lib/el3_runtime/aarch64/context_mgmt.c

/*
 * Copyright (c) 2013-2024, Arm Limited and Contributors. All rights reserved.
 * Copyright (c) 2022, NVIDIA Corporation. All rights reserved.
 *
 * SPDX-License-Identifier: BSD-3-Clause
 */

#include <assert.h>
#include <stdbool.h>
#include <string.h>

#include <platform_def.h>

#include <arch.h>
#include <arch_helpers.h>
#include <arch_features.h>
#include <bl31/interrupt_mgmt.h>
#include <common/bl_common.h>
#include <common/debug.h>
#include <context.h>
#include <drivers/arm/gicv3.h>
#include <lib/el3_runtime/context_mgmt.h>
#include <lib/el3_runtime/cpu_data.h>
#include <lib/el3_runtime/pubsub_events.h>
#include <lib/extensions/amu.h>
#include <lib/extensions/brbe.h>
#include <lib/extensions/mpam.h>
#include <lib/extensions/pmuv3.h>
#include <lib/extensions/sme.h>
#include <lib/extensions/spe.h>
#include <lib/extensions/sve.h>
#include <lib/extensions/sys_reg_trace.h>
#include <lib/extensions/trbe.h>
#include <lib/extensions/trf.h>
#include <lib/utils.h>

#if ENABLE_FEAT_TWED
/* Make sure delay value fits within the range(0-15) */
CASSERT(((TWED_DELAY & ~SCR_TWEDEL_MASK) == 0U), assert_twed_delay_value_check);
#endif /* ENABLE_FEAT_TWED */

per_world_context_t per_world_context[CPU_DATA_CONTEXT_NUM];
static bool has_secure_perworld_init;

static void manage_extensions_nonsecure(cpu_context_t *ctx);
static void manage_extensions_secure(cpu_context_t *ctx);
static void manage_extensions_secure_per_world(void);

static void setup_el1_context(cpu_context_t *ctx, const struct entry_point_info *ep)
{
	u_register_t sctlr_elx, actlr_elx;

	/*
	 * Initialise SCTLR_EL1 to the reset value corresponding to the target
	 * execution state setting all fields rather than relying on the hw.
	 * Some fields have architecturally UNKNOWN reset values and these are
	 * set to zero.
	 *
	 * SCTLR.EE: Endianness is taken from the entrypoint attributes.
	 *
	 * SCTLR.M, SCTLR.C and SCTLR.I: These fields must be zero (as
	 * required by PSCI specification)
	 */
	sctlr_elx = (EP_GET_EE(ep->h.attr) != 0U) ? SCTLR_EE_BIT : 0UL;
	if (GET_RW(ep->spsr) == MODE_RW_64) {
		sctlr_elx |= SCTLR_EL1_RES1;
	} else {
		/*
		 * If the target execution state is AArch32 then the following
		 * fields need to be set.
		 *
		 * SCTRL_EL1.nTWE: Set to one so that EL0 execution of WFE
		 *  instructions are not trapped to EL1.
		 *
		 * SCTLR_EL1.nTWI: Set to one so that EL0 execution of WFI
		 *  instructions are not trapped to EL1.
		 *
		 * SCTLR_EL1.CP15BEN: Set to one to enable EL0 execution of the
		 *  CP15DMB, CP15DSB, and CP15ISB instructions.
		 */
		sctlr_elx |= SCTLR_AARCH32_EL1_RES1 | SCTLR_CP15BEN_BIT
					| SCTLR_NTWI_BIT | SCTLR_NTWE_BIT;
	}

#if ERRATA_A75_764081
	/*
	 * If workaround of errata 764081 for Cortex-A75 is used then set
	 * SCTLR_EL1.IESB to enable Implicit Error Synchronization Barrier.
	 */
	sctlr_elx |= SCTLR_IESB_BIT;
#endif
	/* Store the initialised SCTLR_EL1 value in the cpu_context */
	write_ctx_reg(get_el1_sysregs_ctx(ctx), CTX_SCTLR_EL1, sctlr_elx);

	/*
	 * Base the context ACTLR_EL1 on the current value, as it is
	 * implementation defined. The context restore process will write
	 * the value from the context to the actual register and can cause
	 * problems for processor cores that don't expect certain bits to
	 * be zero.
	 */
	actlr_elx = read_actlr_el1();
	write_ctx_reg((get_el1_sysregs_ctx(ctx)), (CTX_ACTLR_EL1), (actlr_elx));
}

/******************************************************************************
 * This function performs initializations that are specific to SECURE state
 * and updates the cpu context specified by 'ctx'.
 *****************************************************************************/
static void setup_secure_context(cpu_context_t *ctx, const struct entry_point_info *ep)
{
	u_register_t scr_el3;
	el3_state_t *state;

	state = get_el3state_ctx(ctx);
	scr_el3 = read_ctx_reg(state, CTX_SCR_EL3);

#if defined(IMAGE_BL31) && !defined(SPD_spmd)
	/*
	 * SCR_EL3.IRQ, SCR_EL3.FIQ: Enable the physical FIQ and IRQ routing as
	 * indicated by the interrupt routing model for BL31.
	 */
	scr_el3 |= get_scr_el3_from_routing_model(SECURE);
#endif

	/* Allow access to Allocation Tags when FEAT_MTE2 is implemented and enabled. */
	if (is_feat_mte2_supported()) {
		scr_el3 |= SCR_ATA_BIT;
	}

	write_ctx_reg(state, CTX_SCR_EL3, scr_el3);

	/*
	 * Initialize EL1 context registers unless SPMC is running
	 * at S-EL2.
	 */
#if !SPMD_SPM_AT_SEL2
	setup_el1_context(ctx, ep);
#endif

	manage_extensions_secure(ctx);

	/**
	 * manage_extensions_secure_per_world api has to be executed once,
	 * as the registers getting initialised, maintain constant value across
	 * all the cpus for the secure world.
	 * Henceforth, this check ensures that the registers are initialised once
	 * and avoids re-initialization from multiple cores.
	 */
	if (!has_secure_perworld_init) {
		manage_extensions_secure_per_world();
	}

}

#if ENABLE_RME
/******************************************************************************
 * This function performs initializations that are specific to REALM state
 * and updates the cpu context specified by 'ctx'.
 *****************************************************************************/
static void setup_realm_context(cpu_context_t *ctx, const struct entry_point_info *ep)
{
	u_register_t scr_el3;
	el3_state_t *state;

	state = get_el3state_ctx(ctx);
	scr_el3 = read_ctx_reg(state, CTX_SCR_EL3);

	scr_el3 |= SCR_NS_BIT | SCR_NSE_BIT;

	/* CSV2 version 2 and above */
	if (is_feat_csv2_2_supported()) {
		/* Enable access to the SCXTNUM_ELx registers. */
		scr_el3 |= SCR_EnSCXT_BIT;
	}

	write_ctx_reg(state, CTX_SCR_EL3, scr_el3);
}
#endif /* ENABLE_RME */

/******************************************************************************
 * This function performs initializations that are specific to NON-SECURE state
 * and updates the cpu context specified by 'ctx'.
 *****************************************************************************/
static void setup_ns_context(cpu_context_t *ctx, const struct entry_point_info *ep)
{
	u_register_t scr_el3;
	el3_state_t *state;

	state = get_el3state_ctx(ctx);
	scr_el3 = read_ctx_reg(state, CTX_SCR_EL3);

	/* SCR_NS: Set the NS bit */
	scr_el3 |= SCR_NS_BIT;

	/* Allow access to Allocation Tags when FEAT_MTE2 is implemented and enabled. */
	if (is_feat_mte2_supported()) {
		scr_el3 |= SCR_ATA_BIT;
	}

#if !CTX_INCLUDE_PAUTH_REGS
	/*
	 * Pointer Authentication feature, if present, is always enabled by default
	 * for Non secure lower exception levels. We do not have an explicit
	 * flag to set it.
	 * CTX_INCLUDE_PAUTH_REGS flag, is explicitly used to enable for lower
	 * exception levels of secure and realm worlds.
	 *
	 * To prevent the leakage between the worlds during world switch,
	 * we enable it only for the non-secure world.
	 *
	 * If the Secure/realm world wants to use pointer authentication,
	 * CTX_INCLUDE_PAUTH_REGS must be explicitly set to 1, in which case
	 * it will be enabled globally for all the contexts.
	 *
	 * SCR_EL3.API: Set to one to not trap any PAuth instructions at ELs
	 *  other than EL3
	 *
	 * SCR_EL3.APK: Set to one to not trap any PAuth key values at ELs other
	 *  than EL3
	 */
	scr_el3 |= SCR_API_BIT | SCR_APK_BIT;

#endif /* CTX_INCLUDE_PAUTH_REGS */

#if HANDLE_EA_EL3_FIRST_NS
	/* SCR_EL3.EA: Route External Abort and SError Interrupt to EL3. */
	scr_el3 |= SCR_EA_BIT;
#endif

#if RAS_TRAP_NS_ERR_REC_ACCESS
	/*
	 * SCR_EL3.TERR: Trap Error record accesses. Accesses to the RAS ERR
	 * and RAS ERX registers from EL1 and EL2(from any security state)
	 * are trapped to EL3.
	 * Set here to trap only for NS EL1/EL2
	 *
	 */
	scr_el3 |= SCR_TERR_BIT;
#endif

	/* CSV2 version 2 and above */
	if (is_feat_csv2_2_supported()) {
		/* Enable access to the SCXTNUM_ELx registers. */
		scr_el3 |= SCR_EnSCXT_BIT;
	}

