4a0e7d79cb926ee2a302ce78a2cfca247afbc0f4
[linux-3.10.git] / arch / sparc / kernel / process_64.c
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/elfcore.h>
31 #include <linux/sysrq.h>
32 #include <linux/nmi.h>
33
34 #include <asm/uaccess.h>
35 #include <asm/system.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
52 #include "kstack.h"
53
54 static void sparc64_yield(int cpu)
55 {
56         if (tlb_type != hypervisor) {
57                 touch_nmi_watchdog();
58                 return;
59         }
60
61         clear_thread_flag(TIF_POLLING_NRFLAG);
62         smp_mb__after_clear_bit();
63
64         while (!need_resched() && !cpu_is_offline(cpu)) {
65                 unsigned long pstate;
66
67                 /* Disable interrupts. */
68                 __asm__ __volatile__(
69                         "rdpr %%pstate, %0\n\t"
70                         "andn %0, %1, %0\n\t"
71                         "wrpr %0, %%g0, %%pstate"
72                         : "=&r" (pstate)
73                         : "i" (PSTATE_IE));
74
75                 if (!need_resched() && !cpu_is_offline(cpu))
76                         sun4v_cpu_yield();
77
78                 /* Re-enable interrupts. */
79                 __asm__ __volatile__(
80                         "rdpr %%pstate, %0\n\t"
81                         "or %0, %1, %0\n\t"
82                         "wrpr %0, %%g0, %%pstate"
83                         : "=&r" (pstate)
84                         : "i" (PSTATE_IE));
85         }
86
87         set_thread_flag(TIF_POLLING_NRFLAG);
88 }
89
90 /* The idle loop on sparc64. */
91 void cpu_idle(void)
92 {
93         int cpu = smp_processor_id();
94
95         set_thread_flag(TIF_POLLING_NRFLAG);
96
97         while(1) {
98                 tick_nohz_idle_enter_norcu();
99
100                 while (!need_resched() && !cpu_is_offline(cpu))
101                         sparc64_yield(cpu);
102
103                 tick_nohz_idle_exit_norcu();
104
105                 preempt_enable_no_resched();
106
107 #ifdef CONFIG_HOTPLUG_CPU
108                 if (cpu_is_offline(cpu))
109                         cpu_play_dead();
110 #endif
111
112                 schedule();
113                 preempt_disable();
114         }
115 }
116
117 #ifdef CONFIG_COMPAT
118 static void show_regwindow32(struct pt_regs *regs)
119 {
120         struct reg_window32 __user *rw;
121         struct reg_window32 r_w;
122         mm_segment_t old_fs;
123         
124         __asm__ __volatile__ ("flushw");
125         rw = compat_ptr((unsigned)regs->u_regs[14]);
126         old_fs = get_fs();
127         set_fs (USER_DS);
128         if (copy_from_user (&r_w, rw, sizeof(r_w))) {
129                 set_fs (old_fs);
130                 return;
131         }
132
133         set_fs (old_fs);                        
134         printk("l0: %08x l1: %08x l2: %08x l3: %08x "
135                "l4: %08x l5: %08x l6: %08x l7: %08x\n",
136                r_w.locals[0], r_w.locals[1], r_w.locals[2], r_w.locals[3],
137                r_w.locals[4], r_w.locals[5], r_w.locals[6], r_w.locals[7]);
138         printk("i0: %08x i1: %08x i2: %08x i3: %08x "
139                "i4: %08x i5: %08x i6: %08x i7: %08x\n",
140                r_w.ins[0], r_w.ins[1], r_w.ins[2], r_w.ins[3],
141                r_w.ins[4], r_w.ins[5], r_w.ins[6], r_w.ins[7]);
142 }
143 #else
144 #define show_regwindow32(regs)  do { } while (0)
145 #endif
146
147 static void show_regwindow(struct pt_regs *regs)
148 {
149         struct reg_window __user *rw;
150         struct reg_window *rwk;
151         struct reg_window r_w;
152         mm_segment_t old_fs;
153
154         if ((regs->tstate & TSTATE_PRIV) || !(test_thread_flag(TIF_32BIT))) {
155                 __asm__ __volatile__ ("flushw");
156                 rw = (struct reg_window __user *)
157                         (regs->u_regs[14] + STACK_BIAS);
158                 rwk = (struct reg_window *)
159                         (regs->u_regs[14] + STACK_BIAS);
160                 if (!(regs->tstate & TSTATE_PRIV)) {
