diff options
| -rw-r--r-- | arch/arm/lib/Makefile | 3 | ||||
| -rw-r--r-- | arch/arm/lib/call_with_stack.S | 44 |
2 files changed, 46 insertions, 1 deletions
diff --git a/arch/arm/lib/Makefile b/arch/arm/lib/Makefile index cf73a7f742dd..0ade0acc1ed9 100644 --- a/arch/arm/lib/Makefile +++ b/arch/arm/lib/Makefile @@ -13,7 +13,8 @@ lib-y := backtrace.o changebit.o csumipv6.o csumpartial.o \ testchangebit.o testclearbit.o testsetbit.o \ ashldi3.o ashrdi3.o lshrdi3.o muldi3.o \ ucmpdi2.o lib1funcs.o div64.o \ - io-readsb.o io-writesb.o io-readsl.o io-writesl.o + io-readsb.o io-writesb.o io-readsl.o io-writesl.o \ + call_with_stack.o mmu-y := clear_user.o copy_page.o getuser.o putuser.o diff --git a/arch/arm/lib/call_with_stack.S b/arch/arm/lib/call_with_stack.S new file mode 100644 index 000000000000..916c80f13ae7 --- /dev/null +++ b/arch/arm/lib/call_with_stack.S @@ -0,0 +1,44 @@ +/* + * arch/arm/lib/call_with_stack.S + * + * Copyright (C) 2011 ARM Ltd. + * Written by Will Deacon <will.deacon@arm.com> + * + * This program is free software; you can redistribute it and/or modify + * it under the terms of the GNU General Public License version 2 as + * published by the Free Software Foundation. + * + * This program is distributed in the hope that it will be useful, + * but WITHOUT ANY WARRANTY; without even the implied warranty of + * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the + * GNU General Public License for more details. + * + * You should have received a copy of the GNU General Public License + * along with this program; if not, write to the Free Software + * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA + */ + +#include <linux/linkage.h> +#include <asm/assembler.h> + +/* + * void call_with_stack(void (*fn)(void *), void *arg, void *sp) + * + * Change the stack to that pointed at by sp, then invoke fn(arg) with + * the new stack. + */ +ENTRY(call_with_stack) + str sp, [r2, #-4]! + str lr, [r2, #-4]! + + mov sp, r2 + mov r2, r0 + mov r0, r1 + + adr lr, BSYM(1f) + mov pc, r2 + +1: ldr lr, [sp] + ldr sp, [sp, #4] + mov pc, lr +ENDPROC(call_with_stack) |