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>

15 files changed, 66 insertions, 34 deletions

diff --git a/drivers/md/Kconfig b/drivers/md/Kconfig
index 2281b5098e95..449d0b9cac14 100644
--- a/drivers/md/Kconfig
+++ b/drivers/md/Kconfig
@@ -121,6 +121,7 @@ config MD_RAID10
 config MD_RAID456
         tristate "RAID-4/RAID-5/RAID-6 mode"
         depends on BLK_DEV_MD
+        select MD_RAID6_PQ
         select ASYNC_MEMCPY
         select ASYNC_XOR
         ---help---
@@ -180,6 +181,9 @@ config MD_RAID5_RESHAPE
 
           If unsure, say Y.
 
+config MD_RAID6_PQ
+        tristate
+
 config MD_MULTIPATH
         tristate "Multipath I/O support"
         depends on BLK_DEV_MD
diff --git a/drivers/md/Makefile b/drivers/md/Makefile
index 3b118da575ee..45cc5951d928 100644
--- a/drivers/md/Makefile
+++ b/drivers/md/Makefile
@@ -9,7 +9,8 @@ dm-snapshot-y	+= dm-snap.o dm-exception-store.o dm-snap-transient.o \
                     dm-snap-persistent.o
 dm-mirror-y     += dm-raid1.o
 md-mod-y        += md.o bitmap.o
-raid456-y       += raid5.o raid6algos.o raid6recov.o raid6tables.o \
+raid456-y       += raid5.o
+raid6_pq-y      += raid6algos.o raid6recov.o raid6tables.o \
                    raid6int1.o raid6int2.o raid6int4.o \
                    raid6int8.o raid6int16.o raid6int32.o \
                    raid6altivec1.o raid6altivec2.o raid6altivec4.o \
@@ -26,6 +27,7 @@ obj-$(CONFIG_MD_LINEAR)		+= linear.o
 obj-$(CONFIG_MD_RAID0)          += raid0.o
 obj-$(CONFIG_MD_RAID1)          += raid1.o
 obj-$(CONFIG_MD_RAID10)         += raid10.o
+obj-$(CONFIG_MD_RAID6_PQ)       += raid6_pq.o
 obj-$(CONFIG_MD_RAID456)        += raid456.o
 obj-$(CONFIG_MD_MULTIPATH)      += multipath.o
 obj-$(CONFIG_MD_FAULTY)         += faulty.o
diff --git a/drivers/md/mktables.c b/drivers/md/mktables.c
index b61d5767aae7..3b1500843bba 100644
--- a/drivers/md/mktables.c
+++ b/drivers/md/mktables.c
@@ -59,7 +59,7 @@ int main(int argc, char *argv[])
         uint8_t v;
         uint8_t exptbl[256], invtbl[256];
 
-        printf("#include \"raid6.h\"\n");
+        printf("#include <linux/raid/pq.h>\n");
 
         /* Compute multiplication table */
         printf("\nconst u8  __attribute__((aligned(256)))\n"
@@ -76,6 +76,9 @@ int main(int argc, char *argv[])
                 printf("\t},\n");
         }
         printf("};\n");
+        printf("#ifdef __KERNEL__\n");
+        printf("EXPORT_SYMBOL(raid6_gfmul);\n");
+        printf("#endif\n");
 
         /* Compute power-of-2 table (exponent) */
         v = 1;
@@ -92,6 +95,9 @@ int main(int argc, char *argv[])
                 }
         }
         printf("};\n");
+        printf("#ifdef __KERNEL__\n");
+        printf("EXPORT_SYMBOL(raid6_gfexp);\n");
+        printf("#endif\n");
 
         /* Compute inverse table x^-1 == x^254 */
         printf("\nconst u8 __attribute__((aligned(256)))\n"
@@ -104,6 +110,9 @@ int main(int argc, char *argv[])
                 }
         }
         printf("};\n");
+        printf("#ifdef __KERNEL__\n");
+        printf("EXPORT_SYMBOL(raid6_gfinv);\n");
+        printf("#endif\n");
 
         /* Compute inv(2^x + 1) (exponent-xor-inverse) table */
         printf("\nconst u8 __attribute__((aligned(256)))\n"
@@ -115,6 +124,9 @@ int main(int argc, char *argv[])
                                (j == 7) ? '\n' : ' ');
         }
         printf("};\n");
+        printf("#ifdef __KERNEL__\n");
+        printf("EXPORT_SYMBOL(raid6_gfexi);\n");
+        printf("#endif\n");
 
         return 0;
 }
diff --git a/drivers/md/raid5.c b/drivers/md/raid5.c
index e1ee181b79bb..1f1b054ff0b6 100644
--- a/drivers/md/raid5.c
+++ b/drivers/md/raid5.c
@@ -45,11 +45,11 @@
 
