From: Arnd Bergmann <a...@arndb.de>

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: Geert Uytterhoeven <ge...@linux-m68k.org>
Acked-by: Geert Uytterhoeven <ge...@linux-m68k.org>
Tested-by: Geert Uytterhoeven <ge...@linux-m68k.org>
Reviewed-by: Linus Walleij <linus.wall...@linaro.org>
Signed-off-by: Arnd Bergmann <a...@arndb.de>
---
 .../features/time/clockevents/arch-support.txt       |  6 +++---
 arch/alpha/Kconfig                                   |  1 -
 arch/arc/Kconfig                                     |  1 -
 arch/arm/Kconfig                                     | 12 ------------
 arch/arm64/Kconfig                                   |  1 -
 arch/arm64/Kconfig.platforms                         |  1 -
 arch/c6x/Kconfig                                     |  1 -
 arch/csky/Kconfig                                    |  1 -
 arch/h8300/Kconfig                                   |  1 -
 arch/hexagon/Kconfig                                 |  1 -
 arch/m68k/Kconfig.cpu                                |  1 -
 arch/microblaze/Kconfig                              |  1 -
 arch/mips/Kconfig                                    |  1 -
 arch/nds32/Kconfig                                   |  1 -
 arch/nios2/Kconfig                                   |  1 -
 arch/openrisc/Kconfig                                |  1 -
 arch/powerpc/Kconfig                                 |  1 -
 arch/riscv/Kconfig                                   |  1 -
 arch/s390/Kconfig                                    |  1 -
 arch/sh/Kconfig                                      |  1 -
 arch/sparc/Kconfig                                   |  1 -
 arch/um/Kconfig                                      |  1 -
 arch/x86/Kconfig                                     |  1 -
 arch/xtensa/Kconfig                                  |  1 -
 kernel/time/Kconfig                                  |  2 +-
 25 files changed, 4 insertions(+), 38 deletions(-)

diff --git a/Documentation/features/time/clockevents/arch-support.txt 
b/Documentation/features/time/clockevents/arch-support.txt
index 61a5c9d68c15..6863a3fbddad 100644
--- a/Documentation/features/time/clockevents/arch-support.txt
+++ b/Documentation/features/time/clockevents/arch-support.txt
@@ -1,6 +1,6 @@
 #
 # 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  |
diff --git a/arch/alpha/Kconfig b/arch/alpha/Kconfig
index d6e9fc7a7b19..f0a700946cac 100644
--- a/arch/alpha/Kconfig
+++ b/arch/alpha/Kconfig
@@ -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
diff --git a/arch/arc/Kconfig b/arch/arc/Kconfig
index 0a89cc9def65..061eb8e23739 100644
--- a/arch/arc/Kconfig
+++ b/arch/arc/Kconfig
@@ -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
diff --git a/arch/arm/Kconfig b/arch/arm/Kconfig
index dbadfa186f72..04a37a4cd9e0 100644
--- a/arch/arm/Kconfig
+++ b/arch/arm/Kconfig
@@ -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
diff --git a/arch/arm64/Kconfig b/arch/arm64/Kconfig
index f858c352f72a..fee87e4104fd 100644
--- a/arch/arm64/Kconfig
+++ b/arch/arm64/Kconfig
@@ -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
diff --git a/arch/arm64/Kconfig.platforms b/arch/arm64/Kconfig.platforms
index 6f2494dd6d60..748e6d8c3b94 100644
--- a/arch/arm64/Kconfig.platforms
+++ b/arch/arm64/Kconfig.platforms
@@ -256,7 +256,6 @@ config ARCH_TEGRA
        select ARM_GIC_PM
        select CLKSRC_MMIO
        select TIMER_OF
-       select GENERIC_CLOCKEVENTS
        select GPIOLIB
        select PINCTRL
        select PM
diff --git a/arch/c6x/Kconfig b/arch/c6x/Kconfig
index 48d66bf0465d..bdeeac28b1be 100644
--- a/arch/c6x/Kconfig
+++ b/arch/c6x/Kconfig
@@ -19,7 +19,6 @@ config C6X
        select IRQ_DOMAIN
        select OF
        select OF_EARLY_FLATTREE
-       select GENERIC_CLOCKEVENTS
        select MODULES_USE_ELF_RELA
        select MMU_GATHER_NO_RANGE if MMU
        select SET_FS
diff --git a/arch/csky/Kconfig b/arch/csky/Kconfig
index 268fad5f51cf..28fdf8303dff 100644
--- a/arch/csky/Kconfig
+++ b/arch/csky/Kconfig
@@ -28,7 +28,6 @@ config CSKY
        select GENERIC_LIB_UCMPDI2
        select GENERIC_ALLOCATOR
        select GENERIC_ATOMIC64
-       select GENERIC_CLOCKEVENTS
        select GENERIC_CPU_DEVICES
        select GENERIC_IRQ_CHIP
        select GENERIC_IRQ_PROBE
diff --git a/arch/h8300/Kconfig b/arch/h8300/Kconfig
index 7945de067e9f..3e3e0f16f7e0 100644
--- a/arch/h8300/Kconfig
+++ b/arch/h8300/Kconfig
@@ -12,7 +12,6 @@ config H8300
        select FRAME_POINTER
        select GENERIC_CPU_DEVICES
        select MODULES_USE_ELF_RELA
-       select GENERIC_CLOCKEVENTS
        select COMMON_CLK
        select ARCH_WANT_FRAME_POINTERS
        select OF
diff --git a/arch/hexagon/Kconfig b/arch/hexagon/Kconfig
index f2afabbadd43..6e00c16a36b5 100644
--- a/arch/hexagon/Kconfig
+++ b/arch/hexagon/Kconfig
@@ -27,7 +27,6 @@ config HEXAGON
        select GENERIC_IOMAP
        select GENERIC_SMP_IDLE_THREAD
        select STACKTRACE_SUPPORT
-       select GENERIC_CLOCKEVENTS
        select GENERIC_CLOCKEVENTS_BROADCAST
        select MODULES_USE_ELF_RELA
        select GENERIC_CPU_DEVICES
diff --git a/arch/m68k/Kconfig.cpu b/arch/m68k/Kconfig.cpu
index 648054d4f860..ce09f993d858 100644
--- a/arch/m68k/Kconfig.cpu
+++ b/arch/m68k/Kconfig.cpu
@@ -318,7 +318,6 @@ config M54xx
 
