Merge branch 'master' of /pub/scm/linux/kernel/git/torvalds/linux-2.6
[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/module.h>
14 #include <linux/sched.h>
15 #include <linux/kernel.h>
16 #include <linux/mm.h>
17 #include <linux/stddef.h>
18 #include <linux/unistd.h>
19 #include <linux/slab.h>
20 #include <linux/user.h>
21 #include <linux/a.out.h>
22 #include <linux/delay.h>
23 #include <linux/reboot.h>
24 #include <linux/interrupt.h>
25 #include <linux/kallsyms.h>
26 #include <linux/init.h>
27 #include <linux/cpu.h>
28 #include <linux/elfcore.h>
29 #include <linux/pm.h>
30 #include <linux/tick.h>
31 #include <linux/utsname.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 static const char *processor_modes[] = {
41   "USER_26", "FIQ_26" , "IRQ_26" , "SVC_26" , "UK4_26" , "UK5_26" , "UK6_26" , "UK7_26" ,
42   "UK8_26" , "UK9_26" , "UK10_26", "UK11_26", "UK12_26", "UK13_26", "UK14_26", "UK15_26",
43   "USER_32", "FIQ_32" , "IRQ_32" , "SVC_32" , "UK4_32" , "UK5_32" , "UK6_32" , "ABT_32" ,
44   "UK8_32" , "UK9_32" , "UK10_32", "UND_32" , "UK12_32", "UK13_32", "UK14_32", "SYS_32"
45 };
46
47 static const char *isa_modes[] = {
48   "ARM" , "Thumb" , "Jazelle", "ThumbEE"
49 };
50
51 extern void setup_mm_for_reboot(char mode);
52
53 static volatile int hlt_counter;
54
55 #include <asm/arch/system.h>
56
57 void disable_hlt(void)
58 {
59         hlt_counter++;
60 }
61
62 EXPORT_SYMBOL(disable_hlt);
63
64 void enable_hlt(void)
65 {
66         hlt_counter--;
67 }
68
69 EXPORT_SYMBOL(enable_hlt);
70
71 static int __init nohlt_setup(char *__unused)
72 {
73         hlt_counter = 1;
74         return 1;
75 }
76
77 static int __init hlt_setup(char *__unused)
78 {
79         hlt_counter = 0;
80         return 1;
81 }
82
83 __setup("nohlt", nohlt_setup);
84 __setup("hlt", hlt_setup);
85
86 void arm_machine_restart(char mode)
87 {
88         /*
89          * Clean and disable cache, and turn off interrupts
90          */
91         cpu_proc_fin();
92
93         /*
94          * Tell the mm system that we are going to reboot -
95          * we may need it to insert some 1:1 mappings so that
96          * soft boot works.
97          */
98         setup_mm_for_reboot(mode);
99
100         /*
101          * Now call the architecture specific reboot code.
102          */
103         arch_reset(mode);
104
105         /*
106          * Whoops - the architecture was unable to reboot.
107          * Tell the user!
108          */
109         mdelay(1000);
110         printk("Reboot failed -- System halted\n");
111         while (1);
112 }
113
114 /*
115  * Function pointers to optional machine specific functions
116  */
117 void (*pm_idle)(void);
118 EXPORT_SYMBOL(pm_idle);
119
120 void (*pm_power_off)(void);
121 EXPORT_SYMBOL(pm_power_off);
122
123 void (*arm_pm_restart)(char str) = arm_machine_restart;
124 EXPORT_SYMBOL_GPL(arm_pm_restart);
125
126
127 /*
128  * This is our default idle handler.  We need to disable
129  * interrupts here to ensure we don't miss a wakeup call.
130  */
131 static void default_idle(void)
132 {
133         if (hlt_counter)
134                 cpu_relax();
135         else {
136                 local_irq_disable();
137                 if (!need_resched()) {
138                         timer_dyn_reprogram();
139                         arch_idle();
140                 }
141                 local_irq_enable();
142         }
143 }
144
145 /*
146  * The idle thread.  We try to conserve power, while trying to keep
147  * overall latency low.  The architecture specific idle is passed
148  * a value to indicate the level of "idleness" of the system.
