err.no Git - linux-2.6/blob - arch/sparc64/kernel/process.c

   1 /*  arch/sparc64/kernel/process.c
   2  *
   3  *  Copyright (C) 1995, 1996 David S. Miller (davem@caip.rutgers.edu)
   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
  34 #include <asm/oplib.h>
  35 #include <asm/uaccess.h>
  36 #include <asm/system.h>
  37 #include <asm/page.h>
  38 #include <asm/pgalloc.h>
  39 #include <asm/pgtable.h>
  40 #include <asm/processor.h>
  41 #include <asm/pstate.h>
  42 #include <asm/elf.h>
  43 #include <asm/fpumacro.h>
  44 #include <asm/head.h>
  45 #include <asm/cpudata.h>
  46 #include <asm/mmu_context.h>
  47 #include <asm/unistd.h>
  48 #include <asm/hypervisor.h>
  49 #include <asm/sstate.h>
  50 #include <asm/reboot.h>
  51 #include <asm/syscalls.h>
  52
  53 /* #define VERBOSE_SHOWREGS */
  54
  55 static void sparc64_yield(int cpu)
  56 {
  57         if (tlb_type != hypervisor)
  58                 return;
  59
  60         clear_thread_flag(TIF_POLLING_NRFLAG);
  61         smp_mb__after_clear_bit();
  62
  63         while (!need_resched() && !cpu_is_offline(cpu)) {
  64                 unsigned long pstate;
  65
  66                 /* Disable interrupts. */
  67                 __asm__ __volatile__(
  68                         "rdpr %%pstate, %0\n\t"
  69                         "andn %0, %1, %0\n\t"
  70                         "wrpr %0, %%g0, %%pstate"
  71                         : "=&r" (pstate)
  72                         : "i" (PSTATE_IE));
  73
  74                 if (!need_resched() && !cpu_is_offline(cpu))
  75                         sun4v_cpu_yield();
  76
  77                 /* Re-enable interrupts. */
  78                 __asm__ __volatile__(
  79                         "rdpr %%pstate, %0\n\t"
  80                         "or %0, %1, %0\n\t"
  81                         "wrpr %0, %%g0, %%pstate"
  82                         : "=&r" (pstate)
  83                         : "i" (PSTATE_IE));
  84         }
  85
  86         set_thread_flag(TIF_POLLING_NRFLAG);
  87 }
  88
  89 /* The idle loop on sparc64. */
  90 void cpu_idle(void)
  91 {
  92         int cpu = smp_processor_id();
  93
  94         set_thread_flag(TIF_POLLING_NRFLAG);
  95
  96         while(1) {
  97                 tick_nohz_stop_sched_tick();
  98
  99                 while (!need_resched() && !cpu_is_offline(cpu))
 100                         sparc64_yield(cpu);
 101
 102                 tick_nohz_restart_sched_tick();
 103
 104                 preempt_enable_no_resched();
 105
 106 #ifdef CONFIG_HOTPLUG_CPU
 107                 if (cpu_is_offline(cpu))
 108                         cpu_play_dead();
 109 #endif
 110
 111                 schedule();
 112                 preempt_disable();
 113         }
 114 }
 115
 116 void machine_halt(void)
 117 {
 118         sstate_halt();
 119         prom_halt();
 120         panic("Halt failed!");
 121 }
 122
 123 void machine_alt_power_off(void)
 124 {
 125         sstate_poweroff();
 126         prom_halt_power_off();
 127         panic("Power-off failed!");
 128 }
 129
 130 void machine_restart(char * cmd)
 131 {
 132         char *p;
 133
 134         sstate_reboot();
 135         p = strchr (reboot_command, '\n');
 136         if (p) *p = 0;
 137         if (cmd)
 138                 prom_reboot(cmd);
 139         if (*reboot_command)
 140                 prom_reboot(reboot_command);
 141         prom_reboot("");
 142         panic("Reboot failed!");
 143 }
 144
 145 #ifdef CONFIG_COMPAT
 146 static void show_regwindow32(struct pt_regs *regs)
 147 {
 148         struct reg_window32 __user *rw;
