Commit 255461c5 authored by Al Viro's avatar Al Viro
Browse files

mn10300: split ret_from_fork, simplify kernel_thread() 



Signed-off-by: default avatarAl Viro <viro@zeniv.linux.org.uk>
parent 49ed3398

arch/mn10300/kernel/Makefile

+1 −1
Original line number Diff line number Diff line
@@ -7,7 +7,7 @@ fpu-obj-y := fpu-nofpu.o fpu-nofpu-low.o 
fpu-obj-$(CONFIG_FPU) := fpu.o fpu-low.o



obj-y   := process.o signal.o entry.o traps.o irq.o \

	   ptrace.o setup.o time.o sys_mn10300.o io.o kthread.o \

	   ptrace.o setup.o time.o sys_mn10300.o io.o \

	   switch_to.o mn10300_ksyms.o kernel_execve.o $(fpu-obj-y) \

	   csrc-mn10300.o cevt-mn10300.o

arch/mn10300/kernel/entry.S

+7 −0
Original line number Diff line number Diff line
@@ -55,6 +55,13 @@ ENTRY(ret_from_fork) 
	mov	d0,(REG_D0,fp)

	jmp	syscall_exit



ENTRY(ret_from_kernel_thread)

	call	schedule_tail[],0

	mov	(REG_D0,fp),d0

	mov	(REG_A0,fp),a0

	calls	(a0)

	jmp	sys_exit



###############################################################################

#

# system call handler

arch/mn10300/kernel/internal.h

+1 −5
Original line number Diff line number Diff line
@@ -14,15 +14,11 @@ 
struct clocksource;

struct clock_event_device;



/*

 * kthread.S

 */

extern int kernel_thread_helper(int);



/*

 * entry.S

 */

extern void ret_from_fork(struct task_struct *) __attribute__((noreturn));

extern void ret_from_kernel_thread(struct task_struct *) __attribute__((noreturn));



/*

 * smp-low.S

arch/mn10300/kernel/kthread.S

deleted100644 → 0
+0 −31
Original line number Diff line number Diff line 
/* MN10300 Kernel thread trampoline function

 *

 * Copyright (C) 2007 Red Hat, Inc. All Rights Reserved.

 * Written by Mark Salter (msalter@redhat.com)

 *

 * This program is free software; you can redistribute it and/or

 * modify it under the terms of the GNU General Public Licence

 * as published by the Free Software Foundation; either version

 * 2 of the Licence, or (at your option) any later version.

 */

	.text



###############################################################################

#

# kernel_thread_helper - trampoline for kernel_thread()

#

# On entry:

#   A2 = address of function to call

#   D2 = function argument

#

###############################################################################

	.globl	kernel_thread_helper

	.type	kernel_thread_helper,@function

kernel_thread_helper:

	mov	do_exit,d1

	mov	d1,(sp)

	mov	d1,mdr

	mov	d2,d0

	jmp	(a2)



	.size	kernel_thread_helper,.-kernel_thread_helper

arch/mn10300/kernel/process.c

+18 −34
Original line number Diff line number Diff line
@@ -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;



	/* 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_regs->e2 = current_frame()->d3;



		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;