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  ******************************************************************************/
feature_panic(char * feat_name)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__))
check_feature(int state,unsigned long field,const char * feat_name,unsigned int min,unsigned int max)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  ***********************************************/
read_feat_pauth(void)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 
read_feat_rng_trap_id_field(void)73 static unsigned int read_feat_rng_trap_id_field(void)
74 {
75 	return ISOLATE_FIELD(read_id_aa64pfr1_el1(), ID_AA64PFR1_EL1_RNDR_TRAP_SHIFT,
76 			     ID_AA64PFR1_EL1_RNDR_TRAP_MASK);
77 }
78 
read_feat_bti_id_field(void)79 static unsigned int read_feat_bti_id_field(void)
80 {
81 	return ISOLATE_FIELD(read_id_aa64pfr1_el1(), ID_AA64PFR1_EL1_BT_SHIFT,
82 			     ID_AA64PFR1_EL1_BT_MASK);
83 }
84 
read_feat_sb_id_field(void)85 static unsigned int read_feat_sb_id_field(void)
86 {
87 	return ISOLATE_FIELD(read_id_aa64isar1_el1(), ID_AA64ISAR1_SB_SHIFT,
88 			     ID_AA64ISAR1_SB_MASK);
89 }
90 
read_feat_csv2_id_field(void)91 static unsigned int read_feat_csv2_id_field(void)
92 {
93 	return ISOLATE_FIELD(read_id_aa64pfr0_el1(), ID_AA64PFR0_CSV2_SHIFT,
94 			     ID_AA64PFR0_CSV2_MASK);
95 }
96 
read_feat_pmuv3_id_field(void)97 static unsigned int read_feat_pmuv3_id_field(void)
98 {
99 	return ISOLATE_FIELD(read_id_aa64dfr0_el1(), ID_AA64DFR0_PMUVER_SHIFT,
100 			     ID_AA64DFR0_PMUVER_MASK);
101 }
102 
read_feat_vhe_id_field(void)103 static unsigned int read_feat_vhe_id_field(void)
104 {
105 	return ISOLATE_FIELD(read_id_aa64mmfr1_el1(), ID_AA64MMFR1_EL1_VHE_SHIFT,
106 			     ID_AA64MMFR1_EL1_VHE_MASK);
107 }
108 
read_feat_sve_id_field(void)109 static unsigned int read_feat_sve_id_field(void)
110 {
111 	return ISOLATE_FIELD(read_id_aa64pfr0_el1(), ID_AA64PFR0_SVE_SHIFT,
112 			     ID_AA64PFR0_SVE_MASK);
113 }
114 
read_feat_ras_id_field(void)115 static unsigned int read_feat_ras_id_field(void)
116 {
117 	return ISOLATE_FIELD(read_id_aa64pfr0_el1(), ID_AA64PFR0_RAS_SHIFT,
118 			     ID_AA64PFR0_RAS_MASK);
119 }
120 
read_feat_dit_id_field(void)121 static unsigned int read_feat_dit_id_field(void)
122 {
123 	return ISOLATE_FIELD(read_id_aa64pfr0_el1(), ID_AA64PFR0_DIT_SHIFT,
124 			     ID_AA64PFR0_DIT_MASK);
125 }
126 
read_feat_amu_id_field(void)127 static unsigned int  read_feat_amu_id_field(void)
128 {
129 	return ISOLATE_FIELD(read_id_aa64pfr0_el1(), ID_AA64PFR0_AMU_SHIFT,
130 			     ID_AA64PFR0_AMU_MASK);
131 }
132 
read_feat_mpam_version(void)133 static unsigned int read_feat_mpam_version(void)
134 {
135 	return (unsigned int)((((read_id_aa64pfr0_el1() >>
136 		ID_AA64PFR0_MPAM_SHIFT) & ID_AA64PFR0_MPAM_MASK) << 4) |
137 			((read_id_aa64pfr1_el1() >>
138 		ID_AA64PFR1_MPAM_FRAC_SHIFT) & ID_AA64PFR1_MPAM_FRAC_MASK));
139 }
140 
read_feat_nv_id_field(void)141 static unsigned int read_feat_nv_id_field(void)
142 {
143 	return ISOLATE_FIELD(read_id_aa64mmfr2_el1(), ID_AA64MMFR2_EL1_NV_SHIFT,
144 			     ID_AA64MMFR2_EL1_NV_MASK);
145 }
146 
read_feat_sel2_id_field(void)147 static unsigned int read_feat_sel2_id_field(void)
148 {
149 	return ISOLATE_FIELD(read_id_aa64pfr0_el1(), ID_AA64PFR0_SEL2_SHIFT,
