arch/avr32/kernel/process.c

   1 /*
   2  * Copyright (C) 2004-2006 Atmel Corporation
   3  *
   4  * This program is free software; you can redistribute it and/or modify
   5  * it under the terms of the GNU General Public License version 2 as
   6  * published by the Free Software Foundation.
   7  */
   8 #include <linux/sched.h>
   9 #include <linux/module.h>
  10 #include <linux/kallsyms.h>
  11 #include <linux/fs.h>
  12 #include <linux/ptrace.h>
  13 #include <linux/reboot.h>
  14 <<<<<<< HEAD:arch/avr32/kernel/process.c
  15 =======
  16 #include <linux/tick.h>
  17 >>>>>>> 264e3e889d86e552b4191d69bb60f4f3b383135a:arch/avr32/kernel/process.c
  18 #include <linux/uaccess.h>
  19 #include <linux/unistd.h>
  20
  21 #include <asm/sysreg.h>
  22 #include <asm/ocd.h>
  23
  24 void (*pm_power_off)(void) = NULL;
  25 EXPORT_SYMBOL(pm_power_off);
  26
  27 extern void cpu_idle_sleep(void);
  28
  29 /*
  30  * This file handles the architecture-dependent parts of process handling..
  31  */
  32
  33 void cpu_idle(void)
  34 {
  35         /* endless idle loop with no priority at all */
  36         while (1) {
  37 <<<<<<< HEAD:arch/avr32/kernel/process.c
  38 =======
  39                 tick_nohz_stop_sched_tick();
  40 >>>>>>> 264e3e889d86e552b4191d69bb60f4f3b383135a:arch/avr32/kernel/process.c
  41                 while (!need_resched())
  42                         cpu_idle_sleep();
  43 <<<<<<< HEAD:arch/avr32/kernel/process.c
  44 =======
  45                 tick_nohz_restart_sched_tick();
  46 >>>>>>> 264e3e889d86e552b4191d69bb60f4f3b383135a:arch/avr32/kernel/process.c
  47                 preempt_enable_no_resched();
  48                 schedule();
  49                 preempt_disable();
  50         }
  51 }
  52
  53 void machine_halt(void)
  54 {
  55         /*
  56          * Enter Stop mode. The 32 kHz oscillator will keep running so
  57          * the RTC will keep the time properly and the system will
  58          * boot quickly.
  59          */
  60         asm volatile("sleep 3\n\t"
  61                      "sub pc, -2");
  62 }
  63
  64 void machine_power_off(void)
  65 {
  66 }
  67
  68 void machine_restart(char *cmd)
  69 {
  70         ocd_write(DC, (1 << OCD_DC_DBE_BIT));
  71         ocd_write(DC, (1 << OCD_DC_RES_BIT));
  72         while (1) ;
  73 }
  74
  75 /*
  76  * PC is actually discarded when returning from a system call -- the
  77  * return address must be stored in LR. This function will make sure
  78  * LR points to do_exit before starting the thread.
  79  *
  80  * Also, when returning from fork(), r12 is 0, so we must copy the
  81  * argument as well.
  82  *
  83  *  r0 : The argument to the main thread function
  84  *  r1 : The address of do_exit
  85  *  r2 : The address of the main thread function
  86  */
  87 asmlinkage extern void kernel_thread_helper(void);
  88 __asm__("       .type   kernel_thread_helper, @function\n"
  89         "kernel_thread_helper:\n"
  90         "       mov     r12, r0\n"
  91         "       mov     lr, r2\n"
  92         "       mov     pc, r1\n"
  93         "       .size   kernel_thread_helper, . - kernel_thread_helper");
  94
  95 int kernel_thread(int (*fn)(void *), void *arg, unsigned long flags)
  96 {
  97         struct pt_regs regs;
  98
  99         memset(&regs, 0, sizeof(regs));
 100
 101         regs.r0 = (unsigned long)arg;
 102         regs.r1 = (unsigned long)fn;
 103         regs.r2 = (unsigned long)do_exit;
 104         regs.lr = (unsigned long)kernel_thread_helper;
 105         regs.pc = (unsigned long)kernel_thread_helper;
 106         regs.sr = MODE_SUPERVISOR;
 107
 108         return do_fork(flags | CLONE_VM | CLONE_UNTRACED,
 109                        0, &regs, 0, NULL, NULL);
 110 }
 111 EXPORT_SYMBOL(kernel_thread);
 112
 113 /*
 114  * Free current thread data structures etc
 115  */
 116 void exit_thread(void)
 117 {
 118         ocd_disable(current);
 119 }
 120
 121 void flush_thread(void)
 122 {
 123         /* nothing to do */
 124 }
 125
 126 void release_thread(struct task_struct *dead_task)
