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2020-01-13md/raid6: fix algorithm choice under larger PAGE_SIZEZhengyuan Liu1-0/+4
There are several algorithms available for raid6 to generate xor and syndrome parity, including basic int1, int2 ... int32 and SIMD optimized implementation like sse and neon. To test and choose the best algorithms at the initial stage, we need provide enough disk data to feed the algorithms. However, the disk number we provided depends on page size and gfmul table, seeing bellow: const int disks = (65536/PAGE_SIZE) + 2; So when come to 64K PAGE_SIZE, there is only one data disk plus 2 parity disk, as a result the chosed algorithm is not reliable. For example, on my arm64 machine with 64K page enabled, it will choose intx32 as the best one, although the NEON implementation is better. This patch tries to fix the problem by defining a constant raid6 disk number to supporting arbitrary page size. Suggested-by: H. Peter Anvin <hpa@zytor.com> Signed-off-by: Zhengyuan Liu <liuzhengyuan@kylinos.cn> Signed-off-by: Song Liu <songliubraving@fb.com>
2020-01-13raid6/test: fix a compilation warningZhengyuan Liu1-0/+2
The compilation warning is redefination showed as following: In file included from tables.c:2: ../../../include/linux/export.h:180: warning: "EXPORT_SYMBOL" redefined #define EXPORT_SYMBOL(sym) __EXPORT_SYMBOL(sym, "") In file included from tables.c:1: ../../../include/linux/raid/pq.h:61: note: this is the location of the previous definition #define EXPORT_SYMBOL(sym) Fixes: 69a94abb82ee ("export.h, genksyms: do not make genksyms calculate CRC of trimmed symbols") Signed-off-by: Zhengyuan Liu <liuzhengyuan@kylinos.cn> Signed-off-by: Song Liu <songliubraving@fb.com>
2020-01-13raid6/test: fix a compilation errorZhengyuan Liu1-1/+0
The compilation error is redeclaration showed as following: In file included from ../../../include/linux/limits.h:6, from /usr/include/x86_64-linux-gnu/bits/local_lim.h:38, from /usr/include/x86_64-linux-gnu/bits/posix1_lim.h:161, from /usr/include/limits.h:183, from /usr/lib/gcc/x86_64-linux-gnu/8/include-fixed/limits.h:194, from /usr/lib/gcc/x86_64-linux-gnu/8/include-fixed/syslimits.h:7, from /usr/lib/gcc/x86_64-linux-gnu/8/include-fixed/limits.h:34, from ../../../include/linux/raid/pq.h:30, from algos.c:14: ../../../include/linux/types.h:114:15: error: conflicting types for ‘int64_t’ typedef s64 int64_t; ^~~~~~~ In file included from /usr/include/stdint.h:34, from /usr/lib/gcc/x86_64-linux-gnu/8/include/stdint.h:9, from /usr/include/inttypes.h:27, from ../../../include/linux/raid/pq.h:29, from algos.c:14: /usr/include/x86_64-linux-gnu/bits/stdint-intn.h:27:19: note: previous \ declaration of ‘int64_t’ was here typedef __int64_t int64_t; Fixes: 54d50897d544 ("linux/kernel.h: split *_MAX and *_MIN macros into <linux/limits.h>") Signed-off-by: Zhengyuan Liu <liuzhengyuan@kylinos.cn> Signed-off-by: Song Liu <songliubraving@fb.com>
2019-05-24treewide: Replace GPLv2 boilerplate/reference with SPDX - rule 48Thomas Gleixner1-6/+1
Based on 1 normalized pattern(s): this program is free software you can redistribute it and or modify it under the terms of the gnu general public license as published by the free software foundation inc 53 temple place ste 330 boston ma 02111 1307 usa either version 2 of the license or at your option any later version incorporated herein by reference extracted by the scancode license scanner the SPDX license identifier GPL-2.0-or-later has been chosen to replace the boilerplate/reference in 13 file(s). Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Reviewed-by: Allison Randal <allison@lohutok.net> Reviewed-by: Kate Stewart <kstewart@linuxfoundation.org> Cc: linux-spdx@vger.kernel.org Link: https://lkml.kernel.org/r/20190520170858.645641371@linutronix.de Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2018-12-20lib/raid6: add option to skip algo benchmarkingDaniel Verkamp1-0/+3
