xref: /rk3399_ARM-atf/lib/el3_runtime/aarch64/context_mgmt.c (revision 989362581c6bd1b894ad943204ec97cbe81d12ee)
1 /*
2  * Copyright (c) 2013-2025, Arm Limited and Contributors. All rights reserved.
3  * Copyright (c) 2022, NVIDIA Corporation. All rights reserved.
4  *
5  * SPDX-License-Identifier: BSD-3-Clause
6  */
7 
8 #include <assert.h>
9 #include <stdbool.h>
10 #include <string.h>
11 
12 #include <platform_def.h>
13 
14 #include <arch.h>
15 #include <arch_helpers.h>
16 #include <arch_features.h>
17 #include <bl31/interrupt_mgmt.h>
18 #include <common/bl_common.h>
19 #include <common/debug.h>
20 #include <context.h>
21 #include <drivers/arm/gicv3.h>
22 #include <lib/cpus/cpu_ops.h>
23 #include <lib/cpus/errata.h>
24 #include <lib/el3_runtime/context_mgmt.h>
25 #include <lib/el3_runtime/cpu_data.h>
26 #include <lib/el3_runtime/pubsub_events.h>
27 #include <lib/extensions/amu.h>
28 #include <lib/extensions/brbe.h>
29 #include <lib/extensions/cpa2.h>
30 #include <lib/extensions/debug_v8p9.h>
31 #include <lib/extensions/fgt2.h>
32 #include <lib/extensions/idte3.h>
33 #include <lib/extensions/mpam.h>
34 #include <lib/extensions/pauth.h>
35 #include <lib/extensions/pmuv3.h>
36 #include <lib/extensions/sme.h>
37 #include <lib/extensions/spe.h>
38 #include <lib/extensions/sve.h>
39 #include <lib/extensions/sysreg128.h>
40 #include <lib/extensions/sys_reg_trace.h>
41 #include <lib/extensions/tcr2.h>
42 #include <lib/extensions/trbe.h>
43 #include <lib/extensions/trf.h>
44 #include <lib/utils.h>
45 
46 #if ENABLE_FEAT_TWED
47 /* Make sure delay value fits within the range(0-15) */
48 CASSERT(((TWED_DELAY & ~SCR_TWEDEL_MASK) == 0U), assert_twed_delay_value_check);
49 #endif /* ENABLE_FEAT_TWED */
50 
51 per_world_context_t per_world_context[CPU_CONTEXT_NUM];
52 PER_CPU_DEFINE(world_amu_regs_t, world_amu_ctx[CPU_CONTEXT_NUM]);
53 
54 static void manage_extensions_nonsecure(cpu_context_t *ctx);
55 static void manage_extensions_secure(cpu_context_t *ctx);
56 
57 #if ((IMAGE_BL1) || (IMAGE_BL31 && (!CTX_INCLUDE_EL2_REGS)))
58 static void setup_el1_context(cpu_context_t *ctx, const struct entry_point_info *ep)
59 {
60 	u_register_t sctlr_elx, actlr_elx;
61 
62 	/*
63 	 * Initialise SCTLR_EL1 to the reset value corresponding to the target
64 	 * execution state setting all fields rather than relying on the hw.
65 	 * Some fields have architecturally UNKNOWN reset values and these are
66 	 * set to zero.
67 	 *
68 	 * SCTLR.EE: Endianness is taken from the entrypoint attributes.
69 	 *
70 	 * SCTLR.M, SCTLR.C and SCTLR.I: These fields must be zero (as
71 	 * required by PSCI specification)
72 	 */
73 	sctlr_elx = (EP_GET_EE(ep->h.attr) != 0U) ? SCTLR_EE_BIT : 0UL;
74 	if (GET_RW(ep->spsr) == MODE_RW_64) {
75 		sctlr_elx |= SCTLR_EL1_RES1;
76 	} else {
77 		/*
78 		 * If the target execution state is AArch32 then the following
79 		 * fields need to be set.
80 		 *
81 		 * SCTRL_EL1.nTWE: Set to one so that EL0 execution of WFE
82 		 *  instructions are not trapped to EL1.
83 		 *
84 		 * SCTLR_EL1.nTWI: Set to one so that EL0 execution of WFI
85 		 *  instructions are not trapped to EL1.
86 		 *
87 		 * SCTLR_EL1.CP15BEN: Set to one to enable EL0 execution of the
88 		 *  CP15DMB, CP15DSB, and CP15ISB instructions.
89 		 */
90 		sctlr_elx |= SCTLR_AARCH32_EL1_RES1 | SCTLR_CP15BEN_BIT
91 					| SCTLR_NTWI_BIT | SCTLR_NTWE_BIT;
92 	}
93 
94 	/*
95 	 * If workaround of errata 764081 for Cortex-A75 is used then set
96 	 * SCTLR_EL1.IESB to enable Implicit Error Synchronization Barrier.
97 	 */
98 	if (errata_a75_764081_applies()) {
99 		sctlr_elx |= SCTLR_IESB_BIT;
100 	}
101 
102 	/* Store the initialised SCTLR_EL1 value in the cpu_context */
103 	write_ctx_sctlr_el1_reg_errata(ctx, sctlr_elx);
104 
105 	/*
106 	 * Base the context ACTLR_EL1 on the current value, as it is
107 	 * implementation defined. The context restore process will write
108 	 * the value from the context to the actual register and can cause
109 	 * problems for processor cores that don't expect certain bits to
110 	 * be zero.
111 	 */
112 	actlr_elx = read_actlr_el1();
113 	write_el1_ctx_common(get_el1_sysregs_ctx(ctx), actlr_el1, actlr_elx);
114 }
115 #endif /* (IMAGE_BL1) || (IMAGE_BL31 && (!CTX_INCLUDE_EL2_REGS)) */
116 
117 /******************************************************************************
118  * This function performs initializations that are specific to SECURE state
119  * and updates the cpu context specified by 'ctx'.
120  *****************************************************************************/
121 static void setup_secure_context(cpu_context_t *ctx, const struct entry_point_info *ep)
122 {
123 	u_register_t scr_el3;
124 	el3_state_t *state;
125 
126 	state = get_el3state_ctx(ctx);
127 	scr_el3 = read_ctx_reg(state, CTX_SCR_EL3);
128 
129 #if defined(IMAGE_BL31) && !defined(SPD_spmd)
130 	/*
131 	 * SCR_EL3.IRQ, SCR_EL3.FIQ: Enable the physical FIQ and IRQ routing as
132 	 * indicated by the interrupt routing model for BL31.
133 	 */
134 	scr_el3 |= get_scr_el3_from_routing_model(SECURE);
135 #endif
136 
137 	/* Allow access to Allocation Tags when FEAT_MTE2 is implemented and enabled. */
138 	if (is_feat_mte2_supported()) {
139 		scr_el3 |= SCR_ATA_BIT;
140 	}
141 
142 	write_ctx_reg(state, CTX_SCR_EL3, scr_el3);
143 
144 	/*
145 	 * Initialize EL1 context registers unless SPMC is running
146 	 * at S-EL2.
147 	 */
148 #if !CTX_INCLUDE_EL2_REGS || IMAGE_BL1
149 	setup_el1_context(ctx, ep);
150 #endif
151 
152 	manage_extensions_secure(ctx);
153 }
154 
155 #if ENABLE_RME && IMAGE_BL31
156 /******************************************************************************
157  * This function performs initializations that are specific to REALM state
158  * and updates the cpu context specified by 'ctx'.
159  *
160  * NOTE: any changes to this function must be verified by an RMMD maintainer.
161  *****************************************************************************/
162 static void setup_realm_context(cpu_context_t *ctx, const struct entry_point_info *ep)
163 {
164 	u_register_t scr_el3;
165 	el3_state_t *state;
166 	el2_sysregs_t *el2_ctx;
167 
168 	state = get_el3state_ctx(ctx);
169 	scr_el3 = read_ctx_reg(state, CTX_SCR_EL3);
170 	el2_ctx = get_el2_sysregs_ctx(ctx);
171 
172 	scr_el3 |= SCR_NS_BIT | SCR_NSE_BIT;
173 
174 	write_el2_ctx_common(el2_ctx, spsr_el2, SPSR_EL2_REALM);
175 
176 	/* CSV2 version 2 and above */
177 	if (is_feat_csv2_2_supported()) {
178 		/* Enable access to the SCXTNUM_ELx registers. */
179 		scr_el3 |= SCR_EnSCXT_BIT;
180 	}
181 
182 	if (is_feat_sctlr2_supported()) {
183 		/* Set the SCTLR2En bit in SCR_EL3 to enable access to
184 		 * SCTLR2_ELx registers.
185 		 */
186 		scr_el3 |= SCR_SCTLR2En_BIT;
187 	}
188 
189 	if (is_feat_d128_supported()) {
190 		/*
191 		 * Set the D128En bit in SCR_EL3 to enable access to 128-bit
192 		 * versions of TTBR0_EL1, TTBR1_EL1, RCWMASK_EL1, RCWSMASK_EL1,
193 		 * PAR_EL1 and TTBR1_EL2, TTBR0_EL2 and VTTBR_EL2 registers.
194 		 */
195 		scr_el3 |= SCR_D128En_BIT;
196 	}
197 
198 	write_ctx_reg(state, CTX_SCR_EL3, scr_el3);
199 
200 	if (is_feat_fgt2_supported()) {
201 		fgt2_enable(ctx);
202 	}
203 
204 	if (is_feat_debugv8p9_supported()) {
205 		debugv8p9_extended_bp_wp_enable(ctx);
206 	}
207 
208 	if (is_feat_brbe_supported()) {
209 		brbe_enable(ctx);
210 	}
211 
212 	/*
213 	 * Enable access to TPIDR2_EL0 if SME/SME2 is enabled for Non Secure world.
214 	 */
215 	if (is_feat_sme_supported()) {
216 		sme_enable(ctx);
217 	}
218 
219 	if (is_feat_spe_supported()) {
220 		spe_disable_realm(ctx);
221 	}
222 
223 	if (is_feat_trbe_supported()) {
224 		trbe_disable_realm(ctx);
225 	}
226 }
227 #endif /* ENABLE_RME && IMAGE_BL31 */
228 
229 /******************************************************************************
230  * This function performs initializations that are specific to NON-SECURE state
231  * and updates the cpu context specified by 'ctx'.
232  *****************************************************************************/
233 static void setup_ns_context(cpu_context_t *ctx, const struct entry_point_info *ep)
234 {
235 	u_register_t scr_el3;
236 	el3_state_t *state;
237 
238 	state = get_el3state_ctx(ctx);
239 	scr_el3 = read_ctx_reg(state, CTX_SCR_EL3);
240 
241 	/* SCR_NS: Set the NS bit */
242 	scr_el3 |= SCR_NS_BIT;
243 
244 	/* Allow access to Allocation Tags when FEAT_MTE2 is implemented and enabled. */
245 	if (is_feat_mte2_supported()) {
246 		scr_el3 |= SCR_ATA_BIT;
247 	}
248 
249 	/*
250 	 * Pointer Authentication feature, if present, is always enabled by
251 	 * default for Non secure lower exception levels. We do not have an
252 	 * explicit flag to set it. To prevent the leakage between the worlds
253 	 * during world switch, we enable it only for the non-secure world.
254 	 *
255 	 * CTX_INCLUDE_PAUTH_REGS flag, is explicitly used to enable for lower
256 	 * exception levels of secure and realm worlds.
257 	 *
258 	 * If the Secure/realm world wants to use pointer authentication,
259 	 * CTX_INCLUDE_PAUTH_REGS must be explicitly set to 1, in which case
260 	 * it will be enabled globally for all the contexts.
261 	 *
262 	 * SCR_EL3.API: Set to one to not trap any PAuth instructions at ELs
263 	 *  other than EL3
264 	 *
265 	 * SCR_EL3.APK: Set to one to not trap any PAuth key values at ELs other
266 	 *  than EL3
267 	 */
268 	if (!is_ctx_pauth_supported()) {
269 		scr_el3 |= SCR_API_BIT | SCR_APK_BIT;
270 	}
271 
272 #if HANDLE_EA_EL3_FIRST_NS
273 	/* SCR_EL3.EA: Route External Abort and SError Interrupt to EL3. */
274 	scr_el3 |= SCR_EA_BIT;
275 #endif
276 
277 #if RAS_TRAP_NS_ERR_REC_ACCESS
278 	/*
279 	 * SCR_EL3.TERR: Trap Error record accesses. Accesses to the RAS ERR
280 	 * and RAS ERX registers from EL1 and EL2(from any security state)
281 	 * are trapped to EL3.
