From: Krzysztof Kozlowski Subject: Re: [PATCH 0/6] lib/crc32: treewide: Use existing define with polynomial Date: Wed, 18 Jul 2018 08:33:56 +0200 Message-ID: References: <20180717160541.3843-1-krzk@kernel.org> <20180718001258.GA210746@gmail.com> Mime-Version: 1.0 Content-Type: text/plain; charset="UTF-8" Cc: Herbert Xu , "David S. Miller" , Maxime Coquelin , Alexandre Torgue , Tom Lendacky , Siva Reddy Kallam , Prashant Sreedharan , Michael Chan , Fugang Duan , Pantelis Antoniou , Vitaly Bordug , Jose Abreu , Larry Finger , Florian Schilhabel , Greg Kroah-Hartman , Thomas Gleixner , linux-kernel@vger.kernel.org, linux-crypto@vger.kernel.org, linux-arm-kern To: Eric Biggers Return-path: In-Reply-To: <20180718001258.GA210746@gmail.com> Sender: linux-kernel-owner@vger.kernel.org List-Id: linux-crypto.vger.kernel.org On 18 July 2018 at 02:12, Eric Biggers 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