Merge tag 'md/4.3' of git://neil.brown.name/md

Pull md updates from Neil Brown:

 - an assortment of little fixes, several for minor races only likely to
   be hit during testing

 - further cluster-md-raid1 development, not ready for real use yet.

 - new RAID6 syndrome code for ARM NEON

 - fix a race where a write can return before failure of one device is
   properly recorded in metadata, so an immediate crash might result in
   that write being lost.

* tag 'md/4.3' of git://neil.brown.name/md: (33 commits)
  md/raid5: ensure device failure recorded before write request returns.
  md/raid5: use bio_list for the list of bios to return.
  md/raid10: ensure device failure recorded before write request returns.
  md/raid1: ensure device failure recorded before write request returns.
  md-cluster: remove inappropriate try_module_get from join()
  md: extend spinlock protection in register_md_cluster_operations
  md-cluster: Read the disk bitmap sb and check if it needs recovery
  md-cluster: only call complete(&cinfo->completion) when node join cluster
  md-cluster: add missed lockres_free
  md-cluster: remove the unused sb_lock
  md-cluster: init suspend_list and suspend_lock early in join
  md-cluster: add the error check if failed to get dlm lock
  md-cluster: init completion within lockres_init
  md-cluster: fix deadlock issue on message lock
  md-cluster: transfer the resync ownership to another node
  md-cluster: split recover_slot for future code reuse
  md-cluster: use %pU to print UUIDs
  md: setup safemode_timer before it's being used
  md/raid5: handle possible race as reshape completes.
  md: sync sync_completed has correct value as recovery finishes.
  ...

2 files changed, 58 insertions, 1 deletions

diff --git a/lib/raid6/neon.c b/lib/raid6/neon.c
index d9ad6ee..7076ef1 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 1b9ed79..4fa51b7 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$$);
+	}
+}