LXR linux/arch/arm64/kernel/jump

   1/*
   2 * Copyright (C) 2013 Huawei Ltd.
   3 * Author: Jiang Liu <liuj97@gmail.com>
   4 *
   5 * Based on arch/arm/kernel/jump_label.c
   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, see <http://www.gnu.org/licenses/>.
  18 */
  19#include <linux/kernel.h>
  20#include <linux/jump_label.h>
  21#include <asm/insn.h>
  22
  23#ifdef HAVE_JUMP_LABEL
  24
  25void arch_jump_label_transform(struct jump_entry *entry,
  26                               enum jump_label_type type)
  27{
  28        void *addr = (void *)entry->code;
  29        u32 insn;
  30
  31        if (type == JUMP_LABEL_JMP) {
  32                insn = aarch64_insn_gen_branch_imm(entry->code,
  33                                                   entry->target,
  34                                                   AARCH64_INSN_BRANCH_NOLINK);
  35        } else {
  36                insn = aarch64_insn_gen_nop();
  37        }
  38
  39        aarch64_insn_patch_text(&addr, &insn, 1);
  40}
  41
  42void arch_jump_label_transform_static(struct jump_entry *entry,
  43                                      enum jump_label_type type)
  44{
  45        /*
  46         * We use the architected A64 NOP in arch_static_branch, so there's no
  47         * need to patch an identical A64 NOP over the top of it here. The core
  48         * will call arch_jump_label_transform from a module notifier if the
  49         * NOP needs to be replaced by a branch.
  50         */
  51}
  52
  53#endif  /* HAVE_JUMP_LABEL */
  54