xref: /linux/lib/raid6/s390vx.uc (revision e80a48bade619ec5a92230b3d4ae84bfc2746822)
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#include <asm/vx-insn.h>
17
18#define NSIZE 16
19
20static inline void LOAD_CONST(void)
21{
22	asm volatile("VREPIB %v24,7");
23	asm volatile("VREPIB %v25,0x1d");
24}
25
26/*
27 * The SHLBYTE() operation shifts each of the 16 bytes in
28 * vector register y left by 1 bit and stores the result in
29 * vector register x.
30 */
31static inline void SHLBYTE(int x, int y)
32{
33	asm volatile ("VAB %0,%1,%1" : : "i" (x), "i" (y));
34}
35
36/*
37 * For each of the 16 bytes in the vector register y the MASK()
38 * operation returns 0xFF if the high bit of the byte is 1,
39 * or 0x00 if the high bit is 0. The result is stored in vector
40 * register x.
41 */
42static inline void MASK(int x, int y)
43{
44	asm volatile ("VESRAVB	%0,%1,24" : : "i" (x), "i" (y));
45}
46
47static inline void AND(int x, int y, int z)
48{
49	asm volatile ("VN %0,%1,%2" : : "i" (x), "i" (y), "i" (z));
50}
51
52static inline void XOR(int x, int y, int z)
53{
54	asm volatile ("VX %0,%1,%2" : : "i" (x), "i" (y), "i" (z));
55}
56
57static inline void LOAD_DATA(int x, u8 *ptr)
58{
59	typedef struct { u8 _[16 * $#]; } addrtype;
60	register addrtype *__ptr asm("1") = (addrtype *) ptr;
61
62	asm volatile ("VLM %2,%3,0,%1"
63		      : : "m" (*__ptr), "a" (__ptr), "i" (x),
64			  "i" (x + $# - 1));
65}
66
67static inline void STORE_DATA(int x, u8 *ptr)
68{
69	typedef struct { u8 _[16 * $#]; } 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),
74			"i" (x + $# - 1));
75}
76
77static inline void COPY_VEC(int x, int y)
78{
79	asm volatile ("VLR %0,%1" : : "i" (x), "i" (y));
80}
81
82static void raid6_s390vx$#_gen_syndrome(int disks, size_t bytes, void **ptrs)
83{
84	struct kernel_fpu vxstate;
85	u8 **dptr, *p, *q;
86	int d, z, z0;
87
88	kernel_fpu_begin(&vxstate, KERNEL_VXR);
89	LOAD_CONST();
90
91	dptr = (u8 **) ptrs;
92	z0 = disks - 3;		/* Highest data disk */
93	p = dptr[z0 + 1];	/* XOR parity */
94	q = dptr[z0 + 2];	/* RS syndrome */
95
96	for (d = 0; d < bytes; d += $#*NSIZE) {
97		LOAD_DATA(0,&dptr[z0][d]);
98		COPY_VEC(8+$$,0+$$);
99		for (z = z0 - 1; z >= 0; z--) {
100			MASK(16+$$,8+$$);
101			AND(16+$$,16+$$,25);
102			SHLBYTE(8+$$,8+$$);
103			XOR(8+$$,8+$$,16+$$);
104			LOAD_DATA(16,&dptr[z][d]);
105			XOR(0+$$,0+$$,16+$$);
106			XOR(8+$$,8+$$,16+$$);
107		}
108		STORE_DATA(0,&p[d]);
109		STORE_DATA(8,&q[d]);
110	}
111	kernel_fpu_end(&vxstate, KERNEL_VXR);
112}
113
114static void raid6_s390vx$#_xor_syndrome(int disks, int start, int stop,
115					size_t bytes, void **ptrs)
116{
117	struct kernel_fpu vxstate;
118	u8 **dptr, *p, *q;
119	int d, z, z0;
120
121	dptr = (u8 **) ptrs;
122	z0 = stop;		/* P/Q right side optimization */
123	p = dptr[disks - 2];	/* XOR parity */
124	q = dptr[disks - 1];	/* RS syndrome */
125
126	kernel_fpu_begin(&vxstate, KERNEL_VXR);
127	LOAD_CONST();
128
129	for (d = 0; d < bytes; d += $#*NSIZE) {
130		/* P/Q data pages */
131		LOAD_DATA(0,&dptr[z0][d]);
132		COPY_VEC(8+$$,0+$$);
133		for (z = z0 - 1; z >= start; z--) {
134			MASK(16+$$,8+$$);
135			AND(16+$$,16+$$,25);
136			SHLBYTE(8+$$,8+$$);
137			XOR(8+$$,8+$$,16+$$);
138			LOAD_DATA(16,&dptr[z][d]);
139			XOR(0+$$,0+$$,16+$$);
140			XOR(8+$$,8+$$,16+$$);
141		}
142		/* P/Q left side optimization */
143		for (z = start - 1; z >= 0; z--) {
144			MASK(16+$$,8+$$);
145			AND(16+$$,16+$$,25);
146			SHLBYTE(8+$$,8+$$);
147			XOR(8+$$,8+$$,16+$$);
148		}
149		LOAD_DATA(16,&p[d]);
150		XOR(16+$$,16+$$,0+$$);
151		STORE_DATA(16,&p[d]);
152		LOAD_DATA(16,&q[d]);
153		XOR(16+$$,16+$$,8+$$);
154		STORE_DATA(16,&q[d]);
155	}
156	kernel_fpu_end(&vxstate, KERNEL_VXR);
157}
158
159static int raid6_s390vx$#_valid(void)
160{
161	return MACHINE_HAS_VX;
162}
163
164const struct raid6_calls raid6_s390vx$# = {
165	raid6_s390vx$#_gen_syndrome,
166	raid6_s390vx$#_xor_syndrome,
167	raid6_s390vx$#_valid,
168	"vx128x$#",
169	1
170};
171