66255434128a2e6ebf6b144d5d030003fe4ebaca
[linux-2.6.git] / arch / sparc64 / kernel / process.c
1 /*  $Id: process.c,v 1.131 2002/02/09 19:49:30 davem Exp $
2  *  arch/sparc64/kernel/process.c
3  *
4  *  Copyright (C) 1995, 1996 David S. Miller (davem@caip.rutgers.edu)
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/config.h>
16 #include <linux/errno.h>
17 #include <linux/module.h>
18 #include <linux/sched.h>
19 #include <linux/kernel.h>
20 #include <linux/kallsyms.h>
21 #include <linux/mm.h>
22 #include <linux/smp.h>
23 #include <linux/smp_lock.h>
24 #include <linux/stddef.h>
25 #include <linux/ptrace.h>
26 #include <linux/slab.h>
27 #include <linux/user.h>
28 #include <linux/a.out.h>
29 #include <linux/config.h>
30 #include <linux/reboot.h>
31 #include <linux/delay.h>
32 #include <linux/compat.h>
33 #include <linux/init.h>
34
35 #include <asm/oplib.h>
36 #include <asm/uaccess.h>
37 #include <asm/system.h>
38 #include <asm/page.h>
39 #include <asm/pgalloc.h>
40 #include <asm/pgtable.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/unistd.h>
48
49 /* #define VERBOSE_SHOWREGS */
50
51 /*
52  * Nothing special yet...
53  */
54 void default_idle(void)
55 {
56 }
57
58 #ifndef CONFIG_SMP
59
60 /*
61  * the idle loop on a Sparc... ;)
62  */
63 void cpu_idle(void)
64 {
65         /* endless idle loop with no priority at all */
66         for (;;) {
67                 /* If current->work.need_resched is zero we should really
68                  * setup for a system wakup event and execute a shutdown
69                  * instruction.
70                  *
71                  * But this requires writing back the contents of the
72                  * L2 cache etc. so implement this later. -DaveM
73                  */
74                 while (!need_resched())
75                         barrier();
76
77                 schedule();
78                 check_pgt_cache();
79         }
80 }
81
82 #else
83
84 /*
85  * the idle loop on a UltraMultiPenguin...
86  */
87 #define idle_me_harder()        (cpu_data(smp_processor_id()).idle_volume += 1)
88 #define unidle_me()             (cpu_data(smp_processor_id()).idle_volume = 0)
89 void cpu_idle(void)
90 {
91         set_thread_flag(TIF_POLLING_NRFLAG);
92         while(1) {
93                 if (need_resched()) {
94                         unidle_me();
95                         clear_thread_flag(TIF_POLLING_NRFLAG);
96                         schedule();
97                         set_thread_flag(TIF_POLLING_NRFLAG);
98                         check_pgt_cache();
99                 }
100                 idle_me_harder();
101
102                 /* The store ordering is so that IRQ handlers on
103                  * other cpus see our increasing idleness for the buddy
104                  * redistribution algorithm.  -DaveM
105                  */
106                 membar_storeload_storestore();
107         }
108 }
109
110 #endif
111
112 extern char reboot_command [];
113
114 extern void (*prom_palette)(int);
115 extern void (*prom_keyboard)(void);
116
117 void machine_halt(void)
118 {
119         if (!serial_console && prom_palette)
120                 prom_palette (1);
121         if (prom_keyboard)
122                 prom_keyboard();
123         prom_halt();
124         panic("Halt failed!");
125 }
126
127 void machine_alt_power_off(void)
128 {
129         if (!serial_console && prom_palette)
130                 prom_palette(1);
131         if (prom_keyboard)
132                 prom_keyboard();
133         prom_halt_power_off();
134         panic("Power-off failed!");
135 }
136
137 void machine_restart(char * cmd)
138 {
139         char *p;
140         
141         p = strchr (reboot_command, '\n');
142         if (p) *p = 0;
143         if (!serial_console && prom_palette)
144                 prom_palette (1);
145         if (prom_keyboard)
146                 prom_keyboard();
147         if (cmd)