 127 {
 128         /* do nothing */
 129 }
 130
 131 static void dump_mem(const char *str, const char *log_lvl,
 132                      unsigned long bottom, unsigned long top)
 133 {
 134         unsigned long p;
 135         int i;
 136
 137         printk("%s%s(0x%08lx to 0x%08lx)\n", log_lvl, str, bottom, top);
 138
 139         for (p = bottom & ~31; p < top; ) {
 140                 printk("%s%04lx: ", log_lvl, p & 0xffff);
 141
 142                 for (i = 0; i < 8; i++, p += 4) {
 143                         unsigned int val;
 144
 145                         if (p < bottom || p >= top)
 146                                 printk("         ");
 147                         else {
 148                                 if (__get_user(val, (unsigned int __user *)p)) {
 149                                         printk("\n");
 150                                         goto out;
 151                                 }
 152                                 printk("%08x ", val);
 153                         }
 154                 }
 155                 printk("\n");
 156         }
 157
 158 out:
 159         return;
 160 }
 161
 162 static inline int valid_stack_ptr(struct thread_info *tinfo, unsigned long p)
 163 {
 164         return (p > (unsigned long)tinfo)
 165                 && (p < (unsigned long)tinfo + THREAD_SIZE - 3);
 166 }
 167
 168 #ifdef CONFIG_FRAME_POINTER
 169 static void show_trace_log_lvl(struct task_struct *tsk, unsigned long *sp,
 170                                struct pt_regs *regs, const char *log_lvl)
 171 {
 172         unsigned long lr, fp;
 173         struct thread_info *tinfo;
 174
 175         if (regs)
 176                 fp = regs->r7;
 177         else if (tsk == current)
 178                 asm("mov %0, r7" : "=r"(fp));
 179         else
 180                 fp = tsk->thread.cpu_context.r7;
 181
 182         /*
 183          * Walk the stack as long as the frame pointer (a) is within
 184          * the kernel stack of the task, and (b) it doesn't move
 185          * downwards.
 186          */
 187         tinfo = task_thread_info(tsk);
 188         printk("%sCall trace:\n", log_lvl);
 189         while (valid_stack_ptr(tinfo, fp)) {
 190                 unsigned long new_fp;
 191
 192                 lr = *(unsigned long *)fp;
 193 #ifdef CONFIG_KALLSYMS
 194                 printk("%s [<%08lx>] ", log_lvl, lr);
 195 #else
 196                 printk(" [<%08lx>] ", lr);
 197 #endif
 198                 print_symbol("%s\n", lr);
 199
 200                 new_fp = *(unsigned long *)(fp + 4);
 201                 if (new_fp <= fp)
 202                         break;
 203                 fp = new_fp;
 204         }
 205         printk("\n");
 206 }
 207 #else
 208 static void show_trace_log_lvl(struct task_struct *tsk, unsigned long *sp,
 209                                struct pt_regs *regs, const char *log_lvl)
 210 {
 211         unsigned long addr;
 212
 213         printk("%sCall trace:\n", log_lvl);
 214
 215         while (!kstack_end(sp)) {
 216                 addr = *sp++;
 217                 if (kernel_text_address(addr)) {
 218 #ifdef CONFIG_KALLSYMS
 219                         printk("%s [<%08lx>] ", log_lvl, addr);
 220 #else
 221                         printk(" [<%08lx>] ", addr);
 222 #endif
 223                         print_symbol("%s\n", addr);
 224                 }
 225         }
 226         printk("\n");
 227 }
 228 #endif
 229
 230 void show_stack_log_lvl(struct task_struct *tsk, unsigned long sp,
 231                         struct pt_regs *regs, const char *log_lvl)
 232 {
 233         struct thread_info *tinfo;
 234
 235         if (sp == 0) {
 236                 if (tsk)
 237                         sp = tsk->thread.cpu_context.ksp;
 238                 else
 239                         sp = (unsigned long)&tinfo;
 240         }
 241         if (!tsk)
 242                 tsk = current;
 243
 244         tinfo = task_thread_info(tsk);
 245
 246         if (valid_stack_ptr(tinfo, sp)) {
