xhci: Register second xHCI roothub.

This patch changes the xHCI driver to allocate two roothubs.  This touches
the driver initialization and shutdown paths, roothub emulation code, and
port status change event handlers.  This is a rather large patch, but it
can't be broken up, or it would break git-bisect.

Make the xHCI driver register its own PCI probe function.  This will call
the USB core to create the USB 2.0 roothub, and then create the USB 3.0
roothub.  This gets the code for registering a shared roothub out of the
USB core, and allows other HCDs later to decide if and how many shared
roothubs they want to allocate.

Make sure the xHCI's reset method marks the xHCI host controller's primary
roothub as the USB 2.0 roothub.  This ensures that the high speed bus will
be processed first when the PCI device is resumed, and any USB 3.0 devices
that have migrated over to high speed will migrate back after being reset.
This ensures that USB persist works with these odd devices.

The reset method will also mark the xHCI USB2 roothub as having an
integrated TT.  Like EHCI host controllers with a "rate matching hub" the
xHCI USB 2.0 roothub doesn't have an OHCI or UHCI companion controller.
It doesn't really have a TT, but we'll lie and say it has an integrated
TT.  We need to do this because the USB core will reject LS/FS devices
under a HS hub without a TT.

Other details:
-------------

The roothub emulation code is changed to return the correct number of
ports for the two roothubs.  For the USB 3.0 roothub, it only reports the
USB 3.0 ports.  For the USB 2.0 roothub, it reports all the LS/FS/HS
ports.  The code to disable a port now checks the speed of the roothub,
and refuses to disable SuperSpeed ports under the USB 3.0 roothub.

The code for initializing a new device context must be changed to set the
proper roothub port number.  Since we've split the xHCI host into two
roothubs, we can't just use the port number in the ancestor hub.  Instead,
we loop through the array of hardware port status register speeds and find
the Nth port with a similar speed.

The port status change event handler is updated to figure out whether the
port that reported the change is a USB 3.0 port, or a non-SuperSpeed port.
Once it figures out the port speed, it kicks the proper roothub.

The function to find a slot ID based on the port index is updated to take
into account that the two roothubs will have over-lapping port indexes.
It checks that the virtual device with a matching port index is the same
speed as the passed in roothub.

There's also changes to the driver initialization and shutdown paths:

 1. Make sure that the xhci_hcd pointer is shared across the two
    usb_hcd structures.  The xhci_hcd pointer is allocated and the
    registers are mapped in when xhci_pci_setup() is called with the
    primary HCD.  When xhci_pci_setup() is called with the non-primary
    HCD, the xhci_hcd pointer is stored.

 2. Make sure to set the sg_tablesize for both usb_hcd structures.  Set
    the PCI DMA mask for the non-primary HCD to allow for 64-bit or 32-bit
    DMA.  (The PCI DMA mask is set from the primary HCD further down in
    the xhci_pci_setup() function.)

 3. Ensure that the host controller doesn't start kicking khubd in
    response to port status changes before both usb_hcd structures are
    registered.  xhci_run() only starts the xHC running once it has been
    called with the non-primary roothub.  Similarly, the xhci_stop()
    function only halts the host controller when it is called with the
    non-primary HCD.  Then on the second call, it resets and cleans up the
    MSI-X irqs.

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

6 files changed, 341 insertions, 88 deletions

diff --git a/drivers/usb/host/xhci-hub.c b/drivers/usb/host/xhci-hub.c
index 4c3788c128df..ee4af076a8fe 100644
--- a/drivers/usb/host/xhci-hub.c
+++ b/drivers/usb/host/xhci-hub.c
@@ -28,13 +28,20 @@
 #define PORT_RWC_BITS   (PORT_CSC | PORT_PEC | PORT_WRC | PORT_OCC | \
                          PORT_RC | PORT_PLC | PORT_PE)
 
-static void xhci_hub_descriptor(struct xhci_hcd *xhci,
+static void xhci_hub_descriptor(struct usb_hcd *hcd, struct xhci_hcd *xhci,
                 struct usb_hub_descriptor *desc)
 {
         int ports;
         u16 temp;
 
