arch/sh64/kernel/process.c

   1 /*
   2  * This file is subject to the terms and conditions of the GNU General Public
   3  * License.  See the file "COPYING" in the main directory of this archive
   4  * for more details.
   5  *
   6  * arch/sh64/kernel/process.c
   7  *
   8  * Copyright (C) 2000, 2001  Paolo Alberelli
   9  * Copyright (C) 2003  Paul Mundt
  10  * Copyright (C) 2003, 2004 Richard Curnow
  11  *
  12  * Started from SH3/4 version:
  13  *   Copyright (C) 1999, 2000  Niibe Yutaka & Kaz Kojima
  14  *
  15  *   In turn started from i386 version:
  16  *     Copyright (C) 1995  Linus Torvalds
  17  *
  18  */
  19
  20 /*
  21  * This file handles the architecture-dependent parts of process handling..
  22  */
  23 #include <linux/mm.h>
  24 #include <linux/ptrace.h>
  25 #include <linux/reboot.h>
  26 #include <linux/init.h>
  27 #include <linux/module.h>
  28 #include <asm/uaccess.h>
  29 #include <asm/pgtable.h>
  30
  31 struct task_struct *last_task_used_math = NULL;
  32
  33 static int hlt_counter = 1;
  34
  35 #define HARD_IDLE_TIMEOUT (HZ / 3)
  36
  37 void disable_hlt(void)
  38 {
  39         hlt_counter++;
  40 }
  41
  42 void enable_hlt(void)
  43 {
  44         hlt_counter--;
  45 }
  46
  47 static int __init nohlt_setup(char *__unused)
  48 {
  49         hlt_counter = 1;
  50         return 1;
  51 }
  52
  53 static int __init hlt_setup(char *__unused)
  54 {
  55         hlt_counter = 0;
  56         return 1;
  57 }
  58
  59 __setup("nohlt", nohlt_setup);
  60 __setup("hlt", hlt_setup);
  61
  62 static inline void hlt(void)
  63 {
  64         __asm__ __volatile__ ("sleep" : : : "memory");
  65 }
  66
  67 /*
  68  * The idle loop on a uniprocessor SH..
  69  */
  70 void cpu_idle(void)
  71 {
  72         /* endless idle loop with no priority at all */
  73         while (1) {
  74                 if (hlt_counter) {
  75                         while (!need_resched())
  76                                 cpu_relax();
  77                 } else {
  78                         local_irq_disable();
  79                         while (!need_resched()) {
  80                                 local_irq_enable();
  81                                 hlt();
  82                                 local_irq_disable();
  83                         }
  84                         local_irq_enable();
  85                 }
  86                 preempt_enable_no_resched();
  87                 schedule();
  88                 preempt_disable();
  89         }
  90
  91 }
  92
  93 void machine_restart(char * __unused)
  94 {
  95         extern void phys_stext(void);
  96
  97         phys_stext();
  98 }
  99
 100 void machine_halt(void)
 101 {
 102         for (;;);
 103 }
 104
 105 void machine_power_off(void)
 106 {
 107         extern void enter_deep_standby(void);
 108
 109         enter_deep_standby();
 110 }
 111
 112 void (*pm_power_off)(void) = machine_power_off;
 113 EXPORT_SYMBOL(pm_power_off);
 114
 115 void show_regs(struct pt_regs * regs)
 116 {
 117         unsigned long long ah, al, bh, bl, ch, cl;
 118
 119         printk("\n");
 120
 121         ah = (regs->pc) >> 32;
 122         al = (regs->pc) & 0xffffffff;
 123         bh = (regs->regs[18]) >> 32;
 124         bl = (regs->regs[18]) & 0xffffffff;
 125         ch = (regs->regs[15]) >> 32;