#ifdef IMAGE_BL31
	/*
	 * SCR_EL3.IRQ, SCR_EL3.FIQ: Enable the physical FIQ and IRQ routing as
	 *  indicated by the interrupt routing model for BL31.
	 */
	scr_el3 |= get_scr_el3_from_routing_model(NON_SECURE);
#endif
	write_ctx_reg(state, CTX_SCR_EL3, scr_el3);

	/* Initialize EL1 context registers */
	setup_el1_context(ctx, ep);

	/* Initialize EL2 context registers */
#if CTX_INCLUDE_EL2_REGS

	/*
	 * Initialize SCTLR_EL2 context register using Endianness value
	 * taken from the entrypoint attribute.
	 */
	u_register_t sctlr_el2_val = (EP_GET_EE(ep->h.attr) != 0U) ? SCTLR_EE_BIT : 0UL;
	sctlr_el2_val |= SCTLR_EL2_RES1;
	write_el2_ctx_common(get_el2_sysregs_ctx(ctx), sctlr_el2, sctlr_el2_val);


	if (is_feat_hcx_supported()) {
		/*
		 * Initialize register HCRX_EL2 with its init value.
		 * As the value of HCRX_EL2 is UNKNOWN on reset, there is a
		 * chance that this can lead to unexpected behavior in lower
		 * ELs that have not been updated since the introduction of
		 * this feature if not properly initialized, especially when
		 * it comes to those bits that enable/disable traps.
		 */
		write_el2_ctx_hcx(get_el2_sysregs_ctx(ctx), hcrx_el2,
			HCRX_EL2_INIT_VAL);
	}

	if (is_feat_fgt_supported()) {
		/*
		 * Initialize HFG*_EL2 registers with a default value so legacy
		 * systems unaware of FEAT_FGT do not get trapped due to their lack
		 * of initialization for this feature.
		 */
		write_el2_ctx_fgt(get_el2_sysregs_ctx(ctx), hfgitr_el2,
			HFGITR_EL2_INIT_VAL);
		write_el2_ctx_fgt(get_el2_sysregs_ctx(ctx), hfgrtr_el2,
			HFGRTR_EL2_INIT_VAL);
		write_el2_ctx_fgt(get_el2_sysregs_ctx(ctx), hfgwtr_el2,
			HFGWTR_EL2_INIT_VAL);
	}

#endif /* CTX_INCLUDE_EL2_REGS */

	manage_extensions_nonsecure(ctx);
}

/*******************************************************************************
 * The following function performs initialization of the cpu_context 'ctx'
 * for first use that is common to all security states, and sets the
 * initial entrypoint state as specified by the entry_point_info structure.
 *
 * The EE and ST attributes are used to configure the endianness and secure
 * timer availability for the new execution context.
 ******************************************************************************/
static void setup_context_common(cpu_context_t *ctx, const entry_point_info_t *ep)
{
	u_register_t scr_el3;
	el3_state_t *state;
	gp_regs_t *gp_regs;

	state = get_el3state_ctx(ctx);

	/* Clear any residual register values from the context */
	zeromem(ctx, sizeof(*ctx));

	/*
	 * The lower-EL context is zeroed so that no stale values leak to a world.
	 * It is assumed that an all-zero lower-EL context is good enough for it
	 * to boot correctly. However, there are very few registers where this
	 * is not true and some values need to be recreated.
	 */
#if CTX_INCLUDE_EL2_REGS
	el2_sysregs_t *el2_ctx = get_el2_sysregs_ctx(ctx);

	/*
	 * These bits are set in the gicv3 driver. Losing them (especially the
	 * SRE bit) is problematic for all worlds. Henceforth recreate them.
	 */
	u_register_t icc_sre_el2_val = ICC_SRE_DIB_BIT | ICC_SRE_DFB_BIT |
				   ICC_SRE_EN_BIT | ICC_SRE_SRE_BIT;
	write_el2_ctx_common(el2_ctx, icc_sre_el2, icc_sre_el2_val);
#endif /* CTX_INCLUDE_EL2_REGS */

	/* Start with a clean SCR_EL3 copy as all relevant values are set */
	scr_el3 = SCR_RESET_VAL;

	/*
	 * SCR_EL3.TWE: Set to zero so that execution of WFE instructions at
	 *  EL2, EL1 and EL0 are not trapped to EL3.
	 *
	 * SCR_EL3.TWI: Set to zero so that execution of WFI instructions at
	 *  EL2, EL1 and EL0 are not trapped to EL3.
	 *
	 * SCR_EL3.SMD: Set to zero to enable SMC calls at EL1 and above, from
	 *  both Security states and both Execution states.
	 *
	 * SCR_EL3.SIF: Set to one to disable secure instruction execution from
	 *  Non-secure memory.
	 */
	scr_el3 &= ~(SCR_TWE_BIT | SCR_TWI_BIT | SCR_SMD_BIT);

	scr_el3 |= SCR_SIF_BIT;

	/*
	 * SCR_EL3.RW: Set the execution state, AArch32 or AArch64, for next
	 *  Exception level as specified by SPSR.
	 */
	if (GET_RW(ep->spsr) == MODE_RW_64) {
		scr_el3 |= SCR_RW_BIT;
	}

	/*
	 * SCR_EL3.ST: Traps Secure EL1 accesses to the Counter-timer Physical
	 * Secure timer registers to EL3, from AArch64 state only, if specified
	 * by the entrypoint attributes. If SEL2 is present and enabled, the ST
	 * bit always behaves as 1 (i.e. secure physical timer register access
	 * is not trapped)
	 */
	if (EP_GET_ST(ep->h.attr) != 0U) {
		scr_el3 |= SCR_ST_BIT;
	}

	/*
	 * If FEAT_HCX is enabled, enable access to HCRX_EL2 by setting
	 * SCR_EL3.HXEn.
	 */
	if (is_feat_hcx_supported()) {
		scr_el3 |= SCR_HXEn_BIT;
	}

	/*
	 * If FEAT_RNG_TRAP is enabled, all reads of the RNDR and RNDRRS
	 * registers are trapped to EL3.
	 */
#if ENABLE_FEAT_RNG_TRAP
	scr_el3 |= SCR_TRNDR_BIT;
#endif

#if FAULT_INJECTION_SUPPORT
	/* Enable fault injection from lower ELs */
	scr_el3 |= SCR_FIEN_BIT;
#endif

#if CTX_INCLUDE_PAUTH_REGS
	/*
	 * Enable Pointer Authentication globally for all the worlds.
	 *
	 * SCR_EL3.API: Set to one to not trap any PAuth instructions at ELs
	 *  other than EL3
	 *
	 * SCR_EL3.APK: Set to one to not trap any PAuth key values at ELs other
	 *  than EL3
	 */
	scr_el3 |= SCR_API_BIT | SCR_APK_BIT;
#endif /* CTX_INCLUDE_PAUTH_REGS */

	/*
	 * SCR_EL3.TCR2EN: Enable access to TCR2_ELx for AArch64 if present.
	 */
	if (is_feat_tcr2_supported() && (GET_RW(ep->spsr) == MODE_RW_64)) {
		scr_el3 |= SCR_TCR2EN_BIT;
	}

	/*
	 * SCR_EL3.PIEN: Enable permission indirection and overlay
	 * registers for AArch64 if present.
	 */
	if (is_feat_sxpie_supported() || is_feat_sxpoe_supported()) {
		scr_el3 |= SCR_PIEN_BIT;
	}

	/*
	 * SCR_EL3.GCSEn: Enable GCS registers for AArch64 if present.
	 */
	if ((is_feat_gcs_supported()) && (GET_RW(ep->spsr) == MODE_RW_64)) {
		scr_el3 |= SCR_GCSEn_BIT;
	}

	/*
	 * SCR_EL3.HCE: Enable HVC instructions if next execution state is
	 * AArch64 and next EL is EL2, or if next execution state is AArch32 and
	 * next mode is Hyp.
	 * SCR_EL3.FGTEn: Enable Fine Grained Virtualization Traps under the
	 * same conditions as HVC instructions and when the processor supports
	 * ARMv8.6-FGT.
	 * SCR_EL3.ECVEn: Enable Enhanced Counter Virtualization (ECV)
	 * CNTPOFF_EL2 register under the same conditions as HVC instructions
	 * and when the processor supports ECV.
	 */
	if (((GET_RW(ep->spsr) == MODE_RW_64) && (GET_EL(ep->spsr) == MODE_EL2))
	    || ((GET_RW(ep->spsr) != MODE_RW_64)
		&& (GET_M32(ep->spsr) == MODE32_hyp))) {
		scr_el3 |= SCR_HCE_BIT;

		if (is_feat_fgt_supported()) {
			scr_el3 |= SCR_FGTEN_BIT;
		}

		if (is_feat_ecv_supported()) {
			scr_el3 |= SCR_ECVEN_BIT;
		}
	}

	/* Enable WFE trap delay in SCR_EL3 if supported and configured */
	if (is_feat_twed_supported()) {
		/* Set delay in SCR_EL3 */
		scr_el3 &= ~(SCR_TWEDEL_MASK << SCR_TWEDEL_SHIFT);
		scr_el3 |= ((TWED_DELAY & SCR_TWEDEL_MASK)
				<< SCR_TWEDEL_SHIFT);

		/* Enable WFE delay */
		scr_el3 |= SCR_TWEDEn_BIT;
	}

#if IMAGE_BL31 && defined(SPD_spmd) && SPMD_SPM_AT_SEL2
	/* Enable S-EL2 if FEAT_SEL2 is implemented for all the contexts. */
	if (is_feat_sel2_supported()) {
		scr_el3 |= SCR_EEL2_BIT;
	}
#endif /* (IMAGE_BL31 && defined(SPD_spmd) && SPMD_SPM_AT_SEL2) */

