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