<feed xmlns='http://www.w3.org/2005/Atom'>
<title>user/sven/linux.git/lib/raid6, branch v4.14.130</title>
<subtitle>Linux Kernel
</subtitle>
<id>https://git.stealer.net/cgit.cgi/user/sven/linux.git/atom?h=v4.14.130</id>
<link rel='self' href='https://git.stealer.net/cgit.cgi/user/sven/linux.git/atom?h=v4.14.130'/>
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<updated>2019-04-05T20:31:34Z</updated>
<entry>
<title>ARM: 8833/1: Ensure that NEON code always compiles with Clang</title>
<updated>2019-04-05T20:31:34Z</updated>
<author>
<name>Nathan Chancellor</name>
<email>natechancellor@gmail.com</email>
</author>
<published>2019-02-02T02:34:36Z</published>
<link rel='alternate' type='text/html' href='https://git.stealer.net/cgit.cgi/user/sven/linux.git/commit/?id=416b593a22b80ab7ff4e6cefca147e7657d95b6f'/>
<id>urn:sha1:416b593a22b80ab7ff4e6cefca147e7657d95b6f</id>
<content type='text'>
[ 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.

&gt;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 &amp; NeonFPU) &amp;&amp; !SoftFloat &amp;&amp; ArchVersion &gt;= 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 &amp; ~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 &lt;ard.biesheuvel@linaro.org&gt;
Signed-off-by: Nathan Chancellor &lt;natechancellor@gmail.com&gt;
Acked-by: Nicolas Pitre &lt;nico@linaro.org&gt;
Reviewed-by: Nick Desaulniers &lt;ndesaulniers@google.com&gt;
Reviewed-by: Stefan Agner &lt;stefan@agner.ch&gt;
Signed-off-by: Russell King &lt;rmk+kernel@armlinux.org.uk&gt;
Signed-off-by: Sasha Levin &lt;sashal@kernel.org&gt;
</content>
</entry>
<entry>
<title>raid6/ppc: Fix build for clang</title>
<updated>2019-01-13T09:01:04Z</updated>
<author>
<name>Joel Stanley</name>
<email>joel@jms.id.au</email>
</author>
<published>2018-11-02T00:44:55Z</published>
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<id>urn:sha1:1f33700bdf421490aef65bb794dbd9d9837f7ea0</id>
<content type='text'>
commit e213574a449f7a57d4202c1869bbc7680b6b5521 upstream.

We cannot build these files with clang as it does not allow altivec
instructions in assembly when -msoft-float is passed.

Jinsong Ji &lt;jji@us.ibm.com&gt; wrote:
&gt; We currently disable Altivec/VSX support when enabling soft-float.  So
&gt; any usage of vector builtins will break.
&gt;
&gt; Enable Altivec/VSX with soft-float may need quite some clean up work, so
&gt; I guess this is currently a limitation.
&gt;
&gt; Removing -msoft-float will make it work (and we are lucky that no
&gt; floating point instructions will be generated as well).

This is a workaround until the issue is resolved in clang.