 149         struct reg_window32 r_w;
 150         mm_segment_t old_fs;
 151
 152         __asm__ __volatile__ ("flushw");
 153         rw = compat_ptr((unsigned)regs->u_regs[14]);
 154         old_fs = get_fs();
 155         set_fs (USER_DS);
 156         if (copy_from_user (&r_w, rw, sizeof(r_w))) {
 157                 set_fs (old_fs);
 158                 return;
 159         }
 160
 161         set_fs (old_fs);
 162         printk("l0: %08x l1: %08x l2: %08x l3: %08x "
 163                "l4: %08x l5: %08x l6: %08x l7: %08x\n",
 164                r_w.locals[0], r_w.locals[1], r_w.locals[2], r_w.locals[3],
 165                r_w.locals[4], r_w.locals[5], r_w.locals[6], r_w.locals[7]);
 166         printk("i0: %08x i1: %08x i2: %08x i3: %08x "
 167                "i4: %08x i5: %08x i6: %08x i7: %08x\n",
 168                r_w.ins[0], r_w.ins[1], r_w.ins[2], r_w.ins[3],
 169                r_w.ins[4], r_w.ins[5], r_w.ins[6], r_w.ins[7]);
 170 }
 171 #else
 172 #define show_regwindow32(regs)  do { } while (0)
 173 #endif
 174
 175 static void show_regwindow(struct pt_regs *regs)
 176 {
 177         struct reg_window __user *rw;
 178         struct reg_window *rwk;
 179         struct reg_window r_w;
 180         mm_segment_t old_fs;
 181
 182         if ((regs->tstate & TSTATE_PRIV) || !(test_thread_flag(TIF_32BIT))) {
 183                 __asm__ __volatile__ ("flushw");
 184                 rw = (struct reg_window __user *)
 185                         (regs->u_regs[14] + STACK_BIAS);
 186                 rwk = (struct reg_window *)
 187                         (regs->u_regs[14] + STACK_BIAS);
 188                 if (!(regs->tstate & TSTATE_PRIV)) {
 189                         old_fs = get_fs();
 190                         set_fs (USER_DS);
 191                         if (copy_from_user (&r_w, rw, sizeof(r_w))) {
 192                                 set_fs (old_fs);
 193                                 return;
 194                         }
 195                         rwk = &r_w;
 196                         set_fs (old_fs);
 197                 }
 198         } else {
 199                 show_regwindow32(regs);
 200                 return;
 201         }
 202         printk("l0: %016lx l1: %016lx l2: %016lx l3: %016lx\n",
 203                rwk->locals[0], rwk->locals[1], rwk->locals[2], rwk->locals[3]);
 204         printk("l4: %016lx l5: %016lx l6: %016lx l7: %016lx\n",
 205                rwk->locals[4], rwk->locals[5], rwk->locals[6], rwk->locals[7]);
 206         printk("i0: %016lx i1: %016lx i2: %016lx i3: %016lx\n",
 207                rwk->ins[0], rwk->ins[1], rwk->ins[2], rwk->ins[3]);
 208         printk("i4: %016lx i5: %016lx i6: %016lx i7: %016lx\n",
 209                rwk->ins[4], rwk->ins[5], rwk->ins[6], rwk->ins[7]);
 210         if (regs->tstate & TSTATE_PRIV)
 211                 print_symbol("I7: <%s>\n", rwk->ins[7]);
 212 }
 213
 214 #ifdef CONFIG_SMP
 215 static DEFINE_SPINLOCK(regdump_lock);
 216 #endif
 217
 218 void __show_regs(struct pt_regs * regs)
 219 {
 220 #ifdef CONFIG_SMP
 221         unsigned long flags;
 222
 223         /* Protect against xcall ipis which might lead to livelock on the lock */
 224         __asm__ __volatile__("rdpr      %%pstate, %0\n\t"
 225                              "wrpr      %0, %1, %%pstate"
 226                              : "=r" (flags)
 227                              : "i" (PSTATE_IE));
 228         spin_lock(&regdump_lock);
 229 #endif
 230         printk("TSTATE: %016lx TPC: %016lx TNPC: %016lx Y: %08x    %s\n", regs->tstate,
