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1 | /* -*- 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, | |
8 | * Bostom 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 | * raid6altivec$#.c | |
15 | * | |
16 | * $#-way unrolled portable integer math RAID-6 instruction set | |
17 | * | |
18 | * This file is postprocessed using unroll.pl | |
19 | * | |
20 | * <benh> hpa: in process, | |
21 | * you can just "steal" the vec unit with enable_kernel_altivec() (but | |
22 | * bracked this with preempt_disable/enable or in a lock) | |
23 | */ | |
24 | ||
25 | #include "raid6.h" | |
26 | ||
27 | #ifdef CONFIG_ALTIVEC | |
28 | ||
29 | #include <altivec.h> | |
30 | #include <asm/system.h> | |
31 | #include <asm/cputable.h> | |
32 | ||
33 | /* | |
34 | * This is the C data type to use | |
35 | */ | |
36 | ||
37 | typedef vector unsigned char unative_t; | |
38 | ||
39 | #define NBYTES(x) ((vector unsigned char) {x,x,x,x, x,x,x,x, x,x,x,x, x,x,x,x}) | |
40 | #define NSIZE sizeof(unative_t) | |
41 | ||
42 | /* | |
43 | * The SHLBYTE() operation shifts each byte left by 1, *not* | |
44 | * rolling over into the next byte | |
45 | */ | |
46 | static inline __attribute_const__ unative_t SHLBYTE(unative_t v) | |
47 | { | |
48 | return vec_add(v,v); | |
49 | } | |
50 | ||
51 | /* | |
52 | * The MASK() operation returns 0xFF in any byte for which the high | |
53 | * bit is 1, 0x00 for any byte for which the high bit is 0. | |
54 | */ | |
55 | static inline __attribute_const__ unative_t MASK(unative_t v) | |
56 | { | |
57 | unative_t zv = NBYTES(0); | |
58 | ||
59 | /* vec_cmpgt returns a vector bool char; thus the need for the cast */ | |
60 | return (unative_t)vec_cmpgt(zv, v); | |
61 | } | |
62 | ||
63 | ||
64 | /* This is noinline to make damned sure that gcc doesn't move any of the | |
65 | Altivec code around the enable/disable code */ | |
66 | static void noinline | |
67 | raid6_altivec$#_gen_syndrome_real(int disks, size_t bytes, void **ptrs) | |
68 | { | |
69 | u8 **dptr = (u8 **)ptrs; | |
70 | u8 *p, *q; | |
71 | int d, z, z0; | |
72 | ||
73 | unative_t wd$$, wq$$, wp$$, w1$$, w2$$; | |
74 | unative_t x1d = NBYTES(0x1d); | |
75 | ||
76 | z0 = disks - 3; /* Highest data disk */ | |
77 | p = dptr[z0+1]; /* XOR parity */ | |
78 | q = dptr[z0+2]; /* RS syndrome */ | |
79 | ||
80 | for ( d = 0 ; d < bytes ; d += NSIZE*$# ) { | |
81 | wq$$ = wp$$ = *(unative_t *)&dptr[z0][d+$$*NSIZE]; | |
82 | for ( z = z0-1 ; z >= 0 ; z-- ) { | |
83 | wd$$ = *(unative_t *)&dptr[z][d+$$*NSIZE]; | |
84 | wp$$ = vec_xor(wp$$, wd$$); | |
85 | w2$$ = MASK(wq$$); | |
86 | w1$$ = SHLBYTE(wq$$); | |
87 | w2$$ = vec_and(w2$$, x1d); | |
88 | w1$$ = vec_xor(w1$$, w2$$); | |
89 | wq$$ = vec_xor(w1$$, wd$$); | |
90 | } | |
91 | *(unative_t *)&p[d+NSIZE*$$] = wp$$; | |
92 | *(unative_t *)&q[d+NSIZE*$$] = wq$$; | |
93 | } | |
94 | } | |
95 | ||
96 | static void raid6_altivec$#_gen_syndrome(int disks, size_t bytes, void **ptrs) | |
97 | { | |
98 | preempt_disable(); | |
99 | enable_kernel_altivec(); | |
100 | ||
101 | raid6_altivec$#_gen_syndrome_real(disks, bytes, ptrs); | |
102 | ||
103 | preempt_enable(); | |
104 | } | |
105 | ||
106 | int raid6_have_altivec(void); | |
107 | #if $# == 1 | |
108 | int raid6_have_altivec(void) | |
109 | { | |
110 | /* This assumes either all CPUs have Altivec or none does */ | |
111 | return cpu_has_feature(CPU_FTR_ALTIVEC); | |
112 | } | |
113 | #endif | |
114 | ||
115 | const struct raid6_calls raid6_altivec$# = { | |
116 | raid6_altivec$#_gen_syndrome, | |
117 | raid6_have_altivec, | |
118 | "altivecx$#", | |
119 | 0 | |
120 | }; | |
121 | ||
122 | #endif /* CONFIG_ALTIVEC */ |