irqchip/riscv-imsic: Implement irq_force_complete_move() for IMSIC

Implement irq_force_complete_move() for IMSIC driver so that in-flight
vector movements on a CPU can be cleaned-up when the CPU goes down.

Signed-off-by: Anup Patel <apatel@ventanamicro.com>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Link: https://lore.kernel.org/all/20250217085657.789309-9-apatel@ventanamicro.com

diff --git a/drivers/irqchip/irq-riscv-imsic-platform.c b/drivers/irqchip/irq-riscv-imsic-platform.c
index 9a5e7b4541f6e937008c23e18d627a326eb9fe39..b9e3f9030bdf0f905c77d335cda1d4569f5c6dd4 100644 (file)
--- a/drivers/irqchip/irq-riscv-imsic-platform.c
+++ b/drivers/irqchip/irq-riscv-imsic-platform.c
@@ -129,6 +129,37 @@ static int imsic_irq_set_affinity(struct irq_data *d, const struct cpumask *mask
 
        return IRQ_SET_MASK_OK_DONE;
 }
+
+static void imsic_irq_force_complete_move(struct irq_data *d)
+{
+       struct imsic_vector *mvec, *vec = irq_data_get_irq_chip_data(d);
+       unsigned int cpu = smp_processor_id();
+
+       if (WARN_ON(!vec))
+               return;
+
+       /* Do nothing if there is no in-flight move */
+       mvec = imsic_vector_get_move(vec);
+       if (!mvec)
+               return;
+
+       /* Do nothing if the old IMSIC vector does not belong to current CPU */
+       if (mvec->cpu != cpu)
+               return;
+
+       /*
+        * The best we can do is force cleanup the old IMSIC vector.
+        *
+        * The challenges over here are same as x86 vector domain so
+        * refer to the comments in irq_force_complete_move() function
+        * implemented at arch/x86/kernel/apic/vector.c.
+        */
+
+       /* Force cleanup in-flight move */
+       pr_info("IRQ fixup: irq %d move in progress, old vector cpu %d local_id %d\n",
+               d->irq, mvec->cpu, mvec->local_id);
+       imsic_vector_force_move_cleanup(vec);
+}
 #endif
 
 static struct irq_chip imsic_irq_base_chip = {
@@ -137,6 +168,7 @@ static struct irq_chip imsic_irq_base_chip = {
        .irq_unmask             = imsic_irq_unmask,
 #ifdef CONFIG_SMP
        .irq_set_affinity       = imsic_irq_set_affinity,
+       .irq_force_complete_move = imsic_irq_force_complete_move,
 #endif
        .irq_retrigger          = imsic_irq_retrigger,
        .irq_compose_msi_msg    = imsic_irq_compose_msg,

diff --git a/drivers/irqchip/irq-riscv-imsic-state.c b/drivers/irqchip/irq-riscv-imsic-state.c
index 1aeba76d72795a455e2318ac41c6227761f906e6..eb0a9b6a523915b68b0dfdf9d62caba1def0cc17 100644 (file)
--- a/drivers/irqchip/irq-riscv-imsic-state.c
+++ b/drivers/irqchip/irq-riscv-imsic-state.c
@@ -311,6 +311,23 @@ void imsic_vector_unmask(struct imsic_vector *vec)
        raw_spin_unlock(&lpriv->lock);
 }
 
+void imsic_vector_force_move_cleanup(struct imsic_vector *vec)
+{
+       struct imsic_local_priv *lpriv;
+       struct imsic_vector *mvec;
+       unsigned long flags;
+
+       lpriv = per_cpu_ptr(imsic->lpriv, vec->cpu);
+       raw_spin_lock_irqsave(&lpriv->lock, flags);
+
+       mvec = READ_ONCE(vec->move_prev);
+       WRITE_ONCE(vec->move_prev, NULL);
+       if (mvec)
+               imsic_vector_free(mvec);
+
+       raw_spin_unlock_irqrestore(&lpriv->lock, flags);
+}
+
 static bool imsic_vector_move_update(struct imsic_local_priv *lpriv,
                                     struct imsic_vector *vec, bool is_old_vec,
                                     bool new_enable, struct imsic_vector *move_vec)

diff --git a/drivers/irqchip/irq-riscv-imsic-state.h b/drivers/irqchip/irq-riscv-imsic-state.h
index f02842b84ed582af258aeabb360fcf96c136cb80..19dea0c77738e811e3553621834e6c4a85f1f782 100644 (file)
--- a/drivers/irqchip/irq-riscv-imsic-state.h
+++ b/drivers/irqchip/irq-riscv-imsic-state.h
@@ -91,6 +91,7 @@ static inline struct imsic_vector *imsic_vector_get_move(struct imsic_vector *ve
        return READ_ONCE(vec->move_prev);
 }
 
+void imsic_vector_force_move_cleanup(struct imsic_vector *vec);
 void imsic_vector_move(struct imsic_vector *old_vec, struct imsic_vector *new_vec);
 
 struct imsic_vector *imsic_vector_from_local_id(unsigned int cpu, unsigned int local_id);