xref: /rk3399_ARM-atf/lib/el3_runtime/aarch64/context_mgmt.c (revision 4c700c1563aff7b51df95f17e952e050b9b4e37f)
1 /*
2  * Copyright (c) 2013-2023, 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/el3_runtime/context_mgmt.h>
23 #include <lib/el3_runtime/pubsub_events.h>
24 #include <lib/extensions/amu.h>
25 #include <lib/extensions/brbe.h>
26 #include <lib/extensions/mpam.h>
27 #include <lib/extensions/pmuv3.h>
28 #include <lib/extensions/sme.h>
29 #include <lib/extensions/spe.h>
30 #include <lib/extensions/sve.h>
31 #include <lib/extensions/sys_reg_trace.h>
32 #include <lib/extensions/trbe.h>
33 #include <lib/extensions/trf.h>
34 #include <lib/utils.h>
35 
36 #if ENABLE_FEAT_TWED
37 /* Make sure delay value fits within the range(0-15) */
38 CASSERT(((TWED_DELAY & ~SCR_TWEDEL_MASK) == 0U), assert_twed_delay_value_check);
39 #endif /* ENABLE_FEAT_TWED */
40 
41 static void manage_extensions_nonsecure(cpu_context_t *ctx);
42 static void manage_extensions_secure(cpu_context_t *ctx);
43 
44 static void setup_el1_context(cpu_context_t *ctx, const struct entry_point_info *ep)
45 {
46 	u_register_t sctlr_elx, actlr_elx;
47 
48 	/*
49 	 * Initialise SCTLR_EL1 to the reset value corresponding to the target
50 	 * execution state setting all fields rather than relying on the hw.
51 	 * Some fields have architecturally UNKNOWN reset values and these are
52 	 * set to zero.
53 	 *
54 	 * SCTLR.EE: Endianness is taken from the entrypoint attributes.
55 	 *
56 	 * SCTLR.M, SCTLR.C and SCTLR.I: These fields must be zero (as
57 	 * required by PSCI specification)
58 	 */
59 	sctlr_elx = (EP_GET_EE(ep->h.attr) != 0U) ? SCTLR_EE_BIT : 0UL;
60 	if (GET_RW(ep->spsr) == MODE_RW_64) {
61 		sctlr_elx |= SCTLR_EL1_RES1;
62 	} else {
63 		/*
64 		 * If the target execution state is AArch32 then the following
65 		 * fields need to be set.
66 		 *
67 		 * SCTRL_EL1.nTWE: Set to one so that EL0 execution of WFE
68 		 *  instructions are not trapped to EL1.
69 		 *
70 		 * SCTLR_EL1.nTWI: Set to one so that EL0 execution of WFI
71 		 *  instructions are not trapped to EL1.
72 		 *
73 		 * SCTLR_EL1.CP15BEN: Set to one to enable EL0 execution of the
74 		 *  CP15DMB, CP15DSB, and CP15ISB instructions.
75 		 */
76 		sctlr_elx |= SCTLR_AARCH32_EL1_RES1 | SCTLR_CP15BEN_BIT
77 					| SCTLR_NTWI_BIT | SCTLR_NTWE_BIT;
78 	}
79 
80 #if ERRATA_A75_764081
81 	/*
82 	 * If workaround of errata 764081 for Cortex-A75 is used then set
83 	 * SCTLR_EL1.IESB to enable Implicit Error Synchronization Barrier.
84 	 */
85 	sctlr_elx |= SCTLR_IESB_BIT;
86 #endif
87 	/* Store the initialised SCTLR_EL1 value in the cpu_context */
88 	write_ctx_reg(get_el1_sysregs_ctx(ctx), CTX_SCTLR_EL1, sctlr_elx);
89 
90 	/*
91 	 * Base the context ACTLR_EL1 on the current value, as it is
92 	 * implementation defined. The context restore process will write
93 	 * the value from the context to the actual register and can cause
94 	 * problems for processor cores that don't expect certain bits to
95 	 * be zero.
96 	 */
97 	actlr_elx = read_actlr_el1();
98 	write_ctx_reg((get_el1_sysregs_ctx(ctx)), (CTX_ACTLR_EL1), (actlr_elx));
99 }
100 
101 /******************************************************************************
102  * This function performs initializations that are specific to SECURE state
103  * and updates the cpu context specified by 'ctx'.
104  *****************************************************************************/
105 static void setup_secure_context(cpu_context_t *ctx, const struct entry_point_info *ep)
106 {
107 	u_register_t scr_el3;
108 	el3_state_t *state;
109 
110 	state = get_el3state_ctx(ctx);
111 	scr_el3 = read_ctx_reg(state, CTX_SCR_EL3);
112 
113 #if defined(IMAGE_BL31) && !defined(SPD_spmd)
114 	/*
115 	 * SCR_EL3.IRQ, SCR_EL3.FIQ: Enable the physical FIQ and IRQ routing as
116 	 * indicated by the interrupt routing model for BL31.
117 	 */
118 	scr_el3 |= get_scr_el3_from_routing_model(SECURE);
119 #endif
120 
121 #if !CTX_INCLUDE_MTE_REGS || ENABLE_ASSERTIONS
122 	/* Get Memory Tagging Extension support level */
123 	unsigned int mte = get_armv8_5_mte_support();
124 #endif
125 	/*
126 	 * Allow access to Allocation Tags when CTX_INCLUDE_MTE_REGS
127 	 * is set, or when MTE is only implemented at EL0.
128 	 */
129 #if CTX_INCLUDE_MTE_REGS
130 	assert((mte == MTE_IMPLEMENTED_ELX) || (mte == MTE_IMPLEMENTED_ASY));
131 	scr_el3 |= SCR_ATA_BIT;
132 #else
133 	if (mte == MTE_IMPLEMENTED_EL0) {
134 		scr_el3 |= SCR_ATA_BIT;
135 	}
136 #endif /* CTX_INCLUDE_MTE_REGS */
137 
138 	/* Enable S-EL2 if the next EL is EL2 and S-EL2 is present */
139 	if ((GET_EL(ep->spsr) == MODE_EL2) && is_feat_sel2_supported()) {
140 		if (GET_RW(ep->spsr) != MODE_RW_64) {
141 			ERROR("S-EL2 can not be used in AArch32\n.");
142 			panic();
143 		}
144 
145 		scr_el3 |= SCR_EEL2_BIT;
146 	}
147 
148 	write_ctx_reg(state, CTX_SCR_EL3, scr_el3);
149 
150 	/*
151 	 * Initialize EL1 context registers unless SPMC is running
152 	 * at S-EL2.
153 	 */
154 #if !SPMD_SPM_AT_SEL2
155 	setup_el1_context(ctx, ep);
156 #endif
157 
158 	manage_extensions_secure(ctx);
159 }
160 
161 #if ENABLE_RME
162 /******************************************************************************
163  * This function performs initializations that are specific to REALM state
164  * and updates the cpu context specified by 'ctx'.
