xref: /OK3568_Linux_fs/kernel/lib/raid6/altivec.uc (revision 4882a59341e53eb6f0b4789bf948001014eff981)
1*4882a593Smuzhiyun/* -*- linux-c -*- ------------------------------------------------------- *
2*4882a593Smuzhiyun *
3*4882a593Smuzhiyun *   Copyright 2002-2004 H. Peter Anvin - All Rights Reserved
4*4882a593Smuzhiyun *
5*4882a593Smuzhiyun *   This program is free software; you can redistribute it and/or modify
6*4882a593Smuzhiyun *   it under the terms of the GNU General Public License as published by
7*4882a593Smuzhiyun *   the Free Software Foundation, Inc., 53 Temple Place Ste 330,
8*4882a593Smuzhiyun *   Boston MA 02111-1307, USA; either version 2 of the License, or
9*4882a593Smuzhiyun *   (at your option) any later version; incorporated herein by reference.
10*4882a593Smuzhiyun *
11*4882a593Smuzhiyun * ----------------------------------------------------------------------- */
12*4882a593Smuzhiyun
13*4882a593Smuzhiyun/*
14*4882a593Smuzhiyun * raid6altivec$#.c
15*4882a593Smuzhiyun *
16*4882a593Smuzhiyun * $#-way unrolled portable integer math RAID-6 instruction set
17*4882a593Smuzhiyun *
18*4882a593Smuzhiyun * This file is postprocessed using unroll.awk
19*4882a593Smuzhiyun *
20*4882a593Smuzhiyun * <benh> hpa: in process,
21*4882a593Smuzhiyun * you can just "steal" the vec unit with enable_kernel_altivec() (but
22*4882a593Smuzhiyun * bracked this with preempt_disable/enable or in a lock)
23*4882a593Smuzhiyun */
24*4882a593Smuzhiyun
25*4882a593Smuzhiyun#include <linux/raid/pq.h>
26*4882a593Smuzhiyun
27*4882a593Smuzhiyun#ifdef CONFIG_ALTIVEC
28*4882a593Smuzhiyun
29*4882a593Smuzhiyun#include <altivec.h>
30*4882a593Smuzhiyun#ifdef __KERNEL__
31*4882a593Smuzhiyun# include <asm/cputable.h>
32*4882a593Smuzhiyun# include <asm/switch_to.h>
33*4882a593Smuzhiyun#endif /* __KERNEL__ */
34*4882a593Smuzhiyun
35*4882a593Smuzhiyun/*
36*4882a593Smuzhiyun * This is the C data type to use.  We use a vector of
37*4882a593Smuzhiyun * signed char so vec_cmpgt() will generate the right
38*4882a593Smuzhiyun * instruction.
39*4882a593Smuzhiyun */
40*4882a593Smuzhiyun
41*4882a593Smuzhiyuntypedef vector signed char unative_t;
42*4882a593Smuzhiyun
43*4882a593Smuzhiyun#define NBYTES(x) ((vector signed char) {x,x,x,x, x,x,x,x, x,x,x,x, x,x,x,x})
44*4882a593Smuzhiyun#define NSIZE	sizeof(unative_t)
45*4882a593Smuzhiyun
46*4882a593Smuzhiyun/*
47*4882a593Smuzhiyun * The SHLBYTE() operation shifts each byte left by 1, *not*
48*4882a593Smuzhiyun * rolling over into the next byte
49*4882a593Smuzhiyun */
50*4882a593Smuzhiyunstatic inline __attribute_const__ unative_t SHLBYTE(unative_t v)
51*4882a593Smuzhiyun{
52*4882a593Smuzhiyun	return vec_add(v,v);
53*4882a593Smuzhiyun}
54*4882a593Smuzhiyun
55*4882a593Smuzhiyun/*
56*4882a593Smuzhiyun * The MASK() operation returns 0xFF in any byte for which the high
57*4882a593Smuzhiyun * bit is 1, 0x00 for any byte for which the high bit is 0.
