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 static const char *processor_modes[] = {
  40   "USER_26", "FIQ_26" , "IRQ_26" , "SVC_26" , "UK4_26" , "UK5_26" , "UK6_26" , "UK7_26" ,
  41   "UK8_26" , "UK9_26" , "UK10_26", "UK11_26", "UK12_26", "UK13_26", "UK14_26", "UK15_26",
  42   "USER_32", "FIQ_32" , "IRQ_32" , "SVC_32" , "UK4_32" , "UK5_32" , "UK6_32" , "ABT_32" ,
  43   "UK8_32" , "UK9_32" , "UK10_32", "UND_32" , "UK12_32", "UK13_32", "UK14_32", "SYS_32"
  44 };
  45
  46 extern void setup_mm_for_reboot(char mode);
  47
  48 static volatile int hlt_counter;
  49
  50 #include <asm/arch/system.h>
  51
  52 void disable_hlt(void)
  53 {
  54         hlt_counter++;
  55 }
  56
  57 EXPORT_SYMBOL(disable_hlt);
  58
  59 void enable_hlt(void)
  60 {
  61         hlt_counter--;
  62 }
  63
  64 EXPORT_SYMBOL(enable_hlt);
  65
  66 static int __init nohlt_setup(char *__unused)
  67 {
  68         hlt_counter = 1;
  69         return 1;
  70 }
  71
  72 static int __init hlt_setup(char *__unused)
  73 {
  74         hlt_counter = 0;
  75         return 1;
  76 }
  77
  78 __setup("nohlt", nohlt_setup);
  79 __setup("hlt", hlt_setup);
  80
  81 void arm_machine_restart(char mode)
  82 {
  83         /*
  84          * Clean and disable cache, and turn off interrupts
  85          */
  86         cpu_proc_fin();
  87
  88         /*
  89          * Tell the mm system that we are going to reboot -
  90          * we may need it to insert some 1:1 mappings so that
  91          * soft boot works.
  92          */
  93         setup_mm_for_reboot(mode);
  94
  95         /*
  96          * Now call the architecture specific reboot code.
  97          */
  98         arch_reset(mode);
  99
 100         /*
 101          * Whoops - the architecture was unable to reboot.
 102          * Tell the user!
 103          */
 104         mdelay(1000);
 105         printk("Reboot failed -- System halted\n");
 106         while (1);
 107 }
 108
 109 /*
 110  * Function pointers to optional machine specific functions
 111  */
 112 void (*pm_idle)(void);
 113 EXPORT_SYMBOL(pm_idle);
 114
 115 void (*pm_power_off)(void);
 116 EXPORT_SYMBOL(pm_power_off);
 117
 118 void (*arm_pm_restart)(char str) = arm_machine_restart;
 119 EXPORT_SYMBOL_GPL(arm_pm_restart);
 120
 121
 122 /*
 123  * This is our default idle handler.  We need to disable
 124  * interrupts here to ensure we don't miss a wakeup call.
 125  */
 126 static void default_idle(void)
 127 {
 128         if (hlt_counter)
 129                 cpu_relax();
 130         else {
 131                 local_irq_disable();
 132                 if (!need_resched()) {
 133                         timer_dyn_reprogram();
 134                         arch_idle();
 135                 }
 136                 local_irq_enable();
 137         }
 138 }
 139
 140 /*
 141  * The idle thread.  We try to conserve power, while trying to keep
 142  * overall latency low.  The architecture specific idle is passed
 143  * a value to indicate the level of "idleness" of the system.
