xref: /linux/arch/sparc/kernel/process_64.c (revision 37744feebc086908fd89760650f458ab19071750)
1 // SPDX-License-Identifier: GPL-2.0
2 /*  arch/sparc64/kernel/process.c
3  *
4  *  Copyright (C) 1995, 1996, 2008 David S. Miller (davem@davemloft.net)
5  *  Copyright (C) 1996       Eddie C. Dost   (ecd@skynet.be)
6  *  Copyright (C) 1997, 1998 Jakub Jelinek   (jj@sunsite.mff.cuni.cz)
7  */
8 
9 /*
10  * This file handles the architecture-dependent parts of process handling..
11  */
12 
13 #include <stdarg.h>
14 
15 #include <linux/errno.h>
16 #include <linux/export.h>
17 #include <linux/sched.h>
18 #include <linux/sched/debug.h>
19 #include <linux/sched/task.h>
20 #include <linux/sched/task_stack.h>
21 #include <linux/kernel.h>
22 #include <linux/mm.h>
23 #include <linux/fs.h>
24 #include <linux/smp.h>
25 #include <linux/stddef.h>
26 #include <linux/ptrace.h>
27 #include <linux/slab.h>
28 #include <linux/user.h>
29 #include <linux/delay.h>
30 #include <linux/compat.h>
31 #include <linux/tick.h>
32 #include <linux/init.h>
33 #include <linux/cpu.h>
34 #include <linux/perf_event.h>
35 #include <linux/elfcore.h>
36 #include <linux/sysrq.h>
37 #include <linux/nmi.h>
38 #include <linux/context_tracking.h>
39 #include <linux/signal.h>
40 
41 #include <linux/uaccess.h>
42 #include <asm/page.h>
43 #include <asm/pgalloc.h>
44 #include <asm/pgtable.h>
45 #include <asm/processor.h>
46 #include <asm/pstate.h>
47 #include <asm/elf.h>
48 #include <asm/fpumacro.h>
49 #include <asm/head.h>
50 #include <asm/cpudata.h>
51 #include <asm/mmu_context.h>
52 #include <asm/unistd.h>
53 #include <asm/hypervisor.h>
54 #include <asm/syscalls.h>
55 #include <asm/irq_regs.h>
56 #include <asm/smp.h>
57 #include <asm/pcr.h>
58 
59 #include "kstack.h"
60 
61 /* Idle loop support on sparc64. */
62 void arch_cpu_idle(void)
63 {
64 	if (tlb_type != hypervisor) {
65 		touch_nmi_watchdog();
66 		local_irq_enable();
67 	} else {
68 		unsigned long pstate;
69 
70 		local_irq_enable();
71 
72                 /* The sun4v sleeping code requires that we have PSTATE.IE cleared over
73                  * the cpu sleep hypervisor call.
74                  */
75 		__asm__ __volatile__(
76 			"rdpr %%pstate, %0\n\t"
77 			"andn %0, %1, %0\n\t"
78 			"wrpr %0, %%g0, %%pstate"
79 			: "=&r" (pstate)
80 			: "i" (PSTATE_IE));
81 
82 		if (!need_resched() && !cpu_is_offline(smp_processor_id())) {
83 			sun4v_cpu_yield();
84 			/* If resumed by cpu_poke then we need to explicitly
85 			 * call scheduler_ipi().
