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   __FUNCTION__, ##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/config.h>
  25 #include <linux/module.h>
  26 #include <linux/ptrace.h>
  27 #include <linux/unistd.h>
  28 #include <linux/slab.h>
  29 #include <linux/hardirq.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 static int hlt_counter=0;
  40
  41 /*
  42  * Return saved PC of a blocked thread.
  43  */
  44 unsigned long thread_saved_pc(struct task_struct *tsk)
  45 {
  46         return tsk->thread.lr;
  47 }
  48
  49 /*
  50  * Powermanagement idle function, if any..
  51  */
  52 void (*pm_idle)(void) = NULL;
  53
  54 void disable_hlt(void)
  55 {
  56         hlt_counter++;
  57 }
  58
  59 EXPORT_SYMBOL(disable_hlt);
  60
  61 void enable_hlt(void)
  62 {
  63         hlt_counter--;
  64 }
  65
  66 EXPORT_SYMBOL(enable_hlt);
  67
  68 /*
  69  * We use this is we don't have any better
  70  * idle routine..
  71  */
  72 void default_idle(void)
  73 {
  74         /* M32R_FIXME: Please use "cpu_sleep" mode.  */
  75         cpu_relax();
  76 }
  77
  78 /*
  79  * On SMP it's slightly faster (but much more power-consuming!)
  80  * to poll the ->work.need_resched flag instead of waiting for the
  81  * cross-CPU IPI to arrive. Use this option with caution.
  82  */
  83 static void poll_idle (void)
  84 {
  85         /* M32R_FIXME */
  86         cpu_relax();
  87 }
  88
  89 /*
  90  * The idle thread. There's no useful work to be
  91  * done, so just try to conserve power and have a
  92  * low exit latency (ie sit in a loop waiting for
  93  * somebody to say that they'd like to reschedule)
  94  */
  95 void cpu_idle (void)
  96 {
  97         /* endless idle loop with no priority at all */
  98         while (1) {
  99                 while (!need_resched()) {
 100                         void (*idle)(void) = pm_idle;
 101
 102                         if (!idle)
 103                                 idle = default_idle;
 104
 105                         idle();
 106                 }
 107                 schedule();
 108         }
 109 }
 110
 111 void machine_restart(char *__unused)
 112 {
 113         printk("Please push reset button!\n");
 114         while (1)
 115                 cpu_relax();
 116 }
 117
 118 void machine_halt(void)
 119 {
 120         printk("Please push reset button!\n");
 121         while (1)
 122                 cpu_relax();
 123 }
 124
 125 void machine_power_off(void)
 126 {
 127         /* M32R_FIXME */
 128 }
 129
 130 static int __init idle_setup (char *str)
 131 {
 132         if (!strncmp(str, "poll", 4)) {
 133                 printk("using poll in idle threads.\n");
 134                 pm_idle = poll_idle;
 135         } else if (!strncmp(str, "sleep", 4)) {
 136                 printk("using sleep in idle threads.\n");
 137                 pm_idle = default_idle;
 138         }
 139
 140         return 1;
 141 }
 142
 143 __setup("idle=", idle_setup);
 144
 145 void show_regs(struct pt_regs * regs)
 146 {
 147         printk("\n");
 148         printk("BPC[%08lx]:PSW[%08lx]:LR [%08lx]:FP [%08lx]\n", \
 149           regs->bpc, regs->psw, regs->lr, regs->fp);
 150         printk("BBPC[%08lx]:BBPSW[%08lx]:SPU[%08lx]:SPI[%08lx]\n", \
 151           regs->bbpc, regs->bbpsw, regs->spu, regs->spi);
 152         printk("R0 [%08lx]:R1 [%08lx]:R2 [%08lx]:R3 [%08lx]\n", \
 153           regs->r0, regs->r1, regs->r2, regs->r3);
 154         printk("R4 [%08lx]:R5 [%08lx]:R6 [%08lx]:R7 [%08lx]\n", \
 155           regs->r4, regs->r5, regs->r6, regs->r7);
 156         printk("R8 [%08lx]:R9 [%08lx]:R10[%08lx]:R11[%08lx]\n", \
 157           regs->r8, regs->r9, regs->r10, regs->r11);
 158         printk("R12[%08lx]\n", \
 159           regs->r12);
 160
 161 #if defined(CONFIG_ISA_M32R2) && defined(CONFIG_ISA_DSP_LEVEL2)
 162         printk("ACC0H[%08lx]:ACC0L[%08lx]\n", \
 163           regs->acc0h, regs->acc0l);
 164         printk("ACC1H[%08lx]:ACC1L[%08lx]\n", \
 165           regs->acc1h, regs->acc1l);
 166 #elif defined(CONFIG_ISA_M32R2) || defined(CONFIG_ISA_M32R)
 167         printk("ACCH[%08lx]:ACCL[%08lx]\n", \
 168           regs->acch, regs->accl);
 169 #else
 170 #error unknown isa configuration
 171 #endif
 172 }
 173
 174 /*
 175  * Create a kernel thread
 176  */
 177
 178 /*
 179  * This is the mechanism for creating a new kernel thread.
 180  *
 181  * NOTE! Only a kernel-only process(ie the swapper or direct descendants
 182  * who haven't done an "execve()") should use this: it will work within
 183  * a system call from a "real" process, but the process memory space will
 184  * not be free'd until both the parent and the child have exited.
