xref: /openbmc/linux/arch/ia64/kernel/process.c (revision 87c2ce3b)
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 #define __KERNEL_SYSCALLS__	/* see <asm/unistd.h> */
12 #include <linux/config.h>
13 
14 #include <linux/cpu.h>
15 #include <linux/pm.h>
16 #include <linux/elf.h>
17 #include <linux/errno.h>
18 #include <linux/kallsyms.h>
19 #include <linux/kernel.h>
20 #include <linux/mm.h>
21 #include <linux/module.h>
22 #include <linux/notifier.h>
23 #include <linux/personality.h>
24 #include <linux/sched.h>
25 #include <linux/slab.h>
26 #include <linux/smp_lock.h>
27 #include <linux/stddef.h>
28 #include <linux/thread_info.h>
29 #include <linux/unistd.h>
30 #include <linux/efi.h>
31 #include <linux/interrupt.h>
32 #include <linux/delay.h>
33 #include <linux/kprobes.h>
34 
35 #include <asm/cpu.h>
36 #include <asm/delay.h>
37 #include <asm/elf.h>
38 #include <asm/ia32.h>
39 #include <asm/irq.h>
40 #include <asm/kdebug.h>
41 #include <asm/pgalloc.h>
42 #include <asm/processor.h>
43 #include <asm/sal.h>
44 #include <asm/tlbflush.h>
45 #include <asm/uaccess.h>
46 #include <asm/unwind.h>
47 #include <asm/user.h>
48 
49 #include "entry.h"
50 
51 #ifdef CONFIG_PERFMON
52 # include <asm/perfmon.h>
53 #endif
54 
55 #include "sigframe.h"
56 
57 void (*ia64_mark_idle)(int);
58 static DEFINE_PER_CPU(unsigned int, cpu_idle_state);
59 
60 unsigned long boot_option_idle_override = 0;
61 EXPORT_SYMBOL(boot_option_idle_override);
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", current->pid, smp_processor_id(), current->comm);
113 	printk("psr : %016lx ifs : %016lx ip  : [<%016lx>]    %s\n",
114 	       regs->cr_ipsr, regs->cr_ifs, ip, print_tainted());
115 	print_symbol("ip is at %s\n", ip);
116 	printk("unat: %016lx pfs : %016lx rsc : %016lx\n",
117 	       regs->ar_unat, regs->ar_pfs, regs->ar_rsc);
118 	printk("rnat: %016lx bsps: %016lx pr  : %016lx\n",
119 	       regs->ar_rnat, regs->ar_bspstore, regs->pr);
120 	printk("ldrs: %016lx ccv : %016lx fpsr: %016lx\n",
121 	       regs->loadrs, regs->ar_ccv, regs->ar_fpsr);
122 	printk("csd : %016lx ssd : %016lx\n", regs->ar_csd, regs->ar_ssd);
123 	printk("b0  : %016lx b6  : %016lx b7  : %016lx\n", regs->b0, regs->b6, regs->b7);
124 	printk("f6  : %05lx%016lx f7  : %05lx%016lx\n",
125 	       regs->f6.u.bits[1], regs->f6.u.bits[0],
126 	       regs->f7.u.bits[1], regs->f7.u.bits[0]);
127 	printk("f8  : %05lx%016lx f9  : %05lx%016lx\n",
128 	       regs->f8.u.bits[1], regs->f8.u.bits[0],
129 	       regs->f9.u.bits[1], regs->f9.u.bits[0]);
130 	printk("f10 : %05lx%016lx f11 : %05lx%016lx\n",
131 	       regs->f10.u.bits[1], regs->f10.u.bits[0],
132 	       regs->f11.u.bits[1], regs->f11.u.bits[0]);
133 
134 	printk("r1  : %016lx r2  : %016lx r3  : %016lx\n", regs->r1, regs->r2, regs->r3);
135 	printk("r8  : %016lx r9  : %016lx r10 : %016lx\n", regs->r8, regs->r9, regs->r10);
136 	printk("r11 : %016lx r12 : %016lx r13 : %016lx\n", regs->r11, regs->r12, regs->r13);