-        ports = HCS_MAX_PORTS(xhci->hcs_params1);
+        if (hcd->speed == HCD_USB3)
+                ports = xhci->num_usb3_ports;
+        else
+                ports = xhci->num_usb2_ports;
+
+        /* FIXME: return a USB 3.0 hub descriptor if this request was for the
+         * USB3 roothub.
+         */
 
         /* USB 3.0 hubs have a different descriptor, but we fake this for now */
         desc->bDescriptorType = 0x29;
@@ -134,18 +141,22 @@ u32 xhci_port_state_to_neutral(u32 state)
 
 /*
  * find slot id based on port number.
+ * @port: The one-based port number from one of the two split roothubs.
  */
 int xhci_find_slot_id_by_port(struct usb_hcd *hcd, struct xhci_hcd *xhci,
                 u16 port)
 {
         int slot_id;
         int i;
+        enum usb_device_speed speed;
 
         slot_id = 0;
         for (i = 0; i < MAX_HC_SLOTS; i++) {
                 if (!xhci->devs[i])
                         continue;
-                if (xhci->devs[i]->port == port) {
+                speed = xhci->devs[i]->udev->speed;
+                if (((speed == USB_SPEED_SUPER) == (hcd->speed == HCD_USB3))
+                                && xhci->devs[i]->port == port) {
                         slot_id = i;
                         break;
                 }
@@ -226,11 +237,11 @@ void xhci_ring_device(struct xhci_hcd *xhci, int slot_id)
         return;
 }
 
-static void xhci_disable_port(struct xhci_hcd *xhci, u16 wIndex,
-                u32 __iomem *addr, u32 port_status)
+static void xhci_disable_port(struct usb_hcd *hcd, struct xhci_hcd *xhci,
+                u16 wIndex, u32 __iomem *addr, u32 port_status)
 {
         /* Don't allow the USB core to disable SuperSpeed ports. */
-        if (xhci->port_array[wIndex] == 0x03) {
+        if (hcd->speed == HCD_USB3) {
                 xhci_dbg(xhci, "Ignoring request to disable "
                                 "SuperSpeed port.\n");
                 return;
@@ -289,18 +300,16 @@ int xhci_hub_control(struct usb_hcd *hcd, u16 typeReq, u16 wValue,
         unsigned long flags;
         u32 temp, temp1, status;
         int retval = 0;
-        u32 __iomem *port_array[15 + USB_MAXCHILDREN];
-        int i;
+        u32 __iomem **port_array;
         int slot_id;
         struct xhci_bus_state *bus_state;
 
-        ports = HCS_MAX_PORTS(xhci->hcs_params1);
-        for (i = 0; i < ports; i++) {
-                if (i < xhci->num_usb3_ports)
-                        port_array[i] = xhci->usb3_ports[i];
-                else
-                        port_array[i] =
-                                xhci->usb2_ports[i - xhci->num_usb3_ports];
+        if (hcd->speed == HCD_USB3) {
+                ports = xhci->num_usb3_ports;
+                port_array = xhci->usb3_ports;
+        } else {
+                ports = xhci->num_usb2_ports;
+                port_array = xhci->usb2_ports;
         }
         bus_state = &xhci->bus_state[hcd_index(hcd)];
 
@@ -311,7 +320,8 @@ int xhci_hub_control(struct usb_hcd *hcd, u16 typeReq, u16 wValue,
                 memset(buf, 0, 4);
                 break;
         case GetHubDescriptor:
-                xhci_hub_descriptor(xhci, (struct usb_hub_descriptor *) buf);
+                xhci_hub_descriptor(hcd, xhci,
+                                (struct usb_hub_descriptor *) buf);
                 break;
         case GetPortStatus:
                 if (!wIndex || wIndex > ports)
@@ -518,7 +528,7 @@ int xhci_hub_control(struct usb_hcd *hcd, u16 typeReq, u16 wValue,
                                         port_array[wIndex], temp);
                         break;
                 case USB_PORT_FEAT_ENABLE:
-                        xhci_disable_port(xhci, wIndex,
+                        xhci_disable_port(hcd, xhci, wIndex,
                                         port_array[wIndex], temp);
                         break;
                 default:
@@ -550,16 +560,15 @@ int xhci_hub_status_data(struct usb_hcd *hcd, char *buf)
         int i, retval;
         struct xhci_hcd *xhci = hcd_to_xhci(hcd);
         int ports;
-        u32 __iomem *port_array[15 + USB_MAXCHILDREN];
+        u32 __iomem **port_array;
         struct xhci_bus_state *bus_state;
 