282 	 * Set here to trap only for NS EL1/EL2
283 	 */
284 	scr_el3 |= SCR_TERR_BIT;
285 #endif
286 
287 	/* CSV2 version 2 and above */
288 	if (is_feat_csv2_2_supported()) {
289 		/* Enable access to the SCXTNUM_ELx registers. */
290 		scr_el3 |= SCR_EnSCXT_BIT;
291 	}
292 
293 #ifdef IMAGE_BL31
294 	/*
295 	 * SCR_EL3.IRQ, SCR_EL3.FIQ: Enable the physical FIQ and IRQ routing as
296 	 *  indicated by the interrupt routing model for BL31.
297 	 */
298 	scr_el3 |= get_scr_el3_from_routing_model(NON_SECURE);
299 #endif
300 
301 	if (is_feat_the_supported()) {
302 		/* Set the RCWMASKEn bit in SCR_EL3 to enable access to
303 		 * RCWMASK_EL1 and RCWSMASK_EL1 registers.
304 		 */
305 		scr_el3 |= SCR_RCWMASKEn_BIT;
306 	}
307 
308 	if (is_feat_sctlr2_supported()) {
309 		/* Set the SCTLR2En bit in SCR_EL3 to enable access to
310 		 * SCTLR2_ELx registers.
311 		 */
312 		scr_el3 |= SCR_SCTLR2En_BIT;
313 	}
314 
315 	if (is_feat_d128_supported()) {
316 		/* Set the D128En bit in SCR_EL3 to enable access to 128-bit
317 		 * versions of TTBR0_EL1, TTBR1_EL1, RCWMASK_EL1, RCWSMASK_EL1,
318 		 * PAR_EL1 and TTBR1_EL2, TTBR0_EL2 and VTTBR_EL2 registers.
319 		 */
320 		scr_el3 |= SCR_D128En_BIT;
321 	}
322 
323 	if (is_feat_fpmr_supported()) {
324 		/* Set the EnFPM bit in SCR_EL3 to enable access to FPMR
325 		 * register.
326 		 */
327 		scr_el3 |= SCR_EnFPM_BIT;
328 	}
329 
330 	if (is_feat_aie_supported()) {
331 		/* Set the AIEn bit in SCR_EL3 to enable access to (A)MAIR2
332 		 * system registers from NS world.
333 		 */
334 		scr_el3 |= SCR_AIEn_BIT;
335 	}
336 
337 	if (is_feat_pfar_supported()) {
338 		/* Set the PFAREn bit in SCR_EL3 to enable access to the PFAR
339 		 * system registers from NS world.
340 		 */
341 		scr_el3 |= SCR_PFAREn_BIT;
342 	}
343 
344 	write_ctx_reg(state, CTX_SCR_EL3, scr_el3);
345 
346 	/* Initialize EL2 context registers */
347 #if (CTX_INCLUDE_EL2_REGS && IMAGE_BL31)
348 	if (is_feat_hcx_supported()) {
349 		/*
350 		 * Initialize register HCRX_EL2 with its init value.
351 		 * As the value of HCRX_EL2 is UNKNOWN on reset, there is a
352 		 * chance that this can lead to unexpected behavior in lower
353 		 * ELs that have not been updated since the introduction of
354 		 * this feature if not properly initialized, especially when
355 		 * it comes to those bits that enable/disable traps.
356 		 */
357 		write_el2_ctx_hcx(get_el2_sysregs_ctx(ctx), hcrx_el2,
358 			HCRX_EL2_INIT_VAL);
359 	}
360 
361 	if (is_feat_fgt_supported()) {
362 		/*
363 		 * Initialize HFG*_EL2 registers with a default value so legacy
364 		 * systems unaware of FEAT_FGT do not get trapped due to their lack
365 		 * of initialization for this feature.
366 		 */
367 		write_el2_ctx_fgt(get_el2_sysregs_ctx(ctx), hfgitr_el2,
368 			HFGITR_EL2_INIT_VAL);
369 		write_el2_ctx_fgt(get_el2_sysregs_ctx(ctx), hfgrtr_el2,
370 			HFGRTR_EL2_INIT_VAL);
371 		write_el2_ctx_fgt(get_el2_sysregs_ctx(ctx), hfgwtr_el2,
372 			HFGWTR_EL2_INIT_VAL);
373 	}
374 #else
375 	/* Initialize EL1 context registers */
376 	setup_el1_context(ctx, ep);
377 #endif /* (CTX_INCLUDE_EL2_REGS && IMAGE_BL31) */
378 
379 	manage_extensions_nonsecure(ctx);
380 }
381 
382 /*******************************************************************************
383  * The following function performs initialization of the cpu_context 'ctx'
384  * for first use that is common to all security states, and sets the
385  * initial entrypoint state as specified by the entry_point_info structure.
386  *
387  * The EE and ST attributes are used to configure the endianness and secure
388  * timer availability for the new execution context.
389  ******************************************************************************/
390 static void setup_context_common(cpu_context_t *ctx, const entry_point_info_t *ep)
391 {
392 	u_register_t scr_el3;
393 	u_register_t mdcr_el3;
394 	el3_state_t *state;
395 	gp_regs_t *gp_regs;
396 
397 	state = get_el3state_ctx(ctx);
398 
399 	/* Clear any residual register values from the context */
400 	zeromem(ctx, sizeof(*ctx));
401 
402 	/*
403 	 * The lower-EL context is zeroed so that no stale values leak to a world.
404 	 * It is assumed that an all-zero lower-EL context is good enough for it
405 	 * to boot correctly. However, there are very few registers where this
406 	 * is not true and some values need to be recreated.
407 	 */
408 #if (CTX_INCLUDE_EL2_REGS && IMAGE_BL31)
409 	el2_sysregs_t *el2_ctx = get_el2_sysregs_ctx(ctx);
410 
411 	/*
412 	 * These bits are set in the gicv3 driver. Losing them (especially the
413 	 * SRE bit) is problematic for all worlds. Henceforth recreate them.
414 	 */
415 	u_register_t icc_sre_el2_val = ICC_SRE_DIB_BIT | ICC_SRE_DFB_BIT |
416 				   ICC_SRE_EN_BIT | ICC_SRE_SRE_BIT;
417 	write_el2_ctx_common(el2_ctx, icc_sre_el2, icc_sre_el2_val);
418 
419 	/*
420 	 * The actlr_el2 register can be initialized in platform's reset handler
421 	 * and it may contain access control bits (e.g. CLUSTERPMUEN bit).
422 	 */
423 	write_el2_ctx_common(el2_ctx, actlr_el2, read_actlr_el2());
424 #endif /* (CTX_INCLUDE_EL2_REGS && IMAGE_BL31) */
425 
426 	/* Start with a clean SCR_EL3 copy as all relevant values are set */
427 	scr_el3 = SCR_RESET_VAL;
428 
429 	/*
430 	 * SCR_EL3.TWE: Set to zero so that execution of WFE instructions at
431 	 *  EL2, EL1 and EL0 are not trapped to EL3.
432 	 *
433 	 * SCR_EL3.TWI: Set to zero so that execution of WFI instructions at
434 	 *  EL2, EL1 and EL0 are not trapped to EL3.
435 	 *
436 	 * SCR_EL3.SMD: Set to zero to enable SMC calls at EL1 and above, from
437 	 *  both Security states and both Execution states.
438 	 *
439 	 * SCR_EL3.SIF: Set to one to disable secure instruction execution from
440 	 *  Non-secure memory.
441 	 */
442 	scr_el3 &= ~(SCR_TWE_BIT | SCR_TWI_BIT | SCR_SMD_BIT);
443 
444 	scr_el3 |= SCR_SIF_BIT;
445 
446 	/*
447 	 * SCR_EL3.RW: Set the execution state, AArch32 or AArch64, for next
448 	 *  Exception level as specified by SPSR.
449 	 */
450 	if (GET_RW(ep->spsr) == MODE_RW_64) {
451 		scr_el3 |= SCR_RW_BIT;
452 	}
453 
454 	/*
455 	 * SCR_EL3.HCE: Enable HVC instructions if next execution state is
456 	 * AArch64 and next EL is EL2, or if next execution state is AArch32 and
457 	 * next mode is Hyp.
458 	 */
459 	if (((GET_RW(ep->spsr) == MODE_RW_64) && (GET_EL(ep->spsr) == MODE_EL2))
460 	    || ((GET_RW(ep->spsr) != MODE_RW_64)
461 		&& (GET_M32(ep->spsr) == MODE32_hyp))) {
462 		scr_el3 |= SCR_HCE_BIT;
463 	}
464 
465 	/*
466 	 * SCR_EL3.ST: Traps Secure EL1 accesses to the Counter-timer Physical
467 	 * Secure timer registers to EL3, from AArch64 state only, if specified
468 	 * by the entrypoint attributes. If SEL2 is present and enabled, the ST
469 	 * bit always behaves as 1 (i.e. secure physical timer register access
470 	 * is not trapped)
471 	 */
472 	if (EP_GET_ST(ep->h.attr) != 0U) {
473 		scr_el3 |= SCR_ST_BIT;
474 	}
475 
476 	/*
477 	 * If FEAT_HCX is enabled, enable access to HCRX_EL2 by setting
478 	 * SCR_EL3.HXEn.
479 	 */
480 	if (is_feat_hcx_supported()) {
481 		scr_el3 |= SCR_HXEn_BIT;
482 	}
483 
484 	/*
485 	 * If FEAT_LS64_ACCDATA is enabled, enable access to ACCDATA_EL1 by
486 	 * setting SCR_EL3.ADEn and allow the ST64BV0 instruction by setting
487 	 * SCR_EL3.EnAS0.
488 	 */
489 	if (is_feat_ls64_accdata_supported()) {
490 		scr_el3 |= SCR_ADEn_BIT | SCR_EnAS0_BIT;
491 	}
492 
493 	/*
494 	 * If FEAT_RNG_TRAP is enabled, all reads of the RNDR and RNDRRS
495 	 * registers are trapped to EL3.
496 	 */
497 	if (is_feat_rng_trap_supported()) {
498 		scr_el3 |= SCR_TRNDR_BIT;
499 	}
500 
501 #if FAULT_INJECTION_SUPPORT
502 	/* Enable fault injection from lower ELs */
503 	scr_el3 |= SCR_FIEN_BIT;
504 #endif
505 
506 	/*
507 	 * Enable Pointer Authentication globally for all the worlds.
508 	 *
509 	 * SCR_EL3.API: Set to one to not trap any PAuth instructions at ELs
510 	 *  other than EL3
511 	 *
512 	 * SCR_EL3.APK: Set to one to not trap any PAuth key values at ELs other
513 	 *  than EL3
514 	 */
515 	if (is_ctx_pauth_supported()) {
516 		scr_el3 |= SCR_API_BIT | SCR_APK_BIT;
517 	}
518 
519 	/*
520 	 * SCR_EL3.PIEN: Enable permission indirection and overlay
521 	 * registers for AArch64 if present.
522 	 */
523 	if (is_feat_sxpie_supported() || is_feat_sxpoe_supported()) {
524 		scr_el3 |= SCR_PIEN_BIT;
525 	}
526 
527 	/* SCR_EL3.GCSEn: Enable GCS registers. */
528 	if (is_feat_gcs_supported()) {
529 		scr_el3 |= SCR_GCSEn_BIT;
530 	}
531 
532 	/* SCR_EL3.FGTEn: Enable Fine Grained Virtualization Traps */
533 	if (is_feat_fgt_supported()) {
534 		scr_el3 |= SCR_FGTEN_BIT;
535 	}
536 
537 	/* SCR_EL3.ECVEn: Do not trap the CNTPOFF_EL2 register */
538 	if (is_feat_ecv_supported()) {
539 		scr_el3 |= SCR_ECVEN_BIT;
540 	}
541 
542 	/* Enable WFE trap delay in SCR_EL3 if supported and configured */
543 	if (is_feat_twed_supported()) {
544 		/* Set delay in SCR_EL3 */
545 		scr_el3 &= ~(SCR_TWEDEL_MASK << SCR_TWEDEL_SHIFT);
546 		scr_el3 |= ((TWED_DELAY & SCR_TWEDEL_MASK)
547 				<< SCR_TWEDEL_SHIFT);
548 
549 		/* Enable WFE delay */
550 		scr_el3 |= SCR_TWEDEn_BIT;
551 	}
552 
553 #if IMAGE_BL31 && defined(SPD_spmd) && SPMD_SPM_AT_SEL2
554 	/* Enable S-EL2 if FEAT_SEL2 is implemented for all the contexts. */
555 	if (is_feat_sel2_supported()) {
556 		scr_el3 |= SCR_EEL2_BIT;
557 	}
558 #endif /* (IMAGE_BL31 && defined(SPD_spmd) && SPMD_SPM_AT_SEL2) */
559 
560 	if (is_feat_mec_supported()) {
561 		scr_el3 |= SCR_MECEn_BIT;
562 	}
563 
564 	/*
565 	 * Populate EL3 state so that we've the right context
566 	 * before doing ERET
567 	 */
568 	write_ctx_reg(state, CTX_SCR_EL3, scr_el3);
569 	write_ctx_reg(state, CTX_ELR_EL3, ep->pc);
570 	write_ctx_reg(state, CTX_SPSR_EL3, ep->spsr);
571 
572 	/* Start with a clean MDCR_EL3 copy as all relevant values are set */
573 	mdcr_el3 = MDCR_EL3_RESET_VAL;
574 
575 	/* ---------------------------------------------------------------------
576 	 * Initialise MDCR_EL3, setting all fields rather than relying on hw.
