xref: /openbmc/linux/arch/sparc/kernel/process_64.c (revision e23feb16)
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 /* Idle loop support on sparc64. */
56 void arch_cpu_idle(void)
57 {
58 	if (tlb_type != hypervisor) {
59 		touch_nmi_watchdog();
60 	} else {
61 		unsigned long pstate;
62 
63                 /* The sun4v sleeping code requires that we have PSTATE.IE cleared over
64                  * the cpu sleep hypervisor call.
65                  */
66 		__asm__ __volatile__(
67 			"rdpr %%pstate, %0\n\t"
68 			"andn %0, %1, %0\n\t"
69 			"wrpr %0, %%g0, %%pstate"
70 			: "=&r" (pstate)
71 			: "i" (PSTATE_IE));
72 
73 		if (!need_resched() && !cpu_is_offline(smp_processor_id()))
74 			sun4v_cpu_yield();
75 
76 		/* Re-enable interrupts. */
77 		__asm__ __volatile__(
78 			"rdpr %%pstate, %0\n\t"
79 			"or %0, %1, %0\n\t"
80 			"wrpr %0, %%g0, %%pstate"
81 			: "=&r" (pstate)
82 			: "i" (PSTATE_IE));
83 	}
84 	local_irq_enable();
85 }
86 
87 #ifdef CONFIG_HOTPLUG_CPU
88 void arch_cpu_idle_dead()
89 {
90 	sched_preempt_enable_no_resched();
91 	cpu_play_dead();
92 }
93 #endif
94 
95 #ifdef CONFIG_COMPAT
96 static void show_regwindow32(struct pt_regs *regs)
97 {
98 	struct reg_window32 __user *rw;
99 	struct reg_window32 r_w;
100 	mm_segment_t old_fs;
101 
102 	__asm__ __volatile__ ("flushw");
103 	rw = compat_ptr((unsigned)regs->u_regs[14]);
104 	old_fs = get_fs();
105 	set_fs (USER_DS);
106 	if (copy_from_user (&r_w, rw, sizeof(r_w))) {
107 		set_fs (old_fs);
108 		return;
109 	}
110 
111 	set_fs (old_fs);
112 	printk("l0: %08x l1: %08x l2: %08x l3: %08x "
113 	       "l4: %08x l5: %08x l6: %08x l7: %08x\n",
114 	       r_w.locals[0], r_w.locals[1], r_w.locals[2], r_w.locals[3],
115 	       r_w.locals[4], r_w.locals[5], r_w.locals[6], r_w.locals[7]);
116 	printk("i0: %08x i1: %08x i2: %08x i3: %08x "
117 	       "i4: %08x i5: %08x i6: %08x i7: %08x\n",
118 	       r_w.ins[0], r_w.ins[1], r_w.ins[2], r_w.ins[3],
119 	       r_w.ins[4], r_w.ins[5], r_w.ins[6], r_w.ins[7]);
120 }
121 #else
122 #define show_regwindow32(regs)	do { } while (0)
123 #endif
124 
125 static void show_regwindow(struct pt_regs *regs)
126 {
127 	struct reg_window __user *rw;
128 	struct reg_window *rwk;
129 	struct reg_window r_w;
130 	mm_segment_t old_fs;
131 
132 	if ((regs->tstate & TSTATE_PRIV) || !(test_thread_flag(TIF_32BIT))) {
133 		__asm__ __volatile__ ("flushw");
134 		rw = (struct reg_window __user *)
135 			(regs->u_regs[14] + STACK_BIAS);
136 		rwk = (struct reg_window *)
137 			(regs->u_regs[14] + STACK_BIAS);
138 		if (!(regs->tstate & TSTATE_PRIV)) {
139 			old_fs = get_fs();
140 			set_fs (USER_DS);
141 			if (copy_from_user (&r_w, rw, sizeof(r_w))) {
142 				set_fs (old_fs);
143 				return;
144 			}
145 			rwk = &r_w;
146 			set_fs (old_fs);
147 		}
148 	} else {
149 		show_regwindow32(regs);
150 		return;
151 	}
