zlib: move EXPORT_SYMBOL() and MODULE_LICENSE() out of dfltcc_syms.c

In commit 11fb479ff5d9 ("zlib: export S390 symbols for zlib modules"), I
added EXPORT_SYMBOL()s to dfltcc_inflate.c but then Mikh

zlib: move EXPORT_SYMBOL() and MODULE_LICENSE() out of dfltcc_syms.c

In commit 11fb479ff5d9 ("zlib: export S390 symbols for zlib modules"), I
added EXPORT_SYMBOL()s to dfltcc_inflate.c but then Mikhail said that
these should probably be in dfltcc_syms.c with the other
EXPORT_SYMBOL()s.

However, that is contrary to the current kernel style, which places
EXPORT_SYMBOL() immediately after the function that it applies to, so
move all EXPORT_SYMBOL()s to their respective function locations and
drop the dfltcc_syms.c file. Also move MODULE_LICENSE() from the
deleted file to dfltcc.c.

[[email protected]: remove dfltcc_syms.o from Makefile]
Link: https://lkml.kernel.org/r/[email protected]

Link: https://lkml.kernel.org/r/[email protected]
Fixes: 11fb479ff5d9 ("zlib: export S390 symbols for zlib modules")
Signed-off-by: Randy Dunlap <[email protected]>
Cc: Acked-by: Ilya Leoshkevich <[email protected]>
Acked-by: Christian Borntraeger <[email protected]>
Cc: Zaslonko Mikhail <[email protected]>
Cc: Heiko Carstens <[email protected]>
Cc: Vasily Gorbik <[email protected]>
Signed-off-by: Andrew Morton <[email protected]>
Signed-off-by: Linus Torvalds <[email protected]>

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kbuild: trace functions in subdirectories of lib/

ccflags-remove-$(CONFIG_FUNCTION_TRACER) += $(CC_FLAGS_FTRACE)

exists here in sub-directories of lib/ to keep the behavior of
commit 2464a609ded0 (

kbuild: trace functions in subdirectories of lib/

ccflags-remove-$(CONFIG_FUNCTION_TRACER) += $(CC_FLAGS_FTRACE)

exists here in sub-directories of lib/ to keep the behavior of
commit 2464a609ded0 ("ftrace: do not trace library functions").

Since that commit, not only the objects in lib/ but also the ones in
the sub-directories are excluded from ftrace (although the commit
description did not explicitly mention this).

However, most of library functions in sub-directories are not so hot.
Re-add them to ftrace.

Going forward, only the objects right under lib/ will be excluded.

Cc: Ingo Molnar <[email protected]>
Signed-off-by: Masahiro Yamada <[email protected]>
Acked-by: Steven Rostedt (VMware) <[email protected]>

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kbuild: introduce ccflags-remove-y and asflags-remove-y

CFLAGS_REMOVE_<file>.o filters out flags when compiling a particular
object, but there is no convenient way to do that for every object in
a d

kbuild: introduce ccflags-remove-y and asflags-remove-y

CFLAGS_REMOVE_<file>.o filters out flags when compiling a particular
object, but there is no convenient way to do that for every object in
a directory.

Add ccflags-remove-y and asflags-remove-y to make it easily.

Use ccflags-remove-y to clean up some Makefiles.

The add/remove order works as follows:

[1] KBUILD_CFLAGS specifies compiler flags used globally

[2] ccflags-y adds compiler flags for all objects in the
current Makefile

[3] ccflags-remove-y removes compiler flags for all objects in the
current Makefile (New feature)

[4] CFLAGS_<file> adds compiler flags per file.

[5] CFLAGS_REMOVE_<file> removes compiler flags per file.

Having [3] before [4] allows us to remove flags from most (but not all)
objects in the current Makefile.

For example, kernel/trace/Makefile removes $(CC_FLAGS_FTRACE)
from all objects in the directory, then adds it back to
trace_selftest_dynamic.o and CFLAGS_trace_kprobe_selftest.o

The same applies to lib/livepatch/Makefile.

Please note ccflags-remove-y has no effect to the sub-directories.
In contrast, the previous notation got rid of compiler flags also from
all the sub-directories.

The following are not affected because they have no sub-directories:

arch/arm/boot/compressed/
arch/powerpc/xmon/
arch/sh/
kernel/trace/

However, lib/ has several sub-directories.

To keep the behavior, I added ccflags-remove-y to all Makefiles
in subdirectories of lib/, except the following:

lib/vdso/Makefile - Kbuild does not descend into this Makefile
lib/raid/test/Makefile - This is not used for the kernel build

I think commit 2464a609ded0 ("ftrace: do not trace library functions")
excluded too much. In the next commit, I will remove ccflags-remove-y
from the sub-directories of lib/.

Suggested-by: Sami Tolvanen <[email protected]>
Signed-off-by: Masahiro Yamada <[email protected]>
Acked-by: Steven Rostedt (VMware) <[email protected]>
Acked-by: Michael Ellerman <[email protected]> (powerpc)
Acked-by: Brendan Higgins <[email protected]> (KUnit)
Tested-by: Anders Roxell <[email protected]>

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lib/zlib: add s390 hardware support for kernel zlib_inflate

Add decompression functions to zlib_dfltcc library. Update zlib_inflate
functions with the hooks for s390 hardware support and adjust wor

lib/zlib: add s390 hardware support for kernel zlib_inflate

Add decompression functions to zlib_dfltcc library. Update zlib_inflate
functions with the hooks for s390 hardware support and adjust workspace
structures with extra parameter lists required for hardware inflate
decompression.

