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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 | * 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 | * raid6altivec$#.c |
15 | * |
16 | * $#-way unrolled portable integer math RAID-6 instruction set |
17 | * |
18 | * This file is postprocessed using unroll.awk |
19 | * |
20 | * <benh> hpa: in process, |
21 | * you can just "steal" the vec unit with enable_kernel_altivec() (but |
22 | * bracked this with preempt_disable/enable or in a lock) |
23 | */ |
24 | |
25 | #include <linux/raid/pq.h> |
26 | |
27 | #ifdef CONFIG_ALTIVEC |
28 | |
29 | #include <altivec.h> |
30 | #ifdef __KERNEL__ |
31 | # include <asm/system.h> |
32 | # include <asm/cputable.h> |
33 | #endif |
34 | |
35 | /* |
36 | * This is the C data type to use. We use a vector of |
37 | * signed char so vec_cmpgt() will generate the right |
38 | * instruction. |
39 | */ |
40 | |
41 | typedef vector signed char unative_t; |
42 | |
43 | #define NBYTES(x) ((vector signed char) {x,x,x,x, x,x,x,x, x,x,x,x, x,x,x,x}) |
44 | #define NSIZE sizeof(unative_t) |
45 | |
46 | /* |
47 | * The SHLBYTE() operation shifts each byte left by 1, *not* |
48 | * rolling over into the next byte |
49 | */ |
50 | static inline __attribute_const__ unative_t SHLBYTE(unative_t v) |
51 | { |
52 | return vec_add(v,v); |
53 | } |
54 | |
55 | /* |
56 | * The MASK() operation returns 0xFF in any byte for which the high |
57 | * bit is 1, 0x00 for any byte for which the high bit is 0. |
58 | */ |
59 | static inline __attribute_const__ unative_t MASK(unative_t v) |
60 | { |
61 | unative_t zv = NBYTES(0); |
62 | |
63 | /* vec_cmpgt returns a vector bool char; thus the need for the cast */ |
64 | return (unative_t)vec_cmpgt(zv, v); |
65 | } |
66 | |
67 | |
68 | /* This is noinline to make damned sure that gcc doesn't move any of the |
69 | Altivec code around the enable/disable code */ |
70 | static void noinline |
71 | raid6_altivec$#_gen_syndrome_real(int disks, size_t bytes, void **ptrs) |
72 | { |
73 | u8 **dptr = (u8 **)ptrs; |
74 | u8 *p, *q; |
75 | int d, z, z0; |
76 | |
77 | unative_t wd$$, wq$$, wp$$, w1$$, w2$$; |
78 | unative_t x1d = NBYTES(0x1d); |
79 | |
80 | z0 = disks - 3; /* Highest data disk */ |
81 | p = dptr[z0+1]; /* XOR parity */ |
82 | q = dptr[z0+2]; /* RS syndrome */ |
83 | |
84 | for ( d = 0 ; d < bytes ; d += NSIZE*$# ) { |
85 | wq$$ = wp$$ = *(unative_t *)&dptr[z0][d+$$*NSIZE]; |
86 | for ( z = z0-1 ; z >= 0 ; z-- ) { |
87 | wd$$ = *(unative_t *)&dptr[z][d+$$*NSIZE]; |
88 | wp$$ = vec_xor(wp$$, wd$$); |
89 | w2$$ = MASK(wq$$); |
90 | w1$$ = SHLBYTE(wq$$); |
91 | w2$$ = vec_and(w2$$, x1d); |
92 | w1$$ = vec_xor(w1$$, w2$$); |
93 | wq$$ = vec_xor(w1$$, wd$$); |
94 | } |
95 | *(unative_t *)&p[d+NSIZE*$$] = wp$$; |
96 | *(unative_t *)&q[d+NSIZE*$$] = wq$$; |
97 | } |
98 | } |
99 | |
100 | static void raid6_altivec$#_gen_syndrome(int disks, size_t bytes, void **ptrs) |
101 | { |
102 | preempt_disable(); |
103 | enable_kernel_altivec(); |
104 | |
105 | raid6_altivec$#_gen_syndrome_real(disks, bytes, ptrs); |
106 | |
107 | preempt_enable(); |
108 | } |
109 | |
110 | int raid6_have_altivec(void); |
111 | #if $# == 1 |
112 | int raid6_have_altivec(void) |
113 | { |
114 | /* This assumes either all CPUs have Altivec or none does */ |
115 | # ifdef __KERNEL__ |
116 | return cpu_has_feature(CPU_FTR_ALTIVEC); |
117 | # else |
118 | return 1; |
119 | # endif |
120 | } |
121 | #endif |
122 | |
123 | const struct raid6_calls raid6_altivec$# = { |
124 | raid6_altivec$#_gen_syndrome, |
125 | raid6_have_altivec, |
126 | "altivecx$#", |
127 | 0 |
128 | }; |
129 | |
130 | #endif /* CONFIG_ALTIVEC */ |
131 |
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