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Linux 2.6.31.6
[linux/fpc-iii.git] / arch / sparc / kernel / process_32.c
blob2830b415e2147ecfda36acc99d620408472128bd
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/slab.h>
21 #include <linux/user.h>
22 #include <linux/smp.h>
23 #include <linux/reboot.h>
24 #include <linux/delay.h>
25 #include <linux/pm.h>
26 #include <linux/init.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 while (!need_resched())
132 cpu_relax();
133 preempt_enable_no_resched();
134 schedule();
135 preempt_disable();
136 check_pgt_cache();
137 }
138 }
139
140 #endif
141
142 /* XXX cli/sti -> local_irq_xxx here, check this works once SMP is fixed. */
143 void machine_halt(void)
144 {
145 local_irq_enable();
146 mdelay(8);
147 local_irq_disable();
148 prom_halt();
149 panic("Halt failed!");
150 }
151
152 void machine_restart(char * cmd)
153 {
154 char *p;
155
156 local_irq_enable();
157 mdelay(8);
158 local_irq_disable();
159
160 p = strchr (reboot_command, '\n');
161 if (p) *p = 0;
162 if (cmd)
163 prom_reboot(cmd);
164 if (*reboot_command)
165 prom_reboot(reboot_command);
166 prom_feval ("reset");
167 panic("Reboot failed!");
168 }
169
170 void machine_power_off(void)
171 {
172 if (auxio_power_register &&
173 (strcmp(of_console_device->type, "serial") || scons_pwroff))
174 *auxio_power_register |= AUXIO_POWER_OFF;
175 machine_halt();
176 }
177
178 #if 0
179
180 static DEFINE_SPINLOCK(sparc_backtrace_lock);
181
182 void __show_backtrace(unsigned long fp)
183 {
184 struct reg_window32 *rw;
185 unsigned long flags;
186 int cpu = smp_processor_id();
187
188 spin_lock_irqsave(&sparc_backtrace_lock, flags);
189
190 rw = (struct reg_window32 *)fp;
191 while(rw && (((unsigned long) rw) >= PAGE_OFFSET) &&
192 !(((unsigned long) rw) & 0x7)) {
193 printk("CPU[%d]: ARGS[%08lx,%08lx,%08lx,%08lx,%08lx,%08lx] "
194 "FP[%08lx] CALLER[%08lx]: ", cpu,
195 rw->ins[0], rw->ins[1], rw->ins[2], rw->ins[3],
196 rw->ins[4], rw->ins[5],
197 rw->ins[6],
198 rw->ins[7]);
199 printk("%pS\n", (void *) rw->ins[7]);
200 rw = (struct reg_window32 *) rw->ins[6];
201 }
202 spin_unlock_irqrestore(&sparc_backtrace_lock, flags);
203 }
204
205 #define __SAVE __asm__ __volatile__("save %sp, -0x40, %sp\n\t")
206 #define __RESTORE __asm__ __volatile__("restore %g0, %g0, %g0\n\t")
207 #define __GET_FP(fp) __asm__ __volatile__("mov %%i6, %0" : "=r" (fp))
208
209 void show_backtrace(void)
210 {
211 unsigned long fp;
212
213 __SAVE; __SAVE; __SAVE; __SAVE;
214 __SAVE; __SAVE; __SAVE; __SAVE;
215 __RESTORE; __RESTORE; __RESTORE; __RESTORE;
