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/*
* linux/arch/arm/kernel/process.c
*
* Copyright (C) 1996-2000 Russell King - Converted to ARM.
* Origional Copyright (C) 1995 Linus Torvalds
*
* This program is free software; you can redistribute it and/or modify
* it under the terms of the GNU General Public License version 2 as
* published by the Free Software Foundation.
*/
#include <stdarg.h>
#include <linux/config.h>
#include <linux/sched.h>
#include <linux/kernel.h>
#include <linux/mm.h>
#include <linux/stddef.h>
#include <linux/unistd.h>
#include <linux/ptrace.h>
#include <linux/slab.h>
#include <linux/user.h>
#include <linux/delay.h>
#include <linux/reboot.h>
#include <linux/interrupt.h>
#include <linux/init.h>
#include <asm/system.h>
#include <asm/io.h>
#include <asm/leds.h>
#include <asm/uaccess.h>
/*
* Values for cpu_do_idle()
*/
#define IDLE_WAIT_SLOW 0
#define IDLE_WAIT_FAST 1
#define IDLE_CLOCK_SLOW 2
#define IDLE_CLOCK_FAST 3
extern const char *processor_modes[];
extern void setup_mm_for_reboot(char mode);
static volatile int hlt_counter;
#include <asm/arch/system.h>
void disable_hlt(void)
{
hlt_counter++;
}
void enable_hlt(void)
{
hlt_counter--;
}
static int __init nohlt_setup(char *__unused)
{
hlt_counter = 1;
return 1;
}
static int __init hlt_setup(char *__unused)
{
hlt_counter = 0;
return 1;
}
__setup("nohlt", nohlt_setup);
__setup("hlt", hlt_setup);
/*
* The following aren't currently used.
*/
void (*pm_idle)(void);
void (*pm_power_off)(void);
/*
* The idle thread. We try to conserve power, while trying to keep
* overall latency low. The architecture specific idle is passed
* a value to indicate the level of "idleness" of the system.
*/
void cpu_idle(void)
{
/* endless idle loop with no priority at all */
init_idle();
current->nice = 20;
current->counter = -100;
while (1) {
void (*idle)(void) = pm_idle;
if (!idle)
idle = arch_idle;
leds_event(led_idle_start);
while (!current->need_resched)
idle();
leds_event(led_idle_end);
schedule();
#ifndef CONFIG_NO_PGT_CACHE
check_pgt_cache();
#endif
}
}
static char reboot_mode = 'h';
int __init reboot_setup(char *str)
{
reboot_mode = str[0];
return 1;
}
__setup("reboot=", reboot_setup);
void machine_halt(void)
{
leds_event(led_halted);
}
void machine_power_off(void)
{
leds_event(led_halted);
if (pm_power_off)
pm_power_off();
}
void machine_restart(char * __unused)
{
/*
* Clean and disable cache, and turn off interrupts
*/
cpu_proc_fin();
/*
* Tell the mm system that we are going to reboot -
* we may need it to insert some 1:1 mappings so that
* soft boot works.
*/
setup_mm_for_reboot(reboot_mode);
/*
* Now call the architecture specific reboot code.
*/
arch_reset(reboot_mode);
/*
* Whoops - the architecture was unable to reboot.
* Tell the user!