-        ports = HCS_MAX_PORTS(xhci->hcs_params1);
-        for (i = 0; i < ports; i++) {
-                if (i < xhci->num_usb3_ports)
-                        port_array[i] = xhci->usb3_ports[i];
-                else
-                        port_array[i] =
-                                xhci->usb2_ports[i - xhci->num_usb3_ports];
+        if (hcd->speed == HCD_USB3) {
+                ports = xhci->num_usb3_ports;
+                port_array = xhci->usb3_ports;
+        } else {
+                ports = xhci->num_usb2_ports;
+                port_array = xhci->usb2_ports;
         }
         bus_state = &xhci->bus_state[hcd_index(hcd)];
 
@@ -592,19 +601,18 @@ int xhci_bus_suspend(struct usb_hcd *hcd)
 {
         struct xhci_hcd *xhci = hcd_to_xhci(hcd);
         int max_ports, port_index;
-        u32 __iomem *port_array[15 + USB_MAXCHILDREN];
-        int i;
+        u32 __iomem **port_array;
         struct xhci_bus_state *bus_state;
         unsigned long flags;
 
-        xhci_dbg(xhci, "suspend root hub\n");
-        max_ports = HCS_MAX_PORTS(xhci->hcs_params1);
-        for (i = 0; i < max_ports; i++) {
-                if (i < xhci->num_usb3_ports)
-                        port_array[i] = xhci->usb3_ports[i];
-                else
-                        port_array[i] =
-                                xhci->usb2_ports[i - xhci->num_usb3_ports];
+        if (hcd->speed == HCD_USB3) {
+                max_ports = xhci->num_usb3_ports;
+                port_array = xhci->usb3_ports;
+                xhci_dbg(xhci, "suspend USB 3.0 root hub\n");
+        } else {
+                max_ports = xhci->num_usb2_ports;
+                port_array = xhci->usb2_ports;
+                xhci_dbg(xhci, "suspend USB 2.0 root hub\n");
         }
         bus_state = &xhci->bus_state[hcd_index(hcd)];
 
@@ -685,20 +693,19 @@ int xhci_bus_resume(struct usb_hcd *hcd)
 {
         struct xhci_hcd *xhci = hcd_to_xhci(hcd);
         int max_ports, port_index;
-        u32 __iomem *port_array[15 + USB_MAXCHILDREN];
-        int i;
+        u32 __iomem **port_array;
         struct xhci_bus_state *bus_state;
         u32 temp;
         unsigned long flags;
 
-        xhci_dbg(xhci, "resume root hub\n");
-        max_ports = HCS_MAX_PORTS(xhci->hcs_params1);
-        for (i = 0; i < max_ports; i++) {
-                if (i < xhci->num_usb3_ports)
-                        port_array[i] = xhci->usb3_ports[i];
-                else
-                        port_array[i] =
-                                xhci->usb2_ports[i - xhci->num_usb3_ports];
+        if (hcd->speed == HCD_USB3) {
+                max_ports = xhci->num_usb3_ports;
+                port_array = xhci->usb3_ports;
+                xhci_dbg(xhci, "resume USB 3.0 root hub\n");
+        } else {
+                max_ports = xhci->num_usb2_ports;
+                port_array = xhci->usb2_ports;
+                xhci_dbg(xhci, "resume USB 2.0 root hub\n");
         }
         bus_state = &xhci->bus_state[hcd_index(hcd)];
 
diff --git a/drivers/usb/host/xhci-mem.c b/drivers/usb/host/xhci-mem.c
index bc809cbd570a..180a2abbc868 100644
--- a/drivers/usb/host/xhci-mem.c
+++ b/drivers/usb/host/xhci-mem.c
@@ -814,14 +814,64 @@ void xhci_copy_ep0_dequeue_into_input_ctx(struct xhci_hcd *xhci,
         ep0_ctx->deq |= ep_ring->cycle_state;
 }
 
