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 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 while (!need_resched())
80 idle();
81 preempt_enable_no_resched();
82 schedule();
83 preempt_disable();
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 "lea %%sp@(%c7),%6\n\t" /* reload current */
148 "movel %6@,%6\n\t"
149 "movel %3,%%sp@-\n\t" /* push argument */
150 "jsr %4@\n\t" /* call fn */
151 "movel %0,%%d1\n\t" /* pass exit value */
152 "movel %2,%%d0\n\t" /* exit */
153 "trap #0\n"
154 "1:"
155 : "+d" (retval)
156 : "i" (__NR_clone), "i" (__NR_exit),
157 "r" (arg), "a" (fn), "d" (clone_arg), "r" (current),
158 "i" (-THREAD_SIZE)
159 : "d2");
160
161 pid = retval;
162 }
163
164 set_fs (fs);
165 return pid;
166 }
167 EXPORT_SYMBOL(kernel_thread);
168
flush_thread(void)169 void flush_thread(void)
170 {
171 unsigned long zero = 0;
172
173 current->thread.fs = __USER_DS;
174 if (!FPU_IS_EMU)
175 asm volatile("frestore %0": :"m" (zero));
176 }
177
178 /*
179 * "m68k_fork()".. By the time we get here, the
180 * non-volatile registers have also been saved on the
181 * stack. We do some ugly pointer stuff here.. (see
182 * also copy_thread)
183 */
184
m68k_fork(struct pt_regs * regs)185 asmlinkage int m68k_fork(struct pt_regs *regs)
186 {
187 return do_fork(SIGCHLD, rdusp(), regs, 0, NULL, NULL);
188 }
189
m68k_vfork(struct pt_regs * regs)190 asmlinkage int m68k_vfork(struct pt_regs *regs)
191 {
192 return do_fork(CLONE_VFORK | CLONE_VM | SIGCHLD, rdusp(), regs, 0,
193 NULL, NULL);
194 }
195
m68k_clone(struct pt_regs * regs)196 asmlinkage int m68k_clone(struct pt_regs *regs)
197 {
198 unsigned long clone_flags;
199 unsigned long newsp;
200 int __user *parent_tidptr, *child_tidptr;
201
202 /* syscall2 puts clone_flags in d1 and usp in d2 */
203 clone_flags = regs->d1;
204 newsp = regs->d2;
205 parent_tidptr = (int __user *)regs->d3;
206 child_tidptr = (int __user *)regs->d4;
207 if (!newsp)
208 newsp = rdusp();
209 return do_fork(clone_flags, newsp, regs, 0,
210 parent_tidptr, child_tidptr);
211 }
212
copy_thread(unsigned long clone_flags,unsigned long usp,unsigned long unused,struct task_struct * p,struct pt_regs * regs)213 int copy_thread(unsigned long clone_flags, unsigned long usp,
214 unsigned long unused,
215 struct task_struct * p, struct pt_regs * regs)
216 {
217 struct pt_regs * childregs;
218 struct switch_stack * childstack, *stack;
219 unsigned long *retp;
220
221 childregs = (struct pt_regs *) (task_stack_page(p) + THREAD_SIZE) - 1;
222
223 *childregs = *regs;
224 childregs->d0 = 0;
225
226 retp = ((unsigned long *) regs);
227 stack = ((struct switch_stack *) retp) - 1;
228
229 childstack = ((struct switch_stack *) childregs) - 1;
230 *childstack = *stack;
231 childstack->retpc = (unsigned long)ret_from_fork;
232
233 p->thread.usp = usp;
234 p->thread.ksp = (unsigned long)childstack;
235
236 if (clone_flags & CLONE_SETTLS)
237 task_thread_info(p)->tp_value = regs->d5;
238
239 /*
240 * Must save the current SFC/DFC value, NOT the value when
241 * the parent was last descheduled - RGH 10-08-96
242 */
243 p->thread.fs = get_fs().seg;
244
245 if (!FPU_IS_EMU) {
246 /* Copy the current fpu state */
247 asm volatile ("fsave %0" : : "m" (p->thread.fpstate[0]) : "memory");
248
