Merge with /pub/scm/linux/kernel/git/torvalds/linux-2.6.git
[linux-2.6] / 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/thread_notify.h>
37 #include <asm/uaccess.h>
38 #include <asm/mach/time.h>
39
40 extern const char *processor_modes[];
41 extern void setup_mm_for_reboot(char mode);
42
43 static volatile int hlt_counter;
44
45 #include <asm/arch/system.h>
46
47 void disable_hlt(void)
48 {
49         hlt_counter++;
50 }
51
52 EXPORT_SYMBOL(disable_hlt);
53
54 void enable_hlt(void)
55 {
56         hlt_counter--;
57 }
58
59 EXPORT_SYMBOL(enable_hlt);
60
61 static int __init nohlt_setup(char *__unused)
62 {
63         hlt_counter = 1;
64         return 1;
65 }
66
67 static int __init hlt_setup(char *__unused)
68 {
69         hlt_counter = 0;
70         return 1;
71 }
72
73 __setup("nohlt", nohlt_setup);
74 __setup("hlt", hlt_setup);
75
76 void arm_machine_restart(char mode)
77 {
78         /*
79          * Clean and disable cache, and turn off interrupts
80          */
81         cpu_proc_fin();
82
83         /*
84          * Tell the mm system that we are going to reboot -
85          * we may need it to insert some 1:1 mappings so that
86          * soft boot works.
87          */
88         setup_mm_for_reboot(mode);
89
90         /*
91          * Now call the architecture specific reboot code.
92          */
93         arch_reset(mode);
94
95         /*
96          * Whoops - the architecture was unable to reboot.
97          * Tell the user!
98          */
99         mdelay(1000);
100         printk("Reboot failed -- System halted\n");
101         while (1);
102 }
103
104 /*
105  * Function pointers to optional machine specific functions
106  */
107 void (*pm_idle)(void);
108 EXPORT_SYMBOL(pm_idle);
109
110 void (*pm_power_off)(void);
111 EXPORT_SYMBOL(pm_power_off);
112
113 void (*arm_pm_restart)(char str) = arm_machine_restart;
114 EXPORT_SYMBOL_GPL(arm_pm_restart);
115
116
117 /*
118  * This is our default idle handler.  We need to disable
119  * interrupts here to ensure we don't miss a wakeup call.
120  */
121 static void default_idle(void)
122 {
123         if (hlt_counter)
124                 cpu_relax();
125         else {
126                 local_irq_disable();
127                 if (!need_resched()) {
128                         timer_dyn_reprogram();
129                         arch_idle();
130                 }
131                 local_irq_enable();
132         }
133 }
134
135 /*
136  * The idle thread.  We try to conserve power, while trying to keep
137  * overall latency low.  The architecture specific idle is passed
138  * a value to indicate the level of "idleness" of the system.
139  */
140 void cpu_idle(void)
141 {
142         local_fiq_enable();
143
144         /* endless idle loop with no priority at all */
145         while (1) {
146                 void (*idle)(void) = pm_idle;
147
148 #ifdef CONFIG_HOTPLUG_CPU
149                 if (cpu_is_offline(smp_processor_id())) {
150                         leds_event(led_idle_start);
151                         cpu_die();
152                 }
153 #endif
154
155                 if (!idle)
156                         idle = default_idle;
157                 leds_event(led_idle_start);
158                 while (!need_resched())
159                         idle();
160                 leds_event(led_idle_end);
161                 preempt_enable_no_resched();
162                 schedule();
163                 preempt_disable();
164         }
165 }
166
167 static char reboot_mode = 'h';
168
169 int __init reboot_setup(char *str)
170 {
171         reboot_mode = str[0];
172         return 1;
173 }
174
