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-rw-r--r--drivers/usb/core/hcd.c69
-rw-r--r--drivers/usb/host/xhci-pci.c2
2 files changed, 71 insertions, 0 deletions
diff --git a/drivers/usb/core/hcd.c b/drivers/usb/core/hcd.c
index 6a05e6934455..3aaee2811f01 100644
--- a/drivers/usb/core/hcd.c
+++ b/drivers/usb/core/hcd.c
@@ -1814,6 +1814,75 @@ void usb_hcd_reset_endpoint(struct usb_device *udev,
}
}
+/**
+ * usb_alloc_streams - allocate bulk endpoint stream IDs.
+ * @interface: alternate setting that includes all endpoints.
+ * @eps: array of endpoints that need streams.
+ * @num_eps: number of endpoints in the array.
+ * @num_streams: number of streams to allocate.
+ * @mem_flags: flags hcd should use to allocate memory.
+ *
+ * Sets up a group of bulk endpoints to have num_streams stream IDs available.
+ * Drivers may queue multiple transfers to different stream IDs, which may
+ * complete in a different order than they were queued.
+ */
+int usb_alloc_streams(struct usb_interface *interface,
+ struct usb_host_endpoint **eps, unsigned int num_eps,
+ unsigned int num_streams, gfp_t mem_flags)
+{
+ struct usb_hcd *hcd;
+ struct usb_device *dev;
+ int i;
+
+ dev = interface_to_usbdev(interface);
+ hcd = bus_to_hcd(dev->bus);
+ if (!hcd->driver->alloc_streams || !hcd->driver->free_streams)
+ return -EINVAL;
+ if (dev->speed != USB_SPEED_SUPER)
+ return -EINVAL;
+
+ /* Streams only apply to bulk endpoints. */
+ for (i = 0; i < num_eps; i++)
+ if (!usb_endpoint_xfer_bulk(&eps[i]->desc))
+ return -EINVAL;
+
+ return hcd->driver->alloc_streams(hcd, dev, eps, num_eps,
+ num_streams, mem_flags);
+}
+EXPORT_SYMBOL_GPL(usb_alloc_streams);
+
+/**
+ * usb_free_streams - free bulk endpoint stream IDs.
+ * @interface: alternate setting that includes all endpoints.
+ * @eps: array of endpoints to remove streams from.
+ * @num_eps: number of endpoints in the array.
+ * @mem_flags: flags hcd should use to allocate memory.
+ *
+ * Reverts a group of bulk endpoints back to not using stream IDs.
+ * Can fail if we are given bad arguments, or HCD is broken.
+ */
+void usb_free_streams(struct usb_interface *interface,
+ struct usb_host_endpoint **eps, unsigned int num_eps,
+ gfp_t mem_flags)
+{
+ struct usb_hcd *hcd;
+ struct usb_device *dev;
+ int i;
+
+ dev = interface_to_usbdev(interface);
+ hcd = bus_to_hcd(dev->bus);
+ if (dev->speed != USB_SPEED_SUPER)
+ return;
+
+ /* Streams only apply to bulk endpoints. */
+ for (i = 0; i < num_eps; i++)
+ if (!usb_endpoint_xfer_bulk(&eps[i]->desc))
+ return;
+
+ hcd->driver->free_streams(hcd, dev, eps, num_eps, mem_flags);
+}
+EXPORT_SYMBOL_GPL(usb_free_streams);
+
/* Protect against drivers that try to unlink URBs after the device
* is gone, by waiting until all unlinks for @udev are finished.
* Since we don't currently track URBs by device, simply wait until
diff --git a/drivers/usb/host/xhci-pci.c b/drivers/usb/host/xhci-pci.c
index 98a73cd20cc6..d295bbc15eb7 100644
--- a/drivers/usb/host/xhci-pci.c
+++ b/drivers/usb/host/xhci-pci.c
@@ -132,6 +132,8 @@ static const struct hc_driver xhci_pci_hc_driver = {
.urb_dequeue = xhci_urb_dequeue,
.alloc_dev = xhci_alloc_dev,
.free_dev = xhci_free_dev,
+ .alloc_streams = xhci_alloc_streams,
+ .free_streams = xhci_free_streams,
.add_endpoint = xhci_add_endpoint,
.drop_endpoint = xhci_drop_endpoint,
.endpoint_reset = xhci_endpoint_reset,