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Merge remote-tracking branch 'moduleh/module.h-split'
[linux-2.6/next.git] / arch / sparc / kernel / process_32.c
blobc8cc461ff75f040a974179aa7383ba501dde017a
1 /* linux/arch/sparc/kernel/process.c
2 *
3 * Copyright (C) 1995, 2008 David S. Miller (davem@davemloft.net)
4 * Copyright (C) 1996 Eddie C. Dost (ecd@skynet.be)
5 */
6
7 /*
8 * This file handles the architecture-dependent parts of process handling..
9 */
10
11 #include <stdarg.h>
12
13 #include <linux/errno.h>
14 #include <linux/module.h>
15 #include <linux/sched.h>
16 #include <linux/kernel.h>
17 #include <linux/mm.h>
18 #include <linux/stddef.h>
19 #include <linux/ptrace.h>
20 #include <linux/user.h>
21 #include <linux/smp.h>
22 #include <linux/reboot.h>
23 #include <linux/delay.h>
24 #include <linux/pm.h>
25 #include <linux/init.h>
26 #include <linux/slab.h>
27
28 #include <asm/auxio.h>
29 #include <asm/oplib.h>
30 #include <asm/uaccess.h>
31 #include <asm/system.h>
32 #include <asm/page.h>
33 #include <asm/pgalloc.h>
34 #include <asm/pgtable.h>
35 #include <asm/delay.h>
36 #include <asm/processor.h>
37 #include <asm/psr.h>
38 #include <asm/elf.h>
39 #include <asm/prom.h>
40 #include <asm/unistd.h>
41
42 /*
43 * Power management idle function
44 * Set in pm platform drivers (apc.c and pmc.c)
45 */
46 void (*pm_idle)(void);
47 EXPORT_SYMBOL(pm_idle);
48
49 /*
50 * Power-off handler instantiation for pm.h compliance
51 * This is done via auxio, but could be used as a fallback
52 * handler when auxio is not present-- unused for now...
53 */
54 void (*pm_power_off)(void) = machine_power_off;
55 EXPORT_SYMBOL(pm_power_off);
56
57 /*
58 * sysctl - toggle power-off restriction for serial console
59 * systems in machine_power_off()
60 */
61 int scons_pwroff = 1;
62
63 extern void fpsave(unsigned long *, unsigned long *, void *, unsigned long *);
64
65 struct task_struct *last_task_used_math = NULL;
66 struct thread_info *current_set[NR_CPUS];
67
68 #ifndef CONFIG_SMP
69
70 #define SUN4C_FAULT_HIGH 100
71
72 /*
73 * the idle loop on a Sparc... ;)
74 */
75 void cpu_idle(void)
76 {
77 /* endless idle loop with no priority at all */
78 for (;;) {
79 if (ARCH_SUN4C) {
80 static int count = HZ;
81 static unsigned long last_jiffies;
82 static unsigned long last_faults;
83 static unsigned long fps;
84 unsigned long now;
85 unsigned long faults;
86
87 extern unsigned long sun4c_kernel_faults;
88 extern void sun4c_grow_kernel_ring(void);
89
90 local_irq_disable();
91 now = jiffies;
92 count -= (now - last_jiffies);
93 last_jiffies = now;
94 if (count < 0) {
95 count += HZ;
96 faults = sun4c_kernel_faults;
97 fps = (fps + (faults - last_faults)) >> 1;
98 last_faults = faults;
99 #if 0
