arch/sh/kernel/process_64.c

   1 /*
   2  * arch/sh/kernel/process_64.c
   3  *
   4  * This file handles the architecture-dependent parts of process handling..
   5  *
   6  * Copyright (C) 2000, 2001  Paolo Alberelli
   7  * Copyright (C) 2003 - 2007  Paul Mundt
   8  * Copyright (C) 2003, 2004 Richard Curnow
   9  *
  10  * Started from SH3/4 version:
  11  *   Copyright (C) 1999, 2000  Niibe Yutaka & Kaz Kojima
  12  *
  13  *   In turn started from i386 version:
  14  *     Copyright (C) 1995  Linus Torvalds
  15  *
  16  * This file is subject to the terms and conditions of the GNU General Public
  17  * License.  See the file "COPYING" in the main directory of this archive
  18  * for more details.
  19  */
  20 #include <linux/mm.h>
  21 #include <linux/fs.h>
  22 #include <linux/ptrace.h>
  23 #include <linux/reboot.h>
  24 #include <linux/init.h>
  25 #include <linux/module.h>
  26 #include <linux/proc_fs.h>
  27 #include <linux/io.h>
  28 #include <asm/uaccess.h>
  29 #include <asm/pgtable.h>
  30 #include <asm/mmu_context.h>
  31 #include <asm/fpu.h>
  32
  33 struct task_struct *last_task_used_math = NULL;
  34
  35 static int hlt_counter = 1;
  36
  37 #define HARD_IDLE_TIMEOUT (HZ / 3)
  38
  39 void disable_hlt(void)
  40 {
  41         hlt_counter++;
  42 }
  43
  44 void enable_hlt(void)
  45 {
  46         hlt_counter--;
  47 }
  48
  49 static int __init nohlt_setup(char *__unused)
  50 {
  51         hlt_counter = 1;
  52         return 1;
  53 }
  54
  55 static int __init hlt_setup(char *__unused)
  56 {
  57         hlt_counter = 0;
  58         return 1;
  59 }
  60
  61 __setup("nohlt", nohlt_setup);
  62 __setup("hlt", hlt_setup);
  63
  64 static inline void hlt(void)
  65 {
  66         __asm__ __volatile__ ("sleep" : : : "memory");
  67 }
  68
  69 /*
  70  * The idle loop on a uniprocessor SH..
  71  */
  72 void cpu_idle(void)
  73 {
  74         /* endless idle loop with no priority at all */
  75         while (1) {
  76                 if (hlt_counter) {
  77                         while (!need_resched())
  78                                 cpu_relax();
  79                 } else {
  80                         local_irq_disable();
  81                         while (!need_resched()) {
  82                                 local_irq_enable();
  83                                 hlt();
  84                                 local_irq_disable();
  85                         }
  86                         local_irq_enable();
  87                 }
  88                 preempt_enable_no_resched();
  89                 schedule();
  90                 preempt_disable();
  91         }
  92
  93 }
  94
  95 void machine_restart(char * __unused)
  96 {
  97         extern void phys_stext(void);
  98
  99         phys_stext();
 100 }
 101
 102 void machine_halt(void)
 103 {
 104         for (;;);
 105 }
 106
 107 void machine_power_off(void)
 108 {
 109 #if 0
 110         /* Disable watchdog timer */
 111         ctrl_outl(0xa5000000, WTCSR);
 112         /* Configure deep standby on sleep */
 113         ctrl_outl(0x03, STBCR);
 114 #endif
 115
 116         __asm__ __volatile__ (
 117                 "sleep\n\t"
 118                 "synci\n\t"
 119                 "nop;nop;nop;nop\n\t"
 120         );
 121
 122         panic("Unexpected wakeup!\n");
 123 }
 124
 125 void (*pm_power_off)(void) = machine_power_off;
 126 EXPORT_SYMBOL(pm_power_off);
 127
