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/*
* Accelerated CRC-T10DIF using ARM NEON and Crypto Extensions instructions
*
* Copyright (C) 2016 Linaro Ltd <ard.biesheuvel@linaro.org>
*
* This program is free software; you can redistribute it and/or modify
* it under the terms of the GNU General Public License version 2 as
* published by the Free Software Foundation.
*/
#include <linux/crc-t10dif.h>
#include <linux/init.h>
#include <linux/kernel.h>
#include <linux/module.h>
#include <linux/string.h>
#include <crypto/internal/hash.h>
#include <asm/neon.h>
#include <asm/simd.h>
#define CRC_T10DIF_PMULL_CHUNK_SIZE 16U
asmlinkage u16 crc_t10dif_pmull(u16 init_crc, const u8 buf[], u32 len);
static int crct10dif_init(struct shash_desc *desc)
{
u16 *crc = shash_desc_ctx(desc);
*crc = 0;
return 0;
}
static int crct10dif_update(struct shash_desc *desc, const u8 *data,
unsigned int length)
{
u16 *crc = shash_desc_ctx(desc);
unsigned int l;
if (!may_use_simd()) {
*crc = crc_t10dif_generic(*crc, data, length);
} else {
if (unlikely((u32)data % CRC_T10DIF_PMULL_CHUNK_SIZE)) {
l = min_t(u32, length, CRC_T10DIF_PMULL_CHUNK_SIZE -
((u32)data % CRC_T10DIF_PMULL_CHUNK_SIZE));
*crc = crc_t10dif_generic(*crc, data, l);
length -= l;
data += l;
}
if (length > 0) {
kernel_neon_begin();
*crc = crc_t10dif_pmull(*crc, data, length);
kernel_neon_end();
}
}
return 0;
}
static int crct10dif_final(struct shash_desc *desc, u8 *out)
{
u16 *crc = shash_desc_ctx(desc);
*(u16 *)out = *crc;
return 0;
}
static struct shash_alg crc_t10dif_alg = {
.digestsize = CRC_T10DIF_DIGEST_SIZE,
.init = crct10dif_init,
.update = crct10dif_update,
.final = crct10dif_final,
.descsize = CRC_T10DIF_DIGEST_SIZE,
.base.cra_name = "crct10dif",
.base.cra_driver_name = "crct10dif-arm-ce",
.base.cra_priority = 200,
.base.cra_blocksize = CRC_T10DIF_BLOCK_SIZE,
.base.cra_module = THIS_MODULE,
};
static int __init crc_t10dif_mod_init(void)
{
if (!(elf_hwcap2 & HWCAP2_PMULL))
return -ENODEV;
return crypto_register_shash(&crc_t10dif_alg);
}
static void __exit crc_t10dif_mod_exit(void)
{
crypto_unregister_shash(&crc_t10dif_alg);
}
module_init(crc_t10dif_mod_init);
module_exit(crc_t10dif_mod_exit);
MODULE_AUTHOR("Ard Biesheuvel <ard.biesheuvel@linaro.org>");
MODULE_LICENSE("GPL v2");
MODULE_ALIAS_CRYPTO("crct10dif");
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