This is helpful for systems where fast startup time is important. It is especially nice to avoid benchmarking RAID functions that are never used (for example, BTRFS selects RAID6_PQ even if the parity RAID mode is not in use). This saves 250+ milliseconds of boot time on modern x86 and ARM systems with a dozen or more available implementations. The new option is defaulted to 'y' to match the previous behavior of always benchmarking on init. Signed-off-by: Daniel Verkamp <dverkamp@chromium.org> Signed-off-by: Shaohua Li <shli@fb.com>
2018-12-20lib/raid6: avoid __attribute_const__ redefinitionDaniel Verkamp1-1/+3
This is defined in glibc's sys/cdefs.h on my system with the same definition as the raid6test fallback definition. Add a #ifndef check to avoid a compiler warning about redefining it. Signed-off-by: Daniel Verkamp <dverkamp@chromium.org> Signed-off-by: Shaohua Li <shli@fb.com>
2018-12-20lib/raid6: add missing include for raid6testDaniel Verkamp1-0/+1
Add #include <sys/time.h> for gettimeofday() to fix the compiler warning about an implicitly defined functions. Signed-off-by: Daniel Verkamp <dverkamp@chromium.org> Signed-off-by: Shaohua Li <shli@fb.com>
2018-04-07Merge tag 'powerpc-4.17-1' of ↵Linus Torvalds1-0/+4
git://git.kernel.org/pub/scm/linux/kernel/git/powerpc/linux Pull powerpc updates from Michael Ellerman: "Notable changes: - Support for 4PB user address space on 64-bit, opt-in via mmap(). - Removal of POWER4 support, which was accidentally broken in 2016 and no one noticed, and blocked use of some modern instructions. - Workarounds so that the hypervisor can enable Transactional Memory on Power9. - A series to disable the DAWR (Data Address Watchpoint Register) on Power9. - More information displayed in the meltdown/spectre_v1/v2 sysfs files. - A vpermxor (Power8 Altivec) implementation for the raid6 Q Syndrome. - A big series to make the allocation of our pacas (per cpu area), kernel page tables, and per-cpu stacks NUMA aware when using the Radix MMU on Power9. And as usual many fixes, reworks and cleanups. Thanks to: Aaro Koskinen, Alexandre Belloni, Alexey Kardashevskiy, Alistair Popple, Andy Shevchenko, Aneesh Kumar K.V, Anshuman Khandual, Balbir Singh, Benjamin Herrenschmidt, Christophe Leroy, Christophe Lombard, Cyril Bur, Daniel Axtens, Dave Young, Finn Thain, Frederic Barrat, Gustavo Romero, Horia Geantă, Jonathan Neuschäfer, Kees Cook, Larry Finger, Laurent Dufour, Laurent Vivier, Logan Gunthorpe, Madhavan Srinivasan, Mark Greer, Mark Hairgrove, Markus Elfring, Mathieu Malaterre, Matt Brown, Matt Evans, Mauricio Faria de Oliveira, Michael Neuling, Naveen N. Rao, Nicholas Piggin, Paul Mackerras, Philippe Bergheaud, Ram Pai, Rob Herring, Sam Bobroff, Segher Boessenkool, Simon Guo, Simon Horman, Stewart Smith, Sukadev Bhattiprolu, Suraj Jitindar Singh, Thiago Jung Bauermann, Vaibhav Jain, Vaidyanathan Srinivasan, Vasant Hegde, Wei Yongjun" * tag 'powerpc-4.17-1' of git://git.kernel.org/pub/scm/linux/kernel/git/powerpc/linux: (207 commits) powerpc/64s/idle: Fix restore of AMOR on POWER9 after deep sleep powerpc/64s: Fix POWER9 DD2.2 and above in cputable features powerpc/64s: Fix pkey support in dt_cpu_ftrs, add CPU_FTR_PKEY bit powerpc/64s: Fix dt_cpu_ftrs to have restore_cpu clear unwanted LPCR bits Revert "powerpc/64s/idle: POWER9 ESL=0 stop avoid save/restore overhead" powerpc: iomap.c: introduce io{read|write}64_{lo_hi|hi_lo} powerpc: io.h: move iomap.h include so that it can use readq/writeq defs cxl: Fix possible deadlock when processing page faults from cxllib powerpc/hw_breakpoint: Only disable hw breakpoint if cpu supports it powerpc/mm/radix: Update command line parsing for disable_radix powerpc/mm/radix: Parse disable_radix commandline correctly. powerpc/mm/hugetlb: initialize the pagetable cache correctly for hugetlb powerpc/mm/radix: Update pte fragment count from 16 to 256 on radix powerpc/mm/keys: Update documentation and remove unnecessary check powerpc/64s/idle: POWER9 ESL=0 stop avoid save/restore overhead powerpc/64s/idle: Consolidate power9_offline_stop()/power9_idle_stop() powerpc/powernv: Always stop secondaries before reboot/shutdown powerpc: hard disable irqs in smp_send_stop loop powerpc: use NMI IPI for smp_send_stop powerpc/powernv: Fix SMT4 forcing idle code ...
