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/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/reboot.h>
  26 #include <linux/delay.h>
  27 #include <linux/compat.h>
  28 #include <linux/tick.h>
  29 #include <linux/init.h>
  30 #include <linux/cpu.h>
  31 #include <linux/elfcore.h>
  32 #include <linux/sysrq.h>
  33
  34 #include <asm/oplib.h>
  35 #include <asm/uaccess.h>
  36 #include <asm/system.h>
  37 #include <asm/page.h>
  38 #include <asm/pgalloc.h>
  39 #include <asm/pgtable.h>
  40 #include <asm/processor.h>
  41 #include <asm/pstate.h>
  42 #include <asm/elf.h>
  43 #include <asm/fpumacro.h>
  44 #include <asm/head.h>
  45 #include <asm/cpudata.h>
  46 #include <asm/mmu_context.h>
  47 #include <asm/unistd.h>
  48 #include <asm/hypervisor.h>
  49 #include <asm/sstate.h>
  50 #include <asm/reboot.h>
  51 #include <asm/syscalls.h>
  52 #include <asm/irq_regs.h>
  53 #include <asm/smp.h>
  54
  55 /* #define VERBOSE_SHOWREGS */
  56
  57 static void sparc64_yield(int cpu)
  58 {
  59         if (tlb_type != hypervisor)
  60                 return;
  61
  62         clear_thread_flag(TIF_POLLING_NRFLAG);
  63         smp_mb__after_clear_bit();
  64
  65         while (!need_resched() && !cpu_is_offline(cpu)) {
  66                 unsigned long pstate;
  67
  68                 /* Disable interrupts. */
  69                 __asm__ __volatile__(
  70                         "rdpr %%pstate, %0\n\t"
  71                         "andn %0, %1, %0\n\t"
  72                         "wrpr %0, %%g0, %%pstate"
  73                         : "=&r" (pstate)
  74                         : "i" (PSTATE_IE));
  75
  76                 if (!need_resched() && !cpu_is_offline(cpu))
  77                         sun4v_cpu_yield();
  78
  79                 /* Re-enable interrupts. */
  80                 __asm__ __volatile__(
  81                         "rdpr %%pstate, %0\n\t"
  82                         "or %0, %1, %0\n\t"
  83                         "wrpr %0, %%g0, %%pstate"
  84                         : "=&r" (pstate)
  85                         : "i" (PSTATE_IE));
  86         }
  87
  88         set_thread_flag(TIF_POLLING_NRFLAG);
  89 }
  90
  91 /* The idle loop on sparc64. */
  92 void cpu_idle(void)
  93 {
  94         int cpu = smp_processor_id();
  95
  96         set_thread_flag(TIF_POLLING_NRFLAG);
  97
  98         while(1) {
  99                 tick_nohz_stop_sched_tick(1);
 100
 101                 while (!need_resched() && !cpu_is_offline(cpu))
 102                         sparc64_yield(cpu);
 103
 104                 tick_nohz_restart_sched_tick();
 105
 106                 preempt_enable_no_resched();
 107
 108 #ifdef CONFIG_HOTPLUG_CPU
 109                 if (cpu_is_offline(cpu))
 110                         cpu_play_dead();
 111 #endif
 112
 113                 schedule();
 114                 preempt_disable();
 115         }
 116 }
 117
 118 void machine_halt(void)
 119 {
 120         sstate_halt();
 121         prom_halt();
 122         panic("Halt failed!");
 123 }
 124
 125 void machine_alt_power_off(void)
 126 {
 127         sstate_poweroff();
 128         prom_halt_power_off();
 129         panic("Power-off failed!");
 130 }
 131
 132 void machine_restart(char * cmd)
 133 {
 134         char *p;
 135
 136         sstate_reboot();
 137         p = strchr (reboot_command, '\n');
 138         if (p) *p = 0;
 139         if (cmd)
 140                 prom_reboot(cmd);
 141         if (*reboot_command)
 142                 prom_reboot(reboot_command);
 143         prom_reboot("");
 144         panic("Reboot failed!");
 145 }
 146
 147 #ifdef CONFIG_COMPAT
 148 static void show_regwindow32(struct pt_regs *regs)
 149 {
 150         struct reg_window32 __user *rw;
 151         struct reg_window32 r_w;
 152         mm_segment_t old_fs;
 153
 154         __asm__ __volatile__ ("flushw");
 155         rw = compat_ptr((unsigned)regs->u_regs[14]);
 156         old_fs = get_fs();
 157         set_fs (USER_DS);