165  *****************************************************************************/
166 static void setup_realm_context(cpu_context_t *ctx, const struct entry_point_info *ep)
167 {
168 	u_register_t scr_el3;
169 	el3_state_t *state;
170 
171 	state = get_el3state_ctx(ctx);
172 	scr_el3 = read_ctx_reg(state, CTX_SCR_EL3);
173 
174 	scr_el3 |= SCR_NS_BIT | SCR_NSE_BIT;
175 
176 	if (is_feat_csv2_2_supported()) {
177 		/* Enable access to the SCXTNUM_ELx registers. */
178 		scr_el3 |= SCR_EnSCXT_BIT;
179 	}
180 
181 	write_ctx_reg(state, CTX_SCR_EL3, scr_el3);
182 }
183 #endif /* ENABLE_RME */
184 
185 /******************************************************************************
186  * This function performs initializations that are specific to NON-SECURE state
187  * and updates the cpu context specified by 'ctx'.
188  *****************************************************************************/
189 static void setup_ns_context(cpu_context_t *ctx, const struct entry_point_info *ep)
190 {
191 	u_register_t scr_el3;
192 	el3_state_t *state;
193 
194 	state = get_el3state_ctx(ctx);
195 	scr_el3 = read_ctx_reg(state, CTX_SCR_EL3);
196 
197 	/* SCR_NS: Set the NS bit */
198 	scr_el3 |= SCR_NS_BIT;
199 
200 #if !CTX_INCLUDE_PAUTH_REGS
201 	/*
202 	 * If the pointer authentication registers aren't saved during world
203 	 * switches the value of the registers can be leaked from the Secure to
204 	 * the Non-secure world. To prevent this, rather than enabling pointer
205 	 * authentication everywhere, we only enable it in the Non-secure world.
206 	 *
207 	 * If the Secure world wants to use pointer authentication,
208 	 * CTX_INCLUDE_PAUTH_REGS must be set to 1.
209 	 */
210 	scr_el3 |= SCR_API_BIT | SCR_APK_BIT;
211 #endif /* !CTX_INCLUDE_PAUTH_REGS */
212 
213 	/* Allow access to Allocation Tags when MTE is implemented. */
214 	scr_el3 |= SCR_ATA_BIT;
215 
216 #if HANDLE_EA_EL3_FIRST_NS
217 	/* SCR_EL3.EA: Route External Abort and SError Interrupt to EL3. */
218 	scr_el3 |= SCR_EA_BIT;
219 #endif
220 
221 #if RAS_TRAP_NS_ERR_REC_ACCESS
222 	/*
223 	 * SCR_EL3.TERR: Trap Error record accesses. Accesses to the RAS ERR
224 	 * and RAS ERX registers from EL1 and EL2(from any security state)
225 	 * are trapped to EL3.
226 	 * Set here to trap only for NS EL1/EL2
227 	 *
228 	 */
229 	scr_el3 |= SCR_TERR_BIT;
230 #endif
231 
232 	if (is_feat_csv2_2_supported()) {
233 		/* Enable access to the SCXTNUM_ELx registers. */
234 		scr_el3 |= SCR_EnSCXT_BIT;
235 	}
236 
237 #ifdef IMAGE_BL31
238 	/*
239 	 * SCR_EL3.IRQ, SCR_EL3.FIQ: Enable the physical FIQ and IRQ routing as
240 	 *  indicated by the interrupt routing model for BL31.
241 	 */
242 	scr_el3 |= get_scr_el3_from_routing_model(NON_SECURE);
243 #endif
244 	write_ctx_reg(state, CTX_SCR_EL3, scr_el3);
245 
246 	/* Initialize EL1 context registers */
247 	setup_el1_context(ctx, ep);
248 
249 	/* Initialize EL2 context registers */
250 #if CTX_INCLUDE_EL2_REGS
251 
252 	/*
253 	 * Initialize SCTLR_EL2 context register using Endianness value
254 	 * taken from the entrypoint attribute.
255 	 */
256 	u_register_t sctlr_el2 = (EP_GET_EE(ep->h.attr) != 0U) ? SCTLR_EE_BIT : 0UL;
257 	sctlr_el2 |= SCTLR_EL2_RES1;
258 	write_ctx_reg(get_el2_sysregs_ctx(ctx), CTX_SCTLR_EL2,
259 			sctlr_el2);
260 
261 	/*
262 	 * Program the ICC_SRE_EL2 to make sure the correct bits are set
263 	 * when restoring NS context.
264 	 */
265 	u_register_t icc_sre_el2 = ICC_SRE_DIB_BIT | ICC_SRE_DFB_BIT |
266 				   ICC_SRE_EN_BIT | ICC_SRE_SRE_BIT;
267 	write_ctx_reg(get_el2_sysregs_ctx(ctx), CTX_ICC_SRE_EL2,
268 			icc_sre_el2);
269 
270 	if (is_feat_hcx_supported()) {
271 		/*
272 		 * Initialize register HCRX_EL2 with its init value.
273 		 * As the value of HCRX_EL2 is UNKNOWN on reset, there is a
274 		 * chance that this can lead to unexpected behavior in lower
275 		 * ELs that have not been updated since the introduction of
276 		 * this feature if not properly initialized, especially when
277 		 * it comes to those bits that enable/disable traps.
278 		 */
279 		write_ctx_reg(get_el2_sysregs_ctx(ctx), CTX_HCRX_EL2,
280 			HCRX_EL2_INIT_VAL);
281 	}
282 #endif /* CTX_INCLUDE_EL2_REGS */
283 
284 	manage_extensions_nonsecure(ctx);
285 }
286 
287 /*******************************************************************************
288  * The following function performs initialization of the cpu_context 'ctx'
289  * for first use that is common to all security states, and sets the
290  * initial entrypoint state as specified by the entry_point_info structure.
291  *
292  * The EE and ST attributes are used to configure the endianness and secure
293  * timer availability for the new execution context.
294  ******************************************************************************/
295 static void setup_context_common(cpu_context_t *ctx, const entry_point_info_t *ep)
296 {
297 	u_register_t scr_el3;
298 	el3_state_t *state;
299 	gp_regs_t *gp_regs;
300 
301 	/* Clear any residual register values from the context */
302 	zeromem(ctx, sizeof(*ctx));
303 
304 	/*
305 	 * SCR_EL3 was initialised during reset sequence in macro
306 	 * el3_arch_init_common. This code modifies the SCR_EL3 fields that
307 	 * affect the next EL.
308 	 *
309 	 * The following fields are initially set to zero and then updated to
310 	 * the required value depending on the state of the SPSR_EL3 and the
311 	 * Security state and entrypoint attributes of the next EL.
312 	 */
313 	scr_el3 = read_scr();
314 	scr_el3 &= ~(SCR_NS_BIT | SCR_RW_BIT | SCR_EA_BIT | SCR_FIQ_BIT | SCR_IRQ_BIT |
315 			SCR_ST_BIT | SCR_HCE_BIT | SCR_NSE_BIT);
316 
317 	/*
318 	 * SCR_EL3.RW: Set the execution state, AArch32 or AArch64, for next
319 	 *  Exception level as specified by SPSR.
320 	 */
321 	if (GET_RW(ep->spsr) == MODE_RW_64) {
322 		scr_el3 |= SCR_RW_BIT;
323 	}
324 
325 	/*
326 	 * SCR_EL3.ST: Traps Secure EL1 accesses to the Counter-timer Physical
327 	 * Secure timer registers to EL3, from AArch64 state only, if specified
328 	 * by the entrypoint attributes. If SEL2 is present and enabled, the ST
329 	 * bit always behaves as 1 (i.e. secure physical timer register access
330 	 * is not trapped)
331 	 */
332 	if (EP_GET_ST(ep->h.attr) != 0U) {
333 		scr_el3 |= SCR_ST_BIT;
334 	}
335 
336 	/*
337 	 * If FEAT_HCX is enabled, enable access to HCRX_EL2 by setting
338 	 * SCR_EL3.HXEn.
