Merge master.kernel.org:/pub/scm/linux/kernel/git/jejb/scsi-misc-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
32 #include <asm/leds.h>
33 #include <asm/processor.h>
34 #include <asm/system.h>
35 #include <asm/thread_notify.h>
36 #include <asm/uaccess.h>
37 #include <asm/mach/time.h>
38
39 static const char *processor_modes[] = {
40   "USER_26", "FIQ_26" , "IRQ_26" , "SVC_26" , "UK4_26" , "UK5_26" , "UK6_26" , "UK7_26" ,
41   "UK8_26" , "UK9_26" , "UK10_26", "UK11_26", "UK12_26", "UK13_26", "UK14_26", "UK15_26",
42   "USER_32", "FIQ_32" , "IRQ_32" , "SVC_32" , "UK4_32" , "UK5_32" , "UK6_32" , "ABT_32" ,
43   "UK8_32" , "UK9_32" , "UK10_32", "UND_32" , "UK12_32", "UK13_32", "UK14_32", "SYS_32"
44 };
45
46 extern void setup_mm_for_reboot(char mode);
47
48 static volatile int hlt_counter;
49
50 #include <asm/arch/system.h>
51
52 void disable_hlt(void)
53 {
54         hlt_counter++;
55 }
56
57 EXPORT_SYMBOL(disable_hlt);
58
59 void enable_hlt(void)
60 {
61         hlt_counter--;
62 }
63
64 EXPORT_SYMBOL(enable_hlt);
65
66 static int __init nohlt_setup(char *__unused)
67 {
68         hlt_counter = 1;
69         return 1;
70 }
71
72 static int __init hlt_setup(char *__unused)
73 {
74         hlt_counter = 0;
75         return 1;
76 }
77
78 __setup("nohlt", nohlt_setup);
79 __setup("hlt", hlt_setup);
80
81 void arm_machine_restart(char mode)
82 {
83         /*
84          * Clean and disable cache, and turn off interrupts
85          */
86         cpu_proc_fin();
87
88         /*
89          * Tell the mm system that we are going to reboot -
90          * we may need it to insert some 1:1 mappings so that
91          * soft boot works.
92          */
93         setup_mm_for_reboot(mode);
94
95         /*
96          * Now call the architecture specific reboot code.
97          */
98         arch_reset(mode);
99
100         /*
101          * Whoops - the architecture was unable to reboot.
102          * Tell the user!
103          */
104         mdelay(1000);
105         printk("Reboot failed -- System halted\n");
106         while (1);
107 }
108
109 /*
110  * Function pointers to optional machine specific functions
111  */
112 void (*pm_idle)(void);
113 EXPORT_SYMBOL(pm_idle);
114
115 void (*pm_power_off)(void);
116 EXPORT_SYMBOL(pm_power_off);
117
118 void (*arm_pm_restart)(char str) = arm_machine_restart;
119 EXPORT_SYMBOL_GPL(arm_pm_restart);
120
121
122 /*
123  * This is our default idle handler.  We need to disable
124  * interrupts here to ensure we don't miss a wakeup call.
125  */
126 static void default_idle(void)
127 {
128         if (hlt_counter)
129                 cpu_relax();
130         else {
131                 local_irq_disable();
132                 if (!need_resched()) {
133                         timer_dyn_reprogram();
134                         arch_idle();
135                 }
136                 local_irq_enable();
137         }
138 }
139
140 /*
141  * The idle thread.  We try to conserve power, while trying to keep
142  * overall latency low.  The architecture specific idle is passed
143  * a value to indicate the level of "idleness" of the system.
