xref: /linux/arch/sparc/kernel/process_64.c (revision 0d456bad36d42d16022be045c8a53ddbb59ee478)
1 /*  arch/sparc64/kernel/process.c
2  *
3  *  Copyright (C) 1995, 1996, 2008 David S. Miller (davem@davemloft.net)
4  *  Copyright (C) 1996       Eddie C. Dost   (ecd@skynet.be)
5  *  Copyright (C) 1997, 1998 Jakub Jelinek   (jj@sunsite.mff.cuni.cz)
6  */
7 
8 /*
9  * This file handles the architecture-dependent parts of process handling..
10  */
11 
12 #include <stdarg.h>
13 
14 #include <linux/errno.h>
15 #include <linux/export.h>
16 #include <linux/sched.h>
17 #include <linux/kernel.h>
18 #include <linux/mm.h>
19 #include <linux/fs.h>
20 #include <linux/smp.h>
21 #include <linux/stddef.h>
22 #include <linux/ptrace.h>
23 #include <linux/slab.h>
24 #include <linux/user.h>
25 #include <linux/delay.h>
26 #include <linux/compat.h>
27 #include <linux/tick.h>
28 #include <linux/init.h>
29 #include <linux/cpu.h>
30 #include <linux/perf_event.h>
31 #include <linux/elfcore.h>
32 #include <linux/sysrq.h>
33 #include <linux/nmi.h>
34 
35 #include <asm/uaccess.h>
36 #include <asm/page.h>
37 #include <asm/pgalloc.h>
38 #include <asm/pgtable.h>
39 #include <asm/processor.h>
40 #include <asm/pstate.h>
41 #include <asm/elf.h>
42 #include <asm/fpumacro.h>
43 #include <asm/head.h>
44 #include <asm/cpudata.h>
45 #include <asm/mmu_context.h>
46 #include <asm/unistd.h>
47 #include <asm/hypervisor.h>
48 #include <asm/syscalls.h>
49 #include <asm/irq_regs.h>
50 #include <asm/smp.h>
51 #include <asm/pcr.h>
52 
53 #include "kstack.h"
54 
55 static void sparc64_yield(int cpu)
56 {
57 	if (tlb_type != hypervisor) {
58 		touch_nmi_watchdog();
59 		return;
60 	}
61 
62 	clear_thread_flag(TIF_POLLING_NRFLAG);
63 	smp_mb__after_clear_bit();
64 
65 	while (!need_resched() && !cpu_is_offline(cpu)) {
66 		unsigned long pstate;
67 
68 		/* Disable interrupts. */
69 		__asm__ __volatile__(
70 			"rdpr %%pstate, %0\n\t"
71 			"andn %0, %1, %0\n\t"
72 			"wrpr %0, %%g0, %%pstate"
73 			: "=&r" (pstate)
74 			: "i" (PSTATE_IE));
75 
76 		if (!need_resched() && !cpu_is_offline(cpu))
77 			sun4v_cpu_yield();
78 
79 		/* Re-enable interrupts. */
80 		__asm__ __volatile__(
81 			"rdpr %%pstate, %0\n\t"
82 			"or %0, %1, %0\n\t"
83 			"wrpr %0, %%g0, %%pstate"
84 			: "=&r" (pstate)
85 			: "i" (PSTATE_IE));
86 	}
87 
88 	set_thread_flag(TIF_POLLING_NRFLAG);
89 }
90 
91 /* The idle loop on sparc64. */
92 void cpu_idle(void)
93 {
94 	int cpu = smp_processor_id();
95 
96 	set_thread_flag(TIF_POLLING_NRFLAG);
97 
