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