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
  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 int cpu_idle(void)
  85 {
  86         int ret = -EPERM;
  87
  88         if (current->pid != 0)
  89                 goto out;
  90
  91         /* endless idle loop with no priority at all */
  92         for (;;) {
  93                 if (ARCH_SUN4C_SUN4) {
  94                         static int count = HZ;
  95                         static unsigned long last_jiffies;
  96                         static unsigned long last_faults;
  97                         static unsigned long fps;
  98                         unsigned long now;
  99                         unsigned long faults;
 100                         unsigned long flags;
 101
 102                         extern unsigned long sun4c_kernel_faults;
 103                         extern void sun4c_grow_kernel_ring(void);
 104
 105                         local_irq_save(flags);
 106                         now = jiffies;
 107                         count -= (now - last_jiffies);
 108                         last_jiffies = now;
 109                         if (count < 0) {
 110                                 count += HZ;
 111                                 faults = sun4c_kernel_faults;
 112                                 fps = (fps + (faults - last_faults)) >> 1;
 113                                 last_faults = faults;
 114 #if 0
 115                                 printk("kernel faults / second = %ld\n", fps);
 116 #endif
 117                                 if (fps >= SUN4C_FAULT_HIGH) {
 118                                         sun4c_grow_kernel_ring();
 119                                 }
 120                         }
 121                         local_irq_restore(flags);
 122                 }
 123
 124                 while((!need_resched()) && pm_idle) {
 125                         (*pm_idle)();           /* XXX Huh? On sparc?! */
 126                 }
 127
 128                 schedule();
 129                 check_pgt_cache();
 130         }
 131         ret = 0;
 132 out:
 133         return ret;
 134 }
 135
 136 #else
 137
 138 /* This is being executed in task 0 'user space'. */
 139 int cpu_idle(void)
 140 {
 141         /* endless idle loop with no priority at all */
 142         while(1) {
 143                 if(need_resched()) {
 144                         schedule();
 145                         check_pgt_cache();
 146                 }
 147                 barrier(); /* or else gcc optimizes... */
 148         }
 149 }
 150
 151 #endif
 152
 153 extern char reboot_command [];
 154
 155 extern void (*prom_palette)(int);
 156
 157 /* XXX cli/sti -> local_irq_xxx here, check this works once SMP is fixed. */
 158 void machine_halt(void)
 159 {
 160         local_irq_enable();
 161         mdelay(8);
 162         local_irq_disable();
 163         if (!serial_console && prom_palette)
 164                 prom_palette (1);
 165         prom_halt();
 166         panic("Halt failed!");
 167 }
 168
 169 EXPORT_SYMBOL(machine_halt);
 170
 171 void machine_restart(char * cmd)
 172 {
 173         char *p;
 174
 175         local_irq_enable();
 176         mdelay(8);
 177         local_irq_disable();
 178
 179         p = strchr (reboot_command, '\n');
 180         if (p) *p = 0;
 181         if (!serial_console && prom_palette)
 182                 prom_palette (1);
 183         if (cmd)
 184                 prom_reboot(cmd);
 185         if (*reboot_command)
 186                 prom_reboot(reboot_command);
