lib/raid6: add ARM-NEON accelerated syndrome calculation

[linux-2.6-microblaze.git] / lib / raid6 / neon.uc

diff --git a/lib/raid6/neon.uc b/lib/raid6/neon.uc
new file mode 100644 (file)
index 0000000..1b9ed79
--- /dev/null
+++ b/lib/raid6/neon.uc
@@ -0,0 +1,80 @@
+/* -----------------------------------------------------------------------
+ *
+ *   neon.uc - RAID-6 syndrome calculation using ARM NEON instructions
+ *
+ *   Copyright (C) 2012 Rob Herring
+ *
+ *   Based on altivec.uc:
+ *     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.
+ *
+ * ----------------------------------------------------------------------- */
+
+/*
+ * neon$#.c
+ *
+ * $#-way unrolled NEON intrinsics math RAID-6 instruction set
+ *
+ * This file is postprocessed using unroll.awk
+ */
+
+#include <arm_neon.h>
+
+typedef uint8x16_t unative_t;
+
+#define NBYTES(x) ((unative_t){x,x,x,x, x,x,x,x, x,x,x,x, x,x,x,x})
+#define NSIZE  sizeof(unative_t)
+
+/*
+ * The SHLBYTE() operation shifts each byte left by 1, *not*
+ * rolling over into the next byte
+ */
+static inline unative_t SHLBYTE(unative_t v)
+{
+       return vshlq_n_u8(v, 1);
+}
+
+/*
+ * The MASK() operation returns 0xFF in any byte for which the high
+ * bit is 1, 0x00 for any byte for which the high bit is 0.
+ */
+static inline unative_t MASK(unative_t v)
+{
+       const uint8x16_t temp = NBYTES(0);
+       return (unative_t)vcltq_s8((int8x16_t)v, (int8x16_t)temp);
+}
+
+void raid6_neon$#_gen_syndrome_real(int disks, unsigned long bytes, void **ptrs)
+{
+       uint8_t **dptr = (uint8_t **)ptrs;
+       uint8_t *p, *q;
+       int d, z, z0;
+
+       register unative_t wd$$, wq$$, wp$$, w1$$, w2$$;
+       const unative_t x1d = NBYTES(0x1d);
+
+       z0 = disks - 3;         /* Highest data disk */
+       p = dptr[z0+1];         /* XOR parity */
+       q = dptr[z0+2];         /* RS syndrome */
+
+       for ( d = 0 ; d < bytes ; d += NSIZE*$# ) {
+               wq$$ = wp$$ = vld1q_u8(&dptr[z0][d+$$*NSIZE]);
+               for ( z = z0-1 ; z >= 0 ; z-- ) {
+                       wd$$ = vld1q_u8(&dptr[z][d+$$*NSIZE]);
+                       wp$$ = veorq_u8(wp$$, wd$$);
+                       w2$$ = MASK(wq$$);
+                       w1$$ = SHLBYTE(wq$$);
+
+                       w2$$ = vandq_u8(w2$$, x1d);
+                       w1$$ = veorq_u8(w1$$, w2$$);
+                       wq$$ = veorq_u8(w1$$, wd$$);
+               }
+               vst1q_u8(&p[d+NSIZE*$$], wp$$);
+               vst1q_u8(&q[d+NSIZE*$$], wq$$);
+       }
+}