58*4882a593Smuzhiyun */
59*4882a593Smuzhiyunstatic inline __attribute_const__ unative_t MASK(unative_t v)
60*4882a593Smuzhiyun{
61*4882a593Smuzhiyun	unative_t zv = NBYTES(0);
62*4882a593Smuzhiyun
63*4882a593Smuzhiyun	/* vec_cmpgt returns a vector bool char; thus the need for the cast */
64*4882a593Smuzhiyun	return (unative_t)vec_cmpgt(zv, v);
65*4882a593Smuzhiyun}
66*4882a593Smuzhiyun
67*4882a593Smuzhiyun
68*4882a593Smuzhiyun/* This is noinline to make damned sure that gcc doesn't move any of the
69*4882a593Smuzhiyun   Altivec code around the enable/disable code */
70*4882a593Smuzhiyunstatic void noinline
71*4882a593Smuzhiyunraid6_altivec$#_gen_syndrome_real(int disks, size_t bytes, void **ptrs)
72*4882a593Smuzhiyun{
73*4882a593Smuzhiyun	u8 **dptr = (u8 **)ptrs;
74*4882a593Smuzhiyun	u8 *p, *q;
75*4882a593Smuzhiyun	int d, z, z0;
76*4882a593Smuzhiyun
77*4882a593Smuzhiyun	unative_t wd$$, wq$$, wp$$, w1$$, w2$$;
78*4882a593Smuzhiyun	unative_t x1d = NBYTES(0x1d);
79*4882a593Smuzhiyun
80*4882a593Smuzhiyun	z0 = disks - 3;		/* Highest data disk */
81*4882a593Smuzhiyun	p = dptr[z0+1];		/* XOR parity */
82*4882a593Smuzhiyun	q = dptr[z0+2];		/* RS syndrome */
83*4882a593Smuzhiyun
84*4882a593Smuzhiyun	for ( d = 0 ; d < bytes ; d += NSIZE*$# ) {
85*4882a593Smuzhiyun		wq$$ = wp$$ = *(unative_t *)&dptr[z0][d+$$*NSIZE];
86*4882a593Smuzhiyun		for ( z = z0-1 ; z >= 0 ; z-- ) {
87*4882a593Smuzhiyun			wd$$ = *(unative_t *)&dptr[z][d+$$*NSIZE];
88*4882a593Smuzhiyun			wp$$ = vec_xor(wp$$, wd$$);
89*4882a593Smuzhiyun			w2$$ = MASK(wq$$);
90*4882a593Smuzhiyun			w1$$ = SHLBYTE(wq$$);
91*4882a593Smuzhiyun			w2$$ = vec_and(w2$$, x1d);
92*4882a593Smuzhiyun			w1$$ = vec_xor(w1$$, w2$$);
93*4882a593Smuzhiyun			wq$$ = vec_xor(w1$$, wd$$);
94*4882a593Smuzhiyun		}
95*4882a593Smuzhiyun		*(unative_t *)&p[d+NSIZE*$$] = wp$$;
96*4882a593Smuzhiyun		*(unative_t *)&q[d+NSIZE*$$] = wq$$;
97*4882a593Smuzhiyun	}
98*4882a593Smuzhiyun}
99*4882a593Smuzhiyun
100*4882a593Smuzhiyunstatic void raid6_altivec$#_gen_syndrome(int disks, size_t bytes, void **ptrs)
101*4882a593Smuzhiyun{
102*4882a593Smuzhiyun	preempt_disable();
103*4882a593Smuzhiyun	enable_kernel_altivec();
104*4882a593Smuzhiyun
105*4882a593Smuzhiyun	raid6_altivec$#_gen_syndrome_real(disks, bytes, ptrs);
106*4882a593Smuzhiyun
107*4882a593Smuzhiyun	disable_kernel_altivec();
108*4882a593Smuzhiyun	preempt_enable();
109*4882a593Smuzhiyun}
110*4882a593Smuzhiyun
111*4882a593Smuzhiyunint raid6_have_altivec(void);
112*4882a593Smuzhiyun#if $# == 1
113*4882a593Smuzhiyunint raid6_have_altivec(void)
114*4882a593Smuzhiyun{
115*4882a593Smuzhiyun	/* This assumes either all CPUs have Altivec or none does */
116*4882a593Smuzhiyun# ifdef __KERNEL__
117*4882a593Smuzhiyun	return cpu_has_feature(CPU_FTR_ALTIVEC);
118*4882a593Smuzhiyun# else
119*4882a593Smuzhiyun	return 1;
120*4882a593Smuzhiyun# endif
121*4882a593Smuzhiyun}
122*4882a593Smuzhiyun#endif
123*4882a593Smuzhiyun
124*4882a593Smuzhiyunconst struct raid6_calls raid6_altivec$# = {
125*4882a593Smuzhiyun	raid6_altivec$#_gen_syndrome,
126*4882a593Smuzhiyun	NULL,			/* XOR not yet implemented */
127*4882a593Smuzhiyun	raid6_have_altivec,
128*4882a593Smuzhiyun	"altivecx$#",
129*4882a593Smuzhiyun	0
130*4882a593Smuzhiyun};
131*4882a593Smuzhiyun
132*4882a593Smuzhiyun#endif /* CONFIG_ALTIVEC */
133