 231                regs->tpc, regs->tnpc, regs->y, print_tainted());
 232         print_symbol("TPC: <%s>\n", regs->tpc);
 233         printk("g0: %016lx g1: %016lx g2: %016lx g3: %016lx\n",
 234                regs->u_regs[0], regs->u_regs[1], regs->u_regs[2],
 235                regs->u_regs[3]);
 236         printk("g4: %016lx g5: %016lx g6: %016lx g7: %016lx\n",
 237                regs->u_regs[4], regs->u_regs[5], regs->u_regs[6],
 238                regs->u_regs[7]);
 239         printk("o0: %016lx o1: %016lx o2: %016lx o3: %016lx\n",
 240                regs->u_regs[8], regs->u_regs[9], regs->u_regs[10],
 241                regs->u_regs[11]);
 242         printk("o4: %016lx o5: %016lx sp: %016lx ret_pc: %016lx\n",
 243                regs->u_regs[12], regs->u_regs[13], regs->u_regs[14],
 244                regs->u_regs[15]);
 245         print_symbol("RPC: <%s>\n", regs->u_regs[15]);
 246         show_regwindow(regs);
 247 #ifdef CONFIG_SMP
 248         spin_unlock(&regdump_lock);
 249         __asm__ __volatile__("wrpr      %0, 0, %%pstate"
 250                              : : "r" (flags));
 251 #endif
 252 }
 253
 254 #ifdef VERBOSE_SHOWREGS
 255 static void idump_from_user (unsigned int *pc)
 256 {
 257         int i;
 258         int code;
 259
 260         if((((unsigned long) pc) & 3))
 261                 return;
 262
 263         pc -= 3;
 264         for(i = -3; i < 6; i++) {
 265                 get_user(code, pc);
 266                 printk("%c%08x%c",i?' ':'<',code,i?' ':'>');
 267                 pc++;
 268         }
 269         printk("\n");
 270 }
 271 #endif
 272
 273 void show_regs(struct pt_regs *regs)
 274 {
 275 #ifdef VERBOSE_SHOWREGS
 276         extern long etrap, etraptl1;
 277 #endif
 278         __show_regs(regs);
 279 #if 0
 280 #ifdef CONFIG_SMP
 281         {
 282                 extern void smp_report_regs(void);
 283
 284                 smp_report_regs();
 285         }
 286 #endif
 287 #endif
 288
 289 #ifdef VERBOSE_SHOWREGS
 290         if (regs->tpc >= &etrap && regs->tpc < &etraptl1 &&
 291             regs->u_regs[14] >= (long)current - PAGE_SIZE &&
 292             regs->u_regs[14] < (long)current + 6 * PAGE_SIZE) {
 293                 printk ("*********parent**********\n");
 294                 __show_regs((struct pt_regs *)(regs->u_regs[14] + PTREGS_OFF));
 295                 idump_from_user(((struct pt_regs *)(regs->u_regs[14] + PTREGS_OFF))->tpc);
 296                 printk ("*********endpar**********\n");
 297         }
 298 #endif
 299 }
 300
 301 unsigned long thread_saved_pc(struct task_struct *tsk)
 302 {
 303         struct thread_info *ti = task_thread_info(tsk);
 304         unsigned long ret = 0xdeadbeefUL;
 305
 306         if (ti && ti->ksp) {
 307                 unsigned long *sp;
 308                 sp = (unsigned long *)(ti->ksp + STACK_BIAS);
 309                 if (((unsigned long)sp & (sizeof(long) - 1)) == 0UL &&
 310                     sp[14]) {
 311                         unsigned long *fp;
 312                         fp = (unsigned long *)(sp[14] + STACK_BIAS);
 313                         if (((unsigned long)fp & (sizeof(long) - 1)) == 0UL)
 314                                 ret = fp[15];
 315                 }
 316         }
 317         return ret;
 318 }
 319
 320 /* Free current thread data structures etc.. */
 321 void exit_thread(void)
 322 {
 323         struct thread_info *t = current_thread_info();
 324
 325         if (t->utraps) {
 326                 if (t->utraps[0] < 2)
 327                         kfree (t->utraps);
 328                 else
 329                         t->utraps[0]--;
