arch/m32r/kernel/process.c

   1 /*
   2  *  linux/arch/m32r/kernel/process.c
   3  *    orig : sh
   4  *
   5  *  Copyright (c) 2001, 2002  Hiroyuki Kondo, Hirokazu Takata,
   6  *                            Hitoshi Yamamoto
   7  *  Taken from sh version.
   8  *    Copyright (C) 1995  Linus Torvalds
   9  *    SuperH version:  Copyright (C) 1999, 2000  Niibe Yutaka & Kaz Kojima
  10  */
  11
  12 #undef DEBUG_PROCESS
  13 #ifdef DEBUG_PROCESS
  14 #define DPRINTK(fmt, args...)  printk("%s:%d:%s: " fmt, __FILE__, __LINE__, \
  15   __FUNCTION__, ##args)
  16 #else
  17 #define DPRINTK(fmt, args...)
  18 #endif
  19
  20 /*
  21  * This file handles the architecture-dependent parts of process handling..
  22  */
  23
  24 #include <linux/fs.h>
  25 #include <linux/config.h>
  26 #include <linux/module.h>
  27 #include <linux/ptrace.h>
  28 #include <linux/unistd.h>
  29 #include <linux/slab.h>
  30 #include <linux/hardirq.h>
  31
  32 #include <asm/io.h>
  33 #include <asm/uaccess.h>
  34 #include <asm/mmu_context.h>
  35 #include <asm/elf.h>
  36 #include <asm/m32r.h>
  37
  38 #include <linux/err.h>
  39
  40 static int hlt_counter=0;
  41
  42 /*
  43  * Return saved PC of a blocked thread.
  44  */
  45 unsigned long thread_saved_pc(struct task_struct *tsk)
  46 {
  47         return tsk->thread.lr;
  48 }
  49
  50 /*
  51  * Powermanagement idle function, if any..
  52  */
  53 void (*pm_idle)(void) = NULL;
  54
  55 void disable_hlt(void)
  56 {
  57         hlt_counter++;
  58 }
  59
  60 EXPORT_SYMBOL(disable_hlt);
  61
  62 void enable_hlt(void)
  63 {
  64         hlt_counter--;
  65 }
  66
  67 EXPORT_SYMBOL(enable_hlt);
  68
  69 /*
  70  * We use this is we don't have any better
  71  * idle routine..
  72  */
  73 void default_idle(void)
  74 {
  75         /* M32R_FIXME: Please use "cpu_sleep" mode.  */
  76         cpu_relax();
  77 }
  78
  79 /*
  80  * On SMP it's slightly faster (but much more power-consuming!)
  81  * to poll the ->work.need_resched flag instead of waiting for the
  82  * cross-CPU IPI to arrive. Use this option with caution.
  83  */
  84 static void poll_idle (void)
  85 {
  86         /* M32R_FIXME */
  87         cpu_relax();
  88 }
  89
  90 /*
  91  * The idle thread. There's no useful work to be
  92  * done, so just try to conserve power and have a
  93  * low exit latency (ie sit in a loop waiting for
  94  * somebody to say that they'd like to reschedule)
  95  */
  96 void cpu_idle (void)
  97 {
  98         /* endless idle loop with no priority at all */
  99         while (1) {
 100                 while (!need_resched()) {
 101                         void (*idle)(void) = pm_idle;
 102
 103                         if (!idle)
 104                                 idle = default_idle;
 105
 106                         idle();
 107                 }
 108                 schedule();
 109         }
 110 }
 111
 112 void machine_restart(char *__unused)
 113 {
 114         printk("Please push reset button!\n");
 115         while (1)
 116                 cpu_relax();
 117 }
 118
 119 EXPORT_SYMBOL(machine_restart);
 120
 121 void machine_halt(void)
 122 {
 123         printk("Please push reset button!\n");
