409db6d5ec9994b53a729f755435d3aa518e3aad
[linux-2.6.git] / arch / arm / kernel / process.c
1 /*
2  *  linux/arch/arm/kernel/process.c
3  *
4  *  Copyright (C) 1996-2000 Russell King - Converted to ARM.
5  *  Original Copyright (C) 1995  Linus Torvalds
6  *
7  * This program is free software; you can redistribute it and/or modify
8  * it under the terms of the GNU General Public License version 2 as
9  * published by the Free Software Foundation.
10  */
11 #include <stdarg.h>
12
13 #include <linux/config.h>
14 #include <linux/module.h>
15 #include <linux/sched.h>
16 #include <linux/kernel.h>
17 #include <linux/mm.h>
18 #include <linux/stddef.h>
19 #include <linux/unistd.h>
20 #include <linux/ptrace.h>
21 #include <linux/slab.h>
22 #include <linux/user.h>
23 #include <linux/a.out.h>
24 #include <linux/delay.h>
25 #include <linux/reboot.h>
26 #include <linux/interrupt.h>
27 #include <linux/kallsyms.h>
28 #include <linux/init.h>
29
30 #include <asm/system.h>
31 #include <asm/io.h>
32 #include <asm/leds.h>
33 #include <asm/processor.h>
34 #include <asm/uaccess.h>
35 #include <asm/mach/time.h>
36
37 extern const char *processor_modes[];
38 extern void setup_mm_for_reboot(char mode);
39
40 static volatile int hlt_counter;
41
42 #include <asm/arch/system.h>
43
44 void disable_hlt(void)
45 {
46         hlt_counter++;
47 }
48
49 EXPORT_SYMBOL(disable_hlt);
50
51 void enable_hlt(void)
52 {
53         hlt_counter--;
54 }
55
56 EXPORT_SYMBOL(enable_hlt);
57
58 static int __init nohlt_setup(char *__unused)
59 {
60         hlt_counter = 1;
61         return 1;
62 }
63
64 static int __init hlt_setup(char *__unused)
65 {
66         hlt_counter = 0;
67         return 1;
68 }
69
70 __setup("nohlt", nohlt_setup);
71 __setup("hlt", hlt_setup);
72
73 /*
74  * The following aren't currently used.
75  */
76 void (*pm_idle)(void);
77 EXPORT_SYMBOL(pm_idle);
78
79 void (*pm_power_off)(void);
80 EXPORT_SYMBOL(pm_power_off);
81
82 /*
83  * This is our default idle handler.  We need to disable
84  * interrupts here to ensure we don't miss a wakeup call.
85  */
86 void default_idle(void)
87 {
88         local_irq_disable();
89         if (!need_resched() && !hlt_counter) {
90                 timer_dyn_reprogram();
91                 arch_idle();
92         }
93         local_irq_enable();
94 }
95
96 /*
97  * The idle thread.  We try to conserve power, while trying to keep
98  * overall latency low.  The architecture specific idle is passed
99  * a value to indicate the level of "idleness" of the system.
100  */
101 void cpu_idle(void)
102 {
103         local_fiq_enable();
104
105         /* endless idle loop with no priority at all */
106         while (1) {
107                 void (*idle)(void) = pm_idle;
108                 if (!idle)
109                         idle = default_idle;
110                 preempt_disable();
111                 leds_event(led_idle_start);
112                 while (!need_resched())
113                         idle();
114                 leds_event(led_idle_end);
115                 preempt_enable();
116                 schedule();
117         }
118 }
119
120 static char reboot_mode = 'h';
121
122 int __init reboot_setup(char *str)
123 {
124         reboot_mode = str[0];
125         return 1;
126 }
127
128 __setup("reboot=", reboot_setup);
129
130 void machine_halt(void)
131 {
132 }
133
134
135 void machine_power_off(void)
136 {
137         if (pm_power_off)
138                 pm_power_off();
139 }
140
141
142 void machine_restart(char * __unused)
143 {
144         /*
145          * Clean and disable cache, and turn off interrupts
146          */
147         cpu_proc_fin();
148
149         /*
150          * Tell the mm system that we are going to reboot -
151          * we may need it to insert some 1:1 mappings so that
152          * soft boot works.