 144  */
 145 void cpu_idle(void)
 146 {
 147         local_fiq_enable();
 148
 149         /* endless idle loop with no priority at all */
 150         while (1) {
 151                 void (*idle)(void) = pm_idle;
 152
 153 #ifdef CONFIG_HOTPLUG_CPU
 154                 if (cpu_is_offline(smp_processor_id())) {
 155                         leds_event(led_idle_start);
 156                         cpu_die();
 157                 }
 158 #endif
 159
 160                 if (!idle)
 161                         idle = default_idle;
 162                 leds_event(led_idle_start);
 163                 while (!need_resched())
 164                         idle();
 165                 leds_event(led_idle_end);
 166                 preempt_enable_no_resched();
 167                 schedule();
 168                 preempt_disable();
 169         }
 170 }
 171
 172 static char reboot_mode = 'h';
 173
 174 int __init reboot_setup(char *str)
 175 {
 176         reboot_mode = str[0];
 177         return 1;
 178 }
 179
 180 __setup("reboot=", reboot_setup);
 181
 182 void machine_halt(void)
 183 {
 184 }
 185
 186
 187 void machine_power_off(void)
 188 {
 189         if (pm_power_off)
 190                 pm_power_off();
 191 }
 192
 193 void machine_restart(char * __unused)
 194 {
 195         arm_pm_restart(reboot_mode);
 196 }
 197
 198 void __show_regs(struct pt_regs *regs)
 199 {
 200         unsigned long flags = condition_codes(regs);
 201
 202         printk("CPU: %d\n", smp_processor_id());
 203         print_symbol("PC is at %s\n", instruction_pointer(regs));
 204         print_symbol("LR is at %s\n", regs->ARM_lr);
 205         printk("pc : [<%08lx>]    lr : [<%08lx>]    %s\n"
 206                "sp : %08lx  ip : %08lx  fp : %08lx\n",
 207                 instruction_pointer(regs),
 208                 regs->ARM_lr, print_tainted(), regs->ARM_sp,
 209                 regs->ARM_ip, regs->ARM_fp);
 210         printk("r10: %08lx  r9 : %08lx  r8 : %08lx\n",
 211                 regs->ARM_r10, regs->ARM_r9,
 212                 regs->ARM_r8);
 213         printk("r7 : %08lx  r6 : %08lx  r5 : %08lx  r4 : %08lx\n",
 214                 regs->ARM_r7, regs->ARM_r6,
 215                 regs->ARM_r5, regs->ARM_r4);
 216         printk("r3 : %08lx  r2 : %08lx  r1 : %08lx  r0 : %08lx\n",
 217                 regs->ARM_r3, regs->ARM_r2,
 218                 regs->ARM_r1, regs->ARM_r0);
 219         printk("Flags: %c%c%c%c",
 220                 flags & PSR_N_BIT ? 'N' : 'n',
 221                 flags & PSR_Z_BIT ? 'Z' : 'z',
 222                 flags & PSR_C_BIT ? 'C' : 'c',
 223                 flags & PSR_V_BIT ? 'V' : 'v');
 224         printk("  IRQs o%s  FIQs o%s  Mode %s%s  Segment %s\n",
 225                 interrupts_enabled(regs) ? "n" : "ff",
 226                 fast_interrupts_enabled(regs) ? "n" : "ff",
 227                 processor_modes[processor_mode(regs)],
 228                 thumb_mode(regs) ? " (T)" : "",
 229                 get_fs() == get_ds() ? "kernel" : "user");
 230 #if CONFIG_CPU_CP15
 231         {
 232                 unsigned int ctrl;
 233                   __asm__ (
 234                 "       mrc p15, 0, %0, c1, c0\n"
 235                 : "=r" (ctrl));
 236                 printk("Control: %04X\n", ctrl);
 237         }
 238 #ifdef CONFIG_CPU_CP15_MMU
 239         {
 240                 unsigned int transbase, dac;
 241                   __asm__ (
 242                 "       mrc p15, 0, %0, c2, c0\n"
 243                 "       mrc p15, 0, %1, c3, c0\n"
 244                 : "=r" (transbase), "=r" (dac));
