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
19static __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 + $# - 1, ptr)
44#define COPY_VEC(x, y)		fpu_vlr(x, y)
45
46static void raid6_s390vx$#_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+$$);
71		}
72		STORE_DATA(0,&p[d]);
73		STORE_DATA(8,&q[d]);
74	}
75	kernel_fpu_end(&vxstate, KERNEL_VXR);
76}
77
78static void raid6_s390vx$#_xor_syndrome(int disks, int start, int stop,
79					size_t bytes, void **ptrs)
80{
81	DECLARE_KERNEL_FPU_ONSTACK32(vxstate);
82	u8 **dptr, *p, *q;
83	int d, z, z0;
84
85	dptr = (u8 **) ptrs;
86	z0 = stop;		/* P/Q right side optimization */
87	p = dptr[disks - 2];	/* XOR parity */
88	q = dptr[disks - 1];	/* RS syndrome */
89
90	kernel_fpu_begin(&vxstate, KERNEL_VXR);
91	LOAD_CONST();
92
93	for (d = 0; d < bytes; d += $#*NSIZE) {
94		/* P/Q data pages */
95		LOAD_DATA(0,&dptr[z0][d]);
96		COPY_VEC(8+$$,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
123static int raid6_s390vx$#_valid(void)
124{
125	return cpu_has_vx();
126}
127
128const struct raid6_calls raid6_s390vx$# = {
129	raid6_s390vx$#_gen_syndrome,
130	raid6_s390vx$#_xor_syndrome,
131	raid6_s390vx$#_valid,
132	"vx128x$#",
133	1
134};
135