arch/avr32/kernel/process.c

   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
  26 void (*pm_power_off)(void);
  27 EXPORT_SYMBOL(pm_power_off);
  28
  29 /*
  30  * This file handles the architecture-dependent parts of process handling..
  31  */
  32
  33 void arch_cpu_idle(void)
  34 {
  35         cpu_enter_idle();
  36 }
  37
  38 void machine_halt(void)
  39 {
  40         /*
  41          * Enter Stop mode. The 32 kHz oscillator will keep running so
  42          * the RTC will keep the time properly and the system will
  43          * boot quickly.
  44          */
  45         asm volatile("sleep 3\n\t"
  46                      "sub pc, -2");
  47 }
  48
  49 void machine_power_off(void)
  50 {
  51         if (pm_power_off)
  52                 pm_power_off();
  53 }
  54
  55 void machine_restart(char *cmd)
  56 {
  57         ocd_write(DC, (1 << OCD_DC_DBE_BIT));
  58         ocd_write(DC, (1 << OCD_DC_RES_BIT));
  59         while (1) ;
  60 }
  61
  62 /*
  63  * Free current thread data structures etc
  64  */
  65 void exit_thread(void)
  66 {
  67         ocd_disable(current);
  68 }
  69
  70 void flush_thread(void)
  71 {
  72         /* nothing to do */
  73 }
  74
  75 void release_thread(struct task_struct *dead_task)
  76 {
  77         /* do nothing */
  78 }
  79
  80 static void dump_mem(const char *str, const char *log_lvl,
  81                      unsigned long bottom, unsigned long top)
  82 {
  83         unsigned long p;
  84         int i;
  85
  86         printk("%s%s(0x%08lx to 0x%08lx)\n", log_lvl, str, bottom, top);
  87
  88         for (p = bottom & ~31; p < top; ) {
  89                 printk("%s%04lx: ", log_lvl, p & 0xffff);
  90
  91                 for (i = 0; i < 8; i++, p += 4) {
  92                         unsigned int val;
  93
  94                         if (p < bottom || p >= top)
  95                                 printk("         ");
  96                         else {
  97                                 if (__get_user(val, (unsigned int __user *)p)) {
  98                                         printk("\n");
  99                                         goto out;
 100                                 }
 101                                 printk("%08x ", val);
 102                         }
 103                 }
 104                 printk("\n");
 105         }
 106
 107 out:
 108         return;
 109 }
 110
 111 static inline int valid_stack_ptr(struct thread_info *tinfo, unsigned long p)
 112 {
 113         return (p > (unsigned long)tinfo)
 114                 && (p < (unsigned long)tinfo + THREAD_SIZE - 3);
 115 }
 116
 117 #ifdef CONFIG_FRAME_POINTER
 118 static void show_trace_log_lvl(struct task_struct *tsk, unsigned long *sp,
 119                                struct pt_regs *regs, const char *log_lvl)
 120 {
 121         unsigned long lr, fp;
 122         struct thread_info *tinfo;
 123
 124         if (regs)
 125                 fp = regs->r7;
 126         else if (tsk == current)
 127                 asm("mov %0, r7" : "=r"(fp));
 128         else
 129                 fp = tsk->thread.cpu_context.r7;
 130
 131         /*
 132          * Walk the stack as long as the frame pointer (a) is within
 133          * the kernel stack of the task, and (b) it doesn't move
 134          * downwards.
