xref: /linux/lib/raid6/recov_rvv.c (revision 07fdad3a93756b872da7b53647715c48d0f4a2d0)
1 // SPDX-License-Identifier: GPL-2.0-only
2 /*
3  * Copyright 2024 Institute of Software, CAS.
4  * Author: Chunyan Zhang <zhangchunyan@iscas.ac.cn>
5  */
6 
7 #include <asm/vector.h>
8 #include <linux/raid/pq.h>
9 
10 static int rvv_has_vector(void)
11 {
12 	return has_vector();
13 }
14 
15 static void __raid6_2data_recov_rvv(int bytes, u8 *p, u8 *q, u8 *dp,
16 				    u8 *dq, const u8 *pbmul,
17 				    const u8 *qmul)
18 {
19 	asm volatile (".option	push\n"
20 		      ".option	arch,+v\n"
21 		      "vsetvli	x0, %[avl], e8, m1, ta, ma\n"
22 		      ".option	pop\n"
23 		      : :
24 		      [avl]"r"(16)
25 	);
26 
27 	/*
28 	 * while ( bytes-- ) {
29 	 *	uint8_t px, qx, db;
30 	 *
31 	 *	px	  = *p ^ *dp;
32 	 *	qx	  = qmul[*q ^ *dq];
33 	 *	*dq++ = db = pbmul[px] ^ qx;
34 	 *	*dp++ = db ^ px;
35 	 *	p++; q++;
36 	 * }
37 	 */
38 	while (bytes) {
39 		/*
40 		 * v0:px, v1:dp,
41 		 * v2:qx, v3:dq,
42 		 * v4:vx, v5:vy,
43 		 * v6:qm0, v7:qm1,
44 		 * v8:pm0, v9:pm1,
45 		 * v14:p/qm[vx], v15:p/qm[vy]
46 		 */
47 		asm volatile (".option		push\n"
48 			      ".option		arch,+v\n"
49 			      "vle8.v		v0, (%[px])\n"
50 			      "vle8.v		v1, (%[dp])\n"
51 			      "vxor.vv		v0, v0, v1\n"
52 			      "vle8.v		v2, (%[qx])\n"
53 			      "vle8.v		v3, (%[dq])\n"
54 			      "vxor.vv		v4, v2, v3\n"
55 			      "vsrl.vi		v5, v4, 4\n"
56 			      "vand.vi		v4, v4, 0xf\n"
57 			      "vle8.v		v6, (%[qm0])\n"
58 			      "vle8.v		v7, (%[qm1])\n"
59 			      "vrgather.vv	v14, v6, v4\n" /* v14 = qm[vx] */
60 			      "vrgather.vv	v15, v7, v5\n" /* v15 = qm[vy] */
61 			      "vxor.vv		v2, v14, v15\n" /* v2 = qmul[*q ^ *dq] */
62 
63 			      "vsrl.vi		v5, v0, 4\n"
64 			      "vand.vi		v4, v0, 0xf\n"
65 			      "vle8.v		v8, (%[pm0])\n"
66 			      "vle8.v		v9, (%[pm1])\n"
67 			      "vrgather.vv	v14, v8, v4\n" /* v14 = pm[vx] */
68 			      "vrgather.vv	v15, v9, v5\n" /* v15 = pm[vy] */
69 			      "vxor.vv		v4, v14, v15\n" /* v4 = pbmul[px] */
70 			      "vxor.vv		v3, v4, v2\n" /* v3 = db = pbmul[px] ^ qx */
71 			      "vxor.vv		v1, v3, v0\n" /* v1 = db ^ px; */
72 			      "vse8.v		v3, (%[dq])\n"
73 			      "vse8.v		v1, (%[dp])\n"
74 			      ".option		pop\n"
75 			      : :
76 			      [px]"r"(p),
77 			      [dp]"r"(dp),
78 			      [qx]"r"(q),
79 			      [dq]"r"(dq),
80 			      [qm0]"r"(qmul),
81 			      [qm1]"r"(qmul + 16),
82 			      [pm0]"r"(pbmul),
83 			      [pm1]"r"(pbmul + 16)
84 			      :);
85 
86 		bytes -= 16;
87 		p += 16;
88 		q += 16;
89 		dp += 16;
90 		dq += 16;
91 	}
92 }
93 
94 static void __raid6_datap_recov_rvv(int bytes, u8 *p, u8 *q,
95 				    u8 *dq, const u8 *qmul)
96 {
97 	asm volatile (".option	push\n"
98 		      ".option	arch,+v\n"
99 		      "vsetvli	x0, %[avl], e8, m1, ta, ma\n"
100 		      ".option	pop\n"
101 		      : :
102 		      [avl]"r"(16)
103 	);
104 
105 	/*
106 	 * while (bytes--) {
107 	 *  *p++ ^= *dq = qmul[*q ^ *dq];
108 	 *  q++; dq++;
109 	 * }
110 	 */
111 	while (bytes) {
112 		/*
113 		 * v0:vx, v1:vy,
114 		 * v2:dq, v3:p,
115 		 * v4:qm0, v5:qm1,
116 		 * v10:m[vx], v11:m[vy]
117 		 */
