xref: /openbmc/linux/arch/sparc/kernel/process_64.c (revision 77d84ff8)
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 #include <linux/context_tracking.h>
35 
36 #include <asm/uaccess.h>
37 #include <asm/page.h>
38 #include <asm/pgalloc.h>
39 #include <asm/pgtable.h>
40 #include <asm/processor.h>
41 #include <asm/pstate.h>
42 #include <asm/elf.h>
43 #include <asm/fpumacro.h>
44 #include <asm/head.h>
45 #include <asm/cpudata.h>
46 #include <asm/mmu_context.h>
47 #include <asm/unistd.h>
48 #include <asm/hypervisor.h>
49 #include <asm/syscalls.h>
50 #include <asm/irq_regs.h>
51 #include <asm/smp.h>
52 #include <asm/pcr.h>
53 
54 #include "kstack.h"
55 
56 /* Idle loop support on sparc64. */
57 void arch_cpu_idle(void)
58 {
59 	if (tlb_type != hypervisor) {
60 		touch_nmi_watchdog();
61 	} else {
62 		unsigned long pstate;
63 
64                 /* The sun4v sleeping code requires that we have PSTATE.IE cleared over
65                  * the cpu sleep hypervisor call.
66                  */
67 		__asm__ __volatile__(
68 			"rdpr %%pstate, %0\n\t"
69 			"andn %0, %1, %0\n\t"
70 			"wrpr %0, %%g0, %%pstate"
71 			: "=&r" (pstate)
72 			: "i" (PSTATE_IE));
73 
74 		if (!need_resched() && !cpu_is_offline(smp_processor_id()))
75 			sun4v_cpu_yield();
76 
77 		/* Re-enable interrupts. */
78 		__asm__ __volatile__(
79 			"rdpr %%pstate, %0\n\t"
80 			"or %0, %1, %0\n\t"
81 			"wrpr %0, %%g0, %%pstate"
82 			: "=&r" (pstate)
83 			: "i" (PSTATE_IE));
84 	}
85 	local_irq_enable();
86 }
87 
88 #ifdef CONFIG_HOTPLUG_CPU
89 void arch_cpu_idle_dead()
90 {
91 	sched_preempt_enable_no_resched();
92 	cpu_play_dead();
93 }
94 #endif
95 
96 #ifdef CONFIG_COMPAT
97 static void show_regwindow32(struct pt_regs *regs)
98 {
99 	struct reg_window32 __user *rw;
100 	struct reg_window32 r_w;
101 	mm_segment_t old_fs;
102 
103 	__asm__ __volatile__ ("flushw");
104 	rw = compat_ptr((unsigned)regs->u_regs[14]);
105 	old_fs = get_fs();
106 	set_fs (USER_DS);
107 	if (copy_from_user (&r_w, rw, sizeof(r_w))) {
108 		set_fs (old_fs);
109 		return;
110 	}
111 
112 	set_fs (old_fs);
113 	printk("l0: %08x l1: %08x l2: %08x l3: %08x "
114 	       "l4: %08x l5: %08x l6: %08x l7: %08x\n",
115 	       r_w.locals[0], r_w.locals[1], r_w.locals[2], r_w.locals[3],
116 	       r_w.locals[4], r_w.locals[5], r_w.locals[6], r_w.locals[7]);
117 	printk("i0: %08x i1: %08x i2: %08x i3: %08x "
118 	       "i4: %08x i5: %08x i6: %08x i7: %08x\n",
119 	       r_w.ins[0], r_w.ins[1], r_w.ins[2], r_w.ins[3],
120 	       r_w.ins[4], r_w.ins[5], r_w.ins[6], r_w.ins[7]);
121 }
122 #else
123 #define show_regwindow32(regs)	do { } while (0)
124 #endif
125 
126 static void show_regwindow(struct pt_regs *regs)
127 {
128 	struct reg_window __user *rw;
129 	struct reg_window *rwk;
130 	struct reg_window r_w;
131 	mm_segment_t old_fs;
132 
133 	if ((regs->tstate & TSTATE_PRIV) || !(test_thread_flag(TIF_32BIT))) {
134 		__asm__ __volatile__ ("flushw");
135 		rw = (struct reg_window __user *)
136 			(regs->u_regs[14] + STACK_BIAS);
137 		rwk = (struct reg_window *)
138 			(regs->u_regs[14] + STACK_BIAS);
139 		if (!(regs->tstate & TSTATE_PRIV)) {