86 			 */
87 			scheduler_poke();
88 		}
89 
90 		/* Re-enable interrupts. */
91 		__asm__ __volatile__(
92 			"rdpr %%pstate, %0\n\t"
93 			"or %0, %1, %0\n\t"
94 			"wrpr %0, %%g0, %%pstate"
95 			: "=&r" (pstate)
96 			: "i" (PSTATE_IE));
97 	}
98 }
99 
100 #ifdef CONFIG_HOTPLUG_CPU
101 void arch_cpu_idle_dead(void)
102 {
103 	sched_preempt_enable_no_resched();
104 	cpu_play_dead();
105 }
106 #endif
107 
108 #ifdef CONFIG_COMPAT
109 static void show_regwindow32(struct pt_regs *regs)
110 {
111 	struct reg_window32 __user *rw;
112 	struct reg_window32 r_w;
113 	mm_segment_t old_fs;
114 
115 	__asm__ __volatile__ ("flushw");
116 	rw = compat_ptr((unsigned int)regs->u_regs[14]);
117 	old_fs = get_fs();
118 	set_fs (USER_DS);
119 	if (copy_from_user (&r_w, rw, sizeof(r_w))) {
120 		set_fs (old_fs);
121 		return;
122 	}
123 
124 	set_fs (old_fs);
125 	printk("l0: %08x l1: %08x l2: %08x l3: %08x "
126 	       "l4: %08x l5: %08x l6: %08x l7: %08x\n",
127 	       r_w.locals[0], r_w.locals[1], r_w.locals[2], r_w.locals[3],
128 	       r_w.locals[4], r_w.locals[5], r_w.locals[6], r_w.locals[7]);
129 	printk("i0: %08x i1: %08x i2: %08x i3: %08x "
130 	       "i4: %08x i5: %08x i6: %08x i7: %08x\n",
131 	       r_w.ins[0], r_w.ins[1], r_w.ins[2], r_w.ins[3],
132 	       r_w.ins[4], r_w.ins[5], r_w.ins[6], r_w.ins[7]);
133 }
134 #else
135 #define show_regwindow32(regs)	do { } while (0)
136 #endif
137 
138 static void show_regwindow(struct pt_regs *regs)
139 {
140 	struct reg_window __user *rw;
141 	struct reg_window *rwk;
142 	struct reg_window r_w;
143 	mm_segment_t old_fs;
144 
145 	if ((regs->tstate & TSTATE_PRIV) || !(test_thread_flag(TIF_32BIT))) {
146 		__asm__ __volatile__ ("flushw");
147 		rw = (struct reg_window __user *)
148 			(regs->u_regs[14] + STACK_BIAS);
149 		rwk = (struct reg_window *)
150 			(regs->u_regs[14] + STACK_BIAS);
151 		if (!(regs->tstate & TSTATE_PRIV)) {
152 			old_fs = get_fs();
153 			set_fs (USER_DS);
154 			if (copy_from_user (&r_w, rw, sizeof(r_w))) {
155 				set_fs (old_fs);
156 				return;
157 			}
158 			rwk = &r_w;
159 			set_fs (old_fs);
160 		}
161 	} else {
162 		show_regwindow32(regs);
163 		return;
164 	}
165 	printk("l0: %016lx l1: %016lx l2: %016lx l3: %016lx\n",
166 	       rwk->locals[0], rwk->locals[1], rwk->locals[2], rwk->locals[3]);
167 	printk("l4: %016lx l5: %016lx l6: %016lx l7: %016lx\n",
168 	       rwk->locals[4], rwk->locals[5], rwk->locals[6], rwk->locals[7]);
169 	printk("i0: %016lx i1: %016lx i2: %016lx i3: %016lx\n",
