user/sven/linux.git/lib/raid6, branch v4.4.183

ARM: 8833/1: Ensure that NEON code always compiles with Clang

2019-04-27T07:33:51Z

[ Upstream commit de9c0d49d85dc563549972edc5589d195cd5e859 ] While building arm32 allyesconfig, I ran into the following errors: arch/arm/lib/xor-neon.c:17:2: error: You should compile this file with '-mfloat-abi=softfp -mfpu=neon' In file included from lib/raid6/neon1.c:27: /home/nathan/cbl/prebuilt/lib/clang/8.0.0/include/arm_neon.h:28:2: error: "NEON support not enabled" Building V=1 showed NEON_FLAGS getting passed along to Clang but __ARM_NEON__ was not getting defined. Ultimately, it boils down to Clang only defining __ARM_NEON__ when targeting armv7, rather than armv6k, which is the '-march' value for allyesconfig. >From lib/Basic/Targets/ARM.cpp in the Clang source: // This only gets set when Neon instructions are actually available, unlike // the VFP define, hence the soft float and arch check. This is subtly // different from gcc, we follow the intent which was that it should be set // when Neon instructions are actually available. if ((FPU & NeonFPU) && !SoftFloat && ArchVersion >= 7) { Builder.defineMacro("__ARM_NEON", "1"); Builder.defineMacro("__ARM_NEON__"); // current AArch32 NEON implementations do not support double-precision // floating-point even when it is present in VFP. Builder.defineMacro("__ARM_NEON_FP", "0x" + Twine::utohexstr(HW_FP & ~HW_FP_DP)); } Ard Biesheuvel recommended explicitly adding '-march=armv7-a' at the beginning of the NEON_FLAGS definitions so that __ARM_NEON__ always gets definined by Clang. This doesn't functionally change anything because that code will only run where NEON is supported, which is implicitly armv7. Link: https://github.com/ClangBuiltLinux/linux/issues/287 Suggested-by: Ard Biesheuvel Signed-off-by: Nathan Chancellor Acked-by: Nicolas Pitre Reviewed-by: Nick Desaulniers Reviewed-by: Stefan Agner Signed-off-by: Russell King Signed-off-by: Sasha Levin

lib/raid6: Fix arm64 test build

2018-11-27T15:08:01Z

[ Upstream commit 313a06e636808387822af24c507cba92703568b1 ] The lib/raid6/test fails to build the neon objects on arm64 because the correct machine type is 'aarch64'. Once this is correctly enabled, the neon recovery objects need to be added to the build. Reviewed-by: Ard Biesheuvel Signed-off-by: Jeremy Linton Signed-off-by: Catalin Marinas Signed-off-by: Sasha Levin

md/raid6: delta syndrome for ARM NEON

2015-08-31T17:29:05Z

This implements XOR syndrome calculation using NEON intrinsics. As before, the module can be built for ARM and arm64 from the same source. Relative performance on a Cortex-A57 based system: raid6: int64x1 gen() 905 MB/s raid6: int64x1 xor() 881 MB/s raid6: int64x2 gen() 1343 MB/s raid6: int64x2 xor() 1286 MB/s raid6: int64x4 gen() 1896 MB/s raid6: int64x4 xor() 1321 MB/s raid6: int64x8 gen() 1773 MB/s raid6: int64x8 xor() 1165 MB/s raid6: neonx1 gen() 1834 MB/s raid6: neonx1 xor() 1278 MB/s raid6: neonx2 gen() 2528 MB/s raid6: neonx2 xor() 1942 MB/s raid6: neonx4 gen() 2888 MB/s raid6: neonx4 xor() 2334 MB/s raid6: neonx8 gen() 2957 MB/s raid6: neonx8 xor() 2232 MB/s raid6: using algorithm neonx8 gen() 2957 MB/s raid6: .... xor() 2232 MB/s, rmw enabled Cc: Markus Stockhausen Cc: Neil Brown Signed-off-by: Ard Biesheuvel Signed-off-by: NeilBrown

Merge tag 'powerpc-4.2-1' of git://git.kernel.org/pub/scm/linux/kernel/git/mpe/linux