140 			old_fs = get_fs();
141 			set_fs (USER_DS);
142 			if (copy_from_user (&r_w, rw, sizeof(r_w))) {
143 				set_fs (old_fs);
144 				return;
145 			}
146 			rwk = &r_w;
147 			set_fs (old_fs);
148 		}
149 	} else {
150 		show_regwindow32(regs);
151 		return;
152 	}
153 	printk("l0: %016lx l1: %016lx l2: %016lx l3: %016lx\n",
154 	       rwk->locals[0], rwk->locals[1], rwk->locals[2], rwk->locals[3]);
155 	printk("l4: %016lx l5: %016lx l6: %016lx l7: %016lx\n",
156 	       rwk->locals[4], rwk->locals[5], rwk->locals[6], rwk->locals[7]);
157 	printk("i0: %016lx i1: %016lx i2: %016lx i3: %016lx\n",
158 	       rwk->ins[0], rwk->ins[1], rwk->ins[2], rwk->ins[3]);
159 	printk("i4: %016lx i5: %016lx i6: %016lx i7: %016lx\n",
160 	       rwk->ins[4], rwk->ins[5], rwk->ins[6], rwk->ins[7]);
161 	if (regs->tstate & TSTATE_PRIV)
162 		printk("I7: <%pS>\n", (void *) rwk->ins[7]);
163 }
164 
165 void show_regs(struct pt_regs *regs)
166 {
167 	show_regs_print_info(KERN_DEFAULT);
168 
169 	printk("TSTATE: %016lx TPC: %016lx TNPC: %016lx Y: %08x    %s\n", regs->tstate,
170 	       regs->tpc, regs->tnpc, regs->y, print_tainted());
171 	printk("TPC: <%pS>\n", (void *) regs->tpc);
172 	printk("g0: %016lx g1: %016lx g2: %016lx g3: %016lx\n",
173 	       regs->u_regs[0], regs->u_regs[1], regs->u_regs[2],
174 	       regs->u_regs[3]);
175 	printk("g4: %016lx g5: %016lx g6: %016lx g7: %016lx\n",
176 	       regs->u_regs[4], regs->u_regs[5], regs->u_regs[6],
177 	       regs->u_regs[7]);
178 	printk("o0: %016lx o1: %016lx o2: %016lx o3: %016lx\n",
179 	       regs->u_regs[8], regs->u_regs[9], regs->u_regs[10],
180 	       regs->u_regs[11]);
181 	printk("o4: %016lx o5: %016lx sp: %016lx ret_pc: %016lx\n",
182 	       regs->u_regs[12], regs->u_regs[13], regs->u_regs[14],
183 	       regs->u_regs[15]);
184 	printk("RPC: <%pS>\n", (void *) regs->u_regs[15]);
185 	show_regwindow(regs);
186 	show_stack(current, (unsigned long *) regs->u_regs[UREG_FP]);
187 }
188 
189 union global_cpu_snapshot global_cpu_snapshot[NR_CPUS];
190 static DEFINE_SPINLOCK(global_cpu_snapshot_lock);
191 
192 static void __global_reg_self(struct thread_info *tp, struct pt_regs *regs,
193 			      int this_cpu)
194 {
195 	struct global_reg_snapshot *rp;
196 
197 	flushw_all();
198 
199 	rp = &global_cpu_snapshot[this_cpu].reg;
200 
201 	rp->tstate = regs->tstate;
202 	rp->tpc = regs->tpc;
203 	rp->tnpc = regs->tnpc;
204 	rp->o7 = regs->u_regs[UREG_I7];
205 
206 	if (regs->tstate & TSTATE_PRIV) {
207 		struct reg_window *rw;
208 
209 		rw = (struct reg_window *)
210 			(regs->u_regs[UREG_FP] + STACK_BIAS);
211 		if (kstack_valid(tp, (unsigned long) rw)) {
212 			rp->i7 = rw->ins[7];
213 			rw = (struct reg_window *)
214 				(rw->ins[6] + STACK_BIAS);
215 			if (kstack_valid(tp, (unsigned long) rw))
216 				rp->rpc = rw->ins[7];
217 		}
218 	} else {
219 		rp->i7 = 0;
220 		rp->rpc = 0;
221 	}
222 	rp->thread = tp;
223 }
224 
225 /* In order to avoid hangs we do not try to synchronize with the
226  * global register dump client cpus.  The last store they make is to
227  * the thread pointer, so do a short poll waiting for that to become
228  * non-NULL.
