1 files changed, 290 insertions, 0 deletions
diff --git a/arch/x86/crypto/poly1305_glue.c b/arch/x86/crypto/poly1305_glue.c
new file mode 100644
index 000000000..1dfb8af48
--- /dev/null
+++ b/arch/x86/crypto/poly1305_glue.c
@@ -0,0 +1,290 @@
+// SPDX-License-Identifier: GPL-2.0 OR MIT
+/*
+ * Copyright (C) 2015-2019 Jason A. Donenfeld <Jason@zx2c4.com>. All Rights Reserved.
+ */
+
+#include <crypto/algapi.h>
+#include <crypto/internal/hash.h>
+#include <crypto/internal/poly1305.h>
+#include <crypto/internal/simd.h>
+#include <linux/crypto.h>
+#include <linux/jump_label.h>
+#include <linux/kernel.h>
+#include <linux/module.h>
+#include <linux/sizes.h>
+#include <asm/intel-family.h>
+#include <asm/simd.h>
+
+asmlinkage void poly1305_init_x86_64(void *ctx,
+				     const u8 key[POLY1305_BLOCK_SIZE]);
+asmlinkage void poly1305_blocks_x86_64(void *ctx, const u8 *inp,
+				       const size_t len, const u32 padbit);
+asmlinkage void poly1305_emit_x86_64(void *ctx, u8 mac[POLY1305_DIGEST_SIZE],
+				     const u32 nonce[4]);
+asmlinkage void poly1305_emit_avx(void *ctx, u8 mac[POLY1305_DIGEST_SIZE],
+				  const u32 nonce[4]);
+asmlinkage void poly1305_blocks_avx(void *ctx, const u8 *inp, const size_t len,
+				    const u32 padbit);
+asmlinkage void poly1305_blocks_avx2(void *ctx, const u8 *inp, const size_t len,
+				     const u32 padbit);
+asmlinkage void poly1305_blocks_avx512(void *ctx, const u8 *inp,
+				       const size_t len, const u32 padbit);
+
+static __ro_after_init DEFINE_STATIC_KEY_FALSE(poly1305_use_avx);
+static __ro_after_init DEFINE_STATIC_KEY_FALSE(poly1305_use_avx2);
+static __ro_after_init DEFINE_STATIC_KEY_FALSE(poly1305_use_avx512);
+
+struct poly1305_arch_internal {
+	union {
+		struct {
+			u32 h[5];
+			u32 is_base2_26;
+		};
+		u64 hs[3];
+	};
+	u64 r[2];
+	u64 pad;
+	struct { u32 r2, r1, r4, r3; } rn[9];
+};
+
+/* The AVX code uses base 2^26, while the scalar code uses base 2^64. If we hit
+ * the unfortunate situation of using AVX 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. 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. Z3 proof of below function: https://xn--4db.cc/ltPtHCKN/py
+ */
+static void convert_to_base2_64(void *ctx)
+{
+	struct poly1305_arch_internal *state = ctx;
+	u32 cy;
+
+	if (!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->hs[0] = ((u64)state->h[2] << 52) | ((u64)state->h[1] << 26) | state->h[0];
+	state->hs[1] = ((u64)state->h[4] << 40) | ((u64)state->h[3] << 14) | (state->h[2] >> 12);
+	state->hs[2] = state->h[4] >> 24;
+#define ULT(a, b) ((a ^ ((a ^ b) | ((a - b) ^ b))) >> (sizeof(a) * 8 - 1))
+	cy = (state->hs[2] >> 2) + (state->hs[2] & ~3ULL);
+	state->hs[2] &= 3;
+	state->hs[0] += cy;
+	state->hs[1] += (cy = ULT(state->hs[0], cy));
+	state->hs[2] += ULT(state->hs[1], cy);
+#undef ULT
+	state->is_base2_26 = 0;
+}
+
+static void poly1305_simd_init(void *ctx, const u8 key[POLY1305_BLOCK_SIZE])
+{
+	poly1305_init_x86_64(ctx, key);
+}
+
+static void poly1305_simd_blocks(void *ctx, const u8 *inp, size_t len,
