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/module.h>
  25 #include <linux/ptrace.h>
  26 #include <linux/unistd.h>
  27 #include <linux/slab.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                 preempt_enable_no_resched();
  94                 schedule();
  95                 preempt_disable();
  96         }
  97 }
  98
  99 void machine_restart(char *__unused)
 100 {
 101 #if defined(CONFIG_PLAT_MAPPI3)
 102         outw(1, (unsigned long)PLD_REBOOT);
 103 #endif
 104
 105         printk("Please push reset button!\n");
 106         while (1)
 107                 cpu_relax();
 108 }
 109
 110 void machine_halt(void)
 111 {
 112         printk("Please push reset button!\n");
 113         while (1)
 114                 cpu_relax();
 115 }
 116
 117 void machine_power_off(void)
 118 {
 119         /* M32R_FIXME */
 120 }
 121
 122 static int __init idle_setup (char *str)
 123 {
 124         if (!strncmp(str, "poll", 4)) {
 125                 printk("using poll in idle threads.\n");
 126                 pm_idle = poll_idle;
 127         } else if (!strncmp(str, "sleep", 4)) {
 128                 printk("using sleep in idle threads.\n");
 129                 pm_idle = default_idle;
 130         }
 131
 132         return 1;
 133 }
 134
 135 __setup("idle=", idle_setup);
 136
 137 void show_regs(struct pt_regs * regs)
 138 {
 139         printk("\n");
 140         printk("BPC[%08lx]:PSW[%08lx]:LR [%08lx]:FP [%08lx]\n", \
 141           regs->bpc, regs->psw, regs->lr, regs->fp);
 142         printk("BBPC[%08lx]:BBPSW[%08lx]:SPU[%08lx]:SPI[%08lx]\n", \
 143           regs->bbpc, regs->bbpsw, regs->spu, regs->spi);
 144         printk("R0 [%08lx]:R1 [%08lx]:R2 [%08lx]:R3 [%08lx]\n", \
 145           regs->r0, regs->r1, regs->r2, regs->r3);
 146         printk("R4 [%08lx]:R5 [%08lx]:R6 [%08lx]:R7 [%08lx]\n", \
 147           regs->r4, regs->r5, regs->r6, regs->r7);
 148         printk("R8 [%08lx]:R9 [%08lx]:R10[%08lx]:R11[%08lx]\n", \
 149           regs->r8, regs->r9, regs->r10, regs->r11);
 150         printk("R12[%08lx]\n", \
 151           regs->r12);
 152
 153 #if defined(CONFIG_ISA_M32R2) && defined(CONFIG_ISA_DSP_LEVEL2)
 154         printk("ACC0H[%08lx]:ACC0L[%08lx]\n", \
 155           regs->acc0h, regs->acc0l);
 156         printk("ACC1H[%08lx]:ACC1L[%08lx]\n", \
 157           regs->acc1h, regs->acc1l);
 158 #elif defined(CONFIG_ISA_M32R2) || defined(CONFIG_ISA_M32R)
 159         printk("ACCH[%08lx]:ACCL[%08lx]\n", \
 160           regs->acc0h, regs->acc0l);
 161 #else
 162 #error unknown isa configuration
 163 #endif
 164 }
 165
 166 /*
 167  * Create a kernel thread
 168  */
 169
 170 /*
 171  * This is the mechanism for creating a new kernel thread.
 172  *
 173  * NOTE! Only a kernel-only process(ie the swapper or direct descendants
 174  * who haven't done an "execve()") should use this: it will work within
 175  * a system call from a "real" process, but the process memory space will
 176  * not be free'd until both the parent and the child have exited.
 177  */
 178 static void kernel_thread_helper(void *nouse, int (*fn)(void *), void *arg)
 179 {
 180         fn(arg);
 181         do_exit(-1);
 182 }
 183
 184 int kernel_thread(int (*fn)(void *), void *arg, unsigned long flags)
 185 {
 186         struct pt_regs regs;
 187
 188         memset(&regs, 0, sizeof (regs));
 189         regs.r1 = (unsigned long)fn;
 190         regs.r2 = (unsigned long)arg;
 191
 192         regs.bpc = (unsigned long)kernel_thread_helper;
 193
 194         regs.psw = M32R_PSW_BIE;
 195
 196         /* Ok, create the new process. */
 197         return do_fork(flags | CLONE_VM | CLONE_UNTRACED, 0, &regs, 0, NULL,
 198                 NULL);
 199 }
 200
 201 /*
 202  * Free current thread data structures etc..
