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   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/config.h>
  16 #include <linux/errno.h>
  17 #include <linux/module.h>
  18 #include <linux/sched.h>
  19 #include <linux/kernel.h>
  20 #include <linux/kallsyms.h>
  21 #include <linux/mm.h>
  22 #include <linux/smp.h>
  23 #include <linux/smp_lock.h>
  24 #include <linux/stddef.h>
  25 #include <linux/ptrace.h>
  26 #include <linux/slab.h>
  27 #include <linux/user.h>
  28 #include <linux/a.out.h>
  29 #include <linux/config.h>
  30 #include <linux/reboot.h>
  31 #include <linux/delay.h>
  32 #include <linux/compat.h>
  33 #include <linux/init.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/unistd.h>
  48
  49 /* #define VERBOSE_SHOWREGS */
  50
  51 /*
  52  * Nothing special yet...
  53  */
  54 void default_idle(void)
  55 {
  56 }
  57
  58 #ifndef CONFIG_SMP
  59
  60 /*
  61  * the idle loop on a Sparc... ;)
  62  */
  63 void cpu_idle(void)
  64 {
  65         /* endless idle loop with no priority at all */
  66         for (;;) {
  67                 /* If current->work.need_resched is zero we should really
  68                  * setup for a system wakup event and execute a shutdown
  69                  * instruction.
  70                  *
  71                  * But this requires writing back the contents of the
  72                  * L2 cache etc. so implement this later. -DaveM
  73                  */
  74                 while (!need_resched())
  75                         barrier();
  76
  77                 preempt_enable_no_resched();
  78                 schedule();
  79                 preempt_disable();
  80                 check_pgt_cache();
  81         }
  82 }
  83
  84 #else
  85
  86 /*
  87  * the idle loop on a UltraMultiPenguin...
  88  *
  89  * TIF_POLLING_NRFLAG is set because we do not sleep the cpu
  90  * inside of the idler task, so an interrupt is not needed
  91  * to get a clean fast response.
  92  *
  93  * XXX Reverify this assumption... -DaveM
  94  *
  95  * Addendum: We do want it to do something for the signal
  96  *           delivery case, we detect that by just seeing
  97  *           if we are trying to send this to an idler or not.
  98  */
  99 void cpu_idle(void)
 100 {
 101         cpuinfo_sparc *cpuinfo = &local_cpu_data();
 102         set_thread_flag(TIF_POLLING_NRFLAG);
 103
 104         while(1) {
 105                 if (need_resched()) {
 106                         cpuinfo->idle_volume = 0;
 107                         preempt_enable_no_resched();
 108                         schedule();
 109                         preempt_disable();
 110                         check_pgt_cache();
 111                 }
 112                 cpuinfo->idle_volume++;
 113
 114                 /* The store ordering is so that IRQ handlers on
 115                  * other cpus see our increasing idleness for the buddy
 116                  * redistribution algorithm.  -DaveM
 117                  */
 118                 membar_storeload_storestore();
 119         }
 120 }
 121
 122 #endif
 123
 124 extern char reboot_command [];
 125
 126 extern void (*prom_palette)(int);
 127 extern void (*prom_keyboard)(void);
 128
 129 void machine_halt(void)
 130 {
 131         if (!serial_console && prom_palette)
 132                 prom_palette (1);
 133         if (prom_keyboard)
 134                 prom_keyboard();
 135         prom_halt();
 136         panic("Halt failed!");
 137 }
 138
 139 void machine_alt_power_off(void)
 140 {
 141         if (!serial_console && prom_palette)
 142                 prom_palette(1);
 143         if (prom_keyboard)
 144                 prom_keyboard();
 145         prom_halt_power_off();
 146         panic("Power-off failed!");
 147 }
 148
 149 void machine_restart(char * cmd)
 150 {
 151         char *p;
 152
 153         p = strchr (reboot_command, '\n');
 154         if (p) *p = 0;
 155         if (!serial_console && prom_palette)
