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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/delay.h>
  26 #include <linux/compat.h>
  27 #include <linux/tick.h>
  28 #include <linux/init.h>
  29 #include <linux/cpu.h>
  30 #include <linux/elfcore.h>
  31 #include <linux/sysrq.h>
  32
  33 #include <asm/uaccess.h>
  34 #include <asm/system.h>
  35 #include <asm/page.h>
  36 #include <asm/pgalloc.h>
  37 #include <asm/pgtable.h>
  38 #include <asm/processor.h>
  39 #include <asm/pstate.h>
  40 #include <asm/elf.h>
  41 #include <asm/fpumacro.h>
  42 #include <asm/head.h>
  43 #include <asm/cpudata.h>
  44 #include <asm/mmu_context.h>
  45 #include <asm/unistd.h>
  46 #include <asm/hypervisor.h>
  47 #include <asm/syscalls.h>
  48 #include <asm/irq_regs.h>
  49 #include <asm/smp.h>
  50
  51 #include "kstack.h"
  52
  53 static void sparc64_yield(int cpu)
  54 {
  55         if (tlb_type != hypervisor)
  56                 return;
  57
  58         clear_thread_flag(TIF_POLLING_NRFLAG);
  59         smp_mb__after_clear_bit();
  60
  61         while (!need_resched() && !cpu_is_offline(cpu)) {
  62                 unsigned long pstate;
  63
  64                 /* Disable interrupts. */
  65                 __asm__ __volatile__(
  66                         "rdpr %%pstate, %0\n\t"
  67                         "andn %0, %1, %0\n\t"
  68                         "wrpr %0, %%g0, %%pstate"
  69                         : "=&r" (pstate)
  70                         : "i" (PSTATE_IE));
  71
  72                 if (!need_resched() && !cpu_is_offline(cpu))
  73                         sun4v_cpu_yield();
  74
  75                 /* Re-enable interrupts. */
  76                 __asm__ __volatile__(
  77                         "rdpr %%pstate, %0\n\t"
  78                         "or %0, %1, %0\n\t"
  79                         "wrpr %0, %%g0, %%pstate"
  80                         : "=&r" (pstate)
  81                         : "i" (PSTATE_IE));
  82         }
  83
  84         set_thread_flag(TIF_POLLING_NRFLAG);
  85 }
  86
  87 /* The idle loop on sparc64. */
  88 void cpu_idle(void)
  89 {
  90         int cpu = smp_processor_id();
  91
  92         set_thread_flag(TIF_POLLING_NRFLAG);
  93
  94         while(1) {
  95                 tick_nohz_stop_sched_tick(1);
  96
  97                 while (!need_resched() && !cpu_is_offline(cpu))
  98                         sparc64_yield(cpu);
  99
 100                 tick_nohz_restart_sched_tick();
 101
 102                 preempt_enable_no_resched();
 103
 104 #ifdef CONFIG_HOTPLUG_CPU
 105                 if (cpu_is_offline(cpu))
 106                         cpu_play_dead();
 107 #endif
 108
 109                 schedule();
 110                 preempt_disable();
 111         }
 112 }
 113
 114 #ifdef CONFIG_COMPAT
 115 static void show_regwindow32(struct pt_regs *regs)
 116 {
 117         struct reg_window32 __user *rw;
 118         struct reg_window32 r_w;
 119         mm_segment_t old_fs;
 120
 121         __asm__ __volatile__ ("flushw");
 122         rw = compat_ptr((unsigned)regs->u_regs[14]);
 123         old_fs = get_fs();
 124         set_fs (USER_DS);
 125         if (copy_from_user (&r_w, rw, sizeof(r_w))) {
 126                 set_fs (old_fs);
 127                 return;
 128         }
 129
 130         set_fs (old_fs);
 131         printk("l0: %08x l1: %08x l2: %08x l3: %08x "
 132                "l4: %08x l5: %08x l6: %08x l7: %08x\n",
 133                r_w.locals[0], r_w.locals[1], r_w.locals[2], r_w.locals[3],
 134                r_w.locals[4], r_w.locals[5], r_w.locals[6], r_w.locals[7]);
 135         printk("i0: %08x i1: %08x i2: %08x i3: %08x "
 136                "i4: %08x i5: %08x i6: %08x i7: %08x\n",
 137                r_w.ins[0], r_w.ins[1], r_w.ins[2], r_w.ins[3],
 138                r_w.ins[4], r_w.ins[5], r_w.ins[6], r_w.ins[7]);
 139 }
 140 #else
 141 #define show_regwindow32(regs)  do { } while (0)
 142 #endif
 143
