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v5.14.15
  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/processor.h>
 44#include <asm/sal.h>
 45#include <asm/switch_to.h>
 46#include <asm/tlbflush.h>
 47#include <linux/uaccess.h>
 48#include <asm/unwind.h>
 49#include <asm/user.h>
 50#include <asm/xtp.h>
 51
 52#include "entry.h"
 53
 
 
 
 
 54#include "sigframe.h"
 55
 56void (*ia64_mark_idle)(int);
 57
 58unsigned long boot_option_idle_override = IDLE_NO_OVERRIDE;
 59EXPORT_SYMBOL(boot_option_idle_override);
 
 
 60void (*pm_power_off) (void);
 61EXPORT_SYMBOL(pm_power_off);
 62
 63static void
 64ia64_do_show_stack (struct unw_frame_info *info, void *arg)
 65{
 66	unsigned long ip, sp, bsp;
 67	const char *loglvl = arg;
 68
 69	printk("%s\nCall Trace:\n", loglvl);
 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		printk("%s [<%016lx>] %pS\n"
 
 78			 "                                sp=%016lx bsp=%016lx\n",
 79			 loglvl, ip, (void *)ip, sp, bsp);
 
 80	} while (unw_unwind(info) >= 0);
 81}
 82
 83void
 84show_stack (struct task_struct *task, unsigned long *sp, const char *loglvl)
 85{
 86	if (!task)
 87		unw_init_running(ia64_do_show_stack, (void *)loglvl);
 88	else {
 89		struct unw_frame_info info;
 90
 91		unw_init_from_blocked_task(&info, task);
 92		ia64_do_show_stack(&info, (void *)loglvl);
 93	}
 94}
 95
 96void
 
 
 
 
 
 
 
 
 97show_regs (struct pt_regs *regs)
 98{
 99	unsigned long ip = regs->cr_iip + ia64_psr(regs)->ri;
100
101	print_modules();
102	printk("\n");
103	show_regs_print_info(KERN_DEFAULT);
104	printk("psr : %016lx ifs : %016lx ip  : [<%016lx>]    %s (%s)\n",
105	       regs->cr_ipsr, regs->cr_ifs, ip, print_tainted(),
106	       init_utsname()->release);
107	printk("ip is at %pS\n", (void *)ip);
108	printk("unat: %016lx pfs : %016lx rsc : %016lx\n",
109	       regs->ar_unat, regs->ar_pfs, regs->ar_rsc);
110	printk("rnat: %016lx bsps: %016lx pr  : %016lx\n",
111	       regs->ar_rnat, regs->ar_bspstore, regs->pr);
112	printk("ldrs: %016lx ccv : %016lx fpsr: %016lx\n",
113	       regs->loadrs, regs->ar_ccv, regs->ar_fpsr);
114	printk("csd : %016lx ssd : %016lx\n", regs->ar_csd, regs->ar_ssd);
115	printk("b0  : %016lx b6  : %016lx b7  : %016lx\n", regs->b0, regs->b6, regs->b7);
116	printk("f6  : %05lx%016lx f7  : %05lx%016lx\n",
117	       regs->f6.u.bits[1], regs->f6.u.bits[0],
118	       regs->f7.u.bits[1], regs->f7.u.bits[0]);
119	printk("f8  : %05lx%016lx f9  : %05lx%016lx\n",
120	       regs->f8.u.bits[1], regs->f8.u.bits[0],
121	       regs->f9.u.bits[1], regs->f9.u.bits[0]);
122	printk("f10 : %05lx%016lx f11 : %05lx%016lx\n",
123	       regs->f10.u.bits[1], regs->f10.u.bits[0],
124	       regs->f11.u.bits[1], regs->f11.u.bits[0]);
125
126	printk("r1  : %016lx r2  : %016lx r3  : %016lx\n", regs->r1, regs->r2, regs->r3);
127	printk("r8  : %016lx r9  : %016lx r10 : %016lx\n", regs->r8, regs->r9, regs->r10);
128	printk("r11 : %016lx r12 : %016lx r13 : %016lx\n", regs->r11, regs->r12, regs->r13);
129	printk("r14 : %016lx r15 : %016lx r16 : %016lx\n", regs->r14, regs->r15, regs->r16);
130	printk("r17 : %016lx r18 : %016lx r19 : %016lx\n", regs->r17, regs->r18, regs->r19);
131	printk("r20 : %016lx r21 : %016lx r22 : %016lx\n", regs->r20, regs->r21, regs->r22);
132	printk("r23 : %016lx r24 : %016lx r25 : %016lx\n", regs->r23, regs->r24, regs->r25);
133	printk("r26 : %016lx r27 : %016lx r28 : %016lx\n", regs->r26, regs->r27, regs->r28);
134	printk("r29 : %016lx r30 : %016lx r31 : %016lx\n", regs->r29, regs->r30, regs->r31);
135
136	if (user_mode(regs)) {
137		/* print the stacked registers */
138		unsigned long val, *bsp, ndirty;
139		int i, sof, is_nat = 0;
140
141		sof = regs->cr_ifs & 0x7f;	/* size of frame */
142		ndirty = (regs->loadrs >> 19);
143		bsp = ia64_rse_skip_regs((unsigned long *) regs->ar_bspstore, ndirty);
144		for (i = 0; i < sof; ++i) {
145			get_user(val, (unsigned long __user *) ia64_rse_skip_regs(bsp, i));
146			printk("r%-3u:%c%016lx%s", 32 + i, is_nat ? '*' : ' ', val,
147			       ((i == sof - 1) || (i % 3) == 2) ? "\n" : " ");
148		}
149	} else
150		show_stack(NULL, NULL, KERN_DEFAULT);
151}
152
153/* local support for deprecated console_print */
154void
155console_print(const char *s)
156{
157	printk(KERN_EMERG "%s", s);
158}
159
160void
161do_notify_resume_user(sigset_t *unused, struct sigscratch *scr, long in_syscall)
162{
163	if (fsys_mode(current, &scr->pt)) {
164		/*
165		 * defer signal-handling etc. until we return to
166		 * privilege-level 0.
167		 */
168		if (!ia64_psr(&scr->pt)->lp)
169			ia64_psr(&scr->pt)->lp = 1;
170		return;
171	}
172
 
