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/ptrace.h>
  20 #include <linux/slab.h>
  21 #include <linux/user.h>
  22 #include <linux/a.out.h>
  23 #include <linux/delay.h>
  24 #include <linux/reboot.h>
  25 #include <linux/interrupt.h>
  26 #include <linux/kallsyms.h>
  27 #include <linux/init.h>
  28 #include <linux/cpu.h>
  29 #include <linux/elfcore.h>
  30 #include <linux/pm.h>
  31
  32 #include <asm/leds.h>
  33 #include <asm/processor.h>
  34 #include <asm/system.h>
  35 #include <asm/thread_notify.h>
  36 #include <asm/uaccess.h>
  37 #include <asm/mach/time.h>
  38
  39 extern const char *processor_modes[];
  40 extern void setup_mm_for_reboot(char mode);
  41
  42 static volatile int hlt_counter;
  43
  44 #include <asm/arch/system.h>
  45
  46 void disable_hlt(void)
  47 {
  48         hlt_counter++;
  49 }
  50
  51 EXPORT_SYMBOL(disable_hlt);
  52
  53 void enable_hlt(void)
  54 {
  55         hlt_counter--;
  56 }
  57
  58 EXPORT_SYMBOL(enable_hlt);
  59
  60 static int __init nohlt_setup(char *__unused)
  61 {
  62         hlt_counter = 1;
  63         return 1;
  64 }
  65
  66 static int __init hlt_setup(char *__unused)
  67 {
  68         hlt_counter = 0;
  69         return 1;
  70 }
  71
  72 __setup("nohlt", nohlt_setup);
  73 __setup("hlt", hlt_setup);
  74
  75 void arm_machine_restart(char mode)
  76 {
  77         /*
  78          * Clean and disable cache, and turn off interrupts
  79          */
  80         cpu_proc_fin();
  81
  82         /*
  83          * Tell the mm system that we are going to reboot -
  84          * we may need it to insert some 1:1 mappings so that
  85          * soft boot works.
  86          */
  87         setup_mm_for_reboot(mode);
  88
  89         /*
  90          * Now call the architecture specific reboot code.
  91          */
  92         arch_reset(mode);
  93
  94         /*
  95          * Whoops - the architecture was unable to reboot.
  96          * Tell the user!
  97          */
  98         mdelay(1000);
  99         printk("Reboot failed -- System halted\n");
 100         while (1);
 101 }
 102
 103 /*
 104  * Function pointers to optional machine specific functions
 105  */
 106 void (*pm_idle)(void);
 107 EXPORT_SYMBOL(pm_idle);
 108
 109 void (*pm_power_off)(void);
 110 EXPORT_SYMBOL(pm_power_off);
 111
 112 void (*arm_pm_restart)(char str) = arm_machine_restart;
 113 EXPORT_SYMBOL_GPL(arm_pm_restart);
 114
 115
 116 /*
 117  * This is our default idle handler.  We need to disable
 118  * interrupts here to ensure we don't miss a wakeup call.
 119  */
 120 static void default_idle(void)
 121 {
 122         if (hlt_counter)
 123                 cpu_relax();
 124         else {
 125                 local_irq_disable();
 126                 if (!need_resched()) {
 127                         timer_dyn_reprogram();
 128                         arch_idle();
 129                 }
 130                 local_irq_enable();
 131         }
 132 }
 133
 134 /*
 135  * The idle thread.  We try to conserve power, while trying to keep
 136  * overall latency low.  The architecture specific idle is passed
 137  * a value to indicate the level of "idleness" of the system.
 138  */
 139 void cpu_idle(void)
 140 {
 141         local_fiq_enable();
 142
 143         /* endless idle loop with no priority at all */
 144         while (1) {
 145                 void (*idle)(void) = pm_idle;
 146
 147 #ifdef CONFIG_HOTPLUG_CPU
 148                 if (cpu_is_offline(smp_processor_id())) {
 149                         leds_event(led_idle_start);
 150                         cpu_die();
 151                 }
 152 #endif
 153
 154                 if (!idle)
 155                         idle = default_idle;
 156                 leds_event(led_idle_start);
 157                 while (!need_resched())
 158                         idle();
 159                 leds_event(led_idle_end);
 160                 preempt_enable_no_resched();
 161                 schedule();
 162                 preempt_disable();
 163         }
 164 }
 165
 166 static char reboot_mode = 'h';
 167
 168 int __init reboot_setup(char *str)
 169 {
 170         reboot_mode = str[0];
 171         return 1;
 172 }
 173
 174 __setup("reboot=", reboot_setup);
 175
 176 #if 1   // add by Victor Yu. 03-06-2007
 177         #if defined(CONFIG_ARCH_W311_TEST)      // add by Victor Yu. 07-10-2008
 178 #define SW_READY_LED_OFF()      *(volatile unsigned int *)(CPE_GPIO_BASE) |= (1<<4)
 179         #else
 180 #define SW_READY_LED_OFF()      *(volatile unsigned int *)(CPE_GPIO_BASE) |= (1<<27)
 181         #endif
 182 #endif
 183 void machine_halt(void)
 184 {
 185         SW_READY_LED_OFF();     // add by Victor Yu. 03-06-2007
 186         while ( 1 );    // add by Victor Yu. 02-08-2007
 187 }
 188
 189
 190 void machine_power_off(void)
 191 {
 192         if (pm_power_off)
 193                 pm_power_off();
 194         SW_READY_LED_OFF();     // add by Victor Yu. 03-06-2007
 195         while ( 1 );    // add by Victor Yu. 02-08-2007
 196 }
 197
 198 void machine_restart(char * __unused)
 199 {
 200         /*
 201          * Clean and disable cache, and turn off interrupts
 202          */
 203         cpu_proc_fin();
 204
 205 #ifdef CONFIG_MMU
 206         /*
 207          * Tell the mm system that we are going to reboot -
 208          * we may need it to insert some 1:1 mappings so that
 209          * soft boot works.
