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 static const char *isa_modes[] = { 48 "ARM" , "Thumb" , "Jazelle", "ThumbEE" 49 }; 50 51 extern void setup_mm_for_reboot(char mode); 52 53 static volatile int hlt_counter; 54 55 #include <asm/arch/system.h> 56 57 void disable_hlt(void) 58 { 59 hlt_counter++; 60 } 61 62 EXPORT_SYMBOL(disable_hlt); 63 64 void enable_hlt(void) 65 { 66 hlt_counter--; 67 } 68 69 EXPORT_SYMBOL(enable_hlt); 70 71 static int __init nohlt_setup(char *__unused) 72 { 73 hlt_counter = 1; 74 return 1; 75 } 76 77 static int __init hlt_setup(char *__unused) 78 { 79 hlt_counter = 0; 80 return 1; 81 } 82 83 __setup("nohlt", nohlt_setup); 84 __setup("hlt", hlt_setup); 85 86 void arm_machine_restart(char mode) 87 { 88 /* 89 * Clean and disable cache, and turn off interrupts 90 */ 91 cpu_proc_fin(); 92 93 /* 94 * Tell the mm system that we are going to reboot - 95 * we may need it to insert some 1:1 mappings so that 96 * soft boot works. 97 */ 98 setup_mm_for_reboot(mode); 99 100 /* 101 * Now call the architecture specific reboot code. 102 */ 103 arch_reset(mode); 104 105 /* 106 * Whoops - the architecture was unable to reboot. 107 * Tell the user! 108 */ 109 mdelay(1000); 110 printk("Reboot failed -- System halted\n"); 111 while (1); 112 } 113 114 /* 115 * Function pointers to optional machine specific functions 116 */ 117 void (*pm_idle)(void); 118 EXPORT_SYMBOL(pm_idle); 119 120 void (*pm_power_off)(void); 121 EXPORT_SYMBOL(pm_power_off); 122 123 void (*arm_pm_restart)(char str) = arm_machine_restart; 124 EXPORT_SYMBOL_GPL(arm_pm_restart); 125 126 127 /* 128 * This is our default idle handler. We need to disable 129 * interrupts here to ensure we don't miss a wakeup call. 130 */ 131 static void default_idle(void) 132 { 133 if (hlt_counter) 134 cpu_relax(); 135 else { 136 local_irq_disable(); 137 if (!need_resched()) { 138 timer_dyn_reprogram(); 139 arch_idle(); 140 } 141 local_irq_enable(); 142 } 143 } 144 145 /* 146 * The idle thread. We try to conserve power, while trying to keep 147 * overall latency low. The architecture specific idle is passed 148 * a value to indicate the level of "idleness" of the system. 149 */ 150 void cpu_idle(void) 151 { 152 local_fiq_enable(); 153 154 /* endless idle loop with no priority at all */ 155 while (1) { 156 void (*idle)(void) = pm_idle; 157 158 #ifdef CONFIG_HOTPLUG_CPU 159 if (cpu_is_offline(smp_processor_id())) { 160 leds_event(led_idle_start); 161 cpu_die(); 162 } 163 #endif 164 165 if (!idle) 166 idle = default_idle; 167 leds_event(led_idle_start); 168 tick_nohz_stop_sched_tick(); 169 while (!need_resched()) 170 idle(); 171 leds_event(led_idle_end); 172 tick_nohz_restart_sched_tick(); 173 preempt_enable_no_resched(); 174 schedule(); 175 preempt_disable(); 176 } 177 } 178 179 static char reboot_mode = 'h'; 180 181 int __init reboot_setup(char *str) 182 { 183 reboot_mode = str[0]; 184 return 1; 185 } 186 187 __setup("reboot=", reboot_setup); 188 189 void machine_halt(void) 190 { 191 } 192 193 194 void machine_power_off(void) 195 { 196 if (pm_power_off) 197 pm_power_off(); 198 } 199 200 void machine_restart(char * __unused) 201 { 202 arm_pm_restart(reboot_mode); 203 } 204 205 void __show_regs(struct pt_regs *regs) 206 { 207 unsigned long flags; 208 char buf[64]; 209 210 printk("CPU: %d %s (%s %.