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/* $Id: process.c,v 1.35 2001/10/11 09:18:17 gniibe Exp $
*
* linux/arch/sh/kernel/process.c
*
* Copyright (C) 1995 Linus Torvalds
*
* SuperH version: Copyright (C) 1999, 2000 Niibe Yutaka & Kaz Kojima
*/
/*
* This file handles the architecture-dependent parts of process handling..
*/
#include <linux/unistd.h>
#include <linux/slab.h>
#include <asm/io.h>
#include <asm/uaccess.h>
#include <asm/mmu_context.h>
#include <asm/elf.h>
static int hlt_counter=0;
#define HARD_IDLE_TIMEOUT (HZ / 3)
void disable_hlt(void)
{
hlt_counter++;
}
void enable_hlt(void)
{
hlt_counter--;
}
/*
* The idle loop on a uniprocessor i386..
*/
void cpu_idle(void *unused)
{
/* endless idle loop with no priority at all */
init_idle();
current->nice = 20;
current->counter = -100;
while (1) {
if (hlt_counter) {
if (current->need_resched)
break;
} else {
__cli();
while (!current->need_resched) {
__sti();
asm volatile("sleep" : : : "memory");
__cli();
}
__sti();
}
schedule();
check_pgt_cache();
}
}
void machine_restart(char * __unused)
{
/* SR.BL=1 and invoke address error to let CPU reset (manual reset) */
asm volatile("ldc %0, sr\n\t"
"mov.l @%1, %0" : : "r" (0x10000000), "r" (0x80000001));
}
void machine_halt(void)
{
while (1)
asm volatile("sleep" : : : "memory");
}
void machine_power_off(void)
{
}
void show_regs(struct pt_regs * regs)
{
printk("\n");
printk("PC : %08lx SP : %08lx SR : %08lx TEA : %08x %s\n",
regs->pc, regs->regs[15], regs->sr, ctrl_inl(MMU_TEA), print_tainted());
printk("R0 : %08lx R1 : %08lx R2 : %08lx R3 : %08lx\n",
regs->regs[0],regs->regs[1],
regs->regs[2],regs->regs[3]);
printk("R4 : %08lx R5 : %08lx R6 : %08lx R7 : %08lx\n",
regs->regs[4],regs->regs[5],
regs->regs[6],regs->regs[7]);
printk("R8 : %08lx R9 : %08lx R10 : %08lx R11 : %08lx\n",
regs->regs[8],regs->regs[9],
regs->regs[10],regs->regs[11]);
printk("R12 : %08lx R13 : %08lx R14 : %08lx\n",
regs->regs[12],regs->regs[13],
regs->regs[14]);
printk("MACH: %08lx MACL: %08lx GBR : %08lx PR : %08lx\n",
regs->mach, regs->macl, regs->gbr, regs->pr);
}
struct task_struct * alloc_task_struct(void)
{
/* Get two pages */
return (struct task_struct *) __get_free_pages(GFP_KERNEL,1);
}
void free_task_struct(struct task_struct *p)
{
free_pages((unsigned long) p, 1);
}
/*
* Create a kernel thread
*/
/*
* This is the mechanism for creating a new kernel thread.
*
*/
int kernel_thread(int (*fn)(void *), void * arg, unsigned long flags)
{ /* Don't use this in BL=1(cli). Or else, CPU resets! */
register unsigned long __sc0 __asm__ ("r0");
register unsigned long __sc3 __asm__ ("r3") = __NR_clone;
register unsigned long __sc4 __asm__ ("r4") = (long) flags | CLONE_VM;
register unsigned long __sc5 __asm__ ("r5") = 0;
register unsigned long __sc8 __asm__ ("r8") = (long) arg;
register unsigned long __sc9 __asm__ ("r9") = (long) fn;
__asm__("trapa #0x12\n\t" /* Linux/SH system call */
"tst r0, r0\n\t" /* child or parent? */
"bf 1f\n\t" /* parent - jump */
"jsr @r9\n\t" /* call fn */
" mov r8, r4\n\t" /* push argument */
"mov r0, r4\n\t" /* return value to arg of exit */
"mov %1, r3\n\t" /* exit */
"trapa #0x11\n"
"1:"
: "=z" (__sc0)
: "i" (__NR_exit), "r" (__sc3), "r" (__sc4), "r" (__sc5),
"r" (__sc8), "r" (__sc9)
: "memory", "t");
return __sc0;
}
/*
* Free current thread data structures etc..