 144 static void show_regwindow(struct pt_regs *regs)
 145 {
 146         struct reg_window __user *rw;
 147         struct reg_window *rwk;
 148         struct reg_window r_w;
 149         mm_segment_t old_fs;
 150
 151         if ((regs->tstate & TSTATE_PRIV) || !(test_thread_flag(TIF_32BIT))) {
 152                 __asm__ __volatile__ ("flushw");
 153                 rw = (struct reg_window __user *)
 154                         (regs->u_regs[14] + STACK_BIAS);
 155                 rwk = (struct reg_window *)
 156                         (regs->u_regs[14] + STACK_BIAS);
 157                 if (!(regs->tstate & TSTATE_PRIV)) {
 158                         old_fs = get_fs();
 159                         set_fs (USER_DS);
 160                         if (copy_from_user (&r_w, rw, sizeof(r_w))) {
 161                                 set_fs (old_fs);
 162                                 return;
 163                         }
 164                         rwk = &r_w;
 165                         set_fs (old_fs);
 166                 }
 167         } else {
 168                 show_regwindow32(regs);
 169                 return;
 170         }
 171         printk("l0: %016lx l1: %016lx l2: %016lx l3: %016lx\n",
 172                rwk->locals[0], rwk->locals[1], rwk->locals[2], rwk->locals[3]);
 173         printk("l4: %016lx l5: %016lx l6: %016lx l7: %016lx\n",
 174                rwk->locals[4], rwk->locals[5], rwk->locals[6], rwk->locals[7]);
 175         printk("i0: %016lx i1: %016lx i2: %016lx i3: %016lx\n",
 176                rwk->ins[0], rwk->ins[1], rwk->ins[2], rwk->ins[3]);
 177         printk("i4: %016lx i5: %016lx i6: %016lx i7: %016lx\n",
 178                rwk->ins[4], rwk->ins[5], rwk->ins[6], rwk->ins[7]);
 179         if (regs->tstate & TSTATE_PRIV)
 180                 printk("I7: <%pS>\n", (void *) rwk->ins[7]);
 181 }
 182
 183 void show_regs(struct pt_regs *regs)
 184 {
 185         printk("TSTATE: %016lx TPC: %016lx TNPC: %016lx Y: %08x    %s\n", regs->tstate,
 186                regs->tpc, regs->tnpc, regs->y, print_tainted());
 187         printk("TPC: <%pS>\n", (void *) regs->tpc);
 188         printk("g0: %016lx g1: %016lx g2: %016lx g3: %016lx\n",
 189                regs->u_regs[0], regs->u_regs[1], regs->u_regs[2],
 190                regs->u_regs[3]);
 191         printk("g4: %016lx g5: %016lx g6: %016lx g7: %016lx\n",
 192                regs->u_regs[4], regs->u_regs[5], regs->u_regs[6],
 193                regs->u_regs[7]);
 194         printk("o0: %016lx o1: %016lx o2: %016lx o3: %016lx\n",
 195                regs->u_regs[8], regs->u_regs[9], regs->u_regs[10],
 196                regs->u_regs[11]);
 197         printk("o4: %016lx o5: %016lx sp: %016lx ret_pc: %016lx\n",
 198                regs->u_regs[12], regs->u_regs[13], regs->u_regs[14],
 199                regs->u_regs[15]);
 200         printk("RPC: <%pS>\n", (void *) regs->u_regs[15]);
 201         show_regwindow(regs);
 202 }
 203
 204 struct global_reg_snapshot global_reg_snapshot[NR_CPUS];
 205 static DEFINE_SPINLOCK(global_reg_snapshot_lock);
 206
 207 static void __global_reg_self(struct thread_info *tp, struct pt_regs *regs,
 208                               int this_cpu)
 209 {
 210         flushw_all();
 211
 212         global_reg_snapshot[this_cpu].tstate = regs->tstate;
 213         global_reg_snapshot[this_cpu].tpc = regs->tpc;
 214         global_reg_snapshot[this_cpu].tnpc = regs->tnpc;
 215         global_reg_snapshot[this_cpu].o7 = regs->u_regs[UREG_I7];
 216
 217         if (regs->tstate & TSTATE_PRIV) {
 218                 struct thread_info *tp = current_thread_info();
 219                 struct reg_window *rw;
 220
 221                 rw = (struct reg_window *)
 222                         (regs->u_regs[UREG_FP] + STACK_BIAS);
 223                 if (kstack_valid(tp, (unsigned long) rw)) {
 224                         global_reg_snapshot[this_cpu].i7 = rw->ins[7];
 225                         rw = (struct reg_window *)