 158         if (copy_from_user (&r_w, rw, sizeof(r_w))) {
 159                 set_fs (old_fs);
 160                 return;
 161         }
 162
 163         set_fs (old_fs);
 164         printk("l0: %08x l1: %08x l2: %08x l3: %08x "
 165                "l4: %08x l5: %08x l6: %08x l7: %08x\n",
 166                r_w.locals[0], r_w.locals[1], r_w.locals[2], r_w.locals[3],
 167                r_w.locals[4], r_w.locals[5], r_w.locals[6], r_w.locals[7]);
 168         printk("i0: %08x i1: %08x i2: %08x i3: %08x "
 169                "i4: %08x i5: %08x i6: %08x i7: %08x\n",
 170                r_w.ins[0], r_w.ins[1], r_w.ins[2], r_w.ins[3],
 171                r_w.ins[4], r_w.ins[5], r_w.ins[6], r_w.ins[7]);
 172 }
 173 #else
 174 #define show_regwindow32(regs)  do { } while (0)
 175 #endif
 176
 177 static void show_regwindow(struct pt_regs *regs)
 178 {
 179         struct reg_window __user *rw;
 180         struct reg_window *rwk;
 181         struct reg_window r_w;
 182         mm_segment_t old_fs;
 183
 184         if ((regs->tstate & TSTATE_PRIV) || !(test_thread_flag(TIF_32BIT))) {
 185                 __asm__ __volatile__ ("flushw");
 186                 rw = (struct reg_window __user *)
 187                         (regs->u_regs[14] + STACK_BIAS);
 188                 rwk = (struct reg_window *)
 189                         (regs->u_regs[14] + STACK_BIAS);
 190                 if (!(regs->tstate & TSTATE_PRIV)) {
 191                         old_fs = get_fs();
 192                         set_fs (USER_DS);
 193                         if (copy_from_user (&r_w, rw, sizeof(r_w))) {
 194                                 set_fs (old_fs);
 195                                 return;
 196                         }
 197                         rwk = &r_w;
 198                         set_fs (old_fs);
 199                 }
 200         } else {
 201                 show_regwindow32(regs);
 202                 return;
 203         }
 204         printk("l0: %016lx l1: %016lx l2: %016lx l3: %016lx\n",
 205                rwk->locals[0], rwk->locals[1], rwk->locals[2], rwk->locals[3]);
 206         printk("l4: %016lx l5: %016lx l6: %016lx l7: %016lx\n",
 207                rwk->locals[4], rwk->locals[5], rwk->locals[6], rwk->locals[7]);
 208         printk("i0: %016lx i1: %016lx i2: %016lx i3: %016lx\n",
 209                rwk->ins[0], rwk->ins[1], rwk->ins[2], rwk->ins[3]);
 210         printk("i4: %016lx i5: %016lx i6: %016lx i7: %016lx\n",
 211                rwk->ins[4], rwk->ins[5], rwk->ins[6], rwk->ins[7]);
 212         if (regs->tstate & TSTATE_PRIV)
 213                 printk("I7: <%pS>\n", (void *) rwk->ins[7]);
 214 }
 215
 216 #ifdef CONFIG_SMP
 217 static DEFINE_SPINLOCK(regdump_lock);
 218 #endif
 219
 220 void __show_regs(struct pt_regs * regs)
 221 {
 222 #ifdef CONFIG_SMP
 223         unsigned long flags;
 224
 225         /* Protect against xcall ipis which might lead to livelock on the lock */
 226         __asm__ __volatile__("rdpr      %%pstate, %0\n\t"
 227                              "wrpr      %0, %1, %%pstate"
 228                              : "=r" (flags)
 229                              : "i" (PSTATE_IE));
 230         spin_lock(&regdump_lock);
 231 #endif
 232         printk("TSTATE: %016lx TPC: %016lx TNPC: %016lx Y: %08x    %s\n", regs->tstate,
 233                regs->tpc, regs->tnpc, regs->y, print_tainted());
 234         printk("TPC: <%pS>\n", (void *) regs->tpc);
 235         printk("g0: %016lx g1: %016lx g2: %016lx g3: %016lx\n",
 236                regs->u_regs[0], regs->u_regs[1], regs->u_regs[2],
 237                regs->u_regs[3]);
 238         printk("g4: %016lx g5: %016lx g6: %016lx g7: %016lx\n",
 239                regs->u_regs[4], regs->u_regs[5], regs->u_regs[6],
 240                regs->u_regs[7]);
 241         printk("o0: %016lx o1: %016lx o2: %016lx o3: %016lx\n",
 242                regs->u_regs[8], regs->u_regs[9], regs->u_regs[10],
 243                regs->u_regs[11]);