*/
void exit_thread(void)
{
/* Nothing to do. */
}
void flush_thread(void)
{
#if defined(__sh3__)
/* do nothing */
/* Possibly, set clear debug registers */
#elif defined(__SH4__)
struct task_struct *tsk = current;
/* Forget lazy FPU state */
clear_fpu(tsk);
tsk->used_math = 0;
#endif
}
void release_thread(struct task_struct *dead_task)
{
/* do nothing */
}
/* Fill in the fpu structure for a core dump.. */
int dump_fpu(struct pt_regs *regs, elf_fpregset_t *fpu)
{
#if defined(__SH4__)
int fpvalid;
struct task_struct *tsk = current;
fpvalid = tsk->used_math;
if (fpvalid) {
unsigned long flags;
save_and_cli(flags);
unlazy_fpu(tsk);
restore_flags(flags);
memcpy(fpu, &tsk->thread.fpu.hard, sizeof(*fpu));
}
return fpvalid;
#else
return 0; /* Task didn't use the fpu at all. */
#endif
}
asmlinkage void ret_from_fork(void);
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;
#if defined(__SH4__)
struct task_struct *tsk = current;
if (tsk != &init_task) {
unsigned long flags;
save_and_cli(flags);
unlazy_fpu(tsk);
restore_flags(flags);
p->thread.fpu = current->thread.fpu;
p->used_math = tsk->used_math;
}
#endif
childregs = ((struct pt_regs *)(THREAD_SIZE + (unsigned long) p)) - 1;
*childregs = *regs;
if (user_mode(regs)) {
childregs->regs[15] = usp;
} else {
childregs->regs[15] = (unsigned long)p+2*PAGE_SIZE;
}
childregs->regs[0] = 0; /* Set return value for child */
childregs->sr |= SR_FD; /* Invalidate FPU flag */
p->thread.sp = (unsigned long) childregs;
p->thread.pc = (unsigned long) ret_from_fork;
return 0;
}
/*
* fill in the user structure for a core dump..
*/
void dump_thread(struct pt_regs * regs, struct user * dump)
{
dump->magic = CMAGIC;
dump->start_code = current->mm->start_code;
dump->start_data = current->mm->start_data;
dump->start_stack = regs->regs[15] & ~(PAGE_SIZE - 1);
dump->u_tsize = (current->mm->end_code - dump->start_code) >> PAGE_SHIFT;
dump->u_dsize = (current->mm->brk + (PAGE_SIZE-1) - dump->start_data) >> PAGE_SHIFT;
dump->u_ssize = (current->mm->start_stack - dump->start_stack +
PAGE_SIZE - 1) >> PAGE_SHIFT;
/* Debug registers will come here. */
dump->regs = *regs;
dump->u_fpvalid = dump_fpu(regs, &dump->fpu);
}
/*
* switch_to(x,y) should switch tasks from x to y.
*
*/
void __switch_to(struct task_struct *prev, struct task_struct *next)
{
#if defined(__SH4__)
if (prev != &init_task) {
unsigned long flags;
save_and_cli(flags);
unlazy_fpu(prev);
restore_flags(flags);
}
#endif
/*
* Restore the kernel mode register
* k7 (r7_bank1)
*/
asm volatile("ldc %0, r7_bank"
: /* no output */
:"r" (next));
}
asmlinkage int sys_fork(unsigned long r4, unsigned long r5,
unsigned long r6, unsigned long r7,
struct pt_regs regs)
{
return do_fork(SIGCHLD, regs.regs[15], ®s, 0);
}
asmlinkage int sys_clone(unsigned long clone_flags, unsigned long newsp,
unsigned long r6, unsigned long r7,
struct pt_regs regs)
{
if (!newsp)
newsp = regs.regs[15];
return do_fork(clone_flags, newsp, ®s, 0);
}
/*
* This is trivial, and on the face of it looks like it
* could equally well be done in user mode.
*
* Not so, for quite unobvious reasons - register pressure.
* In user mode vfork() cannot have a stack frame, and if
* done by calling the "clone()" system call directly, you
* do not have enough call-clobbered registers to hold all
* the information you need.
*/
asmlinkage int sys_vfork(unsigned long r4, unsigned long r5,
unsigned long r6, unsigned long r7,
struct pt_regs regs)
{
return do_fork(CLONE_VFORK | CLONE_VM | SIGCHLD, regs.regs[15], ®s, 0);
}
/*
* sys_execve() executes a new program.
*/
asmlinkage int sys_execve(char *ufilename, char **uargv,
char **uenvp, unsigned long r7,
struct pt_regs regs)
{
int error;
char *filename;
filename = getname(ufilename);
error = PTR_ERR(filename);
if (IS_ERR(filename))
goto out;
error = do_execve(filename, uargv, uenvp, ®s);
if (error == 0)
current->ptrace &= ~PT_DTRACE;
putname(filename);
out:
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 schedule_frame;
unsigned long pc;
if (!p || p == current || p->state == TASK_RUNNING)
return 0;
/*
* The same comment as on the Alpha applies here, too ...
*/
pc = thread_saved_pc(&p->thread);
if (pc >= (unsigned long) interruptible_sleep_on && pc < (unsigned long) add_timer) {
schedule_frame = ((unsigned long *)(long)p->thread.sp)[1];
return (unsigned long)((unsigned long *)schedule_frame)[1];
}
return pc;
}
asmlinkage void print_syscall(int x)
{
unsigned long flags, sr;
asm("stc sr, %0": "=r" (sr));
save_and_cli(flags);
printk("%c: %c %c, %c: SYSCALL\n", (x&63)+32,
(current->flags&PF_USEDFPU)?'C':' ',
(init_task.flags&PF_USEDFPU)?'K':' ', (sr&SR_FD)?' ':'F');
restore_flags(flags);
}
asmlinkage void break_point_trap(unsigned long r4, unsigned long r5,
unsigned long r6, unsigned long r7,
struct pt_regs regs)
{
/* Clear tracing. */
ctrl_outw(0, UBC_BBRA);
ctrl_outw(0, UBC_BBRB);
force_sig(SIGTRAP, current);
}
asmlinkage void break_point_trap_software(unsigned long r4, unsigned long r5,
unsigned long r6, unsigned long r7,
struct pt_regs regs)
{
regs.pc -= 2;
force_sig(SIGTRAP, current);
}
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