100 printk("kernel faults / second = %ld\n", fps);
101 #endif
102 if (fps >= SUN4C_FAULT_HIGH) {
103 sun4c_grow_kernel_ring();
104 }
105 }
106 local_irq_enable();
107 }
108
109 if (pm_idle) {
110 while (!need_resched())
111 (*pm_idle)();
112 } else {
113 while (!need_resched())
114 cpu_relax();
115 }
116 preempt_enable_no_resched();
117 schedule();
118 preempt_disable();
119 check_pgt_cache();
120 }
121 }
122
123 #else
124
125 /* This is being executed in task 0 'user space'. */
126 void cpu_idle(void)
127 {
128 set_thread_flag(TIF_POLLING_NRFLAG);
129 /* endless idle loop with no priority at all */
130 while(1) {
131 #ifdef CONFIG_SPARC_LEON
132 if (pm_idle) {
133 while (!need_resched())
134 (*pm_idle)();
135 } else
136 #endif
137 {
138 while (!need_resched())
139 cpu_relax();
140 }
141 preempt_enable_no_resched();
142 schedule();
143 preempt_disable();
144 check_pgt_cache();
145 }
146 }
147
148 #endif
149
150 /* XXX cli/sti -> local_irq_xxx here, check this works once SMP is fixed. */
151 void machine_halt(void)
152 {
153 local_irq_enable();
154 mdelay(8);
155 local_irq_disable();
156 prom_halt();
157 panic("Halt failed!");
158 }
159
160 void machine_restart(char * cmd)
161 {
162 char *p;
163
164 local_irq_enable();
165 mdelay(8);
166 local_irq_disable();
167
168 p = strchr (reboot_command, '\n');
169 if (p) *p = 0;
170 if (cmd)
171 prom_reboot(cmd);
172 if (*reboot_command)
173 prom_reboot(reboot_command);
174 prom_feval ("reset");
175 panic("Reboot failed!");
176 }
177
178 void machine_power_off(void)
179 {
180 if (auxio_power_register &&
181 (strcmp(of_console_device->type, "serial") || scons_pwroff))
182 *auxio_power_register |= AUXIO_POWER_OFF;
183 machine_halt();
184 }
185
186 #if 0
187
188 static DEFINE_SPINLOCK(sparc_backtrace_lock);
189
190 void __show_backtrace(unsigned long fp)
191 {
192 struct reg_window32 *rw;
193 unsigned long flags;
194 int cpu = smp_processor_id();
195
196 spin_lock_irqsave(&sparc_backtrace_lock, flags);
197
198 rw = (struct reg_window32 *)fp;
199 while(rw && (((unsigned long) rw) >= PAGE_OFFSET) &&
200 !(((unsigned long) rw) & 0x7)) {
201 printk("CPU[%d]: ARGS[%08lx,%08lx,%08lx,%08lx,%08lx,%08lx] "
202 "FP[%08lx] CALLER[%08lx]: ", cpu,
203 rw->ins[0], rw->ins[1], rw->ins[2], rw->ins[3],
204 rw->ins[4], rw->ins[5],
205 rw->ins[6],
206 rw->ins[7]);
207 printk("%pS\n", (void *) rw->ins[7]);
208 rw = (struct reg_window32 *) rw->ins[6];
209 }
210 spin_unlock_irqrestore(&sparc_backtrace_lock, flags);
211 }
212
213 #define __SAVE __asm__ __volatile__("save %sp, -0x40, %sp\n\t")
214 #define __RESTORE __asm__ __volatile__("restore %g0, %g0, %g0\n\t")
215 #define __GET_FP(fp) __asm__ __volatile__("mov %%i6, %0" : "=r" (fp))
216
217 void show_backtrace(void)
