arch/sh/kernel/process.c

   1 /* $Id: process.c,v 1.28 2004/05/05 16:54:23 lethal Exp $
   2  *
   3  *  linux/arch/sh/kernel/process.c
   4  *
   5  *  Copyright (C) 1995  Linus Torvalds
   6  *
   7  *  SuperH version:  Copyright (C) 1999, 2000  Niibe Yutaka & Kaz Kojima
   8  */
   9
  10 /*
  11  * This file handles the architecture-dependent parts of process handling..
  12  */
  13
  14 #include <linux/module.h>
  15 #include <linux/unistd.h>
  16 #include <linux/mm.h>
  17 #include <linux/elfcore.h>
  18 #include <linux/slab.h>
  19 #include <linux/a.out.h>
  20 #include <linux/ptrace.h>
  21 #include <linux/platform.h>
  22 #include <linux/kallsyms.h>
  23
  24 #include <asm/io.h>
  25 #include <asm/uaccess.h>
  26 #include <asm/mmu_context.h>
  27 #include <asm/elf.h>
  28 #if defined(CONFIG_SH_HS7751RVOIP)
  29 #include <asm/hs7751rvoip/hs7751rvoip.h>
  30 #elif defined(CONFIG_SH_RTS7751R2D)
  31 #include <asm/rts7751r2d/rts7751r2d.h>
  32 #endif
  33
  34 static int hlt_counter=0;
  35
  36 int ubc_usercnt = 0;
  37
  38 #define HARD_IDLE_TIMEOUT (HZ / 3)
  39
  40 void disable_hlt(void)
  41 {
  42         hlt_counter++;
  43 }
  44
  45 EXPORT_SYMBOL(disable_hlt);
  46
  47 void enable_hlt(void)
  48 {
  49         hlt_counter--;
  50 }
  51
  52 EXPORT_SYMBOL(enable_hlt);
  53
  54 void default_idle(void)
  55 {
  56         /* endless idle loop with no priority at all */
  57         while (1) {
  58                 if (hlt_counter) {
  59                         while (1)
  60                                 if (need_resched())
  61                                         break;
  62                 } else {
  63                         while (!need_resched())
  64                                 cpu_sleep();
  65                 }
  66
  67                 schedule();
  68         }
  69 }
  70
  71 void cpu_idle(void *unused)
  72 {
  73         default_idle();
  74 }
  75
  76 void machine_restart(char * __unused)
  77 {
  78         /* SR.BL=1 and invoke address error to let CPU reset (manual reset) */
  79         asm volatile("ldc %0, sr\n\t"
  80                      "mov.l @%1, %0" : : "r" (0x10000000), "r" (0x80000001));
  81 }
  82
  83 EXPORT_SYMBOL(machine_restart);
  84
  85 void machine_halt(void)
  86 {
  87 #if defined(CONFIG_SH_HS7751RVOIP)
  88         unsigned short value;
  89
  90         value = ctrl_inw(PA_OUTPORTR);
  91         ctrl_outw((value & 0xffdf), PA_OUTPORTR);
  92 #elif defined(CONFIG_SH_RTS7751R2D)
  93         ctrl_outw(0x0001, PA_POWOFF);
  94 #endif
  95         while (1)
  96                 cpu_sleep();
  97 }
  98
  99 EXPORT_SYMBOL(machine_halt);
 100
 101 void machine_power_off(void)
 102 {
 103 #if defined(CONFIG_SH_HS7751RVOIP)
 104         unsigned short value;
 105
 106         value = ctrl_inw(PA_OUTPORTR);
 107         ctrl_outw((value & 0xffdf), PA_OUTPORTR);
 108 #elif defined(CONFIG_SH_RTS7751R2D)
