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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 #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 __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         __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         if (test_ti_thread_flag(t, TIF_ABI_PENDING)) {
 369                 clear_ti_thread_flag(t, TIF_ABI_PENDING);
 370                 if (test_ti_thread_flag(t, TIF_32BIT))
 371                         clear_ti_thread_flag(t, TIF_32BIT);
 372                 else
 373                         set_ti_thread_flag(t, TIF_32BIT);
 374         }
 375
 376         mm = t->task->mm;
 377         if (mm)
 378                 tsb_context_switch(mm);
 379
 380         set_thread_wsaved(0);
 381
 382         /* Turn off performance counters if on. */
 383         if (test_and_clear_thread_flag(TIF_PERFCTR)) {
 384                 t->user_cntd0 = t->user_cntd1 = NULL;
 385                 t->pcr_reg = 0;
 386                 write_pcr(0);
 387         }
 388
 389         /* Clear FPU register state. */
 390         t->fpsaved[0] = 0;
 391
 392         if (get_thread_current_ds() != ASI_AIUS)
 393                 set_fs(USER_DS);
 394 }
 395
 396 /* It's a bit more tricky when 64-bit tasks are involved... */
 397 static unsigned long clone_stackframe(unsigned long csp, unsigned long psp)
 398 {
 399         unsigned long fp, distance, rval;
 400
 401         if (!(test_thread_flag(TIF_32BIT))) {
 402                 csp += STACK_BIAS;
 403                 psp += STACK_BIAS;
 404                 __get_user(fp, &(((struct reg_window __user *)psp)->ins[6]));
 405                 fp += STACK_BIAS;
 406         } else
 407                 __get_user(fp, &(((struct reg_window32 __user *)psp)->ins[6]));
 408
 409         /* Now 8-byte align the stack as this is mandatory in the
 410          * Sparc ABI due to how register windows work.  This hides
 411          * the restriction from thread libraries etc.  -DaveM
 412          */
 413         csp &= ~7UL;
 414
 415         distance = fp - psp;
 416         rval = (csp - distance);
 417         if (copy_in_user((void __user *) rval, (void __user *) psp, distance))
 418                 rval = 0;
 419         else if (test_thread_flag(TIF_32BIT)) {
 420                 if (put_user(((u32)csp),
 421                              &(((struct reg_window32 __user *)rval)->ins[6])))
 422                         rval = 0;
 423         } else {
 424                 if (put_user(((u64)csp - STACK_BIAS),
 425                              &(((struct reg_window __user *)rval)->ins[6])))
 426                         rval = 0;
 427                 else
 428                         rval = rval - STACK_BIAS;
 429         }
 430
 431         return rval;
 432 }
 433
 434 /* Standard stuff. */
 435 static inline void shift_window_buffer(int first_win, int last_win,
 436                                        struct thread_info *t)
 437 {
 438         int i;
 439
 440         for (i = first_win; i < last_win; i++) {
 441                 t->rwbuf_stkptrs[i] = t->rwbuf_stkptrs[i+1];
 442                 memcpy(&t->reg_window[i], &t->reg_window[i+1],
 443                        sizeof(struct reg_window));
 444         }
 445 }
 446
 447 void synchronize_user_stack(void)
 448 {
 449         struct thread_info *t = current_thread_info();
 450         unsigned long window;
 451
 452         flush_user_windows();
 453         if ((window = get_thread_wsaved()) != 0) {
 454                 int winsize = sizeof(struct reg_window);
 455                 int bias = 0;
 456
 457                 if (test_thread_flag(TIF_32BIT))
 458                         winsize = sizeof(struct reg_window32);
 459                 else
 460                         bias = STACK_BIAS;
 461
 462                 window -= 1;
 463                 do {
 464                         unsigned long sp = (t->rwbuf_stkptrs[window] + bias);
 465                         struct reg_window *rwin = &t->reg_window[window];
 466
 467                         if (!copy_to_user((char __user *)sp, rwin, winsize)) {
 468                                 shift_window_buffer(window, get_thread_wsaved() - 1, t);
 469                                 set_thread_wsaved(get_thread_wsaved() - 1);
 470                         }
 471                 } while (window--);
 472         }
 473 }
 474
 475 static void stack_unaligned(unsigned long sp)
 476 {
 477         siginfo_t info;
 478
 479         info.si_signo = SIGBUS;
 480         info.si_errno = 0;
 481         info.si_code = BUS_ADRALN;
 482         info.si_addr = (void __user *) sp;
 483         info.si_trapno = 0;
 484         force_sig_info(SIGBUS, &info, current);
 485 }
 486
 487 void fault_in_user_windows(void)
 488 {
 489         struct thread_info *t = current_thread_info();
 490         unsigned long window;
