1/* 2 * linux/arch/h8300/kernel/process.c 3 * 4 * Yoshinori Sato <ysato@users.sourceforge.jp> 5 * 6 * Based on: 7 * 8 * linux/arch/m68knommu/kernel/process.c 9 * 10 * Copyright (C) 1998 D. Jeff Dionne <jeff@ryeham.ee.ryerson.ca>, 11 * Kenneth Albanowski <kjahds@kjahds.com>, 12 * The Silver Hammer Group, Ltd. 13 * 14 * linux/arch/m68k/kernel/process.c 15 * 16 * Copyright (C) 1995 Hamish Macdonald 17 * 18 * 68060 fixes by Jesper Skov 19 */ 20 21/* 22 * This file handles the architecture-dependent parts of process handling.. 23 */ 24 25#include <linux/errno.h> 26#include <linux/module.h> 27#include <linux/sched.h> 28#include <linux/kernel.h> 29#include <linux/mm.h> 30#include <linux/smp.h> 31#include <linux/smp_lock.h> 32#include <linux/stddef.h> 33#include <linux/unistd.h> 34#include <linux/ptrace.h> 35#include <linux/slab.h> 36#include <linux/user.h> 37#include <linux/a.out.h> 38#include <linux/interrupt.h> 39#include <linux/reboot.h> 40 41#include <asm/uaccess.h> 42#include <asm/system.h> 43#include <asm/traps.h> 44#include <asm/setup.h> 45#include <asm/pgtable.h> 46 47void (*pm_power_off)(void) = NULL; 48EXPORT_SYMBOL(pm_power_off); 49 50asmlinkage void ret_from_fork(void); 51 52/* 53 * The idle loop on an H8/300.. 54 */ 55#if !defined(CONFIG_H8300H_SIM) && !defined(CONFIG_H8S_SIM) 56static void default_idle(void) 57{ 58 local_irq_disable(); 59 if (!need_resched()) { 60 local_irq_enable(); 61 __asm__("sleep"); 62 } else 63 local_irq_enable(); 64} 65#else 66static void default_idle(void) 67{ 68 cpu_relax(); 69} 70#endif 71void (*idle)(void) = default_idle; 72 73/* 74 * The idle thread. There's no useful work to be 75 * done, so just try to conserve power and have a 76 * low exit latency (ie sit in a loop waiting for 77 * somebody to say that they'd like to reschedule) 78 */ 79void cpu_idle(void) 80{ 81 while (1) { 82 while (!need_resched()) 83 idle(); 84 preempt_enable_no_resched(); 85 schedule(); 86 preempt_disable(); 87 } 88} 89 90void machine_restart(char * __unused) 91{ 92 local_irq_disable(); 93 __asm__("jmp @@0"); 94} 95 96void machine_halt(void) 97{ 98 local_irq_disable(); 99 __asm__("sleep"); 100 for (;;); 101} 102 103void machine_power_off(void) 104{ 105 local_irq_disable(); 106 __asm__("sleep"); 107 for (;;); 108} 109 110void show_regs(struct pt_regs * regs) 111{ 112 printk("\nPC: %08lx Status: %02x", 113 regs->pc, regs->ccr); 114 printk("\nORIG_ER0: %08lx ER0: %08lx ER1: %08lx", 115 regs->orig_er0, regs->er0, regs->er1); 116 printk("\nER2: %08lx ER3: %08lx ER4: %08lx ER5: %08lx", 117 regs->er2, regs->er3, regs->er4, regs->er5); 118 printk("\nER6' %08lx ",regs->er6); 119 if (user_mode(regs)) 120 printk("USP: %08lx\n", rdusp()); 121 else 122 printk("\n"); 123} 124 125/* 126 * Create a kernel thread 127 */ 128int kernel_thread(int (*fn)(void *), void * arg, unsigned long flags) 129{ 130 long retval; 131 long clone_arg; 132 mm_segment_t fs; 133 134 fs = get_fs(); 135 set_fs (KERNEL_DS); 136 clone_arg = flags | CLONE_VM; 137 __asm__("mov.l sp,er3\n\t" 138 "sub.l er2,er2\n\t" 139 "mov.l %2,er1\n\t" 140 "mov.l %1,er0\n\t" 141 "trapa #0\n\t" 142 "cmp.l sp,er3\n\t" 143 "beq 1f\n\t" 144 "mov.l %4,er0\n\t" 145 "mov.l %3,er1\n\t" 146 "jsr @er1\n\t" 147 "mov.l %5,er0\n\t" 148 "trapa #0\n" 149 "1:\n\t" 150 "mov.l er0,%0" 151 :"=r"(retval) 152 :"i"(__NR_clone),"g"(clone_arg),"g"(fn),"g"(arg),"i"(__NR_exit) 153 :"er0","er1","er2","er3"); 154 set_fs (fs); 155 return retval; 156} 157 158void flush_thread(void) 159{ 160} 161 162/* 163 * "h8300_fork()".. By the time we get here, the 164 * non-volatile registers have also been saved on the 165 * stack. We do some ugly pointer stuff here.. (see 166 * also copy_thread) 167 */ 168 169asmlinkage int h8300_fork(struct pt_regs *regs) 170{ 171 return -EINVAL; 172} 173 174asmlinkage int h8300_vfork(struct pt_regs *regs) 175{ 176 return do_fork(CLONE_VFORK | CLONE_VM | SIGCHLD, rdusp(), regs, 0, NULL, NULL); 177} 178 179asmlinkage int h8300_clone(struct pt_regs *regs) 180{ 181 unsigned long clone_flags; 182 unsigned long newsp; 183 184 /* syscall2 puts clone_flags in er1 and usp in er2 */ 185 clone_flags = regs->er1; 186 newsp = regs->er2; 187 if (!newsp) 188 newsp = rdusp(); 189 return do_fork(clone_flags, newsp, regs, 0, NULL, NULL); 190 191} 192 193int copy_thread(int nr, unsigned long clone_flags, 194 unsigned long usp, unsigned long topstk, 195 struct task_struct * p, struct pt_regs * regs) 196{ 197 struct pt_regs * childregs; 198 199 childregs = (struct pt_regs *) (THREAD_SIZE + task_stack_page(p)) - 1; 200 201 *childregs = *regs; 202 childregs->retpc = (unsigned long) ret_from_fork; 203 childregs->er0 = 0; 204 205 p->thread.usp = usp; 206 p->thread.ksp = (unsigned long)childregs; 207 208 return 0; 209} 210 211/* 212 * sys_execve() executes a new program. 213 */ 214asmlinkage int sys_execve(char *name, char **argv, char **envp,int dummy,...) 215{ 216 int error; 217 char * filename; 218 struct pt_regs *regs = (struct pt_regs *) ((unsigned char *)&dummy-4); 219 220 lock_kernel(); 221 filename = getname(name); 222 error = PTR_ERR(filename); 223 if (IS_ERR(filename)) 224 goto out; 225 error = do_execve(filename, argv, envp, regs); 226 putname(filename); 227out: 228 unlock_kernel(); 229 return error; 230} 231 232unsigned long thread_saved_pc(struct task_struct *tsk) 233{ 234 return ((struct pt_regs *)tsk->thread.esp0)->pc; 235} 236 237unsigned long get_wchan(struct task_struct *p) 238{ 239 unsigned long fp, pc; 240 unsigned long stack_page; 241 int count = 0; 242 if (!p || p == current || p->state == TASK_RUNNING) 243 return 0; 244 245 stack_page = (unsigned long)p; 246 fp = ((struct pt_regs *)p->thread.ksp)->er6; 247 do { 248 if (fp < stack_page+sizeof(struct thread_info) || 249 fp >= 8184+stack_page) 250 return 0; 251 pc = ((unsigned long *)fp)[1]; 252 if (!in_sched_functions(pc)) 253 return pc; 254 fp = *(unsigned long *) fp; 255 } while (count++ < 16); 256 return 0; 257} 258