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/a.out.h> 22 #include <linux/delay.h> 23 #include <linux/reboot.h> 24 #include <linux/interrupt.h> 25 #include <linux/kallsyms.h> 26 #include <linux/init.h> 27 #include <linux/cpu.h> 28 #include <linux/elfcore.h> 29 #include <linux/pm.h> 30 #include <linux/tick.h> 31 #include <linux/utsname.h> 32 33 #include <asm/leds.h> 34 #include <asm/processor.h> 35 #include <asm/system.h> 36 #include <asm/thread_notify.h> 37 #include <asm/uaccess.h> 38 #include <asm/mach/time.h> 39 40 static const char *processor_modes[] = { 41 "USER_26", "FIQ_26" , "IRQ_26" , "SVC_26" , "UK4_26" , "UK5_26" , "UK6_26" , "UK7_26" , 42 "UK8_26" , "UK9_26" , "UK10_26", "UK11_26", "UK12_26", "UK13_26", "UK14_26", "UK15_26", 43 "USER_32", "FIQ_32" , "IRQ_32" , "SVC_32" , "UK4_32" , "UK5_32" , "UK6_32" , "ABT_32" , 44 "UK8_32" , "UK9_32" , "UK10_32", "UND_32" , "UK12_32", "UK13_32", "UK14_32", "SYS_32" 45 }; 46 47 extern void setup_mm_for_reboot(char mode); 48 49 static volatile int hlt_counter; 50 51 #include <asm/arch/system.h> 52 53 void disable_hlt(void) 54 { 55 hlt_counter++; 56 } 57 58 EXPORT_SYMBOL(disable_hlt); 59 60 void enable_hlt(void) 61 { 62 hlt_counter--; 63 } 64 65 EXPORT_SYMBOL(enable_hlt); 66 67 static int __init nohlt_setup(char *__unused) 68 { 69 hlt_counter = 1; 70 return 1; 71 } 72 73 static int __init hlt_setup(char *__unused) 74 { 75 hlt_counter = 0; 76 return 1; 77 } 78 79 __setup("nohlt", nohlt_setup); 80 __setup("hlt", hlt_setup); 81 82 void arm_machine_restart(char mode) 83 { 84 /* 85 * Clean and disable cache, and turn off interrupts 86 */ 87 cpu_proc_fin(); 88 89 /* 90 * Tell the mm system that we are going to reboot - 91 * we may need it to insert some 1:1 mappings so that 92 * soft boot works. 93 */ 94 setup_mm_for_reboot(mode); 95 96 /* 97 * Now call the architecture specific reboot code. 98 */ 99 arch_reset(mode); 100 101 /* 102 * Whoops - the architecture was unable to reboot. 103 * Tell the user! 104 */ 105 mdelay(1000); 106 printk("Reboot failed -- System halted\n"); 107 while (1); 108 } 109 110 /* 111 * Function pointers to optional machine specific functions 112 */ 113 void (*pm_idle)(void); 114 EXPORT_SYMBOL(pm_idle); 115 116 void (*pm_power_off)(void); 117 EXPORT_SYMBOL(pm_power_off); 118 119 void (*arm_pm_restart)(char str) = arm_machine_restart; 120 EXPORT_SYMBOL_GPL(arm_pm_restart); 121 122 123 /* 124 * This is our default idle handler. We need to disable 125 * interrupts here to ensure we don't miss a wakeup call. 126 */ 127 static void default_idle(void) 128 { 129 if (hlt_counter) 130 cpu_relax(); 131 else { 132 local_irq_disable(); 133 if (!need_resched()) { 134 timer_dyn_reprogram(); 135 arch_idle(); 136 } 137 local_irq_enable(); 138 } 139 } 140 141 /* 142 * The idle thread. We try to conserve power, while trying to keep 143 * overall latency low. The architecture specific idle is passed 144 * a value to indicate the level of "idleness" of the system. 145 */ 146 void cpu_idle(void) 147 { 148 local_fiq_enable(); 149 150 /* endless idle loop with no priority at all */ 151 while (1) { 152 void (*idle)(void) = pm_idle; 153 154 #ifdef CONFIG_HOTPLUG_CPU 155 if (cpu_is_offline(smp_processor_id())) { 156 leds_event(led_idle_start); 157 cpu_die(); 158 } 159 #endif 160 161 if (!idle) 162 idle = default_idle; 163 leds_event(led_idle_start); 164 tick_nohz_stop_sched_tick(); 165 while (!need_resched()) 166 idle(); 167 leds_event(led_idle_end); 168 tick_nohz_restart_sched_tick(); 169 preempt_enable_no_resched(); 170 schedule(); 171 preempt_disable(); 172 } 173 } 174 175 static char reboot_mode = 'h'; 176 177 int __init reboot_setup(char *str) 178 { 179 reboot_mode = str[0]; 180 return 1; 181 } 182 183 __setup("reboot=", reboot_setup); 184 185 void machine_halt(void) 186 { 187 } 188 189 190 void machine_power_off(void) 191 { 192 if (pm_power_off) 193 pm_power_off(); 194 } 195 196 void machine_restart(char * __unused) 197 { 198 arm_pm_restart(reboot_mode); 199 } 200 201 void __show_regs(struct pt_regs *regs) 202 { 203 unsigned long flags; 204 char buf[64]; 205 206 printk("CPU: %d %s (%s %.