arch/sparc64/kernel/process.c

   1 /*  arch/sparc64/kernel/process.c
   2  *
   3  *  Copyright (C) 1995, 1996, 2008 David S. Miller (davem@davemloft.net)
   4  *  Copyright (C) 1996       Eddie C. Dost   (ecd@skynet.be)
   5  *  Copyright (C) 1997, 1998 Jakub Jelinek   (jj@sunsite.mff.cuni.cz)
   6  */
   7
   8 /*
   9  * This file handles the architecture-dependent parts of process handling..
  10  */
  11
  12 #include <stdarg.h>
  13
  14 #include <linux/errno.h>
  15 #include <linux/module.h>
  16 #include <linux/sched.h>
  17 #include <linux/kernel.h>
  18 #include <linux/mm.h>
  19 #include <linux/fs.h>
  20 #include <linux/smp.h>
  21 #include <linux/stddef.h>
  22 #include <linux/ptrace.h>
  23 #include <linux/slab.h>
  24 #include <linux/user.h>
  25 #include <linux/reboot.h>
  26 #include <linux/delay.h>
  27 #include <linux/compat.h>
  28 #include <linux/tick.h>
  29 #include <linux/init.h>
  30 #include <linux/cpu.h>
  31 #include <linux/elfcore.h>
  32 #include <linux/sysrq.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 #include <asm/irq_regs.h>
  53 #include <asm/smp.h>
  54
  55 /* #define VERBOSE_SHOWREGS */
  56
  57 static void sparc64_yield(int cpu)
  58 {
  59         if (tlb_type != hypervisor)
  60                 return;
  61
  62         clear_thread_flag(TIF_POLLING_NRFLAG);
  63         smp_mb__after_clear_bit();
  64
  65         while (!need_resched() && !cpu_is_offline(cpu)) {
  66                 unsigned long pstate;
  67
  68                 /* Disable interrupts. */
  69                 __asm__ __volatile__(
  70                         "rdpr %%pstate, %0\n\t"
  71                         "andn %0, %1, %0\n\t"
  72                         "wrpr %0, %%g0, %%pstate"
  73                         : "=&r" (pstate)
  74                         : "i" (PSTATE_IE));
  75
  76                 if (!need_resched() && !cpu_is_offline(cpu))
  77                         sun4v_cpu_yield();
  78
  79                 /* Re-enable interrupts. */
  80                 __asm__ __volatile__(
  81                         "rdpr %%pstate, %0\n\t"
  82                         "or %0, %1, %0\n\t"
  83                         "wrpr %0, %%g0, %%pstate"
  84                         : "=&r" (pstate)
  85                         : "i" (PSTATE_IE));
  86         }
  87
  88         set_thread_flag(TIF_POLLING_NRFLAG);
  89 }
  90
  91 /* The idle loop on sparc64. */
  92 void cpu_idle(void)
  93 {
  94         int cpu = smp_processor_id();
  95
  96         set_thread_flag(TIF_POLLING_NRFLAG);
  97
  98         while(1) {
  99                 tick_nohz_stop_sched_tick();
 100
 101                 while (!need_resched() && !cpu_is_offline(cpu))
 102                         sparc64_yield(cpu);
 103
 104                 tick_nohz_restart_sched_tick();
 105
 106                 preempt_enable_no_resched();
 107
 108 #ifdef CONFIG_HOTPLUG_CPU
 109                 if (cpu_is_offline(cpu))
 110                         cpu_play_dead();
 111 #endif
 112
 113                 schedule();
 114                 preempt_disable();
 115         }
 116 }
 117
 118 void machine_halt(void)
 119 {
 120         sstate_halt();
 121         prom_halt();
 122         panic("Halt failed!");
 123 }
 124
 125 void machine_alt_power_off(void)
 126 {
 127         sstate_poweroff();
 128         prom_halt_power_off();
 129         panic("Power-off failed!");
 130 }
 131
 132 void machine_restart(char * cmd)
 133 {
 134         char *p;
 135
 136         sstate_reboot();
 137         p = strchr (reboot_command, '\n');
 138         if (p) *p = 0;
 139         if (cmd)
 140                 prom_reboot(cmd);
 141         if (*reboot_command)
 142                 prom_reboot(reboot_command);
 143         prom_reboot("");