577 	 * Some fields are architecturally UNKNOWN on reset.
578 	 *
579 	 * MDCR_EL3.SDD: Set to one to disable AArch64 Secure self-hosted debug.
580 	 *  Debug exceptions, other than Breakpoint Instruction exceptions, are
581 	 *  disabled from all ELs in Secure state.
582 	 *
583 	 * MDCR_EL3.SPD32: Set to 0b10 to disable AArch32 Secure self-hosted
584 	 *  privileged debug from S-EL1.
585 	 *
586 	 * MDCR_EL3.TDOSA: Set to zero so that EL2 and EL2 System register
587 	 *  access to the powerdown debug registers do not trap to EL3.
588 	 *
589 	 * MDCR_EL3.TDA: Set to zero to allow EL0, EL1 and EL2 access to the
590 	 *  debug registers, other than those registers that are controlled by
591 	 *  MDCR_EL3.TDOSA.
592 	 */
593 	mdcr_el3 |= ((MDCR_SDD_BIT | MDCR_SPD32(MDCR_SPD32_DISABLE))
594 			& ~(MDCR_TDA_BIT | MDCR_TDOSA_BIT)) ;
595 	write_ctx_reg(state, CTX_MDCR_EL3, mdcr_el3);
596 
597 #if IMAGE_BL31
598 	/* Enable FEAT_TRF for Non-Secure and prohibit for Secure state. */
599 	if (is_feat_trf_supported()) {
600 		trf_enable(ctx);
601 	}
602 
603 	if (is_feat_tcr2_supported()) {
604 		tcr2_enable(ctx);
605 	}
606 
607 	pmuv3_enable(ctx);
608 
609 	if (is_feat_idte3_supported()) {
610 		idte3_enable(ctx);
611 	}
612 
613 #if CTX_INCLUDE_EL2_REGS && IMAGE_BL31
614 	/*
615 	 * Initialize SCTLR_EL2 context register with reset value.
616 	 */
617 	write_el2_ctx_common(get_el2_sysregs_ctx(ctx), sctlr_el2, SCTLR_EL2_RES1);
618 #endif /* CTX_INCLUDE_EL2_REGS */
619 #endif /* IMAGE_BL31 */
620 
621 	/*
622 	 * Store the X0-X7 value from the entrypoint into the context
623 	 * Use memcpy as we are in control of the layout of the structures
624 	 */
625 	gp_regs = get_gpregs_ctx(ctx);
626 	memcpy((void *)gp_regs, (void *)&ep->args, sizeof(aapcs64_params_t));
627 }
628 
629 /*******************************************************************************
630  * Context management library initialization routine. This library is used by
631  * runtime services to share pointers to 'cpu_context' structures for secure
632  * non-secure and realm states. Management of the structures and their associated
633  * memory is not done by the context management library e.g. the PSCI service
634  * manages the cpu context used for entry from and exit to the non-secure state.
635  * The Secure payload dispatcher service manages the context(s) corresponding to
636  * the secure state. It also uses this library to get access to the non-secure
637  * state cpu context pointers.
638  * Lastly, this library provides the API to make SP_EL3 point to the cpu context
639  * which will be used for programming an entry into a lower EL. The same context
640  * will be used to save state upon exception entry from that EL.
641  ******************************************************************************/
642 void __init cm_init(void)
643 {
644 	/*
645 	 * The context management library has only global data to initialize, but
646 	 * that will be done when the BSS is zeroed out.
647 	 */
648 }
649 
650 /*******************************************************************************
651  * This is the high-level function used to initialize the cpu_context 'ctx' for
652  * first use. It performs initializations that are common to all security states
653  * and initializations specific to the security state specified in 'ep'
654  ******************************************************************************/
655 void cm_setup_context(cpu_context_t *ctx, const entry_point_info_t *ep)
656 {
657 	size_t security_state;
658 
659 	assert(ctx != NULL);
660 
661 	/*
662 	 * Perform initializations that are common
663 	 * to all security states
664 	 */
665 	setup_context_common(ctx, ep);
666 
667 	security_state = GET_SECURITY_STATE(ep->h.attr);
668 
669 	/* Perform security state specific initializations */
670 	switch (security_state) {
671 	case SECURE:
672 		setup_secure_context(ctx, ep);
673 		break;
674 #if ENABLE_RME && IMAGE_BL31
675 	case REALM:
676 		setup_realm_context(ctx, ep);
677 		break;
678 #endif
679 	case NON_SECURE:
680 		setup_ns_context(ctx, ep);
681 		break;
682 	default:
683 		ERROR("Invalid security state\n");
684 		panic();
685 		break;
686 	}
687 }
688 
689 /*******************************************************************************
690  * Enable architecture extensions for EL3 execution. This function only updates
691  * registers in-place which are expected to either never change or be
692  * overwritten by el3_exit. Expects the core_pos of the current core as argument.
693  ******************************************************************************/
694 void __no_pauth cm_manage_extensions_el3(unsigned int my_idx)
695 {
696 	if (is_feat_pauth_supported()) {
697 		pauth_init_enable_el3();
698 	}
699 
700 #if IMAGE_BL31
701 	if (is_feat_sve_supported()) {
702 		sve_init_el3();
703 	}
704 
705 	if (is_feat_amu_supported()) {
706 		amu_init_el3(my_idx);
707 	}
708 
709 	if (is_feat_sme_supported()) {
710 		sme_init_el3();
711 	}
712 
713 	if (is_feat_mpam_supported()) {
714 		mpam_init_el3();
715 	}
716 
717 	if (is_feat_cpa2_supported()) {
718 		cpa2_enable_el3();
719 	}
720 
721 	pmuv3_init_el3();
722 
723 	/* NOTE: must be done last, makes the configuration immutable */
724 	if (is_feat_fgwte3_supported()) {
725 		write_fgwte3_el3(FGWTE3_EL3_EARLY_INIT_VAL);
726 	}
727 #endif /* IMAGE_BL31 */
728 }
729 
730 /******************************************************************************
731  * Function to initialise the registers with the RESET values in the context
732  * memory, which are maintained per world.
733  ******************************************************************************/
734 static void cm_el3_arch_init_per_world(per_world_context_t *per_world_ctx)
735 {
736 	per_world_ctx->ctx_cptr_el3 = CPTR_EL3_RESET_VAL;
737 	per_world_ctx->ctx_mpam3_el3 = MPAM3_EL3_RESET_VAL;
738 }
739 
740 /*******************************************************************************
741  * Initialise per_world_context for Non-Secure world.
742  * This function enables the architecture extensions, which have same value
743  * across the cores for the non-secure world.
744  ******************************************************************************/
745 static void manage_extensions_nonsecure_per_world(void)
746 {
747 	cm_el3_arch_init_per_world(&per_world_context[CPU_CONTEXT_NS]);
748 
749 #if IMAGE_BL31
750 	if (is_feat_sme_supported()) {
751 		sme_enable_per_world(&per_world_context[CPU_CONTEXT_NS]);
752 	}
753 
754 	if (is_feat_sve_supported()) {
755 		sve_enable_per_world(&per_world_context[CPU_CONTEXT_NS]);
756 	}
757 
758 	if (is_feat_amu_supported()) {
759 		amu_enable_per_world(&per_world_context[CPU_CONTEXT_NS]);
760 	}
761 
762 	if (is_feat_sys_reg_trace_supported()) {
763 		sys_reg_trace_enable_per_world(&per_world_context[CPU_CONTEXT_NS]);
764 	}
765 
766 	if (is_feat_mpam_supported()) {
767 		mpam_enable_per_world(&per_world_context[CPU_CONTEXT_NS]);
768 	}
769 
770 	if (is_feat_idte3_supported()) {
771 		idte3_init_cached_idregs_per_world(CPU_CONTEXT_NS);
772 	}
773 #endif /* IMAGE_BL31 */
774 }
775 
776 /*******************************************************************************
777  * Initialise per_world_context for Secure world.
778  * This function enables the architecture extensions, which have same value
779  * across the cores for the secure world.
780  ******************************************************************************/
781 static void manage_extensions_secure_per_world(void)
782 {
783 	cm_el3_arch_init_per_world(&per_world_context[CPU_CONTEXT_SECURE]);
784 
785 #if IMAGE_BL31
786 	if (is_feat_sme_supported()) {
787 
788 		if (ENABLE_SME_FOR_SWD) {
789 		/*
790 		 * Enable SME, SVE, FPU/SIMD in secure context, SPM must ensure
791 		 * SME, SVE, and FPU/SIMD context properly managed.
792 		 */
793 			sme_enable_per_world(&per_world_context[CPU_CONTEXT_SECURE]);
794 		} else {
795 		/*
796 		 * Disable SME, SVE, FPU/SIMD in secure context so non-secure
797 		 * world can safely use the associated registers.
798 		 */
799 			sme_disable_per_world(&per_world_context[CPU_CONTEXT_SECURE]);
800 		}
801 	}
802 	if (is_feat_sve_supported()) {
803 		if (ENABLE_SVE_FOR_SWD) {
804 		/*
805 		 * Enable SVE and FPU in secure context, SPM must ensure
806 		 * that the SVE and FPU register contexts are properly managed.
807 		 */
808 			sve_enable_per_world(&per_world_context[CPU_CONTEXT_SECURE]);
809 		} else {
810 		/*
811 		 * Disable SVE and FPU in secure context so non-secure world
812 		 * can safely use them.
813 		 */
814 			sve_disable_per_world(&per_world_context[CPU_CONTEXT_SECURE]);
815 		}
816 	}
817 
818 	/* NS can access this but Secure shouldn't */
819 	if (is_feat_sys_reg_trace_supported()) {
820 		sys_reg_trace_disable_per_world(&per_world_context[CPU_CONTEXT_SECURE]);
821 	}
822 
823 	if (is_feat_idte3_supported()) {
824 		idte3_init_cached_idregs_per_world(CPU_CONTEXT_SECURE);
825 	}
826 #endif /* IMAGE_BL31 */
827 }
828 
829 static void manage_extensions_realm_per_world(void)
830 {
831 #if ENABLE_RME && IMAGE_BL31
832 	cm_el3_arch_init_per_world(&per_world_context[CPU_CONTEXT_REALM]);
833 
834 	if (is_feat_sve_supported()) {
835 	/*
836 	 * Enable SVE and FPU in realm context when it is enabled for NS.
837 	 * Realm manager must ensure that the SVE and FPU register
838 	 * contexts are properly managed.
839 	 */
840 		sve_enable_per_world(&per_world_context[CPU_CONTEXT_REALM]);
841 	}
842 
843 	/* NS can access this but Realm shouldn't */
844 	if (is_feat_sys_reg_trace_supported()) {
845 		sys_reg_trace_disable_per_world(&per_world_context[CPU_CONTEXT_REALM]);
846 	}
847 
848 	/*
849 	 * If SME/SME2 is supported and enabled for NS world, then disable trapping
850 	 * of SME instructions for Realm world. RMM will save/restore required
851 	 * registers that are shared with SVE/FPU so that Realm can use FPU or SVE.
852 	 */
853 	if (is_feat_sme_supported()) {
854 		sme_enable_per_world(&per_world_context[CPU_CONTEXT_REALM]);
855 	}
856 
857 	/*
858 	 * If FEAT_MPAM is supported and enabled, then disable trapping access
859 	 * to the MPAM registers for Realm world. Instead, RMM will configure
860 	 * the access to be trapped by itself so it can inject undefined aborts
861 	 * back to the Realm.
862 	 */
863 	if (is_feat_mpam_supported()) {
864 		mpam_enable_per_world(&per_world_context[CPU_CONTEXT_REALM]);
865 	}
866 
867 	if (is_feat_idte3_supported()) {
868 		idte3_init_cached_idregs_per_world(CPU_CONTEXT_REALM);
869 	}
870 #endif /* ENABLE_RME && IMAGE_BL31 */
871 }
872 
873 void cm_manage_extensions_per_world(void)
874 {
875 	manage_extensions_nonsecure_per_world();
876 	manage_extensions_secure_per_world();
877 	manage_extensions_realm_per_world();
878 }
879 
880 void cm_init_percpu_once_regs(void)
881 {
882 #if IMAGE_BL31
883 	if (is_feat_idte3_supported()) {
884 		idte3_init_percpu_once_regs(CPU_CONTEXT_NS);
885 		idte3_init_percpu_once_regs(CPU_CONTEXT_SECURE);
886 #if ENABLE_RME
887 		idte3_init_percpu_once_regs(CPU_CONTEXT_REALM);
888 #endif /* ENABLE_RME */
889 	}
890 #endif /* IMAGE_BL31 */
891 }
892 
893 /*******************************************************************************
894  * Enable architecture extensions on first entry to Non-secure world.
