[PATCH v2 00/18] Introduce and use generic parity16/32/64 helper

[Kuan-Wei Chiu <visitorckw@gmail.com>]

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>
---

This patch series is based on next-20250228.

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

Kuan-Wei Chiu (18):
  lib/parity: Add __builtin_parity() fallback implementations
  bitops: Optimize parity8() using __builtin_parity()
  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()
  bitops: Add parity() macro for automatic type-based selection

 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                           |  17 +--
 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                        | 115 ++++++++++++++++--
 lib/Makefile                                  |   2 +-
 lib/bch.c                                     |  14 +--
 lib/parity.c                                  |  48 ++++++++
 16 files changed, 185 insertions(+), 155 deletions(-)
 create mode 100644 lib/parity.c

-- 
2.34.1