	/*
	 * Populate EL3 state so that we've the right context
	 * before doing ERET
	 */
	write_ctx_reg(state, CTX_SCR_EL3, scr_el3);
	write_ctx_reg(state, CTX_ELR_EL3, ep->pc);
	write_ctx_reg(state, CTX_SPSR_EL3, ep->spsr);

	/*
	 * Store the X0-X7 value from the entrypoint into the context
	 * Use memcpy as we are in control of the layout of the structures
	 */
	gp_regs = get_gpregs_ctx(ctx);
	memcpy(gp_regs, (void *)&ep->args, sizeof(aapcs64_params_t));
}

/*******************************************************************************
 * Context management library initialization routine. This library is used by
 * runtime services to share pointers to 'cpu_context' structures for secure
 * non-secure and realm states. Management of the structures and their associated
 * memory is not done by the context management library e.g. the PSCI service
 * manages the cpu context used for entry from and exit to the non-secure state.
 * The Secure payload dispatcher service manages the context(s) corresponding to
 * the secure state. It also uses this library to get access to the non-secure
 * state cpu context pointers.
 * Lastly, this library provides the API to make SP_EL3 point to the cpu context
 * which will be used for programming an entry into a lower EL. The same context
 * will be used to save state upon exception entry from that EL.
 ******************************************************************************/
void __init cm_init(void)
{
	/*
	 * The context management library has only global data to initialize, but
	 * that will be done when the BSS is zeroed out.
	 */
}

/*******************************************************************************
 * This is the high-level function used to initialize the cpu_context 'ctx' for
 * first use. It performs initializations that are common to all security states
 * and initializations specific to the security state specified in 'ep'
 ******************************************************************************/
void cm_setup_context(cpu_context_t *ctx, const entry_point_info_t *ep)
{
	unsigned int security_state;

	assert(ctx != NULL);

	/*
	 * Perform initializations that are common
	 * to all security states
	 */
	setup_context_common(ctx, ep);

	security_state = GET_SECURITY_STATE(ep->h.attr);

	/* Perform security state specific initializations */
	switch (security_state) {
	case SECURE:
		setup_secure_context(ctx, ep);
		break;
#if ENABLE_RME
	case REALM:
		setup_realm_context(ctx, ep);
		break;
#endif
	case NON_SECURE:
		setup_ns_context(ctx, ep);
		break;
	default:
		ERROR("Invalid security state\n");
		panic();
		break;
	}
}

/*******************************************************************************
 * Enable architecture extensions for EL3 execution. This function only updates
 * registers in-place which are expected to either never change or be
 * overwritten by el3_exit.
 ******************************************************************************/
#if IMAGE_BL31
void cm_manage_extensions_el3(void)
{
	if (is_feat_spe_supported()) {
		spe_init_el3();
	}

	if (is_feat_amu_supported()) {
		amu_init_el3();
	}

	if (is_feat_sme_supported()) {
		sme_init_el3();
	}

	if (is_feat_trbe_supported()) {
		trbe_init_el3();
	}

	if (is_feat_brbe_supported()) {
		brbe_init_el3();
	}

	if (is_feat_trf_supported()) {
		trf_init_el3();
	}

	pmuv3_init_el3();
}
#endif /* IMAGE_BL31 */

/******************************************************************************
 * Function to initialise the registers with the RESET values in the context
 * memory, which are maintained per world.
 ******************************************************************************/
#if IMAGE_BL31
void cm_el3_arch_init_per_world(per_world_context_t *per_world_ctx)
{
	/*
	 * Initialise CPTR_EL3, setting all fields rather than relying on hw.
	 *
	 * CPTR_EL3.TFP: Set to zero so that accesses to the V- or Z- registers
	 *  by Advanced SIMD, floating-point or SVE instructions (if
	 *  implemented) do not trap to EL3.
	 *
	 * CPTR_EL3.TCPAC: Set to zero so that accesses to CPACR_EL1,
	 *  CPTR_EL2,CPACR, or HCPTR do not trap to EL3.
	 */
	uint64_t cptr_el3 = CPTR_EL3_RESET_VAL & ~(TCPAC_BIT | TFP_BIT);

	per_world_ctx->ctx_cptr_el3 = cptr_el3;

	/*
	 * Initialize MPAM3_EL3 to its default reset value
	 *
	 * MPAM3_EL3_RESET_VAL sets the MPAM3_EL3.TRAPLOWER bit that forces
	 * all lower ELn MPAM3_EL3 register access to, trap to EL3
	 */

	per_world_ctx->ctx_mpam3_el3 = MPAM3_EL3_RESET_VAL;
}
#endif /* IMAGE_BL31 */

/*******************************************************************************
 * Initialise per_world_context for Non-Secure world.
 * This function enables the architecture extensions, which have same value
 * across the cores for the non-secure world.
 ******************************************************************************/
#if IMAGE_BL31
void manage_extensions_nonsecure_per_world(void)
{
	cm_el3_arch_init_per_world(&per_world_context[CPU_CONTEXT_NS]);

	if (is_feat_sme_supported()) {
		sme_enable_per_world(&per_world_context[CPU_CONTEXT_NS]);
	}

	if (is_feat_sve_supported()) {
		sve_enable_per_world(&per_world_context[CPU_CONTEXT_NS]);
	}

	if (is_feat_amu_supported()) {
		amu_enable_per_world(&per_world_context[CPU_CONTEXT_NS]);
	}

	if (is_feat_sys_reg_trace_supported()) {
		sys_reg_trace_enable_per_world(&per_world_context[CPU_CONTEXT_NS]);
	}

	if (is_feat_mpam_supported()) {
		mpam_enable_per_world(&per_world_context[CPU_CONTEXT_NS]);
	}
}
#endif /* IMAGE_BL31 */

/*******************************************************************************
 * Initialise per_world_context for Secure world.
 * This function enables the architecture extensions, which have same value
 * across the cores for the secure world.
 ******************************************************************************/
static void manage_extensions_secure_per_world(void)
{
#if IMAGE_BL31
	cm_el3_arch_init_per_world(&per_world_context[CPU_CONTEXT_SECURE]);

	if (is_feat_sme_supported()) {

		if (ENABLE_SME_FOR_SWD) {
		/*
		 * Enable SME, SVE, FPU/SIMD in secure context, SPM must ensure
		 * SME, SVE, and FPU/SIMD context properly managed.
		 */
			sme_enable_per_world(&per_world_context[CPU_CONTEXT_SECURE]);
		} else {
		/*
		 * Disable SME, SVE, FPU/SIMD in secure context so non-secure
		 * world can safely use the associated registers.
		 */
			sme_disable_per_world(&per_world_context[CPU_CONTEXT_SECURE]);
		}
	}
	if (is_feat_sve_supported()) {
		if (ENABLE_SVE_FOR_SWD) {
		/*
		 * Enable SVE and FPU in secure context, SPM must ensure
		 * that the SVE and FPU register contexts are properly managed.
		 */
			sve_enable_per_world(&per_world_context[CPU_CONTEXT_SECURE]);
		} else {
		/*
		 * Disable SVE and FPU in secure context so non-secure world
		 * can safely use them.
		 */
			sve_disable_per_world(&per_world_context[CPU_CONTEXT_SECURE]);
		}
	}

	/* NS can access this but Secure shouldn't */
	if (is_feat_sys_reg_trace_supported()) {
		sys_reg_trace_disable_per_world(&per_world_context[CPU_CONTEXT_SECURE]);
	}

	has_secure_perworld_init = true;
#endif /* IMAGE_BL31 */
}

/*******************************************************************************
 * Enable architecture extensions on first entry to Non-secure world.
 ******************************************************************************/
static void manage_extensions_nonsecure(cpu_context_t *ctx)
{
#if IMAGE_BL31
	if (is_feat_amu_supported()) {
		amu_enable(ctx);
	}

	if (is_feat_sme_supported()) {
		sme_enable(ctx);
	}

	pmuv3_enable(ctx);
#endif /* IMAGE_BL31 */
}

/* TODO: move to lib/extensions/pauth when it has been ported to FEAT_STATE */
static __unused void enable_pauth_el2(void)
{
	u_register_t hcr_el2 = read_hcr_el2();
	/*
	 * For Armv8.3 pointer authentication feature, disable traps to EL2 when
	 *  accessing key registers or using pointer authentication instructions
	 *  from lower ELs.
	 */
	hcr_el2 |= (HCR_API_BIT | HCR_APK_BIT);

	write_hcr_el2(hcr_el2);
}

#if INIT_UNUSED_NS_EL2
/*******************************************************************************
 * Enable architecture extensions in-place at EL2 on first entry to Non-secure
 * world when EL2 is empty and unused.
 ******************************************************************************/
static void manage_extensions_nonsecure_el2_unused(void)
{
#if IMAGE_BL31
	if (is_feat_spe_supported()) {
		spe_init_el2_unused();
	}

	if (is_feat_amu_supported()) {
		amu_init_el2_unused();
	}

	if (is_feat_mpam_supported()) {
		mpam_init_el2_unused();
	}

	if (is_feat_trbe_supported()) {
		trbe_init_el2_unused();
	}

	if (is_feat_sys_reg_trace_supported()) {
		sys_reg_trace_init_el2_unused();
	}

	if (is_feat_trf_supported()) {
		trf_init_el2_unused();
	}

	pmuv3_init_el2_unused();

	if (is_feat_sve_supported()) {
		sve_init_el2_unused();
	}

	if (is_feat_sme_supported()) {
		sme_init_el2_unused();
	}

#if ENABLE_PAUTH
	enable_pauth_el2();
#endif /* ENABLE_PAUTH */
#endif /* IMAGE_BL31 */
}
#endif /* INIT_UNUSED_NS_EL2 */

