1 /* 2 * linux/arch/m68k/kernel/process.c 3 * 4 * Copyright (C) 1995 Hamish Macdonald 5 * 6 * 68060 fixes by Jesper Skov 7 */ 8 9 /* 10 * This file handles the architecture-dependent parts of process handling.. 11 */ 12 13 #include <linux/errno.h> 14 #include <linux/module.h> 15 #include <linux/sched.h> 16 #include <linux/kernel.h> 17 #include <linux/mm.h> 18 #include <linux/slab.h> 19 #include <linux/fs.h> 20 #include <linux/smp.h> 21 #include <linux/stddef.h> 22 #include <linux/unistd.h> 23 #include <linux/ptrace.h> 24 #include <linux/user.h> 25 #include <linux/reboot.h> 26 #include <linux/init_task.h> 27 #include <linux/mqueue.h> 28 29 #include <asm/uaccess.h> 30 #include <asm/system.h> 31 #include <asm/traps.h> 32 #include <asm/machdep.h> 33 #include <asm/setup.h> 34 #include <asm/pgtable.h> 35 36 37 asmlinkage void ret_from_fork(void); 38 39 40 /* 41 * Return saved PC from a blocked thread 42 */ 43 unsigned long thread_saved_pc(struct task_struct *tsk) 44 { 45 struct switch_stack *sw = (struct switch_stack *)tsk->thread.ksp; 46 /* Check whether the thread is blocked in resume() */ 47 if (in_sched_functions(sw->retpc)) 48 return ((unsigned long *)sw->a6)[1]; 49 else 50 return sw->retpc; 51 } 52 53 /* 54 * The idle loop on an m68k.. 55 */ 56 static void default_idle(void) 57 { 58 if (!need_resched()) 59 #if defined(MACH_ATARI_ONLY) 60 /* block out HSYNC on the atari (falcon) */ 61 __asm__("stop #0x2200" : : : "cc"); 62 #else 63 __asm__("stop #0x2000" : : : "cc"); 64 #endif 65 } 66 67 void (*idle)(void) = default_idle; 68 69 /* 70 * The idle thread. There's no useful work to be 71 * done, so just try to conserve power and have a 72 * low exit latency (ie sit in a loop waiting for 73 * somebody to say that they'd like to reschedule) 74 */ 75 void cpu_idle(void) 76 { 77 /* endless idle loop with no priority at all */ 78 while (1) { 79 while (!need_resched()) 80 idle(); 81 schedule_preempt_disabled(); 82 } 83 } 84 85 void machine_restart(char * __unused) 86 { 87 if (mach_reset) 88 mach_reset(); 89 for (;;); 90 } 91 92 void machine_halt(void) 93 { 94 if (mach_halt) 95 mach_halt(); 96 for (;;); 97 } 98 99 void machine_power_off(void) 100 { 101 if (mach_power_off) 102 mach_power_off(); 103 for (;;); 104 } 105 106 void (*pm_power_off)(void) = machine_power_off; 107 EXPORT_SYMBOL(pm_power_off); 108 109 void show_regs(struct pt_regs * regs) 110 { 111 printk("\n"); 112 printk("Format %02x Vector: %04x PC: %08lx Status: %04x %s\n", 113 regs->format, regs->vector, regs->pc, regs->sr, print_tainted()); 114 printk("ORIG_D0: %08lx D0: %08lx A2: %08lx A1: %08lx\n", 115 regs->orig_d0, regs->d0, regs->a2, regs->a1); 116 printk("A0: %08lx D5: %08lx D4: %08lx\n", 117 regs->a0, regs->d5, regs->d4); 118 printk("D3: %08lx D2: %08lx D1: %08lx\n", 119 regs->d3, regs->d2, regs->d1); 120 if (!