arch/sparc/kernel/process.c

   1 /*  $Id: process.c,v 1.161 2002/01/23 11:27:32 davem Exp $
   2  *  linux/arch/sparc/kernel/process.c
   3  *
   4  *  Copyright (C) 1995 David S. Miller (davem@caip.rutgers.edu)
   5  *  Copyright (C) 1996 Eddie C. Dost   (ecd@skynet.be)
   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/stddef.h>
  21 #include <linux/ptrace.h>
  22 #include <linux/slab.h>
  23 #include <linux/user.h>
  24 #include <linux/a.out.h>
  25 #include <linux/config.h>
  26 #include <linux/smp.h>
  27 #include <linux/smp_lock.h>
  28 #include <linux/reboot.h>
  29 #include <linux/delay.h>
  30 #include <linux/pm.h>
  31 #include <linux/init.h>
  32
  33 #include <asm/auxio.h>
  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/delay.h>
  41 #include <asm/processor.h>
  42 #include <asm/psr.h>
  43 #include <asm/elf.h>
  44 #include <asm/unistd.h>
  45
  46 /*
  47  * Power management idle function
  48  * Set in pm platform drivers (apc.c and pmc.c)
  49  */
  50 void (*pm_idle)(void);
  51
  52 /*
  53  * Power-off handler instantiation for pm.h compliance
  54  * This is done via auxio, but could be used as a fallback
  55  * handler when auxio is not present-- unused for now...
  56  */
  57 void (*pm_power_off)(void);
  58
  59 /*
  60  * sysctl - toggle power-off restriction for serial console
  61  * systems in machine_power_off()
  62  */
  63 int scons_pwroff = 1;
  64
  65 extern void fpsave(unsigned long *, unsigned long *, void *, unsigned long *);
  66
  67 struct task_struct *last_task_used_math = NULL;
  68 struct thread_info *current_set[NR_CPUS];
  69
  70 /*
  71  * default_idle is new in 2.5. XXX Review, currently stolen from sparc64.
  72  */
  73 void default_idle(void)
  74 {
  75 }
  76
  77 #ifndef CONFIG_SMP
  78
  79 #define SUN4C_FAULT_HIGH 100
  80
  81 /*
  82  * the idle loop on a Sparc... ;)
  83  */
  84 void cpu_idle(void)
  85 {
  86         /* endless idle loop with no priority at all */
  87         for (;;) {
  88                 if (ARCH_SUN4C_SUN4) {
  89                         static int count = HZ;
  90                         static unsigned long last_jiffies;
  91                         static unsigned long last_faults;
  92                         static unsigned long fps;
  93                         unsigned long now;
  94                         unsigned long faults;
  95                         unsigned long flags;
  96
  97                         extern unsigned long sun4c_kernel_faults;
  98                         extern void sun4c_grow_kernel_ring(void);
  99
 100                         local_irq_save(flags);
 101                         now = jiffies;
 102                         count -= (now - last_jiffies);
 103                         last_jiffies = now;
 104                         if (count < 0) {
 105                                 count += HZ;
 106                                 faults = sun4c_kernel_faults;
 107                                 fps = (fps + (faults - last_faults)) >> 1;
 108                                 last_faults = faults;
 109 #if 0
 110                                 printk("kernel faults / second = %ld\n", fps);
 111 #endif
 112                                 if (fps >= SUN4C_FAULT_HIGH) {
 113                                         sun4c_grow_kernel_ring();
 114                                 }
 115                         }
 116                         local_irq_restore(flags);
 117                 }
 118
 119                 while((!need_resched()) && pm_idle) {
 120                         (*pm_idle)();
 121                 }
 122
 123                 schedule();
 124                 check_pgt_cache();
 125         }
 126 }
 127
 128 #else
 129
 130 /* This is being executed in task 0 'user space'. */
 131 void cpu_idle(void)
 132 {
 133         /* endless idle loop with no priority at all */
 134         while(1) {
