2 files changed, 58 insertions, 1 deletions

diff --git a/lib/raid6/neon.c b/lib/raid6/neon.c
index d9ad6ee284f4..7076ef1ba3dd 100644
--- a/lib/raid6/neon.c
+++ b/lib/raid6/neon.c
@@ -40,9 +40,20 @@
                                         (unsigned long)bytes, ptrs);    \
                 kernel_neon_end();                                      \
         }                                                               \
+        static void raid6_neon ## _n ## _xor_syndrome(int disks,        \
+                                        int start, int stop,            \
+                                        size_t bytes, void **ptrs)      \
+        {                                                               \
+                void raid6_neon ## _n  ## _xor_syndrome_real(int,       \
+                                int, int, unsigned long, void**);       \
+                kernel_neon_begin();                                    \
+                raid6_neon ## _n ## _xor_syndrome_real(disks,           \
+                        start, stop, (unsigned long)bytes, ptrs);       \
+                kernel_neon_end();                                      \
+        }                                                               \
         struct raid6_calls const raid6_neonx ## _n = {                  \
                 raid6_neon ## _n ## _gen_syndrome,                      \
-                NULL,           /* XOR not yet implemented */           \
+                raid6_neon ## _n ## _xor_syndrome,                      \
                 raid6_have_neon,                                        \
                 "neonx" #_n,                                            \
                 0                                                       \
diff --git a/lib/raid6/neon.uc b/lib/raid6/neon.uc
index 1b9ed793342d..4fa51b761dd0 100644
--- a/lib/raid6/neon.uc
+++ b/lib/raid6/neon.uc
@@ -3,6 +3,7 @@
  *   neon.uc - RAID-6 syndrome calculation using ARM NEON instructions
  *
  *   Copyright (C) 2012 Rob Herring
+ *   Copyright (C) 2015 Linaro Ltd. <ard.biesheuvel@linaro.org>
  *
  *   Based on altivec.uc:
  *     Copyright 2002-2004 H. Peter Anvin - All Rights Reserved
@@ -78,3 +79,48 @@ void raid6_neon$#_gen_syndrome_real(int disks, unsigned long bytes, void **ptrs)
                 vst1q_u8(&q[d+NSIZE*$$], wq$$);
         }
 }
+
+void raid6_neon$#_xor_syndrome_real(int disks, int start, int stop,
+                                    unsigned long bytes, void **ptrs)
+{
+        uint8_t **dptr = (uint8_t **)ptrs;
+        uint8_t *p, *q;
+        int d, z, z0;
+
+        register unative_t wd$$, wq$$, wp$$, w1$$, w2$$;
+        const unative_t x1d = NBYTES(0x1d);
+
+        z0 = stop;              /* P/Q right side optimization */
+        p = dptr[disks-2];      /* XOR parity */
+        q = dptr[disks-1];      /* RS syndrome */
+
+        for ( d = 0 ; d < bytes ; d += NSIZE*$# ) {
+                wq$$ = vld1q_u8(&dptr[z0][d+$$*NSIZE]);
+                wp$$ = veorq_u8(vld1q_u8(&p[d+$$*NSIZE]), wq$$);
+
+                /* P/Q data pages */
+                for ( z = z0-1 ; z >= start ; z-- ) {
+                        wd$$ = vld1q_u8(&dptr[z][d+$$*NSIZE]);
+                        wp$$ = veorq_u8(wp$$, wd$$);
+                        w2$$ = MASK(wq$$);
+                        w1$$ = SHLBYTE(wq$$);
+
+                        w2$$ = vandq_u8(w2$$, x1d);
+                        w1$$ = veorq_u8(w1$$, w2$$);
+                        wq$$ = veorq_u8(w1$$, wd$$);
+                }
+                /* P/Q left side optimization */
+                for ( z = start-1 ; z >= 0 ; z-- ) {
+                        w2$$ = MASK(wq$$);
+                        w1$$ = SHLBYTE(wq$$);
+
+                        w2$$ = vandq_u8(w2$$, x1d);
+                        wq$$ = veorq_u8(w1$$, w2$$);
+                }
+                w1$$ = vld1q_u8(&q[d+NSIZE*$$]);
+                wq$$ = veorq_u8(wq$$, w1$$);
+
+                vst1q_u8(&p[d+NSIZE*$$], wp$$);
+                vst1q_u8(&q[d+NSIZE*$$], wq$$);
+        }
+}