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   1 /*  $Id: process.c,v 1.131 2002/02/09 19:49:30 davem Exp $
   2  *  arch/sparc64/kernel/process.c
   3  *
   4  *  Copyright (C) 1995, 1996 David S. Miller (davem@caip.rutgers.edu)
   5  *  Copyright (C) 1996       Eddie C. Dost   (ecd@skynet.be)
   6  *  Copyright (C) 1997, 1998 Jakub Jelinek   (jj@sunsite.mff.cuni.cz)
   7  */
   8
   9 /*
  10  * This file handles the architecture-dependent parts of process handling..
  11  */
  12
  13 #include <stdarg.h>
  14
  15 #include <linux/errno.h>
  16 #include <linux/module.h>
  17 #include <linux/sched.h>
  18 #include <linux/kernel.h>
  19 #include <linux/kallsyms.h>
  20 #include <linux/mm.h>
  21 #include <linux/fs.h>
  22 #include <linux/smp.h>
  23 #include <linux/stddef.h>
  24 #include <linux/ptrace.h>
  25 #include <linux/slab.h>
  26 #include <linux/user.h>
  27 #include <linux/reboot.h>
  28 #include <linux/delay.h>
  29 #include <linux/compat.h>
  30 #include <linux/tick.h>
  31 #include <linux/init.h>
  32 #include <linux/cpu.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
  51 /* #define VERBOSE_SHOWREGS */
  52
  53 static void sparc64_yield(int cpu)
  54 {
  55         if (tlb_type != hypervisor)
  56                 return;
  57
  58         clear_thread_flag(TIF_POLLING_NRFLAG);
  59         smp_mb__after_clear_bit();
  60
  61         while (!need_resched() && !cpu_is_offline(cpu)) {
  62                 unsigned long pstate;
  63
  64                 /* Disable interrupts. */
  65                 __asm__ __volatile__(
  66                         "rdpr %%pstate, %0\n\t"
  67                         "andn %0, %1, %0\n\t"
  68                         "wrpr %0, %%g0, %%pstate"
  69                         : "=&r" (pstate)
  70                         : "i" (PSTATE_IE));
  71
  72                 if (!need_resched() && !cpu_is_offline(cpu))
  73                         sun4v_cpu_yield();
  74
  75                 /* Re-enable interrupts. */
  76                 __asm__ __volatile__(
  77                         "rdpr %%pstate, %0\n\t"
  78                         "or %0, %1, %0\n\t"
  79                         "wrpr %0, %%g0, %%pstate"
  80                         : "=&r" (pstate)
  81                         : "i" (PSTATE_IE));
  82         }
  83
  84         set_thread_flag(TIF_POLLING_NRFLAG);
  85 }
  86
  87 /* The idle loop on sparc64. */
  88 void cpu_idle(void)
  89 {
  90         int cpu = smp_processor_id();
  91
  92         set_thread_flag(TIF_POLLING_NRFLAG);
  93
  94         while(1) {
  95                 tick_nohz_stop_sched_tick();
  96
  97                 while (!need_resched() && !cpu_is_offline(cpu))
  98                         sparc64_yield(cpu);
  99
 100                 tick_nohz_restart_sched_tick();
 101
 102                 preempt_enable_no_resched();
 103
 104 #ifdef CONFIG_HOTPLUG_CPU
 105                 if (cpu_is_offline(cpu))
 106                         cpu_play_dead();
 107 #endif
 108
 109                 schedule();
 110                 preempt_disable();
 111         }
 112 }
 113
 114 extern char reboot_command [];
 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 void show_stackframe(struct sparc_stackf *sf)
 215 {
 216         unsigned long size;
 217         unsigned long *stk;
 218         int i;
 219
 220         printk("l0: %016lx l1: %016lx l2: %016lx l3: %016lx\n"
 221                "l4: %016lx l5: %016lx l6: %016lx l7: %016lx\n",
 222                sf->locals[0], sf->locals[1], sf->locals[2], sf->locals[3],
 223                sf->locals[4], sf->locals[5], sf->locals[6], sf->locals[7]);
