arch/sparc/kernel/process_64.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/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 #include <linux/nmi.h>
  33
  34 #include <asm/uaccess.h>
  35 #include <asm/system.h>
  36 #include <asm/page.h>
  37 #include <asm/pgalloc.h>
  38 #include <asm/pgtable.h>
  39 #include <asm/processor.h>
  40 #include <asm/pstate.h>
  41 #include <asm/elf.h>
  42 #include <asm/fpumacro.h>
  43 #include <asm/head.h>
  44 #include <asm/cpudata.h>
  45 #include <asm/mmu_context.h>
  46 #include <asm/unistd.h>
  47 #include <asm/hypervisor.h>
  48 #include <asm/syscalls.h>
  49 #include <asm/irq_regs.h>
  50 #include <asm/smp.h>
  51
  52 #include "kstack.h"
  53
  54 static void sparc64_yield(int cpu)
  55 {
  56         if (tlb_type != hypervisor) {
  57                 touch_nmi_watchdog();
  58                 return;
  59         }
  60
  61         clear_thread_flag(TIF_POLLING_NRFLAG);
  62         smp_mb__after_clear_bit();
  63
  64         while (!need_resched() && !cpu_is_offline(cpu)) {
  65                 unsigned long pstate;
  66
  67                 /* Disable interrupts. */
  68                 __asm__ __volatile__(
  69                         "rdpr %%pstate, %0\n\t"
  70                         "andn %0, %1, %0\n\t"
  71                         "wrpr %0, %%g0, %%pstate"
  72                         : "=&r" (pstate)
  73                         : "i" (PSTATE_IE));
  74
  75                 if (!need_resched() && !cpu_is_offline(cpu))
  76                         sun4v_cpu_yield();
  77
  78                 /* Re-enable interrupts. */
  79                 __asm__ __volatile__(
  80                         "rdpr %%pstate, %0\n\t"
  81                         "or %0, %1, %0\n\t"
  82                         "wrpr %0, %%g0, %%pstate"
  83                         : "=&r" (pstate)
  84                         : "i" (PSTATE_IE));
  85         }
  86
  87         set_thread_flag(TIF_POLLING_NRFLAG);
  88 }
  89
  90 /* The idle loop on sparc64. */
  91 void cpu_idle(void)
  92 {
  93         int cpu = smp_processor_id();
  94
  95         set_thread_flag(TIF_POLLING_NRFLAG);
  96
  97         while(1) {
  98                 tick_nohz_stop_sched_tick(1);
  99
 100                 while (!need_resched() && !cpu_is_offline(cpu))
 101                         sparc64_yield(cpu);
 102
 103                 tick_nohz_restart_sched_tick();
 104
 105                 preempt_enable_no_resched();
 106
 107 #ifdef CONFIG_HOTPLUG_CPU
 108                 if (cpu_is_offline(cpu))
 109                         cpu_play_dead();
 110 #endif
 111
 112                 schedule();
 113                 preempt_disable();
 114         }
 115 }
 116
 117 #ifdef CONFIG_COMPAT
 118 static void show_regwindow32(struct pt_regs *regs)
 119 {
 120         struct reg_window32 __user *rw;
 121         struct reg_window32 r_w;
 122         mm_segment_t old_fs;
 123
 124         __asm__ __volatile__ ("flushw");
 125         rw = compat_ptr((unsigned)regs->u_regs[14]);
 126         old_fs = get_fs();
 127         set_fs (USER_DS);
 128         if (copy_from_user (&r_w, rw, sizeof(r_w))) {
 129                 set_fs (old_fs);
 130                 return;
 131         }
 132
 133         set_fs (old_fs);
 134         printk("l0: %08x l1: %08x l2: %08x l3: %08x "
 135                "l4: %08x l5: %08x l6: %08x l7: %08x\n",
 136                r_w.locals[0], r_w.locals[1], r_w.locals[2], r_w.locals[3],
 137                r_w.locals[4], r_w.locals[5], r_w.locals[6], r_w.locals[7]);
 138         printk("i0: %08x i1: %08x i2: %08x i3: %08x "
 139                "i4: %08x i5: %08x i6: %08x i7: %08x\n",
 140                r_w.ins[0], r_w.ins[1], r_w.ins[2], r_w.ins[3],
 141                r_w.ins[4], r_w.ins[5], r_w.ins[6], r_w.ins[7]);
 142 }
 143 #else
 144 #define show_regwindow32(regs)  do { } while (0)
