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 void machine_halt(void) 177 { 178 } 179 180 181 void machine_power_off(void) 182 { 183 if (pm_power_off) 184 pm_power_off(); 185 } 186 187 void machine_restart(char * __unused) 188 { 189 arm_pm_restart(reboot_mode); 190 } 191 192 void __show_regs(struct pt_regs *regs) 193 { 194 unsigned long flags = condition_codes(regs); 195 196 printk("CPU: %d\n", smp_processor_id()); 197 print_symbol("PC is at %s\n", instruction_pointer(regs)); 198 print_symbol("LR is at %s\n", regs->ARM_lr); 199 printk("pc : [<%08lx>] lr : [<%08lx>] %s\n" 200 "sp : %08lx ip : %08lx fp : %08lx\n", 201 instruction_pointer(regs), 202 regs->ARM_lr, print_tainted(), regs->ARM_sp, 203 regs->ARM_ip, regs->ARM_fp); 204 printk("r10: %08lx r9 : %08lx r8 : %08lx\n", 205 regs->ARM_r10, regs->ARM_r9, 206 regs->ARM_r8); 207 printk("r7 : %08lx r6 : %08lx r5 : %08lx r4 : %08lx\n", 208 regs->ARM_r7, regs->ARM_r6, 209 regs->ARM_r5, regs->ARM_r4); 210 printk("r3 : %08lx r2 : %08lx r1 : %08lx r0 : %08lx\n", 211 regs->ARM_r3, regs->ARM_r2, 212 regs->ARM_r1, regs->ARM_r0); 213 printk("Flags: %c%c%c%c", 214 flags & PSR_N_BIT ? 'N' : 'n', 215 flags & PSR_Z_BIT ? 'Z' : 'z', 216 flags & PSR_C_BIT ? 'C' : 'c', 217 flags & PSR_V_BIT ? 'V' : 'v'); 218 printk(" IRQs o%s FIQs o%s Mode %s%s Segment %s\n", 219 interrupts_enabled(regs) ? "n" : "ff", 220 fast_interrupts_enabled(regs) ? "n" : "ff", 221 processor_modes[processor_mode(regs)], 222 thumb_mode(regs) ? " (T)" : "", 223 get_fs() == get_ds() ? "kernel" : "user"); 224 #if CONFIG_CPU_CP15 225 { 226 unsigned int ctrl; 227 __asm__ ( 228 " mrc p15, 0, %0, c1, c0\n" 229 : "=r" (ctrl)); 230 printk("Control: %04X\n", ctrl); 231 } 232 #ifdef CONFIG_CPU_CP15_MMU 233 { 234 unsigned int transbase, dac; 235 __asm__ ( 236 " mrc p15, 0, %0, c2, c0\n" 237 " mrc p15, 0, %1, c3, c0\n" 238 : "=r" (transbase), "=r" (dac)); 239 printk("Table: %08X DAC: %08X\n", 240 transbase, dac); 241 } 242 #endif 243 #endif 244 } 245 246 void show_regs(struct pt_regs * regs) 247 { 248 printk("\n"); 249 printk("Pid: %d, comm: %20s\n", current->pid, current->comm); 250 __show_regs(regs); 251 __backtrace(); 252 } 253 254 void show_fpregs(struct user_fp *regs) 255 { 256 int i; 257 258 for (i = 0; i < 8; i++) { 259 unsigned long *p; 260 char type; 261 262 p = (unsigned long *)(regs->fpregs + i); 263 264 switch (regs->ftype[i]) { 265 case 1: type = 'f'; break; 266 case 2: type = 'd'; break; 267 case 3: type = 'e'; break; 268 default: type = '?'; break; 269 } 270 if (regs->init_flag) 271 type = '?'; 272 273 printk(" f%d(%c): %08lx %08lx %08lx%c", 274 i, type, p[0], p[1], p[2], i & 1 ? '\n' : ' '); 275 } 276 277 278 printk("FPSR: %08lx FPCR: %08lx\n", 279 (unsigned long)regs->fpsr, 280 (unsigned long)regs->fpcr); 281 } 282 283 /* 284 * Free current thread data structures etc.. 285 */ 286 void exit_thread(void) 287 { 288 } 289 290 ATOMIC_NOTIFIER_HEAD(thread_notify_head); 291 292 EXPORT_SYMBOL_GPL(thread_notify_head); 293 294 void flush_thread(void) 295 { 296 struct thread_info *thread = current_thread_info(); 297 struct task_struct *tsk = current; 298 299 memset(thread->used_cp, 0, sizeof(thread->used_cp)); 300 memset(&tsk->thread.debug, 0, sizeof(struct debug_info)); 301 memset(&thread->fpstate, 0, sizeof(union fp_state)); 302 303 thread_notify(THREAD_NOTIFY_FLUSH, thread); 304 } 305 306 void release_thread(struct task_struct *dead_task) 307 { 308 struct thread_info *thread = task_thread_info(dead_task); 309 310 thread_notify(THREAD_NOTIFY_RELEASE, thread); 311 } 312 313 asmlinkage void ret_from_fork(void) __asm__("ret_from_fork"); 314 315 int 316 copy_thread(int nr, unsigned long clone_flags, unsigned