 187         prom_feval ("reset");
 188         panic("Reboot failed!");
 189 }
 190
 191 EXPORT_SYMBOL(machine_restart);
 192
 193 void machine_power_off(void)
 194 {
 195 #ifdef CONFIG_SUN_AUXIO
 196         if (auxio_power_register && (!serial_console || scons_pwroff))
 197                 *auxio_power_register |= AUXIO_POWER_OFF;
 198 #endif
 199         machine_halt();
 200 }
 201
 202 EXPORT_SYMBOL(machine_power_off);
 203
 204 static spinlock_t sparc_backtrace_lock = SPIN_LOCK_UNLOCKED;
 205
 206 void __show_backtrace(unsigned long fp)
 207 {
 208         struct reg_window *rw;
 209         unsigned long flags;
 210         int cpu = smp_processor_id();
 211
 212         spin_lock_irqsave(&sparc_backtrace_lock, flags);
 213
 214         rw = (struct reg_window *)fp;
 215         while(rw && (((unsigned long) rw) >= PAGE_OFFSET) &&
 216             !(((unsigned long) rw) & 0x7)) {
 217                 printk("CPU[%d]: ARGS[%08lx,%08lx,%08lx,%08lx,%08lx,%08lx] "
 218                        "FP[%08lx] CALLER[%08lx]: ", cpu,
 219                        rw->ins[0], rw->ins[1], rw->ins[2], rw->ins[3],
 220                        rw->ins[4], rw->ins[5],
 221                        rw->ins[6],
 222                        rw->ins[7]);
 223                 print_symbol("%s\n", rw->ins[7]);
 224                 rw = (struct reg_window *) rw->ins[6];
 225         }
 226         spin_unlock_irqrestore(&sparc_backtrace_lock, flags);
 227 }
 228
 229 #define __SAVE __asm__ __volatile__("save %sp, -0x40, %sp\n\t")
 230 #define __RESTORE __asm__ __volatile__("restore %g0, %g0, %g0\n\t")
 231 #define __GET_FP(fp) __asm__ __volatile__("mov %%i6, %0" : "=r" (fp))
 232
 233 void show_backtrace(void)
 234 {
 235         unsigned long fp;
 236
 237         __SAVE; __SAVE; __SAVE; __SAVE;
 238         __SAVE; __SAVE; __SAVE; __SAVE;
 239         __RESTORE; __RESTORE; __RESTORE; __RESTORE;
 240         __RESTORE; __RESTORE; __RESTORE; __RESTORE;
 241
 242         __GET_FP(fp);
 243
 244         __show_backtrace(fp);
 245 }
 246
 247 #ifdef CONFIG_SMP
 248 void smp_show_backtrace_all_cpus(void)
 249 {
 250         xc0((smpfunc_t) show_backtrace);
 251         show_backtrace();
 252 }
 253 #endif
 254
 255 #if 0
 256 void show_stackframe(struct sparc_stackf *sf)
 257 {
 258         unsigned long size;
 259         unsigned long *stk;
 260         int i;
 261
 262         printk("l0: %08lx l1: %08lx l2: %08lx l3: %08lx "
 263                "l4: %08lx l5: %08lx l6: %08lx l7: %08lx\n",
 264                sf->locals[0], sf->locals[1], sf->locals[2], sf->locals[3],
 265                sf->locals[4], sf->locals[5], sf->locals[6], sf->locals[7]);
 266         printk("i0: %08lx i1: %08lx i2: %08lx i3: %08lx "
 267                "i4: %08lx i5: %08lx fp: %08lx i7: %08lx\n",
 268                sf->ins[0], sf->ins[1], sf->ins[2], sf->ins[3],
 269                sf->ins[4], sf->ins[5], (unsigned long)sf->fp, sf->callers_pc);
 270         printk("sp: %08lx x0: %08lx x1: %08lx x2: %08lx "
 271                "x3: %08lx x4: %08lx x5: %08lx xx: %08lx\n",
 272                (unsigned long)sf->structptr, sf->xargs[0], sf->xargs[1],
 273                sf->xargs[2], sf->xargs[3], sf->xargs[4], sf->xargs[5],
 274                sf->xxargs[0]);
 275         size = ((unsigned long)sf->fp) - ((unsigned long)sf);
 276         size -= STACKFRAME_SZ;
 277         stk = (unsigned long *)((unsigned long)sf + STACKFRAME_SZ);
 278         i = 0;
 279         do {
 280                 printk("s%d: %08lx\n", i++, *stk++);