 224         printk("i0: %016lx i1: %016lx i2: %016lx i3: %016lx\n"
 225                "i4: %016lx i5: %016lx fp: %016lx ret_pc: %016lx\n",
 226                sf->ins[0], sf->ins[1], sf->ins[2], sf->ins[3],
 227                sf->ins[4], sf->ins[5], (unsigned long)sf->fp, sf->callers_pc);
 228         printk("sp: %016lx x0: %016lx x1: %016lx x2: %016lx\n"
 229                "x3: %016lx x4: %016lx x5: %016lx xx: %016lx\n",
 230                (unsigned long)sf->structptr, sf->xargs[0], sf->xargs[1],
 231                sf->xargs[2], sf->xargs[3], sf->xargs[4], sf->xargs[5],
 232                sf->xxargs[0]);
 233         size = ((unsigned long)sf->fp) - ((unsigned long)sf);
 234         size -= STACKFRAME_SZ;
 235         stk = (unsigned long *)((unsigned long)sf + STACKFRAME_SZ);
 236         i = 0;
 237         do {
 238                 printk("s%d: %016lx\n", i++, *stk++);
 239         } while ((size -= sizeof(unsigned long)));
 240 }
 241
 242 void show_stackframe32(struct sparc_stackf32 *sf)
 243 {
 244         unsigned long size;
 245         unsigned *stk;
 246         int i;
 247
 248         printk("l0: %08x l1: %08x l2: %08x l3: %08x\n",
 249                sf->locals[0], sf->locals[1], sf->locals[2], sf->locals[3]);
 250         printk("l4: %08x l5: %08x l6: %08x l7: %08x\n",
 251                sf->locals[4], sf->locals[5], sf->locals[6], sf->locals[7]);
 252         printk("i0: %08x i1: %08x i2: %08x i3: %08x\n",
 253                sf->ins[0], sf->ins[1], sf->ins[2], sf->ins[3]);
 254         printk("i4: %08x i5: %08x fp: %08x ret_pc: %08x\n",
 255                sf->ins[4], sf->ins[5], sf->fp, sf->callers_pc);
 256         printk("sp: %08x x0: %08x x1: %08x x2: %08x\n"
 257                "x3: %08x x4: %08x x5: %08x xx: %08x\n",
 258                sf->structptr, sf->xargs[0], sf->xargs[1],
 259                sf->xargs[2], sf->xargs[3], sf->xargs[4], sf->xargs[5],
 260                sf->xxargs[0]);
 261         size = ((unsigned long)sf->fp) - ((unsigned long)sf);
 262         size -= STACKFRAME32_SZ;
 263         stk = (unsigned *)((unsigned long)sf + STACKFRAME32_SZ);
 264         i = 0;
 265         do {
 266                 printk("s%d: %08x\n", i++, *stk++);
 267         } while ((size -= sizeof(unsigned)));
 268 }
 269
 270 #ifdef CONFIG_SMP
 271 static DEFINE_SPINLOCK(regdump_lock);
 272 #endif
 273
 274 void __show_regs(struct pt_regs * regs)
 275 {
 276 #ifdef CONFIG_SMP
 277         unsigned long flags;
 278
 279         /* Protect against xcall ipis which might lead to livelock on the lock */
 280         __asm__ __volatile__("rdpr      %%pstate, %0\n\t"
 281                              "wrpr      %0, %1, %%pstate"
 282                              : "=r" (flags)
 283                              : "i" (PSTATE_IE));
 284         spin_lock(&regdump_lock);
 285 #endif
 286         printk("TSTATE: %016lx TPC: %016lx TNPC: %016lx Y: %08x    %s\n", regs->tstate,
 287                regs->tpc, regs->tnpc, regs->y, print_tainted());
 288         print_symbol("TPC: <%s>\n", regs->tpc);
 289         printk("g0: %016lx g1: %016lx g2: %016lx g3: %016lx\n",
 290                regs->u_regs[0], regs->u_regs[1], regs->u_regs[2],
 291                regs->u_regs[3]);
 292         printk("g4: %016lx g5: %016lx g6: %016lx g7: %016lx\n",
 293                regs->u_regs[4], regs->u_regs[5], regs->u_regs[6],
 294                regs->u_regs[7]);
 295         printk("o0: %016lx o1: %016lx o2: %016lx o3: %016lx\n",
 296                regs->u_regs[8], regs->u_regs[9], regs->u_regs[10],
 297                regs->u_regs[11]);
 298         printk("o4: %016lx o5: %016lx sp: %016lx ret_pc: %016lx\n",