 330         }
 331
 332         if (test_and_clear_thread_flag(TIF_PERFCTR)) {
 333                 t->user_cntd0 = t->user_cntd1 = NULL;
 334                 t->pcr_reg = 0;
 335                 write_pcr(0);
 336         }
 337 }
 338
 339 void flush_thread(void)
 340 {
 341         struct thread_info *t = current_thread_info();
 342         struct mm_struct *mm;
 343
 344         if (test_ti_thread_flag(t, TIF_ABI_PENDING)) {
 345                 clear_ti_thread_flag(t, TIF_ABI_PENDING);
 346                 if (test_ti_thread_flag(t, TIF_32BIT))
 347                         clear_ti_thread_flag(t, TIF_32BIT);
 348                 else
 349                         set_ti_thread_flag(t, TIF_32BIT);
 350         }
 351
 352         mm = t->task->mm;
 353         if (mm)
 354                 tsb_context_switch(mm);
 355
 356         set_thread_wsaved(0);
 357
 358         /* Turn off performance counters if on. */
 359         if (test_and_clear_thread_flag(TIF_PERFCTR)) {
 360                 t->user_cntd0 = t->user_cntd1 = NULL;
 361                 t->pcr_reg = 0;
 362                 write_pcr(0);
 363         }
 364
 365         /* Clear FPU register state. */
 366         t->fpsaved[0] = 0;
 367
 368         if (get_thread_current_ds() != ASI_AIUS)
 369                 set_fs(USER_DS);
 370 }
 371
 372 /* It's a bit more tricky when 64-bit tasks are involved... */
 373 static unsigned long clone_stackframe(unsigned long csp, unsigned long psp)
 374 {
 375         unsigned long fp, distance, rval;
 376
 377         if (!(test_thread_flag(TIF_32BIT))) {
 378                 csp += STACK_BIAS;
 379                 psp += STACK_BIAS;
 380                 __get_user(fp, &(((struct reg_window __user *)psp)->ins[6]));
 381                 fp += STACK_BIAS;
 382         } else
 383                 __get_user(fp, &(((struct reg_window32 __user *)psp)->ins[6]));
 384
 385         /* Now 8-byte align the stack as this is mandatory in the
 386          * Sparc ABI due to how register windows work.  This hides
 387          * the restriction from thread libraries etc.  -DaveM
 388          */
 389         csp &= ~7UL;
 390
 391         distance = fp - psp;
 392         rval = (csp - distance);
 393         if (copy_in_user((void __user *) rval, (void __user *) psp, distance))
 394                 rval = 0;
 395         else if (test_thread_flag(TIF_32BIT)) {
 396                 if (put_user(((u32)csp),
 397                              &(((struct reg_window32 __user *)rval)->ins[6])))
 398                         rval = 0;
 399         } else {
 400                 if (put_user(((u64)csp - STACK_BIAS),
 401                              &(((struct reg_window __user *)rval)->ins[6])))
 402                         rval = 0;
 403                 else
 404                         rval = rval - STACK_BIAS;
 405         }
 406
 407         return rval;
 408 }
 409
 410 /* Standard stuff. */
 411 static inline void shift_window_buffer(int first_win, int last_win,
 412                                        struct thread_info *t)
 413 {
 414         int i;
 415
 416         for (i = first_win; i < last_win; i++) {
 417                 t->rwbuf_stkptrs[i] = t->rwbuf_stkptrs[i+1];
 418                 memcpy(&t->reg_window[i], &t->reg_window[i+1],
 419                        sizeof(struct reg_window));
 420         }
 421 }
 422
 423 void synchronize_user_stack(void)
 424 {
 425         struct thread_info *t = current_thread_info();
 426         unsigned long window;
 427
 428         flush_user_windows();
 429         if ((window = get_thread_wsaved()) != 0) {
