| // SPDX-License-Identifier: GPL-2.0-or-later |
| /* |
| * x64 SIMD accelerated ChaCha and XChaCha stream ciphers, |
| * including ChaCha20 (RFC7539) |
| * |
| * Copyright (C) 2015 Martin Willi |
| */ |
| |
| #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 <asm/simd.h> |
| |
| #define CHACHA_STATE_ALIGN 16 |
| |
| asmlinkage void chacha_block_xor_ssse3(u32 *state, u8 *dst, const u8 *src, |
| unsigned int len, int nrounds); |
| asmlinkage void chacha_4block_xor_ssse3(u32 *state, u8 *dst, const u8 *src, |
| unsigned int len, int nrounds); |
| asmlinkage void hchacha_block_ssse3(const u32 *state, u32 *out, int nrounds); |
| |
| asmlinkage void chacha_2block_xor_avx2(u32 *state, u8 *dst, const u8 *src, |
| unsigned int len, int nrounds); |
| asmlinkage void chacha_4block_xor_avx2(u32 *state, u8 *dst, const u8 *src, |
| unsigned int len, int nrounds); |
| asmlinkage void chacha_8block_xor_avx2(u32 *state, u8 *dst, const u8 *src, |
| unsigned int len, int nrounds); |
| |
| asmlinkage void chacha_2block_xor_avx512vl(u32 *state, u8 *dst, const u8 *src, |
| unsigned int len, int nrounds); |
| asmlinkage void chacha_4block_xor_avx512vl(u32 *state, u8 *dst, const u8 *src, |
| unsigned int len, int nrounds); |
| asmlinkage void chacha_8block_xor_avx512vl(u32 *state, u8 *dst, const u8 *src, |
| unsigned int len, int nrounds); |
| |
| static __ro_after_init DEFINE_STATIC_KEY_FALSE(chacha_use_simd); |
| static __ro_after_init DEFINE_STATIC_KEY_FALSE(chacha_use_avx2); |
| static __ro_after_init DEFINE_STATIC_KEY_FALSE(chacha_use_avx512vl); |
| |
| static unsigned int chacha_advance(unsigned int len, unsigned int maxblocks) |
| { |
| len = min(len, maxblocks * CHACHA_BLOCK_SIZE); |
| return round_up(len, CHACHA_BLOCK_SIZE) / CHACHA_BLOCK_SIZE; |
| } |
| |
| static void chacha_dosimd(u32 *state, u8 *dst, const u8 *src, |
| unsigned int bytes, int nrounds) |
| { |
| if (IS_ENABLED(CONFIG_AS_AVX512) && |
| static_branch_likely(&chacha_use_avx512vl)) { |
| while (bytes >= CHACHA_BLOCK_SIZE * 8) { |
| chacha_8block_xor_avx512vl(state, dst, src, bytes, |
| nrounds); |
| bytes -= CHACHA_BLOCK_SIZE * 8; |
| src += CHACHA_BLOCK_SIZE * 8; |
| dst += CHACHA_BLOCK_SIZE * 8; |
| state[12] += 8; |
| } |
| if (bytes > CHACHA_BLOCK_SIZE * 4) { |
| chacha_8block_xor_avx512vl(state, dst, src, bytes, |
| nrounds); |
| state[12] += chacha_advance(bytes, 8); |
| return; |
| } |
| if (bytes > CHACHA_BLOCK_SIZE * 2) { |
| chacha_4block_xor_avx512vl(state, dst, src, bytes, |
| nrounds); |
| state[12] += chacha_advance(bytes, 4); |
| return; |
| } |
| if (bytes) { |
| chacha_2block_xor_avx512vl(state, dst, src, bytes, |
| nrounds); |
| state[12] += chacha_advance(bytes, 2); |
| return; |
| } |
| } |
| |
| if (static_branch_likely(&chacha_use_avx2)) { |
| while (bytes >= CHACHA_BLOCK_SIZE * 8) { |
| chacha_8block_xor_avx2(state, dst, src, bytes, nrounds); |
| bytes -= CHACHA_BLOCK_SIZE * 8; |
| src += CHACHA_BLOCK_SIZE * 8; |
| dst += CHACHA_BLOCK_SIZE * 8; |
| state[12] += 8; |
| } |
| if (bytes > CHACHA_BLOCK_SIZE * 4) { |
