Add qemu 2.4.0

Change-Id: Ic99cbad4b61f8b127b7dc74d04576c0bcbaaf4f5
Signed-off-by: Yang Zhang <yang.z.zhang@intel.com>

1 files changed, 648 insertions, 0 deletions

diff --git a/qemu/roms/seabios/src/hw/usb-ehci.c b/qemu/roms/seabios/src/hw/usb-ehci.c
new file mode 100644
index 000000000..41f8579ce
--- /dev/null
+++ b/qemu/roms/seabios/src/hw/usb-ehci.c
@@ -0,0 +1,648 @@
+// Code for handling EHCI USB controllers.
+//
+// Copyright (C) 2010-2013  Kevin O'Connor <kevin@koconnor.net>
+//
+// This file may be distributed under the terms of the GNU LGPLv3 license.
+
+#include "biosvar.h" // GET_LOWFLAT
+#include "config.h" // CONFIG_*
+#include "output.h" // dprintf
+#include "malloc.h" // free
+#include "memmap.h" // PAGE_SIZE
+#include "pci.h" // pci_bdf_to_bus
+#include "pci_ids.h" // PCI_CLASS_SERIAL_USB_UHCI
+#include "pci_regs.h" // PCI_BASE_ADDRESS_0
+#include "string.h" // memset
+#include "usb.h" // struct usb_s
+#include "usb-ehci.h" // struct ehci_qh
+#include "util.h" // msleep
+#include "x86.h" // readl
+
+struct usb_ehci_s {
+    struct usb_s usb;
+    struct ehci_caps *caps;
+    struct ehci_regs *regs;
+    struct ehci_qh *async_qh;
+    int checkports;
+};
+
+struct ehci_pipe {
+    struct ehci_qh qh;
+    struct ehci_qtd *next_td, *tds;
+    void *data;
+    struct usb_pipe pipe;
+};
+
+static int PendingEHCI;
+
+
+/****************************************************************
+ * Root hub
+ ****************************************************************/
+
+#define EHCI_TIME_POSTPOWER 20
+#define EHCI_TIME_POSTRESET 2
+
+// Check if device attached to port
+static int
+ehci_hub_detect(struct usbhub_s *hub, u32 port)
+{
+    struct usb_ehci_s *cntl = container_of(hub->cntl, struct usb_ehci_s, usb);
+    u32 *portreg = &cntl->regs->portsc[port];
+    u32 portsc = readl(portreg);
+
+    if (!(portsc & PORT_CONNECT))
+        // No device present
+        return 0;
+
+    if ((portsc & PORT_LINESTATUS_MASK) == PORT_LINESTATUS_KSTATE) {
+        // low speed device
+        writel(portreg, portsc | PORT_OWNER);
+        return -1;
+    }
+
+    // XXX - if just powered up, need to wait for USB_TIME_ATTDB?
+
+    // Begin reset on port
+    portsc = (portsc & ~PORT_PE) | PORT_RESET;
+    writel(portreg, portsc);
+    msleep(USB_TIME_DRSTR);
+    return 1;
+}
+
+// Reset device on port
+static int
+ehci_hub_reset(struct usbhub_s *hub, u32 port)
+{
+    struct usb_ehci_s *cntl = container_of(hub->cntl, struct usb_ehci_s, usb);
+    u32 *portreg = &cntl->regs->portsc[port];
+    u32 portsc = readl(portreg);
+
+    // Finish reset on port
+    portsc &= ~PORT_RESET;
+    writel(portreg, portsc);
+    msleep(EHCI_TIME_POSTRESET);
+
+    portsc = readl(portreg);
+    if (!(portsc & PORT_CONNECT))
+        // No longer connected
+        return -1;
+    if (!(portsc & PORT_PE)) {
+        // full speed device
+        writel(portreg, portsc | PORT_OWNER);
+        return -1;
+    }
+
+    return USB_HIGHSPEED;
+}
+
+// Disable port
+static void
+ehci_hub_disconnect(struct usbhub_s *hub, u32 port)
+{
+    struct usb_ehci_s *cntl = container_of(hub->cntl, struct usb_ehci_s, usb);
+    u32 *portreg = &cntl->regs->portsc[port];
+    u32 portsc = readl(portreg);
+    writel(portreg, portsc & ~PORT_PE);
+}
+
+static struct usbhub_op_s ehci_HubOp = {
+    .detect = ehci_hub_detect,
+    .reset = ehci_hub_reset,
+    .disconnect = ehci_hub_disconnect,
+};
+
+// Find any devices connected to the root hub.
+static int
+check_ehci_ports(struct usb_ehci_s *cntl)
+{
+    // Power up ports.
+    int i;
+    for (i=0; i<cntl->checkports; i++) {
+        u32 *portreg = &cntl->regs->portsc[i];
+        u32 portsc = readl(portreg);
+        if (!(portsc & PORT_POWER)) {
+            portsc |= PORT_POWER;
+            writel(portreg, portsc);
+        }
+    }
+    msleep(EHCI_TIME_POSTPOWER);
+
+    struct usbhub_s hub;
+    memset(&hub, 0, sizeof(hub));
+    hub.cntl = &cntl->usb;
+    hub.portcount = cntl->checkports;
+    hub.op = &ehci_HubOp;
+    usb_enumerate(&hub);
+    return hub.devcount;
+}
+
+
+/****************************************************************
+ * Setup
+ ****************************************************************/
+
+// Wait for next USB async frame to start - for ensuring safe memory release.