339 	 */
340 	if (is_feat_hcx_supported()) {
341 		scr_el3 |= SCR_HXEn_BIT;
342 	}
343 
344 	/*
345 	 * If FEAT_RNG_TRAP is enabled, all reads of the RNDR and RNDRRS
346 	 * registers are trapped to EL3.
347 	 */
348 #if ENABLE_FEAT_RNG_TRAP
349 	scr_el3 |= SCR_TRNDR_BIT;
350 #endif
351 
352 #if FAULT_INJECTION_SUPPORT
353 	/* Enable fault injection from lower ELs */
354 	scr_el3 |= SCR_FIEN_BIT;
355 #endif
356 
357 	/*
358 	 * SCR_EL3.TCR2EN: Enable access to TCR2_ELx for AArch64 if present.
359 	 */
360 	if (is_feat_tcr2_supported() && (GET_RW(ep->spsr) == MODE_RW_64)) {
361 		scr_el3 |= SCR_TCR2EN_BIT;
362 	}
363 
364 	/*
365 	 * SCR_EL3.PIEN: Enable permission indirection and overlay
366 	 * registers for AArch64 if present.
367 	 */
368 	if (is_feat_sxpie_supported() || is_feat_sxpoe_supported()) {
369 		scr_el3 |= SCR_PIEN_BIT;
370 	}
371 
372 	/*
373 	 * SCR_EL3.GCSEn: Enable GCS registers for AArch64 if present.
374 	 */
375 	if ((is_feat_gcs_supported()) && (GET_RW(ep->spsr) == MODE_RW_64)) {
376 		scr_el3 |= SCR_GCSEn_BIT;
377 	}
378 
379 	/*
380 	 * CPTR_EL3 was initialized out of reset, copy that value to the
381 	 * context register.
382 	 */
383 	write_ctx_reg(get_el3state_ctx(ctx), CTX_CPTR_EL3, read_cptr_el3());
384 
385 	/*
386 	 * SCR_EL3.HCE: Enable HVC instructions if next execution state is
387 	 * AArch64 and next EL is EL2, or if next execution state is AArch32 and
388 	 * next mode is Hyp.
389 	 * SCR_EL3.FGTEn: Enable Fine Grained Virtualization Traps under the
390 	 * same conditions as HVC instructions and when the processor supports
391 	 * ARMv8.6-FGT.
392 	 * SCR_EL3.ECVEn: Enable Enhanced Counter Virtualization (ECV)
393 	 * CNTPOFF_EL2 register under the same conditions as HVC instructions
394 	 * and when the processor supports ECV.
395 	 */
396 	if (((GET_RW(ep->spsr) == MODE_RW_64) && (GET_EL(ep->spsr) == MODE_EL2))
397 	    || ((GET_RW(ep->spsr) != MODE_RW_64)
398 		&& (GET_M32(ep->spsr) == MODE32_hyp))) {
399 		scr_el3 |= SCR_HCE_BIT;
400 
401 		if (is_feat_fgt_supported()) {
402 			scr_el3 |= SCR_FGTEN_BIT;
403 		}
404 
405 		if (is_feat_ecv_supported()) {
406 			scr_el3 |= SCR_ECVEN_BIT;
407 		}
408 	}
409 
410 	/* Enable WFE trap delay in SCR_EL3 if supported and configured */
411 	if (is_feat_twed_supported()) {
412 		/* Set delay in SCR_EL3 */
413 		scr_el3 &= ~(SCR_TWEDEL_MASK << SCR_TWEDEL_SHIFT);
414 		scr_el3 |= ((TWED_DELAY & SCR_TWEDEL_MASK)
415 				<< SCR_TWEDEL_SHIFT);
416 
417 		/* Enable WFE delay */
418 		scr_el3 |= SCR_TWEDEn_BIT;
419 	}
420 
421 	/*
422 	 * Populate EL3 state so that we've the right context
423 	 * before doing ERET
424 	 */
425 	state = get_el3state_ctx(ctx);
426 	write_ctx_reg(state, CTX_SCR_EL3, scr_el3);
427 	write_ctx_reg(state, CTX_ELR_EL3, ep->pc);
428 	write_ctx_reg(state, CTX_SPSR_EL3, ep->spsr);
429 
430 	/*
431 	 * Store the X0-X7 value from the entrypoint into the context
432 	 * Use memcpy as we are in control of the layout of the structures
433 	 */
434 	gp_regs = get_gpregs_ctx(ctx);
435 	memcpy(gp_regs, (void *)&ep->args, sizeof(aapcs64_params_t));
436 }
437 
438 /*******************************************************************************
439  * Context management library initialization routine. This library is used by
440  * runtime services to share pointers to 'cpu_context' structures for secure
441  * non-secure and realm states. Management of the structures and their associated
442  * memory is not done by the context management library e.g. the PSCI service
443  * manages the cpu context used for entry from and exit to the non-secure state.
444  * The Secure payload dispatcher service manages the context(s) corresponding to
445  * the secure state. It also uses this library to get access to the non-secure
446  * state cpu context pointers.
447  * Lastly, this library provides the API to make SP_EL3 point to the cpu context
448  * which will be used for programming an entry into a lower EL. The same context
449  * will be used to save state upon exception entry from that EL.
450  ******************************************************************************/
451 void __init cm_init(void)
452 {
453 	/*
454 	 * The context management library has only global data to initialize, but
455 	 * that will be done when the BSS is zeroed out.
456 	 */
457 }
458 
459 /*******************************************************************************
460  * This is the high-level function used to initialize the cpu_context 'ctx' for
461  * first use. It performs initializations that are common to all security states
462  * and initializations specific to the security state specified in 'ep'
463  ******************************************************************************/
464 void cm_setup_context(cpu_context_t *ctx, const entry_point_info_t *ep)
465 {
466 	unsigned int security_state;
467 
468 	assert(ctx != NULL);
469 
470 	/*
471 	 * Perform initializations that are common
472 	 * to all security states
473 	 */
474 	setup_context_common(ctx, ep);
475 
476 	security_state = GET_SECURITY_STATE(ep->h.attr);
477 
478 	/* Perform security state specific initializations */
479 	switch (security_state) {
480 	case SECURE:
481 		setup_secure_context(ctx, ep);
482 		break;
483 #if ENABLE_RME
484 	case REALM:
485 		setup_realm_context(ctx, ep);
486 		break;
487 #endif
488 	case NON_SECURE:
489 		setup_ns_context(ctx, ep);
490 		break;
491 	default:
492 		ERROR("Invalid security state\n");
493 		panic();
494 		break;
495 	}
496 }
497 
498 /*******************************************************************************
499  * Enable architecture extensions for EL3 execution. This function only updates
500  * registers in-place which are expected to either never change or be
501  * overwritten by el3_exit.