98 	while(1) {
99 		tick_nohz_idle_enter();
100 		rcu_idle_enter();
101 
102 		while (!need_resched() && !cpu_is_offline(cpu))
103 			sparc64_yield(cpu);
104 
105 		rcu_idle_exit();
106 		tick_nohz_idle_exit();
107 
108 #ifdef CONFIG_HOTPLUG_CPU
109 		if (cpu_is_offline(cpu)) {
110 			sched_preempt_enable_no_resched();
111 			cpu_play_dead();
112 		}
113 #endif
114 		schedule_preempt_disabled();
115 	}
116 }
117 
118 #ifdef CONFIG_COMPAT
119 static void show_regwindow32(struct pt_regs *regs)
120 {
121 	struct reg_window32 __user *rw;
122 	struct reg_window32 r_w;
123 	mm_segment_t old_fs;
124 
125 	__asm__ __volatile__ ("flushw");
126 	rw = compat_ptr((unsigned)regs->u_regs[14]);
127 	old_fs = get_fs();
128 	set_fs (USER_DS);
129 	if (copy_from_user (&r_w, rw, sizeof(r_w))) {
130 		set_fs (old_fs);
131 		return;
132 	}
133 
134 	set_fs (old_fs);
135 	printk("l0: %08x l1: %08x l2: %08x l3: %08x "
136 	       "l4: %08x l5: %08x l6: %08x l7: %08x\n",
137 	       r_w.locals[0], r_w.locals[1], r_w.locals[2], r_w.locals[3],
138 	       r_w.locals[4], r_w.locals[5], r_w.locals[6], r_w.locals[7]);
139 	printk("i0: %08x i1: %08x i2: %08x i3: %08x "
140 	       "i4: %08x i5: %08x i6: %08x i7: %08x\n",
141 	       r_w.ins[0], r_w.ins[1], r_w.ins[2], r_w.ins[3],
142 	       r_w.ins[4], r_w.ins[5], r_w.ins[6], r_w.ins[7]);
143 }
144 #else
145 #define show_regwindow32(regs)	do { } while (0)
146 #endif
147 
148 static void show_regwindow(struct pt_regs *regs)
149 {
150 	struct reg_window __user *rw;
151 	struct reg_window *rwk;
152 	struct reg_window r_w;
153 	mm_segment_t old_fs;
154 
155 	if ((regs->tstate & TSTATE_PRIV) || !(test_thread_flag(TIF_32BIT))) {
156 		__asm__ __volatile__ ("flushw");
157 		rw = (struct reg_window __user *)
158 			(regs->u_regs[14] + STACK_BIAS);
159 		rwk = (struct reg_window *)
160 			(regs->u_regs[14] + STACK_BIAS);
161 		if (!(regs->tstate & TSTATE_PRIV)) {
162 			old_fs = get_fs();
163 			set_fs (USER_DS);
164 			if (copy_from_user (&r_w, rw, sizeof(r_w))) {
165 				set_fs (old_fs);
166 				return;
167 			}
168 			rwk = &r_w;
169 			set_fs (old_fs);
170 		}
171 	} else {
172 		show_regwindow32(regs);
173 		return;
174 	}
175 	printk("l0: %016lx l1: %016lx l2: %016lx l3: %016lx\n",
176 	       rwk->locals[0], rwk->locals[1], rwk->locals[2], rwk->locals[3]);
177 	printk("l4: %016lx l5: %016lx l6: %016lx l7: %016lx\n",
178 	       rwk->locals[4], rwk->locals[5], rwk->locals[6], rwk->locals[7]);
179 	printk("i0: %016lx i1: %016lx i2: %016lx i3: %016lx\n",