 144         panic("Reboot failed!");
 145 }
 146
 147 #ifdef CONFIG_COMPAT
 148 static void show_regwindow32(struct pt_regs *regs)
 149 {
 150         struct reg_window32 __user *rw;
 151         struct reg_window32 r_w;
 152         mm_segment_t old_fs;
 153
 154         __asm__ __volatile__ ("flushw");
 155         rw = compat_ptr((unsigned)regs->u_regs[14]);
 156         old_fs = get_fs();
 157         set_fs (USER_DS);
 158         if (copy_from_user (&r_w, rw, sizeof(r_w))) {
 159                 set_fs (old_fs);
 160                 return;
 161         }
 162
 163         set_fs (old_fs);
 164         printk("l0: %08x l1: %08x l2: %08x l3: %08x "
 165                "l4: %08x l5: %08x l6: %08x l7: %08x\n",
 166                r_w.locals[0], r_w.locals[1], r_w.locals[2], r_w.locals[3],
 167                r_w.locals[4], r_w.locals[5], r_w.locals[6], r_w.locals[7]);
 168         printk("i0: %08x i1: %08x i2: %08x i3: %08x "
 169                "i4: %08x i5: %08x i6: %08x i7: %08x\n",
 170                r_w.ins[0], r_w.ins[1], r_w.ins[2], r_w.ins[3],
 171                r_w.ins[4], r_w.ins[5], r_w.ins[6], r_w.ins[7]);
 172 }
 173 #else
 174 #define show_regwindow32(regs)  do { } while (0)
 175 #endif
 176
 177 static void show_regwindow(struct pt_regs *regs)
 178 {
 179         struct reg_window __user *rw;
 180         struct reg_window *rwk;
 181         struct reg_window r_w;
 182         mm_segment_t old_fs;
 183
 184         if ((regs->tstate & TSTATE_PRIV) || !(test_thread_flag(TIF_32BIT))) {
 185                 __asm__ __volatile__ ("flushw");
 186                 rw = (struct reg_window __user *)
 187                         (regs->u_regs[14] + STACK_BIAS);
 188                 rwk = (struct reg_window *)
 189                         (regs->u_regs[14] + STACK_BIAS);
 190                 if (!(regs->tstate & TSTATE_PRIV)) {
 191                         old_fs = get_fs();
 192                         set_fs (USER_DS);
 193                         if (copy_from_user (&r_w, rw, sizeof(r_w))) {
 194                                 set_fs (old_fs);
 195                                 return;
 196                         }
 197                         rwk = &r_w;
 198                         set_fs (old_fs);
 199                 }
 200         } else {
 201                 show_regwindow32(regs);
 202                 return;
 203         }
 204         printk("l0: %016lx l1: %016lx l2: %016lx l3: %016lx\n",
 205                rwk->locals[0], rwk->locals[1], rwk->locals[2], rwk->locals[3]);
 206         printk("l4: %016lx l5: %016lx l6: %016lx l7: %016lx\n",
 207                rwk->locals[4], rwk->locals[5], rwk->locals[6], rwk->locals[7]);
 208         printk("i0: %016lx i1: %016lx i2: %016lx i3: %016lx\n",
 209                rwk->ins[0], rwk->ins[1], rwk->ins[2], rwk->ins[3]);
 210         printk("i4: %016lx i5: %016lx i6: %016lx i7: %016lx\n",
 211                rwk->ins[4], rwk->ins[5], rwk->ins[6], rwk->ins[7]);
 212         if (regs->tstate & TSTATE_PRIV)
 213                 printk("I7: <%pS>\n", (void *) rwk->ins[7]);
 214 }
 215
 216 #ifdef CONFIG_SMP
 217 static DEFINE_SPINLOCK(regdump_lock);
 218 #endif
 219
 220 void __show_regs(struct pt_regs * regs)
 221 {
 222 #ifdef CONFIG_SMP
 223         unsigned long flags;
 224
 225         /* Protect against xcall ipis which might lead to livelock on the lock */
 226         __asm__ __volatile__("rdpr      %%pstate, %0\n\t"
 227                              "wrpr      %0, %1, %%pstate"
 228                              : "=r" (flags)
 229                              : "i" (PSTATE_IE));
 230         spin_lock(&regdump_lock);
 231 #endif
 232         printk("TSTATE: %016lx TPC: %016lx TNPC: %016lx Y: %08x    %s\n", regs->tstate,
