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mn10300: split ret_from_fork, simplify kernel_thread()

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Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
This commit is contained in:
Al Viro
2012-09-19 13:05:49 -04:00
parent 49ed3398b7
commit 255461c53a
5 changed files with 27 additions and 71 deletions
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52
arch/mn10300/kernel/process.c
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@@ -166,13 +166,11 @@ void show_regs(struct pt_regs *regs)
*/
int kernel_thread(int (*fn)(void *), void *arg, unsigned long flags)
{
struct pt_regs regs;
struct pt_regs regs = {
.a0 = (unsigned long) fn;
.d0 = (unsigned long) arg;
};
memset(&regs, 0, sizeof(regs));
regs.a2 = (unsigned long) fn;
regs.d2 = (unsigned long) arg;
regs.pc = (unsigned long) kernel_thread_helper;
local_save_flags(regs.epsw);
regs.epsw |= EPSW_IE | EPSW_IM_7;
@@ -180,7 +178,6 @@ int kernel_thread(int (*fn)(void *), void *arg, unsigned long flags)
return do_fork(flags | CLONE_VM | CLONE_UNTRACED, 0, &regs, 0,
NULL, NULL);
}
EXPORT_SYMBOL(kernel_thread);
/*
* free current thread data structures etc..
@@ -227,49 +224,36 @@ int copy_thread(unsigned long clone_flags,
struct task_struct *p, struct pt_regs *kregs)
{
struct thread_info *ti = task_thread_info(p);
struct pt_regs *c_uregs, *c_kregs, *uregs;
struct pt_regs *c_regs;
unsigned long c_ksp;
uregs = current->thread.uregs;
c_ksp = (unsigned long) task_stack_page(p) + THREAD_SIZE;
/* allocate the userspace exception frame and set it up */
c_ksp -= sizeof(struct pt_regs);
c_uregs = (struct pt_regs *) c_ksp;
c_regs = (struct pt_regs *) c_ksp;
p->thread.uregs = c_uregs;
*c_uregs = *uregs;
c_uregs->sp = c_usp;
c_uregs->epsw &= ~EPSW_FE; /* my FPU */
p->thread.uregs = c_regs;
*c_regs = *kregs;
c_regs->sp = c_usp;
c_regs->epsw &= ~EPSW_FE; /* my FPU */
c_ksp -= 12; /* allocate function call ABI slack */
/* the new TLS pointer is passed in as arg #5 to sys_clone() */
if (clone_flags & CLONE_SETTLS)
c_uregs->e2 = current_frame()->d3;
c_regs->e2 = current_frame()->d3;
/* set up the return kernel frame if called from kernel_thread() */
c_kregs = c_uregs;
if (kregs != uregs) {
c_ksp -= sizeof(struct pt_regs);
c_kregs = (struct pt_regs *) c_ksp;
*c_kregs = *kregs;
c_kregs->sp = c_usp;
c_kregs->next = c_uregs;
#ifdef CONFIG_MN10300_CURRENT_IN_E2
c_kregs->e2 = (unsigned long) p; /* current */
#endif
c_ksp -= 12; /* allocate function call ABI slack */
}
if (unlikely(!user_mode(kregs)))
p->thread.pc = (unsigned long) ret_from_kernel_thread;
else
p->thread.pc = (unsigned long) ret_from_fork;
/* set up things up so the scheduler can start the new task */
ti->frame = c_kregs;
p->thread.a3 = (unsigned long) c_kregs;
ti->frame = c_regs;
p->thread.a3 = (unsigned long) c_regs;
p->thread.sp = c_ksp;
p->thread.pc = (unsigned long) ret_from_fork;
p->thread.wchan = (unsigned long) ret_from_fork;
p->thread.wchan = p->thread.pc;
p->thread.usp = c_usp;
return 0;