1/* 2 * Copyright (C) 2004-2006 Atmel Corporation 3 * 4 * This program is free software; you can redistribute it and/or modify 5 * it under the terms of the GNU General Public License version 2 as 6 * published by the Free Software Foundation. 7 */ 8#include <linux/sched.h> 9#include <linux/module.h> 10#include <linux/kallsyms.h> 11#include <linux/fs.h> 12#include <linux/pm.h> 13#include <linux/ptrace.h> 14#include <linux/slab.h> 15#include <linux/reboot.h> 16#include <linux/tick.h> 17#include <linux/uaccess.h> 18#include <linux/unistd.h> 19 20#include <asm/sysreg.h> 21#include <asm/ocd.h> 22#include <asm/syscalls.h> 23 24#include <mach/pm.h> 25 26void (*pm_power_off)(void); 27EXPORT_SYMBOL(pm_power_off); 28 29/* 30 * This file handles the architecture-dependent parts of process handling.. 31 */ 32 33void cpu_idle(void) 34{ 35 /* endless idle loop with no priority at all */ 36 while (1) { 37 tick_nohz_stop_sched_tick(1); 38 while (!need_resched()) 39 cpu_idle_sleep(); 40 tick_nohz_restart_sched_tick(); 41 preempt_enable_no_resched(); 42 schedule(); 43 preempt_disable(); 44 } 45} 46 47void machine_halt(void) 48{ 49 /* 50 * Enter Stop mode. The 32 kHz oscillator will keep running so 51 * the RTC will keep the time properly and the system will 52 * boot quickly. 53 */ 54 asm volatile("sleep 3\n\t" 55 "sub pc, -2"); 56} 57 58void machine_power_off(void) 59{ 60 if (pm_power_off) 61 pm_power_off(); 62} 63 64void machine_restart(char *cmd) 65{ 66 ocd_write(DC, (1 << OCD_DC_DBE_BIT)); 67 ocd_write(DC, (1 << OCD_DC_RES_BIT)); 68 while (1) ; 69} 70 71/* 72 * PC is actually discarded when returning from a system call -- the 73 * return address must be stored in LR. This function will make sure 74 * LR points to do_exit before starting the thread. 75 * 76 * Also, when returning from fork(), r12 is 0, so we must copy the 77 * argument as well. 78 * 79 * r0 : The argument to the main thread function 80 * r1 : The address of do_exit 81 * r2 : The address of the main thread function 82 */ 83asmlinkage extern void kernel_thread_helper(void); 84__asm__(" .type kernel_thread_helper, @function\n" 85 "kernel_thread_helper:\n" 86 " mov r12, r0\n" 87 " mov lr, r2\n" 88 " mov pc, r1\n" 89 " .size kernel_thread_helper, . - kernel_thread_helper"); 90 91int kernel_thread(int (*fn)(void *), void *arg, unsigned long flags) 92{ 93 struct pt_regs regs; 94 95 memset(®s, 0, sizeof(regs)); 96 97 regs.r0 = (unsigned long)arg; 98 regs.r1 = (unsigned long)fn; 99 regs.r2 = (unsigned long)do_exit; 100 regs.lr = (unsigned long)kernel_thread_helper; 101 regs.pc = (unsigned long)kernel_thread_helper; 102 regs.sr = MODE_SUPERVISOR; 103 104 return do_fork(flags | CLONE_VM | CLONE_UNTRACED, 105 0, ®s, 0, NULL, NULL); 106} 107EXPORT_SYMBOL(kernel_thread); 108 109/* 110 * Free current thread data structures etc 111 */ 112void exit_thread(void) 113{ 114 ocd_disable(current); 115} 116 117void flush_thread(void) 118{ 119 /* nothing to do */ 120} 121 122void