 126         cl = (regs->regs[15]) & 0xffffffff;
 127         printk("PC  : %08Lx%08Lx LINK: %08Lx%08Lx SP  : %08Lx%08Lx\n",
 128                ah, al, bh, bl, ch, cl);
 129
 130         ah = (regs->sr) >> 32;
 131         al = (regs->sr) & 0xffffffff;
 132         asm volatile ("getcon   " __TEA ", %0" : "=r" (bh));
 133         asm volatile ("getcon   " __TEA ", %0" : "=r" (bl));
 134         bh = (bh) >> 32;
 135         bl = (bl) & 0xffffffff;
 136         asm volatile ("getcon   " __KCR0 ", %0" : "=r" (ch));
 137         asm volatile ("getcon   " __KCR0 ", %0" : "=r" (cl));
 138         ch = (ch) >> 32;
 139         cl = (cl) & 0xffffffff;
 140         printk("SR  : %08Lx%08Lx TEA : %08Lx%08Lx KCR0: %08Lx%08Lx\n",
 141                ah, al, bh, bl, ch, cl);
 142
 143         ah = (regs->regs[0]) >> 32;
 144         al = (regs->regs[0]) & 0xffffffff;
 145         bh = (regs->regs[1]) >> 32;
 146         bl = (regs->regs[1]) & 0xffffffff;
 147         ch = (regs->regs[2]) >> 32;
 148         cl = (regs->regs[2]) & 0xffffffff;
 149         printk("R0  : %08Lx%08Lx R1  : %08Lx%08Lx R2  : %08Lx%08Lx\n",
 150                ah, al, bh, bl, ch, cl);
 151
 152         ah = (regs->regs[3]) >> 32;
 153         al = (regs->regs[3]) & 0xffffffff;
 154         bh = (regs->regs[4]) >> 32;
 155         bl = (regs->regs[4]) & 0xffffffff;
 156         ch = (regs->regs[5]) >> 32;
 157         cl = (regs->regs[5]) & 0xffffffff;
 158         printk("R3  : %08Lx%08Lx R4  : %08Lx%08Lx R5  : %08Lx%08Lx\n",
 159                ah, al, bh, bl, ch, cl);
 160
 161         ah = (regs->regs[6]) >> 32;
 162         al = (regs->regs[6]) & 0xffffffff;
 163         bh = (regs->regs[7]) >> 32;
 164         bl = (regs->regs[7]) & 0xffffffff;
 165         ch = (regs->regs[8]) >> 32;
 166         cl = (regs->regs[8]) & 0xffffffff;
 167         printk("R6  : %08Lx%08Lx R7  : %08Lx%08Lx R8  : %08Lx%08Lx\n",
 168                ah, al, bh, bl, ch, cl);
 169
 170         ah = (regs->regs[9]) >> 32;
 171         al = (regs->regs[9]) & 0xffffffff;
 172         bh = (regs->regs[10]) >> 32;
 173         bl = (regs->regs[10]) & 0xffffffff;
 174         ch = (regs->regs[11]) >> 32;
 175         cl = (regs->regs[11]) & 0xffffffff;
 176         printk("R9  : %08Lx%08Lx R10 : %08Lx%08Lx R11 : %08Lx%08Lx\n",
 177                ah, al, bh, bl, ch, cl);
 178
 179         ah = (regs->regs[12]) >> 32;
 180         al = (regs->regs[12]) & 0xffffffff;
 181         bh = (regs->regs[13]) >> 32;
 182         bl = (regs->regs[13]) & 0xffffffff;
 183         ch = (regs->regs[14]) >> 32;
 184         cl = (regs->regs[14]) & 0xffffffff;
 185         printk("R12 : %08Lx%08Lx R13 : %08Lx%08Lx R14 : %08Lx%08Lx\n",
 186                ah, al, bh, bl, ch, cl);
 187
 188         ah = (regs->regs[16]) >> 32;
 189         al = (regs->regs[16]) & 0xffffffff;
 190         bh = (regs->regs[17]) >> 32;
 191         bl = (regs->regs[17]) & 0xffffffff;
 192         ch = (regs->regs[19]) >> 32;
 193         cl = (regs->regs[19]) & 0xffffffff;
 194         printk("R16 : %08Lx%08Lx R17 : %08Lx%08Lx R19 : %08Lx%08Lx\n",
 195                ah, al, bh, bl, ch, cl);
 196
 197         ah = (regs->regs[20]) >> 32;
 198         al = (regs->regs[20]) & 0xffffffff;
 199         bh = (regs->regs[21]) >> 32;
 200         bl = (regs->regs[21]) & 0xffffffff;