216 __RESTORE; __RESTORE; __RESTORE; __RESTORE;
217
218 __GET_FP(fp);
219
220 __show_backtrace(fp);
221 }
222
223 #ifdef CONFIG_SMP
224 void smp_show_backtrace_all_cpus(void)
225 {
226 xc0((smpfunc_t) show_backtrace);
227 show_backtrace();
228 }
229 #endif
230
231 void show_stackframe(struct sparc_stackf *sf)
232 {
233 unsigned long size;
234 unsigned long *stk;
235 int i;
236
237 printk("l0: %08lx l1: %08lx l2: %08lx l3: %08lx "
238 "l4: %08lx l5: %08lx l6: %08lx l7: %08lx\n",
239 sf->locals[0], sf->locals[1], sf->locals[2], sf->locals[3],
240 sf->locals[4], sf->locals[5], sf->locals[6], sf->locals[7]);
241 printk("i0: %08lx i1: %08lx i2: %08lx i3: %08lx "
242 "i4: %08lx i5: %08lx fp: %08lx i7: %08lx\n",
243 sf->ins[0], sf->ins[1], sf->ins[2], sf->ins[3],
244 sf->ins[4], sf->ins[5], (unsigned long)sf->fp, sf->callers_pc);
245 printk("sp: %08lx x0: %08lx x1: %08lx x2: %08lx "
246 "x3: %08lx x4: %08lx x5: %08lx xx: %08lx\n",
247 (unsigned long)sf->structptr, sf->xargs[0], sf->xargs[1],
248 sf->xargs[2], sf->xargs[3], sf->xargs[4], sf->xargs[5],
249 sf->xxargs[0]);
250 size = ((unsigned long)sf->fp) - ((unsigned long)sf);
251 size -= STACKFRAME_SZ;
252 stk = (unsigned long *)((unsigned long)sf + STACKFRAME_SZ);
253 i = 0;
254 do {
255 printk("s%d: %08lx\n", i++, *stk++);
256 } while ((size -= sizeof(unsigned long)));
257 }
258 #endif
259
260 void show_regs(struct pt_regs *r)
261 {
262 struct reg_window32 *rw = (struct reg_window32 *) r->u_regs[14];
263
264 printk("PSR: %08lx PC: %08lx NPC: %08lx Y: %08lx %s\n",
265 r->psr, r->pc, r->npc, r->y, print_tainted());
266 printk("PC: <%pS>\n", (void *) r->pc);
267 printk("%%G: %08lx %08lx %08lx %08lx %08lx %08lx %08lx %08lx\n",
268 r->u_regs[0], r->u_regs[1], r->u_regs[2], r->u_regs[3],
269 r->u_regs[4], r->u_regs[5], r->u_regs[6], r->u_regs[7]);
270 printk("%%O: %08lx %08lx %08lx %08lx %08lx %08lx %08lx %08lx\n",
271 r->u_regs[8], r->u_regs[9], r->u_regs[10], r->u_regs[11],
272 r->u_regs[12], r->u_regs[13], r->u_regs[14], r->u_regs[15]);
273 printk("RPC: <%pS>\n", (void *) r->u_regs[15]);
274
275 printk("%%L: %08lx %08lx %08lx %08lx %08lx %08lx %08lx %08lx\n",
276 rw->locals[0], rw->locals[1], rw->locals[2], rw->locals[3],
277 rw->locals[4], rw->locals[5], rw->locals[6], rw->locals[7]);
278 printk("%%I: %08lx %08lx %08lx %08lx %08lx %08lx %08lx %08lx\n",
279 rw->ins[0], rw->ins[1], rw->ins[2], rw->ins[3],
280 rw->ins[4], rw->ins[5], rw->ins[6], rw->ins[7]);
281 }
282
283 /*
284 * The show_stack is an external API which we do not use ourselves.
285 * The oops is printed in die_if_kernel.