 233                regs->tpc, regs->tnpc, regs->y, print_tainted());
 234         printk("TPC: <%pS>\n", (void *) regs->tpc);
 235         printk("g0: %016lx g1: %016lx g2: %016lx g3: %016lx\n",
 236                regs->u_regs[0], regs->u_regs[1], regs->u_regs[2],
 237                regs->u_regs[3]);
 238         printk("g4: %016lx g5: %016lx g6: %016lx g7: %016lx\n",
 239                regs->u_regs[4], regs->u_regs[5], regs->u_regs[6],
 240                regs->u_regs[7]);
 241         printk("o0: %016lx o1: %016lx o2: %016lx o3: %016lx\n",
 242                regs->u_regs[8], regs->u_regs[9], regs->u_regs[10],
 243                regs->u_regs[11]);
 244         printk("o4: %016lx o5: %016lx sp: %016lx ret_pc: %016lx\n",
 245                regs->u_regs[12], regs->u_regs[13], regs->u_regs[14],
 246                regs->u_regs[15]);
 247         printk("RPC: <%pS>\n", (void *) regs->u_regs[15]);
 248         show_regwindow(regs);
 249 #ifdef CONFIG_SMP
 250         spin_unlock(&regdump_lock);
 251         __asm__ __volatile__("wrpr      %0, 0, %%pstate"
 252                              : : "r" (flags));
 253 #endif
 254 }
 255
 256 #ifdef VERBOSE_SHOWREGS
 257 static void idump_from_user (unsigned int *pc)
 258 {
 259         int i;
 260         int code;
 261
 262         if((((unsigned long) pc) & 3))
 263                 return;
 264
 265         pc -= 3;
 266         for(i = -3; i < 6; i++) {
 267                 get_user(code, pc);
 268                 printk("%c%08x%c",i?' ':'<',code,i?' ':'>');
 269                 pc++;
 270         }
 271         printk("\n");
 272 }
 273 #endif
 274
 275 void show_regs(struct pt_regs *regs)
 276 {
 277 #ifdef VERBOSE_SHOWREGS
 278         extern long etrap, etraptl1;
 279 #endif
 280         __show_regs(regs);
 281 #if 0
 282 #ifdef CONFIG_SMP
 283         {
 284                 extern void smp_report_regs(void);
 285
 286                 smp_report_regs();
 287         }
 288 #endif
 289 #endif
 290
 291 #ifdef VERBOSE_SHOWREGS
 292         if (regs->tpc >= &etrap && regs->tpc < &etraptl1 &&
 293             regs->u_regs[14] >= (long)current - PAGE_SIZE &&
 294             regs->u_regs[14] < (long)current + 6 * PAGE_SIZE) {
 295                 printk ("*********parent**********\n");
 296                 __show_regs((struct pt_regs *)(regs->u_regs[14] + PTREGS_OFF));
 297                 idump_from_user(((struct pt_regs *)(regs->u_regs[14] + PTREGS_OFF))->tpc);
 298                 printk ("*********endpar**********\n");
 299         }
 300 #endif
 301 }
 302
 303 #ifdef CONFIG_MAGIC_SYSRQ
 304 struct global_reg_snapshot global_reg_snapshot[NR_CPUS];
 305 static DEFINE_SPINLOCK(global_reg_snapshot_lock);
 306
 307 static void __global_reg_self(struct thread_info *tp, struct pt_regs *regs,
 308                               int this_cpu)
 309 {
 310         flushw_all();
 311
 312         global_reg_snapshot[this_cpu].tstate = regs->tstate;
 313         global_reg_snapshot[this_cpu].tpc = regs->tpc;
 314         global_reg_snapshot[this_cpu].tnpc = regs->tnpc;
 315         global_reg_snapshot[this_cpu].o7 = regs->u_regs[UREG_I7];
 316
 317         if (regs->tstate & TSTATE_PRIV) {
 318                 struct reg_window *rw;
 319
 320                 rw = (struct reg_window *)
 321                         (regs->u_regs[UREG_FP] + STACK_BIAS);
 322                 global_reg_snapshot[this_cpu].i7 = rw->ins[6];
 323         } else
 324                 global_reg_snapshot[this_cpu].i7 = 0;
 325
 326         global_reg_snapshot[this_cpu].thread = tp;
 327 }
 328
 329 /* In order to avoid hangs we do not try to synchronize with the
 330  * global register dump client cpus.  The last store they make is to
 331  * the thread pointer, so do a short poll waiting for that to become
 332  * non-NULL.