 201         ch = (regs->regs[22]) >> 32;
 202         cl = (regs->regs[22]) & 0xffffffff;
 203         printk("R20 : %08Lx%08Lx R21 : %08Lx%08Lx R22 : %08Lx%08Lx\n",
 204                ah, al, bh, bl, ch, cl);
 205
 206         ah = (regs->regs[23]) >> 32;
 207         al = (regs->regs[23]) & 0xffffffff;
 208         bh = (regs->regs[24]) >> 32;
 209         bl = (regs->regs[24]) & 0xffffffff;
 210         ch = (regs->regs[25]) >> 32;
 211         cl = (regs->regs[25]) & 0xffffffff;
 212         printk("R23 : %08Lx%08Lx R24 : %08Lx%08Lx R25 : %08Lx%08Lx\n",
 213                ah, al, bh, bl, ch, cl);
 214
 215         ah = (regs->regs[26]) >> 32;
 216         al = (regs->regs[26]) & 0xffffffff;
 217         bh = (regs->regs[27]) >> 32;
 218         bl = (regs->regs[27]) & 0xffffffff;
 219         ch = (regs->regs[28]) >> 32;
 220         cl = (regs->regs[28]) & 0xffffffff;
 221         printk("R26 : %08Lx%08Lx R27 : %08Lx%08Lx R28 : %08Lx%08Lx\n",
 222                ah, al, bh, bl, ch, cl);
 223
 224         ah = (regs->regs[29]) >> 32;
 225         al = (regs->regs[29]) & 0xffffffff;
 226         bh = (regs->regs[30]) >> 32;
 227         bl = (regs->regs[30]) & 0xffffffff;
 228         ch = (regs->regs[31]) >> 32;
 229         cl = (regs->regs[31]) & 0xffffffff;
 230         printk("R29 : %08Lx%08Lx R30 : %08Lx%08Lx R31 : %08Lx%08Lx\n",
 231                ah, al, bh, bl, ch, cl);
 232
 233         ah = (regs->regs[32]) >> 32;
 234         al = (regs->regs[32]) & 0xffffffff;
 235         bh = (regs->regs[33]) >> 32;
 236         bl = (regs->regs[33]) & 0xffffffff;
 237         ch = (regs->regs[34]) >> 32;
 238         cl = (regs->regs[34]) & 0xffffffff;
 239         printk("R32 : %08Lx%08Lx R33 : %08Lx%08Lx R34 : %08Lx%08Lx\n",
 240                ah, al, bh, bl, ch, cl);
 241
 242         ah = (regs->regs[35]) >> 32;
 243         al = (regs->regs[35]) & 0xffffffff;
 244         bh = (regs->regs[36]) >> 32;
 245         bl = (regs->regs[36]) & 0xffffffff;
 246         ch = (regs->regs[37]) >> 32;
 247         cl = (regs->regs[37]) & 0xffffffff;
 248         printk("R35 : %08Lx%08Lx R36 : %08Lx%08Lx R37 : %08Lx%08Lx\n",
 249                ah, al, bh, bl, ch, cl);
 250
 251         ah = (regs->regs[38]) >> 32;
 252         al = (regs->regs[38]) & 0xffffffff;
 253         bh = (regs->regs[39]) >> 32;
 254         bl = (regs->regs[39]) & 0xffffffff;
 255         ch = (regs->regs[40]) >> 32;
 256         cl = (regs->regs[40]) & 0xffffffff;
 257         printk("R38 : %08Lx%08Lx R39 : %08Lx%08Lx R40 : %08Lx%08Lx\n",
 258                ah, al, bh, bl, ch, cl);
 259
 260         ah = (regs->regs[41]) >> 32;
 261         al = (regs->regs[41]) & 0xffffffff;
 262         bh = (regs->regs[42]) >> 32;
 263         bl = (regs->regs[42]) & 0xffffffff;
 264         ch = (regs->regs[43]) >> 32;
 265         cl = (regs->regs[43]) & 0xffffffff;
 266         printk("R41 : %08Lx%08Lx R42 : %08Lx%08Lx R43 : %08Lx%08Lx\n",
 267                ah, al, bh, bl, ch, cl);
 268
 269         ah = (regs->regs[44]) >> 32;
 270         al = (regs->regs[44]) & 0xffffffff;
 271         bh = (regs->regs[45]) >> 32;
 272         bl = (regs->regs[45]) & 0xffffffff;
 273         ch = (regs->regs[46]) >> 32;
 274         cl = (regs->regs[46]) & 0xffffffff;
 275         printk("R44 : %08Lx%08Lx R45 : %08Lx%08Lx R46 : %08Lx%08Lx\n",
