nohz: prevent tick stop outside of the idle loop
[linux-2.6.git] / arch / sparc64 / kernel / process.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/module.h>
16 #include <linux/sched.h>
17 #include <linux/kernel.h>
18 #include <linux/kallsyms.h>
19 #include <linux/mm.h>
20 #include <linux/fs.h>
21 #include <linux/smp.h>
22 #include <linux/stddef.h>
23 #include <linux/ptrace.h>
24 #include <linux/slab.h>
25 #include <linux/user.h>
26 #include <linux/reboot.h>
27 #include <linux/delay.h>
28 #include <linux/compat.h>
29 #include <linux/tick.h>
30 #include <linux/init.h>
31 #include <linux/cpu.h>
32 #include <linux/elfcore.h>
33 #include <linux/sysrq.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/mmu_context.h>
48 #include <asm/unistd.h>
49 #include <asm/hypervisor.h>
50 #include <asm/sstate.h>
51 #include <asm/reboot.h>
52 #include <asm/syscalls.h>
53 #include <asm/irq_regs.h>
54 #include <asm/smp.h>
55
56 /* #define VERBOSE_SHOWREGS */
57
58 static void sparc64_yield(int cpu)
59 {
60         if (tlb_type != hypervisor)
61                 return;
62
63         clear_thread_flag(TIF_POLLING_NRFLAG);
64         smp_mb__after_clear_bit();
65
66         while (!need_resched() && !cpu_is_offline(cpu)) {
67                 unsigned long pstate;
68
69                 /* Disable interrupts. */
70                 __asm__ __volatile__(
71                         "rdpr %%pstate, %0\n\t"
72                         "andn %0, %1, %0\n\t"
73                         "wrpr %0, %%g0, %%pstate"
74                         : "=&r" (pstate)
75                         : "i" (PSTATE_IE));
76
77                 if (!need_resched() && !cpu_is_offline(cpu))
78                         sun4v_cpu_yield();
79
80                 /* Re-enable interrupts. */
81                 __asm__ __volatile__(
82                         "rdpr %%pstate, %0\n\t"
83                         "or %0, %1, %0\n\t"
84                         "wrpr %0, %%g0, %%pstate"
85                         : "=&r" (pstate)
86                         : "i" (PSTATE_IE));
87         }
88
89         set_thread_flag(TIF_POLLING_NRFLAG);
90 }
91
92 /* The idle loop on sparc64. */
93 void cpu_idle(void)
94 {
95         int cpu = smp_processor_id();
96
97         set_thread_flag(TIF_POLLING_NRFLAG);
98
99         while(1) {
100                 tick_nohz_stop_sched_tick(1);
101
102                 while (!need_resched() && !cpu_is_offline(cpu))
103                         sparc64_yield(cpu);
104
105                 tick_nohz_restart_sched_tick();
106
107                 preempt_enable_no_resched();
108
109 #ifdef CONFIG_HOTPLUG_CPU
110                 if (cpu_is_offline(cpu))
111                         cpu_play_dead();
112 #endif
113
114                 schedule();
115                 preempt_disable();
116         }
117 }
118
119 void machine_halt(void)
120 {
121         sstate_halt();
122         prom_halt();
123         panic("Halt failed!");
124 }
125
126 void machine_alt_power_off(void)
127 {
128         sstate_poweroff();
129         prom_halt_power_off();
130         panic("Power-off failed!");
131 }
132
133 void machine_restart(char * cmd)
134 {
135         char *p;
136         
137         sstate_reboot();
138         p = strchr (reboot_command, '\n');
139         if (p) *p = 0;
140         if (cmd)
141                 prom_reboot(cmd);
142         if (*reboot_command)
143                 prom_reboot(reboot_command);
144         prom_reboot("");
145         panic("Reboot failed!");
146 }
147
148 #ifdef CONFIG_COMPAT
149 static void show_regwindow32(struct pt_regs *regs)
150 {
151         struct reg_window32 __user *rw;