180 	       rwk->ins[0], rwk->ins[1], rwk->ins[2], rwk->ins[3]);
181 	printk("i4: %016lx i5: %016lx i6: %016lx i7: %016lx\n",
182 	       rwk->ins[4], rwk->ins[5], rwk->ins[6], rwk->ins[7]);
183 	if (regs->tstate & TSTATE_PRIV)
184 		printk("I7: <%pS>\n", (void *) rwk->ins[7]);
185 }
186 
187 void show_regs(struct pt_regs *regs)
188 {
189 	printk("TSTATE: %016lx TPC: %016lx TNPC: %016lx Y: %08x    %s\n", regs->tstate,
190 	       regs->tpc, regs->tnpc, regs->y, print_tainted());
191 	printk("TPC: <%pS>\n", (void *) regs->tpc);
192 	printk("g0: %016lx g1: %016lx g2: %016lx g3: %016lx\n",
193 	       regs->u_regs[0], regs->u_regs[1], regs->u_regs[2],
194 	       regs->u_regs[3]);
195 	printk("g4: %016lx g5: %016lx g6: %016lx g7: %016lx\n",
196 	       regs->u_regs[4], regs->u_regs[5], regs->u_regs[6],
197 	       regs->u_regs[7]);
198 	printk("o0: %016lx o1: %016lx o2: %016lx o3: %016lx\n",
199 	       regs->u_regs[8], regs->u_regs[9], regs->u_regs[10],
200 	       regs->u_regs[11]);
201 	printk("o4: %016lx o5: %016lx sp: %016lx ret_pc: %016lx\n",
202 	       regs->u_regs[12], regs->u_regs[13], regs->u_regs[14],
203 	       regs->u_regs[15]);
204 	printk("RPC: <%pS>\n", (void *) regs->u_regs[15]);
205 	show_regwindow(regs);
206 	show_stack(current, (unsigned long *) regs->u_regs[UREG_FP]);
207 }
208 
209 union global_cpu_snapshot global_cpu_snapshot[NR_CPUS];
210 static DEFINE_SPINLOCK(global_cpu_snapshot_lock);
211 
212 static void __global_reg_self(struct thread_info *tp, struct pt_regs *regs,
213 			      int this_cpu)
214 {
215 	struct global_reg_snapshot *rp;
216 
217 	flushw_all();
218 
219 	rp = &global_cpu_snapshot[this_cpu].reg;
220 
221 	rp->tstate = regs->tstate;
222 	rp->tpc = regs->tpc;
223 	rp->tnpc = regs->tnpc;
224 	rp->o7 = regs->u_regs[UREG_I7];
225 
226 	if (regs->tstate & TSTATE_PRIV) {
227 		struct reg_window *rw;
228 
229 		rw = (struct reg_window *)
230 			(regs->u_regs[UREG_FP] + STACK_BIAS);
231 		if (kstack_valid(tp, (unsigned long) rw)) {
232 			rp->i7 = rw->ins[7];
233 			rw = (struct reg_window *)
234 				(rw->ins[6] + STACK_BIAS);
235 			if (kstack_valid(tp, (unsigned long) rw))
236 				rp->rpc = rw->ins[7];
237 		}
238 	} else {
239 		rp->i7 = 0;
240 		rp->rpc = 0;
241 	}
242 	rp->thread = tp;
243 }
244 
245 /* In order to avoid hangs we do not try to synchronize with the
246  * global register dump client cpus.  The last store they make is to
247  * the thread pointer, so do a short poll waiting for that to become
248  * non-NULL.