 135          */
 136         tinfo = task_thread_info(tsk);
 137         printk("%sCall trace:\n", log_lvl);
 138         while (valid_stack_ptr(tinfo, fp)) {
 139                 unsigned long new_fp;
 140
 141                 lr = *(unsigned long *)fp;
 142 #ifdef CONFIG_KALLSYMS
 143                 printk("%s [<%08lx>] ", log_lvl, lr);
 144 #else
 145                 printk(" [<%08lx>] ", lr);
 146 #endif
 147                 print_symbol("%s\n", lr);
 148
 149                 new_fp = *(unsigned long *)(fp + 4);
 150                 if (new_fp <= fp)
 151                         break;
 152                 fp = new_fp;
 153         }
 154         printk("\n");
 155 }
 156 #else
 157 static void show_trace_log_lvl(struct task_struct *tsk, unsigned long *sp,
 158                                struct pt_regs *regs, const char *log_lvl)
 159 {
 160         unsigned long addr;
 161
 162         printk("%sCall trace:\n", log_lvl);
 163
 164         while (!kstack_end(sp)) {
 165                 addr = *sp++;
 166                 if (kernel_text_address(addr)) {
 167 #ifdef CONFIG_KALLSYMS
 168                         printk("%s [<%08lx>] ", log_lvl, addr);
 169 #else
 170                         printk(" [<%08lx>] ", addr);
 171 #endif
 172                         print_symbol("%s\n", addr);
 173                 }
 174         }
 175         printk("\n");
 176 }
 177 #endif
 178
 179 void show_stack_log_lvl(struct task_struct *tsk, unsigned long sp,
 180                         struct pt_regs *regs, const char *log_lvl)
 181 {
 182         struct thread_info *tinfo;
 183
 184         if (sp == 0) {
 185                 if (tsk)
 186                         sp = tsk->thread.cpu_context.ksp;
 187                 else
 188                         sp = (unsigned long)&tinfo;
 189         }
 190         if (!tsk)
 191                 tsk = current;
 192
 193         tinfo = task_thread_info(tsk);
 194
 195         if (valid_stack_ptr(tinfo, sp)) {
 196                 dump_mem("Stack: ", log_lvl, sp,
 197                          THREAD_SIZE + (unsigned long)tinfo);
 198                 show_trace_log_lvl(tsk, (unsigned long *)sp, regs, log_lvl);
 199         }
 200 }
 201
 202 void show_stack(struct task_struct *tsk, unsigned long *stack)
 203 {
 204         show_stack_log_lvl(tsk, (unsigned long)stack, NULL, "");
 205 }
 206
 207 static const char *cpu_modes[] = {
 208         "Application", "Supervisor", "Interrupt level 0", "Interrupt level 1",
 209         "Interrupt level 2", "Interrupt level 3", "Exception", "NMI"
 210 };
 211
 212 void show_regs_log_lvl(struct pt_regs *regs, const char *log_lvl)
 213 {
 214         unsigned long sp = regs->sp;
 215         unsigned long lr = regs->lr;
 216         unsigned long mode = (regs->sr & MODE_MASK) >> MODE_SHIFT;
 217
 218         show_regs_print_info(log_lvl);
 219
 220         if (!user_mode(regs)) {
 221                 sp = (unsigned long)regs + FRAME_SIZE_FULL;
 222
 223                 printk("%s", log_lvl);
 224                 print_symbol("PC is at %s\n", instruction_pointer(regs));
 225                 printk("%s", log_lvl);
 226                 print_symbol("LR is at %s\n", lr);
 227         }
 228
 229         printk("%spc : [<%08lx>]    lr : [<%08lx>]    %s\n"
 230                "%ssp : %08lx  r12: %08lx  r11: %08lx\n",
 231                log_lvl, instruction_pointer(regs), lr, print_tainted(),
 232                log_lvl, sp, regs->r12, regs->r11);
 233         printk("%sr10: %08lx  r9 : %08lx  r8 : %08lx\n",
 234                log_lvl, regs->r10, regs->r9, regs->r8);
 235         printk("%sr7 : %08lx  r6 : %08lx  r5 : %08lx  r4 : %08lx\n",
 236                log_lvl, regs->r7, regs->r6, regs->r5, regs->r4);
 237         printk("%sr3 : %08lx  r2 : %08lx  r1 : %08lx  r0 : %08lx\n",
 238                log_lvl, regs->r3, regs->r2, regs->r1, regs->r0);
 239         printk("%sFlags: %c%c%c%c%c\n", log_lvl,
 240                regs->sr & SR_Q ? 'Q' : 'q',
 241                regs->sr & SR_V ? 'V' : 'v',
 242                regs->sr & SR_N ? 'N' : 'n',
 243                regs->sr & SR_Z ? 'Z' : 'z',
 244                regs->sr & SR_C ? 'C' : 'c');
 245         printk("%sMode bits: %c%c%c%c%c%c%c%c%c%c\n", log_lvl,
 246                regs->sr & SR_H ? 'H' : 'h',
