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 static const char *processor_modes[] = { 40 "USER_26", "FIQ_26" , "IRQ_26" , "SVC_26" , "UK4_26" , "UK5_26" , "UK6_26" , "UK7_26" , 41 "UK8_26" , "UK9_26" , "UK10_26", "UK11_26", "UK12_26", "UK13_26", "UK14_26", "UK15_26", 42 "USER_32", "FIQ_32" , "IRQ_32" , "SVC_32" , "UK4_32" , "UK5_32" , "UK6_32" , "ABT_32" , 43 "UK8_32" , "UK9_32" , "UK10_32", "UND_32" , "UK12_32", "UK13_32", "UK14_32", "SYS_32" 44 }; 45 46 extern void setup_mm_for_reboot(char mode); 47 48 static volatile int hlt_counter; 49 50 #include <asm/arch/system.h> 51 52 void disable_hlt(void) 53 { 54 hlt_counter++; 55 } 56 57 EXPORT_SYMBOL(disable_hlt); 58 59 void enable_hlt(void) 60 { 61 hlt_counter--; 62 } 63 64 EXPORT_SYMBOL(enable_hlt); 65 66 static int __init nohlt_setup(char *__unused) 67 { 68 hlt_counter = 1; 69 return 1; 70 } 71 72 static int __init hlt_setup(char *__unused) 73 { 74 hlt_counter = 0; 75 return 1; 76 } 77 78 __setup("nohlt", nohlt_setup); 79 __setup("hlt", hlt_setup); 80 81 void arm_machine_restart(char mode) 82 { 83 /* 84 * Clean and disable cache, and turn off interrupts 85 */ 86 cpu_proc_fin(); 87 88 /* 89 * Tell the mm system that we are going to reboot - 90 * we may need it to insert some 1:1 mappings so that 91 * soft boot works. 92 */ 93 setup_mm_for_reboot(mode); 94 95 /* 96 * Now call the architecture specific reboot code. 97 */ 98 arch_reset(mode); 99 100 /* 101 * Whoops - the architecture was unable to reboot. 102 * Tell the user! 103 */ 104 mdelay(1000); 105 printk("Reboot failed -- System halted\n"); 106 while (1); 107 } 108 109 /* 110 * Function pointers to optional machine specific functions 111 */ 112 void (*pm_idle)(void); 113 EXPORT_SYMBOL(pm_idle); 114 115 void (*pm_power_off)(void); 116 EXPORT_SYMBOL(pm_power_off); 117 118 void (*arm_pm_restart)(char str) = arm_machine_restart; 119 EXPORT_SYMBOL_GPL(arm_pm_restart); 120 121 122 /* 123 * This is our default idle handler. We need to disable 124 * interrupts here to ensure we don't miss a wakeup call. 125 */ 126 static void default_idle(void) 127 { 128 if (hlt_counter) 129 cpu_relax(); 130 else { 131 local_irq_disable(); 132 if (!need_resched()) { 133 timer_dyn_reprogram(); 134 arch_idle(); 135 } 136 local_irq_enable(); 137 } 138 } 139 140 /* 141 * The idle thread. We try to conserve power, while trying to keep 142 * overall latency low. The architecture specific idle is passed 143 * a value to indicate the level of "idleness" of the system. 144 */ 145 void cpu_idle(void) 146 { 147 local_fiq_enable(); 148 149 /* endless idle loop with no priority at all */ 150 while (1) { 151 void (*idle)(void) = pm_idle; 152 153 #ifdef CONFIG_HOTPLUG_CPU 154 if (cpu_is_offline(smp_processor_id())) { 155 leds_event(led_idle_start); 156 cpu_die(); 157 } 158 #endif 159 160 if (!idle) 161 idle = default_idle; 162 leds_event(led_idle_start); 163 while (!need_resched()) 164 idle(); 165 leds_event(led_idle_end); 166 preempt_enable_no_resched(); 167 schedule(); 168 preempt_disable(); 169 } 170 } 171 172 static char reboot_mode = 'h'; 173 174 int __init reboot_setup(char *str) 175 { 176 reboot_mode = str[0]; 177 return 1; 178 } 179 180 __setup("reboot=", reboot_setup); 181 182 void machine_halt(void) 183 { 184 } 185 186 187 void machine_power_off(void) 188 { 189 if (pm_power_off) 190 pm_power_off(); 191 } 192 193 void machine_restart(char * __unused) 194 { 195 arm_pm_restart(reboot_mode); 196 } 197 198 void __show_regs(struct pt_regs *regs) 199 { 200 unsigned