2 * linux/arch/arm/kernel/process.c
4 * Copyright (C) 1996-2000 Russell King - Converted to ARM.
5 * Original Copyright (C) 1995 Linus Torvalds
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.
13 #include <linux/config.h>
14 #include <linux/module.h>
15 #include <linux/sched.h>
16 #include <linux/kernel.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>
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>
40 extern const char *processor_modes
[];
41 extern void setup_mm_for_reboot(char mode
);
43 static volatile int hlt_counter
;
45 #include <asm/arch/system.h>
47 void disable_hlt(void)
52 EXPORT_SYMBOL(disable_hlt
);
59 EXPORT_SYMBOL(enable_hlt
);
61 static int __init
nohlt_setup(char *__unused
)
67 static int __init
hlt_setup(char *__unused
)
73 __setup("nohlt", nohlt_setup
);
74 __setup("hlt", hlt_setup
);
76 void arm_machine_restart(char mode
)
79 * Clean and disable cache, and turn off interrupts
84 * Tell the mm system that we are going to reboot -
85 * we may need it to insert some 1:1 mappings so that
88 setup_mm_for_reboot(mode
);
91 * Now call the architecture specific reboot code.
96 * Whoops - the architecture was unable to reboot.
100 printk("Reboot failed -- System halted\n");
105 * Function pointers to optional machine specific functions
107 void (*pm_idle
)(void);
108 EXPORT_SYMBOL(pm_idle
);
110 void (*pm_power_off
)(void);
111 EXPORT_SYMBOL(pm_power_off
);
113 void (*arm_pm_restart
)(char str
) = arm_machine_restart
;
114 EXPORT_SYMBOL_GPL(arm_pm_restart
);
118 * This is our default idle handler. We need to disable
119 * interrupts here to ensure we don't miss a wakeup call.
121 static void default_idle(void)
127 if (!need_resched()) {
128 timer_dyn_reprogram();
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.
144 /* endless idle loop with no priority at all */
146 void (*idle
)(void) = pm_idle
;
148 #ifdef CONFIG_HOTPLUG_CPU
149 if (cpu_is_offline(smp_processor_id())) {
150 leds_event(led_idle_start
);
157 leds_event(led_idle_start
);
158 while (!need_resched())
160 leds_event(led_idle_end
);
161 preempt_enable_no_resched();
167 static char reboot_mode
= 'h';
169 int __init
reboot_setup(char *str
)
171 reboot_mode
= str
[0];
175 __setup("reboot=", reboot_setup
);
177 void machine_halt(void)
182 void machine_power_off(void)
188 void machine_restart(char * __unused
)
190 arm_pm_restart(reboot_mode
);
193 void __show_regs(struct pt_regs
*regs
)
195 unsigned long flags
= condition_codes(regs
);
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
,
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");
226 unsigned int ctrl
, transbase
, dac
;
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
);
237 void show_regs(struct pt_regs
* regs
)
240 printk("Pid: %d, comm: %20s\n", current
->pid
, current
->comm
);
245 void show_fpregs(struct user_fp
*regs
)
249 for (i
= 0; i
< 8; i
++) {
253 p
= (unsigned long *)(regs
->fpregs
+ i
);
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;
264 printk(" f%d(%c): %08lx %08lx %08lx%c",
265 i
, type
, p
[0], p
[1], p
[2], i
& 1 ? '\n' : ' ');
269 printk("FPSR: %08lx FPCR: %08lx\n",
270 (unsigned long)regs
->fpsr
,
271 (unsigned long)regs
->fpcr
);
275 * Task structure and kernel stack allocation.
277 struct thread_info_list
{
282 static DEFINE_PER_CPU(struct thread_info_list
, thread_info_list
) = { NULL
, 0 };
284 #define EXTRA_TASK_STRUCT 4
286 struct thread_info
*alloc_thread_info(struct task_struct
*task
)
288 struct thread_info
*thread
= NULL
;
290 if (EXTRA_TASK_STRUCT
) {
291 struct thread_info_list
*th
= &get_cpu_var(thread_info_list
);
292 unsigned long *p
= th
->head
;
295 th
->head
= (unsigned long *)p
[0];
298 put_cpu_var(thread_info_list
);
300 thread
= (struct thread_info
*)p
;
304 thread
= (struct thread_info
*)
305 __get_free_pages(GFP_KERNEL
, THREAD_SIZE_ORDER
);
307 #ifdef CONFIG_DEBUG_STACK_USAGE
309 * The stack must be cleared if you want SYSRQ-T to
310 * give sensible stack usage information
313 memzero(thread
, THREAD_SIZE
);
318 void free_thread_info(struct thread_info
*thread
)
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
;
327 put_cpu_var(thread_info_list
);
330 put_cpu_var(thread_info_list
);
332 free_pages((unsigned long)thread
, THREAD_SIZE_ORDER
);
336 * Free current thread data structures etc..
