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/slab.h> 20 #include <linux/user.h> 21 #include <linux/delay.h> 22 #include <linux/reboot.h> 23 #include <linux/interrupt.h> 24 #include <linux/kallsyms.h> 25 #include <linux/init.h> 26 #include <linux/cpu.h> 27 #include <linux/elfcore.h> 28 #include <linux/pm.h> 29 #include <linux/tick.h> 30 #include <linux/utsname.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 static const char *isa_modes[] = { 47 "ARM" , "Thumb" , "Jazelle", "ThumbEE" 48 }; 49 50 extern void setup_mm_for_reboot(char mode); 51 52 static volatile int hlt_counter; 53 54 #include <asm/arch/system.h> 55 56 void disable_hlt(void) 57 { 58 hlt_counter++; 59 } 60 61 EXPORT_SYMBOL(disable_hlt); 62 63 void enable_hlt(void) 64 { 65 hlt_counter--; 66 } 67 68 EXPORT_SYMBOL(enable_hlt); 69 70 static int __init nohlt_setup(char *__unused) 71 { 72 hlt_counter = 1; 73 return 1; 74 } 75 76 static int __init hlt_setup(char *__unused) 77 { 78 hlt_counter = 0; 79 return 1; 80 } 81 82 __setup("nohlt", nohlt_setup); 83 __setup("hlt", hlt_setup); 84 85 void arm_machine_restart(char mode) 86 { 87 /* 88 * Clean and disable cache, and turn off interrupts 89 */ 90 cpu_proc_fin(); 91 92 /* 93 * Tell the mm system that we are going to reboot - 94 * we may need it to insert some 1:1 mappings so that 95 * soft boot works. 96 */ 97 setup_mm_for_reboot(mode); 98 99 /* 100 * Now call the architecture specific reboot code. 101 */ 102 arch_reset(mode); 103 104 /* 105 * Whoops - the architecture was unable to reboot. 106 * Tell the user! 107 */ 108 mdelay(1000); 109 printk("Reboot failed -- System halted\n"); 110 while (1); 111 } 112 113 /* 114 * Function pointers to optional machine specific functions 115 */ 116 void (*pm_idle)(void); 117 EXPORT_SYMBOL(pm_idle); 118 119 void (*pm_power_off)(void); 120 EXPORT_SYMBOL(pm_power_off); 121 122 void (*arm_pm_restart)(char str) = arm_machine_restart; 123 EXPORT_SYMBOL_GPL(arm_pm_restart); 124 125 126 /* 127 * This is our default idle handler. We need to disable 128 * interrupts here to ensure we don't miss a wakeup call. 129 */ 130 static void default_idle(void) 131 { 132 if (hlt_counter) 133 cpu_relax(); 134 else { 135 local_irq_disable(); 136 if (!need_resched()) { 137 timer_dyn_reprogram(); 138 arch_idle(); 139 } 140 local_irq_enable(); 141 } 142 } 143 144 /* 145 * The idle thread. We try to conserve power, while trying to keep 146 * overall latency low. The architecture specific idle is passed 147 * a value to indicate the level of "idleness" of the system. 148 */ 149 void cpu_idle(void) 150 { 151 local_fiq_enable(); 152 153 /* endless idle loop with no priority at all */ 154 while (1) { 155 void (*idle)(void) = pm_idle; 156 157 #ifdef CONFIG_HOTPLUG_CPU 158 if (cpu_is_offline(smp_processor_id())) { 159 leds_event(led_idle_start); 160 cpu_die(); 161 } 162 #endif 163 164 if (!idle) 165 idle = default_idle; 166 leds_event(led_idle_start); 167 tick_nohz_stop_sched_tick(); 168 while (!need_resched()) 169 idle(); 170 leds_event(led_idle_end); 171 tick_nohz_restart_sched_tick(); 172 preempt_enable_no_resched(); 173 schedule(); 174 preempt_disable(); 175 } 176 } 177 178 static char reboot_mode = 'h'; 179 180 int __init reboot_setup(char *str) 181 { 182 reboot_mode = str[0]; 183 return 1; 184 } 185 186 __setup("reboot=", reboot_setup); 187 188 void machine_halt(void) 189 { 190 } 191 192 193 void machine_power_off(void) 194 { 195 if (pm_power_off) 196 pm_power_off(); 197 } 198 199 void machine_restart(char * __unused) 200 { 201 arm_pm_restart(reboot_mode); 202 } 203 204 void __show_regs(struct pt_regs *regs) 205 { 206 unsigned long flags; 207 char buf[64]; 208 209 printk("CPU: %d %s (%s %.