170 	       rwk->ins[0], rwk->ins[1], rwk->ins[2], rwk->ins[3]);
171 	printk("i4: %016lx i5: %016lx i6: %016lx i7: %016lx\n",
172 	       rwk->ins[4], rwk->ins[5], rwk->ins[6], rwk->ins[7]);
173 	if (regs->tstate & TSTATE_PRIV)
174 		printk("I7: <%pS>\n", (void *) rwk->ins[7]);
175 }
176 
177 void show_regs(struct pt_regs *regs)
178 {
179 	show_regs_print_info(KERN_DEFAULT);
180 
181 	printk("TSTATE: %016lx TPC: %016lx TNPC: %016lx Y: %08x    %s\n", regs->tstate,
182 	       regs->tpc, regs->tnpc, regs->y, print_tainted());
183 	printk("TPC: <%pS>\n", (void *) regs->tpc);
184 	printk("g0: %016lx g1: %016lx g2: %016lx g3: %016lx\n",
185 	       regs->u_regs[0], regs->u_regs[1], regs->u_regs[2],
186 	       regs->u_regs[3]);
187 	printk("g4: %016lx g5: %016lx g6: %016lx g7: %016lx\n",
188 	       regs->u_regs[4], regs->u_regs[5], regs->u_regs[6],
189 	       regs->u_regs[7]);
190 	printk("o0: %016lx o1: %016lx o2: %016lx o3: %016lx\n",
191 	       regs->u_regs[8], regs->u_regs[9], regs->u_regs[10],
192 	       regs->u_regs[11]);
193 	printk("o4: %016lx o5: %016lx sp: %016lx ret_pc: %016lx\n",
194 	       regs->u_regs[12], regs->u_regs[13], regs->u_regs[14],
195 	       regs->u_regs[15]);
196 	printk("RPC: <%pS>\n", (void *) regs->u_regs[15]);
197 	show_regwindow(regs);
198 	show_stack(current, (unsigned long *) regs->u_regs[UREG_FP]);
199 }
200 
201 union global_cpu_snapshot global_cpu_snapshot[NR_CPUS];
202 static DEFINE_SPINLOCK(global_cpu_snapshot_lock);
203 
204 static void __global_reg_self(struct thread_info *tp, struct pt_regs *regs,
205 			      int this_cpu)
206 {
207 	struct global_reg_snapshot *rp;
208 
209 	flushw_all();
210 
211 	rp = &global_cpu_snapshot[this_cpu].reg;
212 
213 	rp->tstate = regs->tstate;
214 	rp->tpc = regs->tpc;
215 	rp->tnpc = regs->tnpc;
216 	rp->o7 = regs->u_regs[UREG_I7];
217 
218 	if (regs->tstate & TSTATE_PRIV) {
219 		struct reg_window *rw;
220 
221 		rw = (struct reg_window *)
222 			(regs->u_regs[UREG_FP] + STACK_BIAS);
223 		if (kstack_valid(tp, (unsigned long) rw)) {
224 			rp->i7 = rw->ins[7];
225 			rw = (struct reg_window *)
226 				(rw->ins[6] + STACK_BIAS);
227 			if (kstack_valid(tp, (unsigned long) rw))
228 				rp->rpc = rw->ins[7];
229 		}
230 	} else {
231 		rp->i7 = 0;
232 		rp->rpc = 0;
233 	}
234 	rp->thread = tp;
235 }
236 
237 /* In order to avoid hangs we do not try to synchronize with the
238  * global register dump client cpus.  The last store they make is to
239  * the thread pointer, so do a short poll waiting for that to become
240  * non-NULL.