2018-03-26raid: remove tile specific raid6 implementationArnd Bergmann1-1/+0
The Tile architecture is getting removed, so we no longer need this either. Acked-by: Ard Biesheuvel <ard.biesheuvel@linaro.org> Signed-off-by: Arnd Bergmann <arnd@arndb.de>
2018-03-20lib/raid6/altivec: Add vpermxor implementation for raid6 Q syndromeMatt Brown1-0/+4
This patch uses the vpermxor instruction to optimise the raid6 Q syndrome. This instruction was made available with POWER8, ISA version 2.07. It allows for both vperm and vxor instructions to be done in a single instruction. This has been tested for correctness on a ppc64le vm with a basic RAID6 setup containing 5 drives. The performance benchmarks are from the raid6test in the /lib/raid6/test directory. These results are from an IBM Firestone machine with ppc64le architecture. The benchmark results show a 35% speed increase over the best existing algorithm for powerpc (altivec). The raid6test has also been run on a big-endian ppc64 vm to ensure it also works for big-endian architectures. Performance benchmarks: raid6: altivecx4 gen() 18773 MB/s raid6: altivecx8 gen() 19438 MB/s raid6: vpermxor4 gen() 25112 MB/s raid6: vpermxor8 gen() 26279 MB/s Signed-off-by: Matt Brown <matthew.brown.dev@gmail.com> Reviewed-by: Daniel Axtens <dja@axtens.net> [mpe: Add VPERMXOR macro so we can build with old binutils] Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
2017-08-09md/raid6: implement recovery using ARM NEON intrinsicsArd Biesheuvel1-0/+1
Provide a NEON accelerated implementation of the recovery algorithm, which supersedes the default byte-by-byte one. Signed-off-by: Ard Biesheuvel <ard.biesheuvel@linaro.org> Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
2017-05-16lib/raid6: Add log-of-2 table for RAID6 HW requiring disk positionAnup Patel1-0/+1
The raid6_gfexp table represents {2}^n values for 0 <= n < 256. The Linux async_tx framework pass values from raid6_gfexp as coefficients for each source to prep_dma_pq() callback of DMA channel with PQ capability. This creates problem for RAID6 offload engines (such as Broadcom SBA) which take disk position (i.e. log of {2}) instead of multiplicative cofficients from raid6_gfexp table. This patch adds raid6_gflog table having log-of-2 value for any given x such that 0 <= x < 256. For any given disk coefficient x, the corresponding disk position is given by raid6_gflog[x]. The RAID6 offload engine driver can use this newly added raid6_gflog table to get disk position from multiplicative coefficient. Signed-off-by: Anup Patel <anup.patel@broadcom.com> Reviewed-by: Scott Branden <scott.branden@broadcom.com> Reviewed-by: Ray Jui <ray.jui@broadcom.com> Acked-by: Shaohua Li <shli@fb.com> Signed-off-by: Vinod Koul <vinod.koul@intel.com>
2016-10-07Merge tag 'md/4.9-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/shli/mdLinus Torvalds1-0/+4
Pull MD updates from Shaohua Li: "This update includes: - new AVX512 instruction based raid6 gen/recovery algorithm - a couple of md-cluster related bug fixes - fix a potential deadlock - set nonrotational bit for raid array with SSD - set correct max_hw_sectors for raid5/6, which hopefuly can improve performance a little bit - other minor fixes" * tag 'md/4.9-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/shli/md: md: set rotational bit raid6/test/test.c: bug fix: Specify aligned(alignment) attributes to the char arrays raid5: handle register_shrinker failure raid5: fix to detect failure of register_shrinker md: fix a potential deadlock md/bitmap: fix wrong cleanup raid5: allow arbitrary max_hw_sectors