xref: /openbmc/linux/arch/ia64/kernel/process.c (revision a1e58bbd)
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 
32 #include <asm/cpu.h>
33 #include <asm/delay.h>
34 #include <asm/elf.h>
35 #include <asm/ia32.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/tlbflush.h>
42 #include <asm/uaccess.h>
43 #include <asm/unwind.h>
44 #include <asm/user.h>
45 
46 #include "entry.h"
47 
48 #ifdef CONFIG_PERFMON
49 # include <asm/perfmon.h>
50 #endif
51 
52 #include "sigframe.h"
53 
54 void (*ia64_mark_idle)(int);
55 
56 unsigned long boot_option_idle_override = 0;
57 EXPORT_SYMBOL(boot_option_idle_override);
58 
59 void
60 ia64_do_show_stack (struct unw_frame_info *info, void *arg)
61 {
62 	unsigned long ip, sp, bsp;
63 	char buf[128];			/* don't make it so big that it overflows the stack! */
64 
65 	printk("\nCall Trace:\n");
66 	do {
67 		unw_get_ip(info, &ip);
68 		if (ip == 0)
69 			break;
70 
71 		unw_get_sp(info, &sp);
72 		unw_get_bsp(info, &bsp);
73 		snprintf(buf, sizeof(buf),
74 			 " [<%016lx>] %%s\n"
75 			 "                                sp=%016lx bsp=%016lx\n",
76 			 ip, sp, bsp);
77 		print_symbol(buf, ip);
78 	} while (unw_unwind(info) >= 0);
79 }
80 
81 void
82 show_stack (struct task_struct *task, unsigned long *sp)
83 {
84 	if (!task)
85 		unw_init_running(ia64_do_show_stack, NULL);
86 	else {
87 		struct unw_frame_info info;
88 
89 		unw_init_from_blocked_task(&info, task);
90 		ia64_do_show_stack(&info, NULL);
91 	}
92 }
93 
94 void
95 dump_stack (void)
96 {
97 	show_stack(NULL, NULL);
98 }
99 
100 EXPORT_SYMBOL(dump_stack);
101 
102 void
103 show_regs (struct pt_regs *regs)
104 {
105 	unsigned long ip = regs->cr_iip + ia64_psr(regs)->ri;
106 
107 	print_modules();
108 	printk("\nPid: %d, CPU %d, comm: %20s\n", task_pid_nr(current),
109 			smp_processor_id(), current->comm);
110 	printk("psr : %016lx ifs : %016lx ip  : [<%016lx>]    %s (%s)\n",
111 	       regs->cr_ipsr, regs->cr_ifs, ip, print_tainted(),
112 	       init_utsname()->release);
113 	print_symbol("ip is at %s\n", ip);
114 	printk("unat: %016lx pfs : %016lx rsc : %016lx\n",
115 	       regs->ar_unat, regs->ar_pfs, regs->ar_rsc);
116 	printk("rnat: %016lx bsps: %016lx pr  : %016lx\n",
117 	       regs->ar_rnat, regs->ar_bspstore, regs->pr);
118 	printk("ldrs: %016lx ccv : %016lx fpsr: %016lx\n",
119 	       regs->loadrs, regs->ar_ccv, regs->ar_fpsr);
120 	printk("csd : %016lx ssd : %016lx\n", regs->ar_csd, regs->ar_ssd);
121 	printk("b0  : %016lx b6  : %016lx b7  : %016lx\n", regs->b0, regs->b6, regs->b7);
122 	printk("f6  : %05lx%016lx f7  : %05lx%016lx\n",
123 	       regs->f6.u.bits[1], regs->f6.u.bits[0],
124 	       regs->f7.u.bits[1], regs->f7.u.bits[0]);
125 	printk("f8  : %05lx%016lx f9  : %05lx%016lx\n",
126 	       regs->f8.u.bits[1], regs->f8.u.bits[0],
127 	       regs->f9.u.bits[1], regs->f9.u.bits[0]);
128 	printk("f10 : %05lx%016lx f11 : %05lx%016lx\n",
129 	       regs->f10.u.bits[1], regs->f10.u.bits[0],
