[PATCH] Don't export machine_restart, machine_halt, or machine_power_off.
[linux-2.6.git] / arch / sh / kernel / process.c
1 /* $Id: process.c,v 1.28 2004/05/05 16:54:23 lethal Exp $
2  *
3  *  linux/arch/sh/kernel/process.c
4  *
5  *  Copyright (C) 1995  Linus Torvalds
6  *
7  *  SuperH version:  Copyright (C) 1999, 2000  Niibe Yutaka & Kaz Kojima
8  */
9
10 /*
11  * This file handles the architecture-dependent parts of process handling..
12  */
13
14 #include <linux/module.h>
15 #include <linux/unistd.h>
16 #include <linux/mm.h>
17 #include <linux/elfcore.h>
18 #include <linux/slab.h>
19 #include <linux/a.out.h>
20 #include <linux/ptrace.h>
21 #include <linux/platform.h>
22 #include <linux/kallsyms.h>
23
24 #include <asm/io.h>
25 #include <asm/uaccess.h>
26 #include <asm/mmu_context.h>
27 #include <asm/elf.h>
28 #if defined(CONFIG_SH_HS7751RVOIP)
29 #include <asm/hs7751rvoip/hs7751rvoip.h>
30 #elif defined(CONFIG_SH_RTS7751R2D)
31 #include <asm/rts7751r2d/rts7751r2d.h>
32 #endif
33
34 static int hlt_counter=0;
35
36 int ubc_usercnt = 0;
37
38 #define HARD_IDLE_TIMEOUT (HZ / 3)
39
40 void disable_hlt(void)
41 {
42         hlt_counter++;
43 }
44
45 EXPORT_SYMBOL(disable_hlt);
46
47 void enable_hlt(void)
48 {
49         hlt_counter--;
50 }
51
52 EXPORT_SYMBOL(enable_hlt);
53
54 void default_idle(void)
55 {
56         /* endless idle loop with no priority at all */
57         while (1) {
58                 if (hlt_counter) {
59                         while (1)
60                                 if (need_resched())
61                                         break;
62                 } else {
63                         while (!need_resched())
64                                 cpu_sleep();
65                 }
66
67                 schedule();
68         }
69 }
70
71 void cpu_idle(void)
72 {
73         default_idle();
74 }
75
76 void machine_restart(char * __unused)
77 {
78         /* SR.BL=1 and invoke address error to let CPU reset (manual reset) */
79         asm volatile("ldc %0, sr\n\t"
80                      "mov.l @%1, %0" : : "r" (0x10000000), "r" (0x80000001));
81 }
82
83 void machine_halt(void)
84 {
85 #if defined(CONFIG_SH_HS7751RVOIP)
86         unsigned short value;
87
88         value = ctrl_inw(PA_OUTPORTR);
89         ctrl_outw((value & 0xffdf), PA_OUTPORTR);
90 #elif defined(CONFIG_SH_RTS7751R2D)
91         ctrl_outw(0x0001, PA_POWOFF);
92 #endif
93         while (1)
94                 cpu_sleep();
95 }
96
97 void machine_power_off(void)
98 {
99 #if defined(CONFIG_SH_HS7751RVOIP)
100         unsigned short value;
101
102         value = ctrl_inw(PA_OUTPORTR);
103         ctrl_outw((value & 0xffdf), PA_OUTPORTR);
104 #elif defined(CONFIG_SH_RTS7751R2D)
105         ctrl_outw(0x0001, PA_POWOFF);
106 #endif
107 }
108
109 void show_regs(struct pt_regs * regs)
110 {
111         printk("\n");
112         printk("Pid : %d, Comm: %20s\n", current->pid, current->comm);
113         print_symbol("PC is at %s\n", regs->pc);
114         printk("PC  : %08lx SP  : %08lx SR  : %08lx ",
115                regs->pc, regs->regs[15], regs->sr);
116 #ifdef CONFIG_MMU
117         printk("TEA : %08x    ", ctrl_inl(MMU_TEA));
118 #else
119         printk("                  ");
120 #endif
121         printk("%s\n", print_tainted());
122
123         printk("R0  : %08lx R1  : %08lx R2  : %08lx R3  : %08lx\n",
124                regs->regs[0],regs->regs[1],
125                regs->regs[2],regs->regs[3]);
126         printk("R4  : %08lx R5  : %08lx R6  : %08lx R7  : %08lx\n",
127                regs->regs[4],regs->regs[5],
128                regs->regs[6],regs->regs[7]);
129         printk("R8  : %08lx R9  : %08lx R10 : %08lx R11 : %08lx\n",
130                regs->regs[8],regs->regs[9],
131                regs->regs[10],regs->regs[11]);
132         printk("R12 : %08lx R13 : %08lx R14 : %08lx\n",
133                regs->regs[12],regs->regs[13],
134                regs->regs[14]);
135         printk("MACH: %08lx MACL: %08lx GBR : %08lx PR  : %08lx\n",
136                regs->mach, regs->macl, regs->gbr, regs->pr);
137
138         /*
139          * If we're in kernel mode, dump the stack too..