 299                regs->u_regs[12], regs->u_regs[13], regs->u_regs[14],
 300                regs->u_regs[15]);
 301         print_symbol("RPC: <%s>\n", regs->u_regs[15]);
 302         show_regwindow(regs);
 303 #ifdef CONFIG_SMP
 304         spin_unlock(&regdump_lock);
 305         __asm__ __volatile__("wrpr      %0, 0, %%pstate"
 306                              : : "r" (flags));
 307 #endif
 308 }
 309
 310 #ifdef VERBOSE_SHOWREGS
 311 static void idump_from_user (unsigned int *pc)
 312 {
 313         int i;
 314         int code;
 315
 316         if((((unsigned long) pc) & 3))
 317                 return;
 318
 319         pc -= 3;
 320         for(i = -3; i < 6; i++) {
 321                 get_user(code, pc);
 322                 printk("%c%08x%c",i?' ':'<',code,i?' ':'>');
 323                 pc++;
 324         }
 325         printk("\n");
 326 }
 327 #endif
 328
 329 void show_regs(struct pt_regs *regs)
 330 {
 331 #ifdef VERBOSE_SHOWREGS
 332         extern long etrap, etraptl1;
 333 #endif
 334         __show_regs(regs);
 335 #if 0
 336 #ifdef CONFIG_SMP
 337         {
 338                 extern void smp_report_regs(void);
 339
 340                 smp_report_regs();
 341         }
 342 #endif
 343 #endif
 344
 345 #ifdef VERBOSE_SHOWREGS
 346         if (regs->tpc >= &etrap && regs->tpc < &etraptl1 &&
 347             regs->u_regs[14] >= (long)current - PAGE_SIZE &&
 348             regs->u_regs[14] < (long)current + 6 * PAGE_SIZE) {
 349                 printk ("*********parent**********\n");
 350                 __show_regs((struct pt_regs *)(regs->u_regs[14] + PTREGS_OFF));
 351                 idump_from_user(((struct pt_regs *)(regs->u_regs[14] + PTREGS_OFF))->tpc);
 352                 printk ("*********endpar**********\n");
 353         }
 354 #endif
 355 }
 356
 357 void show_regs32(struct pt_regs32 *regs)
 358 {
 359         printk("PSR: %08x PC: %08x NPC: %08x Y: %08x    %s\n", regs->psr,
 360                regs->pc, regs->npc, regs->y, print_tainted());
 361         printk("g0: %08x g1: %08x g2: %08x g3: %08x ",
 362                regs->u_regs[0], regs->u_regs[1], regs->u_regs[2],
 363                regs->u_regs[3]);
 364         printk("g4: %08x g5: %08x g6: %08x g7: %08x\n",
 365                regs->u_regs[4], regs->u_regs[5], regs->u_regs[6],
 366                regs->u_regs[7]);
 367         printk("o0: %08x o1: %08x o2: %08x o3: %08x ",
 368                regs->u_regs[8], regs->u_regs[9], regs->u_regs[10],
 369                regs->u_regs[11]);
 370         printk("o4: %08x o5: %08x sp: %08x ret_pc: %08x\n",
 371                regs->u_regs[12], regs->u_regs[13], regs->u_regs[14],
 372                regs->u_regs[15]);
 373 }
 374
 375 unsigned long thread_saved_pc(struct task_struct *tsk)
 376 {
 377         struct thread_info *ti = task_thread_info(tsk);
 378         unsigned long ret = 0xdeadbeefUL;
 379
 380         if (ti && ti->ksp) {
 381                 unsigned long *sp;
 382                 sp = (unsigned long *)(ti->ksp + STACK_BIAS);
 383                 if (((unsigned long)sp & (sizeof(long) - 1)) == 0UL &&
 384                     sp[14]) {
 385                         unsigned long *fp;
 386                         fp = (unsigned long *)(sp[14] + STACK_BIAS);
 387                         if (((unsigned long)fp & (sizeof(long) - 1)) == 0UL)
 388                                 ret = fp[15];
 389                 }
 390         }
 391         return ret;
 392 }
 393
 394 /* Free current thread data structures etc.. */
 395 void exit_thread(void)
 396 {
 397         struct thread_info *t = current_thread_info();
 398
 399         if (t->utraps) {