130 	       regs->f11.u.bits[1], regs->f11.u.bits[0]);
131 
132 	printk("r1  : %016lx r2  : %016lx r3  : %016lx\n", regs->r1, regs->r2, regs->r3);
133 	printk("r8  : %016lx r9  : %016lx r10 : %016lx\n", regs->r8, regs->r9, regs->r10);
134 	printk("r11 : %016lx r12 : %016lx r13 : %016lx\n", regs->r11, regs->r12, regs->r13);
135 	printk("r14 : %016lx r15 : %016lx r16 : %016lx\n", regs->r14, regs->r15, regs->r16);
136 	printk("r17 : %016lx r18 : %016lx r19 : %016lx\n", regs->r17, regs->r18, regs->r19);
137 	printk("r20 : %016lx r21 : %016lx r22 : %016lx\n", regs->r20, regs->r21, regs->r22);
138 	printk("r23 : %016lx r24 : %016lx r25 : %016lx\n", regs->r23, regs->r24, regs->r25);
139 	printk("r26 : %016lx r27 : %016lx r28 : %016lx\n", regs->r26, regs->r27, regs->r28);
140 	printk("r29 : %016lx r30 : %016lx r31 : %016lx\n", regs->r29, regs->r30, regs->r31);
141 
142 	if (user_mode(regs)) {
143 		/* print the stacked registers */
144 		unsigned long val, *bsp, ndirty;
145 		int i, sof, is_nat = 0;
146 
147 		sof = regs->cr_ifs & 0x7f;	/* size of frame */
148 		ndirty = (regs->loadrs >> 19);
149 		bsp = ia64_rse_skip_regs((unsigned long *) regs->ar_bspstore, ndirty);
150 		for (i = 0; i < sof; ++i) {
151 			get_user(val, (unsigned long __user *) ia64_rse_skip_regs(bsp, i));
152 			printk("r%-3u:%c%016lx%s", 32 + i, is_nat ? '*' : ' ', val,
153 			       ((i == sof - 1) || (i % 3) == 2) ? "\n" : " ");
154 		}
155 	} else
156 		show_stack(NULL, NULL);
157 }
158 
159 void tsk_clear_notify_resume(struct task_struct *tsk)
160 {
161 #ifdef CONFIG_PERFMON
162 	if (tsk->thread.pfm_needs_checking)
163 		return;
164 #endif
165 	if (test_ti_thread_flag(task_thread_info(tsk), TIF_RESTORE_RSE))
166 		return;
167 	clear_ti_thread_flag(task_thread_info(tsk), TIF_NOTIFY_RESUME);
168 }
169 
170 void
171 do_notify_resume_user (sigset_t *unused, struct sigscratch *scr, long in_syscall)
172 {
173 	if (fsys_mode(current, &scr->pt)) {
174 		/* defer signal-handling etc. until we return to privilege-level 0.  */
175 		if (!ia64_psr(&scr->pt)->lp)
176 			ia64_psr(&scr->pt)->lp = 1;
177 		return;
178 	}
179 
180 #ifdef CONFIG_PERFMON
181 	if (current->thread.pfm_needs_checking)
182 		pfm_handle_work();
183 #endif
184 
185 	/* deal with pending signal delivery */
186 	if (test_thread_flag(TIF_SIGPENDING)||test_thread_flag(TIF_RESTORE_SIGMASK))
187 		ia64_do_signal(scr, in_syscall);
188 
189 	/* copy user rbs to kernel rbs */
190 	if (unlikely(test_thread_flag(TIF_RESTORE_RSE)))
191 		ia64_sync_krbs();
192 }
193 
194 static int pal_halt        = 1;
195 static int can_do_pal_halt = 1;
196 
197 static int __init nohalt_setup(char * str)
198 {
199 	pal_halt = can_do_pal_halt = 0;
200 	return 1;
201 }
202 __setup("nohalt", nohalt_setup);
203 
204 void
205 update_pal_halt_status(int status)
206 {
207 	can_do_pal_halt = pal_halt && status;
208 }
209 
210 /*
211  * We use this if we don't have any better idle routine..