218 {
219 unsigned long fp;
220
221 __SAVE; __SAVE; __SAVE; __SAVE;
222 __SAVE; __SAVE; __SAVE; __SAVE;
223 __RESTORE; __RESTORE; __RESTORE; __RESTORE;
224 __RESTORE; __RESTORE; __RESTORE; __RESTORE;
225
226 __GET_FP(fp);
227
228 __show_backtrace(fp);
229 }
230
231 #ifdef CONFIG_SMP
232 void smp_show_backtrace_all_cpus(void)
233 {
234 xc0((smpfunc_t) show_backtrace);
235 show_backtrace();
236 }
237 #endif
238
239 void show_stackframe(struct sparc_stackf *sf)
240 {
241 unsigned long size;
242 unsigned long *stk;
243 int i;
244
245 printk("l0: %08lx l1: %08lx l2: %08lx l3: %08lx "
246 "l4: %08lx l5: %08lx l6: %08lx l7: %08lx\n",
247 sf->locals[0], sf->locals[1], sf->locals[2], sf->locals[3],
248 sf->locals[4], sf->locals[5], sf->locals[6], sf->locals[7]);
249 printk("i0: %08lx i1: %08lx i2: %08lx i3: %08lx "
250 "i4: %08lx i5: %08lx fp: %08lx i7: %08lx\n",
251 sf->ins[0], sf->ins[1], sf->ins[2], sf->ins[3],
252 sf->ins[4], sf->ins[5], (unsigned long)sf->fp, sf->callers_pc);
253 printk("sp: %08lx x0: %08lx x1: %08lx x2: %08lx "
254 "x3: %08lx x4: %08lx x5: %08lx xx: %08lx\n",
255 (unsigned long)sf->structptr, sf->xargs[0], sf->xargs[1],
256 sf->xargs[2], sf->xargs[3], sf->xargs[4], sf->xargs[5],
257 sf->xxargs[0]);
258 size = ((unsigned long)sf->fp) - ((unsigned long)sf);
259 size -= STACKFRAME_SZ;
260 stk = (unsigned long *)((unsigned long)sf + STACKFRAME_SZ);
261 i = 0;
262 do {
263 printk("s%d: %08lx\n", i++, *stk++);
264 } while ((size -= sizeof(unsigned long)));
265 }
266 #endif
267
268 void show_regs(struct pt_regs *r)
269 {
270 struct reg_window32 *rw = (struct reg_window32 *) r->u_regs[14];
271
272 printk("PSR: %08lx PC: %08lx NPC: %08lx Y: %08lx %s\n",
273 r->psr, r->pc, r->npc, r->y, print_tainted());
274 printk("PC: <%pS>\n", (void *) r->pc);
275 printk("%%G: %08lx %08lx %08lx %08lx %08lx %08lx %08lx %08lx\n",
276 r->u_regs[0], r->u_regs[1], r->u_regs[2], r->u_regs[3],
277 r->u_regs[4], r->u_regs[5], r->u_regs[6], r->u_regs[7]);
278 printk("%%O: %08lx %08lx %08lx %08lx %08lx %08lx %08lx %08lx\n",
279 r->u_regs[8], r->u_regs[9], r->u_regs[10], r->u_regs[11],
280 r->u_regs[12], r->u_regs[13], r->u_regs[14], r->u_regs[15]);
281 printk("RPC: <%pS>\n", (void *) r->u_regs[15]);
282
283 printk("%%L: %08lx %08lx %08lx %08lx %08lx %08lx %08lx %08lx\n",
284 rw->locals[0], rw->locals[1], rw->locals[2], rw->locals[3],
285 rw->locals[4], rw->locals[5], rw->locals[6], rw->locals[7]);
286 printk("%%I: %08lx %08lx %08lx %08lx %08lx %08lx %08lx %08lx\n",
287 rw->ins[0], rw->ins[1], rw->ins[2], rw->ins[3],
288 rw->ins[4], rw->ins[5], rw->ins[6], rw->ins[7]);
289 }
290
291 /*
292 * The show_stack is an external API which we do not use ourselves.
293 * The oops is printed in die_if_kernel.