 210          */
 211         setup_mm_for_reboot(reboot_mode);
 212 #endif
 213
 214         /*
 215          * Now call the architecture specific reboot code.
 216          */
 217         SW_READY_LED_OFF();     // add by Victor Yu. 03-06-2007
 218         arch_reset(reboot_mode);
 219
 220         /*
 221          * Whoops - the architecture was unable to reboot.
 222          * Tell the user!
 223          */
 224         mdelay(1000);
 225         printk("Reboot failed -- System halted\n");
 226         while (1);
 227 }
 228
 229 void __show_regs(struct pt_regs *regs)
 230 {
 231         unsigned long flags = condition_codes(regs);
 232
 233         printk("CPU: %d\n", smp_processor_id());
 234         print_symbol("PC is at %s\n", instruction_pointer(regs));
 235         print_symbol("LR is at %s\n", regs->ARM_lr);
 236         printk("pc : [<%08lx>]    lr : [<%08lx>]    %s\n"
 237                "sp : %08lx  ip : %08lx  fp : %08lx\n",
 238                 instruction_pointer(regs),
 239                 regs->ARM_lr, print_tainted(), regs->ARM_sp,
 240                 regs->ARM_ip, regs->ARM_fp);
 241         printk("r10: %08lx  r9 : %08lx  r8 : %08lx\n",
 242                 regs->ARM_r10, regs->ARM_r9,
 243                 regs->ARM_r8);
 244         printk("r7 : %08lx  r6 : %08lx  r5 : %08lx  r4 : %08lx\n",
 245                 regs->ARM_r7, regs->ARM_r6,
 246                 regs->ARM_r5, regs->ARM_r4);
 247         printk("r3 : %08lx  r2 : %08lx  r1 : %08lx  r0 : %08lx\n",
 248                 regs->ARM_r3, regs->ARM_r2,
 249                 regs->ARM_r1, regs->ARM_r0);
 250         printk("Flags: %c%c%c%c",
 251                 flags & PSR_N_BIT ? 'N' : 'n',
 252                 flags & PSR_Z_BIT ? 'Z' : 'z',
 253                 flags & PSR_C_BIT ? 'C' : 'c',
 254                 flags & PSR_V_BIT ? 'V' : 'v');
 255         printk("  IRQs o%s  FIQs o%s  Mode %s%s  Segment %s\n",
 256                 interrupts_enabled(regs) ? "n" : "ff",
 257                 fast_interrupts_enabled(regs) ? "n" : "ff",
 258                 processor_modes[processor_mode(regs)],
 259                 thumb_mode(regs) ? " (T)" : "",
 260                 get_fs() == get_ds() ? "kernel" : "user");
 261 #if CONFIG_CPU_CP15
 262         {
 263                 unsigned int ctrl;
 264                   __asm__ (
 265                 "       mrc p15, 0, %0, c1, c0\n"
 266                 : "=r" (ctrl));
 267                 printk("Control: %04X\n", ctrl);
 268         }
 269 #ifdef CONFIG_CPU_CP15_MMU
 270         {
 271                 unsigned int transbase, dac;
 272                   __asm__ (
 273                 "       mrc p15, 0, %0, c2, c0\n"
 274                 "       mrc p15, 0, %1, c3, c0\n"
 275                 : "=r" (transbase), "=r" (dac));
 276                 printk("Table: %08X  DAC: %08X\n",
 277                         transbase, dac);
 278         }
 279 #endif
 280 #endif
 281 }
 282
 283 void show_regs(struct pt_regs * regs)
 284 {
 285         printk("\n");
 286         printk("Pid: %d, comm: %20s\n", current->pid, current->comm);
 287         __show_regs(regs);
 288         __backtrace();
 289 }
 290
 291 void show_fpregs(struct user_fp *regs)
 292 {
 293         int i;
 294
 295         for (i = 0; i < 8; i++) {
 296                 unsigned long *p;
 297                 char type;
 298
 299                 p = (unsigned long *)(regs->fpregs + i);
 300
 301                 switch (regs->ftype[i]) {
 302                         case 1: type = 'f'; break;
 303                         case 2: type = 'd'; break;
 304                         case 3: type = 'e'; break;
 305                         default: type = '?'; break;
 306                 }
 307                 if (regs->init_flag)
 308                         type = '?';
 309
 310                 printk("  f%d(%c): %08lx %08lx %08lx%c",
 311                         i, type, p[0], p[1], p[2], i & 1 ? '\n' : ' ');
 312         }
 313
 314
 315         printk("FPSR: %08lx FPCR: %08lx\n",
 316                 (unsigned long)regs->fpsr,
 317                 (unsigned long)regs->fpcr);
 318 }
 319
 320 /*
 321  * Task structure and kernel stack allocation.