152 	printk("l0: %016lx l1: %016lx l2: %016lx l3: %016lx\n",
153 	       rwk->locals[0], rwk->locals[1], rwk->locals[2], rwk->locals[3]);
154 	printk("l4: %016lx l5: %016lx l6: %016lx l7: %016lx\n",
155 	       rwk->locals[4], rwk->locals[5], rwk->locals[6], rwk->locals[7]);
156 	printk("i0: %016lx i1: %016lx i2: %016lx i3: %016lx\n",
157 	       rwk->ins[0], rwk->ins[1], rwk->ins[2], rwk->ins[3]);
158 	printk("i4: %016lx i5: %016lx i6: %016lx i7: %016lx\n",
159 	       rwk->ins[4], rwk->ins[5], rwk->ins[6], rwk->ins[7]);
160 	if (regs->tstate & TSTATE_PRIV)
161 		printk("I7: <%pS>\n", (void *) rwk->ins[7]);
162 }
163 
164 void show_regs(struct pt_regs *regs)
165 {
166 	show_regs_print_info(KERN_DEFAULT);
167 
168 	printk("TSTATE: %016lx TPC: %016lx TNPC: %016lx Y: %08x    %s\n", regs->tstate,
169 	       regs->tpc, regs->tnpc, regs->y, print_tainted());
170 	printk("TPC: <%pS>\n", (void *) regs->tpc);
171 	printk("g0: %016lx g1: %016lx g2: %016lx g3: %016lx\n",
172 	       regs->u_regs[0], regs->u_regs[1], regs->u_regs[2],
173 	       regs->u_regs[3]);
174 	printk("g4: %016lx g5: %016lx g6: %016lx g7: %016lx\n",
175 	       regs->u_regs[4], regs->u_regs[5], regs->u_regs[6],
176 	       regs->u_regs[7]);
177 	printk("o0: %016lx o1: %016lx o2: %016lx o3: %016lx\n",
178 	       regs->u_regs[8], regs->u_regs[9], regs->u_regs[10],
179 	       regs->u_regs[11]);
180 	printk("o4: %016lx o5: %016lx sp: %016lx ret_pc: %016lx\n",
181 	       regs->u_regs[12], regs->u_regs[13], regs->u_regs[14],
182 	       regs->u_regs[15]);
183 	printk("RPC: <%pS>\n", (void *) regs->u_regs[15]);
184 	show_regwindow(regs);
185 	show_stack(current, (unsigned long *) regs->u_regs[UREG_FP]);
186 }
187 
188 union global_cpu_snapshot global_cpu_snapshot[NR_CPUS];
189 static DEFINE_SPINLOCK(global_cpu_snapshot_lock);
190 
191 static void __global_reg_self(struct thread_info *tp, struct pt_regs *regs,
192 			      int this_cpu)
193 {
194 	struct global_reg_snapshot *rp;
195 
196 	flushw_all();
197 
198 	rp = &global_cpu_snapshot[this_cpu].reg;
199 
200 	rp->tstate = regs->tstate;
201 	rp->tpc = regs->tpc;
202 	rp->tnpc = regs->tnpc;
203 	rp->o7 = regs->u_regs[UREG_I7];
204 
205 	if (regs->tstate & TSTATE_PRIV) {
206 		struct reg_window *rw;
207 
208 		rw = (struct reg_window *)
209 			(regs->u_regs[UREG_FP] + STACK_BIAS);
210 		if (kstack_valid(tp, (unsigned long) rw)) {
211 			rp->i7 = rw->ins[7];
212 			rw = (struct reg_window *)
213 				(rw->ins[6] + STACK_BIAS);
214 			if (kstack_valid(tp, (unsigned long) rw))
215 				rp->rpc = rw->ins[7];
216 		}
217 	} else {
218 		rp->i7 = 0;
219 		rp->rpc = 0;
220 	}
221 	rp->thread = tp;
222 }
223 
224 /* In order to avoid hangs we do not try to synchronize with the
225  * global register dump client cpus.  The last store they make is to
226  * the thread pointer, so do a short poll waiting for that to become
227  * non-NULL.