 109         ctrl_outw(0x0001, PA_POWOFF);
 110 #endif
 111 }
 112
 113 EXPORT_SYMBOL(machine_power_off);
 114
 115 void show_regs(struct pt_regs * regs)
 116 {
 117         printk("\n");
 118         printk("Pid : %d, Comm: %20s\n", current->pid, current->comm);
 119         print_symbol("PC is at %s\n", regs->pc);
 120         printk("PC  : %08lx SP  : %08lx SR  : %08lx ",
 121                regs->pc, regs->regs[15], regs->sr);
 122 #ifdef CONFIG_MMU
 123         printk("TEA : %08x    ", ctrl_inl(MMU_TEA));
 124 #else
 125         printk("                  ");
 126 #endif
 127         printk("%s\n", print_tainted());
 128
 129         printk("R0  : %08lx R1  : %08lx R2  : %08lx R3  : %08lx\n",
 130                regs->regs[0],regs->regs[1],
 131                regs->regs[2],regs->regs[3]);
 132         printk("R4  : %08lx R5  : %08lx R6  : %08lx R7  : %08lx\n",
 133                regs->regs[4],regs->regs[5],
 134                regs->regs[6],regs->regs[7]);
 135         printk("R8  : %08lx R9  : %08lx R10 : %08lx R11 : %08lx\n",
 136                regs->regs[8],regs->regs[9],
 137                regs->regs[10],regs->regs[11]);
 138         printk("R12 : %08lx R13 : %08lx R14 : %08lx\n",
 139                regs->regs[12],regs->regs[13],
 140                regs->regs[14]);
 141         printk("MACH: %08lx MACL: %08lx GBR : %08lx PR  : %08lx\n",
 142                regs->mach, regs->macl, regs->gbr, regs->pr);
 143
 144         /*
 145          * If we're in kernel mode, dump the stack too..
 146          */
 147         if (!user_mode(regs)) {
 148                 extern void show_task(unsigned long *sp);
 149                 unsigned long sp = regs->regs[15];
 150
 151                 show_task((unsigned long *)sp);
 152         }
 153 }
 154
 155 /*
 156  * Create a kernel thread
 157  */
 158
 159 /*
 160  * This is the mechanism for creating a new kernel thread.
 161  *
 162  */
 163 extern void kernel_thread_helper(void);
 164 __asm__(".align 5\n"
 165         "kernel_thread_helper:\n\t"
 166         "jsr    @r5\n\t"
 167         " nop\n\t"
 168         "mov.l  1f, r1\n\t"
 169         "jsr    @r1\n\t"
 170         " mov   r0, r4\n\t"
 171         ".align 2\n\t"
 172         "1:.long do_exit");
 173
 174 int kernel_thread(int (*fn)(void *), void * arg, unsigned long flags)
 175 {       /* Don't use this in BL=1(cli).  Or else, CPU resets! */
 176         struct pt_regs regs;
 177
 178         memset(&regs, 0, sizeof(regs));
 179         regs.regs[4] = (unsigned long) arg;
 180         regs.regs[5] = (unsigned long) fn;
 181
 182         regs.pc = (unsigned long) kernel_thread_helper;
 183         regs.sr = (1 << 30);
 184
 185         /* Ok, create the new process.. */
 186         return do_fork(flags | CLONE_VM | CLONE_UNTRACED, 0, &regs, 0, NULL, NULL);
 187 }
 188
 189 /*
 190  * Free current thread data structures etc..