241  */
242 static void __global_reg_poll(struct global_reg_snapshot *gp)
243 {
244 	int limit = 0;
245 
246 	while (!gp->thread && ++limit < 100) {
247 		barrier();
248 		udelay(1);
249 	}
250 }
251 
252 void arch_trigger_cpumask_backtrace(const cpumask_t *mask, bool exclude_self)
253 {
254 	struct thread_info *tp = current_thread_info();
255 	struct pt_regs *regs = get_irq_regs();
256 	unsigned long flags;
257 	int this_cpu, cpu;
258 
259 	if (!regs)
260 		regs = tp->kregs;
261 
262 	spin_lock_irqsave(&global_cpu_snapshot_lock, flags);
263 
264 	this_cpu = raw_smp_processor_id();
265 
266 	memset(global_cpu_snapshot, 0, sizeof(global_cpu_snapshot));
267 
268 	if (cpumask_test_cpu(this_cpu, mask) && !exclude_self)
269 		__global_reg_self(tp, regs, this_cpu);
270 
271 	smp_fetch_global_regs();
272 
273 	for_each_cpu(cpu, mask) {
274 		struct global_reg_snapshot *gp;
275 
276 		if (exclude_self && cpu == this_cpu)
277 			continue;
278 
279 		gp = &global_cpu_snapshot[cpu].reg;
280 
281 		__global_reg_poll(gp);
282 
283 		tp = gp->thread;
284 		printk("%c CPU[%3d]: TSTATE[%016lx] TPC[%016lx] TNPC[%016lx] TASK[%s:%d]\n",
285 		       (cpu == this_cpu ? '*' : ' '), cpu,
286 		       gp->tstate, gp->tpc, gp->tnpc,
287 		       ((tp && tp->task) ? tp->task->comm : "NULL"),
288 		       ((tp && tp->task) ? tp->task->pid : -1));
289 
290 		if (gp->tstate & TSTATE_PRIV) {
291 			printk("             TPC[%pS] O7[%pS] I7[%pS] RPC[%pS]\n",
292 			       (void *) gp->tpc,
293 			       (void *) gp->o7,
294 			       (void *) gp->i7,
295 			       (void *) gp->rpc);
296 		} else {
297 			printk("             TPC[%lx] O7[%lx] I7[%lx] RPC[%lx]\n",
298 			       gp->tpc, gp->o7, gp->i7, gp->rpc);
299 		}
300 
301 		touch_nmi_watchdog();
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 	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 	if (!pcr_ops)
328 		return;
329 
330 	pp = &global_cpu_snapshot[this_cpu].pmu;
331 
332 	num = 1;
333 	if (tlb_type == hypervisor &&
334 	    sun4v_chip_type >= SUN4V_CHIP_NIAGARA4)
335 		num = 4;
336 
337 	for (i = 0; i < num; i++) {
338 		pp->pcr[i] = pcr_ops->read_pcr(i);
339 		pp->pic[i] = pcr_ops->read_pic(i);
340 	}
341 }
342 
343 static void __global_pmu_poll(struct global_pmu_snapshot *pp)
344 {
345 	int limit = 0;
346 
347 	while (!pp->pcr[0] && ++limit < 100) {
348 		barrier();
349 		udelay(1);
350 	}
351 }
352 
353 static void pmu_snapshot_all_cpus(void)
354 {
355 	unsigned long flags;
356 	int this_cpu, cpu;
357 
358 	spin_lock_irqsave(&global_cpu_snapshot_lock, flags);
359 
360 	memset(global_cpu_snapshot, 0, sizeof(global_cpu_snapshot));
361 
362 	this_cpu = raw_smp_processor_id();
363 
364 	__global_pmu_self(this_cpu);
365 
366 	smp_fetch_global_pmu();
367 
368 	for_each_online_cpu(cpu) {
369 		struct global_pmu_snapshot *pp = &global_cpu_snapshot[cpu].pmu;
370 
371 		__global_pmu_poll(pp);
372 
373 		printk("%c CPU[%3d]: PCR[%08lx:%08lx:%08lx:%08lx] PIC[%08lx:%08lx:%08lx:%08lx]\n",
374 		       (cpu == this_cpu ? '*' : ' '), cpu,
375 		       pp->pcr[0], pp->pcr[1], pp->pcr[2], pp->pcr[3],
376 		       pp->pic[0], pp->pic[1], pp->pic[2], pp->pic[3]);
