/* Copyright (c) (2019,2021) Apple Inc. All rights reserved.
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 * not, directly or indirectly, redistribute the Apple Software or any portions thereof.
 *
 * @APPLE_OSREFERENCE_LICENSE_HEADER_START@
 *
 * This file contains Original Code and/or Modifications of Original Code
 * as defined in and that are subject to the Apple Public Source License
 * Version 2.0 (the 'License'). You may not use this file except in
 * compliance with the License. The rights granted to you under the License
 * may not be used to create, or enable the creation or redistribution of,
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 * Please obtain a copy of the License at
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 *
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#ifndef _CORECRYPTO_CC_INTERNAL_H_
#define _CORECRYPTO_CC_INTERNAL_H_

#include <corecrypto/cc_priv.h>

#if CC_XNU_KERNEL_PRIVATE

#elif CC_KERNEL
#include <libkern/libkern.h>
#else
#include <stdlib.h>
#include <stdio.h>
#endif

#include "cc_macros.h"

extern bool cc_rdrand(uint64_t *rand);

#if CC_BUILT_FOR_TESTING
extern bool (*cc_rdrand_mock)(uint64_t *rand);

extern void (*cc_abort_mock)(const char *msg);
#endif

#if CC_DIT_SUPPORTED

CC_INLINE bool
cc_is_dit_enabled(void)
{
	return __builtin_arm_rsr64("DIT") == (1U << 24);
}

CC_INLINE bool
cc_enable_dit(void)
{
	// DIT might have already been enabled by another corecrypto function, in
	// that case that function is responsible for disabling DIT when returning.
	//
	// This also covers when code _outside_ corecrypto enabled DIT before
	// calling us. In that case we're not responsible for disabling it either.
	if (cc_is_dit_enabled()) {
		return false;
	}

	// Enable DIT.
	__builtin_arm_wsr64("DIT", 1);

	// Check that DIT was enabled.
	cc_try_abort_if(!cc_is_dit_enabled(), "DIT not enabled");

	// To the cleanup function, indicate that we toggled DIT and
	// that cc_disable_dit() should actually disable it again.
	return true;
}

void cc_disable_dit(volatile bool *dit_was_enabled);

#define CC_ENSURE_DIT_ENABLED                    \
    volatile bool _cc_dit_auto_disable           \
	__attribute__((cleanup(cc_disable_dit))) \
	__attribute__((unused)) = cc_enable_dit();

#else

#define CC_ENSURE_DIT_ENABLED

#endif // CC_DIT_SUPPORTED

#endif // _CORECRYPTO_CC_INTERNAL_H_