 185  */
 186 static void kernel_thread_helper(void *nouse, int (*fn)(void *), void *arg)
 187 {
 188         fn(arg);
 189         do_exit(-1);
 190 }
 191
 192 int kernel_thread(int (*fn)(void *), void *arg, unsigned long flags)
 193 {
 194         struct pt_regs regs;
 195
 196         memset(&regs, 0, sizeof (regs));
 197         regs.r1 = (unsigned long)fn;
 198         regs.r2 = (unsigned long)arg;
 199
 200         regs.bpc = (unsigned long)kernel_thread_helper;
 201
 202         regs.psw = M32R_PSW_BIE;
 203
 204         /* Ok, create the new process. */
 205         return do_fork(flags | CLONE_VM | CLONE_UNTRACED, 0, &regs, 0, NULL,
 206                 NULL);
 207 }
 208
 209 /*
 210  * Free current thread data structures etc..
 211  */
 212 void exit_thread(void)
 213 {
 214         /* Nothing to do. */
 215         DPRINTK("pid = %d\n", current->pid);
 216 }
 217
 218 void flush_thread(void)
 219 {
 220         DPRINTK("pid = %d\n", current->pid);
 221         memset(&current->thread.debug_trap, 0, sizeof(struct debug_trap));
 222 }
 223
 224 void release_thread(struct task_struct *dead_task)
 225 {
 226         /* do nothing */
 227         DPRINTK("pid = %d\n", dead_task->pid);
 228 }
 229
 230 /* Fill in the fpu structure for a core dump.. */
 231 int dump_fpu(struct pt_regs *regs, elf_fpregset_t *fpu)
 232 {
 233         return 0; /* Task didn't use the fpu at all. */
 234 }
 235
 236 int copy_thread(int nr, unsigned long clone_flags, unsigned long spu,
 237         unsigned long unused, struct task_struct *tsk, struct pt_regs *regs)
 238 {
 239         struct pt_regs *childregs;
 240         unsigned long sp = (unsigned long)tsk->thread_info + THREAD_SIZE;
 241         extern void ret_from_fork(void);
 242
 243         /* Copy registers */
 244         sp -= sizeof (struct pt_regs);
 245         childregs = (struct pt_regs *)sp;
 246         *childregs = *regs;
 247
 248         childregs->spu = spu;
 249         childregs->r0 = 0;      /* Child gets zero as return value */
 250         regs->r0 = tsk->pid;
 251         tsk->thread.sp = (unsigned long)childregs;
 252         tsk->thread.lr = (unsigned long)ret_from_fork;
 253
 254         return 0;
 255 }
 256
 257 /*
 258  * fill in the user structure for a core dump..
 259  */
 260 void dump_thread(struct pt_regs * regs, struct user * dump)
 261 {
 262         /* M32R_FIXME */
 263 }
 264
 265 /*
 266  * Capture the user space registers if the task is not running (in user space)
 267  */
 268 int dump_task_regs(struct task_struct *tsk, elf_gregset_t *regs)
 269 {
 270         /* M32R_FIXME */
 271         return 1;
 272 }
 273
 274 asmlinkage int sys_fork(unsigned long r0, unsigned long r1, unsigned long r2,
 275         unsigned long r3, unsigned long r4, unsigned long r5, unsigned long r6,
 276         struct pt_regs regs)
 277 {
 278 #ifdef CONFIG_MMU
 279         return do_fork(SIGCHLD, regs.spu, &regs, 0, NULL, NULL);
 280 #else
 281         return -EINVAL;
 282 #endif /* CONFIG_MMU */
 283 }
 284
 285 asmlinkage int sys_clone(unsigned long clone_flags, unsigned long newsp,
 286                          unsigned long parent_tidptr,
 287                          unsigned long child_tidptr,
 288                          unsigned long r4, unsigned long r5, unsigned long r6,
 289                          struct pt_regs regs)
 290 {
 291         if (!newsp)
 292                 newsp = regs.spu;
 293
 294         return do_fork(clone_flags, newsp, &regs, 0,
 295                        (int __user *)parent_tidptr, (int __user *)child_tidptr);
 296 }
 297
 298 /*
 299  * This is trivial, and on the face of it looks like it
 300  * could equally well be done in user mode.
 301  *
 302  * Not so, for quite unobvious reasons - register pressure.
 303  * In user mode vfork() cannot have a stack frame, and if
 304  * done by calling the "clone()" system call directly, you
 305  * do not have enough call-clobbered registers to hold all
 306  * the information you need.
 307  */
 308 asmlinkage int sys_vfork(unsigned long r0, unsigned long r1, unsigned long r2,
 309         unsigned long r3, unsigned long r4, unsigned long r5, unsigned long r6,
 310         struct pt_regs regs)
 311 {
 312         return do_fork(CLONE_VFORK | CLONE_VM | SIGCHLD, regs.spu, &regs, 0,
 313                         NULL, NULL);
 314 }
 315
 316 /*
 317  * sys_execve() executes a new program.
 318  */
 319 asmlinkage int sys_execve(char __user *ufilename, char __user * __user *uargv,
 320                           char __user * __user *uenvp,
 321                           unsigned long r3, unsigned long r4, unsigned long r5,
 322                           unsigned long r6, struct pt_regs regs)
 323 {
 324         int error;
 325         char *filename;
 326
 327         filename = getname(ufilename);
 328         error = PTR_ERR(filename);
 329         if (IS_ERR(filename))
 330                 goto out;
 331
 332         error = do_execve(filename, uargv, uenvp, &regs);
 333         if (error == 0) {
 334                 task_lock(current);
 335                 current->ptrace &= ~PT_DTRACE;
 336                 task_unlock(current);
 337         }
 338         putname(filename);
 339 out:
 340         return error;
 341 }
 342
 343 /*
 344  * These bracket the sleeping functions..
 345  */
 346 #define first_sched     ((unsigned long) scheduling_functions_start_here)
 347 #define last_sched      ((unsigned long) scheduling_functions_end_here)
 348
 349 unsigned long get_wchan(struct task_struct *p)
 350 {
 351         /* M32R_FIXME */
 352         return (0);
 353 }