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 static 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 preempt_enable_no_resched(); 106 schedule(); 107 preempt_disable(); 108 } 109 } 110 111 void machine_restart(char * __unused) 112 { 113 if (mach_reset) 114 mach_reset(); 115 for (;;); 116 } 117 118 void machine_halt(void) 119 { 120 if (mach_halt) 121 mach_halt(); 122 for (;;); 123 } 124 125 void machine_power_off(void) 126 { 127 if (mach_power_off) 128 mach_power_off(); 129 for (;;); 130 } 131 132 void (*pm_power_off)(void) = machine_power_off; 133 EXPORT_SYMBOL(pm_power_off); 134 135 void show_regs(struct pt_regs * regs) 136 { 137 printk("\n"); 138 printk("Format %02x Vector: %04x PC: %08lx Status: %04x %s\n", 139 regs->format, regs->vector, regs->pc, regs->sr, print_tainted()); 140 printk("ORIG_D0: %08lx D0: %08lx A2: %08lx A1: %08lx\n", 141 regs->orig_d0, regs->d0, regs->a2, regs->a1); 142 printk("A0: %08lx D5: %08lx D4: %08lx\n", 143 regs->a0, regs->d5, regs->d4); 144 printk("D3: %08lx D2: %08lx D1: %08lx\n", 145 regs->d3, regs->d2, regs->d1); 146 if (!(regs->sr & PS_S)) 147 printk("USP: %08lx\n", rdusp()); 148 } 149 150 /* 151 * Create a kernel thread 152 */ 153 int kernel_thread(int (*fn)(void *), void * arg, unsigned long flags) 154 { 155 int pid; 156 mm_segment_t fs; 157 158 fs = get_fs(); 159 set_fs (KERNEL_DS); 160 161 { 162 register long retval __asm__ ("d0"); 163 register long clone_arg __asm__ ("d1") = flags | CLONE_VM | CLONE_UNTRACED; 164 165 retval = __NR_clone; 166 __asm__ __volatile__ 167 ("clrl %%d2\n\t" 168 "trap #0\n\t" /* Linux/m68k system call */ 169 "tstl %0\n\t" /* child or parent */ 170 "jne 1f\n\t" /* parent - jump */ 171 "lea %%sp@(%c7),%6\n\t" /* reload current */ 172 "movel %6@,%6\n\t" 173 "movel %3,%%sp@-\n\t" /* push argument */ 174 "jsr %4@\n\t" /* call fn */ 175 "movel %0,%%d1\n\t" /* pass exit value */ 176 "movel %2,%%d0\n\t" /* exit */ 177 "trap #0\n" 178 "1:" 179 : "+d" (retval) 180 : "i" (__NR_clone), "i" (__NR_exit), 181 "r" (arg), "a" (fn), "d" (clone_arg), "r" (current), 182 "i" (-THREAD_SIZE) 183 : "d2"); 184 185 pid = retval; 186 } 187 188 set_fs (fs); 189 return pid; 190 } 191 192 void flush_thread(void) 193 { 194 unsigned long zero = 0; 195 set_fs(USER_DS); 196 current->thread.fs = __USER_DS; 197 if (!FPU_IS_EMU) 198 asm volatile (".chip 68k/68881\n\t" 199 "frestore %0@\n\t" 200 ".chip 68k" : : "a" (&zero)); 201 } 202 203 /* 204 * "m68k_fork()".. By the time we get here, the 205 * non-volatile registers have also been saved on the 206 * stack. We do some ugly pointer stuff here.. (see 207 * also copy_thread) 208 */ 209 210 asmlinkage int m68k_fork(struct pt_regs *regs) 211 { 212 return do_fork(SIGCHLD, rdusp(), regs, 0, NULL, NULL); 213 } 214 215 asmlinkage int m68k_vfork(struct pt_regs *regs) 216 { 217 return do_fork(CLONE_VFORK | CLONE_VM | SIGCHLD, rdusp(), regs, 0, 218 NULL, NULL); 219 } 220 221 asmlinkage int m68k_clone(struct pt_regs *regs) 222 { 223 unsigned long clone_flags; 224 unsigned long newsp; 225 int *parent_tidptr, *child_tidptr; 226 227 /* syscall2 puts clone_flags in d1 and usp in d2 */ 228 clone_flags = regs->d1; 229 newsp = regs->d2; 230 parent_tidptr = (int *)regs->d3; 231 child_tidptr = (int *)regs->d4; 232 if (!newsp) 233 newsp = rdusp(); 234 return do_fork(clone_flags, newsp, regs, 0, 235 parent_tidptr, child_tidptr); 236 } 237 238 int copy_thread(int nr, unsigned long clone_flags, unsigned long usp, 239 unsigned long unused, 240 struct task_struct * p, struct pt_regs * regs) 241 { 242 struct pt_regs * childregs; 243 struct switch_stack * childstack, *stack; 244 unsigned long *retp; 245 246 childregs = (struct pt_regs *) (task_stack_page(p) + THREAD_SIZE) - 1; 247 248 *childregs = *regs; 249 childregs->d0 = 0; 250 251 retp = ((unsigned long *) regs); 252 stack = ((struct switch_stack *) retp) - 1; 253 254 childstack = ((struct switch_stack *) childregs) - 1; 255 *childstack = *stack; 256 childstack->retpc = (unsigned long)ret_from_fork; 257 258 p->thread.usp = usp; 259 p->thread.ksp = (unsigned long)childstack; 260 /* 261 * Must save the current SFC/DFC value, NOT the value when 262 * the parent was last