/*******************************************************************************
 * Enable architecture extensions on first entry to Secure world.
 ******************************************************************************/
static void manage_extensions_secure(cpu_context_t *ctx)
{
#if IMAGE_BL31
	if (is_feat_sme_supported()) {
		if (ENABLE_SME_FOR_SWD) {
		/*
		 * Enable SME, SVE, FPU/SIMD in secure context, secure manager
		 * must ensure SME, SVE, and FPU/SIMD context properly managed.
		 */
			sme_init_el3();
			sme_enable(ctx);
		} else {
		/*
		 * Disable SME, SVE, FPU/SIMD in secure context so non-secure
		 * world can safely use the associated registers.
		 */
			sme_disable(ctx);
		}
	}
#endif /* IMAGE_BL31 */
}

#if !IMAGE_BL1
/*******************************************************************************
 * The following function initializes the cpu_context for a CPU specified by
 * its `cpu_idx` for first use, and sets the initial entrypoint state as
 * specified by the entry_point_info structure.
 ******************************************************************************/
void cm_init_context_by_index(unsigned int cpu_idx,
			      const entry_point_info_t *ep)
{
	cpu_context_t *ctx;
	ctx = cm_get_context_by_index(cpu_idx, GET_SECURITY_STATE(ep->h.attr));
	cm_setup_context(ctx, ep);
}
#endif /* !IMAGE_BL1 */

/*******************************************************************************
 * The following function initializes the cpu_context for the current CPU
 * for first use, and sets the initial entrypoint state as specified by the
 * entry_point_info structure.
 ******************************************************************************/
void cm_init_my_context(const entry_point_info_t *ep)
{
	cpu_context_t *ctx;
	ctx = cm_get_context(GET_SECURITY_STATE(ep->h.attr));
	cm_setup_context(ctx, ep);
}

/* EL2 present but unused, need to disable safely. SCTLR_EL2 can be ignored */
static void init_nonsecure_el2_unused(cpu_context_t *ctx)
{
#if INIT_UNUSED_NS_EL2
	u_register_t hcr_el2 = HCR_RESET_VAL;
	u_register_t mdcr_el2;
	u_register_t scr_el3;

	scr_el3 = read_ctx_reg(get_el3state_ctx(ctx), CTX_SCR_EL3);

	/* Set EL2 register width: Set HCR_EL2.RW to match SCR_EL3.RW */
	if ((scr_el3 & SCR_RW_BIT) != 0U) {
		hcr_el2 |= HCR_RW_BIT;
	}

	write_hcr_el2(hcr_el2);

	/*
	 * Initialise CPTR_EL2 setting all fields rather than relying on the hw.
	 * All fields have architecturally UNKNOWN reset values.
	 */
	write_cptr_el2(CPTR_EL2_RESET_VAL);

	/*
	 * Initialise CNTHCTL_EL2. All fields are architecturally UNKNOWN on
	 * reset and are set to zero except for field(s) listed below.
	 *
	 * CNTHCTL_EL2.EL1PTEN: Set to one to disable traps to Hyp mode of
	 * Non-secure EL0 and EL1 accesses to the physical timer registers.
	 *
	 * CNTHCTL_EL2.EL1PCTEN: Set to one to disable traps to Hyp mode of
	 * Non-secure EL0 and EL1 accesses to the physical counter registers.
	 */
	write_cnthctl_el2(CNTHCTL_RESET_VAL | EL1PCEN_BIT | EL1PCTEN_BIT);

	/*
	 * Initialise CNTVOFF_EL2 to zero as it resets to an architecturally
	 * UNKNOWN value.
	 */
	write_cntvoff_el2(0);

	/*
	 * Set VPIDR_EL2 and VMPIDR_EL2 to match MIDR_EL1 and MPIDR_EL1
	 * respectively.
	 */
	write_vpidr_el2(read_midr_el1());
	write_vmpidr_el2(read_mpidr_el1());

	/*
	 * Initialise VTTBR_EL2. All fields are architecturally UNKNOWN on reset.
	 *
	 * VTTBR_EL2.VMID: Set to zero. Even though EL1&0 stage 2 address
	 * translation is disabled, cache maintenance operations depend on the
	 * VMID.
	 *
	 * VTTBR_EL2.BADDR: Set to zero as EL1&0 stage 2 address translation is
	 * disabled.
	 */
	write_vttbr_el2(VTTBR_RESET_VAL &
		     ~((VTTBR_VMID_MASK << VTTBR_VMID_SHIFT) |
		       (VTTBR_BADDR_MASK << VTTBR_BADDR_SHIFT)));

	/*
	 * Initialise MDCR_EL2, setting all fields rather than relying on hw.
	 * Some fields are architecturally UNKNOWN on reset.
	 *
	 * MDCR_EL2.TDRA: Set to zero so that Non-secure EL0 and EL1 System
	 * register accesses to the Debug ROM registers are not trapped to EL2.
	 *
	 * MDCR_EL2.TDOSA: Set to zero so that Non-secure EL1 System register
	 * accesses to the powerdown debug registers are not trapped to EL2.
	 *
	 * MDCR_EL2.TDA: Set to zero so that System register accesses to the
	 * debug registers do not trap to EL2.
	 *
	 * MDCR_EL2.TDE: Set to zero so that debug exceptions are not routed to
	 * EL2.
	 */
	mdcr_el2 = MDCR_EL2_RESET_VAL &
		 ~(MDCR_EL2_TDRA_BIT | MDCR_EL2_TDOSA_BIT | MDCR_EL2_TDA_BIT |
		   MDCR_EL2_TDE_BIT);

	write_mdcr_el2(mdcr_el2);

	/*
	 * Initialise HSTR_EL2. All fields are architecturally UNKNOWN on reset.
	 *
	 * HSTR_EL2.T<n>: Set all these fields to zero so that Non-secure EL0 or
	 * EL1 accesses to System registers do not trap to EL2.
	 */
	write_hstr_el2(HSTR_EL2_RESET_VAL & ~(HSTR_EL2_T_MASK));

	/*
	 * Initialise CNTHP_CTL_EL2. All fields are architecturally UNKNOWN on
	 * reset.
	 *
	 * CNTHP_CTL_EL2:ENABLE: Set to zero to disable the EL2 physical timer
	 * and prevent timer interrupts.
	 */
	write_cnthp_ctl_el2(CNTHP_CTL_RESET_VAL & ~(CNTHP_CTL_ENABLE_BIT));

	manage_extensions_nonsecure_el2_unused();
#endif /* INIT_UNUSED_NS_EL2 */
}

/*******************************************************************************
 * Prepare the CPU system registers for first entry into realm, secure, or
 * normal world.
 *
 * If execution is requested to EL2 or hyp mode, SCTLR_EL2 is initialized
 * If execution is requested to non-secure EL1 or svc mode, and the CPU supports
 * EL2 then EL2 is disabled by configuring all necessary EL2 registers.
 * For all entries, the EL1 registers are initialized from the cpu_context
 ******************************************************************************/
void cm_prepare_el3_exit(uint32_t security_state)
{
	u_register_t sctlr_elx, scr_el3;
	cpu_context_t *ctx = cm_get_context(security_state);

	assert(ctx != NULL);

	if (security_state == NON_SECURE) {
		uint64_t el2_implemented = el_implemented(2);

		scr_el3 = read_ctx_reg(get_el3state_ctx(ctx),
						 CTX_SCR_EL3);

		if (el2_implemented != EL_IMPL_NONE) {

			/*
			 * If context is not being used for EL2, initialize
			 * HCRX_EL2 with its init value here.
			 */
			if (is_feat_hcx_supported()) {
				write_hcrx_el2(HCRX_EL2_INIT_VAL);
			}

			/*
			 * Initialize Fine-grained trap registers introduced
			 * by FEAT_FGT so all traps are initially disabled when
			 * switching to EL2 or a lower EL, preventing undesired
			 * behavior.
			 */
			if (is_feat_fgt_supported()) {
				/*
				 * Initialize HFG*_EL2 registers with a default
				 * value so legacy systems unaware of FEAT_FGT
				 * do not get trapped due to their lack of
				 * initialization for this feature.
				 */
				write_hfgitr_el2(HFGITR_EL2_INIT_VAL);
				write_hfgrtr_el2(HFGRTR_EL2_INIT_VAL);
				write_hfgwtr_el2(HFGWTR_EL2_INIT_VAL);
			}

			/* Condition to ensure EL2 is being used. */
			if ((scr_el3 & SCR_HCE_BIT) != 0U) {
				/* Use SCTLR_EL1.EE value to initialise sctlr_el2 */
				sctlr_elx = read_ctx_reg(get_el1_sysregs_ctx(ctx),
								CTX_SCTLR_EL1);
				sctlr_elx &= SCTLR_EE_BIT;
				sctlr_elx |= SCTLR_EL2_RES1;
#if ERRATA_A75_764081
				/*
				 * If workaround of errata 764081 for Cortex-A75
				 * is used then set SCTLR_EL2.IESB to enable
				 * Implicit Error Synchronization Barrier.
				 */
				sctlr_elx |= SCTLR_IESB_BIT;
#endif /* ERRATA_A75_764081 */
				write_sctlr_el2(sctlr_elx);
			} else {
				/*
				 * (scr_el3 & SCR_HCE_BIT==0)
				 * EL2 implemented but unused.
				 */
				init_nonsecure_el2_unused(ctx);
			}
		}
	}
	cm_el1_sysregs_context_restore(security_state);
	cm_set_next_eret_context(security_state);
}

