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 fs_struct init_fs = INIT_FS; 44 static struct signal_struct init_signals = INIT_SIGNALS(init_signals); 45 static struct sighand_struct init_sighand = INIT_SIGHAND(init_sighand); 46 struct mm_struct init_mm = INIT_MM(init_mm); 47 48 EXPORT_SYMBOL(init_mm); 49 50 union thread_union init_thread_union 51 __attribute__((section(".data.init_task"), aligned(THREAD_SIZE))) 52 = { INIT_THREAD_INFO(init_task) }; 53 54 /* initial task structure */ 55 struct task_struct init_task = INIT_TASK(init_task); 56 57 EXPORT_SYMBOL(init_task); 58 59 asmlinkage void ret_from_fork(void); 60 61 62 /* 63 * Return saved PC from a blocked thread 64 */ 65 unsigned long thread_saved_pc(struct task_struct *tsk) 66 { 67 struct switch_stack *sw = (struct switch_stack *)tsk->thread.ksp; 68 /* Check whether the thread is blocked in resume() */ 69 if (in_sched_functions(sw->retpc)) 70 return ((unsigned long *)sw->a6)[1]; 71 else 72 return sw->retpc; 73 } 74 75 /* 76 * The idle loop on an m68k.. 77 */ 78 static void default_idle(void) 79 { 80 if (!need_resched()) 81 #if defined(MACH_ATARI_ONLY) && !defined(CONFIG_HADES) 82 /* block out HSYNC on the atari (falcon) */ 83 __asm__("stop #0x2200" : : : "cc"); 84 #else 85 __asm__("stop #0x2000" : : : "cc"); 86 #endif 87 } 88 89 void (*idle)(void) = default_idle; 90 91 /* 92 * The idle thread. There's no useful work to be 93 * done, so just try to conserve power and have a 94 * low exit latency (ie sit in a loop waiting for 95 * somebody to say that they'd like to reschedule) 96 */ 97 void cpu_idle(void) 98 { 99 /* endless idle loop with no priority at all */ 100 while (1) { 101 while (!need_resched()) 102 idle(); 103 preempt_enable_no_resched(); 104 schedule(); 105 preempt_disable(); 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 (*pm_power_off)(void) = machine_power_off; 131 EXPORT_SYMBOL(pm_power_off); 132 133 void show_regs(struct pt_regs * regs) 134 { 135 printk("\n"); 136 printk("Format %02x Vector: %04x PC: %08lx Status: %04x %s\n", 137 regs->format, regs->vector, regs->pc, regs->sr, print_tainted()); 138 printk("ORIG_D0: %08lx D0: %08lx A2: %08lx A1: %08lx\n", 139 regs->orig_d0, regs->d0, regs->a2, regs->a1); 140 printk("A0: %08lx D5: %08lx D4: %08lx\n", 141 regs->a0, regs->d5, regs->d4); 142 printk("D3: %08lx D2: %08lx D1: %08lx\n", 143 regs->d3, regs->d2, regs->d1); 144 if (!(regs->sr & PS_S)) 145 printk("USP: %08lx\n", rdusp()); 146 } 147 148 /* 149 * Create a kernel thread 150 */ 151 int kernel_thread(int (*fn)(void *), void * arg, unsigned long flags) 152 { 153 int pid; 154 mm_segment_t fs; 155 156 fs = get_fs(); 157 set_fs (KERNEL_DS); 158 159 { 160 register long retval __asm__ ("d0"); 161 register long clone_arg __asm__ ("d1") = flags | CLONE_VM | CLONE_UNTRACED; 162 163 retval = __NR_clone; 164 __asm__ __volatile__ 165 ("clrl %%d2\n\t" 166 "trap #0\n\t" /* Linux/m68k system call */ 167 "tstl %0\n\t" /* child or parent */ 168 "jne 1f\n\t" /* parent - jump */ 169 "lea %%sp@(%c7),%6\n\t" /* reload current */ 170 "movel %6@,%6\n\t" 171 "movel %3,%%sp@-\n\t" /* push argument */ 172 "jsr %4@\n\t" /* call fn */ 173 "movel %0,%%d1\n\t" /* pass exit value */ 174 "movel %2,%%d0\n\t" /* exit */ 175 "trap #0\n" 176 "1:" 177 : "+d" (retval) 178 : "i" (__NR_clone), "i" (__NR_exit), 179 "r" (arg), "a" (fn), "d" (clone_arg), "r" (current), 180 "i" (-THREAD_SIZE) 181 : "d2"); 182 183 pid = retval; 184 } 185 186 set_fs (fs); 187 return pid; 188 } 189 EXPORT_SYMBOL(kernel_thread); 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 __user *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 __user *)regs->d3; 230 child_tidptr = (int __user *)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 EXPORT_SYMBOL(dump_fpu); 315 316 /* 317 * sys_execve() executes a new program. 318 */ 319 asmlinkage int sys_execve(char __user *name, char __user * __user *argv, char __user * __user *envp) 320 { 321 int error; 322 char * filename; 323 struct pt_regs *regs = (struct pt_regs *) &name; 324 325 lock_kernel(); 326 filename = getname(name); 327 error = PTR_ERR(filename); 328 if (IS_ERR(filename)) 329 goto out; 330 error = do_execve(filename, argv, envp, regs); 331 putname(filename); 332 out: 333 unlock_kernel(); 334 return error; 335 } 336 337 unsigned long get_wchan(struct task_struct *p) 338 { 339 unsigned long fp, pc; 340 unsigned long stack_page; 341 int count = 0; 342 if (!p || p == current || p->state == TASK_RUNNING) 343 return 0; 344 345 stack_page = (unsigned long)task_stack_page(p); 346 fp = ((struct switch_stack *)p->thread.ksp)->a6; 347 do { 348 if (fp < stack_page+sizeof(struct thread_info) || 349 fp >= 8184+stack_page) 350 return 0; 351 pc = ((unsigned long *)fp)[1]; 352 if (!in_sched_functions(pc)) 353 return pc; 354 fp = *(unsigned long *) fp; 355 } while (count++ < 16); 356 return 0; 357 } 358