xref: /openbmc/linux/arch/sparc/kernel/process_64.c (revision d236d361)
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/sched/debug.h>
18 #include <linux/sched/task.h>
19 #include <linux/sched/task_stack.h>
20 #include <linux/kernel.h>
21 #include <linux/mm.h>
22 #include <linux/fs.h>
23 #include <linux/smp.h>
24 #include <linux/stddef.h>
25 #include <linux/ptrace.h>
26 #include <linux/slab.h>
27 #include <linux/user.h>
28 #include <linux/delay.h>
29 #include <linux/compat.h>
30 #include <linux/tick.h>
31 #include <linux/init.h>
32 #include <linux/cpu.h>
33 #include <linux/perf_event.h>
34 #include <linux/elfcore.h>
35 #include <linux/sysrq.h>
36 #include <linux/nmi.h>
37 #include <linux/context_tracking.h>
38 
39 #include <linux/uaccess.h>
40 #include <asm/page.h>
41 #include <asm/pgalloc.h>
42 #include <asm/pgtable.h>
43 #include <asm/processor.h>
44 #include <asm/pstate.h>
45 #include <asm/elf.h>
46 #include <asm/fpumacro.h>
47 #include <asm/head.h>
48 #include <asm/cpudata.h>
49 #include <asm/mmu_context.h>
50 #include <asm/unistd.h>
51 #include <asm/hypervisor.h>
52 #include <asm/syscalls.h>
53 #include <asm/irq_regs.h>
54 #include <asm/smp.h>
55 #include <asm/pcr.h>
56 
57 #include "kstack.h"
58 
59 /* Idle loop support on sparc64. */
60 void arch_cpu_idle(void)
61 {
62 	if (tlb_type != hypervisor) {
63 		touch_nmi_watchdog();
64 		local_irq_enable();
65 	} else {
66 		unsigned long pstate;
67 
68 		local_irq_enable();
69 
70                 /* The sun4v sleeping code requires that we have PSTATE.IE cleared over
71                  * the cpu sleep hypervisor call.
72                  */
73 		__asm__ __volatile__(
74 			"rdpr %%pstate, %0\n\t"
75 			"andn %0, %1, %0\n\t"
76 			"wrpr %0, %%g0, %%pstate"
77 			: "=&r" (pstate)
78 			: "i" (PSTATE_IE));
79 
80 		if (!need_resched() && !cpu_is_offline(smp_processor_id()))
81 			sun4v_cpu_yield();
82 
83 		/* Re-enable interrupts. */
84 		__asm__ __volatile__(
85 			"rdpr %%pstate, %0\n\t"
86 			"or %0, %1, %0\n\t"
87 			"wrpr %0, %%g0, %%pstate"
88 			: "=&r" (pstate)
89 			: "i" (PSTATE_IE));
90 	}
91 }
92 
93 #ifdef CONFIG_HOTPLUG_CPU
94 void arch_cpu_idle_dead(void)
95 {
96 	sched_preempt_enable_no_resched();
97 	cpu_play_dead();
98 }
99 #endif
100 
101 #ifdef CONFIG_COMPAT
102 static void show_regwindow32(struct pt_regs *regs)
103 {
104 	struct reg_window32 __user *rw;
105 	struct reg_window32 r_w;
106 	mm_segment_t old_fs;
107 
108 	__asm__ __volatile__ ("flushw");
109 	rw = compat_ptr((unsigned int)regs->u_regs[14]);
110 	old_fs = get_fs();
111 	set_fs (USER_DS);
112 	if (copy_from_user (&r_w, rw, sizeof(r_w))) {
113 		set_fs (old_fs);
114 		return;
115 	}
116 
117 	set_fs (old_fs);
118 	printk("l0: %08x l1: %08x l2: %08x l3: %08x "
119 	       "l4: %08x l5: %08x l6: %08x l7: %08x\n",
120 	       r_w.locals[0], r_w.locals[1], r_w.locals[2], r_w.locals[3],
121 	       r_w.locals[4], r_w.locals[5], r_w.locals[6], r_w.locals[7]);
122 	printk("i0: %08x i1: %08x i2: %08x i3: %08x "
123 	       "i4: %08x i5: %08x i6: %08x i7: %08x\n",
124 	       r_w.ins[0], r_w.ins[1], r_w.ins[2], r_w.ins[3],
125 	       r_w.ins[4], r_w.ins[5], r_w.ins[6], r_w.ins[7]);
126 }
127 #else
128 #define show_regwindow32(regs)	do { } while (0)
129 #endif
130 
131 static void show_regwindow(struct pt_regs *regs)
132 {
133 	struct reg_window __user *rw;
134 	struct reg_window *rwk;
135 	struct reg_window r_w;
136 	mm_segment_t old_fs;
137 