 226                                 (rw->ins[6] + STACK_BIAS);
 227                         if (kstack_valid(tp, (unsigned long) rw))
 228                                 global_reg_snapshot[this_cpu].rpc = rw->ins[7];
 229                 }
 230         } else {
 231                 global_reg_snapshot[this_cpu].i7 = 0;
 232                 global_reg_snapshot[this_cpu].rpc = 0;
 233         }
 234         global_reg_snapshot[this_cpu].thread = tp;
 235 }
 236
 237 /* In order to avoid hangs we do not try to synchronize with the
 238  * global register dump client cpus.  The last store they make is to
 239  * the thread pointer, so do a short poll waiting for that to become
 240  * non-NULL.
 241  */
 242 static void __global_reg_poll(struct global_reg_snapshot *gp)
 243 {
 244         int limit = 0;
 245
 246         while (!gp->thread && ++limit < 100) {
 247                 barrier();
 248                 udelay(1);
 249         }
 250 }
 251
 252 void __trigger_all_cpu_backtrace(void)
 253 {
 254         struct thread_info *tp = current_thread_info();
 255         struct pt_regs *regs = get_irq_regs();
 256         unsigned long flags;
 257         int this_cpu, cpu;
 258
 259         if (!regs)
 260                 regs = tp->kregs;
 261
 262         spin_lock_irqsave(&global_reg_snapshot_lock, flags);
 263
 264         memset(global_reg_snapshot, 0, sizeof(global_reg_snapshot));
 265
 266         this_cpu = raw_smp_processor_id();
 267
 268         __global_reg_self(tp, regs, this_cpu);
 269
 270         smp_fetch_global_regs();
 271
 272         for_each_online_cpu(cpu) {
 273                 struct global_reg_snapshot *gp = &global_reg_snapshot[cpu];
 274                 struct thread_info *tp;
 275
 276                 __global_reg_poll(gp);
 277
 278                 tp = gp->thread;
 279                 printk("%c CPU[%3d]: TSTATE[%016lx] TPC[%016lx] TNPC[%016lx] TASK[%s:%d]\n",
 280                        (cpu == this_cpu ? '*' : ' '), cpu,
 281                        gp->tstate, gp->tpc, gp->tnpc,
 282                        ((tp && tp->task) ? tp->task->comm : "NULL"),
 283                        ((tp && tp->task) ? tp->task->pid : -1));
 284
 285                 if (gp->tstate & TSTATE_PRIV) {
 286                         printk("             TPC[%pS] O7[%pS] I7[%pS] RPC[%pS]\n",
 287                                (void *) gp->tpc,
 288                                (void *) gp->o7,
 289                                (void *) gp->i7,
 290                                (void *) gp->rpc);
 291                 } else {
 292                         printk("             TPC[%lx] O7[%lx] I7[%lx] RPC[%lx]\n",
 293                                gp->tpc, gp->o7, gp->i7, gp->rpc);
 294                 }
 295         }
 296
 297         memset(global_reg_snapshot, 0, sizeof(global_reg_snapshot));
 298
 299         spin_unlock_irqrestore(&global_reg_snapshot_lock, flags);
 300 }
 301
 302 #ifdef CONFIG_MAGIC_SYSRQ
 303
 304 static void sysrq_handle_globreg(int key, struct tty_struct *tty)
 305 {
 306         __trigger_all_cpu_backtrace();
 307 }
 308
 309 static struct sysrq_key_op sparc_globalreg_op = {
 310         .handler        = sysrq_handle_globreg,
 311         .help_msg       = "Globalregs",
 312         .action_msg     = "Show Global CPU Regs",
 313 };
 314
 315 static int __init sparc_globreg_init(void)
 316 {
 317         return register_sysrq_key('y', &sparc_globalreg_op);
 318 }
 319
 320 core_initcall(sparc_globreg_init);
 321
 322 #endif
 323
 324 unsigned long thread_saved_pc(struct task_struct *tsk)
 325 {
 326         struct thread_info *ti = task_thread_info(tsk);
 327         unsigned long ret = 0xdeadbeefUL;
 328
 329         if (ti && ti->ksp) {
 330                 unsigned long *sp;
 331                 sp = (unsigned long *)(ti->ksp + STACK_BIAS);
 332                 if (((unsigned long)sp & (sizeof(long) - 1)) == 0UL &&
 333                     sp[14]) {
 334                         unsigned long *fp;
