[PATCH] sparc64: task_thread_info()
[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                 preempt_enable_no_resched();
78                 schedule();
79                 preempt_disable();
80                 check_pgt_cache();
81         }
82 }
83
84 #else
85
86 /*
87  * the idle loop on a UltraMultiPenguin...
88  *
89  * TIF_POLLING_NRFLAG is set because we do not sleep the cpu
90  * inside of the idler task, so an interrupt is not needed
91  * to get a clean fast response.
92  *
93  * XXX Reverify this assumption... -DaveM
94  *
95  * Addendum: We do want it to do something for the signal
96  *           delivery case, we detect that by just seeing
97  *           if we are trying to send this to an idler or not.
98  */
99 void cpu_idle(void)
100 {
101         cpuinfo_sparc *cpuinfo = &local_cpu_data();
102         set_thread_flag(TIF_POLLING_NRFLAG);
103
104         while(1) {
105                 if (need_resched()) {
106                         cpuinfo->idle_volume = 0;
107                         preempt_enable_no_resched();
108                         schedule();
109                         preempt_disable();
110                         check_pgt_cache();
111                 }
112                 cpuinfo->idle_volume++;
113
114                 /* The store ordering is so that IRQ handlers on
115                  * other cpus see our increasing idleness for the buddy
116                  * redistribution algorithm.  -DaveM
117                  */
118                 membar_storeload_storestore();
119         }
120 }
121
122 #endif
123
124 extern char reboot_command [];
125
126 extern void (*prom_palette)(int);
127 extern void (*prom_keyboard)(void);
128
129 void machine_halt(void)
130 {
131         if (!serial_console && prom_palette)
132                 prom_palette (1);
133         if (prom_keyboard)
134                 prom_keyboard();
135         prom_halt();
136         panic("Halt failed!");
137 }
138
139 void machine_alt_power_off(void)
140 {
141         if (!serial_console && prom_palette)
142                 prom_palette(1);
143         if (prom_keyboard)
144                 prom_keyboard();
145         prom_halt_power_off();
146         panic("Power-off failed!");
147 }
148
149 void machine_restart(char * cmd)
150 {
151         char *p;
152         
153         p = strchr (reboot_command, '\n');
154         if (p) *p = 0;
155         if (!serial_console && prom_palette)
156                 prom_palette (1);
157         if (prom_keyboard)
158                 prom_keyboard();
159         if (cmd)
160                 prom_reboot(cmd);
161         if (*reboot_command)
162                 prom_reboot(reboot_command);
163         prom_reboot("");
164         panic("Reboot failed!");
165 }
166
167 static void show_regwindow32(struct pt_regs *regs)
168 {
169         struct reg_window32 __user *rw;
170         struct reg_window32 r_w;
171         mm_segment_t old_fs;
172         
173         __asm__ __volatile__ ("flushw");
174         rw = compat_ptr((unsigned)regs->u_regs[14]);
175         old_fs = get_fs();
176         set_fs (USER_DS);
177         if (copy_from_user (&r_w, rw, sizeof(r_w))) {
178                 set_fs (old_fs);
179                 return;
180         }
181
182         set_fs (old_fs);                        
183         printk("l0: %08x l1: %08x l2: %08x l3: %08x "
184                "l4: %08x l5: %08x l6: %08x l7: %08x\n",
185                r_w.locals[0], r_w.locals[1], r_w.locals[2], r_w.locals[3],
186                r_w.locals[4], r_w.locals[5], r_w.locals[6], r_w.locals[7]);
187         printk("i0: %08x i1: %08x i2: %08x i3: %08x "
188                "i4: %08x i5: %08x i6: %08x i7: %08x\n",
189                r_w.ins[0], r_w.ins[1], r_w.ins[2], r_w.ins[3],
190                r_w.ins[4], r_w.ins[5], r_w.ins[6], r_w.ins[7]);
191 }
192
193 static void show_regwindow(struct pt_regs *regs)
194 {
195         struct reg_window __user *rw;
196         struct reg_window *rwk;
197         struct reg_window r_w;
