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 } 133 134 135 void machine_power_off(void) 136 { 137 if (pm_power_off) 138 pm_power_off(); 139 } 140 141 142 void machine_restart(char * __unused) 143 { 144 /* 145 * Clean and disable cache, and turn off interrupts 146 */ 147 cpu_proc_fin(); 148 149 /* 150 * Tell the mm system that we are going to reboot - 151 * we may need it to insert some 1:1 mappings so that 152 * soft boot works. 153 */ 154 setup_mm_for_reboot(reboot_mode); 155 156 /* 157 * Now call the architecture specific reboot code. 158 */ 159 arch_reset(reboot_mode); 160 161 /* 162 * Whoops - the architecture was unable to reboot. 163 * Tell the user! 164 */ 165 mdelay(1000); 166 printk("Reboot failed -- System halted\n"); 167 while (1); 168 } 169 170 void __show_regs(struct pt_regs *regs) 171 { 172 unsigned long flags = condition_codes(regs); 173 174 printk("CPU: %d\n", smp_processor_id()); 175 print_symbol("PC is at %s\n", instruction_pointer(regs)); 176 print_symbol("LR is at %s\n", regs->ARM_lr); 177 printk("pc : [<%08lx>] lr : [<%08lx>] %s\n" 178 "sp : %08lx ip : %08lx fp : %08lx\n", 179 instruction_pointer(regs), 180 regs->ARM_lr, print_tainted(), regs->ARM_sp, 181 regs->ARM_ip, regs->ARM_fp); 182 printk("r10: %08lx r9 : %08lx r8 : %08lx\n", 183 regs->ARM_r10, regs->ARM_r9, 184 regs->ARM_r8); 185 printk("r7 : %08lx r6 : %08lx r5 : %08lx r4 : %08lx\n", 186 regs->ARM_r7, regs->ARM_r6, 187 regs->ARM_r5, regs->ARM_r4); 188 printk("r3 : %08lx r2 : %08lx r1 : %08lx r0 : %08lx\n", 189 regs->ARM_r3, regs->ARM_r2, 190 regs->ARM_r1, regs->ARM_r0); 191 printk("Flags: %c%c%c%c", 192 flags & PSR_N_BIT ? 'N' : 'n', 193 flags & PSR_Z_BIT ? 'Z' : 'z', 194 flags & PSR_C_BIT ? 'C' : 'c', 195 flags & PSR_V_BIT ? 'V' : 'v'); 196 printk(" IRQs o%s FIQs o%s Mode %s%s Segment %s\n", 197 interrupts_enabled(regs) ? "n" : "ff", 198 fast_interrupts_enabled(regs) ? "n" : "ff", 199 processor_modes[processor_mode(regs)], 200 thumb_mode(regs) ? " (T)" : "", 201 get_fs() == get_ds() ? "kernel" : "user"); 202 { 203 unsigned int ctrl, transbase, dac; 204 __asm__ ( 205 " mrc p15, 0, %0, c1, c0\n" 206 " mrc p15, 0, %1, c2, c0\n" 207 " mrc p15, 0, %2, c3, c0\n" 208 : "=r" (ctrl), "=r" (transbase), "=r" (dac)); 209 printk("Control: %04X Table: %08X DAC: %08X\n", 210 ctrl, transbase, dac); 211 } 212 } 213 214 void show_regs(struct pt_regs * regs) 215 { 216 printk("\n"); 217 printk("Pid: %d, comm: %20s\n", current->pid, current->comm); 218 __show_regs(regs); 219 __backtrace(); 220 } 221 222 void show_fpregs(struct user_fp *regs) 223 { 224 int i; 225 226 for (i = 0; i < 8; i++) { 227 unsigned long *p; 228 char type; 229 230 p = (unsigned long *)(regs->fpregs + i); 231 232 switch (regs->ftype[i]) { 233 case 1: type = 'f'; break; 234 case 2: type = 'd'; break; 235 case 3: type = 'e'; break; 236 default: type = '?'; break; 237 } 238 if (regs->init_flag) 239 type = '?'; 240 241 printk(" f%d(%c): %08lx %08lx %08lx%c", 242 i, type, p[0], p[1], p[2], i & 1 ? '\n' : ' '); 243 } 244 245 246 printk("FPSR: %08lx FPCR: %08lx\n", 247 (unsigned long)regs->fpsr, 248 (unsigned long)regs->fpcr); 249 } 250 251 /* 252 * Task structure and kernel stack allocation. 