2 * linux/arch/m68k/kernel/process.c
4 * Copyright (C) 1995 Hamish Macdonald
6 * 68060 fixes by Jesper Skov
10 * This file handles the architecture-dependent parts of process handling..
13 #include <linux/config.h>
14 #include <linux/errno.h>
15 #include <linux/module.h>
16 #include <linux/sched.h>
17 #include <linux/kernel.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/a.out.h>
27 #include <linux/reboot.h>
28 #include <linux/init_task.h>
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>
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
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);
49 EXPORT_SYMBOL(init_mm);
51 union thread_union init_thread_union
52 __attribute__((section(".data.init_task"), aligned(THREAD_SIZE)))
53 = { INIT_THREAD_INFO(init_task) };
55 /* initial task structure */
56 struct task_struct init_task = INIT_TASK(init_task);
58 EXPORT_SYMBOL(init_task);
60 asmlinkage void ret_from_fork(void);
64 * Return saved PC from a blocked thread
66 unsigned long thread_saved_pc(struct task_struct *tsk)
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];
77 * The idle loop on an m68k..
79 void default_idle(void)
82 #if defined(MACH_ATARI_ONLY) && !defined(CONFIG_HADES)
83 /* block out HSYNC on the atari (falcon) */
84 __asm__("stop #0x2200" : : : "cc");
86 __asm__("stop #0x2000" : : : "cc");
90 void (*idle)(void) = default_idle;
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)
100 /* endless idle loop with no priority at all */
102 while (!need_resched())
108 void machine_restart(char * __unused)
115 EXPORT_SYMBOL(machine_restart);
117 void machine_halt(void)
124 EXPORT_SYMBOL(machine_halt);
126 void machine_power_off(void)
133 EXPORT_SYMBOL(machine_power_off);
135 void show_regs(struct pt_regs * regs)
138 printk("Format %02x Vector: %04x PC: %08lx Status: %04x %s\n",
139 regs->format, regs->vector, regs->pc, regs->sr, print_tainted());
140 printk("ORIG_D0: %08lx D0: %08lx A2: %08lx A1: %08lx\n",
141 regs->orig_d0, regs->d0, regs->a2, regs->a1);
142 printk("A0: %08lx D5: %08lx D4: %08lx\n",
143 regs->a0, regs->d5, regs->d4);
144 printk("D3: %08lx D2: %08lx D1: %08lx\n",
145 regs->d3, regs->d2, regs->d1);
146 if (!(regs->sr & PS_S))
147 printk("USP: %08lx\n", rdusp());
151 * Create a kernel thread
153 int kernel_thread(int (*fn)(void *), void * arg, unsigned long flags)
162 register long retval __asm__ ("d0");
163 register long clone_arg __asm__ ("d1") = flags | CLONE_VM | CLONE_UNTRACED;
168 "trap #0\n\t" /* Linux/m68k system call */
169 "tstl %0\n\t" /* child or parent */
170 "jne 1f\n\t" /* parent - jump */
171 "lea %%sp@(%c7),%6\n\t" /* reload current */
173 "movel %3,%%sp@-\n\t" /* push argument */
174 "jsr %4@\n\t" /* call fn */
175 "movel %0,%%d1\n\t" /* pass exit value */
176 "movel %2,%%d0\n\t" /* exit */
180 : "i" (__NR_clone), "i" (__NR_exit),
181 "r" (arg), "a" (fn), "d" (clone_arg), "r" (current),
192 void flush_thread(void)
194 unsigned long zero = 0;
196 current->thread.fs = __USER_DS;
198 asm volatile (".chip 68k/68881\n\t"
200 ".chip 68k" : : "a" (&zero));
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
210 asmlinkage int m68k_fork(struct pt_regs *regs)
212 return do_fork(SIGCHLD, rdusp(), regs, 0, NULL, NULL);
215 asmlinkage int m68k_vfork(struct pt_regs *regs)
217 return do_fork(CLONE_VFORK | CLONE_VM | SIGCHLD, rdusp(), regs, 0,
221 asmlinkage int m68k_clone(struct pt_regs *regs)
223 unsigned long clone_flags;
225 int *parent_tidptr, *child_tidptr;
227 /* syscall2 puts clone_flags in d1 and usp in d2 */
228 clone_flags = regs->d1;
230 parent_tidptr = (int *)regs->d3;
231 child_tidptr = (int *)regs->d4;
234 return do_fork(clone_flags & ~CLONE_IDLETASK, newsp, regs, 0,
235 parent_tidptr, child_tidptr);
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)
242 struct pt_regs * childregs;
243 struct switch_stack * childstack, *stack;
244 unsigned long stack_offset, *retp;
246 stack_offset = THREAD_SIZE - sizeof(struct pt_regs);
