[PATCH v2 2/6] crypto: x86/nhpoly1305 - add AVX2 accelerated NHPoly1305

Eric Biggers
2018-11-30T10:10:34Z

From: Eric Biggers <ebiggers@google.com>

Add a 64-bit AVX2 implementation of NHPoly1305, an ε-almost-∆-universal
hash function used in the Adiantum encryption mode. For now, only the
NH portion is actually AVX2-accelerated; the Poly1305 part is less
performance-critical so is just implemented in C.

Signed-off-by: Eric Biggers <ebiggers@google.com>
---
arch/x86/crypto/Makefile | 3 +
arch/x86/crypto/nh-avx2-x86_64.S | 157 +++++++++++++++++++++++++
arch/x86/crypto/nhpoly1305-avx2-glue.c | 77 ++++++++++++
crypto/Kconfig | 8 ++
4 files changed, 245 insertions(+)
create mode 100644 arch/x86/crypto/nh-avx2-x86_64.S
create mode 100644 arch/x86/crypto/nhpoly1305-avx2-glue.c

diff --git a/arch/x86/crypto/Makefile b/arch/x86/crypto/Makefile
index 2a6acb4de373..0b31b16f49d8 100644
--- a/arch/x86/crypto/Makefile
+++ b/arch/x86/crypto/Makefile
@@ -48,6 +48,7 @@ obj-$(CONFIG_CRYPTO_MORUS640_SSE2) += morus640-sse2.o
obj-$(CONFIG_CRYPTO_MORUS1280_SSE2) += morus1280-sse2.o

obj-$(CONFIG_CRYPTO_NHPOLY1305_SSE2) += nhpoly1305-sse2.o
+obj-$(CONFIG_CRYPTO_NHPOLY1305_AVX2) += nhpoly1305-avx2.o

# These modules require assembler to support AVX.
ifeq ($(avx_supported),yes)
@@ -106,6 +107,8 @@ ifeq ($(avx2_supported),yes)
serpent-avx2-y := serpent-avx2-asm_64.o serpent_avx2_glue.o

morus1280-avx2-y := morus1280-avx2-asm.o morus1280-avx2-glue.o
+
+ nhpoly1305-avx2-y := nh-avx2-x86_64.o nhpoly1305-avx2-glue.o
endif