 145 #endif
 146
 147 static void show_regwindow(struct pt_regs *regs)
 148 {
 149         struct reg_window __user *rw;
 150         struct reg_window *rwk;
 151         struct reg_window r_w;
 152         mm_segment_t old_fs;
 153
 154         if ((regs->tstate & TSTATE_PRIV) || !(test_thread_flag(TIF_32BIT))) {
 155                 __asm__ __volatile__ ("flushw");
 156                 rw = (struct reg_window __user *)
 157                         (regs->u_regs[14] + STACK_BIAS);
 158                 rwk = (struct reg_window *)
 159                         (regs->u_regs[14] + STACK_BIAS);
 160                 if (!(regs->tstate & TSTATE_PRIV)) {
 161                         old_fs = get_fs();
 162                         set_fs (USER_DS);
 163                         if (copy_from_user (&r_w, rw, sizeof(r_w))) {
 164                                 set_fs (old_fs);
 165                                 return;
 166                         }
 167                         rwk = &r_w;
 168                         set_fs (old_fs);
 169                 }
 170         } else {
 171                 show_regwindow32(regs);
 172                 return;
 173         }
 174         printk("l0: %016lx l1: %016lx l2: %016lx l3: %016lx\n",
 175                rwk->locals[0], rwk->locals[1], rwk->locals[2], rwk->locals[3]);
 176         printk("l4: %016lx l5: %016lx l6: %016lx l7: %016lx\n",
 177                rwk->locals[4], rwk->locals[5], rwk->locals[6], rwk->locals[7]);
 178         printk("i0: %016lx i1: %016lx i2: %016lx i3: %016lx\n",
 179                rwk->ins[0], rwk->ins[1], rwk->ins[2], rwk->ins[3]);
 180         printk("i4: %016lx i5: %016lx i6: %016lx i7: %016lx\n",
 181                rwk->ins[4], rwk->ins[5], rwk->ins[6], rwk->ins[7]);
 182         if (regs->tstate & TSTATE_PRIV)
 183                 printk("I7: <%pS>\n", (void *) rwk->ins[7]);
 184 }
 185
 186 void show_regs(struct pt_regs *regs)
 187 {
 188         printk("TSTATE: %016lx TPC: %016lx TNPC: %016lx Y: %08x    %s\n", regs->tstate,
 189                regs->tpc, regs->tnpc, regs->y, print_tainted());
 190         printk("TPC: <%pS>\n", (void *) regs->tpc);
 191         printk("g0: %016lx g1: %016lx g2: %016lx g3: %016lx\n",
 192                regs->u_regs[0], regs->u_regs[1], regs->u_regs[2],
 193                regs->u_regs[3]);
 194         printk("g4: %016lx g5: %016lx g6: %016lx g7: %016lx\n",
 195                regs->u_regs[4], regs->u_regs[5], regs->u_regs[6],
 196                regs->u_regs[7]);
 197         printk("o0: %016lx o1: %016lx o2: %016lx o3: %016lx\n",
 198                regs->u_regs[8], regs->u_regs[9], regs->u_regs[10],
 199                regs->u_regs[11]);
 200         printk("o4: %016lx o5: %016lx sp: %016lx ret_pc: %016lx\n",
 201                regs->u_regs[12], regs->u_regs[13], regs->u_regs[14],
 202                regs->u_regs[15]);
 203         printk("RPC: <%pS>\n", (void *) regs->u_regs[15]);
 204         show_regwindow(regs);
 205 }
 206
 207 struct global_reg_snapshot global_reg_snapshot[NR_CPUS];
 208 static DEFINE_SPINLOCK(global_reg_snapshot_lock);
 209
 210 static void __global_reg_self(struct thread_info *tp, struct pt_regs *regs,
 211                               int this_cpu)
 212 {
 213         flushw_all();
 214
 215         global_reg_snapshot[this_cpu].tstate = regs->tstate;
 216         global_reg_snapshot[this_cpu].tpc = regs->tpc;
 217         global_reg_snapshot[this_cpu].tnpc = regs->tnpc;
 218         global_reg_snapshot[this_cpu].o7 = regs->u_regs[UREG_I7];
 219
 220         if (regs->tstate & TSTATE_PRIV) {
 221                 struct reg_window *rw;
 222
 223                 rw = (struct reg_window *)
 224                         (regs->u_regs[UREG_FP] + STACK_BIAS);
 225                 if (kstack_valid(tp, (unsigned long) rw)) {
 226                         global_reg_snapshot[this_cpu].i7 = rw->ins[7];