198         mm_segment_t old_fs;
199
200         if ((regs->tstate & TSTATE_PRIV) || !(test_thread_flag(TIF_32BIT))) {
201                 __asm__ __volatile__ ("flushw");
202                 rw = (struct reg_window __user *)
203                         (regs->u_regs[14] + STACK_BIAS);
204                 rwk = (struct reg_window *)
205                         (regs->u_regs[14] + STACK_BIAS);
206                 if (!(regs->tstate & TSTATE_PRIV)) {
207                         old_fs = get_fs();
208                         set_fs (USER_DS);
209                         if (copy_from_user (&r_w, rw, sizeof(r_w))) {
210                                 set_fs (old_fs);
211                                 return;
212                         }
213                         rwk = &r_w;
214                         set_fs (old_fs);                        
215                 }
216         } else {
217                 show_regwindow32(regs);
218                 return;
219         }
220         printk("l0: %016lx l1: %016lx l2: %016lx l3: %016lx\n",
221                rwk->locals[0], rwk->locals[1], rwk->locals[2], rwk->locals[3]);
222         printk("l4: %016lx l5: %016lx l6: %016lx l7: %016lx\n",
223                rwk->locals[4], rwk->locals[5], rwk->locals[6], rwk->locals[7]);
224         printk("i0: %016lx i1: %016lx i2: %016lx i3: %016lx\n",
225                rwk->ins[0], rwk->ins[1], rwk->ins[2], rwk->ins[3]);
226         printk("i4: %016lx i5: %016lx i6: %016lx i7: %016lx\n",
227                rwk->ins[4], rwk->ins[5], rwk->ins[6], rwk->ins[7]);
228         if (regs->tstate & TSTATE_PRIV)
229                 print_symbol("I7: <%s>\n", rwk->ins[7]);
230 }
231
232 void show_stackframe(struct sparc_stackf *sf)
233 {
234         unsigned long size;
235         unsigned long *stk;
236         int i;
237
238         printk("l0: %016lx l1: %016lx l2: %016lx l3: %016lx\n"
239                "l4: %016lx l5: %016lx l6: %016lx l7: %016lx\n",
240                sf->locals[0], sf->locals[1], sf->locals[2], sf->locals[3],
241                sf->locals[4], sf->locals[5], sf->locals[6], sf->locals[7]);
242         printk("i0: %016lx i1: %016lx i2: %016lx i3: %016lx\n"
243                "i4: %016lx i5: %016lx fp: %016lx ret_pc: %016lx\n",
244                sf->ins[0], sf->ins[1], sf->ins[2], sf->ins[3],
245                sf->ins[4], sf->ins[5], (unsigned long)sf->fp, sf->callers_pc);
246         printk("sp: %016lx x0: %016lx x1: %016lx x2: %016lx\n"
247                "x3: %016lx x4: %016lx x5: %016lx xx: %016lx\n",
248                (unsigned long)sf->structptr, sf->xargs[0], sf->xargs[1],
249                sf->xargs[2], sf->xargs[3], sf->xargs[4], sf->xargs[5],
250                sf->xxargs[0]);
251         size = ((unsigned long)sf->fp) - ((unsigned long)sf);
252         size -= STACKFRAME_SZ;
253         stk = (unsigned long *)((unsigned long)sf + STACKFRAME_SZ);
254         i = 0;
255         do {
256                 printk("s%d: %016lx\n", i++, *stk++);
257         } while ((size -= sizeof(unsigned long)));
258 }
259
260 void show_stackframe32(struct sparc_stackf32 *sf)
261 {
262         unsigned long size;
263         unsigned *stk;
264         int i;
265
266         printk("l0: %08x l1: %08x l2: %08x l3: %08x\n",
267                sf->locals[0], sf->locals[1], sf->locals[2], sf->locals[3]);
268         printk("l4: %08x l5: %08x l6: %08x l7: %08x\n",
269                sf->locals[4], sf->locals[5], sf->locals[6], sf->locals[7]);
270         printk("i0: %08x i1: %08x i2: %08x i3: %08x\n",
271                sf->ins[0], sf->ins[1], sf->ins[2], sf->ins[3]);
272         printk("i4: %08x i5: %08x fp: %08x ret_pc: %08x\n",
273                sf->ins[4], sf->ins[5], sf->fp, sf->callers_pc);
274         printk("sp: %08x x0: %08x x1: %08x x2: %08x\n"
275                "x3: %08x x4: %08x x5: %08x xx: %08x\n",
276                sf->structptr, sf->xargs[0], sf->xargs[1],
277                sf->xargs[2], sf->xargs[3], sf->xargs[4], sf->xargs[5],