895  ******************************************************************************/
896 static void manage_extensions_nonsecure(cpu_context_t *ctx)
897 {
898 #if IMAGE_BL31
899 	/* NOTE: registers are not context switched */
900 	if (is_feat_amu_supported()) {
901 		amu_enable(ctx);
902 	}
903 
904 	if (is_feat_sme_supported()) {
905 		sme_enable(ctx);
906 	}
907 
908 	if (is_feat_fgt2_supported()) {
909 		fgt2_enable(ctx);
910 	}
911 
912 	if (is_feat_debugv8p9_supported()) {
913 		debugv8p9_extended_bp_wp_enable(ctx);
914 	}
915 
916 	if (is_feat_spe_supported()) {
917 		spe_enable_ns(ctx);
918 	}
919 
920 	if (is_feat_trbe_supported()) {
921 		if (check_if_trbe_disable_affected_core()) {
922 			trbe_disable_ns(ctx);
923 		} else {
924 			trbe_enable_ns(ctx);
925 		}
926 	}
927 
928 	if (is_feat_brbe_supported()) {
929 		brbe_enable(ctx);
930 	}
931 #endif /* IMAGE_BL31 */
932 }
933 
934 #if INIT_UNUSED_NS_EL2
935 /*******************************************************************************
936  * Enable architecture extensions in-place at EL2 on first entry to Non-secure
937  * world when EL2 is empty and unused.
938  ******************************************************************************/
939 static void manage_extensions_nonsecure_el2_unused(void)
940 {
941 #if IMAGE_BL31
942 	if (is_feat_spe_supported()) {
943 		spe_init_el2_unused();
944 	}
945 
946 	if (is_feat_amu_supported()) {
947 		amu_init_el2_unused();
948 	}
949 
950 	if (is_feat_mpam_supported()) {
951 		mpam_init_el2_unused();
952 	}
953 
954 	if (is_feat_trbe_supported()) {
955 		trbe_init_el2_unused();
956 	}
957 
958 	if (is_feat_sys_reg_trace_supported()) {
959 		sys_reg_trace_init_el2_unused();
960 	}
961 
962 	if (is_feat_trf_supported()) {
963 		trf_init_el2_unused();
964 	}
965 
966 	pmuv3_init_el2_unused();
967 
968 	if (is_feat_sve_supported()) {
969 		sve_init_el2_unused();
970 	}
971 
972 	if (is_feat_sme_supported()) {
973 		sme_init_el2_unused();
974 	}
975 
976 	if (is_feat_mops_supported() && is_feat_hcx_supported()) {
977 		write_hcrx_el2(read_hcrx_el2() | HCRX_EL2_MSCEn_BIT);
978 	}
979 
980 	if (is_feat_pauth_supported()) {
981 		pauth_enable_el2();
982 	}
983 #endif /* IMAGE_BL31 */
984 }
985 #endif /* INIT_UNUSED_NS_EL2 */
986 
987 /*******************************************************************************
988  * Enable architecture extensions on first entry to Secure world.
989  ******************************************************************************/
990 static void manage_extensions_secure(cpu_context_t *ctx)
991 {
992 #if IMAGE_BL31
993 	if (is_feat_sme_supported()) {
994 		if (ENABLE_SME_FOR_SWD) {
995 		/*
996 		 * Enable SME, SVE, FPU/SIMD in secure context, secure manager
997 		 * must ensure SME, SVE, and FPU/SIMD context properly managed.
998 		 */
999 			sme_init_el3();
1000 			sme_enable(ctx);
1001 		} else {
1002 		/*
1003 		 * Disable SME, SVE, FPU/SIMD in secure context so non-secure
1004 		 * world can safely use the associated registers.
1005 		 */
1006 			sme_disable(ctx);
1007 		}
1008 	}
1009 
1010 	if (is_feat_spe_supported()) {
1011 		spe_disable_secure(ctx);
1012 	}
1013 
1014 	if (is_feat_trbe_supported()) {
1015 		trbe_disable_secure(ctx);
1016 	}
1017 #endif /* IMAGE_BL31 */
1018 }
1019 
1020 /*******************************************************************************
1021  * The following function initializes the cpu_context for the current CPU
1022  * for first use, and sets the initial entrypoint state as specified by the
1023  * entry_point_info structure.
1024  ******************************************************************************/
1025 void cm_init_my_context(const entry_point_info_t *ep)
1026 {
1027 	cpu_context_t *ctx;
1028 	ctx = cm_get_context(GET_SECURITY_STATE(ep->h.attr));
1029 	cm_setup_context(ctx, ep);
1030 }
1031 
1032 /* EL2 present but unused, need to disable safely. SCTLR_EL2 can be ignored */
1033 static void init_nonsecure_el2_unused(cpu_context_t *ctx)
1034 {
1035 #if INIT_UNUSED_NS_EL2
1036 	u_register_t hcr_el2 = HCR_RESET_VAL;
1037 	u_register_t mdcr_el2;
1038 	u_register_t scr_el3;
1039 
1040 	scr_el3 = read_ctx_reg(get_el3state_ctx(ctx), CTX_SCR_EL3);
1041 
1042 	/* Set EL2 register width: Set HCR_EL2.RW to match SCR_EL3.RW */
1043 	if ((scr_el3 & SCR_RW_BIT) != 0U) {
1044 		hcr_el2 |= HCR_RW_BIT;
1045 	}
1046 
1047 	write_hcr_el2(hcr_el2);
1048 
1049 	/*
1050 	 * Initialise CPTR_EL2 setting all fields rather than relying on the hw.
1051 	 * All fields have architecturally UNKNOWN reset values.
1052 	 */
1053 	write_cptr_el2(CPTR_EL2_RESET_VAL);
1054 
1055 	/*
1056 	 * Initialise CNTHCTL_EL2. All fields are architecturally UNKNOWN on
1057 	 * reset and are set to zero except for field(s) listed below.
1058 	 *
1059 	 * CNTHCTL_EL2.EL1PTEN: Set to one to disable traps to Hyp mode of
1060 	 * Non-secure EL0 and EL1 accesses to the physical timer registers.
1061 	 *
1062 	 * CNTHCTL_EL2.EL1PCTEN: Set to one to disable traps to Hyp mode of
1063 	 * Non-secure EL0 and EL1 accesses to the physical counter registers.
1064 	 */
1065 	write_cnthctl_el2(CNTHCTL_RESET_VAL | EL1PCEN_BIT | EL1PCTEN_BIT);
1066 
1067 	/*
1068 	 * Initialise CNTVOFF_EL2 to zero as it resets to an architecturally
1069 	 * UNKNOWN value.
1070 	 */
1071 	write_cntvoff_el2(0);
1072 
1073 	/*
1074 	 * Set VPIDR_EL2 and VMPIDR_EL2 to match MIDR_EL1 and MPIDR_EL1
1075 	 * respectively.
1076 	 */
1077 	write_vpidr_el2(read_midr_el1());
1078 	write_vmpidr_el2(read_mpidr_el1());
1079 
1080 	/*
1081 	 * Initialise VTTBR_EL2. All fields are architecturally UNKNOWN on reset.
1082 	 *
1083 	 * VTTBR_EL2.VMID: Set to zero. Even though EL1&0 stage 2 address
1084 	 * translation is disabled, cache maintenance operations depend on the
1085 	 * VMID.
1086 	 *
1087 	 * VTTBR_EL2.BADDR: Set to zero as EL1&0 stage 2 address translation is
1088 	 * disabled.
1089 	 */
1090 	write_vttbr_el2(VTTBR_RESET_VAL &
1091 		     ~((VTTBR_VMID_MASK << VTTBR_VMID_SHIFT) |
1092 		       (VTTBR_BADDR_MASK << VTTBR_BADDR_SHIFT)));
1093 
1094 	/*
1095 	 * Initialise MDCR_EL2, setting all fields rather than relying on hw.
1096 	 * Some fields are architecturally UNKNOWN on reset.
1097 	 *
1098 	 * MDCR_EL2.TDRA: Set to zero so that Non-secure EL0 and EL1 System
1099 	 * register accesses to the Debug ROM registers are not trapped to EL2.
1100 	 *
1101 	 * MDCR_EL2.TDOSA: Set to zero so that Non-secure EL1 System register
1102 	 * accesses to the powerdown debug registers are not trapped to EL2.
1103 	 *
1104 	 * MDCR_EL2.TDA: Set to zero so that System register accesses to the
1105 	 * debug registers do not trap to EL2.
1106 	 *
1107 	 * MDCR_EL2.TDE: Set to zero so that debug exceptions are not routed to
1108 	 * EL2.
1109 	 */
1110 	mdcr_el2 = MDCR_EL2_RESET_VAL &
1111 		 ~(MDCR_EL2_TDRA_BIT | MDCR_EL2_TDOSA_BIT | MDCR_EL2_TDA_BIT |
1112 		   MDCR_EL2_TDE_BIT);
1113 
1114 	write_mdcr_el2(mdcr_el2);
1115 
1116 	/*
1117 	 * Initialise HSTR_EL2. All fields are architecturally UNKNOWN on reset.
1118 	 *
1119 	 * HSTR_EL2.T<n>: Set all these fields to zero so that Non-secure EL0 or
1120 	 * EL1 accesses to System registers do not trap to EL2.
1121 	 */
1122 	write_hstr_el2(HSTR_EL2_RESET_VAL & ~(HSTR_EL2_T_MASK));
1123 
1124 	/*
1125 	 * Initialise CNTHP_CTL_EL2. All fields are architecturally UNKNOWN on
1126 	 * reset.
1127 	 *
1128 	 * CNTHP_CTL_EL2:ENABLE: Set to zero to disable the EL2 physical timer
1129 	 * and prevent timer interrupts.
1130 	 */
1131 	write_cnthp_ctl_el2(CNTHP_CTL_RESET_VAL & ~(CNTHP_CTL_ENABLE_BIT));
1132 
1133 	manage_extensions_nonsecure_el2_unused();
1134 #endif /* INIT_UNUSED_NS_EL2 */
1135 }
1136 
1137 /*******************************************************************************
1138  * Prepare the CPU system registers for first entry into realm, secure, or
1139  * normal world.
1140  *
1141  * If execution is requested to EL2 or hyp mode, SCTLR_EL2 is initialized
1142  * If execution is requested to non-secure EL1 or svc mode, and the CPU supports
1143  * EL2 then EL2 is disabled by configuring all necessary EL2 registers.
1144  * For all entries, the EL1 registers are initialized from the cpu_context
1145  ******************************************************************************/
1146 void cm_prepare_el3_exit(size_t security_state)
1147 {
1148 	u_register_t sctlr_el2, scr_el3;
1149 	cpu_context_t *ctx = cm_get_context(security_state);
1150 
1151 	assert(ctx != NULL);
1152 
1153 	if (security_state == NON_SECURE) {
1154 		uint64_t el2_implemented = el_implemented(2);
1155 
1156 		scr_el3 = read_ctx_reg(get_el3state_ctx(ctx),
1157 						 CTX_SCR_EL3);
1158 
1159 		if (el2_implemented != EL_IMPL_NONE) {
1160 
1161 			/*
1162 			 * If context is not being used for EL2, initialize
1163 			 * HCRX_EL2 with its init value here.
1164 			 */
1165 			if (is_feat_hcx_supported()) {
1166 				write_hcrx_el2(HCRX_EL2_INIT_VAL);
1167 			}
1168 
1169 			/*
1170 			 * Initialize Fine-grained trap registers introduced
1171 			 * by FEAT_FGT so all traps are initially disabled when
1172 			 * switching to EL2 or a lower EL, preventing undesired
1173 			 * behavior.
1174 			 */
1175 			if (is_feat_fgt_supported()) {
1176 				/*
1177 				 * Initialize HFG*_EL2 registers with a default
1178 				 * value so legacy systems unaware of FEAT_FGT
1179 				 * do not get trapped due to their lack of
1180 				 * initialization for this feature.
