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/config.h> 14 #include <linux/errno.h> 15 #include <linux/module.h> 16 #include <linux/sched.h> 17 #include <linux/kernel.h> 18 #include <linux/mm.h> 19 #include <linux/smp.h> 20 #include <linux/smp_lock.h> 21 #include <linux/stddef.h> 22 #include <linux/unistd.h> 23 #include <linux/ptrace.h> 24 #include <linux/slab.h> 25 #include <linux/user.h> 26 #include <linux/a.out.h> 27 #include <linux/reboot.h> 28 #include <linux/init_task.h> 29 #include <linux/mqueue.h> 30 31 #include <asm/uaccess.h> 32 #include <asm/system.h> 33 #include <asm/traps.h> 34 #include <asm/machdep.h> 35 #include <asm/setup.h> 36 #include <asm/pgtable.h> 37 38 /* 39 * Initial task/thread structure. Make this a per-architecture thing, 40 * because different architectures tend to have different 41 * alignment requirements and potentially different initial 42 * setup. 43 */ 44 static struct fs_struct init_fs = INIT_FS; 45 static struct files_struct init_files = INIT_FILES; 46 static struct signal_struct init_signals = INIT_SIGNALS(init_signals); 47 static struct sighand_struct init_sighand = INIT_SIGHAND(init_sighand); 48 struct mm_struct init_mm = INIT_MM(init_mm); 49 50 EXPORT_SYMBOL(init_mm); 51 52 union thread_union init_thread_union 53 __attribute__((section(".data.init_task"), aligned(THREAD_SIZE))) 54 = { INIT_THREAD_INFO(init_task) }; 55 56 /* initial task structure */ 57 struct task_struct init_task = INIT_TASK(init_task); 58 59 EXPORT_SYMBOL(init_task); 60 61 asmlinkage void ret_from_fork(void); 62 63 64 /* 65 * Return saved PC from a blocked thread 66 */ 67 unsigned long thread_saved_pc(struct task_struct *tsk) 68 { 69 struct switch_stack *sw = (struct switch_stack *)tsk->thread.ksp; 70 /* Check whether the thread is blocked in resume() */ 71 if (in_sched_functions(sw->retpc)) 72 return ((unsigned long *)sw->a6)[1]; 73 else 74 return sw->retpc; 75 } 76 77 /* 78 * The idle loop on an m68k.. 79 */ 80 void default_idle(void) 81 { 82 if (!need_resched()) 83 #if defined(MACH_ATARI_ONLY) && !defined(CONFIG_HADES) 84 /* block out HSYNC on the atari (falcon) */ 85 __asm__("stop #0x2200" : : : "cc"); 86 #else 87 __asm__("stop #0x2000" : : : "cc"); 88 #endif 89 } 90 91 void (*idle)(void) = default_idle; 92 93 /* 94 * The idle thread. There's no useful work to be 95 * done, so just try to conserve power and have a 96 * low exit latency (ie sit in a loop waiting for 97 * somebody to say that they'd like to reschedule) 98 */ 99 void cpu_idle(void) 100 { 101 /* endless idle loop with no priority at all */ 102 while (1) { 103 while (!need_resched()) 104 idle(); 105 schedule(); 106 } 107 } 108 109 void machine_restart(char * __unused) 110 { 111 if (mach_reset) 112 mach_reset(); 113 for (;;); 114 } 115 116 EXPORT_SYMBOL(machine_restart); 117 118 void machine_halt(void) 119 { 120 if (mach_halt) 121 mach_halt(); 122 for (;;); 123 } 124 125 EXPORT_SYMBOL(machine_halt); 126 127 void machine_power_off(void) 128 { 129 if (mach_power_off) 130 mach_power_off(); 131 for (;;); 132 } 133 134 EXPORT_SYMBOL(machine_power_off); 135 136 void show_regs(struct pt_regs * regs) 137 { 138 printk("\n"); 139 printk("Format %02x Vector: %04x PC: %08lx Status: %04x %s\n", 140 regs->format, regs->vector, regs->pc, regs->sr, print_tainted()); 141 printk("ORIG_D0: %08lx D0: %08lx A2: %08lx A1: %08lx\n", 142 regs->orig_d0, regs->d0, regs->a2, regs->a1); 143 printk("A0: %08lx D5: %08lx D4: %08lx\n", 144 regs->a0, regs->d5, regs->d4); 145 printk("D3: %08lx D2: %08lx D1: %08lx\n", 146 regs->d3, regs->d2, regs->d1); 147 if (!