294 */
295 void show_stack(struct task_struct *tsk, unsigned long *_ksp)
296 {
297 unsigned long pc, fp;
298 unsigned long task_base;
299 struct reg_window32 *rw;
300 int count = 0;
301
302 if (tsk != NULL)
303 task_base = (unsigned long) task_stack_page(tsk);
304 else
305 task_base = (unsigned long) current_thread_info();
306
307 fp = (unsigned long) _ksp;
308 do {
309 /* Bogus frame pointer? */
310 if (fp < (task_base + sizeof(struct thread_info)) ||
311 fp >= (task_base + (PAGE_SIZE << 1)))
312 break;
313 rw = (struct reg_window32 *) fp;
314 pc = rw->ins[7];
315 printk("[%08lx : ", pc);
316 printk("%pS ] ", (void *) pc);
317 fp = rw->ins[6];
318 } while (++count < 16);
319 printk("\n");
320 }
321
322 void dump_stack(void)
323 {
324 unsigned long *ksp;
325
326 __asm__ __volatile__("mov %%fp, %0"
327 : "=r" (ksp));
328 show_stack(current, ksp);
329 }
330
331 EXPORT_SYMBOL(dump_stack);
332
333 /*
334 * Note: sparc64 has a pretty intricated thread_saved_pc, check it out.
335 */
336 unsigned long thread_saved_pc(struct task_struct *tsk)
337 {
338 return task_thread_info(tsk)->kpc;
339 }
340
341 /*
342 * Free current thread data structures etc..
343 */
344 void exit_thread(void)
345 {
346 #ifndef CONFIG_SMP
347 if(last_task_used_math == current) {
348 #else
349 if (test_thread_flag(TIF_USEDFPU)) {
350 #endif
351 /* Keep process from leaving FPU in a bogon state. */
352 put_psr(get_psr() | PSR_EF);
353 fpsave(&current->thread.float_regs[0], &current->thread.fsr,
354 &current->thread.fpqueue[0], &current->thread.fpqdepth);
355 #ifndef CONFIG_SMP
356 last_task_used_math = NULL;
357 #else
358 clear_thread_flag(TIF_USEDFPU);
359 #endif
360 }
361 }
362
363 void flush_thread(void)
364 {
365 current_thread_info()->w_saved = 0;
366
367 #ifndef CONFIG_SMP
368 if(last_task_used_math == current) {
369 #else
370 if (test_thread_flag(TIF_USEDFPU)) {
371 #endif
372 /* Clean the fpu. */
373 put_psr(get_psr() | PSR_EF);
374 fpsave(&current->thread.float_regs[0], &current->thread.fsr,
375 &current->thread.fpqueue[0], &current->thread.fpqdepth);
376 #ifndef CONFIG_SMP
377 last_task_used_math = NULL;
378 #else
379 clear_thread_flag(TIF_USEDFPU);
380 #endif
381 }
382
383 /* Now, this task is no longer a kernel thread. */
384 current->thread.current_ds = USER_DS;
385 if (current->thread.flags & SPARC_FLAG_KTHREAD) {
386 current->thread.flags &= ~SPARC_FLAG_KTHREAD;
387
388 /* We must fixup kregs as well. */
389 /* XXX This was not fixed for ti for a while, worked. Unused? */
390 current->thread.kregs = (struct pt_regs *)
391 (task_stack_page(current) + (THREAD_SIZE - TRACEREG_SZ));
392 }
393 }
394
395 static inline struct sparc_stackf __user *
396 clone_stackframe(struct sparc_stackf __user *dst,
397 struct sparc_stackf __user *src)
398 {
399 unsigned long size, fp;
400 struct sparc_stackf *tmp;
401 struct sparc_stackf __user *sp;
402
403 if (get_user(tmp, &src->fp))
404 return NULL;
405
406 fp = (unsigned long) tmp;
407 size = (fp - ((unsigned long) src));
408 fp = (unsigned long) dst;
409 sp = (struct sparc_stackf __user *)(fp - size);
410
411 /* do_fork() grabs the parent semaphore, we must release it
412 * temporarily so we can build the child clone stack frame
413 * without deadlocking.