138 	if ((regs->tstate & TSTATE_PRIV) || !(test_thread_flag(TIF_32BIT))) {
139 		__asm__ __volatile__ ("flushw");
140 		rw = (struct reg_window __user *)
141 			(regs->u_regs[14] + STACK_BIAS);
142 		rwk = (struct reg_window *)
143 			(regs->u_regs[14] + STACK_BIAS);
144 		if (!(regs->tstate & TSTATE_PRIV)) {
145 			old_fs = get_fs();
146 			set_fs (USER_DS);
147 			if (copy_from_user (&r_w, rw, sizeof(r_w))) {
148 				set_fs (old_fs);
149 				return;
150 			}
151 			rwk = &r_w;
152 			set_fs (old_fs);
153 		}
154 	} else {
155 		show_regwindow32(regs);
156 		return;
157 	}
158 	printk("l0: %016lx l1: %016lx l2: %016lx l3: %016lx\n",
159 	       rwk->locals[0], rwk->locals[1], rwk->locals[2], rwk->locals[3]);
160 	printk("l4: %016lx l5: %016lx l6: %016lx l7: %016lx\n",
161 	       rwk->locals[4], rwk->locals[5], rwk->locals[6], rwk->locals[7]);
162 	printk("i0: %016lx i1: %016lx i2: %016lx i3: %016lx\n",
163 	       rwk->ins[0], rwk->ins[1], rwk->ins[2], rwk->ins[3]);
164 	printk("i4: %016lx i5: %016lx i6: %016lx i7: %016lx\n",
165 	       rwk->ins[4], rwk->ins[5], rwk->ins[6], rwk->ins[7]);
166 	if (regs->tstate & TSTATE_PRIV)
167 		printk("I7: <%pS>\n", (void *) rwk->ins[7]);
168 }
169 
170 void show_regs(struct pt_regs *regs)
171 {
172 	show_regs_print_info(KERN_DEFAULT);
173 
174 	printk("TSTATE: %016lx TPC: %016lx TNPC: %016lx Y: %08x    %s\n", regs->tstate,
175 	       regs->tpc, regs->tnpc, regs->y, print_tainted());
176 	printk("TPC: <%pS>\n", (void *) regs->tpc);
177 	printk("g0: %016lx g1: %016lx g2: %016lx g3: %016lx\n",
178 	       regs->u_regs[0], regs->u_regs[1], regs->u_regs[2],
179 	       regs->u_regs[3]);
180 	printk("g4: %016lx g5: %016lx g6: %016lx g7: %016lx\n",
181 	       regs->u_regs[4], regs->u_regs[5], regs->u_regs[6],
182 	       regs->u_regs[7]);
183 	printk("o0: %016lx o1: %016lx o2: %016lx o3: %016lx\n",
184 	       regs->u_regs[8], regs->u_regs[9], regs->u_regs[10],
185 	       regs->u_regs[11]);
186 	printk("o4: %016lx o5: %016lx sp: %016lx ret_pc: %016lx\n",
187 	       regs->u_regs[12], regs->u_regs[13], regs->u_regs[14],
188 	       regs->u_regs[15]);
189 	printk("RPC: <%pS>\n", (void *) regs->u_regs[15]);
190 	show_regwindow(regs);
191 	show_stack(current, (unsigned long *) regs->u_regs[UREG_FP]);
192 }
193 
194 union global_cpu_snapshot global_cpu_snapshot[NR_CPUS];
195 static DEFINE_SPINLOCK(global_cpu_snapshot_lock);
196 
197 static void __global_reg_self(struct thread_info *tp, struct pt_regs *regs,
198 			      int this_cpu)
199 {
200 	struct global_reg_snapshot *rp;
201 
202 	flushw_all();
203 
204 	rp = &global_cpu_snapshot[this_cpu].reg;
205 
206 	rp->tstate = regs->tstate;
207 	rp->tpc = regs->tpc;
208 	rp->tnpc = regs->tnpc;
209 	rp->o7 = regs->u_regs[UREG_I7];
210 
211 	if (regs->tstate & TSTATE_PRIV) {
212 		struct reg_window *rw;
213 
214 		rw = (struct reg_window *)
215 			(regs->u_regs[UREG_FP] + STACK_BIAS);
216 		if (kstack_valid(tp, (unsigned long) rw)) {
217 			rp->i7 = rw->ins[7];
218 			rw = (struct reg_window *)
219 				(rw->ins[6] + STACK_BIAS);
220 			if (kstack_valid(tp, (unsigned long) rw))
221 				rp->rpc = rw->ins[7];
222 		}
223 	} else {
224 		rp->i7 = 0;
225 		rp->rpc = 0;
226 	}
227 	rp->thread = tp;
228 }
229 
230 /* In order to avoid hangs we do not try to synchronize with the
231  * global register dump client cpus.  The last store they make is to
232  * the thread pointer, so do a short poll waiting for that to become
233  * non-NULL.
