xref: /openbmc/linux/arch/ia64/kernel/process.c (revision 9ac8d3fb)
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/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>
32 
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>
46 
47 #include "entry.h"
48 
49 #ifdef CONFIG_PERFMON
50 # include <asm/perfmon.h>
51 #endif
52 
53 #include "sigframe.h"
54 
55 void (*ia64_mark_idle)(int);
56 
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);
63 
64 void
65 ia64_do_show_stack (struct unw_frame_info *info, void *arg)
66 {
67 	unsigned long ip, sp, bsp;
68 	char buf[128];			/* don't make it so big that it overflows the stack! */
69 
70 	printk("\nCall Trace:\n");
71 	do {
72 		unw_get_ip(info, &ip);
73 		if (ip == 0)
74 			break;
75 
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);
84 }
85 
86 void
87 show_stack (struct task_struct *task, unsigned long *sp)
88 {
89 	if (!task)
90 		unw_init_running(ia64_do_show_stack, NULL);
91 	else {
92 		struct unw_frame_info info;
93 
94 		unw_init_from_blocked_task(&info, task);
95 		ia64_do_show_stack(&info, NULL);
96 	}
97 }
98 
99 void
100 dump_stack (void)
101 {
102 	show_stack(NULL, NULL);
103 }
104 
105 EXPORT_SYMBOL(dump_stack);
106 
107 void
108 show_regs (struct pt_regs *regs)
109 {
110 	unsigned long ip = regs->cr_iip + ia64_psr(regs)->ri;
111 
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]);
136 
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);
146 
147 	if (user_mode(regs)) {
148 		/* print the stacked registers */
149 		unsigned long val, *bsp, ndirty;
150 		int i, sof, is_nat = 0;
151 
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" : " ");
159 		}
160 	} else
161 		show_stack(NULL, NULL);
162 }
163 
164 void
165 do_notify_resume_user(sigset_t *unused, struct sigscratch *scr, long in_syscall)
166 {
167 	if (fsys_mode(current, &scr->pt)) {
168 		/*
169 		 * defer signal-handling etc. until we return to
170 		 * privilege-level 0.
171 		 */
172 		if (!ia64_psr(&scr->pt)->lp)
173 			ia64_psr(&scr->pt)->lp = 1;
174 		return;
175 	}
176 
177 #ifdef CONFIG_PERFMON
178 	if (current->thread.pfm_needs_checking)
179 		/*
180 		 * Note: pfm_handle_work() allow us to call it with interrupts
181 		 * disabled, and may enable interrupts within the function.
182 		 */
183 		pfm_handle_work();
184 #endif
185 
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);
190 	}
191 
192 	if (test_thread_flag(TIF_NOTIFY_RESUME)) {
193 		clear_thread_flag(TIF_NOTIFY_RESUME);
194 		tracehook_notify_resume(&scr->pt);
195 	}
196 
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();
201 	}
202 
203 	local_irq_disable();	/* force interrupt disable */
204 }
205 
206 static int pal_halt        = 1;
207 static int can_do_pal_halt = 1;
208 
209 static int __init nohalt_setup(char * str)
210 {
211 	pal_halt = can_do_pal_halt = 0;
212 	return 1;
213 }
214 __setup("nohalt", nohalt_setup);
215 
216 void
217 update_pal_halt_status(int status)
218 {
219 	can_do_pal_halt = pal_halt && status;
220 }
221 
222 /*
223  * We use this if we don't have any better idle routine..
224  */
225 void
226 default_idle (void)
227 {
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();
234 			}
235 			local_irq_enable();
236 		} else
237 			cpu_relax();
238 	}
239 }
240 
241 #ifdef CONFIG_HOTPLUG_CPU
242 /* We don't actually take CPU down, just spin without interrupts. */
243 static inline void play_dead(void)
244 {
245 	unsigned int this_cpu = smp_processor_id();
246 
247 	/* Ack it */
248 	__get_cpu_var(cpu_state) = CPU_DEAD;
249 
250 	max_xtp();
251 	local_irq_disable();
252 	idle_task_exit();
253 	ia64_jump_to_sal(&sal_boot_rendez_state[this_cpu]);
254 	/*
255 	 * The above is a point of no-return, the processor is
256 	 * expected to be in SAL loop now.