161                         old_fs = get_fs();
162                         set_fs (USER_DS);
163                         if (copy_from_user (&r_w, rw, sizeof(r_w))) {
164                                 set_fs (old_fs);
165                                 return;
166                         }
167                         rwk = &r_w;
168                         set_fs (old_fs);                        
169                 }
170         } else {
171                 show_regwindow32(regs);
172                 return;
173         }
174         printk("l0: %016lx l1: %016lx l2: %016lx l3: %016lx\n",
175                rwk->locals[0], rwk->locals[1], rwk->locals[2], rwk->locals[3]);
176         printk("l4: %016lx l5: %016lx l6: %016lx l7: %016lx\n",
177                rwk->locals[4], rwk->locals[5], rwk->locals[6], rwk->locals[7]);
178         printk("i0: %016lx i1: %016lx i2: %016lx i3: %016lx\n",
179                rwk->ins[0], rwk->ins[1], rwk->ins[2], rwk->ins[3]);
180         printk("i4: %016lx i5: %016lx i6: %016lx i7: %016lx\n",
181                rwk->ins[4], rwk->ins[5], rwk->ins[6], rwk->ins[7]);
182         if (regs->tstate & TSTATE_PRIV)
183                 printk("I7: <%pS>\n", (void *) rwk->ins[7]);
184 }
185
186 void show_regs(struct pt_regs *regs)
187 {
188         printk("TSTATE: %016lx TPC: %016lx TNPC: %016lx Y: %08x    %s\n", regs->tstate,
189                regs->tpc, regs->tnpc, regs->y, print_tainted());
190         printk("TPC: <%pS>\n", (void *) regs->tpc);
191         printk("g0: %016lx g1: %016lx g2: %016lx g3: %016lx\n",
192                regs->u_regs[0], regs->u_regs[1], regs->u_regs[2],
193                regs->u_regs[3]);
194         printk("g4: %016lx g5: %016lx g6: %016lx g7: %016lx\n",
195                regs->u_regs[4], regs->u_regs[5], regs->u_regs[6],
196                regs->u_regs[7]);
197         printk("o0: %016lx o1: %016lx o2: %016lx o3: %016lx\n",
198                regs->u_regs[8], regs->u_regs[9], regs->u_regs[10],
199                regs->u_regs[11]);
200         printk("o4: %016lx o5: %016lx sp: %016lx ret_pc: %016lx\n",
201                regs->u_regs[12], regs->u_regs[13], regs->u_regs[14],
202                regs->u_regs[15]);
203         printk("RPC: <%pS>\n", (void *) regs->u_regs[15]);
204         show_regwindow(regs);
205         show_stack(current, (unsigned long *) regs->u_regs[UREG_FP]);
206 }
207
208 struct global_reg_snapshot global_reg_snapshot[NR_CPUS];
209 static DEFINE_SPINLOCK(global_reg_snapshot_lock);
210
211 static void __global_reg_self(struct thread_info *tp, struct pt_regs *regs,
212                               int this_cpu)
213 {
214         flushw_all();
215
216         global_reg_snapshot[this_cpu].tstate = regs->tstate;
217         global_reg_snapshot[this_cpu].tpc = regs->tpc;
218         global_reg_snapshot[this_cpu].tnpc = regs->tnpc;
219         global_reg_snapshot[this_cpu].o7 = regs->u_regs[UREG_I7];
220
221         if (regs->tstate & TSTATE_PRIV) {
222                 struct reg_window *rw;
223
224                 rw = (struct reg_window *)
225                         (regs->u_regs[UREG_FP] + STACK_BIAS);
226                 if (kstack_valid(tp, (unsigned long) rw)) {
227                         global_reg_snapshot[this_cpu].i7 = rw->ins[7];
228                         rw = (struct reg_window *)
229                                 (rw->ins[6] + STACK_BIAS);
230                         if (kstack_valid(tp, (unsigned long) rw))
231                                 global_reg_snapshot[this_cpu].rpc = rw->ins[7];
232                 }
233         } else {
234                 global_reg_snapshot[this_cpu].i7 = 0;
235                 global_reg_snapshot[this_cpu].rpc = 0;
236         }
237         global_reg_snapshot[this_cpu].thread = tp;
238 }
239
240 /* In order to avoid hangs we do not try to synchronize with the
241  * global register dump client cpus.  The last store they make is to
242  * the thread pointer, so do a short poll waiting for that to become
243  * non-NULL.
