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/config.h> 14 #include <linux/module.h> 15 #include <linux/sched.h> 16 #include <linux/kernel.h> 17 #include <linux/mm.h> 18 #include <linux/stddef.h> 19 #include <linux/unistd.h> 20 #include <linux/ptrace.h> 21 #include <linux/slab.h> 22 #include <linux/user.h> 23 #include <linux/a.out.h> 24 #include <linux/delay.h> 25 #include <linux/reboot.h> 26 #include <linux/interrupt.h> 27 #include <linux/kallsyms.h> 28 #include <linux/init.h> 29 30 #include <asm/system.h> 31 #include <asm/io.h> 32 #include <asm/leds.h> 33 #include <asm/processor.h> 34 #include <asm/uaccess.h> 35 #include <asm/mach/time.h> 36 37 extern const char *processor_modes[]; 38 extern void setup_mm_for_reboot(char mode); 39 40 static volatile int hlt_counter; 41 42 #include <asm/arch/system.h> 43 44 void disable_hlt(void) 45 { 46 hlt_counter++; 47 } 48 49 EXPORT_SYMBOL(disable_hlt); 50 51 void enable_hlt(void) 52 { 53 hlt_counter--; 54 } 55 56 EXPORT_SYMBOL(enable_hlt); 57 58 static int __init nohlt_setup(char *__unused) 59 { 60 hlt_counter = 1; 61 return 1; 62 } 63 64 static int __init hlt_setup(char *__unused) 65 { 66 hlt_counter = 0; 67 return 1; 68 } 69 70 __setup("nohlt", nohlt_setup); 71 __setup("hlt", hlt_setup); 72 73 /* 74 * The following aren't currently used. 75 */ 76 void (*pm_idle)(void); 77 EXPORT_SYMBOL(pm_idle); 78 79 void (*pm_power_off)(void); 80 EXPORT_SYMBOL(pm_power_off); 81 82 /* 83 * This is our default idle handler. We need to disable 84 * interrupts here to ensure we don't miss a wakeup call. 85 */ 86 void default_idle(void) 87 { 88 local_irq_disable(); 89 if (!need_resched() && !hlt_counter) { 90 timer_dyn_reprogram(); 91 arch_idle(); 92 } 93 local_irq_enable(); 94 } 95 96 /* 97 * The idle thread. We try to conserve power, while trying to keep 98 * overall latency low. The architecture specific idle is passed 99 * a value to indicate the level of "idleness" of the system. 100 */ 101 void cpu_idle(void) 102 { 103 local_fiq_enable(); 104 105 /* endless idle loop with no priority at all */ 106 while (1) { 107 void (*idle)(void) = pm_idle; 108 if (!idle) 109 idle = default_idle; 110 preempt_disable(); 111 leds_event(led_idle_start); 112 while (!need_resched()) 113 idle(); 114 leds_event(led_idle_end); 115 preempt_enable(); 116 schedule(); 117 } 118 } 119 120 static char reboot_mode = 'h'; 121 122 int __init reboot_setup(char *str) 123 { 124 reboot_mode = str[0]; 125 return 1; 126 } 127 128 __setup("reboot=", reboot_setup); 129 130 void machine_halt(void) 131 { 132 } 133 134 EXPORT_SYMBOL(machine_halt); 135 136 void machine_power_off(void) 137 { 138 if (pm_power_off) 139 pm_power_off(); 140 } 141 142 EXPORT_SYMBOL(machine_power_off); 143 144 void machine_restart(char * __unused) 145 { 146 /* 147 * Clean and disable cache, and turn off interrupts 148 */ 149 cpu_proc_fin(); 150 151 /* 152 * Tell the mm system that we are going to reboot - 153 * we may need it to insert some 1:1 mappings so that 154 * soft boot works. 