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 23 static const struct arm64_mem_crypt_ops *crypt_ops; 24 25 int 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 34 int 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 } 41 EXPORT_SYMBOL_GPL(set_memory_encrypted); 42 43 int 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 } 50 EXPORT_SYMBOL_GPL(set_memory_decrypted); 51