 335                         fp = (unsigned long *)(sp[14] + STACK_BIAS);
 336                         if (((unsigned long)fp & (sizeof(long) - 1)) == 0UL)
 337                                 ret = fp[15];
 338                 }
 339         }
 340         return ret;
 341 }
 342
 343 /* Free current thread data structures etc.. */
 344 void exit_thread(void)
 345 {
 346         struct thread_info *t = current_thread_info();
 347
 348         if (t->utraps) {
 349                 if (t->utraps[0] < 2)
 350                         kfree (t->utraps);
 351                 else
 352                         t->utraps[0]--;
 353         }
 354
 355         if (test_and_clear_thread_flag(TIF_PERFCTR)) {
 356                 t->user_cntd0 = t->user_cntd1 = NULL;
 357                 t->pcr_reg = 0;
 358                 write_pcr(0);
 359         }
 360 }
 361
 362 void flush_thread(void)
 363 {
 364         struct thread_info *t = current_thread_info();
 365         struct mm_struct *mm;
 366
 367         if (test_ti_thread_flag(t, TIF_ABI_PENDING)) {
 368                 clear_ti_thread_flag(t, TIF_ABI_PENDING);
 369                 if (test_ti_thread_flag(t, TIF_32BIT))
 370                         clear_ti_thread_flag(t, TIF_32BIT);
 371                 else
 372                         set_ti_thread_flag(t, TIF_32BIT);
 373         }
 374
 375         mm = t->task->mm;
 376         if (mm)
 377                 tsb_context_switch(mm);
 378
 379         set_thread_wsaved(0);
 380
 381         /* Turn off performance counters if on. */
 382         if (test_and_clear_thread_flag(TIF_PERFCTR)) {
 383                 t->user_cntd0 = t->user_cntd1 = NULL;
 384                 t->pcr_reg = 0;
 385                 write_pcr(0);
 386         }
 387
 388         /* Clear FPU register state. */
 389         t->fpsaved[0] = 0;
 390
 391         if (get_thread_current_ds() != ASI_AIUS)
 392                 set_fs(USER_DS);
 393 }
 394
 395 /* It's a bit more tricky when 64-bit tasks are involved... */
 396 static unsigned long clone_stackframe(unsigned long csp, unsigned long psp)
 397 {
 398         unsigned long fp, distance, rval;
 399
 400         if (!(test_thread_flag(TIF_32BIT))) {
 401                 csp += STACK_BIAS;
 402                 psp += STACK_BIAS;
 403                 __get_user(fp, &(((struct reg_window __user *)psp)->ins[6]));
 404                 fp += STACK_BIAS;
 405         } else
 406                 __get_user(fp, &(((struct reg_window32 __user *)psp)->ins[6]));
 407
 408         /* Now 8-byte align the stack as this is mandatory in the
 409          * Sparc ABI due to how register windows work.  This hides
 410          * the restriction from thread libraries etc.  -DaveM
 411          */
 412         csp &= ~7UL;
 413
 414         distance = fp - psp;
 415         rval = (csp - distance);
 416         if (copy_in_user((void __user *) rval, (void __user *) psp, distance))
 417                 rval = 0;
 418         else if (test_thread_flag(TIF_32BIT)) {
 419                 if (put_user(((u32)csp),
 420                              &(((struct reg_window32 __user *)rval)->ins[6])))
 421                         rval = 0;
 422         } else {
 423                 if (put_user(((u64)csp - STACK_BIAS),
 424                              &(((struct reg_window __user *)rval)->ins[6])))
 425                         rval = 0;
 426                 else
 427                         rval = rval - STACK_BIAS;
 428         }
 429
 430         return rval;
 431 }
 432
 433 /* Standard stuff. */
 434 static inline void shift_window_buffer(int first_win, int last_win,
 435                                        struct thread_info *t)
 436 {
 437         int i;
 438
 439         for (i = first_win; i < last_win; i++) {
 440                 t->rwbuf_stkptrs[i] = t->rwbuf_stkptrs[i+1];
 441                 memcpy(&t->reg_window[i], &t->reg_window[i+1],
 442                        sizeof(struct reg_window));
