From cefafbd561402b0fe6447449364a30315b9b1570 Mon Sep 17 00:00:00 2001 From: Yong-Xuan Wang Date: Fri, 8 May 2026 02:31:21 -0700 Subject: [PATCH] irqchip/riscv-imsic: Clear interrupt move state during CPU offlining Affinity changes of IMSIC interrupts have to be careful to not lose an interrupt in the process. Each vector keeps track of an affinity change in progress with two pointers in struct imsic_vector. imsic_vector::move_prev points to the previous CPU target data and imsic_vector::move_next to the designated new CPU target data. imsic_vector::move_prev on the new CPU can only be cleared after the previous CPU has cleared imsic_vector::move_next, which ususally happens in __imsic_remote_sync(). In case of CPU hot-unplug __imsic_remote_sync() is not invoked because the CPU is already marked offline. That means imsic_vector::move_prev becomes stale until the CPU is onlined again. The stale pointer prevents further affinity changes for the affected interrupts. Solve this by clearing the imsic_vector::move_prev pointers in the CPU hotplug offline path. [ tglx: Replace word salad in change log ] Fixes: 0f67911e821c ("irqchip/riscv-imsic: Separate next and previous pointers in IMSIC vector") Signed-off-by: Yong-Xuan Wang Signed-off-by: Thomas Gleixner Cc: stable@vger.kernel.org Link: https://patch.msgid.link/20260508-imsic-v2-1-e9f08dd46cf5@sifive.com --- drivers/irqchip/irq-riscv-imsic-early.c | 2 ++ 1 file changed, 2 insertions(+) diff --git a/drivers/irqchip/irq-riscv-imsic-early.c b/drivers/irqchip/irq-riscv-imsic-early.c index ba903fa689bd..a7a1852b548c 100644 --- a/drivers/irqchip/irq-riscv-imsic-early.c +++ b/drivers/irqchip/irq-riscv-imsic-early.c @@ -158,6 +158,8 @@ static int imsic_dying_cpu(unsigned int cpu) /* Cleanup IPIs */ imsic_ipi_dying_cpu(); + imsic_local_sync_all(false); + /* Mark per-CPU IMSIC state as offline */ imsic_state_offline();