diff options
Diffstat (limited to 'lib')
| -rw-r--r-- | lib/crypto/Kconfig | 1 | ||||
| -rw-r--r-- | lib/crypto/s390/aes.h | 106 |
2 files changed, 107 insertions, 0 deletions
diff --git a/lib/crypto/Kconfig b/lib/crypto/Kconfig index 2690b5ffc5ca..56a9b4f53b0e 100644 --- a/lib/crypto/Kconfig +++ b/lib/crypto/Kconfig @@ -19,6 +19,7 @@ config CRYPTO_LIB_AES_ARCH default y if PPC && (SPE || (PPC64 && VSX)) default y if RISCV && 64BIT && TOOLCHAIN_HAS_VECTOR_CRYPTO && \ RISCV_EFFICIENT_VECTOR_UNALIGNED_ACCESS + default y if S390 config CRYPTO_LIB_AESCFB tristate diff --git a/lib/crypto/s390/aes.h b/lib/crypto/s390/aes.h new file mode 100644 index 000000000000..5466f6ecbce7 --- /dev/null +++ b/lib/crypto/s390/aes.h @@ -0,0 +1,106 @@ +/* SPDX-License-Identifier: GPL-2.0-or-later */ +/* + * AES optimized using the CP Assist for Cryptographic Functions (CPACF) + * + * Copyright 2026 Google LLC + */ +#include <asm/cpacf.h> +#include <linux/cpufeature.h> + +static __ro_after_init DEFINE_STATIC_KEY_FALSE(have_cpacf_aes128); +static __ro_after_init DEFINE_STATIC_KEY_FALSE(have_cpacf_aes192); +static __ro_after_init DEFINE_STATIC_KEY_FALSE(have_cpacf_aes256); + +/* + * When the CPU supports CPACF AES for the requested key length, we need only + * save a copy of the raw AES key, as that's what the CPACF instructions need. + * + * When unsupported, fall back to the generic key expansion and en/decryption. + */ +static void aes_preparekey_arch(union aes_enckey_arch *k, + union aes_invkey_arch *inv_k, + const u8 *in_key, int key_len, int nrounds) +{ + if (key_len == AES_KEYSIZE_128) { + if (static_branch_likely(&have_cpacf_aes128)) { + memcpy(k->raw_key, in_key, AES_KEYSIZE_128); + return; + } + } else if (key_len == AES_KEYSIZE_192) { + if (static_branch_likely(&have_cpacf_aes192)) { + memcpy(k->raw_key, in_key, AES_KEYSIZE_192); + return; + } + } else { + if (static_branch_likely(&have_cpacf_aes256)) { + memcpy(k->raw_key, in_key, AES_KEYSIZE_256); + return; + } + } + aes_expandkey_generic(k->rndkeys, inv_k ? inv_k->inv_rndkeys : NULL, + in_key, key_len); +} + +static inline bool aes_crypt_s390(const struct aes_enckey *key, + u8 out[AES_BLOCK_SIZE], + const u8 in[AES_BLOCK_SIZE], int decrypt) +{ + if (key->len == AES_KEYSIZE_128) { + if (static_branch_likely(&have_cpacf_aes128)) { + cpacf_km(CPACF_KM_AES_128 | decrypt, + (void *)key->k.raw_key, out, in, + AES_BLOCK_SIZE); + return true; + } + } else if (key->len == AES_KEYSIZE_192) { + if (static_branch_likely(&have_cpacf_aes192)) { + cpacf_km(CPACF_KM_AES_192 | decrypt, + (void *)key->k.raw_key, out, in, + AES_BLOCK_SIZE); + return true; + } + } else { + if (static_branch_likely(&have_cpacf_aes256)) { + cpacf_km(CPACF_KM_AES_256 | decrypt, + (void *)key->k.raw_key, out, in, + AES_BLOCK_SIZE); + return true; + } + } + return false; +} + +static void aes_encrypt_arch(const struct aes_enckey *key, + u8 out[AES_BLOCK_SIZE], + const u8 in[AES_BLOCK_SIZE]) +{ + if (likely(aes_crypt_s390(key, out, in, 0))) + return; + aes_encrypt_generic(key->k.rndkeys, key->nrounds, out, in); +} + +static void aes_decrypt_arch(const struct aes_key *key, + u8 out[AES_BLOCK_SIZE], + const u8 in[AES_BLOCK_SIZE]) +{ + if (likely(aes_crypt_s390((const struct aes_enckey *)key, out, in, + CPACF_DECRYPT))) + return; + aes_decrypt_generic(key->inv_k.inv_rndkeys, key->nrounds, out, in); +} + +#define aes_mod_init_arch aes_mod_init_arch +static void aes_mod_init_arch(void) +{ + if (cpu_have_feature(S390_CPU_FEATURE_MSA)) { + cpacf_mask_t km_functions; + + cpacf_query(CPACF_KM, &km_functions); + if (cpacf_test_func(&km_functions, CPACF_KM_AES_128)) + static_branch_enable(&have_cpacf_aes128); + if (cpacf_test_func(&km_functions, CPACF_KM_AES_192)) + static_branch_enable(&have_cpacf_aes192); + if (cpacf_test_func(&km_functions, CPACF_KM_AES_256)) + static_branch_enable(&have_cpacf_aes256); + } +} |