 128 void show_regs(struct pt_regs * regs)
 129 {
 130         unsigned long long ah, al, bh, bl, ch, cl;
 131
 132         printk("\n");
 133
 134         ah = (regs->pc) >> 32;
 135         al = (regs->pc) & 0xffffffff;
 136         bh = (regs->regs[18]) >> 32;
 137         bl = (regs->regs[18]) & 0xffffffff;
 138         ch = (regs->regs[15]) >> 32;
 139         cl = (regs->regs[15]) & 0xffffffff;
 140         printk("PC  : %08Lx%08Lx LINK: %08Lx%08Lx SP  : %08Lx%08Lx\n",
 141                ah, al, bh, bl, ch, cl);
 142
 143         ah = (regs->sr) >> 32;
 144         al = (regs->sr) & 0xffffffff;
 145         asm volatile ("getcon   " __TEA ", %0" : "=r" (bh));
 146         asm volatile ("getcon   " __TEA ", %0" : "=r" (bl));
 147         bh = (bh) >> 32;
 148         bl = (bl) & 0xffffffff;
 149         asm volatile ("getcon   " __KCR0 ", %0" : "=r" (ch));
 150         asm volatile ("getcon   " __KCR0 ", %0" : "=r" (cl));
 151         ch = (ch) >> 32;
 152         cl = (cl) & 0xffffffff;
 153         printk("SR  : %08Lx%08Lx TEA : %08Lx%08Lx KCR0: %08Lx%08Lx\n",
 154                ah, al, bh, bl, ch, cl);
 155
 156         ah = (regs->regs[0]) >> 32;
 157         al = (regs->regs[0]) & 0xffffffff;
 158         bh = (regs->regs[1]) >> 32;
 159         bl = (regs->regs[1]) & 0xffffffff;
 160         ch = (regs->regs[2]) >> 32;
 161         cl = (regs->regs[2]) & 0xffffffff;
 162         printk("R0  : %08Lx%08Lx R1  : %08Lx%08Lx R2  : %08Lx%08Lx\n",
 163                ah, al, bh, bl, ch, cl);
 164
 165         ah = (regs->regs[3]) >> 32;
 166         al = (regs->regs[3]) & 0xffffffff;
 167         bh = (regs->regs[4]) >> 32;
 168         bl = (regs->regs[4]) & 0xffffffff;
 169         ch = (regs->regs[5]) >> 32;
 170         cl = (regs->regs[5]) & 0xffffffff;
 171         printk("R3  : %08Lx%08Lx R4  : %08Lx%08Lx R5  : %08Lx%08Lx\n",
 172                ah, al, bh, bl, ch, cl);
 173
 174         ah = (regs->regs[6]) >> 32;
 175         al = (regs->regs[6]) & 0xffffffff;
 176         bh = (regs->regs[7]) >> 32;
 177         bl = (regs->regs[7]) & 0xffffffff;
 178         ch = (regs->regs[8]) >> 32;
 179         cl = (regs->regs[8]) & 0xffffffff;
 180         printk("R6  : %08Lx%08Lx R7  : %08Lx%08Lx R8  : %08Lx%08Lx\n",
 181                ah, al, bh, bl, ch, cl);
 182
 183         ah = (regs->regs[9]) >> 32;
 184         al = (regs->regs[9]) & 0xffffffff;
 185         bh = (regs->regs[10]) >> 32;
 186         bl = (regs->regs[10]) & 0xffffffff;
 187         ch = (regs->regs[11]) >> 32;
 188         cl = (regs->regs[11]) & 0xffffffff;
 189         printk("R9  : %08Lx%08Lx R10 : %08Lx%08Lx R11 : %08Lx%08Lx\n",
 190                ah, al, bh, bl, ch, cl);
 191
 192         ah = (regs->regs[12]) >> 32;
 193         al = (regs->regs[12]) & 0xffffffff;
 194         bh = (regs->regs[13]) >> 32;
 195         bl = (regs->regs[13]) & 0xffffffff;
 196         ch = (regs->regs[14]) >> 32;
 197         cl = (regs->regs[14]) & 0xffffffff;
 198         printk("R12 : %08Lx%08Lx R13 : %08Lx%08Lx R14 : %08Lx%08Lx\n",
 199                ah, al, bh, bl, ch, cl);
 200
 201         ah = (regs->regs[16]) >> 32;
 202         al = (regs->regs[16]) & 0xffffffff;
 203         bh = (regs->regs[17]) >> 32;
 204         bl = (regs->regs[17]) & 0xffffffff;
 205         ch = (regs->regs[19]) >> 32;
 206         cl = (regs->regs[19]) & 0xffffffff;
 207         printk("R16 : %08Lx%08Lx R17 : %08Lx%08Lx R19 : %08Lx%08Lx\n",
