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 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 #ifdef CONFIG_SMP
 215 static DEFINE_SPINLOCK(regdump_lock);
 216 #endif
 217
 218 void __show_regs(struct pt_regs * regs)
 219 {
 220 #ifdef CONFIG_SMP
 221         unsigned long flags;
 222
 223         /* Protect against xcall ipis which might lead to livelock on the lock */
 224         __asm__ __volatile__("rdpr      %%pstate, %0\n\t"
 225                              "wrpr      %0, %1, %%pstate"
 226                              : "=r" (flags)
 227                              : "i" (PSTATE_IE));
 228         spin_lock(&regdump_lock);
 229 #endif
 230         printk("TSTATE: %016lx TPC: %016lx TNPC: %016lx Y: %08x    %s\n", regs->tstate,
 231                regs->tpc, regs->tnpc, regs->y, print_tainted());
 232         printk("TPC: <%pS>\n", (void *) regs->tpc);
 233         printk("g0: %016lx g1: %016lx g2: %016lx g3: %016lx\n",
 234                regs->u_regs[0], regs->u_regs[1], regs->u_regs[2],
 235                regs->u_regs[3]);
 236         printk("g4: %016lx g5: %016lx g6: %016lx g7: %016lx\n",
 237                regs->u_regs[4], regs->u_regs[5], regs->u_regs[6],
 238                regs->u_regs[7]);
 239         printk("o0: %016lx o1: %016lx o2: %016lx o3: %016lx\n",
 240                regs->u_regs[8], regs->u_regs[9], regs->u_regs[10],
 241                regs->u_regs[11]);
 242         printk("o4: %016lx o5: %016lx sp: %016lx ret_pc: %016lx\n",
 243                regs->u_regs[12], regs->u_regs[13], regs->u_regs[14],
 244                regs->u_regs[15]);
 245         printk("RPC: <%pS>\n", (void *) regs->u_regs[15]);
 246         show_regwindow(regs);
 247 #ifdef CONFIG_SMP
 248         spin_unlock(&regdump_lock);
 249         __asm__ __volatile__("wrpr      %0, 0, %%pstate"
 250                              : : "r" (flags));
 251 #endif
 252 }
 253
 254 void show_regs(struct pt_regs *regs)
 255 {
 256         __show_regs(regs);
 257 #if 0
 258 #ifdef CONFIG_SMP
 259         {
 260                 extern void smp_report_regs(void);
 261
 262                 smp_report_regs();
 263         }
 264 #endif
 265 #endif
 266 }
 267
 268 struct global_reg_snapshot global_reg_snapshot[NR_CPUS];
 269 static DEFINE_SPINLOCK(global_reg_snapshot_lock);
 270
 271 static bool kstack_valid(struct thread_info *tp, struct reg_window *rw)
 272 {
 273         unsigned long thread_base, fp;
 274
 275         thread_base = (unsigned long) tp;
 276         fp = (unsigned long) rw;
 277
 278         if (fp < (thread_base + sizeof(struct thread_info)) ||
 279             fp >= (thread_base + THREAD_SIZE))
 280                 return false;
 281         return true;
 282 }
 283
 284 static void __global_reg_self(struct thread_info *tp, struct pt_regs *regs,
 285                               int this_cpu)
 286 {
 287         flushw_all();
 288
 289         global_reg_snapshot[this_cpu].tstate = regs->tstate;
 290         global_reg_snapshot[this_cpu].tpc = regs->tpc;
 291         global_reg_snapshot[this_cpu].tnpc = regs->tnpc;
 292         global_reg_snapshot[this_cpu].o7 = regs->u_regs[UREG_I7];
 293
 294         if (regs->tstate & TSTATE_PRIV) {
 295                 struct thread_info *tp = current_thread_info();
 296                 struct reg_window *rw;
 297
 298                 rw = (struct reg_window *)
 299                         (regs->u_regs[UREG_FP] + STACK_BIAS);
 300                 if (kstack_valid(tp, rw)) {
 301                         global_reg_snapshot[this_cpu].i7 = rw->ins[7];
 302                         rw = (struct reg_window *)
 303                                 (rw->ins[6] + STACK_BIAS);
 304                         if (kstack_valid(tp, rw))
 305                                 global_reg_snapshot[this_cpu].rpc = rw->ins[7];
 306                 }
 307         } else {
 308                 global_reg_snapshot[this_cpu].i7 = 0;
 309                 global_reg_snapshot[this_cpu].rpc = 0;
 310         }
 311         global_reg_snapshot[this_cpu].thread = tp;
 312 }
 313
 314 /* In order to avoid hangs we do not try to synchronize with the
 315  * global register dump client cpus.  The last store they make is to
 316  * the thread pointer, so do a short poll waiting for that to become
 317  * non-NULL.
