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 #include <linux/rcupdate.h>
29
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>
35
36
37 asmlinkage void ret_from_fork(void);
38
39
40 /*
41 * Return saved PC from a blocked thread
42 */
thread_saved_pc(struct task_struct * tsk)43 unsigned long thread_saved_pc(struct task_struct *tsk)
44 {
45 struct switch_stack *sw = (struct switch_stack *)tsk->thread.ksp;
46 /* Check whether the thread is blocked in resume() */
47 if (in_sched_functions(sw->retpc))
48 return ((unsigned long *)sw->a6)[1];
49 else
50 return sw->retpc;
51 }
52
53 /*
54 * The idle loop on an m68k..
55 */
default_idle(void)56 static void default_idle(void)
57 {
58 if (!need_resched())
59 #if defined(MACH_ATARI_ONLY)
60 /* block out HSYNC on the atari (falcon) */
61 __asm__("stop #0x2200" : : : "cc");
62 #else
63 __asm__("stop #0x2000" : : : "cc");
64 #endif
65 }
66
67 void (*idle)(void) = default_idle;
68
69 /*
70 * The idle thread. There's no useful work to be
71 * done, so just try to conserve power and have a
72 * low exit latency (ie sit in a loop waiting for
73 * somebody to say that they'd like to reschedule)
74 */
cpu_idle(void)75 void cpu_idle(void)
76 {
77 /* endless idle loop with no priority at all */
78 while (1) {
79 rcu_idle_enter();
80 while (!need_resched())
81 idle();
82 rcu_idle_exit();
83 schedule_preempt_disabled();
84 }
85 }
86
machine_restart(char * __unused)87 void machine_restart(char * __unused)
88 {
89 if (mach_reset)
90 mach_reset();
91 for (;;);
92 }
93
machine_halt(void)94 void machine_halt(void)
95 {
96 if (mach_halt)
97 mach_halt();
98 for (;;);
99 }
100
machine_power_off(void)101 void machine_power_off(void)
102 {
103 if (mach_power_off)
104 mach_power_off();
105 for (;;);
106 }
107
108 void (*pm_power_off)(void) = machine_power_off;
109 EXPORT_SYMBOL(pm_power_off);
110
show_regs(struct pt_regs * regs)111 void show_regs(struct pt_regs * regs)
112 {
113 printk("\n");
114 printk("Format %02x Vector: %04x PC: %08lx Status: %04x %s\n",
115 regs->format, regs->vector, regs->pc, regs->sr, print_tainted());
116 printk("ORIG_D0: %08lx D0: %08lx A2: %08lx A1: %08lx\n",
117 regs->orig_d0, regs->d0, regs->a2, regs->a1);
118 printk("A0: %08lx D5: %08lx D4: %08lx\n",
119 regs->a0, regs->d5, regs->d4);
120 printk("D3: %08lx D2: %08lx D1: %08lx\n",
121 regs->d3, regs->d2, regs->d1);
122 if (!(regs->sr & PS_S))
123 printk("USP: %08lx\n", rdusp());
124 }
125
126 /*
127 * Create a kernel thread
128 */
kernel_thread(int (* fn)(void *),void * arg,unsigned long flags)129 int kernel_thread(int (*fn)(void *), void * arg, unsigned long flags)
130 {
131 int pid;
132 mm_segment_t fs;
133
134 fs = get_fs();
135 set_fs (KERNEL_DS);
136
137 {
138 register long retval __asm__ ("d0");
139 register long clone_arg __asm__ ("d1") = flags | CLONE_VM | CLONE_UNTRACED;
140
141 retval = __NR_clone;
142 __asm__ __volatile__
143 ("clrl %%d2\n\t"
144 "trap #0\n\t" /* Linux/m68k system call */
145 "tstl %0\n\t" /* child or parent */
146 "jne 1f\n\t" /* parent - jump */
147 #ifdef CONFIG_MMU
148 "lea %%sp@(%c7),%6\n\t" /* reload current */
149 "movel %6@,%6\n\t"
150 #endif
151 "movel %3,%%sp@-\n\t" /* push argument */
