1 // SPDX-License-Identifier: GPL-2.0
2 /*
3 * raid6_vx$#.c
4 *
5 * $#-way unrolled RAID6 gen/xor functions for s390
6 * based on the vector facility
7 *
8 * Copyright IBM Corp. 2016
9 * Author(s): Martin Schwidefsky <schwidefsky@de.ibm.com>
10 *
11 * This file is postprocessed using unroll.awk.
12 */
13
14 #include <linux/raid/pq.h>
15 #include <asm/fpu.h>
16
17 #define NSIZE 16
18
19 static __always_inline void LOAD_CONST(void)
20 {
21 fpu_vrepib(24, 0x07);
22 fpu_vrepib(25, 0x1d);
23 }
24
25 /*
26 * The SHLBYTE() operation shifts each of the 16 bytes in
27 * vector register y left by 1 bit and stores the result in
28 * vector register x.
29 */
30 #define SHLBYTE(x, y) fpu_vab(x, y, y)
31
32 /*
33 * For each of the 16 bytes in the vector register y the MASK()
34 * operation returns 0xFF if the high bit of the byte is 1,
35 * or 0x00 if the high bit is 0. The result is stored in vector
36 * register x.
37 */
38 #define MASK(x, y) fpu_vesravb(x, y, 24)
39
40 #define AND(x, y, z) fpu_vn(x, y, z)
41 #define XOR(x, y, z) fpu_vx(x, y, z)
42 #define LOAD_DATA(x, ptr) fpu_vlm(x, x + $# - 1, ptr)
43 #define STORE_DATA(x, ptr) fpu_vstm(x, x + $# - 1, ptr)
44 #define COPY_VEC(x, y) fpu_vlr(x, y)
45
46 static void raid6_s390vx$#_gen_syndrome(int disks, size_t bytes, void **ptrs)
47 {
48 DECLARE_KERNEL_FPU_ONSTACK32(vxstate);
49 u8 **dptr, *p, *q;
50 int d, z, z0;
51
52 kernel_fpu_begin(&vxstate, KERNEL_VXR);
53 LOAD_CONST();
54
55 dptr = (u8 **) ptrs;
56 z0 = disks - 3; /* Highest data disk */
57 p = dptr[z0 + 1]; /* XOR parity */
58 q = dptr[z0 + 2]; /* RS syndrome */
59
60 for (d = 0; d < bytes; d += $#*NSIZE) {
61 LOAD_DATA(0,&dptr[z0][d]);
62 COPY_VEC(8+$$,0+$$);
63 for (z = z0 - 1; z >= 0; z--) {
64 MASK(16+$$,8+$$);
65 AND(16+$$,16+$$,25);
66 SHLBYTE(8+$$,8+$$);
67 XOR(8+$$,8+$$,16+$$);
68 LOAD_DATA(16,&dptr[z][d]);
69 XOR(0+$$,0+$$,16+$$);
70 XOR(8+$$,8+$$,16+$$);
71 }
72 STORE_DATA(0,&p[d]);
73 STORE_DATA(8,&q[d]);
74 }
75 kernel_fpu_end(&vxstate, KERNEL_VXR);
76 }
77
78 static void raid6_s390vx$#_xor_syndrome(int disks, int start, int stop,
79 size_t bytes, void **ptrs)
80 {
81 DECLARE_KERNEL_FPU_ONSTACK32(vxstate);
82 u8 **dptr, *p, *q;
83 int d, z, z0;
84
85 dptr = (u8 **) ptrs;
86 z0 = stop; /* P/Q right side optimization */
87 p = dptr[disks - 2]; /* XOR parity */
88 q = dptr[disks - 1]; /* RS syndrome */
89
90 kernel_fpu_begin(&vxstate, KERNEL_VXR);
91 LOAD_CONST();
92
93 for (d = 0; d < bytes; d += $#*NSIZE) {
94 /* P/Q data pages */
95 LOAD_DATA(0,&dptr[z0][d]);
96 COPY_VEC(8+$$,0+$$);
97 for (z = z0 - 1; z >= start; z--) {
98 MASK(16+$$,8+$$);
99 AND(16+$$,16+$$,25);
100 SHLBYTE(8+$$,8+$$);
101 XOR(8+$$,8+$$,16+$$);
102 LOAD_DATA(16,&dptr[z][d]);
103 XOR(0+$$,0+$$,16+$$);
104 XOR(8+$$,8+$$,16+$$);
105 }
106 /* P/Q left side optimization */
107 for (z = start - 1; z >= 0; z--) {
108 MASK(16+$$,8+$$);
109 AND(16+$$,16+$$,25);
110 SHLBYTE(8+$$,8+$$);
111 XOR(8+$$,8+$$,16+$$);
112 }
113 LOAD_DATA(16,&p[d]);
114 XOR(16+$$,16+$$,0+$$);
115 STORE_DATA(16,&p[d]);
116 LOAD_DATA(16,&q[d]);
117 XOR(16+$$,16+$$,8+$$);
118 STORE_DATA(16,&q[d]);
119 }
120 kernel_fpu_end(&vxstate, KERNEL_VXR);
121 }
122
123 static int raid6_s390vx$#_valid(void)
124 {
125 return cpu_has_vx();
126 }
127
128 const struct raid6_calls raid6_s390vx$# = {
129 raid6_s390vx$#_gen_syndrome,
130 raid6_s390vx$#_xor_syndrome,
131 raid6_s390vx$#_valid,
132 "vx128x$#",
133 1
134 };
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