 245                 printk("Table: %08X  DAC: %08X\n",
 246                         transbase, dac);
 247         }
 248 #endif
 249 #endif
 250 }
 251
 252 void show_regs(struct pt_regs * regs)
 253 {
 254         printk("\n");
 255         printk("Pid: %d, comm: %20s\n", current->pid, current->comm);
 256         __show_regs(regs);
 257         __backtrace();
 258 }
 259
 260 void show_fpregs(struct user_fp *regs)
 261 {
 262         int i;
 263
 264         for (i = 0; i < 8; i++) {
 265                 unsigned long *p;
 266                 char type;
 267
 268                 p = (unsigned long *)(regs->fpregs + i);
 269
 270                 switch (regs->ftype[i]) {
 271                         case 1: type = 'f'; break;
 272                         case 2: type = 'd'; break;
 273                         case 3: type = 'e'; break;
 274                         default: type = '?'; break;
 275                 }
 276                 if (regs->init_flag)
 277                         type = '?';
 278
 279                 printk("  f%d(%c): %08lx %08lx %08lx%c",
 280                         i, type, p[0], p[1], p[2], i & 1 ? '\n' : ' ');
 281         }
 282
 283
 284         printk("FPSR: %08lx FPCR: %08lx\n",
 285                 (unsigned long)regs->fpsr,
 286                 (unsigned long)regs->fpcr);
 287 }
 288
 289 /*
 290  * Free current thread data structures etc..
 291  */
 292 void exit_thread(void)
 293 {
 294 }
 295
 296 ATOMIC_NOTIFIER_HEAD(thread_notify_head);
 297
 298 EXPORT_SYMBOL_GPL(thread_notify_head);
 299
 300 void flush_thread(void)
 301 {
 302         struct thread_info *thread = current_thread_info();
 303         struct task_struct *tsk = current;
 304
 305         memset(thread->used_cp, 0, sizeof(thread->used_cp));
 306         memset(&tsk->thread.debug, 0, sizeof(struct debug_info));
 307         memset(&thread->fpstate, 0, sizeof(union fp_state));
 308
 309         thread_notify(THREAD_NOTIFY_FLUSH, thread);
 310 }
 311
 312 void release_thread(struct task_struct *dead_task)
 313 {
 314         struct thread_info *thread = task_thread_info(dead_task);
 315
 316         thread_notify(THREAD_NOTIFY_RELEASE, thread);
 317 }
 318
 319 asmlinkage void ret_from_fork(void) __asm__("ret_from_fork");
 320
 321 int
 322 copy_thread(int nr, unsigned long clone_flags, unsigned long stack_start,
 323             unsigned long stk_sz, struct task_struct *p, struct pt_regs *regs)
 324 {
 325         struct thread_info *thread = task_thread_info(p);
 326         struct pt_regs *childregs = task_pt_regs(p);
 327
 328         *childregs = *regs;
 329         childregs->ARM_r0 = 0;
 330         childregs->ARM_sp = stack_start;
 331
 332         memset(&thread->cpu_context, 0, sizeof(struct cpu_context_save));
 333         thread->cpu_context.sp = (unsigned long)childregs;
 334         thread->cpu_context.pc = (unsigned long)ret_from_fork;
 335
 336         if (clone_flags & CLONE_SETTLS)
 337                 thread->tp_value = regs->ARM_r3;
 338
 339         return 0;
 340 }
 341
 342 /*
 343  * fill in the fpe structure for a core dump...
 344  */
 345 int dump_fpu (struct pt_regs *regs, struct user_fp *fp)
 346 {
 347         struct thread_info *thread = current_thread_info();
 348         int used_math = thread->used_cp[1] | thread->used_cp[2];
 349
 350         if (used_math)
 351                 memcpy(fp, &thread->fpstate.soft, sizeof (*fp));
 352
 353         return used_math != 0;
 354 }
 355 EXPORT_SYMBOL(dump_fpu);
 356
 357 /*
 358  * fill in the user structure for a core dump..