 
 
 
 
 
 
 
 
173	/* deal with pending signal delivery */
174	if (test_thread_flag(TIF_SIGPENDING) ||
175	    test_thread_flag(TIF_NOTIFY_SIGNAL)) {
176		local_irq_enable();	/* force interrupt enable */
177		ia64_do_signal(scr, in_syscall);
178	}
179
180	if (test_thread_flag(TIF_NOTIFY_RESUME)) {
181		local_irq_enable();	/* force interrupt enable */
182		tracehook_notify_resume(&scr->pt);
183	}
184
185	/* copy user rbs to kernel rbs */
186	if (unlikely(test_thread_flag(TIF_RESTORE_RSE))) {
187		local_irq_enable();	/* force interrupt enable */
188		ia64_sync_krbs();
189	}
190
191	local_irq_disable();	/* force interrupt disable */
192}
193
 
 
 
194static int __init nohalt_setup(char * str)
195{
196	cpu_idle_poll_ctrl(true);
197	return 1;
198}
199__setup("nohalt", nohalt_setup);
200
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
201#ifdef CONFIG_HOTPLUG_CPU
202/* We don't actually take CPU down, just spin without interrupts. */
203static inline void play_dead(void)
204{
205	unsigned int this_cpu = smp_processor_id();
206
207	/* Ack it */
208	__this_cpu_write(cpu_state, CPU_DEAD);
209
210	max_xtp();
211	local_irq_disable();
212	idle_task_exit();
213	ia64_jump_to_sal(&sal_boot_rendez_state[this_cpu]);
214	/*
215	 * The above is a point of no-return, the processor is
216	 * expected to be in SAL loop now.
217	 */
218	BUG();
219}
220#else
221static inline void play_dead(void)
222{
223	BUG();
224}
225#endif /* CONFIG_HOTPLUG_CPU */
226
227void arch_cpu_idle_dead(void)
228{
229	play_dead();
230}
231
232void arch_cpu_idle(void)
233{
234	void (*mark_idle)(int) = ia64_mark_idle;
 
 
 
 
 
 
 
 
 
 
 
 
 
 
235
 
 
236#ifdef CONFIG_SMP
237	min_xtp();
238#endif
239	rmb();
240	if (mark_idle)
241		(*mark_idle)(1);
242
243	raw_safe_halt();
244
245	if (mark_idle)
246		(*mark_idle)(0);
 
 
247#ifdef CONFIG_SMP
248	normal_xtp();
249#endif
 
 
 
 
 
 
250}
251
252void
253ia64_save_extra (struct task_struct *task)
254{
 
 
 
 
255	if ((task->thread.flags & IA64_THREAD_DBG_VALID) != 0)
256		ia64_save_debug_regs(&task->thread.dbr[0]);
 
 
 
 
 
 
 
 
 
257}
258
259void
260ia64_load_extra (struct task_struct *task)
261{
 
 
 
 
262	if ((task->thread.flags & IA64_THREAD_DBG_VALID) != 0)
263		ia64_load_debug_regs(&task->thread.dbr[0]);
 
 
 
 
 
 
 
 
 
264}
265
266/*
267 * Copy the state of an ia-64 thread.
268 *
269 * We get here through the following  call chain:
270 *
271 *	from user-level:	from kernel:
272 *
273 *	<clone syscall>	        <some kernel call frames>
274 *	sys_clone		   :
275 *	kernel_clone		kernel_clone
276 *	copy_thread		copy_thread
277 *
278 * This means that the stack layout is as follows:
279 *
280 *	+---------------------+ (highest addr)
281 *	|   struct pt_regs    |
282 *	+---------------------+
283 *	| struct switch_stack |
284 *	+---------------------+
285 *	|                     |
286 *	|    memory stack     |
287 *	|                     | <-- sp (lowest addr)
288 *	+---------------------+
289 *
290 * Observe that we copy the unat values that are in pt_regs and switch_stack.  Spilling an
291 * integer to address X causes bit N in ar.unat to be set to the NaT bit of the register,
292 * with N=(X & 0x1ff)/8.  Thus, copying the unat value preserves the NaT bits ONLY if the
293 * pt_regs structure in the parent is congruent to that of the child, modulo 512.  Since
294 * the stack is page aligned and the page size is at least 4KB, this is always the case,
295 * so there is nothing to worry about.
296 */
297int
298copy_thread(unsigned long clone_flags, unsigned long user_stack_base,
299	    unsigned long user_stack_size, struct task_struct *p, unsigned long tls)
 