ifeq ($(avx512_supported),yes)
diff --git a/arch/x86/crypto/nh-avx2-x86_64.S b/arch/x86/crypto/nh-avx2-x86_64.S
new file mode 100644
index 000000000000..f7946ea1b704
--- /dev/null
+++ b/arch/x86/crypto/nh-avx2-x86_64.S
@@ -0,0 +1,157 @@
+/* SPDX-License-Identifier: GPL-2.0 */
+/*
+ * NH - ε-almost-universal hash function, x86_64 AVX2 accelerated
+ *
+ * Copyright 2018 Google LLC
+ *
+ * Author: Eric Biggers <ebiggers@google.com>
+ */
+
+#include <linux/linkage.h>
+
+#define PASS0_SUMS %ymm0
+#define PASS1_SUMS %ymm1
+#define PASS2_SUMS %ymm2
+#define PASS3_SUMS %ymm3
+#define K0 %ymm4
+#define K0_XMM %xmm4
+#define K1 %ymm5
+#define K1_XMM %xmm5
+#define K2 %ymm6
+#define K2_XMM %xmm6
+#define K3 %ymm7
+#define K3_XMM %xmm7
+#define T0 %ymm8
+#define T1 %ymm9
+#define T2 %ymm10
+#define T2_XMM %xmm10
+#define T3 %ymm11
+#define T3_XMM %xmm11
+#define T4 %ymm12
+#define T5 %ymm13
+#define T6 %ymm14
+#define T7 %ymm15
+#define KEY %rdi
+#define MESSAGE %rsi
+#define MESSAGE_LEN %rdx
+#define HASH %rcx
+
+.macro _nh_2xstride k0, k1, k2, k3
+
+ // Add message words to key words
+ vpaddd \k0, T3, T0
+ vpaddd \k1, T3, T1
+ vpaddd \k2, T3, T2
+ vpaddd \k3, T3, T3
+
+ // Multiply 32x32 => 64 and accumulate
+ vpshufd $0x10, T0, T4
+ vpshufd $0x32, T0, T0
+ vpshufd $0x10, T1, T5
+ vpshufd $0x32, T1, T1
+ vpshufd $0x10, T2, T6
+ vpshufd $0x32, T2, T2
+ vpshufd $0x10, T3, T7
+ vpshufd $0x32, T3, T3
+ vpmuludq T4, T0, T0
+ vpmuludq T5, T1, T1
+ vpmuludq T6, T2, T2
+ vpmuludq T7, T3, T3
+ vpaddq T0, PASS0_SUMS, PASS0_SUMS
+ vpaddq T1, PASS1_SUMS, PASS1_SUMS
+ vpaddq T2, PASS2_SUMS, PASS2_SUMS
+ vpaddq T3, PASS3_SUMS, PASS3_SUMS
+.endm
+
+/*
+ * void nh_avx2(const u32 *key, const u8 *message, size_t message_len,
+ * u8 hash[NH_HASH_BYTES])
+ *
+ * It's guaranteed that message_len % 16 == 0.
+ */
+ENTRY(nh_avx2)
+
+ vmovdqu 0x00(KEY), K0
+ vmovdqu 0x10(KEY), K1
+ add $0x20, KEY
+ vpxor PASS0_SUMS, PASS0_SUMS, PASS0_SUMS
+ vpxor PASS1_SUMS, PASS1_SUMS, PASS1_SUMS
+ vpxor PASS2_SUMS, PASS2_SUMS, PASS2_SUMS
+ vpxor PASS3_SUMS, PASS3_SUMS, PASS3_SUMS
+
+ sub $0x40, MESSAGE_LEN
+ jl .Lloop4_done
+.Lloop4:
+ vmovdqu (MESSAGE), T3
+ vmovdqu 0x00(KEY), K2
+ vmovdqu 0x10(KEY), K3
+ _nh_2xstride K0, K1, K2, K3
+
+ vmovdqu 0x20(MESSAGE), T3
+ vmovdqu 0x20(KEY), K0
+ vmovdqu 0x30(KEY), K1
+ _nh_2xstride K2, K3, K0, K1
+
+ add $0x40, MESSAGE
+ add $0x40, KEY
+ sub $0x40, MESSAGE_LEN
+ jge .Lloop4
+
+.Lloop4_done:
+ and $0x3f, MESSAGE_LEN
+ jz .Ldone
+
+ cmp $0x20, MESSAGE_LEN
+ jl .Llast
+
+ // 2 or 3 strides remain; do 2 more.
+ vmovdqu (MESSAGE), T3
+ vmovdqu 0x00(KEY), K2
+ vmovdqu 0x10(KEY), K3
+ _nh_2xstride K0, K1, K2, K3
+ add $0x20, MESSAGE
+ add $0x20, KEY
+ sub $0x20, MESSAGE_LEN
+ jz .Ldone
+ vmovdqa K2, K0
+ vmovdqa K3, K1
+.Llast:
+ // Last stride. Zero the high 128 bits of the message and keys so they
+ // don't affect the result when processing them like 2 strides.
+ vmovdqu (MESSAGE), T3_XMM
+ vmovdqa K0_XMM, K0_XMM
+ vmovdqa K1_XMM, K1_XMM
+ vmovdqu 0x00(KEY), K2_XMM
+ vmovdqu 0x10(KEY), K3_XMM
+ _nh_2xstride K0, K1, K2, K3
+
+.Ldone:
+ // Sum the accumulators for each pass, then store the sums to 'hash'
+
+ // PASS0_SUMS is (0A 0B 0C 0D)
+ // PASS1_SUMS is (1A 1B 1C 1D)
+ // PASS2_SUMS is (2A 2B 2C 2D)
+ // PASS3_SUMS is (3A 3B 3C 3D)
+ // We need the horizontal sums:
+ // (0A + 0B + 0C + 0D,
+ // 1A + 1B + 1C + 1D,
+ // 2A + 2B + 2C + 2D,
+ // 3A + 3B + 3C + 3D)
+ //
+
+ vpunpcklqdq PASS1_SUMS, PASS0_SUMS, T0 // T0 = (0A 1A 0C 1C)