502  ******************************************************************************/
503 #if IMAGE_BL31
504 void cm_manage_extensions_el3(void)
505 {
506 	if (is_feat_spe_supported()) {
507 		spe_init_el3();
508 	}
509 
510 	if (is_feat_amu_supported()) {
511 		amu_init_el3();
512 	}
513 
514 	if (is_feat_sme_supported()) {
515 		sme_init_el3();
516 	}
517 
518 	if (is_feat_mpam_supported()) {
519 		mpam_init_el3();
520 	}
521 
522 	if (is_feat_trbe_supported()) {
523 		trbe_init_el3();
524 	}
525 
526 	if (is_feat_brbe_supported()) {
527 		brbe_init_el3();
528 	}
529 
530 	if (is_feat_trf_supported()) {
531 		trf_init_el3();
532 	}
533 
534 	pmuv3_init_el3();
535 }
536 #endif /* IMAGE_BL31 */
537 
538 /*******************************************************************************
539  * Enable architecture extensions on first entry to Non-secure world.
540  ******************************************************************************/
541 static void manage_extensions_nonsecure(cpu_context_t *ctx)
542 {
543 #if IMAGE_BL31
544 	if (is_feat_amu_supported()) {
545 		amu_enable(ctx);
546 	}
547 
548 	/* Enable SVE and FPU/SIMD */
549 	if (is_feat_sve_supported()) {
550 		sve_enable(ctx);
551 	}
552 
553 	if (is_feat_sme_supported()) {
554 		sme_enable(ctx);
555 	}
556 
557 	if (is_feat_sys_reg_trace_supported()) {
558 		sys_reg_trace_enable(ctx);
559 	}
560 
561 	pmuv3_enable(ctx);
562 #endif /* IMAGE_BL31 */
563 }
564 
565 /* TODO: move to lib/extensions/pauth when it has been ported to FEAT_STATE */
566 static __unused void enable_pauth_el2(void)
567 {
568 	u_register_t hcr_el2 = read_hcr_el2();
569 	/*
570 	 * For Armv8.3 pointer authentication feature, disable traps to EL2 when
571 	 *  accessing key registers or using pointer authentication instructions
572 	 *  from lower ELs.
573 	 */
574 	hcr_el2 |= (HCR_API_BIT | HCR_APK_BIT);
575 
576 	write_hcr_el2(hcr_el2);
577 }
578 
579 /*******************************************************************************
580  * Enable architecture extensions in-place at EL2 on first entry to Non-secure
581  * world when EL2 is empty and unused.
582  ******************************************************************************/
583 static void manage_extensions_nonsecure_el2_unused(void)
584 {
585 #if IMAGE_BL31
586 	if (is_feat_spe_supported()) {
587 		spe_init_el2_unused();
588 	}
589 
590 	if (is_feat_amu_supported()) {
591 		amu_init_el2_unused();
592 	}
593 
594 	if (is_feat_mpam_supported()) {
595 		mpam_init_el2_unused();
596 	}
597 
598 	if (is_feat_trbe_supported()) {
599 		trbe_init_el2_unused();
600 	}
601 
602 	if (is_feat_sys_reg_trace_supported()) {
603 		sys_reg_trace_init_el2_unused();
604 	}
605 
606 	if (is_feat_trf_supported()) {
607 		trf_init_el2_unused();
608 	}
609 
610 	pmuv3_init_el2_unused();
611 
612 	if (is_feat_sve_supported()) {
613 		sve_init_el2_unused();
614 	}
615 
616 	if (is_feat_sme_supported()) {
617 		sme_init_el2_unused();
618 	}
619 
620 #if ENABLE_PAUTH
621 	enable_pauth_el2();
622 #endif /* ENABLE_PAUTH */
623 #endif /* IMAGE_BL31 */
624 }
625 
626 /*******************************************************************************
627  * Enable architecture extensions on first entry to Secure world.
628  ******************************************************************************/
629 static void manage_extensions_secure(cpu_context_t *ctx)
630 {
631 #if IMAGE_BL31
632 	if (is_feat_sve_supported()) {
633 		if (ENABLE_SVE_FOR_SWD) {
634 		/*
635 		 * Enable SVE and FPU in secure context, secure manager must
636 		 * ensure that the SVE and FPU register contexts are properly
637 		 * managed.
638 		 */
639 			sve_enable(ctx);
640 		} else {
641 		/*
642 		 * Disable SVE and FPU in secure context so non-secure world
643 		 * can safely use them.
644 		 */
645 			sve_disable(ctx);
646 		}
647 	}
648 
649 	if (is_feat_sme_supported()) {
650 		if (ENABLE_SME_FOR_SWD) {
651 		/*
652 		 * Enable SME, SVE, FPU/SIMD in secure context, secure manager
653 		 * must ensure SME, SVE, and FPU/SIMD context properly managed.
654 		 */
655 			sme_init_el3();
656 			sme_enable(ctx);
657 		} else {
658 		/*
659 		 * Disable SME, SVE, FPU/SIMD in secure context so non-secure
660 		 * world can safely use the associated registers.
661 		 */
662 			sme_disable(ctx);
663 		}
664 	}
665 
666 	/* NS can access this but Secure shouldn't */
667 	if (is_feat_sys_reg_trace_supported()) {
668 		sys_reg_trace_disable(ctx);
669 	}
670 #endif /* IMAGE_BL31 */
671 }
672 
673 /*******************************************************************************
674  * The following function initializes the cpu_context for a CPU specified by
675  * its `cpu_idx` for first use, and sets the initial entrypoint state as
676  * specified by the entry_point_info structure.
677  ******************************************************************************/
678 void cm_init_context_by_index(unsigned int cpu_idx,
679 			      const entry_point_info_t *ep)
680 {
681 	cpu_context_t *ctx;
682 	ctx = cm_get_context_by_index(cpu_idx, GET_SECURITY_STATE(ep->h.attr));
683 	cm_setup_context(ctx, ep);
684 }
685 
686 /*******************************************************************************
687  * The following function initializes the cpu_context for the current CPU
688  * for first use, and sets the initial entrypoint state as specified by the
689  * entry_point_info structure.
690  ******************************************************************************/
691 void cm_init_my_context(const entry_point_info_t *ep)
692 {
693 	cpu_context_t *ctx;
694 	ctx = cm_get_context(GET_SECURITY_STATE(ep->h.attr));
695 	cm_setup_context(ctx, ep);
696 }
697 
698 /* EL2 present but unused, need to disable safely. SCTLR_EL2 can be ignored */
699 static __unused void init_nonsecure_el2_unused(cpu_context_t *ctx)
700 {
701 	u_register_t hcr_el2 = HCR_RESET_VAL;
702 	u_register_t mdcr_el2;
703 	u_register_t scr_el3;
704 
705 	scr_el3 = read_ctx_reg(get_el3state_ctx(ctx), CTX_SCR_EL3);
706 
707 	/* Set EL2 register width: Set HCR_EL2.RW to match SCR_EL3.RW */
708 	if ((scr_el3 & SCR_RW_BIT) != 0U) {
709 		hcr_el2 |= HCR_RW_BIT;
710 	}
711 
712 	write_hcr_el2(hcr_el2);
713 
714 	/*
715 	 * Initialise CPTR_EL2 setting all fields rather than relying on the hw.
716 	 * All fields have architecturally UNKNOWN reset values.
717 	 */
718 	write_cptr_el2(CPTR_EL2_RESET_VAL);
719 
720 	/*
721 	 * Initialise CNTHCTL_EL2. All fields are architecturally UNKNOWN on
722 	 * reset and are set to zero except for field(s) listed below.
