1/* 2 * Copyright (c) 2019, Arm Limited. All rights reserved. 3 * 4 * SPDX-License-Identifier: BSD-3-Clause 5 */ 6 7#include <arch.h> 8#include <asm_macros.S> 9#include <lib/el3_runtime/cpu_data.h> 10 11 .global pauth_init_enable_el1 12 .global pauth_disable_el1 13 .global pauth_init_enable_el3 14 .global pauth_disable_el3 15 .globl pauth_load_bl31_apiakey 16 .globl pauth_load_bl1_apiakey_enable 17 18/* ------------------------------------------------------------- 19 * Program APIAKey_EL1 and enable pointer authentication in EL1 20 * ------------------------------------------------------------- 21 */ 22func pauth_init_enable_el1 23 stp x29, x30, [sp, #-16]! 24 25 /* Initialize platform key */ 26 bl plat_init_apkey 27 28 /* Program instruction key A used by the Trusted Firmware */ 29 msr APIAKeyLo_EL1, x0 30 msr APIAKeyHi_EL1, x1 31 32 /* Enable pointer authentication */ 33 mrs x0, sctlr_el1 34 orr x0, x0, #SCTLR_EnIA_BIT 35 36#if ENABLE_BTI 37 /* Enable PAC branch type compatibility */ 38 bic x0, x0, #(SCTLR_BT0_BIT | SCTLR_BT1_BIT) 39#endif 40 msr sctlr_el1, x0 41 isb 42 43 ldp x29, x30, [sp], #16 44 ret 45endfunc pauth_init_enable_el1 46 47/* ------------------------------------------------------------- 48 * Disable pointer authentication in EL3 49 * ------------------------------------------------------------- 50 */ 51func pauth_disable_el1 52 mrs x0, sctlr_el1 53 bic x0, x0, #SCTLR_EnIA_BIT 54 msr sctlr_el1, x0 55 isb 56 ret 57endfunc pauth_disable_el1 58 59/* ------------------------------------------------------------- 60 * Program APIAKey_EL1 and enable pointer authentication in EL3 61 * ------------------------------------------------------------- 62 */ 63func pauth_init_enable_el3 64 stp x29, x30, [sp, #-16]! 65 66 /* Initialize platform key */ 67 bl plat_init_apkey 68 69 /* Program instruction key A used by the Trusted Firmware */ 70 msr APIAKeyLo_EL1, x0 71 msr APIAKeyHi_EL1, x1 72 73 /* Enable pointer authentication */ 74 mrs x0, sctlr_el3 75 orr x0, x0, #SCTLR_EnIA_BIT 76 77#if ENABLE_BTI 78 /* Enable PAC branch type compatibility */ 79 bic x0, x0, #SCTLR_BT_BIT 80#endif 81 msr sctlr_el3, x0 82 isb 83 84 ldp x29, x30, [sp], #16 85 ret 86endfunc pauth_init_enable_el3 87 88/* ------------------------------------------------------------- 89 * Disable pointer authentication in EL3 90 * ------------------------------------------------------------- 91 */ 92func pauth_disable_el3 93 mrs x0, sctlr_el3 94 bic x0, x0, #SCTLR_EnIA_BIT 95 msr sctlr_el3, x0 96 isb 97 ret 98endfunc pauth_disable_el3 99 100/* ------------------------------------------------------------- 101 * The following functions strictly follow the AArch64 PCS 102 * to use x9-x17 (temporary caller-saved registers) to load 103 * the APIAKey_EL1 and enable pointer authentication. 104 * ------------------------------------------------------------- 105 */ 106func pauth_load_bl31_apiakey 107 /* tpidr_el3 contains the address of cpu_data structure */ 108 mrs x9, tpidr_el3 109 110 /* Load apiakey from cpu_data */ 111 ldp x10, x11, [x9, #CPU_DATA_APIAKEY_OFFSET] 112 113 /* Program instruction key A */ 114 msr APIAKeyLo_EL1, x10 115 msr APIAKeyHi_EL1, x11 116 isb 117 ret 118endfunc pauth_load_bl31_apiakey 119 120func pauth_load_bl1_apiakey_enable 121 /* Load instruction key A used by the Trusted Firmware */ 122 adrp x9, bl1_apiakey 123 add x9, x9, :lo12:bl1_apiakey 124 ldp x10, x11, [x9] 125 126 /* Program instruction key A */ 127 msr APIAKeyLo_EL1, x10 128 msr APIAKeyHi_EL1, x11 129 130 /* Enable pointer authentication */ 131 mrs x9, sctlr_el3 132 orr x9, x9, #SCTLR_EnIA_BIT 133 134#if ENABLE_BTI 135 /* Enable PAC branch type compatibility */ 136 bic x9, x9, #SCTLR_BT_BIT 137#endif 138 msr sctlr_el3, x9 139 isb 140 ret 141endfunc pauth_load_bl1_apiakey_enable 142