228  */
229 static void __global_reg_poll(struct global_reg_snapshot *gp)
230 {
231 	int limit = 0;
232 
233 	while (!gp->thread && ++limit < 100) {
234 		barrier();
235 		udelay(1);
236 	}
237 }
238 
239 void arch_trigger_all_cpu_backtrace(void)
240 {
241 	struct thread_info *tp = current_thread_info();
242 	struct pt_regs *regs = get_irq_regs();
243 	unsigned long flags;
244 	int this_cpu, cpu;
245 
246 	if (!regs)
247 		regs = tp->kregs;
248 
249 	spin_lock_irqsave(&global_cpu_snapshot_lock, flags);
250 
251 	memset(global_cpu_snapshot, 0, sizeof(global_cpu_snapshot));
252 
253 	this_cpu = raw_smp_processor_id();
254 
255 	__global_reg_self(tp, regs, this_cpu);
256 
257 	smp_fetch_global_regs();
258 
259 	for_each_online_cpu(cpu) {
260 		struct global_reg_snapshot *gp = &global_cpu_snapshot[cpu].reg;
261 
262 		__global_reg_poll(gp);
263 
264 		tp = gp->thread;
265 		printk("%c CPU[%3d]: TSTATE[%016lx] TPC[%016lx] TNPC[%016lx] TASK[%s:%d]\n",
266 		       (cpu == this_cpu ? '*' : ' '), cpu,
267 		       gp->tstate, gp->tpc, gp->tnpc,
268 		       ((tp && tp->task) ? tp->task->comm : "NULL"),
269 		       ((tp && tp->task) ? tp->task->pid : -1));
270 
271 		if (gp->tstate & TSTATE_PRIV) {
272 			printk("             TPC[%pS] O7[%pS] I7[%pS] RPC[%pS]\n",
273 			       (void *) gp->tpc,
274 			       (void *) gp->o7,
275 			       (void *) gp->i7,
276 			       (void *) gp->rpc);
277 		} else {
278 			printk("             TPC[%lx] O7[%lx] I7[%lx] RPC[%lx]\n",
279 			       gp->tpc, gp->o7, gp->i7, gp->rpc);
280 		}
281 	}
282 
283 	memset(global_cpu_snapshot, 0, sizeof(global_cpu_snapshot));
284 
285 	spin_unlock_irqrestore(&global_cpu_snapshot_lock, flags);
286 }
287 
288 #ifdef CONFIG_MAGIC_SYSRQ
289 
290 static void sysrq_handle_globreg(int key)
291 {
292 	arch_trigger_all_cpu_backtrace();
293 }
294 
295 static struct sysrq_key_op sparc_globalreg_op = {
296 	.handler	= sysrq_handle_globreg,
297 	.help_msg	= "global-regs(y)",
298 	.action_msg	= "Show Global CPU Regs",
299 };
300 
301 static void __global_pmu_self(int this_cpu)
302 {
303 	struct global_pmu_snapshot *pp;
304 	int i, num;
305 
306 	pp = &global_cpu_snapshot[this_cpu].pmu;
307 
308 	num = 1;
309 	if (tlb_type == hypervisor &&
310 	    sun4v_chip_type >= SUN4V_CHIP_NIAGARA4)
311 		num = 4;
312 
313 	for (i = 0; i < num; i++) {
314 		pp->pcr[i] = pcr_ops->read_pcr(i);
315 		pp->pic[i] = pcr_ops->read_pic(i);
316 	}
317 }
318 
319 static void __global_pmu_poll(struct global_pmu_snapshot *pp)
320 {
321 	int limit = 0;
322 
323 	while (!pp->pcr[0] && ++limit < 100) {
324 		barrier();
325 		udelay(1);
326 	}
327 }
328 
329 static void pmu_snapshot_all_cpus(void)
330 {
331 	unsigned long flags;
332 	int this_cpu, cpu;
333 
334 	spin_lock_irqsave(&global_cpu_snapshot_lock, flags);
335 
336 	memset(global_cpu_snapshot, 0, sizeof(global_cpu_snapshot));
337 
338 	this_cpu = raw_smp_processor_id();
339 
340 	__global_pmu_self(this_cpu);
341 
342 	smp_fetch_global_pmu();