253 */ 254 static unsigned long *thread_info_head; 255 static unsigned int nr_thread_info; 256 257 #define EXTRA_TASK_STRUCT 4 258 259 struct thread_info *alloc_thread_info(struct task_struct *task) 260 { 261 struct thread_info *thread = NULL; 262 263 if (EXTRA_TASK_STRUCT) { 264 unsigned long *p = thread_info_head; 265 266 if (p) { 267 thread_info_head = (unsigned long *)p[0]; 268 nr_thread_info -= 1; 269 } 270 thread = (struct thread_info *)p; 271 } 272 273 if (!thread) 274 thread = (struct thread_info *) 275 __get_free_pages(GFP_KERNEL, THREAD_SIZE_ORDER); 276 277 #ifdef CONFIG_DEBUG_STACK_USAGE 278 /* 279 * The stack must be cleared if you want SYSRQ-T to 280 * give sensible stack usage information 281 */ 282 if (thread) 283 memzero(thread, THREAD_SIZE); 284 #endif 285 return thread; 286 } 287 288 void free_thread_info(struct thread_info *thread) 289 { 290 if (EXTRA_TASK_STRUCT && nr_thread_info < EXTRA_TASK_STRUCT) { 291 unsigned long *p = (unsigned long *)thread; 292 p[0] = (unsigned long)thread_info_head; 293 thread_info_head = p; 294 nr_thread_info += 1; 295 } else 296 free_pages((unsigned long)thread, THREAD_SIZE_ORDER); 297 } 298 299 /* 300 * Free current thread data structures etc.. 301 */ 302 void exit_thread(void) 303 { 304 } 305 306 static void default_fp_init(union fp_state *fp) 307 { 308 memset(fp, 0, sizeof(union fp_state)); 309 } 310 311 void (*fp_init)(union fp_state *) = default_fp_init; 312 EXPORT_SYMBOL(fp_init); 313 314 void flush_thread(void) 315 { 316 struct thread_info *thread = current_thread_info(); 317 struct task_struct *tsk = current; 318 319 memset(thread->used_cp, 0, sizeof(thread->used_cp)); 320 memset(&tsk->thread.debug, 0, sizeof(struct debug_info)); 321 #if defined(CONFIG_IWMMXT) 322 iwmmxt_task_release(thread); 323 #endif 324 fp_init(&thread->fpstate); 325 #if defined(CONFIG_VFP) 326 vfp_flush_thread(&thread->vfpstate); 327 #endif 328 } 329 330 void release_thread(struct task_struct *dead_task) 331 { 332 #if defined(CONFIG_VFP) 333 vfp_release_thread(&dead_task->thread_info->vfpstate); 334 #endif 335 #if defined(CONFIG_IWMMXT) 336 iwmmxt_task_release(dead_task->thread_info); 337 #endif 338 } 339 340 asmlinkage void ret_from_fork(void) __asm__("ret_from_fork"); 341 342 int 343 copy_thread(int nr, unsigned long clone_flags, unsigned long stack_start, 344 unsigned long stk_sz, struct task_struct *p, struct pt_regs *regs) 345 { 346 struct thread_info *thread = p->thread_info; 347 struct pt_regs *childregs; 348 349 childregs = ((struct pt_regs *)((unsigned long)thread + THREAD_START_SP)) - 1; 350 *childregs = *regs; 351 childregs->ARM_r0 = 0; 352 childregs->ARM_sp = stack_start; 353 354 memset(&thread->cpu_context, 0, sizeof(struct cpu_context_save)); 355 thread->cpu_context.sp = (unsigned long)childregs; 356 thread->cpu_context.pc = (unsigned long)ret_from_fork; 357 358 if (clone_flags & CLONE_SETTLS) 359 thread->tp_value = regs->ARM_r3; 360 361 return 0; 362 } 363 364 /* 365 * fill in the fpe