 281         } while ((size -= sizeof(unsigned long)));
 282 }
 283 #endif
 284
 285 void show_regs(struct pt_regs *r)
 286 {
 287         struct reg_window *rw = (struct reg_window *) r->u_regs[14];
 288
 289         printk("PSR: %08lx PC: %08lx NPC: %08lx Y: %08lx    %s\n",
 290                r->psr, r->pc, r->npc, r->y, print_tainted());
 291         print_symbol("PC: <%s>\n", r->pc);
 292         printk("%%G: %08lx %08lx  %08lx %08lx  %08lx %08lx  %08lx %08lx\n",
 293                r->u_regs[0], r->u_regs[1], r->u_regs[2], r->u_regs[3],
 294                r->u_regs[4], r->u_regs[5], r->u_regs[6], r->u_regs[7]);
 295         printk("%%O: %08lx %08lx  %08lx %08lx  %08lx %08lx  %08lx %08lx\n",
 296                r->u_regs[8], r->u_regs[9], r->u_regs[10], r->u_regs[11],
 297                r->u_regs[12], r->u_regs[13], r->u_regs[14], r->u_regs[15]);
 298         print_symbol("RPC: <%s>\n", r->u_regs[15]);
 299
 300         printk("%%L: %08lx %08lx  %08lx %08lx  %08lx %08lx  %08lx %08lx\n",
 301                rw->locals[0], rw->locals[1], rw->locals[2], rw->locals[3],
 302                rw->locals[4], rw->locals[5], rw->locals[6], rw->locals[7]);
 303         printk("%%I: %08lx %08lx  %08lx %08lx  %08lx %08lx  %08lx %08lx\n",
 304                rw->ins[0], rw->ins[1], rw->ins[2], rw->ins[3],
 305                rw->ins[4], rw->ins[5], rw->ins[6], rw->ins[7]);
 306 }
 307
 308 /*
 309  * The show_stack is an external API which we do not use ourselves.
 310  * The oops is printed in die_if_kernel.
 311  */
 312 void show_stack(struct task_struct *tsk, unsigned long *_ksp)
 313 {
 314         unsigned long pc, fp;
 315         unsigned long task_base;
 316         struct reg_window *rw;
 317         int count = 0;
 318
 319         if (tsk != NULL)
 320                 task_base = (unsigned long) tsk->thread_info;
 321         else
 322                 task_base = (unsigned long) current_thread_info();
 323
 324         fp = (unsigned long) _ksp;
 325         do {
 326                 /* Bogus frame pointer? */
 327                 if (fp < (task_base + sizeof(struct thread_info)) ||
 328                     fp >= (task_base + (PAGE_SIZE << 1)))
 329                         break;
 330                 rw = (struct reg_window *) fp;
 331                 pc = rw->ins[7];
 332                 printk("[%08lx : ", pc);
 333                 print_symbol("%s ] ", pc);
 334                 fp = rw->ins[6];
 335         } while (++count < 16);
 336         printk("\n");
 337 }
 338
 339 /*
 340  * Note: sparc64 has a pretty intricated thread_saved_pc, check it out.
 341  */
 342 unsigned long thread_saved_pc(struct task_struct *tsk)
 343 {
 344         return tsk->thread_info->kpc;
 345 }
 346
 347 /*
 348  * Free current thread data structures etc..
 349  */
 350 void exit_thread(void)
 351 {
 352 #ifndef CONFIG_SMP
 353         if(last_task_used_math == current) {
 354 #else
 355         if(current_thread_info()->flags & _TIF_USEDFPU) {
 356 #endif
 357                 /* Keep process from leaving FPU in a bogon state. */
 358                 put_psr(get_psr() | PSR_EF);
 359                 fpsave(&current->thread.float_regs[0], &current->thread.fsr,
 360                        &current->thread.fpqueue[0], &current->thread.fpqdepth);
 361 #ifndef CONFIG_SMP
 362                 last_task_used_math = NULL;
 363 #else
 364                 current_thread_info()->flags &= ~_TIF_USEDFPU;
 365 #endif
 366         }
 367 }
 368
 369 void flush_thread(void)