212  */
213 void
214 default_idle (void)
215 {
216 	local_irq_enable();
217 	while (!need_resched()) {
218 		if (can_do_pal_halt) {
219 			local_irq_disable();
220 			if (!need_resched()) {
221 				safe_halt();
222 			}
223 			local_irq_enable();
224 		} else
225 			cpu_relax();
226 	}
227 }
228 
229 #ifdef CONFIG_HOTPLUG_CPU
230 /* We don't actually take CPU down, just spin without interrupts. */
231 static inline void play_dead(void)
232 {
233 	extern void ia64_cpu_local_tick (void);
234 	unsigned int this_cpu = smp_processor_id();
235 
236 	/* Ack it */
237 	__get_cpu_var(cpu_state) = CPU_DEAD;
238 
239 	max_xtp();
240 	local_irq_disable();
241 	idle_task_exit();
242 	ia64_jump_to_sal(&sal_boot_rendez_state[this_cpu]);
243 	/*
244 	 * The above is a point of no-return, the processor is
245 	 * expected to be in SAL loop now.
246 	 */
247 	BUG();
248 }
249 #else
250 static inline void play_dead(void)
251 {
252 	BUG();
253 }
254 #endif /* CONFIG_HOTPLUG_CPU */
255 
256 static void do_nothing(void *unused)
257 {
258 }
259 
260 /*
261  * cpu_idle_wait - Used to ensure that all the CPUs discard old value of
262  * pm_idle and update to new pm_idle value. Required while changing pm_idle
263  * handler on SMP systems.
264  *
265  * Caller must have changed pm_idle to the new value before the call. Old
266  * pm_idle value will not be used by any CPU after the return of this function.
267  */
268 void cpu_idle_wait(void)
269 {
270 	smp_mb();
271 	/* kick all the CPUs so that they exit out of pm_idle */
272 	smp_call_function(do_nothing, NULL, 0, 1);
273 }
274 EXPORT_SYMBOL_GPL(cpu_idle_wait);
275 
276 void __attribute__((noreturn))
277 cpu_idle (void)
278 {
279 	void (*mark_idle)(int) = ia64_mark_idle;
280   	int cpu = smp_processor_id();
281 
282 	/* endless idle loop with no priority at all */
283 	while (1) {
284 		if (can_do_pal_halt) {
285 			current_thread_info()->status &= ~TS_POLLING;
286 			/*
287 			 * TS_POLLING-cleared state must be visible before we
288 			 * test NEED_RESCHED:
289 			 */
290 			smp_mb();
291 		} else {
292 			current_thread_info()->status |= TS_POLLING;
293 		}
294 
295 		if (!need_resched()) {
296 			void (*idle)(void);
297 #ifdef CONFIG_SMP
298 			min_xtp();
299 #endif
300 			rmb();
301 			if (mark_idle)
302 				(*mark_idle)(1);
303 
304 			idle = pm_idle;
305 			if (!idle)
306 				idle = default_idle;
307 			(*idle)();
308 			if (mark_idle)
309 				(*mark_idle)(0);
310 #ifdef CONFIG_SMP
311 			normal_xtp();
312 #endif
313 		}
314 		preempt_enable_no_resched();
315 		schedule();
316 		preempt_disable();
317 		check_pgt_cache();
318 		if (cpu_is_offline(cpu))
319 			play_dead();
320 	}
321 }
322 
323 void
324 ia64_save_extra (struct task_struct *task)
325 {
326 #ifdef CONFIG_PERFMON
327 	unsigned long info;
328 #endif
329 
330 	if ((task->thread.flags & IA64_THREAD_DBG_VALID) != 0)
331 		ia64_save_debug_regs(&task->thread.dbr[0]);
332 
333 #ifdef CONFIG_PERFMON
334 	if ((task->thread.flags & IA64_THREAD_PM_VALID) != 0)
335 		pfm_save_regs(task);
336 
337 	info = __get_cpu_var(pfm_syst_info);
338 	if (info & PFM_CPUINFO_SYST_WIDE)
339 		pfm_syst_wide_update_task(task, info, 0);
340 #endif
341 
342 #ifdef CONFIG_IA32_SUPPORT
343 	if (IS_IA32_PROCESS(task_pt_regs(task)))
344 		ia32_save_state(task);
345 #endif
346 }
347 
348 void
349 ia64_load_extra (struct task_struct *task)
350 {
351 #ifdef CONFIG_PERFMON
352 	unsigned long info;
353 #endif
354 
355 	if ((task->thread.flags & IA64_THREAD_DBG_VALID) != 0)
356 		ia64_load_debug_regs(&task->thread.dbr[0]);
357 
358 #ifdef CONFIG_PERFMON
359 	if ((task->thread.flags & IA64_THREAD_PM_VALID) != 0)
360 		pfm_load_regs(task);
361 
362 	info = __get_cpu_var(pfm_syst_info);
363 	if (info & PFM_CPUINFO_SYST_WIDE)
364 		pfm_syst_wide_update_task(task, info, 1);
365 #endif
366 
367 #ifdef CONFIG_IA32_SUPPORT
368 	if (IS_IA32_PROCESS(task_pt_regs(task)))
369 		ia32_load_state(task);
370 #endif
371 }
372 
373 /*
374  * Copy the state of an ia-64 thread.