244  */
245 static void __global_reg_poll(struct global_reg_snapshot *gp)
246 {
247         int limit = 0;
248
249         while (!gp->thread && ++limit < 100) {
250                 barrier();
251                 udelay(1);
252         }
253 }
254
255 void arch_trigger_all_cpu_backtrace(void)
256 {
257         struct thread_info *tp = current_thread_info();
258         struct pt_regs *regs = get_irq_regs();
259         unsigned long flags;
260         int this_cpu, cpu;
261
262         if (!regs)
263                 regs = tp->kregs;
264
265         spin_lock_irqsave(&global_reg_snapshot_lock, flags);
266
267         memset(global_reg_snapshot, 0, sizeof(global_reg_snapshot));
268
269         this_cpu = raw_smp_processor_id();
270
271         __global_reg_self(tp, regs, this_cpu);
272
273         smp_fetch_global_regs();
274
275         for_each_online_cpu(cpu) {
276                 struct global_reg_snapshot *gp = &global_reg_snapshot[cpu];
277
278                 __global_reg_poll(gp);
279
280                 tp = gp->thread;
281                 printk("%c CPU[%3d]: TSTATE[%016lx] TPC[%016lx] TNPC[%016lx] TASK[%s:%d]\n",
282                        (cpu == this_cpu ? '*' : ' '), cpu,
283                        gp->tstate, gp->tpc, gp->tnpc,
284                        ((tp && tp->task) ? tp->task->comm : "NULL"),
285                        ((tp && tp->task) ? tp->task->pid : -1));
286
287                 if (gp->tstate & TSTATE_PRIV) {
288                         printk("             TPC[%pS] O7[%pS] I7[%pS] RPC[%pS]\n",
289                                (void *) gp->tpc,
290                                (void *) gp->o7,
291                                (void *) gp->i7,
292                                (void *) gp->rpc);
293                 } else {
294                         printk("             TPC[%lx] O7[%lx] I7[%lx] RPC[%lx]\n",
295                                gp->tpc, gp->o7, gp->i7, gp->rpc);
296                 }
297         }
298
299         memset(global_reg_snapshot, 0, sizeof(global_reg_snapshot));
300
301         spin_unlock_irqrestore(&global_reg_snapshot_lock, flags);
302 }
303
304 #ifdef CONFIG_MAGIC_SYSRQ
305
306 static void sysrq_handle_globreg(int key)
307 {
308         arch_trigger_all_cpu_backtrace();
309 }
310
311 static struct sysrq_key_op sparc_globalreg_op = {
312         .handler        = sysrq_handle_globreg,
313         .help_msg       = "Globalregs",
314         .action_msg     = "Show Global CPU Regs",
315 };
316
317 static int __init sparc_globreg_init(void)
318 {
319         return register_sysrq_key('y', &sparc_globalreg_op);
320 }
321
322 core_initcall(sparc_globreg_init);
323
324 #endif
325
326 unsigned long thread_saved_pc(struct task_struct *tsk)
327 {
328         struct thread_info *ti = task_thread_info(tsk);
329         unsigned long ret = 0xdeadbeefUL;
330         
331         if (ti && ti->ksp) {
332                 unsigned long *sp;
333                 sp = (unsigned long *)(ti->ksp + STACK_BIAS);
334                 if (((unsigned long)sp & (sizeof(long) - 1)) == 0UL &&
335                     sp[14]) {
336                         unsigned long *fp;
337                         fp = (unsigned long *)(sp[14] + STACK_BIAS);
338                         if (((unsigned long)fp & (sizeof(long) - 1)) == 0UL)
339                                 ret = fp[15];
340                 }
341         }
342         return ret;
343 }
344
345 /* Free current thread data structures etc.. */
346 void exit_thread(void)
347 {
348         struct thread_info *t = current_thread_info();
349
350         if (t->utraps) {
351                 if (t->utraps[0] < 2)
352                         kfree (t->utraps);
353                 else
354                         t->utraps[0]--;
355         }
356 }
357
358 void flush_thread(void)
359 {
360         struct thread_info *t = current_thread_info();
361         struct mm_struct *mm;
362
363         mm = t->task->mm;
364         if (mm)
365                 tsb_context_switch(mm);
366
367         set_thread_wsaved(0);
368
369         /* Clear FPU register state. */
370         t->fpsaved[0] = 0;
371 }
372
373 /* It's a bit more tricky when 64-bit tasks are involved... */
374 static unsigned long clone_stackframe(unsigned long csp, unsigned long psp)
375 {
376         unsigned long fp, distance, rval;
377
378         if (!(test_thread_flag(TIF_32BIT))) {
379                 csp += STACK_BIAS;
380                 psp += STACK_BIAS;
381                 __get_user(fp, &(((struct reg_window __user *)psp)->ins[6]));
382                 fp += STACK_BIAS;
383         } else
384                 __get_user(fp, &(((struct reg_window32 __user *)psp)->ins[6]));
385
386         /* Now align the stack as this is mandatory in the Sparc ABI
387          * due to how register windows work.  This hides the
388          * restriction from thread libraries etc.