 156                 prom_palette (1);
 157         if (prom_keyboard)
 158                 prom_keyboard();
 159         if (cmd)
 160                 prom_reboot(cmd);
 161         if (*reboot_command)
 162                 prom_reboot(reboot_command);
 163         prom_reboot("");
 164         panic("Reboot failed!");
 165 }
 166
 167 static void show_regwindow32(struct pt_regs *regs)
 168 {
 169         struct reg_window32 __user *rw;
 170         struct reg_window32 r_w;
 171         mm_segment_t old_fs;
 172
 173         __asm__ __volatile__ ("flushw");
 174         rw = compat_ptr((unsigned)regs->u_regs[14]);
 175         old_fs = get_fs();
 176         set_fs (USER_DS);
 177         if (copy_from_user (&r_w, rw, sizeof(r_w))) {
 178                 set_fs (old_fs);
 179                 return;
 180         }
 181
 182         set_fs (old_fs);
 183         printk("l0: %08x l1: %08x l2: %08x l3: %08x "
 184                "l4: %08x l5: %08x l6: %08x l7: %08x\n",
 185                r_w.locals[0], r_w.locals[1], r_w.locals[2], r_w.locals[3],
 186                r_w.locals[4], r_w.locals[5], r_w.locals[6], r_w.locals[7]);
 187         printk("i0: %08x i1: %08x i2: %08x i3: %08x "
 188                "i4: %08x i5: %08x i6: %08x i7: %08x\n",
 189                r_w.ins[0], r_w.ins[1], r_w.ins[2], r_w.ins[3],
 190                r_w.ins[4], r_w.ins[5], r_w.ins[6], r_w.ins[7]);
 191 }
 192
 193 static void show_regwindow(struct pt_regs *regs)
 194 {
 195         struct reg_window __user *rw;
 196         struct reg_window *rwk;
 197         struct reg_window r_w;
 198         mm_segment_t old_fs;
 199
 200         if ((regs->tstate & TSTATE_PRIV) || !(test_thread_flag(TIF_32BIT))) {
 201                 __asm__ __volatile__ ("flushw");
 202                 rw = (struct reg_window __user *)
 203                         (regs->u_regs[14] + STACK_BIAS);
 204                 rwk = (struct reg_window *)
 205                         (regs->u_regs[14] + STACK_BIAS);
 206                 if (!(regs->tstate & TSTATE_PRIV)) {
 207                         old_fs = get_fs();
 208                         set_fs (USER_DS);
 209                         if (copy_from_user (&r_w, rw, sizeof(r_w))) {
 210                                 set_fs (old_fs);
 211                                 return;
 212                         }
 213                         rwk = &r_w;
 214                         set_fs (old_fs);
 215                 }
 216         } else {
 217                 show_regwindow32(regs);
 218                 return;
 219         }
 220         printk("l0: %016lx l1: %016lx l2: %016lx l3: %016lx\n",
 221                rwk->locals[0], rwk->locals[1], rwk->locals[2], rwk->locals[3]);
 222         printk("l4: %016lx l5: %016lx l6: %016lx l7: %016lx\n",
 223                rwk->locals[4], rwk->locals[5], rwk->locals[6], rwk->locals[7]);
 224         printk("i0: %016lx i1: %016lx i2: %016lx i3: %016lx\n",
 225                rwk->ins[0], rwk->ins[1], rwk->ins[2], rwk->ins[3]);
 226         printk("i4: %016lx i5: %016lx i6: %016lx i7: %016lx\n",
 227                rwk->ins[4], rwk->ins[5], rwk->ins[6], rwk->ins[7]);
 228         if (regs->tstate & TSTATE_PRIV)
 229                 print_symbol("I7: <%s>\n", rwk->ins[7]);
 230 }
 231
 232 void show_stackframe(struct sparc_stackf *sf)
 233 {
 234         unsigned long size;
 235         unsigned long *stk;
 236         int i;
 237
 238         printk("l0: %016lx l1: %016lx l2: %016lx l3: %016lx\n"
 239                "l4: %016lx l5: %016lx l6: %016lx l7: %016lx\n",
 240                sf->locals[0], sf->locals[1], sf->locals[2], sf->locals[3],
 241                sf->locals[4], sf->locals[5], sf->locals[6], sf->locals[7]);
 242         printk("i0: %016lx i1: %016lx i2: %016lx i3: %016lx\n"
 243                "i4: %016lx i5: %016lx fp: %016lx ret_pc: %016lx\n",
 244                sf->ins[0], sf->ins[1], sf->ins[2], sf->ins[3],
 245                sf->ins[4], sf->ins[5], (unsigned long)sf->fp, sf->callers_pc);
