Introduce and use generic parity16/32/64 helper
| From: | Kuan-Wei Chiu <visitorckw-AT-gmail.com> | |
| To: | tglx-AT-linutronix.de, mingo-AT-redhat.com, bp-AT-alien8.de, dave.hansen-AT-linux.intel.com, x86-AT-kernel.org, jk-AT-ozlabs.org, joel-AT-jms.id.au, eajames-AT-linux.ibm.com, andrzej.hajda-AT-intel.com, neil.armstrong-AT-linaro.org, rfoss-AT-kernel.org, maarten.lankhorst-AT-linux.intel.com, mripard-AT-kernel.org, tzimmermann-AT-suse.de, airlied-AT-gmail.com, simona-AT-ffwll.ch, dmitry.torokhov-AT-gmail.com, mchehab-AT-kernel.org, awalls-AT-md.metrocast.net, hverkuil-AT-xs4all.nl, miquel.raynal-AT-bootlin.com, richard-AT-nod.at, vigneshr-AT-ti.com, louis.peens-AT-corigine.com, andrew+netdev-AT-lunn.ch, davem-AT-davemloft.net, edumazet-AT-google.com, pabeni-AT-redhat.com, parthiban.veerasooran-AT-microchip.com, arend.vanspriel-AT-broadcom.com, johannes-AT-sipsolutions.net, gregkh-AT-linuxfoundation.org, jirislaby-AT-kernel.org, yury.norov-AT-gmail.com, akpm-AT-linux-foundation.org | |
| Subject: | [PATCH v3 00/16] Introduce and use generic parity16/32/64 helper | |
| Date: | Fri, 07 Mar 2025 00:25:25 +0800 | |
| Message-ID: | <20250306162541.2633025-1-visitorckw@gmail.com> | |
| Cc: | hpa-AT-zytor.com, alistair-AT-popple.id.au, linux-AT-rasmusvillemoes.dk, Laurent.pinchart-AT-ideasonboard.com, jonas-AT-kwiboo.se, jernej.skrabec-AT-gmail.com, kuba-AT-kernel.org, linux-kernel-AT-vger.kernel.org, linux-fsi-AT-lists.ozlabs.org, dri-devel-AT-lists.freedesktop.org, linux-input-AT-vger.kernel.org, linux-media-AT-vger.kernel.org, linux-mtd-AT-lists.infradead.org, oss-drivers-AT-corigine.com, netdev-AT-vger.kernel.org, linux-wireless-AT-vger.kernel.org, brcm80211-AT-lists.linux.dev, brcm80211-dev-list.pdl-AT-broadcom.com, linux-serial-AT-vger.kernel.org, bpf-AT-vger.kernel.org, jserv-AT-ccns.ncku.edu.tw, Kuan-Wei Chiu <visitorckw-AT-gmail.com>, Yu-Chun Lin <eleanor15x-AT-gmail.com> | |
| Archive-link: | Article |
Several parts of the kernel contain redundant implementations of parity calculations for 16/32/64-bit values. Introduces generic parity16/32/64() helpers in bitops.h, providing a standardized and optimized implementation. Subsequent patches refactor various kernel components to replace open-coded parity calculations with the new helpers, reducing code duplication and improving maintainability. Co-developed-by: Yu-Chun Lin <eleanor15x@gmail.com> Signed-off-by: Yu-Chun Lin <eleanor15x@gmail.com> Signed-off-by: Kuan-Wei Chiu <visitorckw@gmail.com> --- In v3, I use parityXX() instead of the parity() macro since the parity() macro may generate suboptimal code and requires special hacks to make GCC happy. If anyone still prefers a single parity() macro, please let me know. Additionally, I changed parityXX() << y users to !!parityXX() << y because, unlike C++, C does not guarantee that true casts to int as 1. Changes in v3: - Avoid using __builtin_parity. - Change return type to bool. - Drop parity() macro. - Change parityXX() << y to !!parityXX() << y. Changes in v2: - Provide fallback functions for __builtin_parity() when the compiler decides not to inline it - Use __builtin_parity() when no architecture-specific implementation is available - Optimize for constant folding when val is a compile-time constant - Add a generic parity() macro - Drop the x86 bootflag conversion patch since it has been merged into the tip tree v1: https://lore.kernel.org/lkml/20250223164217.2139331-1-vis... v2: https://lore.kernel.org/lkml/20250301142409.2513835-1-vis... Kuan-Wei Chiu (16): bitops: Change parity8() return type to bool bitops: Add parity16(), parity32(), and parity64() helpers media: media/test_drivers: Replace open-coded parity calculation with parity8() media: pci: cx18-av-vbi: Replace open-coded parity calculation with parity8() media: saa7115: Replace open-coded parity calculation with parity8() serial: max3100: Replace open-coded parity calculation with parity8() lib/bch: Replace open-coded parity calculation with parity32() Input: joystick - Replace open-coded parity calculation with parity32() net: ethernet: oa_tc6: Replace open-coded parity calculation with parity32() wifi: brcm80211: Replace open-coded parity calculation with parity32() drm/bridge: dw-hdmi: Replace open-coded parity calculation with parity32() mtd: ssfdc: Replace open-coded parity calculation with parity32() fsi: i2cr: Replace open-coded parity calculation with parity32() fsi: i2cr: Replace open-coded parity calculation with parity64() Input: joystick - Replace open-coded parity calculation with parity64() nfp: bpf: Replace open-coded parity calculation with parity64() drivers/fsi/fsi-master-i2cr.c | 18 ++----- .../drm/bridge/synopsys/dw-hdmi-ahb-audio.c | 8 +-- drivers/input/joystick/grip_mp.c | 17 +----- drivers/input/joystick/sidewinder.c | 24 ++------- drivers/media/i2c/saa7115.c | 12 +---- drivers/media/pci/cx18/cx18-av-vbi.c | 12 +---- .../media/test-drivers/vivid/vivid-vbi-gen.c | 8 +-- drivers/mtd/ssfdc.c | 20 ++----- drivers/net/ethernet/netronome/nfp/nfp_asm.c | 7 +-- drivers/net/ethernet/oa_tc6.c | 19 ++----- .../broadcom/brcm80211/brcmsmac/dma.c | 16 +----- drivers/tty/serial/max3100.c | 3 +- include/linux/bitops.h | 52 +++++++++++++++++-- lib/bch.c | 14 +---- 14 files changed, 77 insertions(+), 153 deletions(-) -- 2.34.1