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Diffstat (limited to 'arch/arm/lib/call_with_stack.S')
| -rw-r--r-- | arch/arm/lib/call_with_stack.S | 51 |
1 files changed, 51 insertions, 0 deletions
diff --git a/arch/arm/lib/call_with_stack.S b/arch/arm/lib/call_with_stack.S new file mode 100644 index 000000000..5030d4e8d --- /dev/null +++ b/arch/arm/lib/call_with_stack.S @@ -0,0 +1,51 @@ +/* SPDX-License-Identifier: GPL-2.0-only */ +/* + * arch/arm/lib/call_with_stack.S + * + * Copyright (C) 2011 ARM Ltd. + * Written by Will Deacon <will.deacon@arm.com> + */ + +#include <linux/linkage.h> +#include <asm/assembler.h> +#include <asm/unwind.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. + * + * The sequence below follows the APCS frame convention for frame pointer + * unwinding, and implements the unwinder annotations needed by the EABI + * unwinder. + */ + +ENTRY(call_with_stack) +#if defined(CONFIG_UNWINDER_FRAME_POINTER) && defined(CONFIG_CC_IS_GCC) + mov ip, sp + push {fp, ip, lr, pc} + sub fp, ip, #4 +#else +UNWIND( .fnstart ) +UNWIND( .save {fpreg, lr} ) + push {fpreg, lr} +UNWIND( .setfp fpreg, sp ) + mov fpreg, sp +#endif + mov sp, r2 + mov r2, r0 + mov r0, r1 + + bl_r r2 + +#if defined(CONFIG_UNWINDER_FRAME_POINTER) && defined(CONFIG_CC_IS_GCC) + ldmdb fp, {fp, sp, pc} +#else + mov sp, fpreg + pop {fpreg, pc} +UNWIND( .fnend ) +#endif + .globl call_with_stack_end +call_with_stack_end: +ENDPROC(call_with_stack) |