1 // SPDX-License-Identifier: GPL-2.0
2 /*
3  * Optimized xor_block operation for RAID4/5
4  *
5  * Copyright IBM Corp. 2016
6  * Author(s): Martin Schwidefsky <[email protected]>
7  */
8 
9 #include <linux/types.h>
10 #include <linux/export.h>
11 #include <linux/raid/xor.h>
12 #include <asm/xor.h>
13 
xor_xc_2(unsigned long bytes,unsigned long * __restrict p1,const unsigned long * __restrict p2)14 static void xor_xc_2(unsigned long bytes, unsigned long * __restrict p1,
15 		     const unsigned long * __restrict p2)
16 {
17 	asm volatile(
18 		"	aghi	%0,-1\n"
19 		"	jm	3f\n"
20 		"	srlg	0,%0,8\n"
21 		"	ltgr	0,0\n"
22 		"	jz	1f\n"
23 		"0:	xc	0(256,%1),0(%2)\n"
24 		"	la	%1,256(%1)\n"
25 		"	la	%2,256(%2)\n"
26 		"	brctg	0,0b\n"
27 		"1:	exrl	%0,2f\n"
28 		"	j	3f\n"
29 		"2:	xc	0(1,%1),0(%2)\n"
30 		"3:\n"
31 		: : "d" (bytes), "a" (p1), "a" (p2)
32 		: "0", "cc", "memory");
33 }
34 
xor_xc_3(unsigned long bytes,unsigned long * __restrict p1,const unsigned long * __restrict p2,const unsigned long * __restrict p3)35 static void xor_xc_3(unsigned long bytes, unsigned long * __restrict p1,
36 		     const unsigned long * __restrict p2,
37 		     const unsigned long * __restrict p3)
38 {
39 	asm volatile(
40 		"	aghi	%0,-1\n"
41 		"	jm	4f\n"
42 		"	srlg	0,%0,8\n"
43 		"	ltgr	0,0\n"
44 		"	jz	1f\n"
45 		"0:	xc	0(256,%1),0(%2)\n"
46 		"	xc	0(256,%1),0(%3)\n"
47 		"	la	%1,256(%1)\n"
48 		"	la	%2,256(%2)\n"
49 		"	la	%3,256(%3)\n"
50 		"	brctg	0,0b\n"
51 		"1:	exrl	%0,2f\n"
52 		"	exrl	%0,3f\n"
53 		"	j	4f\n"
54 		"2:	xc	0(1,%1),0(%2)\n"
55 		"3:	xc	0(1,%1),0(%3)\n"
56 		"4:\n"
57 		: "+d" (bytes), "+a" (p1), "+a" (p2), "+a" (p3)
58 		: : "0", "cc", "memory");
59 }
60 
xor_xc_4(unsigned long bytes,unsigned long * __restrict p1,const unsigned long * __restrict p2,const unsigned long * __restrict p3,const unsigned long * __restrict p4)61 static void xor_xc_4(unsigned long bytes, unsigned long * __restrict p1,
62 		     const unsigned long * __restrict p2,
63 		     const unsigned long * __restrict p3,
64 		     const unsigned long * __restrict p4)
65 {
66 	asm volatile(
67 		"	aghi	%0,-1\n"
68 		"	jm	5f\n"
69 		"	srlg	0,%0,8\n"
70 		"	ltgr	0,0\n"
71 		"	jz	1f\n"
72 		"0:	xc	0(256,%1),0(%2)\n"
73 		"	xc	0(256,%1),0(%3)\n"
74 		"	xc	0(256,%1),0(%4)\n"
75 		"	la	%1,256(%1)\n"
76 		"	la	%2,256(%2)\n"
77 		"	la	%3,256(%3)\n"
78 		"	la	%4,256(%4)\n"
79 		"	brctg	0,0b\n"
80 		"1:	exrl	%0,2f\n"
81 		"	exrl	%0,3f\n"
82 		"	exrl	%0,4f\n"
83 		"	j	5f\n"
84 		"2:	xc	0(1,%1),0(%2)\n"
85 		"3:	xc	0(1,%1),0(%3)\n"
86 		"4:	xc	0(1,%1),0(%4)\n"
87 		"5:\n"
88 		: "+d" (bytes), "+a" (p1), "+a" (p2), "+a" (p3), "+a" (p4)
89 		: : "0", "cc", "memory");
90 }
91 
xor_xc_5(unsigned long bytes,unsigned long * __restrict p1,const unsigned long * __restrict p2,const unsigned long * __restrict p3,const unsigned long * __restrict p4,const unsigned long * __restrict p5)92 static void xor_xc_5(unsigned long bytes, unsigned long * __restrict p1,
93 		     const unsigned long * __restrict p2,
94 		     const unsigned long * __restrict p3,
95 		     const unsigned long * __restrict p4,
96 		     const unsigned long * __restrict p5)
97 {
98 	asm volatile(
99 		"	larl	1,2f\n"
100 		"	aghi	%0,-1\n"
101 		"	jm	6f\n"
102 		"	srlg	0,%0,8\n"
103 		"	ltgr	0,0\n"
104 		"	jz	1f\n"
105 		"0:	xc	0(256,%1),0(%2)\n"
106 		"	xc	0(256,%1),0(%3)\n"
107 		"	xc	0(256,%1),0(%4)\n"
108 		"	xc	0(256,%1),0(%5)\n"
109 		"	la	%1,256(%1)\n"
110 		"	la	%2,256(%2)\n"
111 		"	la	%3,256(%3)\n"
112 		"	la	%4,256(%4)\n"
113 		"	la	%5,256(%5)\n"
114 		"	brctg	0,0b\n"
115 		"1:	exrl	%0,2f\n"
116 		"	exrl	%0,3f\n"
117 		"	exrl	%0,4f\n"
118 		"	exrl	%0,5f\n"
119 		"	j	6f\n"
120 		"2:	xc	0(1,%1),0(%2)\n"
121 		"3:	xc	0(1,%1),0(%3)\n"
122 		"4:	xc	0(1,%1),0(%4)\n"
123 		"5:	xc	0(1,%1),0(%5)\n"
124 		"6:\n"
125 		: "+d" (bytes), "+a" (p1), "+a" (p2), "+a" (p3), "+a" (p4),
126 		  "+a" (p5)
127 		: : "0", "cc", "memory");
128 }
129 
130 struct xor_block_template xor_block_xc = {
131 	.name = "xc",
132 	.do_2 = xor_xc_2,
133 	.do_3 = xor_xc_3,
134 	.do_4 = xor_xc_4,
135 	.do_5 = xor_xc_5,
136 };
137 EXPORT_SYMBOL(xor_block_xc);
138