1 /* 2 * Copyright (c) 2022, 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_SB (Speculation Barrier) 65 *****************************************/ 66 static void read_feat_sb(void) 67 { 68 #if (ENABLE_FEAT_SB == FEAT_STATE_ALWAYS) 69 feat_detect_panic(is_armv8_0_feat_sb_present(), "SB"); 70 #endif 71 } 72 73 /****************************************************** 74 * Feature : FEAT_CSV2_2 (Cache Speculation Variant 2) 75 *****************************************************/ 76 static void read_feat_csv2_2(void) 77 { 78 #if (ENABLE_FEAT_CSV2_2 == FEAT_STATE_ALWAYS) 79 feat_detect_panic(is_armv8_0_feat_csv2_2_present(), "CSV2_2"); 80 #endif 81 } 82 83 /*********************************************** 84 * Feature : FEAT_PAN (Privileged Access Never) 85 **********************************************/ 86 static void read_feat_pan(void) 87 { 88 #if (ENABLE_FEAT_PAN == FEAT_STATE_ALWAYS) 89 feat_detect_panic(is_armv8_1_pan_present(), "PAN"); 90 #endif 91 } 92 93 /******************************************************************************* 94 * Feature : FEAT_RAS (Reliability, Availability, and Serviceability Extension) 95 ******************************************************************************/ 96 static void read_feat_ras(void) 97 { 98 #if (RAS_EXTENSION == FEAT_STATE_ALWAYS) 99 feat_detect_panic(is_armv8_2_feat_ras_present(), "RAS"); 100 #endif 101 } 102 103 /************************************************ 104 * Feature : FEAT_PAUTH (Pointer Authentication) 105 ***********************************************/ 106 static void read_feat_pauth(void) 107 { 108 #if (ENABLE_PAUTH == FEAT_STATE_ALWAYS) || (CTX_INCLUDE_PAUTH_REGS == FEAT_STATE_ALWAYS) 109 feat_detect_panic(is_armv8_3_pauth_present(), "PAUTH"); 110 #endif 111 } 112 113 /************************************************************ 114 * Feature : FEAT_DIT (Data Independent Timing Instructions) 115 ***********************************************************/ 116 static void read_feat_dit(void) 117 { 118 #if (ENABLE_FEAT_DIT == FEAT_STATE_ALWAYS) 119 feat_detect_panic(is_armv8_4_feat_dit_present(), "DIT"); 120 #endif 121 } 122 123 /************************************************************** 124 * Feature : FEAT_NV2 (Enhanced Nested Virtualization Support) 125 *************************************************************/ 126 static void read_feat_nv2(void) 127 { 128 #if (CTX_INCLUDE_NEVE_REGS == FEAT_STATE_ALWAYS) 129 unsigned int nv = get_armv8_4_feat_nv_support(); 130 131 feat_detect_panic((nv == ID_AA64MMFR2_EL1_NV2_SUPPORTED), "NV2"); 132 #endif 133 } 134 135 /*********************************** 136 * Feature : FEAT_SEL2 (Secure EL2) 137 **********************************/ 138 static void read_feat_sel2(void) 139 { 140 #if (ENABLE_FEAT_SEL2 == FEAT_STATE_ALWAYS) 141 feat_detect_panic(is_armv8_4_sel2_present(), "SEL2"); 142 #endif 143 } 144 145 /************************************************ 146 * Feature : FEAT_MTE (Memory Tagging Extension) 147 ***********************************************/ 148 static void read_feat_mte(void) 149 { 150 #if (CTX_INCLUDE_MTE_REGS == FEAT_STATE_ALWAYS) 151 unsigned int mte = get_armv8_5_mte_support(); 152 153 feat_detect_panic((mte != MTE_UNIMPLEMENTED), "MTE"); 154 #endif 155 } 156 157 /*********************************************** 158 * Feature : FEAT_RNG (Random Number Generator) 159 **********************************************/ 160 static void read_feat_rng(void) 161 { 162 #if (ENABLE_FEAT_RNG == FEAT_STATE_ALWAYS) 163 feat_detect_panic(is_armv8_5_rng_present(), "RNG"); 164 #endif 165 } 166 167 /**************************************************** 168 * Feature : FEAT_BTI (Branch Target Identification) 169 ***************************************************/ 170 static void read_feat_bti(void) 171 { 172 #if (ENABLE_BTI == FEAT_STATE_ALWAYS) 173 feat_detect_panic(is_armv8_5_bti_present(), "BTI"); 174 #endif 175 } 176 177 /*********************************************** 178 * Feature : FEAT_AMUv1p1 (AMU Extensions v1.1) 179 **********************************************/ 180 static void read_feat_amuv1p1(void) 181 { 182 #if (ENABLE_FEAT_AMUv1p1 == FEAT_STATE_ALWAYS) 183 feat_detect_panic(is_armv8_6_feat_amuv1p1_present(), "AMUv1p1"); 184 #endif 185 } 186 187 /******************************************************* 188 * Feature : FEAT_ECV (Enhanced Counter Virtualization) 189 ******************************************************/ 190 