 370 {
 371         current_thread_info()->w_saved = 0;
 372
 373         /* No new signal delivery by default */
 374         current->thread.new_signal = 0;
 375 #ifndef CONFIG_SMP
 376         if(last_task_used_math == current) {
 377 #else
 378         if(current_thread_info()->flags & _TIF_USEDFPU) {
 379 #endif
 380                 /* Clean the fpu. */
 381                 put_psr(get_psr() | PSR_EF);
 382                 fpsave(&current->thread.float_regs[0], &current->thread.fsr,
 383                        &current->thread.fpqueue[0], &current->thread.fpqdepth);
 384 #ifndef CONFIG_SMP
 385                 last_task_used_math = NULL;
 386 #else
 387                 current_thread_info()->flags &= ~_TIF_USEDFPU;
 388 #endif
 389         }
 390
 391         /* Now, this task is no longer a kernel thread. */
 392         current->thread.current_ds = USER_DS;
 393         if (current->thread.flags & SPARC_FLAG_KTHREAD) {
 394                 current->thread.flags &= ~SPARC_FLAG_KTHREAD;
 395
 396                 /* We must fixup kregs as well. */
 397                 /* XXX This was not fixed for ti for a while, worked. Unused? */
 398                 current->thread.kregs = (struct pt_regs *)
 399                     ((char *)current->thread_info + (THREAD_SIZE - TRACEREG_SZ));
 400         }
 401 }
 402
 403 static __inline__ struct sparc_stackf __user *
 404 clone_stackframe(struct sparc_stackf __user *dst,
 405                  struct sparc_stackf __user *src)
 406 {
 407         unsigned long size, fp;
 408         struct sparc_stackf *tmp;
 409         struct sparc_stackf __user *sp;
 410
 411         if (get_user(tmp, &src->fp))
 412                 return NULL;
 413
 414         fp = (unsigned long) tmp;
 415         size = (fp - ((unsigned long) src));
 416         fp = (unsigned long) dst;
 417         sp = (struct sparc_stackf __user *)(fp - size);
 418
 419         /* do_fork() grabs the parent semaphore, we must release it
 420          * temporarily so we can build the child clone stack frame
 421          * without deadlocking.
 422          */
 423         if (__copy_user(sp, src, size))
 424                 sp = NULL;
 425         else if (put_user(fp, &sp->fp))
 426                 sp = NULL;
 427
 428         return sp;
 429 }
 430
 431 asmlinkage int sparc_do_fork(unsigned long clone_flags,
 432                              unsigned long stack_start,
 433                              struct pt_regs *regs,
 434                              unsigned long stack_size)
 435 {
 436         unsigned long parent_tid_ptr, child_tid_ptr;
 437
 438         parent_tid_ptr = regs->u_regs[UREG_I2];
 439         child_tid_ptr = regs->u_regs[UREG_I4];
 440
 441         return do_fork(clone_flags, stack_start,
 442                        regs, stack_size,
 443                        (int __user *) parent_tid_ptr,
 444                        (int __user *) child_tid_ptr);
 445 }
 446
 447 /* Copy a Sparc thread.  The fork() return value conventions
 448  * under SunOS are nothing short of bletcherous:
 449  * Parent -->  %o0 == childs  pid, %o1 == 0
 450  * Child  -->  %o0 == parents pid, %o1 == 1
 451  *
 452  * NOTE: We have a separate fork kpsr/kwim because
 453  *       the parent could change these values between
 454  *       sys_fork invocation and when we reach here
 455  *       if the parent should sleep while trying to
 456  *       allocate the task_struct and kernel stack in
 457  *       do_fork().
 458  * XXX See comment above sys_vfork in sparc64. todo.