 247                 dump_mem("Stack: ", log_lvl, sp,
 248                          THREAD_SIZE + (unsigned long)tinfo);
 249                 show_trace_log_lvl(tsk, (unsigned long *)sp, regs, log_lvl);
 250         }
 251 }
 252
 253 void show_stack(struct task_struct *tsk, unsigned long *stack)
 254 {
 255         show_stack_log_lvl(tsk, (unsigned long)stack, NULL, "");
 256 }
 257
 258 void dump_stack(void)
 259 {
 260         unsigned long stack;
 261
 262         show_trace_log_lvl(current, &stack, NULL, "");
 263 }
 264 EXPORT_SYMBOL(dump_stack);
 265
 266 static const char *cpu_modes[] = {
 267         "Application", "Supervisor", "Interrupt level 0", "Interrupt level 1",
 268         "Interrupt level 2", "Interrupt level 3", "Exception", "NMI"
 269 };
 270
 271 void show_regs_log_lvl(struct pt_regs *regs, const char *log_lvl)
 272 {
 273         unsigned long sp = regs->sp;
 274         unsigned long lr = regs->lr;
 275         unsigned long mode = (regs->sr & MODE_MASK) >> MODE_SHIFT;
 276
 277         if (!user_mode(regs)) {
 278                 sp = (unsigned long)regs + FRAME_SIZE_FULL;
 279
 280                 printk("%s", log_lvl);
 281                 print_symbol("PC is at %s\n", instruction_pointer(regs));
 282                 printk("%s", log_lvl);
 283                 print_symbol("LR is at %s\n", lr);
 284         }
 285
 286         printk("%spc : [<%08lx>]    lr : [<%08lx>]    %s\n"
 287                "%ssp : %08lx  r12: %08lx  r11: %08lx\n",
 288                log_lvl, instruction_pointer(regs), lr, print_tainted(),
 289                log_lvl, sp, regs->r12, regs->r11);
 290         printk("%sr10: %08lx  r9 : %08lx  r8 : %08lx\n",
 291                log_lvl, regs->r10, regs->r9, regs->r8);
 292         printk("%sr7 : %08lx  r6 : %08lx  r5 : %08lx  r4 : %08lx\n",
 293                log_lvl, regs->r7, regs->r6, regs->r5, regs->r4);
 294         printk("%sr3 : %08lx  r2 : %08lx  r1 : %08lx  r0 : %08lx\n",
 295                log_lvl, regs->r3, regs->r2, regs->r1, regs->r0);
 296         printk("%sFlags: %c%c%c%c%c\n", log_lvl,
 297                regs->sr & SR_Q ? 'Q' : 'q',
 298                regs->sr & SR_V ? 'V' : 'v',
 299                regs->sr & SR_N ? 'N' : 'n',
 300                regs->sr & SR_Z ? 'Z' : 'z',
 301                regs->sr & SR_C ? 'C' : 'c');
 302         printk("%sMode bits: %c%c%c%c%c%c%c%c%c%c\n", log_lvl,
 303                regs->sr & SR_H ? 'H' : 'h',
 304                regs->sr & SR_J ? 'J' : 'j',
 305                regs->sr & SR_DM ? 'M' : 'm',
 306                regs->sr & SR_D ? 'D' : 'd',
 307                regs->sr & SR_EM ? 'E' : 'e',
 308                regs->sr & SR_I3M ? '3' : '.',
 309                regs->sr & SR_I2M ? '2' : '.',
 310                regs->sr & SR_I1M ? '1' : '.',
 311                regs->sr & SR_I0M ? '0' : '.',
 312                regs->sr & SR_GM ? 'G' : 'g');
 313         printk("%sCPU Mode: %s\n", log_lvl, cpu_modes[mode]);
 314         printk("%sProcess: %s [%d] (task: %p thread: %p)\n",
 315                log_lvl, current->comm, current->pid, current,
 316                task_thread_info(current));
 317 }
 318
 319 void show_regs(struct pt_regs *regs)
 320 {
 321         unsigned long sp = regs->sp;
 322
 323         if (!user_mode(regs))
 324                 sp = (unsigned long)regs + FRAME_SIZE_FULL;
 325
 326         show_regs_log_lvl(regs, "");
 327         show_trace_log_lvl(current, (unsigned long *)sp, regs, "");
 328 }
 329 EXPORT_SYMBOL(show_regs);
 330
 331 /* Fill in the fpu structure for a core dump. This is easy -- we don't have any */
 332 int dump_fpu(struct pt_regs *regs, elf_fpregset_t *fpu)
 333 {
 334         /* Not valid */
 335         return 0;
 336 }
 337
 338 asmlinkage void ret_from_fork(void);
 339
 340 int copy_thread(int nr, unsigned long clone_flags, unsigned long usp,
 341                 unsigned long unused,
 342                 struct task_struct *p, struct pt_regs *regs)
 343 {
 344         struct pt_regs *childregs;
 345
 346         childregs = ((struct pt_regs *)(THREAD_SIZE + (unsigned long)task_stack_page(p))) - 1;