 227                         rw = (struct reg_window *)
 228                                 (rw->ins[6] + STACK_BIAS);
 229                         if (kstack_valid(tp, (unsigned long) rw))
 230                                 global_reg_snapshot[this_cpu].rpc = rw->ins[7];
 231                 }
 232         } else {
 233                 global_reg_snapshot[this_cpu].i7 = 0;
 234                 global_reg_snapshot[this_cpu].rpc = 0;
 235         }
 236         global_reg_snapshot[this_cpu].thread = tp;
 237 }
 238
 239 /* In order to avoid hangs we do not try to synchronize with the
 240  * global register dump client cpus.  The last store they make is to
 241  * the thread pointer, so do a short poll waiting for that to become
 242  * non-NULL.
 243  */
 244 static void __global_reg_poll(struct global_reg_snapshot *gp)
 245 {
 246         int limit = 0;
 247
 248         while (!gp->thread && ++limit < 100) {
 249                 barrier();
 250                 udelay(1);
 251         }
 252 }
 253
 254 void arch_trigger_all_cpu_backtrace(void)
 255 {
 256         struct thread_info *tp = current_thread_info();
 257         struct pt_regs *regs = get_irq_regs();
 258         unsigned long flags;
 259         int this_cpu, cpu;
 260
 261         if (!regs)
 262                 regs = tp->kregs;
 263
 264         spin_lock_irqsave(&global_reg_snapshot_lock, flags);
 265
 266         memset(global_reg_snapshot, 0, sizeof(global_reg_snapshot));
 267
 268         this_cpu = raw_smp_processor_id();
 269
 270         __global_reg_self(tp, regs, this_cpu);
 271
 272         smp_fetch_global_regs();
 273
 274         for_each_online_cpu(cpu) {
 275                 struct global_reg_snapshot *gp = &global_reg_snapshot[cpu];
 276
 277                 __global_reg_poll(gp);
 278
 279                 tp = gp->thread;
 280                 printk("%c CPU[%3d]: TSTATE[%016lx] TPC[%016lx] TNPC[%016lx] TASK[%s:%d]\n",
 281                        (cpu == this_cpu ? '*' : ' '), cpu,
 282                        gp->tstate, gp->tpc, gp->tnpc,
 283                        ((tp && tp->task) ? tp->task->comm : "NULL"),
 284                        ((tp && tp->task) ? tp->task->pid : -1));
 285
 286                 if (gp->tstate & TSTATE_PRIV) {
 287                         printk("             TPC[%pS] O7[%pS] I7[%pS] RPC[%pS]\n",
 288                                (void *) gp->tpc,
 289                                (void *) gp->o7,
 290                                (void *) gp->i7,
 291                                (void *) gp->rpc);
 292                 } else {
 293                         printk("             TPC[%lx] O7[%lx] I7[%lx] RPC[%lx]\n",
 294                                gp->tpc, gp->o7, gp->i7, gp->rpc);
 295                 }
 296         }
 297
 298         memset(global_reg_snapshot, 0, sizeof(global_reg_snapshot));
 299
 300         spin_unlock_irqrestore(&global_reg_snapshot_lock, flags);
 301 }
 302
 303 #ifdef CONFIG_MAGIC_SYSRQ
 304
 305 static void sysrq_handle_globreg(int key, struct tty_struct *tty)
 306 {
 307         arch_trigger_all_cpu_backtrace();
 308 }
 309
 310 static struct sysrq_key_op sparc_globalreg_op = {
 311         .handler        = sysrq_handle_globreg,
 312         .help_msg       = "Globalregs",
 313         .action_msg     = "Show Global CPU Regs",
 314 };
 315
 316 static int __init sparc_globreg_init(void)
 317 {
 318         return register_sysrq_key('y', &sparc_globalreg_op);
 319 }
 320
 321 core_initcall(sparc_globreg_init);
 322
 323 #endif
 324
 325 unsigned long thread_saved_pc(struct task_struct *tsk)
 326 {
 327         struct thread_info *ti = task_thread_info(tsk);
 328         unsigned long ret = 0xdeadbeefUL;
 329
 330         if (ti && ti->ksp) {
 331                 unsigned long *sp;
 332                 sp = (unsigned long *)(ti->ksp + STACK_BIAS);
