get_ar(info, UNW_AR_RSC, &dst[45]);
555 	/*
556 	 * For bsp and bspstore, unw_get_ar() would return the kernel
557 	 * addresses, but we need the user-level addresses instead:
558 	 */
559 	dst[46] = urbs_end;	/* note: by convention PT_AR_BSP points to the end of the urbs! */
560 	dst[47] = pt->ar_bspstore;
561 	dst[48] = ar_rnat;
562 	unw_get_ar(info, UNW_AR_CCV, &dst[49]);
563 	unw_get_ar(info, UNW_AR_UNAT, &dst[50]);
564 	unw_get_ar(info, UNW_AR_FPSR, &dst[51]);
565 	dst[52] = pt->ar_pfs;	/* UNW_AR_PFS is == to pt->cr_ifs for interrupt frames */
566 	unw_get_ar(info, UNW_AR_LC, &dst[53]);
567 	unw_get_ar(info, UNW_AR_EC, &dst[54]);
568 	unw_get_ar(info, UNW_AR_CSD, &dst[55]);
569 	unw_get_ar(info, UNW_AR_SSD, &dst[56]);
570 }
571 
572 void
573 do_dump_task_fpu (struct task_struct *task, struct unw_frame_info *info, void *arg)
574 {
575 	elf_fpreg_t *dst = arg;
576 	int i;
577 
578 	memset(dst, 0, sizeof(elf_fpregset_t));	/* don't leak any "random" bits */
579 
580 	if (unw_unwind_to_user(info) < 0)
581 		return;
582 
583 	/* f0 is 0.0, f1 is 1.0 */
584 
585 	for (i = 2; i < 32; ++i)
586 		unw_get_fr(info, i, dst + i);
587 
588 	ia64_flush_fph(task);
589 	if ((task->thread.flags & IA64_THREAD_FPH_VALID) != 0)
590 		memcpy(dst + 32, task->thread.fph, 96*16);
591 }
592 
593 void
594 do_copy_regs (struct unw_frame_info *info, void *arg)
595 {
596 	do_copy_task_regs(current, info, arg);
597 }
598 
599 void
600 do_dump_fpu (struct unw_frame_info *info, void *arg)
601 {
602 	do_dump_task_fpu(current, info, arg);
603 }
604 
605 void
606 ia64_elf_core_copy_regs (struct pt_regs *pt, elf_gregset_t dst)
607 {
608 	unw_init_running(do_copy_regs, dst);
609 }
610 
611 int
612 dump_fpu (struct pt_regs *pt, elf_fpregset_t dst)
613 {
614 	unw_init_running(do_dump_fpu, dst);
615 	return 1;	/* f0-f31 are always valid so we always return 1 */
616 }
617 
618 /*
619  * Flush thread state.  This is called when a thread does an execve().
620  */
621 void
622 flush_thread (void)
623 {
624 	/* drop floating-point and debug-register state if it exists: */
625 	current->thread.flags &= ~(IA64_THREAD_FPH_VALID | IA64_THREAD_DBG_VALID);
626 	ia64_drop_fpu(current);
627 }
628 
629 /*
630  * Clean up state associated with current thread.  This is called when
631  * the thread calls exit().
632  */
633 void
634 exit_thread (void)
635 {
636 
637 	ia64_drop_fpu(current);
638 #ifdef CONFIG_PERFMON
639        /* if needed, stop monitoring and flush state to perfmon context */
640 	if (current->thread.pfm_context)
641 		pfm_exit_thread(current);
642 
643 	/* free debug register resources */
644 	if (current->thread.flags & IA64_THREAD_DBG_VALID)
645 		pfm_release_debug_registers(current);
646 #endif
647 }
648 
649 unsigned long
650 get_wchan (struct task_struct *p)
651 {
652 	struct unw_frame_info info;
653 	unsigned long ip;
654 	int count = 0;
655 
656 	if (!p || p == current || p->state == TASK_RUNNING)
657 		return 0;
658 
659 	/*
660 	 * Note: p may not be a blocked task (it could be current or
661 	 * another process running on some other CPU.  Rather than
662 	 * trying to determine if p is really blocked, we just assume
663 	 * it's blocked and rely on the unwind routines to fail
664 	 * gracefully if the process wasn't really blocked after all.
665 	 * --davidm 99/12/15
666 	 */
667 	unw_init_from_blocked_task(&info, p);
668 	do {
669 		if (p->state == TASK_RUNNING)
670 			return 0;
671 		if (unw_unwind(&info) < 0)
672 			return 0;
673 		unw_get_ip(&info, &ip);
674 		if (!in_sched_functions(ip))
675 			return ip;
676 	} while (count++ < 16);
677 	return 0;
678 }
679 
680 void
681 cpu_halt (void)
682 {
683 	pal_power_mgmt_info_u_t power_info[8];
684 	unsigned long min_power;
685 	int i, min_power_state;
686 
687 	if (ia64_pal_halt_info(power_info) != 0)
688 		return;
689 
690 	min_power_state = 0;
691 	min_power = power_info[0].pal_power_mgmt_info_s.power_consumption;
692 	for (i = 1; i < 8; ++i)
693 		if (power_info[i].pal_power_mgmt_info_s.im
694 		    && power_info[i].pal_power_mgmt_info_s.power_consumption < min_power) {
695 			min_power = power_info[i].pal_power_mgmt_info_s.power_consumption;
696 			min_power_state = i;
697 		}
698 
699 	while (1)
700 		ia64_pal_halt(min_power_state);
701 }
702 
703 void machine_shutdown(void)
704 {
705 #ifdef CONFIG_HOTPLUG_CPU
706 	int cpu;
707 
708 	for_each_online_cpu(cpu) {
709 		if (cpu != smp_processor_id())
710 			cpu_down(cpu);
711 	}
712 #endif
713 #ifdef CONFIG_KEXEC
714 	kexec_disable_iosapic();
715 #endif
716 }
717 
718 void
719 machine_restart (char *restart_cmd)
720 {
721 	(void) notify_die(DIE_MACHINE_RESTART, restart_cmd, NULL, 0, 0, 0);
722 	(*efi.reset_system)(EFI_RESET_WARM, 0, 0, NULL);
723 }
724 
725 void
726 machine_halt (void)
727 {
728 	(void) notify_die(DIE_MACHINE_HALT, "", NULL, 0, 0, 0);
729 	cpu_halt();
730 }
731 
732 void
733 machine_power_off (void)
734 {
735 	if (pm_power_off)
736 		pm_power_off();
737 	machine_halt();
738 }
739 
740