278                sf->xxargs[0]);
279         size = ((unsigned long)sf->fp) - ((unsigned long)sf);
280         size -= STACKFRAME32_SZ;
281         stk = (unsigned *)((unsigned long)sf + STACKFRAME32_SZ);
282         i = 0;
283         do {
284                 printk("s%d: %08x\n", i++, *stk++);
285         } while ((size -= sizeof(unsigned)));
286 }
287
288 #ifdef CONFIG_SMP
289 static DEFINE_SPINLOCK(regdump_lock);
290 #endif
291
292 void __show_regs(struct pt_regs * regs)
293 {
294 #ifdef CONFIG_SMP
295         unsigned long flags;
296
297         /* Protect against xcall ipis which might lead to livelock on the lock */
298         __asm__ __volatile__("rdpr      %%pstate, %0\n\t"
299                              "wrpr      %0, %1, %%pstate"
300                              : "=r" (flags)
301                              : "i" (PSTATE_IE));
302         spin_lock(&regdump_lock);
303 #endif
304         printk("TSTATE: %016lx TPC: %016lx TNPC: %016lx Y: %08x    %s\n", regs->tstate,
305                regs->tpc, regs->tnpc, regs->y, print_tainted());
306         print_symbol("TPC: <%s>\n", regs->tpc);
307         printk("g0: %016lx g1: %016lx g2: %016lx g3: %016lx\n",
308                regs->u_regs[0], regs->u_regs[1], regs->u_regs[2],
309                regs->u_regs[3]);
310         printk("g4: %016lx g5: %016lx g6: %016lx g7: %016lx\n",
311                regs->u_regs[4], regs->u_regs[5], regs->u_regs[6],
312                regs->u_regs[7]);
313         printk("o0: %016lx o1: %016lx o2: %016lx o3: %016lx\n",
314                regs->u_regs[8], regs->u_regs[9], regs->u_regs[10],
315                regs->u_regs[11]);
316         printk("o4: %016lx o5: %016lx sp: %016lx ret_pc: %016lx\n",
317                regs->u_regs[12], regs->u_regs[13], regs->u_regs[14],
318                regs->u_regs[15]);
319         print_symbol("RPC: <%s>\n", regs->u_regs[15]);
320         show_regwindow(regs);
321 #ifdef CONFIG_SMP
322         spin_unlock(&regdump_lock);
323         __asm__ __volatile__("wrpr      %0, 0, %%pstate"
324                              : : "r" (flags));
325 #endif
326 }
327
328 #ifdef VERBOSE_SHOWREGS
329 static void idump_from_user (unsigned int *pc)
330 {
331         int i;
332         int code;
333         
334         if((((unsigned long) pc) & 3))
335                 return;
336         
337         pc -= 3;
338         for(i = -3; i < 6; i++) {
339                 get_user(code, pc);
340                 printk("%c%08x%c",i?' ':'<',code,i?' ':'>');
341                 pc++;
342         }
343         printk("\n");
344 }
345 #endif
346
347 void show_regs(struct pt_regs *regs)
348 {
349 #ifdef VERBOSE_SHOWREGS
350         extern long etrap, etraptl1;
351 #endif
352         __show_regs(regs);
353 #ifdef CONFIG_SMP
354         {
355                 extern void smp_report_regs(void);
356
357                 smp_report_regs();
358         }
359 #endif
360
361 #ifdef VERBOSE_SHOWREGS 
362         if (regs->tpc >= &etrap && regs->tpc < &etraptl1 &&
363             regs->u_regs[14] >= (long)current - PAGE_SIZE &&
364             regs->u_regs[14] < (long)current + 6 * PAGE_SIZE) {
365                 printk ("*********parent**********\n");
366                 __show_regs((struct pt_regs *)(regs->u_regs[14] + PTREGS_OFF));
367                 idump_from_user(((struct pt_regs *)(regs->u_regs[14] + PTREGS_OFF))->tpc);
368                 printk ("*********endpar**********\n");
369         }
370 #endif
371 }
372
373 void show_regs32(struct pt_regs32 *regs)
374 {
375         printk("PSR: %08x PC: %08x NPC: %08x Y: %08x    %s\n", regs->psr,
376                regs->pc, regs->npc, regs->y, print_tainted());
377         printk("g0: %08x g1: %08x g2: %08x g3: %08x ",
378                regs->u_regs[0], regs->u_regs[1], regs->u_regs[2],
379                regs->u_regs[3]);
380         printk("g4: %08x g5: %08x g6: %08x g7: %08x\n",
381                regs->u_regs[4], regs->u_regs[5], regs->u_regs[6],
382                regs->u_regs[7]);
