[PATCH v4 13/14] crypto: arm/nhpoly1305 - add NEON-accelerated NHPoly1305

Eric Biggers
2018-11-17T01:29:21Z

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

Signed-off-by: Eric Biggers <ebiggers@google.com>
---
arch/arm/crypto/Kconfig | 5 ++
arch/arm/crypto/Makefile | 2 +
arch/arm/crypto/nh-neon-core.S | 116 +++++++++++++++++++++++++
arch/arm/crypto/nhpoly1305-neon-glue.c | 77 ++++++++++++++++
4 files changed, 200 insertions(+)
create mode 100644 arch/arm/crypto/nh-neon-core.S
create mode 100644 arch/arm/crypto/nhpoly1305-neon-glue.c

diff --git a/arch/arm/crypto/Kconfig b/arch/arm/crypto/Kconfig
index 59c674cf08ef..a95322b59799 100644
--- a/arch/arm/crypto/Kconfig
+++ b/arch/arm/crypto/Kconfig
@@ -131,4 +131,9 @@ config CRYPTO_CHACHA20_NEON
select CRYPTO_BLKCIPHER
select CRYPTO_CHACHA20

+config CRYPTO_NHPOLY1305_NEON
+ tristate "NEON accelerated NHPoly1305 hash function (for Adiantum)"
+ depends on KERNEL_MODE_NEON
+ select CRYPTO_NHPOLY1305
+
endif
diff --git a/arch/arm/crypto/Makefile b/arch/arm/crypto/Makefile
index 005482ff9504..b65d6bfab8e6 100644
--- a/arch/arm/crypto/Makefile
+++ b/arch/arm/crypto/Makefile
@@ -10,6 +10,7 @@ obj-$(CONFIG_CRYPTO_SHA1_ARM_NEON) += sha1-arm-neon.o
obj-$(CONFIG_CRYPTO_SHA256_ARM) += sha256-arm.o
obj-$(CONFIG_CRYPTO_SHA512_ARM) += sha512-arm.o
obj-$(CONFIG_CRYPTO_CHACHA20_NEON) += chacha-neon.o
+obj-$(CONFIG_CRYPTO_NHPOLY1305_NEON) += nhpoly1305-neon.o

ce-obj-$(CONFIG_CRYPTO_AES_ARM_CE) += aes-arm-ce.o
ce-obj-$(CONFIG_CRYPTO_SHA1_ARM_CE) += sha1-arm-ce.o
@@ -53,6 +54,7 @@ ghash-arm-ce-y := ghash-ce-core.o ghash-ce-glue.o
crct10dif-arm-ce-y := crct10dif-ce-core.o crct10dif-ce-glue.o
crc32-arm-ce-y:= crc32-ce-core.o crc32-ce-glue.o
chacha-neon-y := chacha-neon-core.o chacha-neon-glue.o
+nhpoly1305-neon-y := nh-neon-core.o nhpoly1305-neon-glue.o