144  */
145 void cpu_idle(void)
146 {
147         local_fiq_enable();
148
149         /* endless idle loop with no priority at all */
150         while (1) {
151                 void (*idle)(void) = pm_idle;
152
153 #ifdef CONFIG_HOTPLUG_CPU
154                 if (cpu_is_offline(smp_processor_id())) {
155                         leds_event(led_idle_start);
156                         cpu_die();
157                 }
158 #endif
159
160                 if (!idle)
161                         idle = default_idle;
162                 leds_event(led_idle_start);
163                 tick_nohz_stop_sched_tick();
164                 while (!need_resched())
165                         idle();
166                 leds_event(led_idle_end);
167                 tick_nohz_restart_sched_tick();
168                 preempt_enable_no_resched();
169                 schedule();
170                 preempt_disable();
171         }
172 }
173
174 static char reboot_mode = 'h';
175
176 int __init reboot_setup(char *str)
177 {
178         reboot_mode = str[0];
179         return 1;
180 }
181
182 __setup("reboot=", reboot_setup);
183
184 void machine_halt(void)
185 {
186 }
187
188
189 void machine_power_off(void)
190 {
191         if (pm_power_off)
192                 pm_power_off();
193 }
194
195 void machine_restart(char * __unused)
196 {
197         arm_pm_restart(reboot_mode);
198 }
199
200 void __show_regs(struct pt_regs *regs)
201 {
202         unsigned long flags = condition_codes(regs);
203
204         printk("CPU: %d\n", smp_processor_id());
205         print_symbol("PC is at %s\n", instruction_pointer(regs));
206         print_symbol("LR is at %s\n", regs->ARM_lr);
207         printk("pc : [<%08lx>]    lr : [<%08lx>]    %s\n"
208                "sp : %08lx  ip : %08lx  fp : %08lx\n",
209                 instruction_pointer(regs),
210                 regs->ARM_lr, print_tainted(), regs->ARM_sp,
211                 regs->ARM_ip, regs->ARM_fp);
212         printk("r10: %08lx  r9 : %08lx  r8 : %08lx\n",
213                 regs->ARM_r10, regs->ARM_r9,
214                 regs->ARM_r8);
215         printk("r7 : %08lx  r6 : %08lx  r5 : %08lx  r4 : %08lx\n",
216                 regs->ARM_r7, regs->ARM_r6,
217                 regs->ARM_r5, regs->ARM_r4);
218         printk("r3 : %08lx  r2 : %08lx  r1 : %08lx  r0 : %08lx\n",
219                 regs->ARM_r3, regs->ARM_r2,
220                 regs->ARM_r1, regs->ARM_r0);
221         printk("Flags: %c%c%c%c",
222                 flags & PSR_N_BIT ? 'N' : 'n',
223                 flags & PSR_Z_BIT ? 'Z' : 'z',
224                 flags & PSR_C_BIT ? 'C' : 'c',
225                 flags & PSR_V_BIT ? 'V' : 'v');
226         printk("  IRQs o%s  FIQs o%s  Mode %s%s  Segment %s\n",
227                 interrupts_enabled(regs) ? "n" : "ff",
228                 fast_interrupts_enabled(regs) ? "n" : "ff",
229                 processor_modes[processor_mode(regs)],
230                 thumb_mode(regs) ? " (T)" : "",
231                 get_fs() == get_ds() ? "kernel" : "user");
232 #if CONFIG_CPU_CP15
233         {
234                 unsigned int ctrl;
235                   __asm__ (
236                 "       mrc p15, 0, %0, c1, c0\n"
237                 : "=r" (ctrl));
238                 printk("Control: %04X\n", ctrl);
239         }
240 #ifdef CONFIG_CPU_CP15_MMU
241         {
242                 unsigned int transbase, dac;
243                   __asm__ (
244                 "       mrc p15, 0, %0, c2, c0\n"
245                 "       mrc p15, 0, %1, c3, c0\n"
246                 : "=r" (transbase), "=r" (dac));
247                 printk("Table: %08X  DAC: %08X\n",
248                         transbase, dac);
249         }
250 #endif
251 #endif
252 }
253
254 void show_regs(struct pt_regs * regs)
255 {
256         printk("\n");
257         printk("Pid: %d, comm: %20s\n", current->pid, current->comm);
258         __show_regs(regs);
259         __backtrace();
260 }
261
262 void show_fpregs(struct user_fp *regs)
263 {
264         int i;
265
266         for (i = 0; i < 8; i++) {
267                 unsigned long *p;
268                 char type;
269
270                 p = (unsigned long *)(regs->fpregs + i);
271
272                 switch (regs->ftype[i]) {
273                         case 1: type = 'f'; break;
274                         case 2: type = 'd'; break;
275                         case 3: type = 'e'; break;
276                         default: type = '?'; break;
277                 }
278                 if (regs->init_flag)
279                         type = '?';
280
281                 printk("  f%d(%c): %08lx %08lx %08lx%c",
282                         i, type, p[0], p[1], p[2], i & 1 ? '\n' : ' ');
283         }
284                         
285
286         printk("FPSR: %08lx FPCR: %08lx\n",
287                 (unsigned long)regs->fpsr,
288                 (unsigned long)regs->fpcr);
289 }
290
291 /*
292  * Free current thread data structures etc..
293  */
294 void exit_thread(void)
295 {
296 }
297
298 ATOMIC_NOTIFIER_HEAD(thread_notify_head);
299
300 EXPORT_SYMBOL_GPL(thread_notify_head);
301
302 void flush_thread(void)
303 {
304         struct thread_info *thread = current_thread_info();
305         struct task_struct *tsk = current;
306
307         memset(thread->used_cp, 0, sizeof(thread->used_cp));
308         memset(&tsk->thread.debug, 0, sizeof(struct debug_info));
309         memset(&thread->fpstate, 0, sizeof(union fp_state));
310
311         thread_notify(THREAD_NOTIFY_FLUSH, thread);
312 }
313
314 void release_thread(struct task_struct *dead_task)
315 {
316         struct thread_info *thread = task_thread_info(dead_task);
317
318         thread_notify(THREAD_NOTIFY_RELEASE, thread);
319 }
320
321 asmlinkage void ret_from_fork(void) __asm__("ret_from_fork");
322
323 int
324 copy_thread(int nr, unsigned long clone_flags, unsigned long stack_start,
325             unsigned long stk_sz, struct task_struct *p, struct pt_regs *regs)
326 {
327         struct thread_info *thread = task_thread_info(p);
328         struct pt_regs *childregs = task_pt_regs(p);
329
330         *childregs = *regs;
331         childregs->ARM_r0 = 0;
332         childregs->ARM_sp = stack_start;
333
334         memset(&thread->cpu_context, 0, sizeof(struct cpu_context_save));
335         thread->cpu_context.sp = (unsigned long)childregs;
336         thread->cpu_context.pc = (unsigned long)ret_from_fork;
337
338         if (clone_flags & CLONE_SETTLS)
339                 thread->tp_value = regs->ARM_r3;
340
341         return 0;
342 }
343
344 /*
345  * fill in the fpe structure for a core dump...