249  */
250 static void __global_reg_poll(struct global_reg_snapshot *gp)
251 {
252 	int limit = 0;
253 
254 	while (!gp->thread && ++limit < 100) {
255 		barrier();
256 		udelay(1);
257 	}
258 }
259 
260 void arch_trigger_all_cpu_backtrace(void)
261 {
262 	struct thread_info *tp = current_thread_info();
263 	struct pt_regs *regs = get_irq_regs();
264 	unsigned long flags;
265 	int this_cpu, cpu;
266 
267 	if (!regs)
268 		regs = tp->kregs;
269 
270 	spin_lock_irqsave(&global_cpu_snapshot_lock, flags);
271 
272 	memset(global_cpu_snapshot, 0, sizeof(global_cpu_snapshot));
273 
274 	this_cpu = raw_smp_processor_id();
275 
276 	__global_reg_self(tp, regs, this_cpu);
277 
278 	smp_fetch_global_regs();
279 
280 	for_each_online_cpu(cpu) {
281 		struct global_reg_snapshot *gp = &global_cpu_snapshot[cpu].reg;
282 
283 		__global_reg_poll(gp);
284 
285 		tp = gp->thread;
286 		printk("%c CPU[%3d]: TSTATE[%016lx] TPC[%016lx] TNPC[%016lx] TASK[%s:%d]\n",
287 		       (cpu == this_cpu ? '*' : ' '), cpu,
288 		       gp->tstate, gp->tpc, gp->tnpc,
289 		       ((tp && tp->task) ? tp->task->comm : "NULL"),
290 		       ((tp && tp->task) ? tp->task->pid : -1));
291 
292 		if (gp->tstate & TSTATE_PRIV) {
293 			printk("             TPC[%pS] O7[%pS] I7[%pS] RPC[%pS]\n",
294 			       (void *) gp->tpc,
295 			       (void *) gp->o7,
296 			       (void *) gp->i7,
297 			       (void *) gp->rpc);
298 		} else {
299 			printk("             TPC[%lx] O7[%lx] I7[%lx] RPC[%lx]\n",
300 			       gp->tpc, gp->o7, gp->i7, gp->rpc);
301 		}
302 	}
303 
304 	memset(global_cpu_snapshot, 0, sizeof(global_cpu_snapshot));
305 
306 	spin_unlock_irqrestore(&global_cpu_snapshot_lock, flags);
307 }
308 
309 #ifdef CONFIG_MAGIC_SYSRQ
310 
311 static void sysrq_handle_globreg(int key)
312 {
313 	arch_trigger_all_cpu_backtrace();
314 }
315 
316 static struct sysrq_key_op sparc_globalreg_op = {
317 	.handler	= sysrq_handle_globreg,
318 	.help_msg	= "global-regs(Y)",
319 	.action_msg	= "Show Global CPU Regs",
320 };
321 
322 static void __global_pmu_self(int this_cpu)
323 {
324 	struct global_pmu_snapshot *pp;
325 	int i, num;
326 
327 	pp = &global_cpu_snapshot[this_cpu].pmu;
328 
329 	num = 1;
330 	if (tlb_type == hypervisor &&
331 	    sun4v_chip_type >= SUN4V_CHIP_NIAGARA4)
332 		num = 4;
333 
334 	for (i = 0; i < num; i++) {
335 		pp->pcr[i] = pcr_ops->read_pcr(i);
336 		pp->pic[i] = pcr_ops->read_pic(i);
337 	}
338 }
339 
340 static void __global_pmu_poll(struct global_pmu_snapshot *pp)
341 {
342 	int limit = 0;
343 
344 	while (!pp->pcr[0] && ++limit < 100) {
345 		barrier();
346 		udelay(1);
347 	}
348 }
349 
350 static void pmu_snapshot_all_cpus(void)
351 {
352 	unsigned long flags;
353 	int this_cpu, cpu;
354 
355 	spin_lock_irqsave(&global_cpu_snapshot_lock, flags);
356 
357 	memset(global_cpu_snapshot, 0, sizeof(global_cpu_snapshot));
358 
359 	this_cpu = raw_smp_processor_id();
360 
361 	__global_pmu_self(this_cpu);
362 
363 	smp_fetch_global_pmu();
