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/export.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/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                 touch_nmi_watchdog();
  57                 return;
  58         }
  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_idle_enter();
  98                 rcu_idle_enter();
  99
 100                 while (!need_resched() && !cpu_is_offline(cpu))
 101                         sparc64_yield(cpu);
 102
 103                 rcu_idle_exit();
 104                 tick_nohz_idle_exit();
 105
 106 #ifdef CONFIG_HOTPLUG_CPU
 107                 if (cpu_is_offline(cpu)) {
 108                         sched_preempt_enable_no_resched();
 109                         cpu_play_dead();
 110                 }
 111 #endif
 112                 schedule_preempt_disabled();
 113         }
 114 }
 115
 116 #ifdef CONFIG_COMPAT
 117 static void show_regwindow32(struct pt_regs *regs)
 118 {
 119         struct reg_window32 __user *rw;
 120         struct reg_window32 r_w;
 121         mm_segment_t old_fs;
 122
 123         __asm__ __volatile__ ("flushw");
 124         rw = compat_ptr((unsigned)regs->u_regs[14]);
 125         old_fs = get_fs();
 126         set_fs (USER_DS);
 127         if (copy_from_user (&r_w, rw, sizeof(r_w))) {
 128                 set_fs (old_fs);
 129                 return;
 130         }
 131
 132         set_fs (old_fs);
 133         printk("l0: %08x l1: %08x l2: %08x l3: %08x "
 134                "l4: %08x l5: %08x l6: %08x l7: %08x\n",
 135                r_w.locals[0], r_w.locals[1], r_w.locals[2], r_w.locals[3],
 136                r_w.locals[4], r_w.locals[5], r_w.locals[6], r_w.locals[7]);
 137         printk("i0: %08x i1: %08x i2: %08x i3: %08x "
 138                "i4: %08x i5: %08x i6: %08x i7: %08x\n",
 139                r_w.ins[0], r_w.ins[1], r_w.ins[2], r_w.ins[3],
 140                r_w.ins[4], r_w.ins[5], r_w.ins[6], r_w.ins[7]);
 141 }
 142 #else
 143 #define show_regwindow32(regs)  do { } while (0)
 144 #endif
 145
 146 static void show_regwindow(struct pt_regs *regs)
 147 {
 148         struct reg_window __user *rw;
 149         struct reg_window *rwk;
 150         struct reg_window r_w;
 151         mm_segment_t old_fs;
 152
 153         if ((regs->tstate & TSTATE_PRIV) || !(test_thread_flag(TIF_32BIT))) {
 154                 __asm__ __volatile__ ("flushw");
 155                 rw = (struct reg_window __user *)
 156                         (regs->u_regs[14] + STACK_BIAS);
 157                 rwk = (struct reg_window *)
 158                         (regs->u_regs[14] + STACK_BIAS);
 159                 if (!(regs->tstate & TSTATE_PRIV)) {
 160                         old_fs = get_fs();
 161                         set_fs (USER_DS);
 162                         if (copy_from_user (&r_w, rw, sizeof(r_w))) {
 163                                 set_fs (old_fs);
 164                                 return;
 165                         }
 166                         rwk = &r_w;
 167                         set_fs (old_fs);
 168                 }
 169         } else {
 170                 show_regwindow32(regs);