 333                 if (((unsigned long)sp & (sizeof(long) - 1)) == 0UL &&
 334                     sp[14]) {
 335                         unsigned long *fp;
 336                         fp = (unsigned long *)(sp[14] + STACK_BIAS);
 337                         if (((unsigned long)fp & (sizeof(long) - 1)) == 0UL)
 338                                 ret = fp[15];
 339                 }
 340         }
 341         return ret;
 342 }
 343
 344 /* Free current thread data structures etc.. */
 345 void exit_thread(void)
 346 {
 347         struct thread_info *t = current_thread_info();
 348
 349         if (t->utraps) {
 350                 if (t->utraps[0] < 2)
 351                         kfree (t->utraps);
 352                 else
 353                         t->utraps[0]--;
 354         }
 355
 356         if (test_and_clear_thread_flag(TIF_PERFCTR)) {
 357                 t->user_cntd0 = t->user_cntd1 = NULL;
 358                 t->pcr_reg = 0;
 359                 write_pcr(0);
 360         }
 361 }
 362
 363 void flush_thread(void)
 364 {
 365         struct thread_info *t = current_thread_info();
 366         struct mm_struct *mm;
 367
 368         mm = t->task->mm;
 369         if (mm)
 370                 tsb_context_switch(mm);
 371
 372         set_thread_wsaved(0);
 373
 374         /* Turn off performance counters if on. */
 375         if (test_and_clear_thread_flag(TIF_PERFCTR)) {
 376                 t->user_cntd0 = t->user_cntd1 = NULL;
 377                 t->pcr_reg = 0;
 378                 write_pcr(0);
 379         }
 380
 381         /* Clear FPU register state. */
 382         t->fpsaved[0] = 0;
 383
 384         if (get_thread_current_ds() != ASI_AIUS)
 385                 set_fs(USER_DS);
 386 }
 387
 388 /* It's a bit more tricky when 64-bit tasks are involved... */
 389 static unsigned long clone_stackframe(unsigned long csp, unsigned long psp)
 390 {
 391         unsigned long fp, distance, rval;
 392
 393         if (!(test_thread_flag(TIF_32BIT))) {
 394                 csp += STACK_BIAS;
 395                 psp += STACK_BIAS;
 396                 __get_user(fp, &(((struct reg_window __user *)psp)->ins[6]));
 397                 fp += STACK_BIAS;
 398         } else
 399                 __get_user(fp, &(((struct reg_window32 __user *)psp)->ins[6]));
 400
 401         /* Now 8-byte align the stack as this is mandatory in the
 402          * Sparc ABI due to how register windows work.  This hides
 403          * the restriction from thread libraries etc.  -DaveM
 404          */
 405         csp &= ~7UL;
 406
 407         distance = fp - psp;
 408         rval = (csp - distance);
 409         if (copy_in_user((void __user *) rval, (void __user *) psp, distance))
 410                 rval = 0;
 411         else if (test_thread_flag(TIF_32BIT)) {
 412                 if (put_user(((u32)csp),
 413                              &(((struct reg_window32 __user *)rval)->ins[6])))
 414                         rval = 0;
 415         } else {
 416                 if (put_user(((u64)csp - STACK_BIAS),
 417                              &(((struct reg_window __user *)rval)->ins[6])))
 418                         rval = 0;
 419                 else
 420                         rval = rval - STACK_BIAS;
 421         }
 422
 423         return rval;
 424 }
 425
 426 /* Standard stuff. */
 427 static inline void shift_window_buffer(int first_win, int last_win,
 428                                        struct thread_info *t)
 429 {
 430         int i;
 431
 432         for (i = first_win; i < last_win; i++) {
 433                 t->rwbuf_stkptrs[i] = t->rwbuf_stkptrs[i+1];
 434                 memcpy(&t->reg_window[i], &t->reg_window[i+1],
 435                        sizeof(struct reg_window));
 436         }
 437 }
 438
 439 void synchronize_user_stack(void)
 440 {
 441         struct thread_info *t = current_thread_info();
