[PATCH] ARM: showregs
[sfrench/cifs-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
36 extern const char *processor_modes[];
37 extern void setup_mm_for_reboot(char mode);
38
39 static volatile int hlt_counter;
40
41 #include <asm/arch/system.h>
42
43 void disable_hlt(void)
44 {
45         hlt_counter++;
46 }
47
48 EXPORT_SYMBOL(disable_hlt);
49
50 void enable_hlt(void)
51 {
52         hlt_counter--;
53 }
54
55 EXPORT_SYMBOL(enable_hlt);
56
57 static int __init nohlt_setup(char *__unused)
58 {
59         hlt_counter = 1;
60         return 1;
61 }
62
63 static int __init hlt_setup(char *__unused)
64 {
65         hlt_counter = 0;
66         return 1;
67 }
68
69 __setup("nohlt", nohlt_setup);
70 __setup("hlt", hlt_setup);
71
72 /*
73  * The following aren't currently used.
74  */
75 void (*pm_idle)(void);
76 EXPORT_SYMBOL(pm_idle);
77
78 void (*pm_power_off)(void);
79 EXPORT_SYMBOL(pm_power_off);
80
81 /*
82  * This is our default idle handler.  We need to disable
83  * interrupts here to ensure we don't miss a wakeup call.
84  */
85 void default_idle(void)
86 {
87         local_irq_disable();
88         if (!need_resched() && !hlt_counter)
89                 arch_idle();
90         local_irq_enable();
91 }
92
93 /*
94  * The idle thread.  We try to conserve power, while trying to keep
95  * overall latency low.  The architecture specific idle is passed
96  * a value to indicate the level of "idleness" of the system.
97  */
98 void cpu_idle(void)
99 {
100         local_fiq_enable();
101
102         /* endless idle loop with no priority at all */
103         while (1) {
104                 void (*idle)(void) = pm_idle;
105                 if (!idle)
106                         idle = default_idle;
107                 preempt_disable();
108                 leds_event(led_idle_start);
109                 while (!need_resched())
110                         idle();
111                 leds_event(led_idle_end);
112                 preempt_enable();
113                 schedule();
114         }
115 }
116
117 static char reboot_mode = 'h';
118
119 int __init reboot_setup(char *str)
120 {
121         reboot_mode = str[0];
122         return 1;
123 }
124
125 __setup("reboot=", reboot_setup);
126
127 void machine_halt(void)
128 {
129 }
130
131 EXPORT_SYMBOL(machine_halt);
132
133 void machine_power_off(void)
134 {
135         if (pm_power_off)
136                 pm_power_off();
137 }
138
139 EXPORT_SYMBOL(machine_power_off);
140
141 void machine_restart(char * __unused)
142 {
143         /*
144          * Clean and disable cache, and turn off interrupts
145          */
146         cpu_proc_fin();
147
148         /*
149          * Tell the mm system that we are going to reboot -
150          * we may need it to insert some 1:1 mappings so that
151          * soft boot works.
152          */
153         setup_mm_for_reboot(reboot_mode);
154
155         /*
156          * Now call the architecture specific reboot code.
157          */
158         arch_reset(reboot_mode);
159
160         /*
161          * Whoops - the architecture was unable to reboot.
162          * Tell the user!
