linux/arch/m32r/kernel/process.c
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   1/*
   2 *  linux/arch/m32r/kernel/process.c
   3 *
   4 *  Copyright (c) 2001, 2002  Hiroyuki Kondo, Hirokazu Takata,
   5 *                            Hitoshi Yamamoto
   6 *  Taken from sh version.
   7 *    Copyright (C) 1995  Linus Torvalds
   8 *    SuperH version:  Copyright (C) 1999, 2000  Niibe Yutaka & Kaz Kojima
   9 */
  10
  11#undef DEBUG_PROCESS
  12#ifdef DEBUG_PROCESS
  13#define DPRINTK(fmt, args...)  printk("%s:%d:%s: " fmt, __FILE__, __LINE__, \
  14  __func__, ##args)
  15#else
  16#define DPRINTK(fmt, args...)
  17#endif
  18
  19/*
  20 * This file handles the architecture-dependent parts of process handling..
  21 */
  22
  23#include <linux/fs.h>
  24#include <linux/slab.h>
  25#include <linux/module.h>
  26#include <linux/ptrace.h>
  27#include <linux/unistd.h>
  28#include <linux/hardirq.h>
  29
  30#include <asm/io.h>
  31#include <asm/uaccess.h>
  32#include <asm/mmu_context.h>
  33#include <asm/elf.h>
  34#include <asm/m32r.h>
  35
  36#include <linux/err.h>
  37
  38/*
  39 * Return saved PC of a blocked thread.
  40 */
  41unsigned long thread_saved_pc(struct task_struct *tsk)
  42{
  43        return tsk->thread.lr;
  44}
  45
  46/*
  47 * Powermanagement idle function, if any..
  48 */
  49static void (*pm_idle)(void) = NULL;
  50
  51void (*pm_power_off)(void) = NULL;
  52EXPORT_SYMBOL(pm_power_off);
  53
  54/*
  55 * We use this is we don't have any better
  56 * idle routine..
  57 */
  58static void default_idle(void)
  59{
  60        /* M32R_FIXME: Please use "cpu_sleep" mode.  */
  61        cpu_relax();
  62}
  63
  64/*
  65 * On SMP it's slightly faster (but much more power-consuming!)
  66 * to poll the ->work.need_resched flag instead of waiting for the
  67 * cross-CPU IPI to arrive. Use this option with caution.
  68 */
  69static void poll_idle (void)
  70{
  71        /* M32R_FIXME */
  72        cpu_relax();
  73}
  74
  75/*
  76 * The idle thread. There's no useful work to be
  77 * done, so just try to conserve power and have a
  78 * low exit latency (ie sit in a loop waiting for
  79 * somebody to say that they'd like to reschedule)
  80 */
  81void cpu_idle (void)
  82{
  83        /* endless idle loop with no priority at all */
  84        while (1) {
  85                while (!need_resched()) {
  86                        void (*idle)(void) = pm_idle;
  87
  88                        if (!idle)
  89                                idle = default_idle;
  90
  91                        idle();
  92                }
  93                preempt_enable_no_resched();
  94                schedule();
  95                preempt_disable();
  96        }
  97}
  98
  99void machine_restart(char *__unused)
 100{
 101#if defined(CONFIG_PLAT_MAPPI3)
 102        outw(1, (unsigned long)PLD_REBOOT);
 103#endif
 104
 105        printk("Please push reset button!\n");
 106        while (1)
 107                cpu_relax();
 108}
 109
 110void machine_halt(void)
 111{
