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authorAl Viro <viro@zeniv.linux.org.uk>2012-09-16 20:05:09 +0400
committerAl Viro <viro@zeniv.linux.org.uk>2012-10-01 08:44:44 +0400
commit533e6903bea0440816a0f517b0845ccea4cc7917 (patch)
treebc01397ec305de38476ab9dab8b33c1b2d492379 /arch/m68k/kernel/process.c
parent0973c687e05a802a757664722678d2b5016f1c1c (diff)
downloadlinux-533e6903bea0440816a0f517b0845ccea4cc7917.tar.xz
m68k: split ret_from_fork(), simplify kernel_thread()
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
Diffstat (limited to 'arch/m68k/kernel/process.c')
-rw-r--r--arch/m68k/kernel/process.c84
1 files changed, 24 insertions, 60 deletions
diff --git a/arch/m68k/kernel/process.c b/arch/m68k/kernel/process.c
index c488e3cfab53..b3d4760c9750 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 @@ void show_regs(struct pt_regs * regs)
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 @@ asmlinkage int m68k_clone(struct pt_regs *regs)
}
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 @@ int copy_thread(unsigned long clone_flags, unsigned long usp,
*/
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 */