release_thread(struct task_struct *dead_task) 123{ 124 /* do nothing */ 125} 126 127static void dump_mem(const char *str, const char *log_lvl, 128 unsigned long bottom, unsigned long top) 129{ 130 unsigned long p; 131 int i; 132 133 printk("%s%s(0x%08lx to 0x%08lx)\n", log_lvl, str, bottom, top); 134 135 for (p = bottom & ~31; p < top; ) { 136 printk("%s%04lx: ", log_lvl, p & 0xffff); 137 138 for (i = 0; i < 8; i++, p += 4) { 139 unsigned int val; 140 141 if (p < bottom || p >= top) 142 printk(" "); 143 else { 144 if (__get_user(val, (unsigned int __user *)p)) { 145 printk("\n"); 146 goto out; 147 } 148 printk("%08x ", val); 149 } 150 } 151 printk("\n"); 152 } 153 154out: 155 return; 156} 157 158static inline int valid_stack_ptr(struct thread_info *tinfo, unsigned long p) 159{ 160 return (p > (unsigned long)tinfo) 161 && (p < (unsigned long)tinfo + THREAD_SIZE - 3); 162} 163 164#ifdef CONFIG_FRAME_POINTER 165static void show_trace_log_lvl(struct task_struct *tsk, unsigned long *sp, 166 struct pt_regs *regs, const char *log_lvl) 167{ 168 unsigned long lr, fp; 169 struct thread_info *tinfo; 170 171 if (regs) 172 fp = regs->r7; 173 else if (tsk == current) 174 asm("mov %0, r7" : "=r"(fp)); 175 else 176 fp = tsk->thread.cpu_context.r7; 177 178 /* 179 * Walk the stack as long as the frame pointer (a) is within 180 * the kernel stack of the task, and (b) it doesn't move 181 * downwards. 182 */ 183 tinfo = task_thread_info(tsk); 184 printk("%sCall trace:\n", log_lvl); 185 while (valid_stack_ptr(tinfo, fp)) { 186 unsigned long new_fp; 187 188 lr = *(unsigned long *)fp; 189#ifdef CONFIG_KALLSYMS 190 printk("%s [<%08lx>] ", log_lvl, lr); 191#else 192 printk(" [<%08lx>] ", lr); 193#endif 194 print_symbol("%s\n", lr); 195 196 new_fp = *(unsigned long *)(fp + 4); 197 if (new_fp <= fp) 198 break; 199 fp = new_fp; 200 } 201 printk("\n"); 202} 203#else 204static void show_trace_log_lvl(struct task_struct *tsk, unsigned long *sp, 205 struct pt_regs *regs, const char *log_lvl) 206{ 207 unsigned long addr; 208 209 printk("%sCall trace:\n", log_lvl); 210 211 while (!kstack_end(sp)) { 212 addr = *sp++; 213 if (kernel_text_address(addr)) { 214#ifdef CONFIG_KALLSYMS 215 printk("%s [<%08lx>] ", log_lvl, addr); 216#else 217 printk(" [<%08lx>] ", addr); 218#endif 219 print_symbol("%s\n", addr); 220 } 221 } 222 printk("\n"); 223} 224#endif 225 226void show_stack_log_lvl(struct task_struct *tsk, unsigned long sp, 227 struct pt_regs *regs, const char *log_lvl) 228{ 229 struct thread_info *tinfo; 230 231 if (sp == 0) { 232 if (tsk) 233 sp = tsk->thread.cpu_context.ksp; 234 else 235 sp = (unsigned long)&tinfo; 236 } 237 if (!tsk) 238 tsk = current; 239 240 tinfo = task_thread_info(tsk); 241 242 if (valid_stack_ptr(tinfo, sp)) { 243 dump_mem("Stack: ", log_lvl, sp, 244 THREAD_SIZE + (unsigned long)tinfo); 245 show_trace_log_lvl(tsk, (unsigned long *)sp, regs, log_lvl); 246 } 247} 248 249void show_stack(struct task_struct *tsk, unsigned long *stack) 250{ 251 