137 	printk("r14 : %016lx r15 : %016lx r16 : %016lx\n", regs->r14, regs->r15, regs->r16);
138 	printk("r17 : %016lx r18 : %016lx r19 : %016lx\n", regs->r17, regs->r18, regs->r19);
139 	printk("r20 : %016lx r21 : %016lx r22 : %016lx\n", regs->r20, regs->r21, regs->r22);
140 	printk("r23 : %016lx r24 : %016lx r25 : %016lx\n", regs->r23, regs->r24, regs->r25);
141 	printk("r26 : %016lx r27 : %016lx r28 : %016lx\n", regs->r26, regs->r27, regs->r28);
142 	printk("r29 : %016lx r30 : %016lx r31 : %016lx\n", regs->r29, regs->r30, regs->r31);
143 
144 	if (user_mode(regs)) {
145 		/* print the stacked registers */
146 		unsigned long val, *bsp, ndirty;
147 		int i, sof, is_nat = 0;
148 
149 		sof = regs->cr_ifs & 0x7f;	/* size of frame */
150 		ndirty = (regs->loadrs >> 19);
151 		bsp = ia64_rse_skip_regs((unsigned long *) regs->ar_bspstore, ndirty);
152 		for (i = 0; i < sof; ++i) {
153 			get_user(val, (unsigned long __user *) ia64_rse_skip_regs(bsp, i));
154 			printk("r%-3u:%c%016lx%s", 32 + i, is_nat ? '*' : ' ', val,
155 			       ((i == sof - 1) || (i % 3) == 2) ? "\n" : " ");
156 		}
157 	} else
158 		show_stack(NULL, NULL);
159 }
160 
161 void
162 do_notify_resume_user (sigset_t *oldset, struct sigscratch *scr, long in_syscall)
163 {
164 	if (fsys_mode(current, &scr->pt)) {
165 		/* defer signal-handling etc. until we return to privilege-level 0.  */
166 		if (!ia64_psr(&scr->pt)->lp)
167 			ia64_psr(&scr->pt)->lp = 1;
168 		return;
169 	}
170 
171 #ifdef CONFIG_PERFMON
172 	if (current->thread.pfm_needs_checking)
173 		pfm_handle_work();
174 #endif
175 
176 	/* deal with pending signal delivery */
177 	if (test_thread_flag(TIF_SIGPENDING))
178 		ia64_do_signal(oldset, scr, in_syscall);
179 }
180 
181 static int pal_halt        = 1;
182 static int can_do_pal_halt = 1;
183 
184 static int __init nohalt_setup(char * str)
185 {
186 	pal_halt = can_do_pal_halt = 0;
187 	return 1;
188 }
189 __setup("nohalt", nohalt_setup);
190 
191 void
192 update_pal_halt_status(int status)
193 {
194 	can_do_pal_halt = pal_halt && status;
195 }
196 
197 /*
198  * We use this if we don't have any better idle routine..
199  */
200 void
201 default_idle (void)
202 {
203 	local_irq_enable();
204 	while (!need_resched()) {
205 		if (can_do_pal_halt)
206 			safe_halt();
207 		else
208 			cpu_relax();
209 	}
210 }
211 
212 #ifdef CONFIG_HOTPLUG_CPU
213 /* We don't actually take CPU down, just spin without interrupts. */
214 static inline void play_dead(void)
215 {
216 	extern void ia64_cpu_local_tick (void);
217 	unsigned int this_cpu = smp_processor_id();
218 
219 	/* Ack it */
220 	__get_cpu_var(cpu_state) = CPU_DEAD;
221 
222 	max_xtp();
223 	local_irq_disable();
224 	idle_task_exit();
225 	ia64_jump_to_sal(&sal_boot_rendez_state[this_cpu]);
226 	/*
227 	 * The above is a point of no-return, the processor is
228 	 * expected to be in SAL loop now.
