fc754c024a
Instead of yielding from the bowels of the asm routine if a reschedule is needed, divide up the input into 4 KB chunks in the C glue. This simplifies the code substantially, and avoids scheduling out the task with the asm routine on the call stack, which is undesirable from a CFI/instrumentation point of view. Signed-off-by: Ard Biesheuvel <ardb@kernel.org> Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
144 lines
3.5 KiB
C
144 lines
3.5 KiB
C
// SPDX-License-Identifier: GPL-2.0-only
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/*
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* Accelerated CRC-T10DIF using arm64 NEON and Crypto Extensions instructions
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*
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* Copyright (C) 2016 - 2017 Linaro Ltd <ard.biesheuvel@linaro.org>
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*/
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#include <linux/cpufeature.h>
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#include <linux/crc-t10dif.h>
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#include <linux/init.h>
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#include <linux/kernel.h>
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#include <linux/module.h>
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#include <linux/string.h>
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#include <crypto/internal/hash.h>
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#include <crypto/internal/simd.h>
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#include <asm/neon.h>
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#include <asm/simd.h>
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#define CRC_T10DIF_PMULL_CHUNK_SIZE 16U
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asmlinkage u16 crc_t10dif_pmull_p8(u16 init_crc, const u8 *buf, size_t len);
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asmlinkage u16 crc_t10dif_pmull_p64(u16 init_crc, const u8 *buf, size_t len);
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static int crct10dif_init(struct shash_desc *desc)
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{
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u16 *crc = shash_desc_ctx(desc);
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*crc = 0;
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return 0;
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}
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static int crct10dif_update_pmull_p8(struct shash_desc *desc, const u8 *data,
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unsigned int length)
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{
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u16 *crc = shash_desc_ctx(desc);
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if (length >= CRC_T10DIF_PMULL_CHUNK_SIZE && crypto_simd_usable()) {
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do {
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unsigned int chunk = length;
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if (chunk > SZ_4K + CRC_T10DIF_PMULL_CHUNK_SIZE)
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chunk = SZ_4K;
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kernel_neon_begin();
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*crc = crc_t10dif_pmull_p8(*crc, data, chunk);
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kernel_neon_end();
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data += chunk;
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length -= chunk;
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} while (length);
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} else {
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*crc = crc_t10dif_generic(*crc, data, length);
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}
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return 0;
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}
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static int crct10dif_update_pmull_p64(struct shash_desc *desc, const u8 *data,
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unsigned int length)
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{
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u16 *crc = shash_desc_ctx(desc);
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if (length >= CRC_T10DIF_PMULL_CHUNK_SIZE && crypto_simd_usable()) {
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do {
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unsigned int chunk = length;
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if (chunk > SZ_4K + CRC_T10DIF_PMULL_CHUNK_SIZE)
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chunk = SZ_4K;
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kernel_neon_begin();
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*crc = crc_t10dif_pmull_p64(*crc, data, chunk);
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kernel_neon_end();
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data += chunk;
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length -= chunk;
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} while (length);
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} else {
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*crc = crc_t10dif_generic(*crc, data, length);
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}
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return 0;
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}
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static int crct10dif_final(struct shash_desc *desc, u8 *out)
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{
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u16 *crc = shash_desc_ctx(desc);
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*(u16 *)out = *crc;
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return 0;
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}
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static struct shash_alg crc_t10dif_alg[] = {{
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.digestsize = CRC_T10DIF_DIGEST_SIZE,
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.init = crct10dif_init,
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.update = crct10dif_update_pmull_p8,
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.final = crct10dif_final,
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.descsize = CRC_T10DIF_DIGEST_SIZE,
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.base.cra_name = "crct10dif",
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.base.cra_driver_name = "crct10dif-arm64-neon",
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.base.cra_priority = 100,
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.base.cra_blocksize = CRC_T10DIF_BLOCK_SIZE,
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.base.cra_module = THIS_MODULE,
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}, {
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.digestsize = CRC_T10DIF_DIGEST_SIZE,
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.init = crct10dif_init,
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.update = crct10dif_update_pmull_p64,
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.final = crct10dif_final,
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.descsize = CRC_T10DIF_DIGEST_SIZE,
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.base.cra_name = "crct10dif",
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.base.cra_driver_name = "crct10dif-arm64-ce",
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.base.cra_priority = 200,
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.base.cra_blocksize = CRC_T10DIF_BLOCK_SIZE,
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.base.cra_module = THIS_MODULE,
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}};
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static int __init crc_t10dif_mod_init(void)
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{
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if (cpu_have_named_feature(PMULL))
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return crypto_register_shashes(crc_t10dif_alg,
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ARRAY_SIZE(crc_t10dif_alg));
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else
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/* only register the first array element */
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return crypto_register_shash(crc_t10dif_alg);
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}
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static void __exit crc_t10dif_mod_exit(void)
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{
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if (cpu_have_named_feature(PMULL))
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crypto_unregister_shashes(crc_t10dif_alg,
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ARRAY_SIZE(crc_t10dif_alg));
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else
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crypto_unregister_shash(crc_t10dif_alg);
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}
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module_cpu_feature_match(ASIMD, crc_t10dif_mod_init);
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module_exit(crc_t10dif_mod_exit);
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MODULE_AUTHOR("Ard Biesheuvel <ard.biesheuvel@linaro.org>");
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MODULE_LICENSE("GPL v2");
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MODULE_ALIAS_CRYPTO("crct10dif");
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MODULE_ALIAS_CRYPTO("crct10dif-arm64-ce");
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