 276                ah, al, bh, bl, ch, cl);
 277
 278         ah = (regs->regs[47]) >> 32;
 279         al = (regs->regs[47]) & 0xffffffff;
 280         bh = (regs->regs[48]) >> 32;
 281         bl = (regs->regs[48]) & 0xffffffff;
 282         ch = (regs->regs[49]) >> 32;
 283         cl = (regs->regs[49]) & 0xffffffff;
 284         printk("R47 : %08Lx%08Lx R48 : %08Lx%08Lx R49 : %08Lx%08Lx\n",
 285                ah, al, bh, bl, ch, cl);
 286
 287         ah = (regs->regs[50]) >> 32;
 288         al = (regs->regs[50]) & 0xffffffff;
 289         bh = (regs->regs[51]) >> 32;
 290         bl = (regs->regs[51]) & 0xffffffff;
 291         ch = (regs->regs[52]) >> 32;
 292         cl = (regs->regs[52]) & 0xffffffff;
 293         printk("R50 : %08Lx%08Lx R51 : %08Lx%08Lx R52 : %08Lx%08Lx\n",
 294                ah, al, bh, bl, ch, cl);
 295
 296         ah = (regs->regs[53]) >> 32;
 297         al = (regs->regs[53]) & 0xffffffff;
 298         bh = (regs->regs[54]) >> 32;
 299         bl = (regs->regs[54]) & 0xffffffff;
 300         ch = (regs->regs[55]) >> 32;
 301         cl = (regs->regs[55]) & 0xffffffff;
 302         printk("R53 : %08Lx%08Lx R54 : %08Lx%08Lx R55 : %08Lx%08Lx\n",
 303                ah, al, bh, bl, ch, cl);
 304
 305         ah = (regs->regs[56]) >> 32;
 306         al = (regs->regs[56]) & 0xffffffff;
 307         bh = (regs->regs[57]) >> 32;
 308         bl = (regs->regs[57]) & 0xffffffff;
 309         ch = (regs->regs[58]) >> 32;
 310         cl = (regs->regs[58]) & 0xffffffff;
 311         printk("R56 : %08Lx%08Lx R57 : %08Lx%08Lx R58 : %08Lx%08Lx\n",
 312                ah, al, bh, bl, ch, cl);
 313
 314         ah = (regs->regs[59]) >> 32;
 315         al = (regs->regs[59]) & 0xffffffff;
 316         bh = (regs->regs[60]) >> 32;
 317         bl = (regs->regs[60]) & 0xffffffff;
 318         ch = (regs->regs[61]) >> 32;
 319         cl = (regs->regs[61]) & 0xffffffff;
 320         printk("R59 : %08Lx%08Lx R60 : %08Lx%08Lx R61 : %08Lx%08Lx\n",
 321                ah, al, bh, bl, ch, cl);
 322
 323         ah = (regs->regs[62]) >> 32;
 324         al = (regs->regs[62]) & 0xffffffff;
 325         bh = (regs->tregs[0]) >> 32;
 326         bl = (regs->tregs[0]) & 0xffffffff;
 327         ch = (regs->tregs[1]) >> 32;
 328         cl = (regs->tregs[1]) & 0xffffffff;
 329         printk("R62 : %08Lx%08Lx T0  : %08Lx%08Lx T1  : %08Lx%08Lx\n",
 330                ah, al, bh, bl, ch, cl);
 331
 332         ah = (regs->tregs[2]) >> 32;
 333         al = (regs->tregs[2]) & 0xffffffff;
 334         bh = (regs->tregs[3]) >> 32;
 335         bl = (regs->tregs[3]) & 0xffffffff;
 336         ch = (regs->tregs[4]) >> 32;
 337         cl = (regs->tregs[4]) & 0xffffffff;
 338         printk("T2  : %08Lx%08Lx T3  : %08Lx%08Lx T4  : %08Lx%08Lx\n",
 339                ah, al, bh, bl, ch, cl);
 340
 341         ah = (regs->tregs[5]) >> 32;
 342         al = (regs->tregs[5]) & 0xffffffff;
 343         bh = (regs->tregs[6]) >> 32;
 344         bl = (regs->tregs[6]) & 0xffffffff;
 345         ch = (regs->tregs[7]) >> 32;
 346         cl = (regs->tregs[7]) & 0xffffffff;
 347         printk("T5  : %08Lx%08Lx T6  : %08Lx%08Lx T7  : %08Lx%08Lx\n",
 348                ah, al, bh, bl, ch, cl);
 349
 350         /*
 351          * If we're in kernel mode, dump the stack too..