346  */
347 int dump_fpu (struct pt_regs *regs, struct user_fp *fp)
348 {
349         struct thread_info *thread = current_thread_info();
350         int used_math = thread->used_cp[1] | thread->used_cp[2];
351
352         if (used_math)
353                 memcpy(fp, &thread->fpstate.soft, sizeof (*fp));
354
355         return used_math != 0;
356 }
357 EXPORT_SYMBOL(dump_fpu);
358
359 /*
360  * fill in the user structure for a core dump..
361  */
362 void dump_thread(struct pt_regs * regs, struct user * dump)
363 {
364         struct task_struct *tsk = current;
365
366         dump->magic = CMAGIC;
367         dump->start_code = tsk->mm->start_code;
368         dump->start_stack = regs->ARM_sp & ~(PAGE_SIZE - 1);
369
370         dump->u_tsize = (tsk->mm->end_code - tsk->mm->start_code) >> PAGE_SHIFT;
371         dump->u_dsize = (tsk->mm->brk - tsk->mm->start_data + PAGE_SIZE - 1) >> PAGE_SHIFT;
372         dump->u_ssize = 0;
373
374         dump->u_debugreg[0] = tsk->thread.debug.bp[0].address;
375         dump->u_debugreg[1] = tsk->thread.debug.bp[1].address;
376         dump->u_debugreg[2] = tsk->thread.debug.bp[0].insn.arm;
377         dump->u_debugreg[3] = tsk->thread.debug.bp[1].insn.arm;
378         dump->u_debugreg[4] = tsk->thread.debug.nsaved;
379
380         if (dump->start_stack < 0x04000000)
381                 dump->u_ssize = (0x04000000 - dump->start_stack) >> PAGE_SHIFT;
382
383         dump->regs = *regs;
384         dump->u_fpvalid = dump_fpu (regs, &dump->u_fp);
385 }
386 EXPORT_SYMBOL(dump_thread);
387
388 /*
389  * Shuffle the argument into the correct register before calling the
390  * thread function.  r1 is the thread argument, r2 is the pointer to
391  * the thread function, and r3 points to the exit function.
392  */
393 extern void kernel_thread_helper(void);
394 asm(    ".section .text\n"
395 "       .align\n"
396 "       .type   kernel_thread_helper, #function\n"
397 "kernel_thread_helper:\n"
398 "       mov     r0, r1\n"
399 "       mov     lr, r3\n"
400 "       mov     pc, r2\n"
401 "       .size   kernel_thread_helper, . - kernel_thread_helper\n"
402 "       .previous");
403
404 /*
405  * Create a kernel thread.
406  */
407 pid_t kernel_thread(int (*fn)(void *), void *arg, unsigned long flags)
408 {
409         struct pt_regs regs;
410
411         memset(&regs, 0, sizeof(regs));
412
413         regs.ARM_r1 = (unsigned long)arg;
414         regs.ARM_r2 = (unsigned long)fn;
415         regs.ARM_r3 = (unsigned long)do_exit;
416         regs.ARM_pc = (unsigned long)kernel_thread_helper;
417         regs.ARM_cpsr = SVC_MODE;
418
419         return do_fork(flags|CLONE_VM|CLONE_UNTRACED, 0, &regs, 0, NULL, NULL);
420 }
421 EXPORT_SYMBOL(kernel_thread);
422
423 unsigned long get_wchan(struct task_struct *p)
424 {
425         unsigned long fp, lr;
426         unsigned long stack_start, stack_end;
427         int count = 0;
428         if (!p || p == current || p->state == TASK_RUNNING)
429                 return 0;
430
431         stack_start = (unsigned long)end_of_stack(p);
432         stack_end = (unsigned long)task_stack_page(p) + THREAD_SIZE;
433
434         fp = thread_saved_fp(p);
435         do {
436                 if (fp < stack_start || fp > stack_end)
437                         return 0;
438                 lr = pc_pointer (((unsigned long *)fp)[-1]);
439                 if (!in_sched_functions(lr))
440                         return lr;
441                 fp = *(unsigned long *) (fp - 12);
442         } while (count ++ < 16);
443         return 0;
444 }