 191  */
 192 void exit_thread(void)
 193 {
 194         if (current->thread.ubc_pc) {
 195                 current->thread.ubc_pc = 0;
 196                 ubc_usercnt -= 1;
 197         }
 198 }
 199
 200 void flush_thread(void)
 201 {
 202 #if defined(CONFIG_CPU_SH4)
 203         struct task_struct *tsk = current;
 204         struct pt_regs *regs = (struct pt_regs *)
 205                                 ((unsigned long)tsk->thread_info
 206                                  + THREAD_SIZE - sizeof(struct pt_regs)
 207                                  - sizeof(unsigned long));
 208
 209         /* Forget lazy FPU state */
 210         clear_fpu(tsk, regs);
 211         tsk->used_math = 0;
 212 #endif
 213 }
 214
 215 void release_thread(struct task_struct *dead_task)
 216 {
 217         /* do nothing */
 218 }
 219
 220 /* Fill in the fpu structure for a core dump.. */
 221 int dump_fpu(struct pt_regs *regs, elf_fpregset_t *fpu)
 222 {
 223         int fpvalid = 0;
 224
 225 #if defined(CONFIG_CPU_SH4)
 226         struct task_struct *tsk = current;
 227
 228         fpvalid = tsk->used_math;
 229         if (fpvalid) {
 230                 unlazy_fpu(tsk, regs);
 231                 memcpy(fpu, &tsk->thread.fpu.hard, sizeof(*fpu));
 232         }
 233 #endif
 234
 235         return fpvalid;
 236 }
 237
 238 /*
 239  * Capture the user space registers if the task is not running (in user space)
 240  */
 241 int dump_task_regs(struct task_struct *tsk, elf_gregset_t *regs)
 242 {
 243         struct pt_regs ptregs;
 244
 245         ptregs = *(struct pt_regs *)
 246                 ((unsigned long)tsk->thread_info + THREAD_SIZE
 247                  - sizeof(struct pt_regs)
 248 #ifdef CONFIG_SH_DSP
 249                  - sizeof(struct pt_dspregs)
 250 #endif
 251                  - sizeof(unsigned long));
 252         elf_core_copy_regs(regs, &ptregs);
 253
 254         return 1;
 255 }
 256
 257 int
 258 dump_task_fpu (struct task_struct *tsk, elf_fpregset_t *fpu)
 259 {
 260         int fpvalid = 0;
 261
 262 #if defined(CONFIG_CPU_SH4)
 263         fpvalid = tsk->used_math;
 264         if (fpvalid) {
 265                 struct pt_regs *regs = (struct pt_regs *)
 266                                         ((unsigned long)tsk->thread_info
 267                                          + THREAD_SIZE - sizeof(struct pt_regs)
 268                                          - sizeof(unsigned long));
 269                 unlazy_fpu(tsk, regs);
 270                 memcpy(fpu, &tsk->thread.fpu.hard, sizeof(*fpu));
 271         }
 272 #endif
 273
 274         return fpvalid;
 275 }
 276
 277 asmlinkage void ret_from_fork(void);
 278
 279 int copy_thread(int nr, unsigned long clone_flags, unsigned long usp,
 280                 unsigned long unused,
 281                 struct task_struct *p, struct pt_regs *regs)
 282 {
 283         struct pt_regs *childregs;
 284 #if defined(CONFIG_CPU_SH4)
 285         struct task_struct *tsk = current;
 286
 287         unlazy_fpu(tsk, regs);
 288         p->thread.fpu = tsk->thread.fpu;
 289         p->used_math = tsk->used_math;
 290 #endif
 291
 292         childregs = ((struct pt_regs *)
 293                 (THREAD_SIZE + (unsigned long) p->thread_info)
 294 #ifdef CONFIG_SH_DSP
 295                 - sizeof(struct pt_dspregs)
 296 #endif
 297                 - sizeof(unsigned long)) - 1;
 298         *childregs = *regs;
 299
 300         if (user_mode(regs)) {
 301                 childregs->regs[15] = usp;
 302         } else {
 303                 childregs->regs[15] = (unsigned long)p->thread_info + THREAD_SIZE;
 304         }
 305         if (clone_flags & CLONE_SETTLS) {
 306                 childregs->gbr = childregs->regs[0];
 307         }
 308         childregs->regs[0] = 0; /* Set return value for child */
 309         p->set_child_tid = p->clear_child_tid = NULL;
 310
 311         p->thread.sp = (unsigned long) childregs;
 312         p->thread.pc = (unsigned long) ret_from_fork;
 313
 314         p->thread.ubc_pc = 0;
 315
 316         return 0;
 317 }
 318
 319 /*
 320  * fill in the user structure for a core dump..