389          */
390         csp &= ~15UL;
391
392         distance = fp - psp;
393         rval = (csp - distance);
394         if (copy_in_user((void __user *) rval, (void __user *) psp, distance))
395                 rval = 0;
396         else if (test_thread_flag(TIF_32BIT)) {
397                 if (put_user(((u32)csp),
398                              &(((struct reg_window32 __user *)rval)->ins[6])))
399                         rval = 0;
400         } else {
401                 if (put_user(((u64)csp - STACK_BIAS),
402                              &(((struct reg_window __user *)rval)->ins[6])))
403                         rval = 0;
404                 else
405                         rval = rval - STACK_BIAS;
406         }
407
408         return rval;
409 }
410
411 /* Standard stuff. */
412 static inline void shift_window_buffer(int first_win, int last_win,
413                                        struct thread_info *t)
414 {
415         int i;
416
417         for (i = first_win; i < last_win; i++) {
418                 t->rwbuf_stkptrs[i] = t->rwbuf_stkptrs[i+1];
419                 memcpy(&t->reg_window[i], &t->reg_window[i+1],
420                        sizeof(struct reg_window));
421         }
422 }
423
424 void synchronize_user_stack(void)
425 {
426         struct thread_info *t = current_thread_info();
427         unsigned long window;
428
429         flush_user_windows();
430         if ((window = get_thread_wsaved()) != 0) {
431                 int winsize = sizeof(struct reg_window);
432                 int bias = 0;
433
434                 if (test_thread_flag(TIF_32BIT))
435                         winsize = sizeof(struct reg_window32);
436                 else
437                         bias = STACK_BIAS;
438
439                 window -= 1;
440                 do {
441                         unsigned long sp = (t->rwbuf_stkptrs[window] + bias);
442                         struct reg_window *rwin = &t->reg_window[window];
443
444                         if (!copy_to_user((char __user *)sp, rwin, winsize)) {
445                                 shift_window_buffer(window, get_thread_wsaved() - 1, t);
446                                 set_thread_wsaved(get_thread_wsaved() - 1);
447                         }
448                 } while (window--);
449         }
450 }
451
452 static void stack_unaligned(unsigned long sp)
453 {
454         siginfo_t info;
455
456         info.si_signo = SIGBUS;
457         info.si_errno = 0;
458         info.si_code = BUS_ADRALN;
459         info.si_addr = (void __user *) sp;
460         info.si_trapno = 0;
461         force_sig_info(SIGBUS, &info, current);
462 }
463
464 void fault_in_user_windows(void)
465 {
466         struct thread_info *t = current_thread_info();
467         unsigned long window;
468         int winsize = sizeof(struct reg_window);
469         int bias = 0;
470
471         if (test_thread_flag(TIF_32BIT))
472                 winsize = sizeof(struct reg_window32);
473         else
474                 bias = STACK_BIAS;
475
476         flush_user_windows();
477         window = get_thread_wsaved();
478
479         if (likely(window != 0)) {
480                 window -= 1;
481                 do {
482                         unsigned long sp = (t->rwbuf_stkptrs[window] + bias);
483                         struct reg_window *rwin = &t->reg_window[window];
484
485                         if (unlikely(sp & 0x7UL))
486                                 stack_unaligned(sp);
487
488                         if (unlikely(copy_to_user((char __user *)sp,
489                                                   rwin, winsize)))
490                                 goto barf;
491                 } while (window--);
492         }
493         set_thread_wsaved(0);