300{
301	extern char ia64_ret_from_clone;
302	struct switch_stack *child_stack, *stack;
303	unsigned long rbs, child_rbs, rbs_size;
304	struct pt_regs *child_ptregs;
305	struct pt_regs *regs = current_pt_regs();
306	int retval = 0;
307
 
 
 
 
 
 
 
 
 
 
 
308	child_ptregs = (struct pt_regs *) ((unsigned long) p + IA64_STK_OFFSET) - 1;
309	child_stack = (struct switch_stack *) child_ptregs - 1;
310
 
 
 
311	rbs = (unsigned long) current + IA64_RBS_OFFSET;
312	child_rbs = (unsigned long) p + IA64_RBS_OFFSET;
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
313
314	/* copy parts of thread_struct: */
315	p->thread.ksp = (unsigned long) child_stack - 16;
316
 
 
 
 
 
 
 
 
317	/*
318	 * NOTE: The calling convention considers all floating point
319	 * registers in the high partition (fph) to be scratch.  Since
320	 * the only way to get to this point is through a system call,
321	 * we know that the values in fph are all dead.  Hence, there
322	 * is no need to inherit the fph state from the parent to the
323	 * child and all we have to do is to make sure that
324	 * IA64_THREAD_FPH_VALID is cleared in the child.
325	 *
326	 * XXX We could push this optimization a bit further by
327	 * clearing IA64_THREAD_FPH_VALID on ANY system call.
328	 * However, it's not clear this is worth doing.  Also, it
329	 * would be a slight deviation from the normal Linux system
330	 * call behavior where scratch registers are preserved across
331	 * system calls (unless used by the system call itself).
332	 */
333#	define THREAD_FLAGS_TO_CLEAR	(IA64_THREAD_FPH_VALID | IA64_THREAD_DBG_VALID \
334					 | IA64_THREAD_PM_VALID)
335#	define THREAD_FLAGS_TO_SET	0
336	p->thread.flags = ((current->thread.flags & ~THREAD_FLAGS_TO_CLEAR)
337			   | THREAD_FLAGS_TO_SET);
338
339	ia64_drop_fpu(p);	/* don't pick up stale state from a CPU's fph */
340
341	if (unlikely(p->flags & (PF_KTHREAD | PF_IO_WORKER))) {
342		if (unlikely(!user_stack_base)) {
343			/* fork_idle() called us */
344			return 0;
345		}
346		memset(child_stack, 0, sizeof(*child_ptregs) + sizeof(*child_stack));
347		child_stack->r4 = user_stack_base;	/* payload */
348		child_stack->r5 = user_stack_size;	/* argument */
349		/*
350		 * Preserve PSR bits, except for bits 32-34 and 37-45,
351		 * which we can't read.
352		 */
353		child_ptregs->cr_ipsr = ia64_getreg(_IA64_REG_PSR) | IA64_PSR_BN;
354		/* mark as valid, empty frame */
355		child_ptregs->cr_ifs = 1UL << 63;
356		child_stack->ar_fpsr = child_ptregs->ar_fpsr
357			= ia64_getreg(_IA64_REG_AR_FPSR);
358		child_stack->pr = (1 << PRED_KERNEL_STACK);
359		child_stack->ar_bspstore = child_rbs;
360		child_stack->b0 = (unsigned long) &ia64_ret_from_clone;
361
362		/* stop some PSR bits from being inherited.
363		 * the psr.up/psr.pp bits must be cleared on fork but inherited on execve()
364		 * therefore we must specify them explicitly here and not include them in
365		 * IA64_PSR_BITS_TO_CLEAR.
366		 */
367		child_ptregs->cr_ipsr = ((child_ptregs->cr_ipsr | IA64_PSR_BITS_TO_SET)
368				 & ~(IA64_PSR_BITS_TO_CLEAR | IA64_PSR_PP | IA64_PSR_UP));
369
370		return 0;
371	}
372	stack = ((struct switch_stack *) regs) - 1;
373	/* copy parent's switch_stack & pt_regs to child: */
374	memcpy(child_stack, stack, sizeof(*child_ptregs) + sizeof(*child_stack));
375
376	/* copy the parent's register backing store to the child: */
377	rbs_size = stack->ar_bspstore - rbs;
378	memcpy((void *) child_rbs, (void *) rbs, rbs_size);
379	if (clone_flags & CLONE_SETTLS)
380		child_ptregs->r13 = tls;
381	if (user_stack_base) {
382		child_ptregs->r12 = user_stack_base + user_stack_size - 16;
383		child_ptregs->ar_bspstore = user_stack_base;