149  */
150 void cpu_idle(void)
151 {
152         local_fiq_enable();
153
154         /* endless idle loop with no priority at all */
155         while (1) {
156                 void (*idle)(void) = pm_idle;
157
158 #ifdef CONFIG_HOTPLUG_CPU
159                 if (cpu_is_offline(smp_processor_id())) {
160                         leds_event(led_idle_start);
161                         cpu_die();
162                 }
163 #endif
164
165                 if (!idle)
166                         idle = default_idle;
167                 leds_event(led_idle_start);
168                 tick_nohz_stop_sched_tick();
169                 while (!need_resched())
170                         idle();
171                 leds_event(led_idle_end);
172                 tick_nohz_restart_sched_tick();
173                 preempt_enable_no_resched();
174                 schedule();
175                 preempt_disable();
176         }
177 }
178
179 static char reboot_mode = 'h';
180
181 int __init reboot_setup(char *str)
182 {
183         reboot_mode = str[0];
184         return 1;
185 }
186
187 __setup("reboot=", reboot_setup);
188
189 void machine_halt(void)
190 {
191 }
192
193
194 void machine_power_off(void)
195 {
196         if (pm_power_off)
197                 pm_power_off();
198 }
199
200 void machine_restart(char * __unused)
201 {
202         arm_pm_restart(reboot_mode);
203 }
204
205 void __show_regs(struct pt_regs *regs)
206 {
207         unsigned long flags;
208         char buf[64];
209
210         printk("CPU: %d    %s  (%s %.*s)\n",
211                 smp_processor_id(), print_tainted(), init_utsname()->release,
212                 (int)strcspn(init_utsname()->version, " "),
213                 init_utsname()->version);
214         print_symbol("PC is at %s\n", instruction_pointer(regs));
215         print_symbol("LR is at %s\n", regs->ARM_lr);
216         printk("pc : [<%08lx>]    lr : [<%08lx>]    psr: %08lx\n"
217                "sp : %08lx  ip : %08lx  fp : %08lx\n",
218                 regs->ARM_pc, regs->ARM_lr, regs->ARM_cpsr,
219                 regs->ARM_sp, regs->ARM_ip, regs->ARM_fp);
220         printk("r10: %08lx  r9 : %08lx  r8 : %08lx\n",
221                 regs->ARM_r10, regs->ARM_r9,
222                 regs->ARM_r8);
223         printk("r7 : %08lx  r6 : %08lx  r5 : %08lx  r4 : %08lx\n",
224                 regs->ARM_r7, regs->ARM_r6,
225                 regs->ARM_r5, regs->ARM_r4);
226         printk("r3 : %08lx  r2 : %08lx  r1 : %08lx  r0 : %08lx\n",
227                 regs->ARM_r3, regs->ARM_r2,
228                 regs->ARM_r1, regs->ARM_r0);
229
230         flags = regs->ARM_cpsr;
231         buf[0] = flags & PSR_N_BIT ? 'N' : 'n';
232         buf[1] = flags & PSR_Z_BIT ? 'Z' : 'z';
233         buf[2] = flags & PSR_C_BIT ? 'C' : 'c';
234         buf[3] = flags & PSR_V_BIT ? 'V' : 'v';
235         buf[4] = '\0';
236
237         printk("Flags: %s  IRQs o%s  FIQs o%s  Mode %s  ISA %s  Segment %s\n",
238                 buf, interrupts_enabled(regs) ? "n" : "ff",
239                 fast_interrupts_enabled(regs) ? "n" : "ff",
240                 processor_modes[processor_mode(regs)],
241                 isa_modes[isa_mode(regs)],
242                 get_fs() == get_ds() ? "kernel" : "user");
243 #ifdef CONFIG_CPU_CP15
244         {
245                 unsigned int ctrl;
246
247                 buf[0] = '\0';
248 #ifdef CONFIG_CPU_CP15_MMU
249                 {
