lib/crc64: rename CRC64-Rocksoft to CRC64-NVME

This CRC64 variant comes from the NVME NVM Command Set Specification
(https://nvmexpress.org/wp-content/uploads/NVM-Express-NVM-Command-Set-Specificati

lib/crc64: rename CRC64-Rocksoft to CRC64-NVME

This CRC64 variant comes from the NVME NVM Command Set Specification
(https://nvmexpress.org/wp-content/uploads/NVM-Express-NVM-Command-Set-Specification-1.0e-2024.07.29-Ratified.pdf).

The "Rocksoft Model CRC Algorithm", published in 1993 and available at
https://www.zlib.net/crc_v3.txt, is a generalized CRC algorithm that can
calculate any variant of CRC, given a list of parameters such as
polynomial, bit order, etc. It is not a CRC variant.

The NVME NVM Command Set Specification has a table that gives the
"Rocksoft Model Parameters" for the CRC variant it uses. When support
for this CRC variant was added to Linux, this table seems to have been
misinterpreted as naming the CRC variant the "Rocksoft" CRC. In fact,
the table names the CRC variant as the "NVM Express 64b CRC".

Most implementations of this CRC variant outside Linux have been calling
it CRC64-NVME. Therefore, update Linux to match.

While at it, remove the superfluous "update" from the function name, so
crc64_rocksoft_update() is now just crc64_nvme(), matching most of the
other CRC library functions.

Reviewed-by: Ard Biesheuvel <[email protected]>
Reviewed-by: "Martin K. Petersen" <[email protected]>
Acked-by: Keith Busch <[email protected]>
Link: https://lore.kernel.org/r/[email protected]
Signed-off-by: Eric Biggers <[email protected]>

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lib: add rocksoft model crc64

The NVM Express specification extended data integrity fields to 64 bits
using the Rocksoft parameters. Add the poly to the crc64 table
generation, and provide a generic

lib: add rocksoft model crc64

The NVM Express specification extended data integrity fields to 64 bits
using the Rocksoft parameters. Add the poly to the crc64 table
generation, and provide a generic library routine implementing the
algorithm.

The Rocksoft 64-bit CRC model parameters are as follows:
Poly: 0xAD93D23594C93659
Initial value: 0xFFFFFFFFFFFFFFFF
Reflected Input: True
Reflected Output: True
Xor Final: 0xFFFFFFFFFFFFFFFF

Since this model used reflected bits, the implementation generates the
reflected table so the result is ordered consistently.

Cc: Christoph Hellwig <[email protected]>
Cc: Hannes Reinecke <[email protected]>
Cc: Martin K. Petersen <[email protected]>
Signed-off-by: Keith Busch <[email protected]>
Reviewed-by: Martin K. Petersen <[email protected]>
Link: https://lore.kernel.org/r/[email protected]
Signed-off-by: Jens Axboe <[email protected]>

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lib: don't depend on linux headers being installed.

gen_crc64table requires linux include files to be installed in
/usr/include/linux. This is a new requrement so hosts that could
previously build

lib: don't depend on linux headers being installed.

gen_crc64table requires linux include files to be installed in
/usr/include/linux. This is a new requrement so hosts that could
previously build the kernel, now cannot.

gen_crc64table makes this requirement by including <linux/swab.h>, but
nothing from that header is actaully used.

So remove the #include, so that the linux headers no longer need to be
installed.

Fixes: feba04fd2cf8 ("lib: add crc64 calculation routines")
Signed-off-by: NeilBrown <[email protected]>
Acked-by: Coly Li <[email protected]>
Signed-off-by: Linus Torvalds <[email protected]>

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lib: add crc64 calculation routines

Patch series "add crc64 calculation as kernel library", v5.

This patchset adds basic implementation of crc64 calculation as a Linux
kernel library. Since bcache

lib: add crc64 calculation routines

Patch series "add crc64 calculation as kernel library", v5.

This patchset adds basic implementation of crc64 calculation as a Linux
kernel library. Since bcache already does crc64 by itself, this patchset
also modifies bcache code to use the new crc64 library routine.

Currently bcache is the only user of crc64 calculation, another potential
user is bcachefs which is on the way to be in mainline kernel. Therefore
it makes sense to make crc64 calculation to be a public library.

bcache uses crc64 as storage checksum, if a change of crc lib routines
results an inconsistent result, the unmatched checksum may make bcache
'think' the on-disk is corrupted, such a change should be avoided or
detected as early as possible. Therefore a patch is being prepared which
adds a crc test framework, to check consistency of different calculations.

This patch (of 2):

Add the re-write crc64 calculation routines for Linux kernel. The CRC64
polynomical arithmetic follows ECMA-182 specification, inspired by CRC
paper of Dr. Ross N. Williams (see
http://www.ross.net/crc/download/crc_v3.txt) and other public domain
implementations.

All the changes work in this way,
- When Linux kernel is built, host program lib/gen_crc64table.c will be
compiled to lib/gen_crc64table and executed.
- The output of gen_crc64table execution is an array called as lookup
table (a.k.a POLY 0x42f0e1eba9ea369) which contain 256 64-bit long
numbers, this table is dumped into header file lib/crc64table.h.
- Then the header file is included by lib/crc64.c for normal 64bit crc
calculation.
- Function declaration of the crc64 calculation routines is placed in
include/linux/crc64.h

Currently bcache is the only user of crc64_be(), another potential user is
bcachefs which is on the way to be in mainline kernel. Therefore it makes
sense to move crc64 calculation into lib/crc64.c as public code.

[[email protected]: fix review comments from v4]
Link: http://lkml.kernel.org/r/[email protected]
Link: http://lkml.kernel.org/r/[email protected]
Signed-off-by: Coly Li <[email protected]>
Co-developed-by: Andy Shevchenko <[email protected]>
Signed-off-by: Andy Shevchenko <[email protected]>
Reviewed-by: Hannes Reinecke <[email protected]>
Cc: Greg Kroah-Hartman <[email protected]>
Cc: Andy Shevchenko <[email protected]>
Cc: Michael Lyle <[email protected]>
Cc: Kent Overstreet <[email protected]>
Cc: Thomas Gleixner <[email protected]>
Cc: Kate Stewart <[email protected]>
Cc: Eric Biggers <[email protected]>
Cc: Randy Dunlap <[email protected]>
Cc: Noah Massey <[email protected]>
Signed-off-by: Andrew Morton <[email protected]>
Signed-off-by: Linus Torvalds <[email protected]>

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