ifdef REGENERATE_ARM_CRYPTO
quiet_cmd_perl = PERL $@
diff --git a/arch/arm/crypto/nh-neon-core.S b/arch/arm/crypto/nh-neon-core.S
new file mode 100644
index 000000000000..434d80ab531c
--- /dev/null
+++ b/arch/arm/crypto/nh-neon-core.S
@@ -0,0 +1,116 @@
+/* SPDX-License-Identifier: GPL-2.0 */
+/*
+ * NH - ε-almost-universal hash function, NEON accelerated version
+ *
+ * Copyright 2018 Google LLC
+ *
+ * Author: Eric Biggers <ebiggers@google.com>
+ */
+
+#include <linux/linkage.h>
+
+ .text
+ .fpu neon
+
+ KEY .req r0
+ MESSAGE .req r1
+ MESSAGE_LEN .req r2
+ HASH .req r3
+
+ PASS0_SUMS .req q0
+ PASS0_SUM_A .req d0
+ PASS0_SUM_B .req d1
+ PASS1_SUMS .req q1
+ PASS1_SUM_A .req d2
+ PASS1_SUM_B .req d3
+ PASS2_SUMS .req q2
+ PASS2_SUM_A .req d4
+ PASS2_SUM_B .req d5
+ PASS3_SUMS .req q3
+ PASS3_SUM_A .req d6
+ PASS3_SUM_B .req d7
+ K0 .req q4
+ K1 .req q5
+ K2 .req q6
+ K3 .req q7
+ T0 .req q8
+ T0_L .req d16
+ T0_H .req d17
+ T1 .req q9
+ T1_L .req d18
+ T1_H .req d19
+ T2 .req q10
+ T2_L .req d20
+ T2_H .req d21
+ T3 .req q11
+ T3_L .req d22
+ T3_H .req d23
+
+.macro _nh_stride k0, k1, k2, k3
+
+ // Load next message stride
+ vld1.8 {T3}, [MESSAGE]!
+
+ // Load next key stride
+ vld1.32 {\k3}, [KEY]!
+
+ // Add message words to key words
+ vadd.u32 T0, T3, \k0
+ vadd.u32 T1, T3, \k1
+ vadd.u32 T2, T3, \k2
+ vadd.u32 T3, T3, \k3
+
+ // Multiply 32x32 => 64 and accumulate
+ vmlal.u32 PASS0_SUMS, T0_L, T0_H
+ vmlal.u32 PASS1_SUMS, T1_L, T1_H
+ vmlal.u32 PASS2_SUMS, T2_L, T2_H
+ vmlal.u32 PASS3_SUMS, T3_L, T3_H
+.endm
+
+/*
+ * void nh_neon(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_neon)
+
+ vld1.32 {K0,K1}, [KEY]!
+ vmov.u64 PASS0_SUMS, #0
+ vmov.u64 PASS1_SUMS, #0
+ vld1.32 {K2}, [KEY]!
+ vmov.u64 PASS2_SUMS, #0
+ vmov.u64 PASS3_SUMS, #0
+
+ subs MESSAGE_LEN, MESSAGE_LEN, #64
+ blt .Lloop4_done
+.Lloop4:
+ _nh_stride K0, K1, K2, K3
+ _nh_stride K1, K2, K3, K0
+ _nh_stride K2, K3, K0, K1
+ _nh_stride K3, K0, K1, K2
+ subs MESSAGE_LEN, MESSAGE_LEN, #64
+ bge .Lloop4
+
+.Lloop4_done:
+ ands MESSAGE_LEN, MESSAGE_LEN, #63
+ beq .Ldone
+ _nh_stride K0, K1, K2, K3
+
+ subs MESSAGE_LEN, MESSAGE_LEN, #16
+ beq .Ldone
+ _nh_stride K1, K2, K3, K0
+
+ subs MESSAGE_LEN, MESSAGE_LEN, #16
+ beq .Ldone
+ _nh_stride K2, K3, K0, K1
+
+.Ldone:
+ // Sum the accumulators for each pass, then store the sums to 'hash'
+ vadd.u64 T0_L, PASS0_SUM_A, PASS0_SUM_B
+ vadd.u64 T0_H, PASS1_SUM_A, PASS1_SUM_B
+ vadd.u64 T1_L, PASS2_SUM_A, PASS2_SUM_B
+ vadd.u64 T1_H, PASS3_SUM_A, PASS3_SUM_B
+ vst1.8 {T0-T1}, [HASH]
+ bx lr
+ENDPROC(nh_neon)
diff --git a/arch/arm/crypto/nhpoly1305-neon-glue.c b/arch/arm/crypto/nhpoly1305-neon-glue.c
new file mode 100644
index 000000000000..49aae87cb2bc
--- /dev/null
+++ b/arch/arm/crypto/nhpoly1305-neon-glue.c
@@ -0,0 +1,77 @@
+// SPDX-License-Identifier: GPL-2.0
+/*
+ * NHPoly1305 - ε-almost-∆-universal hash function for Adiantum
+ * (NEON accelerated version)
+ *
+ * Copyright 2018 Google LLC
+ */
+
+#include <asm/neon.h>
+#include <asm/simd.h>
+#include <crypto/internal/hash.h>
+#include <crypto/nhpoly1305.h>
+#include <linux/module.h>
+
+asmlinkage void nh_neon(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_neon(const u32 *key, const u8 *message, size_t message_len,
+ __le64 hash[NH_NUM_PASSES])
+{
+ nh_neon(key, message, message_len, (u8 *)hash);
+}
+
+static int nhpoly1305_neon_update(struct shash_desc *desc,
+ const u8 *src, unsigned int srclen)
+{
+ if (srclen < 64 || !may_use_simd())
+ return crypto_nhpoly1305_update(desc, src, srclen);
+
+ do {
+ unsigned int n = min_t(unsigned int, srclen, PAGE_SIZE);
+
+ kernel_neon_begin();
+ crypto_nhpoly1305_update_helper(desc, src, n, _nh_neon);
+ kernel_neon_end();
+ src += n;
+ srclen -= n;
+ } while (srclen);
+ return 0;
+}
+
+static struct shash_alg nhpoly1305_alg = {
+ .base.cra_name = "nhpoly1305",
+ .base.cra_driver_name = "nhpoly1305-neon",
+ .base.cra_priority = 200,
+ .base.cra_ctxsize = sizeof(struct nhpoly1305_key),
+ .base.cra_module = THIS_MODULE,
+ .digestsize = POLY1305_DIGEST_SIZE,
+ .init = crypto_nhpoly1305_init,
+ .update = nhpoly1305_neon_update,
+ .final = crypto_nhpoly1305_final,
+ .setkey = crypto_nhpoly1305_setkey,
+ .descsize = sizeof(struct nhpoly1305_state),
+};
+
+static int __init nhpoly1305_mod_init(void)
+{
+ if (!(elf_hwcap & HWCAP_NEON))
+ 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 (NEON-accelerated)");
+MODULE_LICENSE("GPL v2");
+MODULE_AUTHOR("Eric Biggers <ebiggers@google.com>");
+MODULE_ALIAS_CRYPTO("nhpoly1305");
+MODULE_ALIAS_CRYPTO("nhpoly1305-neon");
--
2.19.1.1215.g8438c0b245-goog