343 
344 	for_each_online_cpu(cpu) {
345 		struct global_pmu_snapshot *pp = &global_cpu_snapshot[cpu].pmu;
346 
347 		__global_pmu_poll(pp);
348 
349 		printk("%c CPU[%3d]: PCR[%08lx:%08lx:%08lx:%08lx] PIC[%08lx:%08lx:%08lx:%08lx]\n",
350 		       (cpu == this_cpu ? '*' : ' '), cpu,
351 		       pp->pcr[0], pp->pcr[1], pp->pcr[2], pp->pcr[3],
352 		       pp->pic[0], pp->pic[1], pp->pic[2], pp->pic[3]);
353 	}
354 
355 	memset(global_cpu_snapshot, 0, sizeof(global_cpu_snapshot));
356 
357 	spin_unlock_irqrestore(&global_cpu_snapshot_lock, flags);
358 }
359 
360 static void sysrq_handle_globpmu(int key)
361 {
362 	pmu_snapshot_all_cpus();
363 }
364 
365 static struct sysrq_key_op sparc_globalpmu_op = {
366 	.handler	= sysrq_handle_globpmu,
367 	.help_msg	= "global-pmu(x)",
368 	.action_msg	= "Show Global PMU Regs",
369 };
370 
371 static int __init sparc_sysrq_init(void)
372 {
373 	int ret = register_sysrq_key('y', &sparc_globalreg_op);
374 
375 	if (!ret)
376 		ret = register_sysrq_key('x', &sparc_globalpmu_op);
377 	return ret;
378 }
379 
380 core_initcall(sparc_sysrq_init);
381 
382 #endif
383 
384 unsigned long thread_saved_pc(struct task_struct *tsk)
385 {
386 	struct thread_info *ti = task_thread_info(tsk);
387 	unsigned long ret = 0xdeadbeefUL;
388 
389 	if (ti && ti->ksp) {
390 		unsigned long *sp;
391 		sp = (unsigned long *)(ti->ksp + STACK_BIAS);
392 		if (((unsigned long)sp & (sizeof(long) - 1)) == 0UL &&
393 		    sp[14]) {
394 			unsigned long *fp;
395 			fp = (unsigned long *)(sp[14] + STACK_BIAS);
396 			if (((unsigned long)fp & (sizeof(long) - 1)) == 0UL)
397 				ret = fp[15];
398 		}
399 	}
400 	return ret;
401 }
402 
403 /* Free current thread data structures etc.. */
404 void exit_thread(void)
405 {
406 	struct thread_info *t = current_thread_info();
407 
408 	if (t->utraps) {
409 		if (t->utraps[0] < 2)
410 			kfree (t->utraps);
411 		else
412 			t->utraps[0]--;
413 	}
414 }
415 
416 void flush_thread(void)
417 {
418 	struct thread_info *t = current_thread_info();
419 	struct mm_struct *mm;
420 
421 	mm = t->task->mm;
422 	if (mm)
423 		tsb_context_switch(mm);
424 
425 	set_thread_wsaved(0);
426 
427 	/* Clear FPU register state. */
428 	t->fpsaved[0] = 0;
429 }
430 
431 /* It's a bit more tricky when 64-bit tasks are involved... */
432 static unsigned long clone_stackframe(unsigned long csp, unsigned long psp)
433 {
434 	bool stack_64bit = test_thread_64bit_stack(psp);
435 	unsigned long fp, distance, rval;
436 
437 	if (stack_64bit) {
438 		csp += STACK_BIAS;
439 		psp += STACK_BIAS;
440 		__get_user(fp, &(((struct reg_window __user *)psp)->ins[6]));
441 		fp += STACK_BIAS;
442 		if (test_thread_flag(TIF_32BIT))
443 			fp &= 0xffffffff;
444 	} else
445 		__get_user(fp, &(((struct reg_window32 __user *)psp)->ins[6]));
446 
447 	/* Now align the stack as this is mandatory in the Sparc ABI
448 	 * due to how register windows work.  This hides the
449 	 * restriction from thread libraries etc.