286 */
287 void show_stack(struct task_struct *tsk, unsigned long *_ksp)
288 {
289 unsigned long pc, fp;
290 unsigned long task_base;
291 struct reg_window32 *rw;
292 int count = 0;
293
294 if (tsk != NULL)
295 task_base = (unsigned long) task_stack_page(tsk);
296 else
297 task_base = (unsigned long) current_thread_info();
298
299 fp = (unsigned long) _ksp;
300 do {
301 /* Bogus frame pointer? */
302 if (fp < (task_base + sizeof(struct thread_info)) ||
303 fp >= (task_base + (PAGE_SIZE << 1)))
304 break;
305 rw = (struct reg_window32 *) fp;
306 pc = rw->ins[7];
307 printk("[%08lx : ", pc);
308 printk("%pS ] ", (void *) pc);
309 fp = rw->ins[6];
310 } while (++count < 16);
311 printk("\n");
312 }
313
314 void dump_stack(void)
315 {
316 unsigned long *ksp;
317
318 __asm__ __volatile__("mov %%fp, %0"
319 : "=r" (ksp));
320 show_stack(current, ksp);
321 }
322
323 EXPORT_SYMBOL(dump_stack);
324
325 /*
326 * Note: sparc64 has a pretty intricated thread_saved_pc, check it out.
327 */
328 unsigned long thread_saved_pc(struct task_struct *tsk)
329 {
330 return task_thread_info(tsk)->kpc;
331 }
332
333 /*
334 * Free current thread data structures etc..
335 */
336 void exit_thread(void)
337 {
338 #ifndef CONFIG_SMP
339 if(last_task_used_math == current) {
340 #else
341 if (test_thread_flag(TIF_USEDFPU)) {
342 #endif
343 /* Keep process from leaving FPU in a bogon state. */
344 put_psr(get_psr() | PSR_EF);
345 fpsave(&current->thread.float_regs[0], &current->thread.fsr,
346 &current->thread.fpqueue[0], &current->thread.fpqdepth);
347 #ifndef CONFIG_SMP
348 last_task_used_math = NULL;
349 #else
350 clear_thread_flag(TIF_USEDFPU);
351 #endif
352 }
353 }
354
355 void flush_thread(void)
356 {
357 current_thread_info()->w_saved = 0;
358
359 #ifndef CONFIG_SMP
360 if(last_task_used_math == current) {
361 #else
362 if (test_thread_flag(TIF_USEDFPU)) {
363 #endif
364 /* Clean the fpu. */
365 put_psr(get_psr() | PSR_EF);
366 fpsave(&current->thread.float_regs[0], &current->thread.fsr,
367 &current->thread.fpqueue[0], &current->thread.fpqdepth);
368 #ifndef CONFIG_SMP
369 last_task_used_math = NULL;
370 #else
371 clear_thread_flag(TIF_USEDFPU);
372 #endif
373 }
374
375 /* Now, this task is no longer a kernel thread. */
376 current->thread.current_ds = USER_DS;
377 if (current->thread.flags & SPARC_FLAG_KTHREAD) {
378 current->thread.flags &= ~SPARC_FLAG_KTHREAD;
379
380 /* We must fixup kregs as well. */
381 /* XXX This was not fixed for ti for a while, worked. Unused? */
382 current->thread.kregs = (struct pt_regs *)
383 (task_stack_page(current) + (THREAD_SIZE - TRACEREG_SZ));
384 }
385 }
386
387 static inline struct sparc_stackf __user *
388 clone_stackframe(struct sparc_stackf __user *dst,
389 struct sparc_stackf __user *src)
390 {
391 unsigned long size, fp;
392 struct sparc_stackf *tmp;
393 struct sparc_stackf __user *sp;
394
395 if (get_user(tmp, &src->fp))
396 return NULL;
397
398 fp = (unsigned long) tmp;
399 size = (fp - ((unsigned long) src));
400 fp = (unsigned long) dst;
401 sp = (struct sparc_stackf __user *)(fp - size);
402
403 /* do_fork() grabs the parent semaphore, we must release it
404 * temporarily so we can build the child clone stack frame
405 * without deadlocking.