 491         int winsize = sizeof(struct reg_window);
 492         int bias = 0;
 493
 494         if (test_thread_flag(TIF_32BIT))
 495                 winsize = sizeof(struct reg_window32);
 496         else
 497                 bias = STACK_BIAS;
 498
 499         flush_user_windows();
 500         window = get_thread_wsaved();
 501
 502         if (likely(window != 0)) {
 503                 window -= 1;
 504                 do {
 505                         unsigned long sp = (t->rwbuf_stkptrs[window] + bias);
 506                         struct reg_window *rwin = &t->reg_window[window];
 507
 508                         if (unlikely(sp & 0x7UL))
 509                                 stack_unaligned(sp);
 510
 511                         if (unlikely(copy_to_user((char __user *)sp,
 512                                                   rwin, winsize)))
 513                                 goto barf;
 514                 } while (window--);
 515         }
 516         set_thread_wsaved(0);
 517         return;
 518
 519 barf:
 520         set_thread_wsaved(window + 1);
 521         do_exit(SIGILL);
 522 }
 523
 524 asmlinkage long sparc_do_fork(unsigned long clone_flags,
 525                               unsigned long stack_start,
 526                               struct pt_regs *regs,
 527                               unsigned long stack_size)
 528 {
 529         int __user *parent_tid_ptr, *child_tid_ptr;
 530         unsigned long orig_i1 = regs->u_regs[UREG_I1];
 531         long ret;
 532
 533 #ifdef CONFIG_COMPAT
 534         if (test_thread_flag(TIF_32BIT)) {
 535                 parent_tid_ptr = compat_ptr(regs->u_regs[UREG_I2]);
 536                 child_tid_ptr = compat_ptr(regs->u_regs[UREG_I4]);
 537         } else
 538 #endif
 539         {
 540                 parent_tid_ptr = (int __user *) regs->u_regs[UREG_I2];
 541                 child_tid_ptr = (int __user *) regs->u_regs[UREG_I4];
 542         }
 543
 544         ret = do_fork(clone_flags, stack_start,
 545                       regs, stack_size,
 546                       parent_tid_ptr, child_tid_ptr);
 547
 548         /* If we get an error and potentially restart the system
 549          * call, we're screwed because copy_thread() clobbered
 550          * the parent's %o1.  So detect that case and restore it
 551          * here.
 552          */
 553         if ((unsigned long)ret >= -ERESTART_RESTARTBLOCK)
 554                 regs->u_regs[UREG_I1] = orig_i1;
 555
 556         return ret;
 557 }
 558
 559 /* Copy a Sparc thread.  The fork() return value conventions
 560  * under SunOS are nothing short of bletcherous:
 561  * Parent -->  %o0 == childs  pid, %o1 == 0
 562  * Child  -->  %o0 == parents pid, %o1 == 1
 563  */
 564 int copy_thread(unsigned long clone_flags, unsigned long sp,
 565                 unsigned long unused,
 566                 struct task_struct *p, struct pt_regs *regs)
 567 {
 568         struct thread_info *t = task_thread_info(p);
 569         struct sparc_stackf *parent_sf;
 570         unsigned long child_stack_sz;
 571         char *child_trap_frame;
 572         int kernel_thread;
 573
 574         kernel_thread = (regs->tstate & TSTATE_PRIV) ? 1 : 0;
 575         parent_sf = ((struct sparc_stackf *) regs) - 1;
 576
 577         /* Calculate offset to stack_frame & pt_regs */
 578         child_stack_sz = ((STACKFRAME_SZ + TRACEREG_SZ) +
 579                           (kernel_thread ? STACKFRAME_SZ : 0));
 580         child_trap_frame = (task_stack_page(p) +
 581                             (THREAD_SIZE - child_stack_sz));
 582         memcpy(child_trap_frame, parent_sf, child_stack_sz);
 583
 584         t->flags = (t->flags & ~((0xffUL << TI_FLAG_CWP_SHIFT) |
 585                                  (0xffUL << TI_FLAG_CURRENT_DS_SHIFT))) |
 586                 (((regs->tstate + 1) & TSTATE_CWP) << TI_FLAG_CWP_SHIFT);
 587         t->new_child = 1;
 588         t->ksp = ((unsigned long) child_trap_frame) - STACK_BIAS;
 589         t->kregs = (struct pt_regs *) (child_trap_frame +
 590                                        sizeof(struct sparc_stackf));
 591         t->fpsaved[0] = 0;
 592
 593         if (kernel_thread) {
 594                 struct sparc_stackf *child_sf = (struct sparc_stackf *)
 595                         (child_trap_frame + (STACKFRAME_SZ + TRACEREG_SZ));
 596
 597                 /* Zero terminate the stack backtrace.  */
 598                 child_sf->fp = NULL;
 599                 t->kregs->u_regs[UREG_FP] =
 600                   ((unsigned long) child_sf) - STACK_BIAS;
 601
 602                 /* Special case, if we are spawning a kernel thread from
 603                  * a userspace task (usermode helper, NFS or similar), we
 604                  * must disable performance counters in the child because
 605                  * the address space and protection realm are changing.