375  *
376  * We get here through the following  call chain:
377  *
378  *	from user-level:	from kernel:
379  *
380  *	<clone syscall>	        <some kernel call frames>
381  *	sys_clone		   :
382  *	do_fork			do_fork
383  *	copy_thread		copy_thread
384  *
385  * This means that the stack layout is as follows:
386  *
387  *	+---------------------+ (highest addr)
388  *	|   struct pt_regs    |
389  *	+---------------------+
390  *	| struct switch_stack |
391  *	+---------------------+
392  *	|                     |
393  *	|    memory stack     |
394  *	|                     | <-- sp (lowest addr)
395  *	+---------------------+
396  *
397  * Observe that we copy the unat values that are in pt_regs and switch_stack.  Spilling an
398  * integer to address X causes bit N in ar.unat to be set to the NaT bit of the register,
399  * with N=(X & 0x1ff)/8.  Thus, copying the unat value preserves the NaT bits ONLY if the
400  * pt_regs structure in the parent is congruent to that of the child, modulo 512.  Since
401  * the stack is page aligned and the page size is at least 4KB, this is always the case,
402  * so there is nothing to worry about.
403  */
404 int
405 copy_thread (int nr, unsigned long clone_flags,
406 	     unsigned long user_stack_base, unsigned long user_stack_size,
407 	     struct task_struct *p, struct pt_regs *regs)
408 {
409 	extern char ia64_ret_from_clone, ia32_ret_from_clone;
410 	struct switch_stack *child_stack, *stack;
411 	unsigned long rbs, child_rbs, rbs_size;
412 	struct pt_regs *child_ptregs;
413 	int retval = 0;
414 
415 #ifdef CONFIG_SMP
416 	/*
417 	 * For SMP idle threads, fork_by_hand() calls do_fork with
418 	 * NULL regs.
419 	 */
420 	if (!regs)
421 		return 0;
422 #endif
423 
424 	stack = ((struct switch_stack *) regs) - 1;
425 
426 	child_ptregs = (struct pt_regs *) ((unsigned long) p + IA64_STK_OFFSET) - 1;
427 	child_stack = (struct switch_stack *) child_ptregs - 1;
428 
429 	/* copy parent's switch_stack & pt_regs to child: */
430 	memcpy(child_stack, stack, sizeof(*child_ptregs) + sizeof(*child_stack));
431 
432 	rbs = (unsigned long) current + IA64_RBS_OFFSET;
433 	child_rbs = (unsigned long) p + IA64_RBS_OFFSET;
434 	rbs_size = stack->ar_bspstore - rbs;
435 
436 	/* copy the parent's register backing store to the child: */
437 	memcpy((void *) child_rbs, (void *) rbs, rbs_size);
438 
439 	if (likely(user_mode(child_ptregs))) {
440 		if ((clone_flags & CLONE_SETTLS) && !IS_IA32_PROCESS(regs))
441 			child_ptregs->r13 = regs->r16;	/* see sys_clone2() in entry.S */
442 		if (user_stack_base) {
443 			child_ptregs->r12 = user_stack_base + user_stack_size - 16;
444 			child_ptregs->ar_bspstore = user_stack_base;
445 			child_ptregs->ar_rnat = 0;
446 			child_ptregs->loadrs = 0;
447 		}
448 	} else {
449 		/*
450 		 * Note: we simply preserve the relative position of
451 		 * the stack pointer here.  There is no need to
452 		 * allocate a scratch area here, since that will have
453 		 * been taken care of by the caller of sys_clone()
454 		 * already.
