USB: xhci: Refactor code to free or cache endpoint rings.
[safe/jmp/linux-2.6] / drivers / usb / host / xhci-hcd.c
index a99c119..451f53e 100644 (file)
 
 #include <linux/irq.h>
 #include <linux/module.h>
+#include <linux/moduleparam.h>
 
 #include "xhci.h"
 
 #define DRIVER_AUTHOR "Sarah Sharp"
 #define DRIVER_DESC "'eXtensible' Host Controller (xHC) Driver"
 
+/* Some 0.95 hardware can't handle the chain bit on a Link TRB being cleared */
+static int link_quirk;
+module_param(link_quirk, int, S_IRUGO | S_IWUSR);
+MODULE_PARM_DESC(link_quirk, "Don't clear the chain bit on a link TRB");
+
 /* TODO: copied from ehci-hcd.c - can this be refactored? */
 /*
  * handshake - spin reading hc until handshake completes or fails
@@ -61,22 +67,14 @@ static int handshake(struct xhci_hcd *xhci, void __iomem *ptr,
 }
 
 /*
- * Force HC into halt state.
- *
- * Disable any IRQs and clear the run/stop bit.
- * HC will complete any current and actively pipelined transactions, and
- * should halt within 16 microframes of the run/stop bit being cleared.
- * Read HC Halted bit in the status register to see when the HC is finished.
- * XXX: shouldn't we set HC_STATE_HALT here somewhere?
+ * Disable interrupts and begin the xHCI halting process.
  */
-int xhci_halt(struct xhci_hcd *xhci)
+void xhci_quiesce(struct xhci_hcd *xhci)
 {
        u32 halted;
        u32 cmd;
        u32 mask;
 
-       xhci_dbg(xhci, "// Halt the HC\n");
-       /* Disable all interrupts from the host controller */
        mask = ~(XHCI_IRQS);
        halted = xhci_readl(xhci, &xhci->op_regs->status) & STS_HALT;
        if (!halted)
@@ -85,6 +83,21 @@ int xhci_halt(struct xhci_hcd *xhci)
        cmd = xhci_readl(xhci, &xhci->op_regs->command);
        cmd &= mask;
        xhci_writel(xhci, cmd, &xhci->op_regs->command);
+}
+
+/*
+ * Force HC into halt state.
+ *
+ * Disable any IRQs and clear the run/stop bit.
+ * HC will complete any current and actively pipelined transactions, and
+ * should halt within 16 microframes of the run/stop bit being cleared.
+ * Read HC Halted bit in the status register to see when the HC is finished.
+ * XXX: shouldn't we set HC_STATE_HALT here somewhere?
+ */
+int xhci_halt(struct xhci_hcd *xhci)
+{
+       xhci_dbg(xhci, "// Halt the HC\n");
+       xhci_quiesce(xhci);
 
        return handshake(xhci, &xhci->op_regs->status,
                        STS_HALT, STS_HALT, XHCI_MAX_HALT_USEC);
@@ -103,7 +116,10 @@ int xhci_reset(struct xhci_hcd *xhci)
        u32 state;
 
        state = xhci_readl(xhci, &xhci->op_regs->status);
-       BUG_ON((state & STS_HALT) == 0);
+       if ((state & STS_HALT) == 0) {
+               xhci_warn(xhci, "Host controller not halted, aborting reset.\n");
+               return 0;
+       }
 
        xhci_dbg(xhci, "// Reset the HC\n");
        command = xhci_readl(xhci, &xhci->op_regs->command);
@@ -115,28 +131,6 @@ int xhci_reset(struct xhci_hcd *xhci)
        return handshake(xhci, &xhci->op_regs->command, CMD_RESET, 0, 250 * 1000);
 }
 
-/*
- * Stop the HC from processing the endpoint queues.
- */
-static void xhci_quiesce(struct xhci_hcd *xhci)
-{
-       /*
-        * Queues are per endpoint, so we need to disable an endpoint or slot.
-        *
-        * To disable a slot, we need to insert a disable slot command on the
-        * command ring and ring the doorbell.  This will also free any internal
-        * resources associated with the slot (which might not be what we want).
-        *
-        * A Release Endpoint command sounds better - doesn't free internal HC
-        * memory, but removes the endpoints from the schedule and releases the
-        * bandwidth, disables the doorbells, and clears the endpoint enable
-        * flag.  Usually used prior to a set interface command.
-        *
-        * TODO: Implement after command ring code is done.
-        */
-       BUG_ON(!HC_IS_RUNNING(xhci_to_hcd(xhci)->state));
-       xhci_dbg(xhci, "Finished quiescing -- code not written yet\n");
-}
 
 #if 0
 /* Set up MSI-X table for entry 0 (may claim other entries later) */
@@ -211,6 +205,12 @@ int xhci_init(struct usb_hcd *hcd)
 
        xhci_dbg(xhci, "xhci_init\n");
        spin_lock_init(&xhci->lock);
+       if (link_quirk) {
+               xhci_dbg(xhci, "QUIRK: Not clearing Link TRB chain bits.\n");
+               xhci->quirks |= XHCI_LINK_TRB_QUIRK;
+       } else {
+               xhci_dbg(xhci, "xHCI doesn't need link TRB QUIRK\n");
+       }
        retval = xhci_mem_init(xhci, GFP_KERNEL);
        xhci_dbg(xhci, "Finished xhci_init\n");
 
@@ -226,6 +226,7 @@ int xhci_init(struct usb_hcd *hcd)
 static void xhci_work(struct xhci_hcd *xhci)
 {
        u32 temp;
+       u64 temp_64;
 
        /*
         * Clear the op reg interrupt status first,
@@ -245,12 +246,18 @@ static void xhci_work(struct xhci_hcd *xhci)
        /* Flush posted writes */
        xhci_readl(xhci, &xhci->ir_set->irq_pending);
 
-       /* FIXME this should be a delayed service routine that clears the EHB */
-       handle_event(xhci);
-
-       /* Clear the event handler busy flag; the event ring should be empty. */
-       temp = xhci_readl(xhci, &xhci->ir_set->erst_dequeue[0]);
-       xhci_writel(xhci, temp & ~ERST_EHB, &xhci->ir_set->erst_dequeue[0]);
+       if (xhci->xhc_state & XHCI_STATE_DYING)
+               xhci_dbg(xhci, "xHCI dying, ignoring interrupt. "
+                               "Shouldn't IRQs be disabled?\n");
+       else
+               /* FIXME this should be a delayed service routine
+                * that clears the EHB.
+                */
+               xhci_handle_event(xhci);
+
+       /* Clear the event handler busy flag (RW1C); the event ring should be empty. */
+       temp_64 = xhci_read_64(xhci, &xhci->ir_set->erst_dequeue);
+       xhci_write_64(xhci, temp_64 | ERST_EHB, &xhci->ir_set->erst_dequeue);
        /* Flush posted writes -- FIXME is this necessary? */
        xhci_readl(xhci, &xhci->ir_set->irq_pending);
 }
@@ -266,21 +273,36 @@ irqreturn_t xhci_irq(struct usb_hcd *hcd)
 {
        struct xhci_hcd *xhci = hcd_to_xhci(hcd);
        u32 temp, temp2;
+       union xhci_trb *trb;
 
        spin_lock(&xhci->lock);
+       trb = xhci->event_ring->dequeue;
        /* Check if the xHC generated the interrupt, or the irq is shared */
        temp = xhci_readl(xhci, &xhci->op_regs->status);
        temp2 = xhci_readl(xhci, &xhci->ir_set->irq_pending);
+       if (temp == 0xffffffff && temp2 == 0xffffffff)
+               goto hw_died;
+
        if (!(temp & STS_EINT) && !ER_IRQ_PENDING(temp2)) {
                spin_unlock(&xhci->lock);
                return IRQ_NONE;
        }
+       xhci_dbg(xhci, "op reg status = %08x\n", temp);
+       xhci_dbg(xhci, "ir set irq_pending = %08x\n", temp2);
+       xhci_dbg(xhci, "Event ring dequeue ptr:\n");
+       xhci_dbg(xhci, "@%llx %08x %08x %08x %08x\n",
+                       (unsigned long long)xhci_trb_virt_to_dma(xhci->event_ring->deq_seg, trb),
+                       lower_32_bits(trb->link.segment_ptr),
+                       upper_32_bits(trb->link.segment_ptr),
+                       (unsigned int) trb->link.intr_target,
+                       (unsigned int) trb->link.control);
 
-       temp = xhci_readl(xhci, &xhci->op_regs->status);
        if (temp & STS_FATAL) {
                xhci_warn(xhci, "WARNING: Host System Error\n");
                xhci_halt(xhci);
+hw_died:
                xhci_to_hcd(xhci)->state = HC_STATE_HALT;
+               spin_unlock(&xhci->lock);
                return -ESHUTDOWN;
        }
 
@@ -291,10 +313,11 @@ irqreturn_t xhci_irq(struct usb_hcd *hcd)
 }
 
 #ifdef CONFIG_USB_XHCI_HCD_DEBUGGING
-void event_ring_work(unsigned long arg)
+void xhci_event_ring_work(unsigned long arg)
 {
        unsigned long flags;
        int temp;
+       u64 temp_64;
        struct xhci_hcd *xhci = (struct xhci_hcd *) arg;
        int i, j;
 