338 void exit_thread(void)
342 ATOMIC_NOTIFIER_HEAD(thread_notify_head
);
344 EXPORT_SYMBOL_GPL(thread_notify_head
);
346 void flush_thread(void)
348 struct thread_info
*thread
= current_thread_info();
349 struct task_struct
*tsk
= current
;
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
));
355 thread_notify(THREAD_NOTIFY_FLUSH
, thread
);
356 #if defined(CONFIG_IWMMXT)
357 iwmmxt_task_release(thread
);
361 void release_thread(struct task_struct
*dead_task
)
363 struct thread_info
*thread
= task_thread_info(dead_task
);
365 thread_notify(THREAD_NOTIFY_RELEASE
, thread
);
366 #if defined(CONFIG_IWMMXT)
367 iwmmxt_task_release(thread
);
371 asmlinkage
void ret_from_fork(void) __asm__("ret_from_fork");
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
)
377 struct thread_info
*thread
= task_thread_info(p
);
378 struct pt_regs
*childregs
= task_pt_regs(p
);
381 childregs
->ARM_r0
= 0;
382 childregs
->ARM_sp
= stack_start
;
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
;
388 if (clone_flags
& CLONE_SETTLS
)
389 thread
->tp_value
= regs
->ARM_r3
;
395 * fill in the fpe structure for a core dump...
397 int dump_fpu (struct pt_regs
*regs
, struct user_fp
*fp
)
399 struct thread_info
*thread
= current_thread_info();
400 int used_math
= thread
->used_cp
[1] | thread
->used_cp
[2];
403 memcpy(fp
, &thread
->fpstate
.soft
, sizeof (*fp
));
405 return used_math
!= 0;
407 EXPORT_SYMBOL(dump_fpu
);
410 * fill in the user structure for a core dump..
412 void dump_thread(struct pt_regs
* regs
, struct user
* dump
)
414 struct task_struct
*tsk
= current
;
416 dump
->magic
= CMAGIC
;
417 dump
->start_code
= tsk
->mm
->start_code
;
418 dump
->start_stack
= regs
->ARM_sp
& ~(PAGE_SIZE
- 1);
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
;
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
;
430 if (dump
->start_stack
< 0x04000000)
431 dump
->u_ssize
= (0x04000000 - dump
->start_stack
) >> PAGE_SHIFT
;
434 dump
->u_fpvalid
= dump_fpu (regs
, &dump
->u_fp
);
436 EXPORT_SYMBOL(dump_thread
);
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.
443 extern void kernel_thread_helper(void);
444 asm( ".section .text\n"
446 " .type kernel_thread_helper, #function\n"
447 "kernel_thread_helper:\n"
451 " .size kernel_thread_helper, . - kernel_thread_helper\n"
455 * Create a kernel thread.
457 pid_t
kernel_thread(int (*fn
)(void *), void *arg
, unsigned long flags
)
461 memset(®s
, 0, sizeof(regs
));
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
;
469 return do_fork(flags
|CLONE_VM
|CLONE_UNTRACED
, 0, ®s
, 0, NULL
, NULL
);
471 EXPORT_SYMBOL(kernel_thread
);
473 unsigned long get_wchan(struct task_struct
*p
)
475 unsigned long fp
, lr
;
476 unsigned long stack_start
, stack_end
;
478 if (!p
|| p
== current
|| p
->state
== TASK_RUNNING
)
481 stack_start
= (unsigned long)end_of_stack(p
);
482 stack_end
= (unsigned long)task_stack_page(p
) + THREAD_SIZE
;
484 fp
= thread_saved_fp(p
);
486 if (fp
< stack_start
|| fp
> stack_end
)
488 lr
= pc_pointer (((unsigned long *)fp
)[-1]);
489 if (!in_sched_functions(lr
))
491 fp
= *(unsigned long *) (fp
- 12);
492 } while (count
++ < 16);