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 void machine_halt(void) 117 { 118 if (mach_halt) 119 mach_halt(); 120 for (;;); 121 } 122 123 void machine_power_off(void) 124 { 125 if (mach_power_off) 126 mach_power_off(); 127 for (;;); 128 } 129 130 void show_regs(struct pt_regs * regs) 131 { 132 printk("\n"); 133 printk("Format %02x Vector: %04x PC: %08lx Status: %04x %s\n", 134 regs->format, regs->vector, regs->pc, regs->sr, print_tainted()); 135 printk("ORIG_D0: %08lx D0: %08lx A2: %08lx A1: %08lx\n", 136 regs->orig_d0, regs->d0, regs->a2, regs->a1); 137 printk("A0: %08lx D5: %08lx D4: %08lx\n", 138 regs->a0, regs->d5, regs->d4); 139 printk("D3: %08lx D2: %08lx D1: %08lx\n", 140 regs->d3, regs->d2, regs->d1); 141 if (!(regs->sr & PS_S)) 142 printk("USP: %08lx\n", rdusp()); 143 } 144 145 /* 146 * Create a kernel thread 147 */ 148 int kernel_thread(int (*fn)(void *), void * arg, unsigned long flags) 149 { 150 int pid; 151 mm_segment_t fs; 152 153 fs = get_fs(); 154 set_fs (KERNEL_DS); 155 156 { 157 register long retval __asm__ ("d0"); 158 register long clone_arg __asm__ ("d1") = flags | CLONE_VM | CLONE_UNTRACED; 159 160 retval = __NR_clone; 161 __asm__ __volatile__ 162 ("clrl %%d2\n\t" 163 "trap #0\n\t" /* Linux/m68k system call */ 164 "tstl %0\n\t" /* child or parent */ 165 "jne 1f\n\t" /* parent - jump */ 166 "lea %%sp@(%c7),%6\n\t" /* reload current */ 167 "movel %6@,%6\n\t" 168 "movel %3,%%sp@-\n\t" /* push argument */ 169 "jsr %4@\n\t" /* call fn */ 170 "movel %0,%%d1\n\t" /* pass exit value */ 171 "movel %2,%%d0\n\t" /* exit */ 172 "trap #0\n" 173 "1:" 174 : "+d" (retval) 175 : "i" (__NR_clone), "i" (__NR_exit), 176 "r" (arg), "a" (fn), "d" (clone_arg), "r" (current), 177 "i" (-THREAD_SIZE) 178 : "d2"); 179 180 pid = retval; 181 } 182 183 set_fs (fs); 184 return pid; 185 } 186 187 void flush_thread(void) 188 { 189 unsigned long zero = 0; 190 set_fs(USER_DS); 191 current->thread.fs = __USER_DS; 192 if (!FPU_IS_EMU) 193 asm volatile (".chip 68k/68881\n\t" 194 "frestore %0@\n\t" 195 ".chip 68k" : : "a" (&zero)); 196 } 197 198 /* 199 * "m68k_fork()".. By the time we get here, the 200 * non-volatile registers have also been saved on the 201 * stack. We do some ugly pointer stuff here.. (see 202 * also copy_thread) 203 */ 204 205 asmlinkage int m68k_fork(struct pt_regs *regs) 206 { 207 return do_fork(SIGCHLD, rdusp(), regs, 0, NULL, NULL); 208 } 209 210 asmlinkage int m68k_vfork(struct pt_regs *regs) 211 { 212 return do_fork(CLONE_VFORK | CLONE_VM | SIGCHLD, rdusp(), regs, 0, 213 NULL, NULL); 214 } 215 216 asmlinkage int m68k_clone(struct pt_regs *regs) 217 { 218 unsigned long clone_flags; 219 unsigned long newsp; 220 int *parent_tidptr, *child_tidptr; 221 222 /* syscall2 puts clone_flags in d1 and usp in d2 */ 223 clone_flags = regs->d1; 224 newsp = regs->d2; 225 parent_tidptr = (int *)regs->d3; 226 child_tidptr = (int *)regs->d4; 227 if (!newsp) 228 newsp = rdusp(); 229 return do_fork(clone_flags, newsp, regs, 0, 230 parent_tidptr, child_tidptr); 231 } 232 233 int copy_thread(int nr, unsigned long clone_flags, unsigned long usp, 234 unsigned long unused, 235 struct task_struct * p, struct pt_regs * regs) 236 { 237 struct pt_regs * childregs; 238 struct switch_stack * childstack, *stack; 239 unsigned long stack_offset, *retp; 240 241 stack_offset = THREAD_SIZE - sizeof(struct pt_regs); 242 childregs = (struct pt_regs *) ((unsigned long) (p->thread_info) + stack_offset); 243 244 *childregs = *regs; 245 childregs->d0 = 0; 246 247 retp = ((unsigned long *) regs); 248 stack = ((struct switch_stack *) retp) - 1; 249 250 childstack = ((struct switch_stack *) childregs) - 1; 251 *childstack = *stack; 252 childstack->retpc = (unsigned long)ret_from_fork; 253 254 p->thread.usp = usp; 255 p->thread.ksp = (unsigned long)childstack; 256 /* 257 * Must save the current SFC/DFC value, NOT the value when 258 * the parent was last descheduled - RGH 10-08-96 259 */ 260 p->thread.fs = get_fs().seg; 261 262 if (!FPU_IS_EMU) { 263 /* Copy the current fpu state */ 