152         struct reg_window32 r_w;
153         mm_segment_t old_fs;
154         
155         __asm__ __volatile__ ("flushw");
156         rw = compat_ptr((unsigned)regs->u_regs[14]);
157         old_fs = get_fs();
158         set_fs (USER_DS);
159         if (copy_from_user (&r_w, rw, sizeof(r_w))) {
160                 set_fs (old_fs);
161                 return;
162         }
163
164         set_fs (old_fs);                        
165         printk("l0: %08x l1: %08x l2: %08x l3: %08x "
166                "l4: %08x l5: %08x l6: %08x l7: %08x\n",
167                r_w.locals[0], r_w.locals[1], r_w.locals[2], r_w.locals[3],
168                r_w.locals[4], r_w.locals[5], r_w.locals[6], r_w.locals[7]);
169         printk("i0: %08x i1: %08x i2: %08x i3: %08x "
170                "i4: %08x i5: %08x i6: %08x i7: %08x\n",
171                r_w.ins[0], r_w.ins[1], r_w.ins[2], r_w.ins[3],
172                r_w.ins[4], r_w.ins[5], r_w.ins[6], r_w.ins[7]);
173 }
174 #else
175 #define show_regwindow32(regs)  do { } while (0)
176 #endif
177
178 static void show_regwindow(struct pt_regs *regs)
179 {
180         struct reg_window __user *rw;
181         struct reg_window *rwk;
182         struct reg_window r_w;
183         mm_segment_t old_fs;
184
185         if ((regs->tstate & TSTATE_PRIV) || !(test_thread_flag(TIF_32BIT))) {
186                 __asm__ __volatile__ ("flushw");
187                 rw = (struct reg_window __user *)
188                         (regs->u_regs[14] + STACK_BIAS);
189                 rwk = (struct reg_window *)
190                         (regs->u_regs[14] + STACK_BIAS);
191                 if (!(regs->tstate & TSTATE_PRIV)) {
192                         old_fs = get_fs();
193                         set_fs (USER_DS);
194                         if (copy_from_user (&r_w, rw, sizeof(r_w))) {
195                                 set_fs (old_fs);
196                                 return;
197                         }
198                         rwk = &r_w;
199                         set_fs (old_fs);                        
200                 }
201         } else {
202                 show_regwindow32(regs);
203                 return;
204         }
205         printk("l0: %016lx l1: %016lx l2: %016lx l3: %016lx\n",
206                rwk->locals[0], rwk->locals[1], rwk->locals[2], rwk->locals[3]);
207         printk("l4: %016lx l5: %016lx l6: %016lx l7: %016lx\n",
208                rwk->locals[4], rwk->locals[5], rwk->locals[6], rwk->locals[7]);
209         printk("i0: %016lx i1: %016lx i2: %016lx i3: %016lx\n",
210                rwk->ins[0], rwk->ins[1], rwk->ins[2], rwk->ins[3]);
211         printk("i4: %016lx i5: %016lx i6: %016lx i7: %016lx\n",
212                rwk->ins[4], rwk->ins[5], rwk->ins[6], rwk->ins[7]);
213         if (regs->tstate & TSTATE_PRIV)
214                 print_symbol("I7: <%s>\n", rwk->ins[7]);
215 }
216
217 #ifdef CONFIG_SMP
218 static DEFINE_SPINLOCK(regdump_lock);
219 #endif
220
221 void __show_regs(struct pt_regs * regs)
222 {
223 #ifdef CONFIG_SMP
224         unsigned long flags;
225
226         /* Protect against xcall ipis which might lead to livelock on the lock */
227         __asm__ __volatile__("rdpr      %%pstate, %0\n\t"
228                              "wrpr      %0, %1, %%pstate"
229                              : "=r" (flags)
230                              : "i" (PSTATE_IE));
231         spin_lock(&regdump_lock);
232 #endif
233         printk("TSTATE: %016lx TPC: %016lx TNPC: %016lx Y: %08x    %s\n", regs->tstate,
234                regs->tpc, regs->tnpc, regs->y, print_tainted());