406 */
407 if (__copy_user(sp, src, size))
408 sp = NULL;
409 else if (put_user(fp, &sp->fp))
410 sp = NULL;
411
412 return sp;
413 }
414
415 asmlinkage int sparc_do_fork(unsigned long clone_flags,
416 unsigned long stack_start,
417 struct pt_regs *regs,
418 unsigned long stack_size)
419 {
420 unsigned long parent_tid_ptr, child_tid_ptr;
421 unsigned long orig_i1 = regs->u_regs[UREG_I1];
422 long ret;
423
424 parent_tid_ptr = regs->u_regs[UREG_I2];
425 child_tid_ptr = regs->u_regs[UREG_I4];
426
427 ret = do_fork(clone_flags, stack_start,
428 regs, stack_size,
429 (int __user *) parent_tid_ptr,
430 (int __user *) child_tid_ptr);
431
432 /* If we get an error and potentially restart the system
433 * call, we're screwed because copy_thread() clobbered
434 * the parent's %o1. So detect that case and restore it
435 * here.
436 */
437 if ((unsigned long)ret >= -ERESTART_RESTARTBLOCK)
438 regs->u_regs[UREG_I1] = orig_i1;
439
440 return ret;
441 }
442
443 /* Copy a Sparc thread. The fork() return value conventions
444 * under SunOS are nothing short of bletcherous:
445 * Parent --> %o0 == childs pid, %o1 == 0
446 * Child --> %o0 == parents pid, %o1 == 1
447 *
448 * NOTE: We have a separate fork kpsr/kwim because
449 * the parent could change these values between
450 * sys_fork invocation and when we reach here
451 * if the parent should sleep while trying to
452 * allocate the task_struct and kernel stack in
453 * do_fork().
454 * XXX See comment above sys_vfork in sparc64. todo.
455 */
456 extern void ret_from_fork(void);
457
458 int copy_thread(unsigned long clone_flags, unsigned long sp,
459 unsigned long unused,
460 struct task_struct *p, struct pt_regs *regs)
461 {
462 struct thread_info *ti = task_thread_info(p);
463 struct pt_regs *childregs;
464 char *new_stack;
465
466 #ifndef CONFIG_SMP
467 if(last_task_used_math == current) {
468 #else
469 if (test_thread_flag(TIF_USEDFPU)) {
470 #endif
471 put_psr(get_psr() | PSR_EF);
472 fpsave(&p->thread.float_regs[0], &p->thread.fsr,
473 &p->thread.fpqueue[0], &p->thread.fpqdepth);
474 #ifdef CONFIG_SMP
475 clear_thread_flag(TIF_USEDFPU);
476 #endif
477 }
478
479 /*
480 * p->thread_info new_stack childregs
481 * ! ! ! {if(PSR_PS) }
482 * V V (stk.fr.) V (pt_regs) { (stk.fr.) }
483 * +----- - - - - - ------+===========+============={+==========}+
484 */
485 new_stack = task_stack_page(p) + THREAD_SIZE;
486 if (regs->psr & PSR_PS)
487 new_stack -= STACKFRAME_SZ;
488 new_stack -= STACKFRAME_SZ + TRACEREG_SZ;
489 memcpy(new_stack, (char *)regs - STACKFRAME_SZ, STACKFRAME_SZ + TRACEREG_SZ);
490 childregs = (struct pt_regs *) (new_stack + STACKFRAME_SZ);
491
492 /*
493 * A new process must start with interrupts closed in 2.5,
494 * because this is how Mingo's scheduler works (see schedule_tail
495 * and finish_arch_switch). If we do not do it, a timer interrupt hits
496 * before we unlock, attempts to re-take the rq->lock, and then we die.
497 * Thus, kpsr|=PSR_PIL.