long flags = condition_codes(regs); 201 202 printk("CPU: %d\n", smp_processor_id()); 203 print_symbol("PC is at %s\n", instruction_pointer(regs)); 204 print_symbol("LR is at %s\n", regs->ARM_lr); 205 printk("pc : [<%08lx>] lr : [<%08lx>] %s\n" 206 "sp : %08lx ip : %08lx fp : %08lx\n", 207 instruction_pointer(regs), 208 regs->ARM_lr, print_tainted(), regs->ARM_sp, 209 regs->ARM_ip, regs->ARM_fp); 210 printk("r10: %08lx r9 : %08lx r8 : %08lx\n", 211 regs->ARM_r10, regs->ARM_r9, 212 regs->ARM_r8); 213 printk("r7 : %08lx r6 : %08lx r5 : %08lx r4 : %08lx\n", 214 regs->ARM_r7, regs->ARM_r6, 215 regs->ARM_r5, regs->ARM_r4); 216 printk("r3 : %08lx r2 : %08lx r1 : %08lx r0 : %08lx\n", 217 regs->ARM_r3, regs->ARM_r2, 218 regs->ARM_r1, regs->ARM_r0); 219 printk("Flags: %c%c%c%c", 220 flags & PSR_N_BIT ? 'N' : 'n', 221 flags & PSR_Z_BIT ? 'Z' : 'z', 222 flags & PSR_C_BIT ? 'C' : 'c', 223 flags & PSR_V_BIT ? 'V' : 'v'); 224 printk(" IRQs o%s FIQs o%s Mode %s%s Segment %s\n", 225 interrupts_enabled(regs) ? "n" : "ff", 226 fast_interrupts_enabled(regs) ? "n" : "ff", 227 processor_modes[processor_mode(regs)], 228 thumb_mode(regs) ? " (T)" : "", 229 get_fs() == get_ds() ? "kernel" : "user"); 230 #if CONFIG_CPU_CP15 231 { 232 unsigned int ctrl; 233 __asm__ ( 234 " mrc p15, 0, %0, c1, c0\n" 235 : "=r" (ctrl)); 236 printk("Control: %04X\n", ctrl); 237 } 238 #ifdef CONFIG_CPU_CP15_MMU 239 { 240 unsigned int transbase, dac; 241 __asm__ ( 242 " mrc p15, 0, %0, c2, c0\n" 243 " mrc p15, 0, %1, c3, c0\n" 244 : "=r" (transbase), "=r" (dac)); 245 printk("Table: %08X DAC: %08X\n", 246 transbase, dac); 247 } 248 #endif 249 #endif 250 } 251 252 void show_regs(struct pt_regs * regs) 253 { 254 printk("\n"); 255 printk("Pid: %d, comm: %20s\n", current->pid, current->comm); 256 __show_regs(regs); 257 __backtrace(); 258 } 259 260 void show_fpregs(struct user_fp *regs) 261 { 262 int i; 263 264 for (i = 0; i < 8; i++) { 265 unsigned long *p; 266 char type; 267 268 p = (unsigned long *)(regs->fpregs + i); 269 270 switch (regs->ftype[i]) { 271 case 1: type = 'f'; break; 272 case 2: type = 'd'; break; 273 case 3: type = 'e'; break; 274 default: type = '?'; break; 275 } 276 if (regs->init_flag) 277 type = '?'; 278 279 printk(" f%d(%c): %08lx %08lx %08lx%c", 280 i, type, p[0], p[1], p[2], i & 1 ? '\n' : ' '); 281 } 282 283 284 printk("FPSR: %08lx FPCR: %08lx\n", 285 (unsigned long)regs->fpsr, 286 (unsigned long)regs->fpcr); 287 } 288 289 /* 290 * Free current thread data structures etc.. 291 */ 292 void exit_thread(void) 293 { 294 } 295 296 ATOMIC_NOTIFIER_HEAD(thread_notify_head); 297 298 EXPORT_SYMBOL_GPL(thread_notify_head); 299 300 void flush_thread(void) 301 { 302 struct thread_info *thread = current_thread_info(); 303 struct task_struct *tsk = current; 304 305 memset(thread->used_cp, 0, sizeof(thread->used_cp)); 306 memset(&tsk->thread.debug, 0, sizeof(struct debug_info)); 307 memset(&thread->fpstate, 0, sizeof(union fp_state)); 308 309 thread_notify(THREAD_NOTIFY_FLUSH, thread); 310 } 311 312 void release_thread(struct task_struct *dead_task) 313 { 314 struct thread_info *thread = task_thread_info(dead_task); 315 316 thread_notify(THREAD_NOTIFY_RELEASE, thread); 317 } 318 319 asmlinkage void ret_from_fork(void) __asm__("ret_from_fork"); 320 321 int 322 copy_thread(int nr, unsigned long clone_flags, unsigned long stack_start, 323 unsigned long stk_sz, struct task_struct *p, struct pt_regs *regs) 324 { 325 struct thread_info *thread = task_thread_info(p); 326 struct pt_regs *childregs = task_pt_regs(p); 327 328 *childregs = *regs; 329 childregs->ARM_r0 = 0; 330 childregs->ARM_sp = stack_start; 331 332 memset(&thread->cpu_context, 0, sizeof(struct cpu_context_save)); 333 thread->cpu_context.sp = (unsigned long)childregs; 334 thread->cpu_context.pc = (unsigned long)ret_from_fork; 335 336 if (clone_flags & CLONE_SETTLS) 337 thread->tp_value = regs->ARM_r3; 338 339 return 0; 340 } 341 342 /* 343 * fill in the fpe structure for a core dump... 344 */ 345 int dump_fpu (struct pt_regs *regs, struct user_fp *fp) 346 { 347 struct thread_info *thread = current_thread_info(); 348 int used_math = thread->used_cp[1] | thread->used_cp[2]; 349 350 if (used_math) 351 memcpy(fp, &thread->fpstate.soft, sizeof (*fp)); 352 353 return used_math != 0; 354 } 355 EXPORT_SYMBOL(dump_fpu); 356 357 /* 358 * fill in the user structure for a core dump.. 359 */ 360 void dump_thread(struct pt_regs * regs, struct user * dump) 361 { 362 struct task_struct *tsk = current; 363 364 dump->magic = CMAGIC; 365 dump->start_code = tsk->mm->start_code; 366 dump->start_stack = regs->ARM_sp & ~(PAGE_SIZE - 1); 367 368 dump->u_tsize = (tsk->mm->end_code - tsk->mm->start_code) >> PAGE_SHIFT; 369 dump->u_dsize = (tsk->mm->brk - tsk->mm->start_data + PAGE_SIZE - 1) >> PAGE_SHIFT; 370 dump->u_ssize = 0; 371 372 dump->u_debugreg[0] = tsk->thread.debug.bp[0].address; 373 dump->u_debugreg[1] = tsk->thread.debug.bp[1].address; 374 dump->u_debugreg[2] = tsk->thread.debug.bp[0].insn.arm; 375 dump->u_debugreg[3] = tsk->thread.debug.bp[1].insn.arm; 376 dump->u_debugreg[4] = tsk->thread.debug.nsaved; 377 378 if (dump->start_stack < 0x04000000) 379 dump->u_ssize = (0x04000000 - dump->start_stack) >> PAGE_SHIFT; 380 381 dump->regs = *regs; 382 dump->u_fpvalid = dump_fpu (regs, &dump->u_fp); 383 } 384 EXPORT_SYMBOL(dump_thread); 385 386 /* 387 * Shuffle the argument into the correct register before calling the 388 * thread function. r1 is the thread argument, r2 is the pointer to 389 * the thread function, and r3 points to the exit function. 390 */ 391 extern void kernel_thread_helper(void); 392 asm( ".section .text\n" 393 " .align\n" 394 " .type kernel_thread_helper, #function\n" 395 "kernel_thread_helper:\n" 396 " mov r0, r1\n" 397 " mov lr, r3\n" 398 " mov pc, r2\n" 399 " .size kernel_thread_helper, . - kernel_thread_helper\n" 400 " .previous"); 401 402 /* 403 * Create a kernel thread. 404 */ 405 pid_t kernel_thread(int (*fn)(void *), void *arg, unsigned long flags) 406 { 407 struct pt_regs regs; 408 409 memset(®s, 0, sizeof(regs)); 410 411 regs.ARM_r1 = (unsigned long)arg; 412 regs.ARM_r2 = (unsigned long)fn; 413 regs.ARM_r3 = (unsigned long)do_exit; 414 regs.ARM_pc = (unsigned long)kernel_thread_helper; 415 regs.ARM_cpsr = SVC_MODE; 416 417 return do_fork(flags|CLONE_VM|CLONE_UNTRACED, 0, ®s, 0, NULL, NULL); 418 } 419 EXPORT_SYMBOL(kernel_thread); 420 421 unsigned long get_wchan(struct task_struct *p) 422 { 423 unsigned long fp, lr; 424 unsigned long stack_start, stack_end; 425 int count = 0; 426 if (!p || p == current || p->state == TASK_RUNNING) 427 return 0; 428 429 stack_start = (unsigned long)end_of_stack(p); 430 stack_end = (unsigned long)task_stack_page(p) + THREAD_SIZE; 431 432 fp = thread_saved_fp(p); 433 do { 434 if (fp < stack_start || fp > stack_end) 435 return 0; 436 lr = pc_pointer (((unsigned long *)fp)[-1]); 437 if (!in_sched_functions(lr)) 438 return lr; 439 fp = *(unsigned long *) (fp - 12); 440 } while (count ++ < 16); 441 return 0; 442 } 443