455 		 */
456 		child_ptregs->r12 = (unsigned long) child_ptregs - 16; /* kernel sp */
457 		child_ptregs->r13 = (unsigned long) p;		/* set `current' pointer */
458 	}
459 	child_stack->ar_bspstore = child_rbs + rbs_size;
460 	if (IS_IA32_PROCESS(regs))
461 		child_stack->b0 = (unsigned long) &ia32_ret_from_clone;
462 	else
463 		child_stack->b0 = (unsigned long) &ia64_ret_from_clone;
464 
465 	/* copy parts of thread_struct: */
466 	p->thread.ksp = (unsigned long) child_stack - 16;
467 
468 	/* stop some PSR bits from being inherited.
469 	 * the psr.up/psr.pp bits must be cleared on fork but inherited on execve()
470 	 * therefore we must specify them explicitly here and not include them in
471 	 * IA64_PSR_BITS_TO_CLEAR.
472 	 */
473 	child_ptregs->cr_ipsr = ((child_ptregs->cr_ipsr | IA64_PSR_BITS_TO_SET)
474 				 & ~(IA64_PSR_BITS_TO_CLEAR | IA64_PSR_PP | IA64_PSR_UP));
475 
476 	/*
477 	 * NOTE: The calling convention considers all floating point
478 	 * registers in the high partition (fph) to be scratch.  Since
479 	 * the only way to get to this point is through a system call,
480 	 * we know that the values in fph are all dead.  Hence, there
481 	 * is no need to inherit the fph state from the parent to the
482 	 * child and all we have to do is to make sure that
483 	 * IA64_THREAD_FPH_VALID is cleared in the child.
484 	 *
485 	 * XXX We could push this optimization a bit further by
486 	 * clearing IA64_THREAD_FPH_VALID on ANY system call.
487 	 * However, it's not clear this is worth doing.  Also, it
488 	 * would be a slight deviation from the normal Linux system
489 	 * call behavior where scratch registers are preserved across
490 	 * system calls (unless used by the system call itself).
491 	 */
492 #	define THREAD_FLAGS_TO_CLEAR	(IA64_THREAD_FPH_VALID | IA64_THREAD_DBG_VALID \
493 					 | IA64_THREAD_PM_VALID)
494 #	define THREAD_FLAGS_TO_SET	0
495 	p->thread.flags = ((current->thread.flags & ~THREAD_FLAGS_TO_CLEAR)
496 			   | THREAD_FLAGS_TO_SET);
497 	ia64_drop_fpu(p);	/* don't pick up stale state from a CPU's fph */
498 #ifdef CONFIG_IA32_SUPPORT
499 	/*
500 	 * If we're cloning an IA32 task then save the IA32 extra
501 	 * state from the current task to the new task
502 	 */
503 	if (IS_IA32_PROCESS(task_pt_regs(current))) {
504 		ia32_save_state(p);
505 		if (clone_flags & CLONE_SETTLS)
506 			retval = ia32_clone_tls(p, child_ptregs);
507 
508 		/* Copy partially mapped page list */
509 		if (!retval)
510 			retval = ia32_copy_ia64_partial_page_list(p,
511 								clone_flags);
512 	}
513 #endif
514 
515 #ifdef CONFIG_PERFMON
516 	if (current->thread.pfm_context)
517 		pfm_inherit(p, child_ptregs);
518 #endif
519 	return retval;
520 }
521 
522 static void
523 do_copy_task_regs (struct task_struct *task, struct unw_frame_info *info, void *arg)
524 {
525 	unsigned long mask, sp, nat_bits = 0, ar_rnat, urbs_end, cfm;
526 	unsigned long uninitialized_var(ip);	/* GCC be quiet */
527 	elf_greg_t *dst = arg;
528 	struct pt_regs *pt;
529 	char nat;
