linux/drivers/crypto/vmx/ghash.c

185 lines
4.5 KiB
C

// SPDX-License-Identifier: GPL-2.0
/**
* GHASH routines supporting VMX instructions on the Power 8
*
* Copyright (C) 2015, 2019 International Business Machines Inc.
*
* Author: Marcelo Henrique Cerri <mhcerri@br.ibm.com>
*
* Extended by Daniel Axtens <dja@axtens.net> to replace the fallback
* mechanism. The new approach is based on arm64 code, which is:
* Copyright (C) 2014 - 2018 Linaro Ltd. <ard.biesheuvel@linaro.org>
*/
#include <linux/types.h>
#include <linux/err.h>
#include <linux/crypto.h>
#include <linux/delay.h>
#include <asm/simd.h>
#include <asm/switch_to.h>
#include <crypto/aes.h>
#include <crypto/ghash.h>
#include <crypto/scatterwalk.h>
#include <crypto/internal/hash.h>
#include <crypto/internal/simd.h>
#include <crypto/b128ops.h>
void gcm_init_p8(u128 htable[16], const u64 Xi[2]);
void gcm_gmult_p8(u64 Xi[2], const u128 htable[16]);
void gcm_ghash_p8(u64 Xi[2], const u128 htable[16],
const u8 *in, size_t len);
struct p8_ghash_ctx {
/* key used by vector asm */
u128 htable[16];
/* key used by software fallback */
be128 key;
};
struct p8_ghash_desc_ctx {
u64 shash[2];
u8 buffer[GHASH_DIGEST_SIZE];
int bytes;
};
static int p8_ghash_init(struct shash_desc *desc)
{
struct p8_ghash_desc_ctx *dctx = shash_desc_ctx(desc);
dctx->bytes = 0;
memset(dctx->shash, 0, GHASH_DIGEST_SIZE);
return 0;
}
static int p8_ghash_setkey(struct crypto_shash *tfm, const u8 *key,
unsigned int keylen)
{
struct p8_ghash_ctx *ctx = crypto_tfm_ctx(crypto_shash_tfm(tfm));
if (keylen != GHASH_BLOCK_SIZE)
return -EINVAL;
preempt_disable();
pagefault_disable();
enable_kernel_vsx();
gcm_init_p8(ctx->htable, (const u64 *) key);
disable_kernel_vsx();
pagefault_enable();
preempt_enable();
memcpy(&ctx->key, key, GHASH_BLOCK_SIZE);
return 0;
}
static inline void __ghash_block(struct p8_ghash_ctx *ctx,
struct p8_ghash_desc_ctx *dctx)
{
if (crypto_simd_usable()) {
preempt_disable();
pagefault_disable();
enable_kernel_vsx();
gcm_ghash_p8(dctx->shash, ctx->htable,
dctx->buffer, GHASH_DIGEST_SIZE);
disable_kernel_vsx();
pagefault_enable();
preempt_enable();
} else {
crypto_xor((u8 *)dctx->shash, dctx->buffer, GHASH_BLOCK_SIZE);
gf128mul_lle((be128 *)dctx->shash, &ctx->key);
}
}
static inline void __ghash_blocks(struct p8_ghash_ctx *ctx,
struct p8_ghash_desc_ctx *dctx,
const u8 *src, unsigned int srclen)
{
if (crypto_simd_usable()) {
preempt_disable();
pagefault_disable();
enable_kernel_vsx();
gcm_ghash_p8(dctx->shash, ctx->htable,
src, srclen);
disable_kernel_vsx();
pagefault_enable();
preempt_enable();
} else {
while (srclen >= GHASH_BLOCK_SIZE) {
crypto_xor((u8 *)dctx->shash, src, GHASH_BLOCK_SIZE);
gf128mul_lle((be128 *)dctx->shash, &ctx->key);
srclen -= GHASH_BLOCK_SIZE;
src += GHASH_BLOCK_SIZE;
}
}
}
static int p8_ghash_update(struct shash_desc *desc,
const u8 *src, unsigned int srclen)
{
unsigned int len;
struct p8_ghash_ctx *ctx = crypto_tfm_ctx(crypto_shash_tfm(desc->tfm));
struct p8_ghash_desc_ctx *dctx = shash_desc_ctx(desc);
if (dctx->bytes) {
if (dctx->bytes + srclen < GHASH_DIGEST_SIZE) {
memcpy(dctx->buffer + dctx->bytes, src,
srclen);
dctx->bytes += srclen;
return 0;
}
memcpy(dctx->buffer + dctx->bytes, src,
GHASH_DIGEST_SIZE - dctx->bytes);
__ghash_block(ctx, dctx);
src += GHASH_DIGEST_SIZE - dctx->bytes;
srclen -= GHASH_DIGEST_SIZE - dctx->bytes;
dctx->bytes = 0;
}
len = srclen & ~(GHASH_DIGEST_SIZE - 1);
if (len) {
__ghash_blocks(ctx, dctx, src, len);
src += len;
srclen -= len;
}
if (srclen) {
memcpy(dctx->buffer, src, srclen);
dctx->bytes = srclen;
}
return 0;
}
static int p8_ghash_final(struct shash_desc *desc, u8 *out)
{
int i;
struct p8_ghash_ctx *ctx = crypto_tfm_ctx(crypto_shash_tfm(desc->tfm));
struct p8_ghash_desc_ctx *dctx = shash_desc_ctx(desc);
if (dctx->bytes) {
for (i = dctx->bytes; i < GHASH_DIGEST_SIZE; i++)
dctx->buffer[i] = 0;
__ghash_block(ctx, dctx);
dctx->bytes = 0;
}
memcpy(out, dctx->shash, GHASH_DIGEST_SIZE);
return 0;
}
struct shash_alg p8_ghash_alg = {
.digestsize = GHASH_DIGEST_SIZE,
.init = p8_ghash_init,
.update = p8_ghash_update,
.final = p8_ghash_final,
.setkey = p8_ghash_setkey,
.descsize = sizeof(struct p8_ghash_desc_ctx)
+ sizeof(struct ghash_desc_ctx),
.base = {
.cra_name = "ghash",
.cra_driver_name = "p8_ghash",
.cra_priority = 1000,
.cra_blocksize = GHASH_BLOCK_SIZE,
.cra_ctxsize = sizeof(struct p8_ghash_ctx),
.cra_module = THIS_MODULE,
},
};