414 */
415 if (__copy_user(sp, src, size))
416 sp = NULL;
417 else if (put_user(fp, &sp->fp))
418 sp = NULL;
419
420 return sp;
421 }
422
423 asmlinkage int sparc_do_fork(unsigned long clone_flags,
424 unsigned long stack_start,
425 struct pt_regs *regs,
426 unsigned long stack_size)
427 {
428 unsigned long parent_tid_ptr, child_tid_ptr;
429 unsigned long orig_i1 = regs->u_regs[UREG_I1];
430 long ret;
431
432 parent_tid_ptr = regs->u_regs[UREG_I2];
433 child_tid_ptr = regs->u_regs[UREG_I4];
434
435 ret = do_fork(clone_flags, stack_start,
436 regs, stack_size,
437 (int __user *) parent_tid_ptr,
438 (int __user *) child_tid_ptr);
439
440 /* If we get an error and potentially restart the system
441 * call, we're screwed because copy_thread() clobbered
442 * the parent's %o1. So detect that case and restore it
443 * here.
444 */
445 if ((unsigned long)ret >= -ERESTART_RESTARTBLOCK)
446 regs->u_regs[UREG_I1] = orig_i1;
447
448 return ret;
449 }
450
451 /* Copy a Sparc thread. The fork() return value conventions
452 * under SunOS are nothing short of bletcherous:
453 * Parent --> %o0 == childs pid, %o1 == 0
454 * Child --> %o0 == parents pid, %o1 == 1
455 *
456 * NOTE: We have a separate fork kpsr/kwim because
457 * the parent could change these values between
458 * sys_fork invocation and when we reach here
459 * if the parent should sleep while trying to
460 * allocate the task_struct and kernel stack in
461 * do_fork().
462 * XXX See comment above sys_vfork in sparc64. todo.
463 */
464 extern void ret_from_fork(void);
465
466 int copy_thread(unsigned long clone_flags, unsigned long sp,
467 unsigned long unused,
468 struct task_struct *p, struct pt_regs *regs)
469 {
470 struct thread_info *ti = task_thread_info(p);
471 struct pt_regs *childregs;
472 char *new_stack;
473
474 #ifndef CONFIG_SMP
475 if(last_task_used_math == current) {
476 #else
477 if (test_thread_flag(TIF_USEDFPU)) {
478 #endif
479 put_psr(get_psr() | PSR_EF);
480 fpsave(&p->thread.float_regs[0], &p->thread.fsr,
481 &p->thread.fpqueue[0], &p->thread.fpqdepth);
482 #ifdef CONFIG_SMP
483 clear_thread_flag(TIF_USEDFPU);
484 #endif
485 }
486
487 /*
488 * p->thread_info new_stack childregs
489 * ! ! ! {if(PSR_PS) }
490 * V V (stk.fr.) V (pt_regs) { (stk.fr.) }
491 * +----- - - - - - ------+===========+============={+==========}+
492 */
493 new_stack = task_stack_page(p) + THREAD_SIZE;
494 if (regs->psr & PSR_PS)
495 new_stack -= STACKFRAME_SZ;
496 new_stack -= STACKFRAME_SZ + TRACEREG_SZ;
497 memcpy(new_stack, (char *)regs - STACKFRAME_SZ, STACKFRAME_SZ + TRACEREG_SZ);
498 childregs = (struct pt_regs *) (new_stack + STACKFRAME_SZ);
499
500 /*
501 * A new process must start with interrupts closed in 2.5,
502 * because this is how Mingo's scheduler works (see schedule_tail
503 * and finish_arch_switch). If we do not do it, a timer interrupt hits
504 * before we unlock, attempts to re-take the rq->lock, and then we die.
505 * Thus, kpsr|=PSR_PIL.
