crypto: nx - fix build warnings when DEBUG_FS is not enabled

Fix build warnings when DEBUG_FS is not enabled by using an empty
do-while loop instead of a value:

In file included from ../drivers/crypto/nx/nx.c:27:
../drivers/crypto/nx/nx.c: In function 'nx_register_algs':
../drivers/crypto/nx/nx.h:173:33: warning: statement with no effect [-Wunused-value]
173 | #define NX_DEBUGFS_INIT(drv) (0)
../drivers/crypto/nx/nx.c:573:9: note: in expansion of macro 'NX_DEBUGFS_INIT'
573 | NX_DEBUGFS_INIT(&nx_driver);
../drivers/crypto/nx/nx.c: In function 'nx_remove':
../drivers/crypto/nx/nx.h:174:33: warning: statement with no effect [-Wunused-value]
174 | #define NX_DEBUGFS_FINI(drv) (0)
../drivers/crypto/nx/nx.c:793:17: note: in expansion of macro 'NX_DEBUGFS_FINI'
793 | NX_DEBUGFS_FINI(&nx_driver);

Also, there is no need to build nx_debugfs.o when DEBUG_FS is not
enabled, so change the Makefile to accommodate that.

Fixes: ae0222b7289d ("powerpc/crypto: nx driver code supporting nx encryption")
Fixes: aef7b31c8833 ("powerpc/crypto: Build files for the nx device driver")
Signed-off-by: Randy Dunlap <rdunlap@infradead.org>
Cc: Breno Leitão <leitao@debian.org>
Cc: Nayna Jain <nayna@linux.ibm.com>
Cc: Paulo Flabiano Smorigo <pfsmorigo@gmail.com>
Cc: Herbert Xu <herbert@gondor.apana.org.au>
Cc: "David S. Miller" <davem@davemloft.net>
Cc: linux-crypto@vger.kernel.org
Cc: Michael Ellerman <mpe@ellerman.id.au>
Cc: Nicholas Piggin <npiggin@gmail.com>
Cc: Christophe Leroy <christophe.leroy@csgroup.eu>
Cc: linuxppc-dev@lists.ozlabs.org
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>

crypto/nx: Rename nx-842-pseries file name to nx-common-pseries

Rename nx-842-pseries.c to nx-common-pseries.c to add code for new
GZIP compression type. The actual functionality is not changed in
this patch.

Signed-off-by: Haren Myneni <haren@linux.ibm.com>
Acked-by: Herbert Xu <herbert@gondor.apana.org.au>
Acked-by: Nicholas Piggin <npiggin@gmail.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/1fcf672209a14ea8944bd3e49c8a7381c8f450f8.camel@linux.ibm.com

crypto/nx: Rename nx-842-powernv file name to nx-common-powernv

Rename nx-842-powernv.c to nx-common-powernv.c to add code for setup
and enable new GZIP compression type. The actual functionality is not
changed in this patch.

Signed-off-by: Haren Myneni <haren@linux.ibm.com>
Acked-by: Herbert Xu <herbert@gondor.apana.org.au>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/1587114200.2275.1113.camel@hbabu-laptop

License cleanup: add SPDX GPL-2.0 license identifier to files with no license

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 & 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 >5
lines of source
- File already had some variant of a license header in it (even if <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 <kstewart@linuxfoundation.org>
Reviewed-by: Philippe Ombredanne <pombredanne@nexb.com>
Reviewed-by: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

crypto: nx - make platform drivers directly register with crypto

Remove the common 'platform' registration module, and move the crypto
compression driver registration into each of the pSeries and PowerNV
platform NX 842 drivers. Change the nx-842.c code into simple common
functions that each platform driver uses to perform constraints-based
buffer changes, i.e. realigning and/or resizing buffers to match the
driver's hardware requirements.

The common 'platform' module was my mistake to create - since each
platform driver will only load/operate when running on its own
platform (i.e. a pSeries platform or a PowerNV platform), they can
directly register with the crypto subsystem, using the same alg and
driver name. This removes unneeded complexity.

Signed-off-by: Dan Streetman <ddstreet@ieee.org>
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>

crypto: nx - rename nx-842-crypto.c to nx-842.c

The last commit merged nx-842.c's code into nx-842-crypto.c. It
did not rename nx-842-crypto.c to nx-842.c, in order to let the
patch more clearly show what was merged. This just renames
nx-842-crypto.c to nx-842.c, with no changes to its code.

