[PATCH 0/7] vDSO: Replace CONFIG_GENERIC_GETTIMEOFDAY ifdeffery with IS_ENABLED()

[PATCH 0/7] vDSO: Replace CONFIG_GENERIC_GETTIMEOFDAY ifdeffery with IS_ENABLED()

[Thomas Weißschuh]

Provide dummy declarations of the VDSO_CLOCKMODE_* constants and use
those to replace some ugly ifdeffery with cleaner IS_ENABLED() checks.

Signed-off-by: Thomas Weißschuh <thomas.weissschuh@linutronix.de>
---
Thomas Weißschuh (7):
      kbuild: support generated asm-headers in subdirectories
      vDSO: Make clockmode constants available without CONFIG_GENERIC_GETTIMEOFDAY
      MIPS: csrc-r4k: Replace CONFIG_GENERIC_GETTIMEOFDAY ifdeffery with IS_ENABLED()
      clocksource/drivers/mips-gic-timer: Replace CONFIG_GENERIC_GETTIMEOFDAY ifdeffery with IS_ENABLED()
      clocksource/drivers/arm_arch_timer: Replace CONFIG_GENERIC_GETTIMEOFDAY ifdeffery with IS_ENABLED()
      clocksource/drivers/timer-riscv: Replace CONFIG_GENERIC_GETTIMEOFDAY ifdeffery with IS_ENABLED()
      LoongArch: Replace CONFIG_GENERIC_GETTIMEOFDAY ifdeffery with IS_ENABLED()

 arch/loongarch/kernel/time.c           |  5 ++---
 arch/mips/kernel/csrc-r4k.c            |  4 +---
 drivers/clocksource/arm_arch_timer.c   |  7 ++-----
 drivers/clocksource/mips-gic-timer.c   |  5 ++---
 drivers/clocksource/timer-riscv.c      |  7 ++-----
 include/asm-generic/Kbuild             |  1 +
 include/asm-generic/vdso/clocksource.h |  0
 include/vdso/clocksource.h             |  7 +++++--
 scripts/Makefile.asm-headers           | 11 +++++------
 9 files changed, 20 insertions(+), 27 deletions(-)
---
base-commit: dc59e4fea9d83f03bad6bddf3fa2e52491777482
change-id: 20260605-vdso-arch-clockmodes-bfcaf9a2c848

Best regards,
--  
Thomas Weißschuh <thomas.weissschuh@linutronix.de>

[PATCH 1/7] kbuild: support generated asm-headers in subdirectories

[Thomas Weißschuh]

Extend the asm-header stub generation to also handle subdirectories.
An upcoming vdso/ header refactoring requires this.

Signed-off-by: Thomas Weißschuh <thomas.weissschuh@linutronix.de>
---
 scripts/Makefile.asm-headers | 11 +++++------
 1 file changed, 5 insertions(+), 6 deletions(-)

diff --git a/scripts/Makefile.asm-headers b/scripts/Makefile.asm-headers
index 8a4856e74180..772b53ffdeb4 100644
--- a/scripts/Makefile.asm-headers
+++ b/scripts/Makefile.asm-headers
@@ -48,14 +48,13 @@ syscall-y   := $(addprefix $(obj)/, $(syscall-y))
 generated-y := $(addprefix $(obj)/, $(generated-y))
 
 # Remove stale wrappers when the corresponding files are removed from generic-y
-old-headers := $(wildcard $(obj)/*.h)
+old-headers := $(shell test -d $(obj) && find $(obj) -name *.h)
 unwanted    := $(filter-out $(generic-y) $(generated-y) $(syscall-y),$(old-headers))
 
-quiet_cmd_wrap = WRAP    $@
-      cmd_wrap = echo "\#include <asm-generic/$*.h>" > $@
+filechk_wrap = echo "\#include <asm-generic/$*.h>"
 
 quiet_cmd_remove = REMOVE  $(unwanted)
-      cmd_remove = rm -f $(unwanted)
+      cmd_remove = rm -f $(unwanted); find $(obj) -type -d -empty -delete
 
 quiet_cmd_syshdr = SYSHDR  $@
       cmd_syshdr = $(CONFIG_SHELL) $(syshdr) \
@@ -74,8 +73,8 @@ all: $(generic-y) $(syscall-y)
 	$(if $(unwanted),$(call cmd,remove))
 	@:
 