 244         printk("o4: %016lx o5: %016lx sp: %016lx ret_pc: %016lx\n",
 245                regs->u_regs[12], regs->u_regs[13], regs->u_regs[14],
 246                regs->u_regs[15]);
 247         printk("RPC: <%pS>\n", (void *) regs->u_regs[15]);
 248         show_regwindow(regs);
 249 #ifdef CONFIG_SMP
 250         spin_unlock(&regdump_lock);
 251         __asm__ __volatile__("wrpr      %0, 0, %%pstate"
 252                              : : "r" (flags));
 253 #endif
 254 }
 255
 256 #ifdef VERBOSE_SHOWREGS
 257 static void idump_from_user (unsigned int *pc)
 258 {
 259         int i;
 260         int code;
 261
 262         if((((unsigned long) pc) & 3))
 263                 return;
 264
 265         pc -= 3;
 266         for(i = -3; i < 6; i++) {
 267                 get_user(code, pc);
 268                 printk("%c%08x%c",i?' ':'<',code,i?' ':'>');
 269                 pc++;
 270         }
 271         printk("\n");
 272 }
 273 #endif
 274
 275 void show_regs(struct pt_regs *regs)
 276 {
 277 #ifdef VERBOSE_SHOWREGS
 278         extern long etrap, etraptl1;
 279 #endif
 280         __show_regs(regs);
 281 #if 0
 282 #ifdef CONFIG_SMP
 283         {
 284                 extern void smp_report_regs(void);
 285
 286                 smp_report_regs();
 287         }
 288 #endif
 289 #endif
 290
 291 #ifdef VERBOSE_SHOWREGS
 292         if (regs->tpc >= &etrap && regs->tpc < &etraptl1 &&
 293             regs->u_regs[14] >= (long)current - PAGE_SIZE &&
 294             regs->u_regs[14] < (long)current + 6 * PAGE_SIZE) {
 295                 printk ("*********parent**********\n");
 296                 __show_regs((struct pt_regs *)(regs->u_regs[14] + PTREGS_OFF));
 297                 idump_from_user(((struct pt_regs *)(regs->u_regs[14] + PTREGS_OFF))->tpc);
 298                 printk ("*********endpar**********\n");
 299         }
 300 #endif
 301 }
 302
 303 #ifdef CONFIG_MAGIC_SYSRQ
 304 struct global_reg_snapshot global_reg_snapshot[NR_CPUS];
 305 static DEFINE_SPINLOCK(global_reg_snapshot_lock);
 306
 307 static bool kstack_valid(struct thread_info *tp, struct reg_window *rw)
 308 {
 309         unsigned long thread_base, fp;
 310
 311         thread_base = (unsigned long) tp;
 312         fp = (unsigned long) rw;
 313
 314         if (fp < (thread_base + sizeof(struct thread_info)) ||
 315             fp >= (thread_base + THREAD_SIZE))
 316                 return false;
 317         return true;
 318 }
 319
 320 static void __global_reg_self(struct thread_info *tp, struct pt_regs *regs,
 321                               int this_cpu)
 322 {
 323         flushw_all();
 324
 325         global_reg_snapshot[this_cpu].tstate = regs->tstate;
 326         global_reg_snapshot[this_cpu].tpc = regs->tpc;
 327         global_reg_snapshot[this_cpu].tnpc = regs->tnpc;
 328         global_reg_snapshot[this_cpu].o7 = regs->u_regs[UREG_I7];
 329
 330         if (regs->tstate & TSTATE_PRIV) {
 331                 struct thread_info *tp = current_thread_info();
 332                 struct reg_window *rw;
 333
 334                 rw = (struct reg_window *)
 335                         (regs->u_regs[UREG_FP] + STACK_BIAS);
 336                 if (kstack_valid(tp, rw)) {
 337                         global_reg_snapshot[this_cpu].i7 = rw->ins[7];
 338                         rw = (struct reg_window *)
 339                                 (rw->ins[6] + STACK_BIAS);
 340                         if (kstack_valid(tp, rw))
 341                                 global_reg_snapshot[this_cpu].rpc = rw->ins[7];
 342                 }
 343         } else {
 344                 global_reg_snapshot[this_cpu].i7 = 0;
 345                 global_reg_snapshot[this_cpu].rpc = 0;
 346         }
 347         global_reg_snapshot[this_cpu].thread = tp;
 348 }
 349
 350 /* In order to avoid hangs we do not try to synchronize with the
 351  * global register dump client cpus.  The last store they make is to
 352  * the thread pointer, so do a short poll waiting for that to become
 353  * non-NULL.
 354  */
 355 static void __global_reg_poll(struct global_reg_snapshot *gp)
 356 {
 357         int limit = 0;
 358
 359         while (!gp->thread && ++limit < 100) {
 360                 barrier();
 361                 udelay(1);
 362         }
 363 }
 364
 365 static void sysrq_handle_globreg(int key, struct tty_struct *tty)
 366 {
 367         struct thread_info *tp = current_thread_info();
 368         struct pt_regs *regs = get_irq_regs();
 369         unsigned long flags;
 370         int this_cpu, cpu;
 371
 372         if (!regs)
 373                 regs = tp->kregs;
 374
 375         spin_lock_irqsave(&global_reg_snapshot_lock, flags);
 376
 377         memset(global_reg_snapshot, 0, sizeof(global_reg_snapshot));
 378
 379         this_cpu = raw_smp_processor_id();
 380
 381         __global_reg_self(tp, regs, this_cpu);
 382
 383         smp_fetch_global_regs();
 384
 385         for_each_online_cpu(cpu) {
 386                 struct global_reg_snapshot *gp = &global_reg_snapshot[cpu];
 387                 struct thread_info *tp;
 388
 389                 __global_reg_poll(gp);
 390
 391                 tp = gp->thread;
 392                 printk("%c CPU[%3d]: TSTATE[%016lx] TPC[%016lx] TNPC[%016lx] TASK[%s:%d]\n",
 393                        (cpu == this_cpu ? '*' : ' '), cpu,
 394                        gp->tstate, gp->tpc, gp->tnpc,
 395                        ((tp && tp->task) ? tp->task->comm : "NULL"),
 396                        ((tp && tp->task) ? tp->task->pid : -1));
 397
 398                 if (gp->tstate & TSTATE_PRIV) {
 399                         printk("             TPC[%pS] O7[%pS] I7[%pS] RPC[%pS]\n",
 400                                (void *) gp->tpc,
 401                                (void *) gp->o7,
 402                                (void *) gp->i7,
 403                                (void *) gp->rpc);
 404                 } else {
 405                         printk("             TPC[%lx] O7[%lx] I7[%lx] RPC[%lx]\n",
 406                                gp->tpc, gp->o7, gp->i7, gp->rpc);
 407                 }
 408         }
 409
 410         memset(global_reg_snapshot, 0, sizeof(global_reg_snapshot));
 411
 412         spin_unlock_irqrestore(&global_reg_snapshot_lock, flags);
 413 }
 414
 415 static struct sysrq_key_op sparc_globalreg_op = {
 416         .handler        = sysrq_handle_globreg,
 417         .help_msg       = "Globalregs",
 418         .action_msg     = "Show Global CPU Regs",
 419 };
 420
 421 static int __init sparc_globreg_init(void)
 422 {
 423         return register_sysrq_key('y', &sparc_globalreg_op);
 424 }
 425
 426 core_initcall(sparc_globreg_init);
 427
 428 #endif
 429
 430 unsigned long thread_saved_pc(struct task_struct *tsk)
 431 {
 432         struct thread_info *ti = task_thread_info(tsk);
 433         unsigned long ret = 0xdeadbeefUL;
 434
 435         if (ti && ti->ksp) {
 436                 unsigned long *sp;
 437                 sp = (unsigned long *)(ti->ksp + STACK_BIAS);
 438                 if (((unsigned long)sp & (sizeof(long) - 1)) == 0UL &&
 439                     sp[14]) {
 440                         unsigned long *fp;
 441                         fp = (unsigned long *)(sp[14] + STACK_BIAS);
 442                         if (((unsigned long)fp & (sizeof(long) - 1)) == 0UL)
 443                                 ret = fp[15];
 444                 }
 445         }
 446         return ret;
 447 }
 448
 449 /* Free current thread data structures etc.. */
 450 void exit_thread(void)
 451 {
 452         struct thread_info *t = current_thread_info();
 453
 454         if (t->utraps) {
 455                 if (t->utraps[0] < 2)
 456                         kfree (t->utraps);
 457                 else
 458                         t->utraps[0]--;
 459         }
 460
 461         if (test_and_clear_thread_flag(TIF_PERFCTR)) {
 462                 t->user_cntd0 = t->user_cntd1 = NULL;
 463                 t->pcr_reg = 0;
 464                 write_pcr(0);
 465         }
 466 }
 467
 468 void flush_thread(void)
 469 {
 470         struct thread_info *t = current_thread_info();
 471         struct mm_struct *mm;
 472
 473         if (test_ti_thread_flag(t, TIF_ABI_PENDING)) {
 474                 clear_ti_thread_flag(t, TIF_ABI_PENDING);
 475                 if (test_ti_thread_flag(t, TIF_32BIT))
 476                         clear_ti_thread_flag(t, TIF_32BIT);
 477                 else
 478                         set_ti_thread_flag(t, TIF_32BIT);
 479         }
 480
 481         mm = t->task->mm;
 482         if (mm)