364 
365 	for_each_online_cpu(cpu) {
366 		struct global_pmu_snapshot *pp = &global_cpu_snapshot[cpu].pmu;
367 
368 		__global_pmu_poll(pp);
369 
370 		printk("%c CPU[%3d]: PCR[%08lx:%08lx:%08lx:%08lx] PIC[%08lx:%08lx:%08lx:%08lx]\n",
371 		       (cpu == this_cpu ? '*' : ' '), cpu,
372 		       pp->pcr[0], pp->pcr[1], pp->pcr[2], pp->pcr[3],
373 		       pp->pic[0], pp->pic[1], pp->pic[2], pp->pic[3]);
374 	}
375 
376 	memset(global_cpu_snapshot, 0, sizeof(global_cpu_snapshot));
377 
378 	spin_unlock_irqrestore(&global_cpu_snapshot_lock, flags);
379 }
380 
381 static void sysrq_handle_globpmu(int key)
382 {
383 	pmu_snapshot_all_cpus();
384 }
385 
386 static struct sysrq_key_op sparc_globalpmu_op = {
387 	.handler	= sysrq_handle_globpmu,
388 	.help_msg	= "global-pmu(X)",
389 	.action_msg	= "Show Global PMU Regs",
390 };
391 
392 static int __init sparc_sysrq_init(void)
393 {
394 	int ret = register_sysrq_key('y', &sparc_globalreg_op);
395 
396 	if (!ret)
397 		ret = register_sysrq_key('x', &sparc_globalpmu_op);
398 	return ret;
399 }
400 
401 core_initcall(sparc_sysrq_init);
402 
403 #endif
404 
405 unsigned long thread_saved_pc(struct task_struct *tsk)
406 {
407 	struct thread_info *ti = task_thread_info(tsk);
408 	unsigned long ret = 0xdeadbeefUL;
409 
410 	if (ti && ti->ksp) {
411 		unsigned long *sp;
412 		sp = (unsigned long *)(ti->ksp + STACK_BIAS);
413 		if (((unsigned long)sp & (sizeof(long) - 1)) == 0UL &&
414 		    sp[14]) {
415 			unsigned long *fp;
416 			fp = (unsigned long *)(sp[14] + STACK_BIAS);
417 			if (((unsigned long)fp & (sizeof(long) - 1)) == 0UL)
418 				ret = fp[15];
419 		}
420 	}
421 	return ret;
422 }
423 
424 /* Free current thread data structures etc.. */
425 void exit_thread(void)
426 {
427 	struct thread_info *t = current_thread_info();
428 
429 	if (t->utraps) {
430 		if (t->utraps[0] < 2)
431 			kfree (t->utraps);
432 		else
433 			t->utraps[0]--;
434 	}
435 }
436 
437 void flush_thread(void)
438 {
439 	struct thread_info *t = current_thread_info();
440 	struct mm_struct *mm;
441 
442 	mm = t->task->mm;
443 	if (mm)
444 		tsb_context_switch(mm);
445 
446 	set_thread_wsaved(0);
447 
448 	/* Clear FPU register state. */
449 	t->fpsaved[0] = 0;
450 }
451 
452 /* It's a bit more tricky when 64-bit tasks are involved... */
453 static unsigned long clone_stackframe(unsigned long csp, unsigned long psp)
454 {
455 	bool stack_64bit = test_thread_64bit_stack(psp);
456 	unsigned long fp, distance, rval;
457 
458 	if (stack_64bit) {
459 		csp += STACK_BIAS;
460 		psp += STACK_BIAS;
461 		__get_user(fp, &(((struct reg_window __user *)psp)->ins[6]));
462 		fp += STACK_BIAS;
463 		if (test_thread_flag(TIF_32BIT))
464 			fp &= 0xffffffff;
465 	} else
466 		__get_user(fp, &(((struct reg_window32 __user *)psp)->ins[6]));
467 
468 	/* Now align the stack as this is mandatory in the Sparc ABI
469 	 * due to how register windows work.  This hides the
470 	 * restriction from thread libraries etc.