383         printk("o0: %08x o1: %08x o2: %08x o3: %08x ",
384                regs->u_regs[8], regs->u_regs[9], regs->u_regs[10],
385                regs->u_regs[11]);
386         printk("o4: %08x o5: %08x sp: %08x ret_pc: %08x\n",
387                regs->u_regs[12], regs->u_regs[13], regs->u_regs[14],
388                regs->u_regs[15]);
389 }
390
391 unsigned long thread_saved_pc(struct task_struct *tsk)
392 {
393         struct thread_info *ti = task_thread_info(tsk);
394         unsigned long ret = 0xdeadbeefUL;
395         
396         if (ti && ti->ksp) {
397                 unsigned long *sp;
398                 sp = (unsigned long *)(ti->ksp + STACK_BIAS);
399                 if (((unsigned long)sp & (sizeof(long) - 1)) == 0UL &&
400                     sp[14]) {
401                         unsigned long *fp;
402                         fp = (unsigned long *)(sp[14] + STACK_BIAS);
403                         if (((unsigned long)fp & (sizeof(long) - 1)) == 0UL)
404                                 ret = fp[15];
405                 }
406         }
407         return ret;
408 }
409
410 /* Free current thread data structures etc.. */
411 void exit_thread(void)
412 {
413         struct thread_info *t = current_thread_info();
414
415         if (t->utraps) {
416                 if (t->utraps[0] < 2)
417                         kfree (t->utraps);
418                 else
419                         t->utraps[0]--;
420         }
421
422         if (test_and_clear_thread_flag(TIF_PERFCTR)) {
423                 t->user_cntd0 = t->user_cntd1 = NULL;
424                 t->pcr_reg = 0;
425                 write_pcr(0);
426         }
427 }
428
429 void flush_thread(void)
430 {
431         struct thread_info *t = current_thread_info();
432
433         if (t->flags & _TIF_ABI_PENDING)
434                 t->flags ^= (_TIF_ABI_PENDING | _TIF_32BIT);
435
436         if (t->task->mm) {
437                 unsigned long pgd_cache = 0UL;
438                 if (test_thread_flag(TIF_32BIT)) {
439                         struct mm_struct *mm = t->task->mm;
440                         pgd_t *pgd0 = &mm->pgd[0];
441                         pud_t *pud0 = pud_offset(pgd0, 0);
442
443                         if (pud_none(*pud0)) {
444                                 pmd_t *page = pmd_alloc_one(mm, 0);
445                                 pud_set(pud0, page);
446                         }
447                         pgd_cache = get_pgd_cache(pgd0);
448                 }
449                 __asm__ __volatile__("stxa %0, [%1] %2\n\t"
450                                      "membar #Sync"
451                                      : /* no outputs */
452                                      : "r" (pgd_cache),
453                                      "r" (TSB_REG),
454                                      "i" (ASI_DMMU));
455         }
456         set_thread_wsaved(0);
457
458         /* Turn off performance counters if on. */
459         if (test_and_clear_thread_flag(TIF_PERFCTR)) {
460                 t->user_cntd0 = t->user_cntd1 = NULL;
461                 t->pcr_reg = 0;
462                 write_pcr(0);
463         }
464
465         /* Clear FPU register state. */
466         t->fpsaved[0] = 0;
467         
468         if (get_thread_current_ds() != ASI_AIUS)
469                 set_fs(USER_DS);
470
471         /* Init new signal delivery disposition. */
472         clear_thread_flag(TIF_NEWSIGNALS);
473 }
474
475 /* It's a bit more tricky when 64-bit tasks are involved... */
476 static unsigned long clone_stackframe(unsigned long csp, unsigned long psp)
477 {
478         unsigned long fp, distance, rval;
479
480         if (!(test_thread_flag(TIF_32BIT))) {
481                 csp += STACK_BIAS;
482                 psp += STACK_BIAS;
483                 __get_user(fp, &(((struct reg_window __user *)psp)->ins[6]));
484                 fp += STACK_BIAS;
485         } else
486                 __get_user(fp, &(((struct reg_window32 __user *)psp)->ins[6]));
487