 135                 if(need_resched()) {
 136                         schedule();
 137                         check_pgt_cache();
 138                 }
 139                 barrier(); /* or else gcc optimizes... */
 140         }
 141 }
 142
 143 #endif
 144
 145 extern char reboot_command [];
 146
 147 extern void (*prom_palette)(int);
 148
 149 /* XXX cli/sti -> local_irq_xxx here, check this works once SMP is fixed. */
 150 void machine_halt(void)
 151 {
 152         local_irq_enable();
 153         mdelay(8);
 154         local_irq_disable();
 155         if (!serial_console && prom_palette)
 156                 prom_palette (1);
 157         prom_halt();
 158         panic("Halt failed!");
 159 }
 160
 161 EXPORT_SYMBOL(machine_halt);
 162
 163 void machine_restart(char * cmd)
 164 {
 165         char *p;
 166
 167         local_irq_enable();
 168         mdelay(8);
 169         local_irq_disable();
 170
 171         p = strchr (reboot_command, '\n');
 172         if (p) *p = 0;
 173         if (!serial_console && prom_palette)
 174                 prom_palette (1);
 175         if (cmd)
 176                 prom_reboot(cmd);
 177         if (*reboot_command)
 178                 prom_reboot(reboot_command);
 179         prom_feval ("reset");
 180         panic("Reboot failed!");
 181 }
 182
 183 EXPORT_SYMBOL(machine_restart);
 184
 185 void machine_power_off(void)
 186 {
 187 #ifdef CONFIG_SUN_AUXIO
 188         if (auxio_power_register && (!serial_console || scons_pwroff))
 189                 *auxio_power_register |= AUXIO_POWER_OFF;
 190 #endif
 191         machine_halt();
 192 }
 193
 194 EXPORT_SYMBOL(machine_power_off);
 195
 196 static DEFINE_SPINLOCK(sparc_backtrace_lock);
 197
 198 void __show_backtrace(unsigned long fp)
 199 {
 200         struct reg_window *rw;
 201         unsigned long flags;
 202         int cpu = smp_processor_id();
 203
 204         spin_lock_irqsave(&sparc_backtrace_lock, flags);
 205
 206         rw = (struct reg_window *)fp;
 207         while(rw && (((unsigned long) rw) >= PAGE_OFFSET) &&
 208             !(((unsigned long) rw) & 0x7)) {
 209                 printk("CPU[%d]: ARGS[%08lx,%08lx,%08lx,%08lx,%08lx,%08lx] "
 210                        "FP[%08lx] CALLER[%08lx]: ", cpu,
 211                        rw->ins[0], rw->ins[1], rw->ins[2], rw->ins[3],
 212                        rw->ins[4], rw->ins[5],
 213                        rw->ins[6],
 214                        rw->ins[7]);
 215                 print_symbol("%s\n", rw->ins[7]);
 216                 rw = (struct reg_window *) rw->ins[6];
 217         }
 218         spin_unlock_irqrestore(&sparc_backtrace_lock, flags);
 219 }
 220
 221 #define __SAVE __asm__ __volatile__("save %sp, -0x40, %sp\n\t")
 222 #define __RESTORE __asm__ __volatile__("restore %g0, %g0, %g0\n\t")
 223 #define __GET_FP(fp) __asm__ __volatile__("mov %%i6, %0" : "=r" (fp))
 224
 225 void show_backtrace(void)
 226 {
 227         unsigned long fp;
 228
 229         __SAVE; __SAVE; __SAVE; __SAVE;
 230         __SAVE; __SAVE; __SAVE; __SAVE;
 231         __RESTORE; __RESTORE; __RESTORE; __RESTORE;
 232         __RESTORE; __RESTORE; __RESTORE; __RESTORE;
 233
 234         __GET_FP(fp);
 235
 236         __show_backtrace(fp);
 237 }
 238
 239 #ifdef CONFIG_SMP
 240 void smp_show_backtrace_all_cpus(void)
 241 {
 242         xc0((smpfunc_t) show_backtrace);
 243         show_backtrace();
 244 }
 245 #endif
 246
 247 #if 0
 248 void show_stackframe(struct sparc_stackf *sf)
 249 {
 250         unsigned long size;
 251         unsigned long *stk;
 252         int i;
 253
 254         printk("l0: %08lx l1: %08lx l2: %08lx l3: %08lx "
 255                "l4: %08lx l5: %08lx l6: %08lx l7: %08lx\n",
 256                sf->locals[0], sf->locals[1], sf->locals[2], sf->locals[3],
 257                sf->locals[4], sf->locals[5], sf->locals[6], sf->locals[7]);
