err.no Git - linux-2.6/blob - arch/sparc64/kernel/process.c

   1 /*  $Id: process.c,v 1.131 2002/02/09 19:49:30 davem Exp $
   2  *  arch/sparc64/kernel/process.c
   3  *
   4  *  Copyright (C) 1995, 1996 David S. Miller (davem@caip.rutgers.edu)
   5  *  Copyright (C) 1996       Eddie C. Dost   (ecd@skynet.be)
   6  *  Copyright (C) 1997, 1998 Jakub Jelinek   (jj@sunsite.mff.cuni.cz)
   7  */
   8
   9 /*
  10  * This file handles the architecture-dependent parts of process handling..
  11  */
  12
  13 #include <stdarg.h>
  14
  15 #include <linux/errno.h>
  16 #include <linux/module.h>
  17 #include <linux/sched.h>
  18 #include <linux/kernel.h>
  19 #include <linux/kallsyms.h>
  20 #include <linux/mm.h>
  21 #include <linux/fs.h>
  22 #include <linux/smp.h>
  23 #include <linux/stddef.h>
  24 #include <linux/ptrace.h>
  25 #include <linux/slab.h>
  26 #include <linux/user.h>
  27 #include <linux/reboot.h>
  28 #include <linux/delay.h>
  29 #include <linux/compat.h>
  30 #include <linux/tick.h>
  31 #include <linux/init.h>
  32 #include <linux/cpu.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
  52 /* #define VERBOSE_SHOWREGS */
  53
  54 static void sparc64_yield(int cpu)
  55 {
  56         if (tlb_type != hypervisor)
  57                 return;
  58
  59         clear_thread_flag(TIF_POLLING_NRFLAG);
  60         smp_mb__after_clear_bit();
  61
  62         while (!need_resched() && !cpu_is_offline(cpu)) {
  63                 unsigned long pstate;
  64
  65                 /* Disable interrupts. */
  66                 __asm__ __volatile__(
  67                         "rdpr %%pstate, %0\n\t"
  68                         "andn %0, %1, %0\n\t"
  69                         "wrpr %0, %%g0, %%pstate"
  70                         : "=&r" (pstate)
  71                         : "i" (PSTATE_IE));
  72
  73                 if (!need_resched() && !cpu_is_offline(cpu))
  74                         sun4v_cpu_yield();
  75
  76                 /* Re-enable interrupts. */
  77                 __asm__ __volatile__(
  78                         "rdpr %%pstate, %0\n\t"
  79                         "or %0, %1, %0\n\t"
  80                         "wrpr %0, %%g0, %%pstate"
  81                         : "=&r" (pstate)
  82                         : "i" (PSTATE_IE));
  83         }
  84
  85         set_thread_flag(TIF_POLLING_NRFLAG);
  86 }
  87
  88 /* The idle loop on sparc64. */
  89 void cpu_idle(void)
  90 {
  91         int cpu = smp_processor_id();
  92
  93         set_thread_flag(TIF_POLLING_NRFLAG);
  94
  95         while(1) {
  96                 tick_nohz_stop_sched_tick();
  97
  98                 while (!need_resched() && !cpu_is_offline(cpu))
  99                         sparc64_yield(cpu);
 100
 101                 tick_nohz_restart_sched_tick();
 102
 103                 preempt_enable_no_resched();
 104
 105 #ifdef CONFIG_HOTPLUG_CPU
 106                 if (cpu_is_offline(cpu))
 107                         cpu_play_dead();
 108 #endif
 109
 110                 schedule();
 111                 preempt_disable();
 112         }
 113 }
 114
 115 extern char reboot_command [];
 116
 117 void machine_halt(void)
 118 {
 119         sstate_halt();
 120         prom_halt();
 121         panic("Halt failed!");
 122 }
 123
 124 void machine_alt_power_off(void)
 125 {
 126         sstate_poweroff();
 127         prom_halt_power_off();
 128         panic("Power-off failed!");
 129 }
 130
 131 void machine_restart(char * cmd)
 132 {
 133         char *p;
 134
 135         sstate_reboot();
 136         p = strchr (reboot_command, '\n');
 137         if (p) *p = 0;
 138         if (cmd)
 139                 prom_reboot(cmd);
 140         if (*reboot_command)
 141                 prom_reboot(reboot_command);
 142         prom_reboot("");