235         print_symbol("TPC: <%s>\n", regs->tpc);
236         printk("g0: %016lx g1: %016lx g2: %016lx g3: %016lx\n",
237                regs->u_regs[0], regs->u_regs[1], regs->u_regs[2],
238                regs->u_regs[3]);
239         printk("g4: %016lx g5: %016lx g6: %016lx g7: %016lx\n",
240                regs->u_regs[4], regs->u_regs[5], regs->u_regs[6],
241                regs->u_regs[7]);
242         printk("o0: %016lx o1: %016lx o2: %016lx o3: %016lx\n",
243                regs->u_regs[8], regs->u_regs[9], regs->u_regs[10],
244                regs->u_regs[11]);
245         printk("o4: %016lx o5: %016lx sp: %016lx ret_pc: %016lx\n",
246                regs->u_regs[12], regs->u_regs[13], regs->u_regs[14],
247                regs->u_regs[15]);
248         print_symbol("RPC: <%s>\n", regs->u_regs[15]);
249         show_regwindow(regs);
250 #ifdef CONFIG_SMP
251         spin_unlock(&regdump_lock);
252         __asm__ __volatile__("wrpr      %0, 0, %%pstate"
253                              : : "r" (flags));
254 #endif
255 }
256
257 #ifdef VERBOSE_SHOWREGS
258 static void idump_from_user (unsigned int *pc)
259 {
260         int i;
261         int code;
262         
263         if((((unsigned long) pc) & 3))
264                 return;
265         
266         pc -= 3;
267         for(i = -3; i < 6; i++) {
268                 get_user(code, pc);
269                 printk("%c%08x%c",i?' ':'<',code,i?' ':'>');
270                 pc++;
271         }
272         printk("\n");
273 }
274 #endif
275
276 void show_regs(struct pt_regs *regs)
277 {
278 #ifdef VERBOSE_SHOWREGS
279         extern long etrap, etraptl1;
280 #endif
281         __show_regs(regs);
282 #if 0
283 #ifdef CONFIG_SMP
284         {
285                 extern void smp_report_regs(void);
286
287                 smp_report_regs();
288         }
289 #endif
290 #endif
291
292 #ifdef VERBOSE_SHOWREGS 
293         if (regs->tpc >= &etrap && regs->tpc < &etraptl1 &&
294             regs->u_regs[14] >= (long)current - PAGE_SIZE &&
295             regs->u_regs[14] < (long)current + 6 * PAGE_SIZE) {
296                 printk ("*********parent**********\n");
297                 __show_regs((struct pt_regs *)(regs->u_regs[14] + PTREGS_OFF));
298                 idump_from_user(((struct pt_regs *)(regs->u_regs[14] + PTREGS_OFF))->tpc);
299                 printk ("*********endpar**********\n");
300         }
301 #endif
302 }
303
304 #ifdef CONFIG_MAGIC_SYSRQ
305 struct global_reg_snapshot global_reg_snapshot[NR_CPUS];
306 static DEFINE_SPINLOCK(global_reg_snapshot_lock);
307
308 static void __global_reg_self(struct thread_info *tp, struct pt_regs *regs,
309                               int this_cpu)
310 {
311         flushw_all();
312
313         global_reg_snapshot[this_cpu].tstate = regs->tstate;
314         global_reg_snapshot[this_cpu].tpc = regs->tpc;
315         global_reg_snapshot[this_cpu].tnpc = regs->tnpc;
316         global_reg_snapshot[this_cpu].o7 = regs->u_regs[UREG_I7];
317
318         if (regs->tstate & TSTATE_PRIV) {
319                 struct reg_window *rw;
320
321                 rw = (struct reg_window *)
322                         (regs->u_regs[UREG_FP] + STACK_BIAS);
323                 global_reg_snapshot[this_cpu].i7 = rw->ins[6];
324         } else
325                 global_reg_snapshot[this_cpu].i7 = 0;
326
327         global_reg_snapshot[this_cpu].thread = tp;
328 }
329
330 /* In order to avoid hangs we do not try to synchronize with the
331  * global register dump client cpus.  The last store they make is to
332  * the thread pointer, so do a short poll waiting for that to become
333  * non-NULL.
