acrn-kernel/arch/cris/kernel/process.c

264 lines
6.9 KiB
C

/* $Id: process.c,v 1.21 2005/03/04 08:16:17 starvik Exp $
*
* linux/arch/cris/kernel/process.c
*
* Copyright (C) 1995 Linus Torvalds
* Copyright (C) 2000-2002 Axis Communications AB
*
* Authors: Bjorn Wesen (bjornw@axis.com)
*
* $Log: process.c,v $
* Revision 1.21 2005/03/04 08:16:17 starvik
* Merge of Linux 2.6.11.
*
* Revision 1.20 2005/01/18 05:57:22 starvik
* Renamed hlt_counter to cris_hlt_counter and made it global.
*
* Revision 1.19 2004/10/19 13:07:43 starvik
* Merge of Linux 2.6.9
*
* Revision 1.18 2004/08/16 12:37:23 starvik
* Merge of Linux 2.6.8
*
* Revision 1.17 2004/04/05 13:53:48 starvik
* Merge of Linux 2.6.5
*
* Revision 1.16 2003/10/27 08:04:33 starvik
* Merge of Linux 2.6.0-test9
*
* Revision 1.15 2003/09/11 07:29:52 starvik
* Merge of Linux 2.6.0-test5
*
* Revision 1.14 2003/06/10 10:21:12 johana
* Moved thread_saved_pc() from arch/cris/kernel/process.c to
* subarch specific process.c. arch-v32 has an erp, no irp.
*
* Revision 1.13 2003/04/09 05:20:47 starvik
* Merge of Linux 2.5.67
*
* Revision 1.12 2002/12/11 15:41:11 starvik
* Extracted v10 (ETRAX 100LX) specific stuff to arch/cris/arch-v10/kernel
*
* Revision 1.11 2002/12/10 09:00:10 starvik
* Merge of Linux 2.5.51
*
* Revision 1.10 2002/11/27 08:42:34 starvik
* Argument to user_regs() is thread_info*
*
* Revision 1.9 2002/11/26 09:44:21 starvik
* New threads exits through ret_from_fork (necessary for preemptive scheduling)
*
* Revision 1.8 2002/11/19 14:35:24 starvik
* Changes from linux 2.4
* Changed struct initializer syntax to the currently prefered notation
*
* Revision 1.7 2002/11/18 07:39:42 starvik
* thread_saved_pc moved here from processor.h
*
* Revision 1.6 2002/11/14 06:51:27 starvik
* Made cpu_idle more similar with other archs
* init_task_union -> init_thread_union
* Updated for new interrupt macros
* sys_clone and do_fork have a new argument, user_tid
*
* Revision 1.5 2002/11/05 06:45:11 starvik
* Merge of Linux 2.5.45
*
* Revision 1.4 2002/02/05 15:37:44 bjornw
* Need init_task.h
*
* Revision 1.3 2002/01/21 15:22:49 bjornw
* current->counter is gone
*
* Revision 1.22 2001/11/13 09:40:43 orjanf
* Added dump_fpu (needed for core dumps).
*
* Revision 1.21 2001/11/12 18:26:21 pkj
* Fixed compiler warnings.
*
* Revision 1.20 2001/10/03 08:21:39 jonashg
* cause_of_death does not exist if CONFIG_SVINTO_SIM is defined.
*
* Revision 1.19 2001/09/26 11:52:54 bjornw
* INIT_MMAP is gone in 2.4.10
*
* Revision 1.18 2001/08/21 21:43:51 hp
* Move last watchdog fix inside #ifdef CONFIG_ETRAX_WATCHDOG
*
* Revision 1.17 2001/08/21 13:48:01 jonashg
* Added fix by HP to avoid oops when doing a hard_reset_now.
*
* Revision 1.16 2001/06/21 02:00:40 hp
* * entry.S: Include asm/unistd.h.
* (_sys_call_table): Use section .rodata, not .data.
* (_kernel_thread): Move from...
* * process.c: ... here.
* * entryoffsets.c (VAL): Break out from...
* (OF): Use VAL.
* (LCLONE_VM): New asmified value from CLONE_VM.
*
* Revision 1.15 2001/06/20 16:31:57 hp
* Add comments to describe empty functions according to review.
*
* Revision 1.14 2001/05/29 11:27:59 markusl
* Fixed so that hard_reset_now will do reset even if watchdog wasn't enabled
*
* Revision 1.13 2001/03/20 19:44:06 bjornw
* Use the 7th syscall argument for regs instead of current_regs
*
*/
/*
* 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);
/*
* 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;
}