384		child_ptregs->ar_rnat = 0;
385		child_ptregs->loadrs = 0;
386	}
387	child_stack->ar_bspstore = child_rbs + rbs_size;
388	child_stack->b0 = (unsigned long) &ia64_ret_from_clone;
389
390	/* stop some PSR bits from being inherited.
391	 * the psr.up/psr.pp bits must be cleared on fork but inherited on execve()
392	 * therefore we must specify them explicitly here and not include them in
393	 * IA64_PSR_BITS_TO_CLEAR.
394	 */
395	child_ptregs->cr_ipsr = ((child_ptregs->cr_ipsr | IA64_PSR_BITS_TO_SET)
396				 & ~(IA64_PSR_BITS_TO_CLEAR | IA64_PSR_PP | IA64_PSR_UP));
397	return retval;
398}
399
400asmlinkage long ia64_clone(unsigned long clone_flags, unsigned long stack_start,
401			   unsigned long stack_size, unsigned long parent_tidptr,
402			   unsigned long child_tidptr, unsigned long tls)
403{
404	struct kernel_clone_args args = {
405		.flags		= (lower_32_bits(clone_flags) & ~CSIGNAL),
406		.pidfd		= (int __user *)parent_tidptr,
407		.child_tid	= (int __user *)child_tidptr,
408		.parent_tid	= (int __user *)parent_tidptr,
409		.exit_signal	= (lower_32_bits(clone_flags) & CSIGNAL),
410		.stack		= stack_start,
411		.stack_size	= stack_size,
412		.tls		= tls,
413	};
414
415	return kernel_clone(&args);
416}
417
418static void
419do_copy_task_regs (struct task_struct *task, struct unw_frame_info *info, void *arg)
420{
421	unsigned long mask, sp, nat_bits = 0, ar_rnat, urbs_end, cfm;
422	unsigned long ip;
423	elf_greg_t *dst = arg;
424	struct pt_regs *pt;
425	char nat;
426	int i;
427
428	memset(dst, 0, sizeof(elf_gregset_t));	/* don't leak any kernel bits to user-level */
429
430	if (unw_unwind_to_user(info) < 0)
431		return;
432
433	unw_get_sp(info, &sp);
434	pt = (struct pt_regs *) (sp + 16);
435
436	urbs_end = ia64_get_user_rbs_end(task, pt, &cfm);
437
438	if (ia64_sync_user_rbs(task, info->sw, pt->ar_bspstore, urbs_end) < 0)
439		return;
440
441	ia64_peek(task, info->sw, urbs_end, (long) ia64_rse_rnat_addr((long *) urbs_end),
442		  &ar_rnat);
443
444	/*
445	 * coredump format:
446	 *	r0-r31
447	 *	NaT bits (for r0-r31; bit N == 1 iff rN is a NaT)
448	 *	predicate registers (p0-p63)
449	 *	b0-b7
450	 *	ip cfm user-mask
451	 *	ar.rsc ar.bsp ar.bspstore ar.rnat
452	 *	ar.ccv ar.unat ar.fpsr ar.pfs ar.lc ar.ec
453	 */
454
455	/* r0 is zero */
456	for (i = 1, mask = (1UL << i); i < 32; ++i) {
457		unw_get_gr(info, i, &dst[i], &nat);
458		if (nat)
459			nat_bits |= mask;
460		mask <<= 1;
461	}
462	dst[32] = nat_bits;
463	unw_get_pr(info, &dst[33]);
464
465	for (i = 0; i < 8; ++i)
466		unw_get_br(info, i, &dst[34 + i]);
467
468	unw_get_rp(info, &ip);
469	dst[42] = ip + ia64_psr(pt)->ri;
470	dst[43] = cfm;
471	dst[44] = pt->cr_ipsr & IA64_PSR_UM;
472
473	unw_get_ar(info, UNW_AR_RSC, &dst[45]);
474	/*
475	 * For bsp and bspstore, unw_get_ar() would return the kernel
476	 * addresses, but we need the user-level addresses instead:
477	 */
478	dst[46] = urbs_end;	/* note: by convention PT_AR_BSP points to the end of the urbs! */
479	dst[47] = pt->ar_bspstore;
480	dst[48] = ar_rnat;
481	unw_get_ar(info, UNW_AR_CCV, &dst[49]);
482	unw_get_ar(info, UNW_AR_UNAT, &dst[50]);
483	unw_get_ar(info, UNW_AR_FPSR, &dst[51]);
484	dst[52] = pt->ar_pfs;	/* UNW_AR_PFS is == to pt->cr_ifs for interrupt frames */
485	unw_get_ar(info, UNW_AR_LC, &dst[53]);
486	unw_get_ar(info, UNW_AR_EC, &dst[54]);
487	unw_get_ar(info, UNW_AR_CSD, &dst[55]);
488	unw_get_ar(info, UNW_AR_SSD, &dst[56]);
489}
490
491static void
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
492do_copy_regs (struct unw_frame_info *info, void *arg)
493{
494	do_copy_task_regs(current, info, arg);
495}
496
497void
 
