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 static const char *isa_modes[] = {
  48   "ARM" , "Thumb" , "Jazelle", "ThumbEE"
  49 };
  50
  51 extern void setup_mm_for_reboot(char mode);
  52
  53 static volatile int hlt_counter;
  54
  55 #include <asm/arch/system.h>
  56
  57 void disable_hlt(void)
  58 {
  59         hlt_counter++;
  60 }
  61
  62 EXPORT_SYMBOL(disable_hlt);
  63
  64 void enable_hlt(void)
  65 {
  66         hlt_counter--;
  67 }
  68
  69 EXPORT_SYMBOL(enable_hlt);
  70
  71 static int __init nohlt_setup(char *__unused)
  72 {
  73         hlt_counter = 1;
  74         return 1;
  75 }
  76
  77 static int __init hlt_setup(char *__unused)
  78 {
  79         hlt_counter = 0;
  80         return 1;
  81 }
  82
  83 __setup("nohlt", nohlt_setup);
  84 __setup("hlt", hlt_setup);
  85
  86 void arm_machine_restart(char mode)
  87 {
  88         /*
  89          * Clean and disable cache, and turn off interrupts
  90          */
  91         cpu_proc_fin();
  92
  93         /*
  94          * Tell the mm system that we are going to reboot -
  95          * we may need it to insert some 1:1 mappings so that
  96          * soft boot works.
  97          */
  98         setup_mm_for_reboot(mode);
  99
 100         /*
 101          * Now call the architecture specific reboot code.
 102          */
 103         arch_reset(mode);
 104
 105         /*
 106          * Whoops - the architecture was unable to reboot.
 107          * Tell the user!
 108          */
 109         mdelay(1000);
 110         printk("Reboot failed -- System halted\n");
 111         while (1);
 112 }
 113
 114 /*
 115  * Function pointers to optional machine specific functions
 116  */
 117 void (*pm_idle)(void);
 118 EXPORT_SYMBOL(pm_idle);
 119
 120 void (*pm_power_off)(void);
 121 EXPORT_SYMBOL(pm_power_off);
 122
 123 void (*arm_pm_restart)(char str) = arm_machine_restart;
 124 EXPORT_SYMBOL_GPL(arm_pm_restart);
 125
 126
 127 /*
 128  * This is our default idle handler.  We need to disable
 129  * interrupts here to ensure we don't miss a wakeup call.
 130  */
 131 static void default_idle(void)
 132 {
 133         if (hlt_counter)
 134                 cpu_relax();
 135         else {
 136                 local_irq_disable();
 137                 if (!need_resched()) {
 138                         timer_dyn_reprogram();
 139                         arch_idle();
 140                 }
 141                 local_irq_enable();
 142         }
 143 }
 144
 145 /*
 146  * The idle thread.  We try to conserve power, while trying to keep
 147  * overall latency low.  The architecture specific idle is passed
 148  * a value to indicate the level of "idleness" of the system.
 149  */
 150 void cpu_idle(void)
 151 {
 152         local_fiq_enable();
 153
 154         /* endless idle loop with no priority at all */
 155         while (1) {
 156                 void (*idle)(void) = pm_idle;
 157
 158 #ifdef CONFIG_HOTPLUG_CPU
 159                 if (cpu_is_offline(smp_processor_id())) {
 160                         leds_event(led_idle_start);
 161                         cpu_die();
 162                 }
 163 #endif
 164
 165                 if (!idle)
 166                         idle = default_idle;
 167                 leds_event(led_idle_start);
 168                 tick_nohz_stop_sched_tick();
 169                 while (!need_resched())
 170                         idle();
 171                 leds_event(led_idle_end);
 172                 tick_nohz_restart_sched_tick();
 173                 preempt_enable_no_resched();
 174                 schedule();
 175                 preempt_disable();
 176         }
 177 }
 178
 179 static char reboot_mode = 'h';
 180
 181 int __init reboot_setup(char *str)
 182 {
 183         reboot_mode = str[0];
 184         return 1;
 185 }
 186
 187 __setup("reboot=", reboot_setup);
 188
 189 void machine_halt(void)
 190 {
 191 }
 192
 193
 194 void machine_power_off(void)
 195 {
 196         if (pm_power_off)
 197                 pm_power_off();
 198 }
 199
 200 void machine_restart(char * __unused)
 201 {
 202         arm_pm_restart(reboot_mode);
 203 }
 204
 205 void __show_regs(struct pt_regs *regs)
 206 {
 207         unsigned long flags;
 208         char buf[64];
 209
 210         printk("CPU: %d    %s  (%s %.*s)\n",
 211                 smp_processor_id(), print_tainted(), init_utsname()->release,
 212                 (int)strcspn(init_utsname()->version, " "),
 213                 init_utsname()->version);
 214         print_symbol("PC is at %s\n", instruction_pointer(regs));
 215         print_symbol("LR is at %s\n", regs->ARM_lr);
 216         printk("pc : [<%08lx>]    lr : [<%08lx>]    psr: %08lx\n"
 217                "sp : %08lx  ip : %08lx  fp : %08lx\n",
 218                 regs->ARM_pc, regs->ARM_lr, regs->ARM_cpsr,
 219                 regs->ARM_sp, regs->ARM_ip, regs->ARM_fp);
