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 #include <linux/errno.h>
13 #include <linux/export.h>
14 #include <linux/sched.h>
15 #include <linux/sched/debug.h>
16 #include <linux/sched/task.h>
17 #include <linux/sched/task_stack.h>
18 #include <linux/kernel.h>
19 #include <linux/mm.h>
20 #include <linux/fs.h>
21 #include <linux/smp.h>
22 #include <linux/stddef.h>
23 #include <linux/ptrace.h>
24 #include <linux/slab.h>
25 #include <linux/user.h>
26 #include <linux/delay.h>
27 #include <linux/compat.h>
28 #include <linux/tick.h>
29 #include <linux/init.h>
30 #include <linux/cpu.h>
31 #include <linux/perf_event.h>
32 #include <linux/elfcore.h>
33 #include <linux/sysrq.h>
34 #include <linux/nmi.h>
35 #include <linux/context_tracking.h>
36 #include <linux/signal.h>
37
38 #include <linux/uaccess.h>
39 #include <asm/page.h>
40 #include <asm/pgalloc.h>
41 #include <asm/processor.h>
42 #include <asm/pstate.h>
43 #include <asm/elf.h>
44 #include <asm/fpumacro.h>
45 #include <asm/head.h>
46 #include <asm/cpudata.h>
47 #include <asm/mmu_context.h>
48 #include <asm/unistd.h>
49 #include <asm/hypervisor.h>
50 #include <asm/syscalls.h>
51 #include <asm/irq_regs.h>
52 #include <asm/smp.h>
53 #include <asm/pcr.h>
54
55 #include "kstack.h"
56
57 /* Idle loop support on sparc64. */
arch_cpu_idle(void)58 void arch_cpu_idle(void)
59 {
60 if (tlb_type != hypervisor) {
61 touch_nmi_watchdog();
62 raw_local_irq_enable();
63 } else {
64 unsigned long pstate;
65
66 raw_local_irq_enable();
67
68 /* The sun4v sleeping code requires that we have PSTATE.IE cleared over
69 * the cpu sleep hypervisor call.
70 */
71 __asm__ __volatile__(
72 "rdpr %%pstate, %0\n\t"
73 "andn %0, %1, %0\n\t"
74 "wrpr %0, %%g0, %%pstate"
75 : "=&r" (pstate)
76 : "i" (PSTATE_IE));
77
78 if (!need_resched() && !cpu_is_offline(smp_processor_id())) {
79 sun4v_cpu_yield();
80 /* If resumed by cpu_poke then we need to explicitly
81 * call scheduler_ipi().
82 */
83 scheduler_poke();
84 }
85
86 /* Re-enable interrupts. */
87 __asm__ __volatile__(
88 "rdpr %%pstate, %0\n\t"
89 "or %0, %1, %0\n\t"
90 "wrpr %0, %%g0, %%pstate"
91 : "=&r" (pstate)
92 : "i" (PSTATE_IE));
93 }
94 }
95
96 #ifdef CONFIG_HOTPLUG_CPU
arch_cpu_idle_dead(void)97 void arch_cpu_idle_dead(void)
98 {
99 sched_preempt_enable_no_resched();
100 cpu_play_dead();
101 }
102 #endif
103
104 #ifdef CONFIG_COMPAT
show_regwindow32(struct pt_regs * regs)105 static void show_regwindow32(struct pt_regs *regs)
106 {
107 struct reg_window32 __user *rw;
108 struct reg_window32 r_w;
109
110 __asm__ __volatile__ ("flushw");
111 rw = compat_ptr((unsigned int)regs->u_regs[14]);
112 if (copy_from_user (&r_w, rw, sizeof(r_w))) {
113 return;
114 }
115
116 printk("l0: %08x l1: %08x l2: %08x l3: %08x "
117 "l4: %08x l5: %08x l6: %08x l7: %08x\n",
118 r_w.locals[0], r_w.locals[1], r_w.locals[2], r_w.locals[3],
119 r_w.locals[4], r_w.locals[5], r_w.locals[6], r_w.locals[7]);
120 printk("i0: %08x i1: %08x i2: %08x i3: %08x "
121 "i4: %08x i5: %08x i6: %08x i7: %08x\n",
122 r_w.ins[0], r_w.ins[1], r_w.ins[2], r_w.ins[3],
123 r_w.ins[4], r_w.ins[5], r_w.ins[6], r_w.ins[7]);
124 }
125 #else
126 #define show_regwindow32(regs) do { } while (0)
127 #endif
128
show_regwindow(struct pt_regs * regs)129 static void show_regwindow(struct pt_regs *regs)
130 {
131 struct reg_window __user *rw;
