linux/arch/s390/crypto/chacha-glue.c
Heiko Carstens 0a5f9b382c s390/cpufeature: rework to allow more than only hwcap bits
Rework cpufeature implementation to allow for various cpu feature
indications, which is not only limited to hwcap bits. This is achieved
by adding a sequential list of cpu feature numbers, where each of them
is mapped to an entry which indicates what this number is about.

Each entry contains a type member, which indicates what feature
name space to look into (e.g. hwcap, or cpu facility). If wanted this
allows also to automatically load modules only in e.g. z/VM
configurations.

Signed-off-by: Heiko Carstens <hca@linux.ibm.com>
Signed-off-by: Steffen Eiden <seiden@linux.ibm.com>
Reviewed-by: Claudio Imbrenda <imbrenda@linux.ibm.com>
Reviewed-by: Hendrik Brueckner <brueckner@linux.ibm.com>
Link: https://lore.kernel.org/r/20220713125644.16121-2-seiden@linux.ibm.com
Signed-off-by: Alexander Gordeev <agordeev@linux.ibm.com>
2022-07-19 16:18:49 +02:00

131 lines
3.4 KiB
C

// SPDX-License-Identifier: GPL-2.0
/*
* s390 ChaCha stream cipher.
*
* Copyright IBM Corp. 2021
*/
#define KMSG_COMPONENT "chacha_s390"
#define pr_fmt(fmt) KMSG_COMPONENT ": " fmt
#include <crypto/internal/chacha.h>
#include <crypto/internal/skcipher.h>
#include <crypto/algapi.h>
#include <linux/cpufeature.h>
#include <linux/kernel.h>
#include <linux/module.h>
#include <linux/sizes.h>
#include <asm/fpu/api.h>
#include "chacha-s390.h"
static void chacha20_crypt_s390(u32 *state, u8 *dst, const u8 *src,
unsigned int nbytes, const u32 *key,
u32 *counter)
{
struct kernel_fpu vxstate;
kernel_fpu_begin(&vxstate, KERNEL_VXR);
chacha20_vx(dst, src, nbytes, key, counter);
kernel_fpu_end(&vxstate, KERNEL_VXR);
*counter += round_up(nbytes, CHACHA_BLOCK_SIZE) / CHACHA_BLOCK_SIZE;
}
static int chacha20_s390(struct skcipher_request *req)
{
struct crypto_skcipher *tfm = crypto_skcipher_reqtfm(req);
struct chacha_ctx *ctx = crypto_skcipher_ctx(tfm);
u32 state[CHACHA_STATE_WORDS] __aligned(16);
struct skcipher_walk walk;
unsigned int nbytes;
int rc;
rc = skcipher_walk_virt(&walk, req, false);
chacha_init_generic(state, ctx->key, req->iv);
while (walk.nbytes > 0) {
nbytes = walk.nbytes;
if (nbytes < walk.total)
nbytes = round_down(nbytes, walk.stride);
if (nbytes <= CHACHA_BLOCK_SIZE) {
chacha_crypt_generic(state, walk.dst.virt.addr,
walk.src.virt.addr, nbytes,
ctx->nrounds);
} else {
chacha20_crypt_s390(state, walk.dst.virt.addr,
walk.src.virt.addr, nbytes,
&state[4], &state[12]);
}
rc = skcipher_walk_done(&walk, walk.nbytes - nbytes);
}
return rc;
}
void hchacha_block_arch(const u32 *state, u32 *stream, int nrounds)
{
/* TODO: implement hchacha_block_arch() in assembly */
hchacha_block_generic(state, stream, nrounds);
}
EXPORT_SYMBOL(hchacha_block_arch);
void chacha_init_arch(u32 *state, const u32 *key, const u8 *iv)
{
chacha_init_generic(state, key, iv);
}
EXPORT_SYMBOL(chacha_init_arch);
void chacha_crypt_arch(u32 *state, u8 *dst, const u8 *src,
unsigned int bytes, int nrounds)
{
/* s390 chacha20 implementation has 20 rounds hard-coded,
* it cannot handle a block of data or less, but otherwise
* it can handle data of arbitrary size
*/
if (bytes <= CHACHA_BLOCK_SIZE || nrounds != 20)
chacha_crypt_generic(state, dst, src, bytes, nrounds);
else
chacha20_crypt_s390(state, dst, src, bytes,
&state[4], &state[12]);
}
EXPORT_SYMBOL(chacha_crypt_arch);
static struct skcipher_alg chacha_algs[] = {
{
.base.cra_name = "chacha20",
.base.cra_driver_name = "chacha20-s390",
.base.cra_priority = 900,
.base.cra_blocksize = 1,
.base.cra_ctxsize = sizeof(struct chacha_ctx),
.base.cra_module = THIS_MODULE,
.min_keysize = CHACHA_KEY_SIZE,
.max_keysize = CHACHA_KEY_SIZE,
.ivsize = CHACHA_IV_SIZE,
.chunksize = CHACHA_BLOCK_SIZE,
.setkey = chacha20_setkey,
.encrypt = chacha20_s390,
.decrypt = chacha20_s390,
}
};
static int __init chacha_mod_init(void)
{
return IS_REACHABLE(CONFIG_CRYPTO_SKCIPHER) ?
crypto_register_skciphers(chacha_algs, ARRAY_SIZE(chacha_algs)) : 0;
}
static void __exit chacha_mod_fini(void)
{
if (IS_REACHABLE(CONFIG_CRYPTO_SKCIPHER))
crypto_unregister_skciphers(chacha_algs, ARRAY_SIZE(chacha_algs));
}
module_cpu_feature_match(S390_CPU_FEATURE_VXRS, chacha_mod_init);
module_exit(chacha_mod_fini);
MODULE_DESCRIPTION("ChaCha20 stream cipher");
MODULE_LICENSE("GPL v2");
MODULE_ALIAS_CRYPTO("chacha20");