 606                  */
 607                 if (t->flags & _TIF_PERFCTR) {
 608                         t->user_cntd0 = t->user_cntd1 = NULL;
 609                         t->pcr_reg = 0;
 610                         t->flags &= ~_TIF_PERFCTR;
 611                 }
 612                 t->flags |= ((long)ASI_P << TI_FLAG_CURRENT_DS_SHIFT);
 613                 t->kregs->u_regs[UREG_G6] = (unsigned long) t;
 614                 t->kregs->u_regs[UREG_G4] = (unsigned long) t->task;
 615         } else {
 616                 if (t->flags & _TIF_32BIT) {
 617                         sp &= 0x00000000ffffffffUL;
 618                         regs->u_regs[UREG_FP] &= 0x00000000ffffffffUL;
 619                 }
 620                 t->kregs->u_regs[UREG_FP] = sp;
 621                 t->flags |= ((long)ASI_AIUS << TI_FLAG_CURRENT_DS_SHIFT);
 622                 if (sp != regs->u_regs[UREG_FP]) {
 623                         unsigned long csp;
 624
 625                         csp = clone_stackframe(sp, regs->u_regs[UREG_FP]);
 626                         if (!csp)
 627                                 return -EFAULT;
 628                         t->kregs->u_regs[UREG_FP] = csp;
 629                 }
 630                 if (t->utraps)
 631                         t->utraps[0]++;
 632         }
 633
 634         /* Set the return value for the child. */
 635         t->kregs->u_regs[UREG_I0] = current->pid;
 636         t->kregs->u_regs[UREG_I1] = 1;
 637
 638         /* Set the second return value for the parent. */
 639         regs->u_regs[UREG_I1] = 0;
 640
 641         if (clone_flags & CLONE_SETTLS)
 642                 t->kregs->u_regs[UREG_G7] = regs->u_regs[UREG_I3];
 643
 644         return 0;
 645 }
 646
 647 /*
 648  * This is the mechanism for creating a new kernel thread.
 649  *
 650  * NOTE! Only a kernel-only process(ie the swapper or direct descendants
 651  * who haven't done an "execve()") should use this: it will work within
 652  * a system call from a "real" process, but the process memory space will
 653  * not be freed until both the parent and the child have exited.
 654  */
 655 pid_t kernel_thread(int (*fn)(void *), void * arg, unsigned long flags)
 656 {
 657         long retval;
 658
 659         /* If the parent runs before fn(arg) is called by the child,
 660          * the input registers of this function can be clobbered.
 661          * So we stash 'fn' and 'arg' into global registers which
 662          * will not be modified by the parent.
 663          */
 664         __asm__ __volatile__("mov %4, %%g2\n\t"    /* Save FN into global */
 665                              "mov %5, %%g3\n\t"    /* Save ARG into global */
 666                              "mov %1, %%g1\n\t"    /* Clone syscall nr. */
 667                              "mov %2, %%o0\n\t"    /* Clone flags. */
 668                              "mov 0, %%o1\n\t"     /* usp arg == 0 */
 669                              "t 0x6d\n\t"          /* Linux/Sparc clone(). */
 670                              "brz,a,pn %%o1, 1f\n\t" /* Parent, just return. */
 671                              " mov %%o0, %0\n\t"
 672                              "jmpl %%g2, %%o7\n\t"   /* Call the function. */
 673                              " mov %%g3, %%o0\n\t"   /* Set arg in delay. */
 674                              "mov %3, %%g1\n\t"
 675                              "t 0x6d\n\t"          /* Linux/Sparc exit(). */
 676                              /* Notreached by child. */
 677                              "1:" :
 678                              "=r" (retval) :
 679                              "i" (__NR_clone), "r" (flags | CLONE_VM | CLONE_UNTRACED),
 680                              "i" (__NR_exit),  "r" (fn), "r" (arg) :
 681                              "g1", "g2", "g3", "o0", "o1", "memory", "cc");
 682         return retval;
 683 }
 684 EXPORT_SYMBOL(kernel_thread);
 685
 686 typedef struct {
 687         union {
 688                 unsigned int    pr_regs[32];
 689                 unsigned long   pr_dregs[16];
 690         } pr_fr;
 691         unsigned int __unused;
 692         unsigned int    pr_fsr;
 693         unsigned char   pr_qcnt;
 694         unsigned char   pr_q_entrysize;
 695         unsigned char   pr_en;
 696         unsigned int    pr_q[64];
 697 } elf_fpregset_t32;
 698
 699 /*
 700  * fill in the fpu structure for a core dump.
 701  */
 702 int dump_fpu (struct pt_regs * regs, elf_fpregset_t * fpregs)
 703 {
 704         unsigned long *kfpregs = current_thread_info()->fpregs;
 705         unsigned long fprs = current_thread_info()->fpsaved[0];
 706
 707         if (test_thread_flag(TIF_32BIT)) {
 708                 elf_fpregset_t32 *fpregs32 = (elf_fpregset_t32 *)fpregs;
 709
 710                 if (fprs & FPRS_DL)
 711                         memcpy(&fpregs32->pr_fr.pr_regs[0], kfpregs,
 712                                sizeof(unsigned int) * 32);
 713                 else
 714                         memset(&fpregs32->pr_fr.pr_regs[0], 0,
 715                                sizeof(unsigned int) * 32);
 716                 fpregs32->pr_qcnt = 0;
 717                 fpregs32->pr_q_entrysize = 8;
 718                 memset(&fpregs32->pr_q[0], 0,
 719                        (sizeof(unsigned int) * 64));
 720                 if (fprs & FPRS_FEF) {
 721                         fpregs32->pr_fsr = (unsigned int) current_thread_info()->xfsr[0];
 722                         fpregs32->pr_en = 1;
 723                 } else {
 724                         fpregs32->pr_fsr = 0;
 725                         fpregs32->pr_en = 0;
 726                 }
 727         } else {
 728                 if(fprs & FPRS_DL)
 729                         memcpy(&fpregs->pr_regs[0], kfpregs,
 730                                sizeof(unsigned int) * 32);
 731                 else
 732                         memset(&fpregs->pr_regs[0], 0,
 733                                sizeof(unsigned int) * 32);
 734                 if(fprs & FPRS_DU)
 735                         memcpy(&fpregs->pr_regs[16], kfpregs+16,
 736                                sizeof(unsigned int) * 32);
 737                 else
 738                         memset(&fpregs->pr_regs[16], 0,
 739                                sizeof(unsigned int) * 32);
 740                 if(fprs & FPRS_FEF) {
 741                         fpregs->pr_fsr = current_thread_info()->xfsr[0];
 742                         fpregs->pr_gsr = current_thread_info()->gsr[0];
 743                 } else {
 744                         fpregs->pr_fsr = fpregs->pr_gsr = 0;
 745                 }
 746                 fpregs->pr_fprs = fprs;
 747         }
 748         return 1;
 749 }
 750 EXPORT_SYMBOL(dump_fpu);
 751
 752 /*
 753  * sparc_execve() executes a new program after the asm stub has set
 754  * things up for us.  This should basically do what I want it to.
 755  */
 756 asmlinkage int sparc_execve(struct pt_regs *regs)
 757 {
 758         int error, base = 0;
 759         char *filename;
 760
 761         /* User register window flush is done by entry.S */
 762
 763         /* Check for indirect call. */
 764         if (regs->u_regs[UREG_G1] == 0)
 765                 base = 1;
 766
 767         filename = getname((char __user *)regs->u_regs[base + UREG_I0]);
 768         error = PTR_ERR(filename);
 769         if (IS_ERR(filename))
 770                 goto out;
 771         error = do_execve(filename,
 772                           (char __user * __user *)
 773                           regs->u_regs[base + UREG_I1],
 774                           (char __user * __user *)
 775                           regs->u_regs[base + UREG_I2], regs);
 776         putname(filename);
 777         if (!error) {
 778                 fprs_write(0);
 779                 current_thread_info()->xfsr[0] = 0;
 780                 current_thread_info()->fpsaved[0] = 0;
 781                 regs->tstate &= ~TSTATE_PEF;
 782         }
 783 out:
 784         return error;
 785 }
 786
 787 unsigned long get_wchan(struct task_struct *task)
 788 {
 789         unsigned long pc, fp, bias = 0;
 790         struct thread_info *tp;
 791         struct reg_window *rw;
 792         unsigned long ret = 0;
 793         int count = 0;
 794
 795         if (!task || task == current ||
 796             task->state == TASK_RUNNING)
 797                 goto out;
 798
 799         tp = task_thread_info(task);
 800         bias = STACK_BIAS;
 801         fp = task_thread_info(task)->ksp + bias;
 802
 803         do {
 804                 if (!kstack_valid(tp, fp))
 805                         break;
 806                 rw = (struct reg_window *) fp;
 807                 pc = rw->ins[7];
 808                 if (!in_sched_functions(pc)) {
 809                         ret = pc;
 810                         goto out;
 811                 }
 812                 fp = rw->ins[6] + bias;
 813         } while (++count < 16);
 814
 815 out:
 816         return ret;
 817 }