148                 prom_reboot(cmd);
149         if (*reboot_command)
150                 prom_reboot(reboot_command);
151         prom_reboot("");
152         panic("Reboot failed!");
153 }
154
155 static void show_regwindow32(struct pt_regs *regs)
156 {
157         struct reg_window32 __user *rw;
158         struct reg_window32 r_w;
159         mm_segment_t old_fs;
160         
161         __asm__ __volatile__ ("flushw");
162         rw = compat_ptr((unsigned)regs->u_regs[14]);
163         old_fs = get_fs();
164         set_fs (USER_DS);
165         if (copy_from_user (&r_w, rw, sizeof(r_w))) {
166                 set_fs (old_fs);
167                 return;
168         }
169
170         set_fs (old_fs);                        
171         printk("l0: %08x l1: %08x l2: %08x l3: %08x "
172                "l4: %08x l5: %08x l6: %08x l7: %08x\n",
173                r_w.locals[0], r_w.locals[1], r_w.locals[2], r_w.locals[3],
174                r_w.locals[4], r_w.locals[5], r_w.locals[6], r_w.locals[7]);
175         printk("i0: %08x i1: %08x i2: %08x i3: %08x "
176                "i4: %08x i5: %08x i6: %08x i7: %08x\n",
177                r_w.ins[0], r_w.ins[1], r_w.ins[2], r_w.ins[3],
178                r_w.ins[4], r_w.ins[5], r_w.ins[6], r_w.ins[7]);
179 }
180
181 static void show_regwindow(struct pt_regs *regs)
182 {
183         struct reg_window __user *rw;
184         struct reg_window *rwk;
185         struct reg_window r_w;
186         mm_segment_t old_fs;
187
188         if ((regs->tstate & TSTATE_PRIV) || !(test_thread_flag(TIF_32BIT))) {
189                 __asm__ __volatile__ ("flushw");
190                 rw = (struct reg_window __user *)
191                         (regs->u_regs[14] + STACK_BIAS);
192                 rwk = (struct reg_window *)
193                         (regs->u_regs[14] + STACK_BIAS);
194                 if (!(regs->tstate & TSTATE_PRIV)) {
195                         old_fs = get_fs();
196                         set_fs (USER_DS);
197                         if (copy_from_user (&r_w, rw, sizeof(r_w))) {
198                                 set_fs (old_fs);
199                                 return;
200                         }
201                         rwk = &r_w;
202                         set_fs (old_fs);                        
203                 }
204         } else {
205                 show_regwindow32(regs);
206                 return;
207         }
208         printk("l0: %016lx l1: %016lx l2: %016lx l3: %016lx\n",
209                rwk->locals[0], rwk->locals[1], rwk->locals[2], rwk->locals[3]);
210         printk("l4: %016lx l5: %016lx l6: %016lx l7: %016lx\n",
211                rwk->locals[4], rwk->locals[5], rwk->locals[6], rwk->locals[7]);
212         printk("i0: %016lx i1: %016lx i2: %016lx i3: %016lx\n",
213                rwk->ins[0], rwk->ins[1], rwk->ins[2], rwk->ins[3]);
214         printk("i4: %016lx i5: %016lx i6: %016lx i7: %016lx\n",
215                rwk->ins[4], rwk->ins[5], rwk->ins[6], rwk->ins[7]);
216         if (regs->tstate & TSTATE_PRIV)
217                 print_symbol("I7: <%s>\n", rwk->ins[7]);
218 }
219
220 void show_stackframe(struct sparc_stackf *sf)
221 {
222         unsigned long size;
223         unsigned long *stk;
224         int i;
225
226         printk("l0: %016lx l1: %016lx l2: %016lx l3: %016lx\n"
227                "l4: %016lx l5: %016lx l6: %016lx l7: %016lx\n",
228                sf->locals[0], sf->locals[1], sf->locals[2], sf->locals[3],
229                sf->locals[4], sf->locals[5], sf->locals[6], sf->locals[7]);
230         printk("i0: %016lx i1: %016lx i2: %016lx i3: %016lx\n"
231                "i4: %016lx i5: %016lx fp: %016lx ret_pc: %016lx\n",
232                sf->ins[0], sf->ins[1], sf->ins[2], sf->ins[3],
233                sf->ins[4], sf->ins[5], (unsigned long)sf->fp, sf->callers_pc);
234         printk("sp: %016lx x0: %016lx x1: %016lx x2: %016lx\n"
