/*
* linux/arch/m68k/kernel/process.c
*
* Copyright (C) 1995 Hamish Macdonald
*
* 68060 fixes by Jesper Skov
*/
/*
* This file handles the architecture-dependent parts of process handling..
*/
#include <linux/errno.h>
#include <linux/module.h>
#include <linux/sched.h>
#include <linux/kernel.h>
#include <linux/mm.h>
#include <linux/fs.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/reboot.h>
#include <linux/init_task.h>
#include <linux/mqueue.h>
#include <asm/uaccess.h>
#include <asm/system.h>
#include <asm/traps.h>
#include <asm/machdep.h>
#include <asm/setup.h>
#include <asm/pgtable.h>
/*
* Initial task/thread structure. Make this a per-architecture thing,
* because different architectures tend to have different
* alignment requirements and potentially different initial
* setup.
*/
static struct signal_struct init_signals = INIT_SIGNALS(init_signals);
static struct sighand_struct init_sighand = INIT_SIGHAND(init_sighand);
union thread_union init_thread_union
__attribute__((section(".data.init_task"), aligned(THREAD_SIZE)))
= { INIT_THREAD_INFO(init_task) };
/* initial task structure */
struct task_struct init_task = INIT_TASK(init_task);
EXPORT_SYMBOL(init_task);
asmlinkage void ret_from_fork(void);
/*
* Return saved PC from a blocked thread
*/
unsigned long thread_saved_pc(struct task_struct *tsk)
{
struct switch_stack *sw = (struct switch_stack *)tsk->thread.ksp;
/* Check whether the thread is blocked in resume() */
if (in_sched_functions(sw->retpc))
return ((unsigned long *)sw->a6)[1];
else
return sw->retpc;
}
/*
* The idle loop on an m68k..
*/
static void default_idle(void)
{
if (!need_resched())
#if defined(MACH_ATARI_ONLY)
/* block out HSYNC on the atari (falcon) */
__asm__("stop #0x2200" : : : "cc");
#else
__asm__("stop #0x2000" : : : "cc");
#endif
}
void (*idle)(void) = default_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)
{
/* endless idle loop with no priority at all */
while (1) {
while (!need_resched())
idle();
preempt_enable_no_resched();
schedule();
preempt_disable();
}
}
void machine_restart(char * __unused)
{
if (mach_reset)
mach_reset();
for (;;);
}
void machine_halt(void)
{
if (mach_halt)
mach_halt();
for (;;);
}
void machine_power_off(void)
{
if (mach_power_off)
mach_power_off();
for (;;);
}
void (*pm_power_off)(void) = machine_power_off;
EXPORT_SYMBOL(pm_power_off);
void show_regs(struct pt_regs * regs)
{
printk("\n");
printk("Format %02x Vector: %04x PC: %08lx Status: %04x %s\n",
regs->format, regs->vector, regs->pc, regs->sr, print_tainted());
printk("ORIG_D0: %08lx D0: %08lx A2: %08lx A1: %08lx\n",
regs->orig_d0, regs->d0, regs->a2, 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());
}
/*
* Create a kernel thread
*/
int kernel_thread(int (*fn)(void *), void * arg, unsigned long flags)
{
int pid;
mm_segment_t fs;
fs = get_fs();
set_fs (KERNEL_DS);
{
register long retval __asm__ ("d0");
register long clone_arg __asm__ ("d1") = flags | CLONE_VM | CLONE_UNTRACED;
retval = __NR_clone;
__asm__ __volatile__
("clrl %%d2\n\t"
"trap #0\n\t" /* Linux/m68k system call */
"tstl %0\n\t" /* child or parent */
"jne 1f\n\t" /* parent - jump */
"lea %%sp@(%c7),%6\n\t" /* reload current */
"movel %6@,%6\n\t"
"movel %3,%%sp@-\n\t" /* push argument */
"jsr %4@\n\t" /* call fn */
"movel %0,%%d1\n\t" /* pass exit value */
"movel %2,%%d0\n\t" /* exit */
"trap #0\n"
"1:"
: "+d" (retval)
: "i" (__NR_clone), "i" (__NR_exit),
"r" (arg), "a" (fn), "d" (clone_arg), "r" (current),
"i" (-THREAD_SIZE)
: "d2");
pid = retval;
}
set_fs (fs);
return pid;