153          */
154         setup_mm_for_reboot(reboot_mode);
155
156         /*
157          * Now call the architecture specific reboot code.
158          */
159         arch_reset(reboot_mode);
160
161         /*
162          * Whoops - the architecture was unable to reboot.
163          * Tell the user!
164          */
165         mdelay(1000);
166         printk("Reboot failed -- System halted\n");
167         while (1);
168 }
169
170 void __show_regs(struct pt_regs *regs)
171 {
172         unsigned long flags = condition_codes(regs);
173
174         printk("CPU: %d\n", smp_processor_id());
175         print_symbol("PC is at %s\n", instruction_pointer(regs));
176         print_symbol("LR is at %s\n", regs->ARM_lr);
177         printk("pc : [<%08lx>]    lr : [<%08lx>]    %s\n"
178                "sp : %08lx  ip : %08lx  fp : %08lx\n",
179                 instruction_pointer(regs),
180                 regs->ARM_lr, print_tainted(), regs->ARM_sp,
181                 regs->ARM_ip, regs->ARM_fp);
182         printk("r10: %08lx  r9 : %08lx  r8 : %08lx\n",
183                 regs->ARM_r10, regs->ARM_r9,
184                 regs->ARM_r8);
185         printk("r7 : %08lx  r6 : %08lx  r5 : %08lx  r4 : %08lx\n",
186                 regs->ARM_r7, regs->ARM_r6,
187                 regs->ARM_r5, regs->ARM_r4);
188         printk("r3 : %08lx  r2 : %08lx  r1 : %08lx  r0 : %08lx\n",
189                 regs->ARM_r3, regs->ARM_r2,
190                 regs->ARM_r1, regs->ARM_r0);
191         printk("Flags: %c%c%c%c",
192                 flags & PSR_N_BIT ? 'N' : 'n',
193                 flags & PSR_Z_BIT ? 'Z' : 'z',
194                 flags & PSR_C_BIT ? 'C' : 'c',
195                 flags & PSR_V_BIT ? 'V' : 'v');
196         printk("  IRQs o%s  FIQs o%s  Mode %s%s  Segment %s\n",
197                 interrupts_enabled(regs) ? "n" : "ff",
198                 fast_interrupts_enabled(regs) ? "n" : "ff",
199                 processor_modes[processor_mode(regs)],
200                 thumb_mode(regs) ? " (T)" : "",
201                 get_fs() == get_ds() ? "kernel" : "user");
202         {
203                 unsigned int ctrl, transbase, dac;
204                   __asm__ (
205                 "       mrc p15, 0, %0, c1, c0\n"
206                 "       mrc p15, 0, %1, c2, c0\n"
207                 "       mrc p15, 0, %2, c3, c0\n"
208                 : "=r" (ctrl), "=r" (transbase), "=r" (dac));
209                 printk("Control: %04X  Table: %08X  DAC: %08X\n",
210                         ctrl, transbase, dac);
211         }
212 }
213
214 void show_regs(struct pt_regs * regs)
215 {
216         printk("\n");
217         printk("Pid: %d, comm: %20s\n", current->pid, current->comm);
218         __show_regs(regs);
219         __backtrace();
220 }
221
222 void show_fpregs(struct user_fp *regs)
223 {
224         int i;
225
226         for (i = 0; i < 8; i++) {
227                 unsigned long *p;
228                 char type;
229
230                 p = (unsigned long *)(regs->fpregs + i);
231
232                 switch (regs->ftype[i]) {
233                         case 1: type = 'f'; break;
234                         case 2: type = 'd'; break;
235                         case 3: type = 'e'; break;
236                         default: type = '?'; break;
237                 }
238                 if (regs->init_flag)
239                         type = '?';
240
241                 printk("  f%d(%c): %08lx %08lx %08lx%c",
242                         i, type, p[0], p[1], p[2], i & 1 ? '\n' : ' ');
243         }
244                         
245
246         printk("FPSR: %08lx FPCR: %08lx\n",
247                 (unsigned long)regs->fpsr,
248                 (unsigned long)regs->fpcr);
249 }
250
251 /*
252  * Task structure and kernel stack allocation.
