arch/m32r/kernel/process.c

   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 #include <linux/rcupdate.h>
  30
  31 #include <asm/io.h>
  32 #include <asm/uaccess.h>
  33 #include <asm/mmu_context.h>
  34 #include <asm/elf.h>
  35 #include <asm/m32r.h>
  36
  37 #include <linux/err.h>
  38
  39 /*
  40  * Return saved PC of a blocked thread.
  41  */
  42 unsigned long thread_saved_pc(struct task_struct *tsk)
  43 {
  44         return tsk->thread.lr;
  45 }
  46
  47 /*
  48  * Powermanagement idle function, if any..
  49  */
  50 static void (*pm_idle)(void) = NULL;
  51
  52 void (*pm_power_off)(void) = NULL;
  53 EXPORT_SYMBOL(pm_power_off);
  54
  55 /*
  56  * We use this is we don't have any better
  57  * idle routine..
  58  */
  59 static void default_idle(void)
  60 {
  61         /* M32R_FIXME: Please use "cpu_sleep" mode.  */
  62         cpu_relax();
  63 }
  64
  65 /*
  66  * On SMP it's slightly faster (but much more power-consuming!)
  67  * to poll the ->work.need_resched flag instead of waiting for the
  68  * cross-CPU IPI to arrive. Use this option with caution.
  69  */
  70 static void poll_idle (void)
  71 {
  72         /* M32R_FIXME */
  73         cpu_relax();
  74 }
  75
  76 /*
  77  * The idle thread. There's no useful work to be
  78  * done, so just try to conserve power and have a
  79  * low exit latency (ie sit in a loop waiting for
  80  * somebody to say that they'd like to reschedule)
  81  */
  82 void cpu_idle (void)
  83 {
  84         /* endless idle loop with no priority at all */
  85         while (1) {
  86                 rcu_idle_enter();
  87                 while (!need_resched()) {
  88                         void (*idle)(void) = pm_idle;
  89
  90                         if (!idle)
  91                                 idle = default_idle;
  92
  93                         idle();
  94                 }
  95                 rcu_idle_exit();
  96                 schedule_preempt_disabled();
  97         }
  98 }
  99
 100 void machine_restart(char *__unused)
 101 {
 102 #if defined(CONFIG_PLAT_MAPPI3)
 103         outw(1, (unsigned long)PLD_REBOOT);
 104 #endif
 105
 106         printk("Please push reset button!\n");
 107         while (1)
 108                 cpu_relax();
 109 }
 110
 111 void machine_halt(void)
 112 {
 113         printk("Please push reset button!\n");
 114         while (1)
 115                 cpu_relax();
 116 }
 117
 118 void machine_power_off(void)
 119 {
 120         /* M32R_FIXME */
 121 }
 122
 123 static int __init idle_setup (char *str)
 124 {
 125         if (!strncmp(str, "poll", 4)) {
 126                 printk("using poll in idle threads.\n");
 127                 pm_idle = poll_idle;
 128         } else if (!strncmp(str, "sleep", 4)) {
 129                 printk("using sleep in idle threads.\n");
 130                 pm_idle = default_idle;
 131         }
 132
 133         return 1;
 134 }
 135
 136 __setup("idle=", idle_setup);
 137
 138 void show_regs(struct pt_regs * regs)
 139 {
 140         printk("\n");
 141         printk("BPC[%08lx]:PSW[%08lx]:LR [%08lx]:FP [%08lx]\n", \
 142           regs->bpc, regs->psw, regs->lr, regs->fp);
 143         printk("BBPC[%08lx]:BBPSW[%08lx]:SPU[%08lx]:SPI[%08lx]\n", \
 144           regs->bbpc, regs->bbpsw, regs->spu, regs->spi);
 145         printk("R0 [%08lx]:R1 [%08lx]:R2 [%08lx]:R3 [%08lx]\n", \
 146           regs->r0, regs->r1, regs->r2, regs->r3);
 147         printk("R4 [%08lx]:R5 [%08lx]:R6 [%08lx]:R7 [%08lx]\n", \
 148           regs->r4, regs->r5, regs->r6, regs->r7);
 149         printk("R8 [%08lx]:R9 [%08lx]:R10[%08lx]:R11[%08lx]\n", \
 150           regs->r8, regs->r9, regs->r10, regs->r11);
 151         printk("R12[%08lx]\n", \
 152           regs->r12);
 153
 154 #if defined(CONFIG_ISA_M32R2) && defined(CONFIG_ISA_DSP_LEVEL2)
 155         printk("ACC0H[%08lx]:ACC0L[%08lx]\n", \
 156           regs->acc0h, regs->acc0l);
 157         printk("ACC1H[%08lx]:ACC1L[%08lx]\n", \
 158           regs->acc1h, regs->acc1l);
 159 #elif defined(CONFIG_ISA_M32R2) || defined(CONFIG_ISA_M32R)
 160         printk("ACCH[%08lx]:ACCL[%08lx]\n", \
 161           regs->acc0h, regs->acc0l);
 162 #else
 163 #error unknown isa configuration
 164 #endif
 165 }
 166
 167 /*
 168  * Free current thread data structures etc..
 169  */
 170 void exit_thread(void)
 171 {
 172         /* Nothing to do. */
 173         DPRINTK("pid = %d\n", current->pid);
 174 }
 175
 176 void flush_thread(void)
 177 {
 178         DPRINTK("pid = %d\n", current->pid);
 179         memset(&current->thread.debug_trap, 0, sizeof(struct debug_trap));
 180 }
 181
 182 void release_thread(struct task_struct *dead_task)
 183 {
 184         /* do nothing */
 185         DPRINTK("pid = %d\n", dead_task->pid);
 186 }
 187
 188 /* Fill in the fpu structure for a core dump.. */
 189 int dump_fpu(struct pt_regs *regs, elf_fpregset_t *fpu)
 190 {
 191         return 0; /* Task didn't use the fpu at all. */
 192 }
 193
 194 int copy_thread(unsigned long clone_flags, unsigned long spu,
 195         unsigned long arg, struct task_struct *tsk)
 196 {
 197         struct pt_regs *childregs = task_pt_regs(tsk);
 198         extern void ret_from_fork(void);
 199         extern void ret_from_kernel_thread(void);
 200
 201         if (unlikely(tsk->flags & PF_KTHREAD)) {
 202                 memset(childregs, 0, sizeof(struct pt_regs));
 203                 childregs->psw = M32R_PSW_BIE;
 204                 childregs->r1 = spu;    /* fn */
 205                 childregs->r0 = arg;
 206                 tsk->thread.lr = (unsigned long)ret_from_kernel_thread;
 207         } else {
 208                 /* Copy registers */
 209                 *childregs = *current_pt_regs();
 210                 if (spu)
 211                         childregs->spu = spu;
 212                 childregs->r0 = 0;      /* Child gets zero as return value */
 213                 tsk->thread.lr = (unsigned long)ret_from_fork;
 214         }
 215         tsk->thread.sp = (unsigned long)childregs;
 216
 217         return 0;
 218 }
 219
 220 /*
 221  * These bracket the sleeping functions..
 222  */
 223 #define first_sched     ((unsigned long) scheduling_functions_start_here)
 224 #define last_sched      ((unsigned long) scheduling_functions_end_here)
 225
 226 unsigned long get_wchan(struct task_struct *p)
 227 {
 228         /* M32R_FIXME */
 229         return (0);
 230 }