249 if (!CPU_IS_060 ? p->thread.fpstate[0] : p->thread.fpstate[2]) {
250 if (CPU_IS_COLDFIRE) {
251 asm volatile ("fmovemd %/fp0-%/fp7,%0\n\t"
252 "fmovel %/fpiar,%1\n\t"
253 "fmovel %/fpcr,%2\n\t"
254 "fmovel %/fpsr,%3"
255 :
256 : "m" (p->thread.fp[0]),
257 "m" (p->thread.fpcntl[0]),
258 "m" (p->thread.fpcntl[1]),
259 "m" (p->thread.fpcntl[2])
260 : "memory");
261 } else {
262 asm volatile ("fmovemx %/fp0-%/fp7,%0\n\t"
263 "fmoveml %/fpiar/%/fpcr/%/fpsr,%1"
264 :
265 : "m" (p->thread.fp[0]),
266 "m" (p->thread.fpcntl[0])
267 : "memory");
268 }
269 }
270
271 /* Restore the state in case the fpu was busy */
272 asm volatile ("frestore %0" : : "m" (p->thread.fpstate[0]));
273 }
274
275 return 0;
276 }
277
278 /* Fill in the fpu structure for a core dump. */
279
dump_fpu(struct pt_regs * regs,struct user_m68kfp_struct * fpu)280 int dump_fpu (struct pt_regs *regs, struct user_m68kfp_struct *fpu)
281 {
282 char fpustate[216];
283
284 if (FPU_IS_EMU) {
285 int i;
286
287 memcpy(fpu->fpcntl, current->thread.fpcntl, 12);
288 memcpy(fpu->fpregs, current->thread.fp, 96);
289 /* Convert internal fpu reg representation
290 * into long double format
291 */
292 for (i = 0; i < 24; i += 3)
293 fpu->fpregs[i] = ((fpu->fpregs[i] & 0xffff0000) << 15) |
294 ((fpu->fpregs[i] & 0x0000ffff) << 16);
295 return 1;
296 }
297
298 /* First dump the fpu context to avoid protocol violation. */
299 asm volatile ("fsave %0" :: "m" (fpustate[0]) : "memory");
300 if (!CPU_IS_060 ? !fpustate[0] : !fpustate[2])
301 return 0;
302
303 if (CPU_IS_COLDFIRE) {
304 asm volatile ("fmovel %/fpiar,%0\n\t"
305 "fmovel %/fpcr,%1\n\t"
306 "fmovel %/fpsr,%2\n\t"
307 "fmovemd %/fp0-%/fp7,%3"
308 :
309 : "m" (fpu->fpcntl[0]),
310 "m" (fpu->fpcntl[1]),
311 "m" (fpu->fpcntl[2]),
312 "m" (fpu->fpregs[0])
313 : "memory");
314 } else {
315 asm volatile ("fmovem %/fpiar/%/fpcr/%/fpsr,%0"
316 :
317 : "m" (fpu->fpcntl[0])
318 : "memory");
319 asm volatile ("fmovemx %/fp0-%/fp7,%0"
320 :
321 : "m" (fpu->fpregs[0])
322 : "memory");
323 }
324
325 return 1;
326 }
327 EXPORT_SYMBOL(dump_fpu);
328
329 /*
330 * sys_execve() executes a new program.
331 */
sys_execve(const char __user * name,const char __user * const __user * argv,const char __user * const __user * envp)332 asmlinkage int sys_execve(const char __user *name,
333 const char __user *const __user *argv,
334 const char __user *const __user *envp)
335 {
336 int error;
337 char * filename;
338 struct pt_regs *regs = (struct pt_regs *) &name;
339
340 filename = getname(name);
341 error = PTR_ERR(filename);
342 if (IS_ERR(filename))
343 return error;
344 error = do_execve(filename, argv, envp, regs);
345 putname(filename);
346 return error;
347 }
348
get_wchan(struct task_struct * p)349 unsigned long get_wchan(struct task_struct *p)
350 {
351 unsigned long fp, pc;
352 unsigned long stack_page;
353 int count = 0;
354 if (!p || p == current || p->state == TASK_RUNNING)
355 return 0;
356
357 stack_page = (unsigned long)task_stack_page(p);
358 fp = ((struct switch_stack *)p->thread.ksp)->a6;
359 do {
360 if (fp < stack_page+sizeof(struct thread_info) ||
361 fp >= 8184+stack_page)
362 return 0;
363 pc = ((unsigned long *)fp)[1];
364 if (!in_sched_functions(pc))
365 return pc;
366 fp = *(unsigned long *) fp;
367 } while (count++ < 16);
368 return 0;
369 }
370