+				 const u32 padbit)
+{
+	struct poly1305_arch_internal *state = ctx;
+
+	/* SIMD disables preemption, so relax after processing each page. */
+	BUILD_BUG_ON(SZ_4K < POLY1305_BLOCK_SIZE ||
+		     SZ_4K % POLY1305_BLOCK_SIZE);
+
+	if (!static_branch_likely(&poly1305_use_avx) ||
+	    (len < (POLY1305_BLOCK_SIZE * 18) && !state->is_base2_26) ||
+	    !crypto_simd_usable()) {
+		convert_to_base2_64(ctx);
+		poly1305_blocks_x86_64(ctx, inp, len, padbit);
+		return;
+	}
+
+	do {
+		const size_t bytes = min_t(size_t, len, SZ_4K);
+
+		kernel_fpu_begin();
+		if (IS_ENABLED(CONFIG_AS_AVX512) && static_branch_likely(&poly1305_use_avx512))
+			poly1305_blocks_avx512(ctx, inp, bytes, padbit);
+		else if (static_branch_likely(&poly1305_use_avx2))
+			poly1305_blocks_avx2(ctx, inp, bytes, padbit);
+		else
+			poly1305_blocks_avx(ctx, inp, bytes, padbit);
+		kernel_fpu_end();
+
+		len -= bytes;
+		inp += bytes;
+	} while (len);
+}
+
+static void poly1305_simd_emit(void *ctx, u8 mac[POLY1305_DIGEST_SIZE],
+			       const u32 nonce[4])
+{
+	if (!static_branch_likely(&poly1305_use_avx))
+		poly1305_emit_x86_64(ctx, mac, nonce);
+	else
+		poly1305_emit_avx(ctx, mac, nonce);
+}
+
+void poly1305_init_arch(struct poly1305_desc_ctx *dctx, const u8 key[POLY1305_KEY_SIZE])
+{
+	poly1305_simd_init(&dctx->h, key);
+	dctx->s[0] = get_unaligned_le32(&key[16]);
+	dctx->s[1] = get_unaligned_le32(&key[20]);
+	dctx->s[2] = get_unaligned_le32(&key[24]);
+	dctx->s[3] = get_unaligned_le32(&key[28]);
+	dctx->buflen = 0;
+	dctx->sset = true;
+}
+EXPORT_SYMBOL(poly1305_init_arch);
+
+static unsigned int crypto_poly1305_setdctxkey(struct poly1305_desc_ctx *dctx,
+					       const u8 *inp, unsigned int len)
+{
+	unsigned int acc = 0;
+	if (unlikely(!dctx->sset)) {
+		if (!dctx->rset && len >= POLY1305_BLOCK_SIZE) {
+			poly1305_simd_init(&dctx->h, inp);
+			inp += POLY1305_BLOCK_SIZE;
+			len -= POLY1305_BLOCK_SIZE;
+			acc += POLY1305_BLOCK_SIZE;
+			dctx->rset = 1;
+		}
+		if (len >= POLY1305_BLOCK_SIZE) {
+			dctx->s[0] = get_unaligned_le32(&inp[0]);
+			dctx->s[1] = get_unaligned_le32(&inp[4]);
+			dctx->s[2] = get_unaligned_le32(&inp[8]);
+			dctx->s[3] = get_unaligned_le32(&inp[12]);
+			acc += POLY1305_BLOCK_SIZE;
+			dctx->sset = true;
+		}
+	}
+	return acc;
+}
+
+void poly1305_update_arch(struct poly1305_desc_ctx *dctx, const u8 *src,
+			  unsigned int srclen)
+{
+	unsigned int bytes, used;
+
+	if (unlikely(dctx->buflen)) {
+		bytes = min(srclen, POLY1305_BLOCK_SIZE - dctx->buflen);
+		memcpy(dctx->buf + dctx->buflen, src, bytes);
+		src += bytes;
+		srclen -= bytes;
+		dctx->buflen += bytes;
+
+		if (dctx->buflen == POLY1305_BLOCK_SIZE) {
+			if (likely(!crypto_poly1305_setdctxkey(dctx, dctx->buf, POLY1305_BLOCK_SIZE)))
+				poly1305_simd_blocks(&dctx->h, dctx->buf, POLY1305_BLOCK_SIZE, 1);
+			dctx->buflen = 0;
+		}
+	}
+
+	if (likely(srclen >= POLY1305_BLOCK_SIZE)) {
+		bytes = round_down(srclen, POLY1305_BLOCK_SIZE);
+		srclen -= bytes;
