xref: /linux/arch/arm64/kernel/static_call.c (revision 441c63ff42c4e666304cdd32d23b5fc6bc1ea3cc)
1 // SPDX-License-Identifier: GPL-2.0
2 #include <linux/static_call.h>
3 #include <linux/memory.h>
4 #include <asm/text-patching.h>
5 
arch_static_call_transform(void * site,void * tramp,void * func,bool tail)6 void arch_static_call_transform(void *site, void *tramp, void *func, bool tail)
7 {
8 	u64 literal;
9 	int ret;
10 
11 	if (!func)
12 		func = __static_call_return0;
13 
14 	/* decode the instructions to discover the literal address */
15 	literal = ALIGN_DOWN((u64)tramp + 4, SZ_4K) +
16 		  aarch64_insn_adrp_get_offset(le32_to_cpup(tramp + 4)) +
17 		  8 * aarch64_insn_decode_immediate(AARCH64_INSN_IMM_12,
18 						    le32_to_cpup(tramp + 8));
19 
20 	ret = aarch64_insn_write_literal_u64((void *)literal, (u64)func);
21 	WARN_ON_ONCE(ret);
22 }
23 EXPORT_SYMBOL_GPL(arch_static_call_transform);
24