 
 
 
 
 
498ia64_elf_core_copy_regs (struct pt_regs *pt, elf_gregset_t dst)
499{
500	unw_init_running(do_copy_regs, dst);
501}
502
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
503/*
504 * Flush thread state.  This is called when a thread does an execve().
505 */
506void
507flush_thread (void)
508{
509	/* drop floating-point and debug-register state if it exists: */
510	current->thread.flags &= ~(IA64_THREAD_FPH_VALID | IA64_THREAD_DBG_VALID);
511	ia64_drop_fpu(current);
512}
513
514/*
515 * Clean up state associated with a thread.  This is called when
516 * the thread calls exit().
517 */
518void
519exit_thread (struct task_struct *tsk)
520{
521
522	ia64_drop_fpu(tsk);
 
 
 
 
 
 
 
 
 
523}
524
525unsigned long
526get_wchan (struct task_struct *p)
527{
528	struct unw_frame_info info;
529	unsigned long ip;
530	int count = 0;
531
532	if (!p || p == current || task_is_running(p))
533		return 0;
534
535	/*
536	 * Note: p may not be a blocked task (it could be current or
537	 * another process running on some other CPU.  Rather than
538	 * trying to determine if p is really blocked, we just assume
539	 * it's blocked and rely on the unwind routines to fail
540	 * gracefully if the process wasn't really blocked after all.
541	 * --davidm 99/12/15
542	 */
543	unw_init_from_blocked_task(&info, p);
544	do {
545		if (task_is_running(p))
546			return 0;
547		if (unw_unwind(&info) < 0)
548			return 0;
549		unw_get_ip(&info, &ip);
550		if (!in_sched_functions(ip))
551			return ip;
552	} while (count++ < 16);
553	return 0;
554}
555
556void
557cpu_halt (void)
558{
559	pal_power_mgmt_info_u_t power_info[8];
560	unsigned long min_power;
561	int i, min_power_state;
562
563	if (ia64_pal_halt_info(power_info) != 0)
564		return;
565
566	min_power_state = 0;
567	min_power = power_info[0].pal_power_mgmt_info_s.power_consumption;
568	for (i = 1; i < 8; ++i)
569		if (power_info[i].pal_power_mgmt_info_s.im
570		    && power_info[i].pal_power_mgmt_info_s.power_consumption < min_power) {
571			min_power = power_info[i].pal_power_mgmt_info_s.power_consumption;
572			min_power_state = i;
573		}
574
575	while (1)
576		ia64_pal_halt(min_power_state);
577}
578
579void machine_shutdown(void)
580{
581	smp_shutdown_nonboot_cpus(reboot_cpu);
 
582
 
 
 
 
 
583#ifdef CONFIG_KEXEC
584	kexec_disable_iosapic();
585#endif
586}
587
588void
589machine_restart (char *restart_cmd)
590{
591	(void) notify_die(DIE_MACHINE_RESTART, restart_cmd, NULL, 0, 0, 0);
592	efi_reboot(REBOOT_WARM, NULL);
593}
594
595void
596machine_halt (void)
597{
598	(void) notify_die(DIE_MACHINE_HALT, "", NULL, 0, 0, 0);
599	cpu_halt();
600}
601
602void
603machine_power_off (void)
604{
605	if (pm_power_off)
606		pm_power_off();
607	machine_halt();
608}
609
610EXPORT_SYMBOL(ia64_delay_loop);
v3.5.6
 
  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
 33#include <asm/cpu.h>
 34#include <asm/delay.h>
 35#include <asm/elf.h>
 36#include <asm/irq.h>
 37#include <asm/kexec.h>
 38#include <asm/pgalloc.h>
 39#include <asm/processor.h>
 40#include <asm/sal.h>
 41#include <asm/switch_to.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
 55void (*ia64_mark_idle)(int);
 56
 57unsigned long boot_option_idle_override = IDLE_NO_OVERRIDE;
 58EXPORT_SYMBOL(boot_option_idle_override);
 59void (*pm_idle) (void);
 60EXPORT_SYMBOL(pm_idle);
 61void (*pm_power_off) (void);
 62EXPORT_SYMBOL(pm_power_off);
 63
 64void
 65ia64_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
 86void
 87show_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
 99void
100dump_stack (void)
101{
102	show_stack(NULL, NULL);
103}
104
105EXPORT_SYMBOL(dump_stack);
106
107void
108show_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/* local support for deprecated console_print */
165void
166console_print(const char *s)
167{
168	printk(KERN_EMERG "%s", s);
169}
170
171void
172do_notify_resume_user(sigset_t *unused, struct sigscratch *scr, long in_syscall)
173{
174	if (fsys_mode(current, &scr->pt)) {
175		/*
176		 * defer signal-handling etc. until we return to
177		 * privilege-level 0.
178		 */
179		if (!ia64_psr(&scr->pt)->lp)
180			ia64_psr(&scr->pt)->lp = 1;
181		return;
182	}
183
184#ifdef CONFIG_PERFMON
185	if (current->thread.pfm_needs_checking)
186		/*
187		 * Note: pfm_handle_work() allow us to call it with interrupts
188		 * disabled, and may enable interrupts within the function.
189		 */
190		pfm_handle_work();
191#endif
192
193	/* deal with pending signal delivery */
194	if (test_thread_flag(TIF_SIGPENDING)) {
 
195		local_irq_enable();	/* force interrupt enable */
196		ia64_do_signal(scr, in_syscall);
197	}
198
199	if (test_thread_flag(TIF_NOTIFY_RESUME)) {
200		clear_thread_flag(TIF_NOTIFY_RESUME);
201		tracehook_notify_resume(&scr->pt);
202	}
203
204	/* copy user rbs to kernel rbs */
205	if (unlikely(test_thread_flag(TIF_RESTORE_RSE))) {
206		local_irq_enable();	/* force interrupt enable */
207		ia64_sync_krbs();
208	}
209
210	local_irq_disable();	/* force interrupt disable */
211}
212
213static int pal_halt        = 1;
214static int can_do_pal_halt = 1;
215
216static int __init nohalt_setup(char * str)
217{
218	pal_halt = can_do_pal_halt = 0;
219	return 1;
220}
221__setup("nohalt", nohalt_setup);
222
223void
224update_pal_halt_status(int status)
225{
226	can_do_pal_halt = pal_halt && status;
227}
228
229/*
230 * We use this if we don't have any better idle routine..
231 */
232void
233default_idle (void)
234{
235	local_irq_enable();
236	while (!need_resched()) {
237		if (can_do_pal_halt) {
238			local_irq_disable();
239			if (!need_resched()) {
240				safe_halt();
241			}
242			local_irq_enable();
243		} else
244			cpu_relax();
245	}
246}
247
248#ifdef CONFIG_HOTPLUG_CPU
249/* We don't actually take CPU down, just spin without interrupts. */
250static inline void play_dead(void)
251{
252	unsigned int this_cpu = smp_processor_id();
253
254	/* Ack it */
255	__get_cpu_var(cpu_state) = CPU_DEAD;
256
257	max_xtp();
258	local_irq_disable();
259	idle_task_exit();
260	ia64_jump_to_sal(&sal_boot_rendez_state[this_cpu]);
261	/*
262	 * The above is a point of no-return, the processor is
263	 * expected to be in SAL loop now.
264	 */
265	BUG();
266}
267#else
268static inline void play_dead(void)
269{
270	BUG();
271}
272#endif /* CONFIG_HOTPLUG_CPU */
273
274void __attribute__((noreturn))
275cpu_idle (void)
 
