This allows drivers to retrieve the Linux interrupt number instead of
fiddling with MSI descriptors.
msi_get_virq() returns the Linux interrupt number or 0 in case that there
is no entry for the given MSI index.
Signed-off-by: Thomas Gleixner <tglx@xxxxxxxxxxxxx>
---
V2: Simplify the implementation and let PCI deal with the PCI specialities - Marc
---
include/linux/msi.h | 2 ++
kernel/irq/msi.c | 36 ++++++++++++++++++++++++++++++++++++
2 files changed, 38 insertions(+)
--- a/include/linux/msi.h
+++ b/include/linux/msi.h
@@ -170,6 +170,8 @@ static inline bool msi_device_has_proper
static inline void msi_device_set_properties(struct device *dev, unsigned long prop) { }
#endif
+unsigned int msi_get_virq(struct device *dev, unsigned int index);
+
/* Helpers to hide struct msi_desc implementation details */
#define msi_desc_to_dev(desc) ((desc)->dev)
#define dev_to_msi_list(dev) (&(dev)->msi_list)
--- a/kernel/irq/msi.c
+++ b/kernel/irq/msi.c
@@ -129,6 +129,42 @@ int msi_setup_device_data(struct device
return 0;
}
+/**
+ * msi_get_virq - Return Linux interrupt number of a MSI interrupt
+ * @dev: Device to operate on
+ * @index: MSI interrupt index to look for (0-based)
+ *
+ * Return: The Linux interrupt number on success (> 0), 0 if not found
+ */
+unsigned int msi_get_virq(struct device *dev, unsigned int index)
+{
+ struct msi_desc *desc;
+ bool pcimsi;
+
+ if (!dev->msi.data)
+ return 0;
+
+ pcimsi = msi_device_has_property(dev, MSI_PROP_PCI_MSI);
+
+ for_each_msi_entry(desc, dev) {
+ /* PCI-MSI has only one descriptor for multiple interrupts. */
+ if (pcimsi) {
+ if (desc->irq && index < desc->nvec_used)
+ return desc->irq + index;
+ break;
+ }
+
+ /*
+ * PCI-MSIX and platform MSI use a descriptor per
+ * interrupt.
+ */
+ if (desc->msi_index == index)
+ return desc->irq;
+ }
+ return 0;
+}
+EXPORT_SYMBOL_GPL(msi_get_virq);
+
#ifdef CONFIG_SYSFS
static ssize_t msi_mode_show(struct device *dev, struct device_attribute *attr,
char *buf)