 321  */
 322 void dump_thread(struct pt_regs * regs, struct user * dump)
 323 {
 324         dump->magic = CMAGIC;
 325         dump->start_code = current->mm->start_code;
 326         dump->start_data  = current->mm->start_data;
 327         dump->start_stack = regs->regs[15] & ~(PAGE_SIZE - 1);
 328         dump->u_tsize = (current->mm->end_code - dump->start_code) >> PAGE_SHIFT;
 329         dump->u_dsize = (current->mm->brk + (PAGE_SIZE-1) - dump->start_data) >> PAGE_SHIFT;
 330         dump->u_ssize = (current->mm->start_stack - dump->start_stack +
 331                          PAGE_SIZE - 1) >> PAGE_SHIFT;
 332         /* Debug registers will come here. */
 333
 334         dump->regs = *regs;
 335
 336         dump->u_fpvalid = dump_fpu(regs, &dump->fpu);
 337 }
 338
 339 /* Tracing by user break controller.  */
 340 static void
 341 ubc_set_tracing(int asid, unsigned long pc)
 342 {
 343         ctrl_outl(pc, UBC_BARA);
 344
 345         /* We don't have any ASID settings for the SH-2! */
 346         if (cpu_data->type != CPU_SH7604)
 347                 ctrl_outb(asid, UBC_BASRA);
 348
 349         ctrl_outl(0, UBC_BAMRA);
 350
 351         if (cpu_data->type == CPU_SH7729) {
 352                 ctrl_outw(BBR_INST | BBR_READ | BBR_CPU, UBC_BBRA);
 353                 ctrl_outl(BRCR_PCBA | BRCR_PCTE, UBC_BRCR);
 354         } else {
 355                 ctrl_outw(BBR_INST | BBR_READ, UBC_BBRA);
 356                 ctrl_outw(BRCR_PCBA, UBC_BRCR);
 357         }
 358 }
 359
 360 /*
 361  *      switch_to(x,y) should switch tasks from x to y.
 362  *
 363  */
 364 struct task_struct *__switch_to(struct task_struct *prev, struct task_struct *next)
 365 {
 366 #if defined(CONFIG_CPU_SH4)
 367         struct pt_regs *regs = (struct pt_regs *)
 368                                 ((unsigned long)prev->thread_info
 369                                  + THREAD_SIZE - sizeof(struct pt_regs)
 370                                  - sizeof(unsigned long));
 371         unlazy_fpu(prev, regs);
 372 #endif
 373
 374 #ifdef CONFIG_PREEMPT
 375         {
 376                 unsigned long flags;
 377                 struct pt_regs *regs;
 378
 379                 local_irq_save(flags);
 380                 regs = (struct pt_regs *)
 381                         ((unsigned long)prev->thread_info
 382                          + THREAD_SIZE - sizeof(struct pt_regs)
 383 #ifdef CONFIG_SH_DSP
 384                          - sizeof(struct pt_dspregs)
 385 #endif
 386                          - sizeof(unsigned long));
 387                 if (user_mode(regs) && regs->regs[15] >= 0xc0000000) {
 388                         int offset = (int)regs->regs[15];
 389
 390                         /* Reset stack pointer: clear critical region mark */
 391                         regs->regs[15] = regs->regs[1];
 392                         if (regs->pc < regs->regs[0])
 393                                 /* Go to rewind point */
 394                                 regs->pc = regs->regs[0] + offset;
 395                 }
 396                 local_irq_restore(flags);
 397         }
 398 #endif
 399
 400         /*
 401          * Restore the kernel mode register
 402          *      k7 (r7_bank1)
 403          */
 404         asm volatile("ldc       %0, r7_bank"
 405                      : /* no output */
 406                      : "r" (next->thread_info));
 407
 408 #ifdef CONFIG_MMU
 409         /* If no tasks are using the UBC, we're done */
 410         if (ubc_usercnt == 0)
 411                 /* If no tasks are using the UBC, we're done */;
 412         else if (next->thread.ubc_pc && next->mm) {
 413                 ubc_set_tracing(next->mm->context & MMU_CONTEXT_ASID_MASK,
 414                                 next->thread.ubc_pc);
 415         } else {
 416                 ctrl_outw(0, UBC_BBRA);
 417                 ctrl_outw(0, UBC_BBRB);
 418         }
 419 #endif
 420
 421         return prev;
 422 }
 423
 424 asmlinkage int sys_fork(unsigned long r4, unsigned long r5,
 425                         unsigned long r6, unsigned long r7,
 426                         struct pt_regs regs)
 427 {
 428 #ifdef CONFIG_MMU
 429         return do_fork(SIGCHLD, regs.regs[15], &regs, 0, NULL, NULL);
 430 #else
 431         /* fork almost works, enough to trick you into looking elsewhere :-( */
 432         return -EINVAL;
 433 #endif
 434 }
 435
 436 asmlinkage int sys_clone(unsigned long clone_flags, unsigned long newsp,
 437                          unsigned long parent_tidptr,
 438                          unsigned long child_tidptr,
 439                          struct pt_regs regs)
 440 {
 441         if (!newsp)
 442                 newsp = regs.regs[15];
 443         return do_fork(clone_flags, newsp, &regs, 0,
 444                         (int __user *)parent_tidptr, (int __user *)child_tidptr);
 445 }
 446
 447 /*
 448  * This is trivial, and on the face of it looks like it
 449  * could equally well be done in user mode.
 450  *
 451  * Not so, for quite unobvious reasons - register pressure.
 452  * In user mode vfork() cannot have a stack frame, and if
 453  * done by calling the "clone()" system call directly, you
 454  * do not have enough call-clobbered registers to hold all
 455  * the information you need.
 456  */
 457 asmlinkage int sys_vfork(unsigned long r4, unsigned long r5,
 458                          unsigned long r6, unsigned long r7,
 459                          struct pt_regs regs)
 460 {
 461         return do_fork(CLONE_VFORK | CLONE_VM | SIGCHLD, regs.regs[15], &regs,
 462                        0, NULL, NULL);
 463 }
 464
 465 /*
 466  * sys_execve() executes a new program.
 467  */
 468 asmlinkage int sys_execve(char *ufilename, char **uargv,
 469                           char **uenvp, unsigned long r7,
 470                           struct pt_regs regs)
 471 {
 472         int error;
 473         char *filename;
 474
 475         filename = getname((char __user *)ufilename);
 476         error = PTR_ERR(filename);
 477         if (IS_ERR(filename))
 478                 goto out;
 479
 480         error = do_execve(filename,
 481                           (char __user * __user *)uargv,
 482                           (char __user * __user *)uenvp,
 483                           &regs);
 484         if (error == 0)
 485                 current->ptrace &= ~PT_DTRACE;
 486         putname(filename);
 487 out:
 488         return error;
 489 }
 490
 491 unsigned long get_wchan(struct task_struct *p)
 492 {
 493         unsigned long schedule_frame;
 494         unsigned long pc;
 495
 496         if (!p || p == current || p->state == TASK_RUNNING)
 497                 return 0;
 498
 499         /*
 500          * The same comment as on the Alpha applies here, too ...
 501          */
 502         pc = thread_saved_pc(p);
 503         if (in_sched_functions(pc)) {
 504                 schedule_frame = ((unsigned long *)(long)p->thread.sp)[1];
 505                 return (unsigned long)((unsigned long *)schedule_frame)[1];
 506         }
 507         return pc;
 508 }
 509
 510 asmlinkage void break_point_trap(unsigned long r4, unsigned long r5,
 511                                  unsigned long r6, unsigned long r7,
 512                                  struct pt_regs regs)
 513 {
 514         /* Clear tracing.  */
 515         ctrl_outw(0, UBC_BBRA);
 516         ctrl_outw(0, UBC_BBRB);
 517         current->thread.ubc_pc = 0;
 518         ubc_usercnt -= 1;
 519
 520         force_sig(SIGTRAP, current);
 521 }
 522
 523 asmlinkage void break_point_trap_software(unsigned long r4, unsigned long r5,
 524                                           unsigned long r6, unsigned long r7,
 525                                           struct pt_regs regs)
 526 {
 527         regs.pc -= 2;
 528         force_sig(SIGTRAP, current);
 529 }