377 
378 		touch_nmi_watchdog();
379 	}
380 
381 	memset(global_cpu_snapshot, 0, sizeof(global_cpu_snapshot));
382 
383 	spin_unlock_irqrestore(&global_cpu_snapshot_lock, flags);
384 }
385 
386 static void sysrq_handle_globpmu(int key)
387 {
388 	pmu_snapshot_all_cpus();
389 }
390 
391 static struct sysrq_key_op sparc_globalpmu_op = {
392 	.handler	= sysrq_handle_globpmu,
393 	.help_msg	= "global-pmu(x)",
394 	.action_msg	= "Show Global PMU Regs",
395 };
396 
397 static int __init sparc_sysrq_init(void)
398 {
399 	int ret = register_sysrq_key('y', &sparc_globalreg_op);
400 
401 	if (!ret)
402 		ret = register_sysrq_key('x', &sparc_globalpmu_op);
403 	return ret;
404 }
405 
406 core_initcall(sparc_sysrq_init);
407 
408 #endif
409 
410 /* Free current thread data structures etc.. */
411 void exit_thread(struct task_struct *tsk)
412 {
413 	struct thread_info *t = task_thread_info(tsk);
414 
415 	if (t->utraps) {
416 		if (t->utraps[0] < 2)
417 			kfree (t->utraps);
418 		else
419 			t->utraps[0]--;
420 	}
421 }
422 
423 void flush_thread(void)
424 {
425 	struct thread_info *t = current_thread_info();
426 	struct mm_struct *mm;
427 
428 	mm = t->task->mm;
429 	if (mm)
430 		tsb_context_switch(mm);
431 
432 	set_thread_wsaved(0);
433 
434 	/* Clear FPU register state. */
435 	t->fpsaved[0] = 0;
436 }
437 
438 /* It's a bit more tricky when 64-bit tasks are involved... */
439 static unsigned long clone_stackframe(unsigned long csp, unsigned long psp)
440 {
441 	bool stack_64bit = test_thread_64bit_stack(psp);
442 	unsigned long fp, distance, rval;
443 
444 	if (stack_64bit) {
445 		csp += STACK_BIAS;
446 		psp += STACK_BIAS;
447 		__get_user(fp, &(((struct reg_window __user *)psp)->ins[6]));
448 		fp += STACK_BIAS;
449 		if (test_thread_flag(TIF_32BIT))
450 			fp &= 0xffffffff;
451 	} else
452 		__get_user(fp, &(((struct reg_window32 __user *)psp)->ins[6]));
453 
454 	/* Now align the stack as this is mandatory in the Sparc ABI
455 	 * due to how register windows work.  This hides the
456 	 * restriction from thread libraries etc.
457 	 */
458 	csp &= ~15UL;
459 
460 	distance = fp - psp;
461 	rval = (csp - distance);
462 	if (copy_in_user((void __user *) rval, (void __user *) psp, distance))
463 		rval = 0;
464 	else if (!stack_64bit) {
465 		if (put_user(((u32)csp),
466 			     &(((struct reg_window32 __user *)rval)->ins[6])))
467 			rval = 0;
468 	} else {
469 		if (put_user(((u64)csp - STACK_BIAS),
470 			     &(((struct reg_window __user *)rval)->ins[6])))
471 			rval = 0;
472 		else
473 			rval = rval - STACK_BIAS;
474 	}
475 
476 	return rval;
477 }
478 
479 /* Standard stuff. */
480 static inline void shift_window_buffer(int first_win, int last_win,
481 				       struct thread_info *t)
482 {
483 	int i;
484 
485 	for (i = first_win; i < last_win; i++) {
486 		t->rwbuf_stkptrs[i] = t->rwbuf_stkptrs[i+1];
487 		memcpy(&t->reg_window[i], &t->reg_window[i+1],
488 		       sizeof(struct reg_window));
489 	}
490 }
491 
492 void synchronize_user_stack(void)
493 {
494 	struct thread_info *t = current_thread_info();
495 	unsigned long window;
496 
497 	flush_user_windows();