229 	 */
230 	BUG();
231 }
232 #else
233 static inline void play_dead(void)
234 {
235 	BUG();
236 }
237 #endif /* CONFIG_HOTPLUG_CPU */
238 
239 void cpu_idle_wait(void)
240 {
241 	unsigned int cpu, this_cpu = get_cpu();
242 	cpumask_t map;
243 
244 	set_cpus_allowed(current, cpumask_of_cpu(this_cpu));
245 	put_cpu();
246 
247 	cpus_clear(map);
248 	for_each_online_cpu(cpu) {
249 		per_cpu(cpu_idle_state, cpu) = 1;
250 		cpu_set(cpu, map);
251 	}
252 
253 	__get_cpu_var(cpu_idle_state) = 0;
254 
255 	wmb();
256 	do {
257 		ssleep(1);
258 		for_each_online_cpu(cpu) {
259 			if (cpu_isset(cpu, map) && !per_cpu(cpu_idle_state, cpu))
260 				cpu_clear(cpu, map);
261 		}
262 		cpus_and(map, map, cpu_online_map);
263 	} while (!cpus_empty(map));
264 }
265 EXPORT_SYMBOL_GPL(cpu_idle_wait);
266 
267 void __attribute__((noreturn))
268 cpu_idle (void)
269 {
270 	void (*mark_idle)(int) = ia64_mark_idle;
271   	int cpu = smp_processor_id();
272 
273 	/* endless idle loop with no priority at all */
274 	while (1) {
275 		if (can_do_pal_halt)
276 			clear_thread_flag(TIF_POLLING_NRFLAG);
277 		else
278 			set_thread_flag(TIF_POLLING_NRFLAG);
279 
280 		if (!need_resched()) {
281 			void (*idle)(void);
282 #ifdef CONFIG_SMP
283 			min_xtp();
284 #endif
285 			if (__get_cpu_var(cpu_idle_state))
286 				__get_cpu_var(cpu_idle_state) = 0;
287 
288 			rmb();
289 			if (mark_idle)
290 				(*mark_idle)(1);
291 
292 			idle = pm_idle;
293 			if (!idle)
294 				idle = default_idle;
295 			(*idle)();
296 			if (mark_idle)
297 				(*mark_idle)(0);
298 #ifdef CONFIG_SMP
299 			normal_xtp();
300 #endif
301 		}
302 		preempt_enable_no_resched();
303 		schedule();
304 		preempt_disable();
305 		check_pgt_cache();
306 		if (cpu_is_offline(cpu))
307 			play_dead();
308 	}
309 }
310 
311 void
312 ia64_save_extra (struct task_struct *task)
313 {
314 #ifdef CONFIG_PERFMON
315 	unsigned long info;
316 #endif
317 
318 	if ((task->thread.flags & IA64_THREAD_DBG_VALID) != 0)
319 		ia64_save_debug_regs(&task->thread.dbr[0]);
320 
321 #ifdef CONFIG_PERFMON
322 	if ((task->thread.flags & IA64_THREAD_PM_VALID) != 0)
323 		pfm_save_regs(task);
324 
325 	info = __get_cpu_var(pfm_syst_info);
326 	if (info & PFM_CPUINFO_SYST_WIDE)
327 		pfm_syst_wide_update_task(task, info, 0);
328 #endif
329 
330 #ifdef CONFIG_IA32_SUPPORT
331 	if (IS_IA32_PROCESS(ia64_task_regs(task)))
332 		ia32_save_state(task);
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 #ifdef CONFIG_IA32_SUPPORT
356 	if (IS_IA32_PROCESS(ia64_task_regs(task)))
357 		ia32_load_state(task);
358 #endif
359 }
360 
361 /*
362  * Copy the state of an ia-64 thread.
