arch/arm/kernel/process.c

   1 /*
   2  *  linux/arch/arm/kernel/process.c
   3  *
   4  *  Copyright (C) 1996-2000 Russell King - Converted to ARM.
   5  *  Original Copyright (C) 1995  Linus Torvalds
   6  *
   7  * This program is free software; you can redistribute it and/or modify
   8  * it under the terms of the GNU General Public License version 2 as
   9  * published by the Free Software Foundation.
  10  */
  11 #include <stdarg.h>
  12
  13 #include <linux/module.h>
  14 #include <linux/sched.h>
  15 #include <linux/kernel.h>
  16 #include <linux/mm.h>
  17 #include <linux/stddef.h>
  18 #include <linux/unistd.h>
  19 #include <linux/slab.h>
  20 #include <linux/user.h>
  21 #include <linux/a.out.h>
  22 #include <linux/delay.h>
  23 #include <linux/reboot.h>
  24 #include <linux/interrupt.h>
  25 #include <linux/kallsyms.h>
  26 #include <linux/init.h>
  27 #include <linux/cpu.h>
  28 #include <linux/elfcore.h>
  29 #include <linux/pm.h>
  30 #include <linux/tick.h>
  31 #include <linux/utsname.h>
  32
  33 #include <asm/leds.h>
  34 #include <asm/processor.h>
  35 #include <asm/system.h>
  36 #include <asm/thread_notify.h>
  37 #include <asm/uaccess.h>
  38 #include <asm/mach/time.h>
  39
  40 static const char *processor_modes[] = {
  41   "USER_26", "FIQ_26" , "IRQ_26" , "SVC_26" , "UK4_26" , "UK5_26" , "UK6_26" , "UK7_26" ,
  42   "UK8_26" , "UK9_26" , "UK10_26", "UK11_26", "UK12_26", "UK13_26", "UK14_26", "UK15_26",
  43   "USER_32", "FIQ_32" , "IRQ_32" , "SVC_32" , "UK4_32" , "UK5_32" , "UK6_32" , "ABT_32" ,
  44   "UK8_32" , "UK9_32" , "UK10_32", "UND_32" , "UK12_32", "UK13_32", "UK14_32", "SYS_32"
  45 };
  46
  47 extern void setup_mm_for_reboot(char mode);
  48
  49 static volatile int hlt_counter;
  50
  51 #include <asm/arch/system.h>
  52
  53 void disable_hlt(void)
  54 {
  55         hlt_counter++;
  56 }
  57
  58 EXPORT_SYMBOL(disable_hlt);
  59
  60 void enable_hlt(void)
  61 {
  62         hlt_counter--;
  63 }
  64
  65 EXPORT_SYMBOL(enable_hlt);
  66
  67 static int __init nohlt_setup(char *__unused)
  68 {
  69         hlt_counter = 1;
  70         return 1;
  71 }
  72
  73 static int __init hlt_setup(char *__unused)
  74 {
  75         hlt_counter = 0;
  76         return 1;
  77 }
  78
  79 __setup("nohlt", nohlt_setup);
  80 __setup("hlt", hlt_setup);
  81
  82 void arm_machine_restart(char mode)
  83 {
  84         /*
  85          * Clean and disable cache, and turn off interrupts
  86          */
  87         cpu_proc_fin();
  88
  89         /*
  90          * Tell the mm system that we are going to reboot -
  91          * we may need it to insert some 1:1 mappings so that
  92          * soft boot works.
  93          */
  94         setup_mm_for_reboot(mode);
  95
  96         /*
  97          * Now call the architecture specific reboot code.
  98          */
  99         arch_reset(mode);
 100
 101         /*
 102          * Whoops - the architecture was unable to reboot.
 103          * Tell the user!
 104          */
 105         mdelay(1000);
 106         printk("Reboot failed -- System halted\n");
 107         while (1);
 108 }
 109
 110 /*
 111  * Function pointers to optional machine specific functions
 112  */
 113 void (*pm_idle)(void);
 114 EXPORT_SYMBOL(pm_idle);
 115
 116 void (*pm_power_off)(void);
 117 EXPORT_SYMBOL(pm_power_off);
 118
 119 void (*arm_pm_restart)(char str) = arm_machine_restart;
 120 EXPORT_SYMBOL_GPL(arm_pm_restart);
 121
 122
 123 /*
 124  * This is our default idle handler.  We need to disable
 125  * interrupts here to ensure we don't miss a wakeup call.