 459  */
 460 extern void ret_from_fork(void);
 461
 462 int copy_thread(int nr, unsigned long clone_flags, unsigned long sp,
 463                 unsigned long unused,
 464                 struct task_struct *p, struct pt_regs *regs)
 465 {
 466         struct thread_info *ti = p->thread_info;
 467         struct pt_regs *childregs;
 468         char *new_stack;
 469
 470 #ifndef CONFIG_SMP
 471         if(last_task_used_math == current) {
 472 #else
 473         if(current_thread_info()->flags & _TIF_USEDFPU) {
 474 #endif
 475                 put_psr(get_psr() | PSR_EF);
 476                 fpsave(&p->thread.float_regs[0], &p->thread.fsr,
 477                        &p->thread.fpqueue[0], &p->thread.fpqdepth);
 478 #ifdef CONFIG_SMP
 479                 current_thread_info()->flags &= ~_TIF_USEDFPU;
 480 #endif
 481         }
 482
 483         p->set_child_tid = p->clear_child_tid = NULL;
 484
 485         /*
 486          *  p->thread_info         new_stack   childregs
 487          *  !                      !           !             {if(PSR_PS) }
 488          *  V                      V (stk.fr.) V  (pt_regs)  { (stk.fr.) }
 489          *  +----- - - - - - ------+===========+============={+==========}+
 490          */
 491         new_stack = (char*)ti + THREAD_SIZE;
 492         if (regs->psr & PSR_PS)
 493                 new_stack -= STACKFRAME_SZ;
 494         new_stack -= STACKFRAME_SZ + TRACEREG_SZ;
 495         memcpy(new_stack, (char *)regs - STACKFRAME_SZ, STACKFRAME_SZ + TRACEREG_SZ);
 496         childregs = (struct pt_regs *) (new_stack + STACKFRAME_SZ);
 497
 498         /*
 499          * A new process must start with interrupts closed in 2.5,
 500          * because this is how Mingo's scheduler works (see schedule_tail
 501          * and finish_arch_switch). If we do not do it, a timer interrupt hits
 502          * before we unlock, attempts to re-take the rq->lock, and then we die.
 503          * Thus, kpsr|=PSR_PIL.
 504          */
 505         ti->ksp = (unsigned long) new_stack;
 506         ti->kpc = (((unsigned long) ret_from_fork) - 0x8);
 507         ti->kpsr = current->thread.fork_kpsr | PSR_PIL;
 508         ti->kwim = current->thread.fork_kwim;
 509
 510         if(regs->psr & PSR_PS) {
 511                 extern struct pt_regs fake_swapper_regs;
 512
 513                 p->thread.kregs = &fake_swapper_regs;
 514                 new_stack += STACKFRAME_SZ + TRACEREG_SZ;
 515                 childregs->u_regs[UREG_FP] = (unsigned long) new_stack;
 516                 p->thread.flags |= SPARC_FLAG_KTHREAD;
 517                 p->thread.current_ds = KERNEL_DS;
 518                 memcpy(new_stack, (void *)regs->u_regs[UREG_FP], STACKFRAME_SZ);
 519                 childregs->u_regs[UREG_G6] = (unsigned long) ti;
 520         } else {
 521                 p->thread.kregs = childregs;
 522                 childregs->u_regs[UREG_FP] = sp;
 523                 p->thread.flags &= ~SPARC_FLAG_KTHREAD;
 524                 p->thread.current_ds = USER_DS;
 525
 526                 if (sp != regs->u_regs[UREG_FP]) {
 527                         struct sparc_stackf __user *childstack;
 528                         struct sparc_stackf __user *parentstack;
 529
 530                         /*
 531                          * This is a clone() call with supplied user stack.
 532                          * Set some valid stack frames to give to the child.
 533                          */
 534                         childstack = (struct sparc_stackf __user *)
 535                                 (sp & ~0x7UL);
 536                         parentstack = (struct sparc_stackf __user *)
 537                                 regs->u_regs[UREG_FP];
 538
 539 #if 0
 540                         printk("clone: parent stack:\n");
 541                         show_stackframe(parentstack);
 542 #endif
 543
 544                         childstack = clone_stackframe(childstack, parentstack);
 545                         if (!childstack)
 546                                 return -EFAULT;
 547
 548 #if 0
 549                         printk("clone: child stack:\n");
 550                         show_stackframe(childstack);
 551 #endif
 552
 553                         childregs->u_regs[UREG_FP] = (unsigned long)childstack;
 554                 }
 555         }
 556
 557         /* Set the return value for the child. */
 558         childregs->u_regs[UREG_I0] = current->pid;
 559         childregs->u_regs[UREG_I1] = 1;
 560
 561         /* Set the return value for the parent. */
 562         regs->u_regs[UREG_I1] = 0;
 563
 564         if (clone_flags & CLONE_SETTLS)
 565                 childregs->u_regs[UREG_G7] = regs->u_regs[UREG_I3];
 566
 567         return 0;
 568 }
 569
 570 /*
 571  * fill in the user structure for a core dump..
