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	struct raid6_calls const raid6_neonx ## _n = {			\
44		raid6_neon ## _n ## _gen_syndrome,			\
45		NULL,		/* XOR not yet implemented */		\
46		raid6_have_neon,					\
47		"neonx" #_n,						\
48		0							\
49	}
50
51static int raid6_have_neon(void)
52{
53	return cpu_has_neon();
54}
55
56RAID6_NEON_WRAPPER(1);
57RAID6_NEON_WRAPPER(2);
58RAID6_NEON_WRAPPER(4);
59RAID6_NEON_WRAPPER(8);
60