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 000000000000..237bf65ae886
--- /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 1.4 2004/10/22 15:41:47 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;
+}