[ARM] 3593/1: Add reboot and shutdown handlers for Zaurus handhelds
[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 #include <linux/cpu.h>
30 #include <linux/elfcore.h>
31 #include <linux/pm.h>
32
33 #include <asm/leds.h>
34 #include <asm/processor.h>
35 #include <asm/system.h>
36 #include <asm/uaccess.h>
37 #include <asm/mach/time.h>
38
39 extern const char *processor_modes[];
40 extern void setup_mm_for_reboot(char mode);
41
42 static volatile int hlt_counter;
43
44 #include <asm/arch/system.h>
45
46 void disable_hlt(void)
47 {
48         hlt_counter++;
49 }
50
51 EXPORT_SYMBOL(disable_hlt);
52
53 void enable_hlt(void)
54 {
55         hlt_counter--;
56 }
57
58 EXPORT_SYMBOL(enable_hlt);
59
60 static int __init nohlt_setup(char *__unused)
61 {
62         hlt_counter = 1;
63         return 1;
64 }
65
66 static int __init hlt_setup(char *__unused)
67 {
68         hlt_counter = 0;
69         return 1;
70 }
71
72 __setup("nohlt", nohlt_setup);
73 __setup("hlt", hlt_setup);
74
75 void arm_machine_restart(char mode)
76 {
77         /*
78          * Clean and disable cache, and turn off interrupts
79          */
80         cpu_proc_fin();
81
82         /*
83          * Tell the mm system that we are going to reboot -
84          * we may need it to insert some 1:1 mappings so that
85          * soft boot works.
86          */
87         setup_mm_for_reboot(mode);
88
89         /*
90          * Now call the architecture specific reboot code.
91          */
92         arch_reset(mode);
93
94         /*
95          * Whoops - the architecture was unable to reboot.
96          * Tell the user!
97          */
98         mdelay(1000);
99         printk("Reboot failed -- System halted\n");
100         while (1);
101 }
102
103 /*
104  * Function pointers to optional machine specific functions
105  */
106 void (*pm_idle)(void);
107 EXPORT_SYMBOL(pm_idle);
108
109 void (*pm_power_off)(void);
110 EXPORT_SYMBOL(pm_power_off);
111
112 void (*arm_pm_restart)(char str) = arm_machine_restart;
113 EXPORT_SYMBOL_GPL(arm_pm_restart);
114
115
116 /*
117  * This is our default idle handler.  We need to disable
118  * interrupts here to ensure we don't miss a wakeup call.
119  */
120 static void default_idle(void)
121 {
122         if (hlt_counter)
123                 cpu_relax();
124         else {
125                 local_irq_disable();
126                 if (!need_resched()) {
127                         timer_dyn_reprogram();
128                         arch_idle();
129                 }
130                 local_irq_enable();
131         }
132 }
133
134 /*
135  * The idle thread.  We try to conserve power, while trying to keep
136  * overall latency low.  The architecture specific idle is passed
137  * a value to indicate the level of "idleness" of the system.