 258         printk("i0: %08lx i1: %08lx i2: %08lx i3: %08lx "
 259                "i4: %08lx i5: %08lx fp: %08lx i7: %08lx\n",
 260                sf->ins[0], sf->ins[1], sf->ins[2], sf->ins[3],
 261                sf->ins[4], sf->ins[5], (unsigned long)sf->fp, sf->callers_pc);
 262         printk("sp: %08lx x0: %08lx x1: %08lx x2: %08lx "
 263                "x3: %08lx x4: %08lx x5: %08lx xx: %08lx\n",
 264                (unsigned long)sf->structptr, sf->xargs[0], sf->xargs[1],
 265                sf->xargs[2], sf->xargs[3], sf->xargs[4], sf->xargs[5],
 266                sf->xxargs[0]);
 267         size = ((unsigned long)sf->fp) - ((unsigned long)sf);
 268         size -= STACKFRAME_SZ;
 269         stk = (unsigned long *)((unsigned long)sf + STACKFRAME_SZ);
 270         i = 0;
 271         do {
 272                 printk("s%d: %08lx\n", i++, *stk++);
 273         } while ((size -= sizeof(unsigned long)));
 274 }
 275 #endif
 276
 277 void show_regs(struct pt_regs *r)
 278 {
 279         struct reg_window *rw = (struct reg_window *) r->u_regs[14];
 280
 281         printk("PSR: %08lx PC: %08lx NPC: %08lx Y: %08lx    %s\n",
 282                r->psr, r->pc, r->npc, r->y, print_tainted());
 283         print_symbol("PC: <%s>\n", r->pc);
 284         printk("%%G: %08lx %08lx  %08lx %08lx  %08lx %08lx  %08lx %08lx\n",
 285                r->u_regs[0], r->u_regs[1], r->u_regs[2], r->u_regs[3],
 286                r->u_regs[4], r->u_regs[5], r->u_regs[6], r->u_regs[7]);
 287         printk("%%O: %08lx %08lx  %08lx %08lx  %08lx %08lx  %08lx %08lx\n",
 288                r->u_regs[8], r->u_regs[9], r->u_regs[10], r->u_regs[11],
 289                r->u_regs[12], r->u_regs[13], r->u_regs[14], r->u_regs[15]);
 290         print_symbol("RPC: <%s>\n", r->u_regs[15]);
 291
 292         printk("%%L: %08lx %08lx  %08lx %08lx  %08lx %08lx  %08lx %08lx\n",
 293                rw->locals[0], rw->locals[1], rw->locals[2], rw->locals[3],
 294                rw->locals[4], rw->locals[5], rw->locals[6], rw->locals[7]);
 295         printk("%%I: %08lx %08lx  %08lx %08lx  %08lx %08lx  %08lx %08lx\n",
 296                rw->ins[0], rw->ins[1], rw->ins[2], rw->ins[3],
 297                rw->ins[4], rw->ins[5], rw->ins[6], rw->ins[7]);
 298 }
 299
 300 /*
 301  * The show_stack is an external API which we do not use ourselves.
 302  * The oops is printed in die_if_kernel.
 303  */
 304 void show_stack(struct task_struct *tsk, unsigned long *_ksp)
 305 {
 306         unsigned long pc, fp;
 307         unsigned long task_base;
 308         struct reg_window *rw;
 309         int count = 0;
 310
 311         if (tsk != NULL)
 312                 task_base = (unsigned long) tsk->thread_info;
 313         else
 314                 task_base = (unsigned long) current_thread_info();
 315
 316         fp = (unsigned long) _ksp;
 317         do {
 318                 /* Bogus frame pointer? */
 319                 if (fp < (task_base + sizeof(struct thread_info)) ||
 320                     fp >= (task_base + (PAGE_SIZE << 1)))
 321                         break;
 322                 rw = (struct reg_window *) fp;
 323                 pc = rw->ins[7];
 324                 printk("[%08lx : ", pc);
 325                 print_symbol("%s ] ", pc);
 326                 fp = rw->ins[6];
 327         } while (++count < 16);
 328         printk("\n");
 329 }
 330
 331 void dump_stack(void)
 332 {
 333         unsigned long *ksp;
 334
 335         __asm__ __volatile__("mov       %%fp, %0"
 336                              : "=r" (ksp));
 337         show_stack(current, ksp);
 338 }
 339
 340 EXPORT_SYMBOL(dump_stack);
 341
 342 /*
 343  * Note: sparc64 has a pretty intricated thread_saved_pc, check it out.
 344  */
 345 unsigned long thread_saved_pc(struct task_struct *tsk)
 346 {
 347         return tsk->thread_info->kpc;
 348 }
 349
 350 /*
 351  * Free current thread data structures etc..