 359  */
 360 void dump_thread(struct pt_regs * regs, struct user * dump)
 361 {
 362         struct task_struct *tsk = current;
 363
 364         dump->magic = CMAGIC;
 365         dump->start_code = tsk->mm->start_code;
 366         dump->start_stack = regs->ARM_sp & ~(PAGE_SIZE - 1);
 367
 368         dump->u_tsize = (tsk->mm->end_code - tsk->mm->start_code) >> PAGE_SHIFT;
 369         dump->u_dsize = (tsk->mm->brk - tsk->mm->start_data + PAGE_SIZE - 1) >> PAGE_SHIFT;
 370         dump->u_ssize = 0;
 371
 372         dump->u_debugreg[0] = tsk->thread.debug.bp[0].address;
 373         dump->u_debugreg[1] = tsk->thread.debug.bp[1].address;
 374         dump->u_debugreg[2] = tsk->thread.debug.bp[0].insn.arm;
 375         dump->u_debugreg[3] = tsk->thread.debug.bp[1].insn.arm;
 376         dump->u_debugreg[4] = tsk->thread.debug.nsaved;
 377
 378         if (dump->start_stack < 0x04000000)
 379                 dump->u_ssize = (0x04000000 - dump->start_stack) >> PAGE_SHIFT;
 380
 381         dump->regs = *regs;
 382         dump->u_fpvalid = dump_fpu (regs, &dump->u_fp);
 383 }
 384 EXPORT_SYMBOL(dump_thread);
 385
 386 /*
 387  * Shuffle the argument into the correct register before calling the
 388  * thread function.  r1 is the thread argument, r2 is the pointer to
 389  * the thread function, and r3 points to the exit function.
 390  */
 391 extern void kernel_thread_helper(void);
 392 asm(    ".section .text\n"
 393 "       .align\n"
 394 "       .type   kernel_thread_helper, #function\n"
 395 "kernel_thread_helper:\n"
 396 "       mov     r0, r1\n"
 397 "       mov     lr, r3\n"
 398 "       mov     pc, r2\n"
 399 "       .size   kernel_thread_helper, . - kernel_thread_helper\n"
 400 "       .previous");
 401
 402 /*
 403  * Create a kernel thread.
 404  */
 405 pid_t kernel_thread(int (*fn)(void *), void *arg, unsigned long flags)
 406 {
 407         struct pt_regs regs;
 408
 409         memset(&regs, 0, sizeof(regs));
 410
 411         regs.ARM_r1 = (unsigned long)arg;
 412         regs.ARM_r2 = (unsigned long)fn;
 413         regs.ARM_r3 = (unsigned long)do_exit;
 414         regs.ARM_pc = (unsigned long)kernel_thread_helper;
 415         regs.ARM_cpsr = SVC_MODE;
 416
 417         return do_fork(flags|CLONE_VM|CLONE_UNTRACED, 0, &regs, 0, NULL, NULL);
 418 }
 419 EXPORT_SYMBOL(kernel_thread);
 420
 421 unsigned long get_wchan(struct task_struct *p)
 422 {
 423         unsigned long fp, lr;
 424         unsigned long stack_start, stack_end;
 425         int count = 0;
 426         if (!p || p == current || p->state == TASK_RUNNING)
 427                 return 0;
 428
 429         stack_start = (unsigned long)end_of_stack(p);
 430         stack_end = (unsigned long)task_stack_page(p) + THREAD_SIZE;
 431
 432         fp = thread_saved_fp(p);
 433         do {
 434                 if (fp < stack_start || fp > stack_end)
 435                         return 0;
 436                 lr = pc_pointer (((unsigned long *)fp)[-1]);
 437                 if (!in_sched_functions(lr))
 438                         return lr;
 439                 fp = *(unsigned long *) (fp - 12);
 440         } while (count ++ < 16);
 441         return 0;
 442 }