 208                ah, al, bh, bl, ch, cl);
 209
 210         ah = (regs->regs[20]) >> 32;
 211         al = (regs->regs[20]) & 0xffffffff;
 212         bh = (regs->regs[21]) >> 32;
 213         bl = (regs->regs[21]) & 0xffffffff;
 214         ch = (regs->regs[22]) >> 32;
 215         cl = (regs->regs[22]) & 0xffffffff;
 216         printk("R20 : %08Lx%08Lx R21 : %08Lx%08Lx R22 : %08Lx%08Lx\n",
 217                ah, al, bh, bl, ch, cl);
 218
 219         ah = (regs->regs[23]) >> 32;
 220         al = (regs->regs[23]) & 0xffffffff;
 221         bh = (regs->regs[24]) >> 32;
 222         bl = (regs->regs[24]) & 0xffffffff;
 223         ch = (regs->regs[25]) >> 32;
 224         cl = (regs->regs[25]) & 0xffffffff;
 225         printk("R23 : %08Lx%08Lx R24 : %08Lx%08Lx R25 : %08Lx%08Lx\n",
 226                ah, al, bh, bl, ch, cl);
 227
 228         ah = (regs->regs[26]) >> 32;
 229         al = (regs->regs[26]) & 0xffffffff;
 230         bh = (regs->regs[27]) >> 32;
 231         bl = (regs->regs[27]) & 0xffffffff;
 232         ch = (regs->regs[28]) >> 32;
 233         cl = (regs->regs[28]) & 0xffffffff;
 234         printk("R26 : %08Lx%08Lx R27 : %08Lx%08Lx R28 : %08Lx%08Lx\n",
 235                ah, al, bh, bl, ch, cl);
 236
 237         ah = (regs->regs[29]) >> 32;
 238         al = (regs->regs[29]) & 0xffffffff;
 239         bh = (regs->regs[30]) >> 32;
 240         bl = (regs->regs[30]) & 0xffffffff;
 241         ch = (regs->regs[31]) >> 32;
 242         cl = (regs->regs[31]) & 0xffffffff;
 243         printk("R29 : %08Lx%08Lx R30 : %08Lx%08Lx R31 : %08Lx%08Lx\n",
 244                ah, al, bh, bl, ch, cl);
 245
 246         ah = (regs->regs[32]) >> 32;
 247         al = (regs->regs[32]) & 0xffffffff;
 248         bh = (regs->regs[33]) >> 32;
 249         bl = (regs->regs[33]) & 0xffffffff;
 250         ch = (regs->regs[34]) >> 32;
 251         cl = (regs->regs[34]) & 0xffffffff;
 252         printk("R32 : %08Lx%08Lx R33 : %08Lx%08Lx R34 : %08Lx%08Lx\n",
 253                ah, al, bh, bl, ch, cl);
 254
 255         ah = (regs->regs[35]) >> 32;
 256         al = (regs->regs[35]) & 0xffffffff;
 257         bh = (regs->regs[36]) >> 32;
 258         bl = (regs->regs[36]) & 0xffffffff;
 259         ch = (regs->regs[37]) >> 32;
 260         cl = (regs->regs[37]) & 0xffffffff;
 261         printk("R35 : %08Lx%08Lx R36 : %08Lx%08Lx R37 : %08Lx%08Lx\n",
 262                ah, al, bh, bl, ch, cl);
 263
 264         ah = (regs->regs[38]) >> 32;
 265         al = (regs->regs[38]) & 0xffffffff;
 266         bh = (regs->regs[39]) >> 32;
 267         bl = (regs->regs[39]) & 0xffffffff;
 268         ch = (regs->regs[40]) >> 32;
 269         cl = (regs->regs[40]) & 0xffffffff;
 270         printk("R38 : %08Lx%08Lx R39 : %08Lx%08Lx R40 : %08Lx%08Lx\n",
 271                ah, al, bh, bl, ch, cl);
 272
 273         ah = (regs->regs[41]) >> 32;
 274         al = (regs->regs[41]) & 0xffffffff;
 275         bh = (regs->regs[42]) >> 32;
 276         bl = (regs->regs[42]) & 0xffffffff;
 277         ch = (regs->regs[43]) >> 32;
 278         cl = (regs->regs[43]) & 0xffffffff;
 279         printk("R41 : %08Lx%08Lx R42 : %08Lx%08Lx R43 : %08Lx%08Lx\n",
 280                ah, al, bh, bl, ch, cl);
 281
 282         ah = (regs->regs[44]) >> 32;
 283         al = (regs->regs[44]) & 0xffffffff;
 284         bh = (regs->regs[45]) >> 32;
 285         bl = (regs->regs[45]) & 0xffffffff;
 286         ch = (regs->regs[46]) >> 32;