(regs->sr & PS_S)) 121 printk("USP: %08lx\n", rdusp()); 122 } 123 124 /* 125 * Create a kernel thread 126 */ 127 int kernel_thread(int (*fn)(void *), void * arg, unsigned long flags) 128 { 129 int pid; 130 mm_segment_t fs; 131 132 fs = get_fs(); 133 set_fs (KERNEL_DS); 134 135 { 136 register long retval __asm__ ("d0"); 137 register long clone_arg __asm__ ("d1") = flags | CLONE_VM | CLONE_UNTRACED; 138 139 retval = __NR_clone; 140 __asm__ __volatile__ 141 ("clrl %%d2\n\t" 142 "trap #0\n\t" /* Linux/m68k system call */ 143 "tstl %0\n\t" /* child or parent */ 144 "jne 1f\n\t" /* parent - jump */ 145 #ifdef CONFIG_MMU 146 "lea %%sp@(%c7),%6\n\t" /* reload current */ 147 "movel %6@,%6\n\t" 148 #endif 149 "movel %3,%%sp@-\n\t" /* push argument */ 150 "jsr %4@\n\t" /* call fn */ 151 "movel %0,%%d1\n\t" /* pass exit value */ 152 "movel %2,%%d0\n\t" /* exit */ 153 "trap #0\n" 154 "1:" 155 : "+d" (retval) 156 : "i" (__NR_clone), "i" (__NR_exit), 157 "r" (arg), "a" (fn), "d" (clone_arg), "r" (current), 158 "i" (-THREAD_SIZE) 159 : "d2"); 160 161 pid = retval; 162 } 163 164 set_fs (fs); 165 return pid; 166 } 167 EXPORT_SYMBOL(kernel_thread); 168 169 void flush_thread(void) 170 { 171 current->thread.fs = __USER_DS; 172 #ifdef CONFIG_FPU 173 if (!FPU_IS_EMU) { 174 unsigned long zero = 0; 175 asm volatile("frestore %0": :"m" (zero)); 176 } 177 #endif 178 } 179 180 /* 181 * "m68k_fork()".. By the time we get here, the 182 * non-volatile registers have also been saved on the 183 * stack. We do some ugly pointer stuff here.. (see 184 * also copy_thread) 185 */ 186 187 asmlinkage int m68k_fork(struct pt_regs *regs) 188 { 189 #ifdef CONFIG_MMU 190 return do_fork(SIGCHLD, rdusp(), regs, 0, NULL, NULL); 191 #else 192 return -EINVAL; 193 #endif 194 } 195 196 asmlinkage int m68k_vfork(struct pt_regs *regs) 197 { 198 return do_fork(CLONE_VFORK | CLONE_VM | SIGCHLD, rdusp(), regs, 0, 199 NULL, NULL); 200 } 201 202 asmlinkage int m68k_clone(struct pt_regs *regs) 203 { 204 unsigned long clone_flags; 205 unsigned long newsp; 206 int __user *parent_tidptr, *child_tidptr; 207 208 /* syscall2 puts clone_flags in d1 and usp in d2 */ 209 clone_flags = regs->d1; 210 newsp = regs->d2; 211 parent_tidptr = (int __user *)regs->d3; 212 child_tidptr = (int __user *)regs->d4; 213 if (!newsp) 214 newsp = rdusp(); 215 return do_fork(clone_flags, newsp, regs, 0, 216 parent_tidptr, child_tidptr); 217 } 218 219 int copy_thread(unsigned long clone_flags, unsigned long usp, 220 unsigned long unused, 221 struct task_struct * p, struct pt_regs * regs) 222 { 223 struct pt_regs * childregs; 224 struct switch_stack * childstack, *stack; 225 unsigned long *retp; 226 227 childregs = (struct pt_regs *) (task_stack_page(p) + THREAD_SIZE) - 1; 228 229 *childregs = *regs; 230 childregs->d0 = 0; 231 232 retp = ((unsigned long *) regs); 233 stack = ((struct switch_stack *) retp) - 1; 234 235 childstack = ((struct switch_stack *) childregs) - 1; 236 *childstack = *stack; 237 childstack->retpc = (unsigned long)ret_from_fork; 238 239 p->thread.usp = usp; 240 p->thread.ksp = (unsigned long)childstack; 241 242 if (clone_flags & CLONE_SETTLS) 243 task_thread_info(p)->tp_value = regs->d5; 244 245 /* 246 * Must save the current SFC/DFC value, NOT the value when 247 * the parent was last descheduled - RGH 10-08-96 248 */ 249 p->thread.fs = get_fs().seg; 250 251 #ifdef CONFIG_FPU 252 if (!FPU_IS_EMU) { 253 /* Copy the current fpu state */ 254 asm volatile ("fsave %0" : : "m" (p->thread.fpstate[0]) : "memory"); 255 256 