 config COLDFIRE_PIT_TIMER
        bool
-       select GENERIC_CLOCKEVENTS
 
 config COLDFIRE_TIMERS
        bool
diff --git a/arch/microblaze/Kconfig b/arch/microblaze/Kconfig
index 33925ffed68f..2f0d3f431faf 100644
--- a/arch/microblaze/Kconfig
+++ b/arch/microblaze/Kconfig
@@ -17,7 +17,6 @@ config MICROBLAZE
        select COMMON_CLK
        select DMA_DIRECT_REMAP if MMU
        select GENERIC_ATOMIC64
-       select GENERIC_CLOCKEVENTS
        select GENERIC_CPU_DEVICES
        select GENERIC_IDLE_POLL_SETUP
        select GENERIC_IRQ_PROBE
diff --git a/arch/mips/Kconfig b/arch/mips/Kconfig
index 2000bb2b0220..077c4ae09550 100644
--- a/arch/mips/Kconfig
+++ b/arch/mips/Kconfig
@@ -21,7 +21,6 @@ config MIPS
        select CPU_NO_EFFICIENT_FFS if (TARGET_ISA_REV < 1)
        select CPU_PM if CPU_IDLE
        select GENERIC_ATOMIC64 if !64BIT
-       select GENERIC_CLOCKEVENTS
        select GENERIC_CMOS_UPDATE
        select GENERIC_CPU_AUTOPROBE
        select GENERIC_GETTIMEOFDAY
diff --git a/arch/nds32/Kconfig b/arch/nds32/Kconfig
index e8e541fd2267..62313902d75d 100644
--- a/arch/nds32/Kconfig
+++ b/arch/nds32/Kconfig
@@ -17,7 +17,6 @@ config NDS32
        select DMA_DIRECT_REMAP
        select GENERIC_ATOMIC64
        select GENERIC_CPU_DEVICES
-       select GENERIC_CLOCKEVENTS
        select GENERIC_IRQ_CHIP
        select GENERIC_IRQ_SHOW
        select GENERIC_IOREMAP
diff --git a/arch/nios2/Kconfig b/arch/nios2/Kconfig
index c7c6ba6bec9d..c24955c81c92 100644
--- a/arch/nios2/Kconfig
+++ b/arch/nios2/Kconfig
@@ -10,7 +10,6 @@ config NIOS2
        select COMMON_CLK
        select TIMER_OF
        select GENERIC_ATOMIC64
-       select GENERIC_CLOCKEVENTS
        select GENERIC_CPU_DEVICES
        select GENERIC_IRQ_PROBE
        select GENERIC_IRQ_SHOW
diff --git a/arch/openrisc/Kconfig b/arch/openrisc/Kconfig
index 6233c6293180..591acc5990dc 100644
--- a/arch/openrisc/Kconfig
+++ b/arch/openrisc/Kconfig
@@ -24,7 +24,6 @@ config OPENRISC
        select GENERIC_CPU_DEVICES
        select HAVE_UID16
        select GENERIC_ATOMIC64
-       select GENERIC_CLOCKEVENTS
        select GENERIC_CLOCKEVENTS_BROADCAST
        select GENERIC_STRNCPY_FROM_USER
        select GENERIC_STRNLEN_USER
diff --git a/arch/powerpc/Kconfig b/arch/powerpc/Kconfig
index e9f13fe08492..57e2c75f76e9 100644
--- a/arch/powerpc/Kconfig
+++ b/arch/powerpc/Kconfig
@@ -163,7 +163,6 @@ config PPC
        select EDAC_ATOMIC_SCRUB
        select EDAC_SUPPORT
        select GENERIC_ATOMIC64                 if PPC32
-       select GENERIC_CLOCKEVENTS
        select GENERIC_CLOCKEVENTS_BROADCAST    if SMP
        select GENERIC_CMOS_UPDATE
        select GENERIC_CPU_AUTOPROBE
diff --git a/arch/riscv/Kconfig b/arch/riscv/Kconfig
index 44377fd7860e..3842bbb4fe62 100644
--- a/arch/riscv/Kconfig
+++ b/arch/riscv/Kconfig
@@ -37,7 +37,6 @@ config RISCV
        select EDAC_SUPPORT
        select GENERIC_ARCH_TOPOLOGY if SMP
        select GENERIC_ATOMIC64 if !64BIT
-       select GENERIC_CLOCKEVENTS
        select GENERIC_EARLY_IOREMAP
        select GENERIC_GETTIMEOFDAY if HAVE_GENERIC_VDSO