140          */
141         if (!user_mode(regs)) {
142                 extern void show_task(unsigned long *sp);
143                 unsigned long sp = regs->regs[15];
144
145                 show_task((unsigned long *)sp);
146         }
147 }
148
149 /*
150  * Create a kernel thread
151  */
152
153 /*
154  * This is the mechanism for creating a new kernel thread.
155  *
156  */
157 extern void kernel_thread_helper(void);
158 __asm__(".align 5\n"
159         "kernel_thread_helper:\n\t"
160         "jsr    @r5\n\t"
161         " nop\n\t"
162         "mov.l  1f, r1\n\t"
163         "jsr    @r1\n\t"
164         " mov   r0, r4\n\t"
165         ".align 2\n\t"
166         "1:.long do_exit");
167
168 int kernel_thread(int (*fn)(void *), void * arg, unsigned long flags)
169 {       /* Don't use this in BL=1(cli).  Or else, CPU resets! */
170         struct pt_regs regs;
171
172         memset(&regs, 0, sizeof(regs));
173         regs.regs[4] = (unsigned long) arg;
174         regs.regs[5] = (unsigned long) fn;
175
176         regs.pc = (unsigned long) kernel_thread_helper;
177         regs.sr = (1 << 30);
178
179         /* Ok, create the new process.. */
180         return do_fork(flags | CLONE_VM | CLONE_UNTRACED, 0, &regs, 0, NULL, NULL);
181 }
182
183 /*
184  * Free current thread data structures etc..
185  */
186 void exit_thread(void)
187 {
188         if (current->thread.ubc_pc) {
189                 current->thread.ubc_pc = 0;
190                 ubc_usercnt -= 1;
191         }
192 }
193
194 void flush_thread(void)
195 {
196 #if defined(CONFIG_SH_FPU)
197         struct task_struct *tsk = current;
198         struct pt_regs *regs = (struct pt_regs *)
199                                 ((unsigned long)tsk->thread_info
200                                  + THREAD_SIZE - sizeof(struct pt_regs)
201                                  - sizeof(unsigned long));
202
203         /* Forget lazy FPU state */
204         clear_fpu(tsk, regs);
205         clear_used_math();
206 #endif
207 }
208
209 void release_thread(struct task_struct *dead_task)
210 {
211         /* do nothing */
212 }
213
214 /* Fill in the fpu structure for a core dump.. */
215 int dump_fpu(struct pt_regs *regs, elf_fpregset_t *fpu)
216 {
217         int fpvalid = 0;
218
219 #if defined(CONFIG_SH_FPU)
220         struct task_struct *tsk = current;
221
222         fpvalid = !!tsk_used_math(tsk);
223         if (fpvalid) {
224                 unlazy_fpu(tsk, regs);
225                 memcpy(fpu, &tsk->thread.fpu.hard, sizeof(*fpu));
226         }
227 #endif
228
229         return fpvalid;
230 }
231
232 /* 
233  * Capture the user space registers if the task is not running (in user space)
234  */
235 int dump_task_regs(struct task_struct *tsk, elf_gregset_t *regs)
236 {
237         struct pt_regs ptregs;
238         
239         ptregs = *(struct pt_regs *)
240                 ((unsigned long)tsk->thread_info + THREAD_SIZE
241                  - sizeof(struct pt_regs)
242 #ifdef CONFIG_SH_DSP
243                  - sizeof(struct pt_dspregs)
244 #endif
245                  - sizeof(unsigned long));
246         elf_core_copy_regs(regs, &ptregs);
247
248         return 1;
249 }
250
251 int
252 dump_task_fpu (struct task_struct *tsk, elf_fpregset_t *fpu)
253 {
254         int fpvalid = 0;
255
256 #if defined(CONFIG_SH_FPU)
257         fpvalid = !!tsk_used_math(tsk);
258         if (fpvalid) {
