xref: /openbmc/linux/lib/raid6/s390vx.uc (revision feac8c8b)
1// SPDX-License-Identifier: GPL-2.0
2/*
3 * raid6_vx$#.c
4 *
5 * $#-way unrolled RAID6 gen/xor functions for s390
6 * based on the vector facility
7 *
8 * Copyright IBM Corp. 2016
9 * Author(s): Martin Schwidefsky <schwidefsky@de.ibm.com>
10 *
11 * This file is postprocessed using unroll.awk.
12 */
13
14#include <linux/raid/pq.h>
15#include <asm/fpu/api.h>
16
17asm(".include \"asm/vx-insn.h\"\n");
18
19#define NSIZE 16
20
21static inline void LOAD_CONST(void)
22{
23	asm volatile("VREPIB %v24,7");
24	asm volatile("VREPIB %v25,0x1d");
25}
26
27/*
28 * The SHLBYTE() operation shifts each of the 16 bytes in
29 * vector register y left by 1 bit and stores the result in
30 * vector register x.
31 */
32static inline void SHLBYTE(int x, int y)
33{
34	asm volatile ("VAB %0,%1,%1" : : "i" (x), "i" (y));
35}
36
37/*
38 * For each of the 16 bytes in the vector register y the MASK()
39 * operation returns 0xFF if the high bit of the byte is 1,
40 * or 0x00 if the high bit is 0. The result is stored in vector
41 * register x.
42 */
43static inline void MASK(int x, int y)
44{
45	asm volatile ("VESRAVB	%0,%1,24" : : "i" (x), "i" (y));
46}
47
48static inline void AND(int x, int y, int z)
49{
50	asm volatile ("VN %0,%1,%2" : : "i" (x), "i" (y), "i" (z));
51}
52
53static inline void XOR(int x, int y, int z)
54{
55	asm volatile ("VX %0,%1,%2" : : "i" (x), "i" (y), "i" (z));
56}
57
58static inline void LOAD_DATA(int x, int n, u8 *ptr)
59{
60	typedef struct { u8 _[16*n]; } addrtype;
61	register addrtype *__ptr asm("1") = (addrtype *) ptr;
62
63	asm volatile ("VLM %2,%3,0,%r1"
64		      : : "m" (*__ptr), "a" (__ptr), "i" (x), "i" (x + n - 1));
65}
66
67static inline void STORE_DATA(int x, int n, u8 *ptr)
68{
69	typedef struct { u8 _[16*n]; } addrtype;
70	register addrtype *__ptr asm("1") = (addrtype *) ptr;
71
72	asm volatile ("VSTM %2,%3,0,1"
73		      : "=m" (*__ptr) : "a" (__ptr), "i" (x), "i" (x + n - 1));
74}
75
76static inline void COPY_VEC(int x, int y)
77{
78	asm volatile ("VLR %0,%1" : : "i" (x), "i" (y));
79}
80
81static void raid6_s390vx$#_gen_syndrome(int disks, size_t bytes, void **ptrs)
82{
83	struct kernel_fpu vxstate;
84	u8 **dptr, *p, *q;
85	int d, z, z0;
86
87	kernel_fpu_begin(&vxstate, KERNEL_VXR);
88	LOAD_CONST();
89
90	dptr = (u8 **) ptrs;
91	z0 = disks - 3;		/* Highest data disk */
92	p = dptr[z0 + 1];	/* XOR parity */
93	q = dptr[z0 + 2];	/* RS syndrome */
94
95	for (d = 0; d < bytes; d += $#*NSIZE) {
96		LOAD_DATA(0,$#,&dptr[z0][d]);
97		COPY_VEC(8+$$,0+$$);
98		for (z = z0 - 1; z >= 0; z--) {
99			MASK(16+$$,8+$$);
100			AND(16+$$,16+$$,25);
101			SHLBYTE(8+$$,8+$$);
102			XOR(8+$$,8+$$,16+$$);
103			LOAD_DATA(16,$#,&dptr[z][d]);
104			XOR(0+$$,0+$$,16+$$);
105			XOR(8+$$,8+$$,16+$$);
106		}
107		STORE_DATA(0,$#,&p[d]);
108		STORE_DATA(8,$#,&q[d]);
109	}
110	kernel_fpu_end(&vxstate, KERNEL_VXR);
111}
112
113static void raid6_s390vx$#_xor_syndrome(int disks, int start, int stop,
114					size_t bytes, void **ptrs)
115{
116	struct kernel_fpu vxstate;
117	u8 **dptr, *p, *q;
118	int d, z, z0;
119
120	dptr = (u8 **) ptrs;
121	z0 = stop;		/* P/Q right side optimization */
122	p = dptr[disks - 2];	/* XOR parity */
123	q = dptr[disks - 1];	/* RS syndrome */
124
125	kernel_fpu_begin(&vxstate, KERNEL_VXR);
126	LOAD_CONST();
127
128	for (d = 0; d < bytes; d += $#*NSIZE) {
129		/* P/Q data pages */
130		LOAD_DATA(0,$#,&dptr[z0][d]);
131		COPY_VEC(8+$$,0+$$);
132		for (z = z0 - 1; z >= start; z--) {
133			MASK(16+$$,8+$$);
134			AND(16+$$,16+$$,25);
135			SHLBYTE(8+$$,8+$$);
136			XOR(8+$$,8+$$,16+$$);
137			LOAD_DATA(16,$#,&dptr[z][d]);
138			XOR(0+$$,0+$$,16+$$);
139			XOR(8+$$,8+$$,16+$$);
140		}
141		/* P/Q left side optimization */
142		for (z = start - 1; z >= 0; z--) {
143			MASK(16+$$,8+$$);
144			AND(16+$$,16+$$,25);
145			SHLBYTE(8+$$,8+$$);
146			XOR(8+$$,8+$$,16+$$);
147		}
148		LOAD_DATA(16,$#,&p[d]);
149		XOR(16+$$,16+$$,0+$$);
150		STORE_DATA(16,$#,&p[d]);
151		LOAD_DATA(16,$#,&q[d]);
152		XOR(16+$$,16+$$,8+$$);
153		STORE_DATA(16,$#,&q[d]);
154	}
155	kernel_fpu_end(&vxstate, KERNEL_VXR);
156}
157
158static int raid6_s390vx$#_valid(void)
159{
160	return MACHINE_HAS_VX;
161}
162
163const struct raid6_calls raid6_s390vx$# = {
164	raid6_s390vx$#_gen_syndrome,
165	raid6_s390vx$#_xor_syndrome,
166	raid6_s390vx$#_valid,
167	"vx128x$#",
168	1
169};
170