363  *
364  * We get here through the following  call chain:
365  *
366  *	from user-level:	from kernel:
367  *
368  *	<clone syscall>	        <some kernel call frames>
369  *	sys_clone		   :
370  *	do_fork			do_fork
371  *	copy_thread		copy_thread
372  *
373  * This means that the stack layout is as follows:
374  *
375  *	+---------------------+ (highest addr)
376  *	|   struct pt_regs    |
377  *	+---------------------+
378  *	| struct switch_stack |
379  *	+---------------------+
380  *	|                     |
381  *	|    memory stack     |
382  *	|                     | <-- sp (lowest addr)
383  *	+---------------------+
384  *
385  * Observe that we copy the unat values that are in pt_regs and switch_stack.  Spilling an
386  * integer to address X causes bit N in ar.unat to be set to the NaT bit of the register,
387  * with N=(X & 0x1ff)/8.  Thus, copying the unat value preserves the NaT bits ONLY if the
388  * pt_regs structure in the parent is congruent to that of the child, modulo 512.  Since
389  * the stack is page aligned and the page size is at least 4KB, this is always the case,
390  * so there is nothing to worry about.
391  */
392 int
393 copy_thread (int nr, unsigned long clone_flags,
394 	     unsigned long user_stack_base, unsigned long user_stack_size,
395 	     struct task_struct *p, struct pt_regs *regs)
396 {
397 	extern char ia64_ret_from_clone, ia32_ret_from_clone;
398 	struct switch_stack *child_stack, *stack;
399 	unsigned long rbs, child_rbs, rbs_size;
400 	struct pt_regs *child_ptregs;
401 	int retval = 0;
402 
403 #ifdef CONFIG_SMP
404 	/*
405 	 * For SMP idle threads, fork_by_hand() calls do_fork with
406 	 * NULL regs.
407 	 */
408 	if (!regs)
409 		return 0;
410 #endif
411 
412 	stack = ((struct switch_stack *) regs) - 1;
413 
414 	child_ptregs = (struct pt_regs *) ((unsigned long) p + IA64_STK_OFFSET) - 1;
415 	child_stack = (struct switch_stack *) child_ptregs - 1;
416 
417 	/* copy parent's switch_stack & pt_regs to child: */
418 	memcpy(child_stack, stack, sizeof(*child_ptregs) + sizeof(*child_stack));
419 
420 	rbs = (unsigned long) current + IA64_RBS_OFFSET;
421 	child_rbs = (unsigned long) p + IA64_RBS_OFFSET;
422 	rbs_size = stack->ar_bspstore - rbs;
423 
424 	/* copy the parent's register backing store to the child: */
425 	memcpy((void *) child_rbs, (void *) rbs, rbs_size);
426 
427 	if (likely(user_mode(child_ptregs))) {
428 		if ((clone_flags & CLONE_SETTLS) && !IS_IA32_PROCESS(regs))
429 			child_ptregs->r13 = regs->r16;	/* see sys_clone2() in entry.S */
430 		if (user_stack_base) {
431 			child_ptregs->r12 = user_stack_base + user_stack_size - 16;
432 			child_ptregs->ar_bspstore = user_stack_base;
433 			child_ptregs->ar_rnat = 0;
434 			child_ptregs->loadrs = 0;
435 		}
436 	} else {
437 		/*
438 		 * Note: we simply preserve the relative position of
439 		 * the stack pointer here.  There is no need to
440 		 * allocate a scratch area here, since that will have
441 		 * been taken care of by the caller of sys_clone()
442 		 * already.