 124         while (1)
 125                 cpu_relax();
 126 }
 127
 128 EXPORT_SYMBOL(machine_halt);
 129
 130 void machine_power_off(void)
 131 {
 132         /* M32R_FIXME */
 133 }
 134
 135 EXPORT_SYMBOL(machine_power_off);
 136
 137 static int __init idle_setup (char *str)
 138 {
 139         if (!strncmp(str, "poll", 4)) {
 140                 printk("using poll in idle threads.\n");
 141                 pm_idle = poll_idle;
 142         } else if (!strncmp(str, "sleep", 4)) {
 143                 printk("using sleep in idle threads.\n");
 144                 pm_idle = default_idle;
 145         }
 146
 147         return 1;
 148 }
 149
 150 __setup("idle=", idle_setup);
 151
 152 void show_regs(struct pt_regs * regs)
 153 {
 154         printk("\n");
 155         printk("BPC[%08lx]:PSW[%08lx]:LR [%08lx]:FP [%08lx]\n", \
 156           regs->bpc, regs->psw, regs->lr, regs->fp);
 157         printk("BBPC[%08lx]:BBPSW[%08lx]:SPU[%08lx]:SPI[%08lx]\n", \
 158           regs->bbpc, regs->bbpsw, regs->spu, regs->spi);
 159         printk("R0 [%08lx]:R1 [%08lx]:R2 [%08lx]:R3 [%08lx]\n", \
 160           regs->r0, regs->r1, regs->r2, regs->r3);
 161         printk("R4 [%08lx]:R5 [%08lx]:R6 [%08lx]:R7 [%08lx]\n", \
 162           regs->r4, regs->r5, regs->r6, regs->r7);
 163         printk("R8 [%08lx]:R9 [%08lx]:R10[%08lx]:R11[%08lx]\n", \
 164           regs->r8, regs->r9, regs->r10, regs->r11);
 165         printk("R12[%08lx]\n", \
 166           regs->r12);
 167
 168 #if defined(CONFIG_ISA_M32R2) && defined(CONFIG_ISA_DSP_LEVEL2)
 169         printk("ACC0H[%08lx]:ACC0L[%08lx]\n", \
 170           regs->acc0h, regs->acc0l);
 171         printk("ACC1H[%08lx]:ACC1L[%08lx]\n", \
 172           regs->acc1h, regs->acc1l);
 173 #elif defined(CONFIG_ISA_M32R2) || defined(CONFIG_ISA_M32R)
 174         printk("ACCH[%08lx]:ACCL[%08lx]\n", \
 175           regs->acch, regs->accl);
 176 #else
 177 #error unknown isa configuration
 178 #endif
 179 }
 180
 181 /*
 182  * Create a kernel thread
 183  */
 184
 185 /*
 186  * This is the mechanism for creating a new kernel thread.
 187  *
 188  * NOTE! Only a kernel-only process(ie the swapper or direct descendants
 189  * who haven't done an "execve()") should use this: it will work within
 190  * a system call from a "real" process, but the process memory space will
 191  * not be free'd until both the parent and the child have exited.
 192  */
 193 static void kernel_thread_helper(void *nouse, int (*fn)(void *), void *arg)
 194 {
 195         fn(arg);
 196         do_exit(-1);
 197 }
 198
 199 int kernel_thread(int (*fn)(void *), void *arg, unsigned long flags)
 200 {
 201         struct pt_regs regs;
 202
 203         memset(&regs, 0, sizeof (regs));
 204         regs.r1 = (unsigned long)fn;
 205         regs.r2 = (unsigned long)arg;
 206
 207         regs.bpc = (unsigned long)kernel_thread_helper;
 208
 209         regs.psw = M32R_PSW_BIE;
 210
 211         /* Ok, create the new process. */
 212         return do_fork(flags | CLONE_VM | CLONE_UNTRACED, 0, &regs, 0, NULL,
 213                 NULL);
 214 }
 215
 216 /*
 217  * Free current thread data structures etc..