@@ -303,6 +326,12 @@ void event_ring_work(unsigned long arg)
        spin_lock_irqsave(&xhci->lock, flags);
        temp = xhci_readl(xhci, &xhci->op_regs->status);
        xhci_dbg(xhci, "op reg status = 0x%x\n", temp);
+       if (temp == 0xffffffff || (xhci->xhc_state & XHCI_STATE_DYING)) {
+               xhci_dbg(xhci, "HW died, polling stopped.\n");
+               spin_unlock_irqrestore(&xhci->lock, flags);
+               return;
+       }
+
        temp = xhci_readl(xhci, &xhci->ir_set->irq_pending);
        xhci_dbg(xhci, "ir_set 0 pending = 0x%x\n", temp);
        xhci_dbg(xhci, "No-op commands handled = %d\n", xhci->noops_handled);
@@ -311,17 +340,28 @@ void event_ring_work(unsigned long arg)
        xhci_dbg(xhci, "Event ring:\n");
        xhci_debug_segment(xhci, xhci->event_ring->deq_seg);
        xhci_dbg_ring_ptrs(xhci, xhci->event_ring);
-       temp = xhci_readl(xhci, &xhci->ir_set->erst_dequeue[0]);
-       temp &= ERST_PTR_MASK;
-       xhci_dbg(xhci, "ERST deq = 0x%x\n", temp);
+       temp_64 = xhci_read_64(xhci, &xhci->ir_set->erst_dequeue);
+       temp_64 &= ~ERST_PTR_MASK;
+       xhci_dbg(xhci, "ERST deq = 64'h%0lx\n", (long unsigned int) temp_64);
        xhci_dbg(xhci, "Command ring:\n");
        xhci_debug_segment(xhci, xhci->cmd_ring->deq_seg);
        xhci_dbg_ring_ptrs(xhci, xhci->cmd_ring);
        xhci_dbg_cmd_ptrs(xhci);
+       for (i = 0; i < MAX_HC_SLOTS; ++i) {
+               if (!xhci->devs[i])
+                       continue;
+               for (j = 0; j < 31; ++j) {
+                       struct xhci_ring *ring = xhci->devs[i]->eps[j].ring;
+                       if (!ring)
+                               continue;
+                       xhci_dbg(xhci, "Dev %d endpoint ring %d:\n", i, j);
+                       xhci_debug_segment(xhci, ring->deq_seg);
+               }
+       }
 
        if (xhci->noops_submitted != NUM_TEST_NOOPS)
-               if (setup_one_noop(xhci))
-                       ring_cmd_db(xhci);
+               if (xhci_setup_one_noop(xhci))
+                       xhci_ring_cmd_db(xhci);
        spin_unlock_irqrestore(&xhci->lock, flags);
 
        if (!xhci->zombie)
@@ -346,9 +386,13 @@ void event_ring_work(unsigned long arg)
 int xhci_run(struct usb_hcd *hcd)
 {
        u32 temp;
+       u64 temp_64;
        struct xhci_hcd *xhci = hcd_to_xhci(hcd);
        void (*doorbell)(struct xhci_hcd *) = NULL;
 
+       hcd->uses_new_polling = 1;
+       hcd->poll_rh = 0;
+
        xhci_dbg(xhci, "xhci_run\n");
 #if 0  /* FIXME: MSI not setup yet */
        /* Do this at the very last minute */
@@ -361,7 +405,7 @@ int xhci_run(struct usb_hcd *hcd)
 #ifdef CONFIG_USB_XHCI_HCD_DEBUGGING
        init_timer(&xhci->event_ring_timer);
        xhci->event_ring_timer.data = (unsigned long) xhci;
-       xhci->event_ring_timer.function = event_ring_work;
+       xhci->event_ring_timer.function = xhci_event_ring_work;
        /* Poll the event ring */
        xhci->event_ring_timer.expires = jiffies + POLL_TIMEOUT * HZ;
        xhci->zombie = 0;
@@ -369,9 +413,23 @@ int xhci_run(struct usb_hcd *hcd)
        add_timer(&xhci->event_ring_timer);
 #endif
 
+       xhci_dbg(xhci, "Command ring memory map follows:\n");
+       xhci_debug_ring(xhci, xhci->cmd_ring);
+       xhci_dbg_ring_ptrs(xhci, xhci->cmd_ring);
+       xhci_dbg_cmd_ptrs(xhci);
+
+       xhci_dbg(xhci, "ERST memory map follows:\n");
+       xhci_dbg_erst(xhci, &xhci->erst);
+       xhci_dbg(xhci, "Event ring:\n");
+       xhci_debug_ring(xhci, xhci->event_ring);
+       xhci_dbg_ring_ptrs(xhci, xhci->event_ring);
+       temp_64 = xhci_read_64(xhci, &xhci->ir_set->erst_dequeue);
+       temp_64 &= ~ERST_PTR_MASK;
+       xhci_dbg(xhci, "ERST deq = 64'h%0lx\n", (long unsigned int) temp_64);
+
        xhci_dbg(xhci, "// Set the interrupt modulation register\n");
        temp = xhci_readl(xhci, &xhci->ir_set->irq_control);
-       temp &= 0xffff;
+       temp &= ~ER_IRQ_INTERVAL_MASK;
        temp |= (u32) 160;
        xhci_writel(xhci, temp, &xhci->ir_set->irq_control);
 
@@ -384,32 +442,14 @@ int xhci_run(struct usb_hcd *hcd)
        xhci_writel(xhci, temp, &xhci->op_regs->command);
 
        temp = xhci_readl(xhci, &xhci->ir_set->irq_pending);
-       xhci_dbg(xhci, "// Enabling event ring interrupter 0x%x"
-                       " by writing 0x%x to irq_pending\n",
-                       (unsigned int) xhci->ir_set,
-                       (unsigned int) ER_IRQ_ENABLE(temp));
+       xhci_dbg(xhci, "// Enabling event ring interrupter %p by writing 0x%x to irq_pending\n",
+                       xhci->ir_set, (unsigned int) ER_IRQ_ENABLE(temp));
        xhci_writel(xhci, ER_IRQ_ENABLE(temp),
                        &xhci->ir_set->irq_pending);
        xhci_print_ir_set(xhci, xhci->ir_set, 0);
 
        if (NUM_TEST_NOOPS > 0)
-               doorbell = setup_one_noop(xhci);
-
-       xhci_dbg(xhci, "Command ring memory map follows:\n");
-       xhci_debug_ring(xhci, xhci->cmd_ring);
-       xhci_dbg_ring_ptrs(xhci, xhci->cmd_ring);
-       xhci_dbg_cmd_ptrs(xhci);
-
-       xhci_dbg(xhci, "ERST memory map follows:\n");
-       xhci_dbg_erst(xhci, &xhci->erst);
-       xhci_dbg(xhci, "Event ring:\n");
-       xhci_debug_ring(xhci, xhci->event_ring);
-       xhci_dbg_ring_ptrs(xhci, xhci->event_ring);
-       temp = xhci_readl(xhci, &xhci->ir_set->erst_dequeue[1]);
-       xhci_dbg(xhci, "ERST deq upper = 0x%x\n", temp);
-       temp = xhci_readl(xhci, &xhci->ir_set->erst_dequeue[0]);
-       temp &= ERST_PTR_MASK;
-       xhci_dbg(xhci, "ERST deq = 0x%x\n", temp);
+               doorbell = xhci_setup_one_noop(xhci);
 
        temp = xhci_readl(xhci, &xhci->op_regs->command);
        temp |= (CMD_RUN);
@@ -418,8 +458,7 @@ int xhci_run(struct usb_hcd *hcd)
        xhci_writel(xhci, temp, &xhci->op_regs->command);
        /* Flush PCI posted writes */
        temp = xhci_readl(xhci, &xhci->op_regs->command);
-       xhci_dbg(xhci, "// @%x = 0x%x\n",
-                       (unsigned int) &xhci->op_regs->command, temp);
+       xhci_dbg(xhci, "// @%p = 0x%x\n", &xhci->op_regs->command, temp);
        if (doorbell)
                (*doorbell)(xhci);
 
@@ -442,8 +481,6 @@ void xhci_stop(struct usb_hcd *hcd)
        struct xhci_hcd *xhci = hcd_to_xhci(hcd);
 
        spin_lock_irq(&xhci->lock);
-       if (HC_IS_RUNNING(hcd->state))
-               xhci_quiesce(xhci);
        xhci_halt(xhci);
        xhci_reset(xhci);
        spin_unlock_irq(&xhci->lock);
@@ -496,6 +533,1210 @@ void xhci_shutdown(struct usb_hcd *hcd)
 
