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6b9ae8cfaa
Instead of exposing the powerpc-optimized SHA-1 code via powerpc-specific crypto_shash algorithms, instead just implement the sha1_blocks() library function. This is much simpler, it makes the SHA-1 library functions be powerpc-optimized, and it fixes the longstanding issue where the powerpc-optimized SHA-1 code was disabled by default. SHA-1 still remains available through crypto_shash, but individual architectures no longer need to handle it. Note: to see the diff from arch/powerpc/crypto/sha1-spe-glue.c to lib/crypto/powerpc/sha1.h, view this commit with 'git show -M10'. Reviewed-by: Ard Biesheuvel <ardb@kernel.org> Link: https://lore.kernel.org/r/20250712232329.818226-11-ebiggers@kernel.org Signed-off-by: Eric Biggers <ebiggers@kernel.org>
67 lines
1.8 KiB
C
67 lines
1.8 KiB
C
/* SPDX-License-Identifier: GPL-2.0-or-later */
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/*
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* SHA-1 optimized for PowerPC
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*
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* Copyright (c) 2015 Markus Stockhausen <stockhausen@collogia.de>
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*/
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#include <asm/switch_to.h>
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#include <linux/preempt.h>
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#ifdef CONFIG_SPE
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/*
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* MAX_BYTES defines the number of bytes that are allowed to be processed
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* between preempt_disable() and preempt_enable(). SHA1 takes ~1000
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* operations per 64 bytes. e500 cores can issue two arithmetic instructions
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* per clock cycle using one 32/64 bit unit (SU1) and one 32 bit unit (SU2).
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* Thus 2KB of input data will need an estimated maximum of 18,000 cycles.
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* Headroom for cache misses included. Even with the low end model clocked
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* at 667 MHz this equals to a critical time window of less than 27us.
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*
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*/
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#define MAX_BYTES 2048
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asmlinkage void ppc_spe_sha1_transform(struct sha1_block_state *state,
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const u8 *data, u32 nblocks);
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static void spe_begin(void)
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{
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/* We just start SPE operations and will save SPE registers later. */
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preempt_disable();
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enable_kernel_spe();
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}
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static void spe_end(void)
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{
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disable_kernel_spe();
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/* reenable preemption */
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preempt_enable();
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}
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static void sha1_blocks(struct sha1_block_state *state,
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const u8 *data, size_t nblocks)
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{
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do {
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u32 unit = min_t(size_t, nblocks, MAX_BYTES / SHA1_BLOCK_SIZE);
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spe_begin();
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ppc_spe_sha1_transform(state, data, unit);
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spe_end();
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data += unit * SHA1_BLOCK_SIZE;
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nblocks -= unit;
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} while (nblocks);
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}
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#else /* CONFIG_SPE */
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asmlinkage void powerpc_sha_transform(struct sha1_block_state *state,
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const u8 data[SHA1_BLOCK_SIZE]);
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static void sha1_blocks(struct sha1_block_state *state,
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const u8 *data, size_t nblocks)
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{
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do {
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powerpc_sha_transform(state, data);
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data += SHA1_BLOCK_SIZE;
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} while (--nblocks);
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}
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#endif /* !CONFIG_SPE */
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