/* process.c: FRV specific parts of process handling
*
* Copyright (C) 2003-5 Red Hat, Inc. All Rights Reserved.
* Written by David Howells (dhowells@redhat.com)
* - Derived from arch/m68k/kernel/process.c
*
* This program is free software; you can redistribute it and/or
* modify it under the terms of the GNU General Public License
* as published by the Free Software Foundation; either version
* 2 of the License, or (at your option) any later version.
*/
#include <linux/config.h>
#include <linux/errno.h>
#include <linux/sched.h>
#include <linux/kernel.h>
#include <linux/mm.h>
#include <linux/smp.h>
#include <linux/smp_lock.h>
#include <linux/stddef.h>
#include <linux/unistd.h>
#include <linux/ptrace.h>
#include <linux/slab.h>
#include <linux/user.h>
#include <linux/elf.h>
#include <linux/reboot.h>
#include <linux/interrupt.h>
#include <asm/uaccess.h>
#include <asm/system.h>
#include <asm/setup.h>
#include <asm/pgtable.h>
#include <asm/gdb-stub.h>
#include <asm/mb-regs.h>
#include "local.h"
asmlinkage void ret_from_fork(void);
#include <asm/pgalloc.h>
struct task_struct *alloc_task_struct(void)
{
struct task_struct *p = kmalloc(THREAD_SIZE, GFP_KERNEL);
if (p)
atomic_set((atomic_t *)(p+1), 1);
return p;
}
void free_task_struct(struct task_struct *p)
{
if (atomic_dec_and_test((atomic_t *)(p+1)))
kfree(p);
}
static void core_sleep_idle(void)
{
#ifdef LED_DEBUG_SLEEP
/* Show that we're sleeping... */
__set_LEDS(0x55aa);
#endif
frv_cpu_core_sleep();
#ifdef LED_DEBUG_SLEEP
/* ... and that we woke up */
__set_LEDS(0);
#endif
mb();
}
void (*idle)(void) = core_sleep_idle;
/*
* 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)
{
int cpu = smp_processor_id();
/* endless idle loop with no priority at all */
while (1) {
while (!need_resched()) {
irq_stat[cpu].idle_timestamp = jiffies;
if (!frv_dma_inprogress && idle)
idle();
}
preempt_enable_no_resched();
schedule();
preempt_disable();
}
}
void machine_restart(char * __unused)
{
unsigned long reset_addr;
#ifdef CONFIG_GDBSTUB
gdbstub_exit(0);
#endif
if (PSR_IMPLE(__get_PSR()) == PSR_IMPLE_FR551)
reset_addr = 0xfefff500;
else
reset_addr = 0xfeff0500;
/* Software reset. */
asm volatile(" dcef @(gr0,gr0),1 ! membar !"
" sti %1,@(%0,0) !"
" nop ! nop ! nop ! nop ! nop ! "
" nop ! nop ! nop ! nop ! nop ! "
" nop ! nop ! nop ! nop ! nop ! "
" nop ! nop ! nop ! nop ! nop ! "
: : "r" (reset_addr), "r" (1) );
for (;;)
;
}
void machine_halt(void)
{
#ifdef CONFIG_GDBSTUB
gdbstub_exit(0);
#endif
for (;;);
}
void machine_power_off(void)
{
#ifdef CONFIG_GDBSTUB
gdbstub_exit(0);
#endif
for (;;);
}
void flush_thread(void)
{
#if 0 //ndef NO_FPU
unsigned long zero = 0;
#endif
set_fs(USER_DS);
}
inline unsigned long user_stack(const struct pt_regs *regs)
{
while (regs->next_frame)
regs = regs->next_frame;
return user_mode(regs) ? regs->sp : 0;
}
asmlinkage int sys_fork(void)
{
#ifndef CONFIG_MMU
/* fork almost works, enough to trick you into looking elsewhere:-( */
return -EINVAL;
#else
return do_fork(SIGCHLD, user_stack(__frame), __frame, 0, NULL, NULL);
#endif
}
asmlinkage int sys_vfork(void)
{
return do_fork(CLONE_VFORK | CLONE_VM | SIGCHLD, user_stack(__frame), __frame, 0,
NULL, NULL);
}
/*****************************************************************************/
/*
* clone a process
* - tlsptr is retrieved by copy_thread()
*/
asmlinkage int sys_clone(unsigned long clone_flags, unsigned long newsp,
int __user *parent_tidptr, int __user *child_tidptr,
int __user *tlsptr)
{
if (!newsp)
newsp = user_stack(__frame);
return do_fork(clone_flags, newsp, __frame, 0, parent_tidptr, child_tidptr);
} /* end sys_clone() */
/*****************************************************************************/
/*
* This gets called before we allocate a new thread and copy
* the current task into it.