| chacha_8block_xor_avx2(state, dst, src, bytes, nrounds); |
| state[12] += chacha_advance(bytes, 8); |
| return; |
| } |
| if (bytes > CHACHA_BLOCK_SIZE * 2) { |
| chacha_4block_xor_avx2(state, dst, src, bytes, nrounds); |
| state[12] += chacha_advance(bytes, 4); |
| return; |
| } |
| if (bytes > CHACHA_BLOCK_SIZE) { |
| chacha_2block_xor_avx2(state, dst, src, bytes, nrounds); |
| state[12] += chacha_advance(bytes, 2); |
| return; |
| } |
| } |
| |
| while (bytes >= CHACHA_BLOCK_SIZE * 4) { |
| chacha_4block_xor_ssse3(state, dst, src, bytes, nrounds); |
| bytes -= CHACHA_BLOCK_SIZE * 4; |
| src += CHACHA_BLOCK_SIZE * 4; |
| dst += CHACHA_BLOCK_SIZE * 4; |
| state[12] += 4; |
| } |
| if (bytes > CHACHA_BLOCK_SIZE) { |
| chacha_4block_xor_ssse3(state, dst, src, bytes, nrounds); |
| state[12] += chacha_advance(bytes, 4); |
| return; |
| } |
| if (bytes) { |
| chacha_block_xor_ssse3(state, dst, src, bytes, nrounds); |
| state[12]++; |
| } |
| } |
| |
| void hchacha_block_arch(const u32 *state, u32 *stream, int nrounds) |
| { |
| state = PTR_ALIGN(state, CHACHA_STATE_ALIGN); |
| |
| if (!static_branch_likely(&chacha_use_simd) || !crypto_simd_usable()) { |
| hchacha_block_generic(state, stream, nrounds); |
| } else { |
| kernel_fpu_begin(); |
| hchacha_block_ssse3(state, stream, nrounds); |
| kernel_fpu_end(); |
| } |
| } |
| EXPORT_SYMBOL(hchacha_block_arch); |
| |
| void chacha_init_arch(u32 *state, const u32 *key, const u8 *iv) |
| { |
| state = PTR_ALIGN(state, CHACHA_STATE_ALIGN); |
| |
| 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) |
| { |
| state = PTR_ALIGN(state, CHACHA_STATE_ALIGN); |
| |
| if (!static_branch_likely(&chacha_use_simd) || !crypto_simd_usable() || |
| bytes <= CHACHA_BLOCK_SIZE) |
| return chacha_crypt_generic(state, dst, src, bytes, nrounds); |
| |
| do { |
| unsigned int todo = min_t(unsigned int, bytes, SZ_4K); |
| |
| kernel_fpu_begin(); |
| chacha_dosimd(state, dst, src, todo, nrounds); |
| kernel_fpu_end(); |
| |
| bytes -= todo; |
| src += todo; |
| dst += todo; |
| } while (bytes); |
| } |
| EXPORT_SYMBOL(chacha_crypt_arch); |
| |
| static int chacha_simd_stream_xor(struct skcipher_request *req, |
| const struct chacha_ctx *ctx, const u8 *iv) |
| { |
| u32 *state, state_buf[16 + 2] __aligned(8); |
| struct skcipher_walk walk; |
| int err; |
| |
| err = skcipher_walk_virt(&walk, req, false); |
| |
| BUILD_BUG_ON(CHACHA_STATE_ALIGN != 16); |
| state = PTR_ALIGN(state_buf + 0, CHACHA_STATE_ALIGN); |
| |
| chacha_init_generic(state, ctx->key, iv); |
| |
| while (walk.nbytes > 0) { |
| unsigned int nbytes = walk.nbytes; |
| |
| if (nbytes < walk.total) |
| nbytes = round_down(nbytes, walk.stride); |
| |
| if (!static_branch_likely(&chacha_use_simd) || |
| !crypto_simd_usable()) { |
| chacha_crypt_generic(state, walk.dst.virt.addr, |
| walk.src.virt.addr, nbytes, |
| ctx->nrounds); |
| } else { |
| kernel_fpu_begin(); |
| chacha_dosimd(state, walk.dst.virt.addr, |
| walk.src.virt.addr, nbytes, |
| ctx->nrounds); |
| kernel_fpu_end(); |
| } |
