From ebc00dde8a975a543f5e1a7cdac93fef89fefe58 Mon Sep 17 00:00:00 2001 From: Emil Renner Berthing Date: Tue, 14 Jul 2020 09:40:44 +0200 Subject: riscv: Add jump-label implementation MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit Add jump-label implementation based on the ARM64 version and add CONFIG_JUMP_LABEL=y to the defconfigs. Signed-off-by: Emil Renner Berthing Reviewed-by: Björn Töpel Tested-by: Björn Töpel Signed-off-by: Palmer Dabbelt --- arch/riscv/include/asm/jump_label.h | 60 +++++++++++++++++++++++++++++++++++++ 1 file changed, 60 insertions(+) create mode 100644 arch/riscv/include/asm/jump_label.h (limited to 'arch/riscv/include/asm/jump_label.h') diff --git a/arch/riscv/include/asm/jump_label.h b/arch/riscv/include/asm/jump_label.h new file mode 100644 index 000000000000..38af2ec7b9bf --- /dev/null +++ b/arch/riscv/include/asm/jump_label.h @@ -0,0 +1,60 @@ +/* SPDX-License-Identifier: GPL-2.0-only */ +/* + * Copyright (C) 2020 Emil Renner Berthing + * + * Based on arch/arm64/include/asm/jump_label.h + */ +#ifndef __ASM_JUMP_LABEL_H +#define __ASM_JUMP_LABEL_H + +#ifndef __ASSEMBLY__ + +#include +#include + +#define JUMP_LABEL_NOP_SIZE 4 + +static __always_inline bool arch_static_branch(struct static_key *key, + bool branch) +{ + asm_volatile_goto( + " .option push \n\t" + " .option norelax \n\t" + " .option norvc \n\t" + "1: nop \n\t" + " .option pop \n\t" + " .pushsection __jump_table, \"aw\" \n\t" + " .align " RISCV_LGPTR " \n\t" + " .long 1b - ., %l[label] - . \n\t" + " " RISCV_PTR " %0 - . \n\t" + " .popsection \n\t" + : : "i"(&((char *)key)[branch]) : : label); + + return false; +label: + return true; +} + +static __always_inline bool arch_static_branch_jump(struct static_key *key, + bool branch) +{ + asm_volatile_goto( + " .option push \n\t" + " .option norelax \n\t" + " .option norvc \n\t" + "1: jal zero, %l[label] \n\t" + " .option pop \n\t" + " .pushsection __jump_table, \"aw\" \n\t" + " .align " RISCV_LGPTR " \n\t" + " .long 1b - ., %l[label] - . \n\t" + " " RISCV_PTR " %0 - . \n\t" + " .popsection \n\t" + : : "i"(&((char *)key)[branch]) : : label); + + return false; +label: + return true; +} + +#endif /* __ASSEMBLY__ */ +#endif /* __ASM_JUMP_LABEL_H */ -- cgit v1.2.3