 352          */
 353         if (!user_mode(regs)) {
 354                 void show_stack(struct task_struct *tsk, unsigned long *sp);
 355                 unsigned long sp = regs->regs[15] & 0xffffffff;
 356                 struct task_struct *tsk = get_current();
 357
 358                 tsk->thread.kregs = regs;
 359
 360                 show_stack(tsk, (unsigned long *)sp);
 361         }
 362 }
 363
 364 struct task_struct * alloc_task_struct(void)
 365 {
 366         /* Get task descriptor pages */
 367         return (struct task_struct *)
 368                 __get_free_pages(GFP_KERNEL, get_order(THREAD_SIZE));
 369 }
 370
 371 void free_task_struct(struct task_struct *p)
 372 {
 373         free_pages((unsigned long) p, get_order(THREAD_SIZE));
 374 }
 375
 376 /*
 377  * Create a kernel thread
 378  */
 379 ATTRIB_NORET void kernel_thread_helper(void *arg, int (*fn)(void *))
 380 {
 381         do_exit(fn(arg));
 382 }
 383
 384 /*
 385  * This is the mechanism for creating a new kernel thread.
 386  *
 387  * NOTE! Only a kernel-only process(ie the swapper or direct descendants
 388  * who haven't done an "execve()") should use this: it will work within
 389  * a system call from a "real" process, but the process memory space will
 390  * not be free'd until both the parent and the child have exited.
 391  */
 392 int kernel_thread(int (*fn)(void *), void * arg, unsigned long flags)
 393 {
 394         struct pt_regs regs;
 395
 396         memset(&regs, 0, sizeof(regs));
 397         regs.regs[2] = (unsigned long)arg;
 398         regs.regs[3] = (unsigned long)fn;
 399
 400         regs.pc = (unsigned long)kernel_thread_helper;
 401         regs.sr = (1 << 30);
 402
 403         return do_fork(flags | CLONE_VM | CLONE_UNTRACED, 0,
 404                        &regs, 0, NULL, NULL);
 405 }
 406
 407 /*
 408  * Free current thread data structures etc..
 409  */
 410 void exit_thread(void)
 411 {
 412         /* See arch/sparc/kernel/process.c for the precedent for doing this -- RPC.
 413
 414            The SH-5 FPU save/restore approach relies on last_task_used_math
 415            pointing to a live task_struct.  When another task tries to use the
 416            FPU for the 1st time, the FPUDIS trap handling (see
 417            arch/sh64/kernel/fpu.c) will save the existing FPU state to the
 418            FP regs field within last_task_used_math before re-loading the new
 419            task's FPU state (or initialising it if the FPU has been used
 420            before).  So if last_task_used_math is stale, and its page has already been
 421            re-allocated for another use, the consequences are rather grim. Unless we
 422            null it here, there is no other path through which it would get safely
 423            nulled. */
 424
 425 #ifdef CONFIG_SH_FPU
 426         if (last_task_used_math == current) {
 427                 last_task_used_math = NULL;
 428         }
 429 #endif
 430 }
 431
 432 void flush_thread(void)
 433 {
 434
 435         /* Called by fs/exec.c (flush_old_exec) to remove traces of a
 436          * previously running executable. */
 437 #ifdef CONFIG_SH_FPU
 438         if (last_task_used_math == current) {
 439                 last_task_used_math = NULL;
 440         }
 441         /* Force FPU state to be reinitialised after exec */
 442         clear_used_math();
 443 #endif
 444
 445         /* if we are a kernel thread, about to change to user thread,
 446          * update kreg
 447          */
 448         if(current->thread.kregs==&fake_swapper_regs) {
 449           current->thread.kregs =
 450              ((struct pt_regs *)(THREAD_SIZE + (unsigned long) current) - 1);
 451           current->thread.uregs = current->thread.kregs;
 452         }
 453 }
 454
 455 void release_thread(struct task_struct *dead_task)
 456 {
 457         /* do nothing */
 458 }
 459
 460 /* Fill in the fpu structure for a core dump.. */
 461 int dump_fpu(struct pt_regs *regs, elf_fpregset_t *fpu)
 462 {
 463 #ifdef CONFIG_SH_FPU
 464         int fpvalid;