498 */
499 ti->ksp = (unsigned long) new_stack;
500 ti->kpc = (((unsigned long) ret_from_fork) - 0x8);
501 ti->kpsr = current->thread.fork_kpsr | PSR_PIL;
502 ti->kwim = current->thread.fork_kwim;
503
504 if(regs->psr & PSR_PS) {
505 extern struct pt_regs fake_swapper_regs;
506
507 p->thread.kregs = &fake_swapper_regs;
508 new_stack += STACKFRAME_SZ + TRACEREG_SZ;
509 childregs->u_regs[UREG_FP] = (unsigned long) new_stack;
510 p->thread.flags |= SPARC_FLAG_KTHREAD;
511 p->thread.current_ds = KERNEL_DS;
512 memcpy(new_stack, (void *)regs->u_regs[UREG_FP], STACKFRAME_SZ);
513 childregs->u_regs[UREG_G6] = (unsigned long) ti;
514 } else {
515 p->thread.kregs = childregs;
516 childregs->u_regs[UREG_FP] = sp;
517 p->thread.flags &= ~SPARC_FLAG_KTHREAD;
518 p->thread.current_ds = USER_DS;
519
520 if (sp != regs->u_regs[UREG_FP]) {
521 struct sparc_stackf __user *childstack;
522 struct sparc_stackf __user *parentstack;
523
524 /*
525 * This is a clone() call with supplied user stack.
526 * Set some valid stack frames to give to the child.
527 */
528 childstack = (struct sparc_stackf __user *)
529 (sp & ~0x7UL);
530 parentstack = (struct sparc_stackf __user *)
531 regs->u_regs[UREG_FP];
532
533 #if 0
534 printk("clone: parent stack:\n");
535 show_stackframe(parentstack);
536 #endif
537
538 childstack = clone_stackframe(childstack, parentstack);
539 if (!childstack)
540 return -EFAULT;
541
542 #if 0
543 printk("clone: child stack:\n");
544 show_stackframe(childstack);
545 #endif
546
547 childregs->u_regs[UREG_FP] = (unsigned long)childstack;
548 }
549 }
550
551 #ifdef CONFIG_SMP
552 /* FPU must be disabled on SMP. */
553 childregs->psr &= ~PSR_EF;
554 #endif
555
556 /* Set the return value for the child. */
557 childregs->u_regs[UREG_I0] = current->pid;
558 childregs->u_regs[UREG_I1] = 1;
559
560 /* Set the return value for the parent. */
561 regs->u_regs[UREG_I1] = 0;
562
563 if (clone_flags & CLONE_SETTLS)
564 childregs->u_regs[UREG_G7] = regs->u_regs[UREG_I3];
565
566 return 0;
567 }
568
569 /*
570 * fill in the fpu structure for a core dump.
571 */
572 int dump_fpu (struct pt_regs * regs, elf_fpregset_t * fpregs)
573 {
574 if (used_math()) {
575 memset(fpregs, 0, sizeof(*fpregs));
576 fpregs->pr_q_entrysize = 8;
577 return 1;
578 }
579 #ifdef CONFIG_SMP
580 if (test_thread_flag(TIF_USEDFPU)) {
581 put_psr(get_psr() | PSR_EF);
582 fpsave(&current->thread.float_regs[0], &current->thread.fsr,
583 &current->thread.fpqueue[0], &current->thread.fpqdepth);
584 if (regs != NULL) {
585 regs->psr &= ~(PSR_EF);
586 clear_thread_flag(TIF_USEDFPU);
587 }
588 }
589 #else
590 if (current == last_task_used_math) {
591 put_psr(get_psr() | PSR_EF);
592 fpsave(&current->thread.float_regs[0], &current->thread.fsr,
593 &current->thread.fpqueue[0], &current->thread.fpqdepth);
594 if (regs != NULL) {
595 regs->psr &= ~(PSR_EF);
596 last_task_used_math = NULL;
597 }
598 }
599 #endif
600 memcpy(&fpregs->pr_fr.pr_regs[0],
601 &current->thread.float_regs[0],
602 (sizeof(unsigned long) * 32));
603 fpregs->pr_fsr = current->thread.fsr;
604 fpregs->pr_qcnt = current->thread.fpqdepth;
605 fpregs->pr_q_entrysize = 8;
606 fpregs->pr_en = 1;
607 if(fpregs->pr_qcnt != 0) {
608 memcpy(&fpregs->pr_q[0],
609 &current->thread.fpqueue[0],
610 sizeof(struct fpq) * fpregs->pr_qcnt);
611 }
612 /* Zero out the rest. */
613 memset(&fpregs->pr_q[fpregs->pr_qcnt], 0,
614 sizeof(struct fpq) * (32 - fpregs->pr_qcnt));
615 return 1;
616 }
617
618 /*
619 * sparc_execve() executes a new program after the asm stub has set
620 * things up for us. This should basically do what I want it to.