118 		asm volatile (".option		push\n"
119 			      ".option		arch,+v\n"
120 			      "vle8.v		v0, (%[vx])\n"
121 			      "vle8.v		v2, (%[dq])\n"
122 			      "vxor.vv		v0, v0, v2\n"
123 			      "vsrl.vi		v1, v0, 4\n"
124 			      "vand.vi		v0, v0, 0xf\n"
125 			      "vle8.v		v4, (%[qm0])\n"
126 			      "vle8.v		v5, (%[qm1])\n"
127 			      "vrgather.vv	v10, v4, v0\n"
128 			      "vrgather.vv	v11, v5, v1\n"
129 			      "vxor.vv		v0, v10, v11\n"
130 			      "vle8.v		v1, (%[vy])\n"
131 			      "vxor.vv		v1, v0, v1\n"
132 			      "vse8.v		v0, (%[dq])\n"
133 			      "vse8.v		v1, (%[vy])\n"
134 			      ".option		pop\n"
135 			      : :
136 			      [vx]"r"(q),
137 			      [vy]"r"(p),
138 			      [dq]"r"(dq),
139 			      [qm0]"r"(qmul),
140 			      [qm1]"r"(qmul + 16)
141 			      :);
142 
143 		bytes -= 16;
144 		p += 16;
145 		q += 16;
146 		dq += 16;
147 	}
148 }
149 
150 static void raid6_2data_recov_rvv(int disks, size_t bytes, int faila,
151 				  int failb, void **ptrs)
152 {
153 	u8 *p, *q, *dp, *dq;
154 	const u8 *pbmul;	/* P multiplier table for B data */
155 	const u8 *qmul;		/* Q multiplier table (for both) */
156 
157 	p = (u8 *)ptrs[disks - 2];
158 	q = (u8 *)ptrs[disks - 1];
159 
160 	/*
161 	 * Compute syndrome with zero for the missing data pages
162 	 * Use the dead data pages as temporary storage for
163 	 * delta p and delta q
164 	 */
165 	dp = (u8 *)ptrs[faila];
166 	ptrs[faila] = raid6_get_zero_page();
167 	ptrs[disks - 2] = dp;
168 	dq = (u8 *)ptrs[failb];
169 	ptrs[failb] = raid6_get_zero_page();
170 	ptrs[disks - 1] = dq;
171 
172 	raid6_call.gen_syndrome(disks, bytes, ptrs);
173 
174 	/* Restore pointer table */
175 	ptrs[faila]     = dp;
176 	ptrs[failb]     = dq;
177 	ptrs[disks - 2] = p;
178 	ptrs[disks - 1] = q;
179 
180 	/* Now, pick the proper data tables */
181 	pbmul = raid6_vgfmul[raid6_gfexi[failb - faila]];
182 	qmul  = raid6_vgfmul[raid6_gfinv[raid6_gfexp[faila] ^
183 					 raid6_gfexp[failb]]];
184 
185 	kernel_vector_begin();
186 	__raid6_2data_recov_rvv(bytes, p, q, dp, dq, pbmul, qmul);
187 	kernel_vector_end();
188 }
189 
190 static void raid6_datap_recov_rvv(int disks, size_t bytes, int faila,
191 				  void **ptrs)
192 {
193 	u8 *p, *q, *dq;
194 	const u8 *qmul;		/* Q multiplier table */
195 
196 	p = (u8 *)ptrs[disks - 2];
197 	q = (u8 *)ptrs[disks - 1];
198 
199 	/*
200 	 * Compute syndrome with zero for the missing data page
201 	 * Use the dead data page as temporary storage for delta q
202 	 */
203 	dq = (u8 *)ptrs[faila];
204 	ptrs[faila] = raid6_get_zero_page();
205 	ptrs[disks - 1] = dq;
206 
207 	raid6_call.gen_syndrome(disks, bytes, ptrs);
208 
209 	/* Restore pointer table */
210 	ptrs[faila]     = dq;
211 	ptrs[disks - 1] = q;
212 
213 	/* Now, pick the proper data tables */
214 	qmul = raid6_vgfmul[raid6_gfinv[raid6_gfexp[faila]]];
215 
216 	kernel_vector_begin();
217 	__raid6_datap_recov_rvv(bytes, p, q, dq, qmul);
218 	kernel_vector_end();
219 }
220 
221 const struct raid6_recov_calls raid6_recov_rvv = {
222 	.data2		= raid6_2data_recov_rvv,
223 	.datap		= raid6_datap_recov_rvv,
224 	.valid		= rvv_has_vector,
225 	.name		= "rvv",
226 	.priority	= 1,
227 };
228