Link: https://bugs.llvm.org/show_bug.cgi?id=31177
Link: https://github.com/ClangBuiltLinux/linux/issues/239
Signed-off-by: Joel Stanley &lt;joel@jms.id.au&gt;
Reviewed-by: Nick Desaulniers &lt;ndesaulniers@google.com&gt;
Signed-off-by: Michael Ellerman &lt;mpe@ellerman.id.au&gt;
[nc: Use 'ifeq ($(cc-name),clang)' instead of 'ifdef CONFIG_CC_IS_CLANG'
     because that config does not exist in 4.14; the Kconfig rewrite
     that added that config happened in 4.18]
Signed-off-by: Nathan Chancellor &lt;natechancellor@gmail.com&gt;
Signed-off-by: Greg Kroah-Hartman &lt;gregkh@linuxfoundation.org&gt;
</content>
</entry>
<entry>
<title>lib/raid6: Fix arm64 test build</title>
<updated>2018-11-27T15:10:48Z</updated>
<author>
<name>Jeremy Linton</name>
<email>jeremy.linton@arm.com</email>
</author>
<published>2018-11-06T00:14:41Z</published>
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<id>urn:sha1:615a30e8dbc9c60bb35f3687072fb077160ea0b7</id>
<content type='text'>
[ 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 &lt;ard.biesheuvel@linaro.org&gt;
Signed-off-by: Jeremy Linton &lt;jeremy.linton@arm.com&gt;
Signed-off-by: Catalin Marinas &lt;catalin.marinas@arm.com&gt;
Signed-off-by: Sasha Levin &lt;sashal@kernel.org&gt;
</content>
</entry>
<entry>
<title>License cleanup: add SPDX GPL-2.0 license identifier to files with no license</title>
<updated>2017-11-02T10:10:55Z</updated>
<author>
<name>Greg Kroah-Hartman</name>
<email>gregkh@linuxfoundation.org</email>
</author>
<published>2017-11-01T14:07:57Z</published>
<link rel='alternate' type='text/html' href='https://git.stealer.net/cgit.cgi/user/sven/linux.git/commit/?id=b24413180f5600bcb3bb70fbed5cf186b60864bd'/>
<id>urn:sha1:b24413180f5600bcb3bb70fbed5cf186b60864bd</id>
<content type='text'>
Many source files in the tree are missing licensing information, which
makes it harder for compliance tools to determine the correct license.

By default all files without license information are under the default
license of the kernel, which is GPL version 2.

Update the files which contain no license information with the 'GPL-2.0'
SPDX license identifier.  The SPDX identifier is a legally binding
shorthand, which can be used instead of the full boiler plate text.

This patch is based on work done by Thomas Gleixner and Kate Stewart and
Philippe Ombredanne.

How this work was done:

Patches were generated and checked against linux-4.14-rc6 for a subset of
the use cases:
 - file had no licensing information it it.
 - file was a */uapi/* one with no licensing information in it,
 - file was a */uapi/* one with existing licensing information,

Further patches will be generated in subsequent months to fix up cases
where non-standard license headers were used, and references to license
had to be inferred by heuristics based on keywords.

The analysis to determine which SPDX License Identifier to be applied to
a file was done in a spreadsheet of side by side results from of the
output of two independent scanners (ScanCode &amp; Windriver) producing SPDX
tag:value files created by Philippe Ombredanne.  Philippe prepared the
base worksheet, and did an initial spot review of a few 1000 files.

The 4.13 kernel was the starting point of the analysis with 60,537 files
assessed.  Kate Stewart did a file by file comparison of the scanner
results in the spreadsheet to determine which SPDX license identifier(s)
to be applied to the file. She confirmed any determination that was not
immediately clear with lawyers working with the Linux Foundation.

Criteria used to select files for SPDX license identifier tagging was:
 - Files considered eligible had to be source code files.
 - Make and config files were included as candidates if they contained &gt;5
   lines of source
 - File already had some variant of a license header in it (even if &lt;5
   lines).

All documentation files were explicitly excluded.

The following heuristics were used to determine which SPDX license
identifiers to apply.

 - when both scanners couldn't find any license traces, file was
   considered to have no license information in it, and the top level
   COPYING file license applied.

   For non */uapi/* files that summary was:

   SPDX license identifier                            # files
   ---------------------------------------------------|-------
   GPL-2.0                                              11139

   and resulted in the first patch in this series.

   If that file was a */uapi/* path one, it was "GPL-2.0 WITH
   Linux-syscall-note" otherwise it was "GPL-2.0".  Results of that was:

   SPDX license identifier                            # files
   ---------------------------------------------------|-------
   GPL-2.0 WITH Linux-syscall-note                        930

   and resulted in the second patch in this series.