*/
mdelay(1000);
printk("Reboot failed -- System halted\n");
while (1);
}
void show_regs(struct pt_regs * regs)
{
unsigned long flags;
flags = condition_codes(regs);
printk("pc : [<%08lx>] lr : [<%08lx>] %s\n"
"sp : %08lx ip : %08lx fp : %08lx\n",
instruction_pointer(regs),
regs->ARM_lr, print_tainted(), regs->ARM_sp,
regs->ARM_ip, regs->ARM_fp);
printk("r10: %08lx r9 : %08lx r8 : %08lx\n",
regs->ARM_r10, regs->ARM_r9,
regs->ARM_r8);
printk("r7 : %08lx r6 : %08lx r5 : %08lx r4 : %08lx\n",
regs->ARM_r7, regs->ARM_r6,
regs->ARM_r5, regs->ARM_r4);
printk("r3 : %08lx r2 : %08lx r1 : %08lx r0 : %08lx\n",
regs->ARM_r3, regs->ARM_r2,
regs->ARM_r1, regs->ARM_r0);
printk("Flags: %c%c%c%c",
flags & CC_N_BIT ? 'N' : 'n',
flags & CC_Z_BIT ? 'Z' : 'z',
flags & CC_C_BIT ? 'C' : 'c',
flags & CC_V_BIT ? 'V' : 'v');
printk(" IRQs %s FIQs %s Mode %s%s Segment %s\n",
interrupts_enabled(regs) ? "on" : "off",
fast_interrupts_enabled(regs) ? "on" : "off",
processor_modes[processor_mode(regs)],
thumb_mode(regs) ? " (T)" : "",
get_fs() == get_ds() ? "kernel" : "user");
#if defined(CONFIG_CPU_32)
{
int ctrl, transbase, dac;
__asm__ (
" mrc p15, 0, %0, c1, c0\n"
" mrc p15, 0, %1, c2, c0\n"
" mrc p15, 0, %2, c3, c0\n"
: "=r" (ctrl), "=r" (transbase), "=r" (dac));
printk("Control: %04X Table: %08X DAC: %08X\n",
ctrl, transbase, dac);
}
#endif
}
void show_fpregs(struct user_fp *regs)
{
int i;
for (i = 0; i < 8; i++) {
unsigned long *p;
char type;
p = (unsigned long *)(regs->fpregs + i);
switch (regs->ftype[i]) {
case 1: type = 'f'; break;
case 2: type = 'd'; break;
case 3: type = 'e'; break;
default: type = '?'; break;
}
if (regs->init_flag)
type = '?';
printk(" f%d(%c): %08lx %08lx %08lx%c",
i, type, p[0], p[1], p[2], i & 1 ? '\n' : ' ');
}
printk("FPSR: %08lx FPCR: %08lx\n",
(unsigned long)regs->fpsr,
(unsigned long)regs->fpcr);
}
/*
* Task structure and kernel stack allocation.
*/
static struct task_struct *task_struct_head;
static unsigned int nr_task_struct;
#ifdef CONFIG_CPU_32
#define EXTRA_TASK_STRUCT 4
#else
#define EXTRA_TASK_STRUCT 0
#endif
struct task_struct *alloc_task_struct(void)
{
struct task_struct *tsk;
if (EXTRA_TASK_STRUCT)
tsk = task_struct_head;
else
tsk = NULL;
if (tsk) {
task_struct_head = tsk->next_task;
nr_task_struct -= 1;
} else
tsk = ll_alloc_task_struct();
#ifdef CONFIG_SYSRQ
/*
* The stack must be cleared if you want SYSRQ-T to
* give sensible stack usage information
*/
if (tsk) {
char *p = (char *)tsk;
memzero(p+KERNEL_STACK_SIZE, KERNEL_STACK_SIZE);
}
#endif
return tsk;
}
void __free_task_struct(struct task_struct *p)
{
if (EXTRA_TASK_STRUCT && nr_task_struct < EXTRA_TASK_STRUCT) {
p->next_task = task_struct_head;
task_struct_head = p;
nr_task_struct += 1;
} else
ll_free_task_struct(p);
}
/*
* Free current thread data structures etc..