*s)\n", 210 smp_processor_id(), print_tainted(), init_utsname()->release, 211 (int)strcspn(init_utsname()->version, " "), 212 init_utsname()->version); 213 print_symbol("PC is at %s\n", instruction_pointer(regs)); 214 print_symbol("LR is at %s\n", regs->ARM_lr); 215 printk("pc : [<%08lx>] lr : [<%08lx>] psr: %08lx\n" 216 "sp : %08lx ip : %08lx fp : %08lx\n", 217 regs->ARM_pc, regs->ARM_lr, regs->ARM_cpsr, 218 regs->ARM_sp, regs->ARM_ip, regs->ARM_fp); 219 printk("r10: %08lx r9 : %08lx r8 : %08lx\n", 220 regs->ARM_r10, regs->ARM_r9, 221 regs->ARM_r8); 222 printk("r7 : %08lx r6 : %08lx r5 : %08lx r4 : %08lx\n", 223 regs->ARM_r7, regs->ARM_r6, 224 regs->ARM_r5, regs->ARM_r4); 225 printk("r3 : %08lx r2 : %08lx r1 : %08lx r0 : %08lx\n", 226 regs->ARM_r3, regs->ARM_r2, 227 regs->ARM_r1, regs->ARM_r0); 228 229 flags = regs->ARM_cpsr; 230 buf[0] = flags & PSR_N_BIT ? 'N' : 'n'; 231 buf[1] = flags & PSR_Z_BIT ? 'Z' : 'z'; 232 buf[2] = flags & PSR_C_BIT ? 'C' : 'c'; 233 buf[3] = flags & PSR_V_BIT ? 'V' : 'v'; 234 buf[4] = '\0'; 235 236 printk("Flags: %s IRQs o%s FIQs o%s Mode %s ISA %s Segment %s\n", 237 buf, interrupts_enabled(regs) ? "n" : "ff", 238 fast_interrupts_enabled(regs) ? "n" : "ff", 239 processor_modes[processor_mode(regs)], 240 isa_modes[isa_mode(regs)], 241 get_fs() == get_ds() ? "kernel" : "user"); 242 #ifdef CONFIG_CPU_CP15 243 { 244 unsigned int ctrl; 245 246 buf[0] = '\0'; 247 #ifdef CONFIG_CPU_CP15_MMU 248 { 249 unsigned int transbase, dac; 250 asm("mrc p15, 0, %0, c2, c0\n\t" 251 "mrc p15, 0, %1, c3, c0\n" 252 : "=r" (transbase), "=r" (dac)); 253 snprintf(buf, sizeof(buf), " Table: %08x DAC: %08x", 254 transbase, dac); 255 } 256 #endif 257 asm("mrc p15, 0, %0, c1, c0\n" : "=r" (ctrl)); 258 259 printk("Control: %08x%s\n", ctrl, buf); 260 } 261 #endif 262 } 263 264 void show_regs(struct pt_regs * regs) 265 { 266 printk("\n"); 267 printk("Pid: %d, comm: %20s\n", task_pid_nr(current), current->comm); 268 __show_regs(regs); 269 __backtrace(); 270 } 271 272 void show_fpregs(struct user_fp *regs) 273 { 274 int i; 275 276 for (i = 0; i < 8; i++) { 277 unsigned long *p; 278 char type; 279 280 p = (unsigned long *)(regs->fpregs + i); 281 282 switch (regs->ftype[i]) { 283 case 1: type = 'f'; break; 284 case 2: type = 'd'; break; 285 case 3: type = 'e'; break; 286 default: type = '?'; break; 287 } 288 if (regs->init_flag) 289 type = '?'; 290 291 printk(" f%d(%c): %08lx %08lx %08lx%c", 292 i, type, p[0], p[1], p[2], i & 1 ? '\n' : ' '); 293 } 294 295 296 printk("FPSR: %08lx FPCR: %08lx\n", 297 (unsigned long)regs->fpsr, 298 (unsigned long)regs->fpcr); 299 } 300 301 /* 302 * Free current thread data structures etc.. 303 */ 304 void exit_thread(void) 305 { 306 } 307 308 ATOMIC_NOTIFIER_HEAD(thread_notify_head); 309 310 EXPORT_SYMBOL_GPL(thread_notify_head); 311 312 void flush_thread(void) 313 { 314 struct thread_info *thread = current_thread_info(); 315 struct task_struct *tsk = current; 316 317 memset(thread->used_cp, 0, sizeof(thread->used_cp)); 318 memset(&tsk->thread.debug, 0, sizeof(struct debug_info)); 319 memset(&thread->fpstate, 0, sizeof(union fp_state)); 320 321 thread_notify(THREAD_NOTIFY_FLUSH, thread); 322 } 323 324 void release_thread(struct task_struct *dead_task) 325 { 326 struct thread_info *thread = task_thread_info(dead_task); 327 328 thread_notify(THREAD_NOTIFY_RELEASE, thread); 329 } 330 331 asmlinkage void ret_from_fork(void) __asm__("ret_from_fork"); 332 333 int 334 copy_thread(int nr, unsigned long clone_flags, unsigned long stack_start, 335 unsigned long stk_sz, struct task_struct *p, struct pt_regs *regs) 336 { 337 struct thread_info *thread = task_thread_info(p); 338 struct pt_regs *childregs = task_pt_regs(p); 339 340 *childregs = *regs; 341 childregs->ARM_r0 = 0; 342 childregs->ARM_sp = stack_start; 343 344 memset(&thread->cpu_context, 0, sizeof(struct cpu_context_save)); 345 thread->cpu_context.sp = (unsigned long)childregs; 346 thread->cpu_context.pc = (unsigned long)ret_from_fork; 347 348 if (clone_flags & CLONE_SETTLS) 349 thread->tp_value = regs->ARM_r3; 350 351 return 0; 352 } 353 354 /* 355 * fill in the fpe structure for a core dump... 356 */ 357 int dump_fpu (struct pt_regs *regs, struct user_fp *fp) 358 { 359 struct thread_info *thread = current_thread_info(); 360 int used_math = thread->used_cp[1] | thread->used_cp[2]; 361 362 if (used_math) 363 memcpy(fp, &thread->fpstate.soft, sizeof (*fp)); 364 365 return used_math != 0; 366 } 367 EXPORT_SYMBOL(dump_fpu); 368 369 /* 370 * Shuffle the argument into the correct register before calling the 371 * thread function. r1 is the thread argument, r2 is the pointer to 372 * the thread function, and r3 points to the exit function. 373 */ 374 extern void kernel_thread_helper(void); 375 asm( ".section .text\n" 376 " .align\n" 377 " .type kernel_thread_helper, #function\n" 378 "kernel_thread_helper:\n" 379 " mov r0, r1\n" 380 " mov lr, r3\n" 381 " mov pc, r2\n" 382 " .size kernel_thread_helper, . - kernel_thread_helper\n" 383 " .previous"); 384 385 /* 386 * Create a kernel thread. 387 */ 388 pid_t kernel_thread(int (*fn)(void *), void *arg, unsigned long flags) 389 { 390 struct pt_regs regs; 391 392 memset(®s, 0, sizeof(regs)); 393 394 regs.ARM_r1 = (unsigned long)arg; 395 regs.ARM_r2 = (unsigned long)fn; 396 regs.ARM_r3 = (unsigned long)do_exit; 397 regs.ARM_pc = (unsigned long)kernel_thread_helper; 398 regs.ARM_cpsr = SVC_MODE; 399 400 return do_fork(flags|CLONE_VM|CLONE_UNTRACED, 0, ®s, 0, NULL, NULL); 401 } 402 EXPORT_SYMBOL(kernel_thread); 403 404 unsigned long get_wchan(struct task_struct *p) 405 { 406 unsigned long fp, lr; 407 unsigned long stack_start, stack_end; 408 int count = 0; 409 if (!p || p == current || p->state == TASK_RUNNING) 410 return 0; 411 412 stack_start = (unsigned long)end_of_stack(p); 413 stack_end = (unsigned long)task_stack_page(p) + THREAD_SIZE; 414 415 fp = thread_saved_fp(p); 416 do { 417 if (fp < stack_start || fp > stack_end) 418 return 0; 419 lr = pc_pointer (((unsigned long *)fp)[-1]); 420 if (!in_sched_functions(lr)) 421 return lr; 422 fp = *(unsigned long *) (fp - 12); 423 } while (count ++ < 16); 424 return 0; 425 } 426