Link: http://lkml.kernel.org/r/[email protected]
Signed-off-by: Ilya Leoshkevich <[email protected]>
Signed-off-by: Mikhail Zaslonko <[email protected]>
Co-developed-by: Ilya Leoshkevich <[email protected]>
Cc: Chris Mason <[email protected]>
Cc: Christian Borntraeger <[email protected]>
Cc: David Sterba <[email protected]>
Cc: Eduard Shishkin <[email protected]>
Cc: Heiko Carstens <[email protected]>
Cc: Josef Bacik <[email protected]>
Cc: Richard Purdie <[email protected]>
Cc: Vasily Gorbik <[email protected]>
Signed-off-by: Andrew Morton <[email protected]>
Signed-off-by: Linus Torvalds <[email protected]>

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lib/zlib: add s390 hardware support for kernel zlib_deflate

Patch series "S390 hardware support for kernel zlib", v3.

With IBM z15 mainframe the new DFLTCC instruction is available. It
implements

lib/zlib: add s390 hardware support for kernel zlib_deflate

Patch series "S390 hardware support for kernel zlib", v3.

With IBM z15 mainframe the new DFLTCC instruction is available. It
implements deflate algorithm in hardware (Nest Acceleration Unit - NXU)
with estimated compression and decompression performance orders of
magnitude faster than the current zlib.

This patchset adds s390 hardware compression support to kernel zlib.
The code is based on the userspace zlib implementation:

https://github.com/madler/zlib/pull/410

The coding style is also preserved for future maintainability. There is
only limited set of userspace zlib functions represented in kernel.
Apart from that, all the memory allocation should be performed in
advance. Thus, the workarea structures are extended with the parameter
lists required for the DEFLATE CONVENTION CALL instruction.

Since kernel zlib itself does not support gzip headers, only Adler-32
checksum is processed (also can be produced by DFLTCC facility). Like
it was implemented for userspace, kernel zlib will compress in hardware
on level 1, and in software on all other levels. Decompression will
always happen in hardware (when enabled).

Two DFLTCC compression calls produce the same results only when they
both are made on machines of the same generation, and when the
respective buffers have the same offset relative to the start of the
page. Therefore care should be taken when using hardware compression
when reproducible results are desired. However it does always produce
the standard conform output which can be inflated anyway.

The new kernel command line parameter 'dfltcc' is introduced to
configure s390 zlib hardware support:

Format: { on | off | def_only | inf_only | always }
on: s390 zlib hardware support for compression on
level 1 and decompression (default)
off: No s390 zlib hardware support
def_only: s390 zlib hardware support for deflate
only (compression on level 1)
inf_only: s390 zlib hardware support for inflate
only (decompression)
always: Same as 'on' but ignores the selected compression
level always using hardware support (used for debugging)

The main purpose of the integration of the NXU support into the kernel
zlib is the use of hardware deflate in btrfs filesystem with on-the-fly
compression enabled. Apart from that, hardware support can also be used
during boot for decompressing the kernel or the ramdisk image

With the patch for btrfs expanding zlib buffer from 1 to 4 pages (patch
6) the following performance results have been achieved using the
ramdisk with btrfs. These are relative numbers based on throughput rate
and compression ratio for zlib level 1:

Input data Deflate rate Inflate rate Compression ratio
NXU/Software NXU/Software NXU/Software
stream of zeroes 1.46 1.02 1.00
random ASCII data 10.44 3.00 0.96
ASCII text (dickens) 6,21 3.33 0.94
binary data (vmlinux) 8,37 3.90 1.02

This means that s390 hardware deflate can provide up to 10 times faster
compression (on level 1) and up to 4 times faster decompression (refers
to all compression levels) for btrfs zlib.

Disclaimer: Performance results are based on IBM internal tests using DD
command-line utility on btrfs on a Fedora 30 based internal driver in
native LPAR on a z15 system. Results may vary based on individual
workload, configuration and software levels.

This patch (of 9):

Create zlib_dfltcc library with the s390 DEFLATE CONVERSION CALL
implementation and related compression functions. Update zlib_deflate
functions with the hooks for s390 hardware support and adjust workspace
structures with extra parameter lists required for hardware deflate.

Link: http://lkml.kernel.org/r/[email protected]
Signed-off-by: Ilya Leoshkevich <[email protected]>
Signed-off-by: Mikhail Zaslonko <[email protected]>
Co-developed-by: Ilya Leoshkevich <[email protected]>
Cc: Chris Mason <[email protected]>
Cc: Christian Borntraeger <[email protected]>
Cc: David Sterba <[email protected]>
Cc: Eduard Shishkin <[email protected]>
Cc: Heiko Carstens <[email protected]>
Cc: Josef Bacik <[email protected]>
Cc: Richard Purdie <[email protected]>
Cc: Vasily Gorbik <[email protected]>
Signed-off-by: Andrew Morton <[email protected]>
Signed-off-by: Linus Torvalds <[email protected]>

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