 400                 if (t->utraps[0] < 2)
 401                         kfree (t->utraps);
 402                 else
 403                         t->utraps[0]--;
 404         }
 405
 406         if (test_and_clear_thread_flag(TIF_PERFCTR)) {
 407                 t->user_cntd0 = t->user_cntd1 = NULL;
 408                 t->pcr_reg = 0;
 409                 write_pcr(0);
 410         }
 411 }
 412
 413 void flush_thread(void)
 414 {
 415         struct thread_info *t = current_thread_info();
 416         struct mm_struct *mm;
 417
 418         if (test_ti_thread_flag(t, TIF_ABI_PENDING)) {
 419                 clear_ti_thread_flag(t, TIF_ABI_PENDING);
 420                 if (test_ti_thread_flag(t, TIF_32BIT))
 421                         clear_ti_thread_flag(t, TIF_32BIT);
 422                 else
 423                         set_ti_thread_flag(t, TIF_32BIT);
 424         }
 425
 426         mm = t->task->mm;
 427         if (mm)
 428                 tsb_context_switch(mm);
 429
 430         set_thread_wsaved(0);
 431
 432         /* Turn off performance counters if on. */
 433         if (test_and_clear_thread_flag(TIF_PERFCTR)) {
 434                 t->user_cntd0 = t->user_cntd1 = NULL;
 435                 t->pcr_reg = 0;
 436                 write_pcr(0);
 437         }
 438
 439         /* Clear FPU register state. */
 440         t->fpsaved[0] = 0;
 441
 442         if (get_thread_current_ds() != ASI_AIUS)
 443                 set_fs(USER_DS);
 444
 445         /* Init new signal delivery disposition. */
 446         clear_thread_flag(TIF_NEWSIGNALS);
 447 }
 448
 449 /* It's a bit more tricky when 64-bit tasks are involved... */
 450 static unsigned long clone_stackframe(unsigned long csp, unsigned long psp)
 451 {
 452         unsigned long fp, distance, rval;
 453
 454         if (!(test_thread_flag(TIF_32BIT))) {
 455                 csp += STACK_BIAS;
 456                 psp += STACK_BIAS;
 457                 __get_user(fp, &(((struct reg_window __user *)psp)->ins[6]));
 458                 fp += STACK_BIAS;
 459         } else
 460                 __get_user(fp, &(((struct reg_window32 __user *)psp)->ins[6]));
 461
 462         /* Now 8-byte align the stack as this is mandatory in the
 463          * Sparc ABI due to how register windows work.  This hides
 464          * the restriction from thread libraries etc.  -DaveM
 465          */
 466         csp &= ~7UL;
 467
 468         distance = fp - psp;
 469         rval = (csp - distance);
 470         if (copy_in_user((void __user *) rval, (void __user *) psp, distance))
 471                 rval = 0;
 472         else if (test_thread_flag(TIF_32BIT)) {
 473                 if (put_user(((u32)csp),
 474                              &(((struct reg_window32 __user *)rval)->ins[6])))
 475                         rval = 0;
 476         } else {
 477                 if (put_user(((u64)csp - STACK_BIAS),
 478                              &(((struct reg_window __user *)rval)->ins[6])))
 479                         rval = 0;
 480                 else
 481                         rval = rval - STACK_BIAS;
 482         }
 483
 484         return rval;
 485 }
 486
 487 /* Standard stuff. */
 488 static inline void shift_window_buffer(int first_win, int last_win,
 489                                        struct thread_info *t)
 490 {
 491         int i;
 492
 493         for (i = first_win; i < last_win; i++) {
 494                 t->rwbuf_stkptrs[i] = t->rwbuf_stkptrs[i+1];
 495                 memcpy(&t->reg_window[i], &t->reg_window[i+1],
 496                        sizeof(struct reg_window));
 497         }
 498 }
 499