1181 				 */
1182 				write_hfgitr_el2(HFGITR_EL2_INIT_VAL);
1183 				write_hfgrtr_el2(HFGRTR_EL2_INIT_VAL);
1184 				write_hfgwtr_el2(HFGWTR_EL2_INIT_VAL);
1185 			}
1186 
1187 			/* Condition to ensure EL2 is being used. */
1188 			if ((scr_el3 & SCR_HCE_BIT) != 0U) {
1189 				/* Initialize SCTLR_EL2 register with reset value. */
1190 				sctlr_el2 = SCTLR_EL2_RES1;
1191 
1192 				/*
1193 				 * If workaround of errata 764081 for Cortex-A75
1194 				 * is used then set SCTLR_EL2.IESB to enable
1195 				 * Implicit Error Synchronization Barrier.
1196 				 */
1197 				if (errata_a75_764081_applies()) {
1198 					sctlr_el2 |= SCTLR_IESB_BIT;
1199 				}
1200 
1201 				write_sctlr_el2(sctlr_el2);
1202 			} else {
1203 				/*
1204 				 * (scr_el3 & SCR_HCE_BIT==0)
1205 				 * EL2 implemented but unused.
1206 				 */
1207 				init_nonsecure_el2_unused(ctx);
1208 			}
1209 		}
1210 
1211 		if (is_feat_fgwte3_supported()) {
1212 			/*
1213 			 * TCR_EL3 and ACTLR_EL3 could be overwritten
1214 			 * by platforms and hence is locked a bit late.
1215 			 */
1216 			write_fgwte3_el3(FGWTE3_EL3_LATE_INIT_VAL);
1217 		}
1218 	}
1219 #if !CTX_INCLUDE_EL2_REGS || IMAGE_BL1
1220 	/* Restore EL1 system registers, only when CTX_INCLUDE_EL2_REGS=0 */
1221 	cm_el1_sysregs_context_restore(security_state);
1222 #endif
1223 	cm_set_next_eret_context(security_state);
1224 }
1225 
1226 /* Assumes prepare_el3_entry() has disabled counters 2 and 3 */
1227 void cm_sysregs_context_save_amu(unsigned int security_state)
1228 {
1229 	world_amu_regs_t *ctx = PER_CPU_CUR(world_amu_ctx[get_cpu_context_index(security_state)]);
1230 
1231 	ctx->amevcntr02_el0 = read_amevcntr02_el0();
1232 	ctx->amevcntr03_el0 = read_amevcntr03_el0();
1233 }
1234 
1235 void cm_sysregs_context_restore_amu(unsigned int security_state)
1236 {
1237 	world_amu_regs_t *ctx = PER_CPU_CUR(world_amu_ctx[get_cpu_context_index(security_state)]);
1238 
1239 	write_amevcntr02_el0(ctx->amevcntr02_el0);
1240 	write_amevcntr03_el0(ctx->amevcntr03_el0);
1241 }
1242 
1243 #if (CTX_INCLUDE_EL2_REGS && IMAGE_BL31)
1244 
1245 static void el2_sysregs_context_save_fgt(el2_sysregs_t *ctx)
1246 {
1247 	write_el2_ctx_fgt(ctx, hdfgrtr_el2, read_hdfgrtr_el2());
1248 	if (is_feat_amu_supported()) {
1249 		write_el2_ctx_fgt(ctx, hafgrtr_el2, read_hafgrtr_el2());
1250 	}
1251 	write_el2_ctx_fgt(ctx, hdfgwtr_el2, read_hdfgwtr_el2());
1252 	write_el2_ctx_fgt(ctx, hfgitr_el2, read_hfgitr_el2());
1253 	write_el2_ctx_fgt(ctx, hfgrtr_el2, read_hfgrtr_el2());
1254 	write_el2_ctx_fgt(ctx, hfgwtr_el2, read_hfgwtr_el2());
1255 }
1256 
1257 static void el2_sysregs_context_restore_fgt(el2_sysregs_t *ctx)
1258 {
1259 	write_hdfgrtr_el2(read_el2_ctx_fgt(ctx, hdfgrtr_el2));
1260 	if (is_feat_amu_supported()) {
1261 		write_hafgrtr_el2(read_el2_ctx_fgt(ctx, hafgrtr_el2));
1262 	}
1263 	write_hdfgwtr_el2(read_el2_ctx_fgt(ctx, hdfgwtr_el2));
1264 	write_hfgitr_el2(read_el2_ctx_fgt(ctx, hfgitr_el2));
1265 	write_hfgrtr_el2(read_el2_ctx_fgt(ctx, hfgrtr_el2));
1266 	write_hfgwtr_el2(read_el2_ctx_fgt(ctx, hfgwtr_el2));
1267 }
1268 
1269 static void el2_sysregs_context_save_fgt2(el2_sysregs_t *ctx)
1270 {
1271 	write_el2_ctx_fgt2(ctx, hdfgrtr2_el2, read_hdfgrtr2_el2());
1272 	write_el2_ctx_fgt2(ctx, hdfgwtr2_el2, read_hdfgwtr2_el2());
1273 	write_el2_ctx_fgt2(ctx, hfgitr2_el2, read_hfgitr2_el2());
1274 	write_el2_ctx_fgt2(ctx, hfgrtr2_el2, read_hfgrtr2_el2());
1275 	write_el2_ctx_fgt2(ctx, hfgwtr2_el2, read_hfgwtr2_el2());
1276 }
1277 
1278 static void el2_sysregs_context_restore_fgt2(el2_sysregs_t *ctx)
1279 {
1280 	write_hdfgrtr2_el2(read_el2_ctx_fgt2(ctx, hdfgrtr2_el2));
1281 	write_hdfgwtr2_el2(read_el2_ctx_fgt2(ctx, hdfgwtr2_el2));
1282 	write_hfgitr2_el2(read_el2_ctx_fgt2(ctx, hfgitr2_el2));
1283 	write_hfgrtr2_el2(read_el2_ctx_fgt2(ctx, hfgrtr2_el2));
1284 	write_hfgwtr2_el2(read_el2_ctx_fgt2(ctx, hfgwtr2_el2));
1285 }
1286 
1287 static void el2_sysregs_context_save_mpam(el2_sysregs_t *ctx)
1288 {
1289 	u_register_t mpam_idr = read_mpamidr_el1();
1290 
1291 	write_el2_ctx_mpam(ctx, mpam2_el2, read_mpam2_el2());
1292 
1293 	/*
1294 	 * The context registers that we intend to save would be part of the
1295 	 * PE's system register frame only if MPAMIDR_EL1.HAS_HCR == 1.
1296 	 */
1297 	if ((mpam_idr & MPAMIDR_HAS_HCR_BIT) == 0U) {
1298 		return;
1299 	}
1300 
1301 	/*
1302 	 * MPAMHCR_EL2, MPAMVPMV_EL2 and MPAMVPM0_EL2 are always present if
1303 	 * MPAMIDR_HAS_HCR_BIT == 1.
1304 	 */
1305 	write_el2_ctx_mpam(ctx, mpamhcr_el2, read_mpamhcr_el2());
1306 	write_el2_ctx_mpam(ctx, mpamvpm0_el2, read_mpamvpm0_el2());
1307 	write_el2_ctx_mpam(ctx, mpamvpmv_el2, read_mpamvpmv_el2());
1308 
1309 	/*
1310 	 * The number of MPAMVPM registers is implementation defined, their
1311 	 * number is stored in the MPAMIDR_EL1 register.
1312 	 */
1313 	switch ((mpam_idr >> MPAMIDR_EL1_VPMR_MAX_SHIFT) & MPAMIDR_EL1_VPMR_MAX_MASK) {
1314 	case 7:
1315 		write_el2_ctx_mpam(ctx, mpamvpm7_el2, read_mpamvpm7_el2());
1316 		__fallthrough;
1317 	case 6:
1318 		write_el2_ctx_mpam(ctx, mpamvpm6_el2, read_mpamvpm6_el2());
1319 		__fallthrough;
1320 	case 5:
1321 		write_el2_ctx_mpam(ctx, mpamvpm5_el2, read_mpamvpm5_el2());
1322 		__fallthrough;
1323 	case 4:
1324 		write_el2_ctx_mpam(ctx, mpamvpm4_el2, read_mpamvpm4_el2());
1325 		__fallthrough;
1326 	case 3:
1327 		write_el2_ctx_mpam(ctx, mpamvpm3_el2, read_mpamvpm3_el2());
1328 		__fallthrough;
1329 	case 2:
1330 		write_el2_ctx_mpam(ctx, mpamvpm2_el2, read_mpamvpm2_el2());
1331 		__fallthrough;
1332 	case 1:
1333 		write_el2_ctx_mpam(ctx, mpamvpm1_el2, read_mpamvpm1_el2());
1334 		break;
1335 	}
1336 }
1337 
1338 static void el2_sysregs_context_restore_mpam(el2_sysregs_t *ctx)
1339 {
1340 	u_register_t mpam_idr = read_mpamidr_el1();
1341 
1342 	write_mpam2_el2(read_el2_ctx_mpam(ctx, mpam2_el2));
1343 
1344 	if ((mpam_idr & MPAMIDR_HAS_HCR_BIT) == 0U) {
1345 		return;
1346 	}
1347 
1348 	write_mpamhcr_el2(read_el2_ctx_mpam(ctx, mpamhcr_el2));
1349 	write_mpamvpm0_el2(read_el2_ctx_mpam(ctx, mpamvpm0_el2));
1350 	write_mpamvpmv_el2(read_el2_ctx_mpam(ctx, mpamvpmv_el2));
1351 
1352 	switch ((mpam_idr >> MPAMIDR_EL1_VPMR_MAX_SHIFT) & MPAMIDR_EL1_VPMR_MAX_MASK) {
1353 	case 7:
1354 		write_mpamvpm7_el2(read_el2_ctx_mpam(ctx, mpamvpm7_el2));
1355 		__fallthrough;
1356 	case 6:
1357 		write_mpamvpm6_el2(read_el2_ctx_mpam(ctx, mpamvpm6_el2));
1358 		__fallthrough;
1359 	case 5:
1360 		write_mpamvpm5_el2(read_el2_ctx_mpam(ctx, mpamvpm5_el2));
1361 		__fallthrough;
1362 	case 4:
1363 		write_mpamvpm4_el2(read_el2_ctx_mpam(ctx, mpamvpm4_el2));
1364 		__fallthrough;
1365 	case 3:
1366 		write_mpamvpm3_el2(read_el2_ctx_mpam(ctx, mpamvpm3_el2));
1367 		__fallthrough;
1368 	case 2:
1369 		write_mpamvpm2_el2(read_el2_ctx_mpam(ctx, mpamvpm2_el2));
1370 		__fallthrough;
1371 	case 1:
1372 		write_mpamvpm1_el2(read_el2_ctx_mpam(ctx, mpamvpm1_el2));
1373 		break;
1374 	}
1375 }
1376 
1377 /* ---------------------------------------------------------------------------
1378  * The following registers are not added:
1379  * ICH_AP0R<n>_EL2
1380  * ICH_AP1R<n>_EL2
1381  * ICH_LR<n>_EL2
1382  *
1383  * NOTE: For a system with S-EL2 present but not enabled, accessing
1384  * ICC_SRE_EL2 is undefined from EL3. To workaround this change the
1385  * SCR_EL3.NS = 1 before accessing this register.
