1/* -*- linux-c -*- ------------------------------------------------------- *
2 *
3 *   Copyright 2002 H. Peter Anvin - All Rights Reserved
4 *
5 *   This program is free software; you can redistribute it and/or modify
6 *   it under the terms of the GNU General Public License as published by
7 *   the Free Software Foundation, Inc., 53 Temple Place Ste 330,
8 *   Boston MA 02111-1307, USA; either version 2 of the License, or
9 *   (at your option) any later version; incorporated herein by reference.
10 *
11 * ----------------------------------------------------------------------- */
12
13/*
14 * raid6/sse1.c
15 *
16 * SSE-1/MMXEXT implementation of RAID-6 syndrome functions
17 *
18 * This is really an MMX implementation, but it requires SSE-1 or
19 * AMD MMXEXT for prefetch support and a few other features.  The
20 * support for nontemporal memory accesses is enough to make this
21 * worthwhile as a separate implementation.
22 */
23
24#ifdef CONFIG_X86_32
25
26#include <linux/raid/pq.h>
27#include "x86.h"
28
29/* Defined in raid6/mmx.c */
30extern const struct raid6_mmx_constants {
31	u64 x1d;
32} raid6_mmx_constants;
33
34static int raid6_have_sse1_or_mmxext(void)
35{
36	/* Not really boot_cpu but "all_cpus" */
37	return boot_cpu_has(X86_FEATURE_MMX) &&
38		(boot_cpu_has(X86_FEATURE_XMM) ||
39		 boot_cpu_has(X86_FEATURE_MMXEXT));
40}
41
42/*
43 * Plain SSE1 implementation
44 */
45static void raid6_sse11_gen_syndrome(int disks, size_t bytes, void **ptrs)
46{
47	u8 **dptr = (u8 **)ptrs;
48	u8 *p, *q;
49	int d, z, z0;
50
51	z0 = disks - 3;		/* Highest data disk */
52	p = dptr[z0+1];		/* XOR parity */
53	q = dptr[z0+2];		/* RS syndrome */
54
55	kernel_fpu_begin();
56
57	asm volatile("movq %0,%%mm0" : : "m" (raid6_mmx_constants.x1d));
58	asm volatile("pxor %mm5,%mm5");	/* Zero temp */
59
60	for ( d = 0 ; d < bytes ; d += 8 ) {
61		asm volatile("prefetchnta %0" : : "m" (dptr[z0][d]));
62		asm volatile("movq %0,%%mm2" : : "m" (dptr[z0][d])); /* P[0] */
63		asm volatile("prefetchnta %0" : : "m" (dptr[z0-1][d]));
64		asm volatile("movq %mm2,%mm4");	/* Q[0] */
65		asm volatile("movq %0,%%mm6" : : "m" (dptr[z0-1][d]));
66		for ( z = z0-2 ; z >= 0 ; z-- ) {
67			asm volatile("prefetchnta %0" : : "m" (dptr[z][d]));
68			asm volatile("pcmpgtb %mm4,%mm5");
69			asm volatile("paddb %mm4,%mm4");
70			asm volatile("pand %mm0,%mm5");
71			asm volatile("pxor %mm5,%mm4");
72			asm volatile("pxor %mm5,%mm5");
73			asm volatile("pxor %mm6,%mm2");
74			asm volatile("pxor %mm6,%mm4");
75			asm volatile("movq %0,%%mm6" : : "m" (dptr[z][d]));
76		}
77		asm volatile("pcmpgtb %mm4,%mm5");
78		asm volatile("paddb %mm4,%mm4");
79		asm volatile("pand %mm0,%mm5");
80		asm volatile("pxor %mm5,%mm4");
81		asm volatile("pxor %mm5,%mm5");
82		asm volatile("pxor %mm6,%mm2");
83		asm volatile("pxor %mm6,%mm4");
84
85		asm volatile("movntq %%mm2,%0" : "=m" (p[d]));
86		asm volatile("movntq %%mm4,%0" : "=m" (q[d]));
87	}
88
89	asm volatile("sfence" : : : "memory");
90	kernel_fpu_end();
91}
92
93const struct raid6_calls raid6_sse1x1 = {
94	raid6_sse11_gen_syndrome,
95	NULL,			/* XOR not yet implemented */
96	raid6_have_sse1_or_mmxext,
97	"sse1x1",
98	1			/* Has cache hints */
99};
100
101/*
102 * Unrolled-by-2 SSE1 implementation
103 */
104static void raid6_sse12_gen_syndrome(int disks, size_t bytes, void **ptrs)
105{
106	u8 **dptr = (u8 **)ptrs;
107	u8 *p, *q;
108	int d, z, z0;
109
110	z0 = disks - 3;		/* Highest data disk */
111	p = dptr[z0+1];		/* XOR parity */
112	q = dptr[z0+2];		/* RS syndrome */
113
114	kernel_fpu_begin();
115
116	asm volatile("movq %0,%%mm0" : : "m" (raid6_mmx_constants.x1d));
117	asm volatile("pxor %mm5,%mm5");	/* Zero temp */
118	asm volatile("pxor %mm7,%mm7"); /* Zero temp */
119
120	/* We uniformly assume a single prefetch covers at least 16 bytes */
121	for ( d = 0 ; d < bytes ; d += 16 ) {
122		asm volatile("prefetchnta %0" : : "m" (dptr[z0][d]));
123		asm volatile("movq %0,%%mm2" : : "m" (dptr[z0][d])); /* P[0] */
124		asm volatile("movq %0,%%mm3" : : "m" (dptr[z0][d+8])); /* P[1] */
125		asm volatile("movq %mm2,%mm4");	/* Q[0] */
126		asm volatile("movq %mm3,%mm6"); /* Q[1] */
127		for ( z = z0-1 ; z >= 0 ; z-- ) {
128			asm volatile("prefetchnta %0" : : "m" (dptr[z][d]));
129			asm volatile("pcmpgtb %mm4,%mm5");
130			asm volatile("pcmpgtb %mm6,%mm7");
131			asm volatile("paddb %mm4,%mm4");
132			asm volatile("paddb %mm6,%mm6");
133			asm volatile("pand %mm0,%mm5");
134			asm volatile("pand %mm0,%mm7");
135			asm volatile("pxor %mm5,%mm4");
136			asm volatile("pxor %mm7,%mm6");
137			asm volatile("movq %0,%%mm5" : : "m" (dptr[z][d]));
138			asm volatile("movq %0,%%mm7" : : "m" (dptr[z][d+8]));
139			asm volatile("pxor %mm5,%mm2");
140			asm volatile("pxor %mm7,%mm3");
141			asm volatile("pxor %mm5,%mm4");
142			asm volatile("pxor %mm7,%mm6");
143			asm volatile("pxor %mm5,%mm5");
144			asm volatile("pxor %mm7,%mm7");
145		}
146		asm volatile("movntq %%mm2,%0" : "=m" (p[d]));
147		asm volatile("movntq %%mm3,%0" : "=m" (p[d+8]));
148		asm volatile("movntq %%mm4,%0" : "=m" (q[d]));
149		asm volatile("movntq %%mm6,%0" : "=m" (q[d+8]));
150	}
151
152	asm volatile("sfence" : :: "memory");
153	kernel_fpu_end();
154}
155
156const struct raid6_calls raid6_sse1x2 = {
157	raid6_sse12_gen_syndrome,
158	NULL,			/* XOR not yet implemented */
159	raid6_have_sse1_or_mmxext,
160	"sse1x2",
161	1			/* Has cache hints */
162};
163
164#endif
165