443 		 */
444 		child_ptregs->r12 = (unsigned long) child_ptregs - 16; /* kernel sp */
445 		child_ptregs->r13 = (unsigned long) p;		/* set `current' pointer */
446 	}
447 	child_stack->ar_bspstore = child_rbs + rbs_size;
448 	if (IS_IA32_PROCESS(regs))
449 		child_stack->b0 = (unsigned long) &ia32_ret_from_clone;
450 	else
451 		child_stack->b0 = (unsigned long) &ia64_ret_from_clone;
452 
453 	/* copy parts of thread_struct: */
454 	p->thread.ksp = (unsigned long) child_stack - 16;
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 	/*
465 	 * NOTE: The calling convention considers all floating point
466 	 * registers in the high partition (fph) to be scratch.  Since
467 	 * the only way to get to this point is through a system call,
468 	 * we know that the values in fph are all dead.  Hence, there
469 	 * is no need to inherit the fph state from the parent to the
470 	 * child and all we have to do is to make sure that
471 	 * IA64_THREAD_FPH_VALID is cleared in the child.
472 	 *
473 	 * XXX We could push this optimization a bit further by
474 	 * clearing IA64_THREAD_FPH_VALID on ANY system call.
475 	 * However, it's not clear this is worth doing.  Also, it
476 	 * would be a slight deviation from the normal Linux system
477 	 * call behavior where scratch registers are preserved across
478 	 * system calls (unless used by the system call itself).
479 	 */
480 #	define THREAD_FLAGS_TO_CLEAR	(IA64_THREAD_FPH_VALID | IA64_THREAD_DBG_VALID \
481 					 | IA64_THREAD_PM_VALID)
482 #	define THREAD_FLAGS_TO_SET	0
483 	p->thread.flags = ((current->thread.flags & ~THREAD_FLAGS_TO_CLEAR)
484 			   | THREAD_FLAGS_TO_SET);
485 	ia64_drop_fpu(p);	/* don't pick up stale state from a CPU's fph */
486 #ifdef CONFIG_IA32_SUPPORT
487 	/*
488 	 * If we're cloning an IA32 task then save the IA32 extra
489 	 * state from the current task to the new task
490 	 */
491 	if (IS_IA32_PROCESS(ia64_task_regs(current))) {
492 		ia32_save_state(p);
493 		if (clone_flags & CLONE_SETTLS)
494 			retval = ia32_clone_tls(p, child_ptregs);
495 
496 		/* Copy partially mapped page list */
497 		if (!retval)
498 			retval = ia32_copy_partial_page_list(p, clone_flags);
499 	}
500 #endif
501 
502 #ifdef CONFIG_PERFMON
503 	if (current->thread.pfm_context)
504 		pfm_inherit(p, child_ptregs);
505 #endif
506 	return retval;
507 }
508 
509 static void
510 do_copy_task_regs (struct task_struct *task, struct unw_frame_info *info, void *arg)
511 {
512 	unsigned long mask, sp, nat_bits = 0, ip, ar_rnat, urbs_end, cfm;
513 	elf_greg_t *dst = arg;
514 	struct pt_regs *pt;
515 	char nat;
516 	int i;
517 
518 	memset(dst, 0, sizeof(elf_gregset_t));	/* don't leak any kernel bits to user-level */
519 
520 	if (unw_unwind_to_user(info) < 0)
521 		return;
522 
523 	unw_get_sp(info, &sp);
524 	pt = (struct pt_regs *) (sp + 16);
525 
526 	urbs_end = ia64_get_user_rbs_end(task, pt, &cfm);
