v4.19.13 snapshot.
diff --git a/drivers/pci/irq.c b/drivers/pci/irq.c
new file mode 100644
index 0000000..a1de501
--- /dev/null
+++ b/drivers/pci/irq.c
@@ -0,0 +1,124 @@
+// SPDX-License-Identifier: GPL-2.0
+/*
+ * PCI IRQ handling code
+ *
+ * Copyright (c) 2008 James Bottomley <James.Bottomley@HansenPartnership.com>
+ * Copyright (C) 2017 Christoph Hellwig.
+ */
+
+#include <linux/acpi.h>
+#include <linux/device.h>
+#include <linux/kernel.h>
+#include <linux/export.h>
+#include <linux/pci.h>
+
+static void pci_note_irq_problem(struct pci_dev *pdev, const char *reason)
+{
+ struct pci_dev *parent = to_pci_dev(pdev->dev.parent);
+
+ pci_err(pdev, "Potentially misrouted IRQ (Bridge %s %04x:%04x)\n",
+ dev_name(&parent->dev), parent->vendor, parent->device);
+ pci_err(pdev, "%s\n", reason);
+ pci_err(pdev, "Please report to linux-kernel@vger.kernel.org\n");
+ WARN_ON(1);
+}
+
+/**
+ * pci_lost_interrupt - reports a lost PCI interrupt
+ * @pdev: device whose interrupt is lost
+ *
+ * The primary function of this routine is to report a lost interrupt
+ * in a standard way which users can recognise (instead of blaming the
+ * driver).
+ *
+ * Returns:
+ * a suggestion for fixing it (although the driver is not required to
+ * act on this).
+ */
+enum pci_lost_interrupt_reason pci_lost_interrupt(struct pci_dev *pdev)
+{
+ if (pdev->msi_enabled || pdev->msix_enabled) {
+ enum pci_lost_interrupt_reason ret;
+
+ if (pdev->msix_enabled) {
+ pci_note_irq_problem(pdev, "MSIX routing failure");
+ ret = PCI_LOST_IRQ_DISABLE_MSIX;
+ } else {
+ pci_note_irq_problem(pdev, "MSI routing failure");
+ ret = PCI_LOST_IRQ_DISABLE_MSI;
+ }
+ return ret;
+ }
+#ifdef CONFIG_ACPI
+ if (!(acpi_disabled || acpi_noirq)) {
+ pci_note_irq_problem(pdev, "Potential ACPI misrouting please reboot with acpi=noirq");
+ /* currently no way to fix acpi on the fly */
+ return PCI_LOST_IRQ_DISABLE_ACPI;
+ }
+#endif
+ pci_note_irq_problem(pdev, "unknown cause (not MSI or ACPI)");
+ return PCI_LOST_IRQ_NO_INFORMATION;
+}
+EXPORT_SYMBOL(pci_lost_interrupt);
+
+/**
+ * pci_request_irq - allocate an interrupt line for a PCI device
+ * @dev: PCI device to operate on
+ * @nr: device-relative interrupt vector index (0-based).
+ * @handler: Function to be called when the IRQ occurs.
+ * Primary handler for threaded interrupts.
+ * If NULL and thread_fn != NULL the default primary handler is
+ * installed.
+ * @thread_fn: Function called from the IRQ handler thread
+ * If NULL, no IRQ thread is created
+ * @dev_id: Cookie passed back to the handler function
+ * @fmt: Printf-like format string naming the handler
+ *
+ * This call allocates interrupt resources and enables the interrupt line and
+ * IRQ handling. From the point this call is made @handler and @thread_fn may
+ * be invoked. All interrupts requested using this function might be shared.
+ *
+ * @dev_id must not be NULL and must be globally unique.
+ */
+int pci_request_irq(struct pci_dev *dev, unsigned int nr, irq_handler_t handler,
+ irq_handler_t thread_fn, void *dev_id, const char *fmt, ...)
+{
+ va_list ap;
+ int ret;
+ char *devname;
+ unsigned long irqflags = IRQF_SHARED;
+
+ if (!handler)
+ irqflags |= IRQF_ONESHOT;
+
+ va_start(ap, fmt);
+ devname = kvasprintf(GFP_KERNEL, fmt, ap);
+ va_end(ap);
+
+ ret = request_threaded_irq(pci_irq_vector(dev, nr), handler, thread_fn,
+ irqflags, devname, dev_id);
+ if (ret)
+ kfree(devname);
+ return ret;
+}
+EXPORT_SYMBOL(pci_request_irq);
+
+/**
+ * pci_free_irq - free an interrupt allocated with pci_request_irq
+ * @dev: PCI device to operate on
+ * @nr: device-relative interrupt vector index (0-based).
+ * @dev_id: Device identity to free
+ *
+ * Remove an interrupt handler. The handler is removed and if the interrupt
+ * line is no longer in use by any driver it is disabled. The caller must
+ * ensure the interrupt is disabled on the device before calling this function.
+ * The function does not return until any executing interrupts for this IRQ
+ * have completed.
+ *
+ * This function must not be called from interrupt context.
+ */
+void pci_free_irq(struct pci_dev *dev, unsigned int nr, void *dev_id)
+{
+ kfree(free_irq(pci_irq_vector(dev, nr), dev_id));
+}
+EXPORT_SYMBOL(pci_free_irq);