250                         unsigned int transbase, dac;
251                         asm("mrc p15, 0, %0, c2, c0\n\t"
252                             "mrc p15, 0, %1, c3, c0\n"
253                             : "=r" (transbase), "=r" (dac));
254                         snprintf(buf, sizeof(buf), "  Table: %08x  DAC: %08x",
255                                 transbase, dac);
256                 }
257 #endif
258                 asm("mrc p15, 0, %0, c1, c0\n" : "=r" (ctrl));
259
260                 printk("Control: %08x%s\n", ctrl, buf);
261         }
262 #endif
263 }
264
265 void show_regs(struct pt_regs * regs)
266 {
267         printk("\n");
268         printk("Pid: %d, comm: %20s\n", current->pid, current->comm);
269         __show_regs(regs);
270         __backtrace();
271 }
272
273 void show_fpregs(struct user_fp *regs)
274 {
275         int i;
276
277         for (i = 0; i < 8; i++) {
278                 unsigned long *p;
279                 char type;
280
281                 p = (unsigned long *)(regs->fpregs + i);
282
283                 switch (regs->ftype[i]) {
284                         case 1: type = 'f'; break;
285                         case 2: type = 'd'; break;
286                         case 3: type = 'e'; break;
287                         default: type = '?'; break;
288                 }
289                 if (regs->init_flag)
290                         type = '?';
291
292                 printk("  f%d(%c): %08lx %08lx %08lx%c",
293                         i, type, p[0], p[1], p[2], i & 1 ? '\n' : ' ');
294         }
295                         
296
297         printk("FPSR: %08lx FPCR: %08lx\n",
298                 (unsigned long)regs->fpsr,
299                 (unsigned long)regs->fpcr);
300 }
301
302 /*
303  * Free current thread data structures etc..
304  */
305 void exit_thread(void)
306 {
307 }
308
309 ATOMIC_NOTIFIER_HEAD(thread_notify_head);
310
311 EXPORT_SYMBOL_GPL(thread_notify_head);
312
313 void flush_thread(void)
314 {
315         struct thread_info *thread = current_thread_info();
316         struct task_struct *tsk = current;
317
318         memset(thread->used_cp, 0, sizeof(thread->used_cp));
319         memset(&tsk->thread.debug, 0, sizeof(struct debug_info));
320         memset(&thread->fpstate, 0, sizeof(union fp_state));
321
322         thread_notify(THREAD_NOTIFY_FLUSH, thread);
323 }
324
325 void release_thread(struct task_struct *dead_task)
326 {
327         struct thread_info *thread = task_thread_info(dead_task);
328
329         thread_notify(THREAD_NOTIFY_RELEASE, thread);
330 }
331
332 asmlinkage void ret_from_fork(void) __asm__("ret_from_fork");
333
334 int
335 copy_thread(int nr, unsigned long clone_flags, unsigned long stack_start,
336             unsigned long stk_sz, struct task_struct *p, struct pt_regs *regs)
337 {
338         struct thread_info *thread = task_thread_info(p);
339         struct pt_regs *childregs = task_pt_regs(p);
340
341         *childregs = *regs;
342         childregs->ARM_r0 = 0;
343         childregs->ARM_sp = stack_start;
344
345         memset(&thread->cpu_context, 0, sizeof(struct cpu_context_save));
346         thread->cpu_context.sp = (unsigned long)childregs;
347         thread->cpu_context.pc = (unsigned long)ret_from_fork;
348
349         if (clone_flags & CLONE_SETTLS)
350                 thread->tp_value = regs->ARM_r3;
351
352         return 0;
353 }
354
355 /*
356  * fill in the fpe structure for a core dump...