 318  */
 319 static void __global_reg_poll(struct global_reg_snapshot *gp)
 320 {
 321         int limit = 0;
 322
 323         while (!gp->thread && ++limit < 100) {
 324                 barrier();
 325                 udelay(1);
 326         }
 327 }
 328
 329 void __trigger_all_cpu_backtrace(void)
 330 {
 331         struct thread_info *tp = current_thread_info();
 332         struct pt_regs *regs = get_irq_regs();
 333         unsigned long flags;
 334         int this_cpu, cpu;
 335
 336         if (!regs)
 337                 regs = tp->kregs;
 338
 339         spin_lock_irqsave(&global_reg_snapshot_lock, flags);
 340
 341         memset(global_reg_snapshot, 0, sizeof(global_reg_snapshot));
 342
 343         this_cpu = raw_smp_processor_id();
 344
 345         __global_reg_self(tp, regs, this_cpu);
 346
 347         smp_fetch_global_regs();
 348
 349         for_each_online_cpu(cpu) {
 350                 struct global_reg_snapshot *gp = &global_reg_snapshot[cpu];
 351                 struct thread_info *tp;
 352
 353                 __global_reg_poll(gp);
 354
 355                 tp = gp->thread;
 356                 printk("%c CPU[%3d]: TSTATE[%016lx] TPC[%016lx] TNPC[%016lx] TASK[%s:%d]\n",
 357                        (cpu == this_cpu ? '*' : ' '), cpu,
 358                        gp->tstate, gp->tpc, gp->tnpc,
 359                        ((tp && tp->task) ? tp->task->comm : "NULL"),
 360                        ((tp && tp->task) ? tp->task->pid : -1));
 361
 362                 if (gp->tstate & TSTATE_PRIV) {
 363                         printk("             TPC[%pS] O7[%pS] I7[%pS] RPC[%pS]\n",
 364                                (void *) gp->tpc,
 365                                (void *) gp->o7,
 366                                (void *) gp->i7,
 367                                (void *) gp->rpc);
 368                 } else {
 369                         printk("             TPC[%lx] O7[%lx] I7[%lx] RPC[%lx]\n",
 370                                gp->tpc, gp->o7, gp->i7, gp->rpc);
 371                 }
 372         }
 373
 374         memset(global_reg_snapshot, 0, sizeof(global_reg_snapshot));
 375
 376         spin_unlock_irqrestore(&global_reg_snapshot_lock, flags);
 377 }
 378
 379 #ifdef CONFIG_MAGIC_SYSRQ
 380
 381 static void sysrq_handle_globreg(int key, struct tty_struct *tty)
 382 {
 383         __trigger_all_cpu_backtrace();
 384 }
 385
 386 static struct sysrq_key_op sparc_globalreg_op = {
 387         .handler        = sysrq_handle_globreg,
 388         .help_msg       = "Globalregs",
 389         .action_msg     = "Show Global CPU Regs",
 390 };
 391
 392 static int __init sparc_globreg_init(void)
 393 {
 394         return register_sysrq_key('y', &sparc_globalreg_op);
 395 }
 396
 397 core_initcall(sparc_globreg_init);
 398
 399 #endif
 400
 401 unsigned long thread_saved_pc(struct task_struct *tsk)
 402 {
 403         struct thread_info *ti = task_thread_info(tsk);
 404         unsigned long ret = 0xdeadbeefUL;
 405
 406         if (ti && ti->ksp) {
 407                 unsigned long *sp;
 408                 sp = (unsigned long *)(ti->ksp + STACK_BIAS);
 409                 if (((unsigned long)sp & (sizeof(long) - 1)) == 0UL &&
 410                     sp[14]) {
 411                         unsigned long *fp;
 412                         fp = (unsigned long *)(sp[14] + STACK_BIAS);
 413                         if (((unsigned long)fp & (sizeof(long) - 1)) == 0UL)
 414                                 ret = fp[15];
 415                 }
 416         }
 417         return ret;
 418 }
 419
 420 /* Free current thread data structures etc.. */
 421 void exit_thread(void)
 422 {
 423         struct thread_info *t = current_thread_info();
 424