235                "x3: %016lx x4: %016lx x5: %016lx xx: %016lx\n",
236                (unsigned long)sf->structptr, sf->xargs[0], sf->xargs[1],
237                sf->xargs[2], sf->xargs[3], sf->xargs[4], sf->xargs[5],
238                sf->xxargs[0]);
239         size = ((unsigned long)sf->fp) - ((unsigned long)sf);
240         size -= STACKFRAME_SZ;
241         stk = (unsigned long *)((unsigned long)sf + STACKFRAME_SZ);
242         i = 0;
243         do {
244                 printk("s%d: %016lx\n", i++, *stk++);
245         } while ((size -= sizeof(unsigned long)));
246 }
247
248 void show_stackframe32(struct sparc_stackf32 *sf)
249 {
250         unsigned long size;
251         unsigned *stk;
252         int i;
253
254         printk("l0: %08x l1: %08x l2: %08x l3: %08x\n",
255                sf->locals[0], sf->locals[1], sf->locals[2], sf->locals[3]);
256         printk("l4: %08x l5: %08x l6: %08x l7: %08x\n",
257                sf->locals[4], sf->locals[5], sf->locals[6], sf->locals[7]);
258         printk("i0: %08x i1: %08x i2: %08x i3: %08x\n",
259                sf->ins[0], sf->ins[1], sf->ins[2], sf->ins[3]);
260         printk("i4: %08x i5: %08x fp: %08x ret_pc: %08x\n",
261                sf->ins[4], sf->ins[5], sf->fp, sf->callers_pc);
262         printk("sp: %08x x0: %08x x1: %08x x2: %08x\n"
263                "x3: %08x x4: %08x x5: %08x xx: %08x\n",
264                sf->structptr, sf->xargs[0], sf->xargs[1],
265                sf->xargs[2], sf->xargs[3], sf->xargs[4], sf->xargs[5],
266                sf->xxargs[0]);
267         size = ((unsigned long)sf->fp) - ((unsigned long)sf);
268         size -= STACKFRAME32_SZ;
269         stk = (unsigned *)((unsigned long)sf + STACKFRAME32_SZ);
270         i = 0;
271         do {
272                 printk("s%d: %08x\n", i++, *stk++);
273         } while ((size -= sizeof(unsigned)));
274 }
275
276 #ifdef CONFIG_SMP
277 static DEFINE_SPINLOCK(regdump_lock);
278 #endif
279
280 void __show_regs(struct pt_regs * regs)
281 {
282 #ifdef CONFIG_SMP
283         unsigned long flags;
284
285         /* Protect against xcall ipis which might lead to livelock on the lock */
286         __asm__ __volatile__("rdpr      %%pstate, %0\n\t"
287                              "wrpr      %0, %1, %%pstate"
288                              : "=r" (flags)
289                              : "i" (PSTATE_IE));
290         spin_lock(&regdump_lock);
291 #endif
292         printk("TSTATE: %016lx TPC: %016lx TNPC: %016lx Y: %08x    %s\n", regs->tstate,
293                regs->tpc, regs->tnpc, regs->y, print_tainted());
294         print_symbol("TPC: <%s>\n", regs->tpc);
295         printk("g0: %016lx g1: %016lx g2: %016lx g3: %016lx\n",
296                regs->u_regs[0], regs->u_regs[1], regs->u_regs[2],
297                regs->u_regs[3]);
298         printk("g4: %016lx g5: %016lx g6: %016lx g7: %016lx\n",
299                regs->u_regs[4], regs->u_regs[5], regs->u_regs[6],
300                regs->u_regs[7]);
301         printk("o0: %016lx o1: %016lx o2: %016lx o3: %016lx\n",
302                regs->u_regs[8], regs->u_regs[9], regs->u_regs[10],
303                regs->u_regs[11]);
304         printk("o4: %016lx o5: %016lx sp: %016lx ret_pc: %016lx\n",
305                regs->u_regs[12], regs->u_regs[13], regs->u_regs[14],
306                regs->u_regs[15]);
307         print_symbol("RPC: <%s>\n", regs->u_regs[15]);
308         show_regwindow(regs);
309 #ifdef CONFIG_SMP
310         spin_unlock(&regdump_lock);
311         __asm__ __volatile__("wrpr      %0, 0, %%pstate"
312                              : : "r" (flags));
313 #endif
314 }
315
316 #ifdef VERBOSE_SHOWREGS
317 static void idump_from_user (unsigned int *pc)
318 {
319         int i;
320         int code;
321         
322         if((((unsigned long) pc) & 3))
323                 return;
324         
325         pc -= 3;
326         for(i = -3; i < 6; i++) {
