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1 // SPDX-License-Identifier: GPL-2.0
2 /*
3  * Architecture-specific setup.
4  *
5  * Copyright (C) 1998-2003 Hewlett-Packard Co
6  *	David Mosberger-Tang <davidm@hpl.hp.com>
7  * 04/11/17 Ashok Raj	<ashok.raj@intel.com> Added CPU Hotplug Support
8  *
9  * 2005-10-07 Keith Owens <kaos@sgi.com>
10  *	      Add notify_die() hooks.
11  */
12 #include <linux/cpu.h>
13 #include <linux/pm.h>
14 #include <linux/elf.h>
15 #include <linux/errno.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/sched/debug.h>
24 #include <linux/sched/hotplug.h>
25 #include <linux/sched/task.h>
26 #include <linux/sched/task_stack.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/kdebug.h>
34 #include <linux/utsname.h>
35 #include <linux/tracehook.h>
36 #include <linux/rcupdate.h>
37 
38 #include <asm/cpu.h>
39 #include <asm/delay.h>
40 #include <asm/elf.h>
41 #include <asm/irq.h>
42 #include <asm/kexec.h>
43 #include <asm/pgalloc.h>
44 #include <asm/processor.h>
45 #include <asm/sal.h>
46 #include <asm/switch_to.h>
47 #include <asm/tlbflush.h>
48 #include <linux/uaccess.h>
49 #include <asm/unwind.h>
50 #include <asm/user.h>
51 
52 #include "entry.h"
53 
54 #ifdef CONFIG_PERFMON
55 # include <asm/perfmon.h>
56 #endif
57 
58 #include "sigframe.h"
59 
60 void (*ia64_mark_idle)(int);
61 
62 unsigned long boot_option_idle_override = IDLE_NO_OVERRIDE;
63 EXPORT_SYMBOL(boot_option_idle_override);
64 void (*pm_power_off) (void);
65 EXPORT_SYMBOL(pm_power_off);
66 
67 void
ia64_do_show_stack(struct unw_frame_info * info,void * arg)68 ia64_do_show_stack (struct unw_frame_info *info, void *arg)
69 {
70 	unsigned long ip, sp, bsp;
71 
72 	printk("\nCall Trace:\n");
73 	do {
74 		unw_get_ip(info, &ip);
75 		if (ip == 0)
76 			break;
77 
78 		unw_get_sp(info, &sp);
79 		unw_get_bsp(info, &bsp);
80 		printk(" [<%016lx>] %pS\n"
81 			 "                                sp=%016lx bsp=%016lx\n",
82 			 ip, (void *)ip, sp, bsp);
83 	} while (unw_unwind(info) >= 0);
84 }
85 
86 void
show_stack(struct task_struct * task,unsigned long * sp)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
show_regs(struct pt_regs * regs)100 show_regs (struct pt_regs *regs)
101 {
102 	unsigned long ip = regs->cr_iip + ia64_psr(regs)->ri;
103 
104 	print_modules();
105 	printk("\n");
106 	show_regs_print_info(KERN_DEFAULT);
107 	printk("psr : %016lx ifs : %016lx ip  : [<%016lx>]    %s (%s)\n",
108 	       regs->cr_ipsr, regs->cr_ifs, ip, print_tainted(),
109 	       init_utsname()->release);
110 	printk("ip is at %pS\n", (void *)ip);
111 	printk("unat: %016lx pfs : %016lx rsc : %016lx\n",
112 	       regs->ar_unat, regs->ar_pfs, regs->ar_rsc);
113 	printk("rnat: %016lx bsps: %016lx pr  : %016lx\n",
114 	       regs->ar_rnat, regs->ar_bspstore, regs->pr);
115 	printk("ldrs: %016lx ccv : %016lx fpsr: %016lx\n",
116 	       regs->loadrs, regs->ar_ccv, regs->ar_fpsr);