229  */
230 static void __global_reg_poll(struct global_reg_snapshot *gp)
231 {
232 	int limit = 0;
233 
234 	while (!gp->thread && ++limit < 100) {
235 		barrier();
236 		udelay(1);
237 	}
238 }
239 
240 void arch_trigger_all_cpu_backtrace(void)
241 {
242 	struct thread_info *tp = current_thread_info();
243 	struct pt_regs *regs = get_irq_regs();
244 	unsigned long flags;
245 	int this_cpu, cpu;
246 
247 	if (!regs)
248 		regs = tp->kregs;
249 
250 	spin_lock_irqsave(&global_cpu_snapshot_lock, flags);
251 
252 	memset(global_cpu_snapshot, 0, sizeof(global_cpu_snapshot));
253 
254 	this_cpu = raw_smp_processor_id();
255 
256 	__global_reg_self(tp, regs, this_cpu);
257 
258 	smp_fetch_global_regs();
259 
260 	for_each_online_cpu(cpu) {
261 		struct global_reg_snapshot *gp = &global_cpu_snapshot[cpu].reg;
262 
263 		__global_reg_poll(gp);
264 
265 		tp = gp->thread;
266 		printk("%c CPU[%3d]: TSTATE[%016lx] TPC[%016lx] TNPC[%016lx] TASK[%s:%d]\n",
267 		       (cpu == this_cpu ? '*' : ' '), cpu,
268 		       gp->tstate, gp->tpc, gp->tnpc,
269 		       ((tp && tp->task) ? tp->task->comm : "NULL"),
270 		       ((tp && tp->task) ? tp->task->pid : -1));
271 
272 		if (gp->tstate & TSTATE_PRIV) {
273 			printk("             TPC[%pS] O7[%pS] I7[%pS] RPC[%pS]\n",
274 			       (void *) gp->tpc,
275 			       (void *) gp->o7,
276 			       (void *) gp->i7,
277 			       (void *) gp->rpc);
278 		} else {
279 			printk("             TPC[%lx] O7[%lx] I7[%lx] RPC[%lx]\n",
280 			       gp->tpc, gp->o7, gp->i7, gp->rpc);
281 		}
282 	}
283 
284 	memset(global_cpu_snapshot, 0, sizeof(global_cpu_snapshot));
285 
286 	spin_unlock_irqrestore(&global_cpu_snapshot_lock, flags);
287 }
288 
289 #ifdef CONFIG_MAGIC_SYSRQ
290 
291 static void sysrq_handle_globreg(int key)
292 {
293 	arch_trigger_all_cpu_backtrace();
294 }
295 
296 static struct sysrq_key_op sparc_globalreg_op = {
297 	.handler	= sysrq_handle_globreg,
298 	.help_msg	= "global-regs(y)",
299 	.action_msg	= "Show Global CPU Regs",
300 };
301 
302 static void __global_pmu_self(int this_cpu)
303 {
304 	struct global_pmu_snapshot *pp;
305 	int i, num;
306 
307 	pp = &global_cpu_snapshot[this_cpu].pmu;
308 
309 	num = 1;
310 	if (tlb_type == hypervisor &&
311 	    sun4v_chip_type >= SUN4V_CHIP_NIAGARA4)
312 		num = 4;
313 
314 	for (i = 0; i < num; i++) {
315 		pp->pcr[i] = pcr_ops->read_pcr(i);
316 		pp->pic[i] = pcr_ops->read_pic(i);
317 	}
318 }
319 
320 static void __global_pmu_poll(struct global_pmu_snapshot *pp)
321 {
322 	int limit = 0;
323 
324 	while (!pp->pcr[0] && ++limit < 100) {
325 		barrier();
326 		udelay(1);
327 	}
328 }
329 
330 static void pmu_snapshot_all_cpus(void)
331 {
332 	unsigned long flags;
333 	int this_cpu, cpu;
334 
335 	spin_lock_irqsave(&global_cpu_snapshot_lock, flags);
336 
337 	memset(global_cpu_snapshot, 0, sizeof(global_cpu_snapshot));
338 
339 	this_cpu = raw_smp_processor_id();
340 
341 	__global_pmu_self(this_cpu);
342 
343 	smp_fetch_global_pmu();