 112        printk("Please push reset button!\n");
 113        while (1)
 114                cpu_relax();
 115}
 116
 117void machine_power_off(void)
 118{
 119        /* M32R_FIXME */
 120}
 121
 122static int __init idle_setup (char *str)
 123{
 124        if (!strncmp(str, "poll", 4)) {
 125                printk("using poll in idle threads.\n");
 126                pm_idle = poll_idle;
 127        } else if (!strncmp(str, "sleep", 4)) {
 128                printk("using sleep in idle threads.\n");
 129                pm_idle = default_idle;
 130        }
 131
 132        return 1;
 133}
 134
 135__setup("idle=", idle_setup);
 136
 137void show_regs(struct pt_regs * regs)
 138{
 139        printk("\n");
 140        printk("BPC[%08lx]:PSW[%08lx]:LR [%08lx]:FP [%08lx]\n", \
 141          regs->bpc, regs->psw, regs->lr, regs->fp);
 142        printk("BBPC[%08lx]:BBPSW[%08lx]:SPU[%08lx]:SPI[%08lx]\n", \
 143          regs->bbpc, regs->bbpsw, regs->spu, regs->spi);
 144        printk("R0 [%08lx]:R1 [%08lx]:R2 [%08lx]:R3 [%08lx]\n", \
 145          regs->r0, regs->r1, regs->r2, regs->r3);
 146        printk("R4 [%08lx]:R5 [%08lx]:R6 [%08lx]:R7 [%08lx]\n", \
 147          regs->r4, regs->r5, regs->r6, regs->r7);
 148        printk("R8 [%08lx]:R9 [%08lx]:R10[%08lx]:R11[%08lx]\n", \
 149          regs->r8, regs->r9, regs->r10, regs->r11);
 150        printk("R12[%08lx]\n", \
 151          regs->r12);
 152
 153#if defined(CONFIG_ISA_M32R2) && defined(CONFIG_ISA_DSP_LEVEL2)
 154        printk("ACC0H[%08lx]:ACC0L[%08lx]\n", \
 155          regs->acc0h, regs->acc0l);
 156        printk("ACC1H[%08lx]:ACC1L[%08lx]\n", \
 157          regs->acc1h, regs->acc1l);
 158#elif defined(CONFIG_ISA_M32R2) || defined(CONFIG_ISA_M32R)
 159        printk("ACCH[%08lx]:ACCL[%08lx]\n", \
 160          regs->acc0h, regs->acc0l);
 161#else
 162#error unknown isa configuration
 163#endif
 164}
 165
 166/*
 167 * Create a kernel thread
 168 */
 169
 170/*
 171 * This is the mechanism for creating a new kernel thread.
 172 *
 173 * NOTE! Only a kernel-only process(ie the swapper or direct descendants
 174 * who haven't done an "execve()") should use this: it will work within
 175 * a system call from a "real" process, but the process memory space will
 176 * not be free'd until both the parent and the child have exited.
 177 */
 178static void kernel_thread_helper(void *nouse, int (*fn)(void *), void *arg)
 179{
 180        fn(arg);
 181        do_exit(-1);
 182}
 183
 184int kernel_thread(int (*fn)(void *), void *arg, unsigned long flags)
 185{
 186        struct pt_regs regs;
 187
 188        memset(&regs, 0, sizeof (regs));
 189        regs.r1 = (unsigned long)fn;
 190        regs.r2 = (unsigned long)arg;
 191
 192        regs.bpc = (unsigned long)kernel_thread_helper;
 193
 194        regs.psw = M32R_PSW_BIE;
 195
 196        /* Ok, create the new process. */
 197        return do_fork(flags | CLONE_VM | CLONE_UNTRACED, 0, &regs, 0, NULL,
 198                NULL);
 199}
 200
 201/*
 202 * Free current thread data structures etc..