 247                regs->sr & SR_J ? 'J' : 'j',
 248                regs->sr & SR_DM ? 'M' : 'm',
 249                regs->sr & SR_D ? 'D' : 'd',
 250                regs->sr & SR_EM ? 'E' : 'e',
 251                regs->sr & SR_I3M ? '3' : '.',
 252                regs->sr & SR_I2M ? '2' : '.',
 253                regs->sr & SR_I1M ? '1' : '.',
 254                regs->sr & SR_I0M ? '0' : '.',
 255                regs->sr & SR_GM ? 'G' : 'g');
 256         printk("%sCPU Mode: %s\n", log_lvl, cpu_modes[mode]);
 257 }
 258
 259 void show_regs(struct pt_regs *regs)
 260 {
 261         unsigned long sp = regs->sp;
 262
 263         if (!user_mode(regs))
 264                 sp = (unsigned long)regs + FRAME_SIZE_FULL;
 265
 266         show_regs_log_lvl(regs, "");
 267         show_trace_log_lvl(current, (unsigned long *)sp, regs, "");
 268 }
 269 EXPORT_SYMBOL(show_regs);
 270
 271 /* Fill in the fpu structure for a core dump. This is easy -- we don't have any */
 272 int dump_fpu(struct pt_regs *regs, elf_fpregset_t *fpu)
 273 {
 274         /* Not valid */
 275         return 0;
 276 }
 277
 278 asmlinkage void ret_from_fork(void);
 279 asmlinkage void ret_from_kernel_thread(void);
 280 asmlinkage void syscall_return(void);
 281
 282 int copy_thread(unsigned long clone_flags, unsigned long usp,
 283                 unsigned long arg,
 284                 struct task_struct *p)
 285 {
 286         struct pt_regs *childregs = task_pt_regs(p);
 287
 288         if (unlikely(p->flags & PF_KTHREAD)) {
 289                 memset(childregs, 0, sizeof(struct pt_regs));
 290                 p->thread.cpu_context.r0 = arg;
 291                 p->thread.cpu_context.r1 = usp; /* fn */
 292                 p->thread.cpu_context.r2 = (unsigned long)syscall_return;
 293                 p->thread.cpu_context.pc = (unsigned long)ret_from_kernel_thread;
 294                 childregs->sr = MODE_SUPERVISOR;
 295         } else {
 296                 *childregs = *current_pt_regs();
 297                 if (usp)
 298                         childregs->sp = usp;
 299                 childregs->r12 = 0; /* Set return value for child */
 300                 p->thread.cpu_context.pc = (unsigned long)ret_from_fork;
 301         }
 302
 303         p->thread.cpu_context.sr = MODE_SUPERVISOR | SR_GM;
 304         p->thread.cpu_context.ksp = (unsigned long)childregs;
 305
 306         clear_tsk_thread_flag(p, TIF_DEBUG);
 307         if ((clone_flags & CLONE_PTRACE) && test_thread_flag(TIF_DEBUG))
 308                 ocd_enable(p);
 309
 310         return 0;
 311 }
 312
 313 /*
 314  * This function is supposed to answer the question "who called
 315  * schedule()?"
 316  */
 317 unsigned long get_wchan(struct task_struct *p)
 318 {
 319         unsigned long pc;
 320         unsigned long stack_page;
 321
 322         if (!p || p == current || p->state == TASK_RUNNING)
 323                 return 0;
 324
 325         stack_page = (unsigned long)task_stack_page(p);
 326         BUG_ON(!stack_page);
 327
 328         /*
 329          * The stored value of PC is either the address right after
 330          * the call to __switch_to() or ret_from_fork.
 331          */
 332         pc = thread_saved_pc(p);
 333         if (in_sched_functions(pc)) {
 334 #ifdef CONFIG_FRAME_POINTER
 335                 unsigned long fp = p->thread.cpu_context.r7;
 336                 BUG_ON(fp < stack_page || fp > (THREAD_SIZE + stack_page));
 337                 pc = *(unsigned long *)fp;
 338 #else
 339                 /*
 340                  * We depend on the frame size of schedule here, which
 341                  * is actually quite ugly. It might be possible to
 342                  * determine the frame size automatically at build
 343                  * time by doing this:
 344                  *   - compile sched/core.c
 345                  *   - disassemble the resulting sched.o
 346                  *   - look for 'sub sp,??' shortly after '<schedule>:'
 347                  */
 348                 unsigned long sp = p->thread.cpu_context.ksp + 16;
 349                 BUG_ON(sp < stack_page || sp > (THREAD_SIZE + stack_page));
 350                 pc = *(unsigned long *)sp;
 351 #endif
 352         }
 353
 354         return pc;
 355 }