Commit 0774a6ed authored by Arnd Bergmann's avatar Arnd Bergmann
Browse files

timekeeping: default GENERIC_CLOCKEVENTS to enabled 



Almost all machines use GENERIC_CLOCKEVENTS, so it feels wrong to
require each one to select that symbol manually.

Instead, enable it whenever CONFIG_LEGACY_TIMER_TICK is disabled as
a simplification. It should be possible to select both
GENERIC_CLOCKEVENTS and LEGACY_TIMER_TICK from an architecture now
and decide at runtime between the two.

For the clockevents arch-support.txt file, this means that additional
architectures are marked as TODO when they have at least one machine
that still uses LEGACY_TIMER_TICK, rather than being marked 'ok' when
at least one machine has been converted. This means that both m68k and
arm (for riscpc) revert to TODO.

At this point, we could just always enable CONFIG_GENERIC_CLOCKEVENTS
rather than leaving it off when not needed. I built an m68k
defconfig kernel (using gcc-10.1.0) and found that this would add
around 5.5KB in kernel image size:

   text	   data	    bss	    dec	    hex	filename
3861936	1092236	 196656	5150828	 4e986c	obj-m68k/vmlinux-no-clockevent
3866201	1093832	 196184	5156217	 4ead79	obj-m68k/vmlinux-clockevent

On Arm (MACH_RPC), that difference appears to be twice as large,
around 11KB on top of an 6MB vmlinux.

Reviewed-by: default avatarGeert Uytterhoeven <geert@linux-m68k.org>
Acked-by: default avatarGeert Uytterhoeven <geert@linux-m68k.org>
Tested-by: default avatarGeert Uytterhoeven <geert@linux-m68k.org>
Reviewed-by: default avatarLinus Walleij <linus.walleij@linaro.org>
Signed-off-by: default avatarArnd Bergmann <arnd@arndb.de>
parent 56cc7b8a

Documentation/features/time/clockevents/arch-support.txt

+3 −3
Original line number Diff line number Diff line 
#

# Feature name:          clockevents

#         Kconfig:       GENERIC_CLOCKEVENTS

#         Kconfig:       !LEGACY_TIMER_TICK

#         description:   arch support generic clock events

#

    -----------------------
@@ -8,14 +8,14 @@ 
    -----------------------

    |       alpha: |  ok  |

    |         arc: |  ok  |

    |         arm: |  ok  |

    |         arm: | TODO |

    |       arm64: |  ok  |

    |         c6x: |  ok  |

    |        csky: |  ok  |

    |       h8300: |  ok  |

    |     hexagon: |  ok  |

    |        ia64: | TODO |

    |        m68k: |  ok  |

    |        m68k: | TODO |

    |  microblaze: |  ok  |

    |        mips: |  ok  |

    |       nds32: |  ok  |

arch/alpha/Kconfig

+0 −1
Original line number Diff line number Diff line
@@ -27,7 +27,6 @@ config ALPHA 
	select ARCH_WANT_IPC_PARSE_VERSION

	select ARCH_HAVE_NMI_SAFE_CMPXCHG

	select AUDIT_ARCH

	select GENERIC_CLOCKEVENTS

	select GENERIC_CPU_VULNERABILITIES

	select GENERIC_SMP_IDLE_THREAD

	select GENERIC_STRNCPY_FROM_USER

arch/arc/Kconfig

+0 −1
Original line number Diff line number Diff line
@@ -19,7 +19,6 @@ config ARC 
	select COMMON_CLK

	select DMA_DIRECT_REMAP

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

	select GENERIC_CLOCKEVENTS

	select GENERIC_FIND_FIRST_BIT

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

	select GENERIC_IRQ_SHOW

arch/arm/Kconfig

+0 −12
Original line number Diff line number Diff line
@@ -321,7 +321,6 @@ config ARCH_MULTIPLATFORM 
	select AUTO_ZRELADDR

	select TIMER_OF

	select COMMON_CLK

	select GENERIC_CLOCKEVENTS

	select GENERIC_IRQ_MULTI_HANDLER

	select HAVE_PCI

	select PCI_DOMAINS_GENERIC if PCI
@@ -336,7 +335,6 @@ config ARM_SINGLE_ARMV7M 
	select TIMER_OF