264 asm volatile ("fsave %0" : : "m" (p->thread.fpstate[0]) : "memory"); 265 266 if (!CPU_IS_060 ? p->thread.fpstate[0] : p->thread.fpstate[2]) 267 asm volatile ("fmovemx %/fp0-%/fp7,%0\n\t" 268 "fmoveml %/fpiar/%/fpcr/%/fpsr,%1" 269 : : "m" (p->thread.fp[0]), "m" (p->thread.fpcntl[0]) 270 : "memory"); 271 /* Restore the state in case the fpu was busy */ 272 asm volatile ("frestore %0" : : "m" (p->thread.fpstate[0])); 273 } 274 275 return 0; 276 } 277 278 /* Fill in the fpu structure for a core dump. */ 279 280 int dump_fpu (struct pt_regs *regs, struct user_m68kfp_struct *fpu) 281 { 282 char fpustate[216]; 283 284 if (FPU_IS_EMU) { 285 int i; 286 287 memcpy(fpu->fpcntl, current->thread.fpcntl, 12); 288 memcpy(fpu->fpregs, current->thread.fp, 96); 289 /* Convert internal fpu reg representation 290 * into long double format 291 */ 292 for (i = 0; i < 24; i += 3) 293 fpu->fpregs[i] = ((fpu->fpregs[i] & 0xffff0000) << 15) | 294 ((fpu->fpregs[i] & 0x0000ffff) << 16); 295 return 1; 296 } 297 298 /* First dump the fpu context to avoid protocol violation. */ 299 asm volatile ("fsave %0" :: "m" (fpustate[0]) : "memory"); 300 if (!CPU_IS_060 ? !fpustate[0] : !fpustate[2]) 301 return 0; 302 303 asm volatile ("fmovem %/fpiar/%/fpcr/%/fpsr,%0" 304 :: "m" (fpu->fpcntl[0]) 305 : "memory"); 306 asm volatile ("fmovemx %/fp0-%/fp7,%0" 307 :: "m" (fpu->fpregs[0]) 308 : "memory"); 309 return 1; 310 } 311 312 /* 313 * fill in the user structure for a core dump.. 314 */ 315 void dump_thread(struct pt_regs * regs, struct user * dump) 316 { 317 struct switch_stack *sw; 318 319 /* changed the size calculations - should hopefully work better. lbt */ 320 dump->magic = CMAGIC; 321 dump->start_code = 0; 322 dump->start_stack = rdusp() & ~(PAGE_SIZE - 1); 323 dump->u_tsize = ((unsigned long) current->mm->end_code) >> PAGE_SHIFT; 324 dump->u_dsize = ((unsigned long) (current->mm->brk + 325 (PAGE_SIZE-1))) >> PAGE_SHIFT; 326 dump->u_dsize -= dump->u_tsize; 327 dump->u_ssize = 0; 328 329 if (dump->start_stack < TASK_SIZE) 330 dump->u_ssize = ((unsigned long) (TASK_SIZE - dump->start_stack)) >> PAGE_SHIFT; 331 332 dump->u_ar0 = (struct user_regs_struct *)((int)&dump->regs - (int)dump); 333 sw = ((struct switch_stack *)regs) - 1; 334 dump->regs.d1 = regs->d1; 335 dump->regs.d2 = regs->d2; 336 dump->regs.d3 = regs->d3; 337 dump->regs.d4 = regs->d4; 338 dump->regs.d5 = regs->d5; 339 dump->regs.d6 = sw->d6; 340 dump->regs.d7 = sw->d7; 341 dump->regs.a0 = regs->a0; 342 dump->regs.a1 = regs->a1; 343 dump->regs.a2 = regs->a2; 344 dump->regs.a3 = sw->a3; 345 dump->regs.a4 = sw->a4; 346 dump->regs.a5 = sw->a5; 347 dump->regs.a6 = sw->a6; 348 dump->regs.d0 = regs->d0; 349 dump->regs.orig_d0 = regs->orig_d0; 350 dump->regs.stkadj = regs->stkadj; 351 dump->regs.sr = regs->sr; 352 dump->regs.pc = regs->pc; 353 dump->regs.fmtvec = (regs->format << 12) | regs->vector; 354 /* dump floating point stuff */ 355 dump->u_fpvalid = dump_fpu (regs, &dump->m68kfp); 356 } 357 358 /* 359 * sys_execve() executes a new program. 360 */ 361 asmlinkage int sys_execve(char *name, char **argv, char **envp) 362 { 363 int error; 364 char * filename; 365 struct pt_regs *regs = (struct pt_regs *) &name; 366 367 lock_kernel(); 368 filename = getname(name); 369 error = PTR_ERR(filename); 370 if (IS_ERR(filename)) 371 goto out; 372 error = do_execve(filename, argv, envp, regs); 373 putname(filename); 374 out: 375 unlock_kernel(); 376 return error; 377 } 378 379 unsigned long get_wchan(struct task_struct *p) 380 { 381 unsigned long fp, pc; 382 unsigned long stack_page; 383 int count = 0; 384 if (!p || p == current || p->state == TASK_RUNNING) 385 return 0; 386 387 stack_page = (unsigned long)(p->thread_info); 388 fp = ((struct switch_stack *)p->thread.ksp)->a6; 389 do { 390 if (fp < stack_page+sizeof(struct thread_info) || 391 fp >= 8184+stack_page) 392 return 0; 393 pc = ((unsigned long *)fp)[1]; 394 if (!in_sched_functions(pc)) 395 return pc; 396 fp = *(unsigned long *) fp; 397 } while (count++ < 16); 398 return 0; 399 } 400