327                 get_user(code, pc);
328                 printk("%c%08x%c",i?' ':'<',code,i?' ':'>');
329                 pc++;
330         }
331         printk("\n");
332 }
333 #endif
334
335 void show_regs(struct pt_regs *regs)
336 {
337 #ifdef VERBOSE_SHOWREGS
338         extern long etrap, etraptl1;
339 #endif
340         __show_regs(regs);
341 #ifdef CONFIG_SMP
342         {
343                 extern void smp_report_regs(void);
344
345                 smp_report_regs();
346         }
347 #endif
348
349 #ifdef VERBOSE_SHOWREGS 
350         if (regs->tpc >= &etrap && regs->tpc < &etraptl1 &&
351             regs->u_regs[14] >= (long)current - PAGE_SIZE &&
352             regs->u_regs[14] < (long)current + 6 * PAGE_SIZE) {
353                 printk ("*********parent**********\n");
354                 __show_regs((struct pt_regs *)(regs->u_regs[14] + PTREGS_OFF));
355                 idump_from_user(((struct pt_regs *)(regs->u_regs[14] + PTREGS_OFF))->tpc);
356                 printk ("*********endpar**********\n");
357         }
358 #endif
359 }
360
361 void show_regs32(struct pt_regs32 *regs)
362 {
363         printk("PSR: %08x PC: %08x NPC: %08x Y: %08x    %s\n", regs->psr,
364                regs->pc, regs->npc, regs->y, print_tainted());
365         printk("g0: %08x g1: %08x g2: %08x g3: %08x ",
366                regs->u_regs[0], regs->u_regs[1], regs->u_regs[2],
367                regs->u_regs[3]);
368         printk("g4: %08x g5: %08x g6: %08x g7: %08x\n",
369                regs->u_regs[4], regs->u_regs[5], regs->u_regs[6],
370                regs->u_regs[7]);
371         printk("o0: %08x o1: %08x o2: %08x o3: %08x ",
372                regs->u_regs[8], regs->u_regs[9], regs->u_regs[10],
373                regs->u_regs[11]);
374         printk("o4: %08x o5: %08x sp: %08x ret_pc: %08x\n",
375                regs->u_regs[12], regs->u_regs[13], regs->u_regs[14],
376                regs->u_regs[15]);
377 }
378
379 unsigned long thread_saved_pc(struct task_struct *tsk)
380 {
381         struct thread_info *ti = tsk->thread_info;
382         unsigned long ret = 0xdeadbeefUL;
383         
384         if (ti && ti->ksp) {
385                 unsigned long *sp;
386                 sp = (unsigned long *)(ti->ksp + STACK_BIAS);
387                 if (((unsigned long)sp & (sizeof(long) - 1)) == 0UL &&
388                     sp[14]) {
389                         unsigned long *fp;
390                         fp = (unsigned long *)(sp[14] + STACK_BIAS);
391                         if (((unsigned long)fp & (sizeof(long) - 1)) == 0UL)
392                                 ret = fp[15];
393                 }
394         }
395         return ret;
396 }
397
398 /* Free current thread data structures etc.. */
399 void exit_thread(void)
400 {
401         struct thread_info *t = current_thread_info();
402
403         if (t->utraps) {
404                 if (t->utraps[0] < 2)
405                         kfree (t->utraps);
406                 else
407                         t->utraps[0]--;
408         }
409
410         if (test_and_clear_thread_flag(TIF_PERFCTR)) {
411                 t->user_cntd0 = t->user_cntd1 = NULL;
412                 t->pcr_reg = 0;
413                 write_pcr(0);
414         }
415 }
416
417 void flush_thread(void)
418 {
419         struct thread_info *t = current_thread_info();
420
421         if (t->flags & _TIF_ABI_PENDING)
422                 t->flags ^= (_TIF_ABI_PENDING | _TIF_32BIT);
423
424         if (t->task->mm) {
425                 unsigned long pgd_cache = 0UL;
426                 if (test_thread_flag(TIF_32BIT)) {
427                         struct mm_struct *mm = t->task->mm;
428                         pgd_t *pgd0 = &mm->pgd[0];
429                         pud_t *pud0 = pud_offset(pgd0, 0);
430
431                         if (pud_none(*pud0)) {
432                                 pmd_t *page = pmd_alloc_one(mm, 0);
