diff options
Diffstat (limited to 'lib/extensions/pauth')
| -rw-r--r-- | lib/extensions/pauth/pauth_helpers.S | 141 |
1 files changed, 141 insertions, 0 deletions
diff --git a/lib/extensions/pauth/pauth_helpers.S b/lib/extensions/pauth/pauth_helpers.S new file mode 100644 index 0000000..d483c7d --- /dev/null +++ b/lib/extensions/pauth/pauth_helpers.S @@ -0,0 +1,141 @@ +/* + * Copyright (c) 2019, Arm Limited. All rights reserved. + * + * SPDX-License-Identifier: BSD-3-Clause + */ + +#include <arch.h> +#include <asm_macros.S> +#include <lib/el3_runtime/cpu_data.h> + + .global pauth_init_enable_el1 + .global pauth_disable_el1 + .global pauth_init_enable_el3 + .global pauth_disable_el3 + .globl pauth_load_bl31_apiakey + .globl pauth_load_bl1_apiakey_enable + +/* ------------------------------------------------------------- + * Program APIAKey_EL1 and enable pointer authentication in EL1 + * ------------------------------------------------------------- + */ +func pauth_init_enable_el1 + stp x29, x30, [sp, #-16]! + + /* Initialize platform key */ + bl plat_init_apkey + + /* Program instruction key A used by the Trusted Firmware */ + msr APIAKeyLo_EL1, x0 + msr APIAKeyHi_EL1, x1 + + /* Enable pointer authentication */ + mrs x0, sctlr_el1 + orr x0, x0, #SCTLR_EnIA_BIT + +#if ENABLE_BTI + /* Enable PAC branch type compatibility */ + bic x0, x0, #(SCTLR_BT0_BIT | SCTLR_BT1_BIT) +#endif + msr sctlr_el1, x0 + isb + + ldp x29, x30, [sp], #16 + ret +endfunc pauth_init_enable_el1 + +/* ------------------------------------------------------------- + * Disable pointer authentication in EL3 + * ------------------------------------------------------------- + */ +func pauth_disable_el1 + mrs x0, sctlr_el1 + bic x0, x0, #SCTLR_EnIA_BIT + msr sctlr_el1, x0 + isb + ret +endfunc pauth_disable_el1 + +/* ------------------------------------------------------------- + * Program APIAKey_EL1 and enable pointer authentication in EL3 + * ------------------------------------------------------------- + */ +func pauth_init_enable_el3 + stp x29, x30, [sp, #-16]! + + /* Initialize platform key */ + bl plat_init_apkey + + /* Program instruction key A used by the Trusted Firmware */ + msr APIAKeyLo_EL1, x0 + msr APIAKeyHi_EL1, x1 + + /* Enable pointer authentication */ + mrs x0, sctlr_el3 + orr x0, x0, #SCTLR_EnIA_BIT + +#if ENABLE_BTI + /* Enable PAC branch type compatibility */ + bic x0, x0, #SCTLR_BT_BIT +#endif + msr sctlr_el3, x0 + isb + + ldp x29, x30, [sp], #16 + ret +endfunc pauth_init_enable_el3 + +/* ------------------------------------------------------------- + * Disable pointer authentication in EL3 + * ------------------------------------------------------------- + */ +func pauth_disable_el3 + mrs x0, sctlr_el3 + bic x0, x0, #SCTLR_EnIA_BIT + msr sctlr_el3, x0 + isb + ret +endfunc pauth_disable_el3 + +/* ------------------------------------------------------------- + * The following functions strictly follow the AArch64 PCS + * to use x9-x17 (temporary caller-saved registers) to load + * the APIAKey_EL1 and enable pointer authentication. + * ------------------------------------------------------------- + */ +func pauth_load_bl31_apiakey + /* tpidr_el3 contains the address of cpu_data structure */ + mrs x9, tpidr_el3 + + /* Load apiakey from cpu_data */ + ldp x10, x11, [x9, #CPU_DATA_APIAKEY_OFFSET] + + /* Program instruction key A */ + msr APIAKeyLo_EL1, x10 + msr APIAKeyHi_EL1, x11 + isb + ret +endfunc pauth_load_bl31_apiakey + +func pauth_load_bl1_apiakey_enable + /* Load instruction key A used by the Trusted Firmware */ + adrp x9, bl1_apiakey + add x9, x9, :lo12:bl1_apiakey + ldp x10, x11, [x9] + + /* Program instruction key A */ + msr APIAKeyLo_EL1, x10 + msr APIAKeyHi_EL1, x11 + + /* Enable pointer authentication */ + mrs x9, sctlr_el3 + orr x9, x9, #SCTLR_EnIA_BIT + +#if ENABLE_BTI + /* Enable PAC branch type compatibility */ + bic x9, x9, #SCTLR_BT_BIT +#endif + msr sctlr_el3, x9 + isb + ret +endfunc pauth_load_bl1_apiakey_enable |