 443         }
 444 }
 445
 446 void synchronize_user_stack(void)
 447 {
 448         struct thread_info *t = current_thread_info();
 449         unsigned long window;
 450
 451         flush_user_windows();
 452         if ((window = get_thread_wsaved()) != 0) {
 453                 int winsize = sizeof(struct reg_window);
 454                 int bias = 0;
 455
 456                 if (test_thread_flag(TIF_32BIT))
 457                         winsize = sizeof(struct reg_window32);
 458                 else
 459                         bias = STACK_BIAS;
 460
 461                 window -= 1;
 462                 do {
 463                         unsigned long sp = (t->rwbuf_stkptrs[window] + bias);
 464                         struct reg_window *rwin = &t->reg_window[window];
 465
 466                         if (!copy_to_user((char __user *)sp, rwin, winsize)) {
 467                                 shift_window_buffer(window, get_thread_wsaved() - 1, t);
 468                                 set_thread_wsaved(get_thread_wsaved() - 1);
 469                         }
 470                 } while (window--);
 471         }
 472 }
 473
 474 static void stack_unaligned(unsigned long sp)
 475 {
 476         siginfo_t info;
 477
 478         info.si_signo = SIGBUS;
 479         info.si_errno = 0;
 480         info.si_code = BUS_ADRALN;
 481         info.si_addr = (void __user *) sp;
 482         info.si_trapno = 0;
 483         force_sig_info(SIGBUS, &info, current);
 484 }
 485
 486 void fault_in_user_windows(void)
 487 {
 488         struct thread_info *t = current_thread_info();
 489         unsigned long window;
 490         int winsize = sizeof(struct reg_window);
 491         int bias = 0;
 492
 493         if (test_thread_flag(TIF_32BIT))
 494                 winsize = sizeof(struct reg_window32);
 495         else
 496                 bias = STACK_BIAS;
 497
 498         flush_user_windows();
 499         window = get_thread_wsaved();
 500
 501         if (likely(window != 0)) {
 502                 window -= 1;
 503                 do {
 504                         unsigned long sp = (t->rwbuf_stkptrs[window] + bias);
 505                         struct reg_window *rwin = &t->reg_window[window];
 506
 507                         if (unlikely(sp & 0x7UL))
 508                                 stack_unaligned(sp);
 509
 510                         if (unlikely(copy_to_user((char __user *)sp,
 511                                                   rwin, winsize)))
 512                                 goto barf;
 513                 } while (window--);
 514         }
 515         set_thread_wsaved(0);
 516         return;
 517
 518 barf:
 519         set_thread_wsaved(window + 1);
 520         do_exit(SIGILL);
 521 }
 522
 523 asmlinkage long sparc_do_fork(unsigned long clone_flags,
 524                               unsigned long stack_start,
 525                               struct pt_regs *regs,
 526                               unsigned long stack_size)
 527 {
 528         int __user *parent_tid_ptr, *child_tid_ptr;
 529         unsigned long orig_i1 = regs->u_regs[UREG_I1];
 530         long ret;
 531
 532 #ifdef CONFIG_COMPAT
 533         if (test_thread_flag(TIF_32BIT)) {
 534                 parent_tid_ptr = compat_ptr(regs->u_regs[UREG_I2]);
 535                 child_tid_ptr = compat_ptr(regs->u_regs[UREG_I4]);
 536         } else
 537 #endif
 538         {
 539                 parent_tid_ptr = (int __user *) regs->u_regs[UREG_I2];
 540                 child_tid_ptr = (int __user *) regs->u_regs[UREG_I4];
 541         }
 542
 543         ret = do_fork(clone_flags, stack_start,
 544                       regs, stack_size,
 545                       parent_tid_ptr, child_tid_ptr);
 546
 547         /* If we get an error and potentially restart the system
 548          * call, we're screwed because copy_thread() clobbered
 549          * the parent's %o1.  So detect that case and restore it
 550          * here.
