| Alexei Fedorov | f41355c | 2019-09-13 14:11:59 +0100 | [diff] [blame] | 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 | |
| 17 | /* ------------------------------------------------------------- |
| 18 | * Program APIAKey_EL1 and enable pointer authentication in EL1 |
| 19 | * ------------------------------------------------------------- |
| 20 | */ |
| 21 | func pauth_init_enable_el1 |
| 22 | stp x29, x30, [sp, #-16]! |
| 23 | |
| 24 | /* Initialize platform key */ |
| 25 | bl plat_init_apkey |
| 26 | |
| 27 | /* Program instruction key A used by the Trusted Firmware */ |
| 28 | msr APIAKeyLo_EL1, x0 |
| 29 | msr APIAKeyHi_EL1, x1 |
| 30 | |
| 31 | /* Enable pointer authentication */ |
| 32 | mrs x0, sctlr_el1 |
| 33 | orr x0, x0, #SCTLR_EnIA_BIT |
| 34 | |
| 35 | #if ENABLE_BTI |
| 36 | /* Enable PAC branch type compatibility */ |
| 37 | bic x0, x0, #(SCTLR_BT0_BIT | SCTLR_BT1_BIT) |
| 38 | #endif |
| 39 | msr sctlr_el1, x0 |
| 40 | isb |
| 41 | |
| 42 | ldp x29, x30, [sp], #16 |
| 43 | ret |
| 44 | endfunc pauth_init_enable_el1 |
| 45 | |
| 46 | /* ------------------------------------------------------------- |
| 47 | * Disable pointer authentication in EL3 |
| 48 | * ------------------------------------------------------------- |
| 49 | */ |
| 50 | func pauth_disable_el1 |
| 51 | mrs x0, sctlr_el1 |
| 52 | bic x0, x0, #SCTLR_EnIA_BIT |
| 53 | msr sctlr_el1, x0 |
| 54 | isb |
| 55 | ret |
| 56 | endfunc pauth_disable_el1 |
| 57 | |
| 58 | /* ------------------------------------------------------------- |
| 59 | * Program APIAKey_EL1 and enable pointer authentication in EL3 |
| 60 | * ------------------------------------------------------------- |
| 61 | */ |
| 62 | func pauth_init_enable_el3 |
| 63 | stp x29, x30, [sp, #-16]! |
| 64 | |
| 65 | /* Initialize platform key */ |
| 66 | bl plat_init_apkey |
| 67 | |
| 68 | /* Program instruction key A used by the Trusted Firmware */ |
| 69 | msr APIAKeyLo_EL1, x0 |
| 70 | msr APIAKeyHi_EL1, x1 |
| 71 | |
| 72 | /* Enable pointer authentication */ |
| 73 | mrs x0, sctlr_el3 |
| 74 | orr x0, x0, #SCTLR_EnIA_BIT |
| 75 | |
| 76 | #if ENABLE_BTI |
| 77 | /* Enable PAC branch type compatibility */ |
| 78 | bic x0, x0, #SCTLR_BT_BIT |
| 79 | #endif |
| 80 | msr sctlr_el3, x0 |
| 81 | isb |
| 82 | |
| 83 | ldp x29, x30, [sp], #16 |
| 84 | ret |
| 85 | endfunc pauth_init_enable_el3 |
| 86 | |
| 87 | /* ------------------------------------------------------------- |
| 88 | * Disable pointer authentication in EL3 |
| 89 | * ------------------------------------------------------------- |
| 90 | */ |
| 91 | func pauth_disable_el3 |
| 92 | mrs x0, sctlr_el3 |
| 93 | bic x0, x0, #SCTLR_EnIA_BIT |
| 94 | msr sctlr_el3, x0 |
| 95 | isb |
| 96 | ret |
| 97 | endfunc pauth_disable_el3 |
| 98 | |
| 99 | /* ------------------------------------------------------------- |
| 100 | * The following function strictly follows the AArch64 PCS |
| 101 | * to use x9-x17 (temporary caller-saved registers) to load |
| 102 | * the APIAKey_EL1 used by the firmware. |
| 103 | * ------------------------------------------------------------- |
| 104 | */ |
| 105 | func pauth_load_bl31_apiakey |
| 106 | /* tpidr_el3 contains the address of cpu_data structure */ |
| 107 | mrs x9, tpidr_el3 |
| 108 | |
| 109 | /* Load apiakey from cpu_data */ |
| 110 | ldp x10, x11, [x9, #CPU_DATA_APIAKEY_OFFSET] |
| 111 | |
| 112 | /* Program instruction key A */ |
| 113 | msr APIAKeyLo_EL1, x10 |
| 114 | msr APIAKeyHi_EL1, x11 |
| 115 | isb |
| 116 | ret |
| 117 | endfunc pauth_load_bl31_apiakey |