334  */
335 static void __global_reg_poll(struct global_reg_snapshot *gp)
336 {
337         int limit = 0;
338
339         while (!gp->thread && ++limit < 100) {
340                 barrier();
341                 udelay(1);
342         }
343 }
344
345 static void sysrq_handle_globreg(int key, struct tty_struct *tty)
346 {
347         struct thread_info *tp = current_thread_info();
348         struct pt_regs *regs = get_irq_regs();
349 #ifdef CONFIG_KALLSYMS
350         char buffer[KSYM_SYMBOL_LEN];
351 #endif
352         unsigned long flags;
353         int this_cpu, cpu;
354
355         if (!regs)
356                 regs = tp->kregs;
357
358         spin_lock_irqsave(&global_reg_snapshot_lock, flags);
359
360         memset(global_reg_snapshot, 0, sizeof(global_reg_snapshot));
361
362         this_cpu = raw_smp_processor_id();
363
364         __global_reg_self(tp, regs, this_cpu);
365
366         smp_fetch_global_regs();
367
368         for_each_online_cpu(cpu) {
369                 struct global_reg_snapshot *gp = &global_reg_snapshot[cpu];
370                 struct thread_info *tp;
371
372                 __global_reg_poll(gp);
373
374                 tp = gp->thread;
375                 printk("%c CPU[%3d]: TSTATE[%016lx] TPC[%016lx] TNPC[%016lx] TASK[%s:%d]\n",
376                        (cpu == this_cpu ? '*' : ' '), cpu,
377                        gp->tstate, gp->tpc, gp->tnpc,
378                        ((tp && tp->task) ? tp->task->comm : "NULL"),
379                        ((tp && tp->task) ? tp->task->pid : -1));
380 #ifdef CONFIG_KALLSYMS
381                 if (gp->tstate & TSTATE_PRIV) {
382                         sprint_symbol(buffer, gp->tpc);
383                         printk("             TPC[%s] ", buffer);
384                         sprint_symbol(buffer, gp->o7);
385                         printk("O7[%s] ", buffer);
386                         sprint_symbol(buffer, gp->i7);
387                         printk("I7[%s]\n", buffer);
388                 } else
389 #endif
390                 {
391                         printk("             TPC[%lx] O7[%lx] I7[%lx]\n",
392                                gp->tpc, gp->o7, gp->i7);
393                 }
394         }
395
396         memset(global_reg_snapshot, 0, sizeof(global_reg_snapshot));
397
398         spin_unlock_irqrestore(&global_reg_snapshot_lock, flags);
399 }
400
401 static struct sysrq_key_op sparc_globalreg_op = {
402         .handler        = sysrq_handle_globreg,
403         .help_msg       = "Globalregs",
404         .action_msg     = "Show Global CPU Regs",
405 };
406
407 static int __init sparc_globreg_init(void)
408 {
409         return register_sysrq_key('y', &sparc_globalreg_op);
410 }
411
412 core_initcall(sparc_globreg_init);
413
414 #endif
415
416 unsigned long thread_saved_pc(struct task_struct *tsk)
417 {
418         struct thread_info *ti = task_thread_info(tsk);
419         unsigned long ret = 0xdeadbeefUL;
420         
421         if (ti && ti->ksp) {
422                 unsigned long *sp;
423                 sp = (unsigned long *)(ti->ksp + STACK_BIAS);
424                 if (((unsigned long)sp & (sizeof(long) - 1)) == 0UL &&
425                     sp[14]) {
426                         unsigned long *fp;
427                         fp = (unsigned long *)(sp[14] + STACK_BIAS);
428                         if (((unsigned long)fp & (sizeof(long) - 1)) == 0UL)
429                                 ret = fp[15];
430                 }
431         }
432         return ret;
433 }
434
435 /* Free current thread data structures etc.. */
436 void exit_thread(void)
437 {
438         struct thread_info *t = current_thread_info();
439
440         if (t->utraps) {
441                 if (t->utraps[0] < 2)
442                         kfree (t->utraps);
443                 else
444                         t->utraps[0]--;
445         }
446
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
454 void flush_thread(void)
455 {
456         struct thread_info *t = current_thread_info();
457         struct mm_struct *mm;
458
459         if (test_ti_thread_flag(t, TIF_ABI_PENDING)) {
460                 clear_ti_thread_flag(t, TIF_ABI_PENDING);
461                 if (test_ti_thread_flag(t, TIF_32BIT))
462                         clear_ti_thread_flag(t, TIF_32BIT);
463                 else
464                         set_ti_thread_flag(t, TIF_32BIT);
465         }
466
467         mm = t->task->mm;