344 
345 	for_each_online_cpu(cpu) {
346 		struct global_pmu_snapshot *pp = &global_cpu_snapshot[cpu].pmu;
347 
348 		__global_pmu_poll(pp);
349 
350 		printk("%c CPU[%3d]: PCR[%08lx:%08lx:%08lx:%08lx] PIC[%08lx:%08lx:%08lx:%08lx]\n",
351 		       (cpu == this_cpu ? '*' : ' '), cpu,
352 		       pp->pcr[0], pp->pcr[1], pp->pcr[2], pp->pcr[3],
353 		       pp->pic[0], pp->pic[1], pp->pic[2], pp->pic[3]);
354 	}
355 
356 	memset(global_cpu_snapshot, 0, sizeof(global_cpu_snapshot));
357 
358 	spin_unlock_irqrestore(&global_cpu_snapshot_lock, flags);
359 }
360 
361 static void sysrq_handle_globpmu(int key)
362 {
363 	pmu_snapshot_all_cpus();
364 }
365 
366 static struct sysrq_key_op sparc_globalpmu_op = {
367 	.handler	= sysrq_handle_globpmu,
368 	.help_msg	= "global-pmu(x)",
369 	.action_msg	= "Show Global PMU Regs",
370 };
371 
372 static int __init sparc_sysrq_init(void)
373 {
374 	int ret = register_sysrq_key('y', &sparc_globalreg_op);
375 
376 	if (!ret)
377 		ret = register_sysrq_key('x', &sparc_globalpmu_op);
378 	return ret;
379 }
380 
381 core_initcall(sparc_sysrq_init);
382 
383 #endif
384 
385 unsigned long thread_saved_pc(struct task_struct *tsk)
386 {
387 	struct thread_info *ti = task_thread_info(tsk);
388 	unsigned long ret = 0xdeadbeefUL;
389 
390 	if (ti && ti->ksp) {
391 		unsigned long *sp;
392 		sp = (unsigned long *)(ti->ksp + STACK_BIAS);
393 		if (((unsigned long)sp & (sizeof(long) - 1)) == 0UL &&
394 		    sp[14]) {
395 			unsigned long *fp;
396 			fp = (unsigned long *)(sp[14] + STACK_BIAS);
397 			if (((unsigned long)fp & (sizeof(long) - 1)) == 0UL)
398 				ret = fp[15];
399 		}
400 	}
401 	return ret;
402 }
403 
404 /* Free current thread data structures etc.. */
405 void exit_thread(void)
406 {
407 	struct thread_info *t = current_thread_info();
408 
409 	if (t->utraps) {
410 		if (t->utraps[0] < 2)
411 			kfree (t->utraps);
412 		else
413 			t->utraps[0]--;
414 	}
415 }
416 
417 void flush_thread(void)
418 {
419 	struct thread_info *t = current_thread_info();
420 	struct mm_struct *mm;
421 
422 	mm = t->task->mm;
423 	if (mm)
424 		tsb_context_switch(mm);
425 
426 	set_thread_wsaved(0);
427 
428 	/* Clear FPU register state. */
429 	t->fpsaved[0] = 0;
430 }
431 
432 /* It's a bit more tricky when 64-bit tasks are involved... */
433 static unsigned long clone_stackframe(unsigned long csp, unsigned long psp)
434 {
435 	bool stack_64bit = test_thread_64bit_stack(psp);
436 	unsigned long fp, distance, rval;
437 
438 	if (stack_64bit) {
439 		csp += STACK_BIAS;
440 		psp += STACK_BIAS;
441 		__get_user(fp, &(((struct reg_window __user *)psp)->ins[6]));
442 		fp += STACK_BIAS;
443 		if (test_thread_flag(TIF_32BIT))
444 			fp &= 0xffffffff;
445 	} else
446 		__get_user(fp, &(((struct reg_window32 __user *)psp)->ins[6]));
447 
448 	/* Now align the stack as this is mandatory in the Sparc ABI
449 	 * due to how register windows work.  This hides the
450 	 * restriction from thread libraries etc.