 287         cl = (regs->regs[46]) & 0xffffffff;
 288         printk("R44 : %08Lx%08Lx R45 : %08Lx%08Lx R46 : %08Lx%08Lx\n",
 289                ah, al, bh, bl, ch, cl);
 290
 291         ah = (regs->regs[47]) >> 32;
 292         al = (regs->regs[47]) & 0xffffffff;
 293         bh = (regs->regs[48]) >> 32;
 294         bl = (regs->regs[48]) & 0xffffffff;
 295         ch = (regs->regs[49]) >> 32;
 296         cl = (regs->regs[49]) & 0xffffffff;
 297         printk("R47 : %08Lx%08Lx R48 : %08Lx%08Lx R49 : %08Lx%08Lx\n",
 298                ah, al, bh, bl, ch, cl);
 299
 300         ah = (regs->regs[50]) >> 32;
 301         al = (regs->regs[50]) & 0xffffffff;
 302         bh = (regs->regs[51]) >> 32;
 303         bl = (regs->regs[51]) & 0xffffffff;
 304         ch = (regs->regs[52]) >> 32;
 305         cl = (regs->regs[52]) & 0xffffffff;
 306         printk("R50 : %08Lx%08Lx R51 : %08Lx%08Lx R52 : %08Lx%08Lx\n",
 307                ah, al, bh, bl, ch, cl);
 308
 309         ah = (regs->regs[53]) >> 32;
 310         al = (regs->regs[53]) & 0xffffffff;
 311         bh = (regs->regs[54]) >> 32;
 312         bl = (regs->regs[54]) & 0xffffffff;
 313         ch = (regs->regs[55]) >> 32;
 314         cl = (regs->regs[55]) & 0xffffffff;
 315         printk("R53 : %08Lx%08Lx R54 : %08Lx%08Lx R55 : %08Lx%08Lx\n",
 316                ah, al, bh, bl, ch, cl);
 317
 318         ah = (regs->regs[56]) >> 32;
 319         al = (regs->regs[56]) & 0xffffffff;
 320         bh = (regs->regs[57]) >> 32;
 321         bl = (regs->regs[57]) & 0xffffffff;
 322         ch = (regs->regs[58]) >> 32;
 323         cl = (regs->regs[58]) & 0xffffffff;
 324         printk("R56 : %08Lx%08Lx R57 : %08Lx%08Lx R58 : %08Lx%08Lx\n",
 325                ah, al, bh, bl, ch, cl);
 326
 327         ah = (regs->regs[59]) >> 32;
 328         al = (regs->regs[59]) & 0xffffffff;
 329         bh = (regs->regs[60]) >> 32;
 330         bl = (regs->regs[60]) & 0xffffffff;
 331         ch = (regs->regs[61]) >> 32;
 332         cl = (regs->regs[61]) & 0xffffffff;
 333         printk("R59 : %08Lx%08Lx R60 : %08Lx%08Lx R61 : %08Lx%08Lx\n",
 334                ah, al, bh, bl, ch, cl);
 335
 336         ah = (regs->regs[62]) >> 32;
 337         al = (regs->regs[62]) & 0xffffffff;
 338         bh = (regs->tregs[0]) >> 32;
 339         bl = (regs->tregs[0]) & 0xffffffff;
 340         ch = (regs->tregs[1]) >> 32;
 341         cl = (regs->tregs[1]) & 0xffffffff;
 342         printk("R62 : %08Lx%08Lx T0  : %08Lx%08Lx T1  : %08Lx%08Lx\n",
 343                ah, al, bh, bl, ch, cl);
 344
 345         ah = (regs->tregs[2]) >> 32;
 346         al = (regs->tregs[2]) & 0xffffffff;
 347         bh = (regs->tregs[3]) >> 32;
 348         bl = (regs->tregs[3]) & 0xffffffff;
 349         ch = (regs->tregs[4]) >> 32;
 350         cl = (regs->tregs[4]) & 0xffffffff;
 351         printk("T2  : %08Lx%08Lx T3  : %08Lx%08Lx T4  : %08Lx%08Lx\n",
 352                ah, al, bh, bl, ch, cl);
 353
 354         ah = (regs->tregs[5]) >> 32;
 355         al = (regs->tregs[5]) & 0xffffffff;
 356         bh = (regs->tregs[6]) >> 32;
 357         bl = (regs->tregs[6]) & 0xffffffff;
 358         ch = (regs->tregs[7]) >> 32;
 359         cl = (regs->tregs[7]) & 0xffffffff;
 360         printk("T5  : %08Lx%08Lx T6  : %08Lx%08Lx T7  : %08Lx%08Lx\n",
 361                ah, al, bh, bl, ch, cl);
 362
 363         /*
 364          * If we're in kernel mode, dump the stack too..