show_stack_log_lvl(tsk, (unsigned long)stack, NULL, ""); 252} 253 254void dump_stack(void) 255{ 256 unsigned long stack; 257 258 show_trace_log_lvl(current, &stack, NULL, ""); 259} 260EXPORT_SYMBOL(dump_stack); 261 262static const char *cpu_modes[] = { 263 "Application", "Supervisor", "Interrupt level 0", "Interrupt level 1", 264 "Interrupt level 2", "Interrupt level 3", "Exception", "NMI" 265}; 266 267void show_regs_log_lvl(struct pt_regs *regs, const char *log_lvl) 268{ 269 unsigned long sp = regs->sp; 270 unsigned long lr = regs->lr; 271 unsigned long mode = (regs->sr & MODE_MASK) >> MODE_SHIFT; 272 273 if (!user_mode(regs)) { 274 sp = (unsigned long)regs + FRAME_SIZE_FULL; 275 276 printk("%s", log_lvl); 277 print_symbol("PC is at %s\n", instruction_pointer(regs)); 278 printk("%s", log_lvl); 279 print_symbol("LR is at %s\n", lr); 280 } 281 282 printk("%spc : [<%08lx>] lr : [<%08lx>] %s\n" 283 "%ssp : %08lx r12: %08lx r11: %08lx\n", 284 log_lvl, instruction_pointer(regs), lr, print_tainted(), 285 log_lvl, sp, regs->r12, regs->r11); 286 printk("%sr10: %08lx r9 : %08lx r8 : %08lx\n", 287 log_lvl, regs->r10, regs->r9, regs->r8); 288 printk("%sr7 : %08lx r6 : %08lx r5 : %08lx r4 : %08lx\n", 289 log_lvl, regs->r7, regs->r6, regs->r5, regs->r4); 290 printk("%sr3 : %08lx r2 : %08lx r1 : %08lx r0 : %08lx\n", 291 log_lvl, regs->r3, regs->r2, regs->r1, regs->r0); 292 printk("%sFlags: %c%c%c%c%c\n", log_lvl, 293 regs->sr & SR_Q ? 'Q' : 'q', 294 regs->sr & SR_V ? 'V' : 'v', 295 regs->sr & SR_N ? 'N' : 'n', 296 regs->sr & SR_Z ? 'Z' : 'z', 297 regs->sr & SR_C ? 'C' : 'c'); 298 printk("%sMode bits: %c%c%c%c%c%c%c%c%c%c\n", log_lvl, 299 regs->sr & SR_H ? 'H' : 'h', 300 regs->sr & SR_J ? 'J' : 'j', 301 regs->sr & SR_DM ? 'M' : 'm', 302 regs->sr & SR_D ? 'D' : 'd', 303 regs->sr & SR_EM ? 'E' : 'e', 304 regs->sr & SR_I3M ? '3' : '.', 305 regs->sr & SR_I2M ? '2' : '.', 306 regs->sr & SR_I1M ? '1' : '.', 307 regs->sr & SR_I0M ? '0' : '.', 308 regs->sr & SR_GM ? 'G' : 'g'); 309 printk("%sCPU Mode: %s\n", log_lvl, cpu_modes[mode]); 310 printk("%sProcess: %s [%d] (task: %p thread: %p)\n", 311 log_lvl, current->comm, current->pid, current, 312 task_thread_info(current)); 313} 314 315void show_regs(struct pt_regs *regs) 316{ 317 unsigned long sp = regs->sp; 318 319 if (!user_mode(regs)) 320 sp = (unsigned long)regs + FRAME_SIZE_FULL; 321 322 show_regs_log_lvl(regs, ""); 323 show_trace_log_lvl(current, (unsigned long *)sp, regs, ""); 324} 325EXPORT_SYMBOL(show_regs); 326 327/* Fill in the fpu structure for a core dump. This is easy -- we don't have any */ 328int dump_fpu(struct pt_regs *regs, elf_fpregset_t *fpu) 329{ 330 /* Not valid */ 331 return 0; 332} 333 334asmlinkage void ret_from_fork(void); 335 336int copy_thread(unsigned long clone_flags, unsigned long usp, 337 unsigned long unused, 338 struct task_struct *p, struct pt_regs *regs) 339{ 340 struct pt_regs *childregs; 341 342 childregs = ((struct pt_regs *)(THREAD_SIZE + (unsigned