132 struct reg_window *rwk;
133 struct reg_window r_w;
134
135 if ((regs->tstate & TSTATE_PRIV) || !(test_thread_flag(TIF_32BIT))) {
136 __asm__ __volatile__ ("flushw");
137 rw = (struct reg_window __user *)
138 (regs->u_regs[14] + STACK_BIAS);
139 rwk = (struct reg_window *)
140 (regs->u_regs[14] + STACK_BIAS);
141 if (!(regs->tstate & TSTATE_PRIV)) {
142 if (copy_from_user (&r_w, rw, sizeof(r_w))) {
143 return;
144 }
145 rwk = &r_w;
146 }
147 } else {
148 show_regwindow32(regs);
149 return;
150 }
151 printk("l0: %016lx l1: %016lx l2: %016lx l3: %016lx\n",
152 rwk->locals[0], rwk->locals[1], rwk->locals[2], rwk->locals[3]);
153 printk("l4: %016lx l5: %016lx l6: %016lx l7: %016lx\n",
154 rwk->locals[4], rwk->locals[5], rwk->locals[6], rwk->locals[7]);
155 printk("i0: %016lx i1: %016lx i2: %016lx i3: %016lx\n",
156 rwk->ins[0], rwk->ins[1], rwk->ins[2], rwk->ins[3]);
157 printk("i4: %016lx i5: %016lx i6: %016lx i7: %016lx\n",
158 rwk->ins[4], rwk->ins[5], rwk->ins[6], rwk->ins[7]);
159 if (regs->tstate & TSTATE_PRIV)
160 printk("I7: <%pS>\n", (void *) rwk->ins[7]);
161 }
162
show_regs(struct pt_regs * regs)163 void show_regs(struct pt_regs *regs)
164 {
165 show_regs_print_info(KERN_DEFAULT);
166
167 printk("TSTATE: %016lx TPC: %016lx TNPC: %016lx Y: %08x %s\n", regs->tstate,
168 regs->tpc, regs->tnpc, regs->y, print_tainted());
169 printk("TPC: <%pS>\n", (void *) regs->tpc);
170 printk("g0: %016lx g1: %016lx g2: %016lx g3: %016lx\n",
171 regs->u_regs[0], regs->u_regs[1], regs->u_regs[2],
172 regs->u_regs[3]);
173 printk("g4: %016lx g5: %016lx g6: %016lx g7: %016lx\n",
174 regs->u_regs[4], regs->u_regs[5], regs->u_regs[6],
175 regs->u_regs[7]);
176 printk("o0: %016lx o1: %016lx o2: %016lx o3: %016lx\n",
177 regs->u_regs[8], regs->u_regs[9], regs->u_regs[10],
178 regs->u_regs[11]);
179 printk("o4: %016lx o5: %016lx sp: %016lx ret_pc: %016lx\n",
180 regs->u_regs[12], regs->u_regs[13], regs->u_regs[14],
181 regs->u_regs[15]);
182 printk("RPC: <%pS>\n", (void *) regs->u_regs[15]);
183 show_regwindow(regs);
184 show_stack(current, (unsigned long *)regs->u_regs[UREG_FP], KERN_DEFAULT);
185 }
186
187 union global_cpu_snapshot global_cpu_snapshot[NR_CPUS];
188 static DEFINE_SPINLOCK(global_cpu_snapshot_lock);
189
__global_reg_self(struct thread_info * tp,struct pt_regs * regs,int this_cpu)190 static void __global_reg_self(struct thread_info *tp, struct pt_regs *regs,
191 int this_cpu)
192 {
193 struct global_reg_snapshot *rp;
194
195 flushw_all();
196
197 rp = &global_cpu_snapshot[this_cpu].reg;
198
199 rp->tstate = regs->tstate;
200 rp->tpc = regs->tpc;
201 rp->tnpc = regs->tnpc;
202 rp->o7 = regs->u_regs[UREG_I7];
203
204 if (regs->tstate & TSTATE_PRIV) {
205 struct reg_window *rw;
206
207 rw = (struct reg_window *)
208 (regs->u_regs[UREG_FP] + STACK_BIAS);
209 if (kstack_valid(tp, (unsigned long) rw)) {
210 rp->i7 = rw->ins[7];
211 rw = (struct reg_window *)
212 (rw->ins[6] + STACK_BIAS);
213 if (kstack_valid(tp, (unsigned long) rw))
214 rp->rpc = rw->ins[7];
215 }
216 } else {
217 rp->i7 = 0;
218 rp->rpc = 0;
219 }
220 rp->thread = tp;
221 }
222
223 /* In order to avoid hangs we do not try to synchronize with the
224 * global register dump client cpus. The last store they make is to
225 * the thread pointer, so do a short poll waiting for that to become
226 * non-NULL.