static void read_feat_ecv(void) 191 { 192 #if (ENABLE_FEAT_ECV == FEAT_STATE_ALWAYS) 193 unsigned int ecv = get_armv8_6_ecv_support(); 194 195 feat_detect_panic(((ecv == ID_AA64MMFR0_EL1_ECV_SUPPORTED) || 196 (ecv == ID_AA64MMFR0_EL1_ECV_SELF_SYNCH)), "ECV"); 197 #endif 198 } 199 200 /*********************************************************** 201 * Feature : FEAT_TWED (Delayed Trapping of WFE Instruction) 202 **********************************************************/ 203 static void read_feat_twed(void) 204 { 205 #if (ENABLE_FEAT_TWED == FEAT_STATE_ALWAYS) 206 feat_detect_panic(is_armv8_6_twed_present(), "TWED"); 207 #endif 208 } 209 210 /************************************************** 211 * Feature : FEAT_RME (Realm Management Extension) 212 *************************************************/ 213 static void read_feat_rme(void) 214 { 215 #if (ENABLE_RME == FEAT_STATE_ALWAYS) 216 feat_detect_panic((get_armv9_2_feat_rme_support() != 217 ID_AA64PFR0_FEAT_RME_NOT_SUPPORTED), "RME"); 218 #endif 219 } 220 221 /****************************************************************** 222 * Feature : FEAT_RNG_TRAP (Trapping support for RNDR/RNDRRS) 223 *****************************************************************/ 224 static void read_feat_rng_trap(void) 225 { 226 #if (ENABLE_FEAT_RNG_TRAP == FEAT_STATE_ALWAYS) 227 feat_detect_panic(is_feat_rng_trap_present(), "RNG_TRAP"); 228 #endif 229 } 230 231 /*********************************************************************************** 232 * TF-A supports many Arm architectural features starting from arch version 233 * (8.0 till 8.7+). These features are mostly enabled through build flags. This 234 * mechanism helps in validating these build flags in the early boot phase 235 * either in BL1 or BL31 depending on the platform and assists in identifying 236 * and notifying the features which are enabled but not supported by the PE. 237 * 238 * It reads all the enabled features ID-registers and ensures the features 239 * are supported by the PE. 240 * In case if they aren't it stops booting at an early phase and logs the error 241 * messages, notifying the platforms about the features that are not supported. 242 * 243 * Further the procedure is implemented with a tri-state approach for each feature: 244 * ENABLE_FEAT_xxx = 0 : The feature is disabled statically at compile time 245 * ENABLE_FEAT_xxx = 1 : The feature is enabled and must be present in hardware. 246 * There will be panic if feature is not present at cold boot. 247 * ENABLE_FEAT_xxx = 2 : The feature is enabled but dynamically enabled at runtime 248 * depending on hardware capability. 249 * 250 * For better readability, state values are defined with macros, namely: 251 * { FEAT_STATE_DISABLED, FEAT_STATE_ALWAYS, FEAT_STATE_CHECK }, taking values 252 * { 0, 1, 2 }, respectively, as their naming. 253 **********************************************************************************/ 254 void detect_arch_features(void) 255 { 256 tainted = false; 257 258 /* v8.0 features */ 259 read_feat_sb(); 260 read_feat_csv2_2(); 261 262 /* v8.1 features */ 263 read_feat_pan(); 264 check_feature(ENABLE_FEAT_VHE, read_feat_vhe_id_field(), "VHE", 1, 1); 265 266 /* v8.2 features */ 267 read_feat_ras(); 268 269 /* v8.3 features */ 270 read_feat_pauth(); 271 272 /* v8.4 features */ 273 read_feat_dit(); 274 check_feature(ENABLE_FEAT_AMUv1, read_feat_amu_id_field(), 275 "AMUv1", 1, 2); 276 check_feature(ENABLE_MPAM_FOR_LOWER_ELS, read_feat_mpam_version(), 277 "MPAM", 1, 17); 278 read_feat_nv2(); 279 read_feat_sel2(); 280 check_feature(ENABLE_TRF_FOR_NS, read_feat_trf_id_field(), 281 "TRF", 1, 1); 282 283 /* v8.5 features */ 284 read_feat_mte(); 285 read_feat_rng(); 286 read_feat_bti(); 287 read_feat_rng_trap(); 288 289 /* v8.6 features */ 290 read_feat_amuv1p1(); 291 check_feature(ENABLE_FEAT_FGT, read_feat_fgt_id_field(), "FGT", 1, 1); 292 read_feat_ecv(); 293 read_feat_twed(); 294 295 /* v8.7 features */ 296 check_feature(ENABLE_FEAT_HCX, read_feat_hcx_id_field(), "HCX", 1, 1); 297 298 /* v8.9 features */ 299 check_feature(ENABLE_FEAT_TCR2, read_feat_tcrx_id_field(), 300 "TCR2", 1, 1); 301 302 /* v9.0 features */ 303 check_feature(ENABLE_BRBE_FOR_NS, read_feat_brbe_id_field(), 304 "BRBE", 1, 2); 305 check_feature(ENABLE_TRBE_FOR_NS, read_feat_trbe_id_field(), 306 "TRBE", 1, 1); 307 308 /* v9.2 features */ 309 read_feat_rme(); 310 311 if (tainted) { 312 panic(); 313 } 314 } 315