From 255461c53a91d34e2eddb8c8a2ba39e99065d7c1 Mon Sep 17 00:00:00 2001 From: Al Viro Date: Wed, 19 Sep 2012 13:05:49 -0400 Subject: [PATCH] mn10300: split ret_from_fork, simplify kernel_thread() Signed-off-by: Al Viro --- arch/mn10300/kernel/Makefile | 2 +- arch/mn10300/kernel/entry.S | 7 +++++ arch/mn10300/kernel/internal.h | 6 +--- arch/mn10300/kernel/kthread.S | 31 -------------------- arch/mn10300/kernel/process.c | 52 ++++++++++++---------------------- 5 files changed, 27 insertions(+), 71 deletions(-) delete mode 100644 arch/mn10300/kernel/kthread.S 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 @@ -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 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(®s, 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, ®s, 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; -- GitLab