• Sarah Sharp's avatar
    xhci: Register second xHCI roothub. · f6ff0ac8
    Sarah Sharp authored
    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: default avatarSarah Sharp <sarah.a.sharp@linux.intel.com>
    f6ff0ac8
xhci-hub.c 22.4 KB