138  */
139 void cpu_idle(void)
140 {
141         local_fiq_enable();
142
143         /* endless idle loop with no priority at all */
144         while (1) {
145                 void (*idle)(void) = pm_idle;
146
147 #ifdef CONFIG_HOTPLUG_CPU
148                 if (cpu_is_offline(smp_processor_id())) {
149                         leds_event(led_idle_start);
150                         cpu_die();
151                 }
152 #endif
153
154                 if (!idle)
155                         idle = default_idle;
156                 leds_event(led_idle_start);
157                 while (!need_resched())
158                         idle();
159                 leds_event(led_idle_end);
160                 preempt_enable_no_resched();
161                 schedule();
162                 preempt_disable();
163         }
164 }
165
166 static char reboot_mode = 'h';
167
168 int __init reboot_setup(char *str)
169 {
170         reboot_mode = str[0];
171         return 1;
172 }
173
174 __setup("reboot=", reboot_setup);
175
176 void machine_halt(void)
177 {
178 }
179
180
181 void machine_power_off(void)
182 {
183         if (pm_power_off)
184                 pm_power_off();
185 }
186
187 void machine_restart(char * __unused)
188 {
189         arm_pm_restart(reboot_mode);
190 }
191
192 void __show_regs(struct pt_regs *regs)
193 {
194         unsigned long flags = condition_codes(regs);
195
196         printk("CPU: %d\n", smp_processor_id());
197         print_symbol("PC is at %s\n", instruction_pointer(regs));
198         print_symbol("LR is at %s\n", regs->ARM_lr);
199         printk("pc : [<%08lx>]    lr : [<%08lx>]    %s\n"
200                "sp : %08lx  ip : %08lx  fp : %08lx\n",
201                 instruction_pointer(regs),
202                 regs->ARM_lr, print_tainted(), regs->ARM_sp,
203                 regs->ARM_ip, regs->ARM_fp);
204         printk("r10: %08lx  r9 : %08lx  r8 : %08lx\n",
205                 regs->ARM_r10, regs->ARM_r9,
206                 regs->ARM_r8);
207         printk("r7 : %08lx  r6 : %08lx  r5 : %08lx  r4 : %08lx\n",
208                 regs->ARM_r7, regs->ARM_r6,
209                 regs->ARM_r5, regs->ARM_r4);
210         printk("r3 : %08lx  r2 : %08lx  r1 : %08lx  r0 : %08lx\n",
211                 regs->ARM_r3, regs->ARM_r2,
212                 regs->ARM_r1, regs->ARM_r0);
213         printk("Flags: %c%c%c%c",
214                 flags & PSR_N_BIT ? 'N' : 'n',
215                 flags & PSR_Z_BIT ? 'Z' : 'z',
216                 flags & PSR_C_BIT ? 'C' : 'c',
217                 flags & PSR_V_BIT ? 'V' : 'v');
218         printk("  IRQs o%s  FIQs o%s  Mode %s%s  Segment %s\n",
219                 interrupts_enabled(regs) ? "n" : "ff",
220                 fast_interrupts_enabled(regs) ? "n" : "ff",
221                 processor_modes[processor_mode(regs)],
222                 thumb_mode(regs) ? " (T)" : "",
223                 get_fs() == get_ds() ? "kernel" : "user");
224         {
225                 unsigned int ctrl, transbase, dac;
226                   __asm__ (
227                 "       mrc p15, 0, %0, c1, c0\n"
228                 "       mrc p15, 0, %1, c2, c0\n"
229                 "       mrc p15, 0, %2, c3, c0\n"
230                 : "=r" (ctrl), "=r" (transbase), "=r" (dac));
231                 printk("Control: %04X  Table: %08X  DAC: %08X\n",
232                         ctrl, transbase, dac);
233         }
234 }
235
236 void show_regs(struct pt_regs * regs)
237 {
238         printk("\n");
239         printk("Pid: %d, comm: %20s\n", current->pid, current->comm);
240         __show_regs(regs);
241         __backtrace();
242 }
243
244 void show_fpregs(struct user_fp *regs)
245 {
246         int i;
247
248         for (i = 0; i < 8; i++) {
249                 unsigned long *p;
250                 char type;
251
252                 p = (unsigned long *)(regs->fpregs + i);
253
254                 switch (regs->ftype[i]) {
255                         case 1: type = 'f'; break;
256                         case 2: type = 'd'; break;
257                         case 3: type = 'e'; break;
258                         default: type = '?'; break;
259                 }
260                 if (regs->init_flag)
261                         type = '?';
262
263                 printk("  f%d(%c): %08lx %08lx %08lx%c",
264                         i, type, p[0], p[1], p[2], i & 1 ? '\n' : ' ');
265         }
266                         
267
268         printk("FPSR: %08lx FPCR: %08lx\n",
269                 (unsigned long)regs->fpsr,
270                 (unsigned long)regs->fpcr);
271 }
272
273 /*
274  * Task structure and kernel stack allocation.
