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
  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  */
  41 unsigned long thread_saved_pc(struct task_struct *tsk)
  42 {
  43         return tsk->thread.lr;
  44 }
  45
  46 /*
  47  * Powermanagement idle function, if any..
  48  */
  49 static void (*pm_idle)(void) = NULL;
  50
  51 void (*pm_power_off)(void) = NULL;
  52 EXPORT_SYMBOL(pm_power_off);
  53
  54 /*
  55  * We use this is we don't have any better
  56  * idle routine..
  57  */
  58 static 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  */
  69 static 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  */
  81 void 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                 schedule_preempt_disabled();
  94         }
  95 }
  96
  97 void machine_restart(char *__unused)
  98 {
  99 #if defined(CONFIG_PLAT_MAPPI3)
 100         outw(1, (unsigned long)PLD_REBOOT);
 101 #endif
 102
 103         printk("Please push reset button!\n");
 104         while (1)
 105                 cpu_relax();
 106 }
 107
 108 void machine_halt(void)
 109 {
 110         printk("Please push reset button!\n");
 111         while (1)
 112                 cpu_relax();
 113 }
 114
 115 void machine_power_off(void)
 116 {
 117         /* M32R_FIXME */
 118 }
 119
 120 static int __init idle_setup (char *str)
 121 {
 122         if (!strncmp(str, "poll", 4)) {
 123                 printk("using poll in idle threads.\n");
 124                 pm_idle = poll_idle;
 125         } else if (!strncmp(str, "sleep", 4)) {
 126                 printk("using sleep in idle threads.\n");
 127                 pm_idle = default_idle;
 128         }
 129
 130         return 1;
 131 }
 132
 133 __setup("idle=", idle_setup);
 134
 135 void show_regs(struct pt_regs * regs)
 136 {
 137         printk("\n");
 138         printk("BPC[%08lx]:PSW[%08lx]:LR [%08lx]:FP [%08lx]\n", \
 139           regs->bpc, regs->psw, regs->lr, regs->fp);
 140         printk("BBPC[%08lx]:BBPSW[%08lx]:SPU[%08lx]:SPI[%08lx]\n", \
 141           regs->bbpc, regs->bbpsw, regs->spu, regs->spi);
 142         printk("R0 [%08lx]:R1 [%08lx]:R2 [%08lx]:R3 [%08lx]\n", \
 143           regs->r0, regs->r1, regs->r2, regs->r3);
 144         printk("R4 [%08lx]:R5 [%08lx]:R6 [%08lx]:R7 [%08lx]\n", \
 145           regs->r4, regs->r5, regs->r6, regs->r7);
 146         printk("R8 [%08lx]:R9 [%08lx]:R10[%08lx]:R11[%08lx]\n", \
 147           regs->r8, regs->r9, regs->r10, regs->r11);
 148         printk("R12[%08lx]\n", \
 149           regs->r12);
 150
 151 #if defined(CONFIG_ISA_M32R2) && defined(CONFIG_ISA_DSP_LEVEL2)
 152         printk("ACC0H[%08lx]:ACC0L[%08lx]\n", \
 153           regs->acc0h, regs->acc0l);
 154         printk("ACC1H[%08lx]:ACC1L[%08lx]\n", \
 155           regs->acc1h, regs->acc1l);
 156 #elif defined(CONFIG_ISA_M32R2) || defined(CONFIG_ISA_M32R)
 157         printk("ACCH[%08lx]:ACCL[%08lx]\n", \
 158           regs->acc0h, regs->acc0l);
 159 #else
 160 #error unknown isa configuration
 161 #endif
 162 }
 163
 164 /*
 165  * Create a kernel thread
 166  */
 167
 168 /*
 169  * This is the mechanism for creating a new kernel thread.
 170  *
 171  * NOTE! Only a kernel-only process(ie the swapper or direct descendants
 172  * who haven't done an "execve()") should use this: it will work within
 173  * a system call from a "real" process, but the process memory space will
 174  * not be free'd until both the parent and the child have exited.
 175  */
 176 static void kernel_thread_helper(void *nouse, int (*fn)(void *), void *arg)
 177 {
 178         fn(arg);
 179         do_exit(-1);
 180 }
 181
 182 int kernel_thread(int (*fn)(void *), void *arg, unsigned long flags)
 183 {
 184         struct pt_regs regs;
 185
 186         memset(&regs, 0, sizeof (regs));
 187         regs.r1 = (unsigned long)fn;
 188         regs.r2 = (unsigned long)arg;
 189
 190         regs.bpc = (unsigned long)kernel_thread_helper;
 191
 192         regs.psw = M32R_PSW_BIE;
 193
 194         /* Ok, create the new process. */
 195         return do_fork(flags | CLONE_VM | CLONE_UNTRACED, 0, &regs, 0, NULL,
 196                 NULL);
 197 }
 198
 199 /*
 200  * Free current thread data structures etc..