 425         if (t->utraps) {
 426                 if (t->utraps[0] < 2)
 427                         kfree (t->utraps);
 428                 else
 429                         t->utraps[0]--;
 430         }
 431
 432         if (test_and_clear_thread_flag(TIF_PERFCTR)) {
 433                 t->user_cntd0 = t->user_cntd1 = NULL;
 434                 t->pcr_reg = 0;
 435                 write_pcr(0);
 436         }
 437 }
 438
 439 void flush_thread(void)
 440 {
 441         struct thread_info *t = current_thread_info();
 442         struct mm_struct *mm;
 443
 444         if (test_ti_thread_flag(t, TIF_ABI_PENDING)) {
 445                 clear_ti_thread_flag(t, TIF_ABI_PENDING);
 446                 if (test_ti_thread_flag(t, TIF_32BIT))
 447                         clear_ti_thread_flag(t, TIF_32BIT);
 448                 else
 449                         set_ti_thread_flag(t, TIF_32BIT);
 450         }
 451
 452         mm = t->task->mm;
 453         if (mm)
 454                 tsb_context_switch(mm);
 455
 456         set_thread_wsaved(0);
 457
 458         /* Turn off performance counters if on. */
 459         if (test_and_clear_thread_flag(TIF_PERFCTR)) {
 460                 t->user_cntd0 = t->user_cntd1 = NULL;
 461                 t->pcr_reg = 0;
 462                 write_pcr(0);
 463         }
 464
 465         /* Clear FPU register state. */
 466         t->fpsaved[0] = 0;
 467
 468         if (get_thread_current_ds() != ASI_AIUS)
 469                 set_fs(USER_DS);
 470 }
 471
 472 /* It's a bit more tricky when 64-bit tasks are involved... */
 473 static unsigned long clone_stackframe(unsigned long csp, unsigned long psp)
 474 {
 475         unsigned long fp, distance, rval;
 476
 477         if (!(test_thread_flag(TIF_32BIT))) {
 478                 csp += STACK_BIAS;
 479                 psp += STACK_BIAS;
 480                 __get_user(fp, &(((struct reg_window __user *)psp)->ins[6]));
 481                 fp += STACK_BIAS;
 482         } else
 483                 __get_user(fp, &(((struct reg_window32 __user *)psp)->ins[6]));
 484
 485         /* Now 8-byte align the stack as this is mandatory in the
 486          * Sparc ABI due to how register windows work.  This hides
 487          * the restriction from thread libraries etc.  -DaveM
 488          */
 489         csp &= ~7UL;
 490
 491         distance = fp - psp;
 492         rval = (csp - distance);
 493         if (copy_in_user((void __user *) rval, (void __user *) psp, distance))
 494                 rval = 0;
 495         else if (test_thread_flag(TIF_32BIT)) {
 496                 if (put_user(((u32)csp),
 497                              &(((struct reg_window32 __user *)rval)->ins[6])))
 498                         rval = 0;
 499         } else {
 500                 if (put_user(((u64)csp - STACK_BIAS),
 501                              &(((struct reg_window __user *)rval)->ins[6])))
 502                         rval = 0;
 503                 else
 504                         rval = rval - STACK_BIAS;
 505         }
 506
 507         return rval;
 508 }
 509
 510 /* Standard stuff. */
 511 static inline void shift_window_buffer(int first_win, int last_win,
 512                                        struct thread_info *t)
 513 {
 514         int i;
 515
 516         for (i = first_win; i < last_win; i++) {
 517                 t->rwbuf_stkptrs[i] = t->rwbuf_stkptrs[i+1];
 518                 memcpy(&t->reg_window[i], &t->reg_window[i+1],
 519                        sizeof(struct reg_window));
 520         }
 521 }
 522
 523 void synchronize_user_stack(void)
 524 {
 525         struct thread_info *t = current_thread_info();
 526         unsigned long window;
 527
 528         flush_user_windows();
