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   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
  31 #include <asm/leds.h>
  32 #include <asm/processor.h>
  33 #include <asm/system.h>
  34 #include <asm/thread_notify.h>
  35 #include <asm/uaccess.h>
  36 #include <asm/mach/time.h>
  37
  38 static const char *processor_modes[] = {
  39   "USER_26", "FIQ_26" , "IRQ_26" , "SVC_26" , "UK4_26" , "UK5_26" , "UK6_26" , "UK7_26" ,
  40   "UK8_26" , "UK9_26" , "UK10_26", "UK11_26", "UK12_26", "UK13_26", "UK14_26", "UK15_26",
  41   "USER_32", "FIQ_32" , "IRQ_32" , "SVC_32" , "UK4_32" , "UK5_32" , "UK6_32" , "ABT_32" ,
  42   "UK8_32" , "UK9_32" , "UK10_32", "UND_32" , "UK12_32", "UK13_32", "UK14_32", "SYS_32"
  43 };
  44
  45 extern void setup_mm_for_reboot(char mode);
  46
  47 static volatile int hlt_counter;
  48
  49 #include <asm/arch/system.h>
  50
  51 void disable_hlt(void)
  52 {
  53         hlt_counter++;
  54 }
  55
  56 EXPORT_SYMBOL(disable_hlt);
  57
  58 void enable_hlt(void)
  59 {
  60         hlt_counter--;
  61 }
  62
  63 EXPORT_SYMBOL(enable_hlt);
  64
  65 static int __init nohlt_setup(char *__unused)
  66 {
  67         hlt_counter = 1;
  68         return 1;
  69 }
  70
  71 static int __init hlt_setup(char *__unused)
  72 {
  73         hlt_counter = 0;
  74         return 1;
  75 }
  76
  77 __setup("nohlt", nohlt_setup);
  78 __setup("hlt", hlt_setup);
  79
  80 void arm_machine_restart(char mode)
  81 {
  82         /*
  83          * Clean and disable cache, and turn off interrupts
  84          */
  85         cpu_proc_fin();
  86
  87         /*
  88          * Tell the mm system that we are going to reboot -
  89          * we may need it to insert some 1:1 mappings so that
  90          * soft boot works.
  91          */
  92         setup_mm_for_reboot(mode);
  93
  94         /*
  95          * Now call the architecture specific reboot code.
  96          */
  97         arch_reset(mode);
  98
  99         /*
 100          * Whoops - the architecture was unable to reboot.
 101          * Tell the user!
 102          */
 103         mdelay(1000);
 104         printk("Reboot failed -- System halted\n");
 105         while (1);
 106 }
 107
 108 /*
 109  * Function pointers to optional machine specific functions
 110  */
 111 void (*pm_idle)(void);
 112 EXPORT_SYMBOL(pm_idle);
 113
 114 void (*pm_power_off)(void);
 115 EXPORT_SYMBOL(pm_power_off);
 116
 117 void (*arm_pm_restart)(char str) = arm_machine_restart;
 118 EXPORT_SYMBOL_GPL(arm_pm_restart);
 119
 120
 121 /*
 122  * This is our default idle handler.  We need to disable
 123  * interrupts here to ensure we don't miss a wakeup call.
 124  */
 125 static void default_idle(void)
 126 {
 127         if (hlt_counter)
 128                 cpu_relax();
 129         else {
 130                 local_irq_disable();
 131                 if (!need_resched()) {
 132                         timer_dyn_reprogram();
 133                         arch_idle();
 134                 }
 135                 local_irq_enable();
 136         }
 137 }
 138
 139 /*
 140  * The idle thread.  We try to conserve power, while trying to keep
 141  * overall latency low.  The architecture specific idle is passed
 142  * a value to indicate the level of "idleness" of the system.