 322  */
 323 struct thread_info_list {
 324         unsigned long *head;
 325         unsigned int nr;
 326 };
 327
 328 static DEFINE_PER_CPU(struct thread_info_list, thread_info_list) = { NULL, 0 };
 329
 330 #define EXTRA_TASK_STRUCT       4
 331
 332 struct thread_info *alloc_thread_info(struct task_struct *task)
 333 {
 334         struct thread_info *thread = NULL;
 335
 336         if (EXTRA_TASK_STRUCT) {
 337                 struct thread_info_list *th = &get_cpu_var(thread_info_list);
 338                 unsigned long *p = th->head;
 339
 340                 if (p) {
 341                         th->head = (unsigned long *)p[0];
 342                         th->nr -= 1;
 343                 }
 344                 put_cpu_var(thread_info_list);
 345
 346                 thread = (struct thread_info *)p;
 347         }
 348
 349         if (!thread)
 350                 thread = (struct thread_info *)
 351                            __get_free_pages(GFP_KERNEL, THREAD_SIZE_ORDER);
 352
 353 #ifdef CONFIG_DEBUG_STACK_USAGE
 354         /*
 355          * The stack must be cleared if you want SYSRQ-T to
 356          * give sensible stack usage information
 357          */
 358         if (thread)
 359                 memzero(thread, THREAD_SIZE);
 360 #endif
 361         return thread;
 362 }
 363
 364 void free_thread_info(struct thread_info *thread)
 365 {
 366         if (EXTRA_TASK_STRUCT) {
 367                 struct thread_info_list *th = &get_cpu_var(thread_info_list);
 368                 if (th->nr < EXTRA_TASK_STRUCT) {
 369                         unsigned long *p = (unsigned long *)thread;
 370                         p[0] = (unsigned long)th->head;
 371                         th->head = p;
 372                         th->nr += 1;
 373                         put_cpu_var(thread_info_list);
 374                         return;
 375                 }
 376                 put_cpu_var(thread_info_list);
 377         }
 378         free_pages((unsigned long)thread, THREAD_SIZE_ORDER);
 379 }
 380
 381 /*
 382  * Free current thread data structures etc..
 383  */
 384 void exit_thread(void)
 385 {
 386 }
 387
 388 ATOMIC_NOTIFIER_HEAD(thread_notify_head);
 389
 390 EXPORT_SYMBOL_GPL(thread_notify_head);
 391
 392 void flush_thread(void)
 393 {
 394         struct thread_info *thread = current_thread_info();
 395         struct task_struct *tsk = current;
 396
 397         memset(thread->used_cp, 0, sizeof(thread->used_cp));
 398         memset(&tsk->thread.debug, 0, sizeof(struct debug_info));
 399         memset(&thread->fpstate, 0, sizeof(union fp_state));
 400
 401         thread_notify(THREAD_NOTIFY_FLUSH, thread);
 402 }
 403
 404 void release_thread(struct task_struct *dead_task)
 405 {
 406         struct thread_info *thread = task_thread_info(dead_task);
 407
 408         thread_notify(THREAD_NOTIFY_RELEASE, thread);
 409 }
 410
 411 asmlinkage void ret_from_fork(void) __asm__("ret_from_fork");
 412
 413 int
 414 copy_thread(int nr, unsigned long clone_flags, unsigned long stack_start,
 415             unsigned long stk_sz, struct task_struct *p, struct pt_regs *regs)
 416 {
 417         struct thread_info *thread = task_thread_info(p);
 418         struct pt_regs *childregs = task_pt_regs(p);
 419
 420         *childregs = *regs;
 421         childregs->ARM_r0 = 0;
 422         childregs->ARM_sp = stack_start;
 423
 424         memset(&thread->cpu_context, 0, sizeof(struct cpu_context_save));
 425         thread->cpu_context.sp = (unsigned long)childregs;
 426         thread->cpu_context.pc = (unsigned long)ret_from_fork;
 427
 428         if (clone_flags & CLONE_SETTLS)
 429                 thread->tp_value = regs->ARM_r3;
 430
 431         return 0;
 432 }
 433
 434 /*
 435  * fill in the fpe structure for a core dump...