1386  * ---------------------------------------------------------------------------
1387  */
1388 static void el2_sysregs_context_save_gic(el2_sysregs_t *ctx, uint32_t security_state)
1389 {
1390 	u_register_t scr_el3 = read_scr_el3();
1391 
1392 #if defined(SPD_spmd) && SPMD_SPM_AT_SEL2
1393 	write_el2_ctx_common(ctx, icc_sre_el2, read_icc_sre_el2());
1394 #else
1395 	write_scr_el3(scr_el3 | SCR_NS_BIT);
1396 	isb();
1397 
1398 	write_el2_ctx_common(ctx, icc_sre_el2, read_icc_sre_el2());
1399 
1400 	write_scr_el3(scr_el3);
1401 	isb();
1402 #endif
1403 	write_el2_ctx_common(ctx, ich_hcr_el2, read_ich_hcr_el2());
1404 
1405 	if (errata_ich_vmcr_el2_applies()) {
1406 		if (security_state == SECURE) {
1407 			write_scr_el3(scr_el3 & ~SCR_NS_BIT);
1408 		} else {
1409 			write_scr_el3(scr_el3 | SCR_NS_BIT);
1410 		}
1411 		isb();
1412 	}
1413 
1414 	write_el2_ctx_common(ctx, ich_vmcr_el2, read_ich_vmcr_el2());
1415 
1416 	if (errata_ich_vmcr_el2_applies()) {
1417 		write_scr_el3(scr_el3);
1418 		isb();
1419 	}
1420 }
1421 
1422 static void el2_sysregs_context_restore_gic(el2_sysregs_t *ctx, uint32_t security_state)
1423 {
1424 	u_register_t scr_el3 = read_scr_el3();
1425 
1426 #if defined(SPD_spmd) && SPMD_SPM_AT_SEL2
1427 	write_icc_sre_el2(read_el2_ctx_common(ctx, icc_sre_el2));
1428 #else
1429 	write_scr_el3(scr_el3 | SCR_NS_BIT);
1430 	isb();
1431 
1432 	write_icc_sre_el2(read_el2_ctx_common(ctx, icc_sre_el2));
1433 
1434 	write_scr_el3(scr_el3);
1435 	isb();
1436 #endif
1437 	write_ich_hcr_el2(read_el2_ctx_common(ctx, ich_hcr_el2));
1438 
1439 	if (errata_ich_vmcr_el2_applies()) {
1440 		if (security_state == SECURE) {
1441 			write_scr_el3(scr_el3 & ~SCR_NS_BIT);
1442 		} else {
1443 			write_scr_el3(scr_el3 | SCR_NS_BIT);
1444 		}
1445 		isb();
1446 	}
1447 
1448 	write_ich_vmcr_el2(read_el2_ctx_common(ctx, ich_vmcr_el2));
1449 
1450 	if (errata_ich_vmcr_el2_applies()) {
1451 		write_scr_el3(scr_el3);
1452 		isb();
1453 	}
1454 }
1455 
1456 /* -----------------------------------------------------
1457  * The following registers are not added:
1458  * AMEVCNTVOFF0<n>_EL2
1459  * AMEVCNTVOFF1<n>_EL2
1460  * -----------------------------------------------------
1461  */
1462 static void el2_sysregs_context_save_common(el2_sysregs_t *ctx)
1463 {
1464 	write_el2_ctx_common(ctx, actlr_el2, read_actlr_el2());
1465 	write_el2_ctx_common(ctx, afsr0_el2, read_afsr0_el2());
1466 	write_el2_ctx_common(ctx, afsr1_el2, read_afsr1_el2());
1467 	write_el2_ctx_common(ctx, amair_el2, read_amair_el2());
1468 	write_el2_ctx_common(ctx, cnthctl_el2, read_cnthctl_el2());
1469 	write_el2_ctx_common(ctx, cntvoff_el2, read_cntvoff_el2());
1470 	write_el2_ctx_common(ctx, cptr_el2, read_cptr_el2());
1471 	if (CTX_INCLUDE_AARCH32_REGS) {
1472 		write_el2_ctx_common(ctx, dbgvcr32_el2, read_dbgvcr32_el2());
1473 	}
1474 	write_el2_ctx_common(ctx, elr_el2, read_elr_el2());
1475 	write_el2_ctx_common(ctx, esr_el2, read_esr_el2());
1476 	write_el2_ctx_common(ctx, far_el2, read_far_el2());
1477 	write_el2_ctx_common(ctx, hacr_el2, read_hacr_el2());
1478 	write_el2_ctx_common(ctx, hcr_el2, read_hcr_el2());
1479 	write_el2_ctx_common(ctx, hpfar_el2, read_hpfar_el2());
1480 	write_el2_ctx_common(ctx, hstr_el2, read_hstr_el2());
1481 	write_el2_ctx_common(ctx, mair_el2, read_mair_el2());
1482 	write_el2_ctx_common(ctx, mdcr_el2, read_mdcr_el2());
1483 	write_el2_ctx_common(ctx, sctlr_el2, read_sctlr_el2());
1484 	write_el2_ctx_common(ctx, spsr_el2, read_spsr_el2());
1485 	write_el2_ctx_common(ctx, sp_el2, read_sp_el2());
1486 	write_el2_ctx_common(ctx, tcr_el2, read_tcr_el2());
1487 	write_el2_ctx_common(ctx, tpidr_el2, read_tpidr_el2());
1488 	write_el2_ctx_common(ctx, vbar_el2, read_vbar_el2());
1489 	write_el2_ctx_common(ctx, vmpidr_el2, read_vmpidr_el2());
1490 	write_el2_ctx_common(ctx, vpidr_el2, read_vpidr_el2());
1491 	write_el2_ctx_common(ctx, vtcr_el2, read_vtcr_el2());
1492 
1493 	write_el2_ctx_common_sysreg128(ctx, ttbr0_el2, read_ttbr0_el2());
1494 	write_el2_ctx_common_sysreg128(ctx, vttbr_el2, read_vttbr_el2());
1495 }
1496 
1497 static void el2_sysregs_context_restore_common(el2_sysregs_t *ctx)
1498 {
1499 	write_actlr_el2(read_el2_ctx_common(ctx, actlr_el2));
1500 	write_afsr0_el2(read_el2_ctx_common(ctx, afsr0_el2));
1501 	write_afsr1_el2(read_el2_ctx_common(ctx, afsr1_el2));
1502 	write_amair_el2(read_el2_ctx_common(ctx, amair_el2));
1503 	write_cnthctl_el2(read_el2_ctx_common(ctx, cnthctl_el2));
1504 	write_cntvoff_el2(read_el2_ctx_common(ctx, cntvoff_el2));
1505 	write_cptr_el2(read_el2_ctx_common(ctx, cptr_el2));
1506 	if (CTX_INCLUDE_AARCH32_REGS) {
1507 		write_dbgvcr32_el2(read_el2_ctx_common(ctx, dbgvcr32_el2));
1508 	}
1509 	write_elr_el2(read_el2_ctx_common(ctx, elr_el2));
1510 	write_esr_el2(read_el2_ctx_common(ctx, esr_el2));
1511 	write_far_el2(read_el2_ctx_common(ctx, far_el2));
1512 	write_hacr_el2(read_el2_ctx_common(ctx, hacr_el2));
1513 	write_hcr_el2(read_el2_ctx_common(ctx, hcr_el2));
1514 	write_hpfar_el2(read_el2_ctx_common(ctx, hpfar_el2));
1515 	write_hstr_el2(read_el2_ctx_common(ctx, hstr_el2));
1516 	write_mair_el2(read_el2_ctx_common(ctx, mair_el2));
1517 	write_mdcr_el2(read_el2_ctx_common(ctx, mdcr_el2));
1518 	write_sctlr_el2(read_el2_ctx_common(ctx, sctlr_el2));
1519 	write_spsr_el2(read_el2_ctx_common(ctx, spsr_el2));
1520 	write_sp_el2(read_el2_ctx_common(ctx, sp_el2));
1521 	write_tcr_el2(read_el2_ctx_common(ctx, tcr_el2));
1522 	write_tpidr_el2(read_el2_ctx_common(ctx, tpidr_el2));
1523 	write_ttbr0_el2(read_el2_ctx_common(ctx, ttbr0_el2));
1524 	write_vbar_el2(read_el2_ctx_common(ctx, vbar_el2));
1525 	write_vmpidr_el2(read_el2_ctx_common(ctx, vmpidr_el2));
1526 	write_vpidr_el2(read_el2_ctx_common(ctx, vpidr_el2));
1527 	write_vtcr_el2(read_el2_ctx_common(ctx, vtcr_el2));
1528 	write_vttbr_el2(read_el2_ctx_common(ctx, vttbr_el2));
1529 }
1530 
1531 /*******************************************************************************
1532  * Save EL2 sysreg context
1533  ******************************************************************************/
1534 void cm_el2_sysregs_context_save(uint32_t security_state)
1535 {
1536 	cpu_context_t *ctx;
1537 	el2_sysregs_t *el2_sysregs_ctx;
1538 
1539 	ctx = cm_get_context(security_state);
1540 	assert(ctx != NULL);
1541 
1542 	el2_sysregs_ctx = get_el2_sysregs_ctx(ctx);
1543 
1544 	el2_sysregs_context_save_common(el2_sysregs_ctx);
1545 	el2_sysregs_context_save_gic(el2_sysregs_ctx, security_state);
1546 
1547 	if (is_feat_mte2_supported()) {
1548 		write_el2_ctx_mte2(el2_sysregs_ctx, tfsr_el2, read_tfsr_el2());
1549 	}
1550 
1551 	if (is_feat_mpam_supported()) {
1552 		el2_sysregs_context_save_mpam(el2_sysregs_ctx);
1553 	}
1554 
1555 	if (is_feat_fgt_supported()) {
1556 		el2_sysregs_context_save_fgt(el2_sysregs_ctx);
1557 	}
1558 
1559 	if (is_feat_fgt2_supported()) {
1560 		el2_sysregs_context_save_fgt2(el2_sysregs_ctx);
1561 	}
1562 
1563 	if (is_feat_ecv_v2_supported()) {
1564 		write_el2_ctx_ecv(el2_sysregs_ctx, cntpoff_el2, read_cntpoff_el2());
1565 	}
1566 
1567 	if (is_feat_vhe_supported()) {
1568 		write_el2_ctx_vhe(el2_sysregs_ctx, contextidr_el2,
1569 					read_contextidr_el2());
1570 		write_el2_ctx_vhe_sysreg128(el2_sysregs_ctx, ttbr1_el2, read_ttbr1_el2());
1571 	}
1572 
1573 	if (is_feat_ras_supported()) {
1574 		write_el2_ctx_ras(el2_sysregs_ctx, vdisr_el2, read_vdisr_el2());
1575 		write_el2_ctx_ras(el2_sysregs_ctx, vsesr_el2, read_vsesr_el2());
1576 	}
1577 
1578 	if (is_feat_nv2_supported()) {
1579 		write_el2_ctx_neve(el2_sysregs_ctx, vncr_el2, read_vncr_el2());
1580 	}
1581 
1582 	if (is_feat_trf_supported()) {
1583 		write_el2_ctx_trf(el2_sysregs_ctx, trfcr_el2, read_trfcr_el2());
1584 	}
1585 
1586 	if (is_feat_csv2_2_supported()) {
1587 		write_el2_ctx_csv2_2(el2_sysregs_ctx, scxtnum_el2,
1588 					read_scxtnum_el2());
1589 	}
1590 
1591 	if (is_feat_hcx_supported()) {
1592 		write_el2_ctx_hcx(el2_sysregs_ctx, hcrx_el2, read_hcrx_el2());
1593 	}
1594 
1595 	if (is_feat_tcr2_supported()) {
1596 		write_el2_ctx_tcr2(el2_sysregs_ctx, tcr2_el2, read_tcr2_el2());
1597 	}
1598 
1599 	if (is_feat_s1pie_supported()) {
1600 		write_el2_ctx_sxpie(el2_sysregs_ctx, pire0_el2, read_pire0_el2());
1601 		write_el2_ctx_sxpie(el2_sysregs_ctx, pir_el2, read_pir_el2());
1602 	}
1603 
1604 	if (is_feat_s1poe_supported()) {
1605 		write_el2_ctx_sxpoe(el2_sysregs_ctx, por_el2, read_por_el2());
1606 	}
1607 
1608 	if (is_feat_brbe_supported()) {
1609 		write_el2_ctx_brbe(el2_sysregs_ctx, brbcr_el2, read_brbcr_el2());
1610 	}
1611 
1612 	if (is_feat_s2pie_supported()) {
1613 		write_el2_ctx_s2pie(el2_sysregs_ctx, s2pir_el2, read_s2pir_el2());
1614 	}
1615 
1616 	if (is_feat_gcs_supported()) {
1617 		write_el2_ctx_gcs(el2_sysregs_ctx, gcscr_el2, read_gcscr_el2());
1618 		write_el2_ctx_gcs(el2_sysregs_ctx, gcspr_el2, read_gcspr_el2());
1619 	}
1620 
1621 	if (is_feat_sctlr2_supported()) {
1622 		write_el2_ctx_sctlr2(el2_sysregs_ctx, sctlr2_el2, read_sctlr2_el2());
1623 	}
1624 
1625 	if (is_feat_amu_supported()) {
1626 		cm_sysregs_context_save_amu(security_state);
1627 	}
1628 }
1629 
1630 /*******************************************************************************
1631  * Restore EL2 sysreg context
1632  ******************************************************************************/
1633 void cm_el2_sysregs_context_restore(uint32_t security_state)
1634 {
1635 	cpu_context_t *ctx;
1636 	el2_sysregs_t *el2_sysregs_ctx;
1637 
1638 	ctx = cm_get_context(security_state);
1639 	assert(ctx != NULL);