257 	 */
258 	BUG();
259 }
260 #else
261 static inline void play_dead(void)
262 {
263 	BUG();
264 }
265 #endif /* CONFIG_HOTPLUG_CPU */
266 
267 static void do_nothing(void *unused)
268 {
269 }
270 
271 /*
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.
275  *
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.
278  */
279 void cpu_idle_wait(void)
280 {
281 	smp_mb();
282 	/* kick all the CPUs so that they exit out of pm_idle */
283 	smp_call_function(do_nothing, NULL, 1);
284 }
285 EXPORT_SYMBOL_GPL(cpu_idle_wait);
286 
287 void __attribute__((noreturn))
288 cpu_idle (void)
289 {
290 	void (*mark_idle)(int) = ia64_mark_idle;
291   	int cpu = smp_processor_id();
292 
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;
297 			/*
298 			 * TS_POLLING-cleared state must be visible before we
299 			 * test NEED_RESCHED:
300 			 */
301 			smp_mb();
302 		} else {
303 			current_thread_info()->status |= TS_POLLING;
304 		}
305 
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);
314 
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
324 		}
325 		preempt_enable_no_resched();
326 		schedule();
327 		preempt_disable();
328 		check_pgt_cache();
329 		if (cpu_is_offline(cpu))
330 			play_dead();
331 	}
332 }
333 
334 void
335 ia64_save_extra (struct task_struct *task)
336 {
337 #ifdef CONFIG_PERFMON
338 	unsigned long info;
339 #endif
340 
341 	if ((task->thread.flags & IA64_THREAD_DBG_VALID) != 0)
342 		ia64_save_debug_regs(&task->thread.dbr[0]);
343 
344 #ifdef CONFIG_PERFMON
345 	if ((task->thread.flags & IA64_THREAD_PM_VALID) != 0)
346 		pfm_save_regs(task);
347 
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
352 
353 #ifdef CONFIG_IA32_SUPPORT
354 	if (IS_IA32_PROCESS(task_pt_regs(task)))
355 		ia32_save_state(task);
356 #endif
357 }
358 
359 void
360 ia64_load_extra (struct task_struct *task)
361 {
362 #ifdef CONFIG_PERFMON
363 	unsigned long info;
364 #endif
365 
366 	if ((task->thread.flags & IA64_THREAD_DBG_VALID) != 0)
367 		ia64_load_debug_regs(&task->thread.dbr[0]);
368 
369 #ifdef CONFIG_PERFMON
370 	if ((task->thread.flags & IA64_THREAD_PM_VALID) != 0)
371 		pfm_load_regs(task);
372 
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
377 
378 #ifdef CONFIG_IA32_SUPPORT
379 	if (IS_IA32_PROCESS(task_pt_regs(task)))
380 		ia32_load_state(task);
381 #endif
382 }
383 
384 /*
385  * Copy the state of an ia-64 thread.
386  *
387  * We get here through the following  call chain:
388  *
389  *	from user-level:	from kernel:
390  *
391  *	<clone syscall>	        <some kernel call frames>
392  *	sys_clone		   :
393  *	do_fork			do_fork
394  *	copy_thread		copy_thread
395  *
396  * This means that the stack layout is as follows:
397  *
398  *	+---------------------+ (highest addr)
399  *	|   struct pt_regs    |
400  *	+---------------------+
401  *	| struct switch_stack |
402  *	+---------------------+
403  *	|                     |
404  *	|    memory stack     |
405  *	|                     | <-- sp (lowest addr)
406  *	+---------------------+
407  *
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.
414  */
415 int
416 copy_thread (int nr, unsigned long clone_flags,
417 	     unsigned long user_stack_base, unsigned long user_stack_size,
418 	     struct task_struct *p, struct pt_regs *regs)
419 {
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;
425 
426 #ifdef CONFIG_SMP
427 	/*
428 	 * For SMP idle threads, fork_by_hand() calls do_fork with
429 	 * NULL regs.
