1 files changed, 23 insertions, 0 deletions
diff --git a/arch/arm64/kernel/static_call.c b/arch/arm64/kernel/static_call.c
new file mode 100644
index 000000000000..8b3a19e10871
--- /dev/null
+++ b/arch/arm64/kernel/static_call.c
@@ -0,0 +1,23 @@
+// SPDX-License-Identifier: GPL-2.0
+#include <linux/static_call.h>
+#include <linux/memory.h>
+#include <asm/text-patching.h>
+
+void arch_static_call_transform(void *site, void *tramp, void *func, bool tail)
+{
+	u64 literal;
+	int ret;
+
+	if (!func)
+		func = __static_call_return0;
+
+	/* decode the instructions to discover the literal address */
+	literal = ALIGN_DOWN((u64)tramp + 4, SZ_4K) +
+		  aarch64_insn_adrp_get_offset(le32_to_cpup(tramp + 4)) +
+		  8 * aarch64_insn_decode_immediate(AARCH64_INSN_IMM_12,
+						    le32_to_cpup(tramp + 8));
+
+	ret = aarch64_insn_write_literal_u64((void *)literal, (u64)func);
+	WARN_ON_ONCE(ret);
+}
+EXPORT_SYMBOL_GPL(arch_static_call_transform);