+static void
+ehci_waittick(struct usb_ehci_s *cntl)
+{
+    if (MODE16) {
+        msleep(10);
+        return;
+    }
+    // Wait for access to "doorbell"
+    barrier();
+    u32 cmd, sts;
+    u32 end = timer_calc(100);
+    for (;;) {
+        sts = readl(&cntl->regs->usbsts);
+        if (!(sts & STS_IAA)) {
+            cmd = readl(&cntl->regs->usbcmd);
+            if (!(cmd & CMD_IAAD))
+                break;
+        }
+        if (timer_check(end)) {
+            warn_timeout();
+            return;
+        }
+        yield();
+    }
+    // Ring "doorbell"
+    writel(&cntl->regs->usbcmd, cmd | CMD_IAAD);
+    // Wait for completion
+    for (;;) {
+        sts = readl(&cntl->regs->usbsts);
+        if (sts & STS_IAA)
+            break;
+        if (timer_check(end)) {
+            warn_timeout();
+            return;
+        }
+        yield();
+    }
+    // Ack completion
+    writel(&cntl->regs->usbsts, STS_IAA);
+}
+
+static void
+ehci_free_pipes(struct usb_ehci_s *cntl)
+{
+    dprintf(7, "ehci_free_pipes %p\n", cntl);
+
+    struct ehci_qh *start = cntl->async_qh;
+    struct ehci_qh *pos = start;
+    for (;;) {
+        struct ehci_qh *next = (void*)(pos->next & ~EHCI_PTR_BITS);
+        if (next == start)
+            break;
+        struct ehci_pipe *pipe = container_of(next, struct ehci_pipe, qh);
+        if (usb_is_freelist(&cntl->usb, &pipe->pipe))
+            pos->next = next->next;
+        else
+            pos = next;
+    }
+    ehci_waittick(cntl);
+    for (;;) {
+        struct usb_pipe *usbpipe = cntl->usb.freelist;
+        if (!usbpipe)
+            break;
+        cntl->usb.freelist = usbpipe->freenext;
+        struct ehci_pipe *pipe = container_of(usbpipe, struct ehci_pipe, pipe);
+        free(pipe);
+    }
+}
+
+static void
+configure_ehci(void *data)
+{
+    struct usb_ehci_s *cntl = data;
+
+    // Allocate ram for schedule storage
+    struct ehci_framelist *fl = memalign_high(sizeof(*fl), sizeof(*fl));
+    struct ehci_qh *intr_qh = memalign_high(EHCI_QH_ALIGN, sizeof(*intr_qh));
+    struct ehci_qh *async_qh = memalign_high(EHCI_QH_ALIGN, sizeof(*async_qh));
+    if (!fl || !intr_qh || !async_qh) {
+        warn_noalloc();
+        PendingEHCI--;
+        goto fail;
+    }
+
+    // XXX - check for halted?
+
+    // Reset the HC
+    u32 cmd = readl(&cntl->regs->usbcmd);
+    writel(&cntl->regs->usbcmd, (cmd & ~(CMD_ASE | CMD_PSE)) | CMD_HCRESET);
+    u32 end = timer_calc(250);
+    for (;;) {
+        cmd = readl(&cntl->regs->usbcmd);
+        if (!(cmd & CMD_HCRESET))
+            break;
+        if (timer_check(end)) {
+            warn_timeout();
+            PendingEHCI--;
+            goto fail;
+        }
+        yield();
+    }
+
+    // Disable interrupts (just to be safe).
+    writel(&cntl->regs->usbintr, 0);
+
+    // Set schedule to point to primary intr queue head
+    memset(intr_qh, 0, sizeof(*intr_qh));
+    intr_qh->next = EHCI_PTR_TERM;
+    intr_qh->info2 = (0x01 << QH_SMASK_SHIFT);
+    intr_qh->token = QTD_STS_HALT;
+    intr_qh->qtd_next = intr_qh->alt_next = EHCI_PTR_TERM;
+    int i;
+    for (i=0; i<ARRAY_SIZE(fl->links); i++)
+        fl->links[i] = (u32)intr_qh | EHCI_PTR_QH;
+    writel(&cntl->regs->periodiclistbase, (u32)fl);
+
+    // Set async list to point to primary async queue head
+    memset(async_qh, 0, sizeof(*async_qh));
+    async_qh->next = (u32)async_qh | EHCI_PTR_QH;
+    async_qh->info1 = QH_HEAD;
+    async_qh->token = QTD_STS_HALT;
+    async_qh->qtd_next = async_qh->alt_next = EHCI_PTR_TERM;
+    cntl->async_qh = async_qh;
+    writel(&cntl->regs->asynclistbase, (u32)async_qh);
+
+    // Enable queues
+    writel(&cntl->regs->usbcmd, cmd | CMD_ASE | CMD_PSE | CMD_RUN);
+
+    // Set default of high speed for root hub.