 352  */
 353 void exit_thread(void)
 354 {
 355 #ifndef CONFIG_SMP
 356         if(last_task_used_math == current) {
 357 #else
 358         if(current_thread_info()->flags & _TIF_USEDFPU) {
 359 #endif
 360                 /* Keep process from leaving FPU in a bogon state. */
 361                 put_psr(get_psr() | PSR_EF);
 362                 fpsave(&current->thread.float_regs[0], &current->thread.fsr,
 363                        &current->thread.fpqueue[0], &current->thread.fpqdepth);
 364 #ifndef CONFIG_SMP
 365                 last_task_used_math = NULL;
 366 #else
 367                 current_thread_info()->flags &= ~_TIF_USEDFPU;
 368 #endif
 369         }
 370 }
 371
 372 void flush_thread(void)
 373 {
 374         current_thread_info()->w_saved = 0;
 375
 376         /* No new signal delivery by default */
 377         current->thread.new_signal = 0;
 378 #ifndef CONFIG_SMP
 379         if(last_task_used_math == current) {
 380 #else
 381         if(current_thread_info()->flags & _TIF_USEDFPU) {
 382 #endif
 383                 /* Clean the fpu. */
 384                 put_psr(get_psr() | PSR_EF);
 385                 fpsave(&current->thread.float_regs[0], &current->thread.fsr,
 386                        &current->thread.fpqueue[0], &current->thread.fpqdepth);
 387 #ifndef CONFIG_SMP
 388                 last_task_used_math = NULL;
 389 #else
 390                 current_thread_info()->flags &= ~_TIF_USEDFPU;
 391 #endif
 392         }
 393
 394         /* Now, this task is no longer a kernel thread. */
 395         current->thread.current_ds = USER_DS;
 396         if (current->thread.flags & SPARC_FLAG_KTHREAD) {
 397                 current->thread.flags &= ~SPARC_FLAG_KTHREAD;
 398
 399                 /* We must fixup kregs as well. */
 400                 /* XXX This was not fixed for ti for a while, worked. Unused? */
 401                 current->thread.kregs = (struct pt_regs *)
 402                     ((char *)current->thread_info + (THREAD_SIZE - TRACEREG_SZ));
 403         }
 404 }
 405
 406 static __inline__ struct sparc_stackf __user *
 407 clone_stackframe(struct sparc_stackf __user *dst,
 408                  struct sparc_stackf __user *src)
 409 {
 410         unsigned long size, fp;
 411         struct sparc_stackf *tmp;
 412         struct sparc_stackf __user *sp;
 413
 414         if (get_user(tmp, &src->fp))
 415                 return NULL;
 416
 417         fp = (unsigned long) tmp;
 418         size = (fp - ((unsigned long) src));
 419         fp = (unsigned long) dst;
 420         sp = (struct sparc_stackf __user *)(fp - size);
 421
 422         /* do_fork() grabs the parent semaphore, we must release it
 423          * temporarily so we can build the child clone stack frame
 424          * without deadlocking.
 425          */
 426         if (__copy_user(sp, src, size))
 427                 sp = NULL;
 428         else if (put_user(fp, &sp->fp))
 429                 sp = NULL;
 430
 431         return sp;
 432 }
 433
 434 asmlinkage int sparc_do_fork(unsigned long clone_flags,
 435                              unsigned long stack_start,
 436                              struct pt_regs *regs,
 437                              unsigned long stack_size)
 438 {
 439         unsigned long parent_tid_ptr, child_tid_ptr;
 440
 441         parent_tid_ptr = regs->u_regs[UREG_I2];
 442         child_tid_ptr = regs->u_regs[UREG_I4];
 443
 444         return do_fork(clone_flags, stack_start,
 445                        regs, stack_size,
 446                        (int __user *) parent_tid_ptr,
 447                        (int __user *) child_tid_ptr);
 448 }
 449
 450 /* Copy a Sparc thread.  The fork() return value conventions
 451  * under SunOS are nothing short of bletcherous:
 452  * Parent -->  %o0 == childs  pid, %o1 == 0
 453  * Child  -->  %o0 == parents pid, %o1 == 1
 454  *
 455  * NOTE: We have a separate fork kpsr/kwim because
 456  *       the parent could change these values between
 457  *       sys_fork invocation and when we reach here
 458  *       if the parent should sleep while trying to
 459  *       allocate the task_struct and kernel stack in
 460  *       do_fork().