*s)\n", 211 smp_processor_id(), print_tainted(), init_utsname()->release, 212 (int)strcspn(init_utsname()->version, " "), 213 init_utsname()->version); 214 print_symbol("PC is at %s\n", instruction_pointer(regs)); 215 print_symbol("LR is at %s\n", regs->ARM_lr); 216 printk("pc : [<%08lx>] lr : [<%08lx>] psr: %08lx\n" 217 "sp : %08lx ip : %08lx fp : %08lx\n", 218 regs->ARM_pc, regs->ARM_lr, regs->ARM_cpsr, 219 regs->ARM_sp, regs->ARM_ip, regs->ARM_fp); 220 printk("r10: %08lx r9 : %08lx r8 : %08lx\n", 221 regs->ARM_r10, regs->ARM_r9, 222 regs->ARM_r8); 223 printk("r7 : %08lx r6 : %08lx r5 : %08lx r4 : %08lx\n", 224 regs->ARM_r7, regs->ARM_r6, 225 regs->ARM_r5, regs->ARM_r4); 226 printk("r3 : %08lx r2 : %08lx r1 : %08lx r0 : %08lx\n", 227 regs->ARM_r3, regs->ARM_r2, 228 regs->ARM_r1, regs->ARM_r0); 229 230 flags = regs->ARM_cpsr; 231 buf[0] = flags & PSR_N_BIT ? 'N' : 'n'; 232 buf[1] = flags & PSR_Z_BIT ? 'Z' : 'z'; 233 buf[2] = flags & PSR_C_BIT ? 'C' : 'c'; 234 buf[3] = flags & PSR_V_BIT ? 'V' : 'v'; 235 buf[4] = '\0'; 236 237 printk("Flags: %s IRQs o%s FIQs o%s Mode %s ISA %s Segment %s\n", 238 buf, interrupts_enabled(regs) ? "n" : "ff", 239 fast_interrupts_enabled(regs) ? "n" : "ff", 240 processor_modes[processor_mode(regs)], 241 isa_modes[isa_mode(regs)], 242 get_fs() == get_ds() ? "kernel" : "user"); 243 #ifdef CONFIG_CPU_CP15 244 { 245 unsigned int ctrl; 246 247 buf[0] = '\0'; 248 #ifdef CONFIG_CPU_CP15_MMU 249 { 250 unsigned int transbase, dac; 251 asm("mrc p15, 0, %0, c2, c0\n\t" 252 "mrc p15, 0, %1, c3, c0\n" 253 : "=r" (transbase), "=r" (dac)); 254 snprintf(buf, sizeof(buf), " Table: %08x DAC: %08x", 255 transbase, dac); 256 } 257 #endif 258 asm("mrc p15, 0, %0, c1, c0\n" : "=r" (ctrl)); 259 260 printk("Control: %08x%s\n", ctrl, buf); 261 } 262 #endif 263 } 264 265 void show_regs(struct pt_regs * regs) 266 { 267 printk("\n"); 268 printk("Pid: %d, comm: %20s\n", task_pid_nr(current), current->comm); 269 __show_regs(regs); 270 __backtrace(); 271 } 272 273 void show_fpregs(struct user_fp *regs) 274 { 275 int i; 276 277 for (i = 0; i < 8; i++) { 278 unsigned long *p; 279 char type; 280 281 p = (unsigned long *)(regs->fpregs + i); 282 283 switch (regs->ftype[i]) { 284 case 1: type = 'f'; break; 285 case 2: type = 'd'; break; 286 case 3: type = 'e'; break; 287 default: type = '?'; break; 288 } 289 if (regs->init_flag) 290 type = '?'; 291 292 printk(" f%d(%c): %08lx %08lx %08lx%c", 293 i, type, p[0], p[1], p[2], i & 1 ? '\n' : ' '); 294 } 295 296 297 printk("FPSR: %08lx FPCR: %08lx\n", 298 (unsigned long)regs->fpsr, 299 (unsigned long)regs->fpcr); 300 } 301 302 /* 303 * Free current thread data structures etc.. 304 */ 305 void exit_thread(void) 306 { 307 } 308 309 ATOMIC_NOTIFIER_HEAD(thread_notify_head); 310 311 EXPORT_SYMBOL_GPL(thread_notify_head); 312 313 void flush_thread(void) 314 { 315 struct thread_info *thread = current_thread_info(); 316 struct task_struct *tsk = current; 317 318 memset(thread->used_cp, 0, sizeof(thread->used_cp)); 319 memset(&tsk->thread.debug, 0, sizeof(struct debug_info)); 320 memset(&thread->fpstate, 0, sizeof(union fp_state)); 321 322 thread_notify(THREAD_NOTIFY_FLUSH, thread); 323 } 324 325 void release_thread(struct task_struct *dead_task) 326 { 327 struct thread_info *thread = task_thread_info(dead_task); 328 329 thread_notify(THREAD_NOTIFY_RELEASE, thread); 330 } 331 332 asmlinkage void ret_from_fork(void) __asm__("ret_from_fork"); 333 334 int 335 copy_thread(int nr, unsigned long clone_flags, unsigned long stack_start, 336 unsigned long stk_sz, struct task_struct *p, struct pt_regs *regs) 337 { 338 struct thread_info *thread = task_thread_info(p); 339 struct pt_regs *childregs = task_pt_regs(p); 340 341 *childregs = *regs; 342 childregs->ARM_r0 = 0; 343 childregs->ARM_sp = stack_start; 344 345 memset(&thread->cpu_context, 0, sizeof(struct cpu_context_save)); 346 thread->cpu_context.sp = (unsigned long)childregs; 347 thread->cpu_context.pc = (unsigned long)ret_from_fork; 348 349 if (clone_flags & CLONE_SETTLS) 350 thread->tp_value = regs->ARM_r3; 351 352 return 0; 353 } 354 355 /* 356 * fill in the fpe structure for a core dump... 357 */ 358 int dump_fpu (struct pt_regs *regs, struct user_fp *fp) 359 { 360 struct thread_info *thread = current_thread_info(); 361 int used_math = thread->used_cp[1] | thread->used_cp[2]; 362 363 if (used_math) 364 memcpy(fp, &thread->fpstate.soft, sizeof (*fp)); 365 366 return used_math != 0; 367 } 368 EXPORT_SYMBOL(dump_fpu); 369 370 /* 371 * fill in the user structure for a core dump.. 372 */ 373 void dump_thread(struct pt_regs * regs, struct user * dump) 374 { 375 struct task_struct *tsk = current; 376 377 dump->magic = CMAGIC; 378 dump->start_code = tsk->mm->start_code; 379 dump->start_stack = regs->ARM_sp & ~(PAGE_SIZE - 1); 380 381 dump->u_tsize = (tsk->mm->end_code - tsk->mm->start_code) >> PAGE_SHIFT; 382 dump->u_dsize = (tsk->mm->brk - tsk->mm->start_data + PAGE_SIZE - 1) >> PAGE_SHIFT; 383 dump->u_ssize = 0; 384 385 dump->u_debugreg[0] = tsk->thread.debug.bp[0].address; 386 dump->u_debugreg[1] = tsk->thread.debug.bp[1].address; 387 dump->u_debugreg[2] = tsk->thread.debug.bp[0].insn.arm; 388 dump->u_debugreg[3] = tsk->thread.debug.bp[1].insn.arm; 389 dump->u_debugreg[4] = tsk->thread.debug.nsaved; 390 391 if (dump->start_stack < 0x04000000) 392 dump->u_ssize = (0x04000000 - dump->start_stack) >> PAGE_SHIFT; 393 394 dump->regs = *regs; 395 dump->u_fpvalid = dump_fpu (regs, &dump->u_fp); 396 } 397 EXPORT_SYMBOL(dump_thread); 398 399 /* 400 * Shuffle the argument into the correct register before calling the 401 * thread function. r1 is the thread argument, r2 is the pointer to 402 * the thread function, and r3 points to the exit function. 403 */ 404 extern void kernel_thread_helper(void); 405 asm( ".section .text\n" 406 " .align\n" 407 " .type kernel_thread_helper, #function\n" 408 "kernel_thread_helper:\n" 409 " mov r0, r1\n" 410 " mov lr, r3\n" 411 " mov pc, r2\n" 412 " .size kernel_thread_helper, . - kernel_thread_helper\n" 413 " .previous"); 414 415 /* 416 * Create a kernel thread. 417 */ 418 pid_t kernel_thread(int (*fn)(void *), void *arg, unsigned long flags) 419 { 420 struct pt_regs regs; 421 422 memset(®s, 0, sizeof(regs)); 423 424 regs.ARM_r1 = (unsigned long)arg; 425 regs.ARM_r2 = (unsigned long)fn; 426 regs.ARM_r3 = (unsigned long)do_exit; 427 regs.ARM_pc = (unsigned long)kernel_thread_helper; 428 regs.ARM_cpsr = SVC_MODE; 429 430 return do_fork(flags|CLONE_VM|CLONE_UNTRACED, 0, ®s, 0, NULL, NULL); 431 } 432 EXPORT_SYMBOL(kernel_thread); 433 434 unsigned long get_wchan(struct task_struct *p) 435 { 436 unsigned long fp, lr; 437 unsigned long stack_start, stack_end; 438 int count = 0; 439 if (!p || p == current || p->state == TASK_RUNNING) 440 return 0; 441 442 stack_start = (unsigned long)end_of_stack(p); 443 stack_end = (unsigned long)task_stack_page(p) + THREAD_SIZE; 444 445 fp = thread_saved_fp(p); 446 do { 447 if (fp < stack_start || fp > stack_end) 448 return 0; 449 lr = pc_pointer (((unsigned long *)fp)[-1]); 450 if (!in_sched_functions(lr)) 451 return lr; 452 fp = *(unsigned long *) (fp - 12); 453 } while (count ++ < 16); 454 return 0; 455 } 456