 143         panic("Reboot failed!");
 144 }
 145
 146 #ifdef CONFIG_COMPAT
 147 static void show_regwindow32(struct pt_regs *regs)
 148 {
 149         struct reg_window32 __user *rw;
 150         struct reg_window32 r_w;
 151         mm_segment_t old_fs;
 152
 153         __asm__ __volatile__ ("flushw");
 154         rw = compat_ptr((unsigned)regs->u_regs[14]);
 155         old_fs = get_fs();
 156         set_fs (USER_DS);
 157         if (copy_from_user (&r_w, rw, sizeof(r_w))) {
 158                 set_fs (old_fs);
 159                 return;
 160         }
 161
 162         set_fs (old_fs);
 163         printk("l0: %08x l1: %08x l2: %08x l3: %08x "
 164                "l4: %08x l5: %08x l6: %08x l7: %08x\n",
 165                r_w.locals[0], r_w.locals[1], r_w.locals[2], r_w.locals[3],
 166                r_w.locals[4], r_w.locals[5], r_w.locals[6], r_w.locals[7]);
 167         printk("i0: %08x i1: %08x i2: %08x i3: %08x "
 168                "i4: %08x i5: %08x i6: %08x i7: %08x\n",
 169                r_w.ins[0], r_w.ins[1], r_w.ins[2], r_w.ins[3],
 170                r_w.ins[4], r_w.ins[5], r_w.ins[6], r_w.ins[7]);
 171 }
 172 #else
 173 #define show_regwindow32(regs)  do { } while (0)
 174 #endif
 175
 176 static void show_regwindow(struct pt_regs *regs)
 177 {
 178         struct reg_window __user *rw;
 179         struct reg_window *rwk;
 180         struct reg_window r_w;
 181         mm_segment_t old_fs;
 182
 183         if ((regs->tstate & TSTATE_PRIV) || !(test_thread_flag(TIF_32BIT))) {
 184                 __asm__ __volatile__ ("flushw");
 185                 rw = (struct reg_window __user *)
 186                         (regs->u_regs[14] + STACK_BIAS);
 187                 rwk = (struct reg_window *)
 188                         (regs->u_regs[14] + STACK_BIAS);
 189                 if (!(regs->tstate & TSTATE_PRIV)) {
 190                         old_fs = get_fs();
 191                         set_fs (USER_DS);
 192                         if (copy_from_user (&r_w, rw, sizeof(r_w))) {
 193                                 set_fs (old_fs);
 194                                 return;
 195                         }
 196                         rwk = &r_w;
 197                         set_fs (old_fs);
 198                 }
 199         } else {
 200                 show_regwindow32(regs);
 201                 return;
 202         }
 203         printk("l0: %016lx l1: %016lx l2: %016lx l3: %016lx\n",
 204                rwk->locals[0], rwk->locals[1], rwk->locals[2], rwk->locals[3]);
 205         printk("l4: %016lx l5: %016lx l6: %016lx l7: %016lx\n",
 206                rwk->locals[4], rwk->locals[5], rwk->locals[6], rwk->locals[7]);
 207         printk("i0: %016lx i1: %016lx i2: %016lx i3: %016lx\n",
 208                rwk->ins[0], rwk->ins[1], rwk->ins[2], rwk->ins[3]);
 209         printk("i4: %016lx i5: %016lx i6: %016lx i7: %016lx\n",
 210                rwk->ins[4], rwk->ins[5], rwk->ins[6], rwk->ins[7]);
 211         if (regs->tstate & TSTATE_PRIV)
 212                 print_symbol("I7: <%s>\n", rwk->ins[7]);
 213 }
 214
 215 #ifdef CONFIG_SMP
 216 static DEFINE_SPINLOCK(regdump_lock);
 217 #endif
 218
 219 void __show_regs(struct pt_regs * regs)
 220 {
 221 #ifdef CONFIG_SMP
 222         unsigned long flags;
 223
 224         /* Protect against xcall ipis which might lead to livelock on the lock */
 225         __asm__ __volatile__("rdpr      %%pstate, %0\n\t"
 226                              "wrpr      %0, %1, %%pstate"
 227                              : "=r" (flags)
 228                              : "i" (PSTATE_IE));
 229         spin_lock(&regdump_lock);
 230 #endif
 231         printk("TSTATE: %016lx TPC: %016lx TNPC: %016lx Y: %08x    %s\n", regs->tstate,
 232                regs->tpc, regs->tnpc, regs->y, print_tainted());