 461  * XXX See comment above sys_vfork in sparc64. todo.
 462  */
 463 extern void ret_from_fork(void);
 464
 465 int copy_thread(int nr, unsigned long clone_flags, unsigned long sp,
 466                 unsigned long unused,
 467                 struct task_struct *p, struct pt_regs *regs)
 468 {
 469         struct thread_info *ti = p->thread_info;
 470         struct pt_regs *childregs;
 471         char *new_stack;
 472
 473 #ifndef CONFIG_SMP
 474         if(last_task_used_math == current) {
 475 #else
 476         if(current_thread_info()->flags & _TIF_USEDFPU) {
 477 #endif
 478                 put_psr(get_psr() | PSR_EF);
 479                 fpsave(&p->thread.float_regs[0], &p->thread.fsr,
 480                        &p->thread.fpqueue[0], &p->thread.fpqdepth);
 481 #ifdef CONFIG_SMP
 482                 current_thread_info()->flags &= ~_TIF_USEDFPU;
 483 #endif
 484         }
 485
 486         /*
 487          *  p->thread_info         new_stack   childregs
 488          *  !                      !           !             {if(PSR_PS) }
 489          *  V                      V (stk.fr.) V  (pt_regs)  { (stk.fr.) }
 490          *  +----- - - - - - ------+===========+============={+==========}+
 491          */
 492         new_stack = (char*)ti + THREAD_SIZE;
 493         if (regs->psr & PSR_PS)
 494                 new_stack -= STACKFRAME_SZ;
 495         new_stack -= STACKFRAME_SZ + TRACEREG_SZ;
 496         memcpy(new_stack, (char *)regs - STACKFRAME_SZ, STACKFRAME_SZ + TRACEREG_SZ);
 497         childregs = (struct pt_regs *) (new_stack + STACKFRAME_SZ);
 498
 499         /*
 500          * A new process must start with interrupts closed in 2.5,
 501          * because this is how Mingo's scheduler works (see schedule_tail
 502          * and finish_arch_switch). If we do not do it, a timer interrupt hits
 503          * before we unlock, attempts to re-take the rq->lock, and then we die.
 504          * Thus, kpsr|=PSR_PIL.
 505          */
 506         ti->ksp = (unsigned long) new_stack;
 507         ti->kpc = (((unsigned long) ret_from_fork) - 0x8);
 508         ti->kpsr = current->thread.fork_kpsr | PSR_PIL;
 509         ti->kwim = current->thread.fork_kwim;
 510
 511         if(regs->psr & PSR_PS) {
 512                 extern struct pt_regs fake_swapper_regs;
 513
 514                 p->thread.kregs = &fake_swapper_regs;
 515                 new_stack += STACKFRAME_SZ + TRACEREG_SZ;
 516                 childregs->u_regs[UREG_FP] = (unsigned long) new_stack;
 517                 p->thread.flags |= SPARC_FLAG_KTHREAD;
 518                 p->thread.current_ds = KERNEL_DS;
 519                 memcpy(new_stack, (void *)regs->u_regs[UREG_FP], STACKFRAME_SZ);
 520                 childregs->u_regs[UREG_G6] = (unsigned long) ti;
 521         } else {
 522                 p->thread.kregs = childregs;
 523                 childregs->u_regs[UREG_FP] = sp;
 524                 p->thread.flags &= ~SPARC_FLAG_KTHREAD;
 525                 p->thread.current_ds = USER_DS;
 526
 527                 if (sp != regs->u_regs[UREG_FP]) {
 528                         struct sparc_stackf __user *childstack;
 529                         struct sparc_stackf __user *parentstack;
 530
 531                         /*
 532                          * This is a clone() call with supplied user stack.
 533                          * Set some valid stack frames to give to the child.