long)task_stack_page(p))) - 1; 343 *childregs = *regs; 344 345 if (user_mode(regs)) 346 childregs->sp = usp; 347 else 348 childregs->sp = (unsigned long)task_stack_page(p) + THREAD_SIZE; 349 350 childregs->r12 = 0; /* Set return value for child */ 351 352 p->thread.cpu_context.sr = MODE_SUPERVISOR | SR_GM; 353 p->thread.cpu_context.ksp = (unsigned long)childregs; 354 p->thread.cpu_context.pc = (unsigned long)ret_from_fork; 355 356 clear_tsk_thread_flag(p, TIF_DEBUG); 357 if ((clone_flags & CLONE_PTRACE) && test_thread_flag(TIF_DEBUG)) 358 ocd_enable(p); 359 360 return 0; 361} 362 363/* r12-r8 are dummy parameters to force the compiler to use the stack */ 364asmlinkage int sys_fork(struct pt_regs *regs) 365{ 366 return do_fork(SIGCHLD, regs->sp, regs, 0, NULL, NULL); 367} 368 369asmlinkage int sys_clone(unsigned long clone_flags, unsigned long newsp, 370 unsigned long parent_tidptr, 371 unsigned long child_tidptr, struct pt_regs *regs) 372{ 373 if (!newsp) 374 newsp = regs->sp; 375 return do_fork(clone_flags, newsp, regs, 0, 376 (int __user *)parent_tidptr, 377 (int __user *)child_tidptr); 378} 379 380asmlinkage int sys_vfork(struct pt_regs *regs) 381{ 382 return do_fork(CLONE_VFORK | CLONE_VM | SIGCHLD, regs->sp, regs, 383 0, NULL, NULL); 384} 385 386asmlinkage int sys_execve(const char __user *ufilename, 387 const char __user *const __user *uargv, 388 const char __user *const __user *uenvp, 389 struct pt_regs *regs) 390{ 391 int error; 392 char *filename; 393 394 filename = getname(ufilename); 395 error = PTR_ERR(filename); 396 if (IS_ERR(filename)) 397 goto out; 398 399 error = do_execve(filename, uargv, uenvp, regs); 400 putname(filename); 401 402out: 403 return error; 404} 405 406 407/* 408 * This function is supposed to answer the question "who called 409 * schedule()?" 410 */ 411unsigned long get_wchan(struct task_struct *p) 412{ 413 unsigned long pc; 414 unsigned long stack_page; 415 416 if (!p || p == current || p->state == TASK_RUNNING) 417 return 0; 418 419 stack_page = (unsigned long)task_stack_page(p); 420 BUG_ON(!stack_page); 421 422 /* 423 * The stored value of PC is either the address right after 424 * the call to __switch_to() or ret_from_fork. 425 */ 426 pc = thread_saved_pc(p); 427 if (in_sched_functions(pc)) { 428#ifdef CONFIG_FRAME_POINTER 429 unsigned long fp = p->thread.cpu_context.r7; 430 BUG_ON(fp < stack_page || fp > (THREAD_SIZE + stack_page)); 431 pc = *(unsigned long *)fp; 432#else 433 /* 434 * We depend on the frame size of schedule here, which 435 * is actually quite ugly. It might be possible to 436 * determine the frame size automatically at build 437 * time by doing this: 438 * - compile sched.c 439 * - disassemble the resulting sched.o 440 * - look for 'sub sp,??' shortly after '<schedule>:' 441 */ 442 unsigned long sp = p->thread.cpu_context.ksp + 16; 443 BUG_ON(sp < stack_page || sp > (THREAD_SIZE + stack_page)); 444 pc = *(unsigned long *)sp; 445#endif 446 } 447 448 return pc; 449} 450