| // SPDX-License-Identifier: GPL-2.0 |
| /* |
| * ARM NEON accelerated ChaCha and XChaCha stream ciphers, |
| * including ChaCha20 (RFC7539) |
| * |
| * Copyright (C) 2016-2019 Linaro, Ltd. <ard.biesheuvel@linaro.org> |
| * 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/jump_label.h> |
| #include <linux/kernel.h> |
| #include <linux/module.h> |
| |
| #include <asm/cputype.h> |
| #include <asm/hwcap.h> |
| #include <asm/neon.h> |
| #include <asm/simd.h> |
| |
| asmlinkage void chacha_block_xor_neon(const u32 *state, u8 *dst, const u8 *src, |
| int nrounds); |
| asmlinkage void chacha_4block_xor_neon(const u32 *state, u8 *dst, const u8 *src, |
| int nrounds); |
| asmlinkage void hchacha_block_arm(const u32 *state, u32 *out, int nrounds); |
| asmlinkage void hchacha_block_neon(const u32 *state, u32 *out, int nrounds); |
| |
| asmlinkage void chacha_doarm(u8 *dst, const u8 *src, unsigned int bytes, |
| const u32 *state, int nrounds); |
| |
| static __ro_after_init DEFINE_STATIC_KEY_FALSE(use_neon); |
| |
| static inline bool neon_usable(void) |
| { |
| return static_branch_likely(&use_neon) && crypto_simd_usable(); |
| } |
| |
| static void chacha_doneon(u32 *state, u8 *dst, const u8 *src, |
| unsigned int bytes, int nrounds) |
| { |
| u8 buf[CHACHA_BLOCK_SIZE]; |
| |
| while (bytes >= CHACHA_BLOCK_SIZE * 4) { |
| chacha_4block_xor_neon(state, dst, src, nrounds); |
| bytes -= CHACHA_BLOCK_SIZE * 4; |
| src += CHACHA_BLOCK_SIZE * 4; |
| dst += CHACHA_BLOCK_SIZE * 4; |
| state[12] += 4; |
| } |
| while (bytes >= CHACHA_BLOCK_SIZE) { |
| chacha_block_xor_neon(state, dst, src, nrounds); |
| bytes -= CHACHA_BLOCK_SIZE; |
| src += CHACHA_BLOCK_SIZE; |
| dst += CHACHA_BLOCK_SIZE; |
| state[12]++; |
| } |
| if (bytes) { |
| memcpy(buf, src, bytes); |
| chacha_block_xor_neon(state, buf, buf, nrounds); |
| memcpy(dst, buf, bytes); |
| } |
| } |
| |
| void hchacha_block_arch(const u32 *state, u32 *stream, int nrounds) |
| { |
| if (!IS_ENABLED(CONFIG_KERNEL_MODE_NEON) || !neon_usable()) { |
| hchacha_block_arm(state, stream, nrounds); |
| } else { |
| kernel_neon_begin(); |
| hchacha_block_neon(state, stream, nrounds); |
| kernel_neon_end(); |
| } |
| } |
| 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 (!IS_ENABLED(CONFIG_KERNEL_MODE_NEON) || !neon_usable() || |
| bytes <= CHACHA_BLOCK_SIZE) { |
| chacha_doarm(dst, src, bytes, state, nrounds); |
| state[12] += DIV_ROUND_UP(bytes, CHACHA_BLOCK_SIZE); |
| return; |
| } |
| |
| kernel_neon_begin(); |
| chacha_doneon(state, dst, src, bytes, nrounds); |
| kernel_neon_end(); |
| } |
| EXPORT_SYMBOL(chacha_crypt_arch); |
| |
| static int chacha_stream_xor(struct skcipher_request *req, |
| const struct chacha_ctx *ctx, const u8 *iv, |
| bool neon) |
| { |
| struct skcipher_walk walk; |
| u32 state[16]; |
| int err; |
| |
| err = skcipher_walk_virt(&walk, req, false); |
| |
| 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 (!IS_ENABLED(CONFIG_KERNEL_MODE_NEON) || !neon) { |
| chacha_doarm(walk.dst.virt.addr, walk.src.virt.addr, |
| nbytes, state, ctx->nrounds); |
| state[12] += DIV_ROUND_UP(nbytes, CHACHA_BLOCK_SIZE); |
| } else { |
| kernel_neon_begin(); |
| chacha_doneon(state, walk.dst.virt.addr, |
| walk.src.virt.addr, nbytes, ctx->nrounds); |
| kernel_neon_end(); |
| } |
| err = skcipher_walk_done(&walk, walk.nbytes - nbytes); |
| } |
| |
| return err; |
| } |
| |
| static int do_chacha(struct skcipher_request *req, bool neon) |
| { |
| struct crypto_skcipher *tfm = crypto_skcipher_reqtfm(req); |
| struct chacha_ctx *ctx = crypto_skcipher_ctx(tfm); |
| |
| return chacha_stream_xor(req, ctx, req->iv, neon); |
| } |
| |
| static int chacha_arm(struct skcipher_request *req) |
| { |
| return do_chacha(req, false); |
| } |
| |
| static int chacha_neon(struct skcipher_request *req) |
| { |
| return do_chacha(req, neon_usable()); |
| } |
| |
| static int do_xchacha(struct skcipher_request *req, bool neon) |
| { |
| 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); |
| |
| if (!IS_ENABLED(CONFIG_KERNEL_MODE_NEON) || !neon) { |
| hchacha_block_arm(state, subctx.key, ctx->nrounds); |