 126  */
 127 static void default_idle(void)
 128 {
 129         if (hlt_counter)
 130                 cpu_relax();
 131         else {
 132                 local_irq_disable();
 133                 if (!need_resched()) {
 134                         timer_dyn_reprogram();
 135                         arch_idle();
 136                 }
 137                 local_irq_enable();
 138         }
 139 }
 140
 141 /*
 142  * The idle thread.  We try to conserve power, while trying to keep
 143  * overall latency low.  The architecture specific idle is passed
 144  * a value to indicate the level of "idleness" of the system.
 145  */
 146 void cpu_idle(void)
 147 {
 148         local_fiq_enable();
 149
 150         /* endless idle loop with no priority at all */
 151         while (1) {
 152                 void (*idle)(void) = pm_idle;
 153
 154 #ifdef CONFIG_HOTPLUG_CPU
 155                 if (cpu_is_offline(smp_processor_id())) {
 156                         leds_event(led_idle_start);
 157                         cpu_die();
 158                 }
 159 #endif
 160
 161                 if (!idle)
 162                         idle = default_idle;
 163                 leds_event(led_idle_start);
 164                 tick_nohz_stop_sched_tick();
 165                 while (!need_resched())
 166                         idle();
 167                 leds_event(led_idle_end);
 168                 tick_nohz_restart_sched_tick();
 169                 preempt_enable_no_resched();
 170                 schedule();
 171                 preempt_disable();
 172         }
 173 }
 174
 175 static char reboot_mode = 'h';
 176
 177 int __init reboot_setup(char *str)
 178 {
 179         reboot_mode = str[0];
 180         return 1;
 181 }
 182
 183 __setup("reboot=", reboot_setup);
 184
 185 void machine_halt(void)
 186 {
 187 }
 188
 189
 190 void machine_power_off(void)
 191 {
 192         if (pm_power_off)
 193                 pm_power_off();
 194 }
 195
 196 void machine_restart(char * __unused)
 197 {
 198         arm_pm_restart(reboot_mode);
 199 }
 200
 201 void __show_regs(struct pt_regs *regs)
 202 {
 203         unsigned long flags;
 204         char buf[64];
 205
 206         printk("CPU: %d    %s  (%s %.*s)\n",
 207                 smp_processor_id(), print_tainted(), init_utsname()->release,
 208                 (int)strcspn(init_utsname()->version, " "),
 209                 init_utsname()->version);
 210         print_symbol("PC is at %s\n", instruction_pointer(regs));
 211         print_symbol("LR is at %s\n", regs->ARM_lr);
 212         printk("pc : [<%08lx>]    lr : [<%08lx>]    psr: %08lx\n"
 213                "sp : %08lx  ip : %08lx  fp : %08lx\n",
 214                 regs->ARM_pc, regs->ARM_lr, regs->ARM_cpsr,
 215                 regs->ARM_sp, regs->ARM_ip, regs->ARM_fp);
 216         printk("r10: %08lx  r9 : %08lx  r8 : %08lx\n",
 217                 regs->ARM_r10, regs->ARM_r9,
 218                 regs->ARM_r8);
 219         printk("r7 : %08lx  r6 : %08lx  r5 : %08lx  r4 : %08lx\n",
 220                 regs->ARM_r7, regs->ARM_r6,
 221                 regs->ARM_r5, regs->ARM_r4);
 222         printk("r3 : %08lx  r2 : %08lx  r1 : %08lx  r0 : %08lx\n",
 223                 regs->ARM_r3, regs->ARM_r2,
 224                 regs->ARM_r1, regs->ARM_r0);
 225
 226         flags = regs->ARM_cpsr;
 227         buf[0] = flags & PSR_N_BIT ? 'N' : 'n';
 228         buf[1] = flags & PSR_Z_BIT ? 'Z' : 'z';
 229         buf[2] = flags & PSR_C_BIT ? 'C' : 'c';
 230         buf[3] = flags & PSR_V_BIT ? 'V' : 'v';
 231         buf[4] = '\0';
 232
 233         printk("Flags: %s  IRQs o%s  FIQs o%s  Mode %s%s  Segment %s\n",
 234                 buf, interrupts_enabled(regs) ? "n" : "ff",
 235                 fast_interrupts_enabled(regs) ? "n" : "ff",
 236                 processor_modes[processor_mode(regs)],
