Re: [PATCH 0/6] lib/crc32: treewide: Use existing define with polynomial

[Eric Biggers]

Hi Krzysztof,

On Tue, Jul 17, 2018 at 06:05:35PM +0200, Krzysztof Kozlowski wrote:
> Hi,
> 
> Kernel defines same polynomial for CRC-32 in few places.
> This is unnecessary duplication of the same value. Also this might
> be error-prone for future code - every driver will define the
> polynomial again.
> 
> This is an attempt to unify definition of polynomial.  Few obvious
> hard-coded locations are fixed with define.
> 
> All series depend on each 1/6 and 2/6.
> 
> This could be merged in two different merge windows (1st lib/crc and then
> the rest) or taken through one tree.
> 
> It would be nice to get some testing. Only generic lib/crc, bunzip, xz_crc32
> and Freescale's Ethernet driver were tested on HW.  Rest got just different
> builds.
> 
> Best regards,
> Krzysztof
> 
> Krzysztof Kozlowski (6):
>   lib/crc: Move polynomial definition to separate header
>   lib/crc: Use consistent naming for CRC-32 polynomials
>   crypto: stm32_crc32 - Use existing define with polynomial
>   net: ethernet: Use existing define with polynomial
>   staging: rtl: Use existing define with polynomial
>   lib: Use existing define with polynomial
> 
>  drivers/crypto/stm32/stm32_crc32.c               | 11 ++++-------
>  drivers/net/ethernet/amd/xgbe/xgbe-dev.c         |  4 ++--
>  drivers/net/ethernet/apple/bmac.c                |  8 ++------
>  drivers/net/ethernet/broadcom/tg3.c              |  3 ++-
>  drivers/net/ethernet/freescale/fec_main.c        |  4 ++--
>  drivers/net/ethernet/freescale/fs_enet/fec.h     |  3 ---
>  drivers/net/ethernet/freescale/fs_enet/mac-fec.c |  3 ++-
>  drivers/net/ethernet/micrel/ks8851_mll.c         |  3 ++-
>  drivers/net/ethernet/synopsys/dwc-xlgmac-hw.c    |  4 ++--
>  drivers/staging/rtl8712/rtl871x_security.c       |  5 ++---
>  drivers/staging/rtl8723bs/core/rtw_security.c    |  5 ++---
>  include/linux/crc32poly.h                        | 20 ++++++++++++++++++++
>  lib/crc32.c                                      | 11 ++++++-----
>  lib/crc32defs.h                                  | 14 --------------
>  lib/decompress_bunzip2.c                         |  3 ++-
>  lib/gen_crc32table.c                             |  5 +++--
>  lib/xz/xz_crc32.c                                |  3 ++-
>  17 files changed, 55 insertions(+), 54 deletions(-)
>  create mode 100644 include/linux/crc32poly.h
> 

Did you check whether any of these users can be converted to use the CRC
implementations in lib/, so they wouldn't need the polynomial definition
themselves?

- Eric