451 	 */
452 	csp &= ~15UL;
453 
454 	distance = fp - psp;
455 	rval = (csp - distance);
456 	if (copy_in_user((void __user *) rval, (void __user *) psp, distance))
457 		rval = 0;
458 	else if (!stack_64bit) {
459 		if (put_user(((u32)csp),
460 			     &(((struct reg_window32 __user *)rval)->ins[6])))
461 			rval = 0;
462 	} else {
463 		if (put_user(((u64)csp - STACK_BIAS),
464 			     &(((struct reg_window __user *)rval)->ins[6])))
465 			rval = 0;
466 		else
467 			rval = rval - STACK_BIAS;
468 	}
469 
470 	return rval;
471 }
472 
473 /* Standard stuff. */
474 static inline void shift_window_buffer(int first_win, int last_win,
475 				       struct thread_info *t)
476 {
477 	int i;
478 
479 	for (i = first_win; i < last_win; i++) {
480 		t->rwbuf_stkptrs[i] = t->rwbuf_stkptrs[i+1];
481 		memcpy(&t->reg_window[i], &t->reg_window[i+1],
482 		       sizeof(struct reg_window));
483 	}
484 }
485 
486 void synchronize_user_stack(void)
487 {
488 	struct thread_info *t = current_thread_info();
489 	unsigned long window;
490 
491 	flush_user_windows();
492 	if ((window = get_thread_wsaved()) != 0) {
493 		window -= 1;
494 		do {
495 			struct reg_window *rwin = &t->reg_window[window];
496 			int winsize = sizeof(struct reg_window);
497 			unsigned long sp;
498 
499 			sp = t->rwbuf_stkptrs[window];
500 
501 			if (test_thread_64bit_stack(sp))
502 				sp += STACK_BIAS;
503 			else
504 				winsize = sizeof(struct reg_window32);
505 
506 			if (!copy_to_user((char __user *)sp, rwin, winsize)) {
507 				shift_window_buffer(window, get_thread_wsaved() - 1, t);
508 				set_thread_wsaved(get_thread_wsaved() - 1);
509 			}
510 		} while (window--);
511 	}
512 }
513 
514 static void stack_unaligned(unsigned long sp)
515 {
516 	siginfo_t info;
517 
518 	info.si_signo = SIGBUS;
519 	info.si_errno = 0;
520 	info.si_code = BUS_ADRALN;
521 	info.si_addr = (void __user *) sp;
522 	info.si_trapno = 0;
523 	force_sig_info(SIGBUS, &info, current);
524 }
525 
526 void fault_in_user_windows(void)
527 {
528 	struct thread_info *t = current_thread_info();
529 	unsigned long window;
530 
531 	flush_user_windows();
532 	window = get_thread_wsaved();
533 
534 	if (likely(window != 0)) {
535 		window -= 1;
536 		do {
537 			struct reg_window *rwin = &t->reg_window[window];
538 			int winsize = sizeof(struct reg_window);
539 			unsigned long sp;
540 
541 			sp = t->rwbuf_stkptrs[window];
542 
543 			if (test_thread_64bit_stack(sp))
544 				sp += STACK_BIAS;
545 			else
546 				winsize = sizeof(struct reg_window32);
547 
548 			if (unlikely(sp & 0x7UL))
549 				stack_unaligned(sp);
550 
551 			if (unlikely(copy_to_user((char __user *)sp,
552 						  rwin, winsize)))
553 				goto barf;
554 		} while (window--);
555 	}
556 	set_thread_wsaved(0);
557 	return;
558 
559 barf:
560 	set_thread_wsaved(window + 1);
561 	user_exit();
562 	do_exit(SIGILL);
563 }
564 
565 asmlinkage long sparc_do_fork(unsigned long clone_flags,
566 			      unsigned long stack_start,
567 			      struct pt_regs *regs,
568 			      unsigned long stack_size)
569 {
570 	int __user *parent_tid_ptr, *child_tid_ptr;
571 	unsigned long orig_i1 = regs->u_regs[UREG_I1];
572 	long ret;
573 
574 #ifdef CONFIG_COMPAT
575 	if (test_thread_flag(TIF_32BIT)) {
576 		parent_tid_ptr = compat_ptr(regs->u_regs[UREG_I2]);
577 		child_tid_ptr = compat_ptr(regs->u_regs[UREG_I4]);
578 	} else
579 #endif
580 	{
581 		parent_tid_ptr = (int __user *) regs->u_regs[UREG_I2];
582 		child_tid_ptr = (int __user *) regs->u_regs[UREG_I4];
583 	}
584 
585 	ret = do_fork(clone_flags, stack_start, stack_size,
586 		      parent_tid_ptr, child_tid_ptr);
587 
588 	/* If we get an error and potentially restart the system
589 	 * call, we're screwed because copy_thread() clobbered
590 	 * the parent's %o1.  So detect that case and restore it
591 	 * here.