253  */
254 static unsigned long *thread_info_head;
255 static unsigned int nr_thread_info;
256
257 #define EXTRA_TASK_STRUCT       4
258
259 struct thread_info *alloc_thread_info(struct task_struct *task)
260 {
261         struct thread_info *thread = NULL;
262
263         if (EXTRA_TASK_STRUCT) {
264                 unsigned long *p = thread_info_head;
265
266                 if (p) {
267                         thread_info_head = (unsigned long *)p[0];
268                         nr_thread_info -= 1;
269                 }
270                 thread = (struct thread_info *)p;
271         }
272
273         if (!thread)
274                 thread = (struct thread_info *)
275                            __get_free_pages(GFP_KERNEL, THREAD_SIZE_ORDER);
276
277 #ifdef CONFIG_DEBUG_STACK_USAGE
278         /*
279          * The stack must be cleared if you want SYSRQ-T to
280          * give sensible stack usage information
281          */
282         if (thread)
283                 memzero(thread, THREAD_SIZE);
284 #endif
285         return thread;
286 }
287
288 void free_thread_info(struct thread_info *thread)
289 {
290         if (EXTRA_TASK_STRUCT && nr_thread_info < EXTRA_TASK_STRUCT) {
291                 unsigned long *p = (unsigned long *)thread;
292                 p[0] = (unsigned long)thread_info_head;
293                 thread_info_head = p;
294                 nr_thread_info += 1;
295         } else
296                 free_pages((unsigned long)thread, THREAD_SIZE_ORDER);
297 }
298
299 /*
300  * Free current thread data structures etc..
301  */
302 void exit_thread(void)
303 {
304 }
305
306 static void default_fp_init(union fp_state *fp)
307 {
308         memset(fp, 0, sizeof(union fp_state));
309 }
310
311 void (*fp_init)(union fp_state *) = default_fp_init;
312 EXPORT_SYMBOL(fp_init);
313
314 void flush_thread(void)
315 {
316         struct thread_info *thread = current_thread_info();
317         struct task_struct *tsk = current;
318
319         memset(thread->used_cp, 0, sizeof(thread->used_cp));
320         memset(&tsk->thread.debug, 0, sizeof(struct debug_info));
321 #if defined(CONFIG_IWMMXT)
322         iwmmxt_task_release(thread);
323 #endif
324         fp_init(&thread->fpstate);
325 #if defined(CONFIG_VFP)
326         vfp_flush_thread(&thread->vfpstate);
327 #endif
328 }
329
330 void release_thread(struct task_struct *dead_task)
331 {
332 #if defined(CONFIG_VFP)
333         vfp_release_thread(&dead_task->thread_info->vfpstate);
334 #endif
335 #if defined(CONFIG_IWMMXT)
336         iwmmxt_task_release(dead_task->thread_info);
337 #endif
338 }
339
340 asmlinkage void ret_from_fork(void) __asm__("ret_from_fork");
341
342 int
343 copy_thread(int nr, unsigned long clone_flags, unsigned long stack_start,
344             unsigned long stk_sz, struct task_struct *p, struct pt_regs *regs)
345 {
346         struct thread_info *thread = p->thread_info;
347         struct pt_regs *childregs;
348
349         childregs = ((struct pt_regs *)((unsigned long)thread + THREAD_START_SP)) - 1;
350         *childregs = *regs;
351         childregs->ARM_r0 = 0;
352         childregs->ARM_sp = stack_start;
353
354         memset(&thread->cpu_context, 0, sizeof(struct cpu_context_save));
355         thread->cpu_context.sp = (unsigned long)childregs;
356         thread->cpu_context.pc = (unsigned long)ret_from_fork;
357
358         if (clone_flags & CLONE_SETTLS)
359                 thread->tp_value = regs->ARM_r3;
360
361         return 0;
362 }
363
364 /*
365  * fill in the fpe structure for a core dump...
