1// SPDX-License-Identifier: GPL-2.0-only
 2/*
 3 * Implementation of the memory encryption/decryption API.
 4 *
 5 * Since the low-level details of the operation depend on the
 6 * Confidential Computing environment (e.g. pKVM, CCA, ...), this just
 7 * acts as a top-level dispatcher to whatever hooks may have been
 8 * registered.
 9 *
10 * Author: Will Deacon <will@kernel.org>
11 * Copyright (C) 2024 Google LLC
12 *
13 * "Hello, boils and ghouls!"
14 */
15
16#include <linux/bug.h>
17#include <linux/compiler.h>
18#include <linux/err.h>
19#include <linux/mm.h>
20
21#include <asm/mem_encrypt.h>
22
23static const struct arm64_mem_crypt_ops *crypt_ops;
24
25int arm64_mem_crypt_ops_register(const struct arm64_mem_crypt_ops *ops)
26{
27	if (WARN_ON(crypt_ops))
28		return -EBUSY;
29
30	crypt_ops = ops;
31	return 0;
32}
33
34int set_memory_encrypted(unsigned long addr, int numpages)
35{
36	if (likely(!crypt_ops) || WARN_ON(!PAGE_ALIGNED(addr)))
37		return 0;
38
39	return crypt_ops->encrypt(addr, numpages);
40}
41EXPORT_SYMBOL_GPL(set_memory_encrypted);
42
43int set_memory_decrypted(unsigned long addr, int numpages)
44{
45	if (likely(!crypt_ops) || WARN_ON(!PAGE_ALIGNED(addr)))
46		return 0;
47
48	return crypt_ops->decrypt(addr, numpages);
49}
50EXPORT_SYMBOL_GPL(set_memory_decrypted);