468         if (mm)
469                 tsb_context_switch(mm);
470
471         set_thread_wsaved(0);
472
473         /* Turn off performance counters if on. */
474         if (test_and_clear_thread_flag(TIF_PERFCTR)) {
475                 t->user_cntd0 = t->user_cntd1 = NULL;
476                 t->pcr_reg = 0;
477                 write_pcr(0);
478         }
479
480         /* Clear FPU register state. */
481         t->fpsaved[0] = 0;
482         
483         if (get_thread_current_ds() != ASI_AIUS)
484                 set_fs(USER_DS);
485 }
486
487 /* It's a bit more tricky when 64-bit tasks are involved... */
488 static unsigned long clone_stackframe(unsigned long csp, unsigned long psp)
489 {
490         unsigned long fp, distance, rval;
491
492         if (!(test_thread_flag(TIF_32BIT))) {
493                 csp += STACK_BIAS;
494                 psp += STACK_BIAS;
495                 __get_user(fp, &(((struct reg_window __user *)psp)->ins[6]));
496                 fp += STACK_BIAS;
497         } else
498                 __get_user(fp, &(((struct reg_window32 __user *)psp)->ins[6]));
499
500         /* Now 8-byte align the stack as this is mandatory in the
501          * Sparc ABI due to how register windows work.  This hides
502          * the restriction from thread libraries etc.  -DaveM
503          */
504         csp &= ~7UL;
505
506         distance = fp - psp;
507         rval = (csp - distance);
508         if (copy_in_user((void __user *) rval, (void __user *) psp, distance))
509                 rval = 0;
510         else if (test_thread_flag(TIF_32BIT)) {
511                 if (put_user(((u32)csp),
512                              &(((struct reg_window32 __user *)rval)->ins[6])))
513                         rval = 0;
514         } else {
515                 if (put_user(((u64)csp - STACK_BIAS),
516                              &(((struct reg_window __user *)rval)->ins[6])))
517                         rval = 0;
518                 else
519                         rval = rval - STACK_BIAS;
520         }
521
522         return rval;
523 }
524
525 /* Standard stuff. */
526 static inline void shift_window_buffer(int first_win, int last_win,
527                                        struct thread_info *t)
528 {
529         int i;
530
531         for (i = first_win; i < last_win; i++) {
532                 t->rwbuf_stkptrs[i] = t->rwbuf_stkptrs[i+1];
533                 memcpy(&t->reg_window[i], &t->reg_window[i+1],
534                        sizeof(struct reg_window));
535         }
536 }
537
538 void synchronize_user_stack(void)
539 {
540         struct thread_info *t = current_thread_info();
541         unsigned long window;
542
543         flush_user_windows();
544         if ((window = get_thread_wsaved()) != 0) {
545                 int winsize = sizeof(struct reg_window);
546                 int bias = 0;
547
548                 if (test_thread_flag(TIF_32BIT))
549                         winsize = sizeof(struct reg_window32);
550                 else
551                         bias = STACK_BIAS;
552
553                 window -= 1;
554                 do {
555                         unsigned long sp = (t->rwbuf_stkptrs[window] + bias);
556                         struct reg_window *rwin = &t->reg_window[window];
557
558                         if (!copy_to_user((char __user *)sp, rwin, winsize)) {
559                                 shift_window_buffer(window, get_thread_wsaved() - 1, t);
560                                 set_thread_wsaved(get_thread_wsaved() - 1);
561                         }
562                 } while (window--);
563         }
564 }
565
566 static void stack_unaligned(unsigned long sp)
567 {
568         siginfo_t info;
569
570         info.si_signo = SIGBUS;
571         info.si_errno = 0;
572         info.si_code = BUS_ADRALN;
573         info.si_addr = (void __user *) sp;
574         info.si_trapno = 0;
575         force_sig_info(SIGBUS, &info, current);
576 }
577
578 void fault_in_user_windows(void)
579 {
580         struct thread_info *t = current_thread_info();
581         unsigned long window;
582         int winsize = sizeof(struct reg_window);
583         int bias = 0;
584
585         if (test_thread_flag(TIF_32BIT))
586                 winsize = sizeof(struct reg_window32);
587         else
588                 bias = STACK_BIAS;
589
590         flush_user_windows();
591         window = get_thread_wsaved();
592