150 			     ID_AA64PFR0_SEL2_MASK);
151 }
152 
read_feat_trf_id_field(void)153 static unsigned int read_feat_trf_id_field(void)
154 {
155 	return ISOLATE_FIELD(read_id_aa64dfr0_el1(), ID_AA64DFR0_TRACEFILT_SHIFT,
156 			     ID_AA64DFR0_TRACEFILT_MASK);
157 }
get_armv8_5_mte_support(void)158 static unsigned int get_armv8_5_mte_support(void)
159 {
160 	return ISOLATE_FIELD(read_id_aa64pfr1_el1(), ID_AA64PFR1_EL1_MTE_SHIFT,
161 			     ID_AA64PFR1_EL1_MTE_MASK);
162 }
read_feat_rng_id_field(void)163 static unsigned int read_feat_rng_id_field(void)
164 {
165 	return ISOLATE_FIELD(read_id_aa64isar0_el1(), ID_AA64ISAR0_RNDR_SHIFT,
166 			     ID_AA64ISAR0_RNDR_MASK);
167 }
read_feat_fgt_id_field(void)168 static unsigned int read_feat_fgt_id_field(void)
169 {
170 	return ISOLATE_FIELD(read_id_aa64mmfr0_el1(), ID_AA64MMFR0_EL1_FGT_SHIFT,
171 			     ID_AA64MMFR0_EL1_FGT_MASK);
172 }
read_feat_ecv_id_field(void)173 static unsigned int read_feat_ecv_id_field(void)
174 {
175 	return ISOLATE_FIELD(read_id_aa64mmfr0_el1(), ID_AA64MMFR0_EL1_ECV_SHIFT,
176 			     ID_AA64MMFR0_EL1_ECV_MASK);
177 }
read_feat_twed_id_field(void)178 static unsigned int read_feat_twed_id_field(void)
179 {
180 	return ISOLATE_FIELD(read_id_aa64mmfr1_el1(), ID_AA64MMFR1_EL1_TWED_SHIFT,
181 			     ID_AA64MMFR1_EL1_TWED_MASK);
182 }
183 
read_feat_hcx_id_field(void)184 static unsigned int read_feat_hcx_id_field(void)
185 {
186 	return ISOLATE_FIELD(read_id_aa64mmfr1_el1(), ID_AA64MMFR1_EL1_HCX_SHIFT,
187 			     ID_AA64MMFR1_EL1_HCX_MASK);
188 }
read_feat_tcr2_id_field(void)189 static unsigned int read_feat_tcr2_id_field(void)
190 {
191 	return ISOLATE_FIELD(read_id_aa64mmfr3_el1(), ID_AA64MMFR3_EL1_TCRX_SHIFT,
192 			     ID_AA64MMFR3_EL1_TCRX_MASK);
193 }
read_feat_s2pie_id_field(void)194 static unsigned int read_feat_s2pie_id_field(void)
195 {
196 	return ISOLATE_FIELD(read_id_aa64mmfr3_el1(), ID_AA64MMFR3_EL1_S2PIE_SHIFT,
197 			     ID_AA64MMFR3_EL1_S2PIE_MASK);
198 }
read_feat_s1pie_id_field(void)199 static unsigned int read_feat_s1pie_id_field(void)
200 {
201 	return ISOLATE_FIELD(read_id_aa64mmfr3_el1(), ID_AA64MMFR3_EL1_S1PIE_SHIFT,
202 			     ID_AA64MMFR3_EL1_S1PIE_MASK);
203 }
read_feat_s2poe_id_field(void)204 static unsigned int read_feat_s2poe_id_field(void)
205 {
206 	return ISOLATE_FIELD(read_id_aa64mmfr3_el1(), ID_AA64MMFR3_EL1_S2POE_SHIFT,
207 			     ID_AA64MMFR3_EL1_S2POE_MASK);
208 }
read_feat_s1poe_id_field(void)209 static unsigned int read_feat_s1poe_id_field(void)
210 {
211 	return ISOLATE_FIELD(read_id_aa64mmfr3_el1(), ID_AA64MMFR3_EL1_S1POE_SHIFT,
212 			     ID_AA64MMFR3_EL1_S1POE_MASK);
213 }
read_feat_brbe_id_field(void)214 static unsigned int read_feat_brbe_id_field(void)
215 {
216 	return ISOLATE_FIELD(read_id_aa64dfr0_el1(), ID_AA64DFR0_BRBE_SHIFT,
217 			     ID_AA64DFR0_BRBE_MASK);
218 }
read_feat_trbe_id_field(void)219 static unsigned int read_feat_trbe_id_field(void)
220 {
221 	return ISOLATE_FIELD(read_id_aa64dfr0_el1(), ID_AA64DFR0_TRACEBUFFER_SHIFT,
222 			     ID_AA64DFR0_TRACEBUFFER_MASK);
223 }
read_feat_sme_id_field(void)224 static unsigned int read_feat_sme_id_field(void)
225 {
226 	return ISOLATE_FIELD(read_id_aa64pfr1_el1(), ID_AA64PFR1_EL1_SME_SHIFT,
227 			     ID_AA64PFR1_EL1_SME_MASK);
228 }
read_feat_gcs_id_field(void)229 static unsigned int read_feat_gcs_id_field(void)