 333  */
 334 static void __global_reg_poll(struct global_reg_snapshot *gp)
 335 {
 336         int limit = 0;
 337
 338         while (!gp->thread && ++limit < 100) {
 339                 barrier();
 340                 udelay(1);
 341         }
 342 }
 343
 344 static void sysrq_handle_globreg(int key, struct tty_struct *tty)
 345 {
 346         struct thread_info *tp = current_thread_info();
 347         struct pt_regs *regs = get_irq_regs();
 348         unsigned long flags;
 349         int this_cpu, cpu;
 350
 351         if (!regs)
 352                 regs = tp->kregs;
 353
 354         spin_lock_irqsave(&global_reg_snapshot_lock, flags);
 355
 356         memset(global_reg_snapshot, 0, sizeof(global_reg_snapshot));
 357
 358         this_cpu = raw_smp_processor_id();
 359
 360         __global_reg_self(tp, regs, this_cpu);
 361
 362         smp_fetch_global_regs();
 363
 364         for_each_online_cpu(cpu) {
 365                 struct global_reg_snapshot *gp = &global_reg_snapshot[cpu];
 366                 struct thread_info *tp;
 367
 368                 __global_reg_poll(gp);
 369
 370                 tp = gp->thread;
 371                 printk("%c CPU[%3d]: TSTATE[%016lx] TPC[%016lx] TNPC[%016lx] TASK[%s:%d]\n",
 372                        (cpu == this_cpu ? '*' : ' '), cpu,
 373                        gp->tstate, gp->tpc, gp->tnpc,
 374                        ((tp && tp->task) ? tp->task->comm : "NULL"),
 375                        ((tp && tp->task) ? tp->task->pid : -1));
 376
 377                 if (gp->tstate & TSTATE_PRIV) {
 378                         printk("             TPC[%pS] O7[%pS] I7[%pS]\n",
 379                                (void *) gp->tpc,
 380                                (void *) gp->o7,
 381                                (void *) gp->i7);
 382                 } else {
 383                         printk("             TPC[%lx] O7[%lx] I7[%lx]\n",
 384                                gp->tpc, gp->o7, gp->i7);
 385                 }
 386         }
 387
 388         memset(global_reg_snapshot, 0, sizeof(global_reg_snapshot));
 389
 390         spin_unlock_irqrestore(&global_reg_snapshot_lock, flags);
 391 }
 392
 393 static struct sysrq_key_op sparc_globalreg_op = {
 394         .handler        = sysrq_handle_globreg,
 395         .help_msg       = "Globalregs",
 396         .action_msg     = "Show Global CPU Regs",
 397 };
 398
 399 static int __init sparc_globreg_init(void)
 400 {
 401         return register_sysrq_key('y', &sparc_globalreg_op);
 402 }
 403
 404 core_initcall(sparc_globreg_init);
 405
 406 #endif
 407
 408 unsigned long thread_saved_pc(struct task_struct *tsk)
 409 {
 410         struct thread_info *ti = task_thread_info(tsk);
 411         unsigned long ret = 0xdeadbeefUL;
 412
 413         if (ti && ti->ksp) {
 414                 unsigned long *sp;
 415                 sp = (unsigned long *)(ti->ksp + STACK_BIAS);
 416                 if (((unsigned long)sp & (sizeof(long) - 1)) == 0UL &&
 417                     sp[14]) {
 418                         unsigned long *fp;
 419                         fp = (unsigned long *)(sp[14] + STACK_BIAS);
 420                         if (((unsigned long)fp & (sizeof(long) - 1)) == 0UL)
 421                                 ret = fp[15];
 422                 }
 423         }
 424         return ret;
 425 }
 426
 427 /* Free current thread data structures etc.. */
 428 void exit_thread(void)
 429 {
 430         struct thread_info *t = current_thread_info();
 431
 432         if (t->utraps) {
 433                 if (t->utraps[0] < 2)
 434                         kfree (t->utraps);
 435                 else
 436                         t->utraps[0]--;
 437         }
 438
 439         if (test_and_clear_thread_flag(TIF_PERFCTR)) {
 440                 t->user_cntd0 = t->user_cntd1 = NULL;
 441                 t->pcr_reg = 0;
 442                 write_pcr(0);
 443         }
 444 }
 445
 446 void flush_thread(void)
 447 {
 448         struct thread_info *t = current_thread_info();
 449         struct mm_struct *mm;
 450
 451         if (test_ti_thread_flag(t, TIF_ABI_PENDING)) {
 452                 clear_ti_thread_flag(t, TIF_ABI_PENDING);
 453                 if (test_ti_thread_flag(t, TIF_32BIT))
 454                         clear_ti_thread_flag(t, TIF_32BIT);
 455                 else
 456                         set_ti_thread_flag(t, TIF_32BIT);
 457         }
 458
 459         mm = t->task->mm;
 460         if (mm)
 461                 tsb_context_switch(mm);
