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