 143  */
 144 void cpu_idle(void)
 145 {
 146         local_fiq_enable();
 147
 148         /* endless idle loop with no priority at all */
 149         while (1) {
 150                 void (*idle)(void) = pm_idle;
 151
 152 #ifdef CONFIG_HOTPLUG_CPU
 153                 if (cpu_is_offline(smp_processor_id())) {
 154                         leds_event(led_idle_start);
 155                         cpu_die();
 156                 }
 157 #endif
 158
 159                 if (!idle)
 160                         idle = default_idle;
 161                 leds_event(led_idle_start);
 162                 while (!need_resched())
 163                         idle();
 164                 leds_event(led_idle_end);
 165                 preempt_enable_no_resched();
 166                 schedule();
 167                 preempt_disable();
 168         }
 169 }
 170
 171 static char reboot_mode = 'h';
 172
 173 int __init reboot_setup(char *str)
 174 {
 175         reboot_mode = str[0];
 176         return 1;
 177 }
 178
 179 __setup("reboot=", reboot_setup);
 180
 181 void machine_halt(void)
 182 {
 183 }
 184
 185
 186 void machine_power_off(void)
 187 {
 188         if (pm_power_off)
 189                 pm_power_off();
 190 }
 191
 192 void machine_restart(char * __unused)
 193 {
 194         arm_pm_restart(reboot_mode);
 195 }
 196
 197 void __show_regs(struct pt_regs *regs)
 198 {
 199         unsigned long flags = condition_codes(regs);
 200
 201         printk("CPU: %d\n", smp_processor_id());
 202         print_symbol("PC is at %s\n", instruction_pointer(regs));
 203         print_symbol("LR is at %s\n", regs->ARM_lr);
 204         printk("pc : [<%08lx>]    lr : [<%08lx>]    %s\n"
 205                "sp : %08lx  ip : %08lx  fp : %08lx\n",
 206                 instruction_pointer(regs),
 207                 regs->ARM_lr, print_tainted(), regs->ARM_sp,
 208                 regs->ARM_ip, regs->ARM_fp);
 209         printk("r10: %08lx  r9 : %08lx  r8 : %08lx\n",
 210                 regs->ARM_r10, regs->ARM_r9,
 211                 regs->ARM_r8);
 212         printk("r7 : %08lx  r6 : %08lx  r5 : %08lx  r4 : %08lx\n",
 213                 regs->ARM_r7, regs->ARM_r6,
 214                 regs->ARM_r5, regs->ARM_r4);
 215         printk("r3 : %08lx  r2 : %08lx  r1 : %08lx  r0 : %08lx\n",
 216                 regs->ARM_r3, regs->ARM_r2,
 217                 regs->ARM_r1, regs->ARM_r0);
 218         printk("Flags: %c%c%c%c",
 219                 flags & PSR_N_BIT ? 'N' : 'n',
 220                 flags & PSR_Z_BIT ? 'Z' : 'z',
 221                 flags & PSR_C_BIT ? 'C' : 'c',
 222                 flags & PSR_V_BIT ? 'V' : 'v');
 223         printk("  IRQs o%s  FIQs o%s  Mode %s%s  Segment %s\n",
 224                 interrupts_enabled(regs) ? "n" : "ff",
 225                 fast_interrupts_enabled(regs) ? "n" : "ff",
 226                 processor_modes[processor_mode(regs)],
 227                 thumb_mode(regs) ? " (T)" : "",
 228                 get_fs() == get_ds() ? "kernel" : "user");
 229 #if CONFIG_CPU_CP15
 230         {
 231                 unsigned int ctrl;
 232                   __asm__ (
 233                 "       mrc p15, 0, %0, c1, c0\n"
 234                 : "=r" (ctrl));
 235                 printk("Control: %04X\n", ctrl);
 236         }
 237 #ifdef CONFIG_CPU_CP15_MMU
 238         {
 239                 unsigned int transbase, dac;
 240                   __asm__ (
 241                 "       mrc p15, 0, %0, c2, c0\n"
 242                 "       mrc p15, 0, %1, c3, c0\n"
 243                 : "=r" (transbase), "=r" (dac));