259                 struct pt_regs *regs = (struct pt_regs *)
260                                         ((unsigned long)tsk->thread_info
261                                          + THREAD_SIZE - sizeof(struct pt_regs)
262                                          - sizeof(unsigned long));
263                 unlazy_fpu(tsk, regs);
264                 memcpy(fpu, &tsk->thread.fpu.hard, sizeof(*fpu));
265         }
266 #endif
267
268         return fpvalid;
269 }
270
271 asmlinkage void ret_from_fork(void);
272
273 int copy_thread(int nr, unsigned long clone_flags, unsigned long usp,
274                 unsigned long unused,
275                 struct task_struct *p, struct pt_regs *regs)
276 {
277         struct pt_regs *childregs;
278 #if defined(CONFIG_SH_FPU)
279         struct task_struct *tsk = current;
280
281         unlazy_fpu(tsk, regs);
282         p->thread.fpu = tsk->thread.fpu;
283         copy_to_stopped_child_used_math(p);
284 #endif
285
286         childregs = ((struct pt_regs *)
287                 (THREAD_SIZE + (unsigned long) p->thread_info)
288 #ifdef CONFIG_SH_DSP
289                 - sizeof(struct pt_dspregs)
290 #endif
291                 - sizeof(unsigned long)) - 1;
292         *childregs = *regs;
293
294         if (user_mode(regs)) {
295                 childregs->regs[15] = usp;
296         } else {
297                 childregs->regs[15] = (unsigned long)p->thread_info + THREAD_SIZE;
298         }
299         if (clone_flags & CLONE_SETTLS) {
300                 childregs->gbr = childregs->regs[0];
301         }
302         childregs->regs[0] = 0; /* Set return value for child */
303
304         p->thread.sp = (unsigned long) childregs;
305         p->thread.pc = (unsigned long) ret_from_fork;
306
307         p->thread.ubc_pc = 0;
308
309         return 0;
310 }
311
312 /*
313  * fill in the user structure for a core dump..
314  */
315 void dump_thread(struct pt_regs * regs, struct user * dump)
316 {
317         dump->magic = CMAGIC;
318         dump->start_code = current->mm->start_code;
319         dump->start_data  = current->mm->start_data;
320         dump->start_stack = regs->regs[15] & ~(PAGE_SIZE - 1);
321         dump->u_tsize = (current->mm->end_code - dump->start_code) >> PAGE_SHIFT;
322         dump->u_dsize = (current->mm->brk + (PAGE_SIZE-1) - dump->start_data) >> PAGE_SHIFT;
323         dump->u_ssize = (current->mm->start_stack - dump->start_stack +
324                          PAGE_SIZE - 1) >> PAGE_SHIFT;
325         /* Debug registers will come here. */
326
327         dump->regs = *regs;
328
329         dump->u_fpvalid = dump_fpu(regs, &dump->fpu);
330 }
331
332 /* Tracing by user break controller.  */
333 static void
334 ubc_set_tracing(int asid, unsigned long pc)
335 {
336         ctrl_outl(pc, UBC_BARA);
337
338         /* We don't have any ASID settings for the SH-2! */
339         if (cpu_data->type != CPU_SH7604)
340                 ctrl_outb(asid, UBC_BASRA);
341
342         ctrl_outl(0, UBC_BAMRA);
343
344         if (cpu_data->type == CPU_SH7729) {
345                 ctrl_outw(BBR_INST | BBR_READ | BBR_CPU, UBC_BBRA);
346                 ctrl_outl(BRCR_PCBA | BRCR_PCTE, UBC_BRCR);
347         } else {
348                 ctrl_outw(BBR_INST | BBR_READ, UBC_BBRA);
349                 ctrl_outw(BRCR_PCBA, UBC_BRCR);
350         }
351 }
352
353 /*
354  *      switch_to(x,y) should switch tasks from x to y.