	select COMMON_CLK

	select CPU_V7M

	select GENERIC_CLOCKEVENTS

	select NO_IOPORT_MAP

	select SPARSE_IRQ

	select USE_OF
@@ -351,7 +349,6 @@ config ARCH_EP93XX 
	select CLKDEV_LOOKUP

	select CLKSRC_MMIO

	select CPU_ARM920T

	select GENERIC_CLOCKEVENTS

	select GPIOLIB

	select HAVE_LEGACY_CLK

	help
@@ -361,7 +358,6 @@ config ARCH_FOOTBRIDGE 
	bool "FootBridge"

	select CPU_SA110

	select FOOTBRIDGE

	select GENERIC_CLOCKEVENTS

	select HAVE_IDE

	select NEED_MACH_IO_H if !MMU

	select NEED_MACH_MEMORY_H
@@ -389,7 +385,6 @@ config ARCH_IXP4XX 
	select ARCH_SUPPORTS_BIG_ENDIAN

	select CPU_XSCALE

	select DMABOUNCE if PCI

	select GENERIC_CLOCKEVENTS

	select GENERIC_IRQ_MULTI_HANDLER

	select GPIO_IXP4XX

	select GPIOLIB
@@ -405,7 +400,6 @@ config ARCH_IXP4XX 
config ARCH_DOVE

	bool "Marvell Dove"

	select CPU_PJ4

	select GENERIC_CLOCKEVENTS

	select GENERIC_IRQ_MULTI_HANDLER

	select GPIOLIB

	select HAVE_PCI
@@ -429,7 +423,6 @@ config ARCH_PXA 
	select CLKSRC_MMIO

	select TIMER_OF

	select CPU_XSCALE if !CPU_XSC3

	select GENERIC_CLOCKEVENTS

	select GENERIC_IRQ_MULTI_HANDLER

	select GPIO_PXA

	select GPIOLIB
@@ -470,7 +463,6 @@ config ARCH_SA1100 
	select COMMON_CLK

	select CPU_FREQ

	select CPU_SA1100

	select GENERIC_CLOCKEVENTS

	select GENERIC_IRQ_MULTI_HANDLER

	select GPIOLIB

	select HAVE_IDE
@@ -485,7 +477,6 @@ config ARCH_S3C24XX 
	bool "Samsung S3C24XX SoCs"

	select ATAGS

	select CLKSRC_SAMSUNG_PWM

	select GENERIC_CLOCKEVENTS

	select GPIO_SAMSUNG

	select GPIOLIB

	select GENERIC_IRQ_MULTI_HANDLER
@@ -509,7 +500,6 @@ config ARCH_OMAP1 
	select ARCH_OMAP

	select CLKDEV_LOOKUP

	select CLKSRC_MMIO

	select GENERIC_CLOCKEVENTS

	select GENERIC_IRQ_CHIP

	select GENERIC_IRQ_MULTI_HANDLER

	select GPIOLIB
@@ -772,7 +762,6 @@ config ARCH_ACORN 


config PLAT_IOP

	bool

	select GENERIC_CLOCKEVENTS



config PLAT_ORION

	bool
@@ -1163,7 +1152,6 @@ config HAVE_SMP 
config SMP

	bool "Symmetric Multi-Processing"

	depends on CPU_V6K || CPU_V7

	depends on GENERIC_CLOCKEVENTS

	depends on HAVE_SMP

	depends on MMU || ARM_MPU

	select IRQ_WORK

arch/arm64/Kconfig

+0 −1
Original line number Diff line number Diff line
@@ -101,7 +101,6 @@ config ARM64 
	select FRAME_POINTER

	select GENERIC_ALLOCATOR

	select GENERIC_ARCH_TOPOLOGY

	select GENERIC_CLOCKEVENTS

	select GENERIC_CLOCKEVENTS_BROADCAST

	select GENERIC_CPU_AUTOPROBE

	select GENERIC_CPU_VULNERABILITIES

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