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/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 static int hlt_counter=0;
  39
  40 /*
  41  * Return saved PC of a blocked thread.
  42  */
  43 unsigned long thread_saved_pc(struct task_struct *tsk)
  44 {
  45         return tsk->thread.lr;
  46 }
  47
  48 /*
  49  * Powermanagement idle function, if any..
  50  */
  51 void (*pm_idle)(void) = NULL;
  52 EXPORT_SYMBOL(pm_idle);
  53
  54 void (*pm_power_off)(void) = NULL;
  55 EXPORT_SYMBOL(pm_power_off);
  56
  57 void disable_hlt(void)
  58 {
  59         hlt_counter++;
  60 }
  61
  62 EXPORT_SYMBOL(disable_hlt);
  63
  64 void enable_hlt(void)
  65 {
  66         hlt_counter--;
  67 }
  68
  69 EXPORT_SYMBOL(enable_hlt);
  70
  71 /*
  72  * We use this is we don't have any better
  73  * idle routine..
  74  */
  75 void default_idle(void)
  76 {
  77         /* M32R_FIXME: Please use "cpu_sleep" mode.  */
  78         cpu_relax();
  79 }
  80
  81 /*
  82  * On SMP it's slightly faster (but much more power-consuming!)
  83  * to poll the ->work.need_resched flag instead of waiting for the
  84  * cross-CPU IPI to arrive. Use this option with caution.
  85  */
  86 static void poll_idle (void)
  87 {
  88         /* M32R_FIXME */
  89         cpu_relax();
  90 }
  91
  92 /*
  93  * The idle thread. There's no useful work to be
  94  * done, so just try to conserve power and have a
  95  * low exit latency (ie sit in a loop waiting for
  96  * somebody to say that they'd like to reschedule)
  97  */
  98 void cpu_idle (void)
  99 {
 100         /* endless idle loop with no priority at all */
 101         while (1) {
 102                 while (!need_resched()) {
 103                         void (*idle)(void) = pm_idle;
 104
 105                         if (!idle)
 106                                 idle = default_idle;
 107
 108                         idle();
 109                 }
 110                 preempt_enable_no_resched();
 111                 schedule();
 112                 preempt_disable();
 113         }
 114 }
 115
 116 void machine_restart(char *__unused)
 117 {
 118 #if defined(CONFIG_PLAT_MAPPI3)
 119         outw(1, (unsigned long)PLD_REBOOT);
 120 #endif
 121
 122         printk("Please push reset button!\n");
 123         while (1)
 124                 cpu_relax();
 125 }
 126
 127 void machine_halt(void)
 128 {
 129         printk("Please push reset button!\n");
 130         while (1)
 131                 cpu_relax();
 132 }
 133
 134 void machine_power_off(void)
 135 {
 136         /* M32R_FIXME */
 137 }
 138
 139 static int __init idle_setup (char *str)
 140 {
 141         if (!strncmp(str, "poll", 4)) {
 142                 printk("using poll in idle threads.\n");
 143                 pm_idle = poll_idle;
 144         } else if (!strncmp(str, "sleep", 4)) {
 145                 printk("using sleep in idle threads.\n");
 146                 pm_idle = default_idle;
 147         }
 148
 149         return 1;
 150 }
 151
 152 __setup("idle=", idle_setup);
 153
 154 void show_regs(struct pt_regs * regs)
 155 {
 156         printk("\n");
 157         printk("BPC[%08lx]:PSW[%08lx]:LR [%08lx]:FP [%08lx]\n", \
 158           regs->bpc, regs->psw, regs->lr, regs->fp);
 159         printk("BBPC[%08lx]:BBPSW[%08lx]:SPU[%08lx]:SPI[%08lx]\n", \
 160           regs->bbpc, regs->bbpsw, regs->spu, regs->spi);
 161         printk("R0 [%08lx]:R1 [%08lx]:R2 [%08lx]:R3 [%08lx]\n", \
 162           regs->r0, regs->r1, regs->r2, regs->r3);
 163         printk("R4 [%08lx]:R5 [%08lx]:R6 [%08lx]:R7 [%08lx]\n", \
 164           regs->r4, regs->r5, regs->r6, regs->r7);
 165         printk("R8 [%08lx]:R9 [%08lx]:R10[%08lx]:R11[%08lx]\n", \
 166           regs->r8, regs->r9, regs->r10, regs->r11);
 167         printk("R12[%08lx]\n", \
 168           regs->r12);
 169
 170 #if defined(CONFIG_ISA_M32R2) && defined(CONFIG_ISA_DSP_LEVEL2)
 171         printk("ACC0H[%08lx]:ACC0L[%08lx]\n", \
 172           regs->acc0h, regs->acc0l);
 173         printk("ACC1H[%08lx]:ACC1L[%08lx]\n", \
 174           regs->acc1h, regs->acc1l);
 175 #elif defined(CONFIG_ISA_M32R2) || defined(CONFIG_ISA_M32R)
 176         printk("ACCH[%08lx]:ACCL[%08lx]\n", \
 177           regs->acc0h, regs->acc0l);
 178 #else
 179 #error unknown isa configuration
 180 #endif
 181 }
 182
 183 /*
 184  * Create a kernel thread
 185  */
 186
 187 /*
 188  * This is the mechanism for creating a new kernel thread.
 189  *
 190  * NOTE! Only a kernel-only process(ie the swapper or direct descendants
 191  * who haven't done an "execve()") should use this: it will work within
 192  * a system call from a "real" process, but the process memory space will
 193  * not be free'd until both the parent and the child have exited.