 218  */
 219 void exit_thread(void)
 220 {
 221         /* Nothing to do. */
 222         DPRINTK("pid = %d\n", current->pid);
 223 }
 224
 225 void flush_thread(void)
 226 {
 227         DPRINTK("pid = %d\n", current->pid);
 228         memset(&current->thread.debug_trap, 0, sizeof(struct debug_trap));
 229 }
 230
 231 void release_thread(struct task_struct *dead_task)
 232 {
 233         /* do nothing */
 234         DPRINTK("pid = %d\n", dead_task->pid);
 235 }
 236
 237 /* Fill in the fpu structure for a core dump.. */
 238 int dump_fpu(struct pt_regs *regs, elf_fpregset_t *fpu)
 239 {
 240         return 0; /* Task didn't use the fpu at all. */
 241 }
 242
 243 int copy_thread(int nr, unsigned long clone_flags, unsigned long spu,
 244         unsigned long unused, struct task_struct *tsk, struct pt_regs *regs)
 245 {
 246         struct pt_regs *childregs;
 247         unsigned long sp = (unsigned long)tsk->thread_info + THREAD_SIZE;
 248         extern void ret_from_fork(void);
 249
 250         tsk->set_child_tid = tsk->clear_child_tid = NULL;
 251
 252         /* Copy registers */
 253         sp -= sizeof (struct pt_regs);
 254         childregs = (struct pt_regs *)sp;
 255         *childregs = *regs;
 256
 257         childregs->spu = spu;
 258         childregs->r0 = 0;      /* Child gets zero as return value */
 259         regs->r0 = tsk->pid;
 260         tsk->thread.sp = (unsigned long)childregs;
 261         tsk->thread.lr = (unsigned long)ret_from_fork;
 262
 263         return 0;
 264 }
 265
 266 /*
 267  * fill in the user structure for a core dump..
 268  */
 269 void dump_thread(struct pt_regs * regs, struct user * dump)
 270 {
 271         /* M32R_FIXME */
 272 }
 273
 274 /*
 275  * Capture the user space registers if the task is not running (in user space)
 276  */
 277 int dump_task_regs(struct task_struct *tsk, elf_gregset_t *regs)
 278 {
 279         /* M32R_FIXME */
 280         return 1;
 281 }
 282
 283 asmlinkage int sys_fork(unsigned long r0, unsigned long r1, unsigned long r2,
 284         unsigned long r3, unsigned long r4, unsigned long r5, unsigned long r6,
 285         struct pt_regs regs)
 286 {
 287 #ifdef CONFIG_MMU
 288         return do_fork(SIGCHLD, regs.spu, &regs, 0, NULL, NULL);
 289 #else
 290         return -EINVAL;
 291 #endif /* CONFIG_MMU */
 292 }
 293
 294 asmlinkage int sys_clone(unsigned long clone_flags, unsigned long newsp,
 295         unsigned long r2, unsigned long r3, unsigned long r4, unsigned long r5,
 296         unsigned long r6, struct pt_regs regs)
 297 {
 298         if (!newsp)
 299                 newsp = regs.spu;
 300
 301         return do_fork(clone_flags, newsp, &regs, 0, NULL, NULL);
 302 }
 303
 304 /*
 305  * This is trivial, and on the face of it looks like it
 306  * could equally well be done in user mode.
 307  *
 308  * Not so, for quite unobvious reasons - register pressure.
 309  * In user mode vfork() cannot have a stack frame, and if
 310  * done by calling the "clone()" system call directly, you
 311  * do not have enough call-clobbered registers to hold all
 312  * the information you need.
 313  */
 314 asmlinkage int sys_vfork(unsigned long r0, unsigned long r1, unsigned long r2,
 315         unsigned long r3, unsigned long r4, unsigned long r5, unsigned long r6,
 316         struct pt_regs regs)
 317 {
 318         return do_fork(CLONE_VFORK | CLONE_VM | SIGCHLD, regs.spu, &regs, 0,
 319                         NULL, NULL);
 320 }
 321
 322 /*
 323  * sys_execve() executes a new program.
 324  */
 325 asmlinkage int sys_execve(char __user *ufilename, char __user * __user *uargv, char __user * __user *uenvp,
 326   unsigned long r3, unsigned long r4, unsigned long r5, unsigned long r6,
 327   struct pt_regs regs)
 328 {
 329         int error;
 330         char *filename;
 331
 332         filename = getname(ufilename);
 333         error = PTR_ERR(filename);
 334         if (IS_ERR(filename))
 335                 goto out;
 336
 337         error = do_execve(filename, uargv, uenvp, &regs);
 338         if (error == 0)
 339                 current->ptrace &= ~PT_DTRACE;
 340         putname(filename);
 341 out:
 342         return error;
 343 }
 344
 345 /*
 346  * These bracket the sleeping functions..
 347  */
 348 #define first_sched     ((unsigned long) scheduling_functions_start_here)
 349 #define last_sched      ((unsigned long) scheduling_functions_end_here)
 350
 351 unsigned long get_wchan(struct task_struct *p)
 352 {
 353         /* M32R_FIXME */
 354         return (0);
 355 }
 356