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};