 534                          */
 535                         childstack = (struct sparc_stackf __user *)
 536                                 (sp & ~0x7UL);
 537                         parentstack = (struct sparc_stackf __user *)
 538                                 regs->u_regs[UREG_FP];
 539
 540 #if 0
 541                         printk("clone: parent stack:\n");
 542                         show_stackframe(parentstack);
 543 #endif
 544
 545                         childstack = clone_stackframe(childstack, parentstack);
 546                         if (!childstack)
 547                                 return -EFAULT;
 548
 549 #if 0
 550                         printk("clone: child stack:\n");
 551                         show_stackframe(childstack);
 552 #endif
 553
 554                         childregs->u_regs[UREG_FP] = (unsigned long)childstack;
 555                 }
 556         }
 557
 558 #ifdef CONFIG_SMP
 559         /* FPU must be disabled on SMP. */
 560         childregs->psr &= ~PSR_EF;
 561 #endif
 562
 563         /* Set the return value for the child. */
 564         childregs->u_regs[UREG_I0] = current->pid;
 565         childregs->u_regs[UREG_I1] = 1;
 566
 567         /* Set the return value for the parent. */
 568         regs->u_regs[UREG_I1] = 0;
 569
 570         if (clone_flags & CLONE_SETTLS)
 571                 childregs->u_regs[UREG_G7] = regs->u_regs[UREG_I3];
 572
 573         return 0;
 574 }
 575
 576 /*
 577  * fill in the user structure for a core dump..
 578  */
 579 void dump_thread(struct pt_regs * regs, struct user * dump)
 580 {
 581         unsigned long first_stack_page;
 582
 583         dump->magic = SUNOS_CORE_MAGIC;
 584         dump->len = sizeof(struct user);
 585         dump->regs.psr = regs->psr;
 586         dump->regs.pc = regs->pc;
 587         dump->regs.npc = regs->npc;
 588         dump->regs.y = regs->y;
 589         /* fuck me plenty */
 590         memcpy(&dump->regs.regs[0], &regs->u_regs[1], (sizeof(unsigned long) * 15));
 591         dump->uexec = current->thread.core_exec;
 592         dump->u_tsize = (((unsigned long) current->mm->end_code) -
 593                 ((unsigned long) current->mm->start_code)) & ~(PAGE_SIZE - 1);
 594         dump->u_dsize = ((unsigned long) (current->mm->brk + (PAGE_SIZE-1)));
 595         dump->u_dsize -= dump->u_tsize;
 596         dump->u_dsize &= ~(PAGE_SIZE - 1);
 597         first_stack_page = (regs->u_regs[UREG_FP] & ~(PAGE_SIZE - 1));
 598         dump->u_ssize = (TASK_SIZE - first_stack_page) & ~(PAGE_SIZE - 1);
 599         memcpy(&dump->fpu.fpstatus.fregs.regs[0], &current->thread.float_regs[0], (sizeof(unsigned long) * 32));
 600         dump->fpu.fpstatus.fsr = current->thread.fsr;
 601         dump->fpu.fpstatus.flags = dump->fpu.fpstatus.extra = 0;
 602         dump->fpu.fpstatus.fpq_count = current->thread.fpqdepth;
 603         memcpy(&dump->fpu.fpstatus.fpq[0], &current->thread.fpqueue[0],
 604                ((sizeof(unsigned long) * 2) * 16));
 605         dump->sigcode = 0;
 606 }
 607
 608 /*
 609  * fill in the fpu structure for a core dump.
 610  */
 611 int dump_fpu (struct pt_regs * regs, elf_fpregset_t * fpregs)
 612 {
 613         if (used_math()) {
 614                 memset(fpregs, 0, sizeof(*fpregs));
 615                 fpregs->pr_q_entrysize = 8;
 616                 return 1;
 617         }
 618 #ifdef CONFIG_SMP
 619         if (current_thread_info()->flags & _TIF_USEDFPU) {
 620                 put_psr(get_psr() | PSR_EF);
 621                 fpsave(&current->thread.float_regs[0], &current->thread.fsr,
 622                        &current->thread.fpqueue[0], &current->thread.fpqdepth);
 623                 if (regs != NULL) {
 624                         regs->psr &= ~(PSR_EF);
 625                         current_thread_info()->flags &= ~(_TIF_USEDFPU);
 626                 }
 627         }
 628 #else
 629         if (current == last_task_used_math) {
 630                 put_psr(get_psr() | PSR_EF);
 631                 fpsave(&current->thread.float_regs[0], &current->thread.fsr,
 632                        &current->thread.fpqueue[0], &current->thread.fpqdepth);
 633                 if (regs != NULL) {
 634                         regs->psr &= ~(PSR_EF);
 635                         last_task_used_math = NULL;
 636                 }
 637         }
 638 #endif
 639         memcpy(&fpregs->pr_fr.pr_regs[0],
 640                &current->thread.float_regs[0],
 641                (sizeof(unsigned long) * 32));
 642         fpregs->pr_fsr = current->thread.fsr;
 643         fpregs->pr_qcnt = current->thread.fpqdepth;
 644         fpregs->pr_q_entrysize = 8;
 645         fpregs->pr_en = 1;
 646         if(fpregs->pr_qcnt != 0) {
 647                 memcpy(&fpregs->pr_q[0],
 648                        &current->thread.fpqueue[0],
 649                        sizeof(struct fpq) * fpregs->pr_qcnt);
 650         }
 651         /* Zero out the rest. */
 652         memset(&fpregs->pr_q[fpregs->pr_qcnt], 0,
 653                sizeof(struct fpq) * (32 - fpregs->pr_qcnt));
 654         return 1;
 655 }
 656
 657 /*
 658  * sparc_execve() executes a new program after the asm stub has set
 659  * things up for us.  This should basically do what I want it to.