227 */
__global_reg_poll(struct global_reg_snapshot * gp)228 static void __global_reg_poll(struct global_reg_snapshot *gp)
229 {
230 int limit = 0;
231
232 while (!gp->thread && ++limit < 100) {
233 barrier();
234 udelay(1);
235 }
236 }
237
arch_trigger_cpumask_backtrace(const cpumask_t * mask,bool exclude_self)238 void arch_trigger_cpumask_backtrace(const cpumask_t *mask, bool exclude_self)
239 {
240 struct thread_info *tp = current_thread_info();
241 struct pt_regs *regs = get_irq_regs();
242 unsigned long flags;
243 int this_cpu, cpu;
244
245 if (!regs)
246 regs = tp->kregs;
247
248 spin_lock_irqsave(&global_cpu_snapshot_lock, flags);
249
250 this_cpu = raw_smp_processor_id();
251
252 memset(global_cpu_snapshot, 0, sizeof(global_cpu_snapshot));
253
254 if (cpumask_test_cpu(this_cpu, mask) && !exclude_self)
255 __global_reg_self(tp, regs, this_cpu);
256
257 smp_fetch_global_regs();
258
259 for_each_cpu(cpu, mask) {
260 struct global_reg_snapshot *gp;
261
262 if (exclude_self && cpu == this_cpu)
263 continue;
264
265 gp = &global_cpu_snapshot[cpu].reg;
266
267 __global_reg_poll(gp);
268
269 tp = gp->thread;
270 printk("%c CPU[%3d]: TSTATE[%016lx] TPC[%016lx] TNPC[%016lx] TASK[%s:%d]\n",
271 (cpu == this_cpu ? '*' : ' '), cpu,
272 gp->tstate, gp->tpc, gp->tnpc,
273 ((tp && tp->task) ? tp->task->comm : "NULL"),
274 ((tp && tp->task) ? tp->task->pid : -1));
275
276 if (gp->tstate & TSTATE_PRIV) {
277 printk(" TPC[%pS] O7[%pS] I7[%pS] RPC[%pS]\n",
278 (void *) gp->tpc,
279 (void *) gp->o7,
280 (void *) gp->i7,
281 (void *) gp->rpc);
282 } else {
283 printk(" TPC[%lx] O7[%lx] I7[%lx] RPC[%lx]\n",
284 gp->tpc, gp->o7, gp->i7, gp->rpc);
285 }
286
287 touch_nmi_watchdog();
288 }
289
290 memset(global_cpu_snapshot, 0, sizeof(global_cpu_snapshot));
291
292 spin_unlock_irqrestore(&global_cpu_snapshot_lock, flags);
293 }
294
295 #ifdef CONFIG_MAGIC_SYSRQ
296
sysrq_handle_globreg(int key)297 static void sysrq_handle_globreg(int key)
298 {
299 trigger_all_cpu_backtrace();
300 }
301
302 static const struct sysrq_key_op sparc_globalreg_op = {
303 .handler = sysrq_handle_globreg,
304 .help_msg = "global-regs(y)",
305 .action_msg = "Show Global CPU Regs",
306 };
307
__global_pmu_self(int this_cpu)308 static void __global_pmu_self(int this_cpu)
309 {
310 struct global_pmu_snapshot *pp;
311 int i, num;
312
313 if (!pcr_ops)
314 return;
315
316 pp = &global_cpu_snapshot[this_cpu].pmu;
317
318 num = 1;
319 if (tlb_type == hypervisor &&
320 sun4v_chip_type >= SUN4V_CHIP_NIAGARA4)
321 num = 4;
322
323 for (i = 0; i < num; i++) {
324 pp->pcr[i] = pcr_ops->read_pcr(i);
325 pp->pic[i] = pcr_ops->read_pic(i);
326 }
327 }
328
__global_pmu_poll(struct global_pmu_snapshot * pp)329 static void __global_pmu_poll(struct global_pmu_snapshot *pp)
330 {
331 int limit = 0;
332
333 while (!pp->pcr[0] && ++limit < 100) {
334 barrier();
335 udelay(1);
336 }
337 }
338
