1 /* 2 * Copyright (c) 2022-2023, 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_RAS (Reliability, Availability, and Serviceability Extension) 65 ******************************************************************************/ 66 static void read_feat_ras(void) 67 { 68 #if (RAS_EXTENSION == FEAT_STATE_ALWAYS) 69 feat_detect_panic(is_armv8_2_feat_ras_present(), "RAS"); 70 #endif 71 } 72 73 /************************************************ 74 * Feature : FEAT_PAUTH (Pointer Authentication) 75 ***********************************************/ 76 static void read_feat_pauth(void) 77 { 78 #if (ENABLE_PAUTH == FEAT_STATE_ALWAYS) || (CTX_INCLUDE_PAUTH_REGS == FEAT_STATE_ALWAYS) 79 feat_detect_panic(is_armv8_3_pauth_present(), "PAUTH"); 80 #endif 81 } 82 83 /************************************************************ 84 * Feature : FEAT_DIT (Data Independent Timing Instructions) 85 ***********************************************************/ 86 static void read_feat_dit(void) 87 { 88 #if (ENABLE_FEAT_DIT == FEAT_STATE_ALWAYS) 89 feat_detect_panic(is_armv8_4_feat_dit_present(), "DIT"); 90 #endif 91 } 92 93 /************************************************ 94 * Feature : FEAT_MTE (Memory Tagging Extension) 95 ***********************************************/ 96 static void read_feat_mte(void) 97 { 98 #if (CTX_INCLUDE_MTE_REGS == FEAT_STATE_ALWAYS) 99 unsigned int mte = get_armv8_5_mte_support(); 100 101 feat_detect_panic((mte != MTE_UNIMPLEMENTED), "MTE"); 102 #endif 103 } 104 105 /**************************************************** 106 * Feature : FEAT_BTI (Branch Target Identification) 107 ***************************************************/ 108 static void read_feat_bti(void) 109 { 110 #if (ENABLE_BTI == FEAT_STATE_ALWAYS) 111 feat_detect_panic(is_armv8_5_bti_present(), "BTI"); 112 #endif 113 } 114 115 /************************************************** 116 * Feature : FEAT_RME (Realm Management Extension) 117 *************************************************/ 118 static void read_feat_rme(void) 119 { 120 #if (ENABLE_RME == FEAT_STATE_ALWAYS) 121 feat_detect_panic((get_armv9_2_feat_rme_support() != 122 ID_AA64PFR0_FEAT_RME_NOT_SUPPORTED), "RME"); 123 #endif 124 } 125 126 /****************************************************************** 127 * Feature : FEAT_RNG_TRAP (Trapping support for RNDR/RNDRRS) 128 *****************************************************************/ 129 static void read_feat_rng_trap(void) 130 { 131 #if (ENABLE_FEAT_RNG_TRAP == FEAT_STATE_ALWAYS) 132 feat_detect_panic(is_feat_rng_trap_present(), "RNG_TRAP"); 133 #endif 134 } 135 136 /*********************************************************************************** 137 * TF-A supports many Arm architectural features starting from arch version 138 * (8.0 till 8.7+). These features are mostly enabled through build flags. This 139 * mechanism helps in validating these build flags in the early boot phase 140 * either in BL1 or BL31 depending on the platform and assists in identifying 141 * and notifying the features which are enabled but not supported by the PE. 142 * 143 * It reads all the enabled features ID-registers and ensures the features 144 * are supported by the PE. 145 * In case if they aren't it stops booting at an early phase and logs the error 146 * messages, notifying the platforms about the features that are not supported. 