Initial import

1 files changed, 54 insertions, 0 deletions

diff --git a/lib/reed_solomon/encode_rs.c b/lib/reed_solomon/encode_rs.c
new file mode 100644
index 000000000..0b5b1a672
--- /dev/null
+++ b/lib/reed_solomon/encode_rs.c
@@ -0,0 +1,54 @@
+/*
+ * lib/reed_solomon/encode_rs.c
+ *
+ * Overview:
+ *   Generic Reed Solomon encoder / decoder library
+ *
+ * Copyright 2002, Phil Karn, KA9Q
+ * May be used under the terms of the GNU General Public License (GPL)
+ *
+ * Adaption to the kernel by Thomas Gleixner (tglx@linutronix.de)
+ *
+ * $Id: encode_rs.c,v 1.5 2005/11/07 11:14:59 gleixner Exp $
+ *
+ */
+
+/* Generic data width independent code which is included by the
+ * wrappers.
+ * int encode_rsX (struct rs_control *rs, uintX_t *data, int len, uintY_t *par)
+ */
+{
+	int i, j, pad;
+	int nn = rs->nn;
+	int nroots = rs->nroots;
+	uint16_t *alpha_to = rs->alpha_to;
+	uint16_t *index_of = rs->index_of;
+	uint16_t *genpoly = rs->genpoly;
+	uint16_t fb;
+	uint16_t msk = (uint16_t) rs->nn;
+
+	/* Check length parameter for validity */
+	pad = nn - nroots - len;
+	if (pad < 0 || pad >= nn)
+		return -ERANGE;
+
+	for (i = 0; i < len; i++) {
+		fb = index_of[((((uint16_t) data[i])^invmsk) & msk) ^ par[0]];
+		/* feedback term is non-zero */
+		if (fb != nn) {
+			for (j = 1; j < nroots; j++) {
+				par[j] ^= alpha_to[rs_modnn(rs, fb +
+							 genpoly[nroots - j])];
+			}
+		}
+		/* Shift */
+		memmove(&par[0], &par[1], sizeof(uint16_t) * (nroots - 1));
+		if (fb != nn) {
+			par[nroots - 1] = alpha_to[rs_modnn(rs,
+							    fb + genpoly[0])];
+		} else {
+			par[nroots - 1] = 0;
+		}
+	}
+	return 0;
+}