 
 
 
276{
277	void (*mark_idle)(int) = ia64_mark_idle;
278  	int cpu = smp_processor_id();
279
280	/* endless idle loop with no priority at all */
281	while (1) {
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			idle = pm_idle;
303			if (!idle)
304				idle = default_idle;
305			(*idle)();
306			if (mark_idle)
307				(*mark_idle)(0);
308#ifdef CONFIG_SMP
309			normal_xtp();
310#endif
311		}
312		schedule_preempt_disabled();
313		check_pgt_cache();
314		if (cpu_is_offline(cpu))
315			play_dead();
316	}
317}
318
319void
320ia64_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
339void
340ia64_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 */
390int
391copy_thread(unsigned long clone_flags,
392	     unsigned long user_stack_base, unsigned long user_stack_size,
393	     struct task_struct *p, struct pt_regs *regs)
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	int retval = 0;
400
401#ifdef CONFIG_SMP
402	/*
403	 * For SMP idle threads, fork_by_hand() calls do_fork with
404	 * NULL regs.
405	 */
406	if (!regs)
407		return 0;
408#endif
409
410	stack = ((struct switch_stack *) regs) - 1;
411
412	child_ptregs = (struct pt_regs *) ((unsigned long) p + IA64_STK_OFFSET) - 1;
413	child_stack = (struct switch_stack *) child_ptregs - 1;
414
415	/* copy parent's switch_stack & pt_regs to child: */
416	memcpy(child_stack, stack, sizeof(*child_ptregs) + sizeof(*child_stack));
417
418	rbs = (unsigned long) current + IA64_RBS_OFFSET;
419	child_rbs = (unsigned long) p + IA64_RBS_OFFSET;
420	rbs_size = stack->ar_bspstore - rbs;
421
422	/* copy the parent's register backing store to the child: */
423	memcpy((void *) child_rbs, (void *) rbs, rbs_size);
424
425	if (likely(user_mode(child_ptregs))) {
426		if (clone_flags & CLONE_SETTLS)
427			child_ptregs->r13 = regs->r16;	/* see sys_clone2() in entry.S */
428		if (user_stack_base) {
429			child_ptregs->r12 = user_stack_base + user_stack_size - 16;
430			child_ptregs->ar_bspstore = user_stack_base;
431			child_ptregs->ar_rnat = 0;
432			child_ptregs->loadrs = 0;
433		}
434	} else {
435		/*
436		 * Note: we simply preserve the relative position of
437		 * the stack pointer here.  There is no need to
438		 * allocate a scratch area here, since that will have
439		 * been taken care of by the caller of sys_clone()
440		 * already.
441		 */
442		child_ptregs->r12 = (unsigned long) child_ptregs - 16; /* kernel sp */
443		child_ptregs->r13 = (unsigned long) p;		/* set `current' pointer */
444	}
445	child_stack->ar_bspstore = child_rbs + rbs_size;
446	child_stack->b0 = (unsigned long) &ia64_ret_from_clone;
447
448	/* copy parts of thread_struct: */
449	p->thread.ksp = (unsigned long) child_stack - 16;
450
451	/* stop some PSR bits from being inherited.
452	 * the psr.up/psr.pp bits must be cleared on fork but inherited on execve()
453	 * therefore we must specify them explicitly here and not include them in
454	 * IA64_PSR_BITS_TO_CLEAR.
455	 */
456	child_ptregs->cr_ipsr = ((child_ptregs->cr_ipsr | IA64_PSR_BITS_TO_SET)
457				 & ~(IA64_PSR_BITS_TO_CLEAR | IA64_PSR_PP | IA64_PSR_UP));
458
459	/*
460	 * NOTE: The calling convention considers all floating point
461	 * registers in the high partition (fph) to be scratch.  Since
462	 * the only way to get to this point is through a system call,
463	 * we know that the values in fph are all dead.  Hence, there
464	 * is no need to inherit the fph state from the parent to the
465	 * child and all we have to do is to make sure that
466	 * IA64_THREAD_FPH_VALID is cleared in the child.
467	 *
468	 * XXX We could push this optimization a bit further by
469	 * clearing IA64_THREAD_FPH_VALID on ANY system call.
470	 * However, it's not clear this is worth doing.  Also, it
471	 * would be a slight deviation from the normal Linux system
472	 * call behavior where scratch registers are preserved across
473	 * system calls (unless used by the system call itself).
474	 */
475#	define THREAD_FLAGS_TO_CLEAR	(IA64_THREAD_FPH_VALID | IA64_THREAD_DBG_VALID \
476					 | IA64_THREAD_PM_VALID)
477#	define THREAD_FLAGS_TO_SET	0
478	p->thread.flags = ((current->thread.flags & ~THREAD_FLAGS_TO_CLEAR)
479			   | THREAD_FLAGS_TO_SET);
 