 237                 thumb_mode(regs) ? " (T)" : "",
 238                 get_fs() == get_ds() ? "kernel" : "user");
 239 #ifdef CONFIG_CPU_CP15
 240         {
 241                 unsigned int ctrl;
 242
 243                 buf[0] = '\0';
 244 #ifdef CONFIG_CPU_CP15_MMU
 245                 {
 246                         unsigned int transbase, dac;
 247                         asm("mrc p15, 0, %0, c2, c0\n\t"
 248                             "mrc p15, 0, %1, c3, c0\n"
 249                             : "=r" (transbase), "=r" (dac));
 250                         snprintf(buf, sizeof(buf), "  Table: %08x  DAC: %08x",
 251                                 transbase, dac);
 252                 }
 253 #endif
 254                 asm("mrc p15, 0, %0, c1, c0\n" : "=r" (ctrl));
 255
 256                 printk("Control: %08x%s\n", ctrl, buf);
 257         }
 258 #endif
 259 }
 260
 261 void show_regs(struct pt_regs * regs)
 262 {
 263         printk("\n");
 264         printk("Pid: %d, comm: %20s\n", current->pid, current->comm);
 265         __show_regs(regs);
 266         __backtrace();
 267 }
 268
 269 void show_fpregs(struct user_fp *regs)
 270 {
 271         int i;
 272
 273         for (i = 0; i < 8; i++) {
 274                 unsigned long *p;
 275                 char type;
 276
 277                 p = (unsigned long *)(regs->fpregs + i);
 278
 279                 switch (regs->ftype[i]) {
 280                         case 1: type = 'f'; break;
 281                         case 2: type = 'd'; break;
 282                         case 3: type = 'e'; break;
 283                         default: type = '?'; break;
 284                 }
 285                 if (regs->init_flag)
 286                         type = '?';
 287
 288                 printk("  f%d(%c): %08lx %08lx %08lx%c",
 289                         i, type, p[0], p[1], p[2], i & 1 ? '\n' : ' ');
 290         }
 291
 292
 293         printk("FPSR: %08lx FPCR: %08lx\n",
 294                 (unsigned long)regs->fpsr,
 295                 (unsigned long)regs->fpcr);
 296 }
 297
 298 /*
 299  * Free current thread data structures etc..
 300  */
 301 void exit_thread(void)
 302 {
 303 }
 304
 305 ATOMIC_NOTIFIER_HEAD(thread_notify_head);
 306
 307 EXPORT_SYMBOL_GPL(thread_notify_head);
 308
 309 void flush_thread(void)
 310 {
 311         struct thread_info *thread = current_thread_info();
 312         struct task_struct *tsk = current;
 313
 314         memset(thread->used_cp, 0, sizeof(thread->used_cp));
 315         memset(&tsk->thread.debug, 0, sizeof(struct debug_info));
 316         memset(&thread->fpstate, 0, sizeof(union fp_state));
 317
 318         thread_notify(THREAD_NOTIFY_FLUSH, thread);
 319 }
 320
 321 void release_thread(struct task_struct *dead_task)
 322 {
 323         struct thread_info *thread = task_thread_info(dead_task);
 324
 325         thread_notify(THREAD_NOTIFY_RELEASE, thread);
 326 }
 327
 328 asmlinkage void ret_from_fork(void) __asm__("ret_from_fork");
 329
 330 int
 331 copy_thread(int nr, unsigned long clone_flags, unsigned long stack_start,
 332             unsigned long stk_sz, struct task_struct *p, struct pt_regs *regs)
 333 {
 334         struct thread_info *thread = task_thread_info(p);
 335         struct pt_regs *childregs = task_pt_regs(p);
 336
 337         *childregs = *regs;
 338         childregs->ARM_r0 = 0;
 339         childregs->ARM_sp = stack_start;
 340
 341         memset(&thread->cpu_context, 0, sizeof(struct cpu_context_save));
 342         thread->cpu_context.sp = (unsigned long)childregs;
 343         thread->cpu_context.pc = (unsigned long)ret_from_fork;
 344
 345         if (clone_flags & CLONE_SETTLS)
 346                 thread->tp_value = regs->ARM_r3;
 347
 348         return 0;
 349 }
 350
 351 /*
 352  * fill in the fpe structure for a core dump...