*s)\n", 207 smp_processor_id(), print_tainted(), init_utsname()->release, 208 (int)strcspn(init_utsname()->version, " "), 209 init_utsname()->version); 210 print_symbol("PC is at %s\n", instruction_pointer(regs)); 211 print_symbol("LR is at %s\n", regs->ARM_lr); 212 printk("pc : [<%08lx>] lr : [<%08lx>] psr: %08lx\n" 213 "sp : %08lx ip : %08lx fp : %08lx\n", 214 regs->ARM_pc, regs->ARM_lr, regs->ARM_cpsr, 215 regs->ARM_sp, regs->ARM_ip, regs->ARM_fp); 216 printk("r10: %08lx r9 : %08lx r8 : %08lx\n", 217 regs->ARM_r10, regs->ARM_r9, 218 regs->ARM_r8); 219 printk("r7 : %08lx r6 : %08lx r5 : %08lx r4 : %08lx\n", 220 regs->ARM_r7, regs->ARM_r6, 221 regs->ARM_r5, regs->ARM_r4); 222 printk("r3 : %08lx r2 : %08lx r1 : %08lx r0 : %08lx\n", 223 regs->ARM_r3, regs->ARM_r2, 224 regs->ARM_r1, regs->ARM_r0); 225 226 flags = regs->ARM_cpsr; 227 buf[0] = flags & PSR_N_BIT ? 'N' : 'n'; 228 buf[1] = flags & PSR_Z_BIT ? 'Z' : 'z'; 229 buf[2] = flags & PSR_C_BIT ? 'C' : 'c'; 230 buf[3] = flags & PSR_V_BIT ? 'V' : 'v'; 231 buf[4] = '\0'; 232 233 printk("Flags: %s IRQs o%s FIQs o%s Mode %s%s Segment %s\n", 234 buf, interrupts_enabled(regs) ? "n" : "ff", 235 fast_interrupts_enabled(regs) ? "n" : "ff", 236 processor_modes[processor_mode(regs)], 237 thumb_mode(regs) ? " (T)" : "", 238 get_fs() == get_ds() ? "kernel" : "user"); 239 #ifdef CONFIG_CPU_CP15 240 { 241 unsigned int ctrl; 242 243 buf[0] = '\0'; 244 #ifdef CONFIG_CPU_CP15_MMU 245 { 246 unsigned int transbase, dac; 247 asm("mrc p15, 0, %0, c2, c0\n\t" 248 "mrc p15, 0, %1, c3, c0\n" 249 : "=r" (transbase), "=r" (dac)); 250 snprintf(buf, sizeof(buf), " Table: %08x DAC: %08x", 251 transbase, dac); 252 } 253 #endif 254 asm("mrc p15, 0, %0, c1, c0\n" : "=r" (ctrl)); 255 256 printk("Control: %08x%s\n", ctrl, buf); 257 } 258 #endif 259 } 260 261 void show_regs(struct pt_regs * regs) 262 { 263 printk("\n"); 264 printk("Pid: %d, comm: %20s\n", current->pid, current->comm); 265 __show_regs(regs); 266 __backtrace(); 267 } 268 269 void show_fpregs(struct user_fp *regs) 270 { 271 int i; 272 273 for (i = 0; i < 8; i++) { 274 unsigned long *p; 275 char type; 276 277 p = (unsigned long *)(regs->fpregs + i); 278 279 switch (regs->ftype[i]) { 280 case 1: type = 'f'; break; 281 case 2: type = 'd'; break; 282 case 3: type = 'e'; break; 283 default: type = '?'; break; 284 } 285 if (regs->init_flag) 286 type = '?'; 287 288 printk(" f%d(%c): %08lx %08lx %08lx%c", 289 i, type, p[0], p[1], p[2], i & 1 ? '\n' : ' '); 290 } 291 292 293 printk("FPSR: %08lx FPCR: %08lx\n", 294 (unsigned long)regs->fpsr, 295 (unsigned long)regs->fpcr); 296 } 297 298 /* 299 * Free current thread data structures etc.. 300 */ 301 void exit_thread(void) 302 { 303 } 304 305 ATOMIC_NOTIFIER_HEAD(thread_notify_head); 306 307 EXPORT_SYMBOL_GPL(thread_notify_head); 308 309 void flush_thread(void) 310 { 311 struct thread_info *thread = current_thread_info(); 312 struct task_struct *tsk = current; 313 314 memset(thread->used_cp, 0, sizeof(thread->used_cp)); 315 memset(&tsk->thread.debug, 0, sizeof(struct debug_info)); 316 memset(&thread->fpstate, 0, sizeof(union fp_state)); 317 318 thread_notify(THREAD_NOTIFY_FLUSH, thread); 319 } 320 321 void release_thread(struct task_struct *dead_task) 322 { 323 struct thread_info *thread = task_thread_info(dead_task); 324 325 thread_notify(THREAD_NOTIFY_RELEASE, thread); 326 } 327 328 asmlinkage void ret_from_fork(void) __asm__("ret_from_fork"); 