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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 3/8] clocksource/drivers/arm_arch_timer: Convert counter accessors to a static key alternative
Date: Sun,  2 Aug 2026 17:53:22 +0100	[thread overview]
Message-ID: <20260802165327.385217-4-maz@kernel.org> (raw)
In-Reply-To: <20260802165327.385217-1-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 | 44 ++++++++++++++--------------
 1 file changed, 22 insertions(+), 22 deletions(-)

diff --git a/drivers/clocksource/arm_arch_timer.c b/drivers/clocksource/arm_arch_timer.c
index 8ee317e33c864..f645aa562895b 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();
 }
 
@@ -950,21 +962,11 @@ static void __init arch_counter_register(void)
 	if ((IS_ENABLED(CONFIG_ARM64) && !is_hyp_mode_available()) ||
 	    arch_timer_uses_ppi == ARCH_TIMER_VIRT_PPI ||
 	    arch_timer_uses_ppi == ARCH_TIMER_HYP_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;
@@ -990,10 +992,8 @@ bool read_sched_clock_is_arch_counter(const struct clock_read_data *crd)
 {
 	u64 (*rd)(void) = crd->read_sched_clock;
 
-	return (rd == raw_counter_get_cntvct_stable	||
-		rd == raw_counter_get_cntpct_stable	||
-		rd == arch_counter_get_cntvct		||
-		rd == arch_counter_get_cntpct);
+	return (rd == raw_counter_get_cntvct	||
+		rd == raw_counter_get_cntpct);
 }
 
 static void arch_timer_stop(struct clock_event_device *clk)
-- 
2.47.3


  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 ` Marc Zyngier [this message]
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 ` [PATCH v3 8/8] arm64: Convert __delay_cycles() to arch_timer_read_vcounter() Marc Zyngier

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