147 * 148 * Further the procedure is implemented with a tri-state approach for each feature: 149 * ENABLE_FEAT_xxx = 0 : The feature is disabled statically at compile time 150 * ENABLE_FEAT_xxx = 1 : The feature is enabled and must be present in hardware. 151 * There will be panic if feature is not present at cold boot. 152 * ENABLE_FEAT_xxx = 2 : The feature is enabled but dynamically enabled at runtime 153 * depending on hardware capability. 154 * 155 * For better readability, state values are defined with macros, namely: 156 * { FEAT_STATE_DISABLED, FEAT_STATE_ALWAYS, FEAT_STATE_CHECK }, taking values 157 * { 0, 1, 2 }, respectively, as their naming. 158 **********************************************************************************/ 159 void detect_arch_features(void) 160 { 161 tainted = false; 162 163 /* v8.0 features */ 164 check_feature(ENABLE_FEAT_SB, read_feat_sb_id_field(), "SB", 1, 1); 165 check_feature(ENABLE_FEAT_CSV2_2, read_feat_csv2_id_field(), 166 "CSV2_2", 2, 3); 167 168 /* v8.1 features */ 169 check_feature(ENABLE_FEAT_PAN, read_feat_pan_id_field(), "PAN", 1, 3); 170 check_feature(ENABLE_FEAT_VHE, read_feat_vhe_id_field(), "VHE", 1, 1); 171 172 /* v8.2 features */ 173 read_feat_ras(); 174 check_feature(ENABLE_SVE_FOR_NS, read_feat_sve_id_field(), 175 "SVE", 1, 1); 176 177 /* v8.3 features */ 178 read_feat_pauth(); 179 180 /* v8.4 features */ 181 read_feat_dit(); 182 check_feature(ENABLE_FEAT_AMU, read_feat_amu_id_field(), 183 "AMUv1", 1, 2); 184 check_feature(ENABLE_MPAM_FOR_LOWER_ELS, read_feat_mpam_version(), 185 "MPAM", 1, 17); 186 check_feature(CTX_INCLUDE_NEVE_REGS, read_feat_nv_id_field(), 187 "NV2", 2, 2); 188 check_feature(ENABLE_FEAT_SEL2, read_feat_sel2_id_field(), 189 "SEL2", 1, 1); 190 check_feature(ENABLE_TRF_FOR_NS, read_feat_trf_id_field(), 191 "TRF", 1, 1); 192 193 /* v8.5 features */ 194 read_feat_mte(); 195 check_feature(ENABLE_FEAT_RNG, read_feat_rng_id_field(), "RNG", 1, 1); 196 read_feat_bti(); 197 read_feat_rng_trap(); 198 199 /* v8.6 features */ 200 check_feature(ENABLE_FEAT_AMUv1p1, read_feat_amu_id_field(), 201 "AMUv1p1", 2, 2); 202 check_feature(ENABLE_FEAT_FGT, read_feat_fgt_id_field(), "FGT", 1, 1); 203 check_feature(ENABLE_FEAT_ECV, read_feat_ecv_id_field(), "ECV", 1, 2); 204 check_feature(ENABLE_FEAT_TWED, read_feat_twed_id_field(), 205 "TWED", 1, 1); 206 207 /* v8.7 features */ 208 check_feature(ENABLE_FEAT_HCX, read_feat_hcx_id_field(), "HCX", 1, 1); 209 210 /* v8.9 features */ 211 check_feature(ENABLE_FEAT_TCR2, read_feat_tcrx_id_field(), 212 "TCR2", 1, 1); 213 check_feature(ENABLE_FEAT_S2PIE, read_feat_s2pie_id_field(), 214 "S2PIE", 1, 1); 215 check_feature(ENABLE_FEAT_S1PIE, read_feat_s1pie_id_field(), 216 "S1PIE", 1, 1); 217 check_feature(ENABLE_FEAT_S2POE, read_feat_s2poe_id_field(), 218 "S2POE", 1, 1); 219 check_feature(ENABLE_FEAT_S1POE, read_feat_s1poe_id_field(), 220 "S1POE", 1, 1); 221 222 /* v9.0 features */ 223 check_feature(ENABLE_BRBE_FOR_NS, read_feat_brbe_id_field(), 224 "BRBE", 1, 2); 225 check_feature(ENABLE_TRBE_FOR_NS, read_feat_trbe_id_field(), 226 "TRBE", 1, 1); 227 228 /* v9.2 features */ 229 check_feature(ENABLE_SME_FOR_NS, read_feat_sme_id_field(), 230 "SME", 1, 2); 231 read_feat_rme(); 232 233 if (tainted) { 234 panic(); 235 } 236 } 237