blob: 74fb86b0d2097c658128a7f55bdce30110faeb87 [file] [log] [blame]
// SPDX-License-Identifier: GPL-2.0-or-later
/*
* PowerPC P10 (ppc64le) accelerated ChaCha and XChaCha stream ciphers,
* including ChaCha20 (RFC7539)
*
* Copyright 2023- IBM Corp. All rights reserved.
*/
#include <crypto/algapi.h>
#include <crypto/internal/chacha.h>
#include <crypto/internal/simd.h>
#include <crypto/internal/skcipher.h>
#include <linux/kernel.h>
#include <linux/module.h>
#include <linux/cpufeature.h>
#include <linux/sizes.h>
#include <asm/simd.h>
#include <asm/switch_to.h>
asmlinkage void chacha_p10le_8x(u32 *state, u8 *dst, const u8 *src,
unsigned int len, int nrounds);
static __ro_after_init DEFINE_STATIC_KEY_FALSE(have_p10);
static void vsx_begin(void)
{
preempt_disable();
enable_kernel_vsx();
}
static void vsx_end(void)
{
disable_kernel_vsx();
preempt_enable();
}
static void chacha_p10_do_8x(u32 *state, u8 *dst, const u8 *src,
unsigned int bytes, int nrounds)
{
unsigned int l = bytes & ~0x0FF;
if (l > 0) {
chacha_p10le_8x(state, dst, src, l, nrounds);
bytes -= l;
src += l;
dst += l;
state[12] += l / CHACHA_BLOCK_SIZE;
}
if (bytes > 0)
chacha_crypt_generic(state, dst, src, bytes, nrounds);
}
void hchacha_block_arch(const u32 *state, u32 *stream, int nrounds)
{
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)
{
if (!static_branch_likely(&have_p10) || bytes <= CHACHA_BLOCK_SIZE ||
!crypto_simd_usable())
return chacha_crypt_generic(state, dst, src, bytes, nrounds);
do {
unsigned int todo = min_t(unsigned int, bytes, SZ_4K);
vsx_begin();
chacha_p10_do_8x(state, dst, src, todo, nrounds);
vsx_end();
bytes -= todo;
src += todo;
dst += todo;
} while (bytes);
}
EXPORT_SYMBOL(chacha_crypt_arch);
static int chacha_p10_stream_xor(struct skcipher_request *req,
const struct chacha_ctx *ctx, const u8 *iv)
{
struct skcipher_walk walk;
u32 state[16];
int err;
err = skcipher_walk_virt(&walk, req, false);
if (err)
return err;
chacha_init_generic(state, ctx->key, iv);
while (walk.nbytes > 0) {
unsigned int nbytes = walk.nbytes;
if (nbytes < walk.total)
nbytes = rounddown(nbytes, walk.stride);
if (!crypto_simd_usable()) {
chacha_crypt_generic(state, walk.dst.virt.addr,
walk.src.virt.addr, nbytes,
ctx->nrounds);
} else {
vsx_begin();
chacha_p10_do_8x(state, walk.dst.virt.addr,
walk.src.virt.addr, nbytes, ctx->nrounds);
vsx_end();
}
err = skcipher_walk_done(&walk, walk.nbytes - nbytes);
if (err)
break;
}
return err;
}
static int chacha_p10(struct skcipher_request *req)
{
struct crypto_skcipher *tfm = crypto_skcipher_reqtfm(req);
struct chacha_ctx *ctx = crypto_skcipher_ctx(tfm);
return chacha_p10_stream_xor(req, ctx, req->iv);
}
static int xchacha_p10(struct skcipher_request *req)
{
struct crypto_skcipher *tfm = crypto_skcipher_reqtfm(req);
struct chacha_ctx *ctx = crypto_skcipher_ctx(tfm);
struct chacha_ctx subctx;
u32 state[16];
u8 real_iv[16];
chacha_init_generic(state, ctx->key, req->iv);
hchacha_block_arch(state, subctx.key, ctx->nrounds);
subctx.nrounds = ctx->nrounds;
memcpy(&real_iv[0], req->iv + 24, 8);
memcpy(&real_iv[8], req->iv + 16, 8);
return chacha_p10_stream_xor(req, &subctx, real_iv);
}
static struct skcipher_alg algs[] = {
{
.base.cra_name = "chacha20",
.base.cra_driver_name = "chacha20-p10",
.base.cra_priority = 300,
.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 = chacha_p10,
.decrypt = chacha_p10,
}, {
.base.cra_name = "xchacha20",
.base.cra_driver_name = "xchacha20-p10",
.base.cra_priority = 300,
.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 = XCHACHA_IV_SIZE,
.chunksize = CHACHA_BLOCK_SIZE,
.setkey = chacha20_setkey,
.encrypt = xchacha_p10,
.decrypt = xchacha_p10,
}, {
.base.cra_name = "xchacha12",
.base.cra_driver_name = "xchacha12-p10",
.base.cra_priority = 300,
.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 = XCHACHA_IV_SIZE,
.chunksize = CHACHA_BLOCK_SIZE,
.setkey = chacha12_setkey,
.encrypt = xchacha_p10,
.decrypt = xchacha_p10,
}
};
static int __init chacha_p10_init(void)
{
static_branch_enable(&have_p10);
return crypto_register_skciphers(algs, ARRAY_SIZE(algs));
}
static void __exit chacha_p10_exit(void)
{
crypto_unregister_skciphers(algs, ARRAY_SIZE(algs));
}
module_cpu_feature_match(PPC_MODULE_FEATURE_P10, chacha_p10_init);
module_exit(chacha_p10_exit);
MODULE_DESCRIPTION("ChaCha and XChaCha stream ciphers (P10 accelerated)");
MODULE_AUTHOR("Danny Tsen <dtsen@linux.ibm.com>");
MODULE_LICENSE("GPL v2");
MODULE_ALIAS_CRYPTO("chacha20");
MODULE_ALIAS_CRYPTO("chacha20-p10");
MODULE_ALIAS_CRYPTO("xchacha20");
MODULE_ALIAS_CRYPTO("xchacha20-p10");
MODULE_ALIAS_CRYPTO("xchacha12");
MODULE_ALIAS_CRYPTO("xchacha12-p10");