723 	 *
724 	 * CNTHCTL_EL2.EL1PTEN: Set to one to disable traps to Hyp mode of
725 	 * Non-secure EL0 and EL1 accesses to the physical timer registers.
726 	 *
727 	 * CNTHCTL_EL2.EL1PCTEN: Set to one to disable traps to Hyp mode of
728 	 * Non-secure EL0 and EL1 accesses to the physical counter registers.
729 	 */
730 	write_cnthctl_el2(CNTHCTL_RESET_VAL | EL1PCEN_BIT | EL1PCTEN_BIT);
731 
732 	/*
733 	 * Initialise CNTVOFF_EL2 to zero as it resets to an architecturally
734 	 * UNKNOWN value.
735 	 */
736 	write_cntvoff_el2(0);
737 
738 	/*
739 	 * Set VPIDR_EL2 and VMPIDR_EL2 to match MIDR_EL1 and MPIDR_EL1
740 	 * respectively.
741 	 */
742 	write_vpidr_el2(read_midr_el1());
743 	write_vmpidr_el2(read_mpidr_el1());
744 
745 	/*
746 	 * Initialise VTTBR_EL2. All fields are architecturally UNKNOWN on reset.
747 	 *
748 	 * VTTBR_EL2.VMID: Set to zero. Even though EL1&0 stage 2 address
749 	 * translation is disabled, cache maintenance operations depend on the
750 	 * VMID.
751 	 *
752 	 * VTTBR_EL2.BADDR: Set to zero as EL1&0 stage 2 address translation is
753 	 * disabled.
754 	 */
755 	write_vttbr_el2(VTTBR_RESET_VAL &
756 		     ~((VTTBR_VMID_MASK << VTTBR_VMID_SHIFT) |
757 		       (VTTBR_BADDR_MASK << VTTBR_BADDR_SHIFT)));
758 
759 	/*
760 	 * Initialise MDCR_EL2, setting all fields rather than relying on hw.
761 	 * Some fields are architecturally UNKNOWN on reset.
762 	 *
763 	 * MDCR_EL2.TDRA: Set to zero so that Non-secure EL0 and EL1 System
764 	 * register accesses to the Debug ROM registers are not trapped to EL2.
765 	 *
766 	 * MDCR_EL2.TDOSA: Set to zero so that Non-secure EL1 System register
767 	 * accesses to the powerdown debug registers are not trapped to EL2.
768 	 *
769 	 * MDCR_EL2.TDA: Set to zero so that System register accesses to the
770 	 * debug registers do not trap to EL2.
771 	 *
772 	 * MDCR_EL2.TDE: Set to zero so that debug exceptions are not routed to
773 	 * EL2.
774 	 */
775 	mdcr_el2 = MDCR_EL2_RESET_VAL &
776 		 ~(MDCR_EL2_TDRA_BIT | MDCR_EL2_TDOSA_BIT | MDCR_EL2_TDA_BIT |
777 		   MDCR_EL2_TDE_BIT);
778 
779 	write_mdcr_el2(mdcr_el2);
780 
781 	/*
782 	 * Initialise HSTR_EL2. All fields are architecturally UNKNOWN on reset.
783 	 *
784 	 * HSTR_EL2.T<n>: Set all these fields to zero so that Non-secure EL0 or
785 	 * EL1 accesses to System registers do not trap to EL2.
786 	 */
787 	write_hstr_el2(HSTR_EL2_RESET_VAL & ~(HSTR_EL2_T_MASK));
788 
789 	/*
790 	 * Initialise CNTHP_CTL_EL2. All fields are architecturally UNKNOWN on
791 	 * reset.
792 	 *
793 	 * CNTHP_CTL_EL2:ENABLE: Set to zero to disable the EL2 physical timer
794 	 * and prevent timer interrupts.
795 	 */
796 	write_cnthp_ctl_el2(CNTHP_CTL_RESET_VAL & ~(CNTHP_CTL_ENABLE_BIT));
797 
798 	manage_extensions_nonsecure_el2_unused();
799 }
800 
801 /*******************************************************************************
802  * Prepare the CPU system registers for first entry into realm, secure, or
803  * normal world.
804  *
805  * If execution is requested to EL2 or hyp mode, SCTLR_EL2 is initialized
806  * If execution is requested to non-secure EL1 or svc mode, and the CPU supports
807  * EL2 then EL2 is disabled by configuring all necessary EL2 registers.
808  * For all entries, the EL1 registers are initialized from the cpu_context
809  ******************************************************************************/
810 void cm_prepare_el3_exit(uint32_t security_state)
811 {
812 	u_register_t sctlr_elx, scr_el3;
813 	cpu_context_t *ctx = cm_get_context(security_state);
814 
815 	assert(ctx != NULL);
816 
817 	if (security_state == NON_SECURE) {
818 		uint64_t el2_implemented = el_implemented(2);
819 
820 		scr_el3 = read_ctx_reg(get_el3state_ctx(ctx),
821 						 CTX_SCR_EL3);
822 
823 		if (((scr_el3 & SCR_HCE_BIT) != 0U)
824 			|| (el2_implemented != EL_IMPL_NONE)) {
825 			/*
826 			 * If context is not being used for EL2, initialize
827 			 * HCRX_EL2 with its init value here.
828 			 */
829 			if (is_feat_hcx_supported()) {
830 				write_hcrx_el2(HCRX_EL2_INIT_VAL);
831 			}
832 		}
833 
834 		if ((scr_el3 & SCR_HCE_BIT) != 0U) {
835 			/* Use SCTLR_EL1.EE value to initialise sctlr_el2 */
836 			sctlr_elx = read_ctx_reg(get_el1_sysregs_ctx(ctx),
837 							   CTX_SCTLR_EL1);
838 			sctlr_elx &= SCTLR_EE_BIT;
839 			sctlr_elx |= SCTLR_EL2_RES1;
840 #if ERRATA_A75_764081
841 			/*
842 			 * If workaround of errata 764081 for Cortex-A75 is used
843 			 * then set SCTLR_EL2.IESB to enable Implicit Error
844 			 * Synchronization Barrier.
845 			 */
846 			sctlr_elx |= SCTLR_IESB_BIT;
847 #endif
848 			write_sctlr_el2(sctlr_elx);
849 		} else if (el2_implemented != EL_IMPL_NONE) {
850 			init_nonsecure_el2_unused(ctx);
851 		}
852 	}
853 
854 	cm_el1_sysregs_context_restore(security_state);
855 	cm_set_next_eret_context(security_state);
856 }
857 
858 #if CTX_INCLUDE_EL2_REGS
859 
860 static void el2_sysregs_context_save_fgt(el2_sysregs_t *ctx)
861 {
862 	write_ctx_reg(ctx, CTX_HDFGRTR_EL2, read_hdfgrtr_el2());
863 	if (is_feat_amu_supported()) {
864 		write_ctx_reg(ctx, CTX_HAFGRTR_EL2, read_hafgrtr_el2());
865 	}
866 	write_ctx_reg(ctx, CTX_HDFGWTR_EL2, read_hdfgwtr_el2());
867 	write_ctx_reg(ctx, CTX_HFGITR_EL2, read_hfgitr_el2());
868 	write_ctx_reg(ctx, CTX_HFGRTR_EL2, read_hfgrtr_el2());
869 	write_ctx_reg(ctx, CTX_HFGWTR_EL2, read_hfgwtr_el2());
870 }
871 
872 static void el2_sysregs_context_restore_fgt(el2_sysregs_t *ctx)
873 {
874 	write_hdfgrtr_el2(read_ctx_reg(ctx, CTX_HDFGRTR_EL2));
875 	if (is_feat_amu_supported()) {
876 		write_hafgrtr_el2(read_ctx_reg(ctx, CTX_HAFGRTR_EL2));
877 	}
878 	write_hdfgwtr_el2(read_ctx_reg(ctx, CTX_HDFGWTR_EL2));
879 	write_hfgitr_el2(read_ctx_reg(ctx, CTX_HFGITR_EL2));
880 	write_hfgrtr_el2(read_ctx_reg(ctx, CTX_HFGRTR_EL2));
881 	write_hfgwtr_el2(read_ctx_reg(ctx, CTX_HFGWTR_EL2));
882 }
883 
884 static void el2_sysregs_context_save_mpam(el2_sysregs_t *ctx)
885 {
886 	u_register_t mpam_idr = read_mpamidr_el1();
887 
888 	write_ctx_reg(ctx, CTX_MPAM2_EL2, read_mpam2_el2());
889 
890 	/*
891 	 * The context registers that we intend to save would be part of the
892 	 * PE's system register frame only if MPAMIDR_EL1.HAS_HCR == 1.