1640 
1641 	el2_sysregs_ctx = get_el2_sysregs_ctx(ctx);
1642 
1643 	el2_sysregs_context_restore_common(el2_sysregs_ctx);
1644 	el2_sysregs_context_restore_gic(el2_sysregs_ctx, security_state);
1645 
1646 	if (is_feat_mte2_supported()) {
1647 		write_tfsr_el2(read_el2_ctx_mte2(el2_sysregs_ctx, tfsr_el2));
1648 	}
1649 
1650 	if (is_feat_mpam_supported()) {
1651 		el2_sysregs_context_restore_mpam(el2_sysregs_ctx);
1652 	}
1653 
1654 	if (is_feat_fgt_supported()) {
1655 		el2_sysregs_context_restore_fgt(el2_sysregs_ctx);
1656 	}
1657 
1658 	if (is_feat_fgt2_supported()) {
1659 		el2_sysregs_context_restore_fgt2(el2_sysregs_ctx);
1660 	}
1661 
1662 	if (is_feat_ecv_v2_supported()) {
1663 		write_cntpoff_el2(read_el2_ctx_ecv(el2_sysregs_ctx, cntpoff_el2));
1664 	}
1665 
1666 	if (is_feat_vhe_supported()) {
1667 		write_contextidr_el2(read_el2_ctx_vhe(el2_sysregs_ctx,
1668 					contextidr_el2));
1669 		write_ttbr1_el2(read_el2_ctx_vhe(el2_sysregs_ctx, ttbr1_el2));
1670 	}
1671 
1672 	if (is_feat_ras_supported()) {
1673 		write_vdisr_el2(read_el2_ctx_ras(el2_sysregs_ctx, vdisr_el2));
1674 		write_vsesr_el2(read_el2_ctx_ras(el2_sysregs_ctx, vsesr_el2));
1675 	}
1676 
1677 	if (is_feat_nv2_supported()) {
1678 		write_vncr_el2(read_el2_ctx_neve(el2_sysregs_ctx, vncr_el2));
1679 	}
1680 
1681 	if (is_feat_trf_supported()) {
1682 		write_trfcr_el2(read_el2_ctx_trf(el2_sysregs_ctx, trfcr_el2));
1683 	}
1684 
1685 	if (is_feat_csv2_2_supported()) {
1686 		write_scxtnum_el2(read_el2_ctx_csv2_2(el2_sysregs_ctx,
1687 					scxtnum_el2));
1688 	}
1689 
1690 	if (is_feat_hcx_supported()) {
1691 		write_hcrx_el2(read_el2_ctx_hcx(el2_sysregs_ctx, hcrx_el2));
1692 	}
1693 
1694 	if (is_feat_tcr2_supported()) {
1695 		write_tcr2_el2(read_el2_ctx_tcr2(el2_sysregs_ctx, tcr2_el2));
1696 	}
1697 
1698 	if (is_feat_s1pie_supported()) {
1699 		write_pire0_el2(read_el2_ctx_sxpie(el2_sysregs_ctx, pire0_el2));
1700 		write_pir_el2(read_el2_ctx_sxpie(el2_sysregs_ctx, pir_el2));
1701 	}
1702 
1703 	if (is_feat_s1poe_supported()) {
1704 		write_por_el2(read_el2_ctx_sxpoe(el2_sysregs_ctx, por_el2));
1705 	}
1706 
1707 	if (is_feat_s2pie_supported()) {
1708 		write_s2pir_el2(read_el2_ctx_s2pie(el2_sysregs_ctx, s2pir_el2));
1709 	}
1710 
1711 	if (is_feat_gcs_supported()) {
1712 		write_gcscr_el2(read_el2_ctx_gcs(el2_sysregs_ctx, gcscr_el2));
1713 		write_gcspr_el2(read_el2_ctx_gcs(el2_sysregs_ctx, gcspr_el2));
1714 	}
1715 
1716 	if (is_feat_sctlr2_supported()) {
1717 		write_sctlr2_el2(read_el2_ctx_sctlr2(el2_sysregs_ctx, sctlr2_el2));
1718 	}
1719 
1720 	if (is_feat_brbe_supported()) {
1721 		write_brbcr_el2(read_el2_ctx_brbe(el2_sysregs_ctx, brbcr_el2));
1722 	}
1723 
1724 	if (is_feat_amu_supported()) {
1725 		cm_sysregs_context_restore_amu(security_state);
1726 	}
1727 }
1728 #endif /* (CTX_INCLUDE_EL2_REGS && IMAGE_BL31) */
1729 
1730 /*******************************************************************************
1731  * This function is used to exit to Non-secure world. If CTX_INCLUDE_EL2_REGS
1732  * is enabled, it restores EL1 and EL2 sysreg contexts instead of directly
1733  * updating EL1 and EL2 registers. Otherwise, it calls the generic
1734  * cm_prepare_el3_exit function.
1735  ******************************************************************************/
1736 void cm_prepare_el3_exit_ns(void)
1737 {
1738 #if (CTX_INCLUDE_EL2_REGS && IMAGE_BL31)
1739 #if ENABLE_ASSERTIONS
1740 	cpu_context_t *ctx = cm_get_context(NON_SECURE);
1741 	assert(ctx != NULL);
1742 
1743 	/* Assert that EL2 is used. */
1744 	u_register_t scr_el3 = read_ctx_reg(get_el3state_ctx(ctx), CTX_SCR_EL3);
1745 	assert(((scr_el3 & SCR_HCE_BIT) != 0UL) &&
1746 			(el_implemented(2U) != EL_IMPL_NONE));
1747 #endif /* ENABLE_ASSERTIONS */
1748 
1749 	/* Restore EL2 sysreg contexts */
1750 	cm_el2_sysregs_context_restore(NON_SECURE);
1751 	cm_set_next_eret_context(NON_SECURE);
1752 #else
1753 	cm_prepare_el3_exit(NON_SECURE);
1754 #endif /* (CTX_INCLUDE_EL2_REGS && IMAGE_BL31) */
1755 
1756 	if (is_feat_amu_supported()) {
1757 		cm_sysregs_context_restore_amu(NON_SECURE);
1758 	}
1759 }
1760 
1761 #if ((IMAGE_BL1) || (IMAGE_BL31 && (!CTX_INCLUDE_EL2_REGS)))
1762 /*******************************************************************************
1763  * The next set of six functions are used by runtime services to save and restore
1764  * EL1 context on the 'cpu_context' structure for the specified security state.
1765  ******************************************************************************/
1766 static void el1_sysregs_context_save(el1_sysregs_t *ctx)
1767 {
1768 	write_el1_ctx_common(ctx, spsr_el1, read_spsr_el1());
1769 	write_el1_ctx_common(ctx, elr_el1, read_elr_el1());
1770 
1771 #if (!ERRATA_SPECULATIVE_AT)
1772 	write_el1_ctx_common(ctx, sctlr_el1, read_sctlr_el1());
1773 	write_el1_ctx_common(ctx, tcr_el1, read_tcr_el1());
1774 #endif /* (!ERRATA_SPECULATIVE_AT) */
1775 
1776 	write_el1_ctx_common(ctx, cpacr_el1, read_cpacr_el1());
1777 	write_el1_ctx_common(ctx, csselr_el1, read_csselr_el1());
1778 	write_el1_ctx_common(ctx, sp_el1, read_sp_el1());
1779 	write_el1_ctx_common(ctx, esr_el1, read_esr_el1());
1780 	write_el1_ctx_common(ctx, mair_el1, read_mair_el1());
1781 	write_el1_ctx_common(ctx, amair_el1, read_amair_el1());
1782 	write_el1_ctx_common(ctx, actlr_el1, read_actlr_el1());
1783 	write_el1_ctx_common(ctx, tpidr_el1, read_tpidr_el1());
1784 	write_el1_ctx_common(ctx, tpidr_el0, read_tpidr_el0());
1785 	write_el1_ctx_common(ctx, tpidrro_el0, read_tpidrro_el0());
1786 	write_el1_ctx_common(ctx, far_el1, read_far_el1());
1787 	write_el1_ctx_common(ctx, afsr0_el1, read_afsr0_el1());
1788 	write_el1_ctx_common(ctx, afsr1_el1, read_afsr1_el1());
1789 	write_el1_ctx_common(ctx, contextidr_el1, read_contextidr_el1());
1790 	write_el1_ctx_common(ctx, vbar_el1, read_vbar_el1());
1791 	write_el1_ctx_common(ctx, mdccint_el1, read_mdccint_el1());
1792 	write_el1_ctx_common(ctx, mdscr_el1, read_mdscr_el1());
1793 
1794 	write_el1_ctx_common_sysreg128(ctx, par_el1, read_par_el1());
1795 	write_el1_ctx_common_sysreg128(ctx, ttbr0_el1, read_ttbr0_el1());
1796 	write_el1_ctx_common_sysreg128(ctx, ttbr1_el1, read_ttbr1_el1());
1797 
1798 	if (CTX_INCLUDE_AARCH32_REGS) {
1799 		/* Save Aarch32 registers */
1800 		write_el1_ctx_aarch32(ctx, spsr_abt, read_spsr_abt());
1801 		write_el1_ctx_aarch32(ctx, spsr_und, read_spsr_und());
1802 		write_el1_ctx_aarch32(ctx, spsr_irq, read_spsr_irq());
1803 		write_el1_ctx_aarch32(ctx, spsr_fiq, read_spsr_fiq());
1804 		write_el1_ctx_aarch32(ctx, dacr32_el2, read_dacr32_el2());
1805 		write_el1_ctx_aarch32(ctx, ifsr32_el2, read_ifsr32_el2());
1806 	}
1807 
1808 	/* Save counter-timer kernel control register */
1809 	write_el1_ctx_arch_timer(ctx, cntkctl_el1, read_cntkctl_el1());
1810 #if NS_TIMER_SWITCH
1811 	/* Save NS Timer registers */
1812 	write_el1_ctx_arch_timer(ctx, cntp_ctl_el0, read_cntp_ctl_el0());
1813 	write_el1_ctx_arch_timer(ctx, cntp_cval_el0, read_cntp_cval_el0());
1814 	write_el1_ctx_arch_timer(ctx, cntv_ctl_el0, read_cntv_ctl_el0());
1815 	write_el1_ctx_arch_timer(ctx, cntv_cval_el0, read_cntv_cval_el0());
1816 #endif
1817 
1818 	if (is_feat_mte2_supported()) {
1819 		write_el1_ctx_mte2(ctx, tfsre0_el1, read_tfsre0_el1());
1820 		write_el1_ctx_mte2(ctx, tfsr_el1, read_tfsr_el1());
1821 		write_el1_ctx_mte2(ctx, rgsr_el1, read_rgsr_el1());
1822 		write_el1_ctx_mte2(ctx, gcr_el1, read_gcr_el1());
1823 	}
1824 
1825 	if (is_feat_ras_supported()) {
1826 		write_el1_ctx_ras(ctx, disr_el1, read_disr_el1());
1827 	}
1828 
1829 	if (is_feat_s1pie_supported()) {
1830 		write_el1_ctx_s1pie(ctx, pire0_el1, read_pire0_el1());
1831 		write_el1_ctx_s1pie(ctx, pir_el1, read_pir_el1());
1832 	}
1833 
1834 	if (is_feat_s1poe_supported()) {
1835 		write_el1_ctx_s1poe(ctx, por_el1, read_por_el1());
1836 	}
1837 
1838 	if (is_feat_s2poe_supported()) {
1839 		write_el1_ctx_s2poe(ctx, s2por_el1, read_s2por_el1());
1840 	}
1841 
1842 	if (is_feat_tcr2_supported()) {
1843 		write_el1_ctx_tcr2(ctx, tcr2_el1, read_tcr2_el1());
1844 	}
1845 
1846 	if (is_feat_trf_supported()) {
1847 		write_el1_ctx_trf(ctx, trfcr_el1, read_trfcr_el1());
1848 	}
1849 
1850 	if (is_feat_csv2_2_supported()) {
1851 		write_el1_ctx_csv2_2(ctx, scxtnum_el0, read_scxtnum_el0());
1852 		write_el1_ctx_csv2_2(ctx, scxtnum_el1, read_scxtnum_el1());
1853 	}
1854 
1855 	if (is_feat_gcs_supported()) {
1856 		write_el1_ctx_gcs(ctx, gcscr_el1, read_gcscr_el1());
1857 		write_el1_ctx_gcs(ctx, gcscre0_el1, read_gcscre0_el1());
1858 		write_el1_ctx_gcs(ctx, gcspr_el1, read_gcspr_el1());
1859 		write_el1_ctx_gcs(ctx, gcspr_el0, read_gcspr_el0());
1860 	}
1861 
1862 	if (is_feat_the_supported()) {
1863 		write_el1_ctx_the_sysreg128(ctx, rcwmask_el1, read_rcwmask_el1());
1864 		write_el1_ctx_the_sysreg128(ctx, rcwsmask_el1, read_rcwsmask_el1());
1865 	}
1866 
1867 	if (is_feat_sctlr2_supported()) {
1868 		write_el1_ctx_sctlr2(ctx, sctlr2_el1, read_sctlr2_el1());
1869 	}
1870 
1871 	if (is_feat_ls64_accdata_supported()) {
1872 		write_el1_ctx_ls64(ctx, accdata_el1, read_accdata_el1());
1873 	}
1874 }
1875 
1876 static void el1_sysregs_context_restore(el1_sysregs_t *ctx)
1877 {
1878 	write_spsr_el1(read_el1_ctx_common(ctx, spsr_el1));
1879 	write_elr_el1(read_el1_ctx_common(ctx, elr_el1));
1880 
1881 #if (!ERRATA_SPECULATIVE_AT)
1882 	write_sctlr_el1(read_el1_ctx_common(ctx, sctlr_el1));
1883 	write_tcr_el1(read_el1_ctx_common(ctx, tcr_el1));
1884 #endif /* (!ERRATA_SPECULATIVE_AT) */
1885 