 500 void synchronize_user_stack(void)
 501 {
 502         struct thread_info *t = current_thread_info();
 503         unsigned long window;
 504
 505         flush_user_windows();
 506         if ((window = get_thread_wsaved()) != 0) {
 507                 int winsize = sizeof(struct reg_window);
 508                 int bias = 0;
 509
 510                 if (test_thread_flag(TIF_32BIT))
 511                         winsize = sizeof(struct reg_window32);
 512                 else
 513                         bias = STACK_BIAS;
 514
 515                 window -= 1;
 516                 do {
 517                         unsigned long sp = (t->rwbuf_stkptrs[window] + bias);
 518                         struct reg_window *rwin = &t->reg_window[window];
 519
 520                         if (!copy_to_user((char __user *)sp, rwin, winsize)) {
 521                                 shift_window_buffer(window, get_thread_wsaved() - 1, t);
 522                                 set_thread_wsaved(get_thread_wsaved() - 1);
 523                         }
 524                 } while (window--);
 525         }
 526 }
 527
 528 static void stack_unaligned(unsigned long sp)
 529 {
 530         siginfo_t info;
 531
 532         info.si_signo = SIGBUS;
 533         info.si_errno = 0;
 534         info.si_code = BUS_ADRALN;
 535         info.si_addr = (void __user *) sp;
 536         info.si_trapno = 0;
 537         force_sig_info(SIGBUS, &info, current);
 538 }
 539
 540 void fault_in_user_windows(void)
 541 {
 542         struct thread_info *t = current_thread_info();
 543         unsigned long window;
 544         int winsize = sizeof(struct reg_window);
 545         int bias = 0;
 546
 547         if (test_thread_flag(TIF_32BIT))
 548                 winsize = sizeof(struct reg_window32);
 549         else
 550                 bias = STACK_BIAS;
 551
 552         flush_user_windows();
 553         window = get_thread_wsaved();
 554
 555         if (likely(window != 0)) {
 556                 window -= 1;
 557                 do {
 558                         unsigned long sp = (t->rwbuf_stkptrs[window] + bias);
 559                         struct reg_window *rwin = &t->reg_window[window];
 560
 561                         if (unlikely(sp & 0x7UL))
 562                                 stack_unaligned(sp);
 563
 564                         if (unlikely(copy_to_user((char __user *)sp,
 565                                                   rwin, winsize)))
 566                                 goto barf;
 567                 } while (window--);
 568         }
 569         set_thread_wsaved(0);
 570         return;
 571
 572 barf:
 573         set_thread_wsaved(window + 1);
 574         do_exit(SIGILL);
 575 }
 576
 577 asmlinkage long sparc_do_fork(unsigned long clone_flags,
 578                               unsigned long stack_start,
 579                               struct pt_regs *regs,
 580                               unsigned long stack_size)
 581 {
 582         int __user *parent_tid_ptr, *child_tid_ptr;
 583
 584 #ifdef CONFIG_COMPAT
 585         if (test_thread_flag(TIF_32BIT)) {
 586                 parent_tid_ptr = compat_ptr(regs->u_regs[UREG_I2]);
 587                 child_tid_ptr = compat_ptr(regs->u_regs[UREG_I4]);
 588         } else
 589 #endif
 590         {
 591                 parent_tid_ptr = (int __user *) regs->u_regs[UREG_I2];
 592                 child_tid_ptr = (int __user *) regs->u_regs[UREG_I4];
 593         }
 594
 595         return do_fork(clone_flags, stack_start,
 596                        regs, stack_size,
 597                        parent_tid_ptr, child_tid_ptr);
 598 }
 599
