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efd1d2c8f3
Remove the "ghash-s390" crypto_shash algorithm, and replace it with an implementation of ghash_blocks_arch() for the GHASH library. This makes the GHASH library be optimized with CPACF. It also greatly reduces the amount of s390-specific glue code that is needed, and it fixes the issue where this GHASH optimization was disabled by default. Acked-by: Ard Biesheuvel <ardb@kernel.org> Link: https://lore.kernel.org/r/20260319061723.1140720-14-ebiggers@kernel.org Signed-off-by: Eric Biggers <ebiggers@kernel.org>
55 lines
1.5 KiB
C
55 lines
1.5 KiB
C
/* SPDX-License-Identifier: GPL-2.0-or-later */
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/*
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* GHASH optimized using the CP Assist for Cryptographic Functions (CPACF)
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*
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* Copyright 2026 Google LLC
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*/
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#include <asm/cpacf.h>
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#include <linux/cpufeature.h>
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static __ro_after_init DEFINE_STATIC_KEY_FALSE(have_cpacf_ghash);
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#define ghash_preparekey_arch ghash_preparekey_arch
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static void ghash_preparekey_arch(struct ghash_key *key,
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const u8 raw_key[GHASH_BLOCK_SIZE])
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{
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/* Save key in POLYVAL format for fallback */
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ghash_key_to_polyval(raw_key, &key->h);
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/* Save key in GHASH format for CPACF_KIMD_GHASH */
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memcpy(key->h_raw, raw_key, GHASH_BLOCK_SIZE);
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}
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#define ghash_blocks_arch ghash_blocks_arch
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static void ghash_blocks_arch(struct polyval_elem *acc,
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const struct ghash_key *key,
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const u8 *data, size_t nblocks)
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{
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if (static_branch_likely(&have_cpacf_ghash)) {
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/*
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* CPACF_KIMD_GHASH requires the accumulator and key in a single
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* buffer, each using the GHASH convention.
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*/
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u8 ctx[2][GHASH_BLOCK_SIZE] __aligned(8);
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polyval_acc_to_ghash(acc, ctx[0]);
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memcpy(ctx[1], key->h_raw, GHASH_BLOCK_SIZE);
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cpacf_kimd(CPACF_KIMD_GHASH, ctx, data,
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nblocks * GHASH_BLOCK_SIZE);
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ghash_acc_to_polyval(ctx[0], acc);
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memzero_explicit(ctx, sizeof(ctx));
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} else {
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ghash_blocks_generic(acc, &key->h, data, nblocks);
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}
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}
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#define gf128hash_mod_init_arch gf128hash_mod_init_arch
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static void gf128hash_mod_init_arch(void)
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{
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if (cpu_have_feature(S390_CPU_FEATURE_MSA) &&
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cpacf_query_func(CPACF_KIMD, CPACF_KIMD_GHASH))
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static_branch_enable(&have_cpacf_ghash);
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}
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