1 files changed, 105 insertions, 0 deletions

diff --git a/include/linux/rslib.h b/include/linux/rslib.h
new file mode 100644
index 000000000000..980c8f74d8dc
--- /dev/null
+++ b/include/linux/rslib.h
@@ -0,0 +1,105 @@
+/* 
+ * include/linux/rslib.h
+ *
+ * Overview:
+ *   Generic Reed Solomon encoder / decoder library
+ *   
+ * Copyright (C) 2004 Thomas Gleixner (tglx@linutronix.de)
+ *
+ * RS code lifted from reed solomon library written by Phil Karn
+ * Copyright 2002 Phil Karn, KA9Q
+ *
+ * $Id: rslib.h,v 1.3 2004/10/05 22:08:22 gleixner Exp $
+ *
+ * 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.
+ */
+
+#ifndef _RSLIB_H_
+#define _RSLIB_H_
+
+#include <linux/list.h>
+
+/** 
+ * struct rs_control - rs control structure
+ * 
+ * @mm:         Bits per symbol
+ * @nn:         Symbols per block (= (1<<mm)-1)
+ * @alpha_to:   log lookup table
+ * @index_of:   Antilog lookup table
+ * @genpoly:    Generator polynomial 
+ * @nroots:     Number of generator roots = number of parity symbols
+ * @fcr:        First consecutive root, index form
+ * @prim:       Primitive element, index form 
+ * @iprim:      prim-th root of 1, index form 
+ * @gfpoly:     The primitive generator polynominal 
+ * @users:      Users of this structure 
+ * @list:       List entry for the rs control list
+*/
+struct rs_control {
+        int             mm;
+        int             nn;
+        uint16_t        *alpha_to;
+        uint16_t        *index_of;
+        uint16_t        *genpoly;
+        int             nroots;
+        int             fcr;
+        int             prim;
+        int             iprim;
+        int             gfpoly;
+        int             users;
+        struct list_head list;
+};
+
+/* General purpose RS codec, 8-bit data width, symbol width 1-15 bit  */
+#ifdef CONFIG_REED_SOLOMON_ENC8
+int encode_rs8(struct rs_control *rs, uint8_t *data, int len, uint16_t *par,
+               uint16_t invmsk);
+#endif
+#ifdef CONFIG_REED_SOLOMON_DEC8
+int decode_rs8(struct rs_control *rs, uint8_t *data, uint16_t *par, int len, 
+                uint16_t *s, int no_eras, int *eras_pos, uint16_t invmsk,
+               uint16_t *corr);
+#endif
+
+/* General purpose RS codec, 16-bit data width, symbol width 1-15 bit  */
+#ifdef CONFIG_REED_SOLOMON_ENC16
+int encode_rs16(struct rs_control *rs, uint16_t *data, int len, uint16_t *par,
+                uint16_t invmsk);
+#endif
+#ifdef CONFIG_REED_SOLOMON_DEC16
+int decode_rs16(struct rs_control *rs, uint16_t *data, uint16_t *par, int len,
+                uint16_t *s, int no_eras, int *eras_pos, uint16_t invmsk,
+                uint16_t *corr);
+#endif
+
+/* Create or get a matching rs control structure */
+struct rs_control *init_rs(int symsize, int gfpoly, int fcr, int prim, 
+                           int nroots);
+
+/* Release a rs control structure */
+void free_rs(struct rs_control *rs);
+
+/** modulo replacement for galois field arithmetics
+ *
+ *  @rs:        the rs control structure
+ *  @x:         the value to reduce
+ *
+ *  where
+ *  rs->mm = number of bits per symbol  
+ *  rs->nn = (2^rs->mm) - 1
+ *  
+ *  Simple arithmetic modulo would return a wrong result for values
+ *  >= 3 * rs->nn
+*/
+static inline int rs_modnn(struct rs_control *rs, int x)
+{
+        while (x >= rs->nn) {
+                x -= rs->nn;
+                x = (x >> rs->mm) + (x & rs->nn);
+        }
+        return x;
+}
+
+#endif