#if CTX_INCLUDE_EL2_REGS

static void el2_sysregs_context_save_fgt(el2_sysregs_t *ctx)
{
	write_el2_ctx_fgt(ctx, hdfgrtr_el2, read_hdfgrtr_el2());
	if (is_feat_amu_supported()) {
		write_el2_ctx_fgt(ctx, hafgrtr_el2, read_hafgrtr_el2());
	}
	write_el2_ctx_fgt(ctx, hdfgwtr_el2, read_hdfgwtr_el2());
	write_el2_ctx_fgt(ctx, hfgitr_el2, read_hfgitr_el2());
	write_el2_ctx_fgt(ctx, hfgrtr_el2, read_hfgrtr_el2());
	write_el2_ctx_fgt(ctx, hfgwtr_el2, read_hfgwtr_el2());
}

static void el2_sysregs_context_restore_fgt(el2_sysregs_t *ctx)
{
	write_hdfgrtr_el2(read_el2_ctx_fgt(ctx, hdfgrtr_el2));
	if (is_feat_amu_supported()) {
		write_hafgrtr_el2(read_el2_ctx_fgt(ctx, hafgrtr_el2));
	}
	write_hdfgwtr_el2(read_el2_ctx_fgt(ctx, hdfgwtr_el2));
	write_hfgitr_el2(read_el2_ctx_fgt(ctx, hfgitr_el2));
	write_hfgrtr_el2(read_el2_ctx_fgt(ctx, hfgrtr_el2));
	write_hfgwtr_el2(read_el2_ctx_fgt(ctx, hfgwtr_el2));
}

#if CTX_INCLUDE_MPAM_REGS

static void el2_sysregs_context_save_mpam(mpam_t *ctx)
{
	u_register_t mpam_idr = read_mpamidr_el1();

	write_ctx_reg(ctx, CTX_MPAM2_EL2, read_mpam2_el2());

	/*
	 * The context registers that we intend to save would be part of the
	 * PE's system register frame only if MPAMIDR_EL1.HAS_HCR == 1.
	 */
	if ((mpam_idr & MPAMIDR_HAS_HCR_BIT) == 0U) {
		return;
	}

	/*
	 * MPAMHCR_EL2, MPAMVPMV_EL2 and MPAMVPM0_EL2 are always present if
	 * MPAMIDR_HAS_HCR_BIT == 1.
	 */
	write_ctx_reg(ctx, CTX_MPAMHCR_EL2, read_mpamhcr_el2());
	write_ctx_reg(ctx, CTX_MPAMVPM0_EL2, read_mpamvpm0_el2());
	write_ctx_reg(ctx, CTX_MPAMVPMV_EL2, read_mpamvpmv_el2());

	/*
	 * The number of MPAMVPM registers is implementation defined, their
	 * number is stored in the MPAMIDR_EL1 register.
	 */
	switch ((mpam_idr >> MPAMIDR_EL1_VPMR_MAX_SHIFT) & MPAMIDR_EL1_VPMR_MAX_MASK) {
	case 7:
		write_ctx_reg(ctx, CTX_MPAMVPM7_EL2, read_mpamvpm7_el2());
		__fallthrough;
	case 6:
		write_ctx_reg(ctx, CTX_MPAMVPM6_EL2, read_mpamvpm6_el2());
		__fallthrough;
	case 5:
		write_ctx_reg(ctx, CTX_MPAMVPM5_EL2, read_mpamvpm5_el2());
		__fallthrough;
	case 4:
		write_ctx_reg(ctx, CTX_MPAMVPM4_EL2, read_mpamvpm4_el2());
		__fallthrough;
	case 3:
		write_ctx_reg(ctx, CTX_MPAMVPM3_EL2, read_mpamvpm3_el2());
		__fallthrough;
	case 2:
		write_ctx_reg(ctx, CTX_MPAMVPM2_EL2, read_mpamvpm2_el2());
		__fallthrough;
	case 1:
		write_ctx_reg(ctx, CTX_MPAMVPM1_EL2, read_mpamvpm1_el2());
		break;
	}
}

#endif /* CTX_INCLUDE_MPAM_REGS */

#if CTX_INCLUDE_MPAM_REGS
static void el2_sysregs_context_restore_mpam(mpam_t *ctx)
{
	u_register_t mpam_idr = read_mpamidr_el1();

	write_mpam2_el2(read_ctx_reg(ctx, CTX_MPAM2_EL2));

	if ((mpam_idr & MPAMIDR_HAS_HCR_BIT) == 0U) {
		return;
	}

	write_mpamhcr_el2(read_ctx_reg(ctx, CTX_MPAMHCR_EL2));
	write_mpamvpm0_el2(read_ctx_reg(ctx, CTX_MPAMVPM0_EL2));
	write_mpamvpmv_el2(read_ctx_reg(ctx, CTX_MPAMVPMV_EL2));

	switch ((mpam_idr >> MPAMIDR_EL1_VPMR_MAX_SHIFT) & MPAMIDR_EL1_VPMR_MAX_MASK) {
	case 7:
		write_mpamvpm7_el2(read_ctx_reg(ctx, CTX_MPAMVPM7_EL2));
		__fallthrough;
	case 6:
		write_mpamvpm6_el2(read_ctx_reg(ctx, CTX_MPAMVPM6_EL2));
		__fallthrough;
	case 5:
		write_mpamvpm5_el2(read_ctx_reg(ctx, CTX_MPAMVPM5_EL2));
		__fallthrough;
	case 4:
		write_mpamvpm4_el2(read_ctx_reg(ctx, CTX_MPAMVPM4_EL2));
		__fallthrough;
	case 3:
		write_mpamvpm3_el2(read_ctx_reg(ctx, CTX_MPAMVPM3_EL2));
		__fallthrough;
	case 2:
		write_mpamvpm2_el2(read_ctx_reg(ctx, CTX_MPAMVPM2_EL2));
		__fallthrough;
	case 1:
		write_mpamvpm1_el2(read_ctx_reg(ctx, CTX_MPAMVPM1_EL2));
		break;
	}
}
#endif /* CTX_INCLUDE_MPAM_REGS */

/* ---------------------------------------------------------------------------
 * The following registers are not added:
 * ICH_AP0R<n>_EL2
 * ICH_AP1R<n>_EL2
 * ICH_LR<n>_EL2
 *
 * NOTE: For a system with S-EL2 present but not enabled, accessing
 * ICC_SRE_EL2 is undefined from EL3. To workaround this change the
 * SCR_EL3.NS = 1 before accessing this register.
 * ---------------------------------------------------------------------------
 */
static void el2_sysregs_context_save_gic(el2_sysregs_t *ctx)
{
#if defined(SPD_spmd) && SPMD_SPM_AT_SEL2
	write_el2_ctx_common(ctx, icc_sre_el2, read_icc_sre_el2());
#else
	u_register_t scr_el3 = read_scr_el3();
	write_scr_el3(scr_el3 | SCR_NS_BIT);
	isb();

	write_el2_ctx_common(ctx, icc_sre_el2, read_icc_sre_el2());

	write_scr_el3(scr_el3);
	isb();
#endif
	write_el2_ctx_common(ctx, ich_hcr_el2, read_ich_hcr_el2());
	write_el2_ctx_common(ctx, ich_vmcr_el2, read_ich_vmcr_el2());
}

static void el2_sysregs_context_restore_gic(el2_sysregs_t *ctx)
{
#if defined(SPD_spmd) && SPMD_SPM_AT_SEL2
	write_icc_sre_el2(read_el2_ctx_common(ctx, icc_sre_el2));
#else
	u_register_t scr_el3 = read_scr_el3();
	write_scr_el3(scr_el3 | SCR_NS_BIT);
	isb();

	write_icc_sre_el2(read_el2_ctx_common(ctx, icc_sre_el2));

	write_scr_el3(scr_el3);
	isb();
#endif
	write_ich_hcr_el2(read_el2_ctx_common(ctx, ich_hcr_el2));
	write_ich_vmcr_el2(read_el2_ctx_common(ctx, ich_vmcr_el2));
}

/* -----------------------------------------------------
 * The following registers are not added:
 * AMEVCNTVOFF0<n>_EL2
 * AMEVCNTVOFF1<n>_EL2
 * -----------------------------------------------------
 */
static void el2_sysregs_context_save_common(el2_sysregs_t *ctx)
{
	write_el2_ctx_common(ctx, actlr_el2, read_actlr_el2());
	write_el2_ctx_common(ctx, afsr0_el2, read_afsr0_el2());
	write_el2_ctx_common(ctx, afsr1_el2, read_afsr1_el2());
	write_el2_ctx_common(ctx, amair_el2, read_amair_el2());
	write_el2_ctx_common(ctx, cnthctl_el2, read_cnthctl_el2());
	write_el2_ctx_common(ctx, cntvoff_el2, read_cntvoff_el2());
	write_el2_ctx_common(ctx, cptr_el2, read_cptr_el2());
	if (CTX_INCLUDE_AARCH32_REGS) {
		write_el2_ctx_common(ctx, dbgvcr32_el2, read_dbgvcr32_el2());
	}
	write_el2_ctx_common(ctx, elr_el2, read_elr_el2());
	write_el2_ctx_common(ctx, esr_el2, read_esr_el2());
	write_el2_ctx_common(ctx, far_el2, read_far_el2());
	write_el2_ctx_common(ctx, hacr_el2, read_hacr_el2());
	write_el2_ctx_common(ctx, hcr_el2, read_hcr_el2());
	write_el2_ctx_common(ctx, hpfar_el2, read_hpfar_el2());
	write_el2_ctx_common(ctx, hstr_el2, read_hstr_el2());
	write_el2_ctx_common(ctx, mair_el2, read_mair_el2());
	write_el2_ctx_common(ctx, mdcr_el2, read_mdcr_el2());
	write_el2_ctx_common(ctx, sctlr_el2, read_sctlr_el2());
	write_el2_ctx_common(ctx, spsr_el2, read_spsr_el2());
	write_el2_ctx_common(ctx, sp_el2, read_sp_el2());
	write_el2_ctx_common(ctx, tcr_el2, read_tcr_el2());
	write_el2_ctx_common(ctx, tpidr_el2, read_tpidr_el2());
	write_el2_ctx_common(ctx, ttbr0_el2, read_ttbr0_el2());
	write_el2_ctx_common(ctx, vbar_el2, read_vbar_el2());
	write_el2_ctx_common(ctx, vmpidr_el2, read_vmpidr_el2());
	write_el2_ctx_common(ctx, vpidr_el2, read_vpidr_el2());
	write_el2_ctx_common(ctx, vtcr_el2, read_vtcr_el2());
	write_el2_ctx_common(ctx, vttbr_el2, read_vttbr_el2());
}

