1*4882a593Smuzhiyun /* SPDX-License-Identifier: GPL-2.0-only */ 2*4882a593Smuzhiyun /* 3*4882a593Smuzhiyun * Copyright (C) 2022 ARM Ltd. 4*4882a593Smuzhiyun */ 5*4882a593Smuzhiyun #ifndef __ASM_VECTORS_H 6*4882a593Smuzhiyun #define __ASM_VECTORS_H 7*4882a593Smuzhiyun 8*4882a593Smuzhiyun #include <linux/bug.h> 9*4882a593Smuzhiyun #include <linux/percpu.h> 10*4882a593Smuzhiyun 11*4882a593Smuzhiyun #include <asm/fixmap.h> 12*4882a593Smuzhiyun 13*4882a593Smuzhiyun extern char vectors[]; 14*4882a593Smuzhiyun extern char tramp_vectors[]; 15*4882a593Smuzhiyun extern char __bp_harden_el1_vectors[]; 16*4882a593Smuzhiyun 17*4882a593Smuzhiyun /* 18*4882a593Smuzhiyun * Note: the order of this enum corresponds to two arrays in entry.S: 19*4882a593Smuzhiyun * tramp_vecs and __bp_harden_el1_vectors. By default the canonical 20*4882a593Smuzhiyun * 'full fat' vectors are used directly. 21*4882a593Smuzhiyun */ 22*4882a593Smuzhiyun enum arm64_bp_harden_el1_vectors { 23*4882a593Smuzhiyun #ifdef CONFIG_MITIGATE_SPECTRE_BRANCH_HISTORY 24*4882a593Smuzhiyun /* 25*4882a593Smuzhiyun * Perform the BHB loop mitigation, before branching to the canonical 26*4882a593Smuzhiyun * vectors. 27*4882a593Smuzhiyun */ 28*4882a593Smuzhiyun EL1_VECTOR_BHB_LOOP, 29*4882a593Smuzhiyun 30*4882a593Smuzhiyun /* 31*4882a593Smuzhiyun * Make the SMC call for firmware mitigation, before branching to the 32*4882a593Smuzhiyun * canonical vectors. 33*4882a593Smuzhiyun */ 34*4882a593Smuzhiyun EL1_VECTOR_BHB_FW, 35*4882a593Smuzhiyun 36*4882a593Smuzhiyun /* 37*4882a593Smuzhiyun * Use the ClearBHB instruction, before branching to the canonical 38*4882a593Smuzhiyun * vectors. 39*4882a593Smuzhiyun */ 40*4882a593Smuzhiyun EL1_VECTOR_BHB_CLEAR_INSN, 41*4882a593Smuzhiyun #endif /* CONFIG_MITIGATE_SPECTRE_BRANCH_HISTORY */ 42*4882a593Smuzhiyun 43*4882a593Smuzhiyun /* 44*4882a593Smuzhiyun * Remap the kernel before branching to the canonical vectors. 45*4882a593Smuzhiyun */ 46*4882a593Smuzhiyun EL1_VECTOR_KPTI, 47*4882a593Smuzhiyun }; 48*4882a593Smuzhiyun 49*4882a593Smuzhiyun #ifndef CONFIG_MITIGATE_SPECTRE_BRANCH_HISTORY 50*4882a593Smuzhiyun #define EL1_VECTOR_BHB_LOOP -1 51*4882a593Smuzhiyun #define EL1_VECTOR_BHB_FW -1 52*4882a593Smuzhiyun #define EL1_VECTOR_BHB_CLEAR_INSN -1 53*4882a593Smuzhiyun #endif /* !CONFIG_MITIGATE_SPECTRE_BRANCH_HISTORY */ 54*4882a593Smuzhiyun 55*4882a593Smuzhiyun /* The vectors to use on return from EL0. e.g. to remap the kernel */ 56*4882a593Smuzhiyun DECLARE_PER_CPU_READ_MOSTLY(const char *, this_cpu_vector); 57*4882a593Smuzhiyun 58*4882a593Smuzhiyun #ifndef CONFIG_UNMAP_KERNEL_AT_EL0 59*4882a593Smuzhiyun #define TRAMP_VALIAS 0ul 60*4882a593Smuzhiyun #endif 61*4882a593Smuzhiyun 62*4882a593Smuzhiyun static inline const char * arm64_get_bp_hardening_vector(enum arm64_bp_harden_el1_vectors slot)63*4882a593Smuzhiyunarm64_get_bp_hardening_vector(enum arm64_bp_harden_el1_vectors slot) 64*4882a593Smuzhiyun { 65*4882a593Smuzhiyun if (arm64_kernel_unmapped_at_el0()) 66*4882a593Smuzhiyun return (char *)(TRAMP_VALIAS + SZ_2K * slot); 67*4882a593Smuzhiyun 68*4882a593Smuzhiyun WARN_ON_ONCE(slot == EL1_VECTOR_KPTI); 69*4882a593Smuzhiyun 70*4882a593Smuzhiyun return __bp_harden_el1_vectors + SZ_2K * slot; 71*4882a593Smuzhiyun } 72*4882a593Smuzhiyun 73*4882a593Smuzhiyun #endif /* __ASM_VECTORS_H */ 74