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/*
* 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/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/a.out.h>
#include <linux/reboot.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 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;
struct mm_struct init_mm = INIT_MM(init_mm);
union task_union init_task_union
__attribute__((section("init_task"), aligned(KTHREAD_SIZE)))
= { task: INIT_TASK(init_task_union.task) };
asmlinkage void ret_from_fork(void);
/*
* The idle loop on an m68k..
*/
static void default_idle(void)
{
while(1) {
if (!current->need_resched)
#if defined(MACH_ATARI_ONLY) && !defined(CONFIG_HADES)
/* block out HSYNC on the atari (falcon) */
__asm__("stop #0x2200" : : : "cc");
#else
__asm__("stop #0x2000" : : : "cc");
#endif
schedule();
check_pgt_cache();
}
}
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 */
init_idle();
current->nice = 20;
current->counter = -100;
idle();
}
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 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;
__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 %3,%%sp@-\n\t" /* push argument */
"jsr %4@\n\t" /* call fn */
"movel %0,%%d1\n\t" /* pass exit value */
"movel %2,%0\n\t" /* exit */
"trap #0\n"
"1:"
: "=d" (retval)
: "0" (__NR_clone), "i" (__NR_exit),
"r" (arg), "a" (fn), "d" (clone_arg), "r" (current),
"i" (-KTHREAD_SIZE)
: "d0", "d2");
pid = retval;
}
set_fs (fs);
return pid;
}
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);
}
asmlinkage int m68k_vfork(struct pt_regs *regs)
{
return do_fork(CLONE_VFORK | CLONE_VM | SIGCHLD, rdusp(), regs, 0);
}
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, 0);
}
int copy_thread(int nr, 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 stack_offset, *retp;
stack_offset = KTHREAD_SIZE - sizeof(struct pt_regs);
childregs = (struct pt_regs *) ((unsigned long) p + 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_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;
}
/*
* fill in the user structure for a core dump..
*/
void dump_thread(struct pt_regs * regs, struct user * dump)
{
struct switch_stack *sw;
/* 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 user_regs_struct *)((int)&dump->regs - (int)dump);
sw = ((struct switch_stack *)regs) - 1;
dump->regs.d1 = regs->d1;
dump->regs.d2 = regs->d2;
dump->regs.d3 = regs->d3;
dump->regs.d4 = regs->d4;
dump->regs.d5 = regs->d5;
dump->regs.d6 = sw->d6;
dump->regs.d7 = sw->d7;
dump->regs.a0 = regs->a0;
dump->regs.a1 = regs->a1;
dump->regs.a2 = regs->a2;
dump->regs.a3 = sw->a3;
dump->regs.a4 = sw->a4;
dump->regs.a5 = sw->a5;
dump->regs.a6 = sw->a6;
dump->regs.d0 = regs->d0;
dump->regs.orig_d0 = regs->orig_d0;
dump->regs.stkadj = regs->stkadj;
dump->regs.sr = regs->sr;
dump->regs.pc = regs->pc;
dump->regs.fmtvec = (regs->format << 12) | regs->vector;
/* dump floating point stuff */
dump->u_fpvalid = dump_fpu (regs, &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;
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;
}
/*
* These bracket the sleeping functions..
*/
extern void scheduling_functions_start_here(void);
extern void scheduling_functions_end_here(void);
#define first_sched ((unsigned long) scheduling_functions_start_here)
#define last_sched ((unsigned long) scheduling_functions_end_here)
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)p;
fp = ((struct switch_stack *)p->thread.ksp)->a6;
do {
if (fp < stack_page+sizeof(struct task_struct) ||
fp >= 8184+stack_page)
return 0;
pc = ((unsigned long *)fp)[1];
/* FIXME: This depends on the order of these functions. */
if (pc < first_sched || pc >= last_sched)
return pc;
fp = *(unsigned long *) fp;
} while (count++ < 16);
return 0;
}
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