498 	if ((window = get_thread_wsaved()) != 0) {
499 		window -= 1;
500 		do {
501 			struct reg_window *rwin = &t->reg_window[window];
502 			int winsize = sizeof(struct reg_window);
503 			unsigned long sp;
504 
505 			sp = t->rwbuf_stkptrs[window];
506 
507 			if (test_thread_64bit_stack(sp))
508 				sp += STACK_BIAS;
509 			else
510 				winsize = sizeof(struct reg_window32);
511 
512 			if (!copy_to_user((char __user *)sp, rwin, winsize)) {
513 				shift_window_buffer(window, get_thread_wsaved() - 1, t);
514 				set_thread_wsaved(get_thread_wsaved() - 1);
515 			}
516 		} while (window--);
517 	}
518 }
519 
520 static void stack_unaligned(unsigned long sp)
521 {
522 	force_sig_fault(SIGBUS, BUS_ADRALN, (void __user *) sp, 0);
523 }
524 
525 static const char uwfault32[] = KERN_INFO \
526 	"%s[%d]: bad register window fault: SP %08lx (orig_sp %08lx) TPC %08lx O7 %08lx\n";
527 static const char uwfault64[] = KERN_INFO \
528 	"%s[%d]: bad register window fault: SP %016lx (orig_sp %016lx) TPC %08lx O7 %016lx\n";
529 
530 void fault_in_user_windows(struct pt_regs *regs)
531 {
532 	struct thread_info *t = current_thread_info();
533 	unsigned long window;
534 
535 	flush_user_windows();
536 	window = get_thread_wsaved();
537 
538 	if (likely(window != 0)) {
539 		window -= 1;
540 		do {
541 			struct reg_window *rwin = &t->reg_window[window];
542 			int winsize = sizeof(struct reg_window);
543 			unsigned long sp, orig_sp;
544 
545 			orig_sp = sp = t->rwbuf_stkptrs[window];
546 
547 			if (test_thread_64bit_stack(sp))
548 				sp += STACK_BIAS;
549 			else
550 				winsize = sizeof(struct reg_window32);
551 
552 			if (unlikely(sp & 0x7UL))
553 				stack_unaligned(sp);
554 
555 			if (unlikely(copy_to_user((char __user *)sp,
556 						  rwin, winsize))) {
557 				if (show_unhandled_signals)
558 					printk_ratelimited(is_compat_task() ?
559 							   uwfault32 : uwfault64,
560 							   current->comm, current->pid,
561 							   sp, orig_sp,
562 							   regs->tpc,
563 							   regs->u_regs[UREG_I7]);
564 				goto barf;
565 			}
566 		} while (window--);
567 	}
568 	set_thread_wsaved(0);
569 	return;
570 
571 barf:
572 	set_thread_wsaved(window + 1);
573 	force_sig(SIGSEGV);
574 }
575 
576 asmlinkage long sparc_do_fork(unsigned long clone_flags,
577 			      unsigned long stack_start,
578 			      struct pt_regs *regs,
579 			      unsigned long stack_size)
580 {
581 	int __user *parent_tid_ptr, *child_tid_ptr;
582 	unsigned long orig_i1 = regs->u_regs[UREG_I1];
583 	long ret;
584 
585 #ifdef CONFIG_COMPAT
586 	if (test_thread_flag(TIF_32BIT)) {
587 		parent_tid_ptr = compat_ptr(regs->u_regs[UREG_I2]);
588 		child_tid_ptr = compat_ptr(regs->u_regs[UREG_I4]);
589 	} else
590 #endif
591 	{
592 		parent_tid_ptr = (int __user *) regs->u_regs[UREG_I2];
593 		child_tid_ptr = (int __user *) regs->u_regs[UREG_I4];
594 	}
595 
596 	ret = do_fork(clone_flags, stack_start, stack_size,
597 		      parent_tid_ptr, child_tid_ptr);
598 
599 	/* If we get an error and potentially restart the system
600 	 * call, we're screwed because copy_thread() clobbered
601 	 * the parent's %o1.  So detect that case and restore it
602 	 * here.
