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/errno.h>
14 #include <linux/module.h>
15 #include <linux/sched.h>
16 #include <linux/kernel.h>
18 #include <linux/slab.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 #include <linux/rcupdate.h>
30 #include <asm/uaccess.h>
31 #include <asm/traps.h>
32 #include <asm/machdep.h>
33 #include <asm/setup.h>
34 #include <asm/pgtable.h>
37 asmlinkage void ret_from_fork(void);
38 asmlinkage void ret_from_kernel_thread(void);
42 * Return saved PC from a blocked thread
44 unsigned long thread_saved_pc(struct task_struct *tsk)
46 struct switch_stack *sw = (struct switch_stack *)tsk->thread.ksp;
47 /* Check whether the thread is blocked in resume() */
48 if (in_sched_functions(sw->retpc))
49 return ((unsigned long *)sw->a6)[1];
55 * The idle loop on an m68k..
57 static void default_idle(void)
60 #if defined(MACH_ATARI_ONLY)
61 /* block out HSYNC on the atari (falcon) */
62 __asm__("stop #0x2200" : : : "cc");
64 __asm__("stop #0x2000" : : : "cc");
68 void (*idle)(void) = default_idle;
71 * The idle thread. There's no useful work to be
72 * done, so just try to conserve power and have a
73 * low exit latency (ie sit in a loop waiting for
74 * somebody to say that they'd like to reschedule)
78 /* endless idle loop with no priority at all */
81 while (!need_resched())
84 schedule_preempt_disabled();
88 void machine_restart(char * __unused)
95 void machine_halt(void)
102 void machine_power_off(void)
109 void (*pm_power_off)(void) = machine_power_off;
110 EXPORT_SYMBOL(pm_power_off);
112 void show_regs(struct pt_regs * regs)
115 printk("Format %02x Vector: %04x PC: %08lx Status: %04x %s\n",
116 regs->format, regs->vector, regs->pc, regs->sr, print_tainted());
117 printk("ORIG_D0: %08lx D0: %08lx A2: %08lx A1: %08lx\n",
118 regs->orig_d0, regs->d0, regs->a2, regs->a1);
119 printk("A0: %08lx D5: %08lx D4: %08lx\n",
120 regs->a0, regs->d5, regs->d4);
121 printk("D3: %08lx D2: %08lx D1: %08lx\n",
122 regs->d3, regs->d2, regs->d1);
123 if (!(regs->sr & PS_S))
124 printk("USP: %08lx\n", rdusp());
127 void flush_thread(void)
129 current->thread.fs = __USER_DS;
132 unsigned long zero = 0;
133 asm volatile("frestore %0": :"m" (zero));
139 * Why not generic sys_clone, you ask? m68k passes all arguments on stack.
140 * And we need all registers saved, which means a bunch of stuff pushed
141 * on top of pt_regs, which means that sys_clone() arguments would be
142 * buried. We could, of course, copy them, but it's too costly for no
143 * good reason - generic clone() would have to copy them *again* for
144 * do_fork() anyway. So in this case it's actually better to pass pt_regs *
145 * and extract arguments for do_fork() from there. Eventually we might
146 * go for calling do_fork() directly from the wrapper, but only after we
147 * are finished with do_fork() prototype conversion.
