m68k: split ret_from_fork(), simplify kernel_thread()
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
diff --git a/arch/m68k/Kconfig b/arch/m68k/Kconfig
index b22df94..ccda007 100644
--- a/arch/m68k/Kconfig
+++ b/arch/m68k/Kconfig
@@ -13,6 +13,7 @@
select FPU if MMU
select ARCH_WANT_IPC_PARSE_VERSION
select ARCH_USES_GETTIMEOFFSET if MMU && !COLDFIRE
+ select GENERIC_KERNEL_THREAD
config RWSEM_GENERIC_SPINLOCK
bool
diff --git a/arch/m68k/include/asm/processor.h b/arch/m68k/include/asm/processor.h
index 9b4c82c..ae700f4 100644
--- a/arch/m68k/include/asm/processor.h
+++ b/arch/m68k/include/asm/processor.h
@@ -154,8 +154,6 @@
{
}
-extern int kernel_thread(int (*fn)(void *), void * arg, unsigned long flags);
-
/*
* Free current thread data structures etc..
*/
diff --git a/arch/m68k/kernel/entry.S b/arch/m68k/kernel/entry.S
index 165ee9f..8a01f58 100644
--- a/arch/m68k/kernel/entry.S
+++ b/arch/m68k/kernel/entry.S
@@ -111,6 +111,17 @@
addql #4,%sp
jra ret_from_exception
+ENTRY(ret_from_kernel_thread)
+ | a3 contains the kernel thread payload, d7 - its argument
+ movel %d1,%sp@-
+ jsr schedule_tail
+ GET_CURRENT(%d0)
+ movel %d7,(%sp)
+ jsr %a3@
+ addql #4,%sp
+ movel %d0,(%sp)
+ jra sys_exit
+
#if defined(CONFIG_COLDFIRE) || !defined(CONFIG_MMU)
#ifdef TRAP_DBG_INTERRUPT
diff --git a/arch/m68k/kernel/process.c b/arch/m68k/kernel/process.c
index c488e3c..b3d4760 100644
--- a/arch/m68k/kernel/process.c
+++ b/arch/m68k/kernel/process.c
@@ -34,6 +34,7 @@
asmlinkage void ret_from_fork(void);
+asmlinkage void ret_from_kernel_thread(void);
/*
@@ -120,51 +121,6 @@
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 */
-#ifdef CONFIG_MMU
- "lea %%sp@(%c7),%6\n\t" /* reload current */
- "movel %6@,%6\n\t"
-#endif
- "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)
{
current->thread.fs = __USER_DS;
@@ -216,30 +172,18 @@
}
int copy_thread(unsigned long clone_flags, unsigned long usp,
- unsigned long unused,
+ unsigned long arg,
struct task_struct * p, struct pt_regs * regs)
{
struct pt_regs * childregs;
- struct switch_stack * childstack, *stack;
- unsigned long *retp;
+ struct switch_stack *childstack;
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;
-
- if (clone_flags & CLONE_SETTLS)
- task_thread_info(p)->tp_value = regs->d5;
+ p->thread.esp0 = (unsigned long)childregs;
/*
* Must save the current SFC/DFC value, NOT the value when
@@ -247,6 +191,26 @@
*/
p->thread.fs = get_fs().seg;
+ if (unlikely(!regs)) {
+ /* kernel thread */
+ memset(childstack, 0,
+ sizeof(struct switch_stack) + sizeof(struct pt_regs));
+ childregs->sr = PS_S;
+ childstack->a3 = usp; /* function */
+ childstack->d7 = arg;
+ childstack->retpc = (unsigned long)ret_from_kernel_thread;
+ p->thread.usp = 0;
+ return 0;
+ }
+ *childregs = *regs;
+ childregs->d0 = 0;
+
+ *childstack = ((struct switch_stack *) regs)[-1];
+ childstack->retpc = (unsigned long)ret_from_fork;
+
+ if (clone_flags & CLONE_SETTLS)
+ task_thread_info(p)->tp_value = regs->d5;
+
#ifdef CONFIG_FPU
if (!FPU_IS_EMU) {
/* Copy the current fpu state */