-$(obj)/%.h: $(srctree)/$(generic)/%.h
-	$(call cmd,wrap)
+$(obj)/%.h: $(srctree)/$(generic)/%.h FORCE
+	$(call filechk,wrap)
 
 $(obj)/unistd_%.h: $(syscalltbl) $(syshdr) FORCE
 	$(call if_changed,syshdr)

-- 
2.55.0

[PATCH 2/7] vDSO: Make clockmode constants available without CONFIG_GENERIC_GETTIMEOFDAY

[Thomas Weißschuh]

Some code, for example clocksource drivers, may want to use the vDSO
clockmode constants even when CONFIG_GENERIC_GETTIMEOFDAY=n.
But the symbols are completely hidden in that case, making ugly
ifdeffery necessary.

Provide unlinkable dummy definitions. These can be used with
IS_ENABLED(CONFIG_GENERIC_GETTIMEOFDAY).

As not all architectures provide asm/vdso/clocksource.h,
provide an empty stub in asm-generic for it.

Signed-off-by: Thomas Weißschuh <thomas.weissschuh@linutronix.de>
---
 include/asm-generic/Kbuild             | 1 +
 include/asm-generic/vdso/clocksource.h | 0
 include/vdso/clocksource.h             | 7 +++++--
 3 files changed, 6 insertions(+), 2 deletions(-)

diff --git a/include/asm-generic/Kbuild b/include/asm-generic/Kbuild
index 15df9dcb42a5..2bc00c67dc54 100644
--- a/include/asm-generic/Kbuild
+++ b/include/asm-generic/Kbuild
@@ -62,6 +62,7 @@ mandatory-y += topology.h
 mandatory-y += trace_clock.h
 mandatory-y += uaccess.h
 mandatory-y += unwind_user.h
+mandatory-y += vdso/clocksource.h
 mandatory-y += vermagic.h
 mandatory-y += vga.h
 mandatory-y += video.h
diff --git a/include/asm-generic/vdso/clocksource.h b/include/asm-generic/vdso/clocksource.h
new file mode 100644
index 000000000000..e69de29bb2d1
diff --git a/include/vdso/clocksource.h b/include/vdso/clocksource.h
index c682e7c60273..63ee8c4ea15c 100644
--- a/include/vdso/clocksource.h
+++ b/include/vdso/clocksource.h
@@ -4,9 +4,12 @@
 
 #include <vdso/limits.h>
 
-#ifdef CONFIG_GENERIC_GETTIMEOFDAY
 #include <asm/vdso/clocksource.h>
-#endif /* CONFIG_GENERIC_GETTIMEOFDAY */
+
+#if !IS_ENABLED(CONFIG_GENERIC_GETTIMEOFDAY) && defined(VDSO_ARCH_CLOCKMODES)
+/* Unlinkable dummy stubs */
+extern int VDSO_ARCH_CLOCKMODES;
+#endif
 
 enum vdso_clock_mode {
 	VDSO_CLOCKMODE_NONE,

-- 
2.55.0

[PATCH 3/7] MIPS: csrc-r4k: Replace CONFIG_GENERIC_GETTIMEOFDAY ifdeffery with IS_ENABLED()

[Thomas Weißschuh]

Now that there is a dummy declaration of VDSO_CLOCKMODE_R4K, even if no
vDSO is built, the ugly ifdeffery can be replaced with a cleaner
IS_ENABLED() check.

Signed-off-by: Thomas Weißschuh <thomas.weissschuh@linutronix.de>
---
 arch/mips/kernel/csrc-r4k.c | 4 +---
 1 file changed, 1 insertion(+), 3 deletions(-)

diff --git a/arch/mips/kernel/csrc-r4k.c b/arch/mips/kernel/csrc-r4k.c
index 241a934543a8..63aca74ab299 100644
--- a/arch/mips/kernel/csrc-r4k.c
+++ b/arch/mips/kernel/csrc-r4k.c
@@ -126,14 +126,12 @@ int __init init_r4k_clocksource(void)
 	clocksource_mips.rating = 200;
 	clocksource_mips.rating += clamp(mips_hpt_frequency / 10000000, 0, 99);
 