lib/raid6: Add AVX512 optimized xor_syndrome functions lib/raid6/test/Makefile: Add avx512 gen_syndrome and recovery functions lib/raid6: Add AVX512 optimized recovery functions lib/raid6: Add AVX512 optimized gen_syndrome functions md-cluster: make resync lock also could be interruptted md-cluster: introduce dlm_lock_sync_interruptible to fix tasks hang md-cluster: convert the completion to wait queue md-cluster: protect md_find_rdev_nr_rcu with rcu lock md-cluster: clean related infos of cluster md: changes for MD_STILL_CLOSED flag md-cluster: remove some unnecessary dlm_unlock_sync md-cluster: use FORCEUNLOCK in lockres_free md-cluster: call md_kick_rdev_from_array once ack failed
2016-09-21lib/raid6: Add AVX512 optimized recovery functionsGayatri Kammela1-0/+1
Optimize RAID6 recovery functions to take advantage of the 512-bit ZMM integer instructions introduced in AVX512. AVX512 optimized recovery functions, which is simply based on recov_avx2.c written by Jim Kukunas This patch was tested and benchmarked before submission on a hardware that has AVX512 flags to support such instructions Cc: Jim Kukunas <james.t.kukunas@linux.intel.com> Cc: H. Peter Anvin <hpa@zytor.com> Cc: Fenghua Yu <fenghua.yu@intel.com> Signed-off-by: Megha Dey <megha.dey@linux.intel.com> Signed-off-by: Gayatri Kammela <gayatri.kammela@intel.com> Reviewed-by: Fenghua Yu <fenghua.yu@intel.com> Signed-off-by: Shaohua Li <shli@fb.com>
2016-09-21lib/raid6: Add AVX512 optimized gen_syndrome functionsGayatri Kammela1-0/+3
Optimize RAID6 gen_syndrom functions to take advantage of the 512-bit ZMM integer instructions introduced in AVX512. AVX512 optimized gen_syndrom functions, which is simply based on avx2.c written by Yuanhan Liu and sse2.c written by hpa. The patch was tested and benchmarked before submission on a hardware that has AVX512 flags to support such instructions Cc: H. Peter Anvin <hpa@zytor.com> Cc: Jim Kukunas <james.t.kukunas@linux.intel.com> Cc: Fenghua Yu <fenghua.yu@intel.com> Signed-off-by: Megha Dey <megha.dey@linux.intel.com> Signed-off-by: Gayatri Kammela <gayatri.kammela@intel.com> Reviewed-by: Fenghua Yu <fenghua.yu@intel.com> Signed-off-by: Shaohua Li <shli@fb.com>
2016-09-01RAID/s390: provide raid6 recovery optimizationMartin Schwidefsky1-0/+1
The XC instruction can be used to improve the speed of the raid6 recovery. The loops now operate on blocks of 256 bytes. Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
2016-08-29RAID/s390: add SIMD implementation for raid6 gen/xorMartin Schwidefsky1-0/+1
Using vector registers is slightly faster: raid6: vx128x8 gen() 19705 MB/s raid6: vx128x8 xor() 11886 MB/s raid6: using algorithm vx128x8 gen() 19705 MB/s raid6: .... xor() 11886 MB/s, rmw enabled vs the software algorithms: raid6: int64x1 gen() 3018 MB/s raid6: int64x1 xor() 1429 MB/s raid6: int64x2 gen() 4661 MB/s raid6: int64x2 xor() 3143 MB/s raid6: int64x4 gen() 5392 MB/s raid6: int64x4 xor() 3509 MB/s raid6: int64x8 gen() 4441 MB/s raid6: int64x8 xor() 3207 MB/s raid6: using algorithm int64x4 gen() 5392 MB/s raid6: .... xor() 3509 MB/s, rmw enabled Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
2016-01-21raid6/algos.c : bug fix : Add the missing definitions to the pq.h fileGayatri Kammela1-0/+2
Adding these pr_info and pr_err definitions so as to allow code to be compiled successfully for testing in userspace, since the printk has been replaced by pr_info and pr_err in algos.c Absence of these definitions result in the compilation errors such as ' undefined reference to `pr_info' ' ' undefined reference to `pr_err' ' Cc: NeilBrown <neilb@suse.com> Cc: Anton Blanchard <anton@samba.org> Cc: Fenghua Yu <fenghua.yu@intel.com> Signed-off-by: Gayatri Kammela <gayatri.kammela@intel.com> Signed-off-by: Shaohua Li <shli@fb.com>