163          */
164         mdelay(1000);
165         printk("Reboot failed -- System halted\n");
166         while (1);
167 }
168
169 EXPORT_SYMBOL(machine_restart);
170
171 void __show_regs(struct pt_regs *regs)
172 {
173         unsigned long flags = condition_codes(regs);
174
175         printk("CPU: %d\n", smp_processor_id());
176         print_symbol("PC is at %s\n", instruction_pointer(regs));
177         print_symbol("LR is at %s\n", regs->ARM_lr);
178         printk("pc : [<%08lx>]    lr : [<%08lx>]    %s\n"
179                "sp : %08lx  ip : %08lx  fp : %08lx\n",
180                 instruction_pointer(regs),
181                 regs->ARM_lr, print_tainted(), regs->ARM_sp,
182                 regs->ARM_ip, regs->ARM_fp);
183         printk("r10: %08lx  r9 : %08lx  r8 : %08lx\n",
184                 regs->ARM_r10, regs->ARM_r9,
185                 regs->ARM_r8);
186         printk("r7 : %08lx  r6 : %08lx  r5 : %08lx  r4 : %08lx\n",
187                 regs->ARM_r7, regs->ARM_r6,
188                 regs->ARM_r5, regs->ARM_r4);
189         printk("r3 : %08lx  r2 : %08lx  r1 : %08lx  r0 : %08lx\n",
190                 regs->ARM_r3, regs->ARM_r2,
191                 regs->ARM_r1, regs->ARM_r0);
192         printk("Flags: %c%c%c%c",
193                 flags & PSR_N_BIT ? 'N' : 'n',
194                 flags & PSR_Z_BIT ? 'Z' : 'z',
195                 flags & PSR_C_BIT ? 'C' : 'c',
196                 flags & PSR_V_BIT ? 'V' : 'v');
197         printk("  IRQs o%s  FIQs o%s  Mode %s%s  Segment %s\n",
198                 interrupts_enabled(regs) ? "n" : "ff",
199                 fast_interrupts_enabled(regs) ? "n" : "ff",
200                 processor_modes[processor_mode(regs)],
201                 thumb_mode(regs) ? " (T)" : "",
202                 get_fs() == get_ds() ? "kernel" : "user");
203         {
204                 unsigned int ctrl, transbase, dac;
205                   __asm__ (
206                 "       mrc p15, 0, %0, c1, c0\n"
207                 "       mrc p15, 0, %1, c2, c0\n"
208                 "       mrc p15, 0, %2, c3, c0\n"
209                 : "=r" (ctrl), "=r" (transbase), "=r" (dac));
210                 printk("Control: %04X  Table: %08X  DAC: %08X\n",
211                         ctrl, transbase, dac);
212         }
213 }
214
215 void show_regs(struct pt_regs * regs)
216 {
217         printk("\n");
218         printk("Pid: %d, comm: %20s\n", current->pid, current->comm);
219         __show_regs(regs);
220         __backtrace();
221 }
222
223 void show_fpregs(struct user_fp *regs)
224 {
225         int i;
226
227         for (i = 0; i < 8; i++) {
228                 unsigned long *p;
229                 char type;
230
231                 p = (unsigned long *)(regs->fpregs + i);
232
233                 switch (regs->ftype[i]) {
234                         case 1: type = 'f'; break;
235                         case 2: type = 'd'; break;
236                         case 3: type = 'e'; break;
237                         default: type = '?'; break;
238                 }
239                 if (regs->init_flag)
240                         type = '?';
241
242                 printk("  f%d(%c): %08lx %08lx %08lx%c",
243                         i, type, p[0], p[1], p[2], i & 1 ? '\n' : ' ');
244         }
245                         
246
247         printk("FPSR: %08lx FPCR: %08lx\n",
248                 (unsigned long)regs->fpsr,
249                 (unsigned long)regs->fpcr);
250 }
251
252 /*
253  * Task structure and kernel stack allocation.
254  */
255 static unsigned long *thread_info_head;
256 static unsigned int nr_thread_info;
257
258 #define EXTRA_TASK_STRUCT       4
259 #define ll_alloc_task_struct() ((struct thread_info *) __get_free_pages(GFP_KERNEL,1))
260 #define ll_free_task_struct(p) free_pages((unsigned long)(p),1)
261
262 struct thread_info *alloc_thread_info(struct task_struct *task)
263 {
264         struct thread_info *thread = NULL;
265
266         if (EXTRA_TASK_STRUCT) {
267                 unsigned long *p = thread_info_head;
268
269                 if (p) {
270                         thread_info_head = (unsigned long *)p[0];
271                         nr_thread_info -= 1;
272                 }
273                 thread = (struct thread_info *)p;
274         }
275
276         if (!thread)
277                 thread = ll_alloc_task_struct();
278
279 #ifdef CONFIG_MAGIC_SYSRQ
280         /*
281          * The stack must be cleared if you want SYSRQ-T to
282          * give sensible stack usage information
283          */
284         if (thread) {
285                 char *p = (char *)thread;
286                 memzero(p+KERNEL_STACK_SIZE, KERNEL_STACK_SIZE);
287         }
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                 ll_free_task_struct(thread);
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_SIZE - 8)) - 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_page;
451         int count = 0;
452         if (!p || p == current || p->state == TASK_RUNNING)
453                 return 0;
454
455         stack_page = 4096 + (unsigned long)p->thread_info;
456         fp = thread_saved_fp(p);
457         do {
458                 if (fp < stack_page || fp > 4092+stack_page)
459                         return 0;
460                 lr = pc_pointer (((unsigned long *)fp)[-1]);
461                 if (!in_sched_functions(lr))
462                         return lr;
463                 fp = *(unsigned long *) (fp - 12);
464         } while (count ++ < 16);
465         return 0;
466 }
467 EXPORT_SYMBOL(get_wchan);