xref: /openbmc/linux/arch/arm64/crypto/aes-cipher-core.S (revision 8dd06ef34b6e2f41b29fbf5fc1663780f2524285)
1 /* SPDX-License-Identifier: GPL-2.0-only */
2 /*
3  * Scalar AES core transform
4  *
5  * Copyright (C) 2017 Linaro Ltd <ard.biesheuvel@linaro.org>
6  */
7 
8 #include <linux/linkage.h>
9 #include <asm/assembler.h>
10 #include <asm/cache.h>
11 
12 	.text
13 
14 	rk		.req	x0
15 	out		.req	x1
16 	in		.req	x2
17 	rounds		.req	x3
18 	tt		.req	x2
19 
20 	.macro		__pair1, sz, op, reg0, reg1, in0, in1e, in1d, shift
21 	.ifc		\op\shift, b0
22 	ubfiz		\reg0, \in0, #2, #8
23 	ubfiz		\reg1, \in1e, #2, #8
24 	.else
25 	ubfx		\reg0, \in0, #\shift, #8
26 	ubfx		\reg1, \in1e, #\shift, #8
27 	.endif
28 
29 	/*
30 	 * AArch64 cannot do byte size indexed loads from a table containing
31 	 * 32-bit quantities, i.e., 'ldrb w12, [tt, w12, uxtw #2]' is not a
32 	 * valid instruction. So perform the shift explicitly first for the
33 	 * high bytes (the low byte is shifted implicitly by using ubfiz rather
34 	 * than ubfx above)
35 	 */
36 	.ifnc		\op, b
37 	ldr		\reg0, [tt, \reg0, uxtw #2]
38 	ldr		\reg1, [tt, \reg1, uxtw #2]
39 	.else
40 	.if		\shift > 0
41 	lsl		\reg0, \reg0, #2
42 	lsl		\reg1, \reg1, #2
43 	.endif
44 	ldrb		\reg0, [tt, \reg0, uxtw]
45 	ldrb		\reg1, [tt, \reg1, uxtw]
46 	.endif
47 	.endm
48 
49 	.macro		__pair0, sz, op, reg0, reg1, in0, in1e, in1d, shift
50 	ubfx		\reg0, \in0, #\shift, #8
51 	ubfx		\reg1, \in1d, #\shift, #8
52 	ldr\op		\reg0, [tt, \reg0, uxtw #\sz]
53 	ldr\op		\reg1, [tt, \reg1, uxtw #\sz]
54 	.endm
55 
56 	.macro		__hround, out0, out1, in0, in1, in2, in3, t0, t1, enc, sz, op
57 	ldp		\out0, \out1, [rk], #8
58 
59 	__pair\enc	\sz, \op, w12, w13, \in0, \in1, \in3, 0
60 	__pair\enc	\sz, \op, w14, w15, \in1, \in2, \in0, 8
61 	__pair\enc	\sz, \op, w16, w17, \in2, \in3, \in1, 16
62 	__pair\enc	\sz, \op, \t0, \t1, \in3, \in0, \in2, 24
63 
64 	eor		\out0, \out0, w12
65 	eor		\out1, \out1, w13
66 	eor		\out0, \out0, w14, ror #24
67 	eor		\out1, \out1, w15, ror #24
68 	eor		\out0, \out0, w16, ror #16
69 	eor		\out1, \out1, w17, ror #16
70 	eor		\out0, \out0, \t0, ror #8
71 	eor		\out1, \out1, \t1, ror #8
72 	.endm
73 
74 	.macro		fround, out0, out1, out2, out3, in0, in1, in2, in3, sz=2, op
75 	__hround	\out0, \out1, \in0, \in1, \in2, \in3, \out2, \out3, 1, \sz, \op
76 	__hround	\out2, \out3, \in2, \in3, \in0, \in1, \in1, \in2, 1, \sz, \op
77 	.endm
78 
79 	.macro		iround, out0, out1, out2, out3, in0, in1, in2, in3, sz=2, op
80 	__hround	\out0, \out1, \in0, \in3, \in2, \in1, \out2, \out3, 0, \sz, \op
81 	__hround	\out2, \out3, \in2, \in1, \in0, \in3, \in1, \in0, 0, \sz, \op
82 	.endm
83 
84 	.macro		do_crypt, round, ttab, ltab, bsz
85 	ldp		w4, w5, [in]
86 	ldp		w6, w7, [in, #8]
87 	ldp		w8, w9, [rk], #16
88 	ldp		w10, w11, [rk, #-8]
89 
90 CPU_BE(	rev		w4, w4		)
91 CPU_BE(	rev		w5, w5		)
92 CPU_BE(	rev		w6, w6		)
93 CPU_BE(	rev		w7, w7		)
94 
95 	eor		w4, w4, w8
96 	eor		w5, w5, w9
97 	eor		w6, w6, w10
98 	eor		w7, w7, w11
99 
100 	adr_l		tt, \ttab
101 
102 	tbnz		rounds, #1, 1f
103 
104 0:	\round		w8, w9, w10, w11, w4, w5, w6, w7
105 	\round		w4, w5, w6, w7, w8, w9, w10, w11
106 
107 1:	subs		rounds, rounds, #4
108 	\round		w8, w9, w10, w11, w4, w5, w6, w7
109 	b.ls		3f
110 2:	\round		w4, w5, w6, w7, w8, w9, w10, w11
111 	b		0b
112 3:	adr_l		tt, \ltab
113 	\round		w4, w5, w6, w7, w8, w9, w10, w11, \bsz, b
114 
115 CPU_BE(	rev		w4, w4		)
116 CPU_BE(	rev		w5, w5		)
117 CPU_BE(	rev		w6, w6		)
118 CPU_BE(	rev		w7, w7		)
119 
120 	stp		w4, w5, [out]
121 	stp		w6, w7, [out, #8]
122 	ret
123 	.endm
124 
125 SYM_FUNC_START(__aes_arm64_encrypt)
126 	do_crypt	fround, crypto_ft_tab, crypto_ft_tab + 1, 2
127 SYM_FUNC_END(__aes_arm64_encrypt)
128 
129 	.align		5
130 SYM_FUNC_START(__aes_arm64_decrypt)
131 	do_crypt	iround, crypto_it_tab, crypto_aes_inv_sbox, 0
132 SYM_FUNC_END(__aes_arm64_decrypt)
133