 462
 463         set_thread_wsaved(0);
 464
 465         /* Turn off performance counters if on. */
 466         if (test_and_clear_thread_flag(TIF_PERFCTR)) {
 467                 t->user_cntd0 = t->user_cntd1 = NULL;
 468                 t->pcr_reg = 0;
 469                 write_pcr(0);
 470         }
 471
 472         /* Clear FPU register state. */
 473         t->fpsaved[0] = 0;
 474
 475         if (get_thread_current_ds() != ASI_AIUS)
 476                 set_fs(USER_DS);
 477 }
 478
 479 /* It's a bit more tricky when 64-bit tasks are involved... */
 480 static unsigned long clone_stackframe(unsigned long csp, unsigned long psp)
 481 {
 482         unsigned long fp, distance, rval;
 483
 484         if (!(test_thread_flag(TIF_32BIT))) {
 485                 csp += STACK_BIAS;
 486                 psp += STACK_BIAS;
 487                 __get_user(fp, &(((struct reg_window __user *)psp)->ins[6]));
 488                 fp += STACK_BIAS;
 489         } else
 490                 __get_user(fp, &(((struct reg_window32 __user *)psp)->ins[6]));
 491
 492         /* Now 8-byte align the stack as this is mandatory in the
 493          * Sparc ABI due to how register windows work.  This hides
 494          * the restriction from thread libraries etc.  -DaveM
 495          */
 496         csp &= ~7UL;
 497
 498         distance = fp - psp;
 499         rval = (csp - distance);
 500         if (copy_in_user((void __user *) rval, (void __user *) psp, distance))
 501                 rval = 0;
 502         else if (test_thread_flag(TIF_32BIT)) {
 503                 if (put_user(((u32)csp),
 504                              &(((struct reg_window32 __user *)rval)->ins[6])))
 505                         rval = 0;
 506         } else {
 507                 if (put_user(((u64)csp - STACK_BIAS),
 508                              &(((struct reg_window __user *)rval)->ins[6])))
 509                         rval = 0;
 510                 else
 511                         rval = rval - STACK_BIAS;
 512         }
 513
 514         return rval;
 515 }
 516
 517 /* Standard stuff. */
 518 static inline void shift_window_buffer(int first_win, int last_win,
 519                                        struct thread_info *t)
 520 {
 521         int i;
 522
 523         for (i = first_win; i < last_win; i++) {
 524                 t->rwbuf_stkptrs[i] = t->rwbuf_stkptrs[i+1];
 525                 memcpy(&t->reg_window[i], &t->reg_window[i+1],
 526                        sizeof(struct reg_window));
 527         }
 528 }
 529
 530 void synchronize_user_stack(void)
 531 {
 532         struct thread_info *t = current_thread_info();
 533         unsigned long window;
 534
 535         flush_user_windows();
 536         if ((window = get_thread_wsaved()) != 0) {
 537                 int winsize = sizeof(struct reg_window);
 538                 int bias = 0;
 539
 540                 if (test_thread_flag(TIF_32BIT))
 541                         winsize = sizeof(struct reg_window32);
 542                 else
 543                         bias = STACK_BIAS;
 544
 545                 window -= 1;
 546                 do {
 547                         unsigned long sp = (t->rwbuf_stkptrs[window] + bias);
 548                         struct reg_window *rwin = &t->reg_window[window];
 549
 550                         if (!copy_to_user((char __user *)sp, rwin, winsize)) {
 551                                 shift_window_buffer(window, get_thread_wsaved() - 1, t);
 552                                 set_thread_wsaved(get_thread_wsaved() - 1);
 553                         }
 554                 } while (window--);
 555         }
 556 }
 557
 558 static void stack_unaligned(unsigned long sp)
 559 {
 560         siginfo_t info;
 561
 562         info.si_signo = SIGBUS;
 563         info.si_errno = 0;
 564         info.si_code = BUS_ADRALN;
 565         info.si_addr = (void __user *) sp;
 566         info.si_trapno = 0;
 567         force_sig_info(SIGBUS, &info, current);
 568 }
 569
 570 void fault_in_user_windows(void)
 571 {
 572         struct thread_info *t = current_thread_info();
 573         unsigned long window;
 574         int winsize = sizeof(struct reg_window);
 575         int bias = 0;
 576
 577         if (test_thread_flag(TIF_32BIT))
 578                 winsize = sizeof(struct reg_window32);
 579         else
 580                 bias = STACK_BIAS;
 581
 582         flush_user_windows();
 583         window = get_thread_wsaved();
 584
 585         if (likely(window != 0)) {