275  */
276 struct thread_info_list {
277         unsigned long *head;
278         unsigned int nr;
279 };
280
281 static DEFINE_PER_CPU(struct thread_info_list, thread_info_list) = { NULL, 0 };
282
283 #define EXTRA_TASK_STRUCT       4
284
285 struct thread_info *alloc_thread_info(struct task_struct *task)
286 {
287         struct thread_info *thread = NULL;
288
289         if (EXTRA_TASK_STRUCT) {
290                 struct thread_info_list *th = &get_cpu_var(thread_info_list);
291                 unsigned long *p = th->head;
292
293                 if (p) {
294                         th->head = (unsigned long *)p[0];
295                         th->nr -= 1;
296                 }
297                 put_cpu_var(thread_info_list);
298
299                 thread = (struct thread_info *)p;
300         }
301
302         if (!thread)
303                 thread = (struct thread_info *)
304                            __get_free_pages(GFP_KERNEL, THREAD_SIZE_ORDER);
305
306 #ifdef CONFIG_DEBUG_STACK_USAGE
307         /*
308          * The stack must be cleared if you want SYSRQ-T to
309          * give sensible stack usage information
310          */
311         if (thread)
312                 memzero(thread, THREAD_SIZE);
313 #endif
314         return thread;
315 }
316
317 void free_thread_info(struct thread_info *thread)
318 {
319         if (EXTRA_TASK_STRUCT) {
320                 struct thread_info_list *th = &get_cpu_var(thread_info_list);
321                 if (th->nr < EXTRA_TASK_STRUCT) {
322                         unsigned long *p = (unsigned long *)thread;
323                         p[0] = (unsigned long)th->head;
324                         th->head = p;
325                         th->nr += 1;
326                         put_cpu_var(thread_info_list);
327                         return;
328                 }
329                 put_cpu_var(thread_info_list);
330         }
331         free_pages((unsigned long)thread, THREAD_SIZE_ORDER);
332 }
333
334 /*
335  * Free current thread data structures etc..
336  */
337 void exit_thread(void)
338 {
339 }
340
341 static void default_fp_init(union fp_state *fp)
342 {
343         memset(fp, 0, sizeof(union fp_state));
344 }
345
346 void (*fp_init)(union fp_state *) = default_fp_init;
347 EXPORT_SYMBOL(fp_init);
348
349 void flush_thread(void)
350 {
351         struct thread_info *thread = current_thread_info();
352         struct task_struct *tsk = current;
353
354         memset(thread->used_cp, 0, sizeof(thread->used_cp));
355         memset(&tsk->thread.debug, 0, sizeof(struct debug_info));
356 #if defined(CONFIG_IWMMXT)
357         iwmmxt_task_release(thread);
358 #endif
359         fp_init(&thread->fpstate);
360 #if defined(CONFIG_VFP)
361         vfp_flush_thread(&thread->vfpstate);
362 #endif
363 }
364
365 void release_thread(struct task_struct *dead_task)
366 {
367 #if defined(CONFIG_VFP)
368         vfp_release_thread(&task_thread_info(dead_task)->vfpstate);
369 #endif
370 #if defined(CONFIG_IWMMXT)
371         iwmmxt_task_release(task_thread_info(dead_task));
372 #endif
373 }
374
375 asmlinkage void ret_from_fork(void) __asm__("ret_from_fork");
376
377 int
378 copy_thread(int nr, unsigned long clone_flags, unsigned long stack_start,
379             unsigned long stk_sz, struct task_struct *p, struct pt_regs *regs)
380 {
381         struct thread_info *thread = task_thread_info(p);
382         struct pt_regs *childregs = task_pt_regs(p);
383
384         *childregs = *regs;
385         childregs->ARM_r0 = 0;
386         childregs->ARM_sp = stack_start;
387
388         memset(&thread->cpu_context, 0, sizeof(struct cpu_context_save));
389         thread->cpu_context.sp = (unsigned long)childregs;
390         thread->cpu_context.pc = (unsigned long)ret_from_fork;
391
392         if (clone_flags & CLONE_SETTLS)
393                 thread->tp_value = regs->ARM_r3;
394
395         return 0;
396 }
397
398 /*
399  * fill in the fpe structure for a core dump...