 233         print_symbol("TPC: <%s>\n", regs->tpc);
 234         printk("g0: %016lx g1: %016lx g2: %016lx g3: %016lx\n",
 235                regs->u_regs[0], regs->u_regs[1], regs->u_regs[2],
 236                regs->u_regs[3]);
 237         printk("g4: %016lx g5: %016lx g6: %016lx g7: %016lx\n",
 238                regs->u_regs[4], regs->u_regs[5], regs->u_regs[6],
 239                regs->u_regs[7]);
 240         printk("o0: %016lx o1: %016lx o2: %016lx o3: %016lx\n",
 241                regs->u_regs[8], regs->u_regs[9], regs->u_regs[10],
 242                regs->u_regs[11]);
 243         printk("o4: %016lx o5: %016lx sp: %016lx ret_pc: %016lx\n",
 244                regs->u_regs[12], regs->u_regs[13], regs->u_regs[14],
 245                regs->u_regs[15]);
 246         print_symbol("RPC: <%s>\n", regs->u_regs[15]);
 247         show_regwindow(regs);
 248 #ifdef CONFIG_SMP
 249         spin_unlock(&regdump_lock);
 250         __asm__ __volatile__("wrpr      %0, 0, %%pstate"
 251                              : : "r" (flags));
 252 #endif
 253 }
 254
 255 #ifdef VERBOSE_SHOWREGS
 256 static void idump_from_user (unsigned int *pc)
 257 {
 258         int i;
 259         int code;
 260
 261         if((((unsigned long) pc) & 3))
 262                 return;
 263
 264         pc -= 3;
 265         for(i = -3; i < 6; i++) {
 266                 get_user(code, pc);
 267                 printk("%c%08x%c",i?' ':'<',code,i?' ':'>');
 268                 pc++;
 269         }
 270         printk("\n");
 271 }
 272 #endif
 273
 274 void show_regs(struct pt_regs *regs)
 275 {
 276 #ifdef VERBOSE_SHOWREGS
 277         extern long etrap, etraptl1;
 278 #endif
 279         __show_regs(regs);
 280 #if 0
 281 #ifdef CONFIG_SMP
 282         {
 283                 extern void smp_report_regs(void);
 284
 285                 smp_report_regs();
 286         }
 287 #endif
 288 #endif
 289
 290 #ifdef VERBOSE_SHOWREGS
 291         if (regs->tpc >= &etrap && regs->tpc < &etraptl1 &&
 292             regs->u_regs[14] >= (long)current - PAGE_SIZE &&
 293             regs->u_regs[14] < (long)current + 6 * PAGE_SIZE) {
 294                 printk ("*********parent**********\n");
 295                 __show_regs((struct pt_regs *)(regs->u_regs[14] + PTREGS_OFF));
 296                 idump_from_user(((struct pt_regs *)(regs->u_regs[14] + PTREGS_OFF))->tpc);
 297                 printk ("*********endpar**********\n");
 298         }
 299 #endif
 300 }
 301
 302 void show_regs32(struct pt_regs32 *regs)
 303 {
 304         printk("PSR: %08x PC: %08x NPC: %08x Y: %08x    %s\n", regs->psr,
 305                regs->pc, regs->npc, regs->y, print_tainted());
 306         printk("g0: %08x g1: %08x g2: %08x g3: %08x ",
 307                regs->u_regs[0], regs->u_regs[1], regs->u_regs[2],
 308                regs->u_regs[3]);
 309         printk("g4: %08x g5: %08x g6: %08x g7: %08x\n",
 310                regs->u_regs[4], regs->u_regs[5], regs->u_regs[6],
 311                regs->u_regs[7]);
 312         printk("o0: %08x o1: %08x o2: %08x o3: %08x ",
 313                regs->u_regs[8], regs->u_regs[9], regs->u_regs[10],
 314                regs->u_regs[11]);
 315         printk("o4: %08x o5: %08x sp: %08x ret_pc: %08x\n",
 316                regs->u_regs[12], regs->u_regs[13], regs->u_regs[14],
 317                regs->u_regs[15]);
 318 }
 319
 320 unsigned long thread_saved_pc(struct task_struct *tsk)
 321 {
 322         struct thread_info *ti = task_thread_info(tsk);
 323         unsigned long ret = 0xdeadbeefUL;
 324
 325         if (ti && ti->ksp) {
 326                 unsigned long *sp;
 327                 sp = (unsigned long *)(ti->ksp + STACK_BIAS);
 328                 if (((unsigned long)sp & (sizeof(long) - 1)) == 0UL &&
 329                     sp[14]) {