static void el2_sysregs_context_restore_common(el2_sysregs_t *ctx)
{
	write_actlr_el2(read_el2_ctx_common(ctx, actlr_el2));
	write_afsr0_el2(read_el2_ctx_common(ctx, afsr0_el2));
	write_afsr1_el2(read_el2_ctx_common(ctx, afsr1_el2));
	write_amair_el2(read_el2_ctx_common(ctx, amair_el2));
	write_cnthctl_el2(read_el2_ctx_common(ctx, cnthctl_el2));
	write_cntvoff_el2(read_el2_ctx_common(ctx, cntvoff_el2));
	write_cptr_el2(read_el2_ctx_common(ctx, cptr_el2));
	if (CTX_INCLUDE_AARCH32_REGS) {
		write_dbgvcr32_el2(read_el2_ctx_common(ctx, dbgvcr32_el2));
	}
	write_elr_el2(read_el2_ctx_common(ctx, elr_el2));
	write_esr_el2(read_el2_ctx_common(ctx, esr_el2));
	write_far_el2(read_el2_ctx_common(ctx, far_el2));
	write_hacr_el2(read_el2_ctx_common(ctx, hacr_el2));
	write_hcr_el2(read_el2_ctx_common(ctx, hcr_el2));
	write_hpfar_el2(read_el2_ctx_common(ctx, hpfar_el2));
	write_hstr_el2(read_el2_ctx_common(ctx, hstr_el2));
	write_mair_el2(read_el2_ctx_common(ctx, mair_el2));
	write_mdcr_el2(read_el2_ctx_common(ctx, mdcr_el2));
	write_sctlr_el2(read_el2_ctx_common(ctx, sctlr_el2));
	write_spsr_el2(read_el2_ctx_common(ctx, spsr_el2));
	write_sp_el2(read_el2_ctx_common(ctx, sp_el2));
	write_tcr_el2(read_el2_ctx_common(ctx, tcr_el2));
	write_tpidr_el2(read_el2_ctx_common(ctx, tpidr_el2));
	write_ttbr0_el2(read_el2_ctx_common(ctx, ttbr0_el2));
	write_vbar_el2(read_el2_ctx_common(ctx, vbar_el2));
	write_vmpidr_el2(read_el2_ctx_common(ctx, vmpidr_el2));
	write_vpidr_el2(read_el2_ctx_common(ctx, vpidr_el2));
	write_vtcr_el2(read_el2_ctx_common(ctx, vtcr_el2));
	write_vttbr_el2(read_el2_ctx_common(ctx, vttbr_el2));
}

/*******************************************************************************
 * Save EL2 sysreg context
 ******************************************************************************/
void cm_el2_sysregs_context_save(uint32_t security_state)
{
	cpu_context_t *ctx;
	el2_sysregs_t *el2_sysregs_ctx;

	ctx = cm_get_context(security_state);
	assert(ctx != NULL);

	el2_sysregs_ctx = get_el2_sysregs_ctx(ctx);

	el2_sysregs_context_save_common(el2_sysregs_ctx);
	el2_sysregs_context_save_gic(el2_sysregs_ctx);

	if (is_feat_mte2_supported()) {
		write_el2_ctx_mte2(el2_sysregs_ctx, tfsr_el2, read_tfsr_el2());
	}

#if CTX_INCLUDE_MPAM_REGS
	if (is_feat_mpam_supported()) {
		mpam_t *mpam_ctx = get_mpam_ctx(ctx);
		el2_sysregs_context_save_mpam(mpam_ctx);
	}
#endif

	if (is_feat_fgt_supported()) {
		el2_sysregs_context_save_fgt(el2_sysregs_ctx);
	}

	if (is_feat_ecv_v2_supported()) {
		write_el2_ctx_ecv(el2_sysregs_ctx, cntpoff_el2, read_cntpoff_el2());
	}

	if (is_feat_vhe_supported()) {
		write_el2_ctx_vhe(el2_sysregs_ctx, contextidr_el2,
					read_contextidr_el2());
		write_el2_ctx_vhe(el2_sysregs_ctx, ttbr1_el2, read_ttbr1_el2());
	}

	if (is_feat_ras_supported()) {
		write_el2_ctx_ras(el2_sysregs_ctx, vdisr_el2, read_vdisr_el2());
		write_el2_ctx_ras(el2_sysregs_ctx, vsesr_el2, read_vsesr_el2());
	}

	if (is_feat_nv2_supported()) {
		write_el2_ctx_neve(el2_sysregs_ctx, vncr_el2, read_vncr_el2());
	}

	if (is_feat_trf_supported()) {
		write_el2_ctx_trf(el2_sysregs_ctx, trfcr_el2, read_trfcr_el2());
	}

	if (is_feat_csv2_2_supported()) {
		write_el2_ctx_csv2_2(el2_sysregs_ctx, scxtnum_el2,
					read_scxtnum_el2());
	}

	if (is_feat_hcx_supported()) {
		write_el2_ctx_hcx(el2_sysregs_ctx, hcrx_el2, read_hcrx_el2());
	}

	if (is_feat_tcr2_supported()) {
		write_el2_ctx_tcr2(el2_sysregs_ctx, tcr2_el2, read_tcr2_el2());
	}

	if (is_feat_sxpie_supported()) {
		write_el2_ctx_sxpie(el2_sysregs_ctx, pire0_el2, read_pire0_el2());
		write_el2_ctx_sxpie(el2_sysregs_ctx, pir_el2, read_pir_el2());
	}

	if (is_feat_sxpoe_supported()) {
		write_el2_ctx_sxpoe(el2_sysregs_ctx, por_el2, read_por_el2());
	}

	if (is_feat_s2pie_supported()) {
		write_el2_ctx_s2pie(el2_sysregs_ctx, s2pir_el2, read_s2pir_el2());
	}

	if (is_feat_gcs_supported()) {
		write_el2_ctx_gcs(el2_sysregs_ctx, gcscr_el2, read_gcscr_el2());
		write_el2_ctx_gcs(el2_sysregs_ctx, gcspr_el2, read_gcspr_el2());
	}
}

/*******************************************************************************
 * Restore EL2 sysreg context
 ******************************************************************************/
void cm_el2_sysregs_context_restore(uint32_t security_state)
{
	cpu_context_t *ctx;
	el2_sysregs_t *el2_sysregs_ctx;

	ctx = cm_get_context(security_state);
	assert(ctx != NULL);

	el2_sysregs_ctx = get_el2_sysregs_ctx(ctx);

	el2_sysregs_context_restore_common(el2_sysregs_ctx);
	el2_sysregs_context_restore_gic(el2_sysregs_ctx);

	if (is_feat_mte2_supported()) {
		write_tfsr_el2(read_el2_ctx_mte2(el2_sysregs_ctx, tfsr_el2));
	}

#if CTX_INCLUDE_MPAM_REGS
	if (is_feat_mpam_supported()) {
		mpam_t *mpam_ctx = get_mpam_ctx(ctx);
		el2_sysregs_context_restore_mpam(mpam_ctx);
	}
#endif

	if (is_feat_fgt_supported()) {
		el2_sysregs_context_restore_fgt(el2_sysregs_ctx);
	}

	if (is_feat_ecv_v2_supported()) {
		write_cntpoff_el2(read_el2_ctx_ecv(el2_sysregs_ctx, cntpoff_el2));
	}

	if (is_feat_vhe_supported()) {
		write_contextidr_el2(read_el2_ctx_vhe(el2_sysregs_ctx,
					contextidr_el2));
		write_ttbr1_el2(read_el2_ctx_vhe(el2_sysregs_ctx, ttbr1_el2));
	}

	if (is_feat_ras_supported()) {
		write_vdisr_el2(read_el2_ctx_ras(el2_sysregs_ctx, vdisr_el2));
		write_vsesr_el2(read_el2_ctx_ras(el2_sysregs_ctx, vsesr_el2));
	}

	if (is_feat_nv2_supported()) {
		write_vncr_el2(read_el2_ctx_neve(el2_sysregs_ctx, vncr_el2));
	}

	if (is_feat_trf_supported()) {
		write_trfcr_el2(read_el2_ctx_trf(el2_sysregs_ctx, trfcr_el2));
	}

	if (is_feat_csv2_2_supported()) {
		write_scxtnum_el2(read_el2_ctx_csv2_2(el2_sysregs_ctx,
					scxtnum_el2));
	}

	if (is_feat_hcx_supported()) {
		write_hcrx_el2(read_el2_ctx_hcx(el2_sysregs_ctx, hcrx_el2));
	}

	if (is_feat_tcr2_supported()) {
		write_tcr2_el2(read_el2_ctx_tcr2(el2_sysregs_ctx, tcr2_el2));
	}

	if (is_feat_sxpie_supported()) {
		write_pire0_el2(read_el2_ctx_sxpie(el2_sysregs_ctx, pire0_el2));
		write_pir_el2(read_el2_ctx_sxpie(el2_sysregs_ctx, pir_el2));
	}

	if (is_feat_sxpoe_supported()) {
		write_por_el2(read_el2_ctx_sxpoe(el2_sysregs_ctx, por_el2));
	}

	if (is_feat_s2pie_supported()) {
		write_s2pir_el2(read_el2_ctx_s2pie(el2_sysregs_ctx, s2pir_el2));
	}

	if (is_feat_gcs_supported()) {
		write_gcscr_el2(read_el2_ctx_gcs(el2_sysregs_ctx, gcscr_el2));
		write_gcspr_el2(read_el2_ctx_gcs(el2_sysregs_ctx, gcspr_el2));
	}
}
#endif /* CTX_INCLUDE_EL2_REGS */