*/
void prepare_to_copy(struct task_struct *tsk)
{
//unlazy_fpu(tsk);
} /* end prepare_to_copy() */
/*****************************************************************************/
/*
* set up the kernel stack and exception frames for a new process
*/
int copy_thread(int nr, unsigned long clone_flags,
unsigned long usp, unsigned long topstk,
struct task_struct *p, struct pt_regs *regs)
{
struct pt_regs *childregs0, *childregs, *regs0;
regs0 = __kernel_frame0_ptr;
childregs0 = (struct pt_regs *)
((unsigned long) p->thread_info + THREAD_SIZE - USER_CONTEXT_SIZE);
childregs = childregs0;
/* set up the userspace frame (the only place that the USP is stored) */
*childregs0 = *regs0;
childregs0->gr8 = 0;
childregs0->sp = usp;
childregs0->next_frame = NULL;
/* set up the return kernel frame if called from kernel_thread() */
if (regs != regs0) {
childregs--;
*childregs = *regs;
childregs->sp = (unsigned long) childregs0;
childregs->next_frame = childregs0;
childregs->gr15 = (unsigned long) p->thread_info;
childregs->gr29 = (unsigned long) p;
}
p->set_child_tid = p->clear_child_tid = NULL;
p->thread.frame = childregs;
p->thread.curr = p;
p->thread.sp = (unsigned long) childregs;
p->thread.fp = 0;
p->thread.lr = 0;
p->thread.pc = (unsigned long) ret_from_fork;
p->thread.frame0 = childregs0;
/* the new TLS pointer is passed in as arg #5 to sys_clone() */
if (clone_flags & CLONE_SETTLS)
childregs->gr29 = childregs->gr12;
save_user_regs(p->thread.user);
return 0;
} /* end copy_thread() */
/*
* sys_execve() executes a new program.
*/
asmlinkage int sys_execve(char *name, char **argv, char **envp)
{
int error;
char * filename;
lock_kernel();
filename = getname(name);
error = PTR_ERR(filename);
if (IS_ERR(filename))
goto out;
error = do_execve(filename, argv, envp, __frame);
putname(filename);
out:
unlock_kernel();
return error;
}
unsigned long get_wchan(struct task_struct *p)
{
struct pt_regs *regs0;
unsigned long fp, pc;
unsigned long stack_limit;
int count = 0;
if (!p || p == current || p->state == TASK_RUNNING)
return 0;
stack_limit = (unsigned long) (p + 1);
fp = p->thread.fp;
regs0 = p->thread.frame0;
do {
if (fp < stack_limit || fp >= (unsigned long) regs0 || fp & 3)
return 0;
pc = ((unsigned long *) fp)[2];
/* FIXME: This depends on the order of these functions. */
if (!in_sched_functions(pc))
return pc;
fp = *(unsigned long *) fp;
} while (count++ < 16);
return 0;
}
unsigned long thread_saved_pc(struct task_struct *tsk)
{
/* Check whether the thread is blocked in resume() */
if (in_sched_functions(tsk->thread.pc))
return ((unsigned long *)tsk->thread.fp)[2];
else
return tsk->thread.pc;
}
int elf_check_arch(const struct elf32_hdr *hdr)
{
unsigned long hsr0 = __get_HSR(0);
unsigned long psr = __get_PSR();
if (hdr->e_machine != EM_FRV)
return 0;
switch (hdr->e_flags & EF_FRV_GPR_MASK) {
case EF_FRV_GPR64:
if ((hsr0 & HSR0_GRN) == HSR0_GRN_32)
return 0;
case EF_FRV_GPR32:
case 0:
break;
default:
return 0;
}
switch (hdr->e_flags & EF_FRV_FPR_MASK) {
case EF_FRV_FPR64:
if ((hsr0 & HSR0_FRN) == HSR0_FRN_32)
return 0;
case EF_FRV_FPR32:
case EF_FRV_FPR_NONE:
case 0:
break;
default:
return 0;
}
if ((hdr->e_flags & EF_FRV_MULADD) == EF_FRV_MULADD)
if (PSR_IMPLE(psr) != PSR_IMPLE_FR405 &&
PSR_IMPLE(psr) != PSR_IMPLE_FR451)
return 0;
switch (hdr->e_flags & EF_FRV_CPU_MASK) {
case EF_FRV_CPU_GENERIC:
break;
case EF_FRV_CPU_FR300:
case EF_FRV_CPU_SIMPLE:
case EF_FRV_CPU_TOMCAT:
default:
return 0;
case EF_FRV_CPU_FR400:
if (PSR_IMPLE(psr) != PSR_IMPLE_FR401 &&
PSR_IMPLE(psr) != PSR_IMPLE_FR405 &&
PSR_IMPLE(psr) != PSR_IMPLE_FR451 &&
PSR_IMPLE(psr) != PSR_IMPLE_FR551)
return 0;
break;
case EF_FRV_CPU_FR450:
if (PSR_IMPLE(psr) != PSR_IMPLE_FR451)
return 0;
break;
case EF_FRV_CPU_FR500:
if (PSR_IMPLE(psr) != PSR_IMPLE_FR501)
return 0;
break;
case EF_FRV_CPU_FR550:
if (PSR_IMPLE(psr) != PSR_IMPLE_FR551)
return 0;
break;
}
return 1;
}