 194  */
 195 static void kernel_thread_helper(void *nouse, int (*fn)(void *), void *arg)
 196 {
 197         fn(arg);
 198         do_exit(-1);
 199 }
 200
 201 int kernel_thread(int (*fn)(void *), void *arg, unsigned long flags)
 202 {
 203         struct pt_regs regs;
 204
 205         memset(&regs, 0, sizeof (regs));
 206         regs.r1 = (unsigned long)fn;
 207         regs.r2 = (unsigned long)arg;
 208
 209         regs.bpc = (unsigned long)kernel_thread_helper;
 210
 211         regs.psw = M32R_PSW_BIE;
 212
 213         /* Ok, create the new process. */
 214         return do_fork(flags | CLONE_VM | CLONE_UNTRACED, 0, &regs, 0, NULL,
 215                 NULL);
 216 }
 217
 218 /*
 219  * Free current thread data structures etc..
 220  */
 221 void exit_thread(void)
 222 {
 223         /* Nothing to do. */
 224         DPRINTK("pid = %d\n", current->pid);
 225 }
 226
 227 void flush_thread(void)
 228 {
 229         DPRINTK("pid = %d\n", current->pid);
 230         memset(&current->thread.debug_trap, 0, sizeof(struct debug_trap));
 231 }
 232
 233 void release_thread(struct task_struct *dead_task)
 234 {
 235         /* do nothing */
 236         DPRINTK("pid = %d\n", dead_task->pid);
 237 }
 238
 239 /* Fill in the fpu structure for a core dump.. */
 240 int dump_fpu(struct pt_regs *regs, elf_fpregset_t *fpu)
 241 {
 242         return 0; /* Task didn't use the fpu at all. */
 243 }
 244
 245 int copy_thread(int nr, unsigned long clone_flags, unsigned long spu,
 246         unsigned long unused, struct task_struct *tsk, struct pt_regs *regs)
 247 {
 248         struct pt_regs *childregs = task_pt_regs(tsk);
 249         extern void ret_from_fork(void);
 250
 251         /* Copy registers */
 252         *childregs = *regs;
 253
 254         childregs->spu = spu;
 255         childregs->r0 = 0;      /* Child gets zero as return value */
 256         regs->r0 = tsk->pid;
 257         tsk->thread.sp = (unsigned long)childregs;
 258         tsk->thread.lr = (unsigned long)ret_from_fork;
 259
 260         return 0;
 261 }
 262
 263 /*
 264  * Capture the user space registers if the task is not running (in user space)
 265  */
 266 int dump_task_regs(struct task_struct *tsk, elf_gregset_t *regs)
 267 {
 268         /* M32R_FIXME */
 269         return 1;
 270 }
 271
 272 asmlinkage int sys_fork(unsigned long r0, unsigned long r1, unsigned long r2,
 273         unsigned long r3, unsigned long r4, unsigned long r5, unsigned long r6,
 274         struct pt_regs regs)
 275 {
 276 #ifdef CONFIG_MMU
 277         return do_fork(SIGCHLD, regs.spu, &regs, 0, NULL, NULL);
 278 #else
 279         return -EINVAL;
 280 #endif /* CONFIG_MMU */
 281 }
 282
 283 asmlinkage int sys_clone(unsigned long clone_flags, unsigned long newsp,
 284                          unsigned long parent_tidptr,
 285                          unsigned long child_tidptr,
 286                          unsigned long r4, unsigned long r5, unsigned long r6,
 287                          struct pt_regs regs)
 288 {
 289         if (!newsp)
 290                 newsp = regs.spu;
 291
 292         return do_fork(clone_flags, newsp, &regs, 0,
 293                        (int __user *)parent_tidptr, (int __user *)child_tidptr);
 294 }
 295
 296 /*
 297  * This is trivial, and on the face of it looks like it
 298  * could equally well be done in user mode.
 299  *
 300  * Not so, for quite unobvious reasons - register pressure.
 301  * In user mode vfork() cannot have a stack frame, and if
 302  * done by calling the "clone()" system call directly, you
 303  * do not have enough call-clobbered registers to hold all
 304  * the information you need.
 305  */
 306 asmlinkage int sys_vfork(unsigned long r0, unsigned long r1, unsigned long r2,
 307         unsigned long r3, unsigned long r4, unsigned long r5, unsigned long r6,
 308         struct pt_regs regs)
 309 {
 310         return do_fork(CLONE_VFORK | CLONE_VM | SIGCHLD, regs.spu, &regs, 0,
 311                         NULL, NULL);
 312 }
 313
 314 /*
 315  * sys_execve() executes a new program.
 316  */
 317 asmlinkage int sys_execve(char __user *ufilename, char __user * __user *uargv,
 318                           char __user * __user *uenvp,
 319                           unsigned long r3, unsigned long r4, unsigned long r5,
 320                           unsigned long r6, struct pt_regs regs)
 321 {
 322         int error;
 323         char *filename;
 324
 325         filename = getname(ufilename);
 326         error = PTR_ERR(filename);
 327         if (IS_ERR(filename))
 328                 goto out;
 329
 330         error = do_execve(filename, uargv, uenvp, &regs);
 331         if (error == 0) {
 332                 task_lock(current);
 333                 current->ptrace &= ~PT_DTRACE;
 334                 task_unlock(current);
 335         }
 336         putname(filename);
 337 out:
 338         return error;
 339 }
 340
 341 /*
 342  * These bracket the sleeping functions..
 343  */
 344 #define first_sched     ((unsigned long) scheduling_functions_start_here)
 345 #define last_sched      ((unsigned long) scheduling_functions_end_here)
 346
 347 unsigned long get_wchan(struct task_struct *p)
 348 {
 349         /* M32R_FIXME */
 350         return (0);
 351 }