[PATCH v2 09/11] irqchip/riscv-imsic: Implement irq_force_complete_move() for IMSIC

Anup Patel
2024-12-14T17:36:09Z

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>
---
drivers/irqchip/irq-riscv-imsic-platform.c | 32 ++++++++++++++++++++++
drivers/irqchip/irq-riscv-imsic-state.c | 17 ++++++++++++
drivers/irqchip/irq-riscv-imsic-state.h | 1 +
3 files changed, 50 insertions(+)

diff --git a/drivers/irqchip/irq-riscv-imsic-platform.c b/drivers/irqchip/irq-riscv-imsic-platform.c
index 2fab20d2ce3e..fae47b8ccf73 100644
--- a/drivers/irqchip/irq-riscv-imsic-platform.c
+++ b/drivers/irqchip/irq-riscv-imsic-platform.c
@@ -156,6 +156,37 @@ 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 = {
@@ -164,6 +195,7 @@ 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 da49a160ea09..c915a5cf4187 100644
--- a/drivers/irqchip/irq-riscv-imsic-state.c
+++ b/drivers/irqchip/irq-riscv-imsic-state.c
@@ -323,6 +323,23 @@ 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 f02842b84ed5..19dea0c77738 100644
--- 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);