LXR linux/arch/arm/lib/call_with

   1/*
   2 * arch/arm/lib/call_with_stack.S
   3 *
   4 * Copyright (C) 2011 ARM Ltd.
   5 * Written by Will Deacon <will.deacon@arm.com>
   6 *
   7 * This program is free software; you can redistribute it and/or modify
   8 * it under the terms of the GNU General Public License version 2 as
   9 * published by the Free Software Foundation.
  10 *
  11 * This program is distributed in the hope that it will be useful,
  12 * but WITHOUT ANY WARRANTY; without even the implied warranty of
  13 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  14 * GNU General Public License for more details.
  15 *
  16 * You should have received a copy of the GNU General Public License
  17 * along with this program; if not, write to the Free Software
  18 * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
  19 */
  20
  21#include <linux/linkage.h>
  22#include <asm/assembler.h>
  23
  24/*
  25 * void call_with_stack(void (*fn)(void *), void *arg, void *sp)
  26 *
  27 * Change the stack to that pointed at by sp, then invoke fn(arg) with
  28 * the new stack.
  29 */
  30ENTRY(call_with_stack)
  31        str     sp, [r2, #-4]!
  32        str     lr, [r2, #-4]!
  33
  34        mov     sp, r2
  35        mov     r2, r0
  36        mov     r0, r1
  37
  38        adr     lr, BSYM(1f)
  39        mov     pc, r2
  40
  411:      ldr     lr, [sp]
  42        ldr     sp, [sp, #4]
  43        mov     pc, lr
  44ENDPROC(call_with_stack)
  45