247 childregs = (struct pt_regs *) ((unsigned long) (p->thread_info) + stack_offset);
252 retp = ((unsigned long *) regs);
253 stack = ((struct switch_stack *) retp) - 1;
255 childstack = ((struct switch_stack *) childregs) - 1;
256 *childstack = *stack;
257 childstack->retpc = (unsigned long)ret_from_fork;
260 p->thread.ksp = (unsigned long)childstack;
262 * Must save the current SFC/DFC value, NOT the value when
263 * the parent was last descheduled - RGH 10-08-96
265 p->thread.fs = get_fs().seg;
268 /* Copy the current fpu state */
269 asm volatile ("fsave %0" : : "m" (p->thread.fpstate[0]) : "memory");
271 if (!CPU_IS_060 ? p->thread.fpstate[0] : p->thread.fpstate[2])
272 asm volatile ("fmovemx %/fp0-%/fp7,%0\n\t"
273 "fmoveml %/fpiar/%/fpcr/%/fpsr,%1"
274 : : "m" (p->thread.fp[0]), "m" (p->thread.fpcntl[0])
276 /* Restore the state in case the fpu was busy */
277 asm volatile ("frestore %0" : : "m" (p->thread.fpstate[0]));
283 /* Fill in the fpu structure for a core dump. */
285 int dump_fpu (struct pt_regs *regs, struct user_m68kfp_struct *fpu)
292 memcpy(fpu->fpcntl, current->thread.fpcntl, 12);
293 memcpy(fpu->fpregs, current->thread.fp, 96);
294 /* Convert internal fpu reg representation
295 * into long double format
297 for (i = 0; i < 24; i += 3)
298 fpu->fpregs[i] = ((fpu->fpregs[i] & 0xffff0000) << 15) |
299 ((fpu->fpregs[i] & 0x0000ffff) << 16);
303 /* First dump the fpu context to avoid protocol violation. */
304 asm volatile ("fsave %0" :: "m" (fpustate[0]) : "memory");
305 if (!CPU_IS_060 ? !fpustate[0] : !fpustate[2])
308 asm volatile ("fmovem %/fpiar/%/fpcr/%/fpsr,%0"
309 :: "m" (fpu->fpcntl[0])
311 asm volatile ("fmovemx %/fp0-%/fp7,%0"
312 :: "m" (fpu->fpregs[0])
318 * fill in the user structure for a core dump..
320 void dump_thread(struct pt_regs * regs, struct user * dump)
322 struct switch_stack *sw;
324 /* changed the size calculations - should hopefully work better. lbt */
325 dump->magic = CMAGIC;
326 dump->start_code = 0;
327 dump->start_stack = rdusp() & ~(PAGE_SIZE - 1);
328 dump->u_tsize = ((unsigned long) current->mm->end_code) >> PAGE_SHIFT;
329 dump->u_dsize = ((unsigned long) (current->mm->brk +
330 (PAGE_SIZE-1))) >> PAGE_SHIFT;
331 dump->u_dsize -= dump->u_tsize;
334 if (dump->start_stack < TASK_SIZE)
335 dump->u_ssize = ((unsigned long) (TASK_SIZE - dump->start_stack)) >> PAGE_SHIFT;
337 dump->u_ar0 = (struct user_regs_struct *)((int)&dump->regs - (int)dump);
338 sw = ((struct switch_stack *)regs) - 1;
339 dump->regs.d1 = regs->d1;
340 dump->regs.d2 = regs->d2;
341 dump->regs.d3 = regs->d3;
342 dump->regs.d4 = regs->d4;
343 dump->regs.d5 = regs->d5;
344 dump->regs.d6 = sw->d6;
345 dump->regs.d7 = sw->d7;
346 dump->regs.a0 = regs->a0;
347 dump->regs.a1 = regs->a1;
348 dump->regs.a2 = regs->a2;
349 dump->regs.a3 = sw->a3;
350 dump->regs.a4 = sw->a4;
351 dump->regs.a5 = sw->a5;
352 dump->regs.a6 = sw->a6;
353 dump->regs.d0 = regs->d0;
354 dump->regs.orig_d0 = regs->orig_d0;
355 dump->regs.stkadj = regs->stkadj;
356 dump->regs.sr = regs->sr;
357 dump->regs.pc = regs->pc;
358 dump->regs.fmtvec = (regs->format << 12) | regs->vector;
359 /* dump floating point stuff */
360 dump->u_fpvalid = dump_fpu (regs, &dump->m68kfp);
364 * sys_execve() executes a new program.
366 asmlinkage int sys_execve(char *name, char **argv, char **envp)
370 struct pt_regs *regs = (struct pt_regs *) &name;
373 filename = getname(name);
374 error = PTR_ERR(filename);
375 if (IS_ERR(filename))
377 error = do_execve(filename, argv, envp, regs);
384 unsigned long get_wchan(struct task_struct *p)
386 unsigned long fp, pc;
387 unsigned long stack_page;
389 if (!p || p == current || p->state == TASK_RUNNING)
392 stack_page = (unsigned long)(p->thread_info);
393 fp = ((struct switch_stack *)p->thread.ksp)->a6;
395 if (fp < stack_page+sizeof(struct thread_info) ||
396 fp >= 8184+stack_page)
398 pc = ((unsigned long *)fp)[1];
399 if (!in_sched_functions(pc))
401 fp = *(unsigned long *) fp;
402 } while (count++ < 16);