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 { 225 unsigned int ctrl, transbase, dac; 226 __asm__ ( 227 " mrc p15, 0, %0, c1, c0\n" 228 " mrc p15, 0, %1, c2, c0\n" 229 " mrc p15, 0, %2, c3, c0\n" 230 : "=r" (ctrl), "=r" (transbase), "=r" (dac)); 231 printk("Control: %04X Table: %08X DAC: %08X\n", 232 ctrl, transbase, dac); 233 } 234 } 235 236 void show_regs(struct pt_regs * regs) 237 { 238 printk("\n"); 239 printk("Pid: %d, comm: %20s\n", current->pid, current->comm); 240 __show_regs(regs); 241 __backtrace(); 242 } 243 244 void show_fpregs(struct user_fp *regs) 245 { 246 int i; 247 248 for (i = 0; i < 8; i++) { 249 unsigned long *p; 250 char type; 251 252 p = (unsigned long *)(regs->fpregs + i); 253 254 switch (regs->ftype[i]) { 255 case 1: type = 'f'; break; 256 case 2: type = 'd'; break; 257 case 3: type = 'e'; break; 258 default: type = '?'; break; 259 } 260 if (regs->init_flag) 261 type = '?'; 262 263 printk(" f%d(%c): %08lx %08lx %08lx%c", 264 i, type, p[0], p[1], p[2], i & 1 ? '\n' : ' '); 265 } 266 267 268 printk("FPSR: %08lx FPCR: %08lx\n", 269 (unsigned long)regs->fpsr, 270 (unsigned long)regs->fpcr); 271 } 272 273 /* 274 * Task structure and kernel stack allocation. 275 */ 276 struct thread_info_list { 277 unsigned long *head; 278 unsigned int nr; 279 }; 280 281 static DEFINE_PER_CPU(struct thread_info_list, thread_info_list) = { NULL, 0 }; 282 283 #define EXTRA_TASK_STRUCT 4 284 285 struct thread_info *alloc_thread_info(struct task_struct *task) 286 { 287 struct thread_info *thread = NULL; 288 289 if (EXTRA_TASK_STRUCT) { 290 struct thread_info_list *th = &get_cpu_var(thread_info_list); 291 unsigned long *p = th->head; 292 293 if (p) { 294 th->head = (unsigned long *)p[0]; 295 th->nr -= 1; 296 } 297 put_cpu_var(thread_info_list); 298 299 thread = (struct thread_info *)p; 300 } 301 302 if (!thread) 303 thread = (struct thread_info *) 304 __get_free_pages(GFP_KERNEL, THREAD_SIZE_ORDER); 305 306 #ifdef CONFIG_DEBUG_STACK_USAGE 307 /* 308 * The stack must be cleared if you want SYSRQ-T to 309 * give sensible stack usage information 310 */ 311 if (thread) 312 memzero(thread, THREAD_SIZE); 313 #endif 314 return thread; 315 } 316 317 void free_thread_info(struct thread_info *thread) 318 { 319 if (EXTRA_TASK_STRUCT) { 320 struct thread_info_list *th = &get_cpu_var(thread_info_list); 321 if (th->nr < EXTRA_TASK_STRUCT) { 322 unsigned long *p = (unsigned long *)thread; 323 p[0] = (unsigned long)th->head; 324 th->head = p; 325 th->nr += 1; 326 put_cpu_var(thread_info_list); 327 return; 328 } 329 put_cpu_var(thread_info_list); 330 } 331 free_pages((unsigned long)thread, THREAD_SIZE_ORDER); 332 } 333 334 /* 335 * Free current thread data structures etc.. 336 */ 337 void exit_thread(void) 338 { 339 } 340 341 ATOMIC_NOTIFIER_HEAD(thread_notify_head); 342 343 EXPORT_SYMBOL_GPL(thread_notify_head); 344 345 void flush_thread(void) 346 { 347 struct thread_info *thread = current_thread_info(); 348 struct task_struct *tsk = current; 349 350 memset(thread->used_cp, 0, sizeof(thread->used_cp)); 351 memset(&tsk->thread.debug, 0, sizeof(struct debug_info)); 352 memset(&thread->fpstate, 0, sizeof(union fp_state)); 353 354 thread_notify(THREAD_NOTIFY_FLUSH, thread); 355 } 356 357 void release_thread(struct task_struct *dead_task) 358 { 359 struct thread_info *thread = task_thread_info(dead_task); 360 361 thread_notify(THREAD_NOTIFY_RELEASE, thread); 362 } 363 364 asmlinkage void ret_from_fork(void) __asm__("ret_from_fork"); 365 366 int 367 copy_thread(int nr, unsigned long clone_flags, unsigned long stack_start, 368 unsigned long stk_sz, struct