 436  */
 437 int dump_fpu (struct pt_regs *regs, struct user_fp *fp)
 438 {
 439         struct thread_info *thread = current_thread_info();
 440         int used_math = thread->used_cp[1] | thread->used_cp[2];
 441
 442         if (used_math)
 443                 memcpy(fp, &thread->fpstate.soft, sizeof (*fp));
 444
 445         return used_math != 0;
 446 }
 447 EXPORT_SYMBOL(dump_fpu);
 448
 449 /*
 450  * fill in the user structure for a core dump..
 451  */
 452 void dump_thread(struct pt_regs * regs, struct user * dump)
 453 {
 454         struct task_struct *tsk = current;
 455
 456         dump->magic = CMAGIC;
 457         dump->start_code = tsk->mm->start_code;
 458         dump->start_stack = regs->ARM_sp & ~(PAGE_SIZE - 1);
 459
 460         dump->u_tsize = (tsk->mm->end_code - tsk->mm->start_code) >> PAGE_SHIFT;
 461         dump->u_dsize = (tsk->mm->brk - tsk->mm->start_data + PAGE_SIZE - 1) >> PAGE_SHIFT;
 462         dump->u_ssize = 0;
 463
 464         dump->u_debugreg[0] = tsk->thread.debug.bp[0].address;
 465         dump->u_debugreg[1] = tsk->thread.debug.bp[1].address;
 466         dump->u_debugreg[2] = tsk->thread.debug.bp[0].insn.arm;
 467         dump->u_debugreg[3] = tsk->thread.debug.bp[1].insn.arm;
 468         dump->u_debugreg[4] = tsk->thread.debug.nsaved;
 469
 470         if (dump->start_stack < 0x04000000)
 471                 dump->u_ssize = (0x04000000 - dump->start_stack) >> PAGE_SHIFT;
 472
 473         dump->regs = *regs;
 474         dump->u_fpvalid = dump_fpu (regs, &dump->u_fp);
 475 }
 476 EXPORT_SYMBOL(dump_thread);
 477
 478 /*
 479  * Shuffle the argument into the correct register before calling the
 480  * thread function.  r1 is the thread argument, r2 is the pointer to
 481  * the thread function, and r3 points to the exit function.
 482  */
 483 extern void kernel_thread_helper(void);
 484 asm(    ".section .text\n"
 485 "       .align\n"
 486 "       .type   kernel_thread_helper, #function\n"
 487 "kernel_thread_helper:\n"
 488 "       mov     r0, r1\n"
 489 "       mov     lr, r3\n"
 490 "       mov     pc, r2\n"
 491 "       .size   kernel_thread_helper, . - kernel_thread_helper\n"
 492 "       .previous");
 493
 494 /*
 495  * Create a kernel thread.
 496  */
 497 pid_t kernel_thread(int (*fn)(void *), void *arg, unsigned long flags)
 498 {
 499         struct pt_regs regs;
 500
 501         memset(&regs, 0, sizeof(regs));
 502
 503         regs.ARM_r1 = (unsigned long)arg;
 504         regs.ARM_r2 = (unsigned long)fn;
 505         regs.ARM_r3 = (unsigned long)do_exit;
 506         regs.ARM_pc = (unsigned long)kernel_thread_helper;
 507         regs.ARM_cpsr = SVC_MODE;
 508
 509         return do_fork(flags|CLONE_VM|CLONE_UNTRACED, 0, &regs, 0, NULL, NULL);
 510 }
 511 EXPORT_SYMBOL(kernel_thread);
 512
 513 unsigned long get_wchan(struct task_struct *p)
 514 {
 515         unsigned long fp, lr;
 516         unsigned long stack_start, stack_end;
 517         int count = 0;
 518         if (!p || p == current || p->state == TASK_RUNNING)
 519                 return 0;
 520
 521         stack_start = (unsigned long)end_of_stack(p);
 522         stack_end = (unsigned long)task_stack_page(p) + THREAD_SIZE;
 523
 524         fp = thread_saved_fp(p);
 525         do {
 526                 if (fp < stack_start || fp > stack_end)
 527                         return 0;
 528                 lr = pc_pointer (((unsigned long *)fp)[-1]);
 529                 if (!in_sched_functions(lr))
 530                         return lr;
 531                 fp = *(unsigned long *) (fp - 12);
 532         } while (count ++ < 16);
 533         return 0;
 534 }