[PATCH 0/9] bitfield: add FIELD_GET_SIGNED()

[Yury Norov <ynorov@nvidia.com>]

The bitfields are designed in assumption that fields contain unsigned
integer values, thus extracting the values from the field implies
zero-extending.

Some drivers need to sign-extend their fields, and currently do it like:

	dc_re += sign_extend32(FIELD_GET(0xfff000, tmp), 11);
	dc_im += sign_extend32(FIELD_GET(0xfff, tmp), 11);

It's error-prone because it relies on user to provide the correct
index of the most significant bit.

This series adds a signed version of FIELD_GET(), which is the more
convenient and compiles (on x86_64) to just a couple instructions:
shl and sar.

Patch #1 adds FIELD_GET_SIGNED(), and the rest of the series applies it
tree-wide.

Yury Norov (9):
  bitfield: add FIELD_GET_SIGNED()
  x86/extable: switch to using FIELD_GET_SIGNED()
  iio: intel_dc_ti_adc: switch to using
  iio: magnetometer: yas530: switch to using FIELD_GET_SIGNED()
  iio: pressure: bmp280: switch to using
  iio: mcp9600: switch to using FIELD_GET_SIGNED()
  wifi: rtw89: switch to using FIELD_GET_SIGNED()
  rtc: rv3032: switch to using FIELD_GET_SIGNED()
  ptp: switch to using FIELD_GET_SIGNED()

 arch/x86/include/asm/extable_fixup_types.h       | 13 ++++---------
 arch/x86/mm/extable.c                            |  2 +-
 drivers/iio/adc/intel_dc_ti_adc.c                |  4 ++--
 drivers/iio/magnetometer/yamaha-yas530.c         | 12 ++++++------
 drivers/iio/pressure/bmp280-core.c               |  2 +-
 drivers/iio/temperature/mcp9600.c                |  2 +-
 .../net/wireless/realtek/rtw89/rtw8852a_rfk.c    |  4 ++--
 .../net/wireless/realtek/rtw89/rtw8852b_common.c |  4 ++--
 .../net/wireless/realtek/rtw89/rtw8852b_rfk.c    |  4 ++--
 drivers/net/wireless/realtek/rtw89/rtw8852c.c    |  4 ++--
 drivers/ptp/ptp_fc3.c                            |  4 ++--
 drivers/rtc/rtc-rv3032.c                         |  2 +-
 include/linux/bitfield.h                         | 16 ++++++++++++++++
 13 files changed, 42 insertions(+), 31 deletions(-)

-- 
2.51.0