 171                 return;
 172         }
 173         printk("l0: %016lx l1: %016lx l2: %016lx l3: %016lx\n",
 174                rwk->locals[0], rwk->locals[1], rwk->locals[2], rwk->locals[3]);
 175         printk("l4: %016lx l5: %016lx l6: %016lx l7: %016lx\n",
 176                rwk->locals[4], rwk->locals[5], rwk->locals[6], rwk->locals[7]);
 177         printk("i0: %016lx i1: %016lx i2: %016lx i3: %016lx\n",
 178                rwk->ins[0], rwk->ins[1], rwk->ins[2], rwk->ins[3]);
 179         printk("i4: %016lx i5: %016lx i6: %016lx i7: %016lx\n",
 180                rwk->ins[4], rwk->ins[5], rwk->ins[6], rwk->ins[7]);
 181         if (regs->tstate & TSTATE_PRIV)
 182                 printk("I7: <%pS>\n", (void *) rwk->ins[7]);
 183 }
 184
 185 void show_regs(struct pt_regs *regs)
 186 {
 187         printk("TSTATE: %016lx TPC: %016lx TNPC: %016lx Y: %08x    %s\n", regs->tstate,
 188                regs->tpc, regs->tnpc, regs->y, print_tainted());
 189         printk("TPC: <%pS>\n", (void *) regs->tpc);
 190         printk("g0: %016lx g1: %016lx g2: %016lx g3: %016lx\n",
 191                regs->u_regs[0], regs->u_regs[1], regs->u_regs[2],
 192                regs->u_regs[3]);
 193         printk("g4: %016lx g5: %016lx g6: %016lx g7: %016lx\n",
 194                regs->u_regs[4], regs->u_regs[5], regs->u_regs[6],
 195                regs->u_regs[7]);
 196         printk("o0: %016lx o1: %016lx o2: %016lx o3: %016lx\n",
 197                regs->u_regs[8], regs->u_regs[9], regs->u_regs[10],
 198                regs->u_regs[11]);
 199         printk("o4: %016lx o5: %016lx sp: %016lx ret_pc: %016lx\n",
 200                regs->u_regs[12], regs->u_regs[13], regs->u_regs[14],
 201                regs->u_regs[15]);
 202         printk("RPC: <%pS>\n", (void *) regs->u_regs[15]);
 203         show_regwindow(regs);
 204         show_stack(current, (unsigned long *) regs->u_regs[UREG_FP]);
 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)
 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
 357 void flush_thread(void)
 358 {
 359         struct thread_info *t = current_thread_info();
 360         struct mm_struct *mm;
 361
 362         mm = t->task->mm;
 363         if (mm)
 364                 tsb_context_switch(mm);
 365
 366         set_thread_wsaved(0);
 367
 368         /* Clear FPU register state. */
 369         t->fpsaved[0] = 0;
 370 }
 371
 372 /* It's a bit more tricky when 64-bit tasks are involved... */
 373 static unsigned long clone_stackframe(unsigned long csp, unsigned long psp)
 374 {
 375         unsigned long fp, distance, rval;
 376
 377         if (!(test_thread_flag(TIF_32BIT))) {
 378                 csp += STACK_BIAS;
 379                 psp += STACK_BIAS;
 380                 __get_user(fp, &(((struct reg_window __user *)psp)->ins[6]));
 381                 fp += STACK_BIAS;
 382         } else
 383                 __get_user(fp, &(((struct reg_window32 __user *)psp)->ins[6]));
 384
 385         /* Now align the stack as this is mandatory in the Sparc ABI
 386          * due to how register windows work.  This hides the
 387          * restriction from thread libraries etc.