234  */
235 static void __global_reg_poll(struct global_reg_snapshot *gp)
236 {
237 	int limit = 0;
238 
239 	while (!gp->thread && ++limit < 100) {
240 		barrier();
241 		udelay(1);
242 	}
243 }
244 
245 void arch_trigger_cpumask_backtrace(const cpumask_t *mask, bool exclude_self)
246 {
247 	struct thread_info *tp = current_thread_info();
248 	struct pt_regs *regs = get_irq_regs();
249 	unsigned long flags;
250 	int this_cpu, cpu;
251 
252 	if (!regs)
253 		regs = tp->kregs;
254 
255 	spin_lock_irqsave(&global_cpu_snapshot_lock, flags);
256 
257 	this_cpu = raw_smp_processor_id();
258 
259 	memset(global_cpu_snapshot, 0, sizeof(global_cpu_snapshot));
260 
261 	if (cpumask_test_cpu(this_cpu, mask) && !exclude_self)
262 		__global_reg_self(tp, regs, this_cpu);
263 
264 	smp_fetch_global_regs();
265 
266 	for_each_cpu(cpu, mask) {
267 		struct global_reg_snapshot *gp;
268 
269 		if (exclude_self && cpu == this_cpu)
270 			continue;
271 
272 		gp = &global_cpu_snapshot[cpu].reg;
273 
274 		__global_reg_poll(gp);
275 
276 		tp = gp->thread;
277 		printk("%c CPU[%3d]: TSTATE[%016lx] TPC[%016lx] TNPC[%016lx] TASK[%s:%d]\n",
278 		       (cpu == this_cpu ? '*' : ' '), cpu,
279 		       gp->tstate, gp->tpc, gp->tnpc,
280 		       ((tp && tp->task) ? tp->task->comm : "NULL"),
281 		       ((tp && tp->task) ? tp->task->pid : -1));
282 
283 		if (gp->tstate & TSTATE_PRIV) {
284 			printk("             TPC[%pS] O7[%pS] I7[%pS] RPC[%pS]\n",
285 			       (void *) gp->tpc,
286 			       (void *) gp->o7,
287 			       (void *) gp->i7,
288 			       (void *) gp->rpc);
289 		} else {
290 			printk("             TPC[%lx] O7[%lx] I7[%lx] RPC[%lx]\n",
291 			       gp->tpc, gp->o7, gp->i7, gp->rpc);
292 		}
293 
294 		touch_nmi_watchdog();
295 	}
296 
297 	memset(global_cpu_snapshot, 0, sizeof(global_cpu_snapshot));
298 
299 	spin_unlock_irqrestore(&global_cpu_snapshot_lock, flags);
300 }
301 
302 #ifdef CONFIG_MAGIC_SYSRQ
303 
304 static void sysrq_handle_globreg(int key)
305 {
306 	trigger_all_cpu_backtrace();
307 }
308 
309 static struct sysrq_key_op sparc_globalreg_op = {
310 	.handler	= sysrq_handle_globreg,
311 	.help_msg	= "global-regs(y)",
312 	.action_msg	= "Show Global CPU Regs",
313 };
314 
315 static void __global_pmu_self(int this_cpu)
316 {
317 	struct global_pmu_snapshot *pp;
318 	int i, num;
319 
320 	if (!pcr_ops)
321 		return;
322 
323 	pp = &global_cpu_snapshot[this_cpu].pmu;
324 
325 	num = 1;
326 	if (tlb_type == hypervisor &&
327 	    sun4v_chip_type >= SUN4V_CHIP_NIAGARA4)
328 		num = 4;
329 
330 	for (i = 0; i < num; i++) {
331 		pp->pcr[i] = pcr_ops->read_pcr(i);
332 		pp->pic[i] = pcr_ops->read_pic(i);
333 	}
334 }
335 
336 static void __global_pmu_poll(struct global_pmu_snapshot *pp)
337 {
338 	int limit = 0;
339 
340 	while (!pp->pcr[0] && ++limit < 100) {
341 		barrier();
342 		udelay(1);
343 	}
344 }
345 
346 static void pmu_snapshot_all_cpus(void)
347 {
348 	unsigned long flags;
349 	int this_cpu, cpu;
350 
351 	spin_lock_irqsave(&global_cpu_snapshot_lock, flags);
352 
353 	memset(global_cpu_snapshot, 0, sizeof(global_cpu_snapshot));
354 
