| Kyle Swenson | 8d8f654 | 2021-03-15 11:02:55 -0600 | [diff] [blame^] | 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 | */ |
| 30 | ENTRY(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 | badr lr, 1f |
| 39 | ret r2 |
| 40 | |
| 41 | 1: ldr lr, [sp] |
| 42 | ldr sp, [sp, #4] |
| 43 | ret lr |
| 44 | ENDPROC(call_with_stack) |