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Diffstat (limited to '')
| -rw-r--r-- | common/feat_detect.c | 239 |
1 files changed, 239 insertions, 0 deletions
diff --git a/common/feat_detect.c b/common/feat_detect.c new file mode 100644 index 0000000..be22c6e --- /dev/null +++ b/common/feat_detect.c @@ -0,0 +1,239 @@ +/* + * Copyright (c) 2022-2023, Arm Limited and Contributors. All rights reserved. + * + * SPDX-License-Identifier: BSD-3-Clause + */ + +#include <arch_features.h> +#include <common/debug.h> +#include <common/feat_detect.h> + +static bool tainted; + +/******************************************************************************* + * This section lists the wrapper modules for each feature to evaluate the + * feature states (FEAT_STATE_ALWAYS and FEAT_STATE_CHECK) and perform + * necessary action as below: + * + * It verifies whether the FEAT_XXX (eg: FEAT_SB) is supported by the PE or not. + * Without this check an exception would occur during context save/restore + * routines, if the feature is enabled but not supported by PE. + ******************************************************************************/ + +#define feat_detect_panic(a, b) ((a) ? (void)0 : feature_panic(b)) + +/******************************************************************************* + * Function : feature_panic + * Customised panic function with error logging mechanism to list the feature + * not supported by the PE. + ******************************************************************************/ +static inline void feature_panic(char *feat_name) +{ + ERROR("FEAT_%s not supported by the PE\n", feat_name); + panic(); +} + +/******************************************************************************* + * Function : check_feature + * Check for a valid combination of build time flags (ENABLE_FEAT_xxx) and + * feature availability on the hardware. <min> is the smallest feature + * ID field value that is required for that feature. + * Triggers a panic later if a feature is forcefully enabled, but not + * available on the PE. Also will panic if the hardware feature ID field + * is larger than the maximum known and supported number, specified by <max>. + * + * We force inlining here to let the compiler optimise away the whole check + * if the feature is disabled at build time (FEAT_STATE_DISABLED). + ******************************************************************************/ +static inline void __attribute((__always_inline__)) +check_feature(int state, unsigned long field, const char *feat_name, + unsigned int min, unsigned int max) +{ + if (state == FEAT_STATE_ALWAYS && field < min) { + ERROR("FEAT_%s not supported by the PE\n", feat_name); + tainted = true; + } + if (state >= FEAT_STATE_ALWAYS && field > max) { + ERROR("FEAT_%s is version %ld, but is only known up to version %d\n", + feat_name, field, max); + tainted = true; + } +} + +/************************************************ + * Feature : FEAT_PAUTH (Pointer Authentication) + ***********************************************/ +static void read_feat_pauth(void) +{ +#if (ENABLE_PAUTH == FEAT_STATE_ALWAYS) || (CTX_INCLUDE_PAUTH_REGS == FEAT_STATE_ALWAYS) + feat_detect_panic(is_armv8_3_pauth_present(), "PAUTH"); +#endif +} + +/************************************************ + * Feature : FEAT_MTE (Memory Tagging Extension) + ***********************************************/ +static void read_feat_mte(void) +{ +#if (CTX_INCLUDE_MTE_REGS == FEAT_STATE_ALWAYS) + unsigned int mte = get_armv8_5_mte_support(); + + feat_detect_panic((mte != MTE_UNIMPLEMENTED), "MTE"); +#endif +} + +/**************************************************** + * Feature : FEAT_BTI (Branch Target Identification) + ***************************************************/ +static void read_feat_bti(void) +{ +#if (ENABLE_BTI == FEAT_STATE_ALWAYS) + feat_detect_panic(is_armv8_5_bti_present(), "BTI"); +#endif +} + +/************************************************** + * Feature : FEAT_RME (Realm Management Extension) + *************************************************/ +static void read_feat_rme(void) +{ +#if (ENABLE_RME == FEAT_STATE_ALWAYS) + feat_detect_panic((get_armv9_2_feat_rme_support() != + ID_AA64PFR0_FEAT_RME_NOT_SUPPORTED), "RME"); +#endif +} + +/****************************************************************** + * Feature : FEAT_RNG_TRAP (Trapping support for RNDR/RNDRRS) + *****************************************************************/ +static void read_feat_rng_trap(void) +{ +#if (ENABLE_FEAT_RNG_TRAP == FEAT_STATE_ALWAYS) + feat_detect_panic(is_feat_rng_trap_present(), "RNG_TRAP"); +#endif +} + +/*********************************************************************************** + * TF-A supports many Arm architectural