 203 */
 204void exit_thread(void)
 205{
 206        /* Nothing to do. */
 207        DPRINTK("pid = %d\n", current->pid);
 208}
 209
 210void flush_thread(void)
 211{
 212        DPRINTK("pid = %d\n", current->pid);
 213        memset(&current->thread.debug_trap, 0, sizeof(struct debug_trap));
 214}
 215
 216void release_thread(struct task_struct *dead_task)
 217{
 218        /* do nothing */
 219        DPRINTK("pid = %d\n", dead_task->pid);
 220}
 221
 222/* Fill in the fpu structure for a core dump.. */
 223int dump_fpu(struct pt_regs *regs, elf_fpregset_t *fpu)
 224{
 225        return 0; /* Task didn't use the fpu at all. */
 226}
 227
 228int copy_thread(unsigned long clone_flags, unsigned long spu,
 229        unsigned long unused, struct task_struct *tsk, struct pt_regs *regs)
 230{
 231        struct pt_regs *childregs = task_pt_regs(tsk);
 232        extern void ret_from_fork(void);
 233
 234        /* Copy registers */
 235        *childregs = *regs;
 236
 237        childregs->spu = spu;
 238        childregs->r0 = 0;      /* Child gets zero as return value */
 239        regs->r0 = tsk->pid;
 240        tsk->thread.sp = (unsigned long)childregs;
 241        tsk->thread.lr = (unsigned long)ret_from_fork;
 242
 243        return 0;
 244}
 245
 246asmlinkage int sys_fork(unsigned long r0, unsigned long r1, unsigned long r2,
 247        unsigned long r3, unsigned long r4, unsigned long r5, unsigned long r6,
 248        struct pt_regs regs)
 249{
 250#ifdef CONFIG_MMU
 251        return do_fork(SIGCHLD, regs.spu, &regs, 0, NULL, NULL);
 252#else
 253        return -EINVAL;
 254#endif /* CONFIG_MMU */
 255}
 256
 257asmlinkage int sys_clone(unsigned long clone_flags, unsigned long newsp,
 258                         unsigned long parent_tidptr,
 259                         unsigned long child_tidptr,
 260                         unsigned long r4, unsigned long r5, unsigned long r6,
 261                         struct pt_regs regs)
 262{
 263        if (!newsp)
 264                newsp = regs.spu;
 265
 266        return do_fork(clone_flags, newsp, &regs, 0,
 267                       (int __user *)parent_tidptr, (int __user *)child_tidptr);
 268}
 269
 270/*
 271 * This is trivial, and on the face of it looks like it
 272 * could equally well be done in user mode.
 273 *
 274 * Not so, for quite unobvious reasons - register pressure.
 275 * In user mode vfork() cannot have a stack frame, and if
 276 * done by calling the "clone()" system call directly, you
 277 * do not have enough call-clobbered registers to hold all
 278 * the information you need.
 279 */
 280asmlinkage int sys_vfork(unsigned long r0, unsigned long r1, unsigned long r2,
 281        unsigned long r3, unsigned long r4, unsigned long r5, unsigned long r6,
 282        struct pt_regs regs)
 283{
 284        return do_fork(CLONE_VFORK | CLONE_VM | SIGCHLD, regs.spu, &regs, 0,
 285                        NULL, NULL);
 286}
 287
 288/*
 289 * sys_execve() executes a new program.
 290 */
 291asmlinkage int sys_execve(const char __user *ufilename,
 292                          const char __user *const __user *uargv,
 293                          const char __user *const __user *uenvp,
 294                          unsigned long r3, unsigned long r4, unsigned long r5,
 295                          unsigned long r6, struct pt_regs regs)
 296{
 297        int error;
 298        char *filename;
 299
 300        filename = getname(ufilename);
 301        error = PTR_ERR(filename);
 302        if (IS_ERR(filename))
 303                goto out;
 304
 305        error = do_execve(filename, uargv, uenvp, &regs);
 306        putname(filename);
 307out:
 308        return error;
 309}
 310
 311/*
 312 * These bracket the sleeping functions..
 313 */
 314#define first_sched     ((unsigned long) scheduling_functions_start_here)
 315#define last_sched      ((unsigned long) scheduling_functions_end_here)
 316
 317unsigned long get_wchan(struct task_struct *p)
 318{
 319        /* M32R_FIXME */
 320        return (0);
 321}
 322