149 asmlinkage int m68k_clone(struct pt_regs *regs)
151 /* regs will be equal to current_pt_regs() */
152 return do_fork(regs->d1, regs->d2, regs, 0,
153 (int __user *)regs->d3, (int __user *)regs->d4);
156 int copy_thread(unsigned long clone_flags, unsigned long usp,
158 struct task_struct * p, struct pt_regs * unused)
161 struct switch_stack sw;
165 frame = (struct fork_frame *) (task_stack_page(p) + THREAD_SIZE) - 1;
167 p->thread.ksp = (unsigned long)frame;
168 p->thread.esp0 = (unsigned long)&frame->regs;
171 * Must save the current SFC/DFC value, NOT the value when
172 * the parent was last descheduled - RGH 10-08-96
174 p->thread.fs = get_fs().seg;
176 if (unlikely(p->flags & PF_KTHREAD)) {
178 memset(frame, 0, sizeof(struct fork_frame));
179 frame->regs.sr = PS_S;
180 frame->sw.a3 = usp; /* function */
182 frame->sw.retpc = (unsigned long)ret_from_kernel_thread;
186 memcpy(frame, container_of(current_pt_regs(), struct fork_frame, regs),
187 sizeof(struct fork_frame));
189 frame->sw.retpc = (unsigned long)ret_from_fork;
190 p->thread.usp = usp ?: rdusp();
192 if (clone_flags & CLONE_SETTLS)
193 task_thread_info(p)->tp_value = frame->regs.d5;
197 /* Copy the current fpu state */
198 asm volatile ("fsave %0" : : "m" (p->thread.fpstate[0]) : "memory");
200 if (!CPU_IS_060 ? p->thread.fpstate[0] : p->thread.fpstate[2]) {
201 if (CPU_IS_COLDFIRE) {
202 asm volatile ("fmovemd %/fp0-%/fp7,%0\n\t"
203 "fmovel %/fpiar,%1\n\t"
204 "fmovel %/fpcr,%2\n\t"
207 : "m" (p->thread.fp[0]),
208 "m" (p->thread.fpcntl[0]),
209 "m" (p->thread.fpcntl[1]),
210 "m" (p->thread.fpcntl[2])
213 asm volatile ("fmovemx %/fp0-%/fp7,%0\n\t"
214 "fmoveml %/fpiar/%/fpcr/%/fpsr,%1"
216 : "m" (p->thread.fp[0]),
217 "m" (p->thread.fpcntl[0])
222 /* Restore the state in case the fpu was busy */
223 asm volatile ("frestore %0" : : "m" (p->thread.fpstate[0]));
225 #endif /* CONFIG_FPU */
230 /* Fill in the fpu structure for a core dump. */
232 int dump_fpu (struct pt_regs *regs, struct user_m68kfp_struct *fpu)
239 memcpy(fpu->fpcntl, current->thread.fpcntl, 12);
240 memcpy(fpu->fpregs, current->thread.fp, 96);
241 /* Convert internal fpu reg representation
242 * into long double format
244 for (i = 0; i < 24; i += 3)
245 fpu->fpregs[i] = ((fpu->fpregs[i] & 0xffff0000) << 15) |
246 ((fpu->fpregs[i] & 0x0000ffff) << 16);
250 /* First dump the fpu context to avoid protocol violation. */
251 asm volatile ("fsave %0" :: "m" (fpustate[0]) : "memory");
252 if (!CPU_IS_060 ? !fpustate[0] : !fpustate[2])
255 if (CPU_IS_COLDFIRE) {
256 asm volatile ("fmovel %/fpiar,%0\n\t"
257 "fmovel %/fpcr,%1\n\t"
258 "fmovel %/fpsr,%2\n\t"
259 "fmovemd %/fp0-%/fp7,%3"
261 : "m" (fpu->fpcntl[0]),
262 "m" (fpu->fpcntl[1]),
263 "m" (fpu->fpcntl[2]),
267 asm volatile ("fmovem %/fpiar/%/fpcr/%/fpsr,%0"
269 : "m" (fpu->fpcntl[0])
271 asm volatile ("fmovemx %/fp0-%/fp7,%0"
273 : "m" (fpu->fpregs[0])
279 EXPORT_SYMBOL(dump_fpu);
280 #endif /* CONFIG_FPU */
282 unsigned long get_wchan(struct task_struct *p)
284 unsigned long fp, pc;
285 unsigned long stack_page;
287 if (!p || p == current || p->state == TASK_RUNNING)
290 stack_page = (unsigned long)task_stack_page(p);
291 fp = ((struct switch_stack *)p->thread.ksp)->a6;
293 if (fp < stack_page+sizeof(struct thread_info) ||
294 fp >= 8184+stack_page)
296 pc = ((unsigned long *)fp)[1];
297 if (!in_sched_functions(pc))
299 fp = *(unsigned long *) fp;
300 } while (count++ < 16);