 483                 tsb_context_switch(mm);
 484
 485         set_thread_wsaved(0);
 486
 487         /* Turn off performance counters if on. */
 488         if (test_and_clear_thread_flag(TIF_PERFCTR)) {
 489                 t->user_cntd0 = t->user_cntd1 = NULL;
 490                 t->pcr_reg = 0;
 491                 write_pcr(0);
 492         }
 493
 494         /* Clear FPU register state. */
 495         t->fpsaved[0] = 0;
 496
 497         if (get_thread_current_ds() != ASI_AIUS)
 498                 set_fs(USER_DS);
 499 }
 500
 501 /* It's a bit more tricky when 64-bit tasks are involved... */
 502 static unsigned long clone_stackframe(unsigned long csp, unsigned long psp)
 503 {
 504         unsigned long fp, distance, rval;
 505
 506         if (!(test_thread_flag(TIF_32BIT))) {
 507                 csp += STACK_BIAS;
 508                 psp += STACK_BIAS;
 509                 __get_user(fp, &(((struct reg_window __user *)psp)->ins[6]));
 510                 fp += STACK_BIAS;
 511         } else
 512                 __get_user(fp, &(((struct reg_window32 __user *)psp)->ins[6]));
 513
 514         /* Now 8-byte align the stack as this is mandatory in the
 515          * Sparc ABI due to how register windows work.  This hides
 516          * the restriction from thread libraries etc.  -DaveM
 517          */
 518         csp &= ~7UL;
 519
 520         distance = fp - psp;
 521         rval = (csp - distance);
 522         if (copy_in_user((void __user *) rval, (void __user *) psp, distance))
 523                 rval = 0;
 524         else if (test_thread_flag(TIF_32BIT)) {
 525                 if (put_user(((u32)csp),
 526                              &(((struct reg_window32 __user *)rval)->ins[6])))
 527                         rval = 0;
 528         } else {
 529                 if (put_user(((u64)csp - STACK_BIAS),
 530                              &(((struct reg_window __user *)rval)->ins[6])))
 531                         rval = 0;
 532                 else
 533                         rval = rval - STACK_BIAS;
 534         }
 535
 536         return rval;
 537 }
 538
 539 /* Standard stuff. */
 540 static inline void shift_window_buffer(int first_win, int last_win,
 541                                        struct thread_info *t)
 542 {
 543         int i;
 544
 545         for (i = first_win; i < last_win; i++) {
 546                 t->rwbuf_stkptrs[i] = t->rwbuf_stkptrs[i+1];
 547                 memcpy(&t->reg_window[i], &t->reg_window[i+1],
 548                        sizeof(struct reg_window));
 549         }
 550 }
 551
 552 void synchronize_user_stack(void)
 553 {
 554         struct thread_info *t = current_thread_info();
 555         unsigned long window;
 556
 557         flush_user_windows();
 558         if ((window = get_thread_wsaved()) != 0) {
 559                 int winsize = sizeof(struct reg_window);
 560                 int bias = 0;
 561
 562                 if (test_thread_flag(TIF_32BIT))
 563                         winsize = sizeof(struct reg_window32);
 564                 else
 565                         bias = STACK_BIAS;
 566
 567                 window -= 1;
 568                 do {
 569                         unsigned long sp = (t->rwbuf_stkptrs[window] + bias);
 570                         struct reg_window *rwin = &t->reg_window[window];
 571
 572                         if (!copy_to_user((char __user *)sp, rwin, winsize)) {
 573                                 shift_window_buffer(window, get_thread_wsaved() - 1, t);
 574                                 set_thread_wsaved(get_thread_wsaved() - 1);
 575                         }
 576                 } while (window--);
 577         }
 578 }
 579
 580 static void stack_unaligned(unsigned long sp)
 581 {
 582         siginfo_t info;
 583
 584         info.si_signo = SIGBUS;
 585         info.si_errno = 0;
 586         info.si_code = BUS_ADRALN;
 587         info.si_addr = (void __user *) sp;
 588         info.si_trapno = 0;
 589         force_sig_info(SIGBUS, &info, current);
 590 }
 591
 592 void fault_in_user_windows(void)
 593 {
 594         struct thread_info *t = current_thread_info();
 595         unsigned long window;
 596         int winsize = sizeof(struct reg_window);
 597         int bias = 0;
 598
 599         if (test_thread_flag(TIF_32BIT))
 600                 winsize = sizeof(struct reg_window32);
 601         else
 602                 bias = STACK_BIAS;
 603
 604         flush_user_windows();
 605         window = get_thread_wsaved();
 606
