[PATCH v4 1/5] PCI/MSI: Export pci_msix_prepare_desc() for dynamic MSI-X allocations
From: Shradha Gupta <hidden>
Date: 2025-05-27 15:57:58
Also in:
linux-hyperv, linux-pci, linux-rdma, lkml
Subsystem:
pci subsystem, the rest · Maintainers:
Bjorn Helgaas, Linus Torvalds
For supporting dynamic MSI-X vector allocation by PCI controllers, enabling the flag MSI_FLAG_PCI_MSIX_ALLOC_DYN is not enough, msix_prepare_msi_desc() to prepare the MSI descriptor is also needed. Export pci_msix_prepare_desc() to allow PCI controllers to support dynamic MSI-X vector allocation. Signed-off-by: Shradha Gupta <redacted> Reviewed-by: Haiyang Zhang <haiyangz@microsoft.com> Reviewed-by: Thomas Gleixner <redacted> --- Changes in v3 * Improved the patch description by removing abbreviations --- drivers/pci/msi/irqdomain.c | 5 +++-- include/linux/msi.h | 2 ++ 2 files changed, 5 insertions(+), 2 deletions(-)
diff --git a/drivers/pci/msi/irqdomain.c b/drivers/pci/msi/irqdomain.c
index d7ba8795d60f..43129aa6d6c7 100644
--- a/drivers/pci/msi/irqdomain.c
+++ b/drivers/pci/msi/irqdomain.c@@ -222,13 +222,14 @@ static void pci_irq_unmask_msix(struct irq_data *data) pci_msix_unmask(irq_data_get_msi_desc(data)); } -static void pci_msix_prepare_desc(struct irq_domain *domain, msi_alloc_info_t *arg, - struct msi_desc *desc) +void pci_msix_prepare_desc(struct irq_domain *domain, msi_alloc_info_t *arg, + struct msi_desc *desc) { /* Don't fiddle with preallocated MSI descriptors */ if (!desc->pci.mask_base) msix_prepare_msi_desc(to_pci_dev(desc->dev), desc); } +EXPORT_SYMBOL_GPL(pci_msix_prepare_desc); static const struct msi_domain_template pci_msix_template = { .chip = {
diff --git a/include/linux/msi.h b/include/linux/msi.h
index 86e42742fd0f..d5864d5e75c2 100644
--- a/include/linux/msi.h
+++ b/include/linux/msi.h@@ -691,6 +691,8 @@ struct irq_domain *pci_msi_create_irq_domain(struct fwnode_handle *fwnode, struct irq_domain *parent); u32 pci_msi_domain_get_msi_rid(struct irq_domain *domain, struct pci_dev *pdev); struct irq_domain *pci_msi_get_device_domain(struct pci_dev *pdev); +void pci_msix_prepare_desc(struct irq_domain *domain, msi_alloc_info_t *arg, + struct msi_desc *desc); #else /* CONFIG_PCI_MSI */ static inline struct irq_domain *pci_msi_get_device_domain(struct pci_dev *pdev) {
--
2.34.1