 246         printk("sp: %016lx x0: %016lx x1: %016lx x2: %016lx\n"
 247                "x3: %016lx x4: %016lx x5: %016lx xx: %016lx\n",
 248                (unsigned long)sf->structptr, sf->xargs[0], sf->xargs[1],
 249                sf->xargs[2], sf->xargs[3], sf->xargs[4], sf->xargs[5],
 250                sf->xxargs[0]);
 251         size = ((unsigned long)sf->fp) - ((unsigned long)sf);
 252         size -= STACKFRAME_SZ;
 253         stk = (unsigned long *)((unsigned long)sf + STACKFRAME_SZ);
 254         i = 0;
 255         do {
 256                 printk("s%d: %016lx\n", i++, *stk++);
 257         } while ((size -= sizeof(unsigned long)));
 258 }
 259
 260 void show_stackframe32(struct sparc_stackf32 *sf)
 261 {
 262         unsigned long size;
 263         unsigned *stk;
 264         int i;
 265
 266         printk("l0: %08x l1: %08x l2: %08x l3: %08x\n",
 267                sf->locals[0], sf->locals[1], sf->locals[2], sf->locals[3]);
 268         printk("l4: %08x l5: %08x l6: %08x l7: %08x\n",
 269                sf->locals[4], sf->locals[5], sf->locals[6], sf->locals[7]);
 270         printk("i0: %08x i1: %08x i2: %08x i3: %08x\n",
 271                sf->ins[0], sf->ins[1], sf->ins[2], sf->ins[3]);
 272         printk("i4: %08x i5: %08x fp: %08x ret_pc: %08x\n",
 273                sf->ins[4], sf->ins[5], sf->fp, sf->callers_pc);
 274         printk("sp: %08x x0: %08x x1: %08x x2: %08x\n"
 275                "x3: %08x x4: %08x x5: %08x xx: %08x\n",
 276                sf->structptr, sf->xargs[0], sf->xargs[1],
 277                sf->xargs[2], sf->xargs[3], sf->xargs[4], sf->xargs[5],
 278                sf->xxargs[0]);
 279         size = ((unsigned long)sf->fp) - ((unsigned long)sf);
 280         size -= STACKFRAME32_SZ;
 281         stk = (unsigned *)((unsigned long)sf + STACKFRAME32_SZ);
 282         i = 0;
 283         do {
 284                 printk("s%d: %08x\n", i++, *stk++);
 285         } while ((size -= sizeof(unsigned)));
 286 }
 287
 288 #ifdef CONFIG_SMP
 289 static DEFINE_SPINLOCK(regdump_lock);
 290 #endif
 291
 292 void __show_regs(struct pt_regs * regs)
 293 {
 294 #ifdef CONFIG_SMP
 295         unsigned long flags;
 296
 297         /* Protect against xcall ipis which might lead to livelock on the lock */
 298         __asm__ __volatile__("rdpr      %%pstate, %0\n\t"
 299                              "wrpr      %0, %1, %%pstate"
 300                              : "=r" (flags)
 301                              : "i" (PSTATE_IE));
 302         spin_lock(&regdump_lock);
 303 #endif
 304         printk("TSTATE: %016lx TPC: %016lx TNPC: %016lx Y: %08x    %s\n", regs->tstate,
 305                regs->tpc, regs->tnpc, regs->y, print_tainted());
 306         print_symbol("TPC: <%s>\n", regs->tpc);
 307         printk("g0: %016lx g1: %016lx g2: %016lx g3: %016lx\n",
 308                regs->u_regs[0], regs->u_regs[1], regs->u_regs[2],
 309                regs->u_regs[3]);
 310         printk("g4: %016lx g5: %016lx g6: %016lx g7: %016lx\n",
 311                regs->u_regs[4], regs->u_regs[5], regs->u_regs[6],
 312                regs->u_regs[7]);
 313         printk("o0: %016lx o1: %016lx o2: %016lx o3: %016lx\n",
 314                regs->u_regs[8], regs->u_regs[9], regs->u_regs[10],
 315                regs->u_regs[11]);
 316         printk("o4: %016lx o5: %016lx sp: %016lx ret_pc: %016lx\n",
 317                regs->u_regs[12], regs->u_regs[13], regs->u_regs[14],
 318                regs->u_regs[15]);
 319         print_symbol("RPC: <%s>\n", regs->u_regs[15]);
 320         show_regwindow(regs);
 321 #ifdef CONFIG_SMP
 322         spin_unlock(&regdump_lock);
 323         __asm__ __volatile__("wrpr      %0, 0, %%pstate"
 324                              : : "r" (flags));
 325 #endif
 326 }
 327
 328 #ifdef VERBOSE_SHOWREGS
 329 static void idump_from_user (unsigned int *pc)
 330 {
 331         int i;
 332         int code;
 333
 334         if((((unsigned long) pc) & 3))