-#ifdef CONFIG_GENERIC_GETTIMEOFDAY
 	/*
 	 * R2 onwards makes the count accessible to user mode so it can be used
 	 * by the VDSO (HWREna is configured by configure_hwrena()).
 	 */
-	if (cpu_has_mips_r2_r6 && rdhwr_count_usable())
+	if (IS_ENABLED(CONFIG_GENERIC_GETTIMEOFDAY) && cpu_has_mips_r2_r6 && rdhwr_count_usable())
 		clocksource_mips.vdso_clock_mode = VDSO_CLOCKMODE_R4K;
-#endif
 
 	clocksource_register_hz(&clocksource_mips, mips_hpt_frequency);
 

-- 
2.55.0

[PATCH 4/7] clocksource/drivers/mips-gic-timer: Replace CONFIG_GENERIC_GETTIMEOFDAY ifdeffery with IS_ENABLED()

[Thomas Weißschuh]

Now that there is a dummy declaration of VDSO_CLOCKMODE_GIC, even if no
vDSO is built, the ugly ifdeffery can be replaced with a cleaner
IS_ENABLED() check.

Signed-off-by: Thomas Weißschuh <thomas.weissschuh@linutronix.de>
---
 drivers/clocksource/mips-gic-timer.c | 5 ++---
 1 file changed, 2 insertions(+), 3 deletions(-)

diff --git a/drivers/clocksource/mips-gic-timer.c b/drivers/clocksource/mips-gic-timer.c
index a1669266c94d..0dd30ba3cce7 100644
--- a/drivers/clocksource/mips-gic-timer.c
+++ b/drivers/clocksource/mips-gic-timer.c
@@ -198,9 +198,8 @@ static struct clocksource gic_clocksource = {
 	.name			= "GIC",
 	.read			= gic_hpt_read,
 	.flags			= CLOCK_SOURCE_IS_CONTINUOUS,
-#ifdef CONFIG_GENERIC_GETTIMEOFDAY
-	.vdso_clock_mode	= VDSO_CLOCKMODE_GIC,
-#endif
+	.vdso_clock_mode	= IS_ENABLED(CONFIG_GENERIC_GETTIMEOFDAY) ?
+					VDSO_CLOCKMODE_GIC : VDSO_CLOCKMODE_NONE,
 };
 
 static void gic_clocksource_unstable(char *reason)

-- 
2.55.0

[PATCH 5/7] clocksource/drivers/arm_arch_timer: Replace CONFIG_GENERIC_GETTIMEOFDAY ifdeffery with IS_ENABLED()

[Thomas Weißschuh]

Now that there is a dummy declaration of VDSO_CLOCKMODE_ARCHTIMER,
even if no vDSO is built, the ugly ifdeffery can be replaced with
a cleaner IS_ENABLED() check.

Signed-off-by: Thomas Weißschuh <thomas.weissschuh@linutronix.de>
---
 drivers/clocksource/arm_arch_timer.c | 7 ++-----
 1 file changed, 2 insertions(+), 5 deletions(-)

diff --git a/drivers/clocksource/arm_arch_timer.c b/drivers/clocksource/arm_arch_timer.c
index 4adf756423de..d67125a8730a 100644
--- a/drivers/clocksource/arm_arch_timer.c
+++ b/drivers/clocksource/arm_arch_timer.c
@@ -56,11 +56,8 @@ static struct clock_event_device __percpu *arch_timer_evt;
 static enum arch_timer_ppi_nr arch_timer_uses_ppi __ro_after_init = ARCH_TIMER_VIRT_PPI;
 static bool arch_timer_c3stop __ro_after_init;
 static bool arch_counter_suspend_stop __ro_after_init;
-#ifdef CONFIG_GENERIC_GETTIMEOFDAY
-static enum vdso_clock_mode vdso_default = VDSO_CLOCKMODE_ARCHTIMER;
-#else
-static enum vdso_clock_mode vdso_default = VDSO_CLOCKMODE_NONE;
-#endif /* CONFIG_GENERIC_GETTIMEOFDAY */
+static enum vdso_clock_mode vdso_default = IS_ENABLED(CONFIG_GENERIC_GETTIMEOFDAY) ?
+	VDSO_CLOCKMODE_ARCHTIMER : VDSO_CLOCKMODE_NONE;
 
 static cpumask_t evtstrm_available = CPU_MASK_NONE;
 static bool evtstrm_enable __ro_after_init = IS_ENABLED(CONFIG_ARM_ARCH_TIMER_EVTSTREAM);

-- 
2.55.0

[PATCH 6/7] clocksource/drivers/timer-riscv: Replace CONFIG_GENERIC_GETTIMEOFDAY ifdeffery with IS_ENABLED()

[Thomas Weißschuh]

Now that there is a dummy declaration of VDSO_CLOCKMODE_ARCHTIMER,
even if no vDSO is built, the ugly ifdeffery can be replaced with
a cleaner IS_ENABLED() check.