357  */
358 int dump_fpu (struct pt_regs *regs, struct user_fp *fp)
359 {
360         struct thread_info *thread = current_thread_info();
361         int used_math = thread->used_cp[1] | thread->used_cp[2];
362
363         if (used_math)
364                 memcpy(fp, &thread->fpstate.soft, sizeof (*fp));
365
366         return used_math != 0;
367 }
368 EXPORT_SYMBOL(dump_fpu);
369
370 /*
371  * fill in the user structure for a core dump..
372  */
373 void dump_thread(struct pt_regs * regs, struct user * dump)
374 {
375         struct task_struct *tsk = current;
376
377         dump->magic = CMAGIC;
378         dump->start_code = tsk->mm->start_code;
379         dump->start_stack = regs->ARM_sp & ~(PAGE_SIZE - 1);
380
381         dump->u_tsize = (tsk->mm->end_code - tsk->mm->start_code) >> PAGE_SHIFT;
382         dump->u_dsize = (tsk->mm->brk - tsk->mm->start_data + PAGE_SIZE - 1) >> PAGE_SHIFT;
383         dump->u_ssize = 0;
384
385         dump->u_debugreg[0] = tsk->thread.debug.bp[0].address;
386         dump->u_debugreg[1] = tsk->thread.debug.bp[1].address;
387         dump->u_debugreg[2] = tsk->thread.debug.bp[0].insn.arm;
388         dump->u_debugreg[3] = tsk->thread.debug.bp[1].insn.arm;
389         dump->u_debugreg[4] = tsk->thread.debug.nsaved;
390
391         if (dump->start_stack < 0x04000000)
392                 dump->u_ssize = (0x04000000 - dump->start_stack) >> PAGE_SHIFT;
393
394         dump->regs = *regs;
395         dump->u_fpvalid = dump_fpu (regs, &dump->u_fp);
396 }
397 EXPORT_SYMBOL(dump_thread);
398
399 /*
400  * Shuffle the argument into the correct register before calling the
401  * thread function.  r1 is the thread argument, r2 is the pointer to
402  * the thread function, and r3 points to the exit function.
403  */
404 extern void kernel_thread_helper(void);
405 asm(    ".section .text\n"
406 "       .align\n"
407 "       .type   kernel_thread_helper, #function\n"
408 "kernel_thread_helper:\n"
409 "       mov     r0, r1\n"
410 "       mov     lr, r3\n"
411 "       mov     pc, r2\n"
412 "       .size   kernel_thread_helper, . - kernel_thread_helper\n"
413 "       .previous");
414
415 /*
416  * Create a kernel thread.
417  */
418 pid_t kernel_thread(int (*fn)(void *), void *arg, unsigned long flags)
419 {
420         struct pt_regs regs;
421
422         memset(&regs, 0, sizeof(regs));
423
424         regs.ARM_r1 = (unsigned long)arg;
425         regs.ARM_r2 = (unsigned long)fn;
426         regs.ARM_r3 = (unsigned long)do_exit;
427         regs.ARM_pc = (unsigned long)kernel_thread_helper;
428         regs.ARM_cpsr = SVC_MODE;
429
430         return do_fork(flags|CLONE_VM|CLONE_UNTRACED, 0, &regs, 0, NULL, NULL);
431 }
432 EXPORT_SYMBOL(kernel_thread);
433
434 unsigned long get_wchan(struct task_struct *p)
435 {
436         unsigned long fp, lr;
437         unsigned long stack_start, stack_end;
438         int count = 0;
439         if (!p || p == current || p->state == TASK_RUNNING)
440                 return 0;
441
442         stack_start = (unsigned long)end_of_stack(p);
443         stack_end = (unsigned long)task_stack_page(p) + THREAD_SIZE;
444
445         fp = thread_saved_fp(p);
446         do {
447                 if (fp < stack_start || fp > stack_end)
448                         return 0;
449                 lr = pc_pointer (((unsigned long *)fp)[-1]);
450                 if (!in_sched_functions(lr))
451                         return lr;
452                 fp = *(unsigned long *) (fp - 12);
453         } while (count ++ < 16);
454         return 0;
455 }