488         /* Now 8-byte align the stack as this is mandatory in the
489          * Sparc ABI due to how register windows work.  This hides
490          * the restriction from thread libraries etc.  -DaveM
491          */
492         csp &= ~7UL;
493
494         distance = fp - psp;
495         rval = (csp - distance);
496         if (copy_in_user((void __user *) rval, (void __user *) psp, distance))
497                 rval = 0;
498         else if (test_thread_flag(TIF_32BIT)) {
499                 if (put_user(((u32)csp),
500                              &(((struct reg_window32 __user *)rval)->ins[6])))
501                         rval = 0;
502         } else {
503                 if (put_user(((u64)csp - STACK_BIAS),
504                              &(((struct reg_window __user *)rval)->ins[6])))
505                         rval = 0;
506                 else
507                         rval = rval - STACK_BIAS;
508         }
509
510         return rval;
511 }
512
513 /* Standard stuff. */
514 static inline void shift_window_buffer(int first_win, int last_win,
515                                        struct thread_info *t)
516 {
517         int i;
518
519         for (i = first_win; i < last_win; i++) {
520                 t->rwbuf_stkptrs[i] = t->rwbuf_stkptrs[i+1];
521                 memcpy(&t->reg_window[i], &t->reg_window[i+1],
522                        sizeof(struct reg_window));
523         }
524 }
525
526 void synchronize_user_stack(void)
527 {
528         struct thread_info *t = current_thread_info();
529         unsigned long window;
530
531         flush_user_windows();
532         if ((window = get_thread_wsaved()) != 0) {
533                 int winsize = sizeof(struct reg_window);
534                 int bias = 0;
535
536                 if (test_thread_flag(TIF_32BIT))
537                         winsize = sizeof(struct reg_window32);
538                 else
539                         bias = STACK_BIAS;
540
541                 window -= 1;
542                 do {
543                         unsigned long sp = (t->rwbuf_stkptrs[window] + bias);
544                         struct reg_window *rwin = &t->reg_window[window];
545
546                         if (!copy_to_user((char __user *)sp, rwin, winsize)) {
547                                 shift_window_buffer(window, get_thread_wsaved() - 1, t);
548                                 set_thread_wsaved(get_thread_wsaved() - 1);
549                         }
550                 } while (window--);
551         }
552 }
553
554 void fault_in_user_windows(void)
555 {
556         struct thread_info *t = current_thread_info();
557         unsigned long window;
558         int winsize = sizeof(struct reg_window);
559         int bias = 0;
560
561         if (test_thread_flag(TIF_32BIT))
562                 winsize = sizeof(struct reg_window32);
563         else
564                 bias = STACK_BIAS;
565
566         flush_user_windows();
567         window = get_thread_wsaved();
568
569         if (window != 0) {
570                 window -= 1;
571                 do {
572                         unsigned long sp = (t->rwbuf_stkptrs[window] + bias);
573                         struct reg_window *rwin = &t->reg_window[window];
574
575                         if (copy_to_user((char __user *)sp, rwin, winsize))
576                                 goto barf;
577                 } while (window--);
578         }
579         set_thread_wsaved(0);
580         return;
581
582 barf:
583         set_thread_wsaved(window + 1);
584         do_exit(SIGILL);
585 }
586
587 asmlinkage long sparc_do_fork(unsigned long clone_flags,
588                               unsigned long stack_start,
589                               struct pt_regs *regs,
590                               unsigned long stack_size)
591 {
592         int __user *parent_tid_ptr, *child_tid_ptr;
593
594 #ifdef CONFIG_COMPAT
595         if (test_thread_flag(TIF_32BIT)) {
596                 parent_tid_ptr = compat_ptr(regs->u_regs[UREG_I2]);