527 
528 	if (ia64_sync_user_rbs(task, info->sw, pt->ar_bspstore, urbs_end) < 0)
529 		return;
530 
531 	ia64_peek(task, info->sw, urbs_end, (long) ia64_rse_rnat_addr((long *) urbs_end),
532 		  &ar_rnat);
533 
534 	/*
535 	 * coredump format:
536 	 *	r0-r31
537 	 *	NaT bits (for r0-r31; bit N == 1 iff rN is a NaT)
538 	 *	predicate registers (p0-p63)
539 	 *	b0-b7
540 	 *	ip cfm user-mask
541 	 *	ar.rsc ar.bsp ar.bspstore ar.rnat
542 	 *	ar.ccv ar.unat ar.fpsr ar.pfs ar.lc ar.ec
543 	 */
544 
545 	/* r0 is zero */
546 	for (i = 1, mask = (1UL << i); i < 32; ++i) {
547 		unw_get_gr(info, i, &dst[i], &nat);
548 		if (nat)
549 			nat_bits |= mask;
550 		mask <<= 1;
551 	}
552 	dst[32] = nat_bits;
553 	unw_get_pr(info, &dst[33]);
554 
555 	for (i = 0; i < 8; ++i)
556 		unw_get_br(info, i, &dst[34 + i]);
557 
558 	unw_get_rp(info, &ip);
559 	dst[42] = ip + ia64_psr(pt)->ri;
560 	dst[43] = cfm;
561 	dst[44] = pt->cr_ipsr & IA64_PSR_UM;
562 
563 	unw_get_ar(info, UNW_AR_RSC, &dst[45]);
564 	/*
565 	 * For bsp and bspstore, unw_get_ar() would return the kernel
566 	 * addresses, but we need the user-level addresses instead:
567 	 */
568 	dst[46] = urbs_end;	/* note: by convention PT_AR_BSP points to the end of the urbs! */
569 	dst[47] = pt->ar_bspstore;
570 	dst[48] = ar_rnat;
571 	unw_get_ar(info, UNW_AR_CCV, &dst[49]);
572 	unw_get_ar(info, UNW_AR_UNAT, &dst[50]);
573 	unw_get_ar(info, UNW_AR_FPSR, &dst[51]);
574 	dst[52] = pt->ar_pfs;	/* UNW_AR_PFS is == to pt->cr_ifs for interrupt frames */
575 	unw_get_ar(info, UNW_AR_LC, &dst[53]);
576 	unw_get_ar(info, UNW_AR_EC, &dst[54]);
577 	unw_get_ar(info, UNW_AR_CSD, &dst[55]);
578 	unw_get_ar(info, UNW_AR_SSD, &dst[56]);
579 }
580 
581 void
582 do_dump_task_fpu (struct task_struct *task, struct unw_frame_info *info, void *arg)
583 {
584 	elf_fpreg_t *dst = arg;
585 	int i;
586 
587 	memset(dst, 0, sizeof(elf_fpregset_t));	/* don't leak any "random" bits */
588 
589 	if (unw_unwind_to_user(info) < 0)
590 		return;
591 
592 	/* f0 is 0.0, f1 is 1.0 */
593 
594 	for (i = 2; i < 32; ++i)
595 		unw_get_fr(info, i, dst + i);
596 
597 	ia64_flush_fph(task);
598 	if ((task->thread.flags & IA64_THREAD_FPH_VALID) != 0)
599 		memcpy(dst + 32, task->thread.fph, 96*16);
600 }
601 
602 void
603 do_copy_regs (struct unw_frame_info *info, void *arg)
604 {
605 	do_copy_task_regs(current, info, arg);
606 }
607 
608 void
609 do_dump_fpu (struct unw_frame_info *info, void *arg)
610 {
611 	do_dump_task_fpu(current, info, arg);
612 }
613 
614 int
615 dump_task_regs(struct task_struct *task, elf_gregset_t *regs)
616 {
617 	struct unw_frame_info tcore_info;
618 
619 	if (current == task) {
620 		unw_init_running(do_copy_regs, regs);
621 	} else {
622 		memset(&tcore_info, 0, sizeof(tcore_info));
623 		unw_init_from_blocked_task(&tcore_info, task);
624 		do_copy_task_regs(task, &tcore_info, regs);
