From 8e4bff4cab0ddac6060645b0715210484d02ff40 Mon Sep 17 00:00:00 2001
From: Yuval Adam <_@yuv.al>
Date: Wed, 30 Aug 2017 08:25:59 +0000
Subject: Initial file dump from open source release

---
 include/linux/rslib.h | 109 ++++++++++++++++++++++++++++++++++++++++++++++++++
 1 file changed, 109 insertions(+)
 create mode 100644 include/linux/rslib.h

(limited to 'include/linux/rslib.h')

diff --git a/include/linux/rslib.h b/include/linux/rslib.h
new file mode 100644
index 00000000..746580c1
--- /dev/null
+++ b/include/linux/rslib.h
@@ -0,0 +1,109 @@
+/*
+ * 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 1.4 2005/11/07 11:14:52 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
+ * @gffunc:	Function to generate the field, if non-canonical representation
+ * @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		(*gffunc)(int);
+	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);
+struct rs_control *init_rs_non_canonical(int symsize, int (*func)(int),
+                                         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
-- 
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