 330                         unsigned long *fp;
 331                         fp = (unsigned long *)(sp[14] + STACK_BIAS);
 332                         if (((unsigned long)fp & (sizeof(long) - 1)) == 0UL)
 333                                 ret = fp[15];
 334                 }
 335         }
 336         return ret;
 337 }
 338
 339 /* Free current thread data structures etc.. */
 340 void exit_thread(void)
 341 {
 342         struct thread_info *t = current_thread_info();
 343
 344         if (t->utraps) {
 345                 if (t->utraps[0] < 2)
 346                         kfree (t->utraps);
 347                 else
 348                         t->utraps[0]--;
 349         }
 350
 351         if (test_and_clear_thread_flag(TIF_PERFCTR)) {
 352                 t->user_cntd0 = t->user_cntd1 = NULL;
 353                 t->pcr_reg = 0;
 354                 write_pcr(0);
 355         }
 356 }
 357
 358 void flush_thread(void)
 359 {
 360         struct thread_info *t = current_thread_info();
 361         struct mm_struct *mm;
 362
 363         if (test_ti_thread_flag(t, TIF_ABI_PENDING)) {
 364                 clear_ti_thread_flag(t, TIF_ABI_PENDING);
 365                 if (test_ti_thread_flag(t, TIF_32BIT))
 366                         clear_ti_thread_flag(t, TIF_32BIT);
 367                 else
 368                         set_ti_thread_flag(t, TIF_32BIT);
 369         }
 370
 371         mm = t->task->mm;
 372         if (mm)
 373                 tsb_context_switch(mm);
 374
 375         set_thread_wsaved(0);
 376
 377         /* Turn off performance counters if on. */
 378         if (test_and_clear_thread_flag(TIF_PERFCTR)) {
 379                 t->user_cntd0 = t->user_cntd1 = NULL;
 380                 t->pcr_reg = 0;
 381                 write_pcr(0);
 382         }
 383
 384         /* Clear FPU register state. */
 385         t->fpsaved[0] = 0;
 386
 387         if (get_thread_current_ds() != ASI_AIUS)
 388                 set_fs(USER_DS);
 389
 390         /* Init new signal delivery disposition. */
 391         clear_thread_flag(TIF_NEWSIGNALS);
 392 }
 393
 394 /* It's a bit more tricky when 64-bit tasks are involved... */
 395 static unsigned long clone_stackframe(unsigned long csp, unsigned long psp)
 396 {
 397         unsigned long fp, distance, rval;
 398
 399         if (!(test_thread_flag(TIF_32BIT))) {
 400                 csp += STACK_BIAS;
 401                 psp += STACK_BIAS;
 402                 __get_user(fp, &(((struct reg_window __user *)psp)->ins[6]));
 403                 fp += STACK_BIAS;
 404         } else
 405                 __get_user(fp, &(((struct reg_window32 __user *)psp)->ins[6]));
 406
 407         /* Now 8-byte align the stack as this is mandatory in the
 408          * Sparc ABI due to how register windows work.  This hides
 409          * the restriction from thread libraries etc.  -DaveM
 410          */
 411         csp &= ~7UL;
 412
 413         distance = fp - psp;
 414         rval = (csp - distance);
 415         if (copy_in_user((void __user *) rval, (void __user *) psp, distance))
 416                 rval = 0;
 417         else if (test_thread_flag(TIF_32BIT)) {
 418                 if (put_user(((u32)csp),
 419                              &(((struct reg_window32 __user *)rval)->ins[6])))
 420                         rval = 0;
 421         } else {
 422                 if (put_user(((u64)csp - STACK_BIAS),
 423                              &(((struct reg_window __user *)rval)->ins[6])))
 424                         rval = 0;
 425                 else
 426                         rval = rval - STACK_BIAS;
 427         }
 428
 429         return rval;
 430 }
 431
 432 /* Standard stuff. */
 433 static inline void shift_window_buffer(int first_win, int last_win,
 434                                        struct thread_info *t)