 430                 int winsize = sizeof(struct reg_window);
 431                 int bias = 0;
 432
 433                 if (test_thread_flag(TIF_32BIT))
 434                         winsize = sizeof(struct reg_window32);
 435                 else
 436                         bias = STACK_BIAS;
 437
 438                 window -= 1;
 439                 do {
 440                         unsigned long sp = (t->rwbuf_stkptrs[window] + bias);
 441                         struct reg_window *rwin = &t->reg_window[window];
 442
 443                         if (!copy_to_user((char __user *)sp, rwin, winsize)) {
 444                                 shift_window_buffer(window, get_thread_wsaved() - 1, t);
 445                                 set_thread_wsaved(get_thread_wsaved() - 1);
 446                         }
 447                 } while (window--);
 448         }
 449 }
 450
 451 static void stack_unaligned(unsigned long sp)
 452 {
 453         siginfo_t info;
 454
 455         info.si_signo = SIGBUS;
 456         info.si_errno = 0;
 457         info.si_code = BUS_ADRALN;
 458         info.si_addr = (void __user *) sp;
 459         info.si_trapno = 0;
 460         force_sig_info(SIGBUS, &info, current);
 461 }
 462
 463 void fault_in_user_windows(void)
 464 {
 465         struct thread_info *t = current_thread_info();
 466         unsigned long window;
 467         int winsize = sizeof(struct reg_window);
 468         int bias = 0;
 469
 470         if (test_thread_flag(TIF_32BIT))
 471                 winsize = sizeof(struct reg_window32);
 472         else
 473                 bias = STACK_BIAS;
 474
 475         flush_user_windows();
 476         window = get_thread_wsaved();
 477
 478         if (likely(window != 0)) {
 479                 window -= 1;
 480                 do {
 481                         unsigned long sp = (t->rwbuf_stkptrs[window] + bias);
 482                         struct reg_window *rwin = &t->reg_window[window];
 483
 484                         if (unlikely(sp & 0x7UL))
 485                                 stack_unaligned(sp);
 486
 487                         if (unlikely(copy_to_user((char __user *)sp,
 488                                                   rwin, winsize)))
 489                                 goto barf;
 490                 } while (window--);
 491         }
 492         set_thread_wsaved(0);
 493         return;
 494
 495 barf:
 496         set_thread_wsaved(window + 1);
 497         do_exit(SIGILL);
 498 }
 499
 500 asmlinkage long sparc_do_fork(unsigned long clone_flags,
 501                               unsigned long stack_start,
 502                               struct pt_regs *regs,
 503                               unsigned long stack_size)
 504 {
 505         int __user *parent_tid_ptr, *child_tid_ptr;
 506
 507 #ifdef CONFIG_COMPAT
 508         if (test_thread_flag(TIF_32BIT)) {
 509                 parent_tid_ptr = compat_ptr(regs->u_regs[UREG_I2]);
 510                 child_tid_ptr = compat_ptr(regs->u_regs[UREG_I4]);
 511         } else
 512 #endif
 513         {
 514                 parent_tid_ptr = (int __user *) regs->u_regs[UREG_I2];
 515                 child_tid_ptr = (int __user *) regs->u_regs[UREG_I4];
 516         }
 517
 518         return do_fork(clone_flags, stack_start,
 519                        regs, stack_size,
 520                        parent_tid_ptr, child_tid_ptr);
 521 }
 522
 523 /* Copy a Sparc thread.  The fork() return value conventions
 524  * under SunOS are nothing short of bletcherous:
 525  * Parent -->  %o0 == childs  pid, %o1 == 0