/*******************************************************************************
 * This function is used to exit to Non-secure world. If CTX_INCLUDE_EL2_REGS
 * is enabled, it restores EL1 and EL2 sysreg contexts instead of directly
 * updating EL1 and EL2 registers. Otherwise, it calls the generic
 * cm_prepare_el3_exit function.
 ******************************************************************************/
void cm_prepare_el3_exit_ns(void)
{
#if CTX_INCLUDE_EL2_REGS
#if ENABLE_ASSERTIONS
	cpu_context_t *ctx = cm_get_context(NON_SECURE);
	assert(ctx != NULL);

	/* Assert that EL2 is used. */
	u_register_t scr_el3 = read_ctx_reg(get_el3state_ctx(ctx), CTX_SCR_EL3);
	assert(((scr_el3 & SCR_HCE_BIT) != 0UL) &&
			(el_implemented(2U) != EL_IMPL_NONE));
#endif /* ENABLE_ASSERTIONS */

	/* Restore EL2 and EL1 sysreg contexts */
	cm_el2_sysregs_context_restore(NON_SECURE);
	cm_el1_sysregs_context_restore(NON_SECURE);
	cm_set_next_eret_context(NON_SECURE);
#else
	cm_prepare_el3_exit(NON_SECURE);
#endif /* CTX_INCLUDE_EL2_REGS */
}

static void el1_sysregs_context_save(el1_sysregs_t *ctx)
{
	write_ctx_reg(ctx, CTX_SPSR_EL1, read_spsr_el1());
	write_ctx_reg(ctx, CTX_ELR_EL1, read_elr_el1());

#if !ERRATA_SPECULATIVE_AT
	write_ctx_reg(ctx, CTX_SCTLR_EL1, read_sctlr_el1());
	write_ctx_reg(ctx, CTX_TCR_EL1, read_tcr_el1());
#endif /* (!ERRATA_SPECULATIVE_AT) */

	write_ctx_reg(ctx, CTX_CPACR_EL1, read_cpacr_el1());
	write_ctx_reg(ctx, CTX_CSSELR_EL1, read_csselr_el1());
	write_ctx_reg(ctx, CTX_SP_EL1, read_sp_el1());
	write_ctx_reg(ctx, CTX_ESR_EL1, read_esr_el1());
	write_ctx_reg(ctx, CTX_TTBR0_EL1, read_ttbr0_el1());
	write_ctx_reg(ctx, CTX_TTBR1_EL1, read_ttbr1_el1());
	write_ctx_reg(ctx, CTX_MAIR_EL1, read_mair_el1());
	write_ctx_reg(ctx, CTX_AMAIR_EL1, read_amair_el1());
	write_ctx_reg(ctx, CTX_ACTLR_EL1, read_actlr_el1());
	write_ctx_reg(ctx, CTX_TPIDR_EL1, read_tpidr_el1());
	write_ctx_reg(ctx, CTX_TPIDR_EL0, read_tpidr_el0());
	write_ctx_reg(ctx, CTX_TPIDRRO_EL0, read_tpidrro_el0());
	write_ctx_reg(ctx, CTX_PAR_EL1, read_par_el1());
	write_ctx_reg(ctx, CTX_FAR_EL1, read_far_el1());
	write_ctx_reg(ctx, CTX_AFSR0_EL1, read_afsr0_el1());
	write_ctx_reg(ctx, CTX_AFSR1_EL1, read_afsr1_el1());
	write_ctx_reg(ctx, CTX_CONTEXTIDR_EL1, read_contextidr_el1());
	write_ctx_reg(ctx, CTX_VBAR_EL1, read_vbar_el1());
	write_ctx_reg(ctx, CTX_MDCCINT_EL1, read_mdccint_el1());
	write_ctx_reg(ctx, CTX_MDSCR_EL1, read_mdscr_el1());

#if CTX_INCLUDE_AARCH32_REGS
	write_ctx_reg(ctx, CTX_SPSR_ABT, read_spsr_abt());
	write_ctx_reg(ctx, CTX_SPSR_UND, read_spsr_und());
	write_ctx_reg(ctx, CTX_SPSR_IRQ, read_spsr_irq());
	write_ctx_reg(ctx, CTX_SPSR_FIQ, read_spsr_fiq());
	write_ctx_reg(ctx, CTX_DACR32_EL2, read_dacr32_el2());
	write_ctx_reg(ctx, CTX_IFSR32_EL2, read_ifsr32_el2());
#endif /* CTX_INCLUDE_AARCH32_REGS */

#if NS_TIMER_SWITCH
	write_ctx_reg(ctx, CTX_CNTP_CTL_EL0, read_cntp_ctl_el0());
	write_ctx_reg(ctx, CTX_CNTP_CVAL_EL0, read_cntp_cval_el0());
	write_ctx_reg(ctx, CTX_CNTV_CTL_EL0, read_cntv_ctl_el0());
	write_ctx_reg(ctx, CTX_CNTV_CVAL_EL0, read_cntv_cval_el0());
	write_ctx_reg(ctx, CTX_CNTKCTL_EL1, read_cntkctl_el1());
#endif /* NS_TIMER_SWITCH */

#if ENABLE_FEAT_MTE2
	write_ctx_reg(ctx, CTX_TFSRE0_EL1, read_tfsre0_el1());
	write_ctx_reg(ctx, CTX_TFSR_EL1, read_tfsr_el1());
	write_ctx_reg(ctx, CTX_RGSR_EL1, read_rgsr_el1());
	write_ctx_reg(ctx, CTX_GCR_EL1, read_gcr_el1());
#endif /* ENABLE_FEAT_MTE2 */

#if ENABLE_FEAT_RAS
	if (is_feat_ras_supported()) {
		write_ctx_reg(ctx, CTX_DISR_EL1, read_disr_el1());
	}
#endif

#if ENABLE_FEAT_S1PIE
	if (is_feat_s1pie_supported()) {
		write_ctx_reg(ctx, CTX_PIRE0_EL1, read_pire0_el1());
		write_ctx_reg(ctx, CTX_PIR_EL1, read_pir_el1());
	}
#endif

#if ENABLE_FEAT_S1POE
	if (is_feat_s1poe_supported()) {
		write_ctx_reg(ctx, CTX_POR_EL1, read_por_el1());
	}
#endif

#if ENABLE_FEAT_S2POE
	if (is_feat_s2poe_supported()) {
		write_ctx_reg(ctx, CTX_S2POR_EL1, read_s2por_el1());
	}
#endif

#if ENABLE_FEAT_TCR2
	if (is_feat_tcr2_supported()) {
		write_ctx_reg(ctx, CTX_TCR2_EL1, read_tcr2_el1());
	}
#endif

#if ENABLE_TRF_FOR_NS
	if (is_feat_trf_supported()) {
		write_ctx_reg(ctx, CTX_TRFCR_EL1, read_trfcr_el1());
	}
#endif

#if ENABLE_FEAT_CSV2_2
	if (is_feat_csv2_2_supported()) {
		write_ctx_reg(ctx, CTX_SCXTNUM_EL0, read_scxtnum_el0());
		write_ctx_reg(ctx, CTX_SCXTNUM_EL1, read_scxtnum_el1());
	}
#endif

#if ENABLE_FEAT_GCS
	if (is_feat_gcs_supported()) {
		write_ctx_reg(ctx, CTX_GCSCR_EL1, read_gcscr_el1());
		write_ctx_reg(ctx, CTX_GCSCRE0_EL1, read_gcscre0_el1());
		write_ctx_reg(ctx, CTX_GCSPR_EL1, read_gcspr_el1());
		write_ctx_reg(ctx, CTX_GCSPR_EL0, read_gcspr_el0());
	}
#endif
}

static void el1_sysregs_context_restore(el1_sysregs_t *ctx)
{
	write_spsr_el1(read_ctx_reg(ctx, CTX_SPSR_EL1));
	write_elr_el1(read_ctx_reg(ctx, CTX_ELR_EL1));