 388          */
 389         csp &= ~15UL;
 390
 391         distance = fp - psp;
 392         rval = (csp - distance);
 393         if (copy_in_user((void __user *) rval, (void __user *) psp, distance))
 394                 rval = 0;
 395         else if (test_thread_flag(TIF_32BIT)) {
 396                 if (put_user(((u32)csp),
 397                              &(((struct reg_window32 __user *)rval)->ins[6])))
 398                         rval = 0;
 399         } else {
 400                 if (put_user(((u64)csp - STACK_BIAS),
 401                              &(((struct reg_window __user *)rval)->ins[6])))
 402                         rval = 0;
 403                 else
 404                         rval = rval - STACK_BIAS;
 405         }
 406
 407         return rval;
 408 }
 409
 410 /* Standard stuff. */
 411 static inline void shift_window_buffer(int first_win, int last_win,
 412                                        struct thread_info *t)
 413 {
 414         int i;
 415
 416         for (i = first_win; i < last_win; i++) {
 417                 t->rwbuf_stkptrs[i] = t->rwbuf_stkptrs[i+1];
 418                 memcpy(&t->reg_window[i], &t->reg_window[i+1],
 419                        sizeof(struct reg_window));
 420         }
 421 }
 422
 423 void synchronize_user_stack(void)
 424 {
 425         struct thread_info *t = current_thread_info();
 426         unsigned long window;
 427
 428         flush_user_windows();
 429         if ((window = get_thread_wsaved()) != 0) {
 430                 int winsize = sizeof(struct reg_window);
 431                 int bias = 0;
 432
 433                 if (test_thread_flag(TIF_32BIT))
 434                         winsize = sizeof(struct reg_window32);
 435                 else
 436                         bias = STACK_BIAS;
 437
 438                 window -= 1;
 439                 do {
 440                         unsigned long sp = (t->rwbuf_stkptrs[window] + bias);
 441                         struct reg_window *rwin = &t->reg_window[window];
 442
 443                         if (!copy_to_user((char __user *)sp, rwin, winsize)) {
 444                                 shift_window_buffer(window, get_thread_wsaved() - 1, t);
 445                                 set_thread_wsaved(get_thread_wsaved() - 1);
 446                         }
 447                 } while (window--);
 448         }
 449 }
 450
 451 static void stack_unaligned(unsigned long sp)
 452 {
 453         siginfo_t info;
 454
 455         info.si_signo = SIGBUS;
 456         info.si_errno = 0;
 457         info.si_code = BUS_ADRALN;
 458         info.si_addr = (void __user *) sp;
 459         info.si_trapno = 0;
 460         force_sig_info(SIGBUS, &info, current);
 461 }
 462
 463 void fault_in_user_windows(void)
 464 {
 465         struct thread_info *t = current_thread_info();
 466         unsigned long window;
 467         int winsize = sizeof(struct reg_window);
 468         int bias = 0;
 469
 470         if (test_thread_flag(TIF_32BIT))
 471                 winsize = sizeof(struct reg_window32);
 472         else
 473                 bias = STACK_BIAS;
 474
 475         flush_user_windows();
 476         window = get_thread_wsaved();
 477
 478         if (likely(window != 0)) {
 479                 window -= 1;
 480                 do {
 481                         unsigned long sp = (t->rwbuf_stkptrs[window] + bias);
 482                         struct reg_window *rwin = &t->reg_window[window];
 483
 484                         if (unlikely(sp & 0x7UL))
 485                                 stack_unaligned(sp);
 486
 487                         if (unlikely(copy_to_user((char __user *)sp,
 488                                                   rwin, winsize)))
 489                                 goto barf;
 490                 } while (window--);
 491         }
 492         set_thread_wsaved(0);
 493         return;
 494
 495 barf:
 496         set_thread_wsaved(window + 1);
 497         do_exit(SIGILL);
 498 }
 499
 500 asmlinkage long sparc_do_fork(unsigned long clone_flags,
 501                               unsigned long stack_start,
 502                               struct pt_regs *regs,
 503                               unsigned long stack_size)
 504 {
 505         int __user *parent_tid_ptr, *child_tid_ptr;
 506         unsigned long orig_i1 = regs->u_regs[UREG_I1];
 507         long ret;
 508
 509 #ifdef CONFIG_COMPAT
 510         if (test_thread_flag(TIF_32BIT)) {
 511                 parent_tid_ptr = compat_ptr(regs->u_regs[UREG_I2]);
 512                 child_tid_ptr = compat_ptr(regs->u_regs[UREG_I4]);
 513         } else
 514 #endif
 515         {
 516                 parent_tid_ptr = (int __user *) regs->u_regs[UREG_I2];
 517                 child_tid_ptr = (int __user *) regs->u_regs[UREG_I4];
 518         }
 519
 520         ret = do_fork(clone_flags, stack_start,
 521                       regs, stack_size,
 522                       parent_tid_ptr, child_tid_ptr);
 523
 524         /* If we get an error and potentially restart the system
 525          * call, we're screwed because copy_thread() clobbered
 526          * the parent's %o1.  So detect that case and restore it
 527          * here.