 607         if (likely(window != 0)) {
 608                 window -= 1;
 609                 do {
 610                         unsigned long sp = (t->rwbuf_stkptrs[window] + bias);
 611                         struct reg_window *rwin = &t->reg_window[window];
 612
 613                         if (unlikely(sp & 0x7UL))
 614                                 stack_unaligned(sp);
 615
 616                         if (unlikely(copy_to_user((char __user *)sp,
 617                                                   rwin, winsize)))
 618                                 goto barf;
 619                 } while (window--);
 620         }
 621         set_thread_wsaved(0);
 622         return;
 623
 624 barf:
 625         set_thread_wsaved(window + 1);
 626         do_exit(SIGILL);
 627 }
 628
 629 asmlinkage long sparc_do_fork(unsigned long clone_flags,
 630                               unsigned long stack_start,
 631                               struct pt_regs *regs,
 632                               unsigned long stack_size)
 633 {
 634         int __user *parent_tid_ptr, *child_tid_ptr;
 635         unsigned long orig_i1 = regs->u_regs[UREG_I1];
 636         long ret;
 637
 638 #ifdef CONFIG_COMPAT
 639         if (test_thread_flag(TIF_32BIT)) {
 640                 parent_tid_ptr = compat_ptr(regs->u_regs[UREG_I2]);
 641                 child_tid_ptr = compat_ptr(regs->u_regs[UREG_I4]);
 642         } else
 643 #endif
 644         {
 645                 parent_tid_ptr = (int __user *) regs->u_regs[UREG_I2];
 646                 child_tid_ptr = (int __user *) regs->u_regs[UREG_I4];
 647         }
 648
 649         ret = do_fork(clone_flags, stack_start,
 650                       regs, stack_size,
 651                       parent_tid_ptr, child_tid_ptr);
 652
 653         /* If we get an error and potentially restart the system
 654          * call, we're screwed because copy_thread() clobbered
 655          * the parent's %o1.  So detect that case and restore it
 656          * here.
 657          */
 658         if ((unsigned long)ret >= -ERESTART_RESTARTBLOCK)
 659                 regs->u_regs[UREG_I1] = orig_i1;
 660
 661         return ret;
 662 }
 663
 664 /* Copy a Sparc thread.  The fork() return value conventions
 665  * under SunOS are nothing short of bletcherous:
 666  * Parent -->  %o0 == childs  pid, %o1 == 0
 667  * Child  -->  %o0 == parents pid, %o1 == 1
 668  */
 669 int copy_thread(int nr, unsigned long clone_flags, unsigned long sp,
 670                 unsigned long unused,
 671                 struct task_struct *p, struct pt_regs *regs)
 672 {
 673         struct thread_info *t = task_thread_info(p);
 674         struct sparc_stackf *parent_sf;
 675         unsigned long child_stack_sz;
 676         char *child_trap_frame;
 677         int kernel_thread;
 678
 679         kernel_thread = (regs->tstate & TSTATE_PRIV) ? 1 : 0;
 680         parent_sf = ((struct sparc_stackf *) regs) - 1;
 681
 682         /* Calculate offset to stack_frame & pt_regs */
 683         child_stack_sz = ((STACKFRAME_SZ + TRACEREG_SZ) +
 684                           (kernel_thread ? STACKFRAME_SZ : 0));
 685         child_trap_frame = (task_stack_page(p) +
 686                             (THREAD_SIZE - child_stack_sz));
 687         memcpy(child_trap_frame, parent_sf, child_stack_sz);
 688
 689         t->flags = (t->flags & ~((0xffUL << TI_FLAG_CWP_SHIFT) |
 690                                  (0xffUL << TI_FLAG_CURRENT_DS_SHIFT))) |
 691                 (((regs->tstate + 1) & TSTATE_CWP) << TI_FLAG_CWP_SHIFT);
 692         t->new_child = 1;
 693         t->ksp = ((unsigned long) child_trap_frame) - STACK_BIAS;
 694         t->kregs = (struct pt_regs *) (child_trap_frame +
 695                                        sizeof(struct sparc_stackf));
 696         t->fpsaved[0] = 0;
 697
 698         if (kernel_thread) {
 699                 struct sparc_stackf *child_sf = (struct sparc_stackf *)
 700                         (child_trap_frame + (STACKFRAME_SZ + TRACEREG_SZ));
 701
 702                 /* Zero terminate the stack backtrace.  */
 703                 child_sf->fp = NULL;
 704                 t->kregs->u_regs[UREG_FP] =
 705                   ((unsigned long) child_sf) - STACK_BIAS;
 706
 707                 /* Special case, if we are spawning a kernel thread from
 708                  * a userspace task (usermode helper, NFS or similar), we
 709                  * must disable performance counters in the child because
 710                  * the address space and protection realm are changing.