893 	 */
894 	if ((mpam_idr & MPAMIDR_HAS_HCR_BIT) == 0U) {
895 		return;
896 	}
897 
898 	/*
899 	 * MPAMHCR_EL2, MPAMVPMV_EL2 and MPAMVPM0_EL2 are always present if
900 	 * MPAMIDR_HAS_HCR_BIT == 1.
901 	 */
902 	write_ctx_reg(ctx, CTX_MPAMHCR_EL2, read_mpamhcr_el2());
903 	write_ctx_reg(ctx, CTX_MPAMVPM0_EL2, read_mpamvpm0_el2());
904 	write_ctx_reg(ctx, CTX_MPAMVPMV_EL2, read_mpamvpmv_el2());
905 
906 	/*
907 	 * The number of MPAMVPM registers is implementation defined, their
908 	 * number is stored in the MPAMIDR_EL1 register.
909 	 */
910 	switch ((mpam_idr >> MPAMIDR_EL1_VPMR_MAX_SHIFT) & MPAMIDR_EL1_VPMR_MAX_MASK) {
911 	case 7:
912 		write_ctx_reg(ctx, CTX_MPAMVPM7_EL2, read_mpamvpm7_el2());
913 		__fallthrough;
914 	case 6:
915 		write_ctx_reg(ctx, CTX_MPAMVPM6_EL2, read_mpamvpm6_el2());
916 		__fallthrough;
917 	case 5:
918 		write_ctx_reg(ctx, CTX_MPAMVPM5_EL2, read_mpamvpm5_el2());
919 		__fallthrough;
920 	case 4:
921 		write_ctx_reg(ctx, CTX_MPAMVPM4_EL2, read_mpamvpm4_el2());
922 		__fallthrough;
923 	case 3:
924 		write_ctx_reg(ctx, CTX_MPAMVPM3_EL2, read_mpamvpm3_el2());
925 		__fallthrough;
926 	case 2:
927 		write_ctx_reg(ctx, CTX_MPAMVPM2_EL2, read_mpamvpm2_el2());
928 		__fallthrough;
929 	case 1:
930 		write_ctx_reg(ctx, CTX_MPAMVPM1_EL2, read_mpamvpm1_el2());
931 		break;
932 	}
933 }
934 
935 static void el2_sysregs_context_restore_mpam(el2_sysregs_t *ctx)
936 {
937 	u_register_t mpam_idr = read_mpamidr_el1();
938 
939 	write_mpam2_el2(read_ctx_reg(ctx, CTX_MPAM2_EL2));
940 
941 	if ((mpam_idr & MPAMIDR_HAS_HCR_BIT) == 0U) {
942 		return;
943 	}
944 
945 	write_mpamhcr_el2(read_ctx_reg(ctx, CTX_MPAMHCR_EL2));
946 	write_mpamvpm0_el2(read_ctx_reg(ctx, CTX_MPAMVPM0_EL2));
947 	write_mpamvpmv_el2(read_ctx_reg(ctx, CTX_MPAMVPMV_EL2));
948 
949 	switch ((mpam_idr >> MPAMIDR_EL1_VPMR_MAX_SHIFT) & MPAMIDR_EL1_VPMR_MAX_MASK) {
950 	case 7:
951 		write_mpamvpm7_el2(read_ctx_reg(ctx, CTX_MPAMVPM7_EL2));
952 		__fallthrough;
953 	case 6:
954 		write_mpamvpm6_el2(read_ctx_reg(ctx, CTX_MPAMVPM6_EL2));
955 		__fallthrough;
956 	case 5:
957 		write_mpamvpm5_el2(read_ctx_reg(ctx, CTX_MPAMVPM5_EL2));
958 		__fallthrough;
959 	case 4:
960 		write_mpamvpm4_el2(read_ctx_reg(ctx, CTX_MPAMVPM4_EL2));
961 		__fallthrough;
962 	case 3:
963 		write_mpamvpm3_el2(read_ctx_reg(ctx, CTX_MPAMVPM3_EL2));
964 		__fallthrough;
965 	case 2:
966 		write_mpamvpm2_el2(read_ctx_reg(ctx, CTX_MPAMVPM2_EL2));
967 		__fallthrough;
968 	case 1:
969 		write_mpamvpm1_el2(read_ctx_reg(ctx, CTX_MPAMVPM1_EL2));
970 		break;
971 	}
972 }
973 
974 /*******************************************************************************
975  * Save EL2 sysreg context
976  ******************************************************************************/
977 void cm_el2_sysregs_context_save(uint32_t security_state)
978 {
979 	u_register_t scr_el3 = read_scr();
980 
981 	/*
982 	 * Always save the non-secure and realm EL2 context, only save the
983 	 * S-EL2 context if S-EL2 is enabled.
