crypto: arm64/nhpoly1305 - add NEON-accelerated NHPoly1305

Add an ARM64 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.

Reviewed-by: Ard Biesheuvel <ard.biesheuvel@linaro.org>
Tested-by: Ard Biesheuvel <ard.biesheuvel@linaro.org> # big-endian
Signed-off-by: Eric Biggers <ebiggers@google.com>
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>

diff --git a/arch/arm64/crypto/Kconfig b/arch/arm64/crypto/Kconfig
index a5606823ed4da3ccbe72ee141859ef506a9e9526..3f5aeb786192bf30b330ffa387b82f9599993369 100644 (file)
--- a/arch/arm64/crypto/Kconfig
+++ b/arch/arm64/crypto/Kconfig
@@ -106,6 +106,11 @@ config CRYPTO_CHACHA20_NEON
        select CRYPTO_BLKCIPHER
        select CRYPTO_CHACHA20
 
+config CRYPTO_NHPOLY1305_NEON
+       tristate "NHPoly1305 hash function using NEON instructions (for Adiantum)"
+       depends on KERNEL_MODE_NEON
+       select CRYPTO_NHPOLY1305
+
 config CRYPTO_AES_ARM64_BS
        tristate "AES in ECB/CBC/CTR/XTS modes using bit-sliced NEON algorithm"
        depends on KERNEL_MODE_NEON

diff --git a/arch/arm64/crypto/Makefile b/arch/arm64/crypto/Makefile
index f476fede09ba489463b9d1fb5e19b7345d100e0e..125dbb10a93edecd344a56d24eca69d19e1c5bd9 100644 (file)
--- a/arch/arm64/crypto/Makefile
+++ b/arch/arm64/crypto/Makefile
@@ -53,6 +53,9 @@ sha512-arm64-y := sha512-glue.o sha512-core.o
 obj-$(CONFIG_CRYPTO_CHACHA20_NEON) += chacha20-neon.o
 chacha20-neon-y := chacha20-neon-core.o chacha20-neon-glue.o
 
+obj-$(CONFIG_CRYPTO_NHPOLY1305_NEON) += nhpoly1305-neon.o
+nhpoly1305-neon-y := nh-neon-core.o nhpoly1305-neon-glue.o
+
 obj-$(CONFIG_CRYPTO_AES_ARM64) += aes-arm64.o
 aes-arm64-y := aes-cipher-core.o aes-cipher-glue.o
 

diff --git a/arch/arm64/crypto/nh-neon-core.S b/arch/arm64/crypto/nh-neon-core.S
new file mode 100644 (file)
index 0000000..e05570c
--- /dev/null
+++ b/arch/arm64/crypto/nh-neon-core.S
@@ -0,0 +1,103 @@
+/* SPDX-License-Identifier: GPL-2.0 */
+/*
+ * NH - ε-almost-universal hash function, ARM64 NEON accelerated version
+ *
+ * Copyright 2018 Google LLC
+ *
+ * Author: Eric Biggers <ebiggers@google.com>
+ */
+
+#include <linux/linkage.h>
+
+       KEY             .req    x0
+       MESSAGE         .req    x1
+       MESSAGE_LEN     .req    x2
+       HASH            .req    x3
+
+       PASS0_SUMS      .req    v0
+       PASS1_SUMS      .req    v1
+       PASS2_SUMS      .req    v2
+       PASS3_SUMS      .req    v3
+       K0              .req    v4
+       K1              .req    v5
+       K2              .req    v6
+       K3              .req    v7
+       T0              .req    v8
+       T1              .req    v9
+       T2              .req    v10
+       T3              .req    v11
+       T4              .req    v12
+       T5              .req    v13
+       T6              .req    v14
+       T7              .req    v15
+
+.macro _nh_stride      k0, k1, k2, k3
+
+       // Load next message stride
+       ld1             {T3.16b}, [MESSAGE], #16
+
+       // Load next key stride
+       ld1             {\k3\().4s}, [KEY], #16
+
+       // Add message words to key words
+       add             T0.4s, T3.4s, \k0\().4s
+       add             T1.4s, T3.4s, \k1\().4s
+       add             T2.4s, T3.4s, \k2\().4s
+       add             T3.4s, T3.4s, \k3\().4s
+
+       // Multiply 32x32 => 64 and accumulate
+       mov             T4.d[0], T0.d[1]
+       mov             T5.d[0], T1.d[1]
+       mov             T6.d[0], T2.d[1]
+       mov             T7.d[0], T3.d[1]
+       umlal           PASS0_SUMS.2d, T0.2s, T4.2s
+       umlal           PASS1_SUMS.2d, T1.2s, T5.2s
+       umlal           PASS2_SUMS.2d, T2.2s, T6.2s
+       umlal           PASS3_SUMS.2d, T3.2s, T7.2s
+.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)
+
+       ld1             {K0.4s,K1.4s}, [KEY], #32
+         movi          PASS0_SUMS.2d, #0
+         movi          PASS1_SUMS.2d, #0
+       ld1             {K2.4s}, [KEY], #16
+         movi          PASS2_SUMS.2d, #0
+         movi          PASS3_SUMS.2d, #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'
+       addp            T0.2d, PASS0_SUMS.2d, PASS1_SUMS.2d
+       addp            T1.2d, PASS2_SUMS.2d, PASS3_SUMS.2d
+       st1             {T0.16b,T1.16b}, [HASH]
+       ret
+ENDPROC(nh_neon)

diff --git a/arch/arm64/crypto/nhpoly1305-neon-glue.c b/arch/arm64/crypto/nhpoly1305-neon-glue.c
new file mode 100644 (file)
index 0000000..22cc32a
--- /dev/null
+++ b/arch/arm64/crypto/nhpoly1305-neon-glue.c
@@ -0,0 +1,77 @@
+// SPDX-License-Identifier: GPL-2.0
+/*
+ * NHPoly1305 - ε-almost-∆-universal hash function for Adiantum
+ * (ARM64 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_ASIMD))
+               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");