 529         if ((window = get_thread_wsaved()) != 0) {
 530                 int winsize = sizeof(struct reg_window);
 531                 int bias = 0;
 532
 533                 if (test_thread_flag(TIF_32BIT))
 534                         winsize = sizeof(struct reg_window32);
 535                 else
 536                         bias = STACK_BIAS;
 537
 538                 window -= 1;
 539                 do {
 540                         unsigned long sp = (t->rwbuf_stkptrs[window] + bias);
 541                         struct reg_window *rwin = &t->reg_window[window];
 542
 543                         if (!copy_to_user((char __user *)sp, rwin, winsize)) {
 544                                 shift_window_buffer(window, get_thread_wsaved() - 1, t);
 545                                 set_thread_wsaved(get_thread_wsaved() - 1);
 546                         }
 547                 } while (window--);
 548         }
 549 }
 550
 551 static void stack_unaligned(unsigned long sp)
 552 {
 553         siginfo_t info;
 554
 555         info.si_signo = SIGBUS;
 556         info.si_errno = 0;
 557         info.si_code = BUS_ADRALN;
 558         info.si_addr = (void __user *) sp;
 559         info.si_trapno = 0;
 560         force_sig_info(SIGBUS, &info, current);
 561 }
 562
 563 void fault_in_user_windows(void)
 564 {
 565         struct thread_info *t = current_thread_info();
 566         unsigned long window;
 567         int winsize = sizeof(struct reg_window);
 568         int bias = 0;
 569
 570         if (test_thread_flag(TIF_32BIT))
 571                 winsize = sizeof(struct reg_window32);
 572         else
 573                 bias = STACK_BIAS;
 574
 575         flush_user_windows();
 576         window = get_thread_wsaved();
 577
 578         if (likely(window != 0)) {
 579                 window -= 1;
 580                 do {
 581                         unsigned long sp = (t->rwbuf_stkptrs[window] + bias);
 582                         struct reg_window *rwin = &t->reg_window[window];
 583
 584                         if (unlikely(sp & 0x7UL))
 585                                 stack_unaligned(sp);
 586
 587                         if (unlikely(copy_to_user((char __user *)sp,
 588                                                   rwin, winsize)))
 589                                 goto barf;
 590                 } while (window--);
 591         }
 592         set_thread_wsaved(0);
 593         return;
 594
 595 barf:
 596         set_thread_wsaved(window + 1);
 597         do_exit(SIGILL);
 598 }
 599
 600 asmlinkage long sparc_do_fork(unsigned long clone_flags,
 601                               unsigned long stack_start,
 602                               struct pt_regs *regs,
 603                               unsigned long stack_size)
 604 {
 605         int __user *parent_tid_ptr, *child_tid_ptr;
 606         unsigned long orig_i1 = regs->u_regs[UREG_I1];
 607         long ret;
 608
 609 #ifdef CONFIG_COMPAT
 610         if (test_thread_flag(TIF_32BIT)) {
 611                 parent_tid_ptr = compat_ptr(regs->u_regs[UREG_I2]);
 612                 child_tid_ptr = compat_ptr(regs->u_regs[UREG_I4]);
 613         } else
 614 #endif
 615         {
 616                 parent_tid_ptr = (int __user *) regs->u_regs[UREG_I2];
 617                 child_tid_ptr = (int __user *) regs->u_regs[UREG_I4];
 618         }
 619
 620         ret = do_fork(clone_flags, stack_start,
 621                       regs, stack_size,
 622                       parent_tid_ptr, child_tid_ptr);
 623
 624         /* If we get an error and potentially restart the system
 625          * call, we're screwed because copy_thread() clobbered
 626          * the parent's %o1.  So detect that case and restore it
 627          * here.