 660  */
 661 asmlinkage int sparc_execve(struct pt_regs *regs)
 662 {
 663         int error, base = 0;
 664         char *filename;
 665
 666         /* Check for indirect call. */
 667         if(regs->u_regs[UREG_G1] == 0)
 668                 base = 1;
 669
 670         filename = getname((char __user *)regs->u_regs[base + UREG_I0]);
 671         error = PTR_ERR(filename);
 672         if(IS_ERR(filename))
 673                 goto out;
 674         error = do_execve(filename,
 675                           (char __user * __user *)regs->u_regs[base + UREG_I1],
 676                           (char __user * __user *)regs->u_regs[base + UREG_I2],
 677                           regs);
 678         putname(filename);
 679         if (error == 0) {
 680                 task_lock(current);
 681                 current->ptrace &= ~PT_DTRACE;
 682                 task_unlock(current);
 683         }
 684 out:
 685         return error;
 686 }
 687
 688 /*
 689  * This is the mechanism for creating a new kernel thread.
 690  *
 691  * NOTE! Only a kernel-only process(ie the swapper or direct descendants
 692  * who haven't done an "execve()") should use this: it will work within
 693  * a system call from a "real" process, but the process memory space will
 694  * not be free'd until both the parent and the child have exited.
 695  */
 696 pid_t kernel_thread(int (*fn)(void *), void * arg, unsigned long flags)
 697 {
 698         long retval;
 699
 700         __asm__ __volatile__("mov %4, %%g2\n\t"    /* Set aside fn ptr... */
 701                              "mov %5, %%g3\n\t"    /* and arg. */
 702                              "mov %1, %%g1\n\t"
 703                              "mov %2, %%o0\n\t"    /* Clone flags. */
 704                              "mov 0, %%o1\n\t"     /* usp arg == 0 */
 705                              "t 0x10\n\t"          /* Linux/Sparc clone(). */
 706                              "cmp %%o1, 0\n\t"
 707                              "be 1f\n\t"           /* The parent, just return. */
 708                              " nop\n\t"            /* Delay slot. */
 709                              "jmpl %%g2, %%o7\n\t" /* Call the function. */
 710                              " mov %%g3, %%o0\n\t" /* Get back the arg in delay. */
 711                              "mov %3, %%g1\n\t"
 712                              "t 0x10\n\t"          /* Linux/Sparc exit(). */
 713                              /* Notreached by child. */
 714                              "1: mov %%o0, %0\n\t" :
 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 unsigned long get_wchan(struct task_struct *task)
 723 {
 724         unsigned long pc, fp, bias = 0;
 725         unsigned long task_base = (unsigned long) task;
 726         unsigned long ret = 0;
 727         struct reg_window *rw;
 728         int count = 0;
 729
 730         if (!task || task == current ||
 731             task->state == TASK_RUNNING)
 732                 goto out;
 733
 734         fp = task->thread_info->ksp + bias;
 735         do {
 736                 /* Bogus frame pointer? */
 737                 if (fp < (task_base + sizeof(struct thread_info)) ||
 738                     fp >= (task_base + (2 * PAGE_SIZE)))
 739                         break;
 740                 rw = (struct reg_window *) fp;
 741                 pc = rw->ins[7];
 742                 if (!in_sched_functions(pc)) {
 743                         ret = pc;
 744                         goto out;
 745                 }
 746                 fp = rw->ins[6] + bias;
 747         } while (++count < 16);
 748
 749 out:
 750         return ret;
 751 }
 752