 586                 window -= 1;
 587                 do {
 588                         unsigned long sp = (t->rwbuf_stkptrs[window] + bias);
 589                         struct reg_window *rwin = &t->reg_window[window];
 590
 591                         if (unlikely(sp & 0x7UL))
 592                                 stack_unaligned(sp);
 593
 594                         if (unlikely(copy_to_user((char __user *)sp,
 595                                                   rwin, winsize)))
 596                                 goto barf;
 597                 } while (window--);
 598         }
 599         set_thread_wsaved(0);
 600         return;
 601
 602 barf:
 603         set_thread_wsaved(window + 1);
 604         do_exit(SIGILL);
 605 }
 606
 607 asmlinkage long sparc_do_fork(unsigned long clone_flags,
 608                               unsigned long stack_start,
 609                               struct pt_regs *regs,
 610                               unsigned long stack_size)
 611 {
 612         int __user *parent_tid_ptr, *child_tid_ptr;
 613         unsigned long orig_i1 = regs->u_regs[UREG_I1];
 614         long ret;
 615
 616 #ifdef CONFIG_COMPAT
 617         if (test_thread_flag(TIF_32BIT)) {
 618                 parent_tid_ptr = compat_ptr(regs->u_regs[UREG_I2]);
 619                 child_tid_ptr = compat_ptr(regs->u_regs[UREG_I4]);
 620         } else
 621 #endif
 622         {
 623                 parent_tid_ptr = (int __user *) regs->u_regs[UREG_I2];
 624                 child_tid_ptr = (int __user *) regs->u_regs[UREG_I4];
 625         }
 626
 627         ret = do_fork(clone_flags, stack_start,
 628                       regs, stack_size,
 629                       parent_tid_ptr, child_tid_ptr);
 630
 631         /* If we get an error and potentially restart the system
 632          * call, we're screwed because copy_thread() clobbered
 633          * the parent's %o1.  So detect that case and restore it
 634          * here.
 635          */
 636         if ((unsigned long)ret >= -ERESTART_RESTARTBLOCK)
 637                 regs->u_regs[UREG_I1] = orig_i1;
 638
 639         return ret;
 640 }
 641
 642 /* Copy a Sparc thread.  The fork() return value conventions
 643  * under SunOS are nothing short of bletcherous:
 644  * Parent -->  %o0 == childs  pid, %o1 == 0
 645  * Child  -->  %o0 == parents pid, %o1 == 1
 646  */
 647 int copy_thread(int nr, unsigned long clone_flags, unsigned long sp,
 648                 unsigned long unused,
 649                 struct task_struct *p, struct pt_regs *regs)
 650 {
 651         struct thread_info *t = task_thread_info(p);
 652         struct sparc_stackf *parent_sf;
 653         unsigned long child_stack_sz;
 654         char *child_trap_frame;
 655         int kernel_thread;
 656
 657         kernel_thread = (regs->tstate & TSTATE_PRIV) ? 1 : 0;
 658         parent_sf = ((struct sparc_stackf *) regs) - 1;
 659
 660         /* Calculate offset to stack_frame & pt_regs */
 661         child_stack_sz = ((STACKFRAME_SZ + TRACEREG_SZ) +
 662                           (kernel_thread ? STACKFRAME_SZ : 0));
 663         child_trap_frame = (task_stack_page(p) +
 664                             (THREAD_SIZE - child_stack_sz));
 665         memcpy(child_trap_frame, parent_sf, child_stack_sz);
 666
 667         t->flags = (t->flags & ~((0xffUL << TI_FLAG_CWP_SHIFT) |
 668                                  (0xffUL << TI_FLAG_CURRENT_DS_SHIFT))) |
 669                 (((regs->tstate + 1) & TSTATE_CWP) << TI_FLAG_CWP_SHIFT);
 670         t->new_child = 1;
 671         t->ksp = ((unsigned long) child_trap_frame) - STACK_BIAS;
 672         t->kregs = (struct pt_regs *) (child_trap_frame +
 673                                        sizeof(struct sparc_stackf));
 674         t->fpsaved[0] = 0;
 675
 676         if (kernel_thread) {
 677                 struct sparc_stackf *child_sf = (struct sparc_stackf *)
 678                         (child_trap_frame + (STACKFRAME_SZ + TRACEREG_SZ));
 679
 680                 /* Zero terminate the stack backtrace.  */
 681                 child_sf->fp = NULL;
 682                 t->kregs->u_regs[UREG_FP] =
 683                   ((unsigned long) child_sf) - STACK_BIAS;
 684
 685                 /* Special case, if we are spawning a kernel thread from
 686                  * a userspace task (usermode helper, NFS or similar), we
 687                  * must disable performance counters in the child because
 688                  * the address space and protection realm are changing.