 335                 return;
 336
 337         pc -= 3;
 338         for(i = -3; i < 6; i++) {
 339                 get_user(code, pc);
 340                 printk("%c%08x%c",i?' ':'<',code,i?' ':'>');
 341                 pc++;
 342         }
 343         printk("\n");
 344 }
 345 #endif
 346
 347 void show_regs(struct pt_regs *regs)
 348 {
 349 #ifdef VERBOSE_SHOWREGS
 350         extern long etrap, etraptl1;
 351 #endif
 352         __show_regs(regs);
 353 #ifdef CONFIG_SMP
 354         {
 355                 extern void smp_report_regs(void);
 356
 357                 smp_report_regs();
 358         }
 359 #endif
 360
 361 #ifdef VERBOSE_SHOWREGS
 362         if (regs->tpc >= &etrap && regs->tpc < &etraptl1 &&
 363             regs->u_regs[14] >= (long)current - PAGE_SIZE &&
 364             regs->u_regs[14] < (long)current + 6 * PAGE_SIZE) {
 365                 printk ("*********parent**********\n");
 366                 __show_regs((struct pt_regs *)(regs->u_regs[14] + PTREGS_OFF));
 367                 idump_from_user(((struct pt_regs *)(regs->u_regs[14] + PTREGS_OFF))->tpc);
 368                 printk ("*********endpar**********\n");
 369         }
 370 #endif
 371 }
 372
 373 void show_regs32(struct pt_regs32 *regs)
 374 {
 375         printk("PSR: %08x PC: %08x NPC: %08x Y: %08x    %s\n", regs->psr,
 376                regs->pc, regs->npc, regs->y, print_tainted());
 377         printk("g0: %08x g1: %08x g2: %08x g3: %08x ",
 378                regs->u_regs[0], regs->u_regs[1], regs->u_regs[2],
 379                regs->u_regs[3]);
 380         printk("g4: %08x g5: %08x g6: %08x g7: %08x\n",
 381                regs->u_regs[4], regs->u_regs[5], regs->u_regs[6],
 382                regs->u_regs[7]);
 383         printk("o0: %08x o1: %08x o2: %08x o3: %08x ",
 384                regs->u_regs[8], regs->u_regs[9], regs->u_regs[10],
 385                regs->u_regs[11]);
 386         printk("o4: %08x o5: %08x sp: %08x ret_pc: %08x\n",
 387                regs->u_regs[12], regs->u_regs[13], regs->u_regs[14],
 388                regs->u_regs[15]);
 389 }
 390
 391 unsigned long thread_saved_pc(struct task_struct *tsk)
 392 {
 393         struct thread_info *ti = tsk->thread_info;
 394         unsigned long ret = 0xdeadbeefUL;
 395
 396         if (ti && ti->ksp) {
 397                 unsigned long *sp;
 398                 sp = (unsigned long *)(ti->ksp + STACK_BIAS);
 399                 if (((unsigned long)sp & (sizeof(long) - 1)) == 0UL &&
 400                     sp[14]) {
 401                         unsigned long *fp;
 402                         fp = (unsigned long *)(sp[14] + STACK_BIAS);
 403                         if (((unsigned long)fp & (sizeof(long) - 1)) == 0UL)
 404                                 ret = fp[15];
 405                 }
 406         }
 407         return ret;
 408 }
 409
 410 /* Free current thread data structures etc.. */
 411 void exit_thread(void)
 412 {
 413         struct thread_info *t = current_thread_info();
 414
 415         if (t->utraps) {
 416                 if (t->utraps[0] < 2)
 417                         kfree (t->utraps);
 418                 else
 419                         t->utraps[0]--;
 420         }
 421
 422         if (test_and_clear_thread_flag(TIF_PERFCTR)) {
 423                 t->user_cntd0 = t->user_cntd1 = NULL;
 424                 t->pcr_reg = 0;
 425                 write_pcr(0);
 426         }
 427 }
 428
 429 void flush_thread(void)
 430 {
 431         struct thread_info *t = current_thread_info();
 432
 433         if (t->flags & _TIF_ABI_PENDING)
 434                 t->flags ^= (_TIF_ABI_PENDING | _TIF_32BIT);
 435
 436         if (t->task->mm) {
 437                 unsigned long pgd_cache = 0UL;
 438                 if (test_thread_flag(TIF_32BIT)) {
 439                         struct mm_struct *mm = t->task->mm;
 440                         pgd_t *pgd0 = &mm->pgd[0];
 441                         pud_t *pud0 = pud_offset(pgd0, 0);
 442