 365          */
 366         if (!user_mode(regs)) {
 367                 void show_stack(struct task_struct *tsk, unsigned long *sp);
 368                 unsigned long sp = regs->regs[15] & 0xffffffff;
 369                 struct task_struct *tsk = get_current();
 370
 371                 tsk->thread.kregs = regs;
 372
 373                 show_stack(tsk, (unsigned long *)sp);
 374         }
 375 }
 376
 377 struct task_struct * alloc_task_struct(void)
 378 {
 379         /* Get task descriptor pages */
 380         return (struct task_struct *)
 381                 __get_free_pages(GFP_KERNEL, get_order(THREAD_SIZE));
 382 }
 383
 384 void free_task_struct(struct task_struct *p)
 385 {
 386         free_pages((unsigned long) p, get_order(THREAD_SIZE));
 387 }
 388
 389 /*
 390  * Create a kernel thread
 391  */
 392 ATTRIB_NORET void kernel_thread_helper(void *arg, int (*fn)(void *))
 393 {
 394         do_exit(fn(arg));
 395 }
 396
 397 /*
 398  * This is the mechanism for creating a new kernel thread.
 399  *
 400  * NOTE! Only a kernel-only process(ie the swapper or direct descendants
 401  * who haven't done an "execve()") should use this: it will work within
 402  * a system call from a "real" process, but the process memory space will
 403  * not be freed until both the parent and the child have exited.
 404  */
 405 int kernel_thread(int (*fn)(void *), void * arg, unsigned long flags)
 406 {
 407         struct pt_regs regs;
 408
 409         memset(&regs, 0, sizeof(regs));
 410         regs.regs[2] = (unsigned long)arg;
 411         regs.regs[3] = (unsigned long)fn;
 412
 413         regs.pc = (unsigned long)kernel_thread_helper;
 414         regs.sr = (1 << 30);
 415
 416         return do_fork(flags | CLONE_VM | CLONE_UNTRACED, 0,
 417                        &regs, 0, NULL, NULL);
 418 }
 419
 420 /*
 421  * Free current thread data structures etc..
 422  */
 423 void exit_thread(void)
 424 {
 425         /*
 426          * See arch/sparc/kernel/process.c for the precedent for doing
 427          * this -- RPC.
 428          *
 429          * The SH-5 FPU save/restore approach relies on
 430          * last_task_used_math pointing to a live task_struct.  When
 431          * another task tries to use the FPU for the 1st time, the FPUDIS
 432          * trap handling (see arch/sh/kernel/cpu/sh5/fpu.c) will save the
 433          * existing FPU state to the FP regs field within
 434          * last_task_used_math before re-loading the new task's FPU state
 435          * (or initialising it if the FPU has been used before).  So if
 436          * last_task_used_math is stale, and its page has already been
 437          * re-allocated for another use, the consequences are rather
 438          * grim. Unless we null it here, there is no other path through
 439          * which it would get safely nulled.