 528          */
 529         if ((unsigned long)ret >= -ERESTART_RESTARTBLOCK)
 530                 regs->u_regs[UREG_I1] = orig_i1;
 531
 532         return ret;
 533 }
 534
 535 /* Copy a Sparc thread.  The fork() return value conventions
 536  * under SunOS are nothing short of bletcherous:
 537  * Parent -->  %o0 == childs  pid, %o1 == 0
 538  * Child  -->  %o0 == parents pid, %o1 == 1
 539  */
 540 int copy_thread(unsigned long clone_flags, unsigned long sp,
 541                 unsigned long unused,
 542                 struct task_struct *p, struct pt_regs *regs)
 543 {
 544         struct thread_info *t = task_thread_info(p);
 545         struct sparc_stackf *parent_sf;
 546         unsigned long child_stack_sz;
 547         char *child_trap_frame;
 548         int kernel_thread;
 549
 550         kernel_thread = (regs->tstate & TSTATE_PRIV) ? 1 : 0;
 551         parent_sf = ((struct sparc_stackf *) regs) - 1;
 552
 553         /* Calculate offset to stack_frame & pt_regs */
 554         child_stack_sz = ((STACKFRAME_SZ + TRACEREG_SZ) +
 555                           (kernel_thread ? STACKFRAME_SZ : 0));
 556         child_trap_frame = (task_stack_page(p) +
 557                             (THREAD_SIZE - child_stack_sz));
 558         memcpy(child_trap_frame, parent_sf, child_stack_sz);
 559
 560         t->flags = (t->flags & ~((0xffUL << TI_FLAG_CWP_SHIFT) |
 561                                  (0xffUL << TI_FLAG_CURRENT_DS_SHIFT))) |
 562                 (((regs->tstate + 1) & TSTATE_CWP) << TI_FLAG_CWP_SHIFT);
 563         t->new_child = 1;
 564         t->ksp = ((unsigned long) child_trap_frame) - STACK_BIAS;
 565         t->kregs = (struct pt_regs *) (child_trap_frame +
 566                                        sizeof(struct sparc_stackf));
 567         t->fpsaved[0] = 0;
 568
 569         if (kernel_thread) {
 570                 struct sparc_stackf *child_sf = (struct sparc_stackf *)
 571                         (child_trap_frame + (STACKFRAME_SZ + TRACEREG_SZ));
 572
 573                 /* Zero terminate the stack backtrace.  */
 574                 child_sf->fp = NULL;
 575                 t->kregs->u_regs[UREG_FP] =
 576                   ((unsigned long) child_sf) - STACK_BIAS;
 577
 578                 t->flags |= ((long)ASI_P << TI_FLAG_CURRENT_DS_SHIFT);
 579                 t->kregs->u_regs[UREG_G6] = (unsigned long) t;
 580                 t->kregs->u_regs[UREG_G4] = (unsigned long) t->task;
 581         } else {
 582                 if (t->flags & _TIF_32BIT) {
 583                         sp &= 0x00000000ffffffffUL;
 584                         regs->u_regs[UREG_FP] &= 0x00000000ffffffffUL;
 585                 }
 586                 t->kregs->u_regs[UREG_FP] = sp;
 587                 t->flags |= ((long)ASI_AIUS << TI_FLAG_CURRENT_DS_SHIFT);
 588                 if (sp != regs->u_regs[UREG_FP]) {
 589                         unsigned long csp;
 590
 591                         csp = clone_stackframe(sp, regs->u_regs[UREG_FP]);
 592                         if (!csp)
 593                                 return -EFAULT;
 594                         t->kregs->u_regs[UREG_FP] = csp;
 595                 }
 596                 if (t->utraps)
 597                         t->utraps[0]++;
 598         }
 599
 600         /* Set the return value for the child. */
 601         t->kregs->u_regs[UREG_I0] = current->pid;
 602         t->kregs->u_regs[UREG_I1] = 1;
 603
 604         /* Set the second return value for the parent. */
 605         regs->u_regs[UREG_I1] = 0;
 606
 607         if (clone_flags & CLONE_SETTLS)
 608                 t->kregs->u_regs[UREG_G7] = regs->u_regs[UREG_I3];
 609
 610         return 0;
 611 }
 612
 613 /*
 614  * This is the mechanism for creating a new kernel thread.