 711                  */
 712                 if (t->flags & _TIF_PERFCTR) {
 713                         t->user_cntd0 = t->user_cntd1 = NULL;
 714                         t->pcr_reg = 0;
 715                         t->flags &= ~_TIF_PERFCTR;
 716                 }
 717                 t->flags |= ((long)ASI_P << TI_FLAG_CURRENT_DS_SHIFT);
 718                 t->kregs->u_regs[UREG_G6] = (unsigned long) t;
 719                 t->kregs->u_regs[UREG_G4] = (unsigned long) t->task;
 720         } else {
 721                 if (t->flags & _TIF_32BIT) {
 722                         sp &= 0x00000000ffffffffUL;
 723                         regs->u_regs[UREG_FP] &= 0x00000000ffffffffUL;
 724                 }
 725                 t->kregs->u_regs[UREG_FP] = sp;
 726                 t->flags |= ((long)ASI_AIUS << TI_FLAG_CURRENT_DS_SHIFT);
 727                 if (sp != regs->u_regs[UREG_FP]) {
 728                         unsigned long csp;
 729
 730                         csp = clone_stackframe(sp, regs->u_regs[UREG_FP]);
 731                         if (!csp)
 732                                 return -EFAULT;
 733                         t->kregs->u_regs[UREG_FP] = csp;
 734                 }
 735                 if (t->utraps)
 736                         t->utraps[0]++;
 737         }
 738
 739         /* Set the return value for the child. */
 740         t->kregs->u_regs[UREG_I0] = current->pid;
 741         t->kregs->u_regs[UREG_I1] = 1;
 742
 743         /* Set the second return value for the parent. */
 744         regs->u_regs[UREG_I1] = 0;
 745
 746         if (clone_flags & CLONE_SETTLS)
 747                 t->kregs->u_regs[UREG_G7] = regs->u_regs[UREG_I3];
 748
 749         return 0;
 750 }
 751
 752 /*
 753  * This is the mechanism for creating a new kernel thread.
 754  *
 755  * NOTE! Only a kernel-only process(ie the swapper or direct descendants
 756  * who haven't done an "execve()") should use this: it will work within
 757  * a system call from a "real" process, but the process memory space will
 758  * not be freed until both the parent and the child have exited.
 759  */
 760 pid_t kernel_thread(int (*fn)(void *), void * arg, unsigned long flags)
 761 {
 762         long retval;
 763
 764         /* If the parent runs before fn(arg) is called by the child,
 765          * the input registers of this function can be clobbered.
 766          * So we stash 'fn' and 'arg' into global registers which
 767          * will not be modified by the parent.
 768          */
 769         __asm__ __volatile__("mov %4, %%g2\n\t"    /* Save FN into global */
 770                              "mov %5, %%g3\n\t"    /* Save ARG into global */
 771                              "mov %1, %%g1\n\t"    /* Clone syscall nr. */
 772                              "mov %2, %%o0\n\t"    /* Clone flags. */
 773                              "mov 0, %%o1\n\t"     /* usp arg == 0 */
 774                              "t 0x6d\n\t"          /* Linux/Sparc clone(). */
 775                              "brz,a,pn %%o1, 1f\n\t" /* Parent, just return. */
 776                              " mov %%o0, %0\n\t"
 777                              "jmpl %%g2, %%o7\n\t"   /* Call the function. */
 778                              " mov %%g3, %%o0\n\t"   /* Set arg in delay. */
 779                              "mov %3, %%g1\n\t"
 780                              "t 0x6d\n\t"          /* Linux/Sparc exit(). */
 781                              /* Notreached by child. */
 782                              "1:" :
 783                              "=r" (retval) :
 784                              "i" (__NR_clone), "r" (flags | CLONE_VM | CLONE_UNTRACED),
 785                              "i" (__NR_exit),  "r" (fn), "r" (arg) :
 786                              "g1", "g2", "g3", "o0", "o1", "memory", "cc");
 787         return retval;
 788 }
 789
 790 typedef struct {
 791         union {
 792                 unsigned int    pr_regs[32];
 793                 unsigned long   pr_dregs[16];
 794         } pr_fr;
 795         unsigned int __unused;
 796         unsigned int    pr_fsr;
 797         unsigned char   pr_qcnt;
 798         unsigned char   pr_q_entrysize;
 799         unsigned char   pr_en;
 800         unsigned int    pr_q[64];
 801 } elf_fpregset_t32;
 802
 803 /*
 804  * fill in the fpu structure for a core dump.