 442         unsigned long window;
 443
 444         flush_user_windows();
 445         if ((window = get_thread_wsaved()) != 0) {
 446                 int winsize = sizeof(struct reg_window);
 447                 int bias = 0;
 448
 449                 if (test_thread_flag(TIF_32BIT))
 450                         winsize = sizeof(struct reg_window32);
 451                 else
 452                         bias = STACK_BIAS;
 453
 454                 window -= 1;
 455                 do {
 456                         unsigned long sp = (t->rwbuf_stkptrs[window] + bias);
 457                         struct reg_window *rwin = &t->reg_window[window];
 458
 459                         if (!copy_to_user((char __user *)sp, rwin, winsize)) {
 460                                 shift_window_buffer(window, get_thread_wsaved() - 1, t);
 461                                 set_thread_wsaved(get_thread_wsaved() - 1);
 462                         }
 463                 } while (window--);
 464         }
 465 }
 466
 467 static void stack_unaligned(unsigned long sp)
 468 {
 469         siginfo_t info;
 470
 471         info.si_signo = SIGBUS;
 472         info.si_errno = 0;
 473         info.si_code = BUS_ADRALN;
 474         info.si_addr = (void __user *) sp;
 475         info.si_trapno = 0;
 476         force_sig_info(SIGBUS, &info, current);
 477 }
 478
 479 void fault_in_user_windows(void)
 480 {
 481         struct thread_info *t = current_thread_info();
 482         unsigned long window;
 483         int winsize = sizeof(struct reg_window);
 484         int bias = 0;
 485
 486         if (test_thread_flag(TIF_32BIT))
 487                 winsize = sizeof(struct reg_window32);
 488         else
 489                 bias = STACK_BIAS;
 490
 491         flush_user_windows();
 492         window = get_thread_wsaved();
 493
 494         if (likely(window != 0)) {
 495                 window -= 1;
 496                 do {
 497                         unsigned long sp = (t->rwbuf_stkptrs[window] + bias);
 498                         struct reg_window *rwin = &t->reg_window[window];
 499
 500                         if (unlikely(sp & 0x7UL))
 501                                 stack_unaligned(sp);
 502
 503                         if (unlikely(copy_to_user((char __user *)sp,
 504                                                   rwin, winsize)))
 505                                 goto barf;
 506                 } while (window--);
 507         }
 508         set_thread_wsaved(0);
 509         return;
 510
 511 barf:
 512         set_thread_wsaved(window + 1);
 513         do_exit(SIGILL);
 514 }
 515
 516 asmlinkage long sparc_do_fork(unsigned long clone_flags,
 517                               unsigned long stack_start,
 518                               struct pt_regs *regs,
 519                               unsigned long stack_size)
 520 {
 521         int __user *parent_tid_ptr, *child_tid_ptr;
 522         unsigned long orig_i1 = regs->u_regs[UREG_I1];
 523         long ret;
 524
 525 #ifdef CONFIG_COMPAT
 526         if (test_thread_flag(TIF_32BIT)) {
 527                 parent_tid_ptr = compat_ptr(regs->u_regs[UREG_I2]);
 528                 child_tid_ptr = compat_ptr(regs->u_regs[UREG_I4]);
 529         } else
 530 #endif
 531         {
 532                 parent_tid_ptr = (int __user *) regs->u_regs[UREG_I2];
 533                 child_tid_ptr = (int __user *) regs->u_regs[UREG_I4];
 534         }
 535
 536         ret = do_fork(clone_flags, stack_start,
 537                       regs, stack_size,
 538                       parent_tid_ptr, child_tid_ptr);
 539
 540         /* If we get an error and potentially restart the system
 541          * call, we're screwed because copy_thread() clobbered
 542          * the parent's %o1.  So detect that case and restore it
 543          * here.