117 	printk("csd : %016lx ssd : %016lx\n", regs->ar_csd, regs->ar_ssd);
118 	printk("b0  : %016lx b6  : %016lx b7  : %016lx\n", regs->b0, regs->b6, regs->b7);
119 	printk("f6  : %05lx%016lx f7  : %05lx%016lx\n",
120 	       regs->f6.u.bits[1], regs->f6.u.bits[0],
121 	       regs->f7.u.bits[1], regs->f7.u.bits[0]);
122 	printk("f8  : %05lx%016lx f9  : %05lx%016lx\n",
123 	       regs->f8.u.bits[1], regs->f8.u.bits[0],
124 	       regs->f9.u.bits[1], regs->f9.u.bits[0]);
125 	printk("f10 : %05lx%016lx f11 : %05lx%016lx\n",
126 	       regs->f10.u.bits[1], regs->f10.u.bits[0],
127 	       regs->f11.u.bits[1], regs->f11.u.bits[0]);
128 
129 	printk("r1  : %016lx r2  : %016lx r3  : %016lx\n", regs->r1, regs->r2, regs->r3);
130 	printk("r8  : %016lx r9  : %016lx r10 : %016lx\n", regs->r8, regs->r9, regs->r10);
131 	printk("r11 : %016lx r12 : %016lx r13 : %016lx\n", regs->r11, regs->r12, regs->r13);
132 	printk("r14 : %016lx r15 : %016lx r16 : %016lx\n", regs->r14, regs->r15, regs->r16);
133 	printk("r17 : %016lx r18 : %016lx r19 : %016lx\n", regs->r17, regs->r18, regs->r19);
134 	printk("r20 : %016lx r21 : %016lx r22 : %016lx\n", regs->r20, regs->r21, regs->r22);
135 	printk("r23 : %016lx r24 : %016lx r25 : %016lx\n", regs->r23, regs->r24, regs->r25);
136 	printk("r26 : %016lx r27 : %016lx r28 : %016lx\n", regs->r26, regs->r27, regs->r28);
137 	printk("r29 : %016lx r30 : %016lx r31 : %016lx\n", regs->r29, regs->r30, regs->r31);
138 
139 	if (user_mode(regs)) {
140 		/* print the stacked registers */
141 		unsigned long val, *bsp, ndirty;
142 		int i, sof, is_nat = 0;
143 
144 		sof = regs->cr_ifs & 0x7f;	/* size of frame */
145 		ndirty = (regs->loadrs >> 19);
146 		bsp = ia64_rse_skip_regs((unsigned long *) regs->ar_bspstore, ndirty);
147 		for (i = 0; i < sof; ++i) {
148 			get_user(val, (unsigned long __user *) ia64_rse_skip_regs(bsp, i));
149 			printk("r%-3u:%c%016lx%s", 32 + i, is_nat ? '*' : ' ', val,
150 			       ((i == sof - 1) || (i % 3) == 2) ? "\n" : " ");
151 		}
152 	} else
153 		show_stack(NULL, NULL);
154 }
155 
156 /* local support for deprecated console_print */
157 void
console_print(const char * s)158 console_print(const char *s)
159 {
160 	printk(KERN_EMERG "%s", s);
161 }
162 
163 void
do_notify_resume_user(sigset_t * unused,struct sigscratch * scr,long in_syscall)164 do_notify_resume_user(sigset_t *unused, struct sigscratch *scr, long in_syscall)
165 {
166 	if (fsys_mode(current, &scr->pt)) {
167 		/*
168 		 * defer signal-handling etc. until we return to
169 		 * privilege-level 0.
170 		 */
171 		if (!ia64_psr(&scr->pt)->lp)
172 			ia64_psr(&scr->pt)->lp = 1;
173 		return;
174 	}
175 
176 #ifdef CONFIG_PERFMON
177 	if (current->thread.pfm_needs_checking)
178 		/*
179 		 * Note: pfm_handle_work() allow us to call it with interrupts
180 		 * disabled, and may enable interrupts within the function.