Signed-off-by: Dan Streetman <ddstreet@ieee.org>
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>

crypto: nx - merge nx-compress and nx-compress-crypto

Merge the nx-842.c code into nx-842-crypto.c.

This allows later patches to remove the 'platform' driver, and instead
allow each platform driver to directly register with the crypto
compression api.

Signed-off-by: Dan Streetman <ddstreet@ieee.org>
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>

crypto: nx - prevent nx 842 load if no hw driver

Change the nx-842 common driver to wait for loading of both platform
drivers, and fail loading if the platform driver pointer is not set.
Add an independent platform driver pointer, that the platform drivers
set if they find they are able to load (i.e. if they find their platform
devicetree node(s)).

The problem is currently, the main nx-842 driver will stay loaded even
if there is no platform driver and thus no possible way it can do any
compression or decompression. This allows the crypto 842-nx driver
to load even if it won't actually work. For crypto compression users
(e.g. zswap) that expect an available crypto compression driver to
actually work, this is bad. This patch fixes that, so the 842-nx crypto
compression driver won't load if it doesn't have the driver and hardware
available to perform the compression.

Signed-off-by: Dan Streetman <ddstreet@ieee.org>
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>

crypto: nx - add hardware 842 crypto comp alg

Add crypto compression alg for 842 hardware compression and decompression,
using the alg name "842" and driver_name "842-nx".

This uses only the PowerPC coprocessor hardware for 842 compression. It
also uses the hardware for decompression, but if the hardware fails it will
fall back to the 842 software decompression library, so that decompression
never fails (for valid 842 compressed buffers). A header must be used in
most cases, due to the hardware's restrictions on the buffers being
specifically aligned and sized.

Due to the header this driver adds, compressed buffers it creates cannot be
directly passed to the 842 software library for decompression. However,
compressed buffers created by the software 842 library can be passed to
this driver for hardware 842 decompression (with the exception of buffers
containing the "short data" template, as lib/842/842.h explains).

Signed-off-by: Dan Streetman <ddstreet@ieee.org>
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>

crypto: nx - add PowerNV platform NX-842 driver

Add driver for NX-842 hardware on the PowerNV platform.

This allows the use of the 842 compression hardware coprocessor on
the PowerNV platform.

Signed-off-by: Dan Streetman <ddstreet@ieee.org>
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>

crypto: nx - add NX-842 platform frontend driver

Add NX-842 frontend that allows using either the pSeries platform or
PowerNV platform driver (to be added by later patch) for the NX-842
hardware. Update the MAINTAINERS file to include the new filenames.
Update Kconfig files to clarify titles and descriptions, and correct
dependencies.

Signed-off-by: Dan Streetman <ddstreet@ieee.org>
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>

crypto: nx - rename nx-842.c to nx-842-pseries.c

Move the entire NX-842 driver for the pSeries platform from the file
nx-842.c to nx-842-pseries.c. This is required by later patches that
add NX-842 support for the PowerNV platform.

This patch does not alter the content of the pSeries NX-842 driver at
all, it only changes the filename.

Signed-off-by: Dan Streetman <ddstreet@ieee.org>
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>

powerpc/crypto: add 842 hardware compression driver

This patch adds the driver for interacting with the 842
compression accelerator on IBM Power7+ systems.

The device is a child of the Platform Facilities Option (PFO)
and shows up as a child of the IBM VIO bus.

The compression/decompression API takes the same arguments
as existing compression methods like lzo and deflate. The 842
hardware operates on 4K hardware pages and the driver breaks up
input on 4K boundaries to submit it to the hardware accelerator.

Signed-off-by: Robert Jennings <rcj@linux.vnet.ibm.com>
Signed-off-by: Seth Jennings <sjenning@linux.vnet.ibm.com>
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>

powerpc/crypto: rework Kconfig

This patch creates a new submenu for the NX cryptographic
hardware accelerator and breaks the NX options into their own
Kconfig file under drivers/crypto/nx/Kconfig.

This will permit additional NX functionality to be easily
and more cleanly added in the future without touching
drivers/crypto/Makefile|Kconfig.

Signed-off-by: Seth Jennings <sjenning@linux.vnet.ibm.com>
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>

powerpc/crypto: Build files for the nx device driver

These files support configuring and building the nx device driver.

Signed-off-by: Kent Yoder <key@linux.vnet.ibm.com>
Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>