 443                         if (pud_none(*pud0)) {
 444                                 pmd_t *page = pmd_alloc_one(mm, 0);
 445                                 pud_set(pud0, page);
 446                         }
 447                         pgd_cache = get_pgd_cache(pgd0);
 448                 }
 449                 __asm__ __volatile__("stxa %0, [%1] %2\n\t"
 450                                      "membar #Sync"
 451                                      : /* no outputs */
 452                                      : "r" (pgd_cache),
 453                                      "r" (TSB_REG),
 454                                      "i" (ASI_DMMU));
 455         }
 456         set_thread_wsaved(0);
 457
 458         /* Turn off performance counters if on. */
 459         if (test_and_clear_thread_flag(TIF_PERFCTR)) {
 460                 t->user_cntd0 = t->user_cntd1 = NULL;
 461                 t->pcr_reg = 0;
 462                 write_pcr(0);
 463         }
 464
 465         /* Clear FPU register state. */
 466         t->fpsaved[0] = 0;
 467
 468         if (get_thread_current_ds() != ASI_AIUS)
 469                 set_fs(USER_DS);
 470
 471         /* Init new signal delivery disposition. */
 472         clear_thread_flag(TIF_NEWSIGNALS);
 473 }
 474
 475 /* It's a bit more tricky when 64-bit tasks are involved... */
 476 static unsigned long clone_stackframe(unsigned long csp, unsigned long psp)
 477 {
 478         unsigned long fp, distance, rval;
 479
 480         if (!(test_thread_flag(TIF_32BIT))) {
 481                 csp += STACK_BIAS;
 482                 psp += STACK_BIAS;
 483                 __get_user(fp, &(((struct reg_window __user *)psp)->ins[6]));
 484                 fp += STACK_BIAS;
 485         } else
 486                 __get_user(fp, &(((struct reg_window32 __user *)psp)->ins[6]));
 487
 488         /* Now 8-byte align the stack as this is mandatory in the
 489          * Sparc ABI due to how register windows work.  This hides
 490          * the restriction from thread libraries etc.  -DaveM
 491          */
 492         csp &= ~7UL;
 493
 494         distance = fp - psp;
 495         rval = (csp - distance);
 496         if (copy_in_user((void __user *) rval, (void __user *) psp, distance))
 497                 rval = 0;
 498         else if (test_thread_flag(TIF_32BIT)) {
 499                 if (put_user(((u32)csp),
 500                              &(((struct reg_window32 __user *)rval)->ins[6])))
 501                         rval = 0;
 502         } else {
 503                 if (put_user(((u64)csp - STACK_BIAS),
 504                              &(((struct reg_window __user *)rval)->ins[6])))
 505                         rval = 0;
 506                 else
 507                         rval = rval - STACK_BIAS;
 508         }
 509
 510         return rval;
 511 }
 512
 513 /* Standard stuff. */
 514 static inline void shift_window_buffer(int first_win, int last_win,
 515                                        struct thread_info *t)
 516 {
 517         int i;
 518
 519         for (i = first_win; i < last_win; i++) {
 520                 t->rwbuf_stkptrs[i] = t->rwbuf_stkptrs[i+1];
 521                 memcpy(&t->reg_window[i], &t->reg_window[i+1],
 522                        sizeof(struct reg_window));
 523         }
 524 }
 525
 526 void synchronize_user_stack(void)
 527 {
 528         struct thread_info *t = current_thread_info();
 529         unsigned long window;
 530
 531         flush_user_windows();
 532         if ((window = get_thread_wsaved()) != 0) {
 533                 int winsize = sizeof(struct reg_window);
 534                 int bias = 0;
 535
 536                 if (test_thread_flag(TIF_32BIT))
 537                         winsize = sizeof(struct reg_window32);
 538                 else
 539                         bias = STACK_BIAS;
 540
 541                 window -= 1;
 542                 do {
 543                         unsigned long sp = (t->rwbuf_stkptrs[window] + bias);