 572  */
 573 void dump_thread(struct pt_regs * regs, struct user * dump)
 574 {
 575         unsigned long first_stack_page;
 576
 577         dump->magic = SUNOS_CORE_MAGIC;
 578         dump->len = sizeof(struct user);
 579         dump->regs.psr = regs->psr;
 580         dump->regs.pc = regs->pc;
 581         dump->regs.npc = regs->npc;
 582         dump->regs.y = regs->y;
 583         /* fuck me plenty */
 584         memcpy(&dump->regs.regs[0], &regs->u_regs[1], (sizeof(unsigned long) * 15));
 585         dump->uexec = current->thread.core_exec;
 586         dump->u_tsize = (((unsigned long) current->mm->end_code) -
 587                 ((unsigned long) current->mm->start_code)) & ~(PAGE_SIZE - 1);
 588         dump->u_dsize = ((unsigned long) (current->mm->brk + (PAGE_SIZE-1)));
 589         dump->u_dsize -= dump->u_tsize;
 590         dump->u_dsize &= ~(PAGE_SIZE - 1);
 591         first_stack_page = (regs->u_regs[UREG_FP] & ~(PAGE_SIZE - 1));
 592         dump->u_ssize = (TASK_SIZE - first_stack_page) & ~(PAGE_SIZE - 1);
 593         memcpy(&dump->fpu.fpstatus.fregs.regs[0], &current->thread.float_regs[0], (sizeof(unsigned long) * 32));
 594         dump->fpu.fpstatus.fsr = current->thread.fsr;
 595         dump->fpu.fpstatus.flags = dump->fpu.fpstatus.extra = 0;
 596         dump->fpu.fpstatus.fpq_count = current->thread.fpqdepth;
 597         memcpy(&dump->fpu.fpstatus.fpq[0], &current->thread.fpqueue[0],
 598                ((sizeof(unsigned long) * 2) * 16));
 599         dump->sigcode = 0;
 600 }
 601
 602 /*
 603  * fill in the fpu structure for a core dump.
 604  */
 605 int dump_fpu (struct pt_regs * regs, elf_fpregset_t * fpregs)
 606 {
 607         if (current->used_math == 0) {
 608                 memset(fpregs, 0, sizeof(*fpregs));
 609                 fpregs->pr_q_entrysize = 8;
 610                 return 1;
 611         }
 612 #ifdef CONFIG_SMP
 613         if (current_thread_info()->flags & _TIF_USEDFPU) {
 614                 put_psr(get_psr() | PSR_EF);
 615                 fpsave(&current->thread.float_regs[0], &current->thread.fsr,
 616                        &current->thread.fpqueue[0], &current->thread.fpqdepth);
 617                 if (regs != NULL) {
 618                         regs->psr &= ~(PSR_EF);
 619                         current_thread_info()->flags &= ~(_TIF_USEDFPU);
 620                 }
 621         }
 622 #else
 623         if (current == last_task_used_math) {
 624                 put_psr(get_psr() | PSR_EF);
 625                 fpsave(&current->thread.float_regs[0], &current->thread.fsr,
 626                        &current->thread.fpqueue[0], &current->thread.fpqdepth);
 627                 if (regs != NULL) {
 628                         regs->psr &= ~(PSR_EF);
 629                         last_task_used_math = NULL;
 630                 }
 631         }
 632 #endif
 633         memcpy(&fpregs->pr_fr.pr_regs[0],
 634                &current->thread.float_regs[0],
 635                (sizeof(unsigned long) * 32));
 636         fpregs->pr_fsr = current->thread.fsr;
 637         fpregs->pr_qcnt = current->thread.fpqdepth;
 638         fpregs->pr_q_entrysize = 8;
 639         fpregs->pr_en = 1;
 640         if(fpregs->pr_qcnt != 0) {
 641                 memcpy(&fpregs->pr_q[0],
 642                        &current->thread.fpqueue[0],
 643                        sizeof(struct fpq) * fpregs->pr_qcnt);
 644         }
 645         /* Zero out the rest. */
 646         memset(&fpregs->pr_q[fpregs->pr_qcnt], 0,
 647                sizeof(struct fpq) * (32 - fpregs->pr_qcnt));
 648         return 1;
 649 }
 650
 651 /*
 652  * sparc_execve() executes a new program after the asm stub has set
 653  * things up for us.  This should basically do what I want it to.