 435 {
 436         int i;
 437
 438         for (i = first_win; i < last_win; i++) {
 439                 t->rwbuf_stkptrs[i] = t->rwbuf_stkptrs[i+1];
 440                 memcpy(&t->reg_window[i], &t->reg_window[i+1],
 441                        sizeof(struct reg_window));
 442         }
 443 }
 444
 445 void synchronize_user_stack(void)
 446 {
 447         struct thread_info *t = current_thread_info();
 448         unsigned long window;
 449
 450         flush_user_windows();
 451         if ((window = get_thread_wsaved()) != 0) {
 452                 int winsize = sizeof(struct reg_window);
 453                 int bias = 0;
 454
 455                 if (test_thread_flag(TIF_32BIT))
 456                         winsize = sizeof(struct reg_window32);
 457                 else
 458                         bias = STACK_BIAS;
 459
 460                 window -= 1;
 461                 do {
 462                         unsigned long sp = (t->rwbuf_stkptrs[window] + bias);
 463                         struct reg_window *rwin = &t->reg_window[window];
 464
 465                         if (!copy_to_user((char __user *)sp, rwin, winsize)) {
 466                                 shift_window_buffer(window, get_thread_wsaved() - 1, t);
 467                                 set_thread_wsaved(get_thread_wsaved() - 1);
 468                         }
 469                 } while (window--);
 470         }
 471 }
 472
 473 static void stack_unaligned(unsigned long sp)
 474 {
 475         siginfo_t info;
 476
 477         info.si_signo = SIGBUS;
 478         info.si_errno = 0;
 479         info.si_code = BUS_ADRALN;
 480         info.si_addr = (void __user *) sp;
 481         info.si_trapno = 0;
 482         force_sig_info(SIGBUS, &info, current);
 483 }
 484
 485 void fault_in_user_windows(void)
 486 {
 487         struct thread_info *t = current_thread_info();
 488         unsigned long window;
 489         int winsize = sizeof(struct reg_window);
 490         int bias = 0;
 491
 492         if (test_thread_flag(TIF_32BIT))
 493                 winsize = sizeof(struct reg_window32);
 494         else
 495                 bias = STACK_BIAS;
 496
 497         flush_user_windows();
 498         window = get_thread_wsaved();
 499
 500         if (likely(window != 0)) {
 501                 window -= 1;
 502                 do {
 503                         unsigned long sp = (t->rwbuf_stkptrs[window] + bias);
 504                         struct reg_window *rwin = &t->reg_window[window];
 505
 506                         if (unlikely(sp & 0x7UL))
 507                                 stack_unaligned(sp);
 508
 509                         if (unlikely(copy_to_user((char __user *)sp,
 510                                                   rwin, winsize)))
 511                                 goto barf;
 512                 } while (window--);
 513         }
 514         set_thread_wsaved(0);
 515         return;
 516
 517 barf:
 518         set_thread_wsaved(window + 1);
 519         do_exit(SIGILL);
 520 }
 521
 522 asmlinkage long sparc_do_fork(unsigned long clone_flags,
 523                               unsigned long stack_start,
 524                               struct pt_regs *regs,
 525                               unsigned long stack_size)
 526 {
 527         int __user *parent_tid_ptr, *child_tid_ptr;
 528
 529 #ifdef CONFIG_COMPAT
 530         if (test_thread_flag(TIF_32BIT)) {
 531                 parent_tid_ptr = compat_ptr(regs->u_regs[UREG_I2]);
 532                 child_tid_ptr = compat_ptr(regs->u_regs[UREG_I4]);
 533         } else
 534 #endif
 535         {
 536                 parent_tid_ptr = (int __user *) regs->u_regs[UREG_I2];
 537                 child_tid_ptr = (int __user *) regs->u_regs[UREG_I4];
 538         }
 539
