Merge branch 'irq-core-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip

Pull irq updates from Thomas Gleixner:
 "The irq department provides:

   - Support for MSI to wire bridges and a first user of it

   - More ACPI support for ARM/GIC

   - A new TS-4800 interrupt controller driver

   - RCU based free of interrupt descriptors to support the upcoming
     Intel VMD technology without introducing a locking nightmare

   - The usual pile of fixes and updates to drivers and core code"

* 'irq-core-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: (41 commits)
  irqchip/omap-intc: Add support for spurious irq handling
  irqchip/zevio: Use irq_data_get_chip_type() helper
  irqchip/omap-intc: Remove duplicate setup for IRQ chip type handler
  irqchip/ts4800: Add TS-4800 interrupt controller
  irqchip/ts4800: Add documentation for TS-4800 interrupt controller
  irq/platform-MSI: Increase the maximum MSIs the MSI framework can support
  irqchip/gicv2m: Miscellaneous fixes for v2m resources and SPI ranges
  irqchip/bcm2836: Make code more readable
  irqchip/bcm2836: Tolerate IRQs while no flag is set in ISR
  irqchip/bcm2836: Add SMP support for the 2836
  irqchip/bcm2836: Fix initialization of the LOCAL_IRQ_CNT timers
  irqchip/gic-v2m: acpi: Introducing GICv2m ACPI support
  irqchip/gic-v2m: Refactor to prepare for ACPI support
  irqdomain: Introduce is_fwnode_irqchip helper
  acpi: pci: Setup MSI domain for ACPI based pci devices
  genirq/msi: Export functions to allow MSI domains in modules
  irqchip/mbigen: Implement the mbigen irq chip operation functions
  irqchip/mbigen: Create irq domain for each mbigen device
  irqchip/mgigen: Add platform device driver for mbigen device
  dt-bindings: Documents the mbigen bindings
  ...

1 files changed, 42 insertions, 0 deletions

diff --git a/drivers/pci/pci-acpi.c b/drivers/pci/pci-acpi.c
index a32ba753e413..d3f32d6417ef 100644
--- a/drivers/pci/pci-acpi.c
+++ b/drivers/pci/pci-acpi.c
@@ -9,7 +9,9 @@
 
 #include <linux/delay.h>
 #include <linux/init.h>
+#include <linux/irqdomain.h>
 #include <linux/pci.h>
+#include <linux/msi.h>
 #include <linux/pci_hotplug.h>
 #include <linux/module.h>
 #include <linux/pci-aspm.h>
@@ -689,6 +691,46 @@ static struct acpi_bus_type acpi_pci_bus = {
 	.cleanup = pci_acpi_cleanup,
 };
 
+
+static struct fwnode_handle *(*pci_msi_get_fwnode_cb)(struct device *dev);
+
+/**
+ * pci_msi_register_fwnode_provider - Register callback to retrieve fwnode
+ * @fn:       Callback matching a device to a fwnode that identifies a PCI
+ *            MSI domain.
+ *
+ * This should be called by irqchip driver, which is the parent of
+ * the MSI domain to provide callback interface to query fwnode.
+ */
+void
+pci_msi_register_fwnode_provider(struct fwnode_handle *(*fn)(struct device *))
+{
+	pci_msi_get_fwnode_cb = fn;
+}
+
+/**
+ * pci_host_bridge_acpi_msi_domain - Retrieve MSI domain of a PCI host bridge
+ * @bus:      The PCI host bridge bus.
+ *
+ * This function uses the callback function registered by
+ * pci_msi_register_fwnode_provider() to retrieve the irq_domain with
+ * type DOMAIN_BUS_PCI_MSI of the specified host bridge bus.
+ * This returns NULL on error or when the domain is not found.
+ */
+struct irq_domain *pci_host_bridge_acpi_msi_domain(struct pci_bus *bus)
+{
+	struct fwnode_handle *fwnode;
+
+	if (!pci_msi_get_fwnode_cb)
+		return NULL;
+
+	fwnode = pci_msi_get_fwnode_cb(&bus->dev);
+	if (!fwnode)
+		return NULL;
+
+	return irq_find_matching_fwnode(fwnode, DOMAIN_BUS_PCI_MSI);
+}
+
 static int __init acpi_pci_init(void)
 {
 	int ret;