 347         *childregs = *regs;
 348
 349         if (user_mode(regs))
 350                 childregs->sp = usp;
 351         else
 352                 childregs->sp = (unsigned long)task_stack_page(p) + THREAD_SIZE;
 353
 354         childregs->r12 = 0; /* Set return value for child */
 355
 356         p->thread.cpu_context.sr = MODE_SUPERVISOR | SR_GM;
 357         p->thread.cpu_context.ksp = (unsigned long)childregs;
 358         p->thread.cpu_context.pc = (unsigned long)ret_from_fork;
 359
 360 <<<<<<< HEAD:arch/avr32/kernel/process.c
 361 =======
 362         clear_tsk_thread_flag(p, TIF_DEBUG);
 363 >>>>>>> 264e3e889d86e552b4191d69bb60f4f3b383135a:arch/avr32/kernel/process.c
 364         if ((clone_flags & CLONE_PTRACE) && test_thread_flag(TIF_DEBUG))
 365                 ocd_enable(p);
 366
 367         return 0;
 368 }
 369
 370 /* r12-r8 are dummy parameters to force the compiler to use the stack */
 371 asmlinkage int sys_fork(struct pt_regs *regs)
 372 {
 373         return do_fork(SIGCHLD, regs->sp, regs, 0, NULL, NULL);
 374 }
 375
 376 asmlinkage int sys_clone(unsigned long clone_flags, unsigned long newsp,
 377                          unsigned long parent_tidptr,
 378                          unsigned long child_tidptr, struct pt_regs *regs)
 379 {
 380         if (!newsp)
 381                 newsp = regs->sp;
 382         return do_fork(clone_flags, newsp, regs, 0,
 383                        (int __user *)parent_tidptr,
 384                        (int __user *)child_tidptr);
 385 }
 386
 387 asmlinkage int sys_vfork(struct pt_regs *regs)
 388 {
 389         return do_fork(CLONE_VFORK | CLONE_VM | SIGCHLD, regs->sp, regs,
 390                        0, NULL, NULL);
 391 }
 392
 393 asmlinkage int sys_execve(char __user *ufilename, char __user *__user *uargv,
 394                           char __user *__user *uenvp, struct pt_regs *regs)
 395 {
 396         int error;
 397         char *filename;
 398
 399         filename = getname(ufilename);
 400         error = PTR_ERR(filename);
 401         if (IS_ERR(filename))
 402                 goto out;
 403
 404         error = do_execve(filename, uargv, uenvp, regs);
 405         if (error == 0)
 406                 current->ptrace &= ~PT_DTRACE;
 407         putname(filename);
 408
 409 out:
 410         return error;
 411 }
 412
 413
 414 /*
 415  * This function is supposed to answer the question "who called
 416  * schedule()?"
 417  */
 418 unsigned long get_wchan(struct task_struct *p)
 419 {
 420         unsigned long pc;
 421         unsigned long stack_page;
 422
 423         if (!p || p == current || p->state == TASK_RUNNING)
 424                 return 0;
 425
 426         stack_page = (unsigned long)task_stack_page(p);
 427         BUG_ON(!stack_page);
 428
 429         /*
 430          * The stored value of PC is either the address right after
 431          * the call to __switch_to() or ret_from_fork.
 432          */
 433         pc = thread_saved_pc(p);
 434         if (in_sched_functions(pc)) {
 435 #ifdef CONFIG_FRAME_POINTER
 436                 unsigned long fp = p->thread.cpu_context.r7;
 437                 BUG_ON(fp < stack_page || fp > (THREAD_SIZE + stack_page));
 438                 pc = *(unsigned long *)fp;
 439 #else
 440                 /*
 441                  * We depend on the frame size of schedule here, which
 442                  * is actually quite ugly. It might be possible to
 443                  * determine the frame size automatically at build
 444                  * time by doing this:
 445                  *   - compile sched.c
 446                  *   - disassemble the resulting sched.o
 447                  *   - look for 'sub sp,??' shortly after '<schedule>:'
 448                  */
 449                 unsigned long sp = p->thread.cpu_context.ksp + 16;
 450                 BUG_ON(sp < stack_page || sp > (THREAD_SIZE + stack_page));
 451                 pc = *(unsigned long *)sp;
 452 #endif
 453         }
 454
 455         return pc;
 456 }