 600 /* Copy a Sparc thread.  The fork() return value conventions
 601  * under SunOS are nothing short of bletcherous:
 602  * Parent -->  %o0 == childs  pid, %o1 == 0
 603  * Child  -->  %o0 == parents pid, %o1 == 1
 604  */
 605 int copy_thread(int nr, unsigned long clone_flags, unsigned long sp,
 606                 unsigned long unused,
 607                 struct task_struct *p, struct pt_regs *regs)
 608 {
 609         struct thread_info *t = task_thread_info(p);
 610         char *child_trap_frame;
 611
 612         /* Calculate offset to stack_frame & pt_regs */
 613         child_trap_frame = task_stack_page(p) + (THREAD_SIZE - (TRACEREG_SZ+STACKFRAME_SZ));
 614         memcpy(child_trap_frame, (((struct sparc_stackf *)regs)-1), (TRACEREG_SZ+STACKFRAME_SZ));
 615
 616         t->flags = (t->flags & ~((0xffUL << TI_FLAG_CWP_SHIFT) | (0xffUL << TI_FLAG_CURRENT_DS_SHIFT))) |
 617                 (((regs->tstate + 1) & TSTATE_CWP) << TI_FLAG_CWP_SHIFT);
 618         t->new_child = 1;
 619         t->ksp = ((unsigned long) child_trap_frame) - STACK_BIAS;
 620         t->kregs = (struct pt_regs *)(child_trap_frame+sizeof(struct sparc_stackf));
 621         t->fpsaved[0] = 0;
 622
 623         if (regs->tstate & TSTATE_PRIV) {
 624                 /* Special case, if we are spawning a kernel thread from
 625                  * a userspace task (via KMOD, NFS, or similar) we must
 626                  * disable performance counters in the child because the
 627                  * address space and protection realm are changing.
 628                  */
 629                 if (t->flags & _TIF_PERFCTR) {
 630                         t->user_cntd0 = t->user_cntd1 = NULL;
 631                         t->pcr_reg = 0;
 632                         t->flags &= ~_TIF_PERFCTR;
 633                 }
 634                 t->kregs->u_regs[UREG_FP] = t->ksp;
 635                 t->flags |= ((long)ASI_P << TI_FLAG_CURRENT_DS_SHIFT);
 636                 flush_register_windows();
 637                 memcpy((void *)(t->ksp + STACK_BIAS),
 638                        (void *)(regs->u_regs[UREG_FP] + STACK_BIAS),
 639                        sizeof(struct sparc_stackf));
 640                 t->kregs->u_regs[UREG_G6] = (unsigned long) t;
 641                 t->kregs->u_regs[UREG_G4] = (unsigned long) t->task;
 642         } else {
 643                 if (t->flags & _TIF_32BIT) {
 644                         sp &= 0x00000000ffffffffUL;
 645                         regs->u_regs[UREG_FP] &= 0x00000000ffffffffUL;
 646                 }
 647                 t->kregs->u_regs[UREG_FP] = sp;
 648                 t->flags |= ((long)ASI_AIUS << TI_FLAG_CURRENT_DS_SHIFT);
 649                 if (sp != regs->u_regs[UREG_FP]) {
 650                         unsigned long csp;
 651
 652                         csp = clone_stackframe(sp, regs->u_regs[UREG_FP]);
 653                         if (!csp)
 654                                 return -EFAULT;
 655                         t->kregs->u_regs[UREG_FP] = csp;
 656                 }
 657                 if (t->utraps)
 658                         t->utraps[0]++;
 659         }
 660
 661         /* Set the return value for the child. */
 662         t->kregs->u_regs[UREG_I0] = current->pid;
 663         t->kregs->u_regs[UREG_I1] = 1;
 664
 665         /* Set the second return value for the parent. */
 666         regs->u_regs[UREG_I1] = 0;
 667
 668         if (clone_flags & CLONE_SETTLS)
 669                 t->kregs->u_regs[UREG_G7] = regs->u_regs[UREG_I3];
 670
 671         return 0;
 672 }
 673
 674 /*
 675  * This is the mechanism for creating a new kernel thread.