 544                         struct reg_window *rwin = &t->reg_window[window];
 545
 546                         if (!copy_to_user((char __user *)sp, rwin, winsize)) {
 547                                 shift_window_buffer(window, get_thread_wsaved() - 1, t);
 548                                 set_thread_wsaved(get_thread_wsaved() - 1);
 549                         }
 550                 } while (window--);
 551         }
 552 }
 553
 554 void fault_in_user_windows(void)
 555 {
 556         struct thread_info *t = current_thread_info();
 557         unsigned long window;
 558         int winsize = sizeof(struct reg_window);
 559         int bias = 0;
 560
 561         if (test_thread_flag(TIF_32BIT))
 562                 winsize = sizeof(struct reg_window32);
 563         else
 564                 bias = STACK_BIAS;
 565
 566         flush_user_windows();
 567         window = get_thread_wsaved();
 568
 569         if (window != 0) {
 570                 window -= 1;
 571                 do {
 572                         unsigned long sp = (t->rwbuf_stkptrs[window] + bias);
 573                         struct reg_window *rwin = &t->reg_window[window];
 574
 575                         if (copy_to_user((char __user *)sp, rwin, winsize))
 576                                 goto barf;
 577                 } while (window--);
 578         }
 579         set_thread_wsaved(0);
 580         return;
 581
 582 barf:
 583         set_thread_wsaved(window + 1);
 584         do_exit(SIGILL);
 585 }
 586
 587 asmlinkage long sparc_do_fork(unsigned long clone_flags,
 588                               unsigned long stack_start,
 589                               struct pt_regs *regs,
 590                               unsigned long stack_size)
 591 {
 592         int __user *parent_tid_ptr, *child_tid_ptr;
 593
 594 #ifdef CONFIG_COMPAT
 595         if (test_thread_flag(TIF_32BIT)) {
 596                 parent_tid_ptr = compat_ptr(regs->u_regs[UREG_I2]);
 597                 child_tid_ptr = compat_ptr(regs->u_regs[UREG_I4]);
 598         } else
 599 #endif
 600         {
 601                 parent_tid_ptr = (int __user *) regs->u_regs[UREG_I2];
 602                 child_tid_ptr = (int __user *) regs->u_regs[UREG_I4];
 603         }
 604
 605         return do_fork(clone_flags, stack_start,
 606                        regs, stack_size,
 607                        parent_tid_ptr, child_tid_ptr);
 608 }
 609
 610 /* Copy a Sparc thread.  The fork() return value conventions
 611  * under SunOS are nothing short of bletcherous:
 612  * Parent -->  %o0 == childs  pid, %o1 == 0
 613  * Child  -->  %o0 == parents pid, %o1 == 1
 614  */
 615 int copy_thread(int nr, unsigned long clone_flags, unsigned long sp,
 616                 unsigned long unused,
 617                 struct task_struct *p, struct pt_regs *regs)
 618 {
 619         struct thread_info *t = p->thread_info;
 620         char *child_trap_frame;
 621
 622         /* Calculate offset to stack_frame & pt_regs */
 623         child_trap_frame = ((char *)t) + (THREAD_SIZE - (TRACEREG_SZ+STACKFRAME_SZ));
 624         memcpy(child_trap_frame, (((struct sparc_stackf *)regs)-1), (TRACEREG_SZ+STACKFRAME_SZ));
 625
 626         t->flags = (t->flags & ~((0xffUL << TI_FLAG_CWP_SHIFT) | (0xffUL << TI_FLAG_CURRENT_DS_SHIFT))) |
 627                 (((regs->tstate + 1) & TSTATE_CWP) << TI_FLAG_CWP_SHIFT);
 628         t->new_child = 1;
 629         t->ksp = ((unsigned long) child_trap_frame) - STACK_BIAS;
 630         t->kregs = (struct pt_regs *)(child_trap_frame+sizeof(struct sparc_stackf));
 631         t->fpsaved[0] = 0;
 632
 633         if (regs->tstate & TSTATE_PRIV) {
 634                 /* Special case, if we are spawning a kernel thread from
 635                  * a userspace task (via KMOD, NFS, or similar) we must
 636                  * disable performance counters in the child because the
 637                  * address space and protection realm are changing.