| err = skcipher_walk_done(&walk, walk.nbytes - nbytes); |
| } |
| |
| return err; |
| } |
| |
| static int chacha_simd(struct skcipher_request *req) |
| { |
| struct crypto_skcipher *tfm = crypto_skcipher_reqtfm(req); |
| struct chacha_ctx *ctx = crypto_skcipher_ctx(tfm); |
| |
| return chacha_simd_stream_xor(req, ctx, req->iv); |
| } |
| |
| static int xchacha_simd(struct skcipher_request *req) |
| { |
| struct crypto_skcipher *tfm = crypto_skcipher_reqtfm(req); |
| struct chacha_ctx *ctx = crypto_skcipher_ctx(tfm); |
| u32 *state, state_buf[16 + 2] __aligned(8); |
| struct chacha_ctx subctx; |
| u8 real_iv[16]; |
| |
| BUILD_BUG_ON(CHACHA_STATE_ALIGN != 16); |
| state = PTR_ALIGN(state_buf + 0, CHACHA_STATE_ALIGN); |
| chacha_init_generic(state, ctx->key, req->iv); |
| |
| if (req->cryptlen > CHACHA_BLOCK_SIZE && crypto_simd_usable()) { |
| kernel_fpu_begin(); |
| hchacha_block_ssse3(state, subctx.key, ctx->nrounds); |
| kernel_fpu_end(); |
| } else { |
| hchacha_block_generic(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_simd_stream_xor(req, &subctx, real_iv); |
| } |
| |
| static struct skcipher_alg algs[] = { |
| { |
| .base.cra_name = "chacha20", |
| .base.cra_driver_name = "chacha20-simd", |
| .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_simd, |
| .decrypt = chacha_simd, |
| }, { |
| .base.cra_name = "xchacha20", |
| .base.cra_driver_name = "xchacha20-simd", |
| .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_simd, |
| .decrypt = xchacha_simd, |
| }, { |
| .base.cra_name = "xchacha12", |
| .base.cra_driver_name = "xchacha12-simd", |
| .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_simd, |
| .decrypt = xchacha_simd, |
| }, |
| }; |
| |
| static int __init chacha_simd_mod_init(void) |
| { |
| if (!boot_cpu_has(X86_FEATURE_SSSE3)) |
| return 0; |
| |
| static_branch_enable(&chacha_use_simd); |
| |
| if (boot_cpu_has(X86_FEATURE_AVX) && |
| boot_cpu_has(X86_FEATURE_AVX2) && |
| cpu_has_xfeatures(XFEATURE_MASK_SSE | XFEATURE_MASK_YMM, NULL)) { |
| static_branch_enable(&chacha_use_avx2); |
| |
| if (IS_ENABLED(CONFIG_AS_AVX512) && |
| boot_cpu_has(X86_FEATURE_AVX512VL) && |
| boot_cpu_has(X86_FEATURE_AVX512BW)) /* kmovq */ |
| static_branch_enable(&chacha_use_avx512vl); |
| } |
| return IS_REACHABLE(CONFIG_CRYPTO_SKCIPHER) ? |
| crypto_register_skciphers(algs, ARRAY_SIZE(algs)) : 0; |
| } |
| |
| static void __exit chacha_simd_mod_fini(void) |
| { |
| if (IS_REACHABLE(CONFIG_CRYPTO_SKCIPHER) && boot_cpu_has(X86_FEATURE_SSSE3)) |
| crypto_unregister_skciphers(algs, ARRAY_SIZE(algs)); |
| } |
| |
| module_init(chacha_simd_mod_init); |
| module_exit(chacha_simd_mod_fini); |
| |
| MODULE_LICENSE("GPL"); |
| MODULE_AUTHOR("Martin Willi <martin@strongswan.org>"); |
| MODULE_DESCRIPTION("ChaCha and XChaCha stream ciphers (x64 SIMD accelerated)"); |
| MODULE_ALIAS_CRYPTO("chacha20"); |
| MODULE_ALIAS_CRYPTO("chacha20-simd"); |
| MODULE_ALIAS_CRYPTO("xchacha20"); |
| MODULE_ALIAS_CRYPTO("xchacha20-simd"); |
| MODULE_ALIAS_CRYPTO("xchacha12"); |
| MODULE_ALIAS_CRYPTO("xchacha12-simd"); |