433                                 pud_set(pud0, page);
434                         }
435                         pgd_cache = get_pgd_cache(pgd0);
436                 }
437                 __asm__ __volatile__("stxa %0, [%1] %2\n\t"
438                                      "membar #Sync"
439                                      : /* no outputs */
440                                      : "r" (pgd_cache),
441                                      "r" (TSB_REG),
442                                      "i" (ASI_DMMU));
443         }
444         set_thread_wsaved(0);
445
446         /* Turn off performance counters if on. */
447         if (test_and_clear_thread_flag(TIF_PERFCTR)) {
448                 t->user_cntd0 = t->user_cntd1 = NULL;
449                 t->pcr_reg = 0;
450                 write_pcr(0);
451         }
452
453         /* Clear FPU register state. */
454         t->fpsaved[0] = 0;
455         
456         if (get_thread_current_ds() != ASI_AIUS)
457                 set_fs(USER_DS);
458
459         /* Init new signal delivery disposition. */
460         clear_thread_flag(TIF_NEWSIGNALS);
461 }
462
463 /* It's a bit more tricky when 64-bit tasks are involved... */
464 static unsigned long clone_stackframe(unsigned long csp, unsigned long psp)
465 {
466         unsigned long fp, distance, rval;
467
468         if (!(test_thread_flag(TIF_32BIT))) {
469                 csp += STACK_BIAS;
470                 psp += STACK_BIAS;
471                 __get_user(fp, &(((struct reg_window __user *)psp)->ins[6]));
472                 fp += STACK_BIAS;
473         } else
474                 __get_user(fp, &(((struct reg_window32 __user *)psp)->ins[6]));
475
476         /* Now 8-byte align the stack as this is mandatory in the
477          * Sparc ABI due to how register windows work.  This hides
478          * the restriction from thread libraries etc.  -DaveM
479          */
480         csp &= ~7UL;
481
482         distance = fp - psp;
483         rval = (csp - distance);
484         if (copy_in_user((void __user *) rval, (void __user *) psp, distance))
485                 rval = 0;
486         else if (test_thread_flag(TIF_32BIT)) {
487                 if (put_user(((u32)csp),
488                              &(((struct reg_window32 __user *)rval)->ins[6])))
489                         rval = 0;
490         } else {
491                 if (put_user(((u64)csp - STACK_BIAS),
492                              &(((struct reg_window __user *)rval)->ins[6])))
493                         rval = 0;
494                 else
495                         rval = rval - STACK_BIAS;
496         }
497
498         return rval;
499 }
500
501 /* Standard stuff. */
502 static inline void shift_window_buffer(int first_win, int last_win,
503                                        struct thread_info *t)
504 {
505         int i;
506
507         for (i = first_win; i < last_win; i++) {
508                 t->rwbuf_stkptrs[i] = t->rwbuf_stkptrs[i+1];
509                 memcpy(&t->reg_window[i], &t->reg_window[i+1],
510                        sizeof(struct reg_window));
511         }
512 }
513
514 void synchronize_user_stack(void)
515 {
516         struct thread_info *t = current_thread_info();
517         unsigned long window;
518
519         flush_user_windows();
520         if ((window = get_thread_wsaved()) != 0) {
521                 int winsize = sizeof(struct reg_window);
522                 int bias = 0;
523
524                 if (test_thread_flag(TIF_32BIT))
525                         winsize = sizeof(struct reg_window32);
526                 else
527                         bias = STACK_BIAS;
528
529                 window -= 1;
530                 do {
531                         unsigned long sp = (t->rwbuf_stkptrs[window] + bias);
532                         struct reg_window *rwin = &t->reg_window[window];
533