181 		 */
182 		pfm_handle_work();
183 #endif
184 
185 	/* deal with pending signal delivery */
186 	if (test_thread_flag(TIF_SIGPENDING)) {
187 		local_irq_enable();	/* force interrupt enable */
188 		ia64_do_signal(scr, in_syscall);
189 	}
190 
191 	if (test_and_clear_thread_flag(TIF_NOTIFY_RESUME)) {
192 		local_irq_enable();	/* force interrupt enable */
193 		tracehook_notify_resume(&scr->pt);
194 	}
195 
196 	/* copy user rbs to kernel rbs */
197 	if (unlikely(test_thread_flag(TIF_RESTORE_RSE))) {
198 		local_irq_enable();	/* force interrupt enable */
199 		ia64_sync_krbs();
200 	}
201 
202 	local_irq_disable();	/* force interrupt disable */
203 }
204 
nohalt_setup(char * str)205 static int __init nohalt_setup(char * str)
206 {
207 	cpu_idle_poll_ctrl(true);
208 	return 1;
209 }
210 __setup("nohalt", nohalt_setup);
211 
212 #ifdef CONFIG_HOTPLUG_CPU
213 /* We don't actually take CPU down, just spin without interrupts. */
play_dead(void)214 static inline void play_dead(void)
215 {
216 	unsigned int this_cpu = smp_processor_id();
217 
218 	/* Ack it */
219 	__this_cpu_write(cpu_state, CPU_DEAD);
220 
221 	max_xtp();
222 	local_irq_disable();
223 	idle_task_exit();
224 	ia64_jump_to_sal(&sal_boot_rendez_state[this_cpu]);
225 	/*
226 	 * The above is a point of no-return, the processor is
227 	 * expected to be in SAL loop now.
228 	 */
229 	BUG();
230 }
231 #else
play_dead(void)232 static inline void play_dead(void)
233 {
234 	BUG();
235 }
236 #endif /* CONFIG_HOTPLUG_CPU */
237 
arch_cpu_idle_dead(void)238 void arch_cpu_idle_dead(void)
239 {
240 	play_dead();
241 }
242 
arch_cpu_idle(void)243 void arch_cpu_idle(void)
244 {
245 	void (*mark_idle)(int) = ia64_mark_idle;
246 
247 #ifdef CONFIG_SMP
248 	min_xtp();
249 #endif
250 	rmb();
251 	if (mark_idle)
252 		(*mark_idle)(1);
253 
254 	safe_halt();
255 
256 	if (mark_idle)
257 		(*mark_idle)(0);
258 #ifdef CONFIG_SMP
259 	normal_xtp();
260 #endif
261 }
262 
263 void
ia64_save_extra(struct task_struct * task)264 ia64_save_extra (struct task_struct *task)
265 {
266 #ifdef CONFIG_PERFMON
267 	unsigned long info;
268 #endif
269 
270 	if ((task->thread.flags & IA64_THREAD_DBG_VALID) != 0)
271 		ia64_save_debug_regs(&task->thread.dbr[0]);
272 
273 #ifdef CONFIG_PERFMON
274 	if ((task->thread.flags & IA64_THREAD_PM_VALID) != 0)
275 		pfm_save_regs(task);
276 
277 	info = __this_cpu_read(pfm_syst_info);
278 	if (info & PFM_CPUINFO_SYST_WIDE)
279 		pfm_syst_wide_update_task(task, info, 0);
280 #endif
281 }
282 
283 void
ia64_load_extra(struct task_struct * task)284 ia64_load_extra (struct task_struct *task)
285 {
286 #ifdef CONFIG_PERFMON
287 	unsigned long info;
288 #endif
289 
290 	if ((task->thread.flags & IA64_THREAD_DBG_VALID) != 0)
291 		ia64_load_debug_regs(&task->thread.dbr[0]);
292 
293 #ifdef CONFIG_PERFMON
294 	if ((task->thread.flags & IA64_THREAD_PM_VALID) != 0)
295 		pfm_load_regs(task);
296 
297 	info = __this_cpu_read(pfm_syst_info);
298 	if (info & PFM_CPUINFO_SYST_WIDE)
299 		pfm_syst_wide_update_task(task, info, 1);
300 #endif
301 }
302 
303 /*
304  * Copy the state of an ia-64 thread.