450 	 */
451 	csp &= ~15UL;
452 
453 	distance = fp - psp;
454 	rval = (csp - distance);
455 	if (copy_in_user((void __user *) rval, (void __user *) psp, distance))
456 		rval = 0;
457 	else if (!stack_64bit) {
458 		if (put_user(((u32)csp),
459 			     &(((struct reg_window32 __user *)rval)->ins[6])))
460 			rval = 0;
461 	} else {
462 		if (put_user(((u64)csp - STACK_BIAS),
463 			     &(((struct reg_window __user *)rval)->ins[6])))
464 			rval = 0;
465 		else
466 			rval = rval - STACK_BIAS;
467 	}
468 
469 	return rval;
470 }
471 
472 /* Standard stuff. */
473 static inline void shift_window_buffer(int first_win, int last_win,
474 				       struct thread_info *t)
475 {
476 	int i;
477 
478 	for (i = first_win; i < last_win; i++) {
479 		t->rwbuf_stkptrs[i] = t->rwbuf_stkptrs[i+1];
480 		memcpy(&t->reg_window[i], &t->reg_window[i+1],
481 		       sizeof(struct reg_window));
482 	}
483 }
484 
485 void synchronize_user_stack(void)
486 {
487 	struct thread_info *t = current_thread_info();
488 	unsigned long window;
489 
490 	flush_user_windows();
491 	if ((window = get_thread_wsaved()) != 0) {
492 		window -= 1;
493 		do {
494 			struct reg_window *rwin = &t->reg_window[window];
495 			int winsize = sizeof(struct reg_window);
496 			unsigned long sp;
497 
498 			sp = t->rwbuf_stkptrs[window];
499 
500 			if (test_thread_64bit_stack(sp))
501 				sp += STACK_BIAS;
502 			else
503 				winsize = sizeof(struct reg_window32);
504 
505 			if (!copy_to_user((char __user *)sp, rwin, winsize)) {
506 				shift_window_buffer(window, get_thread_wsaved() - 1, t);
507 				set_thread_wsaved(get_thread_wsaved() - 1);
508 			}
509 		} while (window--);
510 	}
511 }
512 
513 static void stack_unaligned(unsigned long sp)
514 {
515 	siginfo_t info;
516 
517 	info.si_signo = SIGBUS;
518 	info.si_errno = 0;
519 	info.si_code = BUS_ADRALN;
520 	info.si_addr = (void __user *) sp;
521 	info.si_trapno = 0;
522 	force_sig_info(SIGBUS, &info, current);
523 }
524 
525 void fault_in_user_windows(void)
526 {
527 	struct thread_info *t = current_thread_info();
528 	unsigned long window;
529 
530 	flush_user_windows();
531 	window = get_thread_wsaved();
532 
533 	if (likely(window != 0)) {
534 		window -= 1;
535 		do {
536 			struct reg_window *rwin = &t->reg_window[window];
537 			int winsize = sizeof(struct reg_window);
538 			unsigned long sp;
539 
540 			sp = t->rwbuf_stkptrs[window];
541 
542 			if (test_thread_64bit_stack(sp))
543 				sp += STACK_BIAS;
544 			else
545 				winsize = sizeof(struct reg_window32);
546 
547 			if (unlikely(sp & 0x7UL))
548 				stack_unaligned(sp);
549 
550 			if (unlikely(copy_to_user((char __user *)sp,
551 						  rwin, winsize)))
552 				goto barf;
553 		} while (window--);
554 	}
555 	set_thread_wsaved(0);
556 	return;
557 
558 barf:
559 	set_thread_wsaved(window + 1);
560 	do_exit(SIGILL);
561 }
562 
563 asmlinkage long sparc_do_fork(unsigned long clone_flags,
564 			      unsigned long stack_start,
565 			      struct pt_regs *regs,
566 			      unsigned long stack_size)
567 {
568 	int __user *parent_tid_ptr, *child_tid_ptr;
569 	unsigned long orig_i1 = regs->u_regs[UREG_I1];
570 	long ret;
571 
572 #ifdef CONFIG_COMPAT
573 	if (test_thread_flag(TIF_32BIT)) {
574 		parent_tid_ptr = compat_ptr(regs->u_regs[UREG_I2]);
575 		child_tid_ptr = compat_ptr(regs->u_regs[UREG_I4]);
576 	} else
577 #endif
578 	{
579 		parent_tid_ptr = (int __user *) regs->u_regs[UREG_I2];
580 		child_tid_ptr = (int __user *) regs->u_regs[UREG_I4];
581 	}
582 
583 	ret = do_fork(clone_flags, stack_start, stack_size,
584 		      parent_tid_ptr, child_tid_ptr);
585 
586 	/* If we get an error and potentially restart the system
587 	 * call, we're screwed because copy_thread() clobbered
588 	 * the parent's %o1.  So detect that case and restore it
589 	 * here.