| } else { |
| kernel_neon_begin(); |
| hchacha_block_neon(state, subctx.key, ctx->nrounds); |
| kernel_neon_end(); |
| } |
| subctx.nrounds = ctx->nrounds; |
| |
| memcpy(&real_iv[0], req->iv + 24, 8); |
| memcpy(&real_iv[8], req->iv + 16, 8); |
| return chacha_stream_xor(req, &subctx, real_iv, neon); |
| } |
| |
| static int xchacha_arm(struct skcipher_request *req) |
| { |
| return do_xchacha(req, false); |
| } |
| |
| static int xchacha_neon(struct skcipher_request *req) |
| { |
| return do_xchacha(req, neon_usable()); |
| } |
| |
| static struct skcipher_alg arm_algs[] = { |
| { |
| .base.cra_name = "chacha20", |
| .base.cra_driver_name = "chacha20-arm", |
| .base.cra_priority = 200, |
| .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_arm, |
| .decrypt = chacha_arm, |
| }, { |
| .base.cra_name = "xchacha20", |
| .base.cra_driver_name = "xchacha20-arm", |
| .base.cra_priority = 200, |
| .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_arm, |
| .decrypt = xchacha_arm, |
| }, { |
| .base.cra_name = "xchacha12", |
| .base.cra_driver_name = "xchacha12-arm", |
| .base.cra_priority = 200, |
| .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_arm, |
| .decrypt = xchacha_arm, |
| }, |
| }; |
| |
| static struct skcipher_alg neon_algs[] = { |
| { |
| .base.cra_name = "chacha20", |
| .base.cra_driver_name = "chacha20-neon", |
| .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, |
| .walksize = 4 * CHACHA_BLOCK_SIZE, |
| .setkey = chacha20_setkey, |
| .encrypt = chacha_neon, |
| .decrypt = chacha_neon, |
| }, { |
| .base.cra_name = "xchacha20", |
| .base.cra_driver_name = "xchacha20-neon", |
| .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, |
| .walksize = 4 * CHACHA_BLOCK_SIZE, |
| .setkey = chacha20_setkey, |
| .encrypt = xchacha_neon, |
| .decrypt = xchacha_neon, |
| }, { |
| .base.cra_name = "xchacha12", |
| .base.cra_driver_name = "xchacha12-neon", |
| .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, |
| .walksize = 4 * CHACHA_BLOCK_SIZE, |
| .setkey = chacha12_setkey, |
| .encrypt = xchacha_neon, |
| .decrypt = xchacha_neon, |
| } |
| }; |
| |
| static int __init chacha_simd_mod_init(void) |
| { |
| int err = 0; |
| |
| if (IS_REACHABLE(CONFIG_CRYPTO_SKCIPHER)) { |
| err = crypto_register_skciphers(arm_algs, ARRAY_SIZE(arm_algs)); |
| if (err) |
| return err; |
| } |
| |
| if (IS_ENABLED(CONFIG_KERNEL_MODE_NEON) && (elf_hwcap & HWCAP_NEON)) { |
| int i; |
| |
| switch (read_cpuid_part()) { |
| case ARM_CPU_PART_CORTEX_A7: |
| case ARM_CPU_PART_CORTEX_A5: |
| /* |
| * The Cortex-A7 and Cortex-A5 do not perform well with |
| * the NEON implementation but do incredibly with the |
| * scalar one and use less power. |
| */ |
| for (i = 0; i < ARRAY_SIZE(neon_algs); i++) |
| neon_algs[i].base.cra_priority = 0; |
| break; |
| default: |
| static_branch_enable(&use_neon); |
| } |
| |
| if (IS_REACHABLE(CONFIG_CRYPTO_SKCIPHER)) { |
| err = crypto_register_skciphers(neon_algs, ARRAY_SIZE(neon_algs)); |
| if (err) |
| crypto_unregister_skciphers(arm_algs, ARRAY_SIZE(arm_algs)); |
| } |
| } |
| return err; |
| } |
| |
| static void __exit chacha_simd_mod_fini(void) |
| { |
| if (IS_REACHABLE(CONFIG_CRYPTO_SKCIPHER)) { |
| crypto_unregister_skciphers(arm_algs, ARRAY_SIZE(arm_algs)); |
| if (IS_ENABLED(CONFIG_KERNEL_MODE_NEON) && (elf_hwcap & HWCAP_NEON)) |
| crypto_unregister_skciphers(neon_algs, ARRAY_SIZE(neon_algs)); |
| } |
| } |
| |
| module_init(chacha_simd_mod_init); |
| module_exit(chacha_simd_mod_fini); |
| |
| MODULE_DESCRIPTION("ChaCha and XChaCha stream ciphers (scalar and NEON accelerated)"); |
| MODULE_AUTHOR("Ard Biesheuvel <ard.biesheuvel@linaro.org>"); |
| MODULE_LICENSE("GPL v2"); |
| MODULE_ALIAS_CRYPTO("chacha20"); |
| MODULE_ALIAS_CRYPTO("chacha20-arm"); |
| MODULE_ALIAS_CRYPTO("xchacha20"); |
| MODULE_ALIAS_CRYPTO("xchacha20-arm"); |
| MODULE_ALIAS_CRYPTO("xchacha12"); |
| MODULE_ALIAS_CRYPTO("xchacha12-arm"); |
| #ifdef CONFIG_KERNEL_MODE_NEON |
| MODULE_ALIAS_CRYPTO("chacha20-neon"); |
| MODULE_ALIAS_CRYPTO("xchacha20-neon"); |
| MODULE_ALIAS_CRYPTO("xchacha12-neon"); |
| #endif |