155 */ 156 setup_mm_for_reboot(reboot_mode); 157 158 /* 159 * Now call the architecture specific reboot code. 160 */ 161 arch_reset(reboot_mode); 162 163 /* 164 * Whoops - the architecture was unable to reboot. 165 * Tell the user! 166 */ 167 mdelay(1000); 168 printk("Reboot failed -- System halted\n"); 169 while (1); 170 } 171 172 EXPORT_SYMBOL(machine_restart); 173 174 void __show_regs(struct pt_regs *regs) 175 { 176 unsigned long flags = condition_codes(regs); 177 178 printk("CPU: %d\n", smp_processor_id()); 179 print_symbol("PC is at %s\n", instruction_pointer(regs)); 180 print_symbol("LR is at %s\n", regs->ARM_lr); 181 printk("pc : [<%08lx>] lr : [<%08lx>] %s\n" 182 "sp : %08lx ip : %08lx fp : %08lx\n", 183 instruction_pointer(regs), 184 regs->ARM_lr, print_tainted(), regs->ARM_sp, 185 regs->ARM_ip, regs->ARM_fp); 186 printk("r10: %08lx r9 : %08lx r8 : %08lx\n", 187 regs->ARM_r10, regs->ARM_r9, 188 regs->ARM_r8); 189 printk("r7 : %08lx r6 : %08lx r5 : %08lx r4 : %08lx\n", 190 regs->ARM_r7, regs->ARM_r6, 191 regs->ARM_r5, regs->ARM_r4); 192 printk("r3 : %08lx r2 : %08lx r1 : %08lx r0 : %08lx\n", 193 regs->ARM_r3, regs->ARM_r2, 194 regs->ARM_r1, regs->ARM_r0); 195 printk("Flags: %c%c%c%c", 196 flags & PSR_N_BIT ? 'N' : 'n', 197 flags & PSR_Z_BIT ? 'Z' : 'z', 198 flags & PSR_C_BIT ? 'C' : 'c', 199 flags & PSR_V_BIT ? 'V' : 'v'); 200 printk(" IRQs o%s FIQs o%s Mode %s%s Segment %s\n", 201 interrupts_enabled(regs) ? "n" : "ff", 202 fast_interrupts_enabled(regs) ? "n" : "ff", 203 processor_modes[processor_mode(regs)], 204 thumb_mode(regs) ? " (T)" : "", 205 get_fs() == get_ds() ? "kernel" : "user"); 206 { 207 unsigned int ctrl, transbase, dac; 208 __asm__ ( 209 " mrc p15, 0, %0, c1, c0\n" 210 " mrc p15, 0, %1, c2, c0\n" 211 " mrc p15, 0, %2, c3, c0\n" 212 : "=r" (ctrl), "=r" (transbase), "=r" (dac)); 213 printk("Control: %04X Table: %08X DAC: %08X\n", 214 ctrl, transbase, dac); 215 } 216 } 217 218 void show_regs(struct pt_regs * regs) 219 { 220 printk("\n"); 221 printk("Pid: %d, comm: %20s\n", current->pid, current->comm); 222 __show_regs(regs); 223 __backtrace(); 224 } 225 226 void show_fpregs(struct user_fp *regs) 227 { 228 int i; 229 230 for (i = 0; i < 8; i++) { 231 unsigned long *p; 232 char type; 233 234 p = (unsigned long *)(regs->fpregs + i); 235 236 switch (regs->ftype[i]) { 237 case 1: type = 'f'; break; 238 case 2: type = 'd'; break; 239 case 3: type = 'e'; break; 240 default: type = '?'; break; 241 } 242 if (regs->init_flag) 243 type = '?'; 244 245 printk(" f%d(%c): %08lx %08lx %08lx%c", 246 i, type, p[0], p[1], p[2], i & 1 ? '\n' : ' '); 247 } 248 249 250 printk("FPSR: %08lx FPCR: %08lx\n", 251 (unsigned long)regs->fpsr, 252 (unsigned long)regs->fpcr); 253 } 254 255 /* 256 * Task structure and kernel stack allocation. 