471 	 */
472 	csp &= ~15UL;
473 
474 	distance = fp - psp;
475 	rval = (csp - distance);
476 	if (copy_in_user((void __user *) rval, (void __user *) psp, distance))
477 		rval = 0;
478 	else if (!stack_64bit) {
479 		if (put_user(((u32)csp),
480 			     &(((struct reg_window32 __user *)rval)->ins[6])))
481 			rval = 0;
482 	} else {
483 		if (put_user(((u64)csp - STACK_BIAS),
484 			     &(((struct reg_window __user *)rval)->ins[6])))
485 			rval = 0;
486 		else
487 			rval = rval - STACK_BIAS;
488 	}
489 
490 	return rval;
491 }
492 
493 /* Standard stuff. */
494 static inline void shift_window_buffer(int first_win, int last_win,
495 				       struct thread_info *t)
496 {
497 	int i;
498 
499 	for (i = first_win; i < last_win; i++) {
500 		t->rwbuf_stkptrs[i] = t->rwbuf_stkptrs[i+1];
501 		memcpy(&t->reg_window[i], &t->reg_window[i+1],
502 		       sizeof(struct reg_window));
503 	}
504 }
505 
506 void synchronize_user_stack(void)
507 {
508 	struct thread_info *t = current_thread_info();
509 	unsigned long window;
510 
511 	flush_user_windows();
512 	if ((window = get_thread_wsaved()) != 0) {
513 		window -= 1;
514 		do {
515 			struct reg_window *rwin = &t->reg_window[window];
516 			int winsize = sizeof(struct reg_window);
517 			unsigned long sp;
518 
519 			sp = t->rwbuf_stkptrs[window];
520 
521 			if (test_thread_64bit_stack(sp))
522 				sp += STACK_BIAS;
523 			else
524 				winsize = sizeof(struct reg_window32);
525 
526 			if (!copy_to_user((char __user *)sp, rwin, winsize)) {
527 				shift_window_buffer(window, get_thread_wsaved() - 1, t);
528 				set_thread_wsaved(get_thread_wsaved() - 1);
529 			}
530 		} while (window--);
531 	}
532 }
533 
534 static void stack_unaligned(unsigned long sp)
535 {
536 	siginfo_t info;
537 
538 	info.si_signo = SIGBUS;
539 	info.si_errno = 0;
540 	info.si_code = BUS_ADRALN;
541 	info.si_addr = (void __user *) sp;
542 	info.si_trapno = 0;
543 	force_sig_info(SIGBUS, &info, current);
544 }
545 
546 void fault_in_user_windows(void)
547 {
548 	struct thread_info *t = current_thread_info();
549 	unsigned long window;
550 
551 	flush_user_windows();
552 	window = get_thread_wsaved();
553 
554 	if (likely(window != 0)) {
555 		window -= 1;
556 		do {
557 			struct reg_window *rwin = &t->reg_window[window];
558 			int winsize = sizeof(struct reg_window);
559 			unsigned long sp;
560 
561 			sp = t->rwbuf_stkptrs[window];
562 
563 			if (test_thread_64bit_stack(sp))
564 				sp += STACK_BIAS;
565 			else
566 				winsize = sizeof(struct reg_window32);
567 
568 			if (unlikely(sp & 0x7UL))
569 				stack_unaligned(sp);
570 
571 			if (unlikely(copy_to_user((char __user *)sp,
572 						  rwin, winsize)))
573 				goto barf;
574 		} while (window--);
575 	}
576 	set_thread_wsaved(0);
577 	return;
578 
579 barf:
580 	set_thread_wsaved(window + 1);
581 	do_exit(SIGILL);
582 }
583 
584 asmlinkage long sparc_do_fork(unsigned long clone_flags,
585 			      unsigned long stack_start,
586 			      struct pt_regs *regs,
587 			      unsigned long stack_size)
588 {
589 	int __user *parent_tid_ptr, *child_tid_ptr;
590 	unsigned long orig_i1 = regs->u_regs[UREG_I1];
591 	long ret;
592 
593 #ifdef CONFIG_COMPAT
594 	if (test_thread_flag(TIF_32BIT)) {
595 		parent_tid_ptr = compat_ptr(regs->u_regs[UREG_I2]);
596 		child_tid_ptr = compat_ptr(regs->u_regs[UREG_I4]);
597 	} else
598 #endif
599 	{
600 		parent_tid_ptr = (int __user *) regs->u_regs[UREG_I2];
601 		child_tid_ptr = (int __user *) regs->u_regs[UREG_I4];
602 	}
603 
604 	ret = do_fork(clone_flags, stack_start, stack_size,
605 		      parent_tid_ptr, child_tid_ptr);
606 
607 	/* If we get an error and potentially restart the system
608 	 * call, we're screwed because copy_thread() clobbered
609 	 * the parent's %o1.  So detect that case and restore it
610 	 * here.