 676  *
 677  * NOTE! Only a kernel-only process(ie the swapper or direct descendants
 678  * who haven't done an "execve()") should use this: it will work within
 679  * a system call from a "real" process, but the process memory space will
 680  * not be freed until both the parent and the child have exited.
 681  */
 682 pid_t kernel_thread(int (*fn)(void *), void * arg, unsigned long flags)
 683 {
 684         long retval;
 685
 686         /* If the parent runs before fn(arg) is called by the child,
 687          * the input registers of this function can be clobbered.
 688          * So we stash 'fn' and 'arg' into global registers which
 689          * will not be modified by the parent.
 690          */
 691         __asm__ __volatile__("mov %4, %%g2\n\t"    /* Save FN into global */
 692                              "mov %5, %%g3\n\t"    /* Save ARG into global */
 693                              "mov %1, %%g1\n\t"    /* Clone syscall nr. */
 694                              "mov %2, %%o0\n\t"    /* Clone flags. */
 695                              "mov 0, %%o1\n\t"     /* usp arg == 0 */
 696                              "t 0x6d\n\t"          /* Linux/Sparc clone(). */
 697                              "brz,a,pn %%o1, 1f\n\t" /* Parent, just return. */
 698                              " mov %%o0, %0\n\t"
 699                              "jmpl %%g2, %%o7\n\t"   /* Call the function. */
 700                              " mov %%g3, %%o0\n\t"   /* Set arg in delay. */
 701                              "mov %3, %%g1\n\t"
 702                              "t 0x6d\n\t"          /* Linux/Sparc exit(). */
 703                              /* Notreached by child. */
 704                              "1:" :
 705                              "=r" (retval) :
 706                              "i" (__NR_clone), "r" (flags | CLONE_VM | CLONE_UNTRACED),
 707                              "i" (__NR_exit),  "r" (fn), "r" (arg) :
 708                              "g1", "g2", "g3", "o0", "o1", "memory", "cc");
 709         return retval;
 710 }
 711
 712 typedef struct {
 713         union {
 714                 unsigned int    pr_regs[32];
 715                 unsigned long   pr_dregs[16];
 716         } pr_fr;
 717         unsigned int __unused;
 718         unsigned int    pr_fsr;
 719         unsigned char   pr_qcnt;
 720         unsigned char   pr_q_entrysize;
 721         unsigned char   pr_en;
 722         unsigned int    pr_q[64];
 723 } elf_fpregset_t32;
 724
 725 /*
 726  * fill in the fpu structure for a core dump.