506 */
507 ti->ksp = (unsigned long) new_stack;
508 ti->kpc = (((unsigned long) ret_from_fork) - 0x8);
509 ti->kpsr = current->thread.fork_kpsr | PSR_PIL;
510 ti->kwim = current->thread.fork_kwim;
511
512 if(regs->psr & PSR_PS) {
513 extern struct pt_regs fake_swapper_regs;
514
515 p->thread.kregs = &fake_swapper_regs;
516 new_stack += STACKFRAME_SZ + TRACEREG_SZ;
517 childregs->u_regs[UREG_FP] = (unsigned long) new_stack;
518 p->thread.flags |= SPARC_FLAG_KTHREAD;
519 p->thread.current_ds = KERNEL_DS;
520 memcpy(new_stack, (void *)regs->u_regs[UREG_FP], STACKFRAME_SZ);
521 childregs->u_regs[UREG_G6] = (unsigned long) ti;
522 } else {
523 p->thread.kregs = childregs;
524 childregs->u_regs[UREG_FP] = sp;
525 p->thread.flags &= ~SPARC_FLAG_KTHREAD;
526 p->thread.current_ds = USER_DS;
527
528 if (sp != regs->u_regs[UREG_FP]) {
529 struct sparc_stackf __user *childstack;
530 struct sparc_stackf __user *parentstack;
531
532 /*
533 * This is a clone() call with supplied user stack.
534 * Set some valid stack frames to give to the child.
535 */
536 childstack = (struct sparc_stackf __user *)
537 (sp & ~0xfUL);
538 parentstack = (struct sparc_stackf __user *)
539 regs->u_regs[UREG_FP];
540
541 #if 0
542 printk("clone: parent stack:\n");
543 show_stackframe(parentstack);
544 #endif
545
546 childstack = clone_stackframe(childstack, parentstack);
547 if (!childstack)
548 return -EFAULT;
549
550 #if 0
551 printk("clone: child stack:\n");
552 show_stackframe(childstack);
553 #endif
554
555 childregs->u_regs[UREG_FP] = (unsigned long)childstack;
556 }
557 }
558
559 #ifdef CONFIG_SMP
560 /* FPU must be disabled on SMP. */
561 childregs->psr &= ~PSR_EF;
562 #endif
563
564 /* Set the return value for the child. */
565 childregs->u_regs[UREG_I0] = current->pid;
566 childregs->u_regs[UREG_I1] = 1;
567
568 /* Set the return value for the parent. */
569 regs->u_regs[UREG_I1] = 0;
570
571 if (clone_flags & CLONE_SETTLS)
572 childregs->u_regs[UREG_G7] = regs->u_regs[UREG_I3];
573
574 return 0;
575 }
576
577 /*
578 * fill in the fpu structure for a core dump.
579 */
580 int dump_fpu (struct pt_regs * regs, elf_fpregset_t * fpregs)
581 {
582 if (used_math()) {
583 memset(fpregs, 0, sizeof(*fpregs));
584 fpregs->pr_q_entrysize = 8;
585 return 1;
586 }
587 #ifdef CONFIG_SMP
588 if (test_thread_flag(TIF_USEDFPU)) {
589 put_psr(get_psr() | PSR_EF);
590 fpsave(&current->thread.float_regs[0], &current->thread.fsr,
591 &current->thread.fpqueue[0], &current->thread.fpqdepth);
592 if (regs != NULL) {
593 regs->psr &= ~(PSR_EF);
594 clear_thread_flag(TIF_USEDFPU);
595 }
596 }
597 #else
598 if (current == last_task_used_math) {
599 put_psr(get_psr() | PSR_EF);
600 fpsave(&current->thread.float_regs[0], &current->thread.fsr,
601 &current->thread.fpqueue[0], &current->thread.fpqdepth);
602 if (regs != NULL) {
603 regs->psr &= ~(PSR_EF);
604 last_task_used_math = NULL;
605 }
606 }
607 #endif
608 memcpy(&fpregs->pr_fr.pr_regs[0],
609 &current->thread.float_regs[0],
610 (sizeof(unsigned long) * 32));
611 fpregs->pr_fsr = current->thread.fsr;
612 fpregs->pr_qcnt = current->thread.fpqdepth;
613 fpregs->pr_q_entrysize = 8;
614 fpregs->pr_en = 1;
615 if(fpregs->pr_qcnt != 0) {
616 memcpy(&fpregs->pr_q[0],
617 &current->thread.fpqueue[0],
618 sizeof(struct fpq) * fpregs->pr_qcnt);
619 }
620 /* Zero out the rest. */
621 memset(&fpregs->pr_q[fpregs->pr_qcnt], 0,
622 sizeof(struct fpq) * (32 - fpregs->pr_qcnt));
623 return 1;
624 }
625
626 /*
627 * sparc_execve() executes a new program after the asm stub has set
628 * things up for us. This should basically do what I want it to.