2015-04-22md/raid6 algorithms: delta syndrome functionsMarkus Stockhausen1-0/+1
v3: s-o-b comment, explanation of performance and descision for the start/stop implementation Implementing rmw functionality for RAID6 requires optimized syndrome calculation. Up to now we can only generate a complete syndrome. The target P/Q pages are always overwritten. With this patch we provide a framework for inplace P/Q modification. In the first place simply fill those functions with NULL values. xor_syndrome() has two additional parameters: start & stop. These will indicate the first and last page that are changing during a rmw run. That makes it possible to avoid several unneccessary loops and speed up calculation. The caller needs to implement the following logic to make the functions work. 1) xor_syndrome(disks, start, stop, ...): "Remove" all data of source blocks inside P/Q between (and including) start and end. 2) modify any block with start <= block <= stop 3) xor_syndrome(disks, start, stop, ...): "Reinsert" all data of source blocks into P/Q between (and including) start and end. Pages between start and stop that won't be changed should be filled with a pointer to the kernel zero page. The reasons for not taking NULL pages are: 1) Algorithms cross the whole source data line by line. Thus avoid additional branches. 2) Having a NULL page avoids calculating the XOR P parity but still need calulation steps for the Q parity. Depending on the algorithm unrolling that might be only a difference of 2 instructions per loop. The benchmark numbers of the gen_syndrome() functions are displayed in the kernel log. Do the same for the xor_syndrome() functions. This will help to analyze performance problems and give an rough estimate how well the algorithm works. The choice of the fastest algorithm will still depend on the gen_syndrome() performance. With the start/stop page implementation the speed can vary a lot in real life. E.g. a change of page 0 & page 15 on a stripe will be harder to compute than the case where page 0 & page 1 are XOR candidates. To be not to enthusiatic about the expected speeds we will run a worse case test that simulates a change on the upper half of the stripe. So we do: 1) calculation of P/Q for the upper pages 2) continuation of Q for the lower (empty) pages Signed-off-by: Markus Stockhausen <stockhausen@collogia.de> Signed-off-by: NeilBrown <neilb@suse.de>
2013-09-10Merge tag 'md/3.12' of git://neil.brown.name/mdLinus Torvalds1-0/+1
Pull md update from Neil Brown: "Headline item is multithreading for RAID5 so that more IO/sec can be supported on fast (SSD) devices. Also TILE-Gx SIMD suppor for RAID6 calculations and an assortment of bug fixes" * tag 'md/3.12' of git://neil.brown.name/md: raid5: only wakeup necessary threads md/raid5: flush out all pending requests before proceeding with reshape. md/raid5: use seqcount to protect access to shape in make_request. raid5: sysfs entry to control worker thread number raid5: offload stripe handle to workqueue raid5: fix stripe release order raid5: make release_stripe lockless md: avoid deadlock when dirty buffers during md_stop. md: Don't test all of mddev->flags at once. md: Fix apparent cut-and-paste error in super_90_validate raid6/test: replace echo -e with printf RAID: add tilegx SIMD implementation of raid6 md: fix safe_mode buglet. md: don't call md_allow_write in get_bitmap_file.