 /*-------------------------------------------------------------------------*/
 
+/**
+ * xhci_get_endpoint_index - Used for passing endpoint bitmasks between the core and
+ * HCDs.  Find the index for an endpoint given its descriptor.  Use the return
+ * value to right shift 1 for the bitmask.
+ *
+ * Index  = (epnum * 2) + direction - 1,
+ * where direction = 0 for OUT, 1 for IN.
+ * For control endpoints, the IN index is used (OUT index is unused), so
+ * index = (epnum * 2) + direction - 1 = (epnum * 2) + 1 - 1 = (epnum * 2)
+ */
+unsigned int xhci_get_endpoint_index(struct usb_endpoint_descriptor *desc)
+{
+       unsigned int index;
+       if (usb_endpoint_xfer_control(desc))
+               index = (unsigned int) (usb_endpoint_num(desc)*2);
+       else
+               index = (unsigned int) (usb_endpoint_num(desc)*2) +
+                       (usb_endpoint_dir_in(desc) ? 1 : 0) - 1;
+       return index;
+}
+
+/* Find the flag for this endpoint (for use in the control context).  Use the
+ * endpoint index to create a bitmask.  The slot context is bit 0, endpoint 0 is
+ * bit 1, etc.
+ */
+unsigned int xhci_get_endpoint_flag(struct usb_endpoint_descriptor *desc)
+{
+       return 1 << (xhci_get_endpoint_index(desc) + 1);
+}
+
+/* Find the flag for this endpoint (for use in the control context).  Use the
+ * endpoint index to create a bitmask.  The slot context is bit 0, endpoint 0 is
+ * bit 1, etc.
+ */
+unsigned int xhci_get_endpoint_flag_from_index(unsigned int ep_index)
+{
+       return 1 << (ep_index + 1);
+}
+
+/* Compute the last valid endpoint context index.  Basically, this is the
+ * endpoint index plus one.  For slot contexts with more than valid endpoint,
+ * we find the most significant bit set in the added contexts flags.
+ * e.g. ep 1 IN (with epnum 0x81) => added_ctxs = 0b1000
+ * fls(0b1000) = 4, but the endpoint context index is 3, so subtract one.
+ */
+unsigned int xhci_last_valid_endpoint(u32 added_ctxs)
+{
+       return fls(added_ctxs) - 1;
+}
+
+/* Returns 1 if the arguments are OK;
+ * returns 0 this is a root hub; returns -EINVAL for NULL pointers.
+ */
+int xhci_check_args(struct usb_hcd *hcd, struct usb_device *udev,
+               struct usb_host_endpoint *ep, int check_ep, const char *func) {
+       if (!hcd || (check_ep && !ep) || !udev) {
+               printk(KERN_DEBUG "xHCI %s called with invalid args\n",
+                               func);
+               return -EINVAL;
+       }
+       if (!udev->parent) {
+               printk(KERN_DEBUG "xHCI %s called for root hub\n",
+                               func);
+               return 0;
+       }
+       if (!udev->slot_id) {
+               printk(KERN_DEBUG "xHCI %s called with unaddressed device\n",
+                               func);
+               return -EINVAL;
+       }
+       return 1;
+}
+
+static int xhci_configure_endpoint(struct xhci_hcd *xhci,
+               struct usb_device *udev, struct xhci_command *command,
+               bool ctx_change, bool must_succeed);
+
+/*
+ * Full speed devices may have a max packet size greater than 8 bytes, but the
+ * USB core doesn't know that until it reads the first 8 bytes of the
+ * descriptor.  If the usb_device's max packet size changes after that point,
+ * we need to issue an evaluate context command and wait on it.
+ */
+static int xhci_check_maxpacket(struct xhci_hcd *xhci, unsigned int slot_id,
+               unsigned int ep_index, struct urb *urb)
+{
+       struct xhci_container_ctx *in_ctx;
+       struct xhci_container_ctx *out_ctx;
+       struct xhci_input_control_ctx *ctrl_ctx;
+       struct xhci_ep_ctx *ep_ctx;
+       int max_packet_size;
+       int hw_max_packet_size;
+       int ret = 0;
+
+       out_ctx = xhci->devs[slot_id]->out_ctx;
+       ep_ctx = xhci_get_ep_ctx(xhci, out_ctx, ep_index);
+       hw_max_packet_size = MAX_PACKET_DECODED(ep_ctx->ep_info2);
+       max_packet_size = urb->dev->ep0.desc.wMaxPacketSize;
+       if (hw_max_packet_size != max_packet_size) {
+               xhci_dbg(xhci, "Max Packet Size for ep 0 changed.\n");
+               xhci_dbg(xhci, "Max packet size in usb_device = %d\n",
+                               max_packet_size);
+               xhci_dbg(xhci, "Max packet size in xHCI HW = %d\n",
+                               hw_max_packet_size);
+               xhci_dbg(xhci, "Issuing evaluate context command.\n");
+
+               /* Set up the modified control endpoint 0 */
+               xhci_endpoint_copy(xhci, xhci->devs[slot_id]->in_ctx,
+                               xhci->devs[slot_id]->out_ctx, ep_index);
+               in_ctx = xhci->devs[slot_id]->in_ctx;
+               ep_ctx = xhci_get_ep_ctx(xhci, in_ctx, ep_index);
+               ep_ctx->ep_info2 &= ~MAX_PACKET_MASK;
+               ep_ctx->ep_info2 |= MAX_PACKET(max_packet_size);
+
+               /* Set up the input context flags for the command */
+               /* FIXME: This won't work if a non-default control endpoint
+                * changes max packet sizes.
+                */
+               ctrl_ctx = xhci_get_input_control_ctx(xhci, in_ctx);
+               ctrl_ctx->add_flags = EP0_FLAG;
+               ctrl_ctx->drop_flags = 0;
+
+               xhci_dbg(xhci, "Slot %d input context\n", slot_id);
+               xhci_dbg_ctx(xhci, in_ctx, ep_index);
+               xhci_dbg(xhci, "Slot %d output context\n", slot_id);
+               xhci_dbg_ctx(xhci, out_ctx, ep_index);
+
+               ret = xhci_configure_endpoint(xhci, urb->dev, NULL,
+                               true, false);
+
+               /* Clean up the input context for later use by bandwidth
+                * functions.
+                */
+               ctrl_ctx->add_flags = SLOT_FLAG;
+       }
+       return ret;
+}
+
+/*
+ * non-error returns are a promise to giveback() the urb later
+ * we drop ownership so next owner (or urb unlink) can get it
+ */
+int xhci_urb_enqueue(struct usb_hcd *hcd, struct urb *urb, gfp_t mem_flags)
+{
+       struct xhci_hcd *xhci = hcd_to_xhci(hcd);
+       unsigned long flags;
+       int ret = 0;
+       unsigned int slot_id, ep_index;
+
+
+       if (!urb || xhci_check_args(hcd, urb->dev, urb->ep, true, __func__) <= 0)
+               return -EINVAL;
+
+       slot_id = urb->dev->slot_id;
+       ep_index = xhci_get_endpoint_index(&urb->ep->desc);
+
+       if (!xhci->devs || !xhci->devs[slot_id]) {
+               if (!in_interrupt())
+                       dev_warn(&urb->dev->dev, "WARN: urb submitted for dev with no Slot ID\n");
+               ret = -EINVAL;
+               goto exit;
+       }
+       if (!test_bit(HCD_FLAG_HW_ACCESSIBLE, &hcd->flags)) {
+               if (!in_interrupt())
+                       xhci_dbg(xhci, "urb submitted during PCI suspend\n");
+               ret = -ESHUTDOWN;
+               goto exit;
+       }
+       if (usb_endpoint_xfer_control(&urb->ep->desc)) {
+               /* Check to see if the max packet size for the default control
+                * endpoint changed during FS device enumeration
+                */
+               if (urb->dev->speed == USB_SPEED_FULL) {
+                       ret = xhci_check_maxpacket(xhci, slot_id,
+                                       ep_index, urb);
+                       if (ret < 0)
+                               return ret;
+               }
+
+               /* We have a spinlock and interrupts disabled, so we must pass
+                * atomic context to this function, which may allocate memory.
+                */
+               spin_lock_irqsave(&xhci->lock, flags);
+               if (xhci->xhc_state & XHCI_STATE_DYING)
+                       goto dying;
+               ret = xhci_queue_ctrl_tx(xhci, GFP_ATOMIC, urb,
+                               slot_id, ep_index);
+               spin_unlock_irqrestore(&xhci->lock, flags);
+       } else if (usb_endpoint_xfer_bulk(&urb->ep->desc)) {
+               spin_lock_irqsave(&xhci->lock, flags);
+               if (xhci->xhc_state & XHCI_STATE_DYING)
+                       goto dying;
+               ret = xhci_queue_bulk_tx(xhci, GFP_ATOMIC, urb,
+                               slot_id, ep_index);
+               spin_unlock_irqrestore(&xhci->lock, flags);
+       } else if (usb_endpoint_xfer_int(&urb->ep->desc)) {
+               spin_lock_irqsave(&xhci->lock, flags);
+               if (xhci->xhc_state & XHCI_STATE_DYING)
+                       goto dying;