 #include <linux/blkdev.h>
 #include <linux/kthread.h>
+#include <linux/raid/pq.h>
 #include <linux/async_tx.h>
 #include <linux/seq_file.h>
 #include "md.h"
 #include "raid5.h"
-#include "raid6.h"
 #include "bitmap.h"
 
 /*
@@ -94,11 +94,6 @@
 
 #define printk_rl(args...) ((void) (printk_ratelimit() && printk(args)))
 
-#if !RAID6_USE_EMPTY_ZERO_PAGE
-/* In .bss so it's zeroed */
-const char raid6_empty_zero_page[PAGE_SIZE] __attribute__((aligned(256)));
-#endif
-
 /*
  * We maintain a biased count of active stripes in the bottom 16 bits of
  * bi_phys_segments, and a count of processed stripes in the upper 16 bits
@@ -5153,11 +5148,6 @@ static struct mdk_personality raid4_personality =
 
 static int __init raid5_init(void)
 {
-        int e;
-
-        e = raid6_select_algo();
-        if ( e )
-                return e;
         register_md_personality(&raid6_personality);
         register_md_personality(&raid5_personality);
         register_md_personality(&raid4_personality);
diff --git a/drivers/md/raid5.h b/drivers/md/raid5.h
index c172371481c7..2934ee0a39c6 100644
--- a/drivers/md/raid5.h
+++ b/drivers/md/raid5.h
@@ -269,6 +269,8 @@ struct r6_state {
 #define READ_MODIFY_WRITE       2
 /* not a write method, but a compute_parity mode */
 #define CHECK_PARITY            3
+/* Additional compute_parity mode -- updates the parity w/o LOCKING */
+#define UPDATE_PARITY           4
 
 /*
  * Stripe state
diff --git a/drivers/md/raid6algos.c b/drivers/md/raid6algos.c
index 1f6a3c82ee0c..866215ac7f25 100644
--- a/drivers/md/raid6algos.c
+++ b/drivers/md/raid6algos.c
@@ -16,13 +16,20 @@
  * Algorithm list and algorithm selection for RAID-6
  */
 
-#include "raid6.h"
+#include <linux/raid/pq.h>
 #ifndef __KERNEL__
 #include <sys/mman.h>
 #include <stdio.h>
+#else
+#if !RAID6_USE_EMPTY_ZERO_PAGE
+/* In .bss so it's zeroed */
+const char raid6_empty_zero_page[PAGE_SIZE] __attribute__((aligned(256)));
+EXPORT_SYMBOL(raid6_empty_zero_page);
+#endif
 #endif
 
 struct raid6_calls raid6_call;
+EXPORT_SYMBOL_GPL(raid6_call);
 
 /* Various routine sets */
 extern const struct raid6_calls raid6_intx1;
@@ -79,6 +86,7 @@ const struct raid6_calls * const raid6_algos[] = {
 #else
 /* Need more time to be stable in userspace */
 #define RAID6_TIME_JIFFIES_LG2  9
+#define time_before(x, y) ((x) < (y))
 #endif
 
 /* Try to pick the best algorithm */
@@ -152,3 +160,12 @@ int __init raid6_select_algo(void)
 
         return best ? 0 : -EINVAL;
 }
+
+static void raid6_exit(void)
+{
+        do { } while (0);
+}
+
+subsys_initcall(raid6_select_algo);
+module_exit(raid6_exit);
+MODULE_LICENSE("GPL");
diff --git a/drivers/md/raid6altivec.uc b/drivers/md/raid6altivec.uc
index 217580667e0c..699dfeee4944 100644
--- a/drivers/md/raid6altivec.uc
+++ b/drivers/md/raid6altivec.uc
@@ -22,7 +22,7 @@
  * bracked this with preempt_disable/enable or in a lock)
  */
 
-#include "raid6.h"
+#include <linux/raid/pq.h>
 
 #ifdef CONFIG_ALTIVEC
 
diff --git a/drivers/md/raid6int.uc b/drivers/md/raid6int.uc
index 32a0bac3eb3d..f9bf9cba357f 100644
--- a/drivers/md/raid6int.uc
+++ b/drivers/md/raid6int.uc
@@ -18,7 +18,7 @@
  * This file is postprocessed using unroll.pl
  */
 
-#include "raid6.h"
+#include <linux/raid/pq.h>
 
 /*
  * This is the C data type to use
diff --git a/drivers/md/raid6mmx.c b/drivers/md/raid6mmx.c
index 804cb50ecc19..e7f6c13132bf 100644
--- a/drivers/md/raid6mmx.c
+++ b/drivers/md/raid6mmx.c
@@ -18,7 +18,7 @@
 
 #if defined(__i386__) && !defined(__arch_um__)
 
-#include "raid6.h"
+#include <linux/raid/pq.h>
 #include "raid6x86.h"
 
 /* Shared with raid6sse1.c */
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)
diff --git a/drivers/md/raid6sse1.c b/drivers/md/raid6sse1.c
index 15c588905225..b274dd5eab8f 100644
--- a/drivers/md/raid6sse1.c
+++ b/drivers/md/raid6sse1.c
@@ -23,7 +23,7 @@
 
