/* -*- linux-c -*- ------------------------------------------------------- *
   *
   *   Copyright 2002-2004 H. Peter Anvin - All Rights Reserved
   *
   *   This program is free software; you can redistribute it and/or modify
   *   it under the terms of the GNU General Public License as published by
   *   the Free Software Foundation, Inc., 53 Temple Place Ste 330,

   *   Boston MA 02111-1307, USA; either version 2 of the License, or

   *   (at your option) any later version; incorporated herein by reference.
   *
   * ----------------------------------------------------------------------- */
  
  /*

   * int$#.c

   *
   * $#-way unrolled portable integer math RAID-6 instruction set
   *

   * This file is postprocessed using unroll.awk

   */

  #include <linux/raid/pq.h>

  
  /*
   * This is the C data type to use
   */
  
  /* Change this from BITS_PER_LONG if there is something better... */
  #if BITS_PER_LONG == 64
  # define NBYTES(x) ((x) * 0x0101010101010101UL)
  # define NSIZE  8
  # define NSHIFT 3
  # define NSTRING "64"
  typedef u64 unative_t;
  #else
  # define NBYTES(x) ((x) * 0x01010101U)
  # define NSIZE  4
  # define NSHIFT 2
  # define NSTRING "32"
  typedef u32 unative_t;
  #endif
  
  
  
  /*
   * IA-64 wants insane amounts of unrolling.  On other architectures that
   * is just a waste of space.
   */
  #if ($# <= 8) || defined(__ia64__)
  
  
  /*
   * These sub-operations are separate inlines since they can sometimes be
   * specially optimized using architecture-specific hacks.
   */
  
  /*
   * The SHLBYTE() operation shifts each byte left by 1, *not*
   * rolling over into the next byte
   */
  static inline __attribute_const__ unative_t SHLBYTE(unative_t v)
  {
  	unative_t vv;
  
  	vv = (v << 1) & NBYTES(0xfe);
  	return vv;
  }
  
  /*
   * The MASK() operation returns 0xFF in any byte for which the high
   * bit is 1, 0x00 for any byte for which the high bit is 0.
   */
  static inline __attribute_const__ unative_t MASK(unative_t v)
  {
  	unative_t vv;
  
  	vv = v & NBYTES(0x80);
  	vv = (vv << 1) - (vv >> 7); /* Overflow on the top bit is OK */
  	return vv;
  }
  
  
  static void raid6_int$#_gen_syndrome(int disks, size_t bytes, void **ptrs)
  {
  	u8 **dptr = (u8 **)ptrs;
  	u8 *p, *q;
  	int d, z, z0;
  
  	unative_t wd$$, wq$$, wp$$, w1$$, w2$$;
  
  	z0 = disks - 3;		/* Highest data disk */
  	p = dptr[z0+1];		/* XOR parity */
  	q = dptr[z0+2];		/* RS syndrome */
  
  	for ( d = 0 ; d < bytes ; d += NSIZE*$# ) {
  		wq$$ = wp$$ = *(unative_t *)&dptr[z0][d+$$*NSIZE];
  		for ( z = z0-1 ; z >= 0 ; z-- ) {
  			wd$$ = *(unative_t *)&dptr[z][d+$$*NSIZE];
  			wp$$ ^= wd$$;
  			w2$$ = MASK(wq$$);
  			w1$$ = SHLBYTE(wq$$);
  			w2$$ &= NBYTES(0x1d);
  			w1$$ ^= w2$$;
  			wq$$ = w1$$ ^ wd$$;
  		}
  		*(unative_t *)&p[d+NSIZE*$$] = wp$$;
  		*(unative_t *)&q[d+NSIZE*$$] = wq$$;
  	}
  }

  static void raid6_int$#_xor_syndrome(int disks, int start, int stop,
  				     size_t bytes, void **ptrs)
  {
  	u8 **dptr = (u8 **)ptrs;
  	u8 *p, *q;
  	int d, z, z0;
  
  	unative_t wd$$, wq$$, wp$$, w1$$, w2$$;
  
  	z0 = stop;		/* P/Q right side optimization */
  	p = dptr[disks-2];	/* XOR parity */
  	q = dptr[disks-1];	/* RS syndrome */
  
  	for ( d = 0 ; d < bytes ; d += NSIZE*$# ) {
  		/* P/Q data pages */
  		wq$$ = wp$$ = *(unative_t *)&dptr[z0][d+$$*NSIZE];
  		for ( z = z0-1 ; z >= start ; z-- ) {
  			wd$$ = *(unative_t *)&dptr[z][d+$$*NSIZE];
  			wp$$ ^= wd$$;
  			w2$$ = MASK(wq$$);
  			w1$$ = SHLBYTE(wq$$);
  			w2$$ &= NBYTES(0x1d);
  			w1$$ ^= w2$$;
  			wq$$ = w1$$ ^ wd$$;
  		}
  		/* P/Q left side optimization */
  		for ( z = start-1 ; z >= 0 ; z-- ) {
  			w2$$ = MASK(wq$$);
  			w1$$ = SHLBYTE(wq$$);
  			w2$$ &= NBYTES(0x1d);
  			wq$$ = w1$$ ^ w2$$;
  		}
  		*(unative_t *)&p[d+NSIZE*$$] ^= wp$$;
  		*(unative_t *)&q[d+NSIZE*$$] ^= wq$$;
  	}
  
  }

  const struct raid6_calls raid6_intx$# = {
  	raid6_int$#_gen_syndrome,

  	raid6_int$#_xor_syndrome,

  	NULL,			/* always valid */

  	"int" NSTRING "x$#",
  	0
  };
  
  #endif