603 	 */
604 	if ((unsigned long)ret >= -ERESTART_RESTARTBLOCK)
605 		regs->u_regs[UREG_I1] = orig_i1;
606 
607 	return ret;
608 }
609 
610 /* Copy a Sparc thread.  The fork() return value conventions
611  * under SunOS are nothing short of bletcherous:
612  * Parent -->  %o0 == childs  pid, %o1 == 0
613  * Child  -->  %o0 == parents pid, %o1 == 1
614  */
615 int copy_thread(unsigned long clone_flags, unsigned long sp,
616 		unsigned long arg, struct task_struct *p)
617 {
618 	struct thread_info *t = task_thread_info(p);
619 	struct pt_regs *regs = current_pt_regs();
620 	struct sparc_stackf *parent_sf;
621 	unsigned long child_stack_sz;
622 	char *child_trap_frame;
623 
624 	/* Calculate offset to stack_frame & pt_regs */
625 	child_stack_sz = (STACKFRAME_SZ + TRACEREG_SZ);
626 	child_trap_frame = (task_stack_page(p) +
627 			    (THREAD_SIZE - child_stack_sz));
628 
629 	t->new_child = 1;
630 	t->ksp = ((unsigned long) child_trap_frame) - STACK_BIAS;
631 	t->kregs = (struct pt_regs *) (child_trap_frame +
632 				       sizeof(struct sparc_stackf));
633 	t->fpsaved[0] = 0;
634 
635 	if (unlikely(p->flags & PF_KTHREAD)) {
636 		memset(child_trap_frame, 0, child_stack_sz);
637 		__thread_flag_byte_ptr(t)[TI_FLAG_BYTE_CWP] =
638 			(current_pt_regs()->tstate + 1) & TSTATE_CWP;
639 		t->current_ds = ASI_P;
640 		t->kregs->u_regs[UREG_G1] = sp; /* function */
641 		t->kregs->u_regs[UREG_G2] = arg;
642 		return 0;
643 	}
644 
645 	parent_sf = ((struct sparc_stackf *) regs) - 1;
646 	memcpy(child_trap_frame, parent_sf, child_stack_sz);
647 	if (t->flags & _TIF_32BIT) {
648 		sp &= 0x00000000ffffffffUL;
649 		regs->u_regs[UREG_FP] &= 0x00000000ffffffffUL;
650 	}
651 	t->kregs->u_regs[UREG_FP] = sp;
652 	__thread_flag_byte_ptr(t)[TI_FLAG_BYTE_CWP] =
653 		(regs->tstate + 1) & TSTATE_CWP;
654 	t->current_ds = ASI_AIUS;
655 	if (sp != regs->u_regs[UREG_FP]) {
656 		unsigned long csp;
657 
658 		csp = clone_stackframe(sp, regs->u_regs[UREG_FP]);
659 		if (!csp)
660 			return -EFAULT;
661 		t->kregs->u_regs[UREG_FP] = csp;
662 	}
663 	if (t->utraps)
664 		t->utraps[0]++;
665 
666 	/* Set the return value for the child. */
667 	t->kregs->u_regs[UREG_I0] = current->pid;
668 	t->kregs->u_regs[UREG_I1] = 1;
669 
670 	/* Set the second return value for the parent. */
671 	regs->u_regs[UREG_I1] = 0;
672 
673 	if (clone_flags & CLONE_SETTLS)
674 		t->kregs->u_regs[UREG_G7] = regs->u_regs[UREG_I3];
675 
676 	return 0;
677 }
678 
679 /* TIF_MCDPER in thread info flags for current task is updated lazily upon
680  * a context switch. Update this flag in current task's thread flags
681  * before dup so the dup'd task will inherit the current TIF_MCDPER flag.