 440          */
 441 #ifdef CONFIG_SH_FPU
 442         if (last_task_used_math == current) {
 443                 last_task_used_math = NULL;
 444         }
 445 #endif
 446 }
 447
 448 void flush_thread(void)
 449 {
 450
 451         /* Called by fs/exec.c (flush_old_exec) to remove traces of a
 452          * previously running executable. */
 453 #ifdef CONFIG_SH_FPU
 454         if (last_task_used_math == current) {
 455                 last_task_used_math = NULL;
 456         }
 457         /* Force FPU state to be reinitialised after exec */
 458         clear_used_math();
 459 #endif
 460
 461         /* if we are a kernel thread, about to change to user thread,
 462          * update kreg
 463          */
 464         if(current->thread.kregs==&fake_swapper_regs) {
 465           current->thread.kregs =
 466              ((struct pt_regs *)(THREAD_SIZE + (unsigned long) current) - 1);
 467           current->thread.uregs = current->thread.kregs;
 468         }
 469 }
 470
 471 void release_thread(struct task_struct *dead_task)
 472 {
 473         /* do nothing */
 474 }
 475
 476 /* Fill in the fpu structure for a core dump.. */
 477 int dump_fpu(struct pt_regs *regs, elf_fpregset_t *fpu)
 478 {
 479 #ifdef CONFIG_SH_FPU
 480         int fpvalid;
 481         struct task_struct *tsk = current;
 482
 483         fpvalid = !!tsk_used_math(tsk);
 484         if (fpvalid) {
 485                 if (current == last_task_used_math) {
 486                         enable_fpu();
 487                         save_fpu(tsk, regs);
 488                         disable_fpu();
 489                         last_task_used_math = 0;
 490                         regs->sr |= SR_FD;
 491                 }
 492
 493                 memcpy(fpu, &tsk->thread.fpu.hard, sizeof(*fpu));
 494         }
 495
 496         return fpvalid;
 497 #else
 498         return 0; /* Task didn't use the fpu at all. */
 499 #endif
 500 }
 501
 502 asmlinkage void ret_from_fork(void);
 503
 504 int copy_thread(int nr, unsigned long clone_flags, unsigned long usp,
 505                 unsigned long unused,
 506                 struct task_struct *p, struct pt_regs *regs)
 507 {
 508         struct pt_regs *childregs;
 509         unsigned long long se;                  /* Sign extension */
 510
 511 #ifdef CONFIG_SH_FPU
 512         if(last_task_used_math == current) {
 513                 enable_fpu();
 514                 save_fpu(current, regs);
 515                 disable_fpu();
 516                 last_task_used_math = NULL;
 517                 regs->sr |= SR_FD;
 518         }
 519 #endif
 520         /* Copy from sh version */
 521         childregs = (struct pt_regs *)(THREAD_SIZE + task_stack_page(p)) - 1;
 522
 523         *childregs = *regs;
 524
 525         if (user_mode(regs)) {
 526                 childregs->regs[15] = usp;
 527                 p->thread.uregs = childregs;
 528         } else {
 529                 childregs->regs[15] = (unsigned long)task_stack_page(p) + THREAD_SIZE;
 530         }
 531
 532         childregs->regs[9] = 0; /* Set return value for child */
 533         childregs->sr |= SR_FD; /* Invalidate FPU flag */
 534
 535         p->thread.sp = (unsigned long) childregs;
 536         p->thread.pc = (unsigned long) ret_from_fork;
 537
 538         /*
 539          * Sign extend the edited stack.
 540          * Note that thread.pc and thread.pc will stay
 541          * 32-bit wide and context switch must take care
 542          * of NEFF sign extension.
 543          */
 544
 545         se = childregs->regs[15];
 546         se = (se & NEFF_SIGN) ? (se | NEFF_MASK) : se;
 547         childregs->regs[15] = se;
 548
 549         return 0;
 550 }
 551
 552 asmlinkage int sys_fork(unsigned long r2, unsigned long r3,
 553                         unsigned long r4, unsigned long r5,
 554                         unsigned long r6, unsigned long r7,
 555                         struct pt_regs *pregs)
 556 {
 557         return do_fork(SIGCHLD, pregs->regs[15], pregs, 0, 0, 0);
 558 }
 559
 560 asmlinkage int sys_clone(unsigned long clone_flags, unsigned long newsp,
 561                          unsigned long r4, unsigned long r5,
 562                          unsigned long r6, unsigned long r7,
 563                          struct pt_regs *pregs)
 564 {
 565         if (!newsp)
 566                 newsp = pregs->regs[15];
 567         return do_fork(clone_flags, newsp, pregs, 0, 0, 0);
 568 }
 569
 570 /*
 571  * This is trivial, and on the face of it looks like it
 572  * could equally well be done in user mode.
 573  *
 574  * Not so, for quite unobvious reasons - register pressure.
 575  * In user mode vfork() cannot have a stack frame, and if
 576  * done by calling the "clone()" system call directly, you
 577  * do not have enough call-clobbered registers to hold all
 578  * the information you need.
 579  */
 580 asmlinkage int sys_vfork(unsigned long r2, unsigned long r3,
 581                          unsigned long r4, unsigned long r5,
 582                          unsigned long r6, unsigned long r7,
 583                          struct pt_regs *pregs)
 584 {
 585         return do_fork(CLONE_VFORK | CLONE_VM | SIGCHLD, pregs->regs[15], pregs, 0, 0, 0);
 586 }
 587
 588 /*
 589  * sys_execve() executes a new program.