305  *
306  * We get here through the following  call chain:
307  *
308  *	from user-level:	from kernel:
309  *
310  *	<clone syscall>	        <some kernel call frames>
311  *	sys_clone		   :
312  *	do_fork			do_fork
313  *	copy_thread		copy_thread
314  *
315  * This means that the stack layout is as follows:
316  *
317  *	+---------------------+ (highest addr)
318  *	|   struct pt_regs    |
319  *	+---------------------+
320  *	| struct switch_stack |
321  *	+---------------------+
322  *	|                     |
323  *	|    memory stack     |
324  *	|                     | <-- sp (lowest addr)
325  *	+---------------------+
326  *
327  * Observe that we copy the unat values that are in pt_regs and switch_stack.  Spilling an
328  * integer to address X causes bit N in ar.unat to be set to the NaT bit of the register,
329  * with N=(X & 0x1ff)/8.  Thus, copying the unat value preserves the NaT bits ONLY if the
330  * pt_regs structure in the parent is congruent to that of the child, modulo 512.  Since
331  * the stack is page aligned and the page size is at least 4KB, this is always the case,
332  * so there is nothing to worry about.
333  */
334 int
copy_thread(unsigned long clone_flags,unsigned long user_stack_base,unsigned long user_stack_size,struct task_struct * p)335 copy_thread(unsigned long clone_flags,
336 	     unsigned long user_stack_base, unsigned long user_stack_size,
337 	     struct task_struct *p)
338 {
339 	extern char ia64_ret_from_clone;
340 	struct switch_stack *child_stack, *stack;
341 	unsigned long rbs, child_rbs, rbs_size;
342 	struct pt_regs *child_ptregs;
343 	struct pt_regs *regs = current_pt_regs();
344 	int retval = 0;
345 
346 	child_ptregs = (struct pt_regs *) ((unsigned long) p + IA64_STK_OFFSET) - 1;
347 	child_stack = (struct switch_stack *) child_ptregs - 1;
348 
349 	rbs = (unsigned long) current + IA64_RBS_OFFSET;
350 	child_rbs = (unsigned long) p + IA64_RBS_OFFSET;
351 
352 	/* copy parts of thread_struct: */
353 	p->thread.ksp = (unsigned long) child_stack - 16;
354 
355 	/*
356 	 * NOTE: The calling convention considers all floating point
357 	 * registers in the high partition (fph) to be scratch.  Since
358 	 * the only way to get to this point is through a system call,
359 	 * we know that the values in fph are all dead.  Hence, there
360 	 * is no need to inherit the fph state from the parent to the
361 	 * child and all we have to do is to make sure that
362 	 * IA64_THREAD_FPH_VALID is cleared in the child.
363 	 *
364 	 * XXX We could push this optimization a bit further by
365 	 * clearing IA64_THREAD_FPH_VALID on ANY system call.
366 	 * However, it's not clear this is worth doing.  Also, it
367 	 * would be a slight deviation from the normal Linux system
368 	 * call behavior where scratch registers are preserved across
369 	 * system calls (unless used by the system call itself).
370 	 */
371 #	define THREAD_FLAGS_TO_CLEAR	(IA64_THREAD_FPH_VALID | IA64_THREAD_DBG_VALID \
372 					 | IA64_THREAD_PM_VALID)
373 #	define THREAD_FLAGS_TO_SET	0
374 	p->thread.flags = ((current->thread.flags & ~THREAD_FLAGS_TO_CLEAR)
375 			   | THREAD_FLAGS_TO_SET);
376 
377 	ia64_drop_fpu(p);	/* don't pick up stale state from a CPU's fph */
378 
379 	if (unlikely(p->flags & PF_KTHREAD)) {
380 		if (unlikely(!user_stack_base)) {
381 			/* fork_idle() called us */
382 			return 0;
383 		}
384 		memset(child_stack, 0, sizeof(*child_ptregs) + sizeof(*child_stack));
385 		child_stack->r4 = user_stack_base;	/* payload */
386 		child_stack->r5 = user_stack_size;	/* argument */
387 		/*
388 		 * Preserve PSR bits, except for bits 32-34 and 37-45,
389 		 * which we can't read.