355 	this_cpu = raw_smp_processor_id();
356 
357 	__global_pmu_self(this_cpu);
358 
359 	smp_fetch_global_pmu();
360 
361 	for_each_online_cpu(cpu) {
362 		struct global_pmu_snapshot *pp = &global_cpu_snapshot[cpu].pmu;
363 
364 		__global_pmu_poll(pp);
365 
366 		printk("%c CPU[%3d]: PCR[%08lx:%08lx:%08lx:%08lx] PIC[%08lx:%08lx:%08lx:%08lx]\n",
367 		       (cpu == this_cpu ? '*' : ' '), cpu,
368 		       pp->pcr[0], pp->pcr[1], pp->pcr[2], pp->pcr[3],
369 		       pp->pic[0], pp->pic[1], pp->pic[2], pp->pic[3]);
370 
371 		touch_nmi_watchdog();
372 	}
373 
374 	memset(global_cpu_snapshot, 0, sizeof(global_cpu_snapshot));
375 
376 	spin_unlock_irqrestore(&global_cpu_snapshot_lock, flags);
377 }
378 
379 static void sysrq_handle_globpmu(int key)
380 {
381 	pmu_snapshot_all_cpus();
382 }
383 
384 static struct sysrq_key_op sparc_globalpmu_op = {
385 	.handler	= sysrq_handle_globpmu,
386 	.help_msg	= "global-pmu(x)",
387 	.action_msg	= "Show Global PMU Regs",
388 };
389 
390 static int __init sparc_sysrq_init(void)
391 {
392 	int ret = register_sysrq_key('y', &sparc_globalreg_op);
393 
394 	if (!ret)
395 		ret = register_sysrq_key('x', &sparc_globalpmu_op);
396 	return ret;
397 }
398 
399 core_initcall(sparc_sysrq_init);
400 
401 #endif
402 
403 unsigned long thread_saved_pc(struct task_struct *tsk)
404 {
405 	struct thread_info *ti = task_thread_info(tsk);
406 	unsigned long ret = 0xdeadbeefUL;
407 
408 	if (ti && ti->ksp) {
409 		unsigned long *sp;
410 		sp = (unsigned long *)(ti->ksp + STACK_BIAS);
411 		if (((unsigned long)sp & (sizeof(long) - 1)) == 0UL &&
412 		    sp[14]) {
413 			unsigned long *fp;
414 			fp = (unsigned long *)(sp[14] + STACK_BIAS);
415 			if (((unsigned long)fp & (sizeof(long) - 1)) == 0UL)
416 				ret = fp[15];
417 		}
418 	}
419 	return ret;
420 }
421 
422 /* Free current thread data structures etc.. */
423 void exit_thread(struct task_struct *tsk)
424 {
425 	struct thread_info *t = task_thread_info(tsk);
426 
427 	if (t->utraps) {
428 		if (t->utraps[0] < 2)
429 			kfree (t->utraps);
430 		else
431 			t->utraps[0]--;
432 	}
433 }
434 
435 void flush_thread(void)
436 {
437 	struct thread_info *t = current_thread_info();
438 	struct mm_struct *mm;
439 
440 	mm = t->task->mm;
441 	if (mm)
442 		tsb_context_switch(mm);
443 
444 	set_thread_wsaved(0);
445 
446 	/* Clear FPU register state. */
447 	t->fpsaved[0] = 0;
448 }
449 
450 /* It's a bit more tricky when 64-bit tasks are involved... */
451 static unsigned long clone_stackframe(unsigned long csp, unsigned long psp)
452 {
453 	bool stack_64bit = test_thread_64bit_stack(psp);
454 	unsigned long fp, distance, rval;
455 
456 	if (stack_64bit) {
457 		csp += STACK_BIAS;
458 		psp += STACK_BIAS;
459 		__get_user(fp, &(((struct reg_window __user *)psp)->ins[6]));
460 		fp += STACK_BIAS;
461 		if (test_thread_flag(TIF_32BIT))
462 			fp &= 0xffffffff;
463 	} else
464 		__get_user(fp, &(((struct reg_window32 __user *)psp)->ins[6]));
465 
466 	/* Now align the stack as this is mandatory in the Sparc ABI
467 	 * due to how register windows work.  This hides the
468 	 * restriction from thread libraries etc.
