treewide: Replace GPLv2 boilerplate/reference with SPDX - rule 48

Based on 1 normalized pattern(s):

this program is free software you can redistribute it and or modify
it under the terms of the

treewide: Replace GPLv2 boilerplate/reference with SPDX - rule 48

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 <[email protected]>
Reviewed-by: Allison Randal <[email protected]>
Reviewed-by: Kate Stewart <[email protected]>
Cc: [email protected]
Link: https://lkml.kernel.org/r/[email protected]
Signed-off-by: Greg Kroah-Hartman <[email protected]>

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treewide: Align function definition open/close braces

Some functions definitions have either the initial open brace and/or
the closing brace outside of column 1.

Move those braces to column 1.

Thi

treewide: Align function definition open/close braces

Some functions definitions have either the initial open brace and/or
the closing brace outside of column 1.

Move those braces to column 1.

This allows various function analyzers like gnu complexity to work
properly for these modified functions.

Signed-off-by: Joe Perches <[email protected]>
Acked-by: Andy Shevchenko <[email protected]>
Acked-by: Paul Moore <[email protected]>
Acked-by: Alex Deucher <[email protected]>
Acked-by: Dave Chinner <[email protected]>
Reviewed-by: Darrick J. Wong <[email protected]>
Acked-by: Alexandre Belloni <[email protected]>
Acked-by: Martin K. Petersen <[email protected]>
Acked-by: Takashi Iwai <[email protected]>
Acked-by: Mauro Carvalho Chehab <[email protected]>
Acked-by: Rafael J. Wysocki <[email protected]>
Acked-by: Nicolin Chen <[email protected]>
Acked-by: Martin K. Petersen <[email protected]>
Acked-by: Steven Rostedt (VMware) <[email protected]>
Signed-off-by: Jiri Kosina <[email protected]>

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md/raid6 algorithms: xor_syndrome() for SSE2

The second and (last) optimized XOR syndrome calculation. This version
supports right and left side optimization. All CPUs with architecture
older than H

md/raid6 algorithms: xor_syndrome() for SSE2

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 <[email protected]>
Signed-off-by: NeilBrown <[email protected]>

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md/raid6 algorithms: delta syndrome functions

v3: s-o-b comment, explanation of performance and descision for
the start/stop implementation

Implementing rmw functionality for RAID6 requires optimiz

md/raid6 algorithms: delta syndrome functions

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 <[email protected]>
Signed-off-by: NeilBrown <[email protected]>

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lib/raid6: build proper files on corresponding arch

sse and avx2 stuff only exist on x86 arch, and we don't need to build
altivec on x86. And we can do that at lib/raid6/Makefile.

Proposed-by: H. P

lib/raid6: build proper files on corresponding arch

sse and avx2 stuff only exist on x86 arch, and we don't need to build
altivec on x86. And we can do that at lib/raid6/Makefile.

Proposed-by: H. Peter Anvin <[email protected]>
Signed-off-by: Yuanhan Liu <[email protected]>
Reviewed-by: H. Peter Anvin <[email protected]>
Signed-off-by: Jim Kukunas <[email protected]>
Signed-off-by: NeilBrown <[email protected]>

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Further tidyup of raid6 naming in lib/raid6

Rename raid6/raid6x86.h to raid6/x86.h
and modify some comments.

Signed-off-by: NeilBrown <[email protected]>

Rename raid6 files now they're in a 'raid6' directory.

Linus asks 'why "raid6" twice?'. No reason.

Signed-off-by: David Woodhouse <[email protected]>