430 	 */
431 	if (!regs)
432 		return 0;
433 #endif
434 
435 	stack = ((struct switch_stack *) regs) - 1;
436 
437 	child_ptregs = (struct pt_regs *) ((unsigned long) p + IA64_STK_OFFSET) - 1;
438 	child_stack = (struct switch_stack *) child_ptregs - 1;
439 
440 	/* copy parent's switch_stack & pt_regs to child: */
441 	memcpy(child_stack, stack, sizeof(*child_ptregs) + sizeof(*child_stack));
442 
443 	rbs = (unsigned long) current + IA64_RBS_OFFSET;
444 	child_rbs = (unsigned long) p + IA64_RBS_OFFSET;
445 	rbs_size = stack->ar_bspstore - rbs;
446 
447 	/* copy the parent's register backing store to the child: */
448 	memcpy((void *) child_rbs, (void *) rbs, rbs_size);
449 
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;
458 		}
459 	} else {
460 		/*
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.
466 		 */
467 		child_ptregs->r12 = (unsigned long) child_ptregs - 16; /* kernel sp */
468 		child_ptregs->r13 = (unsigned long) p;		/* set `current' pointer */
469 	}
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;
475 
476 	/* copy parts of thread_struct: */
477 	p->thread.ksp = (unsigned long) child_stack - 16;
478 
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.
483 	 */
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));
486 
487 	/*
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.
495 	 *
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).
502 	 */
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
510 	/*
511 	 * If we're cloning an IA32 task then save the IA32 extra
512 	 * state from the current task to the new task
513 	 */
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);
518 
519 		/* Copy partially mapped page list */
520 		if (!retval)
521 			retval = ia32_copy_ia64_partial_page_list(p,
522 								clone_flags);
523 	}
524 #endif
525 
526 #ifdef CONFIG_PERFMON
527 	if (current->thread.pfm_context)
528 		pfm_inherit(p, child_ptregs);
529 #endif
530 	return retval;
531 }
532 
533 static void
534 do_copy_task_regs (struct task_struct *task, struct unw_frame_info *info, void *arg)
535 {
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;
542 
543 	memset(dst, 0, sizeof(elf_gregset_t));	/* don't leak any kernel bits to user-level */
544 
545 	if (unw_unwind_to_user(info) < 0)
546 		return;
547 
548 	unw_get_sp(info, &sp);
549 	pt = (struct pt_regs *) (sp + 16);
550 
551 	urbs_end = ia64_get_user_rbs_end(task, pt, &cfm);
552 
553 	if (ia64_sync_user_rbs(task, info->sw, pt->ar_bspstore, urbs_end) < 0)
554 		return;
555 
556 	ia64_peek(task, info->sw, urbs_end, (long) ia64_rse_rnat_addr((long *) urbs_end),
557 		  &ar_rnat);
558 
559 	/*
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
568 	 */
569 
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;
576 	}
577 	dst[32] = nat_bits;
578 	unw_get_pr(info, &dst[33]);
579 
580 	for (i = 0; i < 8; ++i)
581 		unw_get_br(info, i, &dst[34 + i]);
582 
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;
587 
588 	unw_get_ar(info, UNW_AR_RSC, &dst[45]);
589 	/*
590 	 * For bsp and bspstore, unw_get_ar() would return the kernel
591 	 * addresses, but we need the user-level addresses instead:
592 	 */
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]);
604 }
605 
606 void
607 do_dump_task_fpu (struct task_struct *task, struct unw_frame_info *info, void *arg)
608 {
609 	elf_fpreg_t *dst = arg;
610 	int i;
611 
612 	memset(dst, 0, sizeof(elf_fpregset_t));	/* don't leak any "random" bits */
613 
614 	if (unw_unwind_to_user(info) < 0)
615 		return;
