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/smp_lock.h> 22#include <linux/stddef.h> 23#include <linux/unistd.h> 24#include <linux/ptrace.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 */ 43static struct signal_struct init_signals = INIT_SIGNALS(init_signals); 44static struct sighand_struct init_sighand = INIT_SIGHAND(init_sighand); 45union thread_union init_thread_union __init_task_data 46 __attribute__((aligned(THREAD_SIZE))) = 47 { INIT_THREAD_INFO(init_task) }; 48 49/* initial task structure */ 50struct task_struct init_task = INIT_TASK(init_task); 51 52EXPORT_SYMBOL(init_task); 53 54asmlinkage void ret_from_fork(void); 55 56 57/* 58 * Return saved PC from a blocked thread 59 */ 60unsigned long thread_saved_pc(struct task_struct *tsk) 61{ 62 struct switch_stack *sw = (struct switch_stack *)tsk->thread.ksp; 63 /* Check whether the thread is blocked in resume() */ 64 if (in_sched_functions(sw->retpc)) 65 return ((unsigned long *)sw->a6)[1]; 66 else 67 return sw->retpc; 68} 69 70/* 71 * The idle loop on an m68k.. 72 */ 73static void default_idle(void) 74{ 75 if (!need_resched()) 76#if defined(MACH_ATARI_ONLY) 77 /* block out HSYNC on the atari (falcon) */ 78 __asm__("stop #0x2200" : : : "cc"); 79#else 80 __asm__("stop #0x2000" : : : "cc"); 81#endif 82} 83 84void (*idle)(void) = default_idle; 85 86/* 87 * The idle thread. There's no useful work to be 88 * done, so just try to conserve power and have a 89 * low exit latency (ie sit in a loop waiting for 90 * somebody to say that they'd like to reschedule) 91 */ 92void cpu_idle(void) 93{ 94 /* endless idle loop with no priority at all */ 95 while (1) { 96 while (!need_resched()) 97 idle(); 98 preempt_enable_no_resched(); 99 schedule(); 100 preempt_disable(); 101 } 102} 103 104void machine_restart(char * __unused) 105{ 106 if (mach_reset) 107 mach_reset(); 108 for (;;); 109} 110 111void machine_halt(void) 112{ 113 if (mach_halt) 114 mach_halt(); 115 for (;;); 116} 117 118void machine_power_off(void) 119{ 120 if (mach_power_off) 121 mach_power_off(); 122 for (;;); 123} 124 125void (*pm_power_off)(void) = machine_power_off; 126EXPORT_SYMBOL(pm_power_off); 127 128void show_regs(struct pt_regs * regs) 129{ 130 printk("\n"); 131 printk("Format %02x Vector: %04x PC: %08lx Status: %04x %s\n", 132 regs->format, regs->vector, regs->pc, regs->sr, print_tainted()); 133 printk("ORIG_D0: %08lx D0: %08lx A2: %08lx A1: %08lx\n", 134 regs->orig_d0, regs->d0, regs->a2, regs->a1); 135 printk("A0: %08lx D5: %08lx D4: %08lx\n", 136 regs->a0, regs->d5, regs->d4); 137 printk("D3: %08lx D2: %08lx D1: %08lx\n", 138 regs->d3, regs->d2, regs->d1); 139 if (!(regs->sr & PS_S)) 140 printk("USP: %08lx\n", rdusp()); 141} 142 143/* 144 * Create a kernel thread 145 */ 146int kernel_thread(int (*fn)(void *), void * arg, unsigned long flags) 147{ 148 int pid; 149 mm_segment_t fs; 150 151 fs = get_fs(); 152 set_fs (KERNEL_DS); 153 154 { 155 register long retval __asm__ ("d0"); 156 register long clone_arg __asm__ ("d1") = flags | CLONE_VM | CLONE_UNTRACED; 157 158 retval = __NR_clone; 159 __asm__ __volatile__ 160 ("clrl %%d2\n\t" 161 "trap #0\n\t" /* Linux/m68k system call */ 162 "tstl %0\n\t" /* child or parent */ 163 "jne 1f\n\t" /* parent - jump */ 164 "lea %%sp@(%c7),%6\n\t" /* reload current */ 165 "movel %6@,%6\n\t" 166 "movel %3,%%sp@-\n\t" /* push argument */ 167 "jsr %4@\n\t" /* call fn */ 168 "movel %0,%%d1\n\t" /* pass exit value */ 169 "movel %2,%%d0\n\t" /* exit */ 170 "trap #0\n" 