984 	 */
985 	if ((security_state != SECURE) ||
986 	    ((security_state == SECURE) && ((scr_el3 & SCR_EEL2_BIT) != 0U))) {
987 		cpu_context_t *ctx;
988 		el2_sysregs_t *el2_sysregs_ctx;
989 
990 		ctx = cm_get_context(security_state);
991 		assert(ctx != NULL);
992 
993 		el2_sysregs_ctx = get_el2_sysregs_ctx(ctx);
994 
995 		el2_sysregs_context_save_common(el2_sysregs_ctx);
996 #if CTX_INCLUDE_MTE_REGS
997 		el2_sysregs_context_save_mte(el2_sysregs_ctx);
998 #endif
999 		if (is_feat_mpam_supported()) {
1000 			el2_sysregs_context_save_mpam(el2_sysregs_ctx);
1001 		}
1002 
1003 		if (is_feat_fgt_supported()) {
1004 			el2_sysregs_context_save_fgt(el2_sysregs_ctx);
1005 		}
1006 
1007 		if (is_feat_ecv_v2_supported()) {
1008 			write_ctx_reg(el2_sysregs_ctx, CTX_CNTPOFF_EL2,
1009 				      read_cntpoff_el2());
1010 		}
1011 
1012 		if (is_feat_vhe_supported()) {
1013 			write_ctx_reg(el2_sysregs_ctx, CTX_CONTEXTIDR_EL2,
1014 				      read_contextidr_el2());
1015 			write_ctx_reg(el2_sysregs_ctx, CTX_TTBR1_EL2,
1016 				      read_ttbr1_el2());
1017 		}
1018 
1019 		if (is_feat_ras_supported()) {
1020 			write_ctx_reg(el2_sysregs_ctx, CTX_VDISR_EL2,
1021 				      read_vdisr_el2());
1022 			write_ctx_reg(el2_sysregs_ctx, CTX_VSESR_EL2,
1023 				      read_vsesr_el2());
1024 		}
1025 
1026 		if (is_feat_nv2_supported()) {
1027 			write_ctx_reg(el2_sysregs_ctx, CTX_VNCR_EL2,
1028 				      read_vncr_el2());
1029 		}
1030 
1031 		if (is_feat_trf_supported()) {
1032 			write_ctx_reg(el2_sysregs_ctx, CTX_TRFCR_EL2, read_trfcr_el2());
1033 		}
1034 
1035 		if (is_feat_csv2_2_supported()) {
1036 			write_ctx_reg(el2_sysregs_ctx, CTX_SCXTNUM_EL2,
1037 				      read_scxtnum_el2());
1038 		}
1039 
1040 		if (is_feat_hcx_supported()) {
1041 			write_ctx_reg(el2_sysregs_ctx, CTX_HCRX_EL2, read_hcrx_el2());
1042 		}
1043 		if (is_feat_tcr2_supported()) {
1044 			write_ctx_reg(el2_sysregs_ctx, CTX_TCR2_EL2, read_tcr2_el2());
1045 		}
1046 		if (is_feat_sxpie_supported()) {
1047 			write_ctx_reg(el2_sysregs_ctx, CTX_PIRE0_EL2, read_pire0_el2());
1048 			write_ctx_reg(el2_sysregs_ctx, CTX_PIR_EL2, read_pir_el2());
1049 		}
1050 		if (is_feat_s2pie_supported()) {
1051 			write_ctx_reg(el2_sysregs_ctx, CTX_S2PIR_EL2, read_s2pir_el2());
1052 		}
1053 		if (is_feat_sxpoe_supported()) {
1054 			write_ctx_reg(el2_sysregs_ctx, CTX_POR_EL2, read_por_el2());
1055 		}
1056 		if (is_feat_gcs_supported()) {
1057 			write_ctx_reg(el2_sysregs_ctx, CTX_GCSPR_EL2, read_gcspr_el2());
1058 			write_ctx_reg(el2_sysregs_ctx, CTX_GCSCR_EL2, read_gcscr_el2());
1059 		}
1060 	}
1061 }
1062 
1063 /*******************************************************************************
1064  * Restore EL2 sysreg context
1065  ******************************************************************************/
1066 void cm_el2_sysregs_context_restore(uint32_t security_state)
1067 {
1068 	u_register_t scr_el3 = read_scr();
1069 
1070 	/*
1071 	 * Always restore the non-secure and realm EL2 context, only restore the
1072 	 * S-EL2 context if S-EL2 is enabled.
1073 	 */
1074 	if ((security_state != SECURE) ||
1075 	    ((security_state == SECURE) && ((scr_el3 & SCR_EEL2_BIT) != 0U))) {
1076 		cpu_context_t *ctx;
1077 		el2_sysregs_t *el2_sysregs_ctx;
1078 
1079 		ctx = cm_get_context(security_state);
1080 		assert(ctx != NULL);
1081 
1082 		el2_sysregs_ctx = get_el2_sysregs_ctx(ctx);
1083 
1084 		el2_sysregs_context_restore_common(el2_sysregs_ctx);
1085 #if CTX_INCLUDE_MTE_REGS
1086 		el2_sysregs_context_restore_mte(el2_sysregs_ctx);
1087 #endif
1088 		if (is_feat_mpam_supported()) {
1089 			el2_sysregs_context_restore_mpam(el2_sysregs_ctx);
1090 		}
1091 
1092 		if (is_feat_fgt_supported()) {
1093 			el2_sysregs_context_restore_fgt(el2_sysregs_ctx);
1094 		}
1095 
1096 		if (is_feat_ecv_v2_supported()) {
1097 			write_cntpoff_el2(read_ctx_reg(el2_sysregs_ctx,
1098 						       CTX_CNTPOFF_EL2));
1099 		}
1100 
1101 		if (is_feat_vhe_supported()) {
1102 			write_contextidr_el2(read_ctx_reg(el2_sysregs_ctx, CTX_CONTEXTIDR_EL2));
1103 			write_ttbr1_el2(read_ctx_reg(el2_sysregs_ctx, CTX_TTBR1_EL2));
1104 		}
1105 
1106 		if (is_feat_ras_supported()) {
1107 			write_vdisr_el2(read_ctx_reg(el2_sysregs_ctx, CTX_VDISR_EL2));
1108 			write_vsesr_el2(read_ctx_reg(el2_sysregs_ctx, CTX_VSESR_EL2));
1109 		}
1110 
1111 		if (is_feat_nv2_supported()) {
1112 			write_vncr_el2(read_ctx_reg(el2_sysregs_ctx, CTX_VNCR_EL2));
1113 		}
1114 		if (is_feat_trf_supported()) {
1115 			write_trfcr_el2(read_ctx_reg(el2_sysregs_ctx, CTX_TRFCR_EL2));
1116 		}
1117 
1118 		if (is_feat_csv2_2_supported()) {
1119 			write_scxtnum_el2(read_ctx_reg(el2_sysregs_ctx,
1120 						       CTX_SCXTNUM_EL2));
1121 		}
1122 
1123 		if (is_feat_hcx_supported()) {
1124 			write_hcrx_el2(read_ctx_reg(el2_sysregs_ctx, CTX_HCRX_EL2));
1125 		}
1126 		if (is_feat_tcr2_supported()) {
1127 			write_tcr2_el2(read_ctx_reg(el2_sysregs_ctx, CTX_TCR2_EL2));
1128 		}
1129 		if (is_feat_sxpie_supported()) {
1130 			write_pire0_el2(read_ctx_reg(el2_sysregs_ctx, CTX_PIRE0_EL2));
1131 			write_pir_el2(read_ctx_reg(el2_sysregs_ctx, CTX_PIR_EL2));
1132 		}
1133 		if (is_feat_s2pie_supported()) {
1134 			write_s2pir_el2(read_ctx_reg(el2_sysregs_ctx, CTX_S2PIR_EL2));
1135 		}
1136 		if (is_feat_sxpoe_supported()) {
1137 			write_por_el2(read_ctx_reg(el2_sysregs_ctx, CTX_POR_EL2));
1138 		}
1139 		if (is_feat_gcs_supported()) {
1140 			write_gcscr_el2(read_ctx_reg(el2_sysregs_ctx, CTX_GCSCR_EL2));
1141 			write_gcspr_el2(read_ctx_reg(el2_sysregs_ctx, CTX_GCSPR_EL2));
1142 		}
1143 	}
1144 }
1145 #endif /* CTX_INCLUDE_EL2_REGS */
1146 
1147 /*******************************************************************************
1148  * This function is used to exit to Non-secure world. If CTX_INCLUDE_EL2_REGS
1149  * is enabled, it restores EL1 and EL2 sysreg contexts instead of directly
1150  * updating EL1 and EL2 registers. Otherwise, it calls the generic
1151  * cm_prepare_el3_exit function.
