1 /* 2 * Copyright (c) 2022-2024, Arm Limited and Contributors. All rights reserved. 3 * 4 * SPDX-License-Identifier: BSD-3-Clause 5 */ 6 7 #include <arch_features.h> 8 #include <common/debug.h> 9 #include <common/feat_detect.h> 10 11 static bool tainted; 12 13 /******************************************************************************* 14 * This section lists the wrapper modules for each feature to evaluate the 15 * feature states (FEAT_STATE_ALWAYS and FEAT_STATE_CHECK) and perform 16 * necessary action as below: 17 * 18 * It verifies whether the FEAT_XXX (eg: FEAT_SB) is supported by the PE or not. 19 * Without this check an exception would occur during context save/restore 20 * routines, if the feature is enabled but not supported by PE. 21 ******************************************************************************/ 22 23 #define feat_detect_panic(a, b) ((a) ? (void)0 : feature_panic(b)) 24 25 /******************************************************************************* 26 * Function : feature_panic 27 * Customised panic function with error logging mechanism to list the feature 28 * not supported by the PE. 29 ******************************************************************************/ 30 static inline void feature_panic(char *feat_name) 31 { 32 ERROR("FEAT_%s not supported by the PE\n", feat_name); 33 panic(); 34 } 35 36 /******************************************************************************* 37 * Function : check_feature 38 * Check for a valid combination of build time flags (ENABLE_FEAT_xxx) and 39 * feature availability on the hardware. <min> is the smallest feature 40 * ID field value that is required for that feature. 41 * Triggers a panic later if a feature is forcefully enabled, but not 42 * available on the PE. Also will panic if the hardware feature ID field 43 * is larger than the maximum known and supported number, specified by <max>. 44 * 45 * We force inlining here to let the compiler optimise away the whole check 46 * if the feature is disabled at build time (FEAT_STATE_DISABLED). 47 ******************************************************************************/ 48 static inline void __attribute((__always_inline__)) 49 check_feature(int state, unsigned long field, const char *feat_name, 50 unsigned int min, unsigned int max) 51 { 52 if (state == FEAT_STATE_ALWAYS && field < min) { 53 ERROR("FEAT_%s not supported by the PE\n", feat_name); 54 tainted = true; 55 } 56 if (state >= FEAT_STATE_ALWAYS && field > max) { 57 ERROR("FEAT_%s is version %ld, but is only known up to version %d\n", 58 feat_name, field, max); 59 tainted = true; 60 } 61 } 62 63 /************************************************ 64 * Feature : FEAT_PAUTH (Pointer Authentication) 65 ***********************************************/ 66 static void read_feat_pauth(void) 67 { 68 #if (ENABLE_PAUTH == FEAT_STATE_ALWAYS) || (CTX_INCLUDE_PAUTH_REGS == FEAT_STATE_ALWAYS) 69 feat_detect_panic(is_armv8_3_pauth_present(), "PAUTH"); 70 #endif 71 } 72 73 /**************************************************** 74 * Feature : FEAT_BTI (Branch Target Identification) 75 ***************************************************/ 76 static void read_feat_bti(void) 77 { 78 #if (ENABLE_BTI == FEAT_STATE_ALWAYS) 79 feat_detect_panic(is_feat_bti_present(), "BTI"); 80 #endif 81 } 82 83 /************************************************** 84 * Feature : FEAT_RME (Realm Management Extension) 85 *************************************************/ 86 static void read_feat_rme(void) 87 { 88 #if (ENABLE_RME == FEAT_STATE_ALWAYS) 89 feat_detect_panic(is_feat_rme_present(), "RME"); 90 #endif 91 } 92 93 /****************************************************************** 94 * Feature : FEAT_RNG_TRAP (Trapping support for RNDR/RNDRRS) 95 *****************************************************************/ 96 static void read_feat_rng_trap(void) 97 { 98 #if (ENABLE_FEAT_RNG_TRAP == FEAT_STATE_ALWAYS) 99 feat_detect_panic(is_feat_rng_trap_present(), "RNG_TRAP"); 100 #endif 101 } 102 103 /*********************************************************************************** 104 * TF-A supports many Arm architectural features starting from arch version 105 * (8.0 till 8.7+). These features are mostly enabled through build flags. This 106 * mechanism helps in validating these build flags in the early boot phase 107 * either in BL1 or BL31 depending on the platform and assists in identifying 108 * and notifying the features which are enabled but not supported by the PE. 109 * 110 * It reads all the enabled features ID-registers and ensures the features 111 * are supported by the PE. 112 * In case if they aren't it stops booting at an early phase and logs the error 113 * messages, notifying the platforms about the features that are not supported. 