171 "1:" 172 : "+d" (retval) 173 : "i" (__NR_clone), "i" (__NR_exit), 174 "r" (arg), "a" (fn), "d" (clone_arg), "r" (current), 175 "i" (-THREAD_SIZE) 176 : "d2"); 177 178 pid = retval; 179 } 180 181 set_fs (fs); 182 return pid; 183} 184EXPORT_SYMBOL(kernel_thread); 185 186void flush_thread(void) 187{ 188 unsigned long zero = 0; 189 set_fs(USER_DS); 190 current->thread.fs = __USER_DS; 191 if (!FPU_IS_EMU) 192 asm volatile (".chip 68k/68881\n\t" 193 "frestore %0@\n\t" 194 ".chip 68k" : : "a" (&zero)); 195} 196 197/* 198 * "m68k_fork()".. By the time we get here, the 199 * non-volatile registers have also been saved on the 200 * stack. We do some ugly pointer stuff here.. (see 201 * also copy_thread) 202 */ 203 204asmlinkage int m68k_fork(struct pt_regs *regs) 205{ 206 return do_fork(SIGCHLD, rdusp(), regs, 0, NULL, NULL); 207} 208 209asmlinkage int m68k_vfork(struct pt_regs *regs) 210{ 211 return do_fork(CLONE_VFORK | CLONE_VM | SIGCHLD, rdusp(), regs, 0, 212 NULL, NULL); 213} 214 215asmlinkage int m68k_clone(struct pt_regs *regs) 216{ 217 unsigned long clone_flags; 218 unsigned long newsp; 219 int __user *parent_tidptr, *child_tidptr; 220 221 /* syscall2 puts clone_flags in d1 and usp in d2 */ 222 clone_flags = regs->d1; 223 newsp = regs->d2; 224 parent_tidptr = (int __user *)regs->d3; 225 child_tidptr = (int __user *)regs->d4; 226 if (!newsp) 227 newsp = rdusp(); 228 return do_fork(clone_flags, newsp, regs, 0, 229 parent_tidptr, child_tidptr); 230} 231 232int copy_thread(unsigned long clone_flags, unsigned long usp, 233 unsigned long unused, 234 struct task_struct * p, struct pt_regs * regs) 235{ 236 struct pt_regs * childregs; 237 struct switch_stack * childstack, *stack; 238 unsigned long *retp; 239 240 childregs = (struct pt_regs *) (task_stack_page(p) + THREAD_SIZE) - 1; 241 242 *childregs = *regs; 243 childregs->d0 = 0; 244 245 retp = ((unsigned long *) regs); 246 stack = ((struct switch_stack *) retp) - 1; 247 248 childstack = ((struct switch_stack *) childregs) - 1; 249 *childstack = *stack; 250 childstack->retpc = (unsigned long)ret_from_fork; 251 252 p->thread.usp = usp; 253 p->thread.ksp = (unsigned long)childstack; 254 255 if (clone_flags & CLONE_SETTLS) 256 task_thread_info(p)->tp_value = regs->d5; 257 258 /* 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 282int 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} 313EXPORT_SYMBOL(dump_fpu); 314 315/* 316 * sys_execve() executes a new program. 317 */ 318asmlinkage int sys_execve(const char __user *name, 319 const char __user *const __user *argv, 320 const char __user *const __user *envp) 321{ 322 int error; 323 char * filename; 324 struct pt_regs *regs = (struct pt_regs *) &name; 325 326 filename = getname(name); 327 error = PTR_ERR(filename); 328 if (IS_ERR(filename)) 329 return error; 330 error = do_execve(filename, argv, envp, regs); 331 putname(filename); 332 return error; 333} 334 335unsigned long get_wchan(struct task_struct *p) 336{ 337 unsigned long fp, pc; 338 unsigned long stack_page; 339 int count = 0; 340 if (!p || p == current || p->state == TASK_RUNNING) 341 return 0; 342 343 stack_page = (unsigned long)task_stack_page(p); 344 fp = ((struct switch_stack *)p->thread.ksp)->a6; 345 do { 346 if (fp < stack_page+sizeof(struct thread_info) || 347 fp >= 8184+stack_page) 348 return 0; 349 pc = ((unsigned long *)fp)[1]; 350 if (!in_sched_functions(pc)) 351 return pc; 352 fp = *(unsigned long *) fp; 353 } while (count++ < 16); 354 return 0; 355} 356