329 330 int 331 copy_thread(int nr, unsigned long clone_flags, unsigned long stack_start, 332 unsigned long stk_sz, struct task_struct *p, struct pt_regs *regs) 333 { 334 struct thread_info *thread = task_thread_info(p); 335 struct pt_regs *childregs = task_pt_regs(p); 336 337 *childregs = *regs; 338 childregs->ARM_r0 = 0; 339 childregs->ARM_sp = stack_start; 340 341 memset(&thread->cpu_context, 0, sizeof(struct cpu_context_save)); 342 thread->cpu_context.sp = (unsigned long)childregs; 343 thread->cpu_context.pc = (unsigned long)ret_from_fork; 344 345 if (clone_flags & CLONE_SETTLS) 346 thread->tp_value = regs->ARM_r3; 347 348 return 0; 349 } 350 351 /* 352 * fill in the fpe structure for a core dump... 353 */ 354 int dump_fpu (struct pt_regs *regs, struct user_fp *fp) 355 { 356 struct thread_info *thread = current_thread_info(); 357 int used_math = thread->used_cp[1] | thread->used_cp[2]; 358 359 if (used_math) 360 memcpy(fp, &thread->fpstate.soft, sizeof (*fp)); 361 362 return used_math != 0; 363 } 364 EXPORT_SYMBOL(dump_fpu); 365 366 /* 367 * fill in the user structure for a core dump.. 368 */ 369 void dump_thread(struct pt_regs * regs, struct user * dump) 370 { 371 struct task_struct *tsk = current; 372 373 dump->magic = CMAGIC; 374 dump->start_code = tsk->mm->start_code; 375 dump->start_stack = regs->ARM_sp & ~(PAGE_SIZE - 1); 376 377 dump->u_tsize = (tsk->mm->end_code - tsk->mm->start_code) >> PAGE_SHIFT; 378 dump->u_dsize = (tsk->mm->brk - tsk->mm->start_data + PAGE_SIZE - 1) >> PAGE_SHIFT; 379 dump->u_ssize = 0; 380 381 dump->u_debugreg[0] = tsk->thread.debug.bp[0].address; 382 dump->u_debugreg[1] = tsk->thread.debug.bp[1].address; 383 dump->u_debugreg[2] = tsk->thread.debug.bp[0].insn.arm; 384 dump->u_debugreg[3] = tsk->thread.debug.bp[1].insn.arm; 385 dump->u_debugreg[4] = tsk->thread.debug.nsaved; 386 387 if (dump->start_stack < 0x04000000) 388 dump->u_ssize = (0x04000000 - dump->start_stack) >> PAGE_SHIFT; 389 390 dump->regs = *regs; 391 dump->u_fpvalid = dump_fpu (regs, &dump->u_fp); 392 } 393 EXPORT_SYMBOL(dump_thread); 394 395 /* 396 * Shuffle the argument into the correct register before calling the 397 * thread function. r1 is the thread argument, r2 is the pointer to 398 * the thread function, and r3 points to the exit function. 399 */ 400 extern void kernel_thread_helper(void); 401 asm( ".section .text\n" 402 " .align\n" 403 " .type kernel_thread_helper, #function\n" 404 "kernel_thread_helper:\n" 405 " mov r0, r1\n" 406 " mov lr, r3\n" 407 " mov pc, r2\n" 408 " .size kernel_thread_helper, . - kernel_thread_helper\n" 409 " .previous"); 410 411 /* 412 * Create a kernel thread. 413 */ 414 pid_t kernel_thread(int (*fn)(void *), void *arg, unsigned long flags) 415 { 416 struct pt_regs regs; 417 418 memset(®s, 0, sizeof(regs)); 419 420 regs.ARM_r1 = (unsigned long)arg; 421 regs.ARM_r2 = (unsigned long)fn; 422 regs.ARM_r3 = (unsigned long)do_exit; 423 regs.ARM_pc = (unsigned long)kernel_thread_helper; 424 regs.ARM_cpsr = SVC_MODE; 425 426 return do_fork(flags|CLONE_VM|CLONE_UNTRACED, 0, ®s, 0, NULL, NULL); 427 } 428 EXPORT_SYMBOL(kernel_thread); 429 430 unsigned long get_wchan(struct task_struct *p) 431 { 432 unsigned long fp, lr; 433 unsigned long stack_start, stack_end; 434 int count = 0; 435 if (!p || p == current || p->state == TASK_RUNNING) 436 return 0; 437 438 stack_start = (unsigned long)end_of_stack(p); 439 stack_end = (unsigned long)task_stack_page(p) + THREAD_SIZE; 440 441 fp = thread_saved_fp(p); 442 do { 443 if (fp < stack_start || fp > stack_end) 444 return 0; 445 lr = pc_pointer (((unsigned long *)fp)[-1]); 446 if (!in_sched_functions(lr)) 447 return lr; 448 fp = *(unsigned long *) (fp - 12); 449 } while (count ++ < 16); 450 return 0; 451 } 452