593         if (likely(window != 0)) {
594                 window -= 1;
595                 do {
596                         unsigned long sp = (t->rwbuf_stkptrs[window] + bias);
597                         struct reg_window *rwin = &t->reg_window[window];
598
599                         if (unlikely(sp & 0x7UL))
600                                 stack_unaligned(sp);
601
602                         if (unlikely(copy_to_user((char __user *)sp,
603                                                   rwin, winsize)))
604                                 goto barf;
605                 } while (window--);
606         }
607         set_thread_wsaved(0);
608         return;
609
610 barf:
611         set_thread_wsaved(window + 1);
612         do_exit(SIGILL);
613 }
614
615 asmlinkage long sparc_do_fork(unsigned long clone_flags,
616                               unsigned long stack_start,
617                               struct pt_regs *regs,
618                               unsigned long stack_size)
619 {
620         int __user *parent_tid_ptr, *child_tid_ptr;
621         unsigned long orig_i1 = regs->u_regs[UREG_I1];
622         long ret;
623
624 #ifdef CONFIG_COMPAT
625         if (test_thread_flag(TIF_32BIT)) {
626                 parent_tid_ptr = compat_ptr(regs->u_regs[UREG_I2]);
627                 child_tid_ptr = compat_ptr(regs->u_regs[UREG_I4]);
628         } else
629 #endif
630         {
631                 parent_tid_ptr = (int __user *) regs->u_regs[UREG_I2];
632                 child_tid_ptr = (int __user *) regs->u_regs[UREG_I4];
633         }
634
635         ret = do_fork(clone_flags, stack_start,
636                       regs, stack_size,
637                       parent_tid_ptr, child_tid_ptr);
638
639         /* If we get an error and potentially restart the system
640          * call, we're screwed because copy_thread() clobbered
641          * the parent's %o1.  So detect that case and restore it
642          * here.
643          */
644         if ((unsigned long)ret >= -ERESTART_RESTARTBLOCK)
645                 regs->u_regs[UREG_I1] = orig_i1;
646
647         return ret;
648 }
649
650 /* Copy a Sparc thread.  The fork() return value conventions
651  * under SunOS are nothing short of bletcherous:
652  * Parent -->  %o0 == childs  pid, %o1 == 0
653  * Child  -->  %o0 == parents pid, %o1 == 1
654  */
655 int copy_thread(int nr, unsigned long clone_flags, unsigned long sp,
656                 unsigned long unused,
657                 struct task_struct *p, struct pt_regs *regs)
658 {
659         struct thread_info *t = task_thread_info(p);
660         struct sparc_stackf *parent_sf;
661         unsigned long child_stack_sz;
662         char *child_trap_frame;
663         int kernel_thread;
664
665         kernel_thread = (regs->tstate & TSTATE_PRIV) ? 1 : 0;
666         parent_sf = ((struct sparc_stackf *) regs) - 1;
667
668         /* Calculate offset to stack_frame & pt_regs */
669         child_stack_sz = ((STACKFRAME_SZ + TRACEREG_SZ) +
670                           (kernel_thread ? STACKFRAME_SZ : 0));
671         child_trap_frame = (task_stack_page(p) +
672                             (THREAD_SIZE - child_stack_sz));
673         memcpy(child_trap_frame, parent_sf, child_stack_sz);
674
675         t->flags = (t->flags & ~((0xffUL << TI_FLAG_CWP_SHIFT) |
676                                  (0xffUL << TI_FLAG_CURRENT_DS_SHIFT))) |
677                 (((regs->tstate + 1) & TSTATE_CWP) << TI_FLAG_CWP_SHIFT);
678         t->new_child = 1;
679         t->ksp = ((unsigned long) child_trap_frame) - STACK_BIAS;
680         t->kregs = (struct pt_regs *) (child_trap_frame +
681                                        sizeof(struct sparc_stackf));
682         t->fpsaved[0] = 0;
683
684         if (kernel_thread) {
685                 struct sparc_stackf *child_sf = (struct sparc_stackf *)
686                         (child_trap_frame + (STACKFRAME_SZ + TRACEREG_SZ));
687
688                 /* Zero terminate the stack backtrace.  */
689                 child_sf->fp = NULL;
690                 t->kregs->u_regs[UREG_FP] =
691                   ((unsigned long) child_sf) - STACK_BIAS;
692
693                 /* Special case, if we are spawning a kernel thread from
694                  * a userspace task (via KMOD, NFS, or similar) we must
695                  * disable performance counters in the child because the
696                  * address space and protection realm are changing.