2013-08-27RAID: add tilegx SIMD implementation of raid6Ken Steele1-0/+1
This change adds TILE-Gx SIMD instructions to the software raid (md), modeling the Altivec implementation. This is only for Syndrome generation; there is more that could be done to improve recovery, as in the recent Intel SSE3 recovery implementation. The code unrolls 8 times; this turns out to be the best on tilegx hardware among the set 1, 2, 4, 8 or 16. The code reads one cache-line of data from each disk, stores P and Q then goes to the next cache-line. The test code in sys/linux/lib/raid6/test reports 2008 MB/s data read rate for syndrome generation using 18 disks (16 data and 2 parity). It was 1512 MB/s before this SIMD optimizations. This is running on 1 core with all the data in cache. This is based on the paper The Mathematics of RAID-6. (http://kernel.org/pub/linux/kernel/people/hpa/raid6.pdf). Signed-off-by: Ken Steele <ken@tilera.com> Signed-off-by: Chris Metcalf <cmetcalf@tilera.com> Signed-off-by: NeilBrown <neilb@suse.de>
2013-07-08lib/raid6: add ARM-NEON accelerated syndrome calculationArd Biesheuvel1-0/+5
Rebased/reworked a patch contributed by Rob Herring that uses NEON intrinsics to perform the RAID-6 syndrome calculations. It uses the existing unroll.awk code to generate several unrolled versions of which the best performing one is selected at boot time. Signed-off-by: Ard Biesheuvel <ard.biesheuvel@linaro.org> Acked-by: Nicolas Pitre <nico@linaro.org> Cc: hpa@linux.intel.com
2012-12-13lib/raid6: Add AVX2 optimized gen_syndrome functionsYuanhan Liu1-0/+3
Add AVX2 optimized gen_syndrom functions, which is simply based on sse2.c written by hpa. Signed-off-by: Yuanhan Liu <yuanhan.liu@linux.intel.com> Reviewed-by: H. Peter Anvin <hpa@zytor.com> Signed-off-by: Jim Kukunas <james.t.kukunas@linux.intel.com> Signed-off-by: NeilBrown <neilb@suse.de>
2012-12-13lib/raid6: Add AVX2 optimized recovery functionsJim Kukunas1-0/+1
Optimize RAID6 recovery functions to take advantage of the 256-bit YMM integer instructions introduced in AVX2. The patch was tested and benchmarked before submission. However hardware is not yet released so benchmark numbers cannot be reported. Acked-by: "H. Peter Anvin" <hpa@zytor.com> Signed-off-by: Jim Kukunas <james.t.kukunas@linux.intel.com> Signed-off-by: NeilBrown <neilb@suse.de>
2012-05-22lib/raid6: Add SSSE3 optimized recovery functionsJim Kukunas1-2/+16
Add SSSE3 optimized recovery functions, as well as a system for selecting the most appropriate recovery functions to use. Originally-by: H. Peter Anvin <hpa@zytor.com> Signed-off-by: Jim Kukunas <james.t.kukunas@linux.intel.com> Signed-off-by: NeilBrown <neilb@suse.de>
2011-12-23md: Fix userspace free_pages() macroSteven Rostedt1-1/+1
While using etags to find free_pages(), I stumbled across this debug definition of free_pages() that is to be used while debugging some raid code in userspace. The __get_free_pages() allocates the correct size, but the free_pages() does not match. free_pages(), like __get_free_pages(), takes an order and not a size. Acked-by: H. Peter Anvin <hpa@zytor.com> Signed-off-by: Steven Rostedt <rostedt@goodmis.org> Signed-off-by: NeilBrown <neilb@suse.de>
2010-08-12Make lib/raid6/test build correctly.NeilBrown1-0/+2
Some bit-rot needs to be cleaned out. Signed-off-by: NeilBrown <neilb@suse.de>
2009-12-14md: remove sparse warning:symbol XXX was not declared.NeilBrown1-0/+19
Signed-off-by: NeilBrown <neilb@suse.de>
2009-03-31md/raid6: move raid6 data processing to raid6_pq.koDan Williams1-0/+132
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>