 526  * Child  -->  %o0 == parents pid, %o1 == 1
 527  */
 528 int copy_thread(int nr, unsigned long clone_flags, unsigned long sp,
 529                 unsigned long unused,
 530                 struct task_struct *p, struct pt_regs *regs)
 531 {
 532         struct thread_info *t = task_thread_info(p);
 533         char *child_trap_frame;
 534
 535         /* Calculate offset to stack_frame & pt_regs */
 536         child_trap_frame = task_stack_page(p) + (THREAD_SIZE - (TRACEREG_SZ+STACKFRAME_SZ));
 537         memcpy(child_trap_frame, (((struct sparc_stackf *)regs)-1), (TRACEREG_SZ+STACKFRAME_SZ));
 538
 539         t->flags = (t->flags & ~((0xffUL << TI_FLAG_CWP_SHIFT) | (0xffUL << TI_FLAG_CURRENT_DS_SHIFT))) |
 540                 (((regs->tstate + 1) & TSTATE_CWP) << TI_FLAG_CWP_SHIFT);
 541         t->new_child = 1;
 542         t->ksp = ((unsigned long) child_trap_frame) - STACK_BIAS;
 543         t->kregs = (struct pt_regs *)(child_trap_frame+sizeof(struct sparc_stackf));
 544         t->fpsaved[0] = 0;
 545
 546         if (regs->tstate & TSTATE_PRIV) {
 547                 /* Special case, if we are spawning a kernel thread from
 548                  * a userspace task (via KMOD, NFS, or similar) we must
 549                  * disable performance counters in the child because the
 550                  * address space and protection realm are changing.
 551                  */
 552                 if (t->flags & _TIF_PERFCTR) {
 553                         t->user_cntd0 = t->user_cntd1 = NULL;
 554                         t->pcr_reg = 0;
 555                         t->flags &= ~_TIF_PERFCTR;
 556                 }
 557                 t->kregs->u_regs[UREG_FP] = t->ksp;
 558                 t->flags |= ((long)ASI_P << TI_FLAG_CURRENT_DS_SHIFT);
 559                 flush_register_windows();
 560                 memcpy((void *)(t->ksp + STACK_BIAS),
 561                        (void *)(regs->u_regs[UREG_FP] + STACK_BIAS),
 562                        sizeof(struct sparc_stackf));
 563                 t->kregs->u_regs[UREG_G6] = (unsigned long) t;
 564                 t->kregs->u_regs[UREG_G4] = (unsigned long) t->task;
 565         } else {
 566                 if (t->flags & _TIF_32BIT) {
 567                         sp &= 0x00000000ffffffffUL;
 568                         regs->u_regs[UREG_FP] &= 0x00000000ffffffffUL;
 569                 }
 570                 t->kregs->u_regs[UREG_FP] = sp;
 571                 t->flags |= ((long)ASI_AIUS << TI_FLAG_CURRENT_DS_SHIFT);
 572                 if (sp != regs->u_regs[UREG_FP]) {
 573                         unsigned long csp;
 574
 575                         csp = clone_stackframe(sp, regs->u_regs[UREG_FP]);
 576                         if (!csp)
 577                                 return -EFAULT;
 578                         t->kregs->u_regs[UREG_FP] = csp;
 579                 }
 580                 if (t->utraps)
 581                         t->utraps[0]++;
 582         }
 583
 584         /* Set the return value for the child. */
 585         t->kregs->u_regs[UREG_I0] = current->pid;
 586         t->kregs->u_regs[UREG_I1] = 1;
 587
 588         /* Set the second return value for the parent. */
 589         regs->u_regs[UREG_I1] = 0;
 590
 591         if (clone_flags & CLONE_SETTLS)
 592                 t->kregs->u_regs[UREG_G7] = regs->u_regs[UREG_I3];
 593
 594         /* We do not want to accidently trigger system call restart
 595          * handling in the new thread.  Therefore, clear out the trap
 596          * type, which will make pt_regs_regs_is_syscall() return false.
