6.14-stable review patch. If anyone has any objections, please let me know.
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From: Andrew Bresticker abrestic@rivosinc.com
[ Upstream commit 08fb624802d8786253994d8ebdbbcdaa186f04f5 ]
When starting the local sync timer to synchronize the state of a remote CPU it should be added on the CPU to be synchronized, not the initiating CPU. This results in interrupt delivery being delayed until the timer eventually runs (due to another mask/unmask/migrate operation) on the target CPU.
Fixes: 0f67911e821c ("irqchip/riscv-imsic: Separate next and previous pointers in IMSIC vector") Signed-off-by: Andrew Bresticker abrestic@rivosinc.com Signed-off-by: Thomas Gleixner tglx@linutronix.de Reviewed-by: Anup Patel anup@brainfault.org Link: https://lore.kernel.org/all/20250514171320.3494917-1-abrestic@rivosinc.com Signed-off-by: Sasha Levin sashal@kernel.org --- drivers/irqchip/irq-riscv-imsic-state.c | 10 +++++----- 1 file changed, 5 insertions(+), 5 deletions(-)
diff --git a/drivers/irqchip/irq-riscv-imsic-state.c b/drivers/irqchip/irq-riscv-imsic-state.c index 1aeba76d72795..06ff0e17c0c33 100644 --- a/drivers/irqchip/irq-riscv-imsic-state.c +++ b/drivers/irqchip/irq-riscv-imsic-state.c @@ -186,17 +186,17 @@ static bool __imsic_local_sync(struct imsic_local_priv *lpriv) }
#ifdef CONFIG_SMP -static void __imsic_local_timer_start(struct imsic_local_priv *lpriv) +static void __imsic_local_timer_start(struct imsic_local_priv *lpriv, unsigned int cpu) { lockdep_assert_held(&lpriv->lock);
if (!timer_pending(&lpriv->timer)) { lpriv->timer.expires = jiffies + 1; - add_timer_on(&lpriv->timer, smp_processor_id()); + add_timer_on(&lpriv->timer, cpu); } } #else -static inline void __imsic_local_timer_start(struct imsic_local_priv *lpriv) +static inline void __imsic_local_timer_start(struct imsic_local_priv *lpriv, unsigned int cpu) { } #endif @@ -211,7 +211,7 @@ void imsic_local_sync_all(bool force_all) if (force_all) bitmap_fill(lpriv->dirty_bitmap, imsic->global.nr_ids + 1); if (!__imsic_local_sync(lpriv)) - __imsic_local_timer_start(lpriv); + __imsic_local_timer_start(lpriv, smp_processor_id());
raw_spin_unlock_irqrestore(&lpriv->lock, flags); } @@ -256,7 +256,7 @@ static void __imsic_remote_sync(struct imsic_local_priv *lpriv, unsigned int cpu return; }
- __imsic_local_timer_start(lpriv); + __imsic_local_timer_start(lpriv, cpu); } } #else