534                         if (!copy_to_user((char __user *)sp, rwin, winsize)) {
535                                 shift_window_buffer(window, get_thread_wsaved() - 1, t);
536                                 set_thread_wsaved(get_thread_wsaved() - 1);
537                         }
538                 } while (window--);
539         }
540 }
541
542 void fault_in_user_windows(void)
543 {
544         struct thread_info *t = current_thread_info();
545         unsigned long window;
546         int winsize = sizeof(struct reg_window);
547         int bias = 0;
548
549         if (test_thread_flag(TIF_32BIT))
550                 winsize = sizeof(struct reg_window32);
551         else
552                 bias = STACK_BIAS;
553
554         flush_user_windows();
555         window = get_thread_wsaved();
556
557         if (window != 0) {
558                 window -= 1;
559                 do {
560                         unsigned long sp = (t->rwbuf_stkptrs[window] + bias);
561                         struct reg_window *rwin = &t->reg_window[window];
562
563                         if (copy_to_user((char __user *)sp, rwin, winsize))
564                                 goto barf;
565                 } while (window--);
566         }
567         set_thread_wsaved(0);
568         return;
569
570 barf:
571         set_thread_wsaved(window + 1);
572         do_exit(SIGILL);
573 }
574
575 asmlinkage long sparc_do_fork(unsigned long clone_flags,
576                               unsigned long stack_start,
577                               struct pt_regs *regs,
578                               unsigned long stack_size)
579 {
580         int __user *parent_tid_ptr, *child_tid_ptr;
581
582 #ifdef CONFIG_COMPAT
583         if (test_thread_flag(TIF_32BIT)) {
584                 parent_tid_ptr = compat_ptr(regs->u_regs[UREG_I2]);
585                 child_tid_ptr = compat_ptr(regs->u_regs[UREG_I4]);
586         } else
587 #endif
588         {
589                 parent_tid_ptr = (int __user *) regs->u_regs[UREG_I2];
590                 child_tid_ptr = (int __user *) regs->u_regs[UREG_I4];
591         }
592
593         return do_fork(clone_flags, stack_start,
594                        regs, stack_size,
595                        parent_tid_ptr, child_tid_ptr);
596 }
597
598 /* Copy a Sparc thread.  The fork() return value conventions
599  * under SunOS are nothing short of bletcherous:
600  * Parent -->  %o0 == childs  pid, %o1 == 0
601  * Child  -->  %o0 == parents pid, %o1 == 1
602  */
603 int copy_thread(int nr, unsigned long clone_flags, unsigned long sp,
604                 unsigned long unused,
605                 struct task_struct *p, struct pt_regs *regs)
606 {
607         struct thread_info *t = p->thread_info;
608         char *child_trap_frame;
609
610 #ifdef CONFIG_DEBUG_SPINLOCK
611         p->thread.smp_lock_count = 0;
612         p->thread.smp_lock_pc = 0;
613 #endif
614
615         /* Calculate offset to stack_frame & pt_regs */
616         child_trap_frame = ((char *)t) + (THREAD_SIZE - (TRACEREG_SZ+STACKFRAME_SZ));
617         memcpy(child_trap_frame, (((struct sparc_stackf *)regs)-1), (TRACEREG_SZ+STACKFRAME_SZ));
618
619         t->flags = (t->flags & ~((0xffUL << TI_FLAG_CWP_SHIFT) | (0xffUL << TI_FLAG_CURRENT_DS_SHIFT))) |
620                 (((regs->tstate + 1) & TSTATE_CWP) << TI_FLAG_CWP_SHIFT);
621         t->new_child = 1;
622         t->ksp = ((unsigned long) child_trap_frame) - STACK_BIAS;
623         t->kregs = (struct pt_regs *)(child_trap_frame+sizeof(struct sparc_stackf));
624         t->fpsaved[0] = 0;
625
626         if (regs->tstate & TSTATE_PRIV) {
627                 /* Special case, if we are spawning a kernel thread from
628                  * a userspace task (via KMOD, NFS, or similar) we must
629                  * disable performance counters in the child because the
630                  * address space and protection realm are changing.