 465         struct task_struct *tsk = current;
 466
 467         fpvalid = !!tsk_used_math(tsk);
 468         if (fpvalid) {
 469                 if (current == last_task_used_math) {
 470                         grab_fpu();
 471                         fpsave(&tsk->thread.fpu.hard);
 472                         release_fpu();
 473                         last_task_used_math = 0;
 474                         regs->sr |= SR_FD;
 475                 }
 476
 477                 memcpy(fpu, &tsk->thread.fpu.hard, sizeof(*fpu));
 478         }
 479
 480         return fpvalid;
 481 #else
 482         return 0; /* Task didn't use the fpu at all. */
 483 #endif
 484 }
 485
 486 asmlinkage void ret_from_fork(void);
 487
 488 int copy_thread(int nr, unsigned long clone_flags, unsigned long usp,
 489                 unsigned long unused,
 490                 struct task_struct *p, struct pt_regs *regs)
 491 {
 492         struct pt_regs *childregs;
 493         unsigned long long se;                  /* Sign extension */
 494
 495 #ifdef CONFIG_SH_FPU
 496         if(last_task_used_math == current) {
 497                 grab_fpu();
 498                 fpsave(&current->thread.fpu.hard);
 499                 release_fpu();
 500                 last_task_used_math = NULL;
 501                 regs->sr |= SR_FD;
 502         }
 503 #endif
 504         /* Copy from sh version */
 505         childregs = (struct pt_regs *)(THREAD_SIZE + task_stack_page(p)) - 1;
 506
 507         *childregs = *regs;
 508
 509         if (user_mode(regs)) {
 510                 childregs->regs[15] = usp;
 511                 p->thread.uregs = childregs;
 512         } else {
 513                 childregs->regs[15] = (unsigned long)task_stack_page(p) + THREAD_SIZE;
 514         }
 515
 516         childregs->regs[9] = 0; /* Set return value for child */
 517         childregs->sr |= SR_FD; /* Invalidate FPU flag */
 518
 519         p->thread.sp = (unsigned long) childregs;
 520         p->thread.pc = (unsigned long) ret_from_fork;
 521
 522         /*
 523          * Sign extend the edited stack.
 524          * Note that thread.pc and thread.pc will stay
 525          * 32-bit wide and context switch must take care
 526          * of NEFF sign extension.
 527          */
 528
 529         se = childregs->regs[15];
 530         se = (se & NEFF_SIGN) ? (se | NEFF_MASK) : se;
 531         childregs->regs[15] = se;
 532
 533         return 0;
 534 }
 535
 536 asmlinkage int sys_fork(unsigned long r2, unsigned long r3,
 537                         unsigned long r4, unsigned long r5,
 538                         unsigned long r6, unsigned long r7,
 539                         struct pt_regs *pregs)
 540 {
 541         return do_fork(SIGCHLD, pregs->regs[15], pregs, 0, 0, 0);
 542 }
 543
 544 asmlinkage int sys_clone(unsigned long clone_flags, unsigned long newsp,
 545                          unsigned long r4, unsigned long r5,
 546                          unsigned long r6, unsigned long r7,
 547                          struct pt_regs *pregs)
 548 {
 549         if (!newsp)
 550                 newsp = pregs->regs[15];
 551         return do_fork(clone_flags, newsp, pregs, 0, 0, 0);
 552 }
 553
 554 /*
 555  * This is trivial, and on the face of it looks like it
 556  * could equally well be done in user mode.
 557  *
 558  * Not so, for quite unobvious reasons - register pressure.
 559  * In user mode vfork() cannot have a stack frame, and if
 560  * done by calling the "clone()" system call directly, you
 561  * do not have enough call-clobbered registers to hold all
 562  * the information you need.
 563  */
 564 asmlinkage int sys_vfork(unsigned long r2, unsigned long r3,
 565                          unsigned long r4, unsigned long r5,
 566                          unsigned long r6, unsigned long r7,
 567                          struct pt_regs *pregs)
 568 {
 569         return do_fork(CLONE_VFORK | CLONE_VM | SIGCHLD, pregs->regs[15], pregs, 0, 0, 0);
 570 }
 571
 572 /*
 573  * sys_execve() executes a new program.