625 	}
626 	return 1;
627 }
628 
629 void
630 ia64_elf_core_copy_regs (struct pt_regs *pt, elf_gregset_t dst)
631 {
632 	unw_init_running(do_copy_regs, dst);
633 }
634 
635 int
636 dump_task_fpu (struct task_struct *task, elf_fpregset_t *dst)
637 {
638 	struct unw_frame_info tcore_info;
639 
640 	if (current == task) {
641 		unw_init_running(do_dump_fpu, dst);
642 	} else {
643 		memset(&tcore_info, 0, sizeof(tcore_info));
644 		unw_init_from_blocked_task(&tcore_info, task);
645 		do_dump_task_fpu(task, &tcore_info, dst);
646 	}
647 	return 1;
648 }
649 
650 int
651 dump_fpu (struct pt_regs *pt, elf_fpregset_t dst)
652 {
653 	unw_init_running(do_dump_fpu, dst);
654 	return 1;	/* f0-f31 are always valid so we always return 1 */
655 }
656 
657 long
658 sys_execve (char __user *filename, char __user * __user *argv, char __user * __user *envp,
659 	    struct pt_regs *regs)
660 {
661 	char *fname;
662 	int error;
663 
664 	fname = getname(filename);
665 	error = PTR_ERR(fname);
666 	if (IS_ERR(fname))
667 		goto out;
668 	error = do_execve(fname, argv, envp, regs);
669 	putname(fname);
670 out:
671 	return error;
672 }
673 
674 pid_t
675 kernel_thread (int (*fn)(void *), void *arg, unsigned long flags)
676 {
677 	extern void start_kernel_thread (void);
678 	unsigned long *helper_fptr = (unsigned long *) &start_kernel_thread;
679 	struct {
680 		struct switch_stack sw;
681 		struct pt_regs pt;
682 	} regs;
683 
684 	memset(&regs, 0, sizeof(regs));
685 	regs.pt.cr_iip = helper_fptr[0];	/* set entry point (IP) */
686 	regs.pt.r1 = helper_fptr[1];		/* set GP */
687 	regs.pt.r9 = (unsigned long) fn;	/* 1st argument */
688 	regs.pt.r11 = (unsigned long) arg;	/* 2nd argument */
689 	/* Preserve PSR bits, except for bits 32-34 and 37-45, which we can't read.  */
690 	regs.pt.cr_ipsr = ia64_getreg(_IA64_REG_PSR) | IA64_PSR_BN;
691 	regs.pt.cr_ifs = 1UL << 63;		/* mark as valid, empty frame */
692 	regs.sw.ar_fpsr = regs.pt.ar_fpsr = ia64_getreg(_IA64_REG_AR_FPSR);
693 	regs.sw.ar_bspstore = (unsigned long) current + IA64_RBS_OFFSET;
694 	regs.sw.pr = (1 << PRED_KERNEL_STACK);
695 	return do_fork(flags | CLONE_VM | CLONE_UNTRACED, 0, &regs.pt, 0, NULL, NULL);
696 }
697 EXPORT_SYMBOL(kernel_thread);
698 
699 /* This gets called from kernel_thread() via ia64_invoke_thread_helper().  */
700 int
701 kernel_thread_helper (int (*fn)(void *), void *arg)
702 {
703 #ifdef CONFIG_IA32_SUPPORT
704 	if (IS_IA32_PROCESS(ia64_task_regs(current))) {
705 		/* A kernel thread is always a 64-bit process. */
706 		current->thread.map_base  = DEFAULT_MAP_BASE;
707 		current->thread.task_size = DEFAULT_TASK_SIZE;
708 		ia64_set_kr(IA64_KR_IO_BASE, current->thread.old_iob);
709 		ia64_set_kr(IA64_KR_TSSD, current->thread.old_k1);
710 	}
711 #endif
712 	return (*fn)(arg);
713 }
714 
715 /*
716  * Flush thread state.  This is called when a thread does an execve().
