vppinfra: toeplitz hash

Type: feature
Change-Id: I0ccf280c4b769ee624cfb780146b847a0e8e4942
Signed-off-by: Damjan Marion <dmarion@me.com>

1 files changed, 122 insertions, 0 deletions

diff --git a/src/vppinfra/vector/toeplitz.c b/src/vppinfra/vector/toeplitz.c
new file mode 100644
index 00000000000..b0140d51e6f
--- /dev/null
+++ b/src/vppinfra/vector/toeplitz.c
@@ -0,0 +1,122 @@
+/* SPDX-License-Identifier: Apache-2.0
+ * Copyright(c) 2021 Cisco Systems, Inc.
+ */
+
+#include <vppinfra/clib.h>
+#include <vppinfra/mem.h>
+#include <vppinfra/vector/toeplitz.h>
+
+static u8 default_key[40] = {
+  0x6d, 0x5a, 0x56, 0xda, 0x25, 0x5b, 0x0e, 0xc2, 0x41, 0x67,
+  0x25, 0x3d, 0x43, 0xa3, 0x8f, 0xb0, 0xd0, 0xca, 0x2b, 0xcb,
+  0xae, 0x7b, 0x30, 0xb4, 0x77, 0xcb, 0x2d, 0xa3, 0x80, 0x30,
+  0xf2, 0x0c, 0x6a, 0x42, 0xb7, 0x3b, 0xbe, 0xac, 0x01, 0xfa,
+};
+
+#ifdef __x86_64__
+static_always_inline void
+clib_toeplitz_hash_key_expand_8 (u64x2 kv, u64x8u *m)
+{
+  u64x8 kv4, a, b, shift = { 0, 1, 2, 3, 4, 5, 6, 7 };
+
+  kv4 = (u64x8){ kv[0], kv[1], kv[0], kv[1], kv[0], kv[1], kv[0], kv[1] };
+
+  /* clang-format off */
+  /* create 8 byte-swapped copies of the bytes 0 - 7 */
+  a = (u64x8) u8x64_shuffle (kv4,
+    0x7, 0x6, 0x5, 0x4, 0x3, 0x2, 0x1, 0x0,
+    0x7, 0x6, 0x5, 0x4, 0x3, 0x2, 0x1, 0x0,
+    0x7, 0x6, 0x5, 0x4, 0x3, 0x2, 0x1, 0x0,
+    0x7, 0x6, 0x5, 0x4, 0x3, 0x2, 0x1, 0x0,
+    0x7, 0x6, 0x5, 0x4, 0x3, 0x2, 0x1, 0x0,
+    0x7, 0x6, 0x5, 0x4, 0x3, 0x2, 0x1, 0x0,
+    0x7, 0x6, 0x5, 0x4, 0x3, 0x2, 0x1, 0x0,
+    0x7, 0x6, 0x5, 0x4, 0x3, 0x2, 0x1, 0x0);
+  /* create 8 byte-swapped copies of the bytes 4 - 11 */
+  b = (u64x8) u8x64_shuffle (kv4,
+    0xb, 0xa, 0x9, 0x8, 0x7, 0x6, 0x5, 0x4,
+    0xb, 0xa, 0x9, 0x8, 0x7, 0x6, 0x5, 0x4,
+    0xb, 0xa, 0x9, 0x8, 0x7, 0x6, 0x5, 0x4,
+    0xb, 0xa, 0x9, 0x8, 0x7, 0x6, 0x5, 0x4,
+    0xb, 0xa, 0x9, 0x8, 0x7, 0x6, 0x5, 0x4,
+    0xb, 0xa, 0x9, 0x8, 0x7, 0x6, 0x5, 0x4,
+    0xb, 0xa, 0x9, 0x8, 0x7, 0x6, 0x5, 0x4,
+    0xb, 0xa, 0x9, 0x8, 0x7, 0x6, 0x5, 0x4);
+  /* clang-format on */
+
+  /* shift each 64-bit element for 0 - 7 bits */
+  a <<= shift;
+  b <<= shift;
+
+  /* clang-format off */
+  /* construct eight 8x8 bit matrix used by gf2p8affine */
+  * m = (u64x8) u8x64_shuffle2 (a, b,
+    0x07, 0x0f, 0x17, 0x1f, 0x27, 0x2f, 0x37, 0x3f,
+    0x06, 0x0e, 0x16, 0x1e, 0x26, 0x2e, 0x36, 0x3e,
+    0x05, 0x0d, 0x15, 0x1d, 0x25, 0x2d, 0x35, 0x3d,
+    0x04, 0x0c, 0x14, 0x1c, 0x24, 0x2c, 0x34, 0x3c,
+    0x47, 0x4f, 0x57, 0x5f, 0x67, 0x6f, 0x77, 0x7f,
+    0x46, 0x4e, 0x56, 0x5e, 0x66, 0x6e, 0x76, 0x7e,
+    0x45, 0x4d, 0x55, 0x5d, 0x65, 0x6d, 0x75, 0x7d,
+    0x44, 0x4c, 0x54, 0x5c, 0x64, 0x6c, 0x74, 0x7c);
+  /* clang-format on */
+}
+
+void
+clib_toeplitz_hash_key_expand (u64 *matrixes, u8 *key, int size)
+{
+  u64x8u *m = (u64x8u *) matrixes;
+  u64x2 kv, zero = {};
+
+  while (size >= 8)
+    {
+      kv = *(u64x2u *) key;
+      clib_toeplitz_hash_key_expand_8 (kv, m);
+      key += 8;
+      m++;
+      size -= 8;
+    }
+
+  kv = u64x2_shuffle2 (kv, zero, 1, 2);
+  clib_toeplitz_hash_key_expand_8 (kv, m);
+}
+#endif
+
+__clib_export clib_toeplitz_hash_key_t *
+clib_toeplitz_hash_key_init (u8 *key, u32 keylen)
+{
+  clib_toeplitz_hash_key_t *k;
+  u32 size, gfni_size = 0;
+
+  if (key == 0)
+    {
+      key = default_key;
+      keylen = sizeof (default_key);
+    }
+
+  size =
+    round_pow2 (sizeof (clib_toeplitz_hash_key_t) + round_pow2 (keylen, 16),
+		CLIB_CACHE_LINE_BYTES);
+#ifdef __x86_64__
+  gfni_size = round_pow2 ((keylen + 1) * 8, CLIB_CACHE_LINE_BYTES);
+#endif
+
+  k = clib_mem_alloc_aligned (size + gfni_size, CLIB_CACHE_LINE_BYTES);
+  clib_memset_u8 (k, 0, size + gfni_size);
+  k->key_length = keylen;
+  k->gfni_offset = size;
+  clib_memcpy_fast (k->data, key, keylen);
+
+#ifdef __x86_64__
+  clib_toeplitz_hash_key_expand ((u64 *) ((u8 *) k + k->gfni_offset), k->data,
+				 k->key_length);
+#endif
+
+  return k;
+}
+
+__clib_export void
+clib_toeplitz_hash_key_free (clib_toeplitz_hash_key_t *k)
+{
+  clib_mem_free (k);
+}