[patch V2 08/33] genirq/msi: Provide msi_match_device_domain()

Thomas Gleixner
2022-11-21T14:38:58Z

Provide an interface to match a per device domain bus token. This allows to
query which type of domain is installed for a particular domain id. Will be
used for PCI to avoid frequent create/remove cycles for the MSI resp. MSI-X
domains.

Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
---
include/linux/msi.h | 3 +++
kernel/irq/msi.c | 25 +++++++++++++++++++++++++
2 files changed, 28 insertions(+)

--- a/include/linux/msi.h
+++ b/include/linux/msi.h
@@ -542,6 +542,9 @@ bool msi_create_device_irq_domain(struct
void *chip_data);
void msi_remove_device_irq_domain(struct device *dev, unsigned int domid);

+bool msi_match_device_irq_domain(struct device *dev, unsigned int domid,
+ enum irq_domain_bus_token bus_token);
+
int msi_domain_alloc_irqs_range_locked(struct device *dev, unsigned int domid,
unsigned int first, unsigned int last);
int msi_domain_alloc_irqs_range(struct device *dev, unsigned int domid,
--- a/kernel/irq/msi.c
+++ b/kernel/irq/msi.c
@@ -1021,6 +1021,31 @@ void msi_remove_device_irq_domain(struct
msi_unlock_descs(dev);
}

+/**
+ * msi_match_device_irq_domain - Match a device irq domain against a bus token
+ * @dev: Pointer to the device
+ * @domid: Domain id
+ * @bus_token: Bus token to match against the domain bus token
+ *
+ * Return: True if device domain exists and bus tokens match.
+ */
+bool msi_match_device_irq_domain(struct device *dev, unsigned int domid,
+ enum irq_domain_bus_token bus_token)
+{
+ struct msi_domain_info *info;
+ struct irq_domain *domain;
+ bool ret = false;
+
+ msi_lock_descs(dev);
+ domain = msi_get_device_domain(dev, domid);
+ if (domain && irq_domain_is_msi_device(domain)) {
+ info = domain->host_data;
+ ret = info->bus_token == bus_token;
+ }
+ msi_unlock_descs(dev);
+ return ret;
+}
+
int msi_domain_prepare_irqs(struct irq_domain *domain, struct device *dev,
int nvec, msi_alloc_info_t *arg)
{