175 __setup("reboot=", reboot_setup);
176
177 void machine_halt(void)
178 {
179 }
180
181
182 void machine_power_off(void)
183 {
184         if (pm_power_off)
185                 pm_power_off();
186 }
187
188 void machine_restart(char * __unused)
189 {
190         arm_pm_restart(reboot_mode);
191 }
192
193 void __show_regs(struct pt_regs *regs)
194 {
195         unsigned long flags = condition_codes(regs);
196
197         printk("CPU: %d\n", smp_processor_id());
198         print_symbol("PC is at %s\n", instruction_pointer(regs));
199         print_symbol("LR is at %s\n", regs->ARM_lr);
200         printk("pc : [<%08lx>]    lr : [<%08lx>]    %s\n"
201                "sp : %08lx  ip : %08lx  fp : %08lx\n",
202                 instruction_pointer(regs),
203                 regs->ARM_lr, print_tainted(), regs->ARM_sp,
204                 regs->ARM_ip, regs->ARM_fp);
205         printk("r10: %08lx  r9 : %08lx  r8 : %08lx\n",
206                 regs->ARM_r10, regs->ARM_r9,
207                 regs->ARM_r8);
208         printk("r7 : %08lx  r6 : %08lx  r5 : %08lx  r4 : %08lx\n",
209                 regs->ARM_r7, regs->ARM_r6,
210                 regs->ARM_r5, regs->ARM_r4);
211         printk("r3 : %08lx  r2 : %08lx  r1 : %08lx  r0 : %08lx\n",
212                 regs->ARM_r3, regs->ARM_r2,
213                 regs->ARM_r1, regs->ARM_r0);
214         printk("Flags: %c%c%c%c",
215                 flags & PSR_N_BIT ? 'N' : 'n',
216                 flags & PSR_Z_BIT ? 'Z' : 'z',
217                 flags & PSR_C_BIT ? 'C' : 'c',
218                 flags & PSR_V_BIT ? 'V' : 'v');
219         printk("  IRQs o%s  FIQs o%s  Mode %s%s  Segment %s\n",
220                 interrupts_enabled(regs) ? "n" : "ff",
221                 fast_interrupts_enabled(regs) ? "n" : "ff",
222                 processor_modes[processor_mode(regs)],
223                 thumb_mode(regs) ? " (T)" : "",
224                 get_fs() == get_ds() ? "kernel" : "user");
225         {
226                 unsigned int ctrl, transbase, dac;
227                   __asm__ (
228                 "       mrc p15, 0, %0, c1, c0\n"
229                 "       mrc p15, 0, %1, c2, c0\n"
230                 "       mrc p15, 0, %2, c3, c0\n"
231                 : "=r" (ctrl), "=r" (transbase), "=r" (dac));
232                 printk("Control: %04X  Table: %08X  DAC: %08X\n",
233                         ctrl, transbase, dac);
234         }
235 }
236
237 void show_regs(struct pt_regs * regs)
238 {
239         printk("\n");
240         printk("Pid: %d, comm: %20s\n", current->pid, current->comm);
241         __show_regs(regs);
242         __backtrace();
243 }
244
245 void show_fpregs(struct user_fp *regs)
246 {
247         int i;
248
249         for (i = 0; i < 8; i++) {
250                 unsigned long *p;
251                 char type;
252
253                 p = (unsigned long *)(regs->fpregs + i);
254
255                 switch (regs->ftype[i]) {
256                         case 1: type = 'f'; break;
257                         case 2: type = 'd'; break;
258                         case 3: type = 'e'; break;
259                         default: type = '?'; break;
260                 }
261                 if (regs->init_flag)
262                         type = '?';
263
264                 printk("  f%d(%c): %08lx %08lx %08lx%c",
265                         i, type, p[0], p[1], p[2], i & 1 ? '\n' : ' ');
266         }
267                         
268
269         printk("FPSR: %08lx FPCR: %08lx\n",
270                 (unsigned long)regs->fpsr,
271                 (unsigned long)regs->fpcr);
272 }
273
274 /*
275  * Task structure and kernel stack allocation.
