fixup_irqs() re-injects a pending interrupt on its new target CPU by looking at the outermost domain chip and invoking its irq_retrigger() callback directly. That only works when the outermost chip happens to install an irq_retrigger() callback, which is not guaranteed for every irqchip and could lead to lost interrupts on CPU hot-unplug.
Use irq_chip_retrigger_hierarchy() instead, which walks up the interrupt hierarchy until it finds a chip that implements irq_retrigger(). While at it, move the loop-local variables into the loop scope and use a scoped guard for desc->lock. No functional change intended for chips which already provide an irq_retrigger() callback on the outermost domain. Suggested-by: Thomas Gleixner <[email protected]> Signed-off-by: Naman Jain <[email protected]> --- arch/x86/kernel/irq.c | 23 +++++++---------------- 1 file changed, 7 insertions(+), 16 deletions(-) diff --git a/arch/x86/kernel/irq.c b/arch/x86/kernel/irq.c index 30122f0b3af96..ef1bdd3c4659a 100644 --- a/arch/x86/kernel/irq.c +++ b/arch/x86/kernel/irq.c @@ -466,11 +466,6 @@ DEFINE_IDTENTRY_SYSVEC(sysvec_posted_msi_notification) /* A cpu has been removed from cpu_online_mask. Reset irq affinities. */ void fixup_irqs(void) { - unsigned int vector; - struct irq_desc *desc; - struct irq_data *data; - struct irq_chip *chip; - irq_migrate_all_off_this_cpu(); /* @@ -489,22 +484,18 @@ void fixup_irqs(void) * vector_lock because the cpu is already marked !online, so * nothing else will touch it. */ - for (vector = FIRST_EXTERNAL_VECTOR; vector < NR_VECTORS; vector++) { - if (IS_ERR_OR_NULL(__this_cpu_read(vector_irq[vector]))) + for (unsigned int vector = FIRST_EXTERNAL_VECTOR; vector < NR_VECTORS; vector++) { + struct irq_desc *desc = __this_cpu_read(vector_irq[vector]); + + if (IS_ERR_OR_NULL(desc)) continue; if (is_vector_pending(vector)) { - desc = __this_cpu_read(vector_irq[vector]); - - raw_spin_lock(&desc->lock); - data = irq_desc_get_irq_data(desc); - chip = irq_data_get_irq_chip(data); - if (chip->irq_retrigger) { - chip->irq_retrigger(data); + guard(raw_spinlock)(&desc->lock); + if (irq_chip_retrigger_hierarchy(&desc->irq_data)) __this_cpu_write(vector_irq[vector], VECTOR_RETRIGGERED); - } - raw_spin_unlock(&desc->lock); } + if (__this_cpu_read(vector_irq[vector]) != VECTOR_RETRIGGERED) __this_cpu_write(vector_irq[vector], VECTOR_UNUSED); } -- 2.43.0