 590  */
 591 asmlinkage int sys_execve(char *ufilename, char **uargv,
 592                           char **uenvp, unsigned long r5,
 593                           unsigned long r6, unsigned long r7,
 594                           struct pt_regs *pregs)
 595 {
 596         int error;
 597         char *filename;
 598
 599         lock_kernel();
 600         filename = getname((char __user *)ufilename);
 601         error = PTR_ERR(filename);
 602         if (IS_ERR(filename))
 603                 goto out;
 604
 605         error = do_execve(filename,
 606                           (char __user * __user *)uargv,
 607                           (char __user * __user *)uenvp,
 608                           pregs);
 609         if (error == 0) {
 610                 task_lock(current);
 611                 current->ptrace &= ~PT_DTRACE;
 612                 task_unlock(current);
 613         }
 614         putname(filename);
 615 out:
 616         unlock_kernel();
 617         return error;
 618 }
 619
 620 /*
 621  * These bracket the sleeping functions..
 622  */
 623 extern void interruptible_sleep_on(wait_queue_head_t *q);
 624
 625 #define mid_sched       ((unsigned long) interruptible_sleep_on)
 626
 627 #ifdef CONFIG_FRAME_POINTER
 628 static int in_sh64_switch_to(unsigned long pc)
 629 {
 630         extern char __sh64_switch_to_end;
 631         /* For a sleeping task, the PC is somewhere in the middle of the function,
 632            so we don't have to worry about masking the LSB off */
 633         return (pc >= (unsigned long) sh64_switch_to) &&
 634                (pc < (unsigned long) &__sh64_switch_to_end);
 635 }
 636 #endif
 637
 638 unsigned long get_wchan(struct task_struct *p)
 639 {
 640         unsigned long pc;
 641
 642         if (!p || p == current || p->state == TASK_RUNNING)
 643                 return 0;
 644
 645         /*
 646          * The same comment as on the Alpha applies here, too ...
 647          */
 648         pc = thread_saved_pc(p);
 649
 650 #ifdef CONFIG_FRAME_POINTER
 651         if (in_sh64_switch_to(pc)) {
 652                 unsigned long schedule_fp;
 653                 unsigned long sh64_switch_to_fp;
 654                 unsigned long schedule_caller_pc;
 655
 656                 sh64_switch_to_fp = (long) p->thread.sp;
 657                 /* r14 is saved at offset 4 in the sh64_switch_to frame */
 658                 schedule_fp = *(unsigned long *) (long)(sh64_switch_to_fp + 4);
 659
 660                 /* and the caller of 'schedule' is (currently!) saved at offset 24
 661                    in the frame of schedule (from disasm) */
 662                 schedule_caller_pc = *(unsigned long *) (long)(schedule_fp + 24);
 663                 return schedule_caller_pc;
 664         }
 665 #endif
 666         return pc;
 667 }
 668
 669 /* Provide a /proc/asids file that lists out the
 670    ASIDs currently associated with the processes.  (If the DM.PC register is
 671    examined through the debug link, this shows ASID + PC.  To make use of this,
 672    the PID->ASID relationship needs to be known.  This is primarily for
 673    debugging.)
 674    */
 675
 676 #if defined(CONFIG_SH64_PROC_ASIDS)
 677 static int
 678 asids_proc_info(char *buf, char **start, off_t fpos, int length, int *eof, void *data)
 679 {
 680         int len=0;
 681         struct task_struct *p;
 682         read_lock(&tasklist_lock);
 683         for_each_process(p) {
 684                 int pid = p->pid;
 685
 686                 if (!pid)
 687                         continue;
 688                 if (p->mm)
 689                         len += sprintf(buf+len, "%5d : %02lx\n", pid,
 690                                        asid_cache(smp_processor_id()));
 691                 else
 692                         len += sprintf(buf+len, "%5d : (none)\n", pid);
 693         }
 694         read_unlock(&tasklist_lock);
 695         *eof = 1;
 696         return len;
 697 }
 698
 699 static int __init register_proc_asids(void)
 700 {
 701         create_proc_read_entry("asids", 0, NULL, asids_proc_info, NULL);
 702         return 0;
 703 }
 704 __initcall(register_proc_asids);
 705 #endif