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 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 EXPORT_SYMBOL(kernel_thread); 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 __user *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 __user *)regs->d3; 231 child_tidptr = (int __user *)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 EXPORT_SYMBOL(dump_fpu); 316 317 /* 318 * sys_execve() executes a new program. 319 */ 320 asmlinkage int sys_execve(char __user *name, char __user * __user *argv, char __user * __user *envp) 321 { 322 int error; 323 char * filename; 324 struct pt_regs *regs = (struct pt_regs *) &name; 325 326 lock_kernel(); 327 filename = getname(name); 328 error = PTR_ERR(filename); 329 if (IS_ERR(filename)) 330 goto out; 331 error = do_execve(filename, argv, envp, regs); 332 putname(filename); 333 out: 334 unlock_kernel(); 335 return error; 336 } 337 338 unsigned long get_wchan(struct task_struct *p) 339 { 340 unsigned long fp, pc; 341 unsigned long stack_page; 342 int count = 0; 343 if (!p || p == current || p->state == TASK_RUNNING) 344 return 0; 345 346 stack_page = (unsigned long)task_stack_page(p); 347 fp = ((struct switch_stack *)p->thread.ksp)->a6; 348 do { 349 if (fp < stack_page+sizeof(struct thread_info) || 350 fp >= 8184+stack_page) 351 return 0; 352 pc = ((unsigned long *)fp)[1]; 353 if (!in_sched_functions(pc)) 354 return pc; 355 fp = *(unsigned long *) fp; 356 } while (count++ < 16); 357 return 0; 358 } 359