 - if a file had some form of licensing information in it, and was one
   of the */uapi/* ones, it was denoted with the Linux-syscall-note if
   any GPL family license was found in the file or had no licensing in
   it (per prior point).  Results summary:

   SPDX license identifier                            # files
   ---------------------------------------------------|------
   GPL-2.0 WITH Linux-syscall-note                       270
   GPL-2.0+ WITH Linux-syscall-note                      169
   ((GPL-2.0 WITH Linux-syscall-note) OR BSD-2-Clause)    21
   ((GPL-2.0 WITH Linux-syscall-note) OR BSD-3-Clause)    17
   LGPL-2.1+ WITH Linux-syscall-note                      15
   GPL-1.0+ WITH Linux-syscall-note                       14
   ((GPL-2.0+ WITH Linux-syscall-note) OR BSD-3-Clause)    5
   LGPL-2.0+ WITH Linux-syscall-note                       4
   LGPL-2.1 WITH Linux-syscall-note                        3
   ((GPL-2.0 WITH Linux-syscall-note) OR MIT)              3
   ((GPL-2.0 WITH Linux-syscall-note) AND MIT)             1

   and that resulted in the third patch in this series.

 - when the two scanners agreed on the detected license(s), that became
   the concluded license(s).

 - when there was disagreement between the two scanners (one detected a
   license but the other didn't, or they both detected different
   licenses) a manual inspection of the file occurred.

 - In most cases a manual inspection of the information in the file
   resulted in a clear resolution of the license that should apply (and
   which scanner probably needed to revisit its heuristics).

 - When it was not immediately clear, the license identifier was
   confirmed with lawyers working with the Linux Foundation.

 - If there was any question as to the appropriate license identifier,
   the file was flagged for further research and to be revisited later
   in time.

In total, over 70 hours of logged manual review was done on the
spreadsheet to determine the SPDX license identifiers to apply to the
source files by Kate, Philippe, Thomas and, in some cases, confirmation
by lawyers working with the Linux Foundation.

Kate also obtained a third independent scan of the 4.13 code base from
FOSSology, and compared selected files where the other two scanners
disagreed against that SPDX file, to see if there was new insights.  The
Windriver scanner is based on an older version of FOSSology in part, so
they are related.

Thomas did random spot checks in about 500 files from the spreadsheets
for the uapi headers and agreed with SPDX license identifier in the
files he inspected. For the non-uapi files Thomas did random spot checks
in about 15000 files.

In initial set of patches against 4.14-rc6, 3 files were found to have
copy/paste license identifier errors, and have been fixed to reflect the
correct identifier.

Additionally Philippe spent 10 hours this week doing a detailed manual
inspection and review of the 12,461 patched files from the initial patch
version early this week with:
 - a full scancode scan run, collecting the matched texts, detected
   license ids and scores
 - reviewing anything where there was a license detected (about 500+
   files) to ensure that the applied SPDX license was correct
 - reviewing anything where there was no detection but the patch license
   was not GPL-2.0 WITH Linux-syscall-note to ensure that the applied
   SPDX license was correct

This produced a worksheet with 20 files needing minor correction.  This
worksheet was then exported into 3 different .csv files for the
different types of files to be modified.

These .csv files were then reviewed by Greg.  Thomas wrote a script to
parse the csv files and add the proper SPDX tag to the file, in the
format that the file expected.  This script was further refined by Greg
based on the output to detect more types of files automatically and to
distinguish between header and source .c files (which need different
comment types.)  Finally Greg ran the script using the .csv files to
generate the patches.

Reviewed-by: Kate Stewart &lt;kstewart@linuxfoundation.org&gt;
Reviewed-by: Philippe Ombredanne &lt;pombredanne@nexb.com&gt;
Reviewed-by: Thomas Gleixner &lt;tglx@linutronix.de&gt;
Signed-off-by: Greg Kroah-Hartman &lt;gregkh@linuxfoundation.org&gt;
</content>
</entry>
<entry>
<title>Merge tag 'md/4.14-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/shli/md</title>
<updated>2017-09-07T19:41:48Z</updated>
<author>
<name>Linus Torvalds</name>
<email>torvalds@linux-foundation.org</email>
</author>
<published>2017-09-07T19:41:48Z</published>
<link rel='alternate' type='text/html' href='https://git.stealer.net/cgit.cgi/user/sven/linux.git/commit/?id=3645e6d0dc80be4376f87acc9ee527768387c909'/>
<id>urn:sha1:3645e6d0dc80be4376f87acc9ee527768387c909</id>
<content type='text'>
Pull MD updates from Shaohua Li:
 "This update mainly fixes bugs:

   - Make raid5 ppl support several ppl from Pawel

   - Several raid5-cache bug fixes from Song

   - Bitmap fixes from Neil and Me

   - One raid1/10 regression fix since 4.12 from Me

   - Other small fixes and cleanup"

* tag 'md/4.14-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/shli/md:
  md/bitmap: disable bitmap_resize for file-backed bitmaps.
  raid5-ppl: Recovery support for multiple partial parity logs
  md: Runtime support for multiple ppls
  md/raid0: attach correct cgroup info in bio
  lib/raid6: align AVX512 constants to 512 bits, not bytes
  raid5: remove raid5_build_block
  md/r5cache: call mddev_lock/unlock() in r5c_journal_mode_show
  md: replace seq_release_private with seq_release
  md: notify about new spare disk in the container
  md/raid1/10: reset bio allocated from mempool
  md/raid5: release/flush io in raid5_do_work()
  md/bitmap: copy correct data for bitmap super
</content>
</entry>
<entry>
<title>lib/raid6: align AVX512 constants to 512 bits, not bytes</title>
<updated>2017-08-25T17:21:47Z</updated>
<author>
<name>Denys Vlasenko</name>
<email>dvlasenk@redhat.com</email>
</author>
<published>2017-08-12T17:43:46Z</published>
<link rel='alternate' type='text/html' href='https://git.stealer.net/cgit.cgi/user/sven/linux.git/commit/?id=b5e0fff19bef3a36631bce742e363d3a99590c3a'/>
<id>urn:sha1:b5e0fff19bef3a36631bce742e363d3a99590c3a</id>
<content type='text'>
Signed-off-by: Denys Vlasenko &lt;dvlasenk@redhat.com&gt;
Cc: H. Peter Anvin &lt;hpa@zytor.com&gt;
Cc: mingo@redhat.com
Cc: Jim Kukunas &lt;james.t.kukunas@linux.intel.com&gt;
Cc: Fenghua Yu &lt;fenghua.yu@intel.com&gt;
Cc: Megha Dey &lt;megha.dey@linux.intel.com&gt;
Cc: Gayatri Kammela &lt;gayatri.kammela@intel.com&gt;
Cc: x86@kernel.org
Cc: linux-kernel@vger.kernel.org
Signed-off-by: Shaohua Li &lt;shli@fb.com&gt;
</content>
</entry>
<entry>
<title>md/raid6: implement recovery using ARM NEON intrinsics</title>
<updated>2017-08-09T17:52:07Z</updated>
<author>
<name>Ard Biesheuvel</name>
<email>ard.biesheuvel@linaro.org</email>
</author>
<published>2017-07-13T17:16:01Z</published>
<link rel='alternate' type='text/html' href='https://git.stealer.net/cgit.cgi/user/sven/linux.git/commit/?id=6ec4e2514decd6fb4782a9364fa71d6244d05af4'/>
<id>urn:sha1:6ec4e2514decd6fb4782a9364fa71d6244d05af4</id>
<content type='text'>
Provide a NEON accelerated implementation of the recovery algorithm,
which supersedes the default byte-by-byte one.

