bbea636ff687a57feb1e2a5f240e5f0726485b7a
[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 EXPORT_SYMBOL(machine_halt);
135
136 void machine_power_off(void)
137 {
138         if (pm_power_off)
139                 pm_power_off();
140 }
141
142 EXPORT_SYMBOL(machine_power_off);
143
144 void machine_restart(char * __unused)
145 {
146         /*
147          * Clean and disable cache, and turn off interrupts
148          */
149         cpu_proc_fin();
150
151         /*
152          * Tell the mm system that we are going to reboot -
153          * we may need it to insert some 1:1 mappings so that
154          * soft boot works.
155          */
156         setup_mm_for_reboot(reboot_mode);
157
158         /*
159          * Now call the architecture specific reboot code.
160          */
161         arch_reset(reboot_mode);
162
163         /*
164          * Whoops - the architecture was unable to reboot.
165          * Tell the user!
166          */
167         mdelay(1000);
168         printk("Reboot failed -- System halted\n");
169         while (1);
170 }
171
172 EXPORT_SYMBOL(machine_restart);
173
174 void __show_regs(struct pt_regs *regs)
175 {
176         unsigned long flags = condition_codes(regs);
177
178         printk("CPU: %d\n", smp_processor_id());
179         print_symbol("PC is at %s\n", instruction_pointer(regs));
180         print_symbol("LR is at %s\n", regs->ARM_lr);
181         printk("pc : [<%08lx>]    lr : [<%08lx>]    %s\n"
182                "sp : %08lx  ip : %08lx  fp : %08lx\n",
183                 instruction_pointer(regs),
184                 regs->ARM_lr, print_tainted(), regs->ARM_sp,
185                 regs->ARM_ip, regs->ARM_fp);
186         printk("r10: %08lx  r9 : %08lx  r8 : %08lx\n",
187                 regs->ARM_r10, regs->ARM_r9,
188                 regs->ARM_r8);
189         printk("r7 : %08lx  r6 : %08lx  r5 : %08lx  r4 : %08lx\n",
190                 regs->ARM_r7, regs->ARM_r6,
191                 regs->ARM_r5, regs->ARM_r4);
192         printk("r3 : %08lx  r2 : %08lx  r1 : %08lx  r0 : %08lx\n",
193                 regs->ARM_r3, regs->ARM_r2,
194                 regs->ARM_r1, regs->ARM_r0);
195         printk("Flags: %c%c%c%c",
196                 flags & PSR_N_BIT ? 'N' : 'n',
197                 flags & PSR_Z_BIT ? 'Z' : 'z',
198                 flags & PSR_C_BIT ? 'C' : 'c',
199                 flags & PSR_V_BIT ? 'V' : 'v');
200         printk("  IRQs o%s  FIQs o%s  Mode %s%s  Segment %s\n",
201                 interrupts_enabled(regs) ? "n" : "ff",
202                 fast_interrupts_enabled(regs) ? "n" : "ff",
203                 processor_modes[processor_mode(regs)],
204                 thumb_mode(regs) ? " (T)" : "",
205                 get_fs() == get_ds() ? "kernel" : "user");
206         {
207                 unsigned int ctrl, transbase, dac;
208                   __asm__ (
209                 "       mrc p15, 0, %0, c1, c0\n"
210                 "       mrc p15, 0, %1, c2, c0\n"
211                 "       mrc p15, 0, %2, c3, c0\n"
212                 : "=r" (ctrl), "=r" (transbase), "=r" (dac));
213                 printk("Control: %04X  Table: %08X  DAC: %08X\n",
214                         ctrl, transbase, dac);
215         }
216 }
217
218 void show_regs(struct pt_regs * regs)
219 {
220         printk("\n");
221         printk("Pid: %d, comm: %20s\n", current->pid, current->comm);
222         __show_regs(regs);
223         __backtrace();
224 }
225
226 void show_fpregs(struct user_fp *regs)
227 {
228         int i;
229
230         for (i = 0; i < 8; i++) {
231                 unsigned long *p;
232                 char type;
233
234                 p = (unsigned long *)(regs->fpregs + i);
235
236                 switch (regs->ftype[i]) {
237                         case 1: type = 'f'; break;
238                         case 2: type = 'd'; break;
239                         case 3: type = 'e'; break;
240                         default: type = '?'; break;
241                 }
242                 if (regs->init_flag)
243                         type = '?';
244
245                 printk("  f%d(%c): %08lx %08lx %08lx%c",
246                         i, type, p[0], p[1], p[2], i & 1 ? '\n' : ' ');
247         }
248                         
249
250         printk("FPSR: %08lx FPCR: %08lx\n",
251                 (unsigned long)regs->fpsr,
252                 (unsigned long)regs->fpcr);
253 }
254
255 /*
256  * Task structure and kernel stack allocation.