366  */
367 int dump_fpu (struct pt_regs *regs, struct user_fp *fp)
368 {
369         struct thread_info *thread = current_thread_info();
370         int used_math = thread->used_cp[1] | thread->used_cp[2];
371
372         if (used_math)
373                 memcpy(fp, &thread->fpstate.soft, sizeof (*fp));
374
375         return used_math != 0;
376 }
377 EXPORT_SYMBOL(dump_fpu);
378
379 /*
380  * fill in the user structure for a core dump..
381  */
382 void dump_thread(struct pt_regs * regs, struct user * dump)
383 {
384         struct task_struct *tsk = current;
385
386         dump->magic = CMAGIC;
387         dump->start_code = tsk->mm->start_code;
388         dump->start_stack = regs->ARM_sp & ~(PAGE_SIZE - 1);
389
390         dump->u_tsize = (tsk->mm->end_code - tsk->mm->start_code) >> PAGE_SHIFT;
391         dump->u_dsize = (tsk->mm->brk - tsk->mm->start_data + PAGE_SIZE - 1) >> PAGE_SHIFT;
392         dump->u_ssize = 0;
393
394         dump->u_debugreg[0] = tsk->thread.debug.bp[0].address;
395         dump->u_debugreg[1] = tsk->thread.debug.bp[1].address;
396         dump->u_debugreg[2] = tsk->thread.debug.bp[0].insn.arm;
397         dump->u_debugreg[3] = tsk->thread.debug.bp[1].insn.arm;
398         dump->u_debugreg[4] = tsk->thread.debug.nsaved;
399
400         if (dump->start_stack < 0x04000000)
401                 dump->u_ssize = (0x04000000 - dump->start_stack) >> PAGE_SHIFT;
402
403         dump->regs = *regs;
404         dump->u_fpvalid = dump_fpu (regs, &dump->u_fp);
405 }
406 EXPORT_SYMBOL(dump_thread);
407
408 /*
409  * Shuffle the argument into the correct register before calling the
410  * thread function.  r1 is the thread argument, r2 is the pointer to
411  * the thread function, and r3 points to the exit function.
412  */
413 extern void kernel_thread_helper(void);
414 asm(    ".section .text\n"
415 "       .align\n"
416 "       .type   kernel_thread_helper, #function\n"
417 "kernel_thread_helper:\n"
418 "       mov     r0, r1\n"
419 "       mov     lr, r3\n"
420 "       mov     pc, r2\n"
421 "       .size   kernel_thread_helper, . - kernel_thread_helper\n"
422 "       .previous");
423
424 /*
425  * Create a kernel thread.
426  */
427 pid_t kernel_thread(int (*fn)(void *), void *arg, unsigned long flags)
428 {
429         struct pt_regs regs;
430
431         memset(&regs, 0, sizeof(regs));
432
433         regs.ARM_r1 = (unsigned long)arg;
434         regs.ARM_r2 = (unsigned long)fn;
435         regs.ARM_r3 = (unsigned long)do_exit;
436         regs.ARM_pc = (unsigned long)kernel_thread_helper;
437         regs.ARM_cpsr = SVC_MODE;
438
439         return do_fork(flags|CLONE_VM|CLONE_UNTRACED, 0, &regs, 0, NULL, NULL);
440 }
441 EXPORT_SYMBOL(kernel_thread);
442
443 unsigned long get_wchan(struct task_struct *p)
444 {
445         unsigned long fp, lr;
446         unsigned long stack_start, stack_end;
447         int count = 0;
448         if (!p || p == current || p->state == TASK_RUNNING)
449                 return 0;
450
451         stack_start = (unsigned long)(p->thread_info + 1);
452         stack_end = ((unsigned long)p->thread_info) + THREAD_SIZE;
453
454         fp = thread_saved_fp(p);
455         do {
456                 if (fp < stack_start || fp > stack_end)
457                         return 0;
458                 lr = pc_pointer (((unsigned long *)fp)[-1]);
459                 if (!in_sched_functions(lr))
460                         return lr;
461                 fp = *(unsigned long *) (fp - 12);
462         } while (count ++ < 16);
463         return 0;
464 }
465 EXPORT_SYMBOL(get_wchan);