257 */ 258 static unsigned long *thread_info_head; 259 static unsigned int nr_thread_info; 260 261 #define EXTRA_TASK_STRUCT 4 262 263 struct thread_info *alloc_thread_info(struct task_struct *task) 264 { 265 struct thread_info *thread = NULL; 266 267 if (EXTRA_TASK_STRUCT) { 268 unsigned long *p = thread_info_head; 269 270 if (p) { 271 thread_info_head = (unsigned long *)p[0]; 272 nr_thread_info -= 1; 273 } 274 thread = (struct thread_info *)p; 275 } 276 277 if (!thread) 278 thread = (struct thread_info *) 279 __get_free_pages(GFP_KERNEL, THREAD_SIZE_ORDER); 280 281 #ifdef CONFIG_DEBUG_STACK_USAGE 282 /* 283 * The stack must be cleared if you want SYSRQ-T to 284 * give sensible stack usage information 285 */ 286 if (thread) 287 memzero(thread, THREAD_SIZE); 288 #endif 289 return thread; 290 } 291 292 void free_thread_info(struct thread_info *thread) 293 { 294 if (EXTRA_TASK_STRUCT && nr_thread_info < EXTRA_TASK_STRUCT) { 295 unsigned long *p = (unsigned long *)thread; 296 p[0] = (unsigned long)thread_info_head; 297 thread_info_head = p; 298 nr_thread_info += 1; 299 } else 300 free_pages((unsigned long)thread, THREAD_SIZE_ORDER); 301 } 302 303 /* 304 * Free current thread data structures etc.. 305 */ 306 void exit_thread(void) 307 { 308 } 309 310 static void default_fp_init(union fp_state *fp) 311 { 312 memset(fp, 0, sizeof(union fp_state)); 313 } 314 315 void (*fp_init)(union fp_state *) = default_fp_init; 316 EXPORT_SYMBOL(fp_init); 317 318 void flush_thread(void) 319 { 320 struct thread_info *thread = current_thread_info(); 321 struct task_struct *tsk = current; 322 323 memset(thread->used_cp, 0, sizeof(thread->used_cp)); 324 memset(&tsk->thread.debug, 0, sizeof(struct debug_info)); 325 #if defined(CONFIG_IWMMXT) 326 iwmmxt_task_release(thread); 327 #endif 328 fp_init(&thread->fpstate); 329 #if defined(CONFIG_VFP) 330 vfp_flush_thread(&thread->vfpstate); 331 #endif 332 } 333 334 void release_thread(struct task_struct *dead_task) 335 { 336 #if defined(CONFIG_VFP) 337 vfp_release_thread(&dead_task->thread_info->vfpstate); 338 #endif 339 #if defined(CONFIG_IWMMXT) 340 iwmmxt_task_release(dead_task->thread_info); 341 #endif 342 } 343 344 asmlinkage void ret_from_fork(void) __asm__("ret_from_fork"); 345 346 int 347 copy_thread(int nr, unsigned long clone_flags, unsigned long stack_start, 348 unsigned long stk_sz, struct task_struct *p, struct pt_regs *regs) 349 { 350 struct thread_info *thread = p->thread_info; 351 struct pt_regs *childregs; 352 353 childregs = ((struct pt_regs *)((unsigned long)thread + THREAD_START_SP)) - 1; 354 *childregs = *regs; 355 childregs->ARM_r0 = 0; 356 childregs->ARM_sp = stack_start; 357 358 memset(&thread->cpu_context, 0, sizeof(struct cpu_context_save)); 359 thread->cpu_context.sp = (unsigned long)childregs; 360 thread->cpu_context.pc = (unsigned long)ret_from_fork; 361 362 if (clone_flags & CLONE_SETTLS) 363 thread->tp_value = regs->ARM_r3; 364 365 return 0; 366 } 367 368 /* 369 * fill in the fpe structure for a core dump... 370 */ 371 int dump_fpu (struct pt_regs *regs, struct user_fp *fp) 372 { 373 struct thread_info *thread = current_thread_info(); 374 int used_math = thread->used_cp[1] | thread->used_cp[2]; 375 376 if (used_math) 377 memcpy(fp, &thread->fpstate.soft, sizeof (*fp)); 378 379 return used_math != 0; 380 } 381 EXPORT_SYMBOL(dump_fpu); 382 383 /* 384 * fill in the user structure for a core dump.. 385 */ 386 void dump_thread(struct pt_regs * regs, struct user * dump) 387 { 388 struct task_struct *tsk = current; 389 390 dump->magic = CMAGIC; 391 dump->start_code = tsk->mm->start_code; 392 dump->start_stack = regs->ARM_sp & ~(PAGE_SIZE - 1); 393 394 dump->u_tsize = (tsk->mm->end_code - tsk->mm->start_code) >> PAGE_SHIFT; 395 dump->u_dsize = (tsk->mm->brk - tsk->mm->start_data + PAGE_SIZE - 1) >> PAGE_SHIFT; 396 dump->u_ssize = 0; 397 398 dump->u_debugreg[0] = tsk->thread.debug.bp[0].address; 399 dump->u_debugreg[1] = tsk->thread.debug.bp[1].address; 400 dump->u_debugreg[2] = tsk->thread.debug.bp[0].insn.arm; 401 dump->u_debugreg[3] = tsk->thread.debug.bp[1].insn.arm; 402 dump->u_debugreg[4] = tsk->thread.debug.nsaved; 403 404 if (dump->start_stack < 0x04000000) 405 dump->u_ssize = (0x04000000 - dump->start_stack) >> PAGE_SHIFT; 406 407 dump->regs = *regs; 408 dump->u_fpvalid = dump_fpu (regs, &dump->u_fp); 409 } 410 EXPORT_SYMBOL(dump_thread); 411 412 /* 413 * Shuffle the argument into the correct register before calling the 414 * thread function. r1 is the thread argument, r2 is the pointer to 415 * the thread function, and r3 points to the exit function. 416 */ 417 extern void kernel_thread_helper(void); 418 asm( ".section .text\n" 419 " .align\n" 420 " .type kernel_thread_helper, #function\n" 421 "kernel_thread_helper:\n" 422 " mov r0, r1\n" 423 " mov lr, r3\n" 424 " mov pc, r2\n" 425 " .size kernel_thread_helper, . - kernel_thread_helper\n" 426 " .previous"); 427 428 /* 429 * Create a kernel thread. 430 */ 431 pid_t kernel_thread(int (*fn)(void *), void *arg, unsigned long flags) 432 { 433 struct pt_regs regs; 434 435 memset(®s, 0, sizeof(regs)); 436 437 regs.ARM_r1 = (unsigned long)arg; 438 regs.ARM_r2 = (unsigned long)fn; 439 regs.ARM_r3 = (unsigned long)do_exit; 440 regs.ARM_pc = (unsigned long)kernel_thread_helper; 441 regs.ARM_cpsr = SVC_MODE; 442 443 return do_fork(flags|CLONE_VM|CLONE_UNTRACED, 0, ®s, 0, NULL, NULL); 444 } 445 EXPORT_SYMBOL(kernel_thread); 446 447 unsigned long get_wchan(struct task_struct *p) 448 { 449 unsigned long fp, lr; 450 unsigned long stack_start, stack_end; 451 int count = 0; 452 if (!p || p == current || p->state == TASK_RUNNING) 453 return 0; 454 455 stack_start = (unsigned long)(p->thread_info + 1); 456 stack_end = ((unsigned long)p->thread_info) + THREAD_SIZE; 457 458 fp = thread_saved_fp(p); 459 do { 460 if (fp < stack_start || fp > stack_end) 461 return 0; 462 lr = pc_pointer (((unsigned long *)fp)[-1]); 463 if (!in_sched_functions(lr)) 464 return lr; 465 fp = *(unsigned long *) (fp - 12); 466 } while (count ++ < 16); 467 return 0; 468 } 469 EXPORT_SYMBOL(get_wchan); 470