 544          */
 545         if ((unsigned long)ret >= -ERESTART_RESTARTBLOCK)
 546                 regs->u_regs[UREG_I1] = orig_i1;
 547
 548         return ret;
 549 }
 550
 551 /* Copy a Sparc thread.  The fork() return value conventions
 552  * under SunOS are nothing short of bletcherous:
 553  * Parent -->  %o0 == childs  pid, %o1 == 0
 554  * Child  -->  %o0 == parents pid, %o1 == 1
 555  */
 556 int copy_thread(unsigned long clone_flags, unsigned long sp,
 557                 unsigned long unused,
 558                 struct task_struct *p, struct pt_regs *regs)
 559 {
 560         struct thread_info *t = task_thread_info(p);
 561         struct sparc_stackf *parent_sf;
 562         unsigned long child_stack_sz;
 563         char *child_trap_frame;
 564         int kernel_thread;
 565
 566         kernel_thread = (regs->tstate & TSTATE_PRIV) ? 1 : 0;
 567         parent_sf = ((struct sparc_stackf *) regs) - 1;
 568
 569         /* Calculate offset to stack_frame & pt_regs */
 570         child_stack_sz = ((STACKFRAME_SZ + TRACEREG_SZ) +
 571                           (kernel_thread ? STACKFRAME_SZ : 0));
 572         child_trap_frame = (task_stack_page(p) +
 573                             (THREAD_SIZE - child_stack_sz));
 574         memcpy(child_trap_frame, parent_sf, child_stack_sz);
 575
 576         t->flags = (t->flags & ~((0xffUL << TI_FLAG_CWP_SHIFT) |
 577                                  (0xffUL << TI_FLAG_CURRENT_DS_SHIFT))) |
 578                 (((regs->tstate + 1) & TSTATE_CWP) << TI_FLAG_CWP_SHIFT);
 579         t->new_child = 1;
 580         t->ksp = ((unsigned long) child_trap_frame) - STACK_BIAS;
 581         t->kregs = (struct pt_regs *) (child_trap_frame +
 582                                        sizeof(struct sparc_stackf));
 583         t->fpsaved[0] = 0;
 584
 585         if (kernel_thread) {
 586                 struct sparc_stackf *child_sf = (struct sparc_stackf *)
 587                         (child_trap_frame + (STACKFRAME_SZ + TRACEREG_SZ));
 588
 589                 /* Zero terminate the stack backtrace.  */
 590                 child_sf->fp = NULL;
 591                 t->kregs->u_regs[UREG_FP] =
 592                   ((unsigned long) child_sf) - STACK_BIAS;
 593
 594                 /* Special case, if we are spawning a kernel thread from
 595                  * a userspace task (usermode helper, NFS or similar), we
 596                  * must disable performance counters in the child because
 597                  * the address space and protection realm are changing.