+ vpunpckhqdq PASS1_SUMS, PASS0_SUMS, T1 // T1 = (0B 1B 0D 1D)
+ vpunpcklqdq PASS3_SUMS, PASS2_SUMS, T2 // T2 = (2A 3A 2C 3C)
+ vpunpckhqdq PASS3_SUMS, PASS2_SUMS, T3 // T3 = (2B 3B 2D 3D)
+
+ vinserti128 $0x1, T2_XMM, T0, T4 // T4 = (0A 1A 2A 3A)
+ vinserti128 $0x1, T3_XMM, T1, T5 // T5 = (0B 1B 2B 3B)
+ vperm2i128 $0x31, T2, T0, T0 // T0 = (0C 1C 2C 3C)
+ vperm2i128 $0x31, T3, T1, T1 // T1 = (0D 1D 2D 3D)
+
+ vpaddq T5, T4, T4
+ vpaddq T1, T0, T0
+ vpaddq T4, T0, T0
+ vmovdqu T0, (HASH)
+ ret
+ENDPROC(nh_avx2)
diff --git a/arch/x86/crypto/nhpoly1305-avx2-glue.c b/arch/x86/crypto/nhpoly1305-avx2-glue.c
new file mode 100644
index 000000000000..20d815ea4b6a
--- /dev/null
+++ b/arch/x86/crypto/nhpoly1305-avx2-glue.c
@@ -0,0 +1,77 @@
+// SPDX-License-Identifier: GPL-2.0
+/*
+ * NHPoly1305 - ε-almost-∆-universal hash function for Adiantum
+ * (AVX2 accelerated version)
+ *
+ * Copyright 2018 Google LLC
+ */
+
+#include <crypto/internal/hash.h>
+#include <crypto/nhpoly1305.h>
+#include <linux/module.h>
+#include <asm/fpu/api.h>
+
+asmlinkage void nh_avx2(const u32 *key, const u8 *message, size_t message_len,
+ u8 hash[NH_HASH_BYTES]);
+
+/* wrapper to avoid indirect call to assembly, which doesn't work with CFI */
+static void _nh_avx2(const u32 *key, const u8 *message, size_t message_len,
+ __le64 hash[NH_NUM_PASSES])
+{
+ nh_avx2(key, message, message_len, (u8 *)hash);
+}
+
+static int nhpoly1305_avx2_update(struct shash_desc *desc,
+ const u8 *src, unsigned int srclen)
+{
+ if (srclen < 64 || !irq_fpu_usable())
+ return crypto_nhpoly1305_update(desc, src, srclen);
+
+ do {
+ unsigned int n = min_t(unsigned int, srclen, PAGE_SIZE);
+
+ kernel_fpu_begin();
+ crypto_nhpoly1305_update_helper(desc, src, n, _nh_avx2);
+ kernel_fpu_end();
+ src += n;
+ srclen -= n;
+ } while (srclen);
+ return 0;
+}
+
+static struct shash_alg nhpoly1305_alg = {
+ .base.cra_name = "nhpoly1305",
+ .base.cra_driver_name = "nhpoly1305-avx2",
+ .base.cra_priority = 300,
+ .base.cra_ctxsize = sizeof(struct nhpoly1305_key),
+ .base.cra_module = THIS_MODULE,
+ .digestsize = POLY1305_DIGEST_SIZE,
+ .init = crypto_nhpoly1305_init,
+ .update = nhpoly1305_avx2_update,
+ .final = crypto_nhpoly1305_final,
+ .setkey = crypto_nhpoly1305_setkey,
+ .descsize = sizeof(struct nhpoly1305_state),
+};
+
+static int __init nhpoly1305_mod_init(void)
+{
+ if (!boot_cpu_has(X86_FEATURE_AVX2) ||
+ !boot_cpu_has(X86_FEATURE_OSXSAVE))
+ return -ENODEV;
+
+ return crypto_register_shash(&nhpoly1305_alg);
+}
+
+static void __exit nhpoly1305_mod_exit(void)
+{
+ crypto_unregister_shash(&nhpoly1305_alg);
+}
+
+module_init(nhpoly1305_mod_init);
+module_exit(nhpoly1305_mod_exit);
+
+MODULE_DESCRIPTION("NHPoly1305 ε-almost-∆-universal hash function (AVX2-accelerated)");
+MODULE_LICENSE("GPL v2");
+MODULE_AUTHOR("Eric Biggers <ebiggers@google.com>");
+MODULE_ALIAS_CRYPTO("nhpoly1305");
+MODULE_ALIAS_CRYPTO("nhpoly1305-avx2");
diff --git a/crypto/Kconfig b/crypto/Kconfig
index b85133966d64..e084e2fb6743 100644
--- a/crypto/Kconfig
+++ b/crypto/Kconfig
@@ -509,6 +509,14 @@ config CRYPTO_NHPOLY1305_SSE2
SSE2 optimized implementation of the hash function used by the
Adiantum encryption mode.

+config CRYPTO_NHPOLY1305_AVX2
+ tristate "NHPoly1305 hash function (x86_64 AVX2 implementation)"
+ depends on X86 && 64BIT
+ select CRYPTO_NHPOLY1305
+ help
+ AVX2 optimized implementation of the hash function used by the
+ Adiantum encryption mode.
+
config CRYPTO_ADIANTUM
tristate "Adiantum support"
select CRYPTO_CHACHA20
--
2.20.0.rc0.387.gc7a69e6b6c-goog