2015-06-24T15:46:32Z

Pull powerpc updates from Michael Ellerman: - disable the 32-bit vdso when building LE, so we can build with a 64-bit only toolchain. - EEH fixes from Gavin & Richard. - enable the sys_kcmp syscall from Laurent. - sysfs control for fastsleep workaround from Shreyas. - expose OPAL events as an irq chip by Alistair. - MSI ops moved to pci_controller_ops by Daniel. - fix for kernel to userspace backtraces for perf from Anton. - merge pseries and pseries_le defconfigs from Cyril. - CXL in-kernel API from Mikey. - OPAL prd driver from Jeremy. - fix for DSCR handling & tests from Anshuman. - Powernv flash mtd driver from Cyril. - dynamic DMA Window support on powernv from Alexey. - LLVM clang fixes & workarounds from Anton. - reworked version of the patch to abort syscalls when transactional. - fix the swap encoding to support 4TB, from Aneesh. - various fixes as usual. - Freescale updates from Scott: Highlights include more 8xx optimizations, an e6500 hugetlb optimization, QMan device tree nodes, t1024/t1023 support, and various fixes and cleanup. * tag 'powerpc-4.2-1' of git://git.kernel.org/pub/scm/linux/kernel/git/mpe/linux: (180 commits) cxl: Fix typo in debug print cxl: Add CXL_KERNEL_API config option powerpc/powernv: Fix wrong IOMMU table in pnv_ioda_setup_bus_dma() powerpc/mm: Change the swap encoding in pte. powerpc/mm: PTE_RPN_MAX is not used, remove the same powerpc/tm: Abort syscalls in active transactions powerpc/iommu/ioda2: Enable compile with IOV=on and IOMMU_API=off powerpc/include: Add opal-prd to installed uapi headers powerpc/powernv: fix construction of opal PRD messages powerpc/powernv: Increase opal-irqchip initcall priority powerpc: Make doorbell check preemption safe powerpc/powernv: pnv_init_idle_states() should only run on powernv macintosh/nvram: Remove as unused powerpc: Don't use gcc specific options on clang powerpc: Don't use -mno-strict-align on clang powerpc: Only use -mtraceback=no, -mno-string and -msoft-float if toolchain supports it powerpc: Only use -mabi=altivec if toolchain supports it powerpc: Fix duplicate const clang warning in user access code vfio: powerpc/spapr: Support Dynamic DMA windows vfio: powerpc/spapr: Register memory and define IOMMU v2 ...

powerpc: Only use -mabi=altivec if toolchain supports it

2015-06-11T07:33:05Z

The -mabi=altivec option is not recognised on LLVM, so use call cc-option to check for support. Signed-off-by: Anton Blanchard Signed-off-by: Michael Ellerman

x86/fpu: Rename i387.h to fpu/api.h

2015-05-19T13:47:30Z

We already have fpu/types.h, move i387.h to fpu/api.h. The file name has become a misnomer anyway: it offers generic FPU APIs, but is not limited to i387 functionality. Reviewed-by: Borislav Petkov Cc: Andy Lutomirski Cc: Dave Hansen Cc: Fenghua Yu Cc: H. Peter Anvin Cc: Linus Torvalds Cc: Oleg Nesterov Cc: Peter Zijlstra Cc: Thomas Gleixner Signed-off-by: Ingo Molnar

md/raid6 algorithms: xor_syndrome() for SSE2

2015-04-21T22:00:42Z

The second and (last) optimized XOR syndrome calculation. This version supports right and left side optimization. All CPUs with architecture older than Haswell will benefit from it. It should be noted that SSE2 movntdq kills performance for memory areas that are read and written simultaneously in chunks smaller than cache line size. So use movdqa instead for P/Q writes in sse21 and sse22 XOR functions. Signed-off-by: Markus Stockhausen Signed-off-by: NeilBrown

md/raid6 algorithms: xor_syndrome() for generic int

2015-04-21T22:00:42Z

Start the algorithms with the very basic one. It is left and right optimized. That means we can avoid all calculations for unneeded pages above the right stop offset. For pages below the left start offset we still need the syndrome multiplication but without reading data pages. Signed-off-by: Markus Stockhausen Signed-off-by: NeilBrown

md/raid6 algorithms: improve test program

2015-04-21T22:00:42Z

It is always helpful to have a test tool in place if we implement new data critical algorithms. So add some test routines to the raid6 checker that can prove if the new xor_syndrome() works as expected. Run through all permutations of start/stop pages per algorithm and simulate a xor_syndrome() assisted rmw run. After each rmw check if the recovery algorithm still confirms that the stripe is fine. Signed-off-by: Markus Stockhausen Signed-off-by: NeilBrown

md/raid6 algorithms: delta syndrome functions

2015-04-21T22:00:41Z

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 Signed-off-by: NeilBrown