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_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_NV2 (Enhanced Nested Virtualization Support) 95 *************************************************************/ 96 static void read_feat_nv2(void) 97 { 98 #if (CTX_INCLUDE_NEVE_REGS == FEAT_STATE_ALWAYS) 99 unsigned int nv = get_armv8_4_feat_nv_support(); 100 101 feat_detect_panic((nv == ID_AA64MMFR2_EL1_NV2_SUPPORTED), "NV2"); 102 #endif 103 } 104 105 /*********************************** 106 * Feature : FEAT_SEL2 (Secure EL2) 107 **********************************/ 108 static void read_feat_sel2(void) 109 { 110 #if (ENABLE_FEAT_SEL2 == FEAT_STATE_ALWAYS) 111 feat_detect_panic(is_armv8_4_sel2_present(), "SEL2"); 112 #endif 113 } 114 115 /************************************************ 116 * Feature : FEAT_MTE (Memory Tagging Extension) 117 ***********************************************/ 118 static void read_feat_mte(void) 119 { 120 #if (CTX_INCLUDE_MTE_REGS == FEAT_STATE_ALWAYS) 121 unsigned int mte = get_armv8_5_mte_support(); 122 123 feat_detect_panic((mte != MTE_UNIMPLEMENTED), "MTE"); 124 #endif 125 } 126 127 /*********************************************** 128 * Feature : FEAT_RNG (Random Number Generator) 129 **********************************************/ 130 static void read_feat_rng(void) 131 { 132 #if (ENABLE_FEAT_RNG == FEAT_STATE_ALWAYS) 133 feat_detect_panic(is_armv8_5_rng_present(), "RNG"); 134 #endif 135 } 136 137 /**************************************************** 138 * Feature : FEAT_BTI (Branch Target Identification) 139 ***************************************************/ 140 static void read_feat_bti(void) 141 { 142 #if (ENABLE_BTI == FEAT_STATE_ALWAYS) 143 feat_detect_panic(is_armv8_5_bti_present(), "BTI"); 144 #endif 145 } 146 147 /*********************************************** 148 * Feature : FEAT_AMUv1p1 (AMU Extensions v1.1) 149 **********************************************/ 150 static void read_feat_amuv1p1(void) 151 { 152 #if (ENABLE_FEAT_AMUv1p1 == FEAT_STATE_ALWAYS) 153 feat_detect_panic(is_armv8_6_feat_amuv1p1_present(), "AMUv1p1"); 154 #endif 155 } 156 157 /************************************************** 158 * Feature : FEAT_RME (Realm Management Extension) 159 *************************************************/ 160 static void read_feat_rme(void) 161 { 162 #if (ENABLE_RME == FEAT_STATE_ALWAYS) 163 feat_detect_panic((get_armv9_2_feat_rme_support() != 164 ID_AA64PFR0_FEAT_RME_NOT_SUPPORTED), "RME"); 165 #endif 166 } 167 168 /****************************************************************** 169 * Feature : FEAT_RNG_TRAP (Trapping support for RNDR/RNDRRS) 170 *****************************************************************/ 171 static void read_feat_rng_trap(void) 172 { 173 #if (ENABLE_FEAT_RNG_TRAP == FEAT_STATE_ALWAYS) 174 feat_detect_panic(is_feat_rng_trap_present(), "RNG_TRAP"); 175 #endif 176 } 177 178 /*********************************************************************************** 179 * TF-A supports many Arm architectural features starting from arch version 180 * (8.0 till 8.7+). These features are mostly enabled through build flags. This 181 * mechanism helps in validating these build flags in the early boot phase 182 * either in BL1 or BL31 depending on the platform and assists in identifying 183 * and notifying the features which are enabled but not supported by the PE. 184 * 185 * It reads all the enabled features ID-registers and ensures the features 186 * are supported by the PE. 187 * In case if they aren't it stops booting at an early phase and logs the error 188 * messages, notifying the platforms about the features that are not supported. 189 * 190 * Further the procedure is implemented with a tri-state approach for each feature: 191 * ENABLE_FEAT_xxx = 0 : The feature is disabled statically at compile time 192 * ENABLE_FEAT_xxx = 1 : The feature is enabled and must be present in hardware. 193 * There will be panic if feature is not present at cold boot. 194 * ENABLE_FEAT_xxx = 2 : The feature is enabled but dynamically enabled at runtime 195 * depending on hardware capability. 196 * 197 * For better readability, state values are defined with macros, namely: 198 * { FEAT_STATE_DISABLED, FEAT_STATE_ALWAYS, FEAT_STATE_CHECK }, taking values 199 * { 0, 1, 2 }, respectively, as their naming. 200 **********************************************************************************/ 201 void detect_arch_features(void) 202 { 203 tainted = false; 204 205 /* v8.0 features */ 206 check_feature(ENABLE_FEAT_SB, read_feat_sb_id_field(), "SB", 1, 1); 207 check_feature(ENABLE_FEAT_CSV2_2, read_feat_csv2_id_field(), 208 "CSV2_2", 2, 3); 209 210 /* v8.1 features */ 211 check_feature(ENABLE_FEAT_PAN, read_feat_pan_id_field(), "PAN", 1, 3); 212 check_feature(ENABLE_FEAT_VHE, read_feat_vhe_id_field(), "VHE", 1, 1); 213 214 /* v8.2 features */ 215 read_feat_ras(); 216 217 /* v8.3 features */ 218 read_feat_pauth(); 219 220 /* v8.4 features */ 221 read_feat_dit(); 222 check_feature(ENABLE_FEAT_AMUv1, read_feat_amu_id_field(), 223 "AMUv1", 1, 2); 224 check_feature(ENABLE_MPAM_FOR_LOWER_ELS, read_feat_mpam_version(), 225 "MPAM", 1, 17); 226 read_feat_nv2(); 227 read_feat_sel2(); 228 check_feature(ENABLE_TRF_FOR_NS, read_feat_trf_id_field(), 229 "TRF", 1, 1); 230 231 /* v8.5 features */ 232 read_feat_mte(); 233 read_feat_rng(); 234 read_feat_bti(); 235 read_feat_rng_trap(); 236 237 /* v8.6 features */ 238 read_feat_amuv1p1(); 239 check_feature(ENABLE_FEAT_FGT, read_feat_fgt_id_field(), "FGT", 1, 1); 240 check_feature(ENABLE_FEAT_ECV, read_feat_ecv_id_field(), "ECV", 1, 2); 241 check_feature(ENABLE_FEAT_TWED, read_feat_twed_id_field(), 242 "TWED", 1, 1); 243 244 /* v8.7 features */ 245 check_feature(ENABLE_FEAT_HCX, read_feat_hcx_id_field(), "HCX", 1, 1); 246 247 /* v8.9 features */ 248 check_feature(ENABLE_FEAT_TCR2, read_feat_tcrx_id_field(), 249 "TCR2", 1, 1); 250 251 /* v9.0 features */ 252 check_feature(ENABLE_BRBE_FOR_NS, read_feat_brbe_id_field(), 253 "BRBE", 1, 2); 254 check_feature(ENABLE_TRBE_FOR_NS, read_feat_trbe_id_field(), 255 "TRBE", 1, 1); 256 257 /* v9.2 features */ 258 read_feat_rme(); 259 260 if (tainted) { 261 panic(); 262 } 263 } 264