 628          */
 629         if ((unsigned long)ret >= -ERESTART_RESTARTBLOCK)
 630                 regs->u_regs[UREG_I1] = orig_i1;
 631
 632         return ret;
 633 }
 634
 635 /* Copy a Sparc thread.  The fork() return value conventions
 636  * under SunOS are nothing short of bletcherous:
 637  * Parent -->  %o0 == childs  pid, %o1 == 0
 638  * Child  -->  %o0 == parents pid, %o1 == 1
 639  */
 640 int copy_thread(int nr, unsigned long clone_flags, unsigned long sp,
 641                 unsigned long unused,
 642                 struct task_struct *p, struct pt_regs *regs)
 643 {
 644         struct thread_info *t = task_thread_info(p);
 645         struct sparc_stackf *parent_sf;
 646         unsigned long child_stack_sz;
 647         char *child_trap_frame;
 648         int kernel_thread;
 649
 650         kernel_thread = (regs->tstate & TSTATE_PRIV) ? 1 : 0;
 651         parent_sf = ((struct sparc_stackf *) regs) - 1;
 652
 653         /* Calculate offset to stack_frame & pt_regs */
 654         child_stack_sz = ((STACKFRAME_SZ + TRACEREG_SZ) +
 655                           (kernel_thread ? STACKFRAME_SZ : 0));
 656         child_trap_frame = (task_stack_page(p) +
 657                             (THREAD_SIZE - child_stack_sz));
 658         memcpy(child_trap_frame, parent_sf, child_stack_sz);
 659
 660         t->flags = (t->flags & ~((0xffUL << TI_FLAG_CWP_SHIFT) |
 661                                  (0xffUL << TI_FLAG_CURRENT_DS_SHIFT))) |
 662                 (((regs->tstate + 1) & TSTATE_CWP) << TI_FLAG_CWP_SHIFT);
 663         t->new_child = 1;
 664         t->ksp = ((unsigned long) child_trap_frame) - STACK_BIAS;
 665         t->kregs = (struct pt_regs *) (child_trap_frame +
 666                                        sizeof(struct sparc_stackf));
 667         t->fpsaved[0] = 0;
 668
 669         if (kernel_thread) {
 670                 struct sparc_stackf *child_sf = (struct sparc_stackf *)
 671                         (child_trap_frame + (STACKFRAME_SZ + TRACEREG_SZ));
 672
 673                 /* Zero terminate the stack backtrace.  */
 674                 child_sf->fp = NULL;
 675                 t->kregs->u_regs[UREG_FP] =
 676                   ((unsigned long) child_sf) - STACK_BIAS;
 677
 678                 /* Special case, if we are spawning a kernel thread from
 679                  * a userspace task (usermode helper, NFS or similar), we
 680                  * must disable performance counters in the child because
 681                  * the address space and protection realm are changing.
 682                  */
 683                 if (t->flags & _TIF_PERFCTR) {
 684                         t->user_cntd0 = t->user_cntd1 = NULL;
 685                         t->pcr_reg = 0;
 686                         t->flags &= ~_TIF_PERFCTR;
 687                 }
 688                 t->flags |= ((long)ASI_P << TI_FLAG_CURRENT_DS_SHIFT);
 689                 t->kregs->u_regs[UREG_G6] = (unsigned long) t;
 690                 t->kregs->u_regs[UREG_G4] = (unsigned long) t->task;
 691         } else {
 692                 if (t->flags & _TIF_32BIT) {
 693                         sp &= 0x00000000ffffffffUL;
 694                         regs->u_regs[UREG_FP] &= 0x00000000ffffffffUL;
 695                 }
 696                 t->kregs->u_regs[UREG_FP] = sp;
 697                 t->flags |= ((long)ASI_AIUS << TI_FLAG_CURRENT_DS_SHIFT);
 698                 if (sp != regs->u_regs[UREG_FP]) {
 699                         unsigned long csp;
 700
 701                         csp = clone_stackframe(sp, regs->u_regs[UREG_FP]);
 702                         if (!csp)
 703                                 return -EFAULT;
 704                         t->kregs->u_regs[UREG_FP] = csp;
 705                 }
 706                 if (t->utraps)
 707                         t->utraps[0]++;
 708         }
 709
 710         /* Set the return value for the child. */
 711         t->kregs->u_regs[UREG_I0] = current->pid;
 712         t->kregs->u_regs[UREG_I1] = 1;
 713
 714         /* Set the second return value for the parent. */
 715         regs->u_regs[UREG_I1] = 0;
 716
 717         if (clone_flags & CLONE_SETTLS)
 718                 t->kregs->u_regs[UREG_G7] = regs->u_regs[UREG_I3];
 719
 720         return 0;
 721 }
 722
 723 /*
 724  * This is the mechanism for creating a new kernel thread.