616 
617 	/* f0 is 0.0, f1 is 1.0 */
618 
619 	for (i = 2; i < 32; ++i)
620 		unw_get_fr(info, i, dst + i);
621 
622 	ia64_flush_fph(task);
623 	if ((task->thread.flags & IA64_THREAD_FPH_VALID) != 0)
624 		memcpy(dst + 32, task->thread.fph, 96*16);
625 }
626 
627 void
628 do_copy_regs (struct unw_frame_info *info, void *arg)
629 {
630 	do_copy_task_regs(current, info, arg);
631 }
632 
633 void
634 do_dump_fpu (struct unw_frame_info *info, void *arg)
635 {
636 	do_dump_task_fpu(current, info, arg);
637 }
638 
639 void
640 ia64_elf_core_copy_regs (struct pt_regs *pt, elf_gregset_t dst)
641 {
642 	unw_init_running(do_copy_regs, dst);
643 }
644 
645 int
646 dump_fpu (struct pt_regs *pt, elf_fpregset_t dst)
647 {
648 	unw_init_running(do_dump_fpu, dst);
649 	return 1;	/* f0-f31 are always valid so we always return 1 */
650 }
651 
652 long
653 sys_execve (char __user *filename, char __user * __user *argv, char __user * __user *envp,
654 	    struct pt_regs *regs)
655 {
656 	char *fname;
657 	int error;
658 
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;
667 }
668 
669 pid_t
670 kernel_thread (int (*fn)(void *), void *arg, unsigned long flags)
671 {
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;
678 
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);
691 }
692 EXPORT_SYMBOL(kernel_thread);
693 
694 /* This gets called from kernel_thread() via ia64_invoke_thread_helper().  */
695 int
696 kernel_thread_helper (int (*fn)(void *), void *arg)
697 {
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);
705 	}
706 #endif
707 	return (*fn)(arg);
708 }
709 
710 /*
711  * Flush thread state.  This is called when a thread does an execve().
712  */
713 void
714 flush_thread (void)
715 {
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));
725 	}
726 #endif
727 }
728 
729 /*
730  * Clean up state associated with current thread.  This is called when
731  * the thread calls exit().
732  */
733 void
734 exit_thread (void)
735 {
736 
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);
742 
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);
749 }
750 
751 unsigned long
752 get_wchan (struct task_struct *p)
753 {
754 	struct unw_frame_info info;
755 	unsigned long ip;
756 	int count = 0;
757 
758 	if (!p || p == current || p->state == TASK_RUNNING)
759 		return 0;
760 
761 	/*
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
768 	 */
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;
780 }
781 
782 void
783 cpu_halt (void)
784 {
785 	pal_power_mgmt_info_u_t power_info[8];
786 	unsigned long min_power;
787 	int i, min_power_state;
788 
789 	if (ia64_pal_halt_info(power_info) != 0)
790 		return;
791 
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;
799 		}
800 
801 	while (1)
802 		ia64_pal_halt(min_power_state);
803 }
804 
805 void machine_shutdown(void)
806 {
807 #ifdef CONFIG_HOTPLUG_CPU
808 	int cpu;
809 
810 	for_each_online_cpu(cpu) {
811 		if (cpu != smp_processor_id())
812 			cpu_down(cpu);
813 	}
814 #endif
815 #ifdef CONFIG_KEXEC
816 	kexec_disable_iosapic();
817 #endif
818 }
819 
820 void
821 machine_restart (char *restart_cmd)
822 {
823 	(void) notify_die(DIE_MACHINE_RESTART, restart_cmd, NULL, 0, 0, 0);
824 	(*efi.reset_system)(EFI_RESET_WARM, 0, 0, NULL);
825 }
826 
827 void
828 machine_halt (void)
829 {
830 	(void) notify_die(DIE_MACHINE_HALT, "", NULL, 0, 0, 0);
831 	cpu_halt();
832 }
833 
834 void
835 machine_power_off (void)
836 {
837 	if (pm_power_off)
838 		pm_power_off();
839 	machine_halt();
840 }
841 
842