469 	 */
470 	csp &= ~15UL;
471 
472 	distance = fp - psp;
473 	rval = (csp - distance);
474 	if (copy_in_user((void __user *) rval, (void __user *) psp, distance))
475 		rval = 0;
476 	else if (!stack_64bit) {
477 		if (put_user(((u32)csp),
478 			     &(((struct reg_window32 __user *)rval)->ins[6])))
479 			rval = 0;
480 	} else {
481 		if (put_user(((u64)csp - STACK_BIAS),
482 			     &(((struct reg_window __user *)rval)->ins[6])))
483 			rval = 0;
484 		else
485 			rval = rval - STACK_BIAS;
486 	}
487 
488 	return rval;
489 }
490 
491 /* Standard stuff. */
492 static inline void shift_window_buffer(int first_win, int last_win,
493 				       struct thread_info *t)
494 {
495 	int i;
496 
497 	for (i = first_win; i < last_win; i++) {
498 		t->rwbuf_stkptrs[i] = t->rwbuf_stkptrs[i+1];
499 		memcpy(&t->reg_window[i], &t->reg_window[i+1],
500 		       sizeof(struct reg_window));
501 	}
502 }
503 
504 void synchronize_user_stack(void)
505 {
506 	struct thread_info *t = current_thread_info();
507 	unsigned long window;
508 
509 	flush_user_windows();
510 	if ((window = get_thread_wsaved()) != 0) {
511 		window -= 1;
512 		do {
513 			struct reg_window *rwin = &t->reg_window[window];
514 			int winsize = sizeof(struct reg_window);
515 			unsigned long sp;
516 
517 			sp = t->rwbuf_stkptrs[window];
518 
519 			if (test_thread_64bit_stack(sp))
520 				sp += STACK_BIAS;
521 			else
522 				winsize = sizeof(struct reg_window32);
523 
524 			if (!copy_to_user((char __user *)sp, rwin, winsize)) {
525 				shift_window_buffer(window, get_thread_wsaved() - 1, t);
526 				set_thread_wsaved(get_thread_wsaved() - 1);
527 			}
528 		} while (window--);
529 	}
530 }
531 
532 static void stack_unaligned(unsigned long sp)
533 {
534 	siginfo_t info;
535 
536 	info.si_signo = SIGBUS;
537 	info.si_errno = 0;
538 	info.si_code = BUS_ADRALN;
539 	info.si_addr = (void __user *) sp;
540 	info.si_trapno = 0;
541 	force_sig_info(SIGBUS, &info, current);
542 }
543 
544 void fault_in_user_windows(void)
545 {
546 	struct thread_info *t = current_thread_info();
547 	unsigned long window;
548 
549 	flush_user_windows();
550 	window = get_thread_wsaved();
551 
552 	if (likely(window != 0)) {
553 		window -= 1;
554 		do {
555 			struct reg_window *rwin = &t->reg_window[window];
556 			int winsize = sizeof(struct reg_window);
557 			unsigned long sp;
558 
559 			sp = t->rwbuf_stkptrs[window];
560 
561 			if (test_thread_64bit_stack(sp))
562 				sp += STACK_BIAS;
563 			else
564 				winsize = sizeof(struct reg_window32);
565 
566 			if (unlikely(sp & 0x7UL))
567 				stack_unaligned(sp);
568 
569 			if (unlikely(copy_to_user((char __user *)sp,
570 						  rwin, winsize)))
571 				goto barf;
572 		} while (window--);
573 	}
574 	set_thread_wsaved(0);
575 	return;
576 
577 barf:
578 	set_thread_wsaved(window + 1);
579 	user_exit();
580 	do_exit(SIGILL);
581 }
582 
583 asmlinkage long sparc_do_fork(unsigned long clone_flags,
584 			      unsigned long stack_start,
585 			      struct pt_regs *regs,
586 			      unsigned long stack_size)
587 {
588 	int __user *parent_tid_ptr, *child_tid_ptr;
589 	unsigned long orig_i1 = regs->u_regs[UREG_I1];
590 	long ret;
591 
592 #ifdef CONFIG_COMPAT
593 	if (test_thread_flag(TIF_32BIT)) {
594 		parent_tid_ptr = compat_ptr(regs->u_regs[UREG_I2]);