 725  *
 726  * NOTE! Only a kernel-only process(ie the swapper or direct descendants
 727  * who haven't done an "execve()") should use this: it will work within
 728  * a system call from a "real" process, but the process memory space will
 729  * not be freed until both the parent and the child have exited.
 730  */
 731 pid_t kernel_thread(int (*fn)(void *), void * arg, unsigned long flags)
 732 {
 733         long retval;
 734
 735         /* If the parent runs before fn(arg) is called by the child,
 736          * the input registers of this function can be clobbered.
 737          * So we stash 'fn' and 'arg' into global registers which
 738          * will not be modified by the parent.
 739          */
 740         __asm__ __volatile__("mov %4, %%g2\n\t"    /* Save FN into global */
 741                              "mov %5, %%g3\n\t"    /* Save ARG into global */
 742                              "mov %1, %%g1\n\t"    /* Clone syscall nr. */
 743                              "mov %2, %%o0\n\t"    /* Clone flags. */
 744                              "mov 0, %%o1\n\t"     /* usp arg == 0 */
 745                              "t 0x6d\n\t"          /* Linux/Sparc clone(). */
 746                              "brz,a,pn %%o1, 1f\n\t" /* Parent, just return. */
 747                              " mov %%o0, %0\n\t"
 748                              "jmpl %%g2, %%o7\n\t"   /* Call the function. */
 749                              " mov %%g3, %%o0\n\t"   /* Set arg in delay. */
 750                              "mov %3, %%g1\n\t"
 751                              "t 0x6d\n\t"          /* Linux/Sparc exit(). */
 752                              /* Notreached by child. */
 753                              "1:" :
 754                              "=r" (retval) :
 755                              "i" (__NR_clone), "r" (flags | CLONE_VM | CLONE_UNTRACED),
 756                              "i" (__NR_exit),  "r" (fn), "r" (arg) :
 757                              "g1", "g2", "g3", "o0", "o1", "memory", "cc");
 758         return retval;
 759 }
 760
 761 typedef struct {
 762         union {
 763                 unsigned int    pr_regs[32];
 764                 unsigned long   pr_dregs[16];
 765         } pr_fr;
 766         unsigned int __unused;
 767         unsigned int    pr_fsr;
 768         unsigned char   pr_qcnt;
 769         unsigned char   pr_q_entrysize;
 770         unsigned char   pr_en;
 771         unsigned int    pr_q[64];
 772 } elf_fpregset_t32;
 773
 774 /*
 775  * fill in the fpu structure for a core dump.