 540         return do_fork(clone_flags, stack_start,
 541                        regs, stack_size,
 542                        parent_tid_ptr, child_tid_ptr);
 543 }
 544
 545 /* Copy a Sparc thread.  The fork() return value conventions
 546  * under SunOS are nothing short of bletcherous:
 547  * Parent -->  %o0 == childs  pid, %o1 == 0
 548  * Child  -->  %o0 == parents pid, %o1 == 1
 549  */
 550 int copy_thread(int nr, unsigned long clone_flags, unsigned long sp,
 551                 unsigned long unused,
 552                 struct task_struct *p, struct pt_regs *regs)
 553 {
 554         struct thread_info *t = task_thread_info(p);
 555         char *child_trap_frame;
 556
 557         /* Calculate offset to stack_frame & pt_regs */
 558         child_trap_frame = task_stack_page(p) + (THREAD_SIZE - (TRACEREG_SZ+STACKFRAME_SZ));
 559         memcpy(child_trap_frame, (((struct sparc_stackf *)regs)-1), (TRACEREG_SZ+STACKFRAME_SZ));
 560
 561         t->flags = (t->flags & ~((0xffUL << TI_FLAG_CWP_SHIFT) | (0xffUL << TI_FLAG_CURRENT_DS_SHIFT))) |
 562                 (((regs->tstate + 1) & TSTATE_CWP) << TI_FLAG_CWP_SHIFT);
 563         t->new_child = 1;
 564         t->ksp = ((unsigned long) child_trap_frame) - STACK_BIAS;
 565         t->kregs = (struct pt_regs *)(child_trap_frame+sizeof(struct sparc_stackf));
 566         t->fpsaved[0] = 0;
 567
 568         if (regs->tstate & TSTATE_PRIV) {
 569                 /* Special case, if we are spawning a kernel thread from
 570                  * a userspace task (via KMOD, NFS, or similar) we must
 571                  * disable performance counters in the child because the
 572                  * address space and protection realm are changing.
 573                  */
 574                 if (t->flags & _TIF_PERFCTR) {
 575                         t->user_cntd0 = t->user_cntd1 = NULL;
 576                         t->pcr_reg = 0;
 577                         t->flags &= ~_TIF_PERFCTR;
 578                 }
 579                 t->kregs->u_regs[UREG_FP] = t->ksp;
 580                 t->flags |= ((long)ASI_P << TI_FLAG_CURRENT_DS_SHIFT);
 581                 flush_register_windows();
 582                 memcpy((void *)(t->ksp + STACK_BIAS),
 583                        (void *)(regs->u_regs[UREG_FP] + STACK_BIAS),
 584                        sizeof(struct sparc_stackf));
 585                 t->kregs->u_regs[UREG_G6] = (unsigned long) t;
 586                 t->kregs->u_regs[UREG_G4] = (unsigned long) t->task;
 587         } else {
 588                 if (t->flags & _TIF_32BIT) {
 589                         sp &= 0x00000000ffffffffUL;
 590                         regs->u_regs[UREG_FP] &= 0x00000000ffffffffUL;
 591                 }
 592                 t->kregs->u_regs[UREG_FP] = sp;
 593                 t->flags |= ((long)ASI_AIUS << TI_FLAG_CURRENT_DS_SHIFT);
 594                 if (sp != regs->u_regs[UREG_FP]) {
 595                         unsigned long csp;
 596
 597                         csp = clone_stackframe(sp, regs->u_regs[UREG_FP]);
 598                         if (!csp)
 599                                 return -EFAULT;
 600                         t->kregs->u_regs[UREG_FP] = csp;
 601                 }
 602                 if (t->utraps)
 603                         t->utraps[0]++;
 604         }
 605
 606         /* Set the return value for the child. */
 607         t->kregs->u_regs[UREG_I0] = current->pid;
 608         t->kregs->u_regs[UREG_I1] = 1;
 609
 610         /* Set the second return value for the parent. */
 611         regs->u_regs[UREG_I1] = 0;
 612
 613         if (clone_flags & CLONE_SETTLS)
 614                 t->kregs->u_regs[UREG_G7] = regs->u_regs[UREG_I3];
 615
 616         return 0;
 617 }
 618
 619 /*
 620  * This is the mechanism for creating a new kernel thread.