+/*
+ * The xHCI roothub may have ports of differing speeds in any order in the port
+ * status registers.  xhci->port_array provides an array of the port speed for
+ * each offset into the port status registers.
+ *
+ * The xHCI hardware wants to know the roothub port number that the USB device
+ * 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.
+ */
+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;
+
+        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 == -1)
+                        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;
+}
+
 /* Setup an xHCI virtual device for a Set Address command */
 int xhci_setup_addressable_virt_dev(struct xhci_hcd *xhci, struct usb_device *udev)
 {
         struct xhci_virt_device *dev;
         struct xhci_ep_ctx      *ep0_ctx;
-        struct usb_device       *top_dev;
         struct xhci_slot_ctx    *slot_ctx;
         struct xhci_input_control_ctx *ctrl_ctx;
+        u32                     port_num;
+        struct usb_device *top_dev;
 
         dev = xhci->devs[udev->slot_id];
         /* Slot ID 0 is reserved */
@@ -863,12 +913,17 @@ int xhci_setup_addressable_virt_dev(struct xhci_hcd *xhci, struct usb_device *ud
                 BUG();
         }
         /* Find the root hub port this device is under */
+        port_num = xhci_find_real_port_number(xhci, udev);
+        if (!port_num)
+                return -EINVAL;
+        slot_ctx->dev_info2 |= (u32) ROOT_HUB_PORT(port_num);
+        /* Set the port number in the virtual_device to the faked port number */
         for (top_dev = udev; top_dev->parent && top_dev->parent->parent;
                         top_dev = top_dev->parent)
                 /* Found device below root hub */;
-        slot_ctx->dev_info2 |= (u32) ROOT_HUB_PORT(top_dev->portnum);
         dev->port = top_dev->portnum;
-        xhci_dbg(xhci, "Set root hub portnum to %d\n", top_dev->portnum);
+        xhci_dbg(xhci, "Set root hub portnum to %d\n", port_num);
+        xhci_dbg(xhci, "Set fake root hub portnum to %d\n", dev->port);
 
         /* Is this a LS/FS device under an external HS hub? */
         if (udev->tt && udev->tt->hub->parent) {
@@ -1452,6 +1507,7 @@ void xhci_mem_cleanup(struct xhci_hcd *xhci)
         xhci->page_size = 0;
         xhci->page_shift = 0;
         xhci->bus_state[0].bus_suspended = 0;
+        xhci->bus_state[1].bus_suspended = 0;
 }
 
 static int xhci_test_trb_in_td(struct xhci_hcd *xhci,
@@ -1970,8 +2026,10 @@ int xhci_mem_init(struct xhci_hcd *xhci, gfp_t flags)
         init_completion(&xhci->addr_dev);
         for (i = 0; i < MAX_HC_SLOTS; ++i)
                 xhci->devs[i] = NULL;
-        for (i = 0; i < USB_MAXCHILDREN; ++i)
+        for (i = 0; i < USB_MAXCHILDREN; ++i) {
                 xhci->bus_state[0].resume_done[i] = 0;
+                xhci->bus_state[1].resume_done[i] = 0;
+        }
 
         if (scratchpad_alloc(xhci, flags))
                 goto fail;
diff --git a/drivers/usb/host/xhci-pci.c b/drivers/usb/host/xhci-pci.c
index 009082829364..4a9d55e80f73 100644
--- a/drivers/usb/host/xhci-pci.c
+++ b/drivers/usb/host/xhci-pci.c
@@ -50,18 +50,44 @@ static int xhci_pci_reinit(struct xhci_hcd *xhci, struct pci_dev *pdev)
 /* called during probe() after chip reset completes */
 static int xhci_pci_setup(struct usb_hcd *hcd)
 {
-        struct xhci_hcd         *xhci = hcd_to_xhci(hcd);
+        struct xhci_hcd         *xhci;
         struct pci_dev          *pdev = to_pci_dev(hcd->self.controller);
         int                     retval;
         u32                     temp;
 
         hcd->self.sg_tablesize = TRBS_PER_SEGMENT - 2;
 