276  */
277 struct thread_info_list {
278         unsigned long *head;
279         unsigned int nr;
280 };
281
282 static DEFINE_PER_CPU(struct thread_info_list, thread_info_list) = { NULL, 0 };
283
284 #define EXTRA_TASK_STRUCT       4
285
286 struct thread_info *alloc_thread_info(struct task_struct *task)
287 {
288         struct thread_info *thread = NULL;
289
290         if (EXTRA_TASK_STRUCT) {
291                 struct thread_info_list *th = &get_cpu_var(thread_info_list);
292                 unsigned long *p = th->head;
293
294                 if (p) {
295                         th->head = (unsigned long *)p[0];
296                         th->nr -= 1;
297                 }
298                 put_cpu_var(thread_info_list);
299
300                 thread = (struct thread_info *)p;
301         }
302
303         if (!thread)
304                 thread = (struct thread_info *)
305                            __get_free_pages(GFP_KERNEL, THREAD_SIZE_ORDER);
306
307 #ifdef CONFIG_DEBUG_STACK_USAGE
308         /*
309          * The stack must be cleared if you want SYSRQ-T to
310          * give sensible stack usage information
311          */
312         if (thread)
313                 memzero(thread, THREAD_SIZE);
314 #endif
315         return thread;
316 }
317
318 void free_thread_info(struct thread_info *thread)
319 {
320         if (EXTRA_TASK_STRUCT) {
321                 struct thread_info_list *th = &get_cpu_var(thread_info_list);
322                 if (th->nr < EXTRA_TASK_STRUCT) {
323                         unsigned long *p = (unsigned long *)thread;
324                         p[0] = (unsigned long)th->head;
325                         th->head = p;
326                         th->nr += 1;
327                         put_cpu_var(thread_info_list);
328                         return;
329                 }
330                 put_cpu_var(thread_info_list);
331         }
332         free_pages((unsigned long)thread, THREAD_SIZE_ORDER);
333 }
334
335 /*
336  * Free current thread data structures etc..
337  */
338 void exit_thread(void)
339 {
340 }
341
342 ATOMIC_NOTIFIER_HEAD(thread_notify_head);
343
344 EXPORT_SYMBOL_GPL(thread_notify_head);
345
346 void flush_thread(void)
347 {
348         struct thread_info *thread = current_thread_info();
349         struct task_struct *tsk = current;
350
351         memset(thread->used_cp, 0, sizeof(thread->used_cp));
352         memset(&tsk->thread.debug, 0, sizeof(struct debug_info));
353         memset(&thread->fpstate, 0, sizeof(union fp_state));
354
355         thread_notify(THREAD_NOTIFY_FLUSH, thread);
356 #if defined(CONFIG_IWMMXT)
357         iwmmxt_task_release(thread);
358 #endif
359 }
360
361 void release_thread(struct task_struct *dead_task)
362 {
363         struct thread_info *thread = task_thread_info(dead_task);
364
365         thread_notify(THREAD_NOTIFY_RELEASE, thread);
366 #if defined(CONFIG_IWMMXT)
367         iwmmxt_task_release(thread);
368 #endif
369 }
370
371 asmlinkage void ret_from_fork(void) __asm__("ret_from_fork");
372
373 int
374 copy_thread(int nr, unsigned long clone_flags, unsigned long stack_start,
375             unsigned long stk_sz, struct task_struct *p, struct pt_regs *regs)
376 {
377         struct thread_info *thread = task_thread_info(p);
378         struct pt_regs *childregs = task_pt_regs(p);
379
380         *childregs = *regs;
381         childregs->ARM_r0 = 0;
382         childregs->ARM_sp = stack_start;
383
384         memset(&thread->cpu_context, 0, sizeof(struct cpu_context_save));
385         thread->cpu_context.sp = (unsigned long)childregs;
386         thread->cpu_context.pc = (unsigned long)ret_from_fork;
387
388         if (clone_flags & CLONE_SETTLS)
389                 thread->tp_value = regs->ARM_r3;
390
391         return 0;
392 }
393
394 /*
395  * fill in the fpe structure for a core dump...