(regs->sr & PS_S)) 148 printk("USP: %08lx\n", rdusp()); 149 } 150 151 /* 152 * Create a kernel thread 153 */ 154 int kernel_thread(int (*fn)(void *), void * arg, unsigned long flags) 155 { 156 int pid; 157 mm_segment_t fs; 158 159 fs = get_fs(); 160 set_fs (KERNEL_DS); 161 162 { 163 register long retval __asm__ ("d0"); 164 register long clone_arg __asm__ ("d1") = flags | CLONE_VM | CLONE_UNTRACED; 165 166 retval = __NR_clone; 167 __asm__ __volatile__ 168 ("clrl %%d2\n\t" 169 "trap #0\n\t" /* Linux/m68k system call */ 170 "tstl %0\n\t" /* child or parent */ 171 "jne 1f\n\t" /* parent - jump */ 172 "lea %%sp@(%c7),%6\n\t" /* reload current */ 173 "movel %6@,%6\n\t" 174 "movel %3,%%sp@-\n\t" /* push argument */ 175 "jsr %4@\n\t" /* call fn */ 176 "movel %0,%%d1\n\t" /* pass exit value */ 177 "movel %2,%%d0\n\t" /* exit */ 178 "trap #0\n" 179 "1:" 180 : "+d" (retval) 181 : "i" (__NR_clone), "i" (__NR_exit), 182 "r" (arg), "a" (fn), "d" (clone_arg), "r" (current), 183 "i" (-THREAD_SIZE) 184 : "d2"); 185 186 pid = retval; 187 } 188 189 set_fs (fs); 190 return pid; 191 } 192 193 void flush_thread(void) 194 { 195 unsigned long zero = 0; 196 set_fs(USER_DS); 197 current->thread.fs = __USER_DS; 198 if (!FPU_IS_EMU) 199 asm volatile (".chip 68k/68881\n\t" 200 "frestore %0@\n\t" 201 ".chip 68k" : : "a" (&zero)); 202 } 203 204 /* 205 * "m68k_fork()".. By the time we get here, the 206 * non-volatile registers have also been saved on the 207 * stack. We do some ugly pointer stuff here.. (see 208 * also copy_thread) 209 */ 210 211 asmlinkage int m68k_fork(struct pt_regs *regs) 212 { 213 return do_fork(SIGCHLD, rdusp(), regs, 0, NULL, NULL); 214 } 215 216 asmlinkage int m68k_vfork(struct pt_regs *regs) 217 { 218 return do_fork(CLONE_VFORK | CLONE_VM | SIGCHLD, rdusp(), regs, 0, 219 NULL, NULL); 220 } 221 222 asmlinkage int m68k_clone(struct pt_regs *regs) 223 { 224 unsigned long clone_flags; 225 unsigned long newsp; 226 int *parent_tidptr, *child_tidptr; 227 228 /* syscall2 puts clone_flags in d1 and usp in d2 */ 229 clone_flags = regs->d1; 230 newsp = regs->d2; 231 parent_tidptr = (int *)regs->d3; 232 child_tidptr = (int *)regs->d4; 233 if (!newsp) 234 newsp = rdusp(); 235 return do_fork(clone_flags, newsp, regs, 0, 236 parent_tidptr, child_tidptr); 237 } 238 239 int copy_thread(int nr, unsigned long clone_flags, unsigned long usp, 240 unsigned long unused, 241 struct task_struct * p, struct pt_regs * regs) 242 { 243 struct pt_regs * childregs; 244 struct switch_stack * childstack, *stack; 245 unsigned long stack_offset, *retp; 246 247 stack_offset = THREAD_SIZE - sizeof(struct pt_regs); 248 childregs = (struct pt_regs *) ((unsigned long) (p->thread_info) + stack_offset); 249 250 *childregs = *regs; 251 childregs->d0 = 0; 252 253 retp = ((unsigned long *) regs); 254 stack = ((struct switch_stack *) retp) - 1; 255 256 childstack = ((struct switch_stack *) childregs) - 1; 257 *childstack = *stack; 258 childstack->retpc = (unsigned long)ret_from_fork; 259 260 p->thread.usp = usp; 261 p->thread.ksp = (unsigned long)childstack; 262 /* 263 * Must save the current SFC/DFC value, NOT the value when 264 * the parent was last descheduled - RGH 10-08-96 265 */ 266 p->thread.fs = get_fs().seg; 267 268 if (!FPU_IS_EMU) { 269 /* Copy the current fpu state */ 270 asm volatile ("fsave %0" : : "m" (p->thread.fpstate[0]) : "memory"); 271 272 if (!CPU_IS_060 ? p->thread.fpstate[0] : p->thread.fpstate[2]) 273 asm volatile ("fmovemx %/fp0-%/fp7,%0\n\t" 274 "fmoveml %/fpiar/%/fpcr/%/fpsr,%1" 275 : : "m" (p->thread.fp[0]), "m" (p->thread.fpcntl[0]) 276 : "memory"); 277 /* Restore the state in case the fpu was busy */ 278 asm volatile ("frestore %0" : : "m" (p->thread.fpstate[0])); 279 } 280 281 return 0; 282 } 283 284 /* Fill in the fpu structure for a core dump. */ 285 286 int dump_fpu (struct pt_regs *regs, struct user_m68kfp_struct *fpu) 287 { 288 char fpustate[216]; 289 290 if (FPU_IS_EMU) { 291 int i; 292 293 memcpy(fpu->fpcntl, current->thread.fpcntl, 12); 294 memcpy(fpu->fpregs, current->thread.fp, 96); 295 /* Convert internal fpu reg representation 296 * into long double format 297 */ 298 for (i = 0; i < 24; i += 3) 299 fpu->fpregs[i] = ((fpu->fpregs[i] & 0xffff0000) << 15) | 300 ((fpu->fpregs[i] & 0x0000ffff) << 16); 301 return 1; 302 } 303 304 /* First dump the fpu context to avoid protocol violation. */ 305 asm volatile ("fsave %0" :: "m" (fpustate[0]) : "memory"); 306 if (!CPU_IS_060 ? !fpustate[0] : !fpustate[2]) 307 return 0; 308 309 asm volatile ("fmovem %/fpiar/%/fpcr/%/fpsr,%0" 310 :: "m" (fpu->fpcntl[0]) 311 : "memory"); 312 asm volatile ("fmovemx %/fp0-%/fp7,%0" 313 :: "m" (fpu->fpregs[0]) 314 : "memory"); 315 return 1; 316 } 317 318 /* 319 * fill in the user structure for a core dump.. 320 */ 321 void dump_thread(struct pt_regs * regs, struct user * dump) 322 { 323 struct switch_stack *sw; 324 325 /* changed the size calculations - should hopefully work better. lbt */ 326 dump->magic = CMAGIC; 327 dump->start_code = 0; 328 dump->start_stack = rdusp() & ~(PAGE_SIZE - 1); 329 dump->u_tsize = ((unsigned long) current->mm->end_code) >> PAGE_SHIFT; 330 dump->u_dsize = ((unsigned long) (current->mm->brk + 331 (PAGE_SIZE-1))) >> PAGE_SHIFT; 332 dump->u_dsize -= dump->u_tsize; 333 dump->u_ssize = 0; 334 335 if (dump->start_stack < TASK_SIZE) 336 dump->u_ssize = ((unsigned long) (TASK_SIZE - dump->start_stack)) >> PAGE_SHIFT; 337 338 dump->u_ar0 = (struct user_regs_struct *)((int)&dump->regs - (int)dump); 339 sw = ((struct switch_stack *)regs) - 1; 340 dump->regs.d1 = regs->d1; 341 dump->regs.d2 = regs->d2; 342 dump->regs.d3 = regs->d3; 343 dump->regs.d4 = regs->d4; 344 dump->regs.d5 = regs->d5; 345 dump->regs.d6 = sw->d6; 346 dump->regs.d7 = sw->d7; 347 dump->regs.a0 = regs->a0; 348 dump->regs.a1 = regs->a1; 349 dump->regs.a2 = regs->a2; 350 dump->regs.a3 = sw->a3; 351 dump->regs.a4 = sw->a4; 352 dump->regs.a5 = sw->a5; 353 dump->regs.a6 = sw->a6; 354 dump->regs.d0 = regs->d0; 355 dump->regs.orig_d0 = regs->orig_d0; 356 dump->regs.stkadj = regs->stkadj; 357 dump->regs.sr = regs->sr; 358 dump->regs.pc = regs->pc; 359 dump->regs.fmtvec = (regs->format << 12) | regs->vector; 360 /* dump floating point stuff */ 361 dump->u_fpvalid = dump_fpu (regs, &dump->m68kfp); 362 } 363 364 /* 365 * sys_execve() executes a new program. 366 */ 367 asmlinkage int sys_execve(char *name, char **argv, char **envp) 368 { 369 int error; 370 char * filename; 371 struct pt_regs *regs = (struct pt_regs *) &name; 372 373 lock_kernel(); 374 filename = getname(name); 375 error = PTR_ERR(filename); 376 if (IS_ERR(filename)) 377 goto out; 378 error = do_execve(filename, argv, envp, regs); 379 putname(filename); 380 out: 381 unlock_kernel(); 382 return error; 383 } 384 385 unsigned long get_wchan(struct task_struct *p) 386 { 387 unsigned long fp, pc; 388 unsigned long stack_page; 389 int count = 0; 390 if (!p || p == current || p->state == TASK_RUNNING) 391 return 0; 392 393 stack_page = (unsigned long)(p->thread_info); 394 fp = ((struct switch_stack *)p->thread.ksp)->a6; 395 do { 396 if (fp < stack_page+sizeof(struct thread_info) || 397 fp >= 8184+stack_page) 398 return 0; 399 pc = ((unsigned long *)fp)[1]; 400 if (!in_sched_functions(pc)) 401 return pc; 402 fp = *(unsigned long *) fp; 403 } while (count++ < 16); 404 return 0; 405 } 406