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