linux/arch/avr32/kernel/process.c
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   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 arch_cpu_idle(void)
  34{
  35        cpu_enter_idle();
  36}
  37
  38void 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
  49void machine_power_off(void)
  50{
  51        if (pm_power_off)
  52                pm_power_off();
  53}
  54
  55void 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 */
  65void exit_thread(void)
  66{
  67        ocd_disable(current);
  68}
  69
  70void flush_thread(void)
  71{
  72        /* nothing to do */
  73}
  74
  75void release_thread(struct task_struct *dead_task)
  76{
  77        /* do nothing */
  78}
  79
  80static 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
 107out:
 108        return;
 109}
 110
 111static 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
 118static 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
 157static 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
 179void 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
 202void show_stack(struct task_struct *tsk, unsigned long *stack)
 203{
 204        show_stack_log_lvl(tsk, (unsigned long)stack, NULL, "");
 205}
 206
 207static const char *cpu_modes[] = {
 208        "Application", "Supervisor", "Interrupt level 0", "Interrupt level 1",
 209        "Interrupt level 2", "Interrupt level 3", "Exception", "NMI"
 210};
 211
 212void 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
 259void 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}
 269EXPORT_SYMBOL(show_regs);
 270
 271/* Fill in the fpu structure for a core dump. This is easy -- we don't have any */
 272int dump_fpu(struct pt_regs *regs, elf_fpregset_t *fpu)
 273{
 274        /* Not valid */
 275        return 0;
 276}
 277
 278asmlinkage void ret_from_fork(void);
 279asmlinkage void ret_from_kernel_thread(void);
 280asmlinkage void syscall_return(void);
 281
 282int 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 = 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 */
 317unsigned 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.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}
 356