-        xhci = kzalloc(sizeof(struct xhci_hcd), GFP_KERNEL);
-        if (!xhci)
-                return -ENOMEM;
-        *((struct xhci_hcd **) hcd->hcd_priv) = xhci;
-        xhci->main_hcd = hcd;
+        if (usb_hcd_is_primary_hcd(hcd)) {
+                xhci = kzalloc(sizeof(struct xhci_hcd), GFP_KERNEL);
+                if (!xhci)
+                        return -ENOMEM;
+                *((struct xhci_hcd **) hcd->hcd_priv) = xhci;
+                xhci->main_hcd = hcd;
+                /* Mark the first roothub as being USB 2.0.
+                 * The xHCI driver will register the USB 3.0 roothub.
+                 */
+                hcd->speed = HCD_USB2;
+                hcd->self.root_hub->speed = USB_SPEED_HIGH;
+                /*
+                 * USB 2.0 roothub under xHCI has an integrated TT,
+                 * (rate matching hub) as opposed to having an OHCI/UHCI
+                 * companion controller.
+                 */
+                hcd->has_tt = 1;
+        } else {
+                /* xHCI private pointer was set in xhci_pci_probe for the second
+                 * registered roothub.
+                 */
+                xhci = hcd_to_xhci(hcd);
+                temp = xhci_readl(xhci, &xhci->cap_regs->hcc_params);
+                if (HCC_64BIT_ADDR(temp)) {
+                        xhci_dbg(xhci, "Enabling 64-bit DMA addresses.\n");
+                        dma_set_mask(hcd->self.controller, DMA_BIT_MASK(64));
+                } else {
+                        dma_set_mask(hcd->self.controller, DMA_BIT_MASK(32));
+                }
+                return 0;
+        }
 
         xhci->cap_regs = hcd->regs;
         xhci->op_regs = hcd->regs +
@@ -128,11 +154,67 @@ error:
         return retval;
 }
 
+/*
+ * We need to register our own PCI probe function (instead of the USB core's
+ * function) in order to create a second roothub under xHCI.
+ */
+static int xhci_pci_probe(struct pci_dev *dev, const struct pci_device_id *id)
+{
+        int retval;
+        struct xhci_hcd *xhci;
+        struct hc_driver *driver;
+        struct usb_hcd *hcd;
+
+        driver = (struct hc_driver *)id->driver_data;
+        /* Register the USB 2.0 roothub.
+         * FIXME: USB core must know to register the USB 2.0 roothub first.
+         * This is sort of silly, because we could just set the HCD driver flags
+         * to say USB 2.0, but I'm not sure what the implications would be in
+         * the other parts of the HCD code.
+         */
+        retval = usb_hcd_pci_probe(dev, id);
+
+        if (retval)
+                return retval;
+
+        /* USB 2.0 roothub is stored in the PCI device now. */
+        hcd = dev_get_drvdata(&dev->dev);
+        xhci = hcd_to_xhci(hcd);
+        xhci->shared_hcd = usb_create_shared_hcd(driver, &dev->dev,
+                                pci_name(dev), hcd);
+        if (!xhci->shared_hcd) {
+                retval = -ENOMEM;
+                goto dealloc_usb2_hcd;
+        }
+
+        /* Set the xHCI pointer before xhci_pci_setup() (aka hcd_driver.reset)
+         * is called by usb_add_hcd().
+         */
+        *((struct xhci_hcd **) xhci->shared_hcd->hcd_priv) = xhci;
+
+        retval = usb_add_hcd(xhci->shared_hcd, dev->irq,
+                        IRQF_DISABLED | IRQF_SHARED);
+        if (retval)
+                goto put_usb3_hcd;
+        /* Roothub already marked as USB 3.0 speed */
+        return 0;
+
+put_usb3_hcd:
+        usb_put_hcd(xhci->shared_hcd);
+dealloc_usb2_hcd:
+        usb_hcd_pci_remove(dev);
+        return retval;
+}
+
 static void xhci_pci_remove(struct pci_dev *dev)
 {
         struct xhci_hcd *xhci;
 
         xhci = hcd_to_xhci(pci_get_drvdata(dev));
+        if (xhci->shared_hcd) {
+                usb_remove_hcd(xhci->shared_hcd);
+                usb_put_hcd(xhci->shared_hcd);
+        }
         usb_hcd_pci_remove(dev);
         kfree(xhci);
 }
@@ -170,7 +252,7 @@ static const struct hc_driver xhci_pci_hc_driver = {
          * generic hardware linkage
          */
         .irq =                  xhci_irq,
-        .flags =                HCD_MEMORY | HCD_USB3,
+        .flags =                HCD_MEMORY | HCD_USB3 | HCD_SHARED,
 