pmu_snapshot_all_cpus(void)339 static void pmu_snapshot_all_cpus(void)
340 {
341 unsigned long flags;
342 int this_cpu, cpu;
343
344 spin_lock_irqsave(&global_cpu_snapshot_lock, flags);
345
346 memset(global_cpu_snapshot, 0, sizeof(global_cpu_snapshot));
347
348 this_cpu = raw_smp_processor_id();
349
350 __global_pmu_self(this_cpu);
351
352 smp_fetch_global_pmu();
353
354 for_each_online_cpu(cpu) {
355 struct global_pmu_snapshot *pp = &global_cpu_snapshot[cpu].pmu;
356
357 __global_pmu_poll(pp);
358
359 printk("%c CPU[%3d]: PCR[%08lx:%08lx:%08lx:%08lx] PIC[%08lx:%08lx:%08lx:%08lx]\n",
360 (cpu == this_cpu ? '*' : ' '), cpu,
361 pp->pcr[0], pp->pcr[1], pp->pcr[2], pp->pcr[3],
362 pp->pic[0], pp->pic[1], pp->pic[2], pp->pic[3]);
363
364 touch_nmi_watchdog();
365 }
366
367 memset(global_cpu_snapshot, 0, sizeof(global_cpu_snapshot));
368
369 spin_unlock_irqrestore(&global_cpu_snapshot_lock, flags);
370 }
371
sysrq_handle_globpmu(int key)372 static void sysrq_handle_globpmu(int key)
373 {
374 pmu_snapshot_all_cpus();
375 }
376
377 static const struct sysrq_key_op sparc_globalpmu_op = {
378 .handler = sysrq_handle_globpmu,
379 .help_msg = "global-pmu(x)",
380 .action_msg = "Show Global PMU Regs",
381 };
382
sparc_sysrq_init(void)383 static int __init sparc_sysrq_init(void)
384 {
385 int ret = register_sysrq_key('y', &sparc_globalreg_op);
386
387 if (!ret)
388 ret = register_sysrq_key('x', &sparc_globalpmu_op);
389 return ret;
390 }
391
392 core_initcall(sparc_sysrq_init);
393
394 #endif
395
396 /* Free current thread data structures etc.. */
exit_thread(struct task_struct * tsk)397 void exit_thread(struct task_struct *tsk)
398 {
399 struct thread_info *t = task_thread_info(tsk);
400
401 if (t->utraps) {
402 if (t->utraps[0] < 2)
403 kfree (t->utraps);
404 else
405 t->utraps[0]--;
406 }
407 }
408
flush_thread(void)409 void flush_thread(void)
410 {
411 struct thread_info *t = current_thread_info();
412 struct mm_struct *mm;
413
414 mm = t->task->mm;
415 if (mm)
416 tsb_context_switch(mm);
417
418 set_thread_wsaved(0);
419
420 /* Clear FPU register state. */
421 t->fpsaved[0] = 0;
422 }
423
424 /* It's a bit more tricky when 64-bit tasks are involved... */
clone_stackframe(unsigned long csp,unsigned long psp)425 static unsigned long clone_stackframe(unsigned long csp, unsigned long psp)
426 {
427 bool stack_64bit = test_thread_64bit_stack(psp);
428 unsigned long fp, distance, rval;
429
430 if (stack_64bit) {
431 csp += STACK_BIAS;
432 psp += STACK_BIAS;
433 __get_user(fp, &(((struct reg_window __user *)psp)->ins[6]));
434 fp += STACK_BIAS;
435 if (test_thread_flag(TIF_32BIT))
436 fp &= 0xffffffff;
437 } else
438 __get_user(fp, &(((struct reg_window32 __user *)psp)->ins[6]));
439
440 /* Now align the stack as this is mandatory in the Sparc ABI
441 * due to how register windows work. This hides the
442 * restriction from thread libraries etc.