}
EXPORT_SYMBOL(kernel_thread);
void flush_thread(void)
{
unsigned long zero = 0;
set_fs(USER_DS);
current->thread.fs = __USER_DS;
if (!FPU_IS_EMU)
asm volatile (".chip 68k/68881\n\t"
"frestore %0@\n\t"
".chip 68k" : : "a" (&zero));
}
/*
* "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, 0, NULL, NULL);
}
asmlinkage int m68k_vfork(struct pt_regs *regs)
{
return do_fork(CLONE_VFORK | CLONE_VM | SIGCHLD, rdusp(), regs, 0,
NULL, NULL);
}
asmlinkage int m68k_clone(struct pt_regs *regs)
{
unsigned long clone_flags;
unsigned long newsp;
int __user *parent_tidptr, *child_tidptr;
/* syscall2 puts clone_flags in d1 and usp in d2 */
clone_flags = regs->d1;
newsp = regs->d2;
parent_tidptr = (int __user *)regs->d3;
child_tidptr = (int __user *)regs->d4;
if (!newsp)
newsp = rdusp();
return do_fork(clone_flags, newsp, regs, 0,
parent_tidptr, child_tidptr);
}
int copy_thread(unsigned long clone_flags, unsigned long usp,
unsigned long unused,
struct task_struct * p, struct pt_regs * regs)
{
struct pt_regs * childregs;
struct switch_stack * childstack, *stack;
unsigned long *retp;
childregs = (struct pt_regs *) (task_stack_page(p) + THREAD_SIZE) - 1;
*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_fork;
p->thread.usp = usp;
p->thread.ksp = (unsigned long)childstack;
/*
* Must save the current SFC/DFC value, NOT the value when
* the parent was last descheduled - RGH 10-08-96
*/
p->thread.fs = get_fs().seg;
if (!FPU_IS_EMU) {
/* Copy the current fpu state */
asm volatile ("fsave %0" : : "m" (p->thread.fpstate[0]) : "memory");
if (!CPU_IS_060 ? p->thread.fpstate[0] : p->thread.fpstate[2])
asm volatile ("fmovemx %/fp0-%/fp7,%0\n\t"
"fmoveml %/fpiar/%/fpcr/%/fpsr,%1"
: : "m" (p->thread.fp[0]), "m" (p->thread.fpcntl[0])
: "memory");
/* Restore the state in case the fpu was busy */
asm volatile ("frestore %0" : : "m" (p->thread.fpstate[0]));
}
return 0;
}
/* Fill in the fpu structure for a core dump. */
int dump_fpu (struct pt_regs *regs, struct user_m68kfp_struct *fpu)
{
char fpustate[216];
if (FPU_IS_EMU) {
int i;
memcpy(fpu->fpcntl, current->thread.fpcntl, 12);
memcpy(fpu->fpregs, current->thread.fp, 96);
/* Convert internal fpu reg representation
* into long double format
*/
for (i = 0; i < 24; i += 3)
fpu->fpregs[i] = ((fpu->fpregs[i] & 0xffff0000) << 15) |
((fpu->fpregs[i] & 0x0000ffff) << 16);
return 1;
}
/* First dump the fpu context to avoid protocol violation. */
asm volatile ("fsave %0" :: "m" (fpustate[0]) : "memory");
if (!CPU_IS_060 ? !fpustate[0] : !fpustate[2])
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;
}
EXPORT_SYMBOL(dump_fpu);
/*
* sys_execve() executes a new program.
*/
asmlinkage int sys_execve(char __user *name, char __user * __user *argv, char __user * __user *envp)
{
int error;
char * filename;
struct pt_regs *regs = (struct pt_regs *) &name;
lock_kernel();
filename = getname(name);
error = PTR_ERR(filename);
if (IS_ERR(filename))
goto out;
error = do_execve(filename, argv, envp, regs);
putname(filename);
out:
unlock_kernel();
return error;
}
unsigned long get_wchan(struct task_struct *p)
{
unsigned long fp, pc;
unsigned long stack_page;
int count = 0;
if (!p || p == current || p->state == TASK_RUNNING)
return 0;
stack_page = (unsigned long)task_stack_page(p);
fp = ((struct switch_stack *)p->thread.ksp)->a6;
do {
if (fp < stack_page+sizeof(struct thread_info) ||
fp >= 8184+stack_page)
return 0;
pc = ((unsigned long *)fp)[1];
if (!in_sched_functions(pc))
return pc;
fp = *(unsigned long *) fp;
} while (count++ < 16);
return 0;
}