396  */
397 int dump_fpu (struct pt_regs *regs, struct user_fp *fp)
398 {
399         struct thread_info *thread = current_thread_info();
400         int used_math = thread->used_cp[1] | thread->used_cp[2];
401
402         if (used_math)
403                 memcpy(fp, &thread->fpstate.soft, sizeof (*fp));
404
405         return used_math != 0;
406 }
407 EXPORT_SYMBOL(dump_fpu);
408
409 /*
410  * fill in the user structure for a core dump..
411  */
412 void dump_thread(struct pt_regs * regs, struct user * dump)
413 {
414         struct task_struct *tsk = current;
415
416         dump->magic = CMAGIC;
417         dump->start_code = tsk->mm->start_code;
418         dump->start_stack = regs->ARM_sp & ~(PAGE_SIZE - 1);
419
420         dump->u_tsize = (tsk->mm->end_code - tsk->mm->start_code) >> PAGE_SHIFT;
421         dump->u_dsize = (tsk->mm->brk - tsk->mm->start_data + PAGE_SIZE - 1) >> PAGE_SHIFT;
422         dump->u_ssize = 0;
423
424         dump->u_debugreg[0] = tsk->thread.debug.bp[0].address;
425         dump->u_debugreg[1] = tsk->thread.debug.bp[1].address;
426         dump->u_debugreg[2] = tsk->thread.debug.bp[0].insn.arm;
427         dump->u_debugreg[3] = tsk->thread.debug.bp[1].insn.arm;
428         dump->u_debugreg[4] = tsk->thread.debug.nsaved;
429
430         if (dump->start_stack < 0x04000000)
431                 dump->u_ssize = (0x04000000 - dump->start_stack) >> PAGE_SHIFT;
432
433         dump->regs = *regs;
434         dump->u_fpvalid = dump_fpu (regs, &dump->u_fp);
435 }
436 EXPORT_SYMBOL(dump_thread);
437
438 /*
439  * Shuffle the argument into the correct register before calling the
440  * thread function.  r1 is the thread argument, r2 is the pointer to
441  * the thread function, and r3 points to the exit function.
442  */
443 extern void kernel_thread_helper(void);
444 asm(    ".section .text\n"
445 "       .align\n"
446 "       .type   kernel_thread_helper, #function\n"
447 "kernel_thread_helper:\n"
448 "       mov     r0, r1\n"
449 "       mov     lr, r3\n"
450 "       mov     pc, r2\n"
451 "       .size   kernel_thread_helper, . - kernel_thread_helper\n"
452 "       .previous");
453
454 /*
455  * Create a kernel thread.
456  */
457 pid_t kernel_thread(int (*fn)(void *), void *arg, unsigned long flags)
458 {
459         struct pt_regs regs;
460
461         memset(&regs, 0, sizeof(regs));
462
463         regs.ARM_r1 = (unsigned long)arg;
464         regs.ARM_r2 = (unsigned long)fn;
465         regs.ARM_r3 = (unsigned long)do_exit;
466         regs.ARM_pc = (unsigned long)kernel_thread_helper;
467         regs.ARM_cpsr = SVC_MODE;
468
469         return do_fork(flags|CLONE_VM|CLONE_UNTRACED, 0, &regs, 0, NULL, NULL);
470 }
471 EXPORT_SYMBOL(kernel_thread);
472
473 unsigned long get_wchan(struct task_struct *p)
474 {
475         unsigned long fp, lr;
476         unsigned long stack_start, stack_end;
477         int count = 0;
478         if (!p || p == current || p->state == TASK_RUNNING)
479                 return 0;
480
481         stack_start = (unsigned long)end_of_stack(p);
482         stack_end = (unsigned long)task_stack_page(p) + THREAD_SIZE;
483
484         fp = thread_saved_fp(p);
485         do {
486                 if (fp < stack_start || fp > stack_end)
487                         return 0;
488                 lr = pc_pointer (((unsigned long *)fp)[-1]);
489                 if (!in_sched_functions(lr))
490                         return lr;
491                 fp = *(unsigned long *) (fp - 12);
492         } while (count ++ < 16);
493         return 0;
494 }