595 		child_tid_ptr = compat_ptr(regs->u_regs[UREG_I4]);
596 	} else
597 #endif
598 	{
599 		parent_tid_ptr = (int __user *) regs->u_regs[UREG_I2];
600 		child_tid_ptr = (int __user *) regs->u_regs[UREG_I4];
601 	}
602 
603 	ret = do_fork(clone_flags, stack_start, stack_size,
604 		      parent_tid_ptr, child_tid_ptr);
605 
606 	/* If we get an error and potentially restart the system
607 	 * call, we're screwed because copy_thread() clobbered
608 	 * the parent's %o1.  So detect that case and restore it
609 	 * here.
610 	 */
611 	if ((unsigned long)ret >= -ERESTART_RESTARTBLOCK)
612 		regs->u_regs[UREG_I1] = orig_i1;
613 
614 	return ret;
615 }
616 
617 /* Copy a Sparc thread.  The fork() return value conventions
618  * under SunOS are nothing short of bletcherous:
619  * Parent -->  %o0 == childs  pid, %o1 == 0
620  * Child  -->  %o0 == parents pid, %o1 == 1
621  */
622 int copy_thread(unsigned long clone_flags, unsigned long sp,
623 		unsigned long arg, struct task_struct *p)
624 {
625 	struct thread_info *t = task_thread_info(p);
626 	struct pt_regs *regs = current_pt_regs();
627 	struct sparc_stackf *parent_sf;
628 	unsigned long child_stack_sz;
629 	char *child_trap_frame;
630 
631 	/* Calculate offset to stack_frame & pt_regs */
632 	child_stack_sz = (STACKFRAME_SZ + TRACEREG_SZ);
633 	child_trap_frame = (task_stack_page(p) +
634 			    (THREAD_SIZE - child_stack_sz));
635 
636 	t->new_child = 1;
637 	t->ksp = ((unsigned long) child_trap_frame) - STACK_BIAS;
638 	t->kregs = (struct pt_regs *) (child_trap_frame +
639 				       sizeof(struct sparc_stackf));
640 	t->fpsaved[0] = 0;
641 
642 	if (unlikely(p->flags & PF_KTHREAD)) {
643 		memset(child_trap_frame, 0, child_stack_sz);
644 		__thread_flag_byte_ptr(t)[TI_FLAG_BYTE_CWP] =
645 			(current_pt_regs()->tstate + 1) & TSTATE_CWP;
646 		t->current_ds = ASI_P;
647 		t->kregs->u_regs[UREG_G1] = sp; /* function */
648 		t->kregs->u_regs[UREG_G2] = arg;
649 		return 0;
650 	}
651 
652 	parent_sf = ((struct sparc_stackf *) regs) - 1;
653 	memcpy(child_trap_frame, parent_sf, child_stack_sz);
654 	if (t->flags & _TIF_32BIT) {
655 		sp &= 0x00000000ffffffffUL;
656 		regs->u_regs[UREG_FP] &= 0x00000000ffffffffUL;
657 	}
658 	t->kregs->u_regs[UREG_FP] = sp;
659 	__thread_flag_byte_ptr(t)[TI_FLAG_BYTE_CWP] =
660 		(regs->tstate + 1) & TSTATE_CWP;
661 	t->current_ds = ASI_AIUS;
662 	if (sp != regs->u_regs[UREG_FP]) {
663 		unsigned long csp;
664 
665 		csp = clone_stackframe(sp, regs->u_regs[UREG_FP]);
666 		if (!csp)
667 			return -EFAULT;
668 		t->kregs->u_regs[UREG_FP] = csp;
669 	}
670 	if (t->utraps)
671 		t->utraps[0]++;
672 
673 	/* Set the return value for the child. */
674 	t->kregs->u_regs[UREG_I0] = current->pid;
675 	t->kregs->u_regs[UREG_I1] = 1;
676 
677 	/* Set the second return value for the parent. */
678 	regs->u_regs[UREG_I1] = 0;
679 
680 	if (clone_flags & CLONE_SETTLS)
681 		t->kregs->u_regs[UREG_G7] = regs->u_regs[UREG_I3];
682 
683 	return 0;
684 }
685 
686 typedef struct {
687 	union {
688 		unsigned int	pr_regs[32];
689 		unsigned long	pr_dregs[16];
690 	} pr_fr;
691 	unsigned int __unused;
692 	unsigned int	pr_fsr;
693 	unsigned char	pr_qcnt;
694 	unsigned char	pr_q_entrysize;
695 	unsigned char	pr_en;
696 	unsigned int	pr_q[64];
697 } elf_fpregset_t32;
698 
699 /*
700  * fill in the fpu structure for a core dump.