597                 child_tid_ptr = compat_ptr(regs->u_regs[UREG_I4]);
598         } else
599 #endif
600         {
601                 parent_tid_ptr = (int __user *) regs->u_regs[UREG_I2];
602                 child_tid_ptr = (int __user *) regs->u_regs[UREG_I4];
603         }
604
605         return do_fork(clone_flags, stack_start,
606                        regs, stack_size,
607                        parent_tid_ptr, child_tid_ptr);
608 }
609
610 /* Copy a Sparc thread.  The fork() return value conventions
611  * under SunOS are nothing short of bletcherous:
612  * Parent -->  %o0 == childs  pid, %o1 == 0
613  * Child  -->  %o0 == parents pid, %o1 == 1
614  */
615 int copy_thread(int nr, unsigned long clone_flags, unsigned long sp,
616                 unsigned long unused,
617                 struct task_struct *p, struct pt_regs *regs)
618 {
619         struct thread_info *t = p->thread_info;
620         char *child_trap_frame;
621
622         /* Calculate offset to stack_frame & pt_regs */
623         child_trap_frame = ((char *)t) + (THREAD_SIZE - (TRACEREG_SZ+STACKFRAME_SZ));
624         memcpy(child_trap_frame, (((struct sparc_stackf *)regs)-1), (TRACEREG_SZ+STACKFRAME_SZ));
625
626         t->flags = (t->flags & ~((0xffUL << TI_FLAG_CWP_SHIFT) | (0xffUL << TI_FLAG_CURRENT_DS_SHIFT))) |
627                 (((regs->tstate + 1) & TSTATE_CWP) << TI_FLAG_CWP_SHIFT);
628         t->new_child = 1;
629         t->ksp = ((unsigned long) child_trap_frame) - STACK_BIAS;
630         t->kregs = (struct pt_regs *)(child_trap_frame+sizeof(struct sparc_stackf));
631         t->fpsaved[0] = 0;
632
633         if (regs->tstate & TSTATE_PRIV) {
634                 /* Special case, if we are spawning a kernel thread from
635                  * a userspace task (via KMOD, NFS, or similar) we must
636                  * disable performance counters in the child because the
637                  * address space and protection realm are changing.
638                  */
639                 if (t->flags & _TIF_PERFCTR) {
640                         t->user_cntd0 = t->user_cntd1 = NULL;
641                         t->pcr_reg = 0;
642                         t->flags &= ~_TIF_PERFCTR;
643                 }
644                 t->kregs->u_regs[UREG_FP] = t->ksp;
645                 t->flags |= ((long)ASI_P << TI_FLAG_CURRENT_DS_SHIFT);
646                 flush_register_windows();
647                 memcpy((void *)(t->ksp + STACK_BIAS),
648                        (void *)(regs->u_regs[UREG_FP] + STACK_BIAS),
649                        sizeof(struct sparc_stackf));
650                 t->kregs->u_regs[UREG_G6] = (unsigned long) t;
651                 t->kregs->u_regs[UREG_G4] = (unsigned long) t->task;
652         } else {
653                 if (t->flags & _TIF_32BIT) {
654                         sp &= 0x00000000ffffffffUL;
655                         regs->u_regs[UREG_FP] &= 0x00000000ffffffffUL;
656                 }
657                 t->kregs->u_regs[UREG_FP] = sp;
658                 t->flags |= ((long)ASI_AIUS << TI_FLAG_CURRENT_DS_SHIFT);
659                 if (sp != regs->u_regs[UREG_FP]) {
660                         unsigned long csp;
661
662                         csp = clone_stackframe(sp, regs->u_regs[UREG_FP]);
663                         if (!csp)
664                                 return -EFAULT;
665                         t->kregs->u_regs[UREG_FP] = csp;
666                 }
667                 if (t->utraps)
668                         t->utraps[0]++;
669         }
670
671         /* Set the return value for the child. */
672         t->kregs->u_regs[UREG_I0] = current->pid;
673         t->kregs->u_regs[UREG_I1] = 1;
674
675         /* Set the second return value for the parent. */
676         regs->u_regs[UREG_I1] = 0;
677
678         if (clone_flags & CLONE_SETTLS)
679                 t->kregs->u_regs[UREG_G7] = regs->u_regs[UREG_I3];
680
681         return 0;
682 }
683
684 /*
685  * This is the mechanism for creating a new kernel thread.