629 */
630 asmlinkage int sparc_execve(struct pt_regs *regs)
631 {
632 int error, base = 0;
633 char *filename;
634
635 /* Check for indirect call. */
636 if(regs->u_regs[UREG_G1] == 0)
637 base = 1;
638
639 filename = getname((char __user *)regs->u_regs[base + UREG_I0]);
640 error = PTR_ERR(filename);
641 if(IS_ERR(filename))
642 goto out;
643 error = do_execve(filename,
644 (const char __user *const __user *)
645 regs->u_regs[base + UREG_I1],
646 (const char __user *const __user *)
647 regs->u_regs[base + UREG_I2],
648 regs);
649 putname(filename);
650 out:
651 return error;
652 }
653
654 /*
655 * This is the mechanism for creating a new kernel thread.
656 *
657 * NOTE! Only a kernel-only process(ie the swapper or direct descendants
658 * who haven't done an "execve()") should use this: it will work within
659 * a system call from a "real" process, but the process memory space will
660 * not be freed until both the parent and the child have exited.
661 */
662 pid_t kernel_thread(int (*fn)(void *), void * arg, unsigned long flags)
663 {
664 long retval;
665
666 __asm__ __volatile__("mov %4, %%g2\n\t" /* Set aside fn ptr... */
667 "mov %5, %%g3\n\t" /* and arg. */
668 "mov %1, %%g1\n\t"
669 "mov %2, %%o0\n\t" /* Clone flags. */
670 "mov 0, %%o1\n\t" /* usp arg == 0 */
671 "t 0x10\n\t" /* Linux/Sparc clone(). */
672 "cmp %%o1, 0\n\t"
673 "be 1f\n\t" /* The parent, just return. */
674 " nop\n\t" /* Delay slot. */
675 "jmpl %%g2, %%o7\n\t" /* Call the function. */
676 " mov %%g3, %%o0\n\t" /* Get back the arg in delay. */
677 "mov %3, %%g1\n\t"
678 "t 0x10\n\t" /* Linux/Sparc exit(). */
679 /* Notreached by child. */
680 "1: mov %%o0, %0\n\t" :
681 "=r" (retval) :
682 "i" (__NR_clone), "r" (flags | CLONE_VM | CLONE_UNTRACED),
683 "i" (__NR_exit), "r" (fn), "r" (arg) :
684 "g1", "g2", "g3", "o0", "o1", "memory", "cc");
685 return retval;
686 }
687 EXPORT_SYMBOL(kernel_thread);
688
689 unsigned long get_wchan(struct task_struct *task)
690 {
691 unsigned long pc, fp, bias = 0;
692 unsigned long task_base = (unsigned long) task;
693 unsigned long ret = 0;
694 struct reg_window32 *rw;
695 int count = 0;
696
697 if (!task || task == current ||
698 task->state == TASK_RUNNING)
699 goto out;
700
701 fp = task_thread_info(task)->ksp + bias;
702 do {
703 /* Bogus frame pointer? */
704 if (fp < (task_base + sizeof(struct thread_info)) ||
705 fp >= (task_base + (2 * PAGE_SIZE)))
706 break;
707 rw = (struct reg_window32 *) fp;
708 pc = rw->ins[7];
709 if (!in_sched_functions(pc)) {
710 ret = pc;
711 goto out;
712 }
713 fp = rw->ins[6] + bias;
714 } while (++count < 16);
715
716 out:
717 return ret;
718 }
719
linux-next