494         return;
495
496 barf:
497         set_thread_wsaved(window + 1);
498         do_exit(SIGILL);
499 }
500
501 asmlinkage long sparc_do_fork(unsigned long clone_flags,
502                               unsigned long stack_start,
503                               struct pt_regs *regs,
504                               unsigned long stack_size)
505 {
506         int __user *parent_tid_ptr, *child_tid_ptr;
507         unsigned long orig_i1 = regs->u_regs[UREG_I1];
508         long ret;
509
510 #ifdef CONFIG_COMPAT
511         if (test_thread_flag(TIF_32BIT)) {
512                 parent_tid_ptr = compat_ptr(regs->u_regs[UREG_I2]);
513                 child_tid_ptr = compat_ptr(regs->u_regs[UREG_I4]);
514         } else
515 #endif
516         {
517                 parent_tid_ptr = (int __user *) regs->u_regs[UREG_I2];
518                 child_tid_ptr = (int __user *) regs->u_regs[UREG_I4];
519         }
520
521         ret = do_fork(clone_flags, stack_start,
522                       regs, stack_size,
523                       parent_tid_ptr, child_tid_ptr);
524
525         /* If we get an error and potentially restart the system
526          * call, we're screwed because copy_thread() clobbered
527          * the parent's %o1.  So detect that case and restore it
528          * here.
529          */
530         if ((unsigned long)ret >= -ERESTART_RESTARTBLOCK)
531                 regs->u_regs[UREG_I1] = orig_i1;
532
533         return ret;
534 }
535
536 /* Copy a Sparc thread.  The fork() return value conventions
537  * under SunOS are nothing short of bletcherous:
538  * Parent -->  %o0 == childs  pid, %o1 == 0
539  * Child  -->  %o0 == parents pid, %o1 == 1
540  */
541 int copy_thread(unsigned long clone_flags, unsigned long sp,
542                 unsigned long unused,
543                 struct task_struct *p, struct pt_regs *regs)
544 {
545         struct thread_info *t = task_thread_info(p);
546         struct sparc_stackf *parent_sf;
547         unsigned long child_stack_sz;
548         char *child_trap_frame;
549         int kernel_thread;
550
551         kernel_thread = (regs->tstate & TSTATE_PRIV) ? 1 : 0;
552         parent_sf = ((struct sparc_stackf *) regs) - 1;
553
554         /* Calculate offset to stack_frame & pt_regs */
555         child_stack_sz = ((STACKFRAME_SZ + TRACEREG_SZ) +
556                           (kernel_thread ? STACKFRAME_SZ : 0));
557         child_trap_frame = (task_stack_page(p) +
558                             (THREAD_SIZE - child_stack_sz));
559         memcpy(child_trap_frame, parent_sf, child_stack_sz);
560
561         t->flags = (t->flags & ~((0xffUL << TI_FLAG_CWP_SHIFT) |
562                                  (0xffUL << TI_FLAG_CURRENT_DS_SHIFT))) |
563                 (((regs->tstate + 1) & TSTATE_CWP) << TI_FLAG_CWP_SHIFT);
564         t->new_child = 1;
565         t->ksp = ((unsigned long) child_trap_frame) - STACK_BIAS;
566         t->kregs = (struct pt_regs *) (child_trap_frame +
567                                        sizeof(struct sparc_stackf));
568         t->fpsaved[0] = 0;
569
570         if (kernel_thread) {
571                 struct sparc_stackf *child_sf = (struct sparc_stackf *)
572                         (child_trap_frame + (STACKFRAME_SZ + TRACEREG_SZ));
573
574                 /* Zero terminate the stack backtrace.  */
575                 child_sf->fp = NULL;
576                 t->kregs->u_regs[UREG_FP] =
577                   ((unsigned long) child_sf) - STACK_BIAS;
578
579                 t->flags |= ((long)ASI_P << TI_FLAG_CURRENT_DS_SHIFT);
580                 t->kregs->u_regs[UREG_G6] = (unsigned long) t;
581                 t->kregs->u_regs[UREG_G4] = (unsigned long) t->task;
582         } else {
583                 if (t->flags & _TIF_32BIT) {