 203  */
 204 void exit_thread(void)
 205 {
 206         /* Nothing to do. */
 207         DPRINTK("pid = %d\n", current->pid);
 208 }
 209
 210 void flush_thread(void)
 211 {
 212         DPRINTK("pid = %d\n", current->pid);
 213         memset(&current->thread.debug_trap, 0, sizeof(struct debug_trap));
 214 }
 215
 216 void release_thread(struct task_struct *dead_task)
 217 {
 218         /* do nothing */
 219         DPRINTK("pid = %d\n", dead_task->pid);
 220 }
 221
 222 /* Fill in the fpu structure for a core dump.. */
 223 int dump_fpu(struct pt_regs *regs, elf_fpregset_t *fpu)
 224 {
 225         return 0; /* Task didn't use the fpu at all. */
 226 }
 227
 228 int copy_thread(unsigned long clone_flags, unsigned long spu,
 229         unsigned long unused, struct task_struct *tsk, struct pt_regs *regs)
 230 {
 231         struct pt_regs *childregs = task_pt_regs(tsk);
 232         extern void ret_from_fork(void);
 233
 234         /* Copy registers */
 235         *childregs = *regs;
 236
 237         childregs->spu = spu;
 238         childregs->r0 = 0;      /* Child gets zero as return value */
 239         regs->r0 = tsk->pid;
 240         tsk->thread.sp = (unsigned long)childregs;
 241         tsk->thread.lr = (unsigned long)ret_from_fork;
 242
 243         return 0;
 244 }
 245
 246 asmlinkage int sys_fork(unsigned long r0, unsigned long r1, unsigned long r2,
 247         unsigned long r3, unsigned long r4, unsigned long r5, unsigned long r6,
 248         struct pt_regs regs)
 249 {
 250 #ifdef CONFIG_MMU
 251         return do_fork(SIGCHLD, regs.spu, &regs, 0, NULL, NULL);
 252 #else
 253         return -EINVAL;
 254 #endif /* CONFIG_MMU */
 255 }
 256
 257 asmlinkage int sys_clone(unsigned long clone_flags, unsigned long newsp,
 258                          unsigned long parent_tidptr,
 259                          unsigned long child_tidptr,
 260                          unsigned long r4, unsigned long r5, unsigned long r6,
 261                          struct pt_regs regs)
 262 {
 263         if (!newsp)
 264                 newsp = regs.spu;
 265
 266         return do_fork(clone_flags, newsp, &regs, 0,
 267                        (int __user *)parent_tidptr, (int __user *)child_tidptr);
 268 }
 269
 270 /*
 271  * This is trivial, and on the face of it looks like it
 272  * could equally well be done in user mode.
 273  *
 274  * Not so, for quite unobvious reasons - register pressure.
 275  * In user mode vfork() cannot have a stack frame, and if
 276  * done by calling the "clone()" system call directly, you
 277  * do not have enough call-clobbered registers to hold all
 278  * the information you need.
 279  */
 280 asmlinkage int sys_vfork(unsigned long r0, unsigned long r1, unsigned long r2,
 281         unsigned long r3, unsigned long r4, unsigned long r5, unsigned long r6,
 282         struct pt_regs regs)
 283 {
 284         return do_fork(CLONE_VFORK | CLONE_VM | SIGCHLD, regs.spu, &regs, 0,
 285                         NULL, NULL);
 286 }
 287
 288 /*
 289  * sys_execve() executes a new program.
 290  */
 291 asmlinkage int sys_execve(char __user *ufilename, char __user * __user *uargv,
 292                           char __user * __user *uenvp,
 293                           unsigned long r3, unsigned long r4, unsigned long r5,
 294                           unsigned long r6, struct pt_regs regs)
 295 {
 296         int error;
 297         char *filename;
 298
 299         filename = getname(ufilename);
 300         error = PTR_ERR(filename);
 301         if (IS_ERR(filename))
 302                 goto out;
 303
 304         error = do_execve(filename, uargv, uenvp, &regs);
 305         putname(filename);
 306 out:
 307         return error;
 308 }
 309
 310 /*
 311  * These bracket the sleeping functions..
 312  */
 313 #define first_sched     ((unsigned long) scheduling_functions_start_here)
 314 #define last_sched      ((unsigned long) scheduling_functions_end_here)
 315
 316 unsigned long get_wchan(struct task_struct *p)
 317 {
 318         /* M32R_FIXME */
 319         return (0);
 320 }