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 2/5] clocksource/drivers/arm_arch_timer: Convert counter accessors to a static key alternative
Date: Mon, 2 Mar 2026 10:29:34 +0000 [thread overview]
Message-ID: <20260302102937.1516059-3-maz@kernel.org> (raw)
In-Reply-To: <20260302102937.1516059-1-maz@kernel.org>
Now that we have a reliable static key to control whether our
counter accessors need to be worked around, use it in these
accessors and simplify the logic that picks which accessor to use.
Signed-off-by: Marc Zyngier <maz@kernel.org>
---
drivers/clocksource/arm_arch_timer.c | 38 +++++++++++++++-------------
1 file changed, 20 insertions(+), 18 deletions(-)
diff --git a/drivers/clocksource/arm_arch_timer.c b/drivers/clocksource/arm_arch_timer.c
index c5b42001c9282..723ba698b8c46 100644
--- a/drivers/clocksource/arm_arch_timer.c
+++ b/drivers/clocksource/arm_arch_timer.c
@@ -92,9 +92,12 @@ static int arch_counter_get_width(void)
*/
static inline bool arch_counter_broken_accessors(void);
-static noinstr u64 raw_counter_get_cntpct_stable(void)
+static noinstr u64 raw_counter_get_cntpct(void)
{
- return __arch_counter_get_cntpct_stable();
+ if (arch_counter_broken_accessors())
+ return __arch_counter_get_cntpct_stable();
+
+ return __arch_counter_get_cntpct();
}
static notrace u64 arch_counter_get_cntpct_stable(void)
@@ -108,12 +111,18 @@ static notrace u64 arch_counter_get_cntpct_stable(void)
static noinstr u64 arch_counter_get_cntpct(void)
{
+ if (arch_counter_broken_accessors())
+ return arch_counter_get_cntpct_stable();
+
return __arch_counter_get_cntpct();
}
-static noinstr u64 raw_counter_get_cntvct_stable(void)
+static noinstr u64 raw_counter_get_cntvct(void)
{
- return __arch_counter_get_cntvct_stable();
+ if (arch_counter_broken_accessors())
+ return __arch_counter_get_cntvct_stable();
+
+ return __arch_counter_get_cntvct();
}
static notrace u64 arch_counter_get_cntvct_stable(void)
@@ -127,6 +136,9 @@ static notrace u64 arch_counter_get_cntvct_stable(void)
static noinstr u64 arch_counter_get_cntvct(void)
{
+ if (arch_counter_broken_accessors())
+ return arch_counter_get_cntvct_stable();
+
return __arch_counter_get_cntvct();
}
@@ -946,21 +958,11 @@ static void __init arch_counter_register(void)
if ((IS_ENABLED(CONFIG_ARM64) && !is_hyp_mode_available()) ||
arch_timer_uses_ppi == ARCH_TIMER_VIRT_PPI) {
- if (arch_timer_counter_has_wa()) {
- rd = arch_counter_get_cntvct_stable;
- scr = raw_counter_get_cntvct_stable;
- } else {
- rd = arch_counter_get_cntvct;
- scr = arch_counter_get_cntvct;
- }
+ rd = arch_counter_get_cntvct;
+ scr = raw_counter_get_cntvct;
} else {
- if (arch_timer_counter_has_wa()) {
- rd = arch_counter_get_cntpct_stable;
- scr = raw_counter_get_cntpct_stable;
- } else {
- rd = arch_counter_get_cntpct;
- scr = arch_counter_get_cntpct;
- }
+ rd = arch_counter_get_cntpct;
+ scr = raw_counter_get_cntpct;
}
arch_timer_read_counter = rd;
--
2.47.3
next prev parent reply other threads:[~2026-03-02 10:29 UTC|newest]
Thread overview: 6+ messages / expand[flat|nested] mbox.gz Atom feed top
2026-03-02 10:29 [PATCH 0/5] arm64: arch_timer: Improve errata handling Marc Zyngier
2026-03-02 10:29 ` [PATCH 1/5] clocksource/drivers/arm_arch_timer: Add a static key indicating the need for a runtime workaround Marc Zyngier
2026-03-02 10:29 ` Marc Zyngier [this message]
2026-03-02 10:29 ` [PATCH 3/5] clocksource/drivers/arm_arch_timer: Drop the arch_counter_get_cnt{p,v}ct_stable() accessors Marc Zyngier
2026-03-02 10:29 ` [PATCH 4/5] clocksource/drivers/arm_arch_timer: Expose a direct accessor for the virtual counter Marc Zyngier
2026-03-02 10:29 ` [PATCH 5/5] arm64: Convert __delay_cycles() to arch_timer_read_vcounter() Marc Zyngier
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