152 "jsr %4@\n\t" /* call fn */
153 "movel %0,%%d1\n\t" /* pass exit value */
154 "movel %2,%%d0\n\t" /* exit */
155 "trap #0\n"
156 "1:"
157 : "+d" (retval)
158 : "i" (__NR_clone), "i" (__NR_exit),
159 "r" (arg), "a" (fn), "d" (clone_arg), "r" (current),
160 "i" (-THREAD_SIZE)
161 : "d2");
162
163 pid = retval;
164 }
165
166 set_fs (fs);
167 return pid;
168 }
169 EXPORT_SYMBOL(kernel_thread);
170
flush_thread(void)171 void flush_thread(void)
172 {
173 current->thread.fs = __USER_DS;
174 #ifdef CONFIG_FPU
175 if (!FPU_IS_EMU) {
176 unsigned long zero = 0;
177 asm volatile("frestore %0": :"m" (zero));
178 }
179 #endif
180 }
181
182 /*
183 * "m68k_fork()".. By the time we get here, the
184 * non-volatile registers have also been saved on the
185 * stack. We do some ugly pointer stuff here.. (see
186 * also copy_thread)
187 */
188
m68k_fork(struct pt_regs * regs)189 asmlinkage int m68k_fork(struct pt_regs *regs)
190 {
191 #ifdef CONFIG_MMU
192 return do_fork(SIGCHLD, rdusp(), regs, 0, NULL, NULL);
193 #else
194 return -EINVAL;
195 #endif
196 }
197
m68k_vfork(struct pt_regs * regs)198 asmlinkage int m68k_vfork(struct pt_regs *regs)
199 {
200 return do_fork(CLONE_VFORK | CLONE_VM | SIGCHLD, rdusp(), regs, 0,
201 NULL, NULL);
202 }
203
m68k_clone(struct pt_regs * regs)204 asmlinkage int m68k_clone(struct pt_regs *regs)
205 {
206 unsigned long clone_flags;
207 unsigned long newsp;
208 int __user *parent_tidptr, *child_tidptr;
209
210 /* syscall2 puts clone_flags in d1 and usp in d2 */
211 clone_flags = regs->d1;
212 newsp = regs->d2;
213 parent_tidptr = (int __user *)regs->d3;
214 child_tidptr = (int __user *)regs->d4;
215 if (!newsp)
216 newsp = rdusp();
217 return do_fork(clone_flags, newsp, regs, 0,
218 parent_tidptr, child_tidptr);
219 }
220
copy_thread(unsigned long clone_flags,unsigned long usp,unsigned long unused,struct task_struct * p,struct pt_regs * regs)221 int copy_thread(unsigned long clone_flags, unsigned long usp,
222 unsigned long unused,
223 struct task_struct * p, struct pt_regs * regs)
224 {
225 struct pt_regs * childregs;
226 struct switch_stack * childstack, *stack;
227 unsigned long *retp;
228
229 childregs = (struct pt_regs *) (task_stack_page(p) + THREAD_SIZE) - 1;
230
231 *childregs = *regs;
232 childregs->d0 = 0;
233
234 retp = ((unsigned long *) regs);
235 stack = ((struct switch_stack *) retp) - 1;
236
237 childstack = ((struct switch_stack *) childregs) - 1;
238 *childstack = *stack;
239 childstack->retpc = (unsigned long)ret_from_fork;
240
241 p->thread.usp = usp;
242 p->thread.ksp = (unsigned long)childstack;
243
244 if (clone_flags & CLONE_SETTLS)
245 task_thread_info(p)->tp_value = regs->d5;
246
247 /*
248 * Must save the current SFC/DFC value, NOT the value when
249 * the parent was last descheduled - RGH 10-08-96
250 */
251 p->thread.fs = get_fs().seg;
252
253 #ifdef CONFIG_FPU
254 if (!FPU_IS_EMU) {
255 /* Copy the current fpu state */
256 asm volatile ("fsave %0" : : "m" (p->thread.fpstate[0]) : "memory");
257
258 if (!CPU_IS_060 ? p->thread.fpstate[0] : p->thread.fpstate[2]) {
259 if (CPU_IS_COLDFIRE) {
260 asm volatile ("fmovemd %/fp0-%/fp7,%0\n\t"
261 "fmovel %/fpiar,%1\n\t"
262 "fmovel %/fpcr,%2\n\t"