621 */
622 asmlinkage int sparc_execve(struct pt_regs *regs)
623 {
624 int error, base = 0;
625 char *filename;
626
627 /* Check for indirect call. */
628 if(regs->u_regs[UREG_G1] == 0)
629 base = 1;
630
631 filename = getname((char __user *)regs->u_regs[base + UREG_I0]);
632 error = PTR_ERR(filename);
633 if(IS_ERR(filename))
634 goto out;
635 error = do_execve(filename,
636 (char __user * __user *)regs->u_regs[base + UREG_I1],
637 (char __user * __user *)regs->u_regs[base + UREG_I2],
638 regs);
639 putname(filename);
640 out:
641 return error;
642 }
643
644 /*
645 * This is the mechanism for creating a new kernel thread.
646 *
647 * NOTE! Only a kernel-only process(ie the swapper or direct descendants
648 * who haven't done an "execve()") should use this: it will work within
649 * a system call from a "real" process, but the process memory space will
650 * not be freed until both the parent and the child have exited.
651 */
652 pid_t kernel_thread(int (*fn)(void *), void * arg, unsigned long flags)
653 {
654 long retval;
655
656 __asm__ __volatile__("mov %4, %%g2\n\t" /* Set aside fn ptr... */
657 "mov %5, %%g3\n\t" /* and arg. */
658 "mov %1, %%g1\n\t"
659 "mov %2, %%o0\n\t" /* Clone flags. */
660 "mov 0, %%o1\n\t" /* usp arg == 0 */
661 "t 0x10\n\t" /* Linux/Sparc clone(). */
662 "cmp %%o1, 0\n\t"
663 "be 1f\n\t" /* The parent, just return. */
664 " nop\n\t" /* Delay slot. */
665 "jmpl %%g2, %%o7\n\t" /* Call the function. */
666 " mov %%g3, %%o0\n\t" /* Get back the arg in delay. */
667 "mov %3, %%g1\n\t"
668 "t 0x10\n\t" /* Linux/Sparc exit(). */
669 /* Notreached by child. */
670 "1: mov %%o0, %0\n\t" :
671 "=r" (retval) :
672 "i" (__NR_clone), "r" (flags | CLONE_VM | CLONE_UNTRACED),
673 "i" (__NR_exit), "r" (fn), "r" (arg) :
674 "g1", "g2", "g3", "o0", "o1", "memory", "cc");
675 return retval;
676 }
677 EXPORT_SYMBOL(kernel_thread);
678
679 unsigned long get_wchan(struct task_struct *task)
680 {
681 unsigned long pc, fp, bias = 0;
682 unsigned long task_base = (unsigned long) task;
683 unsigned long ret = 0;
684 struct reg_window32 *rw;
685 int count = 0;
686
687 if (!task || task == current ||
688 task->state == TASK_RUNNING)
689 goto out;
690
691 fp = task_thread_info(task)->ksp + bias;
692 do {
693 /* Bogus frame pointer? */
694 if (fp < (task_base + sizeof(struct thread_info)) ||
695 fp >= (task_base + (2 * PAGE_SIZE)))
696 break;
697 rw = (struct reg_window32 *) fp;
698 pc = rw->ins[7];
699 if (!in_sched_functions(pc)) {
700 ret = pc;
701 goto out;
702 }
703 fp = rw->ins[6] + bias;
704 } while (++count < 16);
705
706 out:
707 return ret;
708 }
709
Linux with added FPC-III support