590 	 */
591 	if ((unsigned long)ret >= -ERESTART_RESTARTBLOCK)
592 		regs->u_regs[UREG_I1] = orig_i1;
593 
594 	return ret;
595 }
596 
597 /* Copy a Sparc thread.  The fork() return value conventions
598  * under SunOS are nothing short of bletcherous:
599  * Parent -->  %o0 == childs  pid, %o1 == 0
600  * Child  -->  %o0 == parents pid, %o1 == 1
601  */
602 int copy_thread(unsigned long clone_flags, unsigned long sp,
603 		unsigned long arg, struct task_struct *p)
604 {
605 	struct thread_info *t = task_thread_info(p);
606 	struct pt_regs *regs = current_pt_regs();
607 	struct sparc_stackf *parent_sf;
608 	unsigned long child_stack_sz;
609 	char *child_trap_frame;
610 
611 	/* Calculate offset to stack_frame & pt_regs */
612 	child_stack_sz = (STACKFRAME_SZ + TRACEREG_SZ);
613 	child_trap_frame = (task_stack_page(p) +
614 			    (THREAD_SIZE - child_stack_sz));
615 
616 	t->new_child = 1;
617 	t->ksp = ((unsigned long) child_trap_frame) - STACK_BIAS;
618 	t->kregs = (struct pt_regs *) (child_trap_frame +
619 				       sizeof(struct sparc_stackf));
620 	t->fpsaved[0] = 0;
621 
622 	if (unlikely(p->flags & PF_KTHREAD)) {
623 		memset(child_trap_frame, 0, child_stack_sz);
624 		__thread_flag_byte_ptr(t)[TI_FLAG_BYTE_CWP] =
625 			(current_pt_regs()->tstate + 1) & TSTATE_CWP;
626 		t->current_ds = ASI_P;
627 		t->kregs->u_regs[UREG_G1] = sp; /* function */
628 		t->kregs->u_regs[UREG_G2] = arg;
629 		return 0;
630 	}
631 
632 	parent_sf = ((struct sparc_stackf *) regs) - 1;
633 	memcpy(child_trap_frame, parent_sf, child_stack_sz);
634 	if (t->flags & _TIF_32BIT) {
635 		sp &= 0x00000000ffffffffUL;
636 		regs->u_regs[UREG_FP] &= 0x00000000ffffffffUL;
637 	}
638 	t->kregs->u_regs[UREG_FP] = sp;
639 	__thread_flag_byte_ptr(t)[TI_FLAG_BYTE_CWP] =
640 		(regs->tstate + 1) & TSTATE_CWP;
641 	t->current_ds = ASI_AIUS;
642 	if (sp != regs->u_regs[UREG_FP]) {
643 		unsigned long csp;
644 
645 		csp = clone_stackframe(sp, regs->u_regs[UREG_FP]);
646 		if (!csp)
647 			return -EFAULT;
648 		t->kregs->u_regs[UREG_FP] = csp;
649 	}
650 	if (t->utraps)
651 		t->utraps[0]++;
652 
653 	/* Set the return value for the child. */
654 	t->kregs->u_regs[UREG_I0] = current->pid;
655 	t->kregs->u_regs[UREG_I1] = 1;
656 
657 	/* Set the second return value for the parent. */
658 	regs->u_regs[UREG_I1] = 0;
659 
660 	if (clone_flags & CLONE_SETTLS)
661 		t->kregs->u_regs[UREG_G7] = regs->u_regs[UREG_I3];
662 
663 	return 0;
664 }
665 
666 typedef struct {
667 	union {
668 		unsigned int	pr_regs[32];
669 		unsigned long	pr_dregs[16];
670 	} pr_fr;
671 	unsigned int __unused;
672 	unsigned int	pr_fsr;
673 	unsigned char	pr_qcnt;
674 	unsigned char	pr_q_entrysize;
675 	unsigned char	pr_en;
676 	unsigned int	pr_q[64];
677 } elf_fpregset_t32;
678 
679 /*
680  * fill in the fpu structure for a core dump.
