Commit c126a53c authored by Yury Norov's avatar Yury Norov
Browse files

arch: remove GENERIC_FIND_FIRST_BIT entirely 

In 5.12 cycle we enabled GENERIC_FIND_FIRST_BIT config option for ARM64
and MIPS. It increased performance and shrunk .text size; and so far
I didn't receive any negative feedback on the change.

https://lore.kernel.org/linux-arch/20210225135700.1381396-1-yury.norov@gmail.com/



Now I think it's a good time to switch all architectures to use
find_{first,last}_bit() unconditionally, and so remove corresponding
config option.

The patch does't introduce functioal changes for arc, arm, arm64, mips,
m68k, s390 and x86, for other architectures I expect improvement both in
performance and .text size.

Signed-off-by: default avatarYury Norov <yury.norov@gmail.com>
Tested-by: Alexander Lobakin <alobakin@pm.me> (mips)
Reviewed-by: Alexander Lobakin <alobakin@pm.me> (mips)
Reviewed-by: default avatarAndy Shevchenko <andriy.shevchenko@linux.intel.com>
Acked-by: default avatarWill Deacon <will@kernel.org>
Tested-by: default avatarWolfram Sang <wsa+renesas@sang-engineering.com>
parent 47d8c156

arch/arc/Kconfig

+0 −1
Original line number Diff line number Diff line
@@ -20,7 +20,6 @@ config ARC 
	select COMMON_CLK

	select DMA_DIRECT_REMAP

	select GENERIC_ATOMIC64 if !ISA_ARCV2 || !(ARC_HAS_LL64 && ARC_HAS_LLSC)

	select GENERIC_FIND_FIRST_BIT

	# for now, we don't need GENERIC_IRQ_PROBE, CONFIG_GENERIC_IRQ_CHIP

	select GENERIC_IRQ_SHOW

	select GENERIC_PCI_IOMAP

arch/arm64/Kconfig

+0 −1
Original line number Diff line number Diff line
@@ -120,7 +120,6 @@ config ARM64 
	select GENERIC_CPU_AUTOPROBE

	select GENERIC_CPU_VULNERABILITIES

	select GENERIC_EARLY_IOREMAP

	select GENERIC_FIND_FIRST_BIT

	select GENERIC_IDLE_POLL_SETUP

	select GENERIC_IRQ_IPI

	select GENERIC_IRQ_PROBE

arch/mips/Kconfig

+0 −1
Original line number Diff line number Diff line
@@ -32,7 +32,6 @@ config MIPS 
	select GENERIC_ATOMIC64 if !64BIT

	select GENERIC_CMOS_UPDATE

	select GENERIC_CPU_AUTOPROBE

	select GENERIC_FIND_FIRST_BIT

	select GENERIC_GETTIMEOFDAY

	select GENERIC_IOMAP

	select GENERIC_IRQ_PROBE

arch/s390/Kconfig

+0 −1
Original line number Diff line number Diff line
@@ -127,7 +127,6 @@ config S390 
	select GENERIC_CPU_AUTOPROBE

	select GENERIC_CPU_VULNERABILITIES

	select GENERIC_ENTRY

	select GENERIC_FIND_FIRST_BIT

	select GENERIC_GETTIMEOFDAY

	select GENERIC_PTDUMP

	select GENERIC_SMP_IDLE_THREAD

arch/x86/Kconfig

+0 −1
Original line number Diff line number Diff line
@@ -136,7 +136,6 @@ config X86 
	select GENERIC_CPU_VULNERABILITIES

	select GENERIC_EARLY_IOREMAP

	select GENERIC_ENTRY

	select GENERIC_FIND_FIRST_BIT

	select GENERIC_IOMAP

	select GENERIC_IRQ_EFFECTIVE_AFF_MASK	if SMP

	select GENERIC_IRQ_MATRIX_ALLOCATOR	if X86_LOCAL_APIC