400  */
401 int dump_fpu (struct pt_regs *regs, struct user_fp *fp)
402 {
403         struct thread_info *thread = current_thread_info();
404         int used_math = thread->used_cp[1] | thread->used_cp[2];
405
406         if (used_math)
407                 memcpy(fp, &thread->fpstate.soft, sizeof (*fp));
408
409         return used_math != 0;
410 }
411 EXPORT_SYMBOL(dump_fpu);
412
413 /*
414  * fill in the user structure for a core dump..
415  */
416 void dump_thread(struct pt_regs * regs, struct user * dump)
417 {
418         struct task_struct *tsk = current;
419
420         dump->magic = CMAGIC;
421         dump->start_code = tsk->mm->start_code;
422         dump->start_stack = regs->ARM_sp & ~(PAGE_SIZE - 1);
423
424         dump->u_tsize = (tsk->mm->end_code - tsk->mm->start_code) >> PAGE_SHIFT;
425         dump->u_dsize = (tsk->mm->brk - tsk->mm->start_data + PAGE_SIZE - 1) >> PAGE_SHIFT;
426         dump->u_ssize = 0;
427
428         dump->u_debugreg[0] = tsk->thread.debug.bp[0].address;
429         dump->u_debugreg[1] = tsk->thread.debug.bp[1].address;
430         dump->u_debugreg[2] = tsk->thread.debug.bp[0].insn.arm;
431         dump->u_debugreg[3] = tsk->thread.debug.bp[1].insn.arm;
432         dump->u_debugreg[4] = tsk->thread.debug.nsaved;
433
434         if (dump->start_stack < 0x04000000)
435                 dump->u_ssize = (0x04000000 - dump->start_stack) >> PAGE_SHIFT;
436
437         dump->regs = *regs;
438         dump->u_fpvalid = dump_fpu (regs, &dump->u_fp);
439 }
440 EXPORT_SYMBOL(dump_thread);
441
442 /*
443  * Shuffle the argument into the correct register before calling the
444  * thread function.  r1 is the thread argument, r2 is the pointer to
445  * the thread function, and r3 points to the exit function.
446  */
447 extern void kernel_thread_helper(void);
448 asm(    ".section .text\n"
449 "       .align\n"
450 "       .type   kernel_thread_helper, #function\n"
451 "kernel_thread_helper:\n"
452 "       mov     r0, r1\n"
453 "       mov     lr, r3\n"
454 "       mov     pc, r2\n"
455 "       .size   kernel_thread_helper, . - kernel_thread_helper\n"
456 "       .previous");
457
458 /*
459  * Create a kernel thread.
460  */
461 pid_t kernel_thread(int (*fn)(void *), void *arg, unsigned long flags)
462 {
463         struct pt_regs regs;
464
465         memset(&regs, 0, sizeof(regs));
466
467         regs.ARM_r1 = (unsigned long)arg;
468         regs.ARM_r2 = (unsigned long)fn;
469         regs.ARM_r3 = (unsigned long)do_exit;
470         regs.ARM_pc = (unsigned long)kernel_thread_helper;
471         regs.ARM_cpsr = SVC_MODE;
472
473         return do_fork(flags|CLONE_VM|CLONE_UNTRACED, 0, &regs, 0, NULL, NULL);
474 }
475 EXPORT_SYMBOL(kernel_thread);
476
477 unsigned long get_wchan(struct task_struct *p)
478 {
479         unsigned long fp, lr;
480         unsigned long stack_start, stack_end;
481         int count = 0;
482         if (!p || p == current || p->state == TASK_RUNNING)
483                 return 0;
484
485         stack_start = (unsigned long)end_of_stack(p);
486         stack_end = (unsigned long)task_stack_page(p) + THREAD_SIZE;
487
488         fp = thread_saved_fp(p);
489         do {
490                 if (fp < stack_start || fp > stack_end)
491                         return 0;
492                 lr = pc_pointer (((unsigned long *)fp)[-1]);
493                 if (!in_sched_functions(lr))
494                         return lr;
495                 fp = *(unsigned long *) (fp - 12);
496         } while (count ++ < 16);
497         return 0;
498 }