+               ret = xhci_queue_intr_tx(xhci, GFP_ATOMIC, urb,
+                               slot_id, ep_index);
+               spin_unlock_irqrestore(&xhci->lock, flags);
+       } else {
+               ret = -EINVAL;
+       }
+exit:
+       return ret;
+dying:
+       xhci_dbg(xhci, "Ep 0x%x: URB %p submitted for "
+                       "non-responsive xHCI host.\n",
+                       urb->ep->desc.bEndpointAddress, urb);
+       spin_unlock_irqrestore(&xhci->lock, flags);
+       return -ESHUTDOWN;
+}
+
+/*
+ * Remove the URB's TD from the endpoint ring.  This may cause the HC to stop
+ * USB transfers, potentially stopping in the middle of a TRB buffer.  The HC
+ * should pick up where it left off in the TD, unless a Set Transfer Ring
+ * Dequeue Pointer is issued.
+ *
+ * The TRBs that make up the buffers for the canceled URB will be "removed" from
+ * the ring.  Since the ring is a contiguous structure, they can't be physically
+ * removed.  Instead, there are two options:
+ *
+ *  1) If the HC is in the middle of processing the URB to be canceled, we
+ *     simply move the ring's dequeue pointer past those TRBs using the Set
+ *     Transfer Ring Dequeue Pointer command.  This will be the common case,
+ *     when drivers timeout on the last submitted URB and attempt to cancel.
+ *
+ *  2) If the HC is in the middle of a different TD, we turn the TRBs into a
+ *     series of 1-TRB transfer no-op TDs.  (No-ops shouldn't be chained.)  The
+ *     HC will need to invalidate the any TRBs it has cached after the stop
+ *     endpoint command, as noted in the xHCI 0.95 errata.
+ *
+ *  3) The TD may have completed by the time the Stop Endpoint Command
+ *     completes, so software needs to handle that case too.
+ *
+ * This function should protect against the TD enqueueing code ringing the
+ * doorbell while this code is waiting for a Stop Endpoint command to complete.
+ * It also needs to account for multiple cancellations on happening at the same
+ * time for the same endpoint.
+ *
+ * Note that this function can be called in any context, or so says
+ * usb_hcd_unlink_urb()
+ */
+int xhci_urb_dequeue(struct usb_hcd *hcd, struct urb *urb, int status)
+{
+       unsigned long flags;
+       int ret;
+       u32 temp;
+       struct xhci_hcd *xhci;
+       struct xhci_td *td;
+       unsigned int ep_index;
+       struct xhci_ring *ep_ring;
+       struct xhci_virt_ep *ep;
+
+       xhci = hcd_to_xhci(hcd);
+       spin_lock_irqsave(&xhci->lock, flags);
+       /* Make sure the URB hasn't completed or been unlinked already */
+       ret = usb_hcd_check_unlink_urb(hcd, urb, status);
+       if (ret || !urb->hcpriv)
+               goto done;
+       temp = xhci_readl(xhci, &xhci->op_regs->status);
+       if (temp == 0xffffffff) {
+               xhci_dbg(xhci, "HW died, freeing TD.\n");
+               td = (struct xhci_td *) urb->hcpriv;
+
+               usb_hcd_unlink_urb_from_ep(hcd, urb);
+               spin_unlock_irqrestore(&xhci->lock, flags);
+               usb_hcd_giveback_urb(xhci_to_hcd(xhci), urb, -ESHUTDOWN);
+               kfree(td);
+               return ret;
+       }
+       if (xhci->xhc_state & XHCI_STATE_DYING) {
+               xhci_dbg(xhci, "Ep 0x%x: URB %p to be canceled on "
+                               "non-responsive xHCI host.\n",
+                               urb->ep->desc.bEndpointAddress, urb);
+               /* Let the stop endpoint command watchdog timer (which set this
+                * state) finish cleaning up the endpoint TD lists.  We must
+                * have caught it in the middle of dropping a lock and giving
+                * back an URB.
+                */
+               goto done;
+       }
+
+       xhci_dbg(xhci, "Cancel URB %p\n", urb);
+       xhci_dbg(xhci, "Event ring:\n");
+       xhci_debug_ring(xhci, xhci->event_ring);
+       ep_index = xhci_get_endpoint_index(&urb->ep->desc);
+       ep = &xhci->devs[urb->dev->slot_id]->eps[ep_index];
+       ep_ring = ep->ring;
+       xhci_dbg(xhci, "Endpoint ring:\n");
+       xhci_debug_ring(xhci, ep_ring);
+       td = (struct xhci_td *) urb->hcpriv;
+
+       list_add_tail(&td->cancelled_td_list, &ep->cancelled_td_list);
+       /* Queue a stop endpoint command, but only if this is
+        * the first cancellation to be handled.
+        */
+       if (!(ep->ep_state & EP_HALT_PENDING)) {
+               ep->ep_state |= EP_HALT_PENDING;
+               ep->stop_cmds_pending++;
+               ep->stop_cmd_timer.expires = jiffies +
+                       XHCI_STOP_EP_CMD_TIMEOUT * HZ;
+               add_timer(&ep->stop_cmd_timer);
+               xhci_queue_stop_endpoint(xhci, urb->dev->slot_id, ep_index);
+               xhci_ring_cmd_db(xhci);
+       }
+done:
+       spin_unlock_irqrestore(&xhci->lock, flags);
+       return ret;
+}
+
+/* Drop an endpoint from a new bandwidth configuration for this device.
+ * Only one call to this function is allowed per endpoint before
+ * check_bandwidth() or reset_bandwidth() must be called.
+ * A call to xhci_drop_endpoint() followed by a call to xhci_add_endpoint() will
+ * add the endpoint to the schedule with possibly new parameters denoted by a
+ * different endpoint descriptor in usb_host_endpoint.
+ * A call to xhci_add_endpoint() followed by a call to xhci_drop_endpoint() is
+ * not allowed.
+ *
+ * The USB core will not allow URBs to be queued to an endpoint that is being
+ * disabled, so there's no need for mutual exclusion to protect
+ * the xhci->devs[slot_id] structure.
+ */
+int xhci_drop_endpoint(struct usb_hcd *hcd, struct usb_device *udev,
+               struct usb_host_endpoint *ep)
+{
+       struct xhci_hcd *xhci;
+       struct xhci_container_ctx *in_ctx, *out_ctx;
+       struct xhci_input_control_ctx *ctrl_ctx;
+       struct xhci_slot_ctx *slot_ctx;
+       unsigned int last_ctx;
+       unsigned int ep_index;
+       struct xhci_ep_ctx *ep_ctx;
+       u32 drop_flag;
+       u32 new_add_flags, new_drop_flags, new_slot_info;
+       int ret;
+
+       ret = xhci_check_args(hcd, udev, ep, 1, __func__);
+       if (ret <= 0)
+               return ret;
+       xhci = hcd_to_xhci(hcd);
+       xhci_dbg(xhci, "%s called for udev %p\n", __func__, udev);
+
+       drop_flag = xhci_get_endpoint_flag(&ep->desc);
+       if (drop_flag == SLOT_FLAG || drop_flag == EP0_FLAG) {
+               xhci_dbg(xhci, "xHCI %s - can't drop slot or ep 0 %#x\n",
+                               __func__, drop_flag);
+               return 0;
+       }
+
+       if (!xhci->devs || !xhci->devs[udev->slot_id]) {
+               xhci_warn(xhci, "xHCI %s called with unaddressed device\n",
+                               __func__);
+               return -EINVAL;
+       }
+
+       in_ctx = xhci->devs[udev->slot_id]->in_ctx;
+       out_ctx = xhci->devs[udev->slot_id]->out_ctx;
+       ctrl_ctx = xhci_get_input_control_ctx(xhci, in_ctx);
+       ep_index = xhci_get_endpoint_index(&ep->desc);
+       ep_ctx = xhci_get_ep_ctx(xhci, out_ctx, ep_index);
+       /* If the HC already knows the endpoint is disabled,
+        * or the HCD has noted it is disabled, ignore this request
+        */
+       if ((ep_ctx->ep_info & EP_STATE_MASK) == EP_STATE_DISABLED ||
+                       ctrl_ctx->drop_flags & xhci_get_endpoint_flag(&ep->desc)) {
+               xhci_warn(xhci, "xHCI %s called with disabled ep %p\n",
+                               __func__, ep);
+               return 0;
+       }
+
+       ctrl_ctx->drop_flags |= drop_flag;
+       new_drop_flags = ctrl_ctx->drop_flags;
+
+       ctrl_ctx->add_flags &= ~drop_flag;
+       new_add_flags = ctrl_ctx->add_flags;
+
+       last_ctx = xhci_last_valid_endpoint(ctrl_ctx->add_flags);
+       slot_ctx = xhci_get_slot_ctx(xhci, in_ctx);
+       /* Update the last valid endpoint context, if we deleted the last one */
+       if ((slot_ctx->dev_info & LAST_CTX_MASK) > LAST_CTX(last_ctx)) {
+               slot_ctx->dev_info &= ~LAST_CTX_MASK;
+               slot_ctx->dev_info |= LAST_CTX(last_ctx);
+       }
+       new_slot_info = slot_ctx->dev_info;
+
+       xhci_endpoint_zero(xhci, xhci->devs[udev->slot_id], ep);
+
+       xhci_dbg(xhci, "drop ep 0x%x, slot id %d, new drop flags = %#x, new add flags = %#x, new slot info = %#x\n",
+                       (unsigned int) ep->desc.bEndpointAddress,
+                       udev->slot_id,
+                       (unsigned int) new_drop_flags,
+                       (unsigned int) new_add_flags,
