1 /*
2 * linux/lib/raid6/neon.c - RAID6 syndrome calculation using ARM NEON intrinsics
3 *
4 * Copyright (C) 2013 Linaro Ltd <ard.biesheuvel@linaro.org>
5 *
6 * This program is free software; you can redistribute it and/or modify
7 * it under the terms of the GNU General Public License version 2 as
8 * published by the Free Software Foundation.
9 */
10
11 #include <linux/raid/pq.h>
12
13 #ifdef __KERNEL__
14 #include <asm/neon.h>
15 #else
16 #define kernel_neon_begin()
17 #define kernel_neon_end()
18 #define cpu_has_neon() (1)
19 #endif
20
21 /*
22 * There are 2 reasons these wrappers are kept in a separate compilation unit
23 * from the actual implementations in neonN.c (generated from neon.uc by
24 * unroll.awk):
25 * - the actual implementations use NEON intrinsics, and the GCC support header
26 * (arm_neon.h) is not fully compatible (type wise) with the kernel;
27 * - the neonN.c files are compiled with -mfpu=neon and optimization enabled,
28 * and we have to make sure that we never use *any* NEON/VFP instructions
29 * outside a kernel_neon_begin()/kernel_neon_end() pair.
30 */
31
32 #define RAID6_NEON_WRAPPER(_n) \
33 static void raid6_neon ## _n ## _gen_syndrome(int disks, \
34 size_t bytes, void **ptrs) \
35 { \
36 void raid6_neon ## _n ## _gen_syndrome_real(int, \
37 unsigned long, void**); \
38 kernel_neon_begin(); \
39 raid6_neon ## _n ## _gen_syndrome_real(disks, \
40 (unsigned long)bytes, ptrs); \
41 kernel_neon_end(); \
42 } \
43 static void raid6_neon ## _n ## _xor_syndrome(int disks, \
44 int start, int stop, \
45 size_t bytes, void **ptrs) \
46 { \
47 void raid6_neon ## _n ## _xor_syndrome_real(int, \
48 int, int, unsigned long, void**); \
49 kernel_neon_begin(); \
50 raid6_neon ## _n ## _xor_syndrome_real(disks, \
51 start, stop, (unsigned long)bytes, ptrs); \
52 kernel_neon_end(); \
53 } \
54 struct raid6_calls const raid6_neonx ## _n = { \
55 raid6_neon ## _n ## _gen_syndrome, \
56 raid6_neon ## _n ## _xor_syndrome, \
57 raid6_have_neon, \
58 "neonx" #_n, \
59 0 \
60 }
61
raid6_have_neon(void)62 static int raid6_have_neon(void)
63 {
64 return cpu_has_neon();
65 }
66
67 RAID6_NEON_WRAPPER(1);
68 RAID6_NEON_WRAPPER(2);
69 RAID6_NEON_WRAPPER(4);
70 RAID6_NEON_WRAPPER(8);
71