 220         printk("r10: %08lx  r9 : %08lx  r8 : %08lx\n",
 221                 regs->ARM_r10, regs->ARM_r9,
 222                 regs->ARM_r8);
 223         printk("r7 : %08lx  r6 : %08lx  r5 : %08lx  r4 : %08lx\n",
 224                 regs->ARM_r7, regs->ARM_r6,
 225                 regs->ARM_r5, regs->ARM_r4);
 226         printk("r3 : %08lx  r2 : %08lx  r1 : %08lx  r0 : %08lx\n",
 227                 regs->ARM_r3, regs->ARM_r2,
 228                 regs->ARM_r1, regs->ARM_r0);
 229
 230         flags = regs->ARM_cpsr;
 231         buf[0] = flags & PSR_N_BIT ? 'N' : 'n';
 232         buf[1] = flags & PSR_Z_BIT ? 'Z' : 'z';
 233         buf[2] = flags & PSR_C_BIT ? 'C' : 'c';
 234         buf[3] = flags & PSR_V_BIT ? 'V' : 'v';
 235         buf[4] = '\0';
 236
 237         printk("Flags: %s  IRQs o%s  FIQs o%s  Mode %s  ISA %s  Segment %s\n",
 238                 buf, interrupts_enabled(regs) ? "n" : "ff",
 239                 fast_interrupts_enabled(regs) ? "n" : "ff",
 240                 processor_modes[processor_mode(regs)],
 241                 isa_modes[isa_mode(regs)],
 242                 get_fs() == get_ds() ? "kernel" : "user");
 243 #ifdef CONFIG_CPU_CP15
 244         {
 245                 unsigned int ctrl;
 246
 247                 buf[0] = '\0';
 248 #ifdef CONFIG_CPU_CP15_MMU
 249                 {
 250                         unsigned int transbase, dac;
 251                         asm("mrc p15, 0, %0, c2, c0\n\t"
 252                             "mrc p15, 0, %1, c3, c0\n"
 253                             : "=r" (transbase), "=r" (dac));
 254                         snprintf(buf, sizeof(buf), "  Table: %08x  DAC: %08x",
 255                                 transbase, dac);
 256                 }
 257 #endif
 258                 asm("mrc p15, 0, %0, c1, c0\n" : "=r" (ctrl));
 259
 260                 printk("Control: %08x%s\n", ctrl, buf);
 261         }
 262 #endif
 263 }
 264
 265 void show_regs(struct pt_regs * regs)
 266 {
 267         printk("\n");
 268         printk("Pid: %d, comm: %20s\n", task_pid_nr(current), current->comm);
 269         __show_regs(regs);
 270         __backtrace();
 271 }
 272
 273 void show_fpregs(struct user_fp *regs)
 274 {
 275         int i;
 276
 277         for (i = 0; i < 8; i++) {
 278                 unsigned long *p;
 279                 char type;
 280
 281                 p = (unsigned long *)(regs->fpregs + i);
 282
 283                 switch (regs->ftype[i]) {
 284                         case 1: type = 'f'; break;
 285                         case 2: type = 'd'; break;
 286                         case 3: type = 'e'; break;
 287                         default: type = '?'; break;
 288                 }
 289                 if (regs->init_flag)
 290                         type = '?';
 291
 292                 printk("  f%d(%c): %08lx %08lx %08lx%c",
 293                         i, type, p[0], p[1], p[2], i & 1 ? '\n' : ' ');
 294         }
 295
 296
 297         printk("FPSR: %08lx FPCR: %08lx\n",
 298                 (unsigned long)regs->fpsr,
 299                 (unsigned long)regs->fpcr);
 300 }
 301
 302 /*
 303  * Free current thread data structures etc..
 304  */
 305 void exit_thread(void)
 306 {
 307 }
 308
 309 ATOMIC_NOTIFIER_HEAD(thread_notify_head);
 310
 311 EXPORT_SYMBOL_GPL(thread_notify_head);
 312
 313 void flush_thread(void)
 314 {
 315         struct thread_info *thread = current_thread_info();
 316         struct task_struct *tsk = current;
 317
 318         memset(thread->used_cp, 0, sizeof(thread->used_cp));
 319         memset(&tsk->thread.debug, 0, sizeof(struct debug_info));
 320         memset(&thread->fpstate, 0, sizeof(union fp_state));
 321
 322         thread_notify(THREAD_NOTIFY_FLUSH, thread);
 323 }
 324
 325 void release_thread(struct task_struct *dead_task)
 326 {
 327         struct thread_info *thread = task_thread_info(dead_task);
 328
 329         thread_notify(THREAD_NOTIFY_RELEASE, thread);
 330 }
 331
 332 asmlinkage void ret_from_fork(void) __asm__("ret_from_fork");
 333
 334 int
 335 copy_thread(int nr, unsigned long clone_flags, unsigned long stack_start,
 336             unsigned long stk_sz, struct task_struct *p, struct pt_regs *regs)
 337 {
 338         struct thread_info *thread = task_thread_info(p);
 339         struct pt_regs *childregs = task_pt_regs(p);
 340
 341         *childregs = *regs;
 342         childregs->ARM_r0 = 0;
 343         childregs->ARM_sp = stack_start;
 344
 345         memset(&thread->cpu_context, 0, sizeof(struct cpu_context_save));
 346         thread->cpu_context.sp = (unsigned long)childregs;
 347         thread->cpu_context.pc = (unsigned long)ret_from_fork;
 348
 349         if (clone_flags & CLONE_SETTLS)
 350                 thread->tp_value = regs->ARM_r3;
 351
 352         return 0;
 353 }
 354
 355 /*
 356  * fill in the fpe structure for a core dump...