task_struct *p, struct pt_regs *regs) 369 { 370 struct thread_info *thread = task_thread_info(p); 371 struct pt_regs *childregs = task_pt_regs(p); 372 373 *childregs = *regs; 374 childregs->ARM_r0 = 0; 375 childregs->ARM_sp = stack_start; 376 377 memset(&thread->cpu_context, 0, sizeof(struct cpu_context_save)); 378 thread->cpu_context.sp = (unsigned long)childregs; 379 thread->cpu_context.pc = (unsigned long)ret_from_fork; 380 381 if (clone_flags & CLONE_SETTLS) 382 thread->tp_value = regs->ARM_r3; 383 384 return 0; 385 } 386 387 /* 388 * fill in the fpe structure for a core dump... 389 */ 390 int dump_fpu (struct pt_regs *regs, struct user_fp *fp) 391 { 392 struct thread_info *thread = current_thread_info(); 393 int used_math = thread->used_cp[1] | thread->used_cp[2]; 394 395 if (used_math) 396 memcpy(fp, &thread->fpstate.soft, sizeof (*fp)); 397 398 return used_math != 0; 399 } 400 EXPORT_SYMBOL(dump_fpu); 401 402 /* 403 * fill in the user structure for a core dump.. 404 */ 405 void dump_thread(struct pt_regs * regs, struct user * dump) 406 { 407 struct task_struct *tsk = current; 408 409 dump->magic = CMAGIC; 410 dump->start_code = tsk->mm->start_code; 411 dump->start_stack = regs->ARM_sp & ~(PAGE_SIZE - 1); 412 413 dump->u_tsize = (tsk->mm->end_code - tsk->mm->start_code) >> PAGE_SHIFT; 414 dump->u_dsize = (tsk->mm->brk - tsk->mm->start_data + PAGE_SIZE - 1) >> PAGE_SHIFT; 415 dump->u_ssize = 0; 416 417 dump->u_debugreg[0] = tsk->thread.debug.bp[0].address; 418 dump->u_debugreg[1] = tsk->thread.debug.bp[1].address; 419 dump->u_debugreg[2] = tsk->thread.debug.bp[0].insn.arm; 420 dump->u_debugreg[3] = tsk->thread.debug.bp[1].insn.arm; 421 dump->u_debugreg[4] = tsk->thread.debug.nsaved; 422 423 if (dump->start_stack < 0x04000000) 424 dump->u_ssize = (0x04000000 - dump->start_stack) >> PAGE_SHIFT; 425 426 dump->regs = *regs; 427 dump->u_fpvalid = dump_fpu (regs, &dump->u_fp); 428 } 429 EXPORT_SYMBOL(dump_thread); 430 431 /* 432 * Shuffle the argument into the correct register before calling the 433 * thread function. r1 is the thread argument, r2 is the pointer to 434 * the thread function, and r3 points to the exit function. 435 */ 436 extern void kernel_thread_helper(void); 437 asm( ".section .text\n" 438 " .align\n" 439 " .type kernel_thread_helper, #function\n" 440 "kernel_thread_helper:\n" 441 " mov r0, r1\n" 442 " mov lr, r3\n" 443 " mov pc, r2\n" 444 " .size kernel_thread_helper, . - kernel_thread_helper\n" 445 " .previous"); 446 447 /* 448 * Create a kernel thread. 449 */ 450 pid_t kernel_thread(int (*fn)(void *), void *arg, unsigned long flags) 451 { 452 struct pt_regs regs; 453 454 memset(®s, 0, sizeof(regs)); 455 456 regs.ARM_r1 = (unsigned long)arg; 457 regs.ARM_r2 = (unsigned long)fn; 458 regs.ARM_r3 = (unsigned long)do_exit; 459 regs.ARM_pc = (unsigned long)kernel_thread_helper; 460 regs.ARM_cpsr = SVC_MODE; 461 462 return do_fork(flags|CLONE_VM|CLONE_UNTRACED, 0, ®s, 0, NULL, NULL); 463 } 464 EXPORT_SYMBOL(kernel_thread); 465 466 unsigned long get_wchan(struct task_struct *p) 467 { 468 unsigned long fp, lr; 469 unsigned long stack_start, stack_end; 470 int count = 0; 471 if (!p || p == current || p->state == TASK_RUNNING) 472 return 0; 473 474 stack_start = (unsigned long)end_of_stack(p); 475 stack_end = (unsigned long)task_stack_page(p) + THREAD_SIZE; 476 477 fp = thread_saved_fp(p); 478 do { 479 if (fp < stack_start || fp > stack_end) 480 return 0; 481 lr = pc_pointer (((unsigned long *)fp)[-1]); 482 if (!in_sched_functions(lr)) 483 return lr; 484 fp = *(unsigned long *) (fp - 12); 485 } while (count ++ < 16); 486 return 0; 487 } 488