 621  *
 622  * NOTE! Only a kernel-only process(ie the swapper or direct descendants
 623  * who haven't done an "execve()") should use this: it will work within
 624  * a system call from a "real" process, but the process memory space will
 625  * not be freed until both the parent and the child have exited.
 626  */
 627 pid_t kernel_thread(int (*fn)(void *), void * arg, unsigned long flags)
 628 {
 629         long retval;
 630
 631         /* If the parent runs before fn(arg) is called by the child,
 632          * the input registers of this function can be clobbered.
 633          * So we stash 'fn' and 'arg' into global registers which
 634          * will not be modified by the parent.
 635          */
 636         __asm__ __volatile__("mov %4, %%g2\n\t"    /* Save FN into global */
 637                              "mov %5, %%g3\n\t"    /* Save ARG into global */
 638                              "mov %1, %%g1\n\t"    /* Clone syscall nr. */
 639                              "mov %2, %%o0\n\t"    /* Clone flags. */
 640                              "mov 0, %%o1\n\t"     /* usp arg == 0 */
 641                              "t 0x6d\n\t"          /* Linux/Sparc clone(). */
 642                              "brz,a,pn %%o1, 1f\n\t" /* Parent, just return. */
 643                              " mov %%o0, %0\n\t"
 644                              "jmpl %%g2, %%o7\n\t"   /* Call the function. */
 645                              " mov %%g3, %%o0\n\t"   /* Set arg in delay. */
 646                              "mov %3, %%g1\n\t"
 647                              "t 0x6d\n\t"          /* Linux/Sparc exit(). */
 648                              /* Notreached by child. */
 649                              "1:" :
 650                              "=r" (retval) :
 651                              "i" (__NR_clone), "r" (flags | CLONE_VM | CLONE_UNTRACED),
 652                              "i" (__NR_exit),  "r" (fn), "r" (arg) :
 653                              "g1", "g2", "g3", "o0", "o1", "memory", "cc");
 654         return retval;
 655 }
 656
 657 typedef struct {
 658         union {
 659                 unsigned int    pr_regs[32];
 660                 unsigned long   pr_dregs[16];
 661         } pr_fr;
 662         unsigned int __unused;
 663         unsigned int    pr_fsr;
 664         unsigned char   pr_qcnt;
 665         unsigned char   pr_q_entrysize;
 666         unsigned char   pr_en;
 667         unsigned int    pr_q[64];
 668 } elf_fpregset_t32;
 669
 670 /*
 671  * fill in the fpu structure for a core dump.