584                         sp &= 0x00000000ffffffffUL;
585                         regs->u_regs[UREG_FP] &= 0x00000000ffffffffUL;
586                 }
587                 t->kregs->u_regs[UREG_FP] = sp;
588                 t->flags |= ((long)ASI_AIUS << TI_FLAG_CURRENT_DS_SHIFT);
589                 if (sp != regs->u_regs[UREG_FP]) {
590                         unsigned long csp;
591
592                         csp = clone_stackframe(sp, regs->u_regs[UREG_FP]);
593                         if (!csp)
594                                 return -EFAULT;
595                         t->kregs->u_regs[UREG_FP] = csp;
596                 }
597                 if (t->utraps)
598                         t->utraps[0]++;
599         }
600
601         /* Set the return value for the child. */
602         t->kregs->u_regs[UREG_I0] = current->pid;
603         t->kregs->u_regs[UREG_I1] = 1;
604
605         /* Set the second return value for the parent. */
606         regs->u_regs[UREG_I1] = 0;
607
608         if (clone_flags & CLONE_SETTLS)
609                 t->kregs->u_regs[UREG_G7] = regs->u_regs[UREG_I3];
610
611         return 0;
612 }
613
614 /*
615  * This is the mechanism for creating a new kernel thread.
616  *
617  * NOTE! Only a kernel-only process(ie the swapper or direct descendants
618  * who haven't done an "execve()") should use this: it will work within
619  * a system call from a "real" process, but the process memory space will
620  * not be freed until both the parent and the child have exited.
621  */
622 pid_t kernel_thread(int (*fn)(void *), void * arg, unsigned long flags)
623 {
624         long retval;
625
626         /* If the parent runs before fn(arg) is called by the child,
627          * the input registers of this function can be clobbered.
628          * So we stash 'fn' and 'arg' into global registers which
629          * will not be modified by the parent.
630          */
631         __asm__ __volatile__("mov %4, %%g2\n\t"    /* Save FN into global */
632                              "mov %5, %%g3\n\t"    /* Save ARG into global */
633                              "mov %1, %%g1\n\t"    /* Clone syscall nr. */
634                              "mov %2, %%o0\n\t"    /* Clone flags. */
635                              "mov 0, %%o1\n\t"     /* usp arg == 0 */
636                              "t 0x6d\n\t"          /* Linux/Sparc clone(). */
637                              "brz,a,pn %%o1, 1f\n\t" /* Parent, just return. */
638                              " mov %%o0, %0\n\t"
639                              "jmpl %%g2, %%o7\n\t"   /* Call the function. */
640                              " mov %%g3, %%o0\n\t"   /* Set arg in delay. */
641                              "mov %3, %%g1\n\t"
642                              "t 0x6d\n\t"          /* Linux/Sparc exit(). */
643                              /* Notreached by child. */
644                              "1:" :
645                              "=r" (retval) :
646                              "i" (__NR_clone), "r" (flags | CLONE_VM | CLONE_UNTRACED),
647                              "i" (__NR_exit),  "r" (fn), "r" (arg) :
648                              "g1", "g2", "g3", "o0", "o1", "memory", "cc");
649         return retval;
650 }
651 EXPORT_SYMBOL(kernel_thread);
652
653 typedef struct {
654         union {
655                 unsigned int    pr_regs[32];
656                 unsigned long   pr_dregs[16];
657         } pr_fr;
658         unsigned int __unused;
659         unsigned int    pr_fsr;
660         unsigned char   pr_qcnt;
661         unsigned char   pr_q_entrysize;
662         unsigned char   pr_en;
663         unsigned int    pr_q[64];
664 } elf_fpregset_t32;
665
666 /*
667  * fill in the fpu structure for a core dump.