 689                  */
 690                 if (t->flags & _TIF_PERFCTR) {
 691                         t->user_cntd0 = t->user_cntd1 = NULL;
 692                         t->pcr_reg = 0;
 693                         t->flags &= ~_TIF_PERFCTR;
 694                 }
 695                 t->flags |= ((long)ASI_P << TI_FLAG_CURRENT_DS_SHIFT);
 696                 t->kregs->u_regs[UREG_G6] = (unsigned long) t;
 697                 t->kregs->u_regs[UREG_G4] = (unsigned long) t->task;
 698         } else {
 699                 if (t->flags & _TIF_32BIT) {
 700                         sp &= 0x00000000ffffffffUL;
 701                         regs->u_regs[UREG_FP] &= 0x00000000ffffffffUL;
 702                 }
 703                 t->kregs->u_regs[UREG_FP] = sp;
 704                 t->flags |= ((long)ASI_AIUS << TI_FLAG_CURRENT_DS_SHIFT);
 705                 if (sp != regs->u_regs[UREG_FP]) {
 706                         unsigned long csp;
 707
 708                         csp = clone_stackframe(sp, regs->u_regs[UREG_FP]);
 709                         if (!csp)
 710                                 return -EFAULT;
 711                         t->kregs->u_regs[UREG_FP] = csp;
 712                 }
 713                 if (t->utraps)
 714                         t->utraps[0]++;
 715         }
 716
 717         /* Set the return value for the child. */
 718         t->kregs->u_regs[UREG_I0] = current->pid;
 719         t->kregs->u_regs[UREG_I1] = 1;
 720
 721         /* Set the second return value for the parent. */
 722         regs->u_regs[UREG_I1] = 0;
 723
 724         if (clone_flags & CLONE_SETTLS)
 725                 t->kregs->u_regs[UREG_G7] = regs->u_regs[UREG_I3];
 726
 727         return 0;
 728 }
 729
 730 /*
 731  * This is the mechanism for creating a new kernel thread.
 732  *
 733  * NOTE! Only a kernel-only process(ie the swapper or direct descendants
 734  * who haven't done an "execve()") should use this: it will work within
 735  * a system call from a "real" process, but the process memory space will
 736  * not be freed until both the parent and the child have exited.
 737  */
 738 pid_t kernel_thread(int (*fn)(void *), void * arg, unsigned long flags)
 739 {
 740         long retval;
 741
 742         /* If the parent runs before fn(arg) is called by the child,
 743          * the input registers of this function can be clobbered.
 744          * So we stash 'fn' and 'arg' into global registers which
 745          * will not be modified by the parent.
 746          */
 747         __asm__ __volatile__("mov %4, %%g2\n\t"    /* Save FN into global */
 748                              "mov %5, %%g3\n\t"    /* Save ARG into global */
 749                              "mov %1, %%g1\n\t"    /* Clone syscall nr. */
 750                              "mov %2, %%o0\n\t"    /* Clone flags. */
 751                              "mov 0, %%o1\n\t"     /* usp arg == 0 */
 752                              "t 0x6d\n\t"          /* Linux/Sparc clone(). */
 753                              "brz,a,pn %%o1, 1f\n\t" /* Parent, just return. */
 754                              " mov %%o0, %0\n\t"
 755                              "jmpl %%g2, %%o7\n\t"   /* Call the function. */
 756                              " mov %%g3, %%o0\n\t"   /* Set arg in delay. */
 757                              "mov %3, %%g1\n\t"
 758                              "t 0x6d\n\t"          /* Linux/Sparc exit(). */
 759                              /* Notreached by child. */
 760                              "1:" :
 761                              "=r" (retval) :
 762                              "i" (__NR_clone), "r" (flags | CLONE_VM | CLONE_UNTRACED),
 763                              "i" (__NR_exit),  "r" (fn), "r" (arg) :
 764                              "g1", "g2", "g3", "o0", "o1", "memory", "cc");
 765         return retval;
 766 }
 767
 768 typedef struct {
 769         union {
 770                 unsigned int    pr_regs[32];
 771                 unsigned long   pr_dregs[16];
 772         } pr_fr;
 773         unsigned int __unused;
 774         unsigned int    pr_fsr;
 775         unsigned char   pr_qcnt;
 776         unsigned char   pr_q_entrysize;
 777         unsigned char   pr_en;
 778         unsigned int    pr_q[64];
 779 } elf_fpregset_t32;
 780
 781 /*
 782  * fill in the fpu structure for a core dump.