480	ia64_drop_fpu(p);	/* don't pick up stale state from a CPU's fph */
481
482#ifdef CONFIG_PERFMON
483	if (current->thread.pfm_context)
484		pfm_inherit(p, child_ptregs);
485#endif
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
486	return retval;
487}
488
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
489static void
490do_copy_task_regs (struct task_struct *task, struct unw_frame_info *info, void *arg)
491{
492	unsigned long mask, sp, nat_bits = 0, ar_rnat, urbs_end, cfm;
493	unsigned long uninitialized_var(ip);	/* GCC be quiet */
494	elf_greg_t *dst = arg;
495	struct pt_regs *pt;
496	char nat;
497	int i;
498
499	memset(dst, 0, sizeof(elf_gregset_t));	/* don't leak any kernel bits to user-level */
500
501	if (unw_unwind_to_user(info) < 0)
502		return;
503
504	unw_get_sp(info, &sp);
505	pt = (struct pt_regs *) (sp + 16);
506
507	urbs_end = ia64_get_user_rbs_end(task, pt, &cfm);
508
509	if (ia64_sync_user_rbs(task, info->sw, pt->ar_bspstore, urbs_end) < 0)
510		return;
511
512	ia64_peek(task, info->sw, urbs_end, (long) ia64_rse_rnat_addr((long *) urbs_end),
513		  &ar_rnat);
514
515	/*
516	 * coredump format:
517	 *	r0-r31
518	 *	NaT bits (for r0-r31; bit N == 1 iff rN is a NaT)
519	 *	predicate registers (p0-p63)
520	 *	b0-b7
521	 *	ip cfm user-mask
522	 *	ar.rsc ar.bsp ar.bspstore ar.rnat
523	 *	ar.ccv ar.unat ar.fpsr ar.pfs ar.lc ar.ec
524	 */
525
526	/* r0 is zero */
527	for (i = 1, mask = (1UL << i); i < 32; ++i) {
528		unw_get_gr(info, i, &dst[i], &nat);
529		if (nat)
530			nat_bits |= mask;
531		mask <<= 1;
532	}
533	dst[32] = nat_bits;
534	unw_get_pr(info, &dst[33]);
535
536	for (i = 0; i < 8; ++i)
537		unw_get_br(info, i, &dst[34 + i]);
538
539	unw_get_rp(info, &ip);
540	dst[42] = ip + ia64_psr(pt)->ri;
541	dst[43] = cfm;
542	dst[44] = pt->cr_ipsr & IA64_PSR_UM;
543
544	unw_get_ar(info, UNW_AR_RSC, &dst[45]);
545	/*
546	 * For bsp and bspstore, unw_get_ar() would return the kernel
547	 * addresses, but we need the user-level addresses instead:
548	 */
549	dst[46] = urbs_end;	/* note: by convention PT_AR_BSP points to the end of the urbs! */
550	dst[47] = pt->ar_bspstore;
551	dst[48] = ar_rnat;
552	unw_get_ar(info, UNW_AR_CCV, &dst[49]);
553	unw_get_ar(info, UNW_AR_UNAT, &dst[50]);
554	unw_get_ar(info, UNW_AR_FPSR, &dst[51]);
555	dst[52] = pt->ar_pfs;	/* UNW_AR_PFS is == to pt->cr_ifs for interrupt frames */
556	unw_get_ar(info, UNW_AR_LC, &dst[53]);
557	unw_get_ar(info, UNW_AR_EC, &dst[54]);
558	unw_get_ar(info, UNW_AR_CSD, &dst[55]);
559	unw_get_ar(info, UNW_AR_SSD, &dst[56]);
560}
561
562void
563do_dump_task_fpu (struct task_struct *task, struct unw_frame_info *info, void *arg)
564{
565	elf_fpreg_t *dst = arg;
566	int i;
567
568	memset(dst, 0, sizeof(elf_fpregset_t));	/* don't leak any "random" bits */
569
570	if (unw_unwind_to_user(info) < 0)
571		return;
572
573	/* f0 is 0.0, f1 is 1.0 */
574
575	for (i = 2; i < 32; ++i)
576		unw_get_fr(info, i, dst + i);
577
578	ia64_flush_fph(task);
579	if ((task->thread.flags & IA64_THREAD_FPH_VALID) != 0)
580		memcpy(dst + 32, task->thread.fph, 96*16);
581}
582
583void
584do_copy_regs (struct unw_frame_info *info, void *arg)
585{
586	do_copy_task_regs(current, info, arg);
587}
588
589void
590do_dump_fpu (struct unw_frame_info *info, void *arg)
591{
592	do_dump_task_fpu(current, info, arg);
593}
594
595void
596ia64_elf_core_copy_regs (struct pt_regs *pt, elf_gregset_t dst)
597{
598	unw_init_running(do_copy_regs, dst);
599}
600
601int
602dump_fpu (struct pt_regs *pt, elf_fpregset_t dst)
603{
604	unw_init_running(do_dump_fpu, dst);
605	return 1;	/* f0-f31 are always valid so we always return 1 */
606}
607
608long
609sys_execve (const char __user *filename,
610	    const char __user *const __user *argv,
611	    const char __user *const __user *envp,
612	    struct pt_regs *regs)
613{
614	char *fname;
615	int error;
616
617	fname = getname(filename);
618	error = PTR_ERR(fname);
619	if (IS_ERR(fname))
620		goto out;
621	error = do_execve(fname, argv, envp, regs);
622	putname(fname);
623out:
624	return error;
625}
626
627pid_t
628kernel_thread (int (*fn)(void *), void *arg, unsigned long flags)
629{
