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