592 	 */
593 	if ((unsigned long)ret >= -ERESTART_RESTARTBLOCK)
594 		regs->u_regs[UREG_I1] = orig_i1;
595 
596 	return ret;
597 }
598 
599 /* Copy a Sparc thread.  The fork() return value conventions
600  * under SunOS are nothing short of bletcherous:
601  * Parent -->  %o0 == childs  pid, %o1 == 0
602  * Child  -->  %o0 == parents pid, %o1 == 1
603  */
604 int copy_thread(unsigned long clone_flags, unsigned long sp,
605 		unsigned long arg, struct task_struct *p)
606 {
607 	struct thread_info *t = task_thread_info(p);
608 	struct pt_regs *regs = current_pt_regs();
609 	struct sparc_stackf *parent_sf;
610 	unsigned long child_stack_sz;
611 	char *child_trap_frame;
612 
613 	/* Calculate offset to stack_frame & pt_regs */
614 	child_stack_sz = (STACKFRAME_SZ + TRACEREG_SZ);
615 	child_trap_frame = (task_stack_page(p) +
616 			    (THREAD_SIZE - child_stack_sz));
617 
618 	t->new_child = 1;
619 	t->ksp = ((unsigned long) child_trap_frame) - STACK_BIAS;
620 	t->kregs = (struct pt_regs *) (child_trap_frame +
621 				       sizeof(struct sparc_stackf));
622 	t->fpsaved[0] = 0;
623 
624 	if (unlikely(p->flags & PF_KTHREAD)) {
625 		memset(child_trap_frame, 0, child_stack_sz);
626 		__thread_flag_byte_ptr(t)[TI_FLAG_BYTE_CWP] =
627 			(current_pt_regs()->tstate + 1) & TSTATE_CWP;
628 		t->current_ds = ASI_P;
629 		t->kregs->u_regs[UREG_G1] = sp; /* function */
630 		t->kregs->u_regs[UREG_G2] = arg;
631 		return 0;
632 	}
633 
634 	parent_sf = ((struct sparc_stackf *) regs) - 1;
635 	memcpy(child_trap_frame, parent_sf, child_stack_sz);
636 	if (t->flags & _TIF_32BIT) {
637 		sp &= 0x00000000ffffffffUL;
638 		regs->u_regs[UREG_FP] &= 0x00000000ffffffffUL;
639 	}
640 	t->kregs->u_regs[UREG_FP] = sp;
641 	__thread_flag_byte_ptr(t)[TI_FLAG_BYTE_CWP] =
642 		(regs->tstate + 1) & TSTATE_CWP;
643 	t->current_ds = ASI_AIUS;
644 	if (sp != regs->u_regs[UREG_FP]) {
645 		unsigned long csp;
646 
647 		csp = clone_stackframe(sp, regs->u_regs[UREG_FP]);
648 		if (!csp)
649 			return -EFAULT;
650 		t->kregs->u_regs[UREG_FP] = csp;
651 	}
652 	if (t->utraps)
653 		t->utraps[0]++;
654 
655 	/* Set the return value for the child. */
656 	t->kregs->u_regs[UREG_I0] = current->pid;
657 	t->kregs->u_regs[UREG_I1] = 1;
658 
659 	/* Set the second return value for the parent. */
660 	regs->u_regs[UREG_I1] = 0;
661 
662 	if (clone_flags & CLONE_SETTLS)
663 		t->kregs->u_regs[UREG_G7] = regs->u_regs[UREG_I3];
664 
665 	return 0;
666 }
667 
668 typedef struct {
669 	union {
670 		unsigned int	pr_regs[32];
671 		unsigned long	pr_dregs[16];
672 	} pr_fr;
673 	unsigned int __unused;
674 	unsigned int	pr_fsr;
675 	unsigned char	pr_qcnt;
676 	unsigned char	pr_q_entrysize;
677 	unsigned char	pr_en;
678 	unsigned int	pr_q[64];
679 } elf_fpregset_t32;
680 
681 /*
682  * fill in the fpu structure for a core dump.