 638                  */
 639                 if (t->flags & _TIF_PERFCTR) {
 640                         t->user_cntd0 = t->user_cntd1 = NULL;
 641                         t->pcr_reg = 0;
 642                         t->flags &= ~_TIF_PERFCTR;
 643                 }
 644                 t->kregs->u_regs[UREG_FP] = t->ksp;
 645                 t->flags |= ((long)ASI_P << TI_FLAG_CURRENT_DS_SHIFT);
 646                 flush_register_windows();
 647                 memcpy((void *)(t->ksp + STACK_BIAS),
 648                        (void *)(regs->u_regs[UREG_FP] + STACK_BIAS),
 649                        sizeof(struct sparc_stackf));
 650                 t->kregs->u_regs[UREG_G6] = (unsigned long) t;
 651                 t->kregs->u_regs[UREG_G4] = (unsigned long) t->task;
 652         } else {
 653                 if (t->flags & _TIF_32BIT) {
 654                         sp &= 0x00000000ffffffffUL;
 655                         regs->u_regs[UREG_FP] &= 0x00000000ffffffffUL;
 656                 }
 657                 t->kregs->u_regs[UREG_FP] = sp;
 658                 t->flags |= ((long)ASI_AIUS << TI_FLAG_CURRENT_DS_SHIFT);
 659                 if (sp != regs->u_regs[UREG_FP]) {
 660                         unsigned long csp;
 661
 662                         csp = clone_stackframe(sp, regs->u_regs[UREG_FP]);
 663                         if (!csp)
 664                                 return -EFAULT;
 665                         t->kregs->u_regs[UREG_FP] = csp;
 666                 }
 667                 if (t->utraps)
 668                         t->utraps[0]++;
 669         }
 670
 671         /* Set the return value for the child. */
 672         t->kregs->u_regs[UREG_I0] = current->pid;
 673         t->kregs->u_regs[UREG_I1] = 1;
 674
 675         /* Set the second return value for the parent. */
 676         regs->u_regs[UREG_I1] = 0;
 677
 678         if (clone_flags & CLONE_SETTLS)
 679                 t->kregs->u_regs[UREG_G7] = regs->u_regs[UREG_I3];
 680
 681         return 0;
 682 }
 683
 684 /*
 685  * This is the mechanism for creating a new kernel thread.
 686  *
 687  * NOTE! Only a kernel-only process(ie the swapper or direct descendants
 688  * who haven't done an "execve()") should use this: it will work within
 689  * a system call from a "real" process, but the process memory space will
 690  * not be free'd until both the parent and the child have exited.
 691  */
 692 pid_t kernel_thread(int (*fn)(void *), void * arg, unsigned long flags)
 693 {
 694         long retval;
 695
 696         /* If the parent runs before fn(arg) is called by the child,
 697          * the input registers of this function can be clobbered.
 698          * So we stash 'fn' and 'arg' into global registers which
 699          * will not be modified by the parent.
 700          */
 701         __asm__ __volatile__("mov %4, %%g2\n\t"    /* Save FN into global */
 702                              "mov %5, %%g3\n\t"    /* Save ARG into global */
 703                              "mov %1, %%g1\n\t"    /* Clone syscall nr. */
 704                              "mov %2, %%o0\n\t"    /* Clone flags. */
 705                              "mov 0, %%o1\n\t"     /* usp arg == 0 */
 706                              "t 0x6d\n\t"          /* Linux/Sparc clone(). */
 707                              "brz,a,pn %%o1, 1f\n\t" /* Parent, just return. */
 708                              " mov %%o0, %0\n\t"
 709                              "jmpl %%g2, %%o7\n\t"   /* Call the function. */
 710                              " mov %%g3, %%o0\n\t"   /* Set arg in delay. */
 711                              "mov %3, %%g1\n\t"
 712                              "t 0x6d\n\t"          /* Linux/Sparc exit(). */
 713                              /* Notreached by child. */
 714                              "1:" :
 715                              "=r" (retval) :
 716                              "i" (__NR_clone), "r" (flags | CLONE_VM | CLONE_UNTRACED),
 717                              "i" (__NR_exit),  "r" (fn), "r" (arg) :
 718                              "g1", "g2", "g3", "o0", "o1", "memory", "cc");
 719         return retval;
 720 }
 721
 722 /*
 723  * fill in the user structure for a core dump..
 724  */
 725 void dump_thread(struct pt_regs * regs, struct user * dump)
 726 {
 727         /* Only should be used for SunOS and ancient a.out
 728          * SparcLinux binaries...  Not worth implementing.
 729          */
 730         memset(dump, 0, sizeof(struct user));
 731 }
 732
 733 typedef struct {
 734         union {
 735                 unsigned int    pr_regs[32];
 736                 unsigned long   pr_dregs[16];
 737         } pr_fr;
 738         unsigned int __unused;
 739         unsigned int    pr_fsr;
 740         unsigned char   pr_qcnt;
 741         unsigned char   pr_q_entrysize;
 742         unsigned char   pr_en;
 743         unsigned int    pr_q[64];
 744 } elf_fpregset_t32;
 745
 746 /*
 747  * fill in the fpu structure for a core dump.
