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