From: Marc Zyngier <maz@kernel.org>
To: linux-arm-kernel@lists.infradead.org, linux-kernel@vger.kernel.org
Cc: Catalin Marinas <catalin.marinas@arm.com>,
Will Deacon <will@kernel.org>,
Mark Rutland <mark.rutland@arm.com>,
Thomas Gleixner <tglx@kernel.org>,
Ben Horgan <ben.horgan@arm.com>,
Daniel Lezcano <daniel.lezcano@linaro.org>
Subject: [PATCH v3 8/8] arm64: Convert __delay_cycles() to arch_timer_read_vcounter()
Date: Sun, 2 Aug 2026 17:53:27 +0100 [thread overview]
Message-ID: <20260802165327.385217-9-maz@kernel.org> (raw)
In-Reply-To: <20260802165327.385217-1-maz@kernel.org>
Relax the need for disabling preemption in __delay_cycles() by
using arch_timer_read_vcounter(), which will disable preemption
only when this is actually required.
Acked-by: Catalin Marinas <catalin.marinas@arm.com>
Signed-off-by: Marc Zyngier <maz@kernel.org>
---
arch/arm64/lib/delay.c | 5 ++---
1 file changed, 2 insertions(+), 3 deletions(-)
diff --git a/arch/arm64/lib/delay.c b/arch/arm64/lib/delay.c
index e278e060e78a9..a667df920697d 100644
--- a/arch/arm64/lib/delay.c
+++ b/arch/arm64/lib/delay.c
@@ -32,10 +32,9 @@ static inline unsigned long xloops_to_cycles(unsigned long xloops)
* Note that userspace cannot change the offset behind our back either,
* as the vcpu mutex is held as long as KVM_RUN is in progress.
*/
-static cycles_t notrace __delay_cycles(void)
+static cycles_t __delay_cycles(void)
{
- guard(preempt_notrace)();
- return __arch_counter_get_cntvct_stable();
+ return arch_timer_read_vcounter();
}
void __delay(unsigned long cycles)
--
2.47.3
prev parent reply other threads:[~2026-08-02 16:53 UTC|newest]
Thread overview: 9+ messages / expand[flat|nested] mbox.gz Atom feed top
2026-08-02 16:53 [PATCH v3 0/8] arm64: arch_timer: Improve errata handling Marc Zyngier
2026-08-02 16:53 ` [PATCH v3 1/8] clocksource/drivers/arm_arch_timer: Add read_sched_clock_is_arch_counter() predicate Marc Zyngier
2026-08-02 16:53 ` [PATCH v3 2/8] clocksource/drivers/arm_arch_timer: Add a static key indicating the need for a runtime workaround Marc Zyngier
2026-08-02 16:53 ` [PATCH v3 3/8] clocksource/drivers/arm_arch_timer: Convert counter accessors to a static key alternative Marc Zyngier
2026-08-02 16:53 ` [PATCH v3 4/8] clocksource/drivers/arm_arch_timer: Drop the arch_counter_get_cnt{p,v}ct_stable() accessors Marc Zyngier
2026-08-02 16:53 ` [PATCH v3 5/8] clocksource/drivers/arm_arch_timer: Turn arch_timer_read_counter into a function Marc Zyngier
2026-08-02 16:53 ` [PATCH v3 6/8] clocksource/drivers/arm_arch_timer: Add command-line control over the counter errata management Marc Zyngier
2026-08-02 16:53 ` [PATCH v3 7/8] clocksource/drivers/arm_arch_timer: Expose a direct accessor for the virtual counter Marc Zyngier
2026-08-02 16:53 ` Marc Zyngier [this message]
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