         /*
          * basic lifecycle operations
@@ -231,7 +313,7 @@ static struct pci_driver xhci_pci_driver = {
         .name =         (char *) hcd_name,
         .id_table =     pci_ids,
 
-        .probe =        usb_hcd_pci_probe,
+        .probe =        xhci_pci_probe,
         .remove =       xhci_pci_remove,
         /* suspend and resume implemented later */
 
diff --git a/drivers/usb/host/xhci-ring.c b/drivers/usb/host/xhci-ring.c
index 7fe9aebd3922..3bdf30dd8ce6 100644
--- a/drivers/usb/host/xhci-ring.c
+++ b/drivers/usb/host/xhci-ring.c
@@ -866,7 +866,7 @@ void xhci_stop_endpoint_command_watchdog(unsigned long arg)
         }
         spin_unlock(&xhci->lock);
         xhci_dbg(xhci, "Calling usb_hc_died()\n");
-        usb_hc_died(xhci_to_hcd(xhci));
+        usb_hc_died(xhci_to_hcd(xhci)->primary_hcd);
         xhci_dbg(xhci, "xHCI host controller is dead.\n");
 }
 
@@ -1155,20 +1155,56 @@ static void handle_vendor_event(struct xhci_hcd *xhci,
                 handle_cmd_completion(xhci, &event->event_cmd);
 }
 
+/* @port_id: the one-based port ID from the hardware (indexed from array of all
+ * port registers -- USB 3.0 and USB 2.0).
+ *
+ * Returns a zero-based port number, which is suitable for indexing into each of
+ * the split roothubs' port arrays and bus state arrays.
+ */
+static unsigned int find_faked_portnum_from_hw_portnum(struct usb_hcd *hcd,
+                struct xhci_hcd *xhci, u32 port_id)
+{
+        unsigned int i;
+        unsigned int num_similar_speed_ports = 0;
+
+        /* port_id from the hardware is 1-based, but port_array[], usb3_ports[],
+         * and usb2_ports are 0-based indexes.  Count the number of similar
+         * speed ports, up to 1 port before this port.
+         */
+        for (i = 0; i < (port_id - 1); 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 == -1)
+                        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) == (hcd->speed == HCD_USB3))
+                        num_similar_speed_ports++;
+        }
+        return num_similar_speed_ports;
+}
+
 static void handle_port_status(struct xhci_hcd *xhci,
                 union xhci_trb *event)
 {
-        struct usb_hcd *hcd = xhci_to_hcd(xhci);
+        struct usb_hcd *hcd;
         u32 port_id;
         u32 temp, temp1;
         int max_ports;
         int slot_id;
         unsigned int faked_port_index;
-        u32 __iomem *port_array[15 + USB_MAXCHILDREN];
-        int i;
+        u8 major_revision;
         struct xhci_bus_state *bus_state;
+        u32 __iomem **port_array;
 
-        bus_state = &xhci->bus_state[0];
         /* Port status change events always have a successful completion code */
         if (GET_COMP_CODE(event->generic.field[2]) != COMP_SUCCESS) {
                 xhci_warn(xhci, "WARN: xHC returned failed port status event\n");
@@ -1183,15 +1219,43 @@ static void handle_port_status(struct xhci_hcd *xhci,
                 goto cleanup;
         }
 
