static struct irq_domain *msi_default_domain;
-static void irq_msi_compose_msg(struct irq_data *data, struct msi_msg *msg)
+static void __irq_msi_compose_msg(struct irq_cfg *cfg, struct msi_msg *msg)
{
- struct irq_cfg *cfg = irqd_cfg(data);
-
msg->address_hi = MSI_ADDR_BASE_HI;
if (x2apic_enabled())
MSI_DATA_VECTOR(cfg->vector);
}
+static void irq_msi_compose_msg(struct irq_data *data, struct msi_msg *msg)
+{
+ __irq_msi_compose_msg(irqd_cfg(data), msg);
+}
+
+static void irq_msi_update_msg(struct irq_data *irqd, struct irq_cfg *cfg)
+{
+ struct msi_msg msg[2] = { [1] = { }, };
+
+ __irq_msi_compose_msg(cfg, msg);
+ irq_data_get_irq_chip(irqd)->irq_write_msi_msg(irqd, msg);
+}
+
+static int
+msi_set_affinity(struct irq_data *irqd, const struct cpumask *mask, bool force)
+{
+ struct irq_cfg old_cfg, *cfg = irqd_cfg(irqd);
+ struct irq_data *parent = irqd->parent_data;
+ unsigned int cpu;
+ int ret;
+
+ /* Save the current configuration */
+ cpu = cpumask_first(irq_data_get_effective_affinity_mask(irqd));
+ old_cfg = *cfg;
+
+ /* Allocate a new target vector */
+ ret = parent->chip->irq_set_affinity(parent, mask, force);
+ if (ret < 0 || ret == IRQ_SET_MASK_OK_DONE)
+ return ret;
+
+ /*
+ * For non-maskable and non-remapped MSI interrupts the migration
+ * to a different destination CPU and a different vector has to be
+ * done careful to handle the possible stray interrupt which can be
+ * caused by the non-atomic update of the address/data pair.
+ *
+ * Direct update is possible when:
+ * - The MSI is maskable (remapped MSI does not use this code path)).
+ * The quirk bit is not set in this case.
+ * - The new vector is the same as the old vector
+ * - The old vector is MANAGED_IRQ_SHUTDOWN_VECTOR (interrupt starts up)
+ * - The new destination CPU is the same as the old destination CPU
+ */
+ if (!irqd_msi_nomask_quirk(irqd) ||
+ cfg->vector == old_cfg.vector ||
+ old_cfg.vector == MANAGED_IRQ_SHUTDOWN_VECTOR ||
+ cfg->dest_apicid == old_cfg.dest_apicid) {
+ irq_msi_update_msg(irqd, cfg);
+ return ret;
+ }
+
+ /*
+ * Paranoia: Validate that the interrupt target is the local
+ * CPU.
+ */
+ if (WARN_ON_ONCE(cpu != smp_processor_id())) {
+ irq_msi_update_msg(irqd, cfg);
+ return ret;
+ }
+
+ /*
+ * Redirect the interrupt to the new vector on the current CPU
+ * first. This might cause a spurious interrupt on this vector if
+ * the device raises an interrupt right between this update and the
+ * update to the final destination CPU.
+ *
+ * If the vector is in use then the installed device handler will
+ * denote it as spurious which is no harm as this is a rare event
+ * and interrupt handlers have to cope with spurious interrupts
+ * anyway. If the vector is unused, then it is marked so it won't
+ * trigger the 'No irq handler for vector' warning in do_IRQ().
+ *
+ * This requires to hold vector lock to prevent concurrent updates to
+ * the affected vector.
+ */
+ lock_vector_lock();
+
+ /*
+ * Mark the new target vector on the local CPU if it is currently
+ * unused. Reuse the VECTOR_RETRIGGERED state which is also used in
+ * the CPU hotplug path for a similar purpose. This cannot be
+ * undone here as the current CPU has interrupts disabled and
+ * cannot handle the interrupt before the whole set_affinity()
+ * section is done. In the CPU unplug case, the current CPU is
+ * about to vanish and will not handle any interrupts anymore. The
+ * vector is cleaned up when the CPU comes online again.
+ */
+ if (IS_ERR_OR_NULL(this_cpu_read(vector_irq[cfg->vector])))
+ this_cpu_write(vector_irq[cfg->vector], VECTOR_RETRIGGERED);
+
+ /* Redirect it to the new vector on the local CPU temporarily */
+ old_cfg.vector = cfg->vector;
+ irq_msi_update_msg(irqd, &old_cfg);
+
+ /* Now transition it to the target CPU */
+ irq_msi_update_msg(irqd, cfg);
+
+ /*
+ * All interrupts after this point are now targeted at the new
+ * vector/CPU.
+ *
+ * Drop vector lock before testing whether the temporary assignment
+ * to the local CPU was hit by an interrupt raised in the device,
+ * because the retrigger function acquires vector lock again.
+ */
+ unlock_vector_lock();
+
+ /*
+ * Check whether the transition raced with a device interrupt and
+ * is pending in the local APICs IRR. It is safe to do this outside
+ * of vector lock as the irq_desc::lock of this interrupt is still
+ * held and interrupts are disabled: The check is not accessing the
+ * underlying vector store. It's just checking the local APIC's
+ * IRR.
+ */
+ if (lapic_vector_set_in_irr(cfg->vector))
+ irq_data_get_irq_chip(irqd)->irq_retrigger(irqd);
+
+ return ret;
+}
+
/*
* IRQ Chip for MSI PCI/PCI-X/PCI-Express Devices,
* which implement the MSI or MSI-X Capability Structure.
.irq_ack = irq_chip_ack_parent,
.irq_retrigger = irq_chip_retrigger_hierarchy,
.irq_compose_msi_msg = irq_msi_compose_msg,
+ .irq_set_affinity = msi_set_affinity,
.flags = IRQCHIP_SKIP_SET_WAKE,
};
}
if (!msi_default_domain)
pr_warn("failed to initialize irqdomain for MSI/MSI-x.\n");
+ else
+ msi_default_domain->flags |= IRQ_DOMAIN_MSI_NOMASK_QUIRK;
}
#ifdef CONFIG_IRQ_REMAP
projects / mirror_ubuntu-bionic-kernel.git / blobdiff