390 		 */
391 		child_ptregs->cr_ipsr = ia64_getreg(_IA64_REG_PSR) | IA64_PSR_BN;
392 		/* mark as valid, empty frame */
393 		child_ptregs->cr_ifs = 1UL << 63;
394 		child_stack->ar_fpsr = child_ptregs->ar_fpsr
395 			= ia64_getreg(_IA64_REG_AR_FPSR);
396 		child_stack->pr = (1 << PRED_KERNEL_STACK);
397 		child_stack->ar_bspstore = child_rbs;
398 		child_stack->b0 = (unsigned long) &ia64_ret_from_clone;
399 
400 		/* stop some PSR bits from being inherited.
401 		 * the psr.up/psr.pp bits must be cleared on fork but inherited on execve()
402 		 * therefore we must specify them explicitly here and not include them in
403 		 * IA64_PSR_BITS_TO_CLEAR.
404 		 */
405 		child_ptregs->cr_ipsr = ((child_ptregs->cr_ipsr | IA64_PSR_BITS_TO_SET)
406 				 & ~(IA64_PSR_BITS_TO_CLEAR | IA64_PSR_PP | IA64_PSR_UP));
407 
408 		return 0;
409 	}
410 	stack = ((struct switch_stack *) regs) - 1;
411 	/* copy parent's switch_stack & pt_regs to child: */
412 	memcpy(child_stack, stack, sizeof(*child_ptregs) + sizeof(*child_stack));
413 
414 	/* copy the parent's register backing store to the child: */
415 	rbs_size = stack->ar_bspstore - rbs;
416 	memcpy((void *) child_rbs, (void *) rbs, rbs_size);
417 	if (clone_flags & CLONE_SETTLS)
418 		child_ptregs->r13 = regs->r16;	/* see sys_clone2() in entry.S */
419 	if (user_stack_base) {
420 		child_ptregs->r12 = user_stack_base + user_stack_size - 16;
421 		child_ptregs->ar_bspstore = user_stack_base;
422 		child_ptregs->ar_rnat = 0;
423 		child_ptregs->loadrs = 0;
424 	}
425 	child_stack->ar_bspstore = child_rbs + rbs_size;
426 	child_stack->b0 = (unsigned long) &ia64_ret_from_clone;
427 
428 	/* stop some PSR bits from being inherited.
429 	 * the psr.up/psr.pp bits must be cleared on fork but inherited on execve()
430 	 * therefore we must specify them explicitly here and not include them in
431 	 * IA64_PSR_BITS_TO_CLEAR.
432 	 */
433 	child_ptregs->cr_ipsr = ((child_ptregs->cr_ipsr | IA64_PSR_BITS_TO_SET)
434 				 & ~(IA64_PSR_BITS_TO_CLEAR | IA64_PSR_PP | IA64_PSR_UP));
435 
436 #ifdef CONFIG_PERFMON
437 	if (current->thread.pfm_context)
438 		pfm_inherit(p, child_ptregs);
439 #endif
440 	return retval;
441 }
442 
443 static void
do_copy_task_regs(struct task_struct * task,struct unw_frame_info * info,void * arg)444 do_copy_task_regs (struct task_struct *task, struct unw_frame_info *info, void *arg)
445 {
446 	unsigned long mask, sp, nat_bits = 0, ar_rnat, urbs_end, cfm;
447 	unsigned long ip;
448 	elf_greg_t *dst = arg;
449 	struct pt_regs *pt;
450 	char nat;
451 	int i;
452 
453 	memset(dst, 0, sizeof(elf_gregset_t));	/* don't leak any kernel bits to user-level */
454 
455 	if (unw_unwind_to_user(info) < 0)
456 		return;
457 
458 	unw_get_sp(info, &sp);
459 	pt = (struct pt_regs *) (sp + 16);
460 
461 	urbs_end = ia64_get_user_rbs_end(task, pt, &cfm);
462 
463 	if (ia64_sync_user_rbs(task, info->sw, pt->ar_bspstore, urbs_end) < 0)
464 		return;
465 
466 	ia64_peek(task, info->sw, urbs_end, (long) ia64_rse_rnat_addr((long *) urbs_end),