631                  */
632                 if (t->flags & _TIF_PERFCTR) {
633                         t->user_cntd0 = t->user_cntd1 = NULL;
634                         t->pcr_reg = 0;
635                         t->flags &= ~_TIF_PERFCTR;
636                 }
637                 t->kregs->u_regs[UREG_FP] = t->ksp;
638                 t->flags |= ((long)ASI_P << TI_FLAG_CURRENT_DS_SHIFT);
639                 flush_register_windows();
640                 memcpy((void *)(t->ksp + STACK_BIAS),
641                        (void *)(regs->u_regs[UREG_FP] + STACK_BIAS),
642                        sizeof(struct sparc_stackf));
643                 t->kregs->u_regs[UREG_G6] = (unsigned long) t;
644                 t->kregs->u_regs[UREG_G4] = (unsigned long) t->task;
645         } else {
646                 if (t->flags & _TIF_32BIT) {
647                         sp &= 0x00000000ffffffffUL;
648                         regs->u_regs[UREG_FP] &= 0x00000000ffffffffUL;
649                 }
650                 t->kregs->u_regs[UREG_FP] = sp;
651                 t->flags |= ((long)ASI_AIUS << TI_FLAG_CURRENT_DS_SHIFT);
652                 if (sp != regs->u_regs[UREG_FP]) {
653                         unsigned long csp;
654
655                         csp = clone_stackframe(sp, regs->u_regs[UREG_FP]);
656                         if (!csp)
657                                 return -EFAULT;
658                         t->kregs->u_regs[UREG_FP] = csp;
659                 }
660                 if (t->utraps)
661                         t->utraps[0]++;
662         }
663
664         /* Set the return value for the child. */
665         t->kregs->u_regs[UREG_I0] = current->pid;
666         t->kregs->u_regs[UREG_I1] = 1;
667
668         /* Set the second return value for the parent. */
669         regs->u_regs[UREG_I1] = 0;
670
671         if (clone_flags & CLONE_SETTLS)
672                 t->kregs->u_regs[UREG_G7] = regs->u_regs[UREG_I3];
673
674         return 0;
675 }
676
677 /*
678  * This is the mechanism for creating a new kernel thread.
679  *
680  * NOTE! Only a kernel-only process(ie the swapper or direct descendants
681  * who haven't done an "execve()") should use this: it will work within
682  * a system call from a "real" process, but the process memory space will
683  * not be free'd until both the parent and the child have exited.
684  */
685 pid_t kernel_thread(int (*fn)(void *), void * arg, unsigned long flags)
686 {
687         long retval;
688
689         /* If the parent runs before fn(arg) is called by the child,
690          * the input registers of this function can be clobbered.
691          * So we stash 'fn' and 'arg' into global registers which
692          * will not be modified by the parent.
693          */
694         __asm__ __volatile__("mov %4, %%g2\n\t"    /* Save FN into global */
695                              "mov %5, %%g3\n\t"    /* Save ARG into global */
696                              "mov %1, %%g1\n\t"    /* Clone syscall nr. */
697                              "mov %2, %%o0\n\t"    /* Clone flags. */
698                              "mov 0, %%o1\n\t"     /* usp arg == 0 */
699                              "t 0x6d\n\t"          /* Linux/Sparc clone(). */
700                              "brz,a,pn %%o1, 1f\n\t" /* Parent, just return. */
701                              " mov %%o0, %0\n\t"
702                              "jmpl %%g2, %%o7\n\t"   /* Call the function. */
703                              " mov %%g3, %%o0\n\t"   /* Set arg in delay. */
704                              "mov %3, %%g1\n\t"
705                              "t 0x6d\n\t"          /* Linux/Sparc exit(). */
706                              /* Notreached by child. */
707                              "1:" :
708                              "=r" (retval) :
709                              "i" (__NR_clone), "r" (flags | CLONE_VM | CLONE_UNTRACED),
710                              "i" (__NR_exit),  "r" (fn), "r" (arg) :
711                              "g1", "g2", "g3", "o0", "o1", "memory", "cc");
712         return retval;
713 }
714
715 /*
716  * fill in the user structure for a core dump..
717  */
718 void dump_thread(struct pt_regs * regs, struct user * dump)
719 {
720         /* Only should be used for SunOS and ancient a.out
721          * SparcLinux binaries...  Not worth implementing.
722          */
723         memset(dump, 0, sizeof(struct user));
724 }
725
726 typedef struct {
727         union {
728                 unsigned int    pr_regs[32];
729                 unsigned long   pr_dregs[16];
730         } pr_fr;
731         unsigned int __unused;
732         unsigned int    pr_fsr;
733         unsigned char   pr_qcnt;
734         unsigned char   pr_q_entrysize;
735         unsigned char   pr_en;
736         unsigned int    pr_q[64];
737 } elf_fpregset_t32;
738
739 /*
740  * fill in the fpu structure for a core dump.
