usb: add find_raw_port_number callback to struct hc_driver()

xhci driver divides the root hub into two logical hubs which work
respectively for usb 2.0 and usb 3.0 devices. They are independent
devices in the usb core. But in the ACPI table, it's one device node
and all usb2.0 and usb3.0 ports are under it. Binding usb port with
its acpi node needs the raw port number which is reflected in the xhci
extended capabilities table. This patch is to add find_raw_port_number
callback to struct hc_driver(), fill it with xhci_find_raw_port_number()
which will return raw port number and add a wrap usb_hcd_find_raw_port_number().

Otherwise, refactor xhci_find_real_port_number(). Using
xhci_find_raw_port_number() to get real index in the HW port status
registers instead of scanning through the xHCI roothub port array.
This can help to speed up.

All addresses in xhci->usb2_ports and xhci->usb3_ports array are
kown good ports and don't include following bad ports in the extended
capabilities talbe.
     (1) root port that doesn't have an entry
     (2) root port with unknown speed
     (3) root port that is listed twice and with different speeds.

So xhci_find_raw_port_number() will only return port num of good ones
and never touch bad ports above.

Signed-off-by: Lan Tianyu <tianyu.lan@intel.com>
Signed-off-by: Sarah Sharp <sarah.a.sharp@linux.intel.com>

1 files changed, 8 insertions, 28 deletions

diff --git a/drivers/usb/host/xhci-mem.c b/drivers/usb/host/xhci-mem.c
index 35616ffbe3ae..6dc238c592bc 100644
--- a/drivers/usb/host/xhci-mem.c
+++ b/drivers/usb/host/xhci-mem.c
@@ -1022,44 +1022,24 @@ void xhci_copy_ep0_dequeue_into_input_ctx(struct xhci_hcd *xhci,
  * is attached to (or the roothub port its ancestor hub is attached to).  All we
  * know is the index of that port under either the USB 2.0 or the USB 3.0
  * roothub, but that doesn't give us the real index into the HW port status
- * registers.  Scan through the xHCI roothub port array, looking for the Nth
- * entry of the correct port speed.  Return the port number of that entry.
+ * registers. Call xhci_find_raw_port_number() to get real index.
  */
 static u32 xhci_find_real_port_number(struct xhci_hcd *xhci,
 		struct usb_device *udev)
 {
 	struct usb_device *top_dev;
-	unsigned int num_similar_speed_ports;
-	unsigned int faked_port_num;
-	int i;
+	struct usb_hcd *hcd;
+
+	if (udev->speed == USB_SPEED_SUPER)
+		hcd = xhci->shared_hcd;
+	else
+		hcd = xhci->main_hcd;
 
 	for (top_dev = udev; top_dev->parent && top_dev->parent->parent;
 			top_dev = top_dev->parent)
 		/* Found device below root hub */;
-	faked_port_num = top_dev->portnum;
-	for (i = 0, num_similar_speed_ports = 0;
-			i < HCS_MAX_PORTS(xhci->hcs_params1); i++) {
-		u8 port_speed = xhci->port_array[i];
-
-		/*
-		 * Skip ports that don't have known speeds, or have duplicate
-		 * Extended Capabilities port speed entries.
-		 */
-		if (port_speed == 0 || port_speed == DUPLICATE_ENTRY)
-			continue;
 
-		/*
-		 * USB 3.0 ports are always under a USB 3.0 hub.  USB 2.0 and
-		 * 1.1 ports are under the USB 2.0 hub.  If the port speed
-		 * matches the device speed, it's a similar speed port.
-		 */
-		if ((port_speed == 0x03) == (udev->speed == USB_SPEED_SUPER))
-			num_similar_speed_ports++;
-		if (num_similar_speed_ports == faked_port_num)
-			/* Roothub ports are numbered from 1 to N */
-			return i+1;
-	}
-	return 0;
+	return	xhci_find_raw_port_number(hcd, top_dev->portnum);
 }
 
 /* Setup an xHCI virtual device for a Set Address command */