630	extern void start_kernel_thread (void);
631	unsigned long *helper_fptr = (unsigned long *) &start_kernel_thread;
632	struct {
633		struct switch_stack sw;
634		struct pt_regs pt;
635	} regs;
636
637	memset(&regs, 0, sizeof(regs));
638	regs.pt.cr_iip = helper_fptr[0];	/* set entry point (IP) */
639	regs.pt.r1 = helper_fptr[1];		/* set GP */
640	regs.pt.r9 = (unsigned long) fn;	/* 1st argument */
641	regs.pt.r11 = (unsigned long) arg;	/* 2nd argument */
642	/* Preserve PSR bits, except for bits 32-34 and 37-45, which we can't read.  */
643	regs.pt.cr_ipsr = ia64_getreg(_IA64_REG_PSR) | IA64_PSR_BN;
644	regs.pt.cr_ifs = 1UL << 63;		/* mark as valid, empty frame */
645	regs.sw.ar_fpsr = regs.pt.ar_fpsr = ia64_getreg(_IA64_REG_AR_FPSR);
646	regs.sw.ar_bspstore = (unsigned long) current + IA64_RBS_OFFSET;
647	regs.sw.pr = (1 << PRED_KERNEL_STACK);
648	return do_fork(flags | CLONE_VM | CLONE_UNTRACED, 0, &regs.pt, 0, NULL, NULL);
649}
650EXPORT_SYMBOL(kernel_thread);
651
652/* This gets called from kernel_thread() via ia64_invoke_thread_helper().  */
653int
654kernel_thread_helper (int (*fn)(void *), void *arg)
655{
656	return (*fn)(arg);
657}
658
659/*
660 * Flush thread state.  This is called when a thread does an execve().
661 */
662void
663flush_thread (void)
664{
665	/* drop floating-point and debug-register state if it exists: */
666	current->thread.flags &= ~(IA64_THREAD_FPH_VALID | IA64_THREAD_DBG_VALID);
667	ia64_drop_fpu(current);
668}
669
670/*
671 * Clean up state associated with current thread.  This is called when
672 * the thread calls exit().
673 */
674void
675exit_thread (void)
676{
677
678	ia64_drop_fpu(current);
679#ifdef CONFIG_PERFMON
680       /* if needed, stop monitoring and flush state to perfmon context */
681	if (current->thread.pfm_context)
682		pfm_exit_thread(current);
683
684	/* free debug register resources */
685	if (current->thread.flags & IA64_THREAD_DBG_VALID)
686		pfm_release_debug_registers(current);
687#endif
688}
689
690unsigned long
691get_wchan (struct task_struct *p)
692{
693	struct unw_frame_info info;
694	unsigned long ip;
695	int count = 0;
696
697	if (!p || p == current || p->state == TASK_RUNNING)
698		return 0;
699
700	/*
701	 * Note: p may not be a blocked task (it could be current or
702	 * another process running on some other CPU.  Rather than
703	 * trying to determine if p is really blocked, we just assume
704	 * it's blocked and rely on the unwind routines to fail
705	 * gracefully if the process wasn't really blocked after all.
706	 * --davidm 99/12/15
707	 */
708	unw_init_from_blocked_task(&info, p);
709	do {
710		if (p->state == TASK_RUNNING)
711			return 0;
712		if (unw_unwind(&info) < 0)
713			return 0;
714		unw_get_ip(&info, &ip);
715		if (!in_sched_functions(ip))
716			return ip;
717	} while (count++ < 16);
718	return 0;
719}
720
721void
722cpu_halt (void)
723{
724	pal_power_mgmt_info_u_t power_info[8];
725	unsigned long min_power;
726	int i, min_power_state;
727
728	if (ia64_pal_halt_info(power_info) != 0)
729		return;
730
731	min_power_state = 0;
732	min_power = power_info[0].pal_power_mgmt_info_s.power_consumption;
733	for (i = 1; i < 8; ++i)
734		if (power_info[i].pal_power_mgmt_info_s.im
735		    && power_info[i].pal_power_mgmt_info_s.power_consumption < min_power) {
736			min_power = power_info[i].pal_power_mgmt_info_s.power_consumption;
737			min_power_state = i;
738		}
739
740	while (1)
741		ia64_pal_halt(min_power_state);
742}
743
744void machine_shutdown(void)
745{
746#ifdef CONFIG_HOTPLUG_CPU
747	int cpu;
748
749	for_each_online_cpu(cpu) {
750		if (cpu != smp_processor_id())
751			cpu_down(cpu);
752	}
753#endif
754#ifdef CONFIG_KEXEC
755	kexec_disable_iosapic();
756#endif
757}
758
759void
760machine_restart (char *restart_cmd)
761{
762	(void) notify_die(DIE_MACHINE_RESTART, restart_cmd, NULL, 0, 0, 0);
763	(*efi.reset_system)(EFI_RESET_WARM, 0, 0, NULL);
764}
765
766void
767machine_halt (void)
768{
769	(void) notify_die(DIE_MACHINE_HALT, "", NULL, 0, 0, 0);
770	cpu_halt();
771}
772
773void
774machine_power_off (void)
775{
776	if (pm_power_off)
777		pm_power_off();
778	machine_halt();
779}
780