 #if defined(__i386__) && !defined(__arch_um__)
 
-#include "raid6.h"
+#include <linux/raid/pq.h>
 #include "raid6x86.h"
 
 /* Defined in raid6mmx.c */
diff --git a/drivers/md/raid6sse2.c b/drivers/md/raid6sse2.c
index 2e92e96275be..6ed6c6c0389f 100644
--- a/drivers/md/raid6sse2.c
+++ b/drivers/md/raid6sse2.c
@@ -19,7 +19,7 @@
 
 #if (defined(__i386__) || defined(__x86_64__)) && !defined(__arch_um__)
 
-#include "raid6.h"
+#include <linux/raid/pq.h>
 #include "raid6x86.h"
 
 static const struct raid6_sse_constants {
diff --git a/drivers/md/raid6test/Makefile b/drivers/md/raid6test/Makefile
index 78e0396adf2a..58ffdf4f5161 100644
--- a/drivers/md/raid6test/Makefile
+++ b/drivers/md/raid6test/Makefile
@@ -5,7 +5,7 @@
 
 CC       = gcc
 OPTFLAGS = -O2                  # Adjust as desired
-CFLAGS   = -I.. -g $(OPTFLAGS)
+CFLAGS   = -I.. -I ../../../include -g $(OPTFLAGS)
 LD       = ld
 PERL     = perl
 AR       = ar
diff --git a/drivers/md/raid6test/test.c b/drivers/md/raid6test/test.c
index 559cc41b2585..7a930318b17d 100644
--- a/drivers/md/raid6test/test.c
+++ b/drivers/md/raid6test/test.c
@@ -17,7 +17,7 @@
 #include <stdlib.h>
 #include <stdio.h>
 #include <string.h>
-#include "raid6.h"
+#include <linux/raid/pq.h>
 
 #define NDISKS          16      /* Including P and Q */
 
diff --git a/drivers/md/raid6.h b/include/linux/raid/pq.h
index 8a9c823bab9e..d92480f8285c 100644
--- a/drivers/md/raid6.h
+++ b/include/linux/raid/pq.h
@@ -19,9 +19,6 @@
 #define RAID6_USE_EMPTY_ZERO_PAGE 0
 #include <linux/blkdev.h>
 
-/* Additional compute_parity mode -- updates the parity w/o LOCKING */
-#define UPDATE_PARITY   4
-
 /* We need a pre-zeroed page... if we don't want to use the kernel-provided
    one define it here */
 #if RAID6_USE_EMPTY_ZERO_PAGE
@@ -64,6 +61,10 @@ extern const char raid6_empty_zero_page[PAGE_SIZE];
 #define enable_kernel_altivec()
 #define disable_kernel_altivec()
 
+#define EXPORT_SYMBOL(sym)
+#define MODULE_LICENSE(licence)
+#define subsys_initcall(x)
+#define module_exit(x)
 #endif /* __KERNEL__ */
 
 /* Routine choices */
@@ -94,9 +95,11 @@ extern const u8 raid6_gfinv[256]      __attribute__((aligned(256)));
 extern const u8 raid6_gfexi[256]      __attribute__((aligned(256)));
 
 /* Recovery routines */
-void raid6_2data_recov(int disks, size_t bytes, int faila, int failb, void **ptrs);
+void raid6_2data_recov(int disks, size_t bytes, int faila, int failb,
+                       void **ptrs);
 void raid6_datap_recov(int disks, size_t bytes, int faila, void **ptrs);
-void raid6_dual_recov(int disks, size_t bytes, int faila, int failb, void **ptrs);
+void raid6_dual_recov(int disks, size_t bytes, int faila, int failb,
+                      void **ptrs);
 
 /* Some definitions to allow code to be compiled for testing in userspace */
 #ifndef __KERNEL__
@@ -104,8 +107,11 @@ void raid6_dual_recov(int disks, size_t bytes, int faila, int failb, void **ptrs
 # define jiffies        raid6_jiffies()
 # define printk         printf
 # define GFP_KERNEL     0
-# define __get_free_pages(x,y)  ((unsigned long)mmap(NULL, PAGE_SIZE << (y), PROT_READ|PROT_WRITE, MAP_PRIVATE|MAP_ANONYMOUS, 0, 0))
-# define free_pages(x,y)        munmap((void *)(x), (y)*PAGE_SIZE)
+# define __get_free_pages(x, y) ((unsigned long)mmap(NULL, PAGE_SIZE << (y), \
+                                                     PROT_READ|PROT_WRITE,   \
+                                                     MAP_PRIVATE|MAP_ANONYMOUS,\
+                                                     0, 0))
+# define free_pages(x, y)       munmap((void *)(x), (y)*PAGE_SIZE)
 
 static inline void cpu_relax(void)
 {