Signed-off-by: Thomas Weißschuh <thomas.weissschuh@linutronix.de>
---
 drivers/clocksource/timer-riscv.c | 7 ++-----
 1 file changed, 2 insertions(+), 5 deletions(-)

diff --git a/drivers/clocksource/timer-riscv.c b/drivers/clocksource/timer-riscv.c
index cfc4d83c42c0..82bd380b3dda 100644
--- a/drivers/clocksource/timer-riscv.c
+++ b/drivers/clocksource/timer-riscv.c
@@ -98,11 +98,8 @@ static struct clocksource riscv_clocksource = {
 	.mask		= CLOCKSOURCE_MASK(64),
 	.flags		= CLOCK_SOURCE_IS_CONTINUOUS,
 	.read		= riscv_clocksource_rdtime,
-#if IS_ENABLED(CONFIG_GENERIC_GETTIMEOFDAY)
-	.vdso_clock_mode = VDSO_CLOCKMODE_ARCHTIMER,
-#else
-	.vdso_clock_mode = VDSO_CLOCKMODE_NONE,
-#endif
+	.vdso_clock_mode = IS_ENABLED(CONFIG_GENERIC_GETTIMEOFDAY) ?
+				VDSO_CLOCKMODE_ARCHTIMER : VDSO_CLOCKMODE_NONE,
 };
 
 static int riscv_timer_starting_cpu(unsigned int cpu)

-- 
2.55.0

[PATCH 7/7] LoongArch: Replace CONFIG_GENERIC_GETTIMEOFDAY ifdeffery with IS_ENABLED()

[Thomas Weißschuh]

Now that there is a dummy declaration of VDSO_CLOCKMODE_CPU, even if no
vDSO is built, the ugly ifdeffery can be replaced with a cleaner
IS_ENABLED() check.

Signed-off-by: Thomas Weißschuh <thomas.weissschuh@linutronix.de>
---
 arch/loongarch/kernel/time.c | 5 ++---
 1 file changed, 2 insertions(+), 3 deletions(-)

diff --git a/arch/loongarch/kernel/time.c b/arch/loongarch/kernel/time.c
index dbaaabcaf6f0..dfc04d9f342e 100644
--- a/arch/loongarch/kernel/time.c
+++ b/arch/loongarch/kernel/time.c
@@ -212,9 +212,8 @@ static struct clocksource clocksource_const = {
 	.read = read_const_counter,
 	.mask = CLOCKSOURCE_MASK(64),
 	.flags = CLOCK_SOURCE_IS_CONTINUOUS,
-#ifdef CONFIG_GENERIC_GETTIMEOFDAY
-	.vdso_clock_mode = VDSO_CLOCKMODE_CPU,
-#endif
+	.vdso_clock_mode = IS_ENABLED(CONFIG_GENERIC_GETTIMEOFDAY) ?
+				VDSO_CLOCKMODE_CPU : VDSO_CLOCKMODE_NONE,
 };
 
 int __init constant_clocksource_init(void)

-- 
2.55.0

Re: [PATCH 5/7] clocksource/drivers/arm_arch_timer: Replace CONFIG_GENERIC_GETTIMEOFDAY ifdeffery with IS_ENABLED()

[Marc Zyngier]

On Thu, 09 Jul 2026 12:32:41 +0100,
Thomas Weißschuh <thomas.weissschuh@linutronix.de> wrote:
> 
> Now that there is a dummy declaration of VDSO_CLOCKMODE_ARCHTIMER,
> even if no vDSO is built, the ugly ifdeffery can be replaced with
> a cleaner IS_ENABLED() check.
> 
> Signed-off-by: Thomas Weißschuh <thomas.weissschuh@linutronix.de>

Acked-by: Marc Zyngier <maz@kernel.org>

	M.

-- 
Jazz isn't dead. It just smells funny.