 244                 printk("Table: %08X  DAC: %08X\n",
 245                         transbase, dac);
 246         }
 247 #endif
 248 #endif
 249 }
 250
 251 void show_regs(struct pt_regs * regs)
 252 {
 253         printk("\n");
 254         printk("Pid: %d, comm: %20s\n", current->pid, current->comm);
 255         __show_regs(regs);
 256         __backtrace();
 257 }
 258
 259 void show_fpregs(struct user_fp *regs)
 260 {
 261         int i;
 262
 263         for (i = 0; i < 8; i++) {
 264                 unsigned long *p;
 265                 char type;
 266
 267                 p = (unsigned long *)(regs->fpregs + i);
 268
 269                 switch (regs->ftype[i]) {
 270                         case 1: type = 'f'; break;
 271                         case 2: type = 'd'; break;
 272                         case 3: type = 'e'; break;
 273                         default: type = '?'; break;
 274                 }
 275                 if (regs->init_flag)
 276                         type = '?';
 277
 278                 printk("  f%d(%c): %08lx %08lx %08lx%c",
 279                         i, type, p[0], p[1], p[2], i & 1 ? '\n' : ' ');
 280         }
 281
 282
 283         printk("FPSR: %08lx FPCR: %08lx\n",
 284                 (unsigned long)regs->fpsr,
 285                 (unsigned long)regs->fpcr);
 286 }
 287
 288 /*
 289  * Free current thread data structures etc..
 290  */
 291 void exit_thread(void)
 292 {
 293 }
 294
 295 ATOMIC_NOTIFIER_HEAD(thread_notify_head);
 296
 297 EXPORT_SYMBOL_GPL(thread_notify_head);
 298
 299 void flush_thread(void)
 300 {
 301         struct thread_info *thread = current_thread_info();
 302         struct task_struct *tsk = current;
 303
 304         memset(thread->used_cp, 0, sizeof(thread->used_cp));
 305         memset(&tsk->thread.debug, 0, sizeof(struct debug_info));
 306         memset(&thread->fpstate, 0, sizeof(union fp_state));
 307
 308         thread_notify(THREAD_NOTIFY_FLUSH, thread);
 309 }
 310
 311 void release_thread(struct task_struct *dead_task)
 312 {
 313         struct thread_info *thread = task_thread_info(dead_task);
 314
 315         thread_notify(THREAD_NOTIFY_RELEASE, thread);
 316 }
 317
 318 asmlinkage void ret_from_fork(void) __asm__("ret_from_fork");
 319
 320 int
 321 copy_thread(int nr, unsigned long clone_flags, unsigned long stack_start,
 322             unsigned long stk_sz, struct task_struct *p, struct pt_regs *regs)
 323 {
 324         struct thread_info *thread = task_thread_info(p);
 325         struct pt_regs *childregs = task_pt_regs(p);
 326
 327         *childregs = *regs;
 328         childregs->ARM_r0 = 0;
 329         childregs->ARM_sp = stack_start;
 330
 331         memset(&thread->cpu_context, 0, sizeof(struct cpu_context_save));
 332         thread->cpu_context.sp = (unsigned long)childregs;
 333         thread->cpu_context.pc = (unsigned long)ret_from_fork;
 334
 335         if (clone_flags & CLONE_SETTLS)
 336                 thread->tp_value = regs->ARM_r3;
 337
 338         return 0;
 339 }
 340
 341 /*
 342  * fill in the fpe structure for a core dump...
 343  */
 344 int dump_fpu (struct pt_regs *regs, struct user_fp *fp)
 345 {
 346         struct thread_info *thread = current_thread_info();
 347         int used_math = thread->used_cp[1] | thread->used_cp[2];
 348
 349         if (used_math)
 350                 memcpy(fp, &thread->fpstate.soft, sizeof (*fp));
 351
 352         return used_math != 0;
 353 }
 354 EXPORT_SYMBOL(dump_fpu);
 355
 356 /*
 357  * fill in the user structure for a core dump..
