md/raid6: move raid6 data processing to raid6_pq.ko

Move the raid6 data processing routines into a standalone module
(raid6_pq) to prepare them to be called from async_tx wrappers and other
non-md drivers/modules.  This precludes a circular dependency of raid456
needing the async modules for data processing while those modules in
turn depend on raid456 for the base level synchronous raid6 routines.

To support this move:
1/ The exportable definitions in raid6.h move to include/linux/raid/pq.h
2/ The raid6_call, recovery calls, and table symbols are exported
3/ Extra #ifdef __KERNEL__ statements to enable the userspace raid6test to
   compile

Signed-off-by: Dan Williams <dan.j.williams@intel.com>
Signed-off-by: NeilBrown <neilb@suse.de>

1 files changed, 5 insertions, 6 deletions

diff --git a/drivers/md/raid6recov.c b/drivers/md/raid6recov.c
index 7a98b8652582..2609f00e0d61 100644
--- a/drivers/md/raid6recov.c
+++ b/drivers/md/raid6recov.c
@@ -18,7 +18,7 @@
  * the syndrome.)
  */
 
-#include "raid6.h"
+#include <linux/raid/pq.h>
 
 /* Recover two failed data blocks. */
 void raid6_2data_recov(int disks, size_t bytes, int faila, int failb,
@@ -63,9 +63,7 @@ void raid6_2data_recov(int disks, size_t bytes, int faila, int failb,
                 p++; q++;
         }
 }
-
-
-
+EXPORT_SYMBOL_GPL(raid6_2data_recov);
 
 /* Recover failure of one data block plus the P block */
 void raid6_datap_recov(int disks, size_t bytes, int faila, void **ptrs)
@@ -97,9 +95,10 @@ void raid6_datap_recov(int disks, size_t bytes, int faila, void **ptrs)
                 q++; dq++;
         }
 }
+EXPORT_SYMBOL_GPL(raid6_datap_recov);
 
-
-#ifndef __KERNEL__              /* Testing only */
+#ifndef __KERNEL__
+/* Testing only */
 
 /* Recover two failed blocks. */
 void raid6_dual_recov(int disks, size_t bytes, int faila, int failb, void **ptrs)