530 	int i;
531 
532 	memset(dst, 0, sizeof(elf_gregset_t));	/* don't leak any kernel bits to user-level */
533 
534 	if (unw_unwind_to_user(info) < 0)
535 		return;
536 
537 	unw_get_sp(info, &sp);
538 	pt = (struct pt_regs *) (sp + 16);
539 
540 	urbs_end = ia64_get_user_rbs_end(task, pt, &cfm);
541 
542 	if (ia64_sync_user_rbs(task, info->sw, pt->ar_bspstore, urbs_end) < 0)
543 		return;
544 
545 	ia64_peek(task, info->sw, urbs_end, (long) ia64_rse_rnat_addr((long *) urbs_end),
546 		  &ar_rnat);
547 
548 	/*
549 	 * coredump format:
550 	 *	r0-r31
551 	 *	NaT bits (for r0-r31; bit N == 1 iff rN is a NaT)
552 	 *	predicate registers (p0-p63)
553 	 *	b0-b7
554 	 *	ip cfm user-mask
555 	 *	ar.rsc ar.bsp ar.bspstore ar.rnat
556 	 *	ar.ccv ar.unat ar.fpsr ar.pfs ar.lc ar.ec
557 	 */
558 
559 	/* r0 is zero */
560 	for (i = 1, mask = (1UL << i); i < 32; ++i) {
561 		unw_get_gr(info, i, &dst[i], &nat);
562 		if (nat)
563 			nat_bits |= mask;
564 		mask <<= 1;
565 	}
566 	dst[32] = nat_bits;
567 	unw_get_pr(info, &dst[33]);
568 
569 	for (i = 0; i < 8; ++i)
570 		unw_get_br(info, i, &dst[34 + i]);
571 
572 	unw_get_rp(info, &ip);
573 	dst[42] = ip + ia64_psr(pt)->ri;
574 	dst[43] = cfm;
575 	dst[44] = pt->cr_ipsr & IA64_PSR_UM;
576 
577 	unw_get_ar(info, UNW_AR_RSC, &dst[45]);
578 	/*
579 	 * For bsp and bspstore, unw_get_ar() would return the kernel
580 	 * addresses, but we need the user-level addresses instead:
581 	 */
582 	dst[46] = urbs_end;	/* note: by convention PT_AR_BSP points to the end of the urbs! */
583 	dst[47] = pt->ar_bspstore;
584 	dst[48] = ar_rnat;
585 	unw_get_ar(info, UNW_AR_CCV, &dst[49]);
586 	unw_get_ar(info, UNW_AR_UNAT, &dst[50]);
587 	unw_get_ar(info, UNW_AR_FPSR, &dst[51]);
588 	dst[52] = pt->ar_pfs;	/* UNW_AR_PFS is == to pt->cr_ifs for interrupt frames */
589 	unw_get_ar(info, UNW_AR_LC, &dst[53]);
590 	unw_get_ar(info, UNW_AR_EC, &dst[54]);
591 	unw_get_ar(info, UNW_AR_CSD, &dst[55]);
592 	unw_get_ar(info, UNW_AR_SSD, &dst[56]);
593 }
594 
595 void
596 do_dump_task_fpu (struct task_struct *task, struct unw_frame_info *info, void *arg)
597 {
598 	elf_fpreg_t *dst = arg;
599 	int i;
600 
601 	memset(dst, 0, sizeof(elf_fpregset_t));	/* don't leak any "random" bits */
602 
603 	if (unw_unwind_to_user(info) < 0)
604 		return;
605 
606 	/* f0 is 0.0, f1 is 1.0 */
607 
608 	for (i = 2; i < 32; ++i)
609 		unw_get_fr(info, i, dst + i);
610 
611 	ia64_flush_fph(task);
612 	if ((task->thread.flags & IA64_THREAD_FPH_VALID) != 0)
613 		memcpy(dst + 32, task->thread.fph, 96*16);
614 }
615 
616 void
617 do_copy_regs (struct unw_frame_info *info, void *arg)
618 {
619 	do_copy_task_regs(current, info, arg);
620 }
621 
622 void
623 do_dump_fpu (struct unw_frame_info *info, void *arg)
624 {
625 	do_dump_task_fpu(current, info, arg);
626 }
627 
628 int
629 dump_task_regs(struct task_struct *task, elf_gregset_t *regs)
630 {
631 	struct unw_frame_info tcore_info;
632 
633 	if (current == task) {
634 		unw_init_running(do_copy_regs, regs);
635 	} else {