741  */
742 int dump_fpu (struct pt_regs * regs, elf_fpregset_t * fpregs)
743 {
744         unsigned long *kfpregs = current_thread_info()->fpregs;
745         unsigned long fprs = current_thread_info()->fpsaved[0];
746
747         if (test_thread_flag(TIF_32BIT)) {
748                 elf_fpregset_t32 *fpregs32 = (elf_fpregset_t32 *)fpregs;
749
750                 if (fprs & FPRS_DL)
751                         memcpy(&fpregs32->pr_fr.pr_regs[0], kfpregs,
752                                sizeof(unsigned int) * 32);
753                 else
754                         memset(&fpregs32->pr_fr.pr_regs[0], 0,
755                                sizeof(unsigned int) * 32);
756                 fpregs32->pr_qcnt = 0;
757                 fpregs32->pr_q_entrysize = 8;
758                 memset(&fpregs32->pr_q[0], 0,
759                        (sizeof(unsigned int) * 64));
760                 if (fprs & FPRS_FEF) {
761                         fpregs32->pr_fsr = (unsigned int) current_thread_info()->xfsr[0];
762                         fpregs32->pr_en = 1;
763                 } else {
764                         fpregs32->pr_fsr = 0;
765                         fpregs32->pr_en = 0;
766                 }
767         } else {
768                 if(fprs & FPRS_DL)
769                         memcpy(&fpregs->pr_regs[0], kfpregs,
770                                sizeof(unsigned int) * 32);
771                 else
772                         memset(&fpregs->pr_regs[0], 0,
773                                sizeof(unsigned int) * 32);
774                 if(fprs & FPRS_DU)
775                         memcpy(&fpregs->pr_regs[16], kfpregs+16,
776                                sizeof(unsigned int) * 32);
777                 else
778                         memset(&fpregs->pr_regs[16], 0,
779                                sizeof(unsigned int) * 32);
780                 if(fprs & FPRS_FEF) {
781                         fpregs->pr_fsr = current_thread_info()->xfsr[0];
782                         fpregs->pr_gsr = current_thread_info()->gsr[0];
783                 } else {
784                         fpregs->pr_fsr = fpregs->pr_gsr = 0;
785                 }
786                 fpregs->pr_fprs = fprs;
787         }
788         return 1;
789 }
790
791 /*
792  * sparc_execve() executes a new program after the asm stub has set
793  * things up for us.  This should basically do what I want it to.
794  */
795 asmlinkage int sparc_execve(struct pt_regs *regs)
796 {
797         int error, base = 0;
798         char *filename;
799
800         /* User register window flush is done by entry.S */
801
802         /* Check for indirect call. */
803         if (regs->u_regs[UREG_G1] == 0)
804                 base = 1;
805
806         filename = getname((char __user *)regs->u_regs[base + UREG_I0]);
807         error = PTR_ERR(filename);
808         if (IS_ERR(filename))
809                 goto out;
810         error = do_execve(filename,
811                           (char __user * __user *)
812                           regs->u_regs[base + UREG_I1],
813                           (char __user * __user *)
814                           regs->u_regs[base + UREG_I2], regs);
815         putname(filename);
816         if (!error) {
817                 fprs_write(0);
818                 current_thread_info()->xfsr[0] = 0;
819                 current_thread_info()->fpsaved[0] = 0;
820                 regs->tstate &= ~TSTATE_PEF;
821                 task_lock(current);
822                 current->ptrace &= ~PT_DTRACE;
823                 task_unlock(current);
824         }
825 out:
826         return error;
827 }
828
829 unsigned long get_wchan(struct task_struct *task)
830 {
831         unsigned long pc, fp, bias = 0;
832         unsigned long thread_info_base;
833         struct reg_window *rw;
834         unsigned long ret = 0;
835         int count = 0; 
836
837         if (!task || task == current ||
838             task->state == TASK_RUNNING)
839                 goto out;
840
841         thread_info_base = (unsigned long) task->thread_info;
842         bias = STACK_BIAS;
843         fp = task->thread_info->ksp + bias;
844
845         do {
846                 /* Bogus frame pointer? */
847                 if (fp < (thread_info_base + sizeof(struct thread_info)) ||
848                     fp >= (thread_info_base + THREAD_SIZE))
849                         break;
850                 rw = (struct reg_window *) fp;
851                 pc = rw->ins[7];
852                 if (!in_sched_functions(pc)) {
853                         ret = pc;
854                         goto out;
855                 }
856                 fp = rw->ins[6] + bias;
857         } while (++count < 16);
858
859 out:
860         return ret;
861 }