features starting from arch version + * (8.0 till 8.7+). These features are mostly enabled through build flags. This + * mechanism helps in validating these build flags in the early boot phase + * either in BL1 or BL31 depending on the platform and assists in identifying + * and notifying the features which are enabled but not supported by the PE. + * + * It reads all the enabled features ID-registers and ensures the features + * are supported by the PE. + * In case if they aren't it stops booting at an early phase and logs the error + * messages, notifying the platforms about the features that are not supported. + * + * Further the procedure is implemented with a tri-state approach for each feature: + * ENABLE_FEAT_xxx = 0 : The feature is disabled statically at compile time + * ENABLE_FEAT_xxx = 1 : The feature is enabled and must be present in hardware. + * There will be panic if feature is not present at cold boot. + * ENABLE_FEAT_xxx = 2 : The feature is enabled but dynamically enabled at runtime + * depending on hardware capability. + * + * For better readability, state values are defined with macros, namely: + * { FEAT_STATE_DISABLED, FEAT_STATE_ALWAYS, FEAT_STATE_CHECK }, taking values + * { 0, 1, 2 }, respectively, as their naming. + **********************************************************************************/ +void detect_arch_features(void) +{ + tainted = false; + + /* v8.0 features */ + check_feature(ENABLE_FEAT_SB, read_feat_sb_id_field(), "SB", 1, 1); + check_feature(ENABLE_FEAT_CSV2_2, read_feat_csv2_id_field(), + "CSV2_2", 2, 3); + /* + * Even though the PMUv3 is an OPTIONAL feature, it is always + * implemented and Arm prescribes so. So assume it will be there and do + * away with a flag for it. This is used to check minor PMUv3px + * revisions so that we catch them as they come along + */ + check_feature(FEAT_STATE_ALWAYS, read_feat_pmuv3_id_field(), + "PMUv3", 1, ID_AA64DFR0_PMUVER_PMUV3P7); + + /* v8.1 features */ + check_feature(ENABLE_FEAT_PAN, read_feat_pan_id_field(), "PAN", 1, 3); + check_feature(ENABLE_FEAT_VHE, read_feat_vhe_id_field(), "VHE", 1, 1); + + /* v8.2 features */ + check_feature(ENABLE_SVE_FOR_NS, read_feat_sve_id_field(), + "SVE", 1, 1); + check_feature(ENABLE_FEAT_RAS, read_feat_ras_id_field(), "RAS", 1, 2); + + /* v8.3 features */ + read_feat_pauth(); + + /* v8.4 features */ + check_feature(ENABLE_FEAT_DIT, read_feat_dit_id_field(), "DIT", 1, 1); + check_feature(ENABLE_FEAT_AMU, read_feat_amu_id_field(), + "AMUv1", 1, 2); + check_feature(ENABLE_FEAT_MPAM, read_feat_mpam_version(), + "MPAM", 1, 17); + check_feature(CTX_INCLUDE_NEVE_REGS, read_feat_nv_id_field(), + "NV2", 2, 2); + check_feature(ENABLE_FEAT_SEL2, read_feat_sel2_id_field(), + "SEL2", 1, 1); + check_feature(ENABLE_TRF_FOR_NS, read_feat_trf_id_field(), + "TRF", 1, 1); + + /* v8.5 features */ + read_feat_mte(); + check_feature(ENABLE_FEAT_RNG, read_feat_rng_id_field(), "RNG", 1, 1); + read_feat_bti(); + read_feat_rng_trap(); + + /* v8.6 features */ + check_feature(ENABLE_FEAT_AMUv1p1, read_feat_amu_id_field(), + "AMUv1p1", 2, 2); + check_feature(ENABLE_FEAT_FGT, read_feat_fgt_id_field(), "FGT", 1, 1); + check_feature(ENABLE_FEAT_ECV, read_feat_ecv_id_field(), "ECV", 1, 2); + check_feature(ENABLE_FEAT_TWED, read_feat_twed_id_field(), + "TWED", 1, 1); + + /* + * even though this is a "DISABLE" it does confusingly perform feature + * enablement duties like all other flags here. Check it against the HW + * feature when we intend to diverge from the default behaviour + */ + check_feature(DISABLE_MTPMU, read_feat_mtpmu_id_field(), "MTPMU", 1, 1); + + /* v8.7 features */ + check_feature(ENABLE_FEAT_HCX, read_feat_hcx_id_field(), "HCX", 1, 1); + + /* v8.9 features */ + check_feature(ENABLE_FEAT_TCR2, read_feat_tcr2_id_field(), + "TCR2", 1, 1); + check_feature(ENABLE_FEAT_S2PIE, read_feat_s2pie_id_field(), + "S2PIE", 1, 1); + check_feature(ENABLE_FEAT_S1PIE, read_feat_s1pie_id_field(), + "S1PIE", 1, 1); + check_feature(ENABLE_FEAT_S2POE, read_feat_s2poe_id_field(), + "S2POE", 1, 1); + check_feature(ENABLE_FEAT_S1POE, read_feat_s1poe_id_field(), + "S1POE", 1, 1); + check_feature(ENABLE_FEAT_MTE_PERM, read_feat_mte_perm_id_field(), + "MTE_PERM", 1, 1); + + /* v9.0 features */ + check_feature(ENABLE_BRBE_FOR_NS, read_feat_brbe_id_field(), + "BRBE", 1, 2); + check_feature(ENABLE_TRBE_FOR_NS, read_feat_trbe_id_field(), + "TRBE", 1, 1); + + /* v9.2 features */ + check_feature(ENABLE_SME_FOR_NS, read_feat_sme_id_field(), + "SME", 1, 2); + check_feature(ENABLE_SME2_FOR_NS, read_feat_sme_id_field(), + "SME2", 2, 2); + + /* v9.4 features */ + check_feature(ENABLE_FEAT_GCS, read_feat_gcs_id_field(), "GCS", 1, 1); + + read_feat_rme(); + + if (tainted) { + panic(); + } +} |