 358  */
 359 void dump_thread(struct pt_regs * regs, struct user * dump)
 360 {
 361         struct task_struct *tsk = current;
 362
 363         dump->magic = CMAGIC;
 364         dump->start_code = tsk->mm->start_code;
 365         dump->start_stack = regs->ARM_sp & ~(PAGE_SIZE - 1);
 366
 367         dump->u_tsize = (tsk->mm->end_code - tsk->mm->start_code) >> PAGE_SHIFT;
 368         dump->u_dsize = (tsk->mm->brk - tsk->mm->start_data + PAGE_SIZE - 1) >> PAGE_SHIFT;
 369         dump->u_ssize = 0;
 370
 371         dump->u_debugreg[0] = tsk->thread.debug.bp[0].address;
 372         dump->u_debugreg[1] = tsk->thread.debug.bp[1].address;
 373         dump->u_debugreg[2] = tsk->thread.debug.bp[0].insn.arm;
 374         dump->u_debugreg[3] = tsk->thread.debug.bp[1].insn.arm;
 375         dump->u_debugreg[4] = tsk->thread.debug.nsaved;
 376
 377         if (dump->start_stack < 0x04000000)
 378                 dump->u_ssize = (0x04000000 - dump->start_stack) >> PAGE_SHIFT;
 379
 380         dump->regs = *regs;
 381         dump->u_fpvalid = dump_fpu (regs, &dump->u_fp);
 382 }
 383 EXPORT_SYMBOL(dump_thread);
 384
 385 /*
 386  * Shuffle the argument into the correct register before calling the
 387  * thread function.  r1 is the thread argument, r2 is the pointer to
 388  * the thread function, and r3 points to the exit function.
 389  */
 390 extern void kernel_thread_helper(void);
 391 asm(    ".section .text\n"
 392 "       .align\n"
 393 "       .type   kernel_thread_helper, #function\n"
 394 "kernel_thread_helper:\n"
 395 "       mov     r0, r1\n"
 396 "       mov     lr, r3\n"
 397 "       mov     pc, r2\n"
 398 "       .size   kernel_thread_helper, . - kernel_thread_helper\n"
 399 "       .previous");
 400
 401 /*
 402  * Create a kernel thread.
 403  */
 404 pid_t kernel_thread(int (*fn)(void *), void *arg, unsigned long flags)
 405 {
 406         struct pt_regs regs;
 407
 408         memset(&regs, 0, sizeof(regs));
 409
 410         regs.ARM_r1 = (unsigned long)arg;
 411         regs.ARM_r2 = (unsigned long)fn;
 412         regs.ARM_r3 = (unsigned long)do_exit;
 413         regs.ARM_pc = (unsigned long)kernel_thread_helper;
 414         regs.ARM_cpsr = SVC_MODE;
 415
 416         return do_fork(flags|CLONE_VM|CLONE_UNTRACED, 0, &regs, 0, NULL, NULL);
 417 }
 418 EXPORT_SYMBOL(kernel_thread);
 419
 420 unsigned long get_wchan(struct task_struct *p)
 421 {
 422         unsigned long fp, lr;
 423         unsigned long stack_start, stack_end;
 424         int count = 0;
 425         if (!p || p == current || p->state == TASK_RUNNING)
 426                 return 0;
 427
 428         stack_start = (unsigned long)end_of_stack(p);
 429         stack_end = (unsigned long)task_stack_page(p) + THREAD_SIZE;
 430
 431         fp = thread_saved_fp(p);
 432         do {
 433                 if (fp < stack_start || fp > stack_end)
 434                         return 0;
 435                 lr = pc_pointer (((unsigned long *)fp)[-1]);
 436                 if (!in_sched_functions(lr))
 437                         return lr;
 438                 fp = *(unsigned long *) (fp - 12);
 439         } while (count ++ < 16);
 440         return 0;
 441 }