 727  */
 728 int dump_fpu (struct pt_regs * regs, elf_fpregset_t * fpregs)
 729 {
 730         unsigned long *kfpregs = current_thread_info()->fpregs;
 731         unsigned long fprs = current_thread_info()->fpsaved[0];
 732
 733         if (test_thread_flag(TIF_32BIT)) {
 734                 elf_fpregset_t32 *fpregs32 = (elf_fpregset_t32 *)fpregs;
 735
 736                 if (fprs & FPRS_DL)
 737                         memcpy(&fpregs32->pr_fr.pr_regs[0], kfpregs,
 738                                sizeof(unsigned int) * 32);
 739                 else
 740                         memset(&fpregs32->pr_fr.pr_regs[0], 0,
 741                                sizeof(unsigned int) * 32);
 742                 fpregs32->pr_qcnt = 0;
 743                 fpregs32->pr_q_entrysize = 8;
 744                 memset(&fpregs32->pr_q[0], 0,
 745                        (sizeof(unsigned int) * 64));
 746                 if (fprs & FPRS_FEF) {
 747                         fpregs32->pr_fsr = (unsigned int) current_thread_info()->xfsr[0];
 748                         fpregs32->pr_en = 1;
 749                 } else {
 750                         fpregs32->pr_fsr = 0;
 751                         fpregs32->pr_en = 0;
 752                 }
 753         } else {
 754                 if(fprs & FPRS_DL)
 755                         memcpy(&fpregs->pr_regs[0], kfpregs,
 756                                sizeof(unsigned int) * 32);
 757                 else
 758                         memset(&fpregs->pr_regs[0], 0,
 759                                sizeof(unsigned int) * 32);
 760                 if(fprs & FPRS_DU)
 761                         memcpy(&fpregs->pr_regs[16], kfpregs+16,
 762                                sizeof(unsigned int) * 32);
 763                 else
 764                         memset(&fpregs->pr_regs[16], 0,
 765                                sizeof(unsigned int) * 32);
 766                 if(fprs & FPRS_FEF) {
 767                         fpregs->pr_fsr = current_thread_info()->xfsr[0];
 768                         fpregs->pr_gsr = current_thread_info()->gsr[0];
 769                 } else {
 770                         fpregs->pr_fsr = fpregs->pr_gsr = 0;
 771                 }
 772                 fpregs->pr_fprs = fprs;
 773         }
 774         return 1;
 775 }
 776
 777 /*
 778  * sparc_execve() executes a new program after the asm stub has set
 779  * things up for us.  This should basically do what I want it to.
 780  */
 781 asmlinkage int sparc_execve(struct pt_regs *regs)
 782 {
 783         int error, base = 0;
 784         char *filename;
 785
 786         /* User register window flush is done by entry.S */
 787
 788         /* Check for indirect call. */
 789         if (regs->u_regs[UREG_G1] == 0)
 790                 base = 1;
 791
 792         filename = getname((char __user *)regs->u_regs[base + UREG_I0]);
 793         error = PTR_ERR(filename);
 794         if (IS_ERR(filename))
 795                 goto out;
 796         error = do_execve(filename,
 797                           (char __user * __user *)
 798                           regs->u_regs[base + UREG_I1],
 799                           (char __user * __user *)
 800                           regs->u_regs[base + UREG_I2], regs);
 801         putname(filename);
 802         if (!error) {
 803                 fprs_write(0);
 804                 current_thread_info()->xfsr[0] = 0;
 805                 current_thread_info()->fpsaved[0] = 0;
 806                 regs->tstate &= ~TSTATE_PEF;
 807                 task_lock(current);
 808                 current->ptrace &= ~PT_DTRACE;
 809                 task_unlock(current);
 810         }
 811 out:
 812         return error;
 813 }
 814
 815 unsigned long get_wchan(struct task_struct *task)
 816 {
 817         unsigned long pc, fp, bias = 0;
 818         unsigned long thread_info_base;
 819         struct reg_window *rw;
 820         unsigned long ret = 0;
 821         int count = 0;
 822
 823         if (!task || task == current ||
 824             task->state == TASK_RUNNING)
 825                 goto out;
 826
 827         thread_info_base = (unsigned long) task_stack_page(task);
 828         bias = STACK_BIAS;
 829         fp = task_thread_info(task)->ksp + bias;
 830
 831         do {
 832                 /* Bogus frame pointer? */
 833                 if (fp < (thread_info_base + sizeof(struct thread_info)) ||
 834                     fp >= (thread_info_base + THREAD_SIZE))
 835                         break;
 836                 rw = (struct reg_window *) fp;
 837                 pc = rw->ins[7];
 838                 if (!in_sched_functions(pc)) {
 839                         ret = pc;
 840                         goto out;
 841                 }
 842                 fp = rw->ins[6] + bias;
 843         } while (++count < 16);
 844
 845 out:
 846         return ret;
 847 }