-        for (i = 0; i < max_ports; i++) {
-                if (i < xhci->num_usb3_ports)
-                        port_array[i] = xhci->usb3_ports[i];
-                else
-                        port_array[i] =
-                                xhci->usb2_ports[i - xhci->num_usb3_ports];
+        /* Figure out which usb_hcd this port is attached to:
+         * is it a USB 3.0 port or a USB 2.0/1.1 port?
+         */
+        major_revision = xhci->port_array[port_id - 1];
+        if (major_revision == 0) {
+                xhci_warn(xhci, "Event for port %u not in "
+                                "Extended Capabilities, ignoring.\n",
+                                port_id);
+                goto cleanup;
         }
+        if (major_revision == (u8) -1) {
+                xhci_warn(xhci, "Event for port %u duplicated in"
+                                "Extended Capabilities, ignoring.\n",
+                                port_id);
+                goto cleanup;
+        }
+
+        /*
+         * Hardware port IDs reported by a Port Status Change Event include USB
+         * 3.0 and USB 2.0 ports.  We want to check if the port has reported a
+         * resume event, but we first need to translate the hardware port ID
+         * into the index into the ports on the correct split roothub, and the
+         * correct bus_state structure.
+         */
+        /* Find the right roothub. */
+        hcd = xhci_to_hcd(xhci);
+        if ((major_revision == 0x03) != (hcd->speed == HCD_USB3))
+                hcd = xhci->shared_hcd;
+        bus_state = &xhci->bus_state[hcd_index(hcd)];
+        if (hcd->speed == HCD_USB3)
+                port_array = xhci->usb3_ports;
+        else
+                port_array = xhci->usb2_ports;
+        /* Find the faked port hub number */
+        faked_port_index = find_faked_portnum_from_hw_portnum(hcd, xhci,
+                        port_id);
 
-        faked_port_index = port_id;
         temp = xhci_readl(xhci, port_array[faked_port_index]);
         if (hcd->state == HC_STATE_SUSPENDED) {
                 xhci_dbg(xhci, "resume root hub\n");
@@ -1228,10 +1292,10 @@ static void handle_port_status(struct xhci_hcd *xhci,
                         xhci_writel(xhci, temp, port_array[faked_port_index]);
                 } else {
                         xhci_dbg(xhci, "resume HS port %d\n", port_id);
-                        bus_state->resume_done[port_id - 1] = jiffies +
+                        bus_state->resume_done[faked_port_index] = jiffies +
                                 msecs_to_jiffies(20);
                         mod_timer(&hcd->rh_timer,
-                                  bus_state->resume_done[port_id - 1]);
+                                  bus_state->resume_done[faked_port_index]);
                         /* Do the rest in GetPortStatus */
                 }
         }
@@ -1242,7 +1306,7 @@ cleanup:
 
         spin_unlock(&xhci->lock);
         /* Pass this up to the core */
-        usb_hcd_poll_rh_status(xhci_to_hcd(xhci));
+        usb_hcd_poll_rh_status(hcd);
         spin_lock(&xhci->lock);
 }
 
diff --git a/drivers/usb/host/xhci.c b/drivers/usb/host/xhci.c
index 8d45bbde3da4..4549068758f5 100644
--- a/drivers/usb/host/xhci.c
+++ b/drivers/usb/host/xhci.c
@@ -375,6 +375,21 @@ void xhci_event_ring_work(unsigned long arg)
 }
 #endif
 
+static int xhci_run_finished(struct xhci_hcd *xhci)
+{
+        if (xhci_start(xhci)) {
+                xhci_halt(xhci);
+                return -ENODEV;
+        }
+        xhci->shared_hcd->state = HC_STATE_RUNNING;
+
+        if (xhci->quirks & XHCI_NEC_HOST)
+                xhci_ring_cmd_db(xhci);
+
+        xhci_dbg(xhci, "Finished xhci_run for USB3 roothub\n");
+        return 0;
+}
+
 /*
  * Start the HC after it was halted.
  *
@@ -395,7 +410,13 @@ int xhci_run(struct usb_hcd *hcd)
         struct xhci_hcd *xhci = hcd_to_xhci(hcd);
         struct pci_dev  *pdev = to_pci_dev(xhci_to_hcd(xhci)->self.controller);
 
+        /* Start the xHCI host controller running only after the USB 2.0 roothub
+         * is setup.
+         */
+
         hcd->uses_new_polling = 1;
+        if (!usb_hcd_is_primary_hcd(hcd))
+                return xhci_run_finished(xhci);
 
         xhci_dbg(xhci, "xhci_run\n");
         /* unregister the legacy interrupt */
@@ -469,16 +490,23 @@ int xhci_run(struct usb_hcd *hcd)
                 xhci_queue_vendor_command(xhci, 0, 0, 0,
                                 TRB_TYPE(TRB_NEC_GET_FW));
 
-        if (xhci_start(xhci)) {
-                xhci_halt(xhci);
-                return -ENODEV;
-        }
+        xhci_dbg(xhci, "Finished xhci_run for USB2 roothub\n");
+        return 0;
+}
 