 783  */
 784 int dump_fpu (struct pt_regs * regs, elf_fpregset_t * fpregs)
 785 {
 786         unsigned long *kfpregs = current_thread_info()->fpregs;
 787         unsigned long fprs = current_thread_info()->fpsaved[0];
 788
 789         if (test_thread_flag(TIF_32BIT)) {
 790                 elf_fpregset_t32 *fpregs32 = (elf_fpregset_t32 *)fpregs;
 791
 792                 if (fprs & FPRS_DL)
 793                         memcpy(&fpregs32->pr_fr.pr_regs[0], kfpregs,
 794                                sizeof(unsigned int) * 32);
 795                 else
 796                         memset(&fpregs32->pr_fr.pr_regs[0], 0,
 797                                sizeof(unsigned int) * 32);
 798                 fpregs32->pr_qcnt = 0;
 799                 fpregs32->pr_q_entrysize = 8;
 800                 memset(&fpregs32->pr_q[0], 0,
 801                        (sizeof(unsigned int) * 64));
 802                 if (fprs & FPRS_FEF) {
 803                         fpregs32->pr_fsr = (unsigned int) current_thread_info()->xfsr[0];
 804                         fpregs32->pr_en = 1;
 805                 } else {
 806                         fpregs32->pr_fsr = 0;
 807                         fpregs32->pr_en = 0;
 808                 }
 809         } else {
 810                 if(fprs & FPRS_DL)
 811                         memcpy(&fpregs->pr_regs[0], kfpregs,
 812                                sizeof(unsigned int) * 32);
 813                 else
 814                         memset(&fpregs->pr_regs[0], 0,
 815                                sizeof(unsigned int) * 32);
 816                 if(fprs & FPRS_DU)
 817                         memcpy(&fpregs->pr_regs[16], kfpregs+16,
 818                                sizeof(unsigned int) * 32);
 819                 else
 820                         memset(&fpregs->pr_regs[16], 0,
 821                                sizeof(unsigned int) * 32);
 822                 if(fprs & FPRS_FEF) {
 823                         fpregs->pr_fsr = current_thread_info()->xfsr[0];
 824                         fpregs->pr_gsr = current_thread_info()->gsr[0];
 825                 } else {
 826                         fpregs->pr_fsr = fpregs->pr_gsr = 0;
 827                 }
 828                 fpregs->pr_fprs = fprs;
 829         }
 830         return 1;
 831 }
 832
 833 /*
 834  * sparc_execve() executes a new program after the asm stub has set
 835  * things up for us.  This should basically do what I want it to.
 836  */
 837 asmlinkage int sparc_execve(struct pt_regs *regs)
 838 {
 839         int error, base = 0;
 840         char *filename;
 841
 842         /* User register window flush is done by entry.S */
 843
 844         /* Check for indirect call. */
 845         if (regs->u_regs[UREG_G1] == 0)
 846                 base = 1;
 847
 848         filename = getname((char __user *)regs->u_regs[base + UREG_I0]);
 849         error = PTR_ERR(filename);
 850         if (IS_ERR(filename))
 851                 goto out;
 852         error = do_execve(filename,
 853                           (char __user * __user *)
 854                           regs->u_regs[base + UREG_I1],
 855                           (char __user * __user *)
 856                           regs->u_regs[base + UREG_I2], regs);
 857         putname(filename);
 858         if (!error) {
 859                 fprs_write(0);
 860                 current_thread_info()->xfsr[0] = 0;
 861                 current_thread_info()->fpsaved[0] = 0;
 862                 regs->tstate &= ~TSTATE_PEF;
 863         }
 864 out:
 865         return error;
 866 }
 867
 868 unsigned long get_wchan(struct task_struct *task)
 869 {
 870         unsigned long pc, fp, bias = 0;
 871         unsigned long thread_info_base;
 872         struct reg_window *rw;
 873         unsigned long ret = 0;
 874         int count = 0;
 875
 876         if (!task || task == current ||
 877             task->state == TASK_RUNNING)
 878                 goto out;
 879
 880         thread_info_base = (unsigned long) task_stack_page(task);
 881         bias = STACK_BIAS;
 882         fp = task_thread_info(task)->ksp + bias;
 883
 884         do {
 885                 /* Bogus frame pointer? */
 886                 if (fp < (thread_info_base + sizeof(struct thread_info)) ||
 887                     fp >= (thread_info_base + THREAD_SIZE))
 888                         break;
 889                 rw = (struct reg_window *) fp;
 890                 pc = rw->ins[7];
 891                 if (!in_sched_functions(pc)) {
 892                         ret = pc;
 893                         goto out;
 894                 }
 895                 fp = rw->ins[6] + bias;
 896         } while (++count < 16);
 897
 898 out:
 899         return ret;
 900 }