 353  */
 354 int dump_fpu (struct pt_regs *regs, struct user_fp *fp)
 355 {
 356         struct thread_info *thread = current_thread_info();
 357         int used_math = thread->used_cp[1] | thread->used_cp[2];
 358
 359         if (used_math)
 360                 memcpy(fp, &thread->fpstate.soft, sizeof (*fp));
 361
 362         return used_math != 0;
 363 }
 364 EXPORT_SYMBOL(dump_fpu);
 365
 366 /*
 367  * fill in the user structure for a core dump..
 368  */
 369 void dump_thread(struct pt_regs * regs, struct user * dump)
 370 {
 371         struct task_struct *tsk = current;
 372
 373         dump->magic = CMAGIC;
 374         dump->start_code = tsk->mm->start_code;
 375         dump->start_stack = regs->ARM_sp & ~(PAGE_SIZE - 1);
 376
 377         dump->u_tsize = (tsk->mm->end_code - tsk->mm->start_code) >> PAGE_SHIFT;
 378         dump->u_dsize = (tsk->mm->brk - tsk->mm->start_data + PAGE_SIZE - 1) >> PAGE_SHIFT;
 379         dump->u_ssize = 0;
 380
 381         dump->u_debugreg[0] = tsk->thread.debug.bp[0].address;
 382         dump->u_debugreg[1] = tsk->thread.debug.bp[1].address;
 383         dump->u_debugreg[2] = tsk->thread.debug.bp[0].insn.arm;
 384         dump->u_debugreg[3] = tsk->thread.debug.bp[1].insn.arm;
 385         dump->u_debugreg[4] = tsk->thread.debug.nsaved;
 386
 387         if (dump->start_stack < 0x04000000)
 388                 dump->u_ssize = (0x04000000 - dump->start_stack) >> PAGE_SHIFT;
 389
 390         dump->regs = *regs;
 391         dump->u_fpvalid = dump_fpu (regs, &dump->u_fp);
 392 }
 393 EXPORT_SYMBOL(dump_thread);
 394
 395 /*
 396  * Shuffle the argument into the correct register before calling the
 397  * thread function.  r1 is the thread argument, r2 is the pointer to
 398  * the thread function, and r3 points to the exit function.
 399  */
 400 extern void kernel_thread_helper(void);
 401 asm(    ".section .text\n"
 402 "       .align\n"
 403 "       .type   kernel_thread_helper, #function\n"
 404 "kernel_thread_helper:\n"
 405 "       mov     r0, r1\n"
 406 "       mov     lr, r3\n"
 407 "       mov     pc, r2\n"
 408 "       .size   kernel_thread_helper, . - kernel_thread_helper\n"
 409 "       .previous");
 410
 411 /*
 412  * Create a kernel thread.
 413  */
 414 pid_t kernel_thread(int (*fn)(void *), void *arg, unsigned long flags)
 415 {
 416         struct pt_regs regs;
 417
 418         memset(&regs, 0, sizeof(regs));
 419
 420         regs.ARM_r1 = (unsigned long)arg;
 421         regs.ARM_r2 = (unsigned long)fn;
 422         regs.ARM_r3 = (unsigned long)do_exit;
 423         regs.ARM_pc = (unsigned long)kernel_thread_helper;
 424         regs.ARM_cpsr = SVC_MODE;
 425
 426         return do_fork(flags|CLONE_VM|CLONE_UNTRACED, 0, &regs, 0, NULL, NULL);
 427 }
 428 EXPORT_SYMBOL(kernel_thread);
 429
 430 unsigned long get_wchan(struct task_struct *p)
 431 {
 432         unsigned long fp, lr;
 433         unsigned long stack_start, stack_end;
 434         int count = 0;
 435         if (!p || p == current || p->state == TASK_RUNNING)
 436                 return 0;
 437
 438         stack_start = (unsigned long)end_of_stack(p);
 439         stack_end = (unsigned long)task_stack_page(p) + THREAD_SIZE;
 440
 441         fp = thread_saved_fp(p);
 442         do {
 443                 if (fp < stack_start || fp > stack_end)
 444                         return 0;
 445                 lr = pc_pointer (((unsigned long *)fp)[-1]);
 446                 if (!in_sched_functions(lr))
 447                         return lr;
 448                 fp = *(unsigned long *) (fp - 12);
 449         } while (count ++ < 16);
 450         return 0;
 451 }