1152  ******************************************************************************/
1153 void cm_prepare_el3_exit_ns(void)
1154 {
1155 #if CTX_INCLUDE_EL2_REGS
1156 #if ENABLE_ASSERTIONS
1157 	cpu_context_t *ctx = cm_get_context(NON_SECURE);
1158 	assert(ctx != NULL);
1159 
1160 	/* Assert that EL2 is used. */
1161 	u_register_t scr_el3 = read_ctx_reg(get_el3state_ctx(ctx), CTX_SCR_EL3);
1162 	assert(((scr_el3 & SCR_HCE_BIT) != 0UL) &&
1163 			(el_implemented(2U) != EL_IMPL_NONE));
1164 #endif /* ENABLE_ASSERTIONS */
1165 
1166 	/*
1167 	 * Set the NS bit to be able to access the ICC_SRE_EL2
1168 	 * register when restoring context.
1169 	 */
1170 	write_scr_el3(read_scr_el3() | SCR_NS_BIT);
1171 
1172 	/*
1173 	 * Ensure the NS bit change is committed before the EL2/EL1
1174 	 * state restoration.
1175 	 */
1176 	isb();
1177 
1178 	/* Restore EL2 and EL1 sysreg contexts */
1179 	cm_el2_sysregs_context_restore(NON_SECURE);
1180 	cm_el1_sysregs_context_restore(NON_SECURE);
1181 	cm_set_next_eret_context(NON_SECURE);
1182 #else
1183 	cm_prepare_el3_exit(NON_SECURE);
1184 #endif /* CTX_INCLUDE_EL2_REGS */
1185 }
1186 
1187 /*******************************************************************************
1188  * The next four functions are used by runtime services to save and restore
1189  * EL1 context on the 'cpu_context' structure for the specified security
1190  * state.
1191  ******************************************************************************/
1192 void cm_el1_sysregs_context_save(uint32_t security_state)
1193 {
1194 	cpu_context_t *ctx;
1195 
1196 	ctx = cm_get_context(security_state);
1197 	assert(ctx != NULL);
1198 
1199 	el1_sysregs_context_save(get_el1_sysregs_ctx(ctx));
1200 
1201 #if IMAGE_BL31
1202 	if (security_state == SECURE)
1203 		PUBLISH_EVENT(cm_exited_secure_world);
1204 	else
1205 		PUBLISH_EVENT(cm_exited_normal_world);
1206 #endif
1207 }
1208 
1209 void cm_el1_sysregs_context_restore(uint32_t security_state)
1210 {
1211 	cpu_context_t *ctx;
1212 
1213 	ctx = cm_get_context(security_state);
1214 	assert(ctx != NULL);
1215 
1216 	el1_sysregs_context_restore(get_el1_sysregs_ctx(ctx));
1217 
1218 #if IMAGE_BL31
1219 	if (security_state == SECURE)
1220 		PUBLISH_EVENT(cm_entering_secure_world);
1221 	else
1222 		PUBLISH_EVENT(cm_entering_normal_world);
1223 #endif
1224 }
1225 
1226 /*******************************************************************************
1227  * This function populates ELR_EL3 member of 'cpu_context' pertaining to the
1228  * given security state with the given entrypoint
1229  ******************************************************************************/
1230 void cm_set_elr_el3(uint32_t security_state, uintptr_t entrypoint)
1231 {
1232 	cpu_context_t *ctx;
1233 	el3_state_t *state;
1234 
1235 	ctx = cm_get_context(security_state);
1236 	assert(ctx != NULL);
1237 
1238 	/* Populate EL3 state so that ERET jumps to the correct entry */
1239 	state = get_el3state_ctx(ctx);
1240 	write_ctx_reg(state, CTX_ELR_EL3, entrypoint);
1241 }
1242 
1243 /*******************************************************************************
1244  * This function populates ELR_EL3 and SPSR_EL3 members of 'cpu_context'
1245  * pertaining to the given security state
1246  ******************************************************************************/
1247 void cm_set_elr_spsr_el3(uint32_t security_state,
1248 			uintptr_t entrypoint, uint32_t spsr)
1249 {
1250 	cpu_context_t *ctx;
1251 	el3_state_t *state;
1252 
1253 	ctx = cm_get_context(security_state);
1254 	assert(ctx != NULL);
1255 
1256 	/* Populate EL3 state so that ERET jumps to the correct entry */
1257 	state = get_el3state_ctx(ctx);
1258 	write_ctx_reg(state, CTX_ELR_EL3, entrypoint);
1259 	write_ctx_reg(state, CTX_SPSR_EL3, spsr);
1260 }
1261 
1262 /*******************************************************************************
1263  * This function updates a single bit in the SCR_EL3 member of the 'cpu_context'
1264  * pertaining to the given security state using the value and bit position
1265  * specified in the parameters. It preserves all other bits.
1266  ******************************************************************************/
1267 void cm_write_scr_el3_bit(uint32_t security_state,
1268 			  uint32_t bit_pos,
1269 			  uint32_t value)
1270 {
1271 	cpu_context_t *ctx;
1272 	el3_state_t *state;
1273 	u_register_t scr_el3;
1274 
1275 	ctx = cm_get_context(security_state);
1276 	assert(ctx != NULL);
1277 
1278 	/* Ensure that the bit position is a valid one */
1279 	assert(((1UL << bit_pos) & SCR_VALID_BIT_MASK) != 0U);
1280 
1281 	/* Ensure that the 'value' is only a bit wide */
1282 	assert(value <= 1U);
1283 
1284 	/*
1285 	 * Get the SCR_EL3 value from the cpu context, clear the desired bit
1286 	 * and set it to its new value.
1287 	 */
1288 	state = get_el3state_ctx(ctx);
1289 	scr_el3 = read_ctx_reg(state, CTX_SCR_EL3);
1290 	scr_el3 &= ~(1UL << bit_pos);
1291 	scr_el3 |= (u_register_t)value << bit_pos;
1292 	write_ctx_reg(state, CTX_SCR_EL3, scr_el3);
1293 }
1294 
1295 /*******************************************************************************
1296  * This function retrieves SCR_EL3 member of 'cpu_context' pertaining to the
1297  * given security state.
1298  ******************************************************************************/
1299 u_register_t cm_get_scr_el3(uint32_t security_state)
1300 {
1301 	cpu_context_t *ctx;
1302 	el3_state_t *state;
1303 
1304 	ctx = cm_get_context(security_state);
1305 	assert(ctx != NULL);
1306 
1307 	/* Populate EL3 state so that ERET jumps to the correct entry */
1308 	state = get_el3state_ctx(ctx);
1309 	return read_ctx_reg(state, CTX_SCR_EL3);
1310 }
1311 
1312 /*******************************************************************************
1313  * This function is used to program the context that's used for exception
1314  * return. This initializes the SP_EL3 to a pointer to a 'cpu_context' set for
1315  * the required security state
1316  ******************************************************************************/
1317 void cm_set_next_eret_context(uint32_t security_state)
1318 {
1319 	cpu_context_t *ctx;
1320 
1321 	ctx = cm_get_context(security_state);
1322 	assert(ctx != NULL);
1323 
1324 	cm_set_next_context(ctx);
1325 }
1326