+    writel(&cntl->regs->configflag, 1);
+    PendingEHCI--;
+
+    // Find devices
+    int count = check_ehci_ports(cntl);
+    ehci_free_pipes(cntl);
+    if (count)
+        // Success
+        return;
+
+    // No devices found - shutdown and free controller.
+    writel(&cntl->regs->usbcmd, cmd & ~CMD_RUN);
+    msleep(4);  // 2ms to stop reading memory - XXX
+fail:
+    free(fl);
+    free(intr_qh);
+    free(async_qh);
+    free(cntl);
+}
+
+static void
+ehci_controller_setup(struct pci_device *pci)
+{
+    wait_preempt();  // Avoid pci_config_readl when preempting
+    u16 bdf = pci->bdf;
+    u32 baseaddr = pci_config_readl(bdf, PCI_BASE_ADDRESS_0);
+    struct ehci_caps *caps = (void*)(baseaddr & PCI_BASE_ADDRESS_MEM_MASK);
+    u32 hcc_params = readl(&caps->hccparams);
+
+    struct usb_ehci_s *cntl = malloc_tmphigh(sizeof(*cntl));
+    if (!cntl) {
+        warn_noalloc();
+        return;
+    }
+    memset(cntl, 0, sizeof(*cntl));
+    cntl->usb.pci = pci;
+    cntl->usb.type = USB_TYPE_EHCI;
+    cntl->caps = caps;
+    cntl->checkports = readl(&cntl->caps->hcsparams) & HCS_N_PORTS_MASK;
+    cntl->regs = (void*)caps + readb(&caps->caplength);
+    if (hcc_params & HCC_64BIT_ADDR)
+        cntl->regs->ctrldssegment = 0;
+    PendingEHCI++;
+
+    dprintf(1, "EHCI init on dev %02x:%02x.%x (regs=%p)\n"
+            , pci_bdf_to_bus(bdf), pci_bdf_to_dev(bdf)
+            , pci_bdf_to_fn(bdf), cntl->regs);
+
+    pci_config_maskw(bdf, PCI_COMMAND, 0, PCI_COMMAND_MASTER);
+
+    // XXX - check for and disable SMM control?
+
+    run_thread(configure_ehci, cntl);
+}
+
+void
+ehci_setup(void)
+{
+    if (! CONFIG_USB_EHCI)
+        return;
+    struct pci_device *pci;
+    foreachpci(pci) {
+        if (pci_classprog(pci) == PCI_CLASS_SERIAL_USB_EHCI)
+            ehci_controller_setup(pci);
+    }
+
+    // Wait for all EHCI controllers to initialize.  This forces OHCI/UHCI
+    // setup to always be after any EHCI ports are routed to EHCI.
+    while (PendingEHCI)
+        yield();
+}
+
+
+/****************************************************************
+ * End point communication
+ ****************************************************************/
+
+// Setup fields in qh
+static void
+ehci_desc2pipe(struct ehci_pipe *pipe, struct usbdevice_s *usbdev
+               , struct usb_endpoint_descriptor *epdesc)
+{
+    usb_desc2pipe(&pipe->pipe, usbdev, epdesc);
+
+    pipe->qh.info1 = ((pipe->pipe.maxpacket << QH_MAXPACKET_SHIFT)
+                      | (pipe->pipe.speed << QH_SPEED_SHIFT)
+                      | (pipe->pipe.ep << QH_EP_SHIFT)
+                      | (pipe->pipe.devaddr << QH_DEVADDR_SHIFT));
+
+    pipe->qh.info2 = (1 << QH_MULT_SHIFT);
+    struct usbdevice_s *hubdev = usbdev->hub->usbdev;
+    if (hubdev) {
+        struct ehci_pipe *hpipe = container_of(
+            hubdev->defpipe, struct ehci_pipe, pipe);
+        if (hpipe->pipe.speed == USB_HIGHSPEED)
+            pipe->qh.info2 |= (((usbdev->port+1) << QH_HUBPORT_SHIFT)
+                               | (hpipe->pipe.devaddr << QH_HUBADDR_SHIFT));
+        else
+            pipe->qh.info2 = hpipe->qh.info2;
+    }
+
+    u8 eptype = epdesc->bmAttributes & USB_ENDPOINT_XFERTYPE_MASK;
+    if (eptype == USB_ENDPOINT_XFER_CONTROL)
+        pipe->qh.info1 |= ((pipe->pipe.speed != USB_HIGHSPEED ? QH_CONTROL : 0)
+                           | QH_TOGGLECONTROL);
+    else if (eptype == USB_ENDPOINT_XFER_INT)
+        pipe->qh.info2 |= (0x01 << QH_SMASK_SHIFT) | (0x1c << QH_CMASK_SHIFT);
+}
+
+static struct usb_pipe *
+ehci_alloc_intr_pipe(struct usbdevice_s *usbdev
+                     , struct usb_endpