arch/sparc64/kernel/process.c

   1 /*  arch/sparc64/kernel/process.c
   2  *
   3  *  Copyright (C) 1995, 1996, 2008 David S. Miller (davem@davemloft.net)
   4  *  Copyright (C) 1996       Eddie C. Dost   (ecd@skynet.be)
   5  *  Copyright (C) 1997, 1998 Jakub Jelinek   (jj@sunsite.mff.cuni.cz)
   6  */
   7
   8 /*
   9  * This file handles the architecture-dependent parts of process handling..
  10  */
  11
  12 #include <stdarg.h>
  13
  14 #include <linux/errno.h>
  15 #include <linux/module.h>
  16 #include <linux/sched.h>
  17 #include <linux/kernel.h>
  18 #include <linux/kallsyms.h>
  19 #include <linux/mm.h>
  20 #include <linux/fs.h>
  21 #include <linux/smp.h>
  22 #include <linux/stddef.h>
  23 #include <linux/ptrace.h>
  24 #include <linux/slab.h>
  25 #include <linux/user.h>
  26 #include <linux/reboot.h>
  27 #include <linux/delay.h>
  28 #include <linux/compat.h>
  29 #include <linux/tick.h>
  30 #include <linux/init.h>
  31 #include <linux/cpu.h>
  32 #include <linux/elfcore.h>
  33 #include <linux/sysrq.h>
  34
  35 #include <asm/oplib.h>
  36 #include <asm/uaccess.h>
  37 #include <asm/system.h>
  38 #include <asm/page.h>
  39 #include <asm/pgalloc.h>
  40 #include <asm/pgtable.h>
  41 #include <asm/processor.h>
  42 #include <asm/pstate.h>
  43 #include <asm/elf.h>
  44 #include <asm/fpumacro.h>
  45 #include <asm/head.h>
  46 #include <asm/cpudata.h>
  47 #include <asm/mmu_context.h>
  48 #include <asm/unistd.h>
  49 #include <asm/hypervisor.h>
  50 #include <asm/sstate.h>
  51 #include <asm/reboot.h>
  52 #include <asm/syscalls.h>
  53 #include <asm/irq_regs.h>
  54 #include <asm/smp.h>
  55
  56 /* #define VERBOSE_SHOWREGS */
  57
  58 static void sparc64_yield(int cpu)
  59 {
  60         if (tlb_type != hypervisor)
  61                 return;
  62
  63         clear_thread_flag(TIF_POLLING_NRFLAG);
  64         smp_mb__after_clear_bit();
  65
  66         while (!need_resched() && !cpu_is_offline(cpu)) {
  67                 unsigned long pstate;
  68
  69                 /* Disable interrupts. */
  70                 __asm__ __volatile__(
  71                         "rdpr %%pstate, %0\n\t"
  72                         "andn %0, %1, %0\n\t"
  73                         "wrpr %0, %%g0, %%pstate"
  74                         : "=&r" (pstate)
  75                         : "i" (PSTATE_IE));
  76
  77                 if (!need_resched() && !cpu_is_offline(cpu))
  78                         sun4v_cpu_yield();
  79
  80                 /* Re-enable interrupts. */
  81                 __asm__ __volatile__(
  82                         "rdpr %%pstate, %0\n\t"
  83                         "or %0, %1, %0\n\t"
  84                         "wrpr %0, %%g0, %%pstate"
  85                         : "=&r" (pstate)
  86                         : "i" (PSTATE_IE));
  87         }
  88
  89         set_thread_flag(TIF_POLLING_NRFLAG);
  90 }
  91
  92 /* The idle loop on sparc64. */
  93 void cpu_idle(void)
  94 {
  95         int cpu = smp_processor_id();
  96
  97         set_thread_flag(TIF_POLLING_NRFLAG);
  98
  99         while(1) {
 100                 tick_nohz_stop_sched_tick(1);
 101
 102                 while (!need_resched() && !cpu_is_offline(cpu))
 103                         sparc64_yield(cpu);
 104
 105                 tick_nohz_restart_sched_tick();
 106
 107                 preempt_enable_no_resched();
 108
 109 #ifdef CONFIG_HOTPLUG_CPU
 110                 if (cpu_is_offline(cpu))
 111                         cpu_play_dead();
 112 #endif
 113
 114                 schedule();
 115                 preempt_disable();
 116         }
 117 }
 118
 119 void machine_halt(void)
 120 {
 121         sstate_halt();
 122         prom_halt();
 123         panic("Halt failed!");
 124 }
 125
 126 void machine_alt_power_off(void)
 127 {
 128         sstate_poweroff();
 129         prom_halt_power_off();
 130         panic("Power-off failed!");
 131 }
 132
 133 void machine_restart(char * cmd)
 134 {
 135         char *p;
 136
 137         sstate_reboot();
 138         p = strchr (reboot_command, '\n');
 139         if (p) *p = 0;
 140         if (cmd)
 141                 prom_reboot(cmd);
 142         if (*reboot_command)
 143                 prom_reboot(reboot_command);
 144         prom_reboot("");
 145         panic("Reboot failed!");
 146 }
 147
 148 #ifdef CONFIG_COMPAT
 149 static void show_regwindow32(struct pt_regs *regs)
 150 {
 151         struct reg_window32 __user *rw;
 152         struct reg_window32 r_w;
 153         mm_segment_t old_fs;
 154
 155         __asm__ __volatile__ ("flushw");
 156         rw = compat_ptr((unsigned)regs->u_regs[14]);
 157         old_fs = get_fs();
 158         set_fs (USER_DS);
 159         if (copy_from_user (&r_w, rw, sizeof(r_w))) {
 160                 set_fs (old_fs);
 161                 return;
 162         }
 163
 164         set_fs (old_fs);
 165         printk("l0: %08x l1: %08x l2: %08x l3: %08x "
 166                "l4: %08x l5: %08x l6: %08x l7: %08x\n",
 167                r_w.locals[0], r_w.locals[1], r_w.locals[2], r_w.locals[3],
 168                r_w.locals[4], r_w.locals[5], r_w.locals[6], r_w.locals[7]);
 169         printk("i0: %08x i1: %08x i2: %08x i3: %08x "
 170                "i4: %08x i5: %08x i6: %08x i7: %08x\n",
 171                r_w.ins[0], r_w.ins[1], r_w.ins[2], r_w.ins[3],
 172                r_w.ins[4], r_w.ins[5], r_w.ins[6], r_w.ins[7]);
 173 }
 174 #else
 175 #define show_regwindow32(regs)  do { } while (0)
 176 #endif
 177
 178 static void show_regwindow(struct pt_regs *regs)
 179 {
 180         struct reg_window __user *rw;
 181         struct reg_window *rwk;
 182         struct reg_window r_w;
 183         mm_segment_t old_fs;
 184
 185         if ((regs->tstate & TSTATE_PRIV) || !(test_thread_flag(TIF_32BIT))) {
 186                 __asm__ __volatile__ ("flushw");
 187                 rw = (struct reg_window __user *)
 188                         (regs->u_regs[14] + STACK_BIAS);
 189                 rwk = (struct reg_window *)
 190                         (regs->u_regs[14] + STACK_BIAS);
 191                 if (!(regs->tstate & TSTATE_PRIV)) {
 192                         old_fs = get_fs();
 193                         set_fs (USER_DS);
 194                         if (copy_from_user (&r_w, rw, sizeof(r_w))) {
 195                                 set_fs (old_fs);
 196                                 return;
 197                         }
 198                         rwk = &r_w;
 199                         set_fs (old_fs);
 200                 }
 201         } else {
 202                 show_regwindow32(regs);
 203                 return;
 204         }
 205         printk("l0: %016lx l1: %016lx l2: %016lx l3: %016lx\n",
 206                rwk->locals[0], rwk->locals[1], rwk->locals[2], rwk->locals[3]);
 207         printk("l4: %016lx l5: %016lx l6: %016lx l7: %016lx\n",
 208                rwk->locals[4], rwk->locals[5], rwk->locals[6], rwk->locals[7]);
 209         printk("i0: %016lx i1: %016lx i2: %016lx i3: %016lx\n",
 210                rwk->ins[0], rwk->ins[1], rwk->ins[2], rwk->ins[3]);
 211         printk("i4: %016lx i5: %016lx i6: %016lx i7: %016lx\n",
 212                rwk->ins[4], rwk->ins[5], rwk->ins[6], rwk->ins[7]);
 213         if (regs->tstate & TSTATE_PRIV)
 214                 print_symbol("I7: <%s>\n", rwk->ins[7]);
 215 }
 216
 217 #ifdef CONFIG_SMP
 218 static DEFINE_SPINLOCK(regdump_lock);
 219 #endif
 220
 221 void __show_regs(struct pt_regs * regs)
 222 {
 223 #ifdef CONFIG_SMP
 224         unsigned long flags;
 225
 226         /* Protect against xcall ipis which might lead to livelock on the lock */
 227         __asm__ __volatile__("rdpr      %%pstate, %0\n\t"
 228                              "wrpr      %0, %1, %%pstate"
 229                              : "=r" (flags)
 230                              : "i" (PSTATE_IE));
 231         spin_lock(&regdump_lock);
 232 #endif
 233         printk("TSTATE: %016lx TPC: %016lx TNPC: %016lx Y: %08x    %s\n", regs->tstate,
 234                regs->tpc, regs->tnpc, regs->y, print_tainted());
 235         print_symbol("TPC: <%s>\n", regs->tpc);
 236         printk("g0: %016lx g1: %016lx g2: %016lx g3: %016lx\n",
 237                regs->u_regs[0], regs->u_regs[1], regs->u_regs[2],
 238                regs->u_regs[3]);
 239         printk("g4: %016lx g5: %016lx g6: %016lx g7: %016lx\n",
 240                regs->u_regs[4], regs->u_regs[5], regs->u_regs[6],
 241                regs->u_regs[7]);
 242         printk("o0: %016lx o1: %016lx o2: %016lx o3: %016lx\n",
 243                regs->u_regs[8], regs->u_regs[9], regs->u_regs[10],
 244                regs->u_regs[11]);
 245         printk("o4: %016lx o5: %016lx sp: %016lx ret_pc: %016lx\n",
 246                regs->u_regs[12], regs->u_regs[13], regs->u_regs[14],
 247                regs->u_regs[15]);
 248         print_symbol("RPC: <%s>\n", regs->u_regs[15]);
 249         show_regwindow(regs);
 250 #ifdef CONFIG_SMP
 251         spin_unlock(&regdump_lock);
 252         __asm__ __volatile__("wrpr      %0, 0, %%pstate"
 253                              : : "r" (flags));
 254 #endif
 255 }
 256
 257 #ifdef VERBOSE_SHOWREGS
 258 static void idump_from_user (unsigned int *pc)
 259 {
 260         int i;
 261         int code;
 262
 263         if((((unsigned long) pc) & 3))
 264                 return;
 265
 266         pc -= 3;
 267         for(i = -3; i < 6; i++) {
 268                 get_user(code, pc);
 269                 printk("%c%08x%c",i?' ':'<',code,i?' ':'>');
 270                 pc++;
 271         }
 272         printk("\n");
 273 }
 274 #endif
 275
 276 void show_regs(struct pt_regs *regs)
 277 {
 278 #ifdef VERBOSE_SHOWREGS
 279         extern long etrap, etraptl1;
 280 #endif
 281         __show_regs(regs);
 282 #if 0
 283 #ifdef CONFIG_SMP
 284         {
 285                 extern void smp_report_regs(void);
 286
 287                 smp_report_regs();
 288         }
 289 #endif
 290 #endif
 291
 292 #ifdef VERBOSE_SHOWREGS
 293         if (regs->tpc >= &etrap && regs->tpc < &etraptl1 &&
 294             regs->u_regs[14] >= (long)current - PAGE_SIZE &&
 295             regs->u_regs[14] < (long)current + 6 * PAGE_SIZE) {
 296                 printk ("*********parent**********\n");
 297                 __show_regs((struct pt_regs *)(regs->u_regs[14] + PTREGS_OFF));
 298                 idump_from_user(((struct pt_regs *)(regs->u_regs[14] + PTREGS_OFF))->tpc);
 299                 printk ("*********endpar**********\n");
 300         }
 301 #endif
 302 }
 303
 304 #ifdef CONFIG_MAGIC_SYSRQ
 305 struct global_reg_snapshot global_reg_snapshot[NR_CPUS];
 306 static DEFINE_SPINLOCK(global_reg_snapshot_lock);
 307
 308 static void __global_reg_self(struct thread_info *tp, struct pt_regs *regs,
 309                               int this_cpu)
 310 {
 311         flushw_all();
 312
 313         global_reg_snapshot[this_cpu].tstate = regs->tstate;
 314         global_reg_snapshot[this_cpu].tpc = regs->tpc;
 315         global_reg_snapshot[this_cpu].tnpc = regs->tnpc;
 316         global_reg_snapshot[this_cpu].o7 = regs->u_regs[UREG_I7];
 317
 318         if (regs->tstate & TSTATE_PRIV) {
 319                 struct reg_window *rw;
 320
 321                 rw = (struct reg_window *)
 322                         (regs->u_regs[UREG_FP] + STACK_BIAS);
 323                 global_reg_snapshot[this_cpu].i7 = rw->ins[6];
 324         } else
 325                 global_reg_snapshot[this_cpu].i7 = 0;
 326
 327         global_reg_snapshot[this_cpu].thread = tp;
 328 }
 329
 330 /* In order to avoid hangs we do not try to synchronize with the
 331  * global register dump client cpus.  The last store they make is to
 332  * the thread pointer, so do a short poll waiting for that to become
 333  * non-NULL.
 334  */
 335 static void __global_reg_poll(struct global_reg_snapshot *gp)
 336 {
 337         int limit = 0;
 338
 339         while (!gp->thread && ++limit < 100) {
 340                 barrier();
 341                 udelay(1);
 342         }
 343 }
 344
 345 static void sysrq_handle_globreg(int key, struct tty_struct *tty)
 346 {
 347         struct thread_info *tp = current_thread_info();
 348         struct pt_regs *regs = get_irq_regs();
 349 #ifdef CONFIG_KALLSYMS
 350         char buffer[KSYM_SYMBOL_LEN];
 351 #endif
 352         unsigned long flags;
 353         int this_cpu, cpu;
 354
 355         if (!regs)
 356                 regs = tp->kregs;
 357
 358         spin_lock_irqsave(&global_reg_snapshot_lock, flags);
 359
 360         memset(global_reg_snapshot, 0, sizeof(global_reg_snapshot));
 361
 362         this_cpu = raw_smp_processor_id();
 363
 364         __global_reg_self(tp, regs, this_cpu);
 365
 366         smp_fetch_global_regs();
 367
 368         for_each_online_cpu(cpu) {
 369                 struct global_reg_snapshot *gp = &global_reg_snapshot[cpu];
 370                 struct thread_info *tp;
 371
 372                 __global_reg_poll(gp);
 373
 374                 tp = gp->thread;
 375                 printk("%c CPU[%3d]: TSTATE[%016lx] TPC[%016lx] TNPC[%016lx] TASK[%s:%d]\n",
 376                        (cpu == this_cpu ? '*' : ' '), cpu,
 377                        gp->tstate, gp->tpc, gp->tnpc,
 378                        ((tp && tp->task) ? tp->task->comm : "NULL"),
 379                        ((tp && tp->task) ? tp->task->pid : -1));
 380 #ifdef CONFIG_KALLSYMS
 381                 if (gp->tstate & TSTATE_PRIV) {
 382                         sprint_symbol(buffer, gp->tpc);
 383                         printk("             TPC[%s] ", buffer);
 384                         sprint_symbol(buffer, gp->o7);
 385                         printk("O7[%s] ", buffer);
 386                         sprint_symbol(buffer, gp->i7);
 387                         printk("I7[%s]\n", buffer);
 388                 } else
 389 #endif
 390                 {
 391                         printk("             TPC[%lx] O7[%lx] I7[%lx]\n",
 392                                gp->tpc, gp->o7, gp->i7);
 393                 }
 394         }
 395
 396         memset(global_reg_snapshot, 0, sizeof(global_reg_snapshot));
 397
 398         spin_unlock_irqrestore(&global_reg_snapshot_lock, flags);
 399 }
 400
 401 static struct sysrq_key_op sparc_globalreg_op = {
 402         .handler        = sysrq_handle_globreg,
 403         .help_msg       = "Globalregs",
 404         .action_msg     = "Show Global CPU Regs",
 405 };
 406
 407 static int __init sparc_globreg_init(void)
 408 {
 409         return register_sysrq_key('y', &sparc_globalreg_op);
 410 }
 411
 412 core_initcall(sparc_globreg_init);
 413
 414 #endif
 415
 416 unsigned long thread_saved_pc(struct task_struct *tsk)
 417 {
 418         struct thread_info *ti = task_thread_info(tsk);
 419         unsigned long ret = 0xdeadbeefUL;
 420
 421         if (ti && ti->ksp) {
 422                 unsigned long *sp;
 423                 sp = (unsigned long *)(ti->ksp + STACK_BIAS);
 424                 if (((unsigned long)sp & (sizeof(long) - 1)) == 0UL &&
 425                     sp[14]) {
 426                         unsigned long *fp;
 427                         fp = (unsigned long *)(sp[14] + STACK_BIAS);
 428                         if (((unsigned long)fp & (sizeof(long) - 1)) == 0UL)
 429                                 ret = fp[15];
 430                 }
 431         }
 432         return ret;
 433 }
 434
 435 /* Free current thread data structures etc.. */
 436 void exit_thread(void)
 437 {
 438         struct thread_info *t = current_thread_info();
 439
 440         if (t->utraps) {
 441                 if (t->utraps[0] < 2)
 442                         kfree (t->utraps);
 443                 else
 444                         t->utraps[0]--;
 445         }
 446
 447         if (test_and_clear_thread_flag(TIF_PERFCTR)) {
 448                 t->user_cntd0 = t->user_cntd1 = NULL;
 449                 t->pcr_reg = 0;
 450                 write_pcr(0);
 451         }
 452 }
 453
 454 void flush_thread(void)
 455 {
 456         struct thread_info *t = current_thread_info();
 457         struct mm_struct *mm;
 458
 459         if (test_ti_thread_flag(t, TIF_ABI_PENDING)) {
 460                 clear_ti_thread_flag(t, TIF_ABI_PENDING);
 461                 if (test_ti_thread_flag(t, TIF_32BIT))
 462                         clear_ti_thread_flag(t, TIF_32BIT);
 463                 else
 464                         set_ti_thread_flag(t, TIF_32BIT);
 465         }
 466
 467         mm = t->task->mm;
 468         if (mm)
 469                 tsb_context_switch(mm);
 470
 471         set_thread_wsaved(0);
 472
 473         /* Turn off performance counters if on. */
 474         if (test_and_clear_thread_flag(TIF_PERFCTR)) {
 475                 t->user_cntd0 = t->user_cntd1 = NULL;
 476                 t->pcr_reg = 0;
 477                 write_pcr(0);
 478         }
 479
 480         /* Clear FPU register state. */
 481         t->fpsaved[0] = 0;
 482
 483         if (get_thread_current_ds() != ASI_AIUS)
 484                 set_fs(USER_DS);
 485 }
 486
 487 /* It's a bit more tricky when 64-bit tasks are involved... */
 488 static unsigned long clone_stackframe(unsigned long csp, unsigned long psp)
 489 {
 490         unsigned long fp, distance, rval;
 491
 492         if (!(test_thread_flag(TIF_32BIT))) {
 493                 csp += STACK_BIAS;
 494                 psp += STACK_BIAS;
 495                 __get_user(fp, &(((struct reg_window __user *)psp)->ins[6]));
 496                 fp += STACK_BIAS;
 497         } else
 498                 __get_user(fp, &(((struct reg_window32 __user *)psp)->ins[6]));
 499
 500         /* Now 8-byte align the stack as this is mandatory in the
 501          * Sparc ABI due to how register windows work.  This hides
 502          * the restriction from thread libraries etc.  -DaveM
 503          */
 504         csp &= ~7UL;
 505
 506         distance = fp - psp;
 507         rval = (csp - distance);
 508         if (copy_in_user((void __user *) rval, (void __user *) psp, distance))
 509                 rval = 0;
 510         else if (test_thread_flag(TIF_32BIT)) {
 511                 if (put_user(((u32)csp),
 512                              &(((struct reg_window32 __user *)rval)->ins[6])))
 513                         rval = 0;
 514         } else {
 515                 if (put_user(((u64)csp - STACK_BIAS),
 516                              &(((struct reg_window __user *)rval)->ins[6])))
 517                         rval = 0;
 518                 else
 519                         rval = rval - STACK_BIAS;
 520         }
 521
 522         return rval;
 523 }
 524
 525 /* Standard stuff. */
 526 static inline void shift_window_buffer(int first_win, int last_win,
 527                                        struct thread_info *t)
 528 {
 529         int i;
 530
 531         for (i = first_win; i < last_win; i++) {
 532                 t->rwbuf_stkptrs[i] = t->rwbuf_stkptrs[i+1];
 533                 memcpy(&t->reg_window[i], &t->reg_window[i+1],
 534                        sizeof(struct reg_window));
 535         }
 536 }
 537
 538 void synchronize_user_stack(void)
 539 {
 540         struct thread_info *t = current_thread_info();
 541         unsigned long window;
 542
 543         flush_user_windows();
 544         if ((window = get_thread_wsaved()) != 0) {
 545                 int winsize = sizeof(struct reg_window);
 546                 int bias = 0;
 547
 548                 if (test_thread_flag(TIF_32BIT))
 549                         winsize = sizeof(struct reg_window32);
 550                 else
 551                         bias = STACK_BIAS;
 552
 553                 window -= 1;
 554                 do {
 555                         unsigned long sp = (t->rwbuf_stkptrs[window] + bias);
 556                         struct reg_window *rwin = &t->reg_window[window];
 557
 558                         if (!copy_to_user((char __user *)sp, rwin, winsize)) {
 559                                 shift_window_buffer(window, get_thread_wsaved() - 1, t);
 560                                 set_thread_wsaved(get_thread_wsaved() - 1);
 561                         }
 562                 } while (window--);
 563         }
 564 }
 565
 566 static void stack_unaligned(unsigned long sp)
 567 {
 568         siginfo_t info;
 569
 570         info.si_signo = SIGBUS;
 571         info.si_errno = 0;
 572         info.si_code = BUS_ADRALN;
 573         info.si_addr = (void __user *) sp;
 574         info.si_trapno = 0;
 575         force_sig_info(SIGBUS, &info, current);
 576 }
 577
 578 void fault_in_user_windows(void)
 579 {
 580         struct thread_info *t = current_thread_info();
 581         unsigned long window;
 582         int winsize = sizeof(struct reg_window);
 583         int bias = 0;
 584
 585         if (test_thread_flag(TIF_32BIT))
 586                 winsize = sizeof(struct reg_window32);
 587         else
 588                 bias = STACK_BIAS;
 589
 590         flush_user_windows();
 591         window = get_thread_wsaved();
 592
 593         if (likely(window != 0)) {
 594                 window -= 1;
 595                 do {
 596                         unsigned long sp = (t->rwbuf_stkptrs[window] + bias);
 597                         struct reg_window *rwin = &t->reg_window[window];
 598
 599                         if (unlikely(sp & 0x7UL))
 600                                 stack_unaligned(sp);
 601
 602                         if (unlikely(copy_to_user((char __user *)sp,
 603                                                   rwin, winsize)))
 604                                 goto barf;
 605                 } while (window--);
 606         }
 607         set_thread_wsaved(0);
 608         return;
 609
 610 barf:
 611         set_thread_wsaved(window + 1);
 612         do_exit(SIGILL);
 613 }
 614
 615 asmlinkage long sparc_do_fork(unsigned long clone_flags,
 616                               unsigned long stack_start,
 617                               struct pt_regs *regs,
 618                               unsigned long stack_size)
 619 {
 620         int __user *parent_tid_ptr, *child_tid_ptr;
 621         unsigned long orig_i1 = regs->u_regs[UREG_I1];
 622         long ret;
 623
 624 #ifdef CONFIG_COMPAT
 625         if (test_thread_flag(TIF_32BIT)) {
 626                 parent_tid_ptr = compat_ptr(regs->u_regs[UREG_I2]);
 627                 child_tid_ptr = compat_ptr(regs->u_regs[UREG_I4]);
 628         } else
 629 #endif
 630         {
 631                 parent_tid_ptr = (int __user *) regs->u_regs[UREG_I2];
 632                 child_tid_ptr = (int __user *) regs->u_regs[UREG_I4];
 633         }
 634
 635         ret = do_fork(clone_flags, stack_start,
 636                       regs, stack_size,
 637                       parent_tid_ptr, child_tid_ptr);
 638
 639         /* If we get an error and potentially restart the system
 640          * call, we're screwed because copy_thread() clobbered
 641          * the parent's %o1.  So detect that case and restore it
 642          * here.
 643          */
 644         if ((unsigned long)ret >= -ERESTART_RESTARTBLOCK)
 645                 regs->u_regs[UREG_I1] = orig_i1;
 646
 647         return ret;
 648 }
 649
 650 /* Copy a Sparc thread.  The fork() return value conventions
 651  * under SunOS are nothing short of bletcherous:
 652  * Parent -->  %o0 == childs  pid, %o1 == 0
 653  * Child  -->  %o0 == parents pid, %o1 == 1
 654  */
 655 int copy_thread(int nr, unsigned long clone_flags, unsigned long sp,
 656                 unsigned long unused,
 657                 struct task_struct *p, struct pt_regs *regs)
 658 {
 659         struct thread_info *t = task_thread_info(p);
 660         struct sparc_stackf *parent_sf;
 661         unsigned long child_stack_sz;
 662         char *child_trap_frame;
 663         int kernel_thread;
 664
 665         kernel_thread = (regs->tstate & TSTATE_PRIV) ? 1 : 0;
 666         parent_sf = ((struct sparc_stackf *) regs) - 1;
 667
 668         /* Calculate offset to stack_frame & pt_regs */
 669         child_stack_sz = ((STACKFRAME_SZ + TRACEREG_SZ) +
 670                           (kernel_thread ? STACKFRAME_SZ : 0));
 671         child_trap_frame = (task_stack_page(p) +
 672                             (THREAD_SIZE - child_stack_sz));
 673         memcpy(child_trap_frame, parent_sf, child_stack_sz);
 674
 675         t->flags = (t->flags & ~((0xffUL << TI_FLAG_CWP_SHIFT) |
 676                                  (0xffUL << TI_FLAG_CURRENT_DS_SHIFT))) |
 677                 (((regs->tstate + 1) & TSTATE_CWP) << TI_FLAG_CWP_SHIFT);
 678         t->new_child = 1;
 679         t->ksp = ((unsigned long) child_trap_frame) - STACK_BIAS;
 680         t->kregs = (struct pt_regs *) (child_trap_frame +
 681                                        sizeof(struct sparc_stackf));
 682         t->fpsaved[0] = 0;
 683
 684         if (kernel_thread) {
 685                 struct sparc_stackf *child_sf = (struct sparc_stackf *)
 686                         (child_trap_frame + (STACKFRAME_SZ + TRACEREG_SZ));
 687
 688                 /* Zero terminate the stack backtrace.  */
 689                 child_sf->fp = NULL;
 690                 t->kregs->u_regs[UREG_FP] =
 691                   ((unsigned long) child_sf) - STACK_BIAS;
 692
 693                 /* Special case, if we are spawning a kernel thread from
 694                  * a userspace task (via KMOD, NFS, or similar) we must
 695                  * disable performance counters in the child because the
 696                  * address space and protection realm are changing.
 697                  */
 698                 if (t->flags & _TIF_PERFCTR) {
 699                         t->user_cntd0 = t->user_cntd1 = NULL;
 700                         t->pcr_reg = 0;
 701                         t->flags &= ~_TIF_PERFCTR;
 702                 }
 703                 t->flags |= ((long)ASI_P << TI_FLAG_CURRENT_DS_SHIFT);
 704                 t->kregs->u_regs[UREG_G6] = (unsigned long) t;
 705                 t->kregs->u_regs[UREG_G4] = (unsigned long) t->task;
 706         } else {
 707                 if (t->flags & _TIF_32BIT) {
 708                         sp &= 0x00000000ffffffffUL;
 709                         regs->u_regs[UREG_FP] &= 0x00000000ffffffffUL;
 710                 }
 711                 t->kregs->u_regs[UREG_FP] = sp;
 712                 t->flags |= ((long)ASI_AIUS << TI_FLAG_CURRENT_DS_SHIFT);
 713                 if (sp != regs->u_regs[UREG_FP]) {
 714                         unsigned long csp;
 715
 716                         csp = clone_stackframe(sp, regs->u_regs[UREG_FP]);
 717                         if (!csp)
 718                                 return -EFAULT;
 719                         t->kregs->u_regs[UREG_FP] = csp;
 720                 }
 721                 if (t->utraps)
 722                         t->utraps[0]++;
 723         }
 724
 725         /* Set the return value for the child. */
 726         t->kregs->u_regs[UREG_I0] = current->pid;
 727         t->kregs->u_regs[UREG_I1] = 1;
 728
 729         /* Set the second return value for the parent. */
 730         regs->u_regs[UREG_I1] = 0;
 731
 732         if (clone_flags & CLONE_SETTLS)
 733                 t->kregs->u_regs[UREG_G7] = regs->u_regs[UREG_I3];
 734
 735         return 0;
 736 }
 737
 738 /*
 739  * This is the mechanism for creating a new kernel thread.
 740  *
 741  * NOTE! Only a kernel-only process(ie the swapper or direct descendants
 742  * who haven't done an "execve()") should use this: it will work within
 743  * a system call from a "real" process, but the process memory space will
 744  * not be freed until both the parent and the child have exited.
 745  */
 746 pid_t kernel_thread(int (*fn)(void *), void * arg, unsigned long flags)
 747 {
 748         long retval;
 749
 750         /* If the parent runs before fn(arg) is called by the child,
 751          * the input registers of this function can be clobbered.
 752          * So we stash 'fn' and 'arg' into global registers which
 753          * will not be modified by the parent.
 754          */
 755         __asm__ __volatile__("mov %4, %%g2\n\t"    /* Save FN into global */
 756                              "mov %5, %%g3\n\t"    /* Save ARG into global */
 757                              "mov %1, %%g1\n\t"    /* Clone syscall nr. */
 758                              "mov %2, %%o0\n\t"    /* Clone flags. */
 759                              "mov 0, %%o1\n\t"     /* usp arg == 0 */
 760                              "t 0x6d\n\t"          /* Linux/Sparc clone(). */
 761                              "brz,a,pn %%o1, 1f\n\t" /* Parent, just return. */
 762                              " mov %%o0, %0\n\t"
 763                              "jmpl %%g2, %%o7\n\t"   /* Call the function. */
 764                              " mov %%g3, %%o0\n\t"   /* Set arg in delay. */
 765                              "mov %3, %%g1\n\t"
 766                              "t 0x6d\n\t"          /* Linux/Sparc exit(). */
 767                              /* Notreached by child. */
 768                              "1:" :
 769                              "=r" (retval) :
 770                              "i" (__NR_clone), "r" (flags | CLONE_VM | CLONE_UNTRACED),
 771                              "i" (__NR_exit),  "r" (fn), "r" (arg) :
 772                              "g1", "g2", "g3", "o0", "o1", "memory", "cc");
 773         return retval;
 774 }
 775
 776 typedef struct {
 777         union {
 778                 unsigned int    pr_regs[32];
 779                 unsigned long   pr_dregs[16];
 780         } pr_fr;
 781         unsigned int __unused;
 782         unsigned int    pr_fsr;
 783         unsigned char   pr_qcnt;
 784         unsigned char   pr_q_entrysize;
 785         unsigned char   pr_en;
 786         unsigned int    pr_q[64];
 787 } elf_fpregset_t32;
 788
 789 /*
 790  * fill in the fpu structure for a core dump.
 791  */
 792 int dump_fpu (struct pt_regs * regs, elf_fpregset_t * fpregs)
 793 {
 794         unsigned long *kfpregs = current_thread_info()->fpregs;
 795         unsigned long fprs = current_thread_info()->fpsaved[0];
 796
 797         if (test_thread_flag(TIF_32BIT)) {
 798                 elf_fpregset_t32 *fpregs32 = (elf_fpregset_t32 *)fpregs;
 799
 800                 if (fprs & FPRS_DL)
 801                         memcpy(&fpregs32->pr_fr.pr_regs[0], kfpregs,
 802                                sizeof(unsigned int) * 32);
 803                 else
 804                         memset(&fpregs32->pr_fr.pr_regs[0], 0,
 805                                sizeof(unsigned int) * 32);
 806                 fpregs32->pr_qcnt = 0;
 807                 fpregs32->pr_q_entrysize = 8;
 808                 memset(&fpregs32->pr_q[0], 0,
 809                        (sizeof(unsigned int) * 64));
 810                 if (fprs & FPRS_FEF) {
 811                         fpregs32->pr_fsr = (unsigned int) current_thread_info()->xfsr[0];
 812                         fpregs32->pr_en = 1;
 813                 } else {
 814                         fpregs32->pr_fsr = 0;
 815                         fpregs32->pr_en = 0;
 816                 }
 817         } else {
 818                 if(fprs & FPRS_DL)
 819                         memcpy(&fpregs->pr_regs[0], kfpregs,
 820                                sizeof(unsigned int) * 32);
 821                 else
 822                         memset(&fpregs->pr_regs[0], 0,
 823                                sizeof(unsigned int) * 32);
 824                 if(fprs & FPRS_DU)
 825                         memcpy(&fpregs->pr_regs[16], kfpregs+16,
 826                                sizeof(unsigned int) * 32);
 827                 else
 828                         memset(&fpregs->pr_regs[16], 0,
 829                                sizeof(unsigned int) * 32);
 830                 if(fprs & FPRS_FEF) {
 831                         fpregs->pr_fsr = current_thread_info()->xfsr[0];
 832                         fpregs->pr_gsr = current_thread_info()->gsr[0];
 833                 } else {
 834                         fpregs->pr_fsr = fpregs->pr_gsr = 0;
 835                 }
 836                 fpregs->pr_fprs = fprs;
 837         }
 838         return 1;
 839 }
 840
 841 /*
 842  * sparc_execve() executes a new program after the asm stub has set
 843  * things up for us.  This should basically do what I want it to.
 844  */
 845 asmlinkage int sparc_execve(struct pt_regs *regs)
 846 {
 847         int error, base = 0;
 848         char *filename;
 849
 850         /* User register window flush is done by entry.S */
 851
 852         /* Check for indirect call. */
 853         if (regs->u_regs[UREG_G1] == 0)
 854                 base = 1;
 855
 856         filename = getname((char __user *)regs->u_regs[base + UREG_I0]);
 857         error = PTR_ERR(filename);
 858         if (IS_ERR(filename))
 859                 goto out;
 860         error = do_execve(filename,
 861                           (char __user * __user *)
 862                           regs->u_regs[base + UREG_I1],
 863                           (char __user * __user *)
 864                           regs->u_regs[base + UREG_I2], regs);
 865         putname(filename);
 866         if (!error) {
 867                 fprs_write(0);
 868                 current_thread_info()->xfsr[0] = 0;
 869                 current_thread_info()->fpsaved[0] = 0;
 870                 regs->tstate &= ~TSTATE_PEF;
 871         }
 872 out:
 873         return error;
 874 }
 875
 876 unsigned long get_wchan(struct task_struct *task)
 877 {
 878         unsigned long pc, fp, bias = 0;
 879         unsigned long thread_info_base;
 880         struct reg_window *rw;
 881         unsigned long ret = 0;
 882         int count = 0;
 883
 884         if (!task || task == current ||
 885             task->state == TASK_RUNNING)
 886                 goto out;
 887
 888         thread_info_base = (unsigned long) task_stack_page(task);
 889         bias = STACK_BIAS;
 890         fp = task_thread_info(task)->ksp + bias;
 891
 892         do {
 893                 /* Bogus frame pointer? */
 894                 if (fp < (thread_info_base + sizeof(struct thread_info)) ||
 895                     fp >= (thread_info_base + THREAD_SIZE))
 896                         break;
 897                 rw = (struct reg_window *) fp;
 898                 pc = rw->ins[7];
 899                 if (!in_sched_functions(pc)) {
 900                         ret = pc;
 901                         goto out;
 902                 }
 903                 fp = rw->ins[6] + bias;
 904         } while (++count < 16);
 905
 906 out:
 907         return ret;
 908 }