1 files changed, 39 insertions, 1 deletions

diff --git a/lib/raid6/int.uc b/lib/raid6/int.uc
index 5ca60bee1388..558aeac9342a 100644
--- a/lib/raid6/int.uc
+++ b/lib/raid6/int.uc
@@ -107,9 +107,47 @@ static void raid6_int$#_gen_syndrome(int disks, size_t bytes, void **ptrs)
         }
 }
 
+static void raid6_int$#_xor_syndrome(int disks, int start, int stop,
+                                     size_t bytes, void **ptrs)
+{
+        u8 **dptr = (u8 **)ptrs;
+        u8 *p, *q;
+        int d, z, z0;
+
+        unative_t wd$$, wq$$, wp$$, w1$$, w2$$;
+
+        z0 = stop;              /* P/Q right side optimization */
+        p = dptr[disks-2];      /* XOR parity */
+        q = dptr[disks-1];      /* RS syndrome */
+
+        for ( d = 0 ; d < bytes ; d += NSIZE*$# ) {
+                /* P/Q data pages */
+                wq$$ = wp$$ = *(unative_t *)&dptr[z0][d+$$*NSIZE];
+                for ( z = z0-1 ; z >= start ; z-- ) {
+                        wd$$ = *(unative_t *)&dptr[z][d+$$*NSIZE];
+                        wp$$ ^= wd$$;
+                        w2$$ = MASK(wq$$);
+                        w1$$ = SHLBYTE(wq$$);
+                        w2$$ &= NBYTES(0x1d);
+                        w1$$ ^= w2$$;
+                        wq$$ = w1$$ ^ wd$$;
+                }
+                /* P/Q left side optimization */
+                for ( z = start-1 ; z >= 0 ; z-- ) {
+                        w2$$ = MASK(wq$$);
+                        w1$$ = SHLBYTE(wq$$);
+                        w2$$ &= NBYTES(0x1d);
+                        wq$$ = w1$$ ^ w2$$;
+                }
+                *(unative_t *)&p[d+NSIZE*$$] ^= wp$$;
+                *(unative_t *)&q[d+NSIZE*$$] ^= wq$$;
+        }
+
+}
+
 const struct raid6_calls raid6_intx$# = {
         raid6_int$#_gen_syndrome,
-        NULL,                   /* XOR not yet implemented */
+        raid6_int$#_xor_syndrome,
         NULL,                   /* always valid */
         "int" NSTRING "x$#",
         0