697                  */
698                 if (t->flags & _TIF_PERFCTR) {
699                         t->user_cntd0 = t->user_cntd1 = NULL;
700                         t->pcr_reg = 0;
701                         t->flags &= ~_TIF_PERFCTR;
702                 }
703                 t->flags |= ((long)ASI_P << TI_FLAG_CURRENT_DS_SHIFT);
704                 t->kregs->u_regs[UREG_G6] = (unsigned long) t;
705                 t->kregs->u_regs[UREG_G4] = (unsigned long) t->task;
706         } else {
707                 if (t->flags & _TIF_32BIT) {
708                         sp &= 0x00000000ffffffffUL;
709                         regs->u_regs[UREG_FP] &= 0x00000000ffffffffUL;
710                 }
711                 t->kregs->u_regs[UREG_FP] = sp;
712                 t->flags |= ((long)ASI_AIUS << TI_FLAG_CURRENT_DS_SHIFT);
713                 if (sp != regs->u_regs[UREG_FP]) {
714                         unsigned long csp;
715
716                         csp = clone_stackframe(sp, regs->u_regs[UREG_FP]);
717                         if (!csp)
718                                 return -EFAULT;
719                         t->kregs->u_regs[UREG_FP] = csp;
720                 }
721                 if (t->utraps)
722                         t->utraps[0]++;
723         }
724
725         /* Set the return value for the child. */
726         t->kregs->u_regs[UREG_I0] = current->pid;
727         t->kregs->u_regs[UREG_I1] = 1;
728
729         /* Set the second return value for the parent. */
730         regs->u_regs[UREG_I1] = 0;
731
732         if (clone_flags & CLONE_SETTLS)
733                 t->kregs->u_regs[UREG_G7] = regs->u_regs[UREG_I3];
734
735         return 0;
736 }
737
738 /*
739  * This is the mechanism for creating a new kernel thread.
740  *
741  * NOTE! Only a kernel-only process(ie the swapper or direct descendants
742  * who haven't done an "execve()") should use this: it will work within
743  * a system call from a "real" process, but the process memory space will
744  * not be freed until both the parent and the child have exited.
745  */
746 pid_t kernel_thread(int (*fn)(void *), void * arg, unsigned long flags)
747 {
748         long retval;
749
750         /* If the parent runs before fn(arg) is called by the child,
751          * the input registers of this function can be clobbered.
752          * So we stash 'fn' and 'arg' into global registers which
753          * will not be modified by the parent.
754          */
755         __asm__ __volatile__("mov %4, %%g2\n\t"    /* Save FN into global */
756                              "mov %5, %%g3\n\t"    /* Save ARG into global */
757                              "mov %1, %%g1\n\t"    /* Clone syscall nr. */
758                              "mov %2, %%o0\n\t"    /* Clone flags. */
759                              "mov 0, %%o1\n\t"     /* usp arg == 0 */
760                              "t 0x6d\n\t"          /* Linux/Sparc clone(). */
761                              "brz,a,pn %%o1, 1f\n\t" /* Parent, just return. */
762                              " mov %%o0, %0\n\t"
763                              "jmpl %%g2, %%o7\n\t"   /* Call the function. */
764                              " mov %%g3, %%o0\n\t"   /* Set arg in delay. */
765                              "mov %3, %%g1\n\t"
766                              "t 0x6d\n\t"          /* Linux/Sparc exit(). */
767                              /* Notreached by child. */
768                              "1:" :
769                              "=r" (retval) :
770                              "i" (__NR_clone), "r" (flags | CLONE_VM | CLONE_UNTRACED),
771                              "i" (__NR_exit),  "r" (fn), "r" (arg) :
772                              "g1", "g2", "g3", "o0", "o1", "memory", "cc");
773         return retval;
774 }
775
776 typedef struct {
777         union {
778                 unsigned int    pr_regs[32];
779                 unsigned long   pr_dregs[16];
780         } pr_fr;
781         unsigned int __unused;
782         unsigned int    pr_fsr;
783         unsigned char   pr_qcnt;
784         unsigned char   pr_q_entrysize;
785         unsigned char   pr_en;
786         unsigned int    pr_q[64];
787 } elf_fpregset_t32;
788
789 /*
790  * fill in the fpu structure for a core dump.
