blob: e6694759dbd010f9d8b98a31d854a19a3491e10a [file] [log] [blame]
// SPDX-License-Identifier: GPL-2.0-only
/*
* Copyright (C) 2020 Emil Renner Berthing
*
* Based on arch/arm64/kernel/jump_label.c
*/
#include <linux/jump_label.h>
#include <linux/kernel.h>
#include <linux/memory.h>
#include <linux/mutex.h>
#include <asm/bug.h>
#include <asm/patch.h>
#define RISCV_INSN_NOP 0x00000013U
#define RISCV_INSN_JAL 0x0000006fU
void arch_jump_label_transform(struct jump_entry *entry,
enum jump_label_type type)
{
void *addr = (void *)jump_entry_code(entry);
u32 insn;
if (type == JUMP_LABEL_JMP) {
long offset = jump_entry_target(entry) - jump_entry_code(entry);
if (WARN_ON(offset & 1 || offset < -524288 || offset >= 524288))
return;
insn = RISCV_INSN_JAL |
(((u32)offset & GENMASK(19, 12)) << (12 - 12)) |
(((u32)offset & GENMASK(11, 11)) << (20 - 11)) |
(((u32)offset & GENMASK(10, 1)) << (21 - 1)) |
(((u32)offset & GENMASK(20, 20)) << (31 - 20));
} else {
insn = RISCV_INSN_NOP;
}
mutex_lock(&text_mutex);
patch_text_nosync(addr, &insn, sizeof(insn));
mutex_unlock(&text_mutex);
}