 598                  */
 599                 if (t->flags & _TIF_PERFCTR) {
 600                         t->user_cntd0 = t->user_cntd1 = NULL;
 601                         t->pcr_reg = 0;
 602                         t->flags &= ~_TIF_PERFCTR;
 603                 }
 604                 t->flags |= ((long)ASI_P << TI_FLAG_CURRENT_DS_SHIFT);
 605                 t->kregs->u_regs[UREG_G6] = (unsigned long) t;
 606                 t->kregs->u_regs[UREG_G4] = (unsigned long) t->task;
 607         } else {
 608                 if (t->flags & _TIF_32BIT) {
 609                         sp &= 0x00000000ffffffffUL;
 610                         regs->u_regs[UREG_FP] &= 0x00000000ffffffffUL;
 611                 }
 612                 t->kregs->u_regs[UREG_FP] = sp;
 613                 t->flags |= ((long)ASI_AIUS << TI_FLAG_CURRENT_DS_SHIFT);
 614                 if (sp != regs->u_regs[UREG_FP]) {
 615                         unsigned long csp;
 616
 617                         csp = clone_stackframe(sp, regs->u_regs[UREG_FP]);
 618                         if (!csp)
 619                                 return -EFAULT;
 620                         t->kregs->u_regs[UREG_FP] = csp;
 621                 }
 622                 if (t->utraps)
 623                         t->utraps[0]++;
 624         }
 625
 626         /* Set the return value for the child. */
 627         t->kregs->u_regs[UREG_I0] = current->pid;
 628         t->kregs->u_regs[UREG_I1] = 1;
 629
 630         /* Set the second return value for the parent. */
 631         regs->u_regs[UREG_I1] = 0;
 632
 633         if (clone_flags & CLONE_SETTLS)
 634                 t->kregs->u_regs[UREG_G7] = regs->u_regs[UREG_I3];
 635
 636         return 0;
 637 }
 638
 639 /*
 640  * This is the mechanism for creating a new kernel thread.
 641  *
 642  * NOTE! Only a kernel-only process(ie the swapper or direct descendants
 643  * who haven't done an "execve()") should use this: it will work within
 644  * a system call from a "real" process, but the process memory space will
 645  * not be freed until both the parent and the child have exited.
 646  */
 647 pid_t kernel_thread(int (*fn)(void *), void * arg, unsigned long flags)
 648 {
 649         long retval;
 650
 651         /* If the parent runs before fn(arg) is called by the child,
 652          * the input registers of this function can be clobbered.
 653          * So we stash 'fn' and 'arg' into global registers which
 654          * will not be modified by the parent.
 655          */
 656         __asm__ __volatile__("mov %4, %%g2\n\t"    /* Save FN into global */
 657                              "mov %5, %%g3\n\t"    /* Save ARG into global */
 658                              "mov %1, %%g1\n\t"    /* Clone syscall nr. */
 659                              "mov %2, %%o0\n\t"    /* Clone flags. */
 660                              "mov 0, %%o1\n\t"     /* usp arg == 0 */
 661                              "t 0x6d\n\t"          /* Linux/Sparc clone(). */
 662                              "brz,a,pn %%o1, 1f\n\t" /* Parent, just return. */
 663                              " mov %%o0, %0\n\t"
 664                              "jmpl %%g2, %%o7\n\t"   /* Call the function. */
 665                              " mov %%g3, %%o0\n\t"   /* Set arg in delay. */
 666                              "mov %3, %%g1\n\t"
 667                              "t 0x6d\n\t"          /* Linux/Sparc exit(). */
 668                              /* Notreached by child. */
 669                              "1:" :
 670                              "=r" (retval) :
 671                              "i" (__NR_clone), "r" (flags | CLONE_VM | CLONE_UNTRACED),
 672                              "i" (__NR_exit),  "r" (fn), "r" (arg) :
 673                              "g1", "g2", "g3", "o0", "o1", "memory", "cc");
 674         return retval;
 675 }
 676 EXPORT_SYMBOL(kernel_thread);
 677
 678 typedef struct {
 679         union {
 680                 unsigned int    pr_regs[32];
 681                 unsigned long   pr_dregs[16];
 682         } pr_fr;
 683         unsigned int __unused;
 684         unsigned int    pr_fsr;
 685         unsigned char   pr_qcnt;
 686         unsigned char   pr_q_entrysize;
 687         unsigned char   pr_en;
 688         unsigned int    pr_q[64];
 689 } elf_fpregset_t32;
 690
 691 /*
 692  * fill in the fpu structure for a core dump.