681  */
682 int dump_fpu (struct pt_regs * regs, elf_fpregset_t * fpregs)
683 {
684 	unsigned long *kfpregs = current_thread_info()->fpregs;
685 	unsigned long fprs = current_thread_info()->fpsaved[0];
686 
687 	if (test_thread_flag(TIF_32BIT)) {
688 		elf_fpregset_t32 *fpregs32 = (elf_fpregset_t32 *)fpregs;
689 
690 		if (fprs & FPRS_DL)
691 			memcpy(&fpregs32->pr_fr.pr_regs[0], kfpregs,
692 			       sizeof(unsigned int) * 32);
693 		else
694 			memset(&fpregs32->pr_fr.pr_regs[0], 0,
695 			       sizeof(unsigned int) * 32);
696 		fpregs32->pr_qcnt = 0;
697 		fpregs32->pr_q_entrysize = 8;
698 		memset(&fpregs32->pr_q[0], 0,
699 		       (sizeof(unsigned int) * 64));
700 		if (fprs & FPRS_FEF) {
701 			fpregs32->pr_fsr = (unsigned int) current_thread_info()->xfsr[0];
702 			fpregs32->pr_en = 1;
703 		} else {
704 			fpregs32->pr_fsr = 0;
705 			fpregs32->pr_en = 0;
706 		}
707 	} else {
708 		if(fprs & FPRS_DL)
709 			memcpy(&fpregs->pr_regs[0], kfpregs,
710 			       sizeof(unsigned int) * 32);
711 		else
712 			memset(&fpregs->pr_regs[0], 0,
713 			       sizeof(unsigned int) * 32);
714 		if(fprs & FPRS_DU)
715 			memcpy(&fpregs->pr_regs[16], kfpregs+16,
716 			       sizeof(unsigned int) * 32);
717 		else
718 			memset(&fpregs->pr_regs[16], 0,
719 			       sizeof(unsigned int) * 32);
720 		if(fprs & FPRS_FEF) {
721 			fpregs->pr_fsr = current_thread_info()->xfsr[0];
722 			fpregs->pr_gsr = current_thread_info()->gsr[0];
723 		} else {
724 			fpregs->pr_fsr = fpregs->pr_gsr = 0;
725 		}
726 		fpregs->pr_fprs = fprs;
727 	}
728 	return 1;
729 }
730 EXPORT_SYMBOL(dump_fpu);
731 
732 unsigned long get_wchan(struct task_struct *task)
733 {
734 	unsigned long pc, fp, bias = 0;
735 	struct thread_info *tp;
736 	struct reg_window *rw;
737         unsigned long ret = 0;
738 	int count = 0;
739 
740 	if (!task || task == current ||
741             task->state == TASK_RUNNING)
742 		goto out;
743 
744 	tp = task_thread_info(task);
745 	bias = STACK_BIAS;
746 	fp = task_thread_info(task)->ksp + bias;
747 
748 	do {
749 		if (!kstack_valid(tp, fp))
750 			break;
751 		rw = (struct reg_window *) fp;
752 		pc = rw->ins[7];
753 		if (!in_sched_functions(pc)) {
754 			ret = pc;
755 			goto out;
756 		}
757 		fp = rw->ins[6] + bias;
758 	} while (++count < 16);
759 
760 out:
761 	return ret;
762 }
763