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