257  */
258 static unsigned long *thread_info_head;
259 static unsigned int nr_thread_info;
260
261 #define EXTRA_TASK_STRUCT       4
262
263 struct thread_info *alloc_thread_info(struct task_struct *task)
264 {
265         struct thread_info *thread = NULL;
266
267         if (EXTRA_TASK_STRUCT) {
268                 unsigned long *p = thread_info_head;
269
270                 if (p) {
271                         thread_info_head = (unsigned long *)p[0];
272                         nr_thread_info -= 1;
273                 }
274                 thread = (struct thread_info *)p;
275         }
276
277         if (!thread)
278                 thread = (struct thread_info *)
279                            __get_free_pages(GFP_KERNEL, THREAD_SIZE_ORDER);
280
281 #ifdef CONFIG_DEBUG_STACK_USAGE
282         /*
283          * The stack must be cleared if you want SYSRQ-T to
284          * give sensible stack usage information
285          */
286         if (thread)
287                 memzero(thread, THREAD_SIZE);
288 #endif
289         return thread;
290 }
291
292 void free_thread_info(struct thread_info *thread)
293 {
294         if (EXTRA_TASK_STRUCT && nr_thread_info < EXTRA_TASK_STRUCT) {
295                 unsigned long *p = (unsigned long *)thread;
296                 p[0] = (unsigned long)thread_info_head;
297                 thread_info_head = p;
298                 nr_thread_info += 1;
299         } else
300                 free_pages((unsigned long)thread, THREAD_SIZE_ORDER);
301 }
302
303 /*
304  * Free current thread data structures etc..
305  */
306 void exit_thread(void)
307 {
308 }
309
310 static void default_fp_init(union fp_state *fp)
311 {
312         memset(fp, 0, sizeof(union fp_state));
313 }
314
315 void (*fp_init)(union fp_state *) = default_fp_init;
316 EXPORT_SYMBOL(fp_init);
317
318 void flush_thread(void)
319 {
320         struct thread_info *thread = current_thread_info();
321         struct task_struct *tsk = current;
322
323         memset(thread->used_cp, 0, sizeof(thread->used_cp));
324         memset(&tsk->thread.debug, 0, sizeof(struct debug_info));
325 #if defined(CONFIG_IWMMXT)
326         iwmmxt_task_release(thread);
327 #endif
328         fp_init(&thread->fpstate);
329 #if defined(CONFIG_VFP)
330         vfp_flush_thread(&thread->vfpstate);
331 #endif
332 }
333
334 void release_thread(struct task_struct *dead_task)
335 {
336 #if defined(CONFIG_VFP)
337         vfp_release_thread(&dead_task->thread_info->vfpstate);
338 #endif
339 #if defined(CONFIG_IWMMXT)
340         iwmmxt_task_release(dead_task->thread_info);
341 #endif
342 }
343
344 asmlinkage void ret_from_fork(void) __asm__("ret_from_fork");
345
346 int
347 copy_thread(int nr, unsigned long clone_flags, unsigned long stack_start,
348             unsigned long stk_sz, struct task_struct *p, struct pt_regs *regs)
349 {
350         struct thread_info *thread = p->thread_info;
351         struct pt_regs *childregs;
352
353         childregs = ((struct pt_regs *)((unsigned long)thread + THREAD_START_SP)) - 1;
354         *childregs = *regs;
355         childregs->ARM_r0 = 0;
356         childregs->ARM_sp = stack_start;
357
358         memset(&thread->cpu_context, 0, sizeof(struct cpu_context_save));
359         thread->cpu_context.sp = (unsigned long)childregs;
360         thread->cpu_context.pc = (unsigned long)ret_from_fork;
361
362         if (clone_flags & CLONE_SETTLS)
363                 thread->tp_value = regs->ARM_r3;
364
365         return 0;
366 }
367
368 /*
369  * fill in the fpe structure for a core dump...
