1 /* SPDX-License-Identifier: GPL-2.0 */
2 /*
3  * NH - ε-almost-universal hash function, x86_64 AVX2 accelerated
4  *
5  * Copyright 2018 Google LLC
6  *
7  * Author: Eric Biggers <ebiggers@google.com>
8  */
9 
10 #include <linux/linkage.h>
11 
12 #define		PASS0_SUMS	%ymm0
13 #define		PASS1_SUMS	%ymm1
14 #define		PASS2_SUMS	%ymm2
15 #define		PASS3_SUMS	%ymm3
16 #define		K0		%ymm4
17 #define		K0_XMM		%xmm4
18 #define		K1		%ymm5
19 #define		K1_XMM		%xmm5
20 #define		K2		%ymm6
21 #define		K2_XMM		%xmm6
22 #define		K3		%ymm7
23 #define		K3_XMM		%xmm7
24 #define		T0		%ymm8
25 #define		T1		%ymm9
26 #define		T2		%ymm10
27 #define		T2_XMM		%xmm10
28 #define		T3		%ymm11
29 #define		T3_XMM		%xmm11
30 #define		T4		%ymm12
31 #define		T5		%ymm13
32 #define		T6		%ymm14
33 #define		T7		%ymm15
34 #define		KEY		%rdi
35 #define		MESSAGE		%rsi
36 #define		MESSAGE_LEN	%rdx
37 #define		HASH		%rcx
38 
39 .macro _nh_2xstride	k0, k1, k2, k3
40 
41 	// Add message words to key words
42 	vpaddd		\k0, T3, T0
43 	vpaddd		\k1, T3, T1
44 	vpaddd		\k2, T3, T2
45 	vpaddd		\k3, T3, T3
46 
47 	// Multiply 32x32 => 64 and accumulate
48 	vpshufd		$0x10, T0, T4
49 	vpshufd		$0x32, T0, T0
50 	vpshufd		$0x10, T1, T5
51 	vpshufd		$0x32, T1, T1
52 	vpshufd		$0x10, T2, T6
53 	vpshufd		$0x32, T2, T2
54 	vpshufd		$0x10, T3, T7
55 	vpshufd		$0x32, T3, T3
56 	vpmuludq	T4, T0, T0
57 	vpmuludq	T5, T1, T1
58 	vpmuludq	T6, T2, T2
59 	vpmuludq	T7, T3, T3
60 	vpaddq		T0, PASS0_SUMS, PASS0_SUMS
61 	vpaddq		T1, PASS1_SUMS, PASS1_SUMS
62 	vpaddq		T2, PASS2_SUMS, PASS2_SUMS
63 	vpaddq		T3, PASS3_SUMS, PASS3_SUMS
64 .endm
65 
66 /*
67  * void nh_avx2(const u32 *key, const u8 *message, size_t message_len,
68  *		u8 hash[NH_HASH_BYTES])
69  *
70  * It's guaranteed that message_len % 16 == 0.
71  */
72 SYM_FUNC_START(nh_avx2)
73 
74 	vmovdqu		0x00(KEY), K0
75 	vmovdqu		0x10(KEY), K1
76 	add		$0x20, KEY
77 	vpxor		PASS0_SUMS, PASS0_SUMS, PASS0_SUMS
78 	vpxor		PASS1_SUMS, PASS1_SUMS, PASS1_SUMS
79 	vpxor		PASS2_SUMS, PASS2_SUMS, PASS2_SUMS
80 	vpxor		PASS3_SUMS, PASS3_SUMS, PASS3_SUMS
81 
82 	sub		$0x40, MESSAGE_LEN
83 	jl		.Lloop4_done
84 .Lloop4:
85 	vmovdqu		(MESSAGE), T3
86 	vmovdqu		0x00(KEY), K2
87 	vmovdqu		0x10(KEY), K3
88 	_nh_2xstride	K0, K1, K2, K3
89 
90 	vmovdqu		0x20(MESSAGE), T3
91 	vmovdqu		0x20(KEY), K0
92 	vmovdqu		0x30(KEY), K1
93 	_nh_2xstride	K2, K3, K0, K1
94 
95 	add		$0x40, MESSAGE
96 	add		$0x40, KEY
97 	sub		$0x40, MESSAGE_LEN
98 	jge		.Lloop4
99 
100 .Lloop4_done:
101 	and		$0x3f, MESSAGE_LEN
102 	jz		.Ldone
103 
104 	cmp		$0x20, MESSAGE_LEN
105 	jl		.Llast
106 
107 	// 2 or 3 strides remain; do 2 more.
108 	vmovdqu		(MESSAGE), T3
109 	vmovdqu		0x00(KEY), K2
110 	vmovdqu		0x10(KEY), K3
111 	_nh_2xstride	K0, K1, K2, K3
112 	add		$0x20, MESSAGE
113 	add		$0x20, KEY
114 	sub		$0x20, MESSAGE_LEN
115 	jz		.Ldone
116 	vmovdqa		K2, K0
117 	vmovdqa		K3, K1
118 .Llast:
119 	// Last stride.  Zero the high 128 bits of the message and keys so they
120 	// don't affect the result when processing them like 2 strides.
121 	vmovdqu		(MESSAGE), T3_XMM
122 	vmovdqa		K0_XMM, K0_XMM
123 	vmovdqa		K1_XMM, K1_XMM
124 	vmovdqu		0x00(KEY), K2_XMM
125 	vmovdqu		0x10(KEY), K3_XMM
126 	_nh_2xstride	K0, K1, K2, K3
127 
128 .Ldone:
129 	// Sum the accumulators for each pass, then store the sums to 'hash'
130 
131 	// PASS0_SUMS is (0A 0B 0C 0D)
132 	// PASS1_SUMS is (1A 1B 1C 1D)
133 	// PASS2_SUMS is (2A 2B 2C 2D)
134 	// PASS3_SUMS is (3A 3B 3C 3D)
135 	// We need the horizontal sums:
136 	//     (0A + 0B + 0C + 0D,
137 	//	1A + 1B + 1C + 1D,
138 	//	2A + 2B + 2C + 2D,
139 	//	3A + 3B + 3C + 3D)
140 	//
141 
142 	vpunpcklqdq	PASS1_SUMS, PASS0_SUMS, T0	// T0 = (0A 1A 0C 1C)
143 	vpunpckhqdq	PASS1_SUMS, PASS0_SUMS, T1	// T1 = (0B 1B 0D 1D)
144 	vpunpcklqdq	PASS3_SUMS, PASS2_SUMS, T2	// T2 = (2A 3A 2C 3C)
145 	vpunpckhqdq	PASS3_SUMS, PASS2_SUMS, T3	// T3 = (2B 3B 2D 3D)
146 
147 	vinserti128	$0x1, T2_XMM, T0, T4		// T4 = (0A 1A 2A 3A)
148 	vinserti128	$0x1, T3_XMM, T1, T5		// T5 = (0B 1B 2B 3B)
149 	vperm2i128	$0x31, T2, T0, T0		// T0 = (0C 1C 2C 3C)
150 	vperm2i128	$0x31, T3, T1, T1		// T1 = (0D 1D 2D 3D)
151 
152 	vpaddq		T5, T4, T4
153 	vpaddq		T1, T0, T0
154 	vpaddq		T4, T0, T0
155 	vmovdqu		T0, (HASH)
156 	RET
157 SYM_FUNC_END(nh_avx2)
158