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lib/raid6/neon.c 2.13 KB
81f7e3824   Eric Lee   Initial Release, ...
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  /*
   * linux/lib/raid6/neon.c - RAID6 syndrome calculation using ARM NEON intrinsics
   *
   * Copyright (C) 2013 Linaro Ltd <ard.biesheuvel@linaro.org>
   *
   * This program is free software; you can redistribute it and/or modify
   * it under the terms of the GNU General Public License version 2 as
   * published by the Free Software Foundation.
   */
  
  #include <linux/raid/pq.h>
  
  #ifdef __KERNEL__
  #include <asm/neon.h>
  #else
  #define kernel_neon_begin()
  #define kernel_neon_end()
  #define cpu_has_neon()		(1)
  #endif
  
  /*
   * There are 2 reasons these wrappers are kept in a separate compilation unit
   * from the actual implementations in neonN.c (generated from neon.uc by
   * unroll.awk):
   * - the actual implementations use NEON intrinsics, and the GCC support header
   *   (arm_neon.h) is not fully compatible (type wise) with the kernel;
   * - the neonN.c files are compiled with -mfpu=neon and optimization enabled,
   *   and we have to make sure that we never use *any* NEON/VFP instructions
   *   outside a kernel_neon_begin()/kernel_neon_end() pair.
   */
  
  #define RAID6_NEON_WRAPPER(_n)						\
  	static void raid6_neon ## _n ## _gen_syndrome(int disks,	\
  					size_t bytes, void **ptrs)	\
  	{								\
  		void raid6_neon ## _n  ## _gen_syndrome_real(int,	\
  						unsigned long, void**);	\
  		kernel_neon_begin();					\
  		raid6_neon ## _n ## _gen_syndrome_real(disks,		\
  					(unsigned long)bytes, ptrs);	\
  		kernel_neon_end();					\
  	}								\
  	static void raid6_neon ## _n ## _xor_syndrome(int disks,	\
  					int start, int stop, 		\
  					size_t bytes, void **ptrs)	\
  	{								\
  		void raid6_neon ## _n  ## _xor_syndrome_real(int,	\
  				int, int, unsigned long, void**);	\
  		kernel_neon_begin();					\
  		raid6_neon ## _n ## _xor_syndrome_real(disks,		\
  			start, stop, (unsigned long)bytes, ptrs);	\
  		kernel_neon_end();					\
  	}								\
  	struct raid6_calls const raid6_neonx ## _n = {			\
  		raid6_neon ## _n ## _gen_syndrome,			\
  		raid6_neon ## _n ## _xor_syndrome,			\
  		raid6_have_neon,					\
  		"neonx" #_n,						\
  		0							\
  	}
  
  static int raid6_have_neon(void)
  {
  	return cpu_has_neon();
  }
  
  RAID6_NEON_WRAPPER(1);
  RAID6_NEON_WRAPPER(2);
  RAID6_NEON_WRAPPER(4);
  RAID6_NEON_WRAPPER(8);