611 	 */
612 	if ((unsigned long)ret >= -ERESTART_RESTARTBLOCK)
613 		regs->u_regs[UREG_I1] = orig_i1;
614 
615 	return ret;
616 }
617 
618 /* Copy a Sparc thread.  The fork() return value conventions
619  * under SunOS are nothing short of bletcherous:
620  * Parent -->  %o0 == childs  pid, %o1 == 0
621  * Child  -->  %o0 == parents pid, %o1 == 1
622  */
623 int copy_thread(unsigned long clone_flags, unsigned long sp,
624 		unsigned long arg, struct task_struct *p)
625 {
626 	struct thread_info *t = task_thread_info(p);
627 	struct pt_regs *regs = current_pt_regs();
628 	struct sparc_stackf *parent_sf;
629 	unsigned long child_stack_sz;
630 	char *child_trap_frame;
631 
632 	/* Calculate offset to stack_frame & pt_regs */
633 	child_stack_sz = (STACKFRAME_SZ + TRACEREG_SZ);
634 	child_trap_frame = (task_stack_page(p) +
635 			    (THREAD_SIZE - child_stack_sz));
636 
637 	t->new_child = 1;
638 	t->ksp = ((unsigned long) child_trap_frame) - STACK_BIAS;
639 	t->kregs = (struct pt_regs *) (child_trap_frame +
640 				       sizeof(struct sparc_stackf));
641 	t->fpsaved[0] = 0;
642 
643 	if (unlikely(p->flags & PF_KTHREAD)) {
644 		memset(child_trap_frame, 0, child_stack_sz);
645 		__thread_flag_byte_ptr(t)[TI_FLAG_BYTE_CWP] =
646 			(current_pt_regs()->tstate + 1) & TSTATE_CWP;
647 		t->current_ds = ASI_P;
648 		t->kregs->u_regs[UREG_G1] = sp; /* function */
649 		t->kregs->u_regs[UREG_G2] = arg;
650 		return 0;
651 	}
652 
653 	parent_sf = ((struct sparc_stackf *) regs) - 1;
654 	memcpy(child_trap_frame, parent_sf, child_stack_sz);
655 	if (t->flags & _TIF_32BIT) {
656 		sp &= 0x00000000ffffffffUL;
657 		regs->u_regs[UREG_FP] &= 0x00000000ffffffffUL;
658 	}
659 	t->kregs->u_regs[UREG_FP] = sp;
660 	__thread_flag_byte_ptr(t)[TI_FLAG_BYTE_CWP] =
661 		(regs->tstate + 1) & TSTATE_CWP;
662 	t->current_ds = ASI_AIUS;
663 	if (sp != regs->u_regs[UREG_FP]) {
664 		unsigned long csp;
665 
666 		csp = clone_stackframe(sp, regs->u_regs[UREG_FP]);
667 		if (!csp)
668 			return -EFAULT;
669 		t->kregs->u_regs[UREG_FP] = csp;
670 	}
671 	if (t->utraps)
672 		t->utraps[0]++;
673 
674 	/* Set the return value for the child. */
675 	t->kregs->u_regs[UREG_I0] = current->pid;
676 	t->kregs->u_regs[UREG_I1] = 1;
677 
678 	/* Set the second return value for the parent. */
679 	regs->u_regs[UREG_I1] = 0;
680 
681 	if (clone_flags & CLONE_SETTLS)
682 		t->kregs->u_regs[UREG_G7] = regs->u_regs[UREG_I3];
683 
684 	return 0;
685 }
686 
687 typedef struct {
688 	union {
689 		unsigned int	pr_regs[32];
690 		unsigned long	pr_dregs[16];
691 	} pr_fr;
692 	unsigned int __unused;
693 	unsigned int	pr_fsr;
694 	unsigned char	pr_qcnt;
695 	unsigned char	pr_q_entrysize;
696 	unsigned char	pr_en;
697 	unsigned int	pr_q[64];
698 } elf_fpregset_t32;
699 
700 /*
701  * fill in the fpu structure for a core dump.