 551          */
 552         if ((unsigned long)ret >= -ERESTART_RESTARTBLOCK)
 553                 regs->u_regs[UREG_I1] = orig_i1;
 554
 555         return ret;
 556 }
 557
 558 /* Copy a Sparc thread.  The fork() return value conventions
 559  * under SunOS are nothing short of bletcherous:
 560  * Parent -->  %o0 == childs  pid, %o1 == 0
 561  * Child  -->  %o0 == parents pid, %o1 == 1
 562  */
 563 int copy_thread(int nr, unsigned long clone_flags, unsigned long sp,
 564                 unsigned long unused,
 565                 struct task_struct *p, struct pt_regs *regs)
 566 {
 567         struct thread_info *t = task_thread_info(p);
 568         struct sparc_stackf *parent_sf;
 569         unsigned long child_stack_sz;
 570         char *child_trap_frame;
 571         int kernel_thread;
 572
 573         kernel_thread = (regs->tstate & TSTATE_PRIV) ? 1 : 0;
 574         parent_sf = ((struct sparc_stackf *) regs) - 1;
 575
 576         /* Calculate offset to stack_frame & pt_regs */
 577         child_stack_sz = ((STACKFRAME_SZ + TRACEREG_SZ) +
 578                           (kernel_thread ? STACKFRAME_SZ : 0));
 579         child_trap_frame = (task_stack_page(p) +
 580                             (THREAD_SIZE - child_stack_sz));
 581         memcpy(child_trap_frame, parent_sf, child_stack_sz);
 582
 583         t->flags = (t->flags & ~((0xffUL << TI_FLAG_CWP_SHIFT) |
 584                                  (0xffUL << TI_FLAG_CURRENT_DS_SHIFT))) |
 585                 (((regs->tstate + 1) & TSTATE_CWP) << TI_FLAG_CWP_SHIFT);
 586         t->new_child = 1;
 587         t->ksp = ((unsigned long) child_trap_frame) - STACK_BIAS;
 588         t->kregs = (struct pt_regs *) (child_trap_frame +
 589                                        sizeof(struct sparc_stackf));
 590         t->fpsaved[0] = 0;
 591
 592         if (kernel_thread) {
 593                 struct sparc_stackf *child_sf = (struct sparc_stackf *)
 594                         (child_trap_frame + (STACKFRAME_SZ + TRACEREG_SZ));
 595
 596                 /* Zero terminate the stack backtrace.  */
 597                 child_sf->fp = NULL;
 598                 t->kregs->u_regs[UREG_FP] =
 599                   ((unsigned long) child_sf) - STACK_BIAS;
 600
 601                 /* Special case, if we are spawning a kernel thread from
 602                  * a userspace task (usermode helper, NFS or similar), we
 603                  * must disable performance counters in the child because
 604                  * the address space and protection realm are changing.