 748  */
 749 int dump_fpu (struct pt_regs * regs, elf_fpregset_t * fpregs)
 750 {
 751         unsigned long *kfpregs = current_thread_info()->fpregs;
 752         unsigned long fprs = current_thread_info()->fpsaved[0];
 753
 754         if (test_thread_flag(TIF_32BIT)) {
 755                 elf_fpregset_t32 *fpregs32 = (elf_fpregset_t32 *)fpregs;
 756
 757                 if (fprs & FPRS_DL)
 758                         memcpy(&fpregs32->pr_fr.pr_regs[0], kfpregs,
 759                                sizeof(unsigned int) * 32);
 760                 else
 761                         memset(&fpregs32->pr_fr.pr_regs[0], 0,
 762                                sizeof(unsigned int) * 32);
 763                 fpregs32->pr_qcnt = 0;
 764                 fpregs32->pr_q_entrysize = 8;
 765                 memset(&fpregs32->pr_q[0], 0,
 766                        (sizeof(unsigned int) * 64));
 767                 if (fprs & FPRS_FEF) {
 768                         fpregs32->pr_fsr = (unsigned int) current_thread_info()->xfsr[0];
 769                         fpregs32->pr_en = 1;
 770                 } else {
 771                         fpregs32->pr_fsr = 0;
 772                         fpregs32->pr_en = 0;
 773                 }
 774         } else {
 775                 if(fprs & FPRS_DL)
 776                         memcpy(&fpregs->pr_regs[0], kfpregs,
 777                                sizeof(unsigned int) * 32);
 778                 else
 779                         memset(&fpregs->pr_regs[0], 0,
 780                                sizeof(unsigned int) * 32);
 781                 if(fprs & FPRS_DU)
 782                         memcpy(&fpregs->pr_regs[16], kfpregs+16,
 783                                sizeof(unsigned int) * 32);
 784                 else
 785                         memset(&fpregs->pr_regs[16], 0,
 786                                sizeof(unsigned int) * 32);
 787                 if(fprs & FPRS_FEF) {
 788                         fpregs->pr_fsr = current_thread_info()->xfsr[0];
 789                         fpregs->pr_gsr = current_thread_info()->gsr[0];
 790                 } else {
 791                         fpregs->pr_fsr = fpregs->pr_gsr = 0;
 792                 }
 793                 fpregs->pr_fprs = fprs;
 794         }
 795         return 1;
 796 }
 797
 798 /*
 799  * sparc_execve() executes a new program after the asm stub has set
 800  * things up for us.  This should basically do what I want it to.
 801  */
 802 asmlinkage int sparc_execve(struct pt_regs *regs)
 803 {
 804         int error, base = 0;
 805         char *filename;
 806
 807         /* User register window flush is done by entry.S */
 808
 809         /* Check for indirect call. */
 810         if (regs->u_regs[UREG_G1] == 0)
 811                 base = 1;
 812
 813         filename = getname((char __user *)regs->u_regs[base + UREG_I0]);
 814         error = PTR_ERR(filename);
 815         if (IS_ERR(filename))
 816                 goto out;
 817         error = do_execve(filename,
 818                           (char __user * __user *)
 819                           regs->u_regs[base + UREG_I1],
 820                           (char __user * __user *)
 821                           regs->u_regs[base + UREG_I2], regs);
 822         putname(filename);
 823         if (!error) {
 824                 fprs_write(0);
 825                 current_thread_info()->xfsr[0] = 0;
 826                 current_thread_info()->fpsaved[0] = 0;
 827                 regs->tstate &= ~TSTATE_PEF;
 828                 task_lock(current);
 829                 current->ptrace &= ~PT_DTRACE;
 830                 task_unlock(current);
 831         }
 832 out:
 833         return error;
 834 }
 835
 836 unsigned long get_wchan(struct task_struct *task)
 837 {
 838         unsigned long pc, fp, bias = 0;
 839         unsigned long thread_info_base;
 840         struct reg_window *rw;
 841         unsigned long ret = 0;
 842         int count = 0;
 843
 844         if (!task || task == current ||
 845             task->state == TASK_RUNNING)
 846                 goto out;
 847
 848         thread_info_base = (unsigned long) task->thread_info;
 849         bias = STACK_BIAS;
 850         fp = task->thread_info->ksp + bias;
 851
 852         do {
 853                 /* Bogus frame pointer? */
 854                 if (fp < (thread_info_base + sizeof(struct thread_info)) ||
 855                     fp >= (thread_info_base + THREAD_SIZE))
 856                         break;
 857                 rw = (struct reg_window *) fp;
 858                 pc = rw->ins[7];
 859                 if (!in_sched_functions(pc)) {
 860                         ret = pc;
 861                         goto out;
 862                 }
 863                 fp = rw->ins[6] + bias;
 864         } while (++count < 16);
 865
 866 out:
 867         return ret;
 868 }