636 		memset(&tcore_info, 0, sizeof(tcore_info));
637 		unw_init_from_blocked_task(&tcore_info, task);
638 		do_copy_task_regs(task, &tcore_info, regs);
639 	}
640 	return 1;
641 }
642 
643 void
644 ia64_elf_core_copy_regs (struct pt_regs *pt, elf_gregset_t dst)
645 {
646 	unw_init_running(do_copy_regs, dst);
647 }
648 
649 int
650 dump_task_fpu (struct task_struct *task, elf_fpregset_t *dst)
651 {
652 	struct unw_frame_info tcore_info;
653 
654 	if (current == task) {
655 		unw_init_running(do_dump_fpu, dst);
656 	} else {
657 		memset(&tcore_info, 0, sizeof(tcore_info));
658 		unw_init_from_blocked_task(&tcore_info, task);
659 		do_dump_task_fpu(task, &tcore_info, dst);
660 	}
661 	return 1;
662 }
663 
664 int
665 dump_fpu (struct pt_regs *pt, elf_fpregset_t dst)
666 {
667 	unw_init_running(do_dump_fpu, dst);
668 	return 1;	/* f0-f31 are always valid so we always return 1 */
669 }
670 
671 long
672 sys_execve (char __user *filename, char __user * __user *argv, char __user * __user *envp,
673 	    struct pt_regs *regs)
674 {
675 	char *fname;
676 	int error;
677 
678 	fname = getname(filename);
679 	error = PTR_ERR(fname);
680 	if (IS_ERR(fname))
681 		goto out;
682 	error = do_execve(fname, argv, envp, regs);
683 	putname(fname);
684 out:
685 	return error;
686 }
687 
688 pid_t
689 kernel_thread (int (*fn)(void *), void *arg, unsigned long flags)
690 {
691 	extern void start_kernel_thread (void);
692 	unsigned long *helper_fptr = (unsigned long *) &start_kernel_thread;
693 	struct {
694 		struct switch_stack sw;
695 		struct pt_regs pt;
696 	} regs;
697 
698 	memset(&regs, 0, sizeof(regs));
699 	regs.pt.cr_iip = helper_fptr[0];	/* set entry point (IP) */
700 	regs.pt.r1 = helper_fptr[1];		/* set GP */
701 	regs.pt.r9 = (unsigned long) fn;	/* 1st argument */
702 	regs.pt.r11 = (unsigned long) arg;	/* 2nd argument */
703 	/* Preserve PSR bits, except for bits 32-34 and 37-45, which we can't read.  */
704 	regs.pt.cr_ipsr = ia64_getreg(_IA64_REG_PSR) | IA64_PSR_BN;
705 	regs.pt.cr_ifs = 1UL << 63;		/* mark as valid, empty frame */
706 	regs.sw.ar_fpsr = regs.pt.ar_fpsr = ia64_getreg(_IA64_REG_AR_FPSR);
707 	regs.sw.ar_bspstore = (unsigned long) current + IA64_RBS_OFFSET;
708 	regs.sw.pr = (1 << PRED_KERNEL_STACK);
709 	return do_fork(flags | CLONE_VM | CLONE_UNTRACED, 0, &regs.pt, 0, NULL, NULL);
710 }
711 EXPORT_SYMBOL(kernel_thread);
712 
713 /* This gets called from kernel_thread() via ia64_invoke_thread_helper().  */
714 int
715 kernel_thread_helper (int (*fn)(void *), void *arg)
716 {
717 #ifdef CONFIG_IA32_SUPPORT
718 	if (IS_IA32_PROCESS(task_pt_regs(current))) {
719 		/* A kernel thread is always a 64-bit process. */
720 		current->thread.map_base  = DEFAULT_MAP_BASE;
721 		current->thread.task_size = DEFAULT_TASK_SIZE;
722 		ia64_set_kr(IA64_KR_IO_BASE, current->thread.old_iob);
723 		ia64_set_kr(IA64_KR_TSSD, current->thread.old_k1);
724 	}
725 #endif
726 	return (*fn)(arg);
727 }
728 
729 /*
730  * Flush thread state.  This is called when a thread does an execve().