701  */
702 int dump_fpu (struct pt_regs * regs, elf_fpregset_t * fpregs)
703 {
704 	unsigned long *kfpregs = current_thread_info()->fpregs;
705 	unsigned long fprs = current_thread_info()->fpsaved[0];
706 
707 	if (test_thread_flag(TIF_32BIT)) {
708 		elf_fpregset_t32 *fpregs32 = (elf_fpregset_t32 *)fpregs;
709 
710 		if (fprs & FPRS_DL)
711 			memcpy(&fpregs32->pr_fr.pr_regs[0], kfpregs,
712 			       sizeof(unsigned int) * 32);
713 		else
714 			memset(&fpregs32->pr_fr.pr_regs[0], 0,
715 			       sizeof(unsigned int) * 32);
716 		fpregs32->pr_qcnt = 0;
717 		fpregs32->pr_q_entrysize = 8;
718 		memset(&fpregs32->pr_q[0], 0,
719 		       (sizeof(unsigned int) * 64));
720 		if (fprs & FPRS_FEF) {
721 			fpregs32->pr_fsr = (unsigned int) current_thread_info()->xfsr[0];
722 			fpregs32->pr_en = 1;
723 		} else {
724 			fpregs32->pr_fsr = 0;
725 			fpregs32->pr_en = 0;
726 		}
727 	} else {
728 		if(fprs & FPRS_DL)
729 			memcpy(&fpregs->pr_regs[0], kfpregs,
730 			       sizeof(unsigned int) * 32);
731 		else
732 			memset(&fpregs->pr_regs[0], 0,
733 			       sizeof(unsigned int) * 32);
734 		if(fprs & FPRS_DU)
735 			memcpy(&fpregs->pr_regs[16], kfpregs+16,
736 			       sizeof(unsigned int) * 32);
737 		else
738 			memset(&fpregs->pr_regs[16], 0,
739 			       sizeof(unsigned int) * 32);
740 		if(fprs & FPRS_FEF) {
741 			fpregs->pr_fsr = current_thread_info()->xfsr[0];
742 			fpregs->pr_gsr = current_thread_info()->gsr[0];
743 		} else {
744 			fpregs->pr_fsr = fpregs->pr_gsr = 0;
745 		}
746 		fpregs->pr_fprs = fprs;
747 	}
748 	return 1;
749 }
750 EXPORT_SYMBOL(dump_fpu);
751 
752 unsigned long get_wchan(struct task_struct *task)
753 {
754 	unsigned long pc, fp, bias = 0;
755 	struct thread_info *tp;
756 	struct reg_window *rw;
757         unsigned long ret = 0;
758 	int count = 0;
759 
760 	if (!task || task == current ||
761             task->state == TASK_RUNNING)
762 		goto out;
763 
764 	tp = task_thread_info(task);
765 	bias = STACK_BIAS;
766 	fp = task_thread_info(task)->ksp + bias;
767 
768 	do {
769 		if (!kstack_valid(tp, fp))
770 			break;
771 		rw = (struct reg_window *) fp;
772 		pc = rw->ins[7];
773 		if (!in_sched_functions(pc)) {
774 			ret = pc;
775 			goto out;
776 		}
777 		fp = rw->ins[6] + bias;
778 	} while (++count < 16);
779 
780 out:
781 	return ret;
782 }
783