xref: /openbmc/linux/lib/raid6/neon.c (revision 7bcae826)
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);
71