 605                  */
 606                 if (t->flags & _TIF_PERFCTR) {
 607                         t->user_cntd0 = t->user_cntd1 = NULL;
 608                         t->pcr_reg = 0;
 609                         t->flags &= ~_TIF_PERFCTR;
 610                 }
 611                 t->flags |= ((long)ASI_P << TI_FLAG_CURRENT_DS_SHIFT);
 612                 t->kregs->u_regs[UREG_G6] = (unsigned long) t;
 613                 t->kregs->u_regs[UREG_G4] = (unsigned long) t->task;
 614         } else {
 615                 if (t->flags & _TIF_32BIT) {
 616                         sp &= 0x00000000ffffffffUL;
 617                         regs->u_regs[UREG_FP] &= 0x00000000ffffffffUL;
 618                 }
 619                 t->kregs->u_regs[UREG_FP] = sp;
 620                 t->flags |= ((long)ASI_AIUS << TI_FLAG_CURRENT_DS_SHIFT);
 621                 if (sp != regs->u_regs[UREG_FP]) {
 622                         unsigned long csp;
 623
 624                         csp = clone_stackframe(sp, regs->u_regs[UREG_FP]);
 625                         if (!csp)
 626                                 return -EFAULT;
 627                         t->kregs->u_regs[UREG_FP] = csp;
 628                 }
 629                 if (t->utraps)
 630                         t->utraps[0]++;
 631         }
 632
 633         /* Set the return value for the child. */
 634         t->kregs->u_regs[UREG_I0] = current->pid;
 635         t->kregs->u_regs[UREG_I1] = 1;
 636
 637         /* Set the second return value for the parent. */
 638         regs->u_regs[UREG_I1] = 0;
 639
 640         if (clone_flags & CLONE_SETTLS)
 641                 t->kregs->u_regs[UREG_G7] = regs->u_regs[UREG_I3];
 642
 643         return 0;
 644 }
 645
 646 /*
 647  * This is the mechanism for creating a new kernel thread.
 648  *
 649  * NOTE! Only a kernel-only process(ie the swapper or direct descendants
 650  * who haven't done an "execve()") should use this: it will work within
 651  * a system call from a "real" process, but the process memory space will
 652  * not be freed until both the parent and the child have exited.
 653  */
 654 pid_t kernel_thread(int (*fn)(void *), void * arg, unsigned long flags)
 655 {
 656         long retval;
 657
 658         /* If the parent runs before fn(arg) is called by the child,
 659          * the input registers of this function can be clobbered.
 660          * So we stash 'fn' and 'arg' into global registers which
 661          * will not be modified by the parent.
 662          */
 663         __asm__ __volatile__("mov %4, %%g2\n\t"    /* Save FN into global */
 664                              "mov %5, %%g3\n\t"    /* Save ARG into global */
 665                              "mov %1, %%g1\n\t"    /* Clone syscall nr. */
 666                              "mov %2, %%o0\n\t"    /* Clone flags. */
 667                              "mov 0, %%o1\n\t"     /* usp arg == 0 */
 668                              "t 0x6d\n\t"          /* Linux/Sparc clone(). */
 669                              "brz,a,pn %%o1, 1f\n\t" /* Parent, just return. */
 670                              " mov %%o0, %0\n\t"
 671                              "jmpl %%g2, %%o7\n\t"   /* Call the function. */
 672                              " mov %%g3, %%o0\n\t"   /* Set arg in delay. */
 673                              "mov %3, %%g1\n\t"
 674                              "t 0x6d\n\t"          /* Linux/Sparc exit(). */
 675                              /* Notreached by child. */
 676                              "1:" :
 677                              "=r" (retval) :
 678                              "i" (__NR_clone), "r" (flags | CLONE_VM | CLONE_UNTRACED),
 679                              "i" (__NR_exit),  "r" (fn), "r" (arg) :
 680                              "g1", "g2", "g3", "o0", "o1", "memory", "cc");
 681         return retval;
 682 }
 683
 684 typedef struct {
 685         union {
 686                 unsigned int    pr_regs[32];
 687                 unsigned long   pr_dregs[16];
 688         } pr_fr;
 689         unsigned int __unused;
 690         unsigned int    pr_fsr;
 691         unsigned char   pr_qcnt;
 692         unsigned char   pr_q_entrysize;
 693         unsigned char   pr_en;
 694         unsigned int    pr_q[64];
 695 } elf_fpregset_t32;
 696
 697 /*
 698  * fill in the fpu structure for a core dump.