443 */
444 csp &= ~15UL;
445
446 distance = fp - psp;
447 rval = (csp - distance);
448 if (raw_copy_in_user((void __user *)rval, (void __user *)psp, distance))
449 rval = 0;
450 else if (!stack_64bit) {
451 if (put_user(((u32)csp),
452 &(((struct reg_window32 __user *)rval)->ins[6])))
453 rval = 0;
454 } else {
455 if (put_user(((u64)csp - STACK_BIAS),
456 &(((struct reg_window __user *)rval)->ins[6])))
457 rval = 0;
458 else
459 rval = rval - STACK_BIAS;
460 }
461
462 return rval;
463 }
464
465 /* Standard stuff. */
shift_window_buffer(int first_win,int last_win,struct thread_info * t)466 static inline void shift_window_buffer(int first_win, int last_win,
467 struct thread_info *t)
468 {
469 int i;
470
471 for (i = first_win; i < last_win; i++) {
472 t->rwbuf_stkptrs[i] = t->rwbuf_stkptrs[i+1];
473 memcpy(&t->reg_window[i], &t->reg_window[i+1],
474 sizeof(struct reg_window));
475 }
476 }
477
synchronize_user_stack(void)478 void synchronize_user_stack(void)
479 {
480 struct thread_info *t = current_thread_info();
481 unsigned long window;
482
483 flush_user_windows();
484 if ((window = get_thread_wsaved()) != 0) {
485 window -= 1;
486 do {
487 struct reg_window *rwin = &t->reg_window[window];
488 int winsize = sizeof(struct reg_window);
489 unsigned long sp;
490
491 sp = t->rwbuf_stkptrs[window];
492
493 if (test_thread_64bit_stack(sp))
494 sp += STACK_BIAS;
495 else
496 winsize = sizeof(struct reg_window32);
497
498 if (!copy_to_user((char __user *)sp, rwin, winsize)) {
499 shift_window_buffer(window, get_thread_wsaved() - 1, t);
500 set_thread_wsaved(get_thread_wsaved() - 1);
501 }
502 } while (window--);
503 }
504 }
505
stack_unaligned(unsigned long sp)506 static void stack_unaligned(unsigned long sp)
507 {
508 force_sig_fault(SIGBUS, BUS_ADRALN, (void __user *) sp);
509 }
510
511 static const char uwfault32[] = KERN_INFO \
512 "%s[%d]: bad register window fault: SP %08lx (orig_sp %08lx) TPC %08lx O7 %08lx\n";
513 static const char uwfault64[] = KERN_INFO \
514 "%s[%d]: bad register window fault: SP %016lx (orig_sp %016lx) TPC %08lx O7 %016lx\n";
515
fault_in_user_windows(struct pt_regs * regs)516 void fault_in_user_windows(struct pt_regs *regs)
517 {
518 struct thread_info *t = current_thread_info();
519 unsigned long window;
520
521 flush_user_windows();
522 window = get_thread_wsaved();
523
524 if (likely(window != 0)) {
525 window -= 1;
526 do {
527 struct reg_window *rwin = &t->reg_window[window];
528 int winsize = sizeof(struct reg_window);
529 unsigned long sp, orig_sp;
530
531 orig_sp = sp = t->rwbuf_stkptrs[window];
532
533 if (test_thread_64bit_stack(sp))
534 sp += STACK_BIAS;
535 else
536 winsize = sizeof(struct reg_window32);
537
538 if (unlikely(sp & 0x7UL))
539 stack_unaligned(sp);
540
541 if (unlikely(copy_to_user((char __user *)sp,
542 rwin, winsize))) {
543 if (show_unhandled_signals)
544 printk_ratelimited(is_compat_task() ?
