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