370  */
371 int dump_fpu (struct pt_regs *regs, struct user_fp *fp)
372 {
373         struct thread_info *thread = current_thread_info();
374         int used_math = thread->used_cp[1] | thread->used_cp[2];
375
376         if (used_math)
377                 memcpy(fp, &thread->fpstate.soft, sizeof (*fp));
378
379         return used_math != 0;
380 }
381 EXPORT_SYMBOL(dump_fpu);
382
383 /*
384  * fill in the user structure for a core dump..
385  */
386 void dump_thread(struct pt_regs * regs, struct user * dump)
387 {
388         struct task_struct *tsk = current;
389
390         dump->magic = CMAGIC;
391         dump->start_code = tsk->mm->start_code;
392         dump->start_stack = regs->ARM_sp & ~(PAGE_SIZE - 1);
393
394         dump->u_tsize = (tsk->mm->end_code - tsk->mm->start_code) >> PAGE_SHIFT;
395         dump->u_dsize = (tsk->mm->brk - tsk->mm->start_data + PAGE_SIZE - 1) >> PAGE_SHIFT;
396         dump->u_ssize = 0;
397
398         dump->u_debugreg[0] = tsk->thread.debug.bp[0].address;
399         dump->u_debugreg[1] = tsk->thread.debug.bp[1].address;
400         dump->u_debugreg[2] = tsk->thread.debug.bp[0].insn.arm;
401         dump->u_debugreg[3] = tsk->thread.debug.bp[1].insn.arm;
402         dump->u_debugreg[4] = tsk->thread.debug.nsaved;
403
404         if (dump->start_stack < 0x04000000)
405                 dump->u_ssize = (0x04000000 - dump->start_stack) >> PAGE_SHIFT;
406
407         dump->regs = *regs;
408         dump->u_fpvalid = dump_fpu (regs, &dump->u_fp);
409 }
410 EXPORT_SYMBOL(dump_thread);
411
412 /*
413  * Shuffle the argument into the correct register before calling the
414  * thread function.  r1 is the thread argument, r2 is the pointer to
415  * the thread function, and r3 points to the exit function.
416  */
417 extern void kernel_thread_helper(void);
418 asm(    ".section .text\n"
419 "       .align\n"
420 "       .type   kernel_thread_helper, #function\n"
421 "kernel_thread_helper:\n"
422 "       mov     r0, r1\n"
423 "       mov     lr, r3\n"
424 "       mov     pc, r2\n"
425 "       .size   kernel_thread_helper, . - kernel_thread_helper\n"
426 "       .previous");
427
428 /*
429  * Create a kernel thread.
430  */
431 pid_t kernel_thread(int (*fn)(void *), void *arg, unsigned long flags)
432 {
433         struct pt_regs regs;
434
435         memset(&regs, 0, sizeof(regs));
436
437         regs.ARM_r1 = (unsigned long)arg;
438         regs.ARM_r2 = (unsigned long)fn;
439         regs.ARM_r3 = (unsigned long)do_exit;
440         regs.ARM_pc = (unsigned long)kernel_thread_helper;
441         regs.ARM_cpsr = SVC_MODE;
442
443         return do_fork(flags|CLONE_VM|CLONE_UNTRACED, 0, &regs, 0, NULL, NULL);
444 }
445 EXPORT_SYMBOL(kernel_thread);
446
447 unsigned long get_wchan(struct task_struct *p)
448 {
449         unsigned long fp, lr;
450         unsigned long stack_start, stack_end;
451         int count = 0;
452         if (!p || p == current || p->state == TASK_RUNNING)
453                 return 0;
454
455         stack_start = (unsigned long)(p->thread_info + 1);
456         stack_end = ((unsigned long)p->thread_info) + THREAD_SIZE;
457
458         fp = thread_saved_fp(p);
459         do {
460                 if (fp < stack_start || fp > stack_end)
461                         return 0;
462                 lr = pc_pointer (((unsigned long *)fp)[-1]);
463                 if (!in_sched_functions(lr))
464                         return lr;
465                 fp = *(unsigned long *) (fp - 12);
466         } while (count ++ < 16);
467         return 0;
468 }
469 EXPORT_SYMBOL(get_wchan);