467 		  &ar_rnat);
468 
469 	/*
470 	 * coredump format:
471 	 *	r0-r31
472 	 *	NaT bits (for r0-r31; bit N == 1 iff rN is a NaT)
473 	 *	predicate registers (p0-p63)
474 	 *	b0-b7
475 	 *	ip cfm user-mask
476 	 *	ar.rsc ar.bsp ar.bspstore ar.rnat
477 	 *	ar.ccv ar.unat ar.fpsr ar.pfs ar.lc ar.ec
478 	 */
479 
480 	/* r0 is zero */
481 	for (i = 1, mask = (1UL << i); i < 32; ++i) {
482 		unw_get_gr(info, i, &dst[i], &nat);
483 		if (nat)
484 			nat_bits |= mask;
485 		mask <<= 1;
486 	}
487 	dst[32] = nat_bits;
488 	unw_get_pr(info, &dst[33]);
489 
490 	for (i = 0; i < 8; ++i)
491 		unw_get_br(info, i, &dst[34 + i]);
492 
493 	unw_get_rp(info, &ip);
494 	dst[42] = ip + ia64_psr(pt)->ri;
495 	dst[43] = cfm;
496 	dst[44] = pt->cr_ipsr & IA64_PSR_UM;
497 
498 	unw_get_ar(info, UNW_AR_RSC, &dst[45]);
499 	/*
500 	 * For bsp and bspstore, unw_get_ar() would return the kernel
501 	 * addresses, but we need the user-level addresses instead:
502 	 */
503 	dst[46] = urbs_end;	/* note: by convention PT_AR_BSP points to the end of the urbs! */
504 	dst[47] = pt->ar_bspstore;
505 	dst[48] = ar_rnat;
506 	unw_get_ar(info, UNW_AR_CCV, &dst[49]);
507 	unw_get_ar(info, UNW_AR_UNAT, &dst[50]);
508 	unw_get_ar(info, UNW_AR_FPSR, &dst[51]);
509 	dst[52] = pt->ar_pfs;	/* UNW_AR_PFS is == to pt->cr_ifs for interrupt frames */
510 	unw_get_ar(info, UNW_AR_LC, &dst[53]);
511 	unw_get_ar(info, UNW_AR_EC, &dst[54]);
512 	unw_get_ar(info, UNW_AR_CSD, &dst[55]);
513 	unw_get_ar(info, UNW_AR_SSD, &dst[56]);
514 }
515 
516 void
do_dump_task_fpu(struct task_struct * task,struct unw_frame_info * info,void * arg)517 do_dump_task_fpu (struct task_struct *task, struct unw_frame_info *info, void *arg)
518 {
519 	elf_fpreg_t *dst = arg;
520 	int i;
521 
522 	memset(dst, 0, sizeof(elf_fpregset_t));	/* don't leak any "random" bits */
523 
524 	if (unw_unwind_to_user(info) < 0)
525 		return;
526 
527 	/* f0 is 0.0, f1 is 1.0 */
528 
529 	for (i = 2; i < 32; ++i)
530 		unw_get_fr(info, i, dst + i);
531 
532 	ia64_flush_fph(task);
533 	if ((task->thread.flags & IA64_THREAD_FPH_VALID) != 0)
534 		memcpy(dst + 32, task->thread.fph, 96*16);
535 }
536 
537 void
do_copy_regs(struct unw_frame_info * info,void * arg)538 do_copy_regs (struct unw_frame_info *info, void *arg)
539 {
540 	do_copy_task_regs(current, info, arg);
541 }
542 
543 void
do_dump_fpu(struct unw_frame_info * info,void * arg)544 do_dump_fpu (struct unw_frame_info *info, void *arg)
545 {
546 	do_dump_task_fpu(current, info, arg);
547 }
548 
549 void
ia64_elf_core_copy_regs(struct pt_regs * pt,elf_gregset_t dst)550 ia64_elf_core_copy_regs (struct pt_regs *pt, elf_gregset_t dst)
551 {
552 	unw_init_running(do_copy_regs, dst);
553 }
554 
555 int
dump_fpu(struct pt_regs * pt,elf_fpregset_t dst)556 dump_fpu (struct pt_regs *pt, elf_fpregset_t dst)
557 {
558 	unw_init_running(do_dump_fpu, dst);
559 	return 1;	/* f0-f31 are always valid so we always return 1 */
560 }
561 
562 /*
563  * Flush thread state.  This is called when a thread does an execve().