*/
void exit_thread(void)
{
}
void flush_thread(void)
{
memset(¤t->thread.debug, 0, sizeof(struct debug_info));
memset(¤t->thread.fpstate, 0, sizeof(union fp_state));
current->used_math = 0;
current->flags &= ~PF_USEDFPU;
}
void release_thread(struct task_struct *dead_task)
{
}
asmlinkage void ret_from_fork(void) __asm__("ret_from_fork");
int copy_thread(int nr, unsigned long clone_flags, unsigned long esp,
unsigned long unused,
struct task_struct * p, struct pt_regs * regs)
{
struct pt_regs * childregs;
struct context_save_struct * save;
atomic_set(&p->thread.refcount, 1);
childregs = ((struct pt_regs *)((unsigned long)p + 8192)) - 1;
*childregs = *regs;
childregs->ARM_r0 = 0;
childregs->ARM_sp = esp;
save = ((struct context_save_struct *)(childregs)) - 1;
*save = INIT_CSS;
save->pc |= (unsigned long)ret_from_fork;
p->thread.save = save;
return 0;
}
/*
* fill in the fpe structure for a core dump...
*/
int dump_fpu (struct pt_regs *regs, struct user_fp *fp)
{
if (current->used_math)
memcpy(fp, ¤t->thread.fpstate.soft, sizeof (*fp));
return current->used_math;
}
/*
* fill in the user structure for a core dump..
*/
void dump_thread(struct pt_regs * regs, struct user * dump)
{
struct task_struct *tsk = current;
dump->magic = CMAGIC;
dump->start_code = tsk->mm->start_code;
dump->start_stack = regs->ARM_sp & ~(PAGE_SIZE - 1);
dump->u_tsize = (tsk->mm->end_code - tsk->mm->start_code) >> PAGE_SHIFT;
dump->u_dsize = (tsk->mm->brk - tsk->mm->start_data + PAGE_SIZE - 1) >> PAGE_SHIFT;
dump->u_ssize = 0;
dump->u_debugreg[0] = tsk->thread.debug.bp[0].address;
dump->u_debugreg[1] = tsk->thread.debug.bp[1].address;
dump->u_debugreg[2] = tsk->thread.debug.bp[0].insn;
dump->u_debugreg[3] = tsk->thread.debug.bp[1].insn;
dump->u_debugreg[4] = tsk->thread.debug.nsaved;
if (dump->start_stack < 0x04000000)
dump->u_ssize = (0x04000000 - dump->start_stack) >> PAGE_SHIFT;
dump->regs = *regs;
dump->u_fpvalid = dump_fpu (regs, &dump->u_fp);
}
/*
* This is the mechanism for creating a new kernel thread.
*
* NOTE! Only a kernel-only process(ie the swapper or direct descendants
* who haven't done an "execve()") should use this: it will work within
* a system call from a "real" process, but the process memory space will
* not be free'd until both the parent and the child have exited.
*/
pid_t kernel_thread(int (*fn)(void *), void *arg, unsigned long flags)
{
pid_t __ret;
__asm__ __volatile__(
"orr r0, %1, %2 @ kernel_thread sys_clone
mov r1, #0
"__syscall(clone)"
movs %0, r0 @ if we are the child
bne 1f
mov fp, #0 @ ensure that fp is zero
mov r0, %4
mov lr, pc
mov pc, %3
b sys_exit
1: "
: "=r" (__ret)
: "Ir" (flags), "I" (CLONE_VM), "r" (fn), "r" (arg)
: "r0", "r1", "lr");
return __ret;
}
/*
* These bracket the sleeping functions..
*/
extern void scheduling_functions_start_here(void);
extern void scheduling_functions_end_here(void);
#define first_sched ((unsigned long) scheduling_functions_start_here)
#define last_sched ((unsigned long) scheduling_functions_end_here)
unsigned long get_wchan(struct task_struct *p)
{
unsigned long fp, lr;
unsigned long stack_page;
int count = 0;
if (!p || p == current || p->state == TASK_RUNNING)
return 0;
stack_page = 4096 + (unsigned long)p;
fp = get_css_fp(&p->thread);
do {
if (fp < stack_page || fp > 4092+stack_page)
return 0;
lr = pc_pointer (((unsigned long *)fp)[-1]);
if (lr < first_sched || lr > last_sched)
return lr;
fp = *(unsigned long *) (fp - 12);
} while (count ++ < 16);
return 0;
}
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