From 9732cafd9dc0206479be919baf0067239f0a63ca Mon Sep 17 00:00:00 2001 From: Jiang Liu Date: Tue, 7 Jan 2014 22:17:13 +0800 Subject: arm64, jump label: optimize jump label implementation Optimize jump label implementation for ARM64 by dynamically patching kernel text. Reviewed-by: Will Deacon Signed-off-by: Jiang Liu Signed-off-by: Catalin Marinas --- arch/arm64/kernel/jump_label.c | 58 ++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 58 insertions(+) create mode 100644 arch/arm64/kernel/jump_label.c (limited to 'arch/arm64/kernel/jump_label.c') diff --git a/arch/arm64/kernel/jump_label.c b/arch/arm64/kernel/jump_label.c new file mode 100644 index 0000000..263a166 --- /dev/null +++ b/arch/arm64/kernel/jump_label.c @@ -0,0 +1,58 @@ +/* + * Copyright (C) 2013 Huawei Ltd. + * Author: Jiang Liu + * + * Based on arch/arm/kernel/jump_label.c + * + * This program is free software; you can redistribute it and/or modify + * it under the terms of the GNU General Public License version 2 as + * published by the Free Software Foundation. + * + * This program is distributed in the hope that it will be useful, + * but WITHOUT ANY WARRANTY; without even the implied warranty of + * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the + * GNU General Public License for more details. + * + * You should have received a copy of the GNU General Public License + * along with this program. If not, see . + */ +#include +#include +#include + +#ifdef HAVE_JUMP_LABEL + +static void __arch_jump_label_transform(struct jump_entry *entry, + enum jump_label_type type, + bool is_static) +{ + void *addr = (void *)entry->code; + u32 insn; + + if (type == JUMP_LABEL_ENABLE) { + insn = aarch64_insn_gen_branch_imm(entry->code, + entry->target, + AARCH64_INSN_BRANCH_NOLINK); + } else { + insn = aarch64_insn_gen_nop(); + } + + if (is_static) + aarch64_insn_patch_text_nosync(addr, insn); + else + aarch64_insn_patch_text(&addr, &insn, 1); +} + +void arch_jump_label_transform(struct jump_entry *entry, + enum jump_label_type type) +{ + __arch_jump_label_transform(entry, type, false); +} + +void arch_jump_label_transform_static(struct jump_entry *entry, + enum jump_label_type type) +{ + __arch_jump_label_transform(entry, type, true); +} + +#endif /* HAVE_JUMP_LABEL */ -- cgit v1.1