linux/arch/cris/kernel/process.c

170 lines
3.8 KiB
C

/*
* linux/arch/cris/kernel/process.c
*
* Copyright (C) 1995 Linus Torvalds
* Copyright (C) 2000-2002 Axis Communications AB
*
* Authors: Bjorn Wesen (bjornw@axis.com)
*
*/
/*
* This file handles the architecture-dependent parts of process handling..
*/
#include <asm/atomic.h>
#include <asm/pgtable.h>
#include <asm/uaccess.h>
#include <asm/irq.h>
#include <asm/system.h>
#include <linux/module.h>
#include <linux/spinlock.h>
#include <linux/fs_struct.h>
#include <linux/init_task.h>
#include <linux/sched.h>
#include <linux/fs.h>
#include <linux/user.h>
#include <linux/elfcore.h>
#include <linux/mqueue.h>
#include <linux/reboot.h>
//#define DEBUG
/*
* Initial task structure. Make this a per-architecture thing,
* because different architectures tend to have different
* alignment requirements and potentially different initial
* setup.
*/
static struct fs_struct init_fs = INIT_FS;
static struct files_struct init_files = INIT_FILES;
static struct signal_struct init_signals = INIT_SIGNALS(init_signals);
static struct sighand_struct init_sighand = INIT_SIGHAND(init_sighand);
struct mm_struct init_mm = INIT_MM(init_mm);
EXPORT_SYMBOL(init_mm);
/*
* Initial thread structure.
*
* We need to make sure that this is 8192-byte aligned due to the
* way process stacks are handled. This is done by having a special
* "init_task" linker map entry..
*/
union thread_union init_thread_union
__attribute__((__section__(".data.init_task"))) =
{ INIT_THREAD_INFO(init_task) };
/*
* Initial task structure.
*
* All other task structs will be allocated on slabs in fork.c
*/
struct task_struct init_task = INIT_TASK(init_task);
EXPORT_SYMBOL(init_task);
/*
* The hlt_counter, disable_hlt and enable_hlt is just here as a hook if
* there would ever be a halt sequence (for power save when idle) with
* some largish delay when halting or resuming *and* a driver that can't
* afford that delay. The hlt_counter would then be checked before
* executing the halt sequence, and the driver marks the unhaltable
* region by enable_hlt/disable_hlt.
*/
int cris_hlt_counter=0;
void disable_hlt(void)
{
cris_hlt_counter++;
}
EXPORT_SYMBOL(disable_hlt);
void enable_hlt(void)
{
cris_hlt_counter--;
}
EXPORT_SYMBOL(enable_hlt);
/*
* The following aren't currently used.
*/
void (*pm_idle)(void);
extern void default_idle(void);
void (*pm_power_off)(void);
EXPORT_SYMBOL(pm_power_off);
/*
* The idle thread. There's no useful work to be
* done, so just try to conserve power and have a
* low exit latency (ie sit in a loop waiting for
* somebody to say that they'd like to reschedule)
*/
void cpu_idle (void)
{
/* endless idle loop with no priority at all */
while (1) {
while (!need_resched()) {
void (*idle)(void);
/*
* Mark this as an RCU critical section so that
* synchronize_kernel() in the unload path waits
* for our completion.
*/
idle = pm_idle;
if (!idle)
idle = default_idle;
idle();
}
preempt_enable_no_resched();
schedule();
preempt_disable();
}
}
void hard_reset_now (void);
void machine_restart(char *cmd)
{
hard_reset_now();
}
/*
* Similar to machine_power_off, but don't shut off power. Add code
* here to freeze the system for e.g. post-mortem debug purpose when
* possible. This halt has nothing to do with the idle halt.
*/
void machine_halt(void)
{
}
/* If or when software power-off is implemented, add code here. */
void machine_power_off(void)
{
}
/*
* When a process does an "exec", machine state like FPU and debug
* registers need to be reset. This is a hook function for that.
* Currently we don't have any such state to reset, so this is empty.
*/
void flush_thread(void)
{
}
/* Fill in the fpu structure for a core dump. */
int dump_fpu(struct pt_regs *regs, elf_fpregset_t *fpu)
{
return 0;
}