+                       (unsigned int) new_slot_info);
+       return 0;
+}
+
+/* Add an endpoint to a new possible bandwidth configuration for this device.
+ * Only one call to this function is allowed per endpoint before
+ * check_bandwidth() or reset_bandwidth() must be called.
+ * A call to xhci_drop_endpoint() followed by a call to xhci_add_endpoint() will
+ * add the endpoint to the schedule with possibly new parameters denoted by a
+ * different endpoint descriptor in usb_host_endpoint.
+ * A call to xhci_add_endpoint() followed by a call to xhci_drop_endpoint() is
+ * not allowed.
+ *
+ * The USB core will not allow URBs to be queued to an endpoint until the
+ * configuration or alt setting is installed in the device, so there's no need
+ * for mutual exclusion to protect the xhci->devs[slot_id] structure.
+ */
+int xhci_add_endpoint(struct usb_hcd *hcd, struct usb_device *udev,
+               struct usb_host_endpoint *ep)
+{
+       struct xhci_hcd *xhci;
+       struct xhci_container_ctx *in_ctx, *out_ctx;
+       unsigned int ep_index;
+       struct xhci_ep_ctx *ep_ctx;
+       struct xhci_slot_ctx *slot_ctx;
+       struct xhci_input_control_ctx *ctrl_ctx;
+       u32 added_ctxs;
+       unsigned int last_ctx;
+       u32 new_add_flags, new_drop_flags, new_slot_info;
+       int ret = 0;
+
+       ret = xhci_check_args(hcd, udev, ep, 1, __func__);
+       if (ret <= 0) {
+               /* So we won't queue a reset ep command for a root hub */
+               ep->hcpriv = NULL;
+               return ret;
+       }
+       xhci = hcd_to_xhci(hcd);
+
+       added_ctxs = xhci_get_endpoint_flag(&ep->desc);
+       last_ctx = xhci_last_valid_endpoint(added_ctxs);
+       if (added_ctxs == SLOT_FLAG || added_ctxs == EP0_FLAG) {
+               /* FIXME when we have to issue an evaluate endpoint command to
+                * deal with ep0 max packet size changing once we get the
+                * descriptors
+                */
+               xhci_dbg(xhci, "xHCI %s - can't add slot or ep 0 %#x\n",
+                               __func__, added_ctxs);
+               return 0;
+       }
+
+       if (!xhci->devs || !xhci->devs[udev->slot_id]) {
+               xhci_warn(xhci, "xHCI %s called with unaddressed device\n",
+                               __func__);
+               return -EINVAL;
+       }
+
+       in_ctx = xhci->devs[udev->slot_id]->in_ctx;
+       out_ctx = xhci->devs[udev->slot_id]->out_ctx;
+       ctrl_ctx = xhci_get_input_control_ctx(xhci, in_ctx);
+       ep_index = xhci_get_endpoint_index(&ep->desc);
+       ep_ctx = xhci_get_ep_ctx(xhci, out_ctx, ep_index);
+       /* If the HCD has already noted the endpoint is enabled,
+        * ignore this request.
+        */
+       if (ctrl_ctx->add_flags & xhci_get_endpoint_flag(&ep->desc)) {
+               xhci_warn(xhci, "xHCI %s called with enabled ep %p\n",
+                               __func__, ep);
+               return 0;
+       }
+
+       /*
+        * Configuration and alternate setting changes must be done in
+        * process context, not interrupt context (or so documenation
+        * for usb_set_interface() and usb_set_configuration() claim).
+        */
+       if (xhci_endpoint_init(xhci, xhci->devs[udev->slot_id],
+                               udev, ep, GFP_KERNEL) < 0) {
+               dev_dbg(&udev->dev, "%s - could not initialize ep %#x\n",
+                               __func__, ep->desc.bEndpointAddress);
+               return -ENOMEM;
+       }
+
+       ctrl_ctx->add_flags |= added_ctxs;
+       new_add_flags = ctrl_ctx->add_flags;
+
+       /* If xhci_endpoint_disable() was called for this endpoint, but the
+        * xHC hasn't been notified yet through the check_bandwidth() call,
+        * this re-adds a new state for the endpoint from the new endpoint
+        * descriptors.  We must drop and re-add this endpoint, so we leave the
+        * drop flags alone.
+        */
+       new_drop_flags = ctrl_ctx->drop_flags;
+
+       slot_ctx = xhci_get_slot_ctx(xhci, in_ctx);
+       /* Update the last valid endpoint context, if we just added one past */
+       if ((slot_ctx->dev_info & LAST_CTX_MASK) < LAST_CTX(last_ctx)) {
+               slot_ctx->dev_info &= ~LAST_CTX_MASK;
+               slot_ctx->dev_info |= LAST_CTX(last_ctx);
+       }
+       new_slot_info = slot_ctx->dev_info;
+
+       /* Store the usb_device pointer for later use */
+       ep->hcpriv = udev;
+
+       xhci_dbg(xhci, "add ep 0x%x, slot id %d, new drop flags = %#x, new add flags = %#x, new slot info = %#x\n",
+                       (unsigned int) ep->desc.bEndpointAddress,
+                       udev->slot_id,
+                       (unsigned int) new_drop_flags,
+                       (unsigned int) new_add_flags,
+                       (unsigned int) new_slot_info);
+       return 0;
+}
+
+static void xhci_zero_in_ctx(struct xhci_hcd *xhci, struct xhci_virt_device *virt_dev)
+{
+       struct xhci_input_control_ctx *ctrl_ctx;
+       struct xhci_ep_ctx *ep_ctx;
+       struct xhci_slot_ctx *slot_ctx;
+       int i;
+
+       /* When a device's add flag and drop flag are zero, any subsequent
+        * configure endpoint command will leave that endpoint's state
+        * untouched.  Make sure we don't leave any old state in the input
+        * endpoint contexts.
+        */
+       ctrl_ctx = xhci_get_input_control_ctx(xhci, virt_dev->in_ctx);
+       ctrl_ctx->drop_flags = 0;
+       ctrl_ctx->add_flags = 0;
+       slot_ctx = xhci_get_slot_ctx(xhci, virt_dev->in_ctx);
+       slot_ctx->dev_info &= ~LAST_CTX_MASK;
+       /* Endpoint 0 is always valid */
+       slot_ctx->dev_info |= LAST_CTX(1);
+       for (i = 1; i < 31; ++i) {
+               ep_ctx = xhci_get_ep_ctx(xhci, virt_dev->in_ctx, i);
+               ep_ctx->ep_info = 0;
+               ep_ctx->ep_info2 = 0;
+               ep_ctx->deq = 0;
+               ep_ctx->tx_info = 0;
+       }
+}
+
+static int xhci_configure_endpoint_result(struct xhci_hcd *xhci,
+               struct usb_device *udev, int *cmd_status)
+{
+       int ret;
+
+       switch (*cmd_status) {
+       case COMP_ENOMEM:
+               dev_warn(&udev->dev, "Not enough host controller resources "
+                               "for new device state.\n");
+               ret = -ENOMEM;
+               /* FIXME: can we allocate more resources for the HC? */
+               break;
+       case COMP_BW_ERR:
+               dev_warn(&udev->dev, "Not enough bandwidth "
+                               "for new device state.\n");
+               ret = -ENOSPC;
+               /* FIXME: can we go back to the old state? */
+               break;
+       case COMP_TRB_ERR:
+               /* the HCD set up something wrong */
+               dev_warn(&udev->dev, "ERROR: Endpoint drop flag = 0, "
+                               "add flag = 1, "
+                               "and endpoint is not disabled.\n");
+               ret = -EINVAL;
+               break;
+       case COMP_SUCCESS:
+               dev_dbg(&udev->dev, "Successful Endpoint Configure command\n");
+               ret = 0;
+               break;
+       default:
+               xhci_err(xhci, "ERROR: unexpected command completion "
+                               "code 0x%x.\n", *cmd_status);
+               ret = -EINVAL;
+               break;
+       }
+       return ret;
+}
+
+static int xhci_evaluate_context_result(struct xhci_hcd *xhci,
+               struct usb_device *udev, int *cmd_status)
+{
+       int ret;
+       struct xhci_virt_device *virt_dev = xhci->devs[udev->slot_id];
+
+       switch (*cmd_status) {
+       case COMP_EINVAL:
+               dev_warn(&udev->dev, "WARN: xHCI driver setup invalid evaluate "
+                               "context command.\n");
+               ret = -EINVAL;
+               break;
+       case COMP_EBADSLT:
+               dev_warn(&udev->dev, "WARN: slot not enabled for"
+                               "evaluate context command.\n");
+       case COMP_CTX_STATE:
+               dev_warn(&udev->dev, "WARN: invalid context state for "
+                               "evaluate context command.\n");
+               xhci_dbg_ctx(xhci, virt_dev->out_ctx, 1);
+               ret = -EINVAL;
+               break;
+       case COMP_SUCCESS:
+               dev_dbg(&udev->dev, "Successful evaluate context command\n");
+               ret = 0;
+               break;
+       default:
+               xhci_err(xhci, "ERROR: unexpected command completion "
+                               "code 0x%x.\n", *cmd_status);
+               ret = -EINVAL;
+               break;
+       }
+       return ret;
+}
+
+/* Issue a configure endpoint command or evaluate context command
+ * and wait for it to finish.
+ */
+static int xhci_configure_endpoint(struct xhci_hcd *xhci,
+               struct usb_device *udev,
+               struct xhci_command *command,
+               bool ctx_change, bool must_succeed)
+{
+       int ret;
+       int timeleft;
+       unsigned long flags;
+       struct xhci_container_ctx *in_ctx;
+       struct completion *cmd_completion;
+       int *cmd_status;
+       struct xhci_virt_device *virt_dev;
+
+       spin_lock_irqsave(&xhci->lock, flags);
+       virt_dev = xhci->devs[udev->slot_id];
+       if (command) {
+               in_ctx = command->in_ctx;
+               cmd_completion = command->completion;
+               cmd_status = &command->status;
+               command->command_trb = xhci->cmd_ring->enqueue;
+               list_add_tail(&command->cmd_list, &virt_dev->cmd_list);
+       } else {
+               in_ctx = virt_dev->in_ctx;
+               cmd_completion = &virt_dev->cmd_completion;
+               cmd_status = &virt_dev->cmd_status;
+       }
+
+       if (!ctx_change)
+               ret = xhci_queue_configure_endpoint(xhci, in_ctx->dma,
+                               udev->slot_id, must_succeed);
+       else
+               ret = xhci_queue_evaluate_context(xhci, in_ctx->dma,
+                               udev->slot_id);
+       if (ret < 0) {
+               if (command)
+                       list_del(&command->cmd_list);
+               spin_unlock_irqrestore(&xhci->lock, flags);
+               xhci_dbg(xhci, "FIXME allocate a new ring segment\n");
+               return -ENOMEM;
+       }
+       xhci_ring_cmd_db(xhci);
+       spin_unlock_irqrestore(&xhci->lock, flags);
+
+       /* Wait for the configure endpoint command to complete */
+       timeleft = wait_for_completion_interruptible_timeout(
+                       cmd_completion,
+                       USB_CTRL_SET_TIMEOUT);
+       if (timeleft <= 0) {
+               xhci_warn(xhci, "%s while waiting for %s command\n",
+                               timeleft == 0 ? "Timeout" : "Signal",
+                               ctx_change == 0 ?
+                                       "configure endpoint" :
+                                       "evaluate context");
+               /* FIXME cancel the configure endpoint command */
+               return -ETIME;
+       }
+
+       if (!ctx_change)
+               return xhci_configure_endpoint_result(xhci, udev, cmd_status);
+       return xhci_evaluate_context_result(xhci, udev, cmd_status);
+}
+
+/* Called after one or more calls to xhci_add_endpoint() or
+ * xhci_drop_endpoint().  If this call fails, the USB core is expected
+ * to call xhci_reset_bandwidth().
+ *
+ * Since we are in the middle of changing either configuration or
+ * installing a new alt setting, the USB core won't allow URBs to be
+ * enqueued for any endpoint on the old config or interface.  Nothing
+ * else should be touching the xhci->devs[slot_id] structure, so we
+ * don't need to take the xhci->lock for manipulating that.
+ */
+int xhci_check_bandwidth(struct usb_hcd *hcd, struct usb_device *udev)
+{
+       int i;
+       int ret = 0;
+       struct xhci_hcd *xhci;
+       struct xhci_virt_device *virt_dev;
+       struct xhci_input_control_ctx *ctrl_ctx;
+       struct xhci_slot_ctx *slot_ctx;
+
+       ret = xhci_check_args(hcd, udev, NULL, 0, __func__);
+       if (ret <= 0)
+               return ret;
+       xhci = hcd_to_xhci(hcd);
+
+       if (!udev->slot_id || !xhci->devs || !xhci->devs[udev->slot_id]) {
+               xhci_warn(xhci, "xHCI %s called with unaddressed device\n",
+                               __func__);
+               return -EINVAL;
+       }
+       xhci_dbg(xhci, "%s called for udev %p\n", __func__, udev);
+       virt_dev = xhci->devs[udev->slot_id];
+
+       /* See section 4.6.6 - A0 = 1; A1 = D0 = D1 = 0 */
+       ctrl_ctx = xhci_get_input_control_ctx(xhci, virt_dev->in_ctx);
+       ctrl_ctx->add_flags |= SLOT_FLAG;
+       ctrl_ctx->add_flags &= ~EP0_FLAG;
+       ctrl_ctx->drop_flags &= ~SLOT_FLAG;
+       ctrl_ctx->drop_flags &= ~EP0_FLAG;
+       xhci_dbg(xhci, "New Input Control Context:\n");
+       slot_ctx = xhci_get_slot_ctx(xhci, virt_dev->in_ctx);
+       xhci_dbg_ctx(xhci, virt_dev->in_ctx,
+                       LAST_CTX_TO_EP_NUM(slot_ctx->dev_info));
+
+       ret = xhci_configure_endpoint(xhci, udev, NULL,
+                       false, false);
+       if (ret) {
+               /* Callee should call reset_bandwidth() */
+               return ret;
+       }
+
+       xhci_dbg(xhci, "Output context after successful config ep cmd:\n");
+       xhci_dbg_ctx(xhci, virt_dev->out_ctx,
+                       LAST_CTX_TO_EP_NUM(slot_ctx->dev_info));
+
+       xhci_zero_in_ctx(xhci, virt_dev);
+       /* Install new rings and free or cache any old rings */
+       for (i = 1; i < 31; ++i) {
+               if (!virt_dev->eps[i].new_ring)
+                       continue;
+               /* Only cache or free the old ring if it exists.
+                * It may not if this is the first add of an endpoint.
+                */
+               if (virt_dev->eps[i].ring) {
+                       xhci_free_or_cache_endpoint_ring(xhci, virt_dev, i);
+               }
+               virt_dev->eps[i].ring = virt_dev->eps[i].new_ring;
+               virt_dev->eps[i].new_ring = NULL;
+       }
+
+       return ret;
+}
+
+void xhci_reset_bandwidth(struct usb_hcd *hcd, struct usb_device *udev)
+{
+       struct xhci_hcd *xhci;
+       struct xhci_virt_device *virt_dev;
+       int i, ret;
+
+       ret = xhci_check_args(hcd, udev, NULL, 0, __func__);
+       if (ret <= 0)
+               return;
+       xhci = hcd_to_xhci(hcd);
+
+       if (!xhci->devs || !xhci->devs[udev->slot_id]) {
+               xhci_warn(xhci, "xHCI %s called with unaddressed device\n",
+                               __func__);
+               return;
+       }
+       xhci_dbg(xhci, "%s called for udev %p\n", __func__, udev);
+       virt_dev = xhci->devs[udev->slot_id];
+       /* Free any rings allocated for added endpoints */
+       for (i = 0; i < 31; ++i) {
+               if (virt_dev->eps[i].new_ring) {
+                       xhci_ring_free(xhci, virt_dev->eps[i].new_ring);
+                       virt_dev->eps[i].new_ring = NULL;
+               }
+       }
+       xhci_zero_in_ctx(xhci, virt_dev);
+}
+
+static void xhci_setup_input_ctx_for_config_ep(struct xhci_hcd *xhci,
+               struct xhci_container_ctx *in_ctx,
+               struct xhci_container_ctx *out_ctx,
+               u32 add_flags, u32 drop_flags)
+{
+       struct xhci_input_control_ctx *ctrl_ctx;
+       ctrl_ctx = xhci_get_input_control_ctx(xhci, in_ctx);
+       ctrl_ctx->add_flags = add_flags;
+       ctrl_ctx->drop_flags = drop_flags;
+       xhci_slot_copy(xhci, in_ctx, out_ctx);
+       ctrl_ctx->add_flags |= SLOT_FLAG;
+
+       xhci_dbg(xhci, "Input Context:\n");
+       xhci_dbg_ctx(xhci, in_ctx, xhci_last_valid_endpoint(add_flags));
+}
+
+void xhci_setup_input_ctx_for_quirk(struct xhci_hcd *xhci,
+               unsigned int slot_id, unsigned int ep_index,
+               struct xhci_dequeue_state *deq_state)
+{
+       struct xhci_container_ctx *in_ctx;
+       struct xhci_ep_ctx *ep_ctx;
+       u32 added_ctxs;
+       dma_addr_t addr;
+
+       xhci_endpoint_copy(xhci, xhci->devs[slot_id]->in_ctx,
+                       xhci->devs[slot_id]->out_ctx, ep_index);
+       in_ctx = xhci->devs[slot_id]->in_ctx;
+       ep_ctx = xhci_get_ep_ctx(xhci, in_ctx, ep_index);
+       addr = xhci_trb_virt_to_dma(deq_state->new_deq_seg,
+                       deq_state->new_deq_ptr);
+       if (addr == 0) {
+               xhci_warn(xhci, "WARN Cannot submit config ep after "
+                               "reset ep command\n");
+               xhci_warn(xhci, "WARN deq seg = %p, deq ptr = %p\n",
+                               deq_state->new_deq_seg,
+                               deq_state->new_deq_ptr);
+               return;
+       }
+       ep_ctx->deq = addr | deq_state->new_cycle_state;
+
+       added_ctxs = xhci_get_endpoint_flag_from_index(ep_index);
+       xhci_setup_input_ctx_for_config_ep(xhci, xhci->devs[slot_id]->in_ctx,
