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