717  */
718 void
719 flush_thread (void)
720 {
721 	/* drop floating-point and debug-register state if it exists: */
722 	current->thread.flags &= ~(IA64_THREAD_FPH_VALID | IA64_THREAD_DBG_VALID);
723 	ia64_drop_fpu(current);
724 #ifdef CONFIG_IA32_SUPPORT
725 	if (IS_IA32_PROCESS(ia64_task_regs(current))) {
726 		ia32_drop_partial_page_list(current);
727 		current->thread.task_size = IA32_PAGE_OFFSET;
728 		set_fs(USER_DS);
729 	}
730 #endif
731 }
732 
733 /*
734  * Clean up state associated with current thread.  This is called when
735  * the thread calls exit().
736  */
737 void
738 exit_thread (void)
739 {
740 
741 	/*
742 	 * Remove function-return probe instances associated with this task
743 	 * and put them back on the free list. Do not insert an exit probe for
744 	 * this function, it will be disabled by kprobe_flush_task if you do.
745 	 */
746 	kprobe_flush_task(current);
747 
748 	ia64_drop_fpu(current);
749 #ifdef CONFIG_PERFMON
750        /* if needed, stop monitoring and flush state to perfmon context */
751 	if (current->thread.pfm_context)
752 		pfm_exit_thread(current);
753 
754 	/* free debug register resources */
755 	if (current->thread.flags & IA64_THREAD_DBG_VALID)
756 		pfm_release_debug_registers(current);
757 #endif
758 	if (IS_IA32_PROCESS(ia64_task_regs(current)))
759 		ia32_drop_partial_page_list(current);
760 }
761 
762 unsigned long
763 get_wchan (struct task_struct *p)
764 {
765 	struct unw_frame_info info;
766 	unsigned long ip;
767 	int count = 0;
768 
769 	/*
770 	 * Note: p may not be a blocked task (it could be current or
771 	 * another process running on some other CPU.  Rather than
772 	 * trying to determine if p is really blocked, we just assume
773 	 * it's blocked and rely on the unwind routines to fail
774 	 * gracefully if the process wasn't really blocked after all.
775 	 * --davidm 99/12/15
776 	 */
777 	unw_init_from_blocked_task(&info, p);
778 	do {
779 		if (unw_unwind(&info) < 0)
780 			return 0;
781 		unw_get_ip(&info, &ip);
782 		if (!in_sched_functions(ip))
783 			return ip;
784 	} while (count++ < 16);
785 	return 0;
786 }
787 
788 void
789 cpu_halt (void)
790 {
791 	pal_power_mgmt_info_u_t power_info[8];
792 	unsigned long min_power;
793 	int i, min_power_state;
794 
795 	if (ia64_pal_halt_info(power_info) != 0)
796 		return;
797 
798 	min_power_state = 0;
799 	min_power = power_info[0].pal_power_mgmt_info_s.power_consumption;
800 	for (i = 1; i < 8; ++i)
801 		if (power_info[i].pal_power_mgmt_info_s.im
802 		    && power_info[i].pal_power_mgmt_info_s.power_consumption < min_power) {
803 			min_power = power_info[i].pal_power_mgmt_info_s.power_consumption;
804 			min_power_state = i;
805 		}
806 
807 	while (1)
808 		ia64_pal_halt(min_power_state);
809 }
810 
811 void
812 machine_restart (char *restart_cmd)
813 {
814 	(void) notify_die(DIE_MACHINE_RESTART, restart_cmd, NULL, 0, 0, 0);
815 	(*efi.reset_system)(EFI_RESET_WARM, 0, 0, NULL);
816 }
817 
818 void
819 machine_halt (void)
820 {
821 	(void) notify_die(DIE_MACHINE_HALT, "", NULL, 0, 0, 0);
822 	cpu_halt();
823 }
824 
825 void
826 machine_power_off (void)
827 {
828 	if (pm_power_off)
829 		pm_power_off();
830 	machine_halt();
831 }
832 
833