Add the flag IRQ_DOMAIN_FLAG_MSI_IMMUTABLE and the API function irq_domain_is_msi_immutable() to check if the MSI controller retains an immutable address/data pair during irq_set_affinity().
Ensure compatibility with MSI users like PCIe Endpoint Doorbell, which require the address/data pair to remain unchanged after setup. Use this function to verify if the MSI controller is immutable. Signed-off-by: Frank Li <frank...@nxp.com> --- change from v14 to v16 - none change from v13 to v14 - Roll back to v12 version because Marc Zyngier have concern about add DOMAIN_BUS_DEVICE_PCI_EP_MSI. https://lore.kernel.org/imx/861pxfq315.wl-...@kernel.org/ Change from v11 to v12 - change to IRQ_DOMAIN_FLAG_MSI_IMMUTABLE to minimized the code change. --- include/linux/irqdomain.h | 7 +++++++ 1 file changed, 7 insertions(+) diff --git a/include/linux/irqdomain.h b/include/linux/irqdomain.h index 33ff41eef8f73..86222602744e9 100644 --- a/include/linux/irqdomain.h +++ b/include/linux/irqdomain.h @@ -231,6 +231,9 @@ enum { /* Irq domain must destroy generic chips when removed */ IRQ_DOMAIN_FLAG_DESTROY_GC = (1 << 10), + /* Address and data pair is mutable when irq_set_affinity() */ + IRQ_DOMAIN_FLAG_MSI_IMMUTABLE = (1 << 11), + /* * Flags starting from IRQ_DOMAIN_FLAG_NONCORE are reserved * for implementation specific purposes and ignored by the @@ -691,6 +694,10 @@ static inline bool irq_domain_is_msi_device(struct irq_domain *domain) return domain->flags & IRQ_DOMAIN_FLAG_MSI_DEVICE; } +static inline bool irq_domain_is_msi_immutable(struct irq_domain *domain) +{ + return domain->flags & IRQ_DOMAIN_FLAG_MSI_IMMUTABLE; +} #else /* CONFIG_IRQ_DOMAIN_HIERARCHY */ static inline int irq_domain_alloc_irqs(struct irq_domain *domain, unsigned int nr_irqs, int node, void *arg) -- 2.34.1