682  */
683 int arch_dup_task_struct(struct task_struct *dst, struct task_struct *src)
684 {
685 	if (adi_capable()) {
686 		register unsigned long tmp_mcdper;
687 
688 		__asm__ __volatile__(
689 			".word 0x83438000\n\t"	/* rd  %mcdper, %g1 */
690 			"mov %%g1, %0\n\t"
691 			: "=r" (tmp_mcdper)
692 			:
693 			: "g1");
694 		if (tmp_mcdper)
695 			set_thread_flag(TIF_MCDPER);
696 		else
697 			clear_thread_flag(TIF_MCDPER);
698 	}
699 
700 	*dst = *src;
701 	return 0;
702 }
703 
704 typedef struct {
705 	union {
706 		unsigned int	pr_regs[32];
707 		unsigned long	pr_dregs[16];
708 	} pr_fr;
709 	unsigned int __unused;
710 	unsigned int	pr_fsr;
711 	unsigned char	pr_qcnt;
712 	unsigned char	pr_q_entrysize;
713 	unsigned char	pr_en;
714 	unsigned int	pr_q[64];
715 } elf_fpregset_t32;
716 
717 /*
718  * fill in the fpu structure for a core dump.
719  */
720 int dump_fpu (struct pt_regs * regs, elf_fpregset_t * fpregs)
721 {
722 	unsigned long *kfpregs = current_thread_info()->fpregs;
723 	unsigned long fprs = current_thread_info()->fpsaved[0];
724 
725 	if (test_thread_flag(TIF_32BIT)) {
726 		elf_fpregset_t32 *fpregs32 = (elf_fpregset_t32 *)fpregs;
727 
728 		if (fprs & FPRS_DL)
729 			memcpy(&fpregs32->pr_fr.pr_regs[0], kfpregs,
730 			       sizeof(unsigned int) * 32);
731 		else
732 			memset(&fpregs32->pr_fr.pr_regs[0], 0,
733 			       sizeof(unsigned int) * 32);
734 		fpregs32->pr_qcnt = 0;
735 		fpregs32->pr_q_entrysize = 8;
736 		memset(&fpregs32->pr_q[0], 0,
737 		       (sizeof(unsigned int) * 64));
738 		if (fprs & FPRS_FEF) {
739 			fpregs32->pr_fsr = (unsigned int) current_thread_info()->xfsr[0];
740 			fpregs32->pr_en = 1;
741 		} else {
742 			fpregs32->pr_fsr = 0;
743 			fpregs32->pr_en = 0;
744 		}
745 	} else {
746 		if(fprs & FPRS_DL)
747 			memcpy(&fpregs->pr_regs[0], kfpregs,
748 			       sizeof(unsigned int) * 32);
749 		else
750 			memset(&fpregs->pr_regs[0], 0,
751 			       sizeof(unsigned int) * 32);
752 		if(fprs & FPRS_DU)
753 			memcpy(&fpregs->pr_regs[16], kfpregs+16,
754 			       sizeof(unsigned int) * 32);
755 		else
756 			memset(&fpregs->pr_regs[16], 0,
757 			       sizeof(unsigned int) * 32);
758 		if(fprs & FPRS_FEF) {
759 			fpregs->pr_fsr = current_thread_info()->xfsr[0];
760 			fpregs->pr_gsr = current_thread_info()->gsr[0];
761 		} else {
762 			fpregs->pr_fsr = fpregs->pr_gsr = 0;
763 		}
764 		fpregs->pr_fprs = fprs;
765 	}
766 	return 1;
767 }
768 EXPORT_SYMBOL(dump_fpu);
769 
770 unsigned long get_wchan(struct task_struct *task)
771 {
772 	unsigned long pc, fp, bias = 0;
773 	struct thread_info *tp;
774 	struct reg_window *rw;
775         unsigned long ret = 0;
776 	int count = 0;
777 
778 	if (!task || task == current ||
779             task->state == TASK_RUNNING)
780 		goto out;
781 
782 	tp = task_thread_info(task);
783 	bias = STACK_BIAS;
784 	fp = task_thread_info(task)->ksp + bias;
785 
786 	do {
787 		if (!kstack_valid(tp, fp))
788 			break;
789 		rw = (struct reg_window *) fp;
790 		pc = rw->ins[7];
791 		if (!in_sched_functions(pc)) {
792 			ret = pc;
793 			goto out;
794 		}
795 		fp = rw->ins[6] + bias;
796 	} while (++count < 16);
797 
798 out:
799 	return ret;
800 }
801