355  *
356  */
357 struct task_struct *__switch_to(struct task_struct *prev, struct task_struct *next)
358 {
359 #if defined(CONFIG_SH_FPU)
360         struct pt_regs *regs = (struct pt_regs *)
361                                 ((unsigned long)prev->thread_info
362                                  + THREAD_SIZE - sizeof(struct pt_regs)
363                                  - sizeof(unsigned long));
364         unlazy_fpu(prev, regs);
365 #endif
366
367 #ifdef CONFIG_PREEMPT
368         {
369                 unsigned long flags;
370                 struct pt_regs *regs;
371
372                 local_irq_save(flags);
373                 regs = (struct pt_regs *)
374                         ((unsigned long)prev->thread_info
375                          + THREAD_SIZE - sizeof(struct pt_regs)
376 #ifdef CONFIG_SH_DSP
377                          - sizeof(struct pt_dspregs)
378 #endif
379                          - sizeof(unsigned long));
380                 if (user_mode(regs) && regs->regs[15] >= 0xc0000000) {
381                         int offset = (int)regs->regs[15];
382
383                         /* Reset stack pointer: clear critical region mark */
384                         regs->regs[15] = regs->regs[1];
385                         if (regs->pc < regs->regs[0])
386                                 /* Go to rewind point */
387                                 regs->pc = regs->regs[0] + offset;
388                 }
389                 local_irq_restore(flags);
390         }
391 #endif
392
393         /*
394          * Restore the kernel mode register
395          *      k7 (r7_bank1)
396          */
397         asm volatile("ldc       %0, r7_bank"
398                      : /* no output */
399                      : "r" (next->thread_info));
400
401 #ifdef CONFIG_MMU
402         /* If no tasks are using the UBC, we're done */
403         if (ubc_usercnt == 0)
404                 /* If no tasks are using the UBC, we're done */;
405         else if (next->thread.ubc_pc && next->mm) {
406                 ubc_set_tracing(next->mm->context & MMU_CONTEXT_ASID_MASK,
407                                 next->thread.ubc_pc);
408         } else {
409                 ctrl_outw(0, UBC_BBRA);
410                 ctrl_outw(0, UBC_BBRB);
411         }
412 #endif
413
414         return prev;
415 }
416
417 asmlinkage int sys_fork(unsigned long r4, unsigned long r5,
418                         unsigned long r6, unsigned long r7,
419                         struct pt_regs regs)
420 {
421 #ifdef CONFIG_MMU
422         return do_fork(SIGCHLD, regs.regs[15], &regs, 0, NULL, NULL);
423 #else
424         /* fork almost works, enough to trick you into looking elsewhere :-( */
425         return -EINVAL;
426 #endif
427 }
428
429 asmlinkage int sys_clone(unsigned long clone_flags, unsigned long newsp,
430                          unsigned long parent_tidptr,
431                          unsigned long child_tidptr,
432                          struct pt_regs regs)
433 {
434         if (!newsp)
435                 newsp = regs.regs[15];
436         return do_fork(clone_flags, newsp, &regs, 0,
437                         (int __user *)parent_tidptr, (int __user *)child_tidptr);
438 }
439
440 /*
441  * This is trivial, and on the face of it looks like it
442  * could equally well be done in user mode.
443  *
444  * Not so, for quite unobvious reasons - register pressure.
445  * In user mode vfork() cannot have a stack frame, and if
446  * done by calling the "clone()" system call directly, you
447  * do not have enough call-clobbered registers to hold all
448  * the information you need.
449  */
450 asmlinkage int sys_vfork(unsigned long r4, unsigned long r5,
451                          unsigned long r6, unsigned long r7,
452                          struct pt_regs regs)
453 {
454         return do_fork(CLONE_VFORK | CLONE_VM | SIGCHLD, regs.regs[15], &regs,
455                        0, NULL, NULL);
456 }
457
458 /*
459  * sys_execve() executes a new program.
460  */
461 asmlinkage int sys_execve(char *ufilename, char **uargv,
462                           char **uenvp, unsigned long r7,
463                           struct pt_regs regs)
464 {
465         int error;
466         char *filename;
467
468         filename = getname((char __user *)ufilename);
469         error = PTR_ERR(filename);
470         if (IS_ERR(filename))
471                 goto out;
472
473         error = do_execve(filename,
474                           (char __user * __user *)uargv,
475                           (char __user * __user *)uenvp,
476                           &regs);
477         if (error == 0) {
478                 task_lock(current);
479                 current->ptrace &= ~PT_DTRACE;
480                 task_unlock(current);
481         }
482         putname(filename);
483 out:
484         return error;
485 }
486
487 unsigned long get_wchan(struct task_struct *p)
488 {
489         unsigned long schedule_frame;
490         unsigned long pc;
491
492         if (!p || p == current || p->state == TASK_RUNNING)
493                 return 0;
494
495         /*
496          * The same comment as on the Alpha applies here, too ...
497          */
498         pc = thread_saved_pc(p);
499         if (in_sched_functions(pc)) {
500                 schedule_frame = ((unsigned long *)(long)p->thread.sp)[1];
501                 return (unsigned long)((unsigned long *)schedule_frame)[1];
502         }
503         return pc;
504 }
505
506 asmlinkage void break_point_trap(unsigned long r4, unsigned long r5,
507                                  unsigned long r6, unsigned long r7,
508                                  struct pt_regs regs)
509 {
510         /* Clear tracing.  */
511         ctrl_outw(0, UBC_BBRA);
512         ctrl_outw(0, UBC_BBRB);
513         current->thread.ubc_pc = 0;
514         ubc_usercnt -= 1;
515
516         force_sig(SIGTRAP, current);
517 }
518
519 asmlinkage void break_point_trap_software(unsigned long r4, unsigned long r5,
520                                           unsigned long r6, unsigned long r7,
521                                           struct pt_regs regs)
522 {
523         regs.pc -= 2;
524         force_sig(SIGTRAP, current);
525 }