GNU Linux-libre 4.4.284-gnu1
[releases.git] / lib / raid6 / neon.c
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
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);