diff --git a/include/linux/msi.h b/include/linux/msi.h index d206239e6fa8..7593fc383dba 100644 --- a/include/linux/msi.h +++ b/include/linux/msi.h @@ -153,6 +153,8 @@ struct msi_device_data { int msi_setup_device_data(struct device *dev); +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) diff --git a/kernel/irq/msi.c b/kernel/irq/msi.c index 8e433f1a24fb..ab5e83f41188 100644 --- a/kernel/irq/msi.c +++ b/kernel/irq/msi.c @@ -105,6 +105,42 @@ int msi_setup_device_data(struct device *dev) 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 = dev_is_pci(dev) ? to_pci_dev(dev)->msi_enabled : false; + + 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)