1 // SPDX-License-Identifier: GPL-2.0-or-later
2 /* -*- linux-c -*- ------------------------------------------------------- *
3 *
4 * Copyright 2002 H. Peter Anvin - All Rights Reserved
5 *
6 * ----------------------------------------------------------------------- */
7
8 /*
9 * raid6/mmx.c
10 *
11 * MMX implementation of RAID-6 syndrome functions
12 */
13
14 #ifdef CONFIG_X86_32
15
16 #include <linux/raid/pq.h>
17 #include "x86.h"
18
19 /* Shared with raid6/sse1.c */
20 const struct raid6_mmx_constants {
21 u64 x1d;
22 } raid6_mmx_constants = {
23 0x1d1d1d1d1d1d1d1dULL,
24 };
25
26 static int raid6_have_mmx(void)
27 {
28 /* Not really "boot_cpu" but "all_cpus" */
29 return boot_cpu_has(X86_FEATURE_MMX);
30 }
31
32 /*
33 * Plain MMX implementation
34 */
35 static void raid6_mmx1_gen_syndrome(int disks, size_t bytes, void **ptrs)
36 {
37 u8 **dptr = (u8 **)ptrs;
38 u8 *p, *q;
39 int d, z, z0;
40
41 z0 = disks - 3; /* Highest data disk */
42 p = dptr[z0+1]; /* XOR parity */
43 q = dptr[z0+2]; /* RS syndrome */
44
45 kernel_fpu_begin();
46
47 asm volatile("movq %0,%%mm0" : : "m" (raid6_mmx_constants.x1d));
48 asm volatile("pxor %mm5,%mm5"); /* Zero temp */
49
50 for ( d = 0 ; d < bytes ; d += 8 ) {
51 asm volatile("movq %0,%%mm2" : : "m" (dptr[z0][d])); /* P[0] */
52 asm volatile("movq %mm2,%mm4"); /* Q[0] */
53 for ( z = z0-1 ; z >= 0 ; z-- ) {
54 asm volatile("movq %0,%%mm6" : : "m" (dptr[z][d]));
55 asm volatile("pcmpgtb %mm4,%mm5");
56 asm volatile("paddb %mm4,%mm4");
57 asm volatile("pand %mm0,%mm5");
58 asm volatile("pxor %mm5,%mm4");
59 asm volatile("pxor %mm5,%mm5");
60 asm volatile("pxor %mm6,%mm2");
61 asm volatile("pxor %mm6,%mm4");
62 }
63 asm volatile("movq %%mm2,%0" : "=m" (p[d]));
64 asm volatile("pxor %mm2,%mm2");
65 asm volatile("movq %%mm4,%0" : "=m" (q[d]));
66 asm volatile("pxor %mm4,%mm4");
67 }
68
69 kernel_fpu_end();
70 }
71
72 const struct raid6_calls raid6_mmxx1 = {
73 raid6_mmx1_gen_syndrome,
74 NULL, /* XOR not yet implemented */
75 raid6_have_mmx,
76 "mmxx1",
77 0
78 };
79
80 /*
81 * Unrolled-by-2 MMX implementation
82 */
83 static void raid6_mmx2_gen_syndrome(int disks, size_t bytes, void **ptrs)
84 {
85 u8 **dptr = (u8 **)ptrs;
86 u8 *p, *q;
87 int d, z, z0;
88
89 z0 = disks - 3; /* Highest data disk */
90 p = dptr[z0+1]; /* XOR parity */
91 q = dptr[z0+2]; /* RS syndrome */
92
93 kernel_fpu_begin();
94
95 asm volatile("movq %0,%%mm0" : : "m" (raid6_mmx_constants.x1d));
96 asm volatile("pxor %mm5,%mm5"); /* Zero temp */
97 asm volatile("pxor %mm7,%mm7"); /* Zero temp */
98
99 for ( d = 0 ; d < bytes ; d += 16 ) {
100 asm volatile("movq %0,%%mm2" : : "m" (dptr[z0][d])); /* P[0] */
101 asm volatile("movq %0,%%mm3" : : "m" (dptr[z0][d+8]));
102 asm volatile("movq %mm2,%mm4"); /* Q[0] */
103 asm volatile("movq %mm3,%mm6"); /* Q[1] */
104 for ( z = z0-1 ; z >= 0 ; z-- ) {
105 asm volatile("pcmpgtb %mm4,%mm5");
106 asm volatile("pcmpgtb %mm6,%mm7");
107 asm volatile("paddb %mm4,%mm4");
108 asm volatile("paddb %mm6,%mm6");
109 asm volatile("pand %mm0,%mm5");
110 asm volatile("pand %mm0,%mm7");
111 asm volatile("pxor %mm5,%mm4");
112 asm volatile("pxor %mm7,%mm6");
113 asm volatile("movq %0,%%mm5" : : "m" (dptr[z][d]));
114 asm volatile("movq %0,%%mm7" : : "m" (dptr[z][d+8]));
115 asm volatile("pxor %mm5,%mm2");
116 asm volatile("pxor %mm7,%mm3");
117 asm volatile("pxor %mm5,%mm4");
118 asm volatile("pxor %mm7,%mm6");
119 asm volatile("pxor %mm5,%mm5");
120 asm volatile("pxor %mm7,%mm7");
121 }
122 asm volatile("movq %%mm2,%0" : "=m" (p[d]));
123 asm volatile("movq %%mm3,%0" : "=m" (p[d+8]));
124 asm volatile("movq %%mm4,%0" : "=m" (q[d]));
125 asm volatile("movq %%mm6,%0" : "=m" (q[d+8]));
126 }
127
128 kernel_fpu_end();
129 }
130
131 const struct raid6_calls raid6_mmxx2 = {
132 raid6_mmx2_gen_syndrome,
133 NULL, /* XOR not yet implemented */
134 raid6_have_mmx,
135 "mmxx2",
136 0
137 };
138
139 #endif
140
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