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Linus Torvalds1da177e2005-04-16 15:20:36 -07001/* -*- linux-c -*- ------------------------------------------------------- *
2 *
3 * Copyright 2002-2004 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,
Atsushi SAKAI93ed05e2009-03-31 14:57:37 +11008 * Boston MA 02111-1307, USA; either version 2 of the License, or
Linus Torvalds1da177e2005-04-16 15:20:36 -07009 * (at your option) any later version; incorporated herein by reference.
10 *
11 * ----------------------------------------------------------------------- */
12
13/*
14 * raid6altivec$#.c
15 *
16 * $#-way unrolled portable integer math RAID-6 instruction set
17 *
Vladimir Dronnikovdce3a7a2009-10-16 16:25:19 +110018 * This file is postprocessed using unroll.awk
Linus Torvalds1da177e2005-04-16 15:20:36 -070019 *
20 * <benh> hpa: in process,
21 * you can just "steal" the vec unit with enable_kernel_altivec() (but
22 * bracked this with preempt_disable/enable or in a lock)
23 */
24
Dan Williamsf701d582009-03-31 15:09:39 +110025#include <linux/raid/pq.h>
Linus Torvalds1da177e2005-04-16 15:20:36 -070026
Linus Torvalds1da177e2005-04-16 15:20:36 -070027#include <altivec.h>
H. Peter Anvind7e70ba2005-09-16 19:27:29 -070028#ifdef __KERNEL__
H. Peter Anvind7e70ba2005-09-16 19:27:29 -070029# include <asm/cputable.h>
David Howellsae3a1972012-03-28 18:30:02 +010030# include <asm/switch_to.h>
Linus Torvalds1da177e2005-04-16 15:20:36 -070031
32/*
H. Peter Anvind7e70ba2005-09-16 19:27:29 -070033 * This is the C data type to use. We use a vector of
34 * signed char so vec_cmpgt() will generate the right
35 * instruction.
Linus Torvalds1da177e2005-04-16 15:20:36 -070036 */
37
H. Peter Anvind7e70ba2005-09-16 19:27:29 -070038typedef vector signed char unative_t;
Linus Torvalds1da177e2005-04-16 15:20:36 -070039
H. Peter Anvind7e70ba2005-09-16 19:27:29 -070040#define NBYTES(x) ((vector signed char) {x,x,x,x, x,x,x,x, x,x,x,x, x,x,x,x})
Linus Torvalds1da177e2005-04-16 15:20:36 -070041#define NSIZE sizeof(unative_t)
42
43/*
44 * The SHLBYTE() operation shifts each byte left by 1, *not*
45 * rolling over into the next byte
46 */
47static inline __attribute_const__ unative_t SHLBYTE(unative_t v)
48{
49 return vec_add(v,v);
50}
51
52/*
53 * The MASK() operation returns 0xFF in any byte for which the high
54 * bit is 1, 0x00 for any byte for which the high bit is 0.
55 */
56static inline __attribute_const__ unative_t MASK(unative_t v)
57{
58 unative_t zv = NBYTES(0);
59
60 /* vec_cmpgt returns a vector bool char; thus the need for the cast */
61 return (unative_t)vec_cmpgt(zv, v);
62}
63
64
65/* This is noinline to make damned sure that gcc doesn't move any of the
66 Altivec code around the enable/disable code */
67static void noinline
68raid6_altivec$#_gen_syndrome_real(int disks, size_t bytes, void **ptrs)
69{
70 u8 **dptr = (u8 **)ptrs;
71 u8 *p, *q;
72 int d, z, z0;
73
74 unative_t wd$$, wq$$, wp$$, w1$$, w2$$;
75 unative_t x1d = NBYTES(0x1d);
76
77 z0 = disks - 3; /* Highest data disk */
78 p = dptr[z0+1]; /* XOR parity */
79 q = dptr[z0+2]; /* RS syndrome */
80
81 for ( d = 0 ; d < bytes ; d += NSIZE*$# ) {
82 wq$$ = wp$$ = *(unative_t *)&dptr[z0][d+$$*NSIZE];
83 for ( z = z0-1 ; z >= 0 ; z-- ) {
84 wd$$ = *(unative_t *)&dptr[z][d+$$*NSIZE];
85 wp$$ = vec_xor(wp$$, wd$$);
86 w2$$ = MASK(wq$$);
87 w1$$ = SHLBYTE(wq$$);
88 w2$$ = vec_and(w2$$, x1d);
89 w1$$ = vec_xor(w1$$, w2$$);
90 wq$$ = vec_xor(w1$$, wd$$);
91 }
92 *(unative_t *)&p[d+NSIZE*$$] = wp$$;
93 *(unative_t *)&q[d+NSIZE*$$] = wq$$;
94 }
95}
96
97static void raid6_altivec$#_gen_syndrome(int disks, size_t bytes, void **ptrs)
98{
99 preempt_disable();
100 enable_kernel_altivec();
101
102 raid6_altivec$#_gen_syndrome_real(disks, bytes, ptrs);
103
104 preempt_enable();
105}
106
107int raid6_have_altivec(void);
108#if $# == 1
109int raid6_have_altivec(void)
110{
111 /* This assumes either all CPUs have Altivec or none does */
H. Peter Anvind7e70ba2005-09-16 19:27:29 -0700112# ifdef __KERNEL__
Linus Torvalds1da177e2005-04-16 15:20:36 -0700113 return cpu_has_feature(CPU_FTR_ALTIVEC);
H. Peter Anvind7e70ba2005-09-16 19:27:29 -0700114# else
115 return 1;
116# endif
Linus Torvalds1da177e2005-04-16 15:20:36 -0700117}
118#endif
119
120const struct raid6_calls raid6_altivec$# = {
121 raid6_altivec$#_gen_syndrome,
122 raid6_have_altivec,
123 "altivecx$#",
124 0
125};
126
127#endif /* CONFIG_ALTIVEC */