 805  */
 806 int dump_fpu (struct pt_regs * regs, elf_fpregset_t * fpregs)
 807 {
 808         unsigned long *kfpregs = current_thread_info()->fpregs;
 809         unsigned long fprs = current_thread_info()->fpsaved[0];
 810
 811         if (test_thread_flag(TIF_32BIT)) {
 812                 elf_fpregset_t32 *fpregs32 = (elf_fpregset_t32 *)fpregs;
 813
 814                 if (fprs & FPRS_DL)
 815                         memcpy(&fpregs32->pr_fr.pr_regs[0], kfpregs,
 816                                sizeof(unsigned int) * 32);
 817                 else
 818                         memset(&fpregs32->pr_fr.pr_regs[0], 0,
 819                                sizeof(unsigned int) * 32);
 820                 fpregs32->pr_qcnt = 0;
 821                 fpregs32->pr_q_entrysize = 8;
 822                 memset(&fpregs32->pr_q[0], 0,
 823                        (sizeof(unsigned int) * 64));
 824                 if (fprs & FPRS_FEF) {
 825                         fpregs32->pr_fsr = (unsigned int) current_thread_info()->xfsr[0];
 826                         fpregs32->pr_en = 1;
 827                 } else {
 828                         fpregs32->pr_fsr = 0;
 829                         fpregs32->pr_en = 0;
 830                 }
 831         } else {
 832                 if(fprs & FPRS_DL)
 833                         memcpy(&fpregs->pr_regs[0], kfpregs,
 834                                sizeof(unsigned int) * 32);
 835                 else
 836                         memset(&fpregs->pr_regs[0], 0,
 837                                sizeof(unsigned int) * 32);
 838                 if(fprs & FPRS_DU)
 839                         memcpy(&fpregs->pr_regs[16], kfpregs+16,
 840                                sizeof(unsigned int) * 32);
 841                 else
 842                         memset(&fpregs->pr_regs[16], 0,
 843                                sizeof(unsigned int) * 32);
 844                 if(fprs & FPRS_FEF) {
 845                         fpregs->pr_fsr = current_thread_info()->xfsr[0];
 846                         fpregs->pr_gsr = current_thread_info()->gsr[0];
 847                 } else {
 848                         fpregs->pr_fsr = fpregs->pr_gsr = 0;
 849                 }
 850                 fpregs->pr_fprs = fprs;
 851         }
 852         return 1;
 853 }
 854
 855 /*
 856  * sparc_execve() executes a new program after the asm stub has set
 857  * things up for us.  This should basically do what I want it to.
 858  */
 859 asmlinkage int sparc_execve(struct pt_regs *regs)
 860 {
 861         int error, base = 0;
 862         char *filename;
 863
 864         /* User register window flush is done by entry.S */
 865
 866         /* Check for indirect call. */
 867         if (regs->u_regs[UREG_G1] == 0)
 868                 base = 1;
 869
 870         filename = getname((char __user *)regs->u_regs[base + UREG_I0]);
 871         error = PTR_ERR(filename);
 872         if (IS_ERR(filename))
 873                 goto out;
 874         error = do_execve(filename,
 875                           (char __user * __user *)
 876                           regs->u_regs[base + UREG_I1],
 877                           (char __user * __user *)
 878                           regs->u_regs[base + UREG_I2], regs);
 879         putname(filename);
 880         if (!error) {
 881                 fprs_write(0);
 882                 current_thread_info()->xfsr[0] = 0;
 883                 current_thread_info()->fpsaved[0] = 0;
 884                 regs->tstate &= ~TSTATE_PEF;
 885         }
 886 out:
 887         return error;
 888 }
 889
 890 unsigned long get_wchan(struct task_struct *task)
 891 {
 892         unsigned long pc, fp, bias = 0;
 893         unsigned long thread_info_base;
 894         struct reg_window *rw;
 895         unsigned long ret = 0;
 896         int count = 0;
 897
 898         if (!task || task == current ||
 899             task->state == TASK_RUNNING)
 900                 goto out;
 901
 902         thread_info_base = (unsigned long) task_stack_page(task);
 903         bias = STACK_BIAS;
 904         fp = task_thread_info(task)->ksp + bias;
 905
 906         do {
 907                 /* Bogus frame pointer? */
 908                 if (fp < (thread_info_base + sizeof(struct thread_info)) ||
 909                     fp >= (thread_info_base + THREAD_SIZE))
 910                         break;
 911                 rw = (struct reg_window *) fp;
 912                 pc = rw->ins[7];
 913                 if (!in_sched_functions(pc)) {
 914                         ret = pc;
 915                         goto out;
 916                 }
 917                 fp = rw->ins[6] + bias;
 918         } while (++count < 16);
 919
 920 out:
 921         return ret;
 922 }