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