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/*
* linux/arch/m68k/kernel/process.c
*
* Copyright (C) 1995 Hamish Macdonald
*/
/*
* This file handles the architecture-dependent parts of process handling..
*/
#include <linux/errno.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/malloc.h>
#include <linux/user.h>
#include <linux/a.out.h>
#include <asm/segment.h>
#include <asm/system.h>
#include <asm/traps.h>
#include <asm/machdep.h>
asmlinkage void ret_from_exception(void);
/*
* The idle loop on an m68k..
*/
asmlinkage int sys_idle(void)
{
if (current->pid != 0)
return -EPERM;
/* endless idle loop with no priority at all */
current->counter = -100;
for (;;)
schedule();
}
void hard_reset_now(void)
{
if (mach_reset)
mach_reset();
}
void show_regs(struct pt_regs * regs)
{
printk("\n");
printk("Format %02x Vector: %04x PC: %08lx Status: %04x\n",
regs->format, regs->vector, regs->pc, regs->sr);
printk("ORIG_D0: %08lx D0: %08lx A1: %08lx\n",
regs->orig_d0, regs->d0, regs->a1);
printk("A0: %08lx D5: %08lx D4: %08lx\n",
regs->a0, regs->d5, regs->d4);
printk("D3: %08lx D2: %08lx D1: %08lx\n",
regs->d3, regs->d2, regs->d1);
if (!(regs->sr & PS_S))
printk("USP: %08lx\n", rdusp());
}
/*
* Free current thread data structures etc..
*/
void exit_thread(void)
{
}
void flush_thread(void)
{
set_fs(USER_DS);
current->tss.fs = USER_DS;
}
/*
* "m68k_fork()".. By the time we get here, the
* non-volatile registers have also been saved on the
* stack. We do some ugly pointer stuff here.. (see
* also copy_thread)
*/
asmlinkage int m68k_fork(struct pt_regs *regs)
{
return do_fork(SIGCHLD, rdusp(), regs);
}
asmlinkage int m68k_clone(struct pt_regs *regs)
{
unsigned long clone_flags;
unsigned long newsp;
/* syscall2 puts clone_flags in d1 and usp in d2 */
clone_flags = regs->d1;
newsp = regs->d2;
if (!newsp)
newsp = rdusp();
return do_fork(clone_flags, newsp, regs);
}
void release_thread(struct task_struct *dead_task)
{
}
void copy_thread(int nr, unsigned long clone_flags, unsigned long usp,
struct task_struct * p, struct pt_regs * regs)
{
struct pt_regs * childregs;
struct switch_stack * childstack, *stack;
unsigned long stack_offset, *retp;
stack_offset = PAGE_SIZE - sizeof(struct pt_regs);
childregs = (struct pt_regs *) (p->kernel_stack_page + stack_offset);
*childregs = *regs;
childregs->d0 = 0;
retp = ((unsigned long *) regs);
stack = ((struct switch_stack *) retp) - 1;
childstack = ((struct switch_stack *) childregs) - 1;
*childstack = *stack;
childstack->retpc = (unsigned long) ret_from_exception;
p->tss.usp = usp;
p->tss.ksp = (unsigned long)childstack;
/* Copy the current fpu state */
asm volatile ("fsave %0" : : "m" (p->tss.fpstate[0]) : "memory");
if (p->tss.fpstate[0])
asm volatile ("fmovemx %/fp0-%/fp7,%0\n\t"
"fmoveml %/fpiar/%/fpcr/%/fpsr,%1"
: : "m" (p->tss.fp[0]), "m" (p->tss.fpcntl[0])
: "memory");
/* Restore the state in case the fpu was busy */
asm volatile ("frestore %0" : : "m" (p->tss.fpstate[0]));
}
/* Fill in the fpu structure for a core dump. */
int dump_fpu (struct user_m68kfp_struct *fpu)
{
char fpustate[216];
/* First dump the fpu context to avoid protocol violation. */
asm volatile ("fsave %0" :: "m" (fpustate[0]) : "memory");
if (!fpustate[0])
return 0;
asm volatile ("fmovem %/fpiar/%/fpcr/%/fpsr,%0"
:: "m" (fpu->fpcntl[0])
: "memory");
asm volatile ("fmovemx %/fp0-%/fp7,%0"
:: "m" (fpu->fpregs[0])
: "memory");
return 1;
}
/*
* fill in the user structure for a core dump..
*/
void dump_thread(struct pt_regs * regs, struct user * dump)
{
/* changed the size calculations - should hopefully work better. lbt */
dump->magic = CMAGIC;
dump->start_code = 0;
dump->start_stack = rdusp() & ~(PAGE_SIZE - 1);
dump->u_tsize = ((unsigned long) current->mm->end_code) >> PAGE_SHIFT;
dump->u_dsize = ((unsigned long) (current->mm->brk +
(PAGE_SIZE-1))) >> PAGE_SHIFT;
dump->u_dsize -= dump->u_tsize;
dump->u_ssize = 0;
if (dump->start_stack < TASK_SIZE)
dump->u_ssize = ((unsigned long) (TASK_SIZE - dump->start_stack)) >> PAGE_SHIFT;
dump->u_ar0 = (struct pt_regs *)(((int)(&dump->regs)) -((int)(dump)));
dump->regs = *regs;
dump->regs2 = ((struct switch_stack *)regs)[-1];
/* dump floating point stuff */
dump->u_fpvalid = dump_fpu (&dump->m68kfp);
}
/*
* sys_execve() executes a new program.
*/
asmlinkage int sys_execve(char *name, char **argv, char **envp)
{
int error;
char * filename;
struct pt_regs *regs = (struct pt_regs *) &name;
error = getname(name, &filename);
if (error)
return error;
error = do_execve(filename, argv, envp, regs);
putname(filename);
return error;
}
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