683  */
684 int dump_fpu (struct pt_regs * regs, elf_fpregset_t * fpregs)
685 {
686 	unsigned long *kfpregs = current_thread_info()->fpregs;
687 	unsigned long fprs = current_thread_info()->fpsaved[0];
688 
689 	if (test_thread_flag(TIF_32BIT)) {
690 		elf_fpregset_t32 *fpregs32 = (elf_fpregset_t32 *)fpregs;
691 
692 		if (fprs & FPRS_DL)
693 			memcpy(&fpregs32->pr_fr.pr_regs[0], kfpregs,
694 			       sizeof(unsigned int) * 32);
695 		else
696 			memset(&fpregs32->pr_fr.pr_regs[0], 0,
697 			       sizeof(unsigned int) * 32);
698 		fpregs32->pr_qcnt = 0;
699 		fpregs32->pr_q_entrysize = 8;
700 		memset(&fpregs32->pr_q[0], 0,
701 		       (sizeof(unsigned int) * 64));
702 		if (fprs & FPRS_FEF) {
703 			fpregs32->pr_fsr = (unsigned int) current_thread_info()->xfsr[0];
704 			fpregs32->pr_en = 1;
705 		} else {
706 			fpregs32->pr_fsr = 0;
707 			fpregs32->pr_en = 0;
708 		}
709 	} else {
710 		if(fprs & FPRS_DL)
711 			memcpy(&fpregs->pr_regs[0], kfpregs,
712 			       sizeof(unsigned int) * 32);
713 		else
714 			memset(&fpregs->pr_regs[0], 0,
715 			       sizeof(unsigned int) * 32);
716 		if(fprs & FPRS_DU)
717 			memcpy(&fpregs->pr_regs[16], kfpregs+16,
718 			       sizeof(unsigned int) * 32);
719 		else
720 			memset(&fpregs->pr_regs[16], 0,
721 			       sizeof(unsigned int) * 32);
722 		if(fprs & FPRS_FEF) {
723 			fpregs->pr_fsr = current_thread_info()->xfsr[0];
724 			fpregs->pr_gsr = current_thread_info()->gsr[0];
725 		} else {
726 			fpregs->pr_fsr = fpregs->pr_gsr = 0;
727 		}
728 		fpregs->pr_fprs = fprs;
729 	}
730 	return 1;
731 }
732 EXPORT_SYMBOL(dump_fpu);
733 
734 unsigned long get_wchan(struct task_struct *task)
735 {
736 	unsigned long pc, fp, bias = 0;
737 	struct thread_info *tp;
738 	struct reg_window *rw;
739         unsigned long ret = 0;
740 	int count = 0;
741 
742 	if (!task || task == current ||
743             task->state == TASK_RUNNING)
744 		goto out;
745 
746 	tp = task_thread_info(task);
747 	bias = STACK_BIAS;
748 	fp = task_thread_info(task)->ksp + bias;
749 
750 	do {
751 		if (!kstack_valid(tp, fp))
752 			break;
753 		rw = (struct reg_window *) fp;
754 		pc = rw->ins[7];
755 		if (!in_sched_functions(pc)) {
756 			ret = pc;
757 			goto out;
758 		}
759 		fp = rw->ins[6] + bias;
760 	} while (++count < 16);
761 
762 out:
763 	return ret;
764 }
765