summaryrefslogtreecommitdiff
diff options
context:
space:
mode:
-rw-r--r--include/linux/irqdomain.h5
-rw-r--r--include/linux/msi.h21
-rw-r--r--kernel/irq/msi.c41
3 files changed, 67 insertions, 0 deletions
diff --git a/include/linux/irqdomain.h b/include/linux/irqdomain.h
index 24b76688c2fb..a668cc015874 100644
--- a/include/linux/irqdomain.h
+++ b/include/linux/irqdomain.h
@@ -46,6 +46,7 @@ struct irq_desc;
struct cpumask;
struct seq_file;
struct irq_affinity_desc;
+struct msi_parent_ops;
#define IRQ_DOMAIN_IRQ_SPEC_PARAMS 16
@@ -134,6 +135,7 @@ struct irq_domain_chip_generic;
* @pm_dev: Pointer to a device that can be utilized for power management
* purposes related to the irq domain.
* @parent: Pointer to parent irq_domain to support hierarchy irq_domains
+ * @msi_parent_ops: Pointer to MSI parent domain methods for per device domain init
*
* Revmap data, used internally by the irq domain code:
* @revmap_size: Size of the linear map table @revmap[]
@@ -157,6 +159,9 @@ struct irq_domain {
#ifdef CONFIG_IRQ_DOMAIN_HIERARCHY
struct irq_domain *parent;
#endif
+#ifdef CONFIG_GENERIC_MSI_IRQ
+ const struct msi_parent_ops *msi_parent_ops;
+#endif
/* reverse map data. The linear map gets appended to the irq_domain */
irq_hw_number_t hwirq_max;
diff --git a/include/linux/msi.h b/include/linux/msi.h
index a4339ebcc035..9bf3cbad1114 100644
--- a/include/linux/msi.h
+++ b/include/linux/msi.h
@@ -500,6 +500,27 @@ enum {
};
+/**
+ * struct msi_parent_ops - MSI parent domain callbacks and configuration info
+ *
+ * @supported_flags: Required: The supported MSI flags of the parent domain
+ * @prefix: Optional: Prefix for the domain and chip name
+ * @init_dev_msi_info: Required: Callback for MSI parent domains to setup parent
+ * domain specific domain flags, domain ops and interrupt chip
+ * callbacks when a per device domain is created.
+ */
+struct msi_parent_ops {
+ u32 supported_flags;
+ const char *prefix;
+ bool (*init_dev_msi_info)(struct device *dev, struct irq_domain *domain,
+ struct irq_domain *msi_parent_domain,
+ struct msi_domain_info *msi_child_info);
+};
+
+bool msi_parent_init_dev_msi_info(struct device *dev, struct irq_domain *domain,
+ struct irq_domain *msi_parent_domain,
+ struct msi_domain_info *msi_child_info);
+
int msi_domain_set_affinity(struct irq_data *data, const struct cpumask *mask,
bool force);
diff --git a/kernel/irq/msi.c b/kernel/irq/msi.c
index 8e653f089f82..c368116e8b08 100644
--- a/kernel/irq/msi.c
+++ b/kernel/irq/msi.c
@@ -788,6 +788,47 @@ struct irq_domain *msi_create_irq_domain(struct fwnode_handle *fwnode,
return domain;
}
+/**
+ * msi_parent_init_dev_msi_info - Delegate initialization of device MSI info down
+ * in the domain hierarchy
+ * @dev: The device for which the domain should be created
+ * @domain: The domain in the hierarchy this op is being called on
+ * @msi_parent_domain: The IRQ_DOMAIN_FLAG_MSI_PARENT domain for the child to
+ * be created
+ * @msi_child_info: The MSI domain info of the IRQ_DOMAIN_FLAG_MSI_DEVICE
+ * domain to be created
+ *
+ * Return: true on success, false otherwise
+ *
+ * This is the most complex problem of per device MSI domains and the
+ * underlying interrupt domain hierarchy:
+ *
+ * The device domain to be initialized requests the broadest feature set
+ * possible and the underlying domain hierarchy puts restrictions on it.
+ *
+ * That's trivial for a simple parent->child relationship, but it gets
+ * interesting with an intermediate domain: root->parent->child. The
+ * intermediate 'parent' can expand the capabilities which the 'root'
+ * domain is providing. So that creates a classic hen and egg problem:
+ * Which entity is doing the restrictions/expansions?
+ *
+ * One solution is to let the root domain handle the initialization that's
+ * why there is the @domain and the @msi_parent_domain pointer.
+ */
+bool msi_parent_init_dev_msi_info(struct device *dev, struct irq_domain *domain,
+ struct irq_domain *msi_parent_domain,
+ struct msi_domain_info *msi_child_info)
+{
+ struct irq_domain *parent = domain->parent;
+
+ if (WARN_ON_ONCE(!parent || !parent->msi_parent_ops ||
+ !parent->msi_parent_ops->init_dev_msi_info))
+ return false;
+
+ return parent->msi_parent_ops->init_dev_msi_info(dev, parent, msi_parent_domain,
+ msi_child_info);
+}
+
int msi_domain_prepare_irqs(struct irq_domain *domain, struct device *dev,
int nvec, msi_alloc_info_t *arg)
{