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linux-next/arch/arm64/kernel/jump_label.c
Jiang Liu 9732cafd9d arm64, jump label: optimize jump label implementation
Optimize jump label implementation for ARM64 by dynamically patching
kernel text.

Reviewed-by: Will Deacon <will.deacon@arm.com>
Signed-off-by: Jiang Liu <liuj97@gmail.com>
Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
2014-01-08 15:23:53 +00:00

59 lines
1.6 KiB
C

/*
* Copyright (C) 2013 Huawei Ltd.
* Author: Jiang Liu <liuj97@gmail.com>
*
* 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 <http://www.gnu.org/licenses/>.
*/
#include <linux/kernel.h>
#include <linux/jump_label.h>
#include <asm/insn.h>
#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 */