668  */
669 int dump_fpu (struct pt_regs * regs, elf_fpregset_t * fpregs)
670 {
671         unsigned long *kfpregs = current_thread_info()->fpregs;
672         unsigned long fprs = current_thread_info()->fpsaved[0];
673
674         if (test_thread_flag(TIF_32BIT)) {
675                 elf_fpregset_t32 *fpregs32 = (elf_fpregset_t32 *)fpregs;
676
677                 if (fprs & FPRS_DL)
678                         memcpy(&fpregs32->pr_fr.pr_regs[0], kfpregs,
679                                sizeof(unsigned int) * 32);
680                 else
681                         memset(&fpregs32->pr_fr.pr_regs[0], 0,
682                                sizeof(unsigned int) * 32);
683                 fpregs32->pr_qcnt = 0;
684                 fpregs32->pr_q_entrysize = 8;
685                 memset(&fpregs32->pr_q[0], 0,
686                        (sizeof(unsigned int) * 64));
687                 if (fprs & FPRS_FEF) {
688                         fpregs32->pr_fsr = (unsigned int) current_thread_info()->xfsr[0];
689                         fpregs32->pr_en = 1;
690                 } else {
691                         fpregs32->pr_fsr = 0;
692                         fpregs32->pr_en = 0;
693                 }
694         } else {
695                 if(fprs & FPRS_DL)
696                         memcpy(&fpregs->pr_regs[0], kfpregs,
697                                sizeof(unsigned int) * 32);
698                 else
699                         memset(&fpregs->pr_regs[0], 0,
700                                sizeof(unsigned int) * 32);
701                 if(fprs & FPRS_DU)
702                         memcpy(&fpregs->pr_regs[16], kfpregs+16,
703                                sizeof(unsigned int) * 32);
704                 else
705                         memset(&fpregs->pr_regs[16], 0,
706                                sizeof(unsigned int) * 32);
707                 if(fprs & FPRS_FEF) {
708                         fpregs->pr_fsr = current_thread_info()->xfsr[0];
709                         fpregs->pr_gsr = current_thread_info()->gsr[0];
710                 } else {
711                         fpregs->pr_fsr = fpregs->pr_gsr = 0;
712                 }
713                 fpregs->pr_fprs = fprs;
714         }
715         return 1;
716 }
717 EXPORT_SYMBOL(dump_fpu);
718
719 /*
720  * sparc_execve() executes a new program after the asm stub has set
721  * things up for us.  This should basically do what I want it to.
722  */
723 asmlinkage int sparc_execve(struct pt_regs *regs)
724 {
725         int error, base = 0;
726         char *filename;
727
728         /* User register window flush is done by entry.S */
729
730         /* Check for indirect call. */
731         if (regs->u_regs[UREG_G1] == 0)
732                 base = 1;
733
734         filename = getname((char __user *)regs->u_regs[base + UREG_I0]);
735         error = PTR_ERR(filename);
736         if (IS_ERR(filename))
737                 goto out;
738         error = do_execve(filename,
739                           (const char __user *const __user *)
740                           regs->u_regs[base + UREG_I1],
741                           (const char __user *const __user *)
742                           regs->u_regs[base + UREG_I2], regs);
743         putname(filename);
744         if (!error) {
745                 fprs_write(0);
746                 current_thread_info()->xfsr[0] = 0;
747                 current_thread_info()->fpsaved[0] = 0;
748                 regs->tstate &= ~TSTATE_PEF;
749         }
750 out:
751         return error;
752 }
753
754 unsigned long get_wchan(struct task_struct *task)
755 {
756         unsigned long pc, fp, bias = 0;
757         struct thread_info *tp;
758         struct reg_window *rw;
759         unsigned long ret = 0;
760         int count = 0; 
761
762         if (!task || task == current ||
763             task->state == TASK_RUNNING)
764                 goto out;
765
766         tp = task_thread_info(task);
767         bias = STACK_BIAS;
768         fp = task_thread_info(task)->ksp + bias;
769
770         do {
771                 if (!kstack_valid(tp, fp))
772                         break;
773                 rw = (struct reg_window *) fp;
774                 pc = rw->ins[7];
775                 if (!in_sched_functions(pc)) {
776                         ret = pc;
777                         goto out;
778                 }
779                 fp = rw->ins[6] + bias;
780         } while (++count < 16);
781
782 out:
783         return ret;
784 }