 615  *
 616  * NOTE! Only a kernel-only process(ie the swapper or direct descendants
 617  * who haven't done an "execve()") should use this: it will work within
 618  * a system call from a "real" process, but the process memory space will
 619  * not be freed until both the parent and the child have exited.
 620  */
 621 pid_t kernel_thread(int (*fn)(void *), void * arg, unsigned long flags)
 622 {
 623         long retval;
 624
 625         /* If the parent runs before fn(arg) is called by the child,
 626          * the input registers of this function can be clobbered.
 627          * So we stash 'fn' and 'arg' into global registers which
 628          * will not be modified by the parent.
 629          */
 630         __asm__ __volatile__("mov %4, %%g2\n\t"    /* Save FN into global */
 631                              "mov %5, %%g3\n\t"    /* Save ARG into global */
 632                              "mov %1, %%g1\n\t"    /* Clone syscall nr. */
 633                              "mov %2, %%o0\n\t"    /* Clone flags. */
 634                              "mov 0, %%o1\n\t"     /* usp arg == 0 */
 635                              "t 0x6d\n\t"          /* Linux/Sparc clone(). */
 636                              "brz,a,pn %%o1, 1f\n\t" /* Parent, just return. */
 637                              " mov %%o0, %0\n\t"
 638                              "jmpl %%g2, %%o7\n\t"   /* Call the function. */
 639                              " mov %%g3, %%o0\n\t"   /* Set arg in delay. */
 640                              "mov %3, %%g1\n\t"
 641                              "t 0x6d\n\t"          /* Linux/Sparc exit(). */
 642                              /* Notreached by child. */
 643                              "1:" :
 644                              "=r" (retval) :
 645                              "i" (__NR_clone), "r" (flags | CLONE_VM | CLONE_UNTRACED),
 646                              "i" (__NR_exit),  "r" (fn), "r" (arg) :
 647                              "g1", "g2", "g3", "o0", "o1", "memory", "cc");
 648         return retval;
 649 }
 650 EXPORT_SYMBOL(kernel_thread);
 651
 652 typedef struct {
 653         union {
 654                 unsigned int    pr_regs[32];
 655                 unsigned long   pr_dregs[16];
 656         } pr_fr;
 657         unsigned int __unused;
 658         unsigned int    pr_fsr;
 659         unsigned char   pr_qcnt;
 660         unsigned char   pr_q_entrysize;
 661         unsigned char   pr_en;
 662         unsigned int    pr_q[64];
 663 } elf_fpregset_t32;
 664
 665 /*
 666  * fill in the fpu structure for a core dump.