263 "fmovel %/fpsr,%3"
264 :
265 : "m" (p->thread.fp[0]),
266 "m" (p->thread.fpcntl[0]),
267 "m" (p->thread.fpcntl[1]),
268 "m" (p->thread.fpcntl[2])
269 : "memory");
270 } else {
271 asm volatile ("fmovemx %/fp0-%/fp7,%0\n\t"
272 "fmoveml %/fpiar/%/fpcr/%/fpsr,%1"
273 :
274 : "m" (p->thread.fp[0]),
275 "m" (p->thread.fpcntl[0])
276 : "memory");
277 }
278 }
279
280 /* Restore the state in case the fpu was busy */
281 asm volatile ("frestore %0" : : "m" (p->thread.fpstate[0]));
282 }
283 #endif /* CONFIG_FPU */
284
285 return 0;
286 }
287
288 /* Fill in the fpu structure for a core dump. */
289 #ifdef CONFIG_FPU
dump_fpu(struct pt_regs * regs,struct user_m68kfp_struct * fpu)290 int dump_fpu (struct pt_regs *regs, struct user_m68kfp_struct *fpu)
291 {
292 char fpustate[216];
293
294 if (FPU_IS_EMU) {
295 int i;
296
297 memcpy(fpu->fpcntl, current->thread.fpcntl, 12);
298 memcpy(fpu->fpregs, current->thread.fp, 96);
299 /* Convert internal fpu reg representation
300 * into long double format
301 */
302 for (i = 0; i < 24; i += 3)
303 fpu->fpregs[i] = ((fpu->fpregs[i] & 0xffff0000) << 15) |
304 ((fpu->fpregs[i] & 0x0000ffff) << 16);
305 return 1;
306 }
307
308 /* First dump the fpu context to avoid protocol violation. */
309 asm volatile ("fsave %0" :: "m" (fpustate[0]) : "memory");
310 if (!CPU_IS_060 ? !fpustate[0] : !fpustate[2])
311 return 0;
312
313 if (CPU_IS_COLDFIRE) {
314 asm volatile ("fmovel %/fpiar,%0\n\t"
315 "fmovel %/fpcr,%1\n\t"
316 "fmovel %/fpsr,%2\n\t"
317 "fmovemd %/fp0-%/fp7,%3"
318 :
319 : "m" (fpu->fpcntl[0]),
320 "m" (fpu->fpcntl[1]),
321 "m" (fpu->fpcntl[2]),
322 "m" (fpu->fpregs[0])
323 : "memory");
324 } else {
325 asm volatile ("fmovem %/fpiar/%/fpcr/%/fpsr,%0"
326 :
327 : "m" (fpu->fpcntl[0])
328 : "memory");
329 asm volatile ("fmovemx %/fp0-%/fp7,%0"
330 :
331 : "m" (fpu->fpregs[0])
332 : "memory");
333 }
334
335 return 1;
336 }
337 EXPORT_SYMBOL(dump_fpu);
338 #endif /* CONFIG_FPU */
339
340 /*
341 * sys_execve() executes a new program.
342 */
sys_execve(const char __user * name,const char __user * const __user * argv,const char __user * const __user * envp)343 asmlinkage int sys_execve(const char __user *name,
344 const char __user *const __user *argv,
345 const char __user *const __user *envp)
346 {
347 int error;
348 char * filename;
349 struct pt_regs *regs = (struct pt_regs *) &name;
350
351 filename = getname(name);
352 error = PTR_ERR(filename);
353 if (IS_ERR(filename))
354 return error;
355 error = do_execve(filename, argv, envp, regs);
356 putname(filename);
357 return error;
358 }
359
get_wchan(struct task_struct * p)360 unsigned long get_wchan(struct task_struct *p)
361 {
362 unsigned long fp, pc;
363 unsigned long stack_page;
364 int count = 0;
365 if (!p || p == current || p->state == TASK_RUNNING)
366 return 0;
367
368 stack_page = (unsigned long)task_stack_page(p);
369 fp = ((struct switch_stack *)p->thread.ksp)->a6;
370 do {
371 if (fp < stack_page+sizeof(struct thread_info) ||
372 fp >= 8184+stack_page)
373 return 0;
374 pc = ((unsigned long *)fp)[1];
375 if (!in_sched_functions(pc))
376 return pc;
377 fp = *(unsigned long *) fp;
378 } while (count++ < 16);
379 return 0;
380 }
381