 693  */
 694 int dump_fpu (struct pt_regs * regs, elf_fpregset_t * fpregs)
 695 {
 696         unsigned long *kfpregs = current_thread_info()->fpregs;
 697         unsigned long fprs = current_thread_info()->fpsaved[0];
 698
 699         if (test_thread_flag(TIF_32BIT)) {
 700                 elf_fpregset_t32 *fpregs32 = (elf_fpregset_t32 *)fpregs;
 701
 702                 if (fprs & FPRS_DL)
 703                         memcpy(&fpregs32->pr_fr.pr_regs[0], kfpregs,
 704                                sizeof(unsigned int) * 32);
 705                 else
 706                         memset(&fpregs32->pr_fr.pr_regs[0], 0,
 707                                sizeof(unsigned int) * 32);
 708                 fpregs32->pr_qcnt = 0;
 709                 fpregs32->pr_q_entrysize = 8;
 710                 memset(&fpregs32->pr_q[0], 0,
 711                        (sizeof(unsigned int) * 64));
 712                 if (fprs & FPRS_FEF) {
 713                         fpregs32->pr_fsr = (unsigned int) current_thread_info()->xfsr[0];
 714                         fpregs32->pr_en = 1;
 715                 } else {
 716                         fpregs32->pr_fsr = 0;
 717                         fpregs32->pr_en = 0;
 718                 }
 719         } else {
 720                 if(fprs & FPRS_DL)
 721                         memcpy(&fpregs->pr_regs[0], kfpregs,
 722                                sizeof(unsigned int) * 32);
 723                 else
 724                         memset(&fpregs->pr_regs[0], 0,
 725                                sizeof(unsigned int) * 32);
 726                 if(fprs & FPRS_DU)
 727                         memcpy(&fpregs->pr_regs[16], kfpregs+16,
 728                                sizeof(unsigned int) * 32);
 729                 else
 730                         memset(&fpregs->pr_regs[16], 0,
 731                                sizeof(unsigned int) * 32);
 732                 if(fprs & FPRS_FEF) {
 733                         fpregs->pr_fsr = current_thread_info()->xfsr[0];
 734                         fpregs->pr_gsr = current_thread_info()->gsr[0];
 735                 } else {
 736                         fpregs->pr_fsr = fpregs->pr_gsr = 0;
 737                 }
 738                 fpregs->pr_fprs = fprs;
 739         }
 740         return 1;
 741 }
 742 EXPORT_SYMBOL(dump_fpu);
 743
 744 /*
 745  * sparc_execve() executes a new program after the asm stub has set
 746  * things up for us.  This should basically do what I want it to.
 747  */
 748 asmlinkage int sparc_execve(struct pt_regs *regs)
 749 {
 750         int error, base = 0;
 751         char *filename;
 752
 753         /* User register window flush is done by entry.S */
 754
 755         /* Check for indirect call. */
 756         if (regs->u_regs[UREG_G1] == 0)
 757                 base = 1;
 758
 759         filename = getname((char __user *)regs->u_regs[base + UREG_I0]);
 760         error = PTR_ERR(filename);
 761         if (IS_ERR(filename))
 762                 goto out;
 763         error = do_execve(filename,
 764                           (char __user * __user *)
 765                           regs->u_regs[base + UREG_I1],
 766                           (char __user * __user *)
 767                           regs->u_regs[base + UREG_I2], regs);
 768         putname(filename);
 769         if (!error) {
 770                 fprs_write(0);
 771                 current_thread_info()->xfsr[0] = 0;
 772                 current_thread_info()->fpsaved[0] = 0;
 773                 regs->tstate &= ~TSTATE_PEF;
 774         }
 775 out:
 776         return error;
 777 }
 778
 779 unsigned long get_wchan(struct task_struct *task)
 780 {
 781         unsigned long pc, fp, bias = 0;
 782         struct thread_info *tp;
 783         struct reg_window *rw;
 784         unsigned long ret = 0;
 785         int count = 0;
 786
 787         if (!task || task == current ||
 788             task->state == TASK_RUNNING)
 789                 goto out;
 790
 791         tp = task_thread_info(task);
 792         bias = STACK_BIAS;
 793         fp = task_thread_info(task)->ksp + bias;
 794
 795         do {
 796                 if (!kstack_valid(tp, fp))
 797                         break;
 798                 rw = (struct reg_window *) fp;
 799                 pc = rw->ins[7];
 800                 if (!in_sched_functions(pc)) {
 801                         ret = pc;
 802                         goto out;
 803                 }
 804                 fp = rw->ins[6] + bias;
 805         } while (++count < 16);
 806
 807 out:
 808         return ret;
 809 }