564  */
565 void
flush_thread(void)566 flush_thread (void)
567 {
568 	/* drop floating-point and debug-register state if it exists: */
569 	current->thread.flags &= ~(IA64_THREAD_FPH_VALID | IA64_THREAD_DBG_VALID);
570 	ia64_drop_fpu(current);
571 }
572 
573 /*
574  * Clean up state associated with a thread.  This is called when
575  * the thread calls exit().
576  */
577 void
exit_thread(struct task_struct * tsk)578 exit_thread (struct task_struct *tsk)
579 {
580 
581 	ia64_drop_fpu(tsk);
582 #ifdef CONFIG_PERFMON
583        /* if needed, stop monitoring and flush state to perfmon context */
584 	if (tsk->thread.pfm_context)
585 		pfm_exit_thread(tsk);
586 
587 	/* free debug register resources */
588 	if (tsk->thread.flags & IA64_THREAD_DBG_VALID)
589 		pfm_release_debug_registers(tsk);
590 #endif
591 }
592 
593 unsigned long
get_wchan(struct task_struct * p)594 get_wchan (struct task_struct *p)
595 {
596 	struct unw_frame_info info;
597 	unsigned long ip;
598 	int count = 0;
599 
600 	if (!p || p == current || p->state == TASK_RUNNING)
601 		return 0;
602 
603 	/*
604 	 * Note: p may not be a blocked task (it could be current or
605 	 * another process running on some other CPU.  Rather than
606 	 * trying to determine if p is really blocked, we just assume
607 	 * it's blocked and rely on the unwind routines to fail
608 	 * gracefully if the process wasn't really blocked after all.
609 	 * --davidm 99/12/15
610 	 */
611 	unw_init_from_blocked_task(&info, p);
612 	do {
613 		if (p->state == TASK_RUNNING)
614 			return 0;
615 		if (unw_unwind(&info) < 0)
616 			return 0;
617 		unw_get_ip(&info, &ip);
618 		if (!in_sched_functions(ip))
619 			return ip;
620 	} while (count++ < 16);
621 	return 0;
622 }
623 
624 void
cpu_halt(void)625 cpu_halt (void)
626 {
627 	pal_power_mgmt_info_u_t power_info[8];
628 	unsigned long min_power;
629 	int i, min_power_state;
630 
631 	if (ia64_pal_halt_info(power_info) != 0)
632 		return;
633 
634 	min_power_state = 0;
635 	min_power = power_info[0].pal_power_mgmt_info_s.power_consumption;
636 	for (i = 1; i < 8; ++i)
637 		if (power_info[i].pal_power_mgmt_info_s.im
638 		    && power_info[i].pal_power_mgmt_info_s.power_consumption < min_power) {
639 			min_power = power_info[i].pal_power_mgmt_info_s.power_consumption;
640 			min_power_state = i;
641 		}
642 
643 	while (1)
644 		ia64_pal_halt(min_power_state);
645 }
646 
machine_shutdown(void)647 void machine_shutdown(void)
648 {
649 #ifdef CONFIG_HOTPLUG_CPU
650 	int cpu;
651 
652 	for_each_online_cpu(cpu) {
653 		if (cpu != smp_processor_id())
654 			cpu_down(cpu);
655 	}
656 #endif
657 #ifdef CONFIG_KEXEC
658 	kexec_disable_iosapic();
659 #endif
660 }
661 
662 void
machine_restart(char * restart_cmd)663 machine_restart (char *restart_cmd)
664 {
665 	(void) notify_die(DIE_MACHINE_RESTART, restart_cmd, NULL, 0, 0, 0);
666 	efi_reboot(REBOOT_WARM, NULL);
667 }
668 
669 void
machine_halt(void)670 machine_halt (void)
671 {
672 	(void) notify_die(DIE_MACHINE_HALT, "", NULL, 0, 0, 0);
673 	cpu_halt();
674 }
675 
676 void
machine_power_off(void)677 machine_power_off (void)
678 {
679 	if (pm_power_off)
680 		pm_power_off();
681 	machine_halt();
682 }
683 
684