descheduled - RGH 10-08-96 263 */ 264 p->thread.fs = get_fs().seg; 265 266 if (!FPU_IS_EMU) { 267 /* Copy the current fpu state */ 268 asm volatile ("fsave %0" : : "m" (p->thread.fpstate[0]) : "memory"); 269 270 if (!CPU_IS_060 ? p->thread.fpstate[0] : p->thread.fpstate[2]) 271 asm volatile ("fmovemx %/fp0-%/fp7,%0\n\t" 272 "fmoveml %/fpiar/%/fpcr/%/fpsr,%1" 273 : : "m" (p->thread.fp[0]), "m" (p->thread.fpcntl[0]) 274 : "memory"); 275 /* Restore the state in case the fpu was busy */ 276 asm volatile ("frestore %0" : : "m" (p->thread.fpstate[0])); 277 } 278 279 return 0; 280 } 281 282 /* Fill in the fpu structure for a core dump. */ 283 284 int dump_fpu (struct pt_regs *regs, struct user_m68kfp_struct *fpu) 285 { 286 char fpustate[216]; 287 288 if (FPU_IS_EMU) { 289 int i; 290 291 memcpy(fpu->fpcntl, current->thread.fpcntl, 12); 292 memcpy(fpu->fpregs, current->thread.fp, 96); 293 /* Convert internal fpu reg representation 294 * into long double format 295 */ 296 for (i = 0; i < 24; i += 3) 297 fpu->fpregs[i] = ((fpu->fpregs[i] & 0xffff0000) << 15) | 298 ((fpu->fpregs[i] & 0x0000ffff) << 16); 299 return 1; 300 } 301 302 /* First dump the fpu context to avoid protocol violation. */ 303 asm volatile ("fsave %0" :: "m" (fpustate[0]) : "memory"); 304 if (!CPU_IS_060 ? !fpustate[0] : !fpustate[2]) 305 return 0; 306 307 asm volatile ("fmovem %/fpiar/%/fpcr/%/fpsr,%0" 308 :: "m" (fpu->fpcntl[0]) 309 : "memory"); 310 asm volatile ("fmovemx %/fp0-%/fp7,%0" 311 :: "m" (fpu->fpregs[0]) 312 : "memory"); 313 return 1; 314 } 315 316 /* 317 * fill in the user structure for a core dump.. 318 */ 319 void dump_thread(struct pt_regs * regs, struct user * dump) 320 { 321 struct switch_stack *sw; 322 323 /* changed the size calculations - should hopefully work better. lbt */ 324 dump->magic = CMAGIC; 325 dump->start_code = 0; 326 dump->start_stack = rdusp() & ~(PAGE_SIZE - 1); 327 dump->u_tsize = ((unsigned long) current->mm->end_code) >> PAGE_SHIFT; 328 dump->u_dsize = ((unsigned long) (current->mm->brk + 329 (PAGE_SIZE-1))) >> PAGE_SHIFT; 330 dump->u_dsize -= dump->u_tsize; 331 dump->u_ssize = 0; 332 333 if (dump->start_stack < TASK_SIZE) 334 dump->u_ssize = ((unsigned long) (TASK_SIZE - dump->start_stack)) >> PAGE_SHIFT; 335 336 dump->u_ar0 = (struct user_regs_struct *)((int)&dump->regs - (int)dump); 337 sw = ((struct switch_stack *)regs) - 1; 338 dump->regs.d1 = regs->d1; 339 dump->regs.d2 = regs->d2; 340 dump->regs.d3 = regs->d3; 341 dump->regs.d4 = regs->d4; 342 dump->regs.d5 = regs->d5; 343 dump->regs.d6 = sw->d6; 344 dump->regs.d7 = sw->d7; 345 dump->regs.a0 = regs->a0; 346 dump->regs.a1 = regs->a1; 347 dump->regs.a2 = regs->a2; 348 dump->regs.a3 = sw->a3; 349 dump->regs.a4 = sw->a4; 350 dump->regs.a5 = sw->a5; 351 dump->regs.a6 = sw->a6; 352 dump->regs.d0 = regs->d0; 353 dump->regs.orig_d0 = regs->orig_d0; 354 dump->regs.stkadj = regs->stkadj; 355 dump->regs.sr = regs->sr; 356 dump->regs.pc = regs->pc; 357 dump->regs.fmtvec = (regs->format << 12) | regs->vector; 358 /* dump floating point stuff */ 359 dump->u_fpvalid = dump_fpu (regs, &dump->m68kfp); 360 } 361 362 /* 363 * sys_execve() executes a new program. 364 */ 365 asmlinkage int sys_execve(char *name, char **argv, char **envp) 366 { 367 int error; 368 char * filename; 369 struct pt_regs *regs = (struct pt_regs *) &name; 370 371 lock_kernel(); 372 filename = getname(name); 373 error = PTR_ERR(filename); 374 if (IS_ERR(filename)) 375 goto out; 376 error = do_execve(filename, argv, envp, regs); 377 putname(filename); 378 out: 379 unlock_kernel(); 380 return error; 381 } 382 383 unsigned long get_wchan(struct task_struct *p) 384 { 385 unsigned long fp, pc; 386 unsigned long stack_page; 387 int count = 0; 388 if (!p || p == current || p->state == TASK_RUNNING) 389 return 0; 390 391 stack_page = (unsigned long)task_stack_page(p); 392 fp = ((struct switch_stack *)p->thread.ksp)->a6; 393 do { 394 if (fp < stack_page+sizeof(struct thread_info) || 395 fp >= 8184+stack_page) 396 return 0; 397 pc = ((unsigned long *)fp)[1]; 398 if (!in_sched_functions(pc)) 399 return pc; 400 fp = *(unsigned long *) fp; 401 } while (count++ < 16); 402 return 0; 403 } 404