545 uwfault32 : uwfault64,
546 current->comm, current->pid,
547 sp, orig_sp,
548 regs->tpc,
549 regs->u_regs[UREG_I7]);
550 goto barf;
551 }
552 } while (window--);
553 }
554 set_thread_wsaved(0);
555 return;
556
557 barf:
558 set_thread_wsaved(window + 1);
559 force_sig(SIGSEGV);
560 }
561
562 /* Copy a Sparc thread. The fork() return value conventions
563 * under SunOS are nothing short of bletcherous:
564 * Parent --> %o0 == childs pid, %o1 == 0
565 * Child --> %o0 == parents pid, %o1 == 1
566 */
copy_thread(struct task_struct * p,const struct kernel_clone_args * args)567 int copy_thread(struct task_struct *p, const struct kernel_clone_args *args)
568 {
569 unsigned long clone_flags = args->flags;
570 unsigned long sp = args->stack;
571 unsigned long tls = args->tls;
572 struct thread_info *t = task_thread_info(p);
573 struct pt_regs *regs = current_pt_regs();
574 struct sparc_stackf *parent_sf;
575 unsigned long child_stack_sz;
576 char *child_trap_frame;
577
578 /* Calculate offset to stack_frame & pt_regs */
579 child_stack_sz = (STACKFRAME_SZ + TRACEREG_SZ);
580 child_trap_frame = (task_stack_page(p) +
581 (THREAD_SIZE - child_stack_sz));
582
583 t->new_child = 1;
584 t->ksp = ((unsigned long) child_trap_frame) - STACK_BIAS;
585 t->kregs = (struct pt_regs *) (child_trap_frame +
586 sizeof(struct sparc_stackf));
587 t->fpsaved[0] = 0;
588
589 if (unlikely(args->fn)) {
590 memset(child_trap_frame, 0, child_stack_sz);
591 __thread_flag_byte_ptr(t)[TI_FLAG_BYTE_CWP] =
592 (current_pt_regs()->tstate + 1) & TSTATE_CWP;
593 t->kregs->u_regs[UREG_G1] = (unsigned long) args->fn;
594 t->kregs->u_regs[UREG_G2] = (unsigned long) args->fn_arg;
595 return 0;
596 }
597
598 parent_sf = ((struct sparc_stackf *) regs) - 1;
599 memcpy(child_trap_frame, parent_sf, child_stack_sz);
600 if (t->flags & _TIF_32BIT) {
601 sp &= 0x00000000ffffffffUL;
602 regs->u_regs[UREG_FP] &= 0x00000000ffffffffUL;
603 }
604 t->kregs->u_regs[UREG_FP] = sp;
605 __thread_flag_byte_ptr(t)[TI_FLAG_BYTE_CWP] =
606 (regs->tstate + 1) & TSTATE_CWP;
607 if (sp != regs->u_regs[UREG_FP]) {
608 unsigned long csp;
609
610 csp = clone_stackframe(sp, regs->u_regs[UREG_FP]);
611 if (!csp)
612 return -EFAULT;
613 t->kregs->u_regs[UREG_FP] = csp;
614 }
615 if (t->utraps)
616 t->utraps[0]++;
617
618 /* Set the return value for the child. */
619 t->kregs->u_regs[UREG_I0] = current->pid;
620 t->kregs->u_regs[UREG_I1] = 1;
621
622 /* Set the second return value for the parent. */
623 regs->u_regs[UREG_I1] = 0;
624
625 if (clone_flags & CLONE_SETTLS)
626 t->kregs->u_regs[UREG_G7] = tls;
627
628 return 0;
629 }
630
631 /* TIF_MCDPER in thread info flags for current task is updated lazily upon
632 * a context switch. Update this flag in current task's thread flags
633 * before dup so the dup'd task will inherit the current TIF_MCDPER flag.
634 */
arch_dup_task_struct(struct task_struct * dst,struct task_struct * src)635 int arch_dup_task_struct(struct task_struct *dst, struct task_struct *src)
636 {
637 if (adi_capable()) {
638 register unsigned long tmp_mcdper;
639
640 __asm__ __volatile__(
641 ".word 0x83438000\n\t" /* rd %mcdper, %g1 */
642 "mov %%g1, %0\n\t"
643 : "=r" (tmp_mcdper)
644 :
645 : "g1");
646 if (tmp_mcdper)
647 set_thread_flag(TIF_MCDPER);
648 else
649 clear_thread_flag(TIF_MCDPER);
650 }
651
652 *dst = *src;
653 return 0;
654 }
655
__get_wchan(struct task_struct * task)656 unsigned long __get_wchan(struct task_struct *task)
657 {
658 unsigned long pc, fp, bias = 0;
659 struct thread_info *tp;
660 struct reg_window *rw;
661 unsigned long ret = 0;
662 int count = 0;
663
664 tp = task_thread_info(task);
665 bias = STACK_BIAS;
666 fp = task_thread_info(task)->ksp + bias;
667
668 do {
669 if (!kstack_valid(tp, fp))
670 break;
671 rw = (struct reg_window *) fp;
672 pc = rw->ins[7];
673 if (!in_sched_functions(pc)) {
674 ret = pc;
675 goto out;
676 }
677 fp = rw->ins[6] + bias;
678 } while (++count < 16);
679
680 out:
681 return ret;
682 }
683