 357  */
 358 int dump_fpu (struct pt_regs *regs, struct user_fp *fp)
 359 {
 360         struct thread_info *thread = current_thread_info();
 361         int used_math = thread->used_cp[1] | thread->used_cp[2];
 362
 363         if (used_math)
 364                 memcpy(fp, &thread->fpstate.soft, sizeof (*fp));
 365
 366         return used_math != 0;
 367 }
 368 EXPORT_SYMBOL(dump_fpu);
 369
 370 /*
 371  * fill in the user structure for a core dump..
 372  */
 373 void dump_thread(struct pt_regs * regs, struct user * dump)
 374 {
 375         struct task_struct *tsk = current;
 376
 377         dump->magic = CMAGIC;
 378         dump->start_code = tsk->mm->start_code;
 379         dump->start_stack = regs->ARM_sp & ~(PAGE_SIZE - 1);
 380
 381         dump->u_tsize = (tsk->mm->end_code - tsk->mm->start_code) >> PAGE_SHIFT;
 382         dump->u_dsize = (tsk->mm->brk - tsk->mm->start_data + PAGE_SIZE - 1) >> PAGE_SHIFT;
 383         dump->u_ssize = 0;
 384
 385         dump->u_debugreg[0] = tsk->thread.debug.bp[0].address;
 386         dump->u_debugreg[1] = tsk->thread.debug.bp[1].address;
 387         dump->u_debugreg[2] = tsk->thread.debug.bp[0].insn.arm;
 388         dump->u_debugreg[3] = tsk->thread.debug.bp[1].insn.arm;
 389         dump->u_debugreg[4] = tsk->thread.debug.nsaved;
 390
 391         if (dump->start_stack < 0x04000000)
 392                 dump->u_ssize = (0x04000000 - dump->start_stack) >> PAGE_SHIFT;
 393
 394         dump->regs = *regs;
 395         dump->u_fpvalid = dump_fpu (regs, &dump->u_fp);
 396 }
 397 EXPORT_SYMBOL(dump_thread);
 398
 399 /*
 400  * Shuffle the argument into the correct register before calling the
 401  * thread function.  r1 is the thread argument, r2 is the pointer to
 402  * the thread function, and r3 points to the exit function.
 403  */
 404 extern void kernel_thread_helper(void);
 405 asm(    ".section .text\n"
 406 "       .align\n"
 407 "       .type   kernel_thread_helper, #function\n"
 408 "kernel_thread_helper:\n"
 409 "       mov     r0, r1\n"
 410 "       mov     lr, r3\n"
 411 "       mov     pc, r2\n"
 412 "       .size   kernel_thread_helper, . - kernel_thread_helper\n"
 413 "       .previous");
 414
 415 /*
 416  * Create a kernel thread.
 417  */
 418 pid_t kernel_thread(int (*fn)(void *), void *arg, unsigned long flags)
 419 {
 420         struct pt_regs regs;
 421
 422         memset(&regs, 0, sizeof(regs));
 423
 424         regs.ARM_r1 = (unsigned long)arg;
 425         regs.ARM_r2 = (unsigned long)fn;
 426         regs.ARM_r3 = (unsigned long)do_exit;
 427         regs.ARM_pc = (unsigned long)kernel_thread_helper;
 428         regs.ARM_cpsr = SVC_MODE;
 429
 430         return do_fork(flags|CLONE_VM|CLONE_UNTRACED, 0, &regs, 0, NULL, NULL);
 431 }
 432 EXPORT_SYMBOL(kernel_thread);
 433
 434 unsigned long get_wchan(struct task_struct *p)
 435 {
 436         unsigned long fp, lr;
 437         unsigned long stack_start, stack_end;
 438         int count = 0;
 439         if (!p || p == current || p->state == TASK_RUNNING)
 440                 return 0;
 441
 442         stack_start = (unsigned long)end_of_stack(p);
 443         stack_end = (unsigned long)task_stack_page(p) + THREAD_SIZE;
 444
 445         fp = thread_saved_fp(p);
 446         do {
 447                 if (fp < stack_start || fp > stack_end)
 448                         return 0;
 449                 lr = pc_pointer (((unsigned long *)fp)[-1]);
 450                 if (!in_sched_functions(lr))
 451                         return lr;
 452                 fp = *(unsigned long *) (fp - 12);
 453         } while (count ++ < 16);
 454         return 0;
 455 }