Signed-off-by: Ard Biesheuvel &lt;ard.biesheuvel@linaro.org&gt;
Signed-off-by: Catalin Marinas &lt;catalin.marinas@arm.com&gt;
</content>
</entry>
<entry>
<title>md/raid6: use faster multiplication for ARM NEON delta syndrome</title>
<updated>2017-08-09T17:51:57Z</updated>
<author>
<name>Ard Biesheuvel</name>
<email>ard.biesheuvel@linaro.org</email>
</author>
<published>2017-07-13T17:16:00Z</published>
<link rel='alternate' type='text/html' href='https://git.stealer.net/cgit.cgi/user/sven/linux.git/commit/?id=35129dde88afad07f54b332d4f9eda2d254b80f2'/>
<id>urn:sha1:35129dde88afad07f54b332d4f9eda2d254b80f2</id>
<content type='text'>
The P/Q left side optimization in the delta syndrome simply involves
repeatedly multiplying a value by polynomial 'x' in GF(2^8). Given
that 'x * x * x * x' equals 'x^4' even in the polynomial world, we
can accelerate this substantially by performing up to 4 such operations
at once, using the NEON instructions for polynomial multiplication.

Results on a Cortex-A57 running in 64-bit mode:

  Before:
  -------
  raid6: neonx1   xor()  1680 MB/s
  raid6: neonx2   xor()  2286 MB/s
  raid6: neonx4   xor()  3162 MB/s
  raid6: neonx8   xor()  3389 MB/s

  After:
  ------
  raid6: neonx1   xor()  2281 MB/s
  raid6: neonx2   xor()  3362 MB/s
  raid6: neonx4   xor()  3787 MB/s
  raid6: neonx8   xor()  4239 MB/s

While we're at it, simplify MASK() by using a signed shift rather than
a vector compare involving a temp register.

Signed-off-by: Ard Biesheuvel &lt;ard.biesheuvel@linaro.org&gt;
Signed-off-by: Catalin Marinas &lt;catalin.marinas@arm.com&gt;
</content>
</entry>
<entry>
<title>lib/raid6: Add log-of-2 table for RAID6 HW requiring disk position</title>
<updated>2017-05-16T04:31:57Z</updated>
<author>
<name>Anup Patel</name>
<email>anup.patel@broadcom.com</email>
</author>
<published>2017-05-15T05:04:52Z</published>
<link rel='alternate' type='text/html' href='https://git.stealer.net/cgit.cgi/user/sven/linux.git/commit/?id=b5dceda1f7ef66cba6f8d766502f242a27f96e6d'/>
<id>urn:sha1:b5dceda1f7ef66cba6f8d766502f242a27f96e6d</id>
<content type='text'>
The raid6_gfexp table represents {2}^n values for 0 &lt;= n &lt; 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 &lt;= x &lt; 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 &lt;anup.patel@broadcom.com&gt;
Reviewed-by: Scott Branden &lt;scott.branden@broadcom.com&gt;
Reviewed-by: Ray Jui &lt;ray.jui@broadcom.com&gt;
Acked-by: Shaohua Li &lt;shli@fb.com&gt;
Signed-off-by: Vinod Koul &lt;vinod.koul@intel.com&gt;
</content>
</entry>
<entry>
<title>lib/raid6: Add AVX2 optimized xor_syndrome functions</title>
<updated>2016-11-07T23:08:20Z</updated>
<author>
<name>Gayatri Kammela</name>
<email>gayatri.kammela@intel.com</email>
</author>
<published>2016-09-30T18:14:49Z</published>
<link rel='alternate' type='text/html' href='https://git.stealer.net/cgit.cgi/user/sven/linux.git/commit/?id=b9bf33a8bd9d8c506f214543e341144cd978c13e'/>
<id>urn:sha1:b9bf33a8bd9d8c506f214543e341144cd978c13e</id>
<content type='text'>
Implement the AVX2 optimization of RAID6 xor_syndrome functions which is
simply based on sse2.c written by hpa.

Cc: H. Peter Anvin &lt;hpa@linux.intel.com&gt;
Cc: Yuanhan Liu &lt;yuanhan.liu@intel.com&gt;
Cc: Fenghua Yu &lt;fenghua.yu@intel.com&gt;
Signed-off-by: Gayatri Kammela &lt;gayatri.kammela@intel.com&gt;
Signed-off-by: Shaohua Li &lt;shli@fb.com&gt;
</content>
</entry>
</feed>