long stack_start, 317 unsigned long stk_sz, struct task_struct *p, struct pt_regs *regs) 318 { 319 struct thread_info *thread = task_thread_info(p); 320 struct pt_regs *childregs = task_pt_regs(p); 321 322 *childregs = *regs; 323 childregs->ARM_r0 = 0; 324 childregs->ARM_sp = stack_start; 325 326 memset(&thread->cpu_context, 0, sizeof(struct cpu_context_save)); 327 thread->cpu_context.sp = (unsigned long)childregs; 328 thread->cpu_context.pc = (unsigned long)ret_from_fork; 329 330 if (clone_flags & CLONE_SETTLS) 331 thread->tp_value = regs->ARM_r3; 332 333 return 0; 334 } 335 336 /* 337 * fill in the fpe structure for a core dump... 338 */ 339 int dump_fpu (struct pt_regs *regs, struct user_fp *fp) 340 { 341 struct thread_info *thread = current_thread_info(); 342 int used_math = thread->used_cp[1] | thread->used_cp[2]; 343 344 if (used_math) 345 memcpy(fp, &thread->fpstate.soft, sizeof (*fp)); 346 347 return used_math != 0; 348 } 349 EXPORT_SYMBOL(dump_fpu); 350 351 /* 352 * fill in the user structure for a core dump.. 353 */ 354 void dump_thread(struct pt_regs * regs, struct user * dump) 355 { 356 struct task_struct *tsk = current; 357 358 dump->magic = CMAGIC; 359 dump->start_code = tsk->mm->start_code; 360 dump->start_stack = regs->ARM_sp & ~(PAGE_SIZE - 1); 361 362 dump->u_tsize = (tsk->mm->end_code - tsk->mm->start_code) >> PAGE_SHIFT; 363 dump->u_dsize = (tsk->mm->brk - tsk->mm->start_data + PAGE_SIZE - 1) >> PAGE_SHIFT; 364 dump->u_ssize = 0; 365 366 dump->u_debugreg[0] = tsk->thread.debug.bp[0].address; 367 dump->u_debugreg[1] = tsk->thread.debug.bp[1].address; 368 dump->u_debugreg[2] = tsk->thread.debug.bp[0].insn.arm; 369 dump->u_debugreg[3] = tsk->thread.debug.bp[1].insn.arm; 370 dump->u_debugreg[4] = tsk->thread.debug.nsaved; 371 372 if (dump->start_stack < 0x04000000) 373 dump->u_ssize = (0x04000000 - dump->start_stack) >> PAGE_SHIFT; 374 375 dump->regs = *regs; 376 dump->u_fpvalid = dump_fpu (regs, &dump->u_fp); 377 } 378 EXPORT_SYMBOL(dump_thread); 379 380 /* 381 * Shuffle the argument into the correct register before calling the 382 * thread function. r1 is the thread argument, r2 is the pointer to 383 * the thread function, and r3 points to the exit function. 384 */ 385 extern void kernel_thread_helper(void); 386 asm( ".section .text\n" 387 " .align\n" 388 " .type kernel_thread_helper, #function\n" 389 "kernel_thread_helper:\n" 390 " mov r0, r1\n" 391 " mov lr, r3\n" 392 " mov pc, r2\n" 393 " .size kernel_thread_helper, . - kernel_thread_helper\n" 394 " .previous"); 395 396 /* 397 * Create a kernel thread. 398 */ 399 pid_t kernel_thread(int (*fn)(void *), void *arg, unsigned long flags) 400 { 401 struct pt_regs regs; 402 403 memset(®s, 0, sizeof(regs)); 404 405 regs.ARM_r1 = (unsigned long)arg; 406 regs.ARM_r2 = (unsigned long)fn; 407 regs.ARM_r3 = (unsigned long)do_exit; 408 regs.ARM_pc = (unsigned long)kernel_thread_helper; 409 regs.ARM_cpsr = SVC_MODE; 410 411 return do_fork(flags|CLONE_VM|CLONE_UNTRACED, 0, ®s, 0, NULL, NULL); 412 } 413 EXPORT_SYMBOL(kernel_thread); 414 415 unsigned long get_wchan(struct task_struct *p) 416 { 417 unsigned long fp, lr; 418 unsigned long stack_start, stack_end; 419 int count = 0; 420 if (!p || p == current || p->state == TASK_RUNNING) 421 return 0; 422 423 stack_start = (unsigned long)end_of_stack(p); 424 stack_end = (unsigned long)task_stack_page(p) + THREAD_SIZE; 425 426 fp = thread_saved_fp(p); 427 do { 428 if (fp < stack_start || fp > stack_end) 429 return 0; 430 lr = pc_pointer (((unsigned long *)fp)[-1]); 431 if (!in_sched_functions(lr)) 432 return lr; 433 fp = *(unsigned long *) (fp - 12); 434 } while (count ++ < 16); 435 return 0; 436 } 437