686  *
687  * NOTE! Only a kernel-only process(ie the swapper or direct descendants
688  * who haven't done an "execve()") should use this: it will work within
689  * a system call from a "real" process, but the process memory space will
690  * not be free'd until both the parent and the child have exited.
691  */
692 pid_t kernel_thread(int (*fn)(void *), void * arg, unsigned long flags)
693 {
694         long retval;
695
696         /* If the parent runs before fn(arg) is called by the child,
697          * the input registers of this function can be clobbered.
698          * So we stash 'fn' and 'arg' into global registers which
699          * will not be modified by the parent.
700          */
701         __asm__ __volatile__("mov %4, %%g2\n\t"    /* Save FN into global */
702                              "mov %5, %%g3\n\t"    /* Save ARG into global */
703                              "mov %1, %%g1\n\t"    /* Clone syscall nr. */
704                              "mov %2, %%o0\n\t"    /* Clone flags. */
705                              "mov 0, %%o1\n\t"     /* usp arg == 0 */
706                              "t 0x6d\n\t"          /* Linux/Sparc clone(). */
707                              "brz,a,pn %%o1, 1f\n\t" /* Parent, just return. */
708                              " mov %%o0, %0\n\t"
709                              "jmpl %%g2, %%o7\n\t"   /* Call the function. */
710                              " mov %%g3, %%o0\n\t"   /* Set arg in delay. */
711                              "mov %3, %%g1\n\t"
712                              "t 0x6d\n\t"          /* Linux/Sparc exit(). */
713                              /* Notreached by child. */
714                              "1:" :
715                              "=r" (retval) :
716                              "i" (__NR_clone), "r" (flags | CLONE_VM | CLONE_UNTRACED),
717                              "i" (__NR_exit),  "r" (fn), "r" (arg) :
718                              "g1", "g2", "g3", "o0", "o1", "memory", "cc");
719         return retval;
720 }
721
722 /*
723  * fill in the user structure for a core dump..
724  */
725 void dump_thread(struct pt_regs * regs, struct user * dump)
726 {
727         /* Only should be used for SunOS and ancient a.out
728          * SparcLinux binaries...  Not worth implementing.
729          */
730         memset(dump, 0, sizeof(struct user));
731 }
732
733 typedef struct {
734         union {
735                 unsigned int    pr_regs[32];
736                 unsigned long   pr_dregs[16];
737         } pr_fr;
738         unsigned int __unused;
739         unsigned int    pr_fsr;
740         unsigned char   pr_qcnt;
741         unsigned char   pr_q_entrysize;
742         unsigned char   pr_en;
743         unsigned int    pr_q[64];
744 } elf_fpregset_t32;
745
746 /*
747  * fill in the fpu structure for a core dump.