structure for a core dump... 366 */ 367 int dump_fpu (struct pt_regs *regs, struct user_fp *fp) 368 { 369 struct thread_info *thread = current_thread_info(); 370 int used_math = thread->used_cp[1] | thread->used_cp[2]; 371 372 if (used_math) 373 memcpy(fp, &thread->fpstate.soft, sizeof (*fp)); 374 375 return used_math != 0; 376 } 377 EXPORT_SYMBOL(dump_fpu); 378 379 /* 380 * fill in the user structure for a core dump.. 381 */ 382 void dump_thread(struct pt_regs * regs, struct user * dump) 383 { 384 struct task_struct *tsk = current; 385 386 dump->magic = CMAGIC; 387 dump->start_code = tsk->mm->start_code; 388 dump->start_stack = regs->ARM_sp & ~(PAGE_SIZE - 1); 389 390 dump->u_tsize = (tsk->mm->end_code - tsk->mm->start_code) >> PAGE_SHIFT; 391 dump->u_dsize = (tsk->mm->brk - tsk->mm->start_data + PAGE_SIZE - 1) >> PAGE_SHIFT; 392 dump->u_ssize = 0; 393 394 dump->u_debugreg[0] = tsk->thread.debug.bp[0].address; 395 dump->u_debugreg[1] = tsk->thread.debug.bp[1].address; 396 dump->u_debugreg[2] = tsk->thread.debug.bp[0].insn.arm; 397 dump->u_debugreg[3] = tsk->thread.debug.bp[1].insn.arm; 398 dump->u_debugreg[4] = tsk->thread.debug.nsaved; 399 400 if (dump->start_stack < 0x04000000) 401 dump->u_ssize = (0x04000000 - dump->start_stack) >> PAGE_SHIFT; 402 403 dump->regs = *regs; 404 dump->u_fpvalid = dump_fpu (regs, &dump->u_fp); 405 } 406 EXPORT_SYMBOL(dump_thread); 407 408 /* 409 * Shuffle the argument into the correct register before calling the 410 * thread function. r1 is the thread argument, r2 is the pointer to 411 * the thread function, and r3 points to the exit function. 412 */ 413 extern void kernel_thread_helper(void); 414 asm( ".section .text\n" 415 " .align\n" 416 " .type kernel_thread_helper, #function\n" 417 "kernel_thread_helper:\n" 418 " mov r0, r1\n" 419 " mov lr, r3\n" 420 " mov pc, r2\n" 421 " .size kernel_thread_helper, . - kernel_thread_helper\n" 422 " .previous"); 423 424 /* 425 * Create a kernel thread. 426 */ 427 pid_t kernel_thread(int (*fn)(void *), void *arg, unsigned long flags) 428 { 429 struct pt_regs regs; 430 431 memset(®s, 0, sizeof(regs)); 432 433 regs.ARM_r1 = (unsigned long)arg; 434 regs.ARM_r2 = (unsigned long)fn; 435 regs.ARM_r3 = (unsigned long)do_exit; 436 regs.ARM_pc = (unsigned long)kernel_thread_helper; 437 regs.ARM_cpsr = SVC_MODE; 438 439 return do_fork(flags|CLONE_VM|CLONE_UNTRACED, 0, ®s, 0, NULL, NULL); 440 } 441 EXPORT_SYMBOL(kernel_thread); 442 443 unsigned long get_wchan(struct task_struct *p) 444 { 445 unsigned long fp, lr; 446 unsigned long stack_start, stack_end; 447 int count = 0; 448 if (!p || p == current || p->state == TASK_RUNNING) 449 return 0; 450 451 stack_start = (unsigned long)(p->thread_info + 1); 452 stack_end = ((unsigned long)p->thread_info) + THREAD_SIZE; 453 454 fp = thread_saved_fp(p); 455 do { 456 if (fp < stack_start || fp > stack_end) 457 return 0; 458 lr = pc_pointer (((unsigned long *)fp)[-1]); 459 if (!in_sched_functions(lr)) 460 return lr; 461 fp = *(unsigned long *) (fp - 12); 462 } while (count ++ < 16); 463 return 0; 464 } 465 EXPORT_SYMBOL(get_wchan); 466