230 {
231 	return ISOLATE_FIELD(read_id_aa64pfr1_el1(), ID_AA64PFR1_EL1_GCS_SHIFT,
232 			     ID_AA64PFR1_EL1_GCS_MASK);
233 }
234 
read_feat_rme_id_field(void)235 static unsigned int read_feat_rme_id_field(void)
236 {
237 	return ISOLATE_FIELD(read_id_aa64pfr0_el1(), ID_AA64PFR0_FEAT_RME_SHIFT,
238 			     ID_AA64PFR0_FEAT_RME_MASK);
239 }
240 
read_feat_pan_id_field(void)241 static unsigned int read_feat_pan_id_field(void)
242 {
243 	return ISOLATE_FIELD(read_id_aa64mmfr1_el1(), ID_AA64MMFR1_EL1_PAN_SHIFT,
244 			     ID_AA64MMFR1_EL1_PAN_MASK);
245 }
246 
read_feat_mtpmu_id_field(void)247 static unsigned int read_feat_mtpmu_id_field(void)
248 {
249 	return ISOLATE_FIELD(read_id_aa64dfr0_el1(), ID_AA64DFR0_MTPMU_SHIFT,
250 			     ID_AA64DFR0_MTPMU_MASK);
251 
252 }
253 
254 /***********************************************************************************
255  * TF-A supports many Arm architectural features starting from arch version
256  * (8.0 till 8.7+). These features are mostly enabled through build flags. This
257  * mechanism helps in validating these build flags in the early boot phase
258  * either in BL1 or BL31 depending on the platform and assists in identifying
259  * and notifying the features which are enabled but not supported by the PE.
260  *
261  * It reads all the enabled features ID-registers and ensures the features
262  * are supported by the PE.
263  * In case if they aren't it stops booting at an early phase and logs the error
264  * messages, notifying the platforms about the features that are not supported.
265  *
266  * Further the procedure is implemented with a tri-state approach for each feature:
267  * ENABLE_FEAT_xxx = 0 : The feature is disabled statically at compile time
268  * ENABLE_FEAT_xxx = 1 : The feature is enabled and must be present in hardware.
269  *                       There will be panic if feature is not present at cold boot.
270  * ENABLE_FEAT_xxx = 2 : The feature is enabled but dynamically enabled at runtime
271  *                       depending on hardware capability.
272  *
273  * For better readability, state values are defined with macros, namely:
274  * { FEAT_STATE_DISABLED, FEAT_STATE_ALWAYS, FEAT_STATE_CHECK }, taking values
275  * { 0, 1, 2 }, respectively, as their naming.
276  **********************************************************************************/
detect_arch_features(void)277 void detect_arch_features(void)
278 {
279 	tainted = false;
280 
281 	/* v8.0 features */
282 	check_feature(ENABLE_FEAT_SB, read_feat_sb_id_field(), "SB", 1, 1);
283 	check_feature(ENABLE_FEAT_CSV2_2, read_feat_csv2_id_field(),
284 		      "CSV2_2", 2, 3);
285 	/*
286 	 * Even though the PMUv3 is an OPTIONAL feature, it is always
287 	 * implemented and Arm prescribes so. So assume it will be there and do
288 	 * away with a flag for it. This is used to check minor PMUv3px
289 	 * revisions so that we catch them as they come along
290 	 */
291 	check_feature(FEAT_STATE_ALWAYS, read_feat_pmuv3_id_field(),
292 		      "PMUv3", 1, ID_AA64DFR0_PMUVER_PMUV3P7);
293 
294 	/* v8.1 features */
295 	check_feature(ENABLE_FEAT_PAN, read_feat_pan_id_field(), "PAN", 1, 3);
296 	check_feature(ENABLE_FEAT_VHE, read_feat_vhe_id_field(), "VHE", 1, 1);
297 
298 	/* v8.2 features */
