On 18 July 2018 at 02:12, Eric Biggers <ebiggers3@xxxxxxxxx> wrote:
> 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?
I did not check but that's interesting point... The Ethernet drivers
(xgbe, tg3, fec, ks8851, dwc-xlgmac) look like could be converted to
generic implementation. The apple/bmac looks weird. The rtl WiFi
drivers in long term can be converted to use generic lib80211 for
encryption (see commit 0d4876f4e977 ("staging:r8188eu: Use lib80211 to
encrypt (TKIP) tx frames")) but that is much bigger task. The
remaining use the polynomials in different aspect:
1. XZ and BUNZIP use it to create CRC tables - probably generic
gen_crc32table.c could be used,
2. stm32_crc32.c uses it to initialize HW CRC accelerator.
I can work on Freescale FEC, xz and bunzip code because these I can
test but I would prefer to do it as follow up.
Best regards,
Krzysztof