 597          */
 598         pt_regs_clear_trap_type(t->kregs);
 599
 600         return 0;
 601 }
 602
 603 /*
 604  * This is the mechanism for creating a new kernel thread.
 605  *
 606  * NOTE! Only a kernel-only process(ie the swapper or direct descendants
 607  * who haven't done an "execve()") should use this: it will work within
 608  * a system call from a "real" process, but the process memory space will
 609  * not be freed until both the parent and the child have exited.
 610  */
 611 pid_t kernel_thread(int (*fn)(void *), void * arg, unsigned long flags)
 612 {
 613         long retval;
 614
 615         /* If the parent runs before fn(arg) is called by the child,
 616          * the input registers of this function can be clobbered.
 617          * So we stash 'fn' and 'arg' into global registers which
 618          * will not be modified by the parent.
 619          */
 620         __asm__ __volatile__("mov %4, %%g2\n\t"    /* Save FN into global */
 621                              "mov %5, %%g3\n\t"    /* Save ARG into global */
 622                              "mov %1, %%g1\n\t"    /* Clone syscall nr. */
 623                              "mov %2, %%o0\n\t"    /* Clone flags. */
 624                              "mov 0, %%o1\n\t"     /* usp arg == 0 */
 625                              "t 0x6d\n\t"          /* Linux/Sparc clone(). */
 626                              "brz,a,pn %%o1, 1f\n\t" /* Parent, just return. */
 627                              " mov %%o0, %0\n\t"
 628                              "jmpl %%g2, %%o7\n\t"   /* Call the function. */
 629                              " mov %%g3, %%o0\n\t"   /* Set arg in delay. */
 630                              "mov %3, %%g1\n\t"
 631                              "t 0x6d\n\t"          /* Linux/Sparc exit(). */
 632                              /* Notreached by child. */
 633                              "1:" :
 634                              "=r" (retval) :
 635                              "i" (__NR_clone), "r" (flags | CLONE_VM | CLONE_UNTRACED),
 636                              "i" (__NR_exit),  "r" (fn), "r" (arg) :
 637                              "g1", "g2", "g3", "o0", "o1", "memory", "cc");
 638         return retval;
 639 }
 640
 641 typedef struct {
 642         union {
 643                 unsigned int    pr_regs[32];
 644                 unsigned long   pr_dregs[16];
 645         } pr_fr;
 646         unsigned int __unused;
 647         unsigned int    pr_fsr;
 648         unsigned char   pr_qcnt;
 649         unsigned char   pr_q_entrysize;
 650         unsigned char   pr_en;
 651         unsigned int    pr_q[64];
 652 } elf_fpregset_t32;
 653
 654 /*
 655  * fill in the fpu structure for a core dump.
