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authorAl Viro <viro@zeniv.linux.org.uk>2012-09-19 13:05:49 -0400
committerAl Viro <viro@zeniv.linux.org.uk>2012-10-01 00:53:24 -0400
commit255461c53a91d34e2eddb8c8a2ba39e99065d7c1 (patch)
tree0c758f750337edf712204b72f9ce5bcec60af1b0
parent49ed3398b75c98c087537a7d5a1a23f86a8c8746 (diff)
mn10300: split ret_from_fork, simplify kernel_thread()
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
-rw-r--r--arch/mn10300/kernel/Makefile2
-rw-r--r--arch/mn10300/kernel/entry.S7
-rw-r--r--arch/mn10300/kernel/internal.h6
-rw-r--r--arch/mn10300/kernel/kthread.S31
-rw-r--r--arch/mn10300/kernel/process.c52
5 files changed, 27 insertions, 71 deletions
diff --git a/arch/mn10300/kernel/Makefile b/arch/mn10300/kernel/Makefile
index d06749173d63..142c12906682 100644
--- a/arch/mn10300/kernel/Makefile
+++ b/arch/mn10300/kernel/Makefile
@@ -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
diff --git a/arch/mn10300/kernel/entry.S b/arch/mn10300/kernel/entry.S
index 8e11f9f48999..000f144230a5 100644
--- a/arch/mn10300/kernel/entry.S
+++ b/arch/mn10300/kernel/entry.S
@@ -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
diff --git a/arch/mn10300/kernel/internal.h b/arch/mn10300/kernel/internal.h
index 2df440105a80..561785581f6c 100644
--- a/arch/mn10300/kernel/internal.h
+++ b/arch/mn10300/kernel/internal.h
@@ -15,14 +15,10 @@ 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
diff --git a/arch/mn10300/kernel/kthread.S b/arch/mn10300/kernel/kthread.S
deleted file mode 100644
index b5ae467ac5ec..000000000000
--- a/arch/mn10300/kernel/kthread.S
+++ /dev/null
@@ -1,31 +0,0 @@
-/* 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
diff --git a/arch/mn10300/kernel/process.c b/arch/mn10300/kernel/process.c
index 7dab0cd36466..be87fbee4da5 100644
--- a/arch/mn10300/kernel/process.c
+++ b/arch/mn10300/kernel/process.c
@@ -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;