 667  */
 668 int dump_fpu (struct pt_regs * regs, elf_fpregset_t * fpregs)
 669 {
 670         unsigned long *kfpregs = current_thread_info()->fpregs;
 671         unsigned long fprs = current_thread_info()->fpsaved[0];
 672
 673         if (test_thread_flag(TIF_32BIT)) {
 674                 elf_fpregset_t32 *fpregs32 = (elf_fpregset_t32 *)fpregs;
 675
 676                 if (fprs & FPRS_DL)
 677                         memcpy(&fpregs32->pr_fr.pr_regs[0], kfpregs,
 678                                sizeof(unsigned int) * 32);
 679                 else
 680                         memset(&fpregs32->pr_fr.pr_regs[0], 0,
 681                                sizeof(unsigned int) * 32);
 682                 fpregs32->pr_qcnt = 0;
 683                 fpregs32->pr_q_entrysize = 8;
 684                 memset(&fpregs32->pr_q[0], 0,
 685                        (sizeof(unsigned int) * 64));
 686                 if (fprs & FPRS_FEF) {
 687                         fpregs32->pr_fsr = (unsigned int) current_thread_info()->xfsr[0];
 688                         fpregs32->pr_en = 1;
 689                 } else {
 690                         fpregs32->pr_fsr = 0;
 691                         fpregs32->pr_en = 0;
 692                 }
 693         } else {
 694                 if(fprs & FPRS_DL)
 695                         memcpy(&fpregs->pr_regs[0], kfpregs,
 696                                sizeof(unsigned int) * 32);
 697                 else
 698                         memset(&fpregs->pr_regs[0], 0,
 699                                sizeof(unsigned int) * 32);
 700                 if(fprs & FPRS_DU)
 701                         memcpy(&fpregs->pr_regs[16], kfpregs+16,
 702                                sizeof(unsigned int) * 32);
 703                 else
 704                         memset(&fpregs->pr_regs[16], 0,
 705                                sizeof(unsigned int) * 32);
 706                 if(fprs & FPRS_FEF) {
 707                         fpregs->pr_fsr = current_thread_info()->xfsr[0];
 708                         fpregs->pr_gsr = current_thread_info()->gsr[0];
 709                 } else {
 710                         fpregs->pr_fsr = fpregs->pr_gsr = 0;
 711                 }
 712                 fpregs->pr_fprs = fprs;
 713         }
 714         return 1;
 715 }
 716 EXPORT_SYMBOL(dump_fpu);
 717
 718 /*
 719  * sparc_execve() executes a new program after the asm stub has set
 720  * things up for us.  This should basically do what I want it to.
 721  */
 722 asmlinkage int sparc_execve(struct pt_regs *regs)
 723 {
 724         int error, base = 0;
 725         struct filename *filename;
 726
 727         /* User register window flush is done by entry.S */
 728
 729         /* Check for indirect call. */
 730         if (regs->u_regs[UREG_G1] == 0)
 731                 base = 1;
 732
 733         filename = getname((char __user *)regs->u_regs[base + UREG_I0]);
 734         error = PTR_ERR(filename);
 735         if (IS_ERR(filename))
 736                 goto out;
 737         error = do_execve(filename->name,
 738                           (const char __user *const __user *)
 739                           regs->u_regs[base + UREG_I1],
 740                           (const char __user *const __user *)
 741                           regs->u_regs[base + UREG_I2], regs);
 742         putname(filename);
 743         if (!error) {
 744                 fprs_write(0);
 745                 current_thread_info()->xfsr[0] = 0;
 746                 current_thread_info()->fpsaved[0] = 0;
 747                 regs->tstate &= ~TSTATE_PEF;
 748         }
 749 out:
 750         return error;
 751 }
 752
 753 unsigned long get_wchan(struct task_struct *task)
 754 {
 755         unsigned long pc, fp, bias = 0;
 756         struct thread_info *tp;
 757         struct reg_window *rw;
 758         unsigned long ret = 0;
 759         int count = 0;
 760
 761         if (!task || task == current ||
 762             task->state == TASK_RUNNING)
 763                 goto out;
 764
 765         tp = task_thread_info(task);
 766         bias = STACK_BIAS;
 767         fp = task_thread_info(task)->ksp + bias;
 768
 769         do {
 770                 if (!kstack_valid(tp, fp))
 771                         break;
 772                 rw = (struct reg_window *) fp;
 773                 pc = rw->ins[7];
 774                 if (!in_sched_functions(pc)) {
 775                         ret = pc;
 776                         goto out;
 777                 }
 778                 fp = rw->ins[6] + bias;
 779         } while (++count < 16);
 780
 781 out:
 782         return ret;
 783 }