1886 	write_cpacr_el1(read_el1_ctx_common(ctx, cpacr_el1));
1887 	write_csselr_el1(read_el1_ctx_common(ctx, csselr_el1));
1888 	write_sp_el1(read_el1_ctx_common(ctx, sp_el1));
1889 	write_esr_el1(read_el1_ctx_common(ctx, esr_el1));
1890 	write_ttbr0_el1(read_el1_ctx_common(ctx, ttbr0_el1));
1891 	write_ttbr1_el1(read_el1_ctx_common(ctx, ttbr1_el1));
1892 	write_mair_el1(read_el1_ctx_common(ctx, mair_el1));
1893 	write_amair_el1(read_el1_ctx_common(ctx, amair_el1));
1894 	write_actlr_el1(read_el1_ctx_common(ctx, actlr_el1));
1895 	write_tpidr_el1(read_el1_ctx_common(ctx, tpidr_el1));
1896 	write_tpidr_el0(read_el1_ctx_common(ctx, tpidr_el0));
1897 	write_tpidrro_el0(read_el1_ctx_common(ctx, tpidrro_el0));
1898 	write_par_el1(read_el1_ctx_common(ctx, par_el1));
1899 	write_far_el1(read_el1_ctx_common(ctx, far_el1));
1900 	write_afsr0_el1(read_el1_ctx_common(ctx, afsr0_el1));
1901 	write_afsr1_el1(read_el1_ctx_common(ctx, afsr1_el1));
1902 	write_contextidr_el1(read_el1_ctx_common(ctx, contextidr_el1));
1903 	write_vbar_el1(read_el1_ctx_common(ctx, vbar_el1));
1904 	write_mdccint_el1(read_el1_ctx_common(ctx, mdccint_el1));
1905 	write_mdscr_el1(read_el1_ctx_common(ctx, mdscr_el1));
1906 
1907 	if (CTX_INCLUDE_AARCH32_REGS) {
1908 		/* Restore Aarch32 registers */
1909 		write_spsr_abt(read_el1_ctx_aarch32(ctx, spsr_abt));
1910 		write_spsr_und(read_el1_ctx_aarch32(ctx, spsr_und));
1911 		write_spsr_irq(read_el1_ctx_aarch32(ctx, spsr_irq));
1912 		write_spsr_fiq(read_el1_ctx_aarch32(ctx, spsr_fiq));
1913 		write_dacr32_el2(read_el1_ctx_aarch32(ctx, dacr32_el2));
1914 		write_ifsr32_el2(read_el1_ctx_aarch32(ctx, ifsr32_el2));
1915 	}
1916 
1917 	/* Restore counter-timer kernel control register */
1918 	write_cntkctl_el1(read_el1_ctx_arch_timer(ctx, cntkctl_el1));
1919 #if NS_TIMER_SWITCH
1920 	/* Restore NS Timer registers */
1921 	write_cntp_ctl_el0(read_el1_ctx_arch_timer(ctx, cntp_ctl_el0));
1922 	write_cntp_cval_el0(read_el1_ctx_arch_timer(ctx, cntp_cval_el0));
1923 	write_cntv_ctl_el0(read_el1_ctx_arch_timer(ctx, cntv_ctl_el0));
1924 	write_cntv_cval_el0(read_el1_ctx_arch_timer(ctx, cntv_cval_el0));
1925 #endif
1926 
1927 	if (is_feat_mte2_supported()) {
1928 		write_tfsre0_el1(read_el1_ctx_mte2(ctx, tfsre0_el1));
1929 		write_tfsr_el1(read_el1_ctx_mte2(ctx, tfsr_el1));
1930 		write_rgsr_el1(read_el1_ctx_mte2(ctx, rgsr_el1));
1931 		write_gcr_el1(read_el1_ctx_mte2(ctx, gcr_el1));
1932 	}
1933 
1934 	if (is_feat_ras_supported()) {
1935 		write_disr_el1(read_el1_ctx_ras(ctx, disr_el1));
1936 	}
1937 
1938 	if (is_feat_s1pie_supported()) {
1939 		write_pire0_el1(read_el1_ctx_s1pie(ctx, pire0_el1));
1940 		write_pir_el1(read_el1_ctx_s1pie(ctx, pir_el1));
1941 	}
1942 
1943 	if (is_feat_s1poe_supported()) {
1944 		write_por_el1(read_el1_ctx_s1poe(ctx, por_el1));
1945 	}
1946 
1947 	if (is_feat_s2poe_supported()) {
1948 		write_s2por_el1(read_el1_ctx_s2poe(ctx, s2por_el1));
1949 	}
1950 
1951 	if (is_feat_tcr2_supported()) {
1952 		write_tcr2_el1(read_el1_ctx_tcr2(ctx, tcr2_el1));
1953 	}
1954 
1955 	if (is_feat_trf_supported()) {
1956 		write_trfcr_el1(read_el1_ctx_trf(ctx, trfcr_el1));
1957 	}
1958 
1959 	if (is_feat_csv2_2_supported()) {
1960 		write_scxtnum_el0(read_el1_ctx_csv2_2(ctx, scxtnum_el0));
1961 		write_scxtnum_el1(read_el1_ctx_csv2_2(ctx, scxtnum_el1));
1962 	}
1963 
1964 	if (is_feat_gcs_supported()) {
1965 		write_gcscr_el1(read_el1_ctx_gcs(ctx, gcscr_el1));
1966 		write_gcscre0_el1(read_el1_ctx_gcs(ctx, gcscre0_el1));
1967 		write_gcspr_el1(read_el1_ctx_gcs(ctx, gcspr_el1));
1968 		write_gcspr_el0(read_el1_ctx_gcs(ctx, gcspr_el0));
1969 	}
1970 
1971 	if (is_feat_the_supported()) {
1972 		write_rcwmask_el1(read_el1_ctx_the(ctx, rcwmask_el1));
1973 		write_rcwsmask_el1(read_el1_ctx_the(ctx, rcwsmask_el1));
1974 	}
1975 
1976 	if (is_feat_sctlr2_supported()) {
1977 		write_sctlr2_el1(read_el1_ctx_sctlr2(ctx, sctlr2_el1));
1978 	}
1979 
1980 	if (is_feat_ls64_accdata_supported()) {
1981 		write_accdata_el1(read_el1_ctx_ls64(ctx, accdata_el1));
1982 	}
1983 }
1984 
1985 /*******************************************************************************
1986  * The next couple of functions are used by runtime services to save and restore
1987  * EL1 context on the 'cpu_context' structure for the specified security state.
1988  ******************************************************************************/
1989 void cm_el1_sysregs_context_save(uint32_t security_state)
1990 {
1991 	cpu_context_t *ctx;
1992 
1993 	ctx = cm_get_context(security_state);
1994 	assert(ctx != NULL);
1995 
1996 	el1_sysregs_context_save(get_el1_sysregs_ctx(ctx));
1997 
1998 #if IMAGE_BL31
1999 	if (is_feat_amu_supported()) {
2000 		cm_sysregs_context_save_amu(security_state);
2001 	}
2002 
2003 	if (security_state == SECURE) {
2004 		PUBLISH_EVENT(cm_exited_secure_world);
2005 	} else {
2006 		PUBLISH_EVENT(cm_exited_normal_world);
2007 	}
2008 #endif
2009 }
2010 
2011 void cm_el1_sysregs_context_restore(uint32_t security_state)
2012 {
2013 	cpu_context_t *ctx;
2014 
2015 	ctx = cm_get_context(security_state);
2016 	assert(ctx != NULL);
2017 
2018 	el1_sysregs_context_restore(get_el1_sysregs_ctx(ctx));
2019 
2020 #if IMAGE_BL31
2021 	if (is_feat_amu_supported()) {
2022 		cm_sysregs_context_restore_amu(security_state);
2023 	}
2024 
2025 	if (security_state == SECURE) {
2026 		PUBLISH_EVENT(cm_entering_secure_world);
2027 	} else {
2028 		PUBLISH_EVENT(cm_entering_normal_world);
2029 	}
2030 #endif
2031 }
2032 
2033 #endif /* ((IMAGE_BL1) || (IMAGE_BL31 && (!CTX_INCLUDE_EL2_REGS))) */
2034 
2035 /*******************************************************************************
2036  * This function populates ELR_EL3 member of 'cpu_context' pertaining to the
2037  * given security state with the given entrypoint
2038  ******************************************************************************/
2039 void cm_set_elr_el3(uint32_t security_state, uintptr_t entrypoint)
2040 {
2041 	cpu_context_t *ctx;
2042 	el3_state_t *state;
2043 
2044 	ctx = cm_get_context(security_state);
2045 	assert(ctx != NULL);
2046 
2047 	/* Populate EL3 state so that ERET jumps to the correct entry */
2048 	state = get_el3state_ctx(ctx);
2049 	write_ctx_reg(state, CTX_ELR_EL3, entrypoint);
2050 }
2051 
2052 /*******************************************************************************
2053  * This function populates ELR_EL3 and SPSR_EL3 members of 'cpu_context'
2054  * pertaining to the given security state
2055  ******************************************************************************/
2056 void cm_set_elr_spsr_el3(uint32_t security_state,
2057 			uintptr_t entrypoint, uint32_t spsr)
2058 {
2059 	cpu_context_t *ctx;
2060 	el3_state_t *state;
2061 
2062 	ctx = cm_get_context(security_state);
2063 	assert(ctx != NULL);
2064 
2065 	/* Populate EL3 state so that ERET jumps to the correct entry */
2066 	state = get_el3state_ctx(ctx);
2067 	write_ctx_reg(state, CTX_ELR_EL3, entrypoint);
2068 	write_ctx_reg(state, CTX_SPSR_EL3, spsr);
2069 }
2070 
2071 /*******************************************************************************
2072  * This function updates a single bit in the SCR_EL3 member of the 'cpu_context'
2073  * pertaining to the given security state using the value and bit position
2074  * specified in the parameters. It preserves all other bits.
2075  ******************************************************************************/
2076 void cm_write_scr_el3_bit(uint32_t security_state,
2077 			  uint32_t bit_pos,
2078 			  uint32_t value)
2079 {
2080 	cpu_context_t *ctx;
2081 	el3_state_t *state;
2082 	u_register_t scr_el3;
2083 
2084 	ctx = cm_get_context(security_state);
2085 	assert(ctx != NULL);
2086 
2087 	/* Ensure that the bit position is a valid one */
2088 	assert(((1UL << bit_pos) & SCR_VALID_BIT_MASK) != 0U);
2089 
2090 	/* Ensure that the 'value' is only a bit wide */
2091 	assert(value <= 1U);
2092 
2093 	/*
2094 	 * Get the SCR_EL3 value from the cpu context, clear the desired bit
2095 	 * and set it to its new value.
2096 	 */
2097 	state = get_el3state_ctx(ctx);
2098 	scr_el3 = read_ctx_reg(state, CTX_SCR_EL3);
2099 	scr_el3 &= ~(1UL << bit_pos);
2100 	scr_el3 |= (u_register_t)value << bit_pos;
2101 	write_ctx_reg(state, CTX_SCR_EL3, scr_el3);
2102 }
2103 
2104 /*******************************************************************************
2105  * This function retrieves SCR_EL3 member of 'cpu_context' pertaining to the
2106  * given security state.
2107  ******************************************************************************/
2108 u_register_t cm_get_scr_el3(uint32_t security_state)
2109 {
2110 	const cpu_context_t *ctx;
2111 	const el3_state_t *state;
2112 
2113 	ctx = cm_get_context(security_state);
2114 	assert(ctx != NULL);
2115 
2116 	/* Populate EL3 state so that ERET jumps to the correct entry */
2117 	state = get_el3state_ctx(ctx);
2118 	return read_ctx_reg(state, CTX_SCR_EL3);
2119 }
2120 
2121 /*******************************************************************************
2122  * This function is used to program the context that's used for exception
2123  * return. This initializes the SP_EL3 to a pointer to a 'cpu_context' set for
2124  * the required security state
2125  ******************************************************************************/
2126 void cm_set_next_eret_context(uint32_t security_state)
2127 {
2128 	cpu_context_t *ctx;
2129 
2130 	ctx = cm_get_context(security_state);
2131 	assert(ctx != NULL);
2132 
2133 	cm_set_next_context(ctx);
2134 }
2135