        select GENERIC_IOREMAP
diff --git a/arch/s390/Kconfig b/arch/s390/Kconfig
index 4a2a12be04c9..db246781844d 100644
--- a/arch/s390/Kconfig
+++ b/arch/s390/Kconfig
@@ -116,7 +116,6 @@ config S390
        select CLONE_BACKWARDS2
        select DMA_OPS if PCI
        select DYNAMIC_FTRACE if FUNCTION_TRACER
-       select GENERIC_CLOCKEVENTS
        select GENERIC_CPU_AUTOPROBE
        select GENERIC_CPU_VULNERABILITIES
        select GENERIC_FIND_FIRST_BIT
diff --git a/arch/sh/Kconfig b/arch/sh/Kconfig
index 159da4ed578f..5fa580219a86 100644
--- a/arch/sh/Kconfig
+++ b/arch/sh/Kconfig
@@ -16,7 +16,6 @@ config SUPERH
        select CPU_NO_EFFICIENT_FFS
        select DMA_DECLARE_COHERENT
        select GENERIC_ATOMIC64
-       select GENERIC_CLOCKEVENTS
        select GENERIC_CMOS_UPDATE if SH_SH03 || SH_DREAMCAST
        select GENERIC_IDLE_POLL_SETUP
        select GENERIC_IRQ_SHOW
diff --git a/arch/sparc/Kconfig b/arch/sparc/Kconfig
index a6ca135442f9..718c51cf2c6c 100644
--- a/arch/sparc/Kconfig
+++ b/arch/sparc/Kconfig
@@ -39,7 +39,6 @@ config SPARC
        select HAVE_EBPF_JIT if SPARC64
        select HAVE_DEBUG_BUGVERBOSE
        select GENERIC_SMP_IDLE_THREAD
-       select GENERIC_CLOCKEVENTS
        select GENERIC_STRNCPY_FROM_USER
        select GENERIC_STRNLEN_USER
        select MODULES_USE_ELF_RELA
diff --git a/arch/um/Kconfig b/arch/um/Kconfig
index 4b799fad8b48..43333e36e0ba 100644
--- a/arch/um/Kconfig
+++ b/arch/um/Kconfig
@@ -17,7 +17,6 @@ config UML
        select NO_DMA
        select GENERIC_IRQ_SHOW
        select GENERIC_CPU_DEVICES
-       select GENERIC_CLOCKEVENTS
        select HAVE_GCC_PLUGINS
        select SET_FS
        select TTY # Needed for line.c
diff --git a/arch/x86/Kconfig b/arch/x86/Kconfig
index f6946b81f74a..0498d7596ccc 100644
--- a/arch/x86/Kconfig
+++ b/arch/x86/Kconfig
@@ -108,7 +108,6 @@ config X86
        select DCACHE_WORD_ACCESS
        select EDAC_ATOMIC_SCRUB
        select EDAC_SUPPORT
-       select GENERIC_CLOCKEVENTS
        select GENERIC_CLOCKEVENTS_BROADCAST    if X86_64 || (X86_32 && 
X86_LOCAL_APIC)
        select GENERIC_CLOCKEVENTS_MIN_ADJUST
        select GENERIC_CMOS_UPDATE
diff --git a/arch/xtensa/Kconfig b/arch/xtensa/Kconfig
index d0dfa50bd0bb..2611ba336af8 100644
--- a/arch/xtensa/Kconfig
+++ b/arch/xtensa/Kconfig
@@ -16,7 +16,6 @@ config XTENSA
        select COMMON_CLK
        select DMA_REMAP if MMU
        select GENERIC_ATOMIC64
-       select GENERIC_CLOCKEVENTS
        select GENERIC_IRQ_SHOW
        select GENERIC_PCI_IOMAP
        select GENERIC_SCHED_CLOCK
diff --git a/kernel/time/Kconfig b/kernel/time/Kconfig
index c6867f29d279..9a41848b6ebb 100644
--- a/kernel/time/Kconfig
+++ b/kernel/time/Kconfig
@@ -28,7 +28,7 @@ config GENERIC_TIME_VSYSCALL
 
 # The generic clock events infrastructure
 config GENERIC_CLOCKEVENTS
-       bool
+       def_bool !LEGACY_TIMER_TICK
 
 # Architecture can handle broadcast in a driver-agnostic way
 config ARCH_HAS_TICK_BROADCAST
-- 
2.27.0

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