+		used = crypto_poly1305_setdctxkey(dctx, src, bytes);
+		if (likely(bytes - used))
+			poly1305_simd_blocks(&dctx->h, src + used, bytes - used, 1);
+		src += bytes;
+	}
+
+	if (unlikely(srclen)) {
+		dctx->buflen = srclen;
+		memcpy(dctx->buf, src, srclen);
+	}
+}
+EXPORT_SYMBOL(poly1305_update_arch);
+
+void poly1305_final_arch(struct poly1305_desc_ctx *dctx, u8 *dst)
+{
+	if (unlikely(dctx->buflen)) {
+		dctx->buf[dctx->buflen++] = 1;
+		memset(dctx->buf + dctx->buflen, 0,
+		       POLY1305_BLOCK_SIZE - dctx->buflen);
+		poly1305_simd_blocks(&dctx->h, dctx->buf, POLY1305_BLOCK_SIZE, 0);
+	}
+
+	poly1305_simd_emit(&dctx->h, dst, dctx->s);
+	memzero_explicit(dctx, sizeof(*dctx));
+}
+EXPORT_SYMBOL(poly1305_final_arch);
+
+static int crypto_poly1305_init(struct shash_desc *desc)
+{
+	struct poly1305_desc_ctx *dctx = shash_desc_ctx(desc);
+
+	*dctx = (struct poly1305_desc_ctx){};
+	return 0;
+}
+
+static int crypto_poly1305_update(struct shash_desc *desc,
+				  const u8 *src, unsigned int srclen)
+{
+	struct poly1305_desc_ctx *dctx = shash_desc_ctx(desc);
+
+	poly1305_update_arch(dctx, src, srclen);
+	return 0;
+}
+
+static int crypto_poly1305_final(struct shash_desc *desc, u8 *dst)
+{
+	struct poly1305_desc_ctx *dctx = shash_desc_ctx(desc);
+
+	if (unlikely(!dctx->sset))
+		return -ENOKEY;
+
+	poly1305_final_arch(dctx, dst);
+	return 0;
+}
+
+static struct shash_alg alg = {
+	.digestsize	= POLY1305_DIGEST_SIZE,
+	.init		= crypto_poly1305_init,
+	.update		= crypto_poly1305_update,
+	.final		= crypto_poly1305_final,
+	.descsize	= sizeof(struct poly1305_desc_ctx),
+	.base		= {
+		.cra_name		= "poly1305",
+		.cra_driver_name	= "poly1305-simd",
+		.cra_priority		= 300,
+		.cra_blocksize		= POLY1305_BLOCK_SIZE,
+		.cra_module		= THIS_MODULE,
+	},
+};
+
+static int __init poly1305_simd_mod_init(void)
+{
+	if (boot_cpu_has(X86_FEATURE_AVX) &&
+	    cpu_has_xfeatures(XFEATURE_MASK_SSE | XFEATURE_MASK_YMM, NULL))
+		static_branch_enable(&poly1305_use_avx);
+	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(&poly1305_use_avx2);
+	if (IS_ENABLED(CONFIG_AS_AVX512) && boot_cpu_has(X86_FEATURE_AVX) &&
+	    boot_cpu_has(X86_FEATURE_AVX2) && boot_cpu_has(X86_FEATURE_AVX512F) &&
+	    cpu_has_xfeatures(XFEATURE_MASK_SSE | XFEATURE_MASK_YMM | XFEATURE_MASK_AVX512, NULL) &&
+	    /* Skylake downclocks unacceptably much when using zmm, but later generations are fast. */
+	    boot_cpu_data.x86_model != INTEL_FAM6_SKYLAKE_X)
+		static_branch_enable(&poly1305_use_avx512);
+	return IS_REACHABLE(CONFIG_CRYPTO_HASH) ? crypto_register_shash(&alg) : 0;
+}
+
+static void __exit poly1305_simd_mod_exit(void)
+{
+	if (IS_REACHABLE(CONFIG_CRYPTO_HASH))
+		crypto_unregister_shash(&alg);
+}
+
+module_init(poly1305_simd_mod_init);
+module_exit(poly1305_simd_mod_exit);
+
+MODULE_LICENSE("GPL");
+MODULE_AUTHOR("Jason A. Donenfeld <Jason@zx2c4.com>");
+MODULE_DESCRIPTION("Poly1305 authenticator");
+MODULE_ALIAS_CRYPTO("poly1305");
+MODULE_ALIAS_CRYPTO("poly1305-simd");