 776  */
 777 int dump_fpu (struct pt_regs * regs, elf_fpregset_t * fpregs)
 778 {
 779         unsigned long *kfpregs = current_thread_info()->fpregs;
 780         unsigned long fprs = current_thread_info()->fpsaved[0];
 781
 782         if (test_thread_flag(TIF_32BIT)) {
 783                 elf_fpregset_t32 *fpregs32 = (elf_fpregset_t32 *)fpregs;
 784
 785                 if (fprs & FPRS_DL)
 786                         memcpy(&fpregs32->pr_fr.pr_regs[0], kfpregs,
 787                                sizeof(unsigned int) * 32);
 788                 else
 789                         memset(&fpregs32->pr_fr.pr_regs[0], 0,
 790                                sizeof(unsigned int) * 32);
 791                 fpregs32->pr_qcnt = 0;
 792                 fpregs32->pr_q_entrysize = 8;
 793                 memset(&fpregs32->pr_q[0], 0,
 794                        (sizeof(unsigned int) * 64));
 795                 if (fprs & FPRS_FEF) {
 796                         fpregs32->pr_fsr = (unsigned int) current_thread_info()->xfsr[0];
 797                         fpregs32->pr_en = 1;
 798                 } else {
 799                         fpregs32->pr_fsr = 0;
 800                         fpregs32->pr_en = 0;
 801                 }
 802         } else {
 803                 if(fprs & FPRS_DL)
 804                         memcpy(&fpregs->pr_regs[0], kfpregs,
 805                                sizeof(unsigned int) * 32);
 806                 else
 807                         memset(&fpregs->pr_regs[0], 0,
 808                                sizeof(unsigned int) * 32);
 809                 if(fprs & FPRS_DU)
 810                         memcpy(&fpregs->pr_regs[16], kfpregs+16,
 811                                sizeof(unsigned int) * 32);
 812                 else
 813                         memset(&fpregs->pr_regs[16], 0,
 814                                sizeof(unsigned int) * 32);
 815                 if(fprs & FPRS_FEF) {
 816                         fpregs->pr_fsr = current_thread_info()->xfsr[0];
 817                         fpregs->pr_gsr = current_thread_info()->gsr[0];
 818                 } else {
 819                         fpregs->pr_fsr = fpregs->pr_gsr = 0;
 820                 }
 821                 fpregs->pr_fprs = fprs;
 822         }
 823         return 1;
 824 }
 825
 826 /*
 827  * sparc_execve() executes a new program after the asm stub has set
 828  * things up for us.  This should basically do what I want it to.
 829  */
 830 asmlinkage int sparc_execve(struct pt_regs *regs)
 831 {
 832         int error, base = 0;
 833         char *filename;
 834
 835         /* User register window flush is done by entry.S */
 836
 837         /* Check for indirect call. */
 838         if (regs->u_regs[UREG_G1] == 0)
 839                 base = 1;
 840
 841         filename = getname((char __user *)regs->u_regs[base + UREG_I0]);
 842         error = PTR_ERR(filename);
 843         if (IS_ERR(filename))
 844                 goto out;
 845         error = do_execve(filename,
 846                           (char __user * __user *)
 847                           regs->u_regs[base + UREG_I1],
 848                           (char __user * __user *)
 849                           regs->u_regs[base + UREG_I2], regs);
 850         putname(filename);
 851         if (!error) {
 852                 fprs_write(0);
 853                 current_thread_info()->xfsr[0] = 0;
 854                 current_thread_info()->fpsaved[0] = 0;
 855                 regs->tstate &= ~TSTATE_PEF;
 856         }
 857 out:
 858         return error;
 859 }
 860
 861 unsigned long get_wchan(struct task_struct *task)
 862 {
 863         unsigned long pc, fp, bias = 0;
 864         unsigned long thread_info_base;
 865         struct reg_window *rw;
 866         unsigned long ret = 0;
 867         int count = 0;
 868
 869         if (!task || task == current ||
 870             task->state == TASK_RUNNING)
 871                 goto out;
 872
 873         thread_info_base = (unsigned long) task_stack_page(task);
 874         bias = STACK_BIAS;
 875         fp = task_thread_info(task)->ksp + bias;
 876
 877         do {
 878                 /* Bogus frame pointer? */
 879                 if (fp < (thread_info_base + sizeof(struct thread_info)) ||
 880                     fp >= (thread_info_base + THREAD_SIZE))
 881                         break;
 882                 rw = (struct reg_window *) fp;
 883                 pc = rw->ins[7];
 884                 if (!in_sched_functions(pc)) {
 885                         ret = pc;
 886                         goto out;
 887                 }
 888                 fp = rw->ins[6] + bias;
 889         } while (++count < 16);
 890
 891 out:
 892         return ret;
 893 }