v4.19.13 snapshot.
diff --git a/drivers/usb/host/xhci-ext-caps.c b/drivers/usb/host/xhci-ext-caps.c
new file mode 100644
index 0000000..399113f
--- /dev/null
+++ b/drivers/usb/host/xhci-ext-caps.c
@@ -0,0 +1,90 @@
+// SPDX-License-Identifier: GPL-2.0
+/*
+ * XHCI extended capability handling
+ *
+ * Copyright (c) 2017 Hans de Goede <hdegoede@redhat.com>
+ */
+
+#include <linux/platform_device.h>
+#include "xhci.h"
+
+#define USB_SW_DRV_NAME "intel_xhci_usb_sw"
+#define USB_SW_RESOURCE_SIZE 0x400
+
+static void xhci_intel_unregister_pdev(void *arg)
+{
+ platform_device_unregister(arg);
+}
+
+static int xhci_create_intel_xhci_sw_pdev(struct xhci_hcd *xhci, u32 cap_offset)
+{
+ struct usb_hcd *hcd = xhci_to_hcd(xhci);
+ struct device *dev = hcd->self.controller;
+ struct platform_device *pdev;
+ struct resource res = { 0, };
+ int ret;
+
+ pdev = platform_device_alloc(USB_SW_DRV_NAME, PLATFORM_DEVID_NONE);
+ if (!pdev) {
+ xhci_err(xhci, "couldn't allocate %s platform device\n",
+ USB_SW_DRV_NAME);
+ return -ENOMEM;
+ }
+
+ res.start = hcd->rsrc_start + cap_offset;
+ res.end = res.start + USB_SW_RESOURCE_SIZE - 1;
+ res.name = USB_SW_DRV_NAME;
+ res.flags = IORESOURCE_MEM;
+
+ ret = platform_device_add_resources(pdev, &res, 1);
+ if (ret) {
+ dev_err(dev, "couldn't add resources to intel_xhci_usb_sw pdev\n");
+ platform_device_put(pdev);
+ return ret;
+ }
+
+ pdev->dev.parent = dev;
+
+ ret = platform_device_add(pdev);
+ if (ret) {
+ dev_err(dev, "couldn't register intel_xhci_usb_sw pdev\n");
+ platform_device_put(pdev);
+ return ret;
+ }
+
+ ret = devm_add_action_or_reset(dev, xhci_intel_unregister_pdev, pdev);
+ if (ret) {
+ dev_err(dev, "couldn't add unregister action for intel_xhci_usb_sw pdev\n");
+ return ret;
+ }
+
+ return 0;
+}
+
+int xhci_ext_cap_init(struct xhci_hcd *xhci)
+{
+ void __iomem *base = &xhci->cap_regs->hc_capbase;
+ u32 offset, val;
+ int ret;
+
+ offset = xhci_find_next_ext_cap(base, 0, 0);
+
+ while (offset) {
+ val = readl(base + offset);
+
+ switch (XHCI_EXT_CAPS_ID(val)) {
+ case XHCI_EXT_CAPS_VENDOR_INTEL:
+ if (xhci->quirks & XHCI_INTEL_USB_ROLE_SW) {
+ ret = xhci_create_intel_xhci_sw_pdev(xhci,
+ offset);
+ if (ret)
+ return ret;
+ }
+ break;
+ }
+ offset = xhci_find_next_ext_cap(base, offset, 0);
+ }
+
+ return 0;
+}
+EXPORT_SYMBOL_GPL(xhci_ext_cap_init);