[RFC PATCH] clocksource/drivers/riscv: Get rid of clocksource_arch_init() callback

From: Prabhakar
Date: Sun Dec 11 2022 - 16:59:25 EST


From: Lad Prabhakar <prabhakar.mahadev-lad.rj@xxxxxxxxxxxxxx>

Having a clocksource_arch_init() callback always sets vdso_clock_mode to
VDSO_CLOCKMODE_ARCHTIMER if GENERIC_GETTIMEOFDAY is enabled, this is
required for the riscv-timer.

This works for platforms where just riscv-timer clocksource is present.
On platforms where other clock sources are available we want them to
register with vdso_clock_mode set to VDSO_CLOCKMODE_NONE.

On the Renesas RZ/Five SoC OSTM block can be used as clocksource [0], to
avoid multiple clock sources being registered as VDSO_CLOCKMODE_ARCHTIMER
move setting of vdso_clock_mode in the riscv-timer driver instead of doing
this in clocksource_arch_init() callback as done similarly for ARM/64
architecture.

[0] drivers/clocksource/renesas-ostm.c

Signed-off-by: Lad Prabhakar <prabhakar.mahadev-lad.rj@xxxxxxxxxxxxxx>
---
arch/riscv/Kconfig | 1 -
arch/riscv/kernel/time.c | 9 ---------
drivers/clocksource/timer-riscv.c | 7 +++++++
3 files changed, 7 insertions(+), 10 deletions(-)

diff --git a/arch/riscv/Kconfig b/arch/riscv/Kconfig
index 7ea12de636bd..b269e062c1b1 100644
--- a/arch/riscv/Kconfig
+++ b/arch/riscv/Kconfig
@@ -12,7 +12,6 @@ config 32BIT

config RISCV
def_bool y
- select ARCH_CLOCKSOURCE_INIT
select ARCH_ENABLE_HUGEPAGE_MIGRATION if HUGETLB_PAGE && MIGRATION
select ARCH_ENABLE_SPLIT_PMD_PTLOCK if PGTABLE_LEVELS > 2
select ARCH_HAS_BINFMT_FLAT
diff --git a/arch/riscv/kernel/time.c b/arch/riscv/kernel/time.c
index 8217b0f67c6c..42bee305e997 100644
--- a/arch/riscv/kernel/time.c
+++ b/arch/riscv/kernel/time.c
@@ -30,12 +30,3 @@ void __init time_init(void)
of_clk_init(NULL);
timer_probe();
}
-
-void clocksource_arch_init(struct clocksource *cs)
-{
-#ifdef CONFIG_GENERIC_GETTIMEOFDAY
- cs->vdso_clock_mode = VDSO_CLOCKMODE_ARCHTIMER;
-#else
- cs->vdso_clock_mode = VDSO_CLOCKMODE_NONE;
-#endif
-}
diff --git a/drivers/clocksource/timer-riscv.c b/drivers/clocksource/timer-riscv.c
index 969a552da8d2..7ec9668cd36d 100644
--- a/drivers/clocksource/timer-riscv.c
+++ b/drivers/clocksource/timer-riscv.c
@@ -29,6 +29,12 @@

static DEFINE_STATIC_KEY_FALSE(riscv_sstc_available);

+#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 int riscv_clock_next_event(unsigned long delta,
struct clock_event_device *ce)
{
@@ -158,6 +164,7 @@ static int __init riscv_timer_init_dt(struct device_node *n)
return -ENODEV;
}

+ riscv_clocksource.vdso_clock_mode = vdso_default;
pr_info("%s: Registering clocksource cpuid [%d] hartid [%lu]\n",
__func__, cpuid, hartid);
error = clocksource_register_hz(&riscv_clocksource, riscv_timebase);
--
2.25.1