+                       xhci->devs[slot_id]->out_ctx, added_ctxs, added_ctxs);
+}
+
+void xhci_cleanup_stalled_ring(struct xhci_hcd *xhci,
+               struct usb_device *udev, unsigned int ep_index)
+{
+       struct xhci_dequeue_state deq_state;
+       struct xhci_virt_ep *ep;
+
+       xhci_dbg(xhci, "Cleaning up stalled endpoint ring\n");
+       ep = &xhci->devs[udev->slot_id]->eps[ep_index];
+       /* We need to move the HW's dequeue pointer past this TD,
+        * or it will attempt to resend it on the next doorbell ring.
+        */
+       xhci_find_new_dequeue_state(xhci, udev->slot_id,
+                       ep_index, ep->stopped_td,
+                       &deq_state);
+
+       /* HW with the reset endpoint quirk will use the saved dequeue state to
+        * issue a configure endpoint command later.
+        */
+       if (!(xhci->quirks & XHCI_RESET_EP_QUIRK)) {
+               xhci_dbg(xhci, "Queueing new dequeue state\n");
+               xhci_queue_new_dequeue_state(xhci, udev->slot_id,
+                               ep_index, &deq_state);
+       } else {
+               /* Better hope no one uses the input context between now and the
+                * reset endpoint completion!
+                */
+               xhci_dbg(xhci, "Setting up input context for "
+                               "configure endpoint command\n");
+               xhci_setup_input_ctx_for_quirk(xhci, udev->slot_id,
+                               ep_index, &deq_state);
+       }
+}
+
+/* Deal with stalled endpoints.  The core should have sent the control message
+ * to clear the halt condition.  However, we need to make the xHCI hardware
+ * reset its sequence number, since a device will expect a sequence number of
+ * zero after the halt condition is cleared.
+ * Context: in_interrupt
+ */
+void xhci_endpoint_reset(struct usb_hcd *hcd,
+               struct usb_host_endpoint *ep)
+{
+       struct xhci_hcd *xhci;
+       struct usb_device *udev;
+       unsigned int ep_index;
+       unsigned long flags;
+       int ret;
+       struct xhci_virt_ep *virt_ep;
+
+       xhci = hcd_to_xhci(hcd);
+       udev = (struct usb_device *) ep->hcpriv;
+       /* Called with a root hub endpoint (or an endpoint that wasn't added
+        * with xhci_add_endpoint()
+        */
+       if (!ep->hcpriv)
+               return;
+       ep_index = xhci_get_endpoint_index(&ep->desc);
+       virt_ep = &xhci->devs[udev->slot_id]->eps[ep_index];
+       if (!virt_ep->stopped_td) {
+               xhci_dbg(xhci, "Endpoint 0x%x not halted, refusing to reset.\n",
+                               ep->desc.bEndpointAddress);
+               return;
+       }
+       if (usb_endpoint_xfer_control(&ep->desc)) {
+               xhci_dbg(xhci, "Control endpoint stall already handled.\n");
+               return;
+       }
+
+       xhci_dbg(xhci, "Queueing reset endpoint command\n");
+       spin_lock_irqsave(&xhci->lock, flags);
+       ret = xhci_queue_reset_ep(xhci, udev->slot_id, ep_index);
+       /*
+        * Can't change the ring dequeue pointer until it's transitioned to the
+        * stopped state, which is only upon a successful reset endpoint
+        * command.  Better hope that last command worked!
+        */
+       if (!ret) {
+               xhci_cleanup_stalled_ring(xhci, udev, ep_index);
+               kfree(virt_ep->stopped_td);
+               xhci_ring_cmd_db(xhci);
+       }
+       spin_unlock_irqrestore(&xhci->lock, flags);
+
+       if (ret)
+               xhci_warn(xhci, "FIXME allocate a new ring segment\n");
+}
+
+/*
+ * At this point, the struct usb_device is about to go away, the device has
+ * disconnected, and all traffic has been stopped and the endpoints have been
+ * disabled.  Free any HC data structures associated with that device.
+ */
+void xhci_free_dev(struct usb_hcd *hcd, struct usb_device *udev)
+{
+       struct xhci_hcd *xhci = hcd_to_xhci(hcd);
+       struct xhci_virt_device *virt_dev;
+       unsigned long flags;
+       u32 state;
+       int i;
+
+       if (udev->slot_id == 0)
+               return;
+       virt_dev = xhci->devs[udev->slot_id];
+       if (!virt_dev)
+               return;
+
+       /* Stop any wayward timer functions (which may grab the lock) */
+       for (i = 0; i < 31; ++i) {
+               virt_dev->eps[i].ep_state &= ~EP_HALT_PENDING;
+               del_timer_sync(&virt_dev->eps[i].stop_cmd_timer);
+       }
+
+       spin_lock_irqsave(&xhci->lock, flags);
+       /* Don't disable the slot if the host controller is dead. */
+       state = xhci_readl(xhci, &xhci->op_regs->status);
+       if (state == 0xffffffff || (xhci->xhc_state & XHCI_STATE_DYING)) {
+               xhci_free_virt_device(xhci, udev->slot_id);
+               spin_unlock_irqrestore(&xhci->lock, flags);
+               return;
+       }
+
+       if (xhci_queue_slot_control(xhci, TRB_DISABLE_SLOT, udev->slot_id)) {
+               spin_unlock_irqrestore(&xhci->lock, flags);
+               xhci_dbg(xhci, "FIXME: allocate a command ring segment\n");
+               return;
+       }
+       xhci_ring_cmd_db(xhci);
+       spin_unlock_irqrestore(&xhci->lock, flags);
+       /*
+        * Event command completion handler will free any data structures
+        * associated with the slot.  XXX Can free sleep?
+        */
+}
+
+/*
+ * Returns 0 if the xHC ran out of device slots, the Enable Slot command
+ * timed out, or allocating memory failed.  Returns 1 on success.
+ */
+int xhci_alloc_dev(struct usb_hcd *hcd, struct usb_device *udev)
+{
+       struct xhci_hcd *xhci = hcd_to_xhci(hcd);
+       unsigned long flags;
+       int timeleft;
+       int ret;
+
+       spin_lock_irqsave(&xhci->lock, flags);
+       ret = xhci_queue_slot_control(xhci, TRB_ENABLE_SLOT, 0);
+       if (ret) {
+               spin_unlock_irqrestore(&xhci->lock, flags);
+               xhci_dbg(xhci, "FIXME: allocate a command ring segment\n");
+               return 0;
+       }
+       xhci_ring_cmd_db(xhci);
+       spin_unlock_irqrestore(&xhci->lock, flags);
+
+       /* XXX: how much time for xHC slot assignment? */
+       timeleft = wait_for_completion_interruptible_timeout(&xhci->addr_dev,
+                       USB_CTRL_SET_TIMEOUT);
+       if (timeleft <= 0) {
+               xhci_warn(xhci, "%s while waiting for a slot\n",
+                               timeleft == 0 ? "Timeout" : "Signal");
+               /* FIXME cancel the enable slot request */
+               return 0;
+       }
+
+       if (!xhci->slot_id) {
+               xhci_err(xhci, "Error while assigning device slot ID\n");
+               return 0;
+       }
+       /* xhci_alloc_virt_device() does not touch rings; no need to lock */
+       if (!xhci_alloc_virt_device(xhci, xhci->slot_id, udev, GFP_KERNEL)) {
+               /* Disable slot, if we can do it without mem alloc */
+               xhci_warn(xhci, "Could not allocate xHCI USB device data structures\n");
+               spin_lock_irqsave(&xhci->lock, flags);
+               if (!xhci_queue_slot_control(xhci, TRB_DISABLE_SLOT, udev->slot_id))
+                       xhci_ring_cmd_db(xhci);
+               spin_unlock_irqrestore(&xhci->lock, flags);
+               return 0;
+       }
+       udev->slot_id = xhci->slot_id;
+       /* Is this a LS or FS device under a HS hub? */
+       /* Hub or peripherial? */
+       return 1;
+}
+
+/*
+ * Issue an Address Device command (which will issue a SetAddress request to
+ * the device).
+ * We should be protected by the usb_address0_mutex in khubd's hub_port_init, so
+ * we should only issue and wait on one address command at the same time.
+ *
+ * We add one to the device address issued by the hardware because the USB core
+ * uses address 1 for the root hubs (even though they're not really devices).
+ */
+int xhci_address_device(struct usb_hcd *hcd, struct usb_device *udev)
+{
+       unsigned long flags;
+       int timeleft;
+       struct xhci_virt_device *virt_dev;
+       int ret = 0;
+       struct xhci_hcd *xhci = hcd_to_xhci(hcd);
+       struct xhci_slot_ctx *slot_ctx;
+       struct xhci_input_control_ctx *ctrl_ctx;
+       u64 temp_64;
+
+       if (!udev->slot_id) {
+               xhci_dbg(xhci, "Bad Slot ID %d\n", udev->slot_id);
+               return -EINVAL;
+       }
+
+       virt_dev = xhci->devs[udev->slot_id];
+
+       /* If this is a Set Address to an unconfigured device, setup ep 0 */
+       if (!udev->config)