if (!CPU_IS_060 ? p->thread.fpstate[0] : p->thread.fpstate[2]) { 257 if (CPU_IS_COLDFIRE) { 258 asm volatile ("fmovemd %/fp0-%/fp7,%0\n\t" 259 "fmovel %/fpiar,%1\n\t" 260 "fmovel %/fpcr,%2\n\t" 261 "fmovel %/fpsr,%3" 262 : 263 : "m" (p->thread.fp[0]), 264 "m" (p->thread.fpcntl[0]), 265 "m" (p->thread.fpcntl[1]), 266 "m" (p->thread.fpcntl[2]) 267 : "memory"); 268 } else { 269 asm volatile ("fmovemx %/fp0-%/fp7,%0\n\t" 270 "fmoveml %/fpiar/%/fpcr/%/fpsr,%1" 271 : 272 : "m" (p->thread.fp[0]), 273 "m" (p->thread.fpcntl[0]) 274 : "memory"); 275 } 276 } 277 278 /* Restore the state in case the fpu was busy */ 279 asm volatile ("frestore %0" : : "m" (p->thread.fpstate[0])); 280 } 281 #endif /* CONFIG_FPU */ 282 283 return 0; 284 } 285 286 /* Fill in the fpu structure for a core dump. */ 287 #ifdef CONFIG_FPU 288 int dump_fpu (struct pt_regs *regs, struct user_m68kfp_struct *fpu) 289 { 290 char fpustate[216]; 291 292 if (FPU_IS_EMU) { 293 int i; 294 295 memcpy(fpu->fpcntl, current->thread.fpcntl, 12); 296 memcpy(fpu->fpregs, current->thread.fp, 96); 297 /* Convert internal fpu reg representation 298 * into long double format 299 */ 300 for (i = 0; i < 24; i += 3) 301 fpu->fpregs[i] = ((fpu->fpregs[i] & 0xffff0000) << 15) | 302 ((fpu->fpregs[i] & 0x0000ffff) << 16); 303 return 1; 304 } 305 306 /* First dump the fpu context to avoid protocol violation. */ 307 asm volatile ("fsave %0" :: "m" (fpustate[0]) : "memory"); 308 if (!CPU_IS_060 ? !fpustate[0] : !fpustate[2]) 309 return 0; 310 311 if (CPU_IS_COLDFIRE) { 312 asm volatile ("fmovel %/fpiar,%0\n\t" 313 "fmovel %/fpcr,%1\n\t" 314 "fmovel %/fpsr,%2\n\t" 315 "fmovemd %/fp0-%/fp7,%3" 316 : 317 : "m" (fpu->fpcntl[0]), 318 "m" (fpu->fpcntl[1]), 319 "m" (fpu->fpcntl[2]), 320 "m" (fpu->fpregs[0]) 321 : "memory"); 322 } else { 323 asm volatile ("fmovem %/fpiar/%/fpcr/%/fpsr,%0" 324 : 325 : "m" (fpu->fpcntl[0]) 326 : "memory"); 327 asm volatile ("fmovemx %/fp0-%/fp7,%0" 328 : 329 : "m" (fpu->fpregs[0]) 330 : "memory"); 331 } 332 333 return 1; 334 } 335 EXPORT_SYMBOL(dump_fpu); 336 #endif /* CONFIG_FPU */ 337 338 /* 339 * sys_execve() executes a new program. 340 */ 341 asmlinkage int sys_execve(const char __user *name, 342 const char __user *const __user *argv, 343 const char __user *const __user *envp) 344 { 345 int error; 346 char * filename; 347 struct pt_regs *regs = (struct pt_regs *) &name; 348 349 filename = getname(name); 350 error = PTR_ERR(filename); 351 if (IS_ERR(filename)) 352 return error; 353 error = do_execve(filename, argv, envp, regs); 354 putname(filename); 355 return error; 356 } 357 358 unsigned long get_wchan(struct task_struct *p) 359 { 360 unsigned long fp, pc; 361 unsigned long stack_page; 362 int count = 0; 363 if (!p || p == current || p->state == TASK_RUNNING) 364 return 0; 365 366 stack_page = (unsigned long)task_stack_page(p); 367 fp = ((struct switch_stack *)p->thread.ksp)->a6; 368 do { 369 if (fp < stack_page+sizeof(struct thread_info) || 370 fp >= 8184+stack_page) 371 return 0; 372 pc = ((unsigned long *)fp)[1]; 373 if (!in_sched_functions(pc)) 374 return pc; 375 fp = *(unsigned long *) fp; 376 } while (count++ < 16); 377 return 0; 378 } 379