[PATCH v2 5/7] genirq/msi: Add msi_domain_populate_irqs

From: Marc Zyngier
Date: Mon Nov 23 2015 - 03:26:45 EST


To be able to allocate interrupts from the MSI layer down,
add a new msi_domain_populate_irqs entry point.

Signed-off-by: Marc Zyngier <marc.zyngier@xxxxxxx>
---
include/linux/msi.h | 2 ++
kernel/irq/msi.c | 40 ++++++++++++++++++++++++++++++++++++++++
2 files changed, 42 insertions(+)

diff --git a/include/linux/msi.h b/include/linux/msi.h
index 1c0bb2c..cee102b 100644
--- a/include/linux/msi.h
+++ b/include/linux/msi.h
@@ -283,6 +283,8 @@ void platform_msi_domain_free_irqs(struct device *dev);
/* When an MSI domain is used as an intermediate domain */
int msi_domain_prepare_irqs(struct irq_domain *domain, struct device *dev,
int nvec, msi_alloc_info_t *args);
+int msi_domain_populate_irqs(struct irq_domain *domain, struct device *dev,
+ int virq, int nvec, msi_alloc_info_t *args);
#endif /* CONFIG_GENERIC_MSI_IRQ_DOMAIN */

#ifdef CONFIG_PCI_MSI_IRQ_DOMAIN
diff --git a/kernel/irq/msi.c b/kernel/irq/msi.c
index 9a85613..15b249e 100644
--- a/kernel/irq/msi.c
+++ b/kernel/irq/msi.c
@@ -266,6 +266,46 @@ int msi_domain_prepare_irqs(struct irq_domain *domain, struct device *dev,
return ret;
}

+int msi_domain_populate_irqs(struct irq_domain *domain, struct device *dev,
+ int virq, int nvec, msi_alloc_info_t *arg)
+{
+ struct msi_domain_info *info = domain->host_data;
+ struct msi_domain_ops *ops = info->ops;
+ struct msi_desc *desc;
+ int ret = 0;
+
+ for_each_msi_entry(desc, dev) {
+ /* Don't even try the multi-MSI brain damage. */
+ if (WARN_ON(!desc->irq || desc->nvec_used != 1)) {
+ ret = -EINVAL;
+ break;
+ }
+
+ if (!(desc->irq >= virq && desc->irq < (virq + nvec)))
+ continue;
+
+ ops->set_desc(arg, desc);
+ /* Assumes the domain mutex is held! */
+ ret = irq_domain_alloc_irqs_recursive(domain, virq, 1, arg);
+ if (ret)
+ break;
+
+ irq_set_msi_desc_off(virq, 0, desc);
+ }
+
+ if (ret) {
+ /* Mop up the damage */
+ for_each_msi_entry(desc, dev) {
+ if (!(desc->irq >= virq && desc->irq < (virq + nvec)))
+ continue;
+
+ irq_domain_free_irqs_common(domain, desc->irq, 1);
+ }
+ }
+
+ return ret;
+}
+
/**
* msi_domain_alloc_irqs - Allocate interrupts from a MSI interrupt domain
* @domain: The domain to allocate from
--
2.1.4

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