748  */
749 int dump_fpu (struct pt_regs * regs, elf_fpregset_t * fpregs)
750 {
751         unsigned long *kfpregs = current_thread_info()->fpregs;
752         unsigned long fprs = current_thread_info()->fpsaved[0];
753
754         if (test_thread_flag(TIF_32BIT)) {
755                 elf_fpregset_t32 *fpregs32 = (elf_fpregset_t32 *)fpregs;
756
757                 if (fprs & FPRS_DL)
758                         memcpy(&fpregs32->pr_fr.pr_regs[0], kfpregs,
759                                sizeof(unsigned int) * 32);
760                 else
761                         memset(&fpregs32->pr_fr.pr_regs[0], 0,
762                                sizeof(unsigned int) * 32);
763                 fpregs32->pr_qcnt = 0;
764                 fpregs32->pr_q_entrysize = 8;
765                 memset(&fpregs32->pr_q[0], 0,
766                        (sizeof(unsigned int) * 64));
767                 if (fprs & FPRS_FEF) {
768                         fpregs32->pr_fsr = (unsigned int) current_thread_info()->xfsr[0];
769                         fpregs32->pr_en = 1;
770                 } else {
771                         fpregs32->pr_fsr = 0;
772                         fpregs32->pr_en = 0;
773                 }
774         } else {
775                 if(fprs & FPRS_DL)
776                         memcpy(&fpregs->pr_regs[0], kfpregs,
777                                sizeof(unsigned int) * 32);
778                 else
779                         memset(&fpregs->pr_regs[0], 0,
780                                sizeof(unsigned int) * 32);
781                 if(fprs & FPRS_DU)
782                         memcpy(&fpregs->pr_regs[16], kfpregs+16,
783                                sizeof(unsigned int) * 32);
784                 else
785                         memset(&fpregs->pr_regs[16], 0,
786                                sizeof(unsigned int) * 32);
787                 if(fprs & FPRS_FEF) {
788                         fpregs->pr_fsr = current_thread_info()->xfsr[0];
789                         fpregs->pr_gsr = current_thread_info()->gsr[0];
790                 } else {
791                         fpregs->pr_fsr = fpregs->pr_gsr = 0;
792                 }
793                 fpregs->pr_fprs = fprs;
794         }
795         return 1;
796 }
797
798 /*
799  * sparc_execve() executes a new program after the asm stub has set
800  * things up for us.  This should basically do what I want it to.
801  */
802 asmlinkage int sparc_execve(struct pt_regs *regs)
803 {
804         int error, base = 0;
805         char *filename;
806
807         /* User register window flush is done by entry.S */
808
809         /* Check for indirect call. */
810         if (regs->u_regs[UREG_G1] == 0)
811                 base = 1;
812
813         filename = getname((char __user *)regs->u_regs[base + UREG_I0]);
814         error = PTR_ERR(filename);
815         if (IS_ERR(filename))
816                 goto out;
817         error = do_execve(filename,
818                           (char __user * __user *)
819                           regs->u_regs[base + UREG_I1],
820                           (char __user * __user *)
821                           regs->u_regs[base + UREG_I2], regs);
822         putname(filename);
823         if (!error) {
824                 fprs_write(0);
825                 current_thread_info()->xfsr[0] = 0;
826                 current_thread_info()->fpsaved[0] = 0;
827                 regs->tstate &= ~TSTATE_PEF;
828                 task_lock(current);
829                 current->ptrace &= ~PT_DTRACE;
830                 task_unlock(current);
831         }
832 out:
833         return error;
834 }
835
836 unsigned long get_wchan(struct task_struct *task)
837 {
838         unsigned long pc, fp, bias = 0;
839         unsigned long thread_info_base;
840         struct reg_window *rw;
841         unsigned long ret = 0;
842         int count = 0; 
843
844         if (!task || task == current ||
845             task->state == TASK_RUNNING)
846                 goto out;
847
848         thread_info_base = (unsigned long) task->thread_info;
849         bias = STACK_BIAS;
850         fp = task_thread_info(task)->ksp + bias;
851
852         do {
853                 /* Bogus frame pointer? */
854                 if (fp < (thread_info_base + sizeof(struct thread_info)) ||
855                     fp >= (thread_info_base + THREAD_SIZE))
856                         break;
857                 rw = (struct reg_window *) fp;
858                 pc = rw->ins[7];
859                 if (!in_sched_functions(pc)) {
860                         ret = pc;
861                         goto out;
862                 }
863                 fp = rw->ins[6] + bias;
864         } while (++count < 16);
865
866 out:
867         return ret;
868 }