 201  */
 202 void exit_thread(void)
 203 {
 204         /* Nothing to do. */
 205         DPRINTK("pid = %d\n", current->pid);
 206 }
 207
 208 void flush_thread(void)
 209 {
 210         DPRINTK("pid = %d\n", current->pid);
 211         memset(&current->thread.debug_trap, 0, sizeof(struct debug_trap));
 212 }
 213
 214 void release_thread(struct task_struct *dead_task)
 215 {
 216         /* do nothing */
 217         DPRINTK("pid = %d\n", dead_task->pid);
 218 }
 219
 220 /* Fill in the fpu structure for a core dump.. */
 221 int dump_fpu(struct pt_regs *regs, elf_fpregset_t *fpu)
 222 {
 223         return 0; /* Task didn't use the fpu at all. */
 224 }
 225
 226 int copy_thread(unsigned long clone_flags, unsigned long spu,
 227         unsigned long unused, struct task_struct *tsk, struct pt_regs *regs)
 228 {
 229         struct pt_regs *childregs = task_pt_regs(tsk);
 230         extern void ret_from_fork(void);
 231
 232         /* Copy registers */
 233         *childregs = *regs;
 234
 235         childregs->spu = spu;
 236         childregs->r0 = 0;      /* Child gets zero as return value */
 237         regs->r0 = tsk->pid;
 238         tsk->thread.sp = (unsigned long)childregs;
 239         tsk->thread.lr = (unsigned long)ret_from_fork;
 240
 241         return 0;
 242 }
 243
 244 asmlinkage int sys_fork(unsigned long r0, unsigned long r1, unsigned long r2,
 245         unsigned long r3, unsigned long r4, unsigned long r5, unsigned long r6,
 246         struct pt_regs regs)
 247 {
 248 #ifdef CONFIG_MMU
 249         return do_fork(SIGCHLD, regs.spu, &regs, 0, NULL, NULL);
 250 #else
 251         return -EINVAL;
 252 #endif /* CONFIG_MMU */
 253 }
 254
 255 asmlinkage int sys_clone(unsigned long clone_flags, unsigned long newsp,
 256                          unsigned long parent_tidptr,
 257                          unsigned long child_tidptr,
 258                          unsigned long r4, unsigned long r5, unsigned long r6,
 259                          struct pt_regs regs)
 260 {
 261         if (!newsp)
 262                 newsp = regs.spu;
 263
 264         return do_fork(clone_flags, newsp, &regs, 0,
 265                        (int __user *)parent_tidptr, (int __user *)child_tidptr);
 266 }
 267
 268 /*
 269  * This is trivial, and on the face of it looks like it
 270  * could equally well be done in user mode.
 271  *
 272  * Not so, for quite unobvious reasons - register pressure.
 273  * In user mode vfork() cannot have a stack frame, and if
 274  * done by calling the "clone()" system call directly, you
 275  * do not have enough call-clobbered registers to hold all
 276  * the information you need.
 277  */
 278 asmlinkage int sys_vfork(unsigned long r0, unsigned long r1, unsigned long r2,
 279         unsigned long r3, unsigned long r4, unsigned long r5, unsigned long r6,
 280         struct pt_regs regs)
 281 {
 282         return do_fork(CLONE_VFORK | CLONE_VM | SIGCHLD, regs.spu, &regs, 0,
 283                         NULL, NULL);
 284 }
 285
 286 /*
 287  * sys_execve() executes a new program.
 288  */
 289 asmlinkage int sys_execve(const char __user *ufilename,
 290                           const char __user *const __user *uargv,
 291                           const char __user *const __user *uenvp,
 292                           unsigned long r3, unsigned long r4, unsigned long r5,
 293                           unsigned long r6, struct pt_regs regs)
 294 {
 295         int error;
 296         char *filename;
 297
 298         filename = getname(ufilename);
 299         error = PTR_ERR(filename);
 300         if (IS_ERR(filename))
 301                 goto out;
 302
 303         error = do_execve(filename, uargv, uenvp, &regs);
 304         putname(filename);
 305 out:
 306         return error;
 307 }
 308
 309 /*
 310  * These bracket the sleeping functions..
 311  */
 312 #define first_sched     ((unsigned long) scheduling_functions_start_here)
 313 #define last_sched      ((unsigned long) scheduling_functions_end_here)
 314
 315 unsigned long get_wchan(struct task_struct *p)
 316 {
 317         /* M32R_FIXME */
 318         return (0);
 319 }