299 	check_feature(ENABLE_SVE_FOR_NS, read_feat_sve_id_field(),
300 		      "SVE", 1, 1);
301 	check_feature(ENABLE_FEAT_RAS, read_feat_ras_id_field(), "RAS", 1, 2);
302 
303 	/* v8.3 features */
304 	/* TODO: Pauth yet to convert to tri-state feat detect logic */
305 	read_feat_pauth();
306 
307 	/* v8.4 features */
308 	check_feature(ENABLE_FEAT_DIT, read_feat_dit_id_field(), "DIT", 1, 1);
309 	check_feature(ENABLE_FEAT_AMU, read_feat_amu_id_field(),
310 		      "AMUv1", 1, 2);
311 	check_feature(ENABLE_FEAT_MPAM, read_feat_mpam_version(),
312 		      "MPAM", 1, 17);
313 	check_feature(CTX_INCLUDE_NEVE_REGS, read_feat_nv_id_field(),
314 		      "NV2", 2, 2);
315 	check_feature(ENABLE_FEAT_SEL2, read_feat_sel2_id_field(),
316 		      "SEL2", 1, 1);
317 	check_feature(ENABLE_TRF_FOR_NS, read_feat_trf_id_field(),
318 		      "TRF", 1, 1);
319 
320 	/* v8.5 features */
321 	check_feature(ENABLE_FEAT_MTE2, get_armv8_5_mte_support(), "MTE2",
322 		      MTE_IMPLEMENTED_ELX, MTE_IMPLEMENTED_ASY);
323 	check_feature(ENABLE_FEAT_RNG, read_feat_rng_id_field(), "RNG", 1, 1);
324 	check_feature(ENABLE_BTI, read_feat_bti_id_field(), "BTI", 1, 1);
325 	check_feature(ENABLE_FEAT_RNG_TRAP, read_feat_rng_trap_id_field(),
326 		      "RNG_TRAP", 1, 1);
327 
328 	/* v8.6 features */
329 	check_feature(ENABLE_FEAT_AMUv1p1, read_feat_amu_id_field(),
330 		      "AMUv1p1", 2, 2);
331 	check_feature(ENABLE_FEAT_FGT, read_feat_fgt_id_field(), "FGT", 1, 1);
332 	check_feature(ENABLE_FEAT_ECV, read_feat_ecv_id_field(), "ECV", 1, 2);
333 	check_feature(ENABLE_FEAT_TWED, read_feat_twed_id_field(),
334 		      "TWED", 1, 1);
335 
336 	/*
337 	 * even though this is a "DISABLE" it does confusingly perform feature
338 	 * enablement duties like all other flags here. Check it against the HW
339 	 * feature when we intend to diverge from the default behaviour
340 	 */
341 	check_feature(DISABLE_MTPMU, read_feat_mtpmu_id_field(), "MTPMU", 1, 1);
342 
343 	/* v8.7 features */
344 	check_feature(ENABLE_FEAT_HCX, read_feat_hcx_id_field(), "HCX", 1, 1);
345 
346 	/* v8.9 features */
347 	check_feature(ENABLE_FEAT_TCR2, read_feat_tcr2_id_field(),
348 		      "TCR2", 1, 1);
349 	check_feature(ENABLE_FEAT_S2PIE, read_feat_s2pie_id_field(),
350 		      "S2PIE", 1, 1);
351 	check_feature(ENABLE_FEAT_S1PIE, read_feat_s1pie_id_field(),
352 		      "S1PIE", 1, 1);
353 	check_feature(ENABLE_FEAT_S2POE, read_feat_s2poe_id_field(),
354 		      "S2POE", 1, 1);
355 	check_feature(ENABLE_FEAT_S1POE, read_feat_s1poe_id_field(),
356 		      "S1POE", 1, 1);
357 	check_feature(ENABLE_FEAT_CSV2_3, read_feat_csv2_id_field(),
358 		      "CSV2_3", 3, 3);
359 
360 	/* v9.0 features */
361 	check_feature(ENABLE_BRBE_FOR_NS, read_feat_brbe_id_field(),
362 		      "BRBE", 1, 2);
363 	check_feature(ENABLE_TRBE_FOR_NS, read_feat_trbe_id_field(),
364 		      "TRBE", 1, 1);
365 
366 	/* v9.2 features */
367 	check_feature(ENABLE_SME_FOR_NS, read_feat_sme_id_field(),
368 		      "SME", 1, 2);
369 	check_feature(ENABLE_SME2_FOR_NS, read_feat_sme_id_field(),
370 		      "SME2", 2, 2);
371 
372 	/* v9.4 features */
373 	check_feature(ENABLE_FEAT_GCS, read_feat_gcs_id_field(), "GCS", 1, 1);
374 	check_feature(ENABLE_RME, read_feat_rme_id_field(), "RME", 1, 1);
375 
376 	if (tainted) {
377 		panic();
378 	}
379 }
380