 699  */
 700 int dump_fpu (struct pt_regs * regs, elf_fpregset_t * fpregs)
 701 {
 702         unsigned long *kfpregs = current_thread_info()->fpregs;
 703         unsigned long fprs = current_thread_info()->fpsaved[0];
 704
 705         if (test_thread_flag(TIF_32BIT)) {
 706                 elf_fpregset_t32 *fpregs32 = (elf_fpregset_t32 *)fpregs;
 707
 708                 if (fprs & FPRS_DL)
 709                         memcpy(&fpregs32->pr_fr.pr_regs[0], kfpregs,
 710                                sizeof(unsigned int) * 32);
 711                 else
 712                         memset(&fpregs32->pr_fr.pr_regs[0], 0,
 713                                sizeof(unsigned int) * 32);
 714                 fpregs32->pr_qcnt = 0;
 715                 fpregs32->pr_q_entrysize = 8;
 716                 memset(&fpregs32->pr_q[0], 0,
 717                        (sizeof(unsigned int) * 64));
 718                 if (fprs & FPRS_FEF) {
 719                         fpregs32->pr_fsr = (unsigned int) current_thread_info()->xfsr[0];
 720                         fpregs32->pr_en = 1;
 721                 } else {
 722                         fpregs32->pr_fsr = 0;
 723                         fpregs32->pr_en = 0;
 724                 }
 725         } else {
 726                 if(fprs & FPRS_DL)
 727                         memcpy(&fpregs->pr_regs[0], kfpregs,
 728                                sizeof(unsigned int) * 32);
 729                 else
 730                         memset(&fpregs->pr_regs[0], 0,
 731                                sizeof(unsigned int) * 32);
 732                 if(fprs & FPRS_DU)
 733                         memcpy(&fpregs->pr_regs[16], kfpregs+16,
 734                                sizeof(unsigned int) * 32);
 735                 else
 736                         memset(&fpregs->pr_regs[16], 0,
 737                                sizeof(unsigned int) * 32);
 738                 if(fprs & FPRS_FEF) {
 739                         fpregs->pr_fsr = current_thread_info()->xfsr[0];
 740                         fpregs->pr_gsr = current_thread_info()->gsr[0];
 741                 } else {
 742                         fpregs->pr_fsr = fpregs->pr_gsr = 0;
 743                 }
 744                 fpregs->pr_fprs = fprs;
 745         }
 746         return 1;
 747 }
 748
 749 /*
 750  * sparc_execve() executes a new program after the asm stub has set
 751  * things up for us.  This should basically do what I want it to.
 752  */
 753 asmlinkage int sparc_execve(struct pt_regs *regs)
 754 {
 755         int error, base = 0;
 756         char *filename;
 757
 758         /* User register window flush is done by entry.S */
 759
 760         /* Check for indirect call. */
 761         if (regs->u_regs[UREG_G1] == 0)
 762                 base = 1;
 763
 764         filename = getname((char __user *)regs->u_regs[base + UREG_I0]);
 765         error = PTR_ERR(filename);
 766         if (IS_ERR(filename))
 767                 goto out;
 768         error = do_execve(filename,
 769                           (char __user * __user *)
 770                           regs->u_regs[base + UREG_I1],
 771                           (char __user * __user *)
 772                           regs->u_regs[base + UREG_I2], regs);
 773         putname(filename);
 774         if (!error) {
 775                 fprs_write(0);
 776                 current_thread_info()->xfsr[0] = 0;
 777                 current_thread_info()->fpsaved[0] = 0;
 778                 regs->tstate &= ~TSTATE_PEF;
 779         }
 780 out:
 781         return error;
 782 }
 783
 784 unsigned long get_wchan(struct task_struct *task)
 785 {
 786         unsigned long pc, fp, bias = 0;
 787         struct thread_info *tp;
 788         struct reg_window *rw;
 789         unsigned long ret = 0;
 790         int count = 0;
 791
 792         if (!task || task == current ||
 793             task->state == TASK_RUNNING)
 794                 goto out;
 795
 796         tp = task_thread_info(task);
 797         bias = STACK_BIAS;
 798         fp = task_thread_info(task)->ksp + bias;
 799
 800         do {
 801                 if (!kstack_valid(tp, fp))
 802                         break;
 803                 rw = (struct reg_window *) fp;
 804                 pc = rw->ins[7];
 805                 if (!in_sched_functions(pc)) {
 806                         ret = pc;
 807                         goto out;
 808                 }
 809                 fp = rw->ins[6] + bias;
 810         } while (++count < 16);
 811
 812 out:
 813         return ret;
 814 }