 672  */
 673 int dump_fpu (struct pt_regs * regs, elf_fpregset_t * fpregs)
 674 {
 675         unsigned long *kfpregs = current_thread_info()->fpregs;
 676         unsigned long fprs = current_thread_info()->fpsaved[0];
 677
 678         if (test_thread_flag(TIF_32BIT)) {
 679                 elf_fpregset_t32 *fpregs32 = (elf_fpregset_t32 *)fpregs;
 680
 681                 if (fprs & FPRS_DL)
 682                         memcpy(&fpregs32->pr_fr.pr_regs[0], kfpregs,
 683                                sizeof(unsigned int) * 32);
 684                 else
 685                         memset(&fpregs32->pr_fr.pr_regs[0], 0,
 686                                sizeof(unsigned int) * 32);
 687                 fpregs32->pr_qcnt = 0;
 688                 fpregs32->pr_q_entrysize = 8;
 689                 memset(&fpregs32->pr_q[0], 0,
 690                        (sizeof(unsigned int) * 64));
 691                 if (fprs & FPRS_FEF) {
 692                         fpregs32->pr_fsr = (unsigned int) current_thread_info()->xfsr[0];
 693                         fpregs32->pr_en = 1;
 694                 } else {
 695                         fpregs32->pr_fsr = 0;
 696                         fpregs32->pr_en = 0;
 697                 }
 698         } else {
 699                 if(fprs & FPRS_DL)
 700                         memcpy(&fpregs->pr_regs[0], kfpregs,
 701                                sizeof(unsigned int) * 32);
 702                 else
 703                         memset(&fpregs->pr_regs[0], 0,
 704                                sizeof(unsigned int) * 32);
 705                 if(fprs & FPRS_DU)
 706                         memcpy(&fpregs->pr_regs[16], kfpregs+16,
 707                                sizeof(unsigned int) * 32);
 708                 else
 709                         memset(&fpregs->pr_regs[16], 0,
 710                                sizeof(unsigned int) * 32);
 711                 if(fprs & FPRS_FEF) {
 712                         fpregs->pr_fsr = current_thread_info()->xfsr[0];
 713                         fpregs->pr_gsr = current_thread_info()->gsr[0];
 714                 } else {
 715                         fpregs->pr_fsr = fpregs->pr_gsr = 0;
 716                 }
 717                 fpregs->pr_fprs = fprs;
 718         }
 719         return 1;
 720 }
 721
 722 /*
 723  * sparc_execve() executes a new program after the asm stub has set
 724  * things up for us.  This should basically do what I want it to.
 725  */
 726 asmlinkage int sparc_execve(struct pt_regs *regs)
 727 {
 728         int error, base = 0;
 729         char *filename;
 730
 731         /* User register window flush is done by entry.S */
 732
 733         /* Check for indirect call. */
 734         if (regs->u_regs[UREG_G1] == 0)
 735                 base = 1;
 736
 737         filename = getname((char __user *)regs->u_regs[base + UREG_I0]);
 738         error = PTR_ERR(filename);
 739         if (IS_ERR(filename))
 740                 goto out;
 741         error = do_execve(filename,
 742                           (char __user * __user *)
 743                           regs->u_regs[base + UREG_I1],
 744                           (char __user * __user *)
 745                           regs->u_regs[base + UREG_I2], regs);
 746         putname(filename);
 747         if (!error) {
 748                 fprs_write(0);
 749                 current_thread_info()->xfsr[0] = 0;
 750                 current_thread_info()->fpsaved[0] = 0;
 751                 regs->tstate &= ~TSTATE_PEF;
 752                 task_lock(current);
 753                 current->ptrace &= ~PT_DTRACE;
 754                 task_unlock(current);
 755         }
 756 out:
 757         return error;
 758 }
 759
 760 unsigned long get_wchan(struct task_struct *task)
 761 {
 762         unsigned long pc, fp, bias = 0;
 763         unsigned long thread_info_base;
 764         struct reg_window *rw;
 765         unsigned long ret = 0;
 766         int count = 0;
 767
 768         if (!task || task == current ||
 769             task->state == TASK_RUNNING)
 770                 goto out;
 771
 772         thread_info_base = (unsigned long) task_stack_page(task);
 773         bias = STACK_BIAS;
 774         fp = task_thread_info(task)->ksp + bias;
 775
 776         do {
 777                 /* Bogus frame pointer? */
 778                 if (fp < (thread_info_base + sizeof(struct thread_info)) ||
 779                     fp >= (thread_info_base + THREAD_SIZE))
 780                         break;
 781                 rw = (struct reg_window *) fp;
 782                 pc = rw->ins[7];
 783                 if (!in_sched_functions(pc)) {
 784                         ret = pc;
 785                         goto out;
 786                 }
 787                 fp = rw->ins[6] + bias;
 788         } while (++count < 16);
 789
 790 out:
 791         return ret;
 792 }