+               xhci_setup_addressable_virt_dev(xhci, udev);
+       /* Otherwise, assume the core has the device configured how it wants */
+       xhci_dbg(xhci, "Slot ID %d Input Context:\n", udev->slot_id);
+       xhci_dbg_ctx(xhci, virt_dev->in_ctx, 2);
+
+       spin_lock_irqsave(&xhci->lock, flags);
+       ret = xhci_queue_address_device(xhci, virt_dev->in_ctx->dma,
+                                       udev->slot_id);
+       if (ret) {
+               spin_unlock_irqrestore(&xhci->lock, flags);
+               xhci_dbg(xhci, "FIXME: allocate a command ring segment\n");
+               return ret;
+       }
+       xhci_ring_cmd_db(xhci);
+       spin_unlock_irqrestore(&xhci->lock, flags);
+
+       /* ctrl tx can take up to 5 sec; XXX: need more time for xHC? */
+       timeleft = wait_for_completion_interruptible_timeout(&xhci->addr_dev,
+                       USB_CTRL_SET_TIMEOUT);
+       /* FIXME: From section 4.3.4: "Software shall be responsible for timing
+        * the SetAddress() "recovery interval" required by USB and aborting the
+        * command on a timeout.
+        */
+       if (timeleft <= 0) {
+               xhci_warn(xhci, "%s while waiting for a slot\n",
+                               timeleft == 0 ? "Timeout" : "Signal");
+               /* FIXME cancel the address device command */
+               return -ETIME;
+       }
+
+       switch (virt_dev->cmd_status) {
+       case COMP_CTX_STATE:
+       case COMP_EBADSLT:
+               xhci_err(xhci, "Setup ERROR: address device command for slot %d.\n",
+                               udev->slot_id);
+               ret = -EINVAL;
+               break;
+       case COMP_TX_ERR:
+               dev_warn(&udev->dev, "Device not responding to set address.\n");
+               ret = -EPROTO;
+               break;
+       case COMP_SUCCESS:
+               xhci_dbg(xhci, "Successful Address Device command\n");
+               break;
+       default:
+               xhci_err(xhci, "ERROR: unexpected command completion "
+                               "code 0x%x.\n", virt_dev->cmd_status);
+               xhci_dbg(xhci, "Slot ID %d Output Context:\n", udev->slot_id);
+               xhci_dbg_ctx(xhci, virt_dev->out_ctx, 2);
+               ret = -EINVAL;
+               break;
+       }
+       if (ret) {
+               return ret;
+       }
+       temp_64 = xhci_read_64(xhci, &xhci->op_regs->dcbaa_ptr);
+       xhci_dbg(xhci, "Op regs DCBAA ptr = %#016llx\n", temp_64);
+       xhci_dbg(xhci, "Slot ID %d dcbaa entry @%p = %#016llx\n",
+                       udev->slot_id,
+                       &xhci->dcbaa->dev_context_ptrs[udev->slot_id],
+                       (unsigned long long)
+                               xhci->dcbaa->dev_context_ptrs[udev->slot_id]);
+       xhci_dbg(xhci, "Output Context DMA address = %#08llx\n",
+                       (unsigned long long)virt_dev->out_ctx->dma);
+       xhci_dbg(xhci, "Slot ID %d Input Context:\n", udev->slot_id);
+       xhci_dbg_ctx(xhci, virt_dev->in_ctx, 2);
+       xhci_dbg(xhci, "Slot ID %d Output Context:\n", udev->slot_id);
+       xhci_dbg_ctx(xhci, virt_dev->out_ctx, 2);
+       /*
+        * USB core uses address 1 for the roothubs, so we add one to the
+        * address given back to us by the HC.
+        */
+       slot_ctx = xhci_get_slot_ctx(xhci, virt_dev->out_ctx);
+       udev->devnum = (slot_ctx->dev_state & DEV_ADDR_MASK) + 1;
+       /* Zero the input context control for later use */
+       ctrl_ctx = xhci_get_input_control_ctx(xhci, virt_dev->in_ctx);
+       ctrl_ctx->add_flags = 0;
+       ctrl_ctx->drop_flags = 0;
+
+       xhci_dbg(xhci, "Device address = %d\n", udev->devnum);
+       /* XXX Meh, not sure if anyone else but choose_address uses this. */
+       set_bit(udev->devnum, udev->bus->devmap.devicemap);
+
+       return 0;
+}
+
+/* Once a hub descriptor is fetched for a device, we need to update the xHC's
+ * internal data structures for the device.
+ */
+int xhci_update_hub_device(struct usb_hcd *hcd, struct usb_device *hdev,
+                       struct usb_tt *tt, gfp_t mem_flags)
+{
+       struct xhci_hcd *xhci = hcd_to_xhci(hcd);
+       struct xhci_virt_device *vdev;
+       struct xhci_command *config_cmd;
+       struct xhci_input_control_ctx *ctrl_ctx;
+       struct xhci_slot_ctx *slot_ctx;
+       unsigned long flags;
+       unsigned think_time;
+       int ret;
+
+       /* Ignore root hubs */
+       if (!hdev->parent)
+               return 0;
+
+       vdev = xhci->devs[hdev->slot_id];
+       if (!vdev) {
+               xhci_warn(xhci, "Cannot update hub desc for unknown device.\n");
+               return -EINVAL;
+       }
+       config_cmd = xhci_alloc_command(xhci, true, mem_flags);
+       if (!config_cmd) {
+               xhci_dbg(xhci, "Could not allocate xHCI command structure.\n");
+               return -ENOMEM;
+       }
+
+       spin_lock_irqsave(&xhci->lock, flags);
+       xhci_slot_copy(xhci, config_cmd->in_ctx, vdev->out_ctx);
+       ctrl_ctx = xhci_get_input_control_ctx(xhci, config_cmd->in_ctx);
+       ctrl_ctx->add_flags |= SLOT_FLAG;
+       slot_ctx = xhci_get_slot_ctx(xhci, config_cmd->in_ctx);
+       slot_ctx->dev_info |= DEV_HUB;
+       if (tt->multi)
+               slot_ctx->dev_info |= DEV_MTT;
+       if (xhci->hci_version > 0x95) {
+               xhci_dbg(xhci, "xHCI version %x needs hub "
+                               "TT think time and number of ports\n",
+                               (unsigned int) xhci->hci_version);
+               slot_ctx->dev_info2 |= XHCI_MAX_PORTS(hdev->maxchild);
+               /* Set TT think time - convert from ns to FS bit times.
+                * 0 = 8 FS bit times, 1 = 16 FS bit times,
+                * 2 = 24 FS bit times, 3 = 32 FS bit times.
+                */
+               think_time = tt->think_time;
+               if (think_time != 0)
+                       think_time = (think_time / 666) - 1;
+               slot_ctx->tt_info |= TT_THINK_TIME(think_time);
+       } else {
+               xhci_dbg(xhci, "xHCI version %x doesn't need hub "
+                               "TT think time or number of ports\n",
+                               (unsigned int) xhci->hci_version);
+       }
+       slot_ctx->dev_state = 0;
+       spin_unlock_irqrestore(&xhci->lock, flags);
+
+       xhci_dbg(xhci, "Set up %s for hub device.\n",
+                       (xhci->hci_version > 0x95) ?
+                       "configure endpoint" : "evaluate context");
+       xhci_dbg(xhci, "Slot %u Input Context:\n", hdev->slot_id);
+       xhci_dbg_ctx(xhci, config_cmd->in_ctx, 0);
+
+       /* Issue and wait for the configure endpoint or
+        * evaluate context command.
+        */
+       if (xhci->hci_version > 0x95)
+               ret = xhci_configure_endpoint(xhci, hdev, config_cmd,
+                               false, false);
+       else
+               ret = xhci_configure_endpoint(xhci, hdev, config_cmd,
+                               true, false);
+
+       xhci_dbg(xhci, "Slot %u Output Context:\n", hdev->slot_id);
+       xhci_dbg_ctx(xhci, vdev->out_ctx, 0);
+
+       xhci_free_command(xhci, config_cmd);
+       return ret;
+}
+
 int xhci_get_frame(struct usb_hcd *hcd)
 {
        struct xhci_hcd *xhci = hcd_to_xhci(hcd);
@@ -519,6 +1760,24 @@ static int __init xhci_hcd_init(void)
                return retval;
        }
 #endif
+       /*
+        * Check the compiler generated sizes of structures that must be laid
+        * out in specific ways for hardware access.
+        */
+       BUILD_BUG_ON(sizeof(struct xhci_doorbell_array) != 256*32/8);
+       BUILD_BUG_ON(sizeof(struct xhci_slot_ctx) != 8*32/8);
+       BUILD_BUG_ON(sizeof(struct xhci_ep_ctx) != 8*32/8);
+       /* xhci_device_control has eight fields, and also
+        * embeds one xhci_slot_ctx and 31 xhci_ep_ctx
+        */
+       BUILD_BUG_ON(sizeof(struct xhci_stream_ctx) != 4*32/8);
+       BUILD_BUG_ON(sizeof(union xhci_trb) != 4*32/8);
+       BUILD_BUG_ON(sizeof(struct xhci_erst_entry) != 4*32/8);
+       BUILD_BUG_ON(sizeof(struct xhci_cap_regs) != 7*32/8);
+       BUILD_BUG_ON(sizeof(struct xhci_intr_reg) != 8*32/8);
+       /* xhci_run_regs has eight fields and embeds 128 xhci_intr_regs */
+       BUILD_BUG_ON(sizeof(struct xhci_run_regs) != (8+8*128)*32/8);
+       BUILD_BUG_ON(sizeof(struct xhci_doorbell_array) != 256*32/8);
        return 0;
 }
 module_init(xhci_hcd_init);