 654  */
 655 asmlinkage int sparc_execve(struct pt_regs *regs)
 656 {
 657         int error, base = 0;
 658         char *filename;
 659
 660         /* Check for indirect call. */
 661         if(regs->u_regs[UREG_G1] == 0)
 662                 base = 1;
 663
 664         filename = getname((char __user *)regs->u_regs[base + UREG_I0]);
 665         error = PTR_ERR(filename);
 666         if(IS_ERR(filename))
 667                 goto out;
 668         error = do_execve(filename,
 669                           (char __user * __user *)regs->u_regs[base + UREG_I1],
 670                           (char __user * __user *)regs->u_regs[base + UREG_I2],
 671                           regs);
 672         putname(filename);
 673         if (error == 0)
 674                 current->ptrace &= ~PT_DTRACE;
 675 out:
 676         return error;
 677 }
 678
 679 /*
 680  * This is the mechanism for creating a new kernel thread.
 681  *
 682  * NOTE! Only a kernel-only process(ie the swapper or direct descendants
 683  * who haven't done an "execve()") should use this: it will work within
 684  * a system call from a "real" process, but the process memory space will
 685  * not be free'd until both the parent and the child have exited.
 686  */
 687 pid_t kernel_thread(int (*fn)(void *), void * arg, unsigned long flags)
 688 {
 689         long retval;
 690
 691         __asm__ __volatile__("mov %4, %%g2\n\t"    /* Set aside fn ptr... */
 692                              "mov %5, %%g3\n\t"    /* and arg. */
 693                              "mov %1, %%g1\n\t"
 694                              "mov %2, %%o0\n\t"    /* Clone flags. */
 695                              "mov 0, %%o1\n\t"     /* usp arg == 0 */
 696                              "t 0x10\n\t"          /* Linux/Sparc clone(). */
 697                              "cmp %%o1, 0\n\t"
 698                              "be 1f\n\t"           /* The parent, just return. */
 699                              " nop\n\t"            /* Delay slot. */
 700                              "jmpl %%g2, %%o7\n\t" /* Call the function. */
 701                              " mov %%g3, %%o0\n\t" /* Get back the arg in delay. */
 702                              "mov %3, %%g1\n\t"
 703                              "t 0x10\n\t"          /* Linux/Sparc exit(). */
 704                              /* Notreached by child. */
 705                              "1: mov %%o0, %0\n\t" :
 706                              "=r" (retval) :
 707                              "i" (__NR_clone), "r" (flags | CLONE_VM | CLONE_UNTRACED),
 708                              "i" (__NR_exit),  "r" (fn), "r" (arg) :
 709                              "g1", "g2", "g3", "o0", "o1", "memory", "cc");
 710         return retval;
 711 }
 712
 713 unsigned long get_wchan(struct task_struct *task)
 714 {
 715         unsigned long pc, fp, bias = 0;
 716         unsigned long task_base = (unsigned long) task;
 717         unsigned long ret = 0;
 718         struct reg_window *rw;
 719         int count = 0;
 720
 721         if (!task || task == current ||
 722             task->state == TASK_RUNNING)
 723                 goto out;
 724
 725         fp = task->thread_info->ksp + bias;
 726         do {
 727                 /* Bogus frame pointer? */
 728                 if (fp < (task_base + sizeof(struct thread_info)) ||
 729                     fp >= (task_base + (2 * PAGE_SIZE)))
 730                         break;
 731                 rw = (struct reg_window *) fp;
 732                 pc = rw->ins[7];
 733                 if (!in_sched_functions(pc)) {
 734                         ret = pc;
 735                         goto out;
 736                 }
 737                 fp = rw->ins[6] + bias;
 738         } while (++count < 16);
 739
 740 out:
 741         return ret;
 742 }
 743