731  */
732 void
733 flush_thread (void)
734 {
735 	/* drop floating-point and debug-register state if it exists: */
736 	current->thread.flags &= ~(IA64_THREAD_FPH_VALID | IA64_THREAD_DBG_VALID);
737 	ia64_drop_fpu(current);
738 #ifdef CONFIG_IA32_SUPPORT
739 	if (IS_IA32_PROCESS(task_pt_regs(current))) {
740 		ia32_drop_ia64_partial_page_list(current);
741 		current->thread.task_size = IA32_PAGE_OFFSET;
742 		set_fs(USER_DS);
743 		memset(current->thread.tls_array, 0, sizeof(current->thread.tls_array));
744 	}
745 #endif
746 }
747 
748 /*
749  * Clean up state associated with current thread.  This is called when
750  * the thread calls exit().
751  */
752 void
753 exit_thread (void)
754 {
755 
756 	ia64_drop_fpu(current);
757 #ifdef CONFIG_PERFMON
758        /* if needed, stop monitoring and flush state to perfmon context */
759 	if (current->thread.pfm_context)
760 		pfm_exit_thread(current);
761 
762 	/* free debug register resources */
763 	if (current->thread.flags & IA64_THREAD_DBG_VALID)
764 		pfm_release_debug_registers(current);
765 #endif
766 	if (IS_IA32_PROCESS(task_pt_regs(current)))
767 		ia32_drop_ia64_partial_page_list(current);
768 }
769 
770 unsigned long
771 get_wchan (struct task_struct *p)
772 {
773 	struct unw_frame_info info;
774 	unsigned long ip;
775 	int count = 0;
776 
777 	if (!p || p == current || p->state == TASK_RUNNING)
778 		return 0;
779 
780 	/*
781 	 * Note: p may not be a blocked task (it could be current or
782 	 * another process running on some other CPU.  Rather than
783 	 * trying to determine if p is really blocked, we just assume
784 	 * it's blocked and rely on the unwind routines to fail
785 	 * gracefully if the process wasn't really blocked after all.
786 	 * --davidm 99/12/15
787 	 */
788 	unw_init_from_blocked_task(&info, p);
789 	do {
790 		if (p->state == TASK_RUNNING)
791 			return 0;
792 		if (unw_unwind(&info) < 0)
793 			return 0;
794 		unw_get_ip(&info, &ip);
795 		if (!in_sched_functions(ip))
796 			return ip;
797 	} while (count++ < 16);
798 	return 0;
799 }
800 
801 void
802 cpu_halt (void)
803 {
804 	pal_power_mgmt_info_u_t power_info[8];
805 	unsigned long min_power;
806 	int i, min_power_state;
807 
808 	if (ia64_pal_halt_info(power_info) != 0)
809 		return;
810 
811 	min_power_state = 0;
812 	min_power = power_info[0].pal_power_mgmt_info_s.power_consumption;
813 	for (i = 1; i < 8; ++i)
814 		if (power_info[i].pal_power_mgmt_info_s.im
815 		    && power_info[i].pal_power_mgmt_info_s.power_consumption < min_power) {
816 			min_power = power_info[i].pal_power_mgmt_info_s.power_consumption;
817 			min_power_state = i;
818 		}
819 
820 	while (1)
821 		ia64_pal_halt(min_power_state);
822 }
823 
824 void machine_shutdown(void)
825 {
826 #ifdef CONFIG_HOTPLUG_CPU
827 	int cpu;
828 
829 	for_each_online_cpu(cpu) {
830 		if (cpu != smp_processor_id())
831 			cpu_down(cpu);
832 	}
833 #endif
834 #ifdef CONFIG_KEXEC
835 	kexec_disable_iosapic();
836 #endif
837 }
838 
839 void
840 machine_restart (char *restart_cmd)
841 {
842 	(void) notify_die(DIE_MACHINE_RESTART, restart_cmd, NULL, 0, 0, 0);
843 	(*efi.reset_system)(EFI_RESET_WARM, 0, 0, NULL);
844 }
845 
846 void
847 machine_halt (void)
848 {
849 	(void) notify_die(DIE_MACHINE_HALT, "", NULL, 0, 0, 0);
850 	cpu_halt();
851 }
852 
853 void
854 machine_power_off (void)
855 {
856 	if (pm_power_off)
857 		pm_power_off();
858 	machine_halt();
859 }
860 
861