 574  */
 575 asmlinkage int sys_execve(char *ufilename, char **uargv,
 576                           char **uenvp, unsigned long r5,
 577                           unsigned long r6, unsigned long r7,
 578                           struct pt_regs *pregs)
 579 {
 580         int error;
 581         char *filename;
 582
 583         lock_kernel();
 584         filename = getname((char __user *)ufilename);
 585         error = PTR_ERR(filename);
 586         if (IS_ERR(filename))
 587                 goto out;
 588
 589         error = do_execve(filename,
 590                           (char __user * __user *)uargv,
 591                           (char __user * __user *)uenvp,
 592                           pregs);
 593         if (error == 0) {
 594                 task_lock(current);
 595                 current->ptrace &= ~PT_DTRACE;
 596                 task_unlock(current);
 597         }
 598         putname(filename);
 599 out:
 600         unlock_kernel();
 601         return error;
 602 }
 603
 604 /*
 605  * These bracket the sleeping functions..
 606  */
 607 extern void interruptible_sleep_on(wait_queue_head_t *q);
 608
 609 #define mid_sched       ((unsigned long) interruptible_sleep_on)
 610
 611 static int in_sh64_switch_to(unsigned long pc)
 612 {
 613         extern char __sh64_switch_to_end;
 614         /* For a sleeping task, the PC is somewhere in the middle of the function,
 615            so we don't have to worry about masking the LSB off */
 616         return (pc >= (unsigned long) sh64_switch_to) &&
 617                (pc < (unsigned long) &__sh64_switch_to_end);
 618 }
 619
 620 unsigned long get_wchan(struct task_struct *p)
 621 {
 622         unsigned long schedule_fp;
 623         unsigned long sh64_switch_to_fp;
 624         unsigned long schedule_caller_pc;
 625         unsigned long pc;
 626
 627         if (!p || p == current || p->state == TASK_RUNNING)
 628                 return 0;
 629
 630         /*
 631          * The same comment as on the Alpha applies here, too ...
 632          */
 633         pc = thread_saved_pc(p);
 634
 635 #ifdef CONFIG_FRAME_POINTER
 636         if (in_sh64_switch_to(pc)) {
 637                 sh64_switch_to_fp = (long) p->thread.sp;
 638                 /* r14 is saved at offset 4 in the sh64_switch_to frame */
 639                 schedule_fp = *(unsigned long *) (long)(sh64_switch_to_fp + 4);
 640
 641                 /* and the caller of 'schedule' is (currently!) saved at offset 24
 642                    in the frame of schedule (from disasm) */
 643                 schedule_caller_pc = *(unsigned long *) (long)(schedule_fp + 24);
 644                 return schedule_caller_pc;
 645         }
 646 #endif
 647         return pc;
 648 }
 649
 650 /* Provide a /proc/asids file that lists out the
 651    ASIDs currently associated with the processes.  (If the DM.PC register is
 652    examined through the debug link, this shows ASID + PC.  To make use of this,
 653    the PID->ASID relationship needs to be known.  This is primarily for
 654    debugging.)
 655    */
 656
 657 #if defined(CONFIG_SH64_PROC_ASIDS)
 658 #include <linux/init.h>
 659 #include <linux/proc_fs.h>
 660
 661 static int
 662 asids_proc_info(char *buf, char **start, off_t fpos, int length, int *eof, void *data)
 663 {
 664         int len=0;
 665         struct task_struct *p;
 666         read_lock(&tasklist_lock);
 667         for_each_process(p) {
 668                 int pid = p->pid;
 669                 struct mm_struct *mm;
 670                 if (!pid) continue;
 671                 mm = p->mm;
 672                 if (mm) {
 673                         unsigned long asid, context;
 674                         context = mm->context;
 675                         asid = (context & 0xff);
 676                         len += sprintf(buf+len, "%5d : %02lx\n", pid, asid);
 677                 } else {
 678                         len += sprintf(buf+len, "%5d : (none)\n", pid);
 679                 }
 680         }
 681         read_unlock(&tasklist_lock);
 682         *eof = 1;
 683         return len;
 684 }
 685
 686 static int __init register_proc_asids(void)
 687 {
 688   create_proc_read_entry("asids", 0, NULL, asids_proc_info, NULL);
 689   return 0;
 690 }
 691
 692 __initcall(register_proc_asids);
 693 #endif
 694