diff options
Diffstat (limited to 'src/crypto/zinc/poly1305/poly1305-arm-glue.c')
| -rw-r--r-- | src/crypto/zinc/poly1305/poly1305-arm-glue.c | 139 |
1 files changed, 139 insertions, 0 deletions
diff --git a/src/crypto/zinc/poly1305/poly1305-arm-glue.c b/src/crypto/zinc/poly1305/poly1305-arm-glue.c new file mode 100644 index 0000000..f91066f --- /dev/null +++ b/src/crypto/zinc/poly1305/poly1305-arm-glue.c @@ -0,0 +1,139 @@ +// SPDX-License-Identifier: GPL-2.0 OR MIT +/* + * Copyright (C) 2015-2018 Jason A. Donenfeld <Jason@zx2c4.com>. All Rights Reserved. + */ + +#include <asm/hwcap.h> +#include <asm/neon.h> + +asmlinkage void poly1305_init_arm(void *ctx, const u8 key[16]); +asmlinkage void poly1305_blocks_arm(void *ctx, const u8 *inp, const size_t len, + const u32 padbit); +asmlinkage void poly1305_emit_arm(void *ctx, u8 mac[16], const u32 nonce[4]); +asmlinkage void poly1305_blocks_neon(void *ctx, const u8 *inp, const size_t len, + const u32 padbit); +asmlinkage void poly1305_emit_neon(void *ctx, u8 mac[16], const u32 nonce[4]); + +static bool poly1305_use_neon __ro_after_init; + +static void __init poly1305_fpu_init(void) +{ +#if defined(CONFIG_ZINC_ARCH_ARM64) + poly1305_use_neon = elf_hwcap & HWCAP_ASIMD; +#elif defined(CONFIG_ZINC_ARCH_ARM) + poly1305_use_neon = elf_hwcap & HWCAP_NEON; +#endif +} + +#if defined(CONFIG_ZINC_ARCH_ARM64) +struct poly1305_arch_internal { + union { + u32 h[5]; + struct { + u64 h0, h1, h2; + }; + }; + u64 is_base2_26; + u64 r[2]; +}; +#elif defined(CONFIG_ZINC_ARCH_ARM) +struct poly1305_arch_internal { + union { + u32 h[5]; + struct { + u64 h0, h1; + u32 h2; + } __packed; + }; + u32 r[4]; + u32 is_base2_26; +}; +#endif + +/* The NEON code uses base 2^26, while the scalar code uses base 2^64 on 64-bit + * and base 2^32 on 32-bit. If we hit the unfortunate situation of using NEON + * and then having to go back to scalar -- because the user is silly and has + * called the update function from two separate contexts -- then we need to + * convert back to the original base before proceeding. The below function is + * written for 64-bit integers, and so we have to swap words at the end on + * big-endian 32-bit. It is possible to reason that the initial reduction below + * is sufficient given the implementation invariants. However, for an avoidance + * of doubt and because this is not performance critical, we do the full + * reduction anyway. + */ +static void convert_to_base2_64(void *ctx) +{ + struct poly1305_arch_internal *state = ctx; + u32 cy; + + if (!IS_ENABLED(CONFIG_KERNEL_MODE_NEON) || !state->is_base2_26) + return; + + cy = state->h[0] >> 26; state->h[0] &= 0x3ffffff; state->h[1] += cy; + cy = state->h[1] >> 26; state->h[1] &= 0x3ffffff; state->h[2] += cy; + cy = state->h[2] >> 26; state->h[2] &= 0x3ffffff; state->h[3] += cy; + cy = state->h[3] >> 26; state->h[3] &= 0x3ffffff; state->h[4] += cy; + state->h0 = ((u64)state->h[2] << 52) | ((u64)state->h[1] << 26) | state->h[0]; + state->h1 = ((u64)state->h[4] << 40) | ((u64)state->h[3] << 14) | (state->h[2] >> 12); + state->h2 = state->h[4] >> 24; + if (IS_ENABLED(CONFIG_ZINC_ARCH_ARM) && IS_ENABLED(CONFIG_CPU_BIG_ENDIAN)) { + state->h0 = rol64(state->h0, 32); + state->h1 = rol64(state->h1, 32); + } +#define ULT(a, b) ((a ^ ((a ^ b) | ((a - b) ^ b))) >> (sizeof(a) * 8 - 1)) + cy = (state->h2 >> 2) + (state->h2 & ~3ULL); + state->h2 &= 3; + state->h0 += cy; + state->h1 += (cy = ULT(state->h0, cy)); + state->h2 += ULT(state->h1, cy); +#undef ULT + state->is_base2_26 = 0; +} + +static inline bool poly1305_init_arch(void *ctx, + const u8 key[POLY1305_KEY_SIZE]) +{ + poly1305_init_arm(ctx, key); + return true; +} + +static inline bool poly1305_blocks_arch(void *ctx, const u8 *inp, + size_t len, const u32 padbit, + simd_context_t *simd_context) +{ + /* SIMD disables preemption, so relax after processing each page. */ + BUILD_BUG_ON(PAGE_SIZE < POLY1305_BLOCK_SIZE || + PAGE_SIZE % POLY1305_BLOCK_SIZE); + + if (!IS_ENABLED(CONFIG_KERNEL_MODE_NEON) || !poly1305_use_neon || + !simd_use(simd_context)) { + convert_to_base2_64(ctx); + poly1305_blocks_arm(ctx, inp, len, padbit); + return true; + } + + for (;;) { + const size_t bytes = min_t(size_t, len, PAGE_SIZE); + + poly1305_blocks_neon(ctx, inp, bytes, padbit); + len -= bytes; + if (!len) + break; + inp += bytes; + simd_relax(simd_context); + } + return true; +} + +static inline bool poly1305_emit_arch(void *ctx, u8 mac[POLY1305_MAC_SIZE], + const u32 nonce[4], + simd_context_t *simd_context) +{ + if (!IS_ENABLED(CONFIG_KERNEL_MODE_NEON) || !poly1305_use_neon || + !simd_use(simd_context)) { + convert_to_base2_64(ctx); + poly1305_emit_arm(ctx, mac, nonce); + } else + poly1305_emit_neon(ctx, mac, nonce); + return true; +} |