702  */
703 int dump_fpu (struct pt_regs * regs, elf_fpregset_t * fpregs)
704 {
705 	unsigned long *kfpregs = current_thread_info()->fpregs;
706 	unsigned long fprs = current_thread_info()->fpsaved[0];
707 
708 	if (test_thread_flag(TIF_32BIT)) {
709 		elf_fpregset_t32 *fpregs32 = (elf_fpregset_t32 *)fpregs;
710 
711 		if (fprs & FPRS_DL)
712 			memcpy(&fpregs32->pr_fr.pr_regs[0], kfpregs,
713 			       sizeof(unsigned int) * 32);
714 		else
715 			memset(&fpregs32->pr_fr.pr_regs[0], 0,
716 			       sizeof(unsigned int) * 32);
717 		fpregs32->pr_qcnt = 0;
718 		fpregs32->pr_q_entrysize = 8;
719 		memset(&fpregs32->pr_q[0], 0,
720 		       (sizeof(unsigned int) * 64));
721 		if (fprs & FPRS_FEF) {
722 			fpregs32->pr_fsr = (unsigned int) current_thread_info()->xfsr[0];
723 			fpregs32->pr_en = 1;
724 		} else {
725 			fpregs32->pr_fsr = 0;
726 			fpregs32->pr_en = 0;
727 		}
728 	} else {
729 		if(fprs & FPRS_DL)
730 			memcpy(&fpregs->pr_regs[0], kfpregs,
731 			       sizeof(unsigned int) * 32);
732 		else
733 			memset(&fpregs->pr_regs[0], 0,
734 			       sizeof(unsigned int) * 32);
735 		if(fprs & FPRS_DU)
736 			memcpy(&fpregs->pr_regs[16], kfpregs+16,
737 			       sizeof(unsigned int) * 32);
738 		else
739 			memset(&fpregs->pr_regs[16], 0,
740 			       sizeof(unsigned int) * 32);
741 		if(fprs & FPRS_FEF) {
742 			fpregs->pr_fsr = current_thread_info()->xfsr[0];
743 			fpregs->pr_gsr = current_thread_info()->gsr[0];
744 		} else {
745 			fpregs->pr_fsr = fpregs->pr_gsr = 0;
746 		}
747 		fpregs->pr_fprs = fprs;
748 	}
749 	return 1;
750 }
751 EXPORT_SYMBOL(dump_fpu);
752 
753 unsigned long get_wchan(struct task_struct *task)
754 {
755 	unsigned long pc, fp, bias = 0;
756 	struct thread_info *tp;
757 	struct reg_window *rw;
758         unsigned long ret = 0;
759 	int count = 0;
760 
761 	if (!task || task == current ||
762             task->state == TASK_RUNNING)
763 		goto out;
764 
765 	tp = task_thread_info(task);
766 	bias = STACK_BIAS;
767 	fp = task_thread_info(task)->ksp + bias;
768 
769 	do {
770 		if (!kstack_valid(tp, fp))
771 			break;
772 		rw = (struct reg_window *) fp;
773 		pc = rw->ins[7];
774 		if (!in_sched_functions(pc)) {
775 			ret = pc;
776 			goto out;
777 		}
778 		fp = rw->ins[6] + bias;
779 	} while (++count < 16);
780 
781 out:
782 	return ret;
783 }
784