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 #include <linux/rcupdate.h> 29 30 #include <asm/uaccess.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 rcu_idle_enter(); 80 while (!need_resched()) 81 idle(); 82 rcu_idle_exit(); 83 schedule_preempt_disabled(); 84 } 85 } 86 87 void machine_restart(char * __unused) 88 { 89 if (mach_reset) 90 mach_reset(); 91 for (;;); 92 } 93 94 void machine_halt(void) 95 { 96 if (mach_halt) 97 mach_halt(); 98 for (;;); 99 } 100 101 void machine_power_off(void) 102 { 103 if (mach_power_off) 104 mach_power_off(); 105 for (;;); 106 } 107 108 void (*pm_power_off)(void) = machine_power_off; 109 EXPORT_SYMBOL(pm_power_off); 110 111 void show_regs(struct pt_regs * regs) 112 { 113 printk("\n"); 114 printk("Format %02x Vector: %04x PC: %08lx Status: %04x %s\n", 115 regs->format, regs->vector, regs->pc, regs->sr, print_tainted()); 116 printk("ORIG_D0: %08lx D0: %08lx A2: %08lx A1: %08lx\n", 117 regs->orig_d0, regs->d0, regs->a2, regs->a1); 118 printk("A0: %08lx D5: %08lx D4: %08lx\n", 119 regs->a0, regs->d5, regs->d4); 120 printk("D3: %08lx D2: %08lx D1: %08lx\n", 121 regs->d3, regs->d2, regs->d1); 122 if (!(regs->sr & PS_S)) 123 printk("USP: %08lx\n", rdusp()); 124 } 125 126 /* 127 * Create a kernel thread 128 */ 129 int kernel_thread(int (*fn)(void *), void * arg, unsigned long flags) 130 { 131 int pid; 132 mm_segment_t fs; 133 134 fs = get_fs(); 135 set_fs (KERNEL_DS); 136 137 { 138 register long retval __asm__ ("d0"); 139 register long clone_arg __asm__ ("d1") = flags | CLONE_VM | CLONE_UNTRACED; 140 141 retval = __NR_clone; 142 __asm__ __volatile__ 143 ("clrl %%d2\n\t" 144 "trap #0\n\t" /* Linux/m68k system call */ 145 "tstl %0\n\t" /* child or parent */ 146 "jne 1f\n\t" /* parent - jump */ 147 #ifdef CONFIG_MMU 148 "lea %%sp@(%c7),%6\n\t" /* reload current */ 149 "movel %6@,%6\n\t" 150 #endif 151 "movel %3,%%sp@-\n\t" /* push argument */ 152 "jsr %4@\n\t" /* call fn */ 153 "movel %0,%%d1\n\t" /* pass exit value */ 154 "movel %2,%%d0\n\t" /* exit */ 155 "trap #0\n" 156 "1:" 157 : "+d" (retval) 158 : "i" (__NR_clone), "i" (__NR_exit), 159 "r" (arg), "a" (fn), "d" (clone_arg), "r" (current), 160 "i" (-THREAD_SIZE) 161 : "d2"); 162 163 pid = retval; 164 } 165 166 set_fs (fs); 167 return pid; 168 } 169 EXPORT_SYMBOL(kernel_thread); 170 171 void flush_thread(void) 172 { 173 current->thread.fs = __USER_DS; 174 #ifdef CONFIG_FPU 175 if (!FPU_IS_EMU) { 176 unsigned long zero = 0; 177 asm volatile("frestore %0": :"m" (zero)); 178 } 179 #endif 180 } 181 182 /* 183 * "m68k_fork()".. By the time we get here, the 184 * non-volatile registers have also been saved on the 185 * stack. We do some ugly pointer stuff here.. (see 186 * also copy_thread) 187 */ 188 189 asmlinkage int m68k_fork(struct pt_regs *regs) 190 { 191 #ifdef CONFIG_MMU 192 return do_fork(SIGCHLD, rdusp(), regs, 0, NULL, NULL); 193 #else 194 return -EINVAL; 195 #endif 196 } 197 198 asmlinkage int m68k_vfork(struct pt_regs *regs) 199 { 200 return do_fork(CLONE_VFORK | CLONE_VM | SIGCHLD, rdusp(), regs, 0, 201 NULL, NULL); 202 } 203 204 asmlinkage int m68k_clone(struct pt_regs *regs) 205 { 206 unsigned long clone_flags; 207 unsigned long newsp; 208 int __user *parent_tidptr, *child_tidptr; 209 210 /* syscall2 puts clone_flags in d1 and usp in d2 */ 211 clone_flags = regs->d1; 212 newsp = regs->d2; 213 parent_tidptr = (int __user *)regs->d3; 214 child_tidptr = (int __user *)regs->d4; 215 if (!newsp) 216 newsp = rdusp(); 217 return do_fork(clone_flags, newsp, regs, 0, 218 parent_tidptr, child_tidptr); 219 } 220 221 int copy_thread(unsigned long clone_flags, unsigned long usp, 222 unsigned long unused, 223 struct task_struct * p, struct pt_regs * regs) 224 { 225 struct pt_regs * childregs; 226 struct switch_stack * childstack, *stack; 227 unsigned long *retp; 228 229 childregs = (struct pt_regs *) (task_stack_page(p) + THREAD_SIZE) - 1; 230 231 *childregs = *regs; 232 childregs->d0 = 0; 233 234 retp = ((unsigned long *) regs); 235 stack = ((struct switch_stack *) retp) - 1; 236 237 childstack = ((struct switch_stack *) childregs) - 1; 238 *childstack = *stack; 239 childstack->retpc = (unsigned long)ret_from_fork; 240 241 p->thread.usp = usp; 242 p->thread.ksp = (unsigned long)childstack; 243 244 if (clone_flags & CLONE_SETTLS) 245 task_thread_info(p)->tp_value = regs->d5; 246 247 /* 248 * Must save the current SFC/DFC value, NOT the value when 249 * the parent was last descheduled - RGH 10-08-96 250 */ 251 p->thread.fs = get_fs().seg; 252 253 #ifdef CONFIG_FPU 254 if (!FPU_IS_EMU) { 255 /* Copy the current fpu state */ 256 asm volatile ("fsave %0" : : "m" (p->thread.fpstate[0]) : "memory"); 257 258 if (!CPU_IS_060 ? p->thread.fpstate[0] : p->thread.fpstate[2]) { 259 if (CPU_IS_COLDFIRE) { 260 asm volatile ("fmovemd %/fp0-%/fp7,%0\n\t" 261 "fmovel %/fpiar,%1\n\t" 262 "fmovel %/fpcr,%2\n\t" 263 "fmovel %/fpsr,%3" 264 : 265 : "m" (p->thread.fp[0]), 266 "m" (p->thread.fpcntl[0]), 267 "m" (p->thread.fpcntl[1]), 268 "m" (p->thread.fpcntl[2]) 269 : "memory"); 270 } else { 271 asm volatile ("fmovemx %/fp0-%/fp7,%0\n\t" 272 "fmoveml %/fpiar/%/fpcr/%/fpsr,%1" 273 : 274 : "m" (p->thread.fp[0]), 275 "m" (p->thread.fpcntl[0]) 276 : "memory"); 277 } 278 } 279 280 /* Restore the state in case the fpu was busy */ 281 asm volatile ("frestore %0" : : "m" (p->thread.fpstate[0])); 282 } 283 #endif /* CONFIG_FPU */ 284 285 return 0; 286 } 287 288 /* Fill in the fpu structure for a core dump. */ 289 #ifdef CONFIG_FPU 290 int dump_fpu (struct pt_regs *regs, struct user_m68kfp_struct *fpu) 291 { 292 char fpustate[216]; 293 294 if (FPU_IS_EMU) { 295 int i; 296 297 memcpy(fpu->fpcntl, current->thread.fpcntl, 12); 298 memcpy(fpu->fpregs, current->thread.fp, 96); 299 /* Convert internal fpu reg representation 300 * into long double format 301 */ 302 for (i = 0; i < 24; i += 3) 303 fpu->fpregs[i] = ((fpu->fpregs[i] & 0xffff0000) << 15) | 304 ((fpu->fpregs[i] & 0x0000ffff) << 16); 305 return 1; 306 } 307 308 /* First dump the fpu context to avoid protocol violation. */ 309 asm volatile ("fsave %0" :: "m" (fpustate[0]) : "memory"); 310 if (!CPU_IS_060 ? !fpustate[0] : !fpustate[2]) 311 return 0; 312 313 if (CPU_IS_COLDFIRE) { 314 asm volatile ("fmovel %/fpiar,%0\n\t" 315 "fmovel %/fpcr,%1\n\t" 316 "fmovel %/fpsr,%2\n\t" 317 "fmovemd %/fp0-%/fp7,%3" 318 : 319 : "m" (fpu->fpcntl[0]), 320 "m" (fpu->fpcntl[1]), 321 "m" (fpu->fpcntl[2]), 322 "m" (fpu->fpregs[0]) 323 : "memory"); 324 } else { 325 asm volatile ("fmovem %/fpiar/%/fpcr/%/fpsr,%0" 326 : 327 : "m" (fpu->fpcntl[0]) 328 : "memory"); 329 asm volatile ("fmovemx %/fp0-%/fp7,%0" 330 : 331 : "m" (fpu->fpregs[0]) 332 : "memory"); 333 } 334 335 return 1; 336 } 337 EXPORT_SYMBOL(dump_fpu); 338 #endif /* CONFIG_FPU */ 339 340 /* 341 * sys_execve() executes a new program. 342 */ 343 asmlinkage int sys_execve(const char __user *name, 344 const char __user *const __user *argv, 345 const char __user *const __user *envp) 346 { 347 int error; 348 char * filename; 349 struct pt_regs *regs = (struct pt_regs *) &name; 350 351 filename = getname(name); 352 error = PTR_ERR(filename); 353 if (IS_ERR(filename)) 354 return error; 355 error = do_execve(filename, argv, envp, regs); 356 putname(filename); 357 return error; 358 } 359 360 unsigned long get_wchan(struct task_struct *p) 361 { 362 unsigned long fp, pc; 363 unsigned long stack_page; 364 int count = 0; 365 if (!p || p == current || p->state == TASK_RUNNING) 366 return 0; 367 368 stack_page = (unsigned long)task_stack_page(p); 369 fp = ((struct switch_stack *)p->thread.ksp)->a6; 370 do { 371 if (fp < stack_page+sizeof(struct thread_info) || 372 fp >= 8184+stack_page) 373 return 0; 374 pc = ((unsigned long *)fp)[1]; 375 if (!in_sched_functions(pc)) 376 return pc; 377 fp = *(unsigned long *) fp; 378 } while (count++ < 16); 379 return 0; 380 } 381