-        if (xhci->quirks & XHCI_NEC_HOST)
-                xhci_ring_cmd_db(xhci);
+static void xhci_only_stop_hcd(struct usb_hcd *hcd)
+{
+        struct xhci_hcd *xhci = hcd_to_xhci(hcd);
 
-        xhci_dbg(xhci, "Finished xhci_run\n");
-        return 0;
+        spin_lock_irq(&xhci->lock);
+        xhci_halt(xhci);
+
+        /* The shared_hcd is going to be deallocated shortly (the USB core only
+         * calls this function when allocation fails in usb_add_hcd(), or
+         * usb_remove_hcd() is called).  So we need to unset xHCI's pointer.
+         */
+        xhci->shared_hcd = NULL;
+        spin_unlock_irq(&xhci->lock);
 }
 
 /*
@@ -495,7 +523,15 @@ void xhci_stop(struct usb_hcd *hcd)
         u32 temp;
         struct xhci_hcd *xhci = hcd_to_xhci(hcd);
 
+        if (!usb_hcd_is_primary_hcd(hcd)) {
+                xhci_only_stop_hcd(xhci->shared_hcd);
+                return;
+        }
+
         spin_lock_irq(&xhci->lock);
+        /* Make sure the xHC is halted for a USB3 roothub
+         * (xhci_stop() could be called as part of failed init).
+         */
         xhci_halt(xhci);
         xhci_reset(xhci);
         spin_unlock_irq(&xhci->lock);
@@ -528,6 +564,8 @@ void xhci_stop(struct usb_hcd *hcd)
  * This is called when the machine is rebooting or halting.  We assume that the
  * machine will be powered off, and the HC's internal state will be reset.
  * Don't bother to free memory.
+ *
+ * This will only ever be called with the main usb_hcd (the USB3 roothub).
  */
 void xhci_shutdown(struct usb_hcd *hcd)
 {
@@ -694,10 +732,12 @@ int xhci_resume(struct xhci_hcd *xhci, bool hibernated)
         struct usb_hcd          *hcd = xhci_to_hcd(xhci);
         int                     retval;
 
-        /* Wait a bit if the bus needs to settle from the transistion to
-         * suspend.
+        /* Wait a bit if either of the roothubs need to settle from the
+         * transistion into bus suspend.
          */
-        if (time_before(jiffies, xhci->bus_state[0].next_statechange))
+        if (time_before(jiffies, xhci->bus_state[0].next_statechange) ||
+                        time_before(jiffies,
+                                xhci->bus_state[1].next_statechange))
                 msleep(100);
 
         spin_lock_irq(&xhci->lock);
diff --git a/drivers/usb/host/xhci.h b/drivers/usb/host/xhci.h
index 443d6333f280..e9217bb288ad 100644
--- a/drivers/usb/host/xhci.h
+++ b/drivers/usb/host/xhci.h
@@ -1174,12 +1174,16 @@ struct xhci_bus_state {
 
 static inline unsigned int hcd_index(struct usb_hcd *hcd)
 {
-        return 0;
+        if (hcd->speed == HCD_USB3)
+                return 0;
+        else
+                return 1;
 }
 
 /* There is one ehci_hci structure per controller */
 struct xhci_hcd {
         struct usb_hcd *main_hcd;
+        struct usb_hcd *shared_hcd;
         /* glue to PCI and HCD framework */
         struct xhci_cap_regs __iomem *cap_regs;
         struct xhci_op_regs __iomem *op_regs;
@@ -1262,10 +1266,8 @@ struct xhci_hcd {
 #define XHCI_LINK_TRB_QUIRK     (1 << 0)
 #define XHCI_RESET_EP_QUIRK     (1 << 1)
 #define XHCI_NEC_HOST           (1 << 2)
-        /* There's only one roothub to keep track of bus suspend info for
-         * (right now).
-         */
-        struct xhci_bus_state   bus_state[1];
+        /* There are two roothubs to keep track of bus suspend info for */
+        struct xhci_bus_state   bus_state[2];
         /* Is each xHCI roothub port a USB 3.0, USB 2.0, or USB 1.1 port? */
         u8                      *port_array;
         /* Array of pointers to USB 3.0 PORTSC registers */