791  */
792 int dump_fpu (struct pt_regs * regs, elf_fpregset_t * fpregs)
793 {
794         unsigned long *kfpregs = current_thread_info()->fpregs;
795         unsigned long fprs = current_thread_info()->fpsaved[0];
796
797         if (test_thread_flag(TIF_32BIT)) {
798                 elf_fpregset_t32 *fpregs32 = (elf_fpregset_t32 *)fpregs;
799
800                 if (fprs & FPRS_DL)
801                         memcpy(&fpregs32->pr_fr.pr_regs[0], kfpregs,
802                                sizeof(unsigned int) * 32);
803                 else
804                         memset(&fpregs32->pr_fr.pr_regs[0], 0,
805                                sizeof(unsigned int) * 32);
806                 fpregs32->pr_qcnt = 0;
807                 fpregs32->pr_q_entrysize = 8;
808                 memset(&fpregs32->pr_q[0], 0,
809                        (sizeof(unsigned int) * 64));
810                 if (fprs & FPRS_FEF) {
811                         fpregs32->pr_fsr = (unsigned int) current_thread_info()->xfsr[0];
812                         fpregs32->pr_en = 1;
813                 } else {
814                         fpregs32->pr_fsr = 0;
815                         fpregs32->pr_en = 0;
816                 }
817         } else {
818                 if(fprs & FPRS_DL)
819                         memcpy(&fpregs->pr_regs[0], kfpregs,
820                                sizeof(unsigned int) * 32);
821                 else
822                         memset(&fpregs->pr_regs[0], 0,
823                                sizeof(unsigned int) * 32);
824                 if(fprs & FPRS_DU)
825                         memcpy(&fpregs->pr_regs[16], kfpregs+16,
826                                sizeof(unsigned int) * 32);
827                 else
828                         memset(&fpregs->pr_regs[16], 0,
829                                sizeof(unsigned int) * 32);
830                 if(fprs & FPRS_FEF) {
831                         fpregs->pr_fsr = current_thread_info()->xfsr[0];
832                         fpregs->pr_gsr = current_thread_info()->gsr[0];
833                 } else {
834                         fpregs->pr_fsr = fpregs->pr_gsr = 0;
835                 }
836                 fpregs->pr_fprs = fprs;
837         }
838         return 1;
839 }
840
841 /*
842  * sparc_execve() executes a new program after the asm stub has set
843  * things up for us.  This should basically do what I want it to.
844  */
845 asmlinkage int sparc_execve(struct pt_regs *regs)
846 {
847         int error, base = 0;
848         char *filename;
849
850         /* User register window flush is done by entry.S */
851
852         /* Check for indirect call. */
853         if (regs->u_regs[UREG_G1] == 0)
854                 base = 1;
855
856         filename = getname((char __user *)regs->u_regs[base + UREG_I0]);
857         error = PTR_ERR(filename);
858         if (IS_ERR(filename))
859                 goto out;
860         error = do_execve(filename,
861                           (char __user * __user *)
862                           regs->u_regs[base + UREG_I1],
863                           (char __user * __user *)
864                           regs->u_regs[base + UREG_I2], regs);
865         putname(filename);
866         if (!error) {
867                 fprs_write(0);
868                 current_thread_info()->xfsr[0] = 0;
869                 current_thread_info()->fpsaved[0] = 0;
870                 regs->tstate &= ~TSTATE_PEF;
871         }
872 out:
873         return error;
874 }
875
876 unsigned long get_wchan(struct task_struct *task)
877 {
878         unsigned long pc, fp, bias = 0;
879         unsigned long thread_info_base;
880         struct reg_window *rw;
881         unsigned long ret = 0;
882         int count = 0; 
883
884         if (!task || task == current ||
885             task->state == TASK_RUNNING)
886                 goto out;
887
888         thread_info_base = (unsigned long) task_stack_page(task);
889         bias = STACK_BIAS;
890         fp = task_thread_info(task)->ksp + bias;
891
892         do {
893                 /* Bogus frame pointer? */
894                 if (fp < (thread_info_base + sizeof(struct thread_info)) ||
895                     fp >= (thread_info_base + THREAD_SIZE))
896                         break;
897                 rw = (struct reg_window *) fp;
898                 pc = rw->ins[7];
899                 if (!in_sched_functions(pc)) {
900                         ret = pc;
901                         goto out;
902                 }
903                 fp = rw->ins[6] + bias;
904         } while (++count < 16);
905
906 out:
907         return ret;
908 }