 656  */
 657 int dump_fpu (struct pt_regs * regs, elf_fpregset_t * fpregs)
 658 {
 659         unsigned long *kfpregs = current_thread_info()->fpregs;
 660         unsigned long fprs = current_thread_info()->fpsaved[0];
 661
 662         if (test_thread_flag(TIF_32BIT)) {
 663                 elf_fpregset_t32 *fpregs32 = (elf_fpregset_t32 *)fpregs;
 664
 665                 if (fprs & FPRS_DL)
 666                         memcpy(&fpregs32->pr_fr.pr_regs[0], kfpregs,
 667                                sizeof(unsigned int) * 32);
 668                 else
 669                         memset(&fpregs32->pr_fr.pr_regs[0], 0,
 670                                sizeof(unsigned int) * 32);
 671                 fpregs32->pr_qcnt = 0;
 672                 fpregs32->pr_q_entrysize = 8;
 673                 memset(&fpregs32->pr_q[0], 0,
 674                        (sizeof(unsigned int) * 64));
 675                 if (fprs & FPRS_FEF) {
 676                         fpregs32->pr_fsr = (unsigned int) current_thread_info()->xfsr[0];
 677                         fpregs32->pr_en = 1;
 678                 } else {
 679                         fpregs32->pr_fsr = 0;
 680                         fpregs32->pr_en = 0;
 681                 }
 682         } else {
 683                 if(fprs & FPRS_DL)
 684                         memcpy(&fpregs->pr_regs[0], kfpregs,
 685                                sizeof(unsigned int) * 32);
 686                 else
 687                         memset(&fpregs->pr_regs[0], 0,
 688                                sizeof(unsigned int) * 32);
 689                 if(fprs & FPRS_DU)
 690                         memcpy(&fpregs->pr_regs[16], kfpregs+16,
 691                                sizeof(unsigned int) * 32);
 692                 else
 693                         memset(&fpregs->pr_regs[16], 0,
 694                                sizeof(unsigned int) * 32);
 695                 if(fprs & FPRS_FEF) {
 696                         fpregs->pr_fsr = current_thread_info()->xfsr[0];
 697                         fpregs->pr_gsr = current_thread_info()->gsr[0];
 698                 } else {
 699                         fpregs->pr_fsr = fpregs->pr_gsr = 0;
 700                 }
 701                 fpregs->pr_fprs = fprs;
 702         }
 703         return 1;
 704 }
 705
 706 /*
 707  * sparc_execve() executes a new program after the asm stub has set
 708  * things up for us.  This should basically do what I want it to.
 709  */
 710 asmlinkage int sparc_execve(struct pt_regs *regs)
 711 {
 712         int error, base = 0;
 713         char *filename;
 714
 715         /* User register window flush is done by entry.S */
 716
 717         /* Check for indirect call. */
 718         if (regs->u_regs[UREG_G1] == 0)
 719                 base = 1;
 720
 721         filename = getname((char __user *)regs->u_regs[base + UREG_I0]);
 722         error = PTR_ERR(filename);
 723         if (IS_ERR(filename))
 724                 goto out;
 725         error = do_execve(filename,
 726                           (char __user * __user *)
 727                           regs->u_regs[base + UREG_I1],
 728                           (char __user * __user *)
 729                           regs->u_regs[base + UREG_I2], regs);
 730         putname(filename);
 731         if (!error) {
 732                 fprs_write(0);
 733                 current_thread_info()->xfsr[0] = 0;
 734                 current_thread_info()->fpsaved[0] = 0;
 735                 regs->tstate &= ~TSTATE_PEF;
 736         }
 737 out:
 738         return error;
 739 }
 740
 741 unsigned long get_wchan(struct task_struct *task)
 742 {
 743         unsigned long pc, fp, bias = 0;
 744         unsigned long thread_info_base;
 745         struct reg_window *rw;
 746         unsigned long ret = 0;
 747         int count = 0;
 748
 749         if (!task || task == current ||
 750             task->state == TASK_RUNNING)
 751                 goto out;
 752
 753         thread_info_base = (unsigned long) task_stack_page(task);
 754         bias = STACK_BIAS;
 755         fp = task_thread_info(task)->ksp + bias;
 756
 757         do {
 758                 /* Bogus frame pointer? */
 759                 if (fp < (thread_info_base + sizeof(struct thread_info)) ||
 760                     fp >= (thread_info_base + THREAD_SIZE))
 761                         break;
 762                 rw = (struct reg_window *) fp;
 763                 pc = rw->ins[7];
 764                 if (!in_sched_functions(pc)) {
 765                         ret = pc;
 766                         goto out;
 767                 }
 768                 fp = rw->ins[6] + bias;
 769         } while (++count < 16);
 770
 771 out:
 772         return ret;
 773 }