114 * 115 * Further the procedure is implemented with a tri-state approach for each feature: 116 * ENABLE_FEAT_xxx = 0 : The feature is disabled statically at compile time 117 * ENABLE_FEAT_xxx = 1 : The feature is enabled and must be present in hardware. 118 * There will be panic if feature is not present at cold boot. 119 * ENABLE_FEAT_xxx = 2 : The feature is enabled but dynamically enabled at runtime 120 * depending on hardware capability. 121 * 122 * For better readability, state values are defined with macros, namely: 123 * { FEAT_STATE_DISABLED, FEAT_STATE_ALWAYS, FEAT_STATE_CHECK }, taking values 124 * { 0, 1, 2 }, respectively, as their naming. 125 **********************************************************************************/ 126 void detect_arch_features(void) 127 { 128 tainted = false; 129 130 /* v8.0 features */ 131 check_feature(ENABLE_FEAT_SB, read_feat_sb_id_field(), "SB", 1, 1); 132 check_feature(ENABLE_FEAT_CSV2_2, read_feat_csv2_id_field(), 133 "CSV2_2", 2, 3); 134 /* 135 * Even though the PMUv3 is an OPTIONAL feature, it is always 136 * implemented and Arm prescribes so. So assume it will be there and do 137 * away with a flag for it. This is used to check minor PMUv3px 138 * revisions so that we catch them as they come along 139 */ 140 check_feature(FEAT_STATE_ALWAYS, read_feat_pmuv3_id_field(), 141 "PMUv3", 1, ID_AA64DFR0_PMUVER_PMUV3P7); 142 143 /* v8.1 features */ 144 check_feature(ENABLE_FEAT_PAN, read_feat_pan_id_field(), "PAN", 1, 3); 145 check_feature(ENABLE_FEAT_VHE, read_feat_vhe_id_field(), "VHE", 1, 1); 146 147 /* v8.2 features */ 148 check_feature(ENABLE_SVE_FOR_NS, read_feat_sve_id_field(), 149 "SVE", 1, 1); 150 check_feature(ENABLE_FEAT_RAS, read_feat_ras_id_field(), "RAS", 1, 2); 151 152 /* v8.3 features */ 153 read_feat_pauth(); 154 155 /* v8.4 features */ 156 check_feature(ENABLE_FEAT_DIT, read_feat_dit_id_field(), "DIT", 1, 1); 157 check_feature(ENABLE_FEAT_AMU, read_feat_amu_id_field(), 158 "AMUv1", 1, 2); 159 check_feature(ENABLE_FEAT_MPAM, read_feat_mpam_version(), 160 "MPAM", 1, 17); 161 check_feature(CTX_INCLUDE_NEVE_REGS, read_feat_nv_id_field(), 162 "NV2", 2, 2); 163 check_feature(ENABLE_FEAT_SEL2, read_feat_sel2_id_field(), 164 "SEL2", 1, 1); 165 check_feature(ENABLE_TRF_FOR_NS, read_feat_trf_id_field(), 166 "TRF", 1, 1); 167 168 /* v8.5 features */ 169 check_feature(ENABLE_FEAT_MTE2, get_armv8_5_mte_support(), "MTE2", 170 MTE_IMPLEMENTED_ELX, MTE_IMPLEMENTED_ASY); 171 check_feature(ENABLE_FEAT_RNG, read_feat_rng_id_field(), "RNG", 1, 1); 172 read_feat_bti(); 173 read_feat_rng_trap(); 174 175 /* v8.6 features */ 176 check_feature(ENABLE_FEAT_AMUv1p1, read_feat_amu_id_field(), 177 "AMUv1p1", 2, 2); 178 check_feature(ENABLE_FEAT_FGT, read_feat_fgt_id_field(), "FGT", 1, 1); 179 check_feature(ENABLE_FEAT_ECV, read_feat_ecv_id_field(), "ECV", 1, 2); 180 check_feature(ENABLE_FEAT_TWED, read_feat_twed_id_field(), 181 "TWED", 1, 1); 182 183 /* 184 * even though this is a "DISABLE" it does confusingly perform feature 185 * enablement duties like all other flags here. Check it against the HW 186 * feature when we intend to diverge from the default behaviour 187 */ 188 check_feature(DISABLE_MTPMU, read_feat_mtpmu_id_field(), "MTPMU", 1, 1); 189 190 /* v8.7 features */ 191 check_feature(ENABLE_FEAT_HCX, read_feat_hcx_id_field(), "HCX", 1, 1); 192 193 /* v8.9 features */ 194 check_feature(ENABLE_FEAT_TCR2, read_feat_tcr2_id_field(), 195 "TCR2", 1, 1); 196 check_feature(ENABLE_FEAT_S2PIE, read_feat_s2pie_id_field(), 197 "S2PIE", 1, 1); 198 check_feature(ENABLE_FEAT_S1PIE, read_feat_s1pie_id_field(), 199 "S1PIE", 1, 1); 200 check_feature(ENABLE_FEAT_S2POE, read_feat_s2poe_id_field(), 201 "S2POE", 1, 1); 202 check_feature(ENABLE_FEAT_S1POE, read_feat_s1poe_id_field(), 203 "S1POE", 1, 1); 204 check_feature(ENABLE_FEAT_CSV2_3, read_feat_csv2_id_field(), 205 "CSV2_3", 3, 3); 206 207 /* v9.0 features */ 208 check_feature(ENABLE_BRBE_FOR_NS, read_feat_brbe_id_field(), 209 "BRBE", 1, 2); 210 check_feature(ENABLE_TRBE_FOR_NS, read_feat_trbe_id_field(), 211 "TRBE", 1, 1); 212 213 /* v9.2 features */ 214 check_feature(ENABLE_SME_FOR_NS, read_feat_sme_id_field(), 215 "SME", 1, 2); 216 check_feature(ENABLE_SME2_FOR_NS, read_feat_sme_id_field(), 217 "SME2", 2, 2); 218 219 /* v9.4 features */ 220 check_feature(ENABLE_FEAT_GCS, read_feat_gcs_id_field(), "GCS", 1, 1); 221 222 read_feat_rme(); 223 224 if (tainted) { 225 panic(); 226 } 227 } 228