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