#if !ERRATA_SPECULATIVE_AT
	write_sctlr_el1(read_ctx_reg(ctx, CTX_SCTLR_EL1));
	write_tcr_el1(read_ctx_reg(ctx, CTX_TCR_EL1));
#endif /* (!ERRATA_SPECULATIVE_AT) */

	write_cpacr_el1(read_ctx_reg(ctx, CTX_CPACR_EL1));
	write_csselr_el1(read_ctx_reg(ctx, CTX_CSSELR_EL1));
	write_sp_el1(read_ctx_reg(ctx, CTX_SP_EL1));
	write_esr_el1(read_ctx_reg(ctx, CTX_ESR_EL1));
	write_ttbr0_el1(read_ctx_reg(ctx, CTX_TTBR0_EL1));
	write_ttbr1_el1(read_ctx_reg(ctx, CTX_TTBR1_EL1));
	write_mair_el1(read_ctx_reg(ctx, CTX_MAIR_EL1));
	write_amair_el1(read_ctx_reg(ctx, CTX_AMAIR_EL1));
	write_actlr_el1(read_ctx_reg(ctx, CTX_ACTLR_EL1));
	write_tpidr_el1(read_ctx_reg(ctx, CTX_TPIDR_EL1));
	write_tpidr_el0(read_ctx_reg(ctx, CTX_TPIDR_EL0));
	write_tpidrro_el0(read_ctx_reg(ctx, CTX_TPIDRRO_EL0));
	write_par_el1(read_ctx_reg(ctx, CTX_PAR_EL1));
	write_far_el1(read_ctx_reg(ctx, CTX_FAR_EL1));
	write_afsr0_el1(read_ctx_reg(ctx, CTX_AFSR0_EL1));
	write_afsr1_el1(read_ctx_reg(ctx, CTX_AFSR1_EL1));
	write_contextidr_el1(read_ctx_reg(ctx, CTX_CONTEXTIDR_EL1));
	write_vbar_el1(read_ctx_reg(ctx, CTX_VBAR_EL1));
	write_mdccint_el1(read_ctx_reg(ctx, CTX_MDCCINT_EL1));
	write_mdscr_el1(read_ctx_reg(ctx, CTX_MDSCR_EL1));

#if CTX_INCLUDE_AARCH32_REGS
	write_spsr_abt(read_ctx_reg(ctx, CTX_SPSR_ABT));
	write_spsr_und(read_ctx_reg(ctx, CTX_SPSR_UND));
	write_spsr_irq(read_ctx_reg(ctx, CTX_SPSR_IRQ));
	write_spsr_fiq(read_ctx_reg(ctx, CTX_SPSR_FIQ));
	write_dacr32_el2(read_ctx_reg(ctx, CTX_DACR32_EL2));
	write_ifsr32_el2(read_ctx_reg(ctx, CTX_IFSR32_EL2));
#endif /* CTX_INCLUDE_AARCH32_REGS */

#if NS_TIMER_SWITCH
	write_cntp_ctl_el0(read_ctx_reg(ctx, CTX_CNTP_CTL_EL0));
	write_cntp_cval_el0(read_ctx_reg(ctx, CTX_CNTP_CVAL_EL0));
	write_cntv_ctl_el0(read_ctx_reg(ctx, CTX_CNTV_CTL_EL0));
	write_cntv_cval_el0(read_ctx_reg(ctx, CTX_CNTV_CVAL_EL0));
	write_cntkctl_el1(read_ctx_reg(ctx, CTX_CNTKCTL_EL1));
#endif /* NS_TIMER_SWITCH */

#if ENABLE_FEAT_MTE2
	write_tfsre0_el1(read_ctx_reg(ctx, CTX_TFSRE0_EL1));
	write_tfsr_el1(read_ctx_reg(ctx, CTX_TFSR_EL1));
	write_rgsr_el1(read_ctx_reg(ctx, CTX_RGSR_EL1));
	write_gcr_el1(read_ctx_reg(ctx, CTX_GCR_EL1));
#endif /* ENABLE_FEAT_MTE2 */

#if ENABLE_FEAT_RAS
	if (is_feat_ras_supported()) {
		write_disr_el1(read_ctx_reg(ctx, CTX_DISR_EL1));
	}
#endif

#if ENABLE_FEAT_S1PIE
	if (is_feat_s1pie_supported()) {
		write_pire0_el1(read_ctx_reg(ctx, CTX_PIRE0_EL1));
		write_pir_el1(read_ctx_reg(ctx, CTX_PIR_EL1));
	}
#endif

#if ENABLE_FEAT_S1POE
	if (is_feat_s1poe_supported()) {
		write_por_el1(read_ctx_reg(ctx, CTX_POR_EL1));
	}
#endif

#if ENABLE_FEAT_S2POE
	if (is_feat_s2poe_supported()) {
		write_s2por_el1(read_ctx_reg(ctx, CTX_S2POR_EL1));
	}
#endif

#if ENABLE_FEAT_TCR2
	if (is_feat_tcr2_supported()) {
		write_tcr2_el1(read_ctx_reg(ctx, CTX_TCR2_EL1));
	}
#endif

#if ENABLE_TRF_FOR_NS
	if (is_feat_trf_supported()) {
		write_trfcr_el1(read_ctx_reg(ctx, CTX_TRFCR_EL1));
	}
#endif

#if ENABLE_FEAT_CSV2_2
	if (is_feat_csv2_2_supported()) {
		write_scxtnum_el0(read_ctx_reg(ctx, CTX_SCXTNUM_EL0));
		write_scxtnum_el1(read_ctx_reg(ctx, CTX_SCXTNUM_EL1));
	}
#endif

#if ENABLE_FEAT_GCS
	if (is_feat_gcs_supported()) {
		write_gcscr_el1(read_ctx_reg(ctx, CTX_GCSCR_EL1));
		write_gcscre0_el1(read_ctx_reg(ctx, CTX_GCSCRE0_EL1));
		write_gcspr_el1(read_ctx_reg(ctx, CTX_GCSPR_EL1));
		write_gcspr_el0(read_ctx_reg(ctx, CTX_GCSPR_EL0));
	}
#endif
}

/*******************************************************************************
 * The next four functions are used by runtime services to save and restore
 * EL1 context on the 'cpu_context' structure for the specified security
 * state.
 ******************************************************************************/
void cm_el1_sysregs_context_save(uint32_t security_state)
{
	cpu_context_t *ctx;

	ctx = cm_get_context(security_state);
	assert(ctx != NULL);

	el1_sysregs_context_save(get_el1_sysregs_ctx(ctx));

#if IMAGE_BL31
	if (security_state == SECURE)
		PUBLISH_EVENT(cm_exited_secure_world);
	else
		PUBLISH_EVENT(cm_exited_normal_world);
#endif
}

void cm_el1_sysregs_context_restore(uint32_t security_state)
{
	cpu_context_t *ctx;

	ctx = cm_get_context(security_state);
	assert(ctx != NULL);

	el1_sysregs_context_restore(get_el1_sysregs_ctx(ctx));

#if IMAGE_BL31
	if (security_state == SECURE)
		PUBLISH_EVENT(cm_entering_secure_world);
	else
		PUBLISH_EVENT(cm_entering_normal_world);
#endif
}

/*******************************************************************************
 * This function populates ELR_EL3 member of 'cpu_context' pertaining to the
 * given security state with the given entrypoint
 ******************************************************************************/
void cm_set_elr_el3(uint32_t security_state, uintptr_t entrypoint)
{
	cpu_context_t *ctx;
	el3_state_t *state;

	ctx = cm_get_context(security_state);
	assert(ctx != NULL);

	/* Populate EL3 state so that ERET jumps to the correct entry */
	state = get_el3state_ctx(ctx);
	write_ctx_reg(state, CTX_ELR_EL3, entrypoint);
}

/*******************************************************************************
 * This function populates ELR_EL3 and SPSR_EL3 members of 'cpu_context'
 * pertaining to the given security state
 ******************************************************************************/
void cm_set_elr_spsr_el3(uint32_t security_state,
			uintptr_t entrypoint, uint32_t spsr)
{
	cpu_context_t *ctx;
	el3_state_t *state;

	ctx = cm_get_context(security_state);
	assert(ctx != NULL);

	/* Populate EL3 state so that ERET jumps to the correct entry */
	state = get_el3state_ctx(ctx);
	write_ctx_reg(state, CTX_ELR_EL3, entrypoint);
	write_ctx_reg(state, CTX_SPSR_EL3, spsr);
}

/*******************************************************************************
 * This function updates a single bit in the SCR_EL3 member of the 'cpu_context'
 * pertaining to the given security state using the value and bit position
 * specified in the parameters. It preserves all other bits.
 ******************************************************************************/
void cm_write_scr_el3_bit(uint32_t security_state,
			  uint32_t bit_pos,
			  uint32_t value)
{
	cpu_context_t *ctx;
	el3_state_t *state;
	u_register_t scr_el3;

	ctx = cm_get_context(security_state);
	assert(ctx != NULL);

	/* Ensure that the bit position is a valid one */
	assert(((1UL << bit_pos) & SCR_VALID_BIT_MASK) != 0U);

	/* Ensure that the 'value' is only a bit wide */
	assert(value <= 1U);

	/*
	 * Get the SCR_EL3 value from the cpu context, clear the desired bit
	 * and set it to its new value.
	 */
	state = get_el3state_ctx(ctx);
	scr_el3 = read_ctx_reg(state, CTX_SCR_EL3);
	scr_el3 &= ~(1UL << bit_pos);
	scr_el3 |= (u_register_t)value << bit_pos;
	write_ctx_reg(state, CTX_SCR_EL3, scr_el3);
}

/*******************************************************************************
 * This function retrieves SCR_EL3 member of 'cpu_context' pertaining to the
 * given security state.
 ******************************************************************************/
u_register_t cm_get_scr_el3(uint32_t security_state)
{
	cpu_context_t *ctx;
	el3_state_t *state;

	ctx = cm_get_context(security_state);
	assert(ctx != NULL);

	/* Populate EL3 state so that ERET jumps to the correct entry */
	state = get_el3state_ctx(ctx);
	return read_ctx_reg(state, CTX_SCR_EL3);
}

/*******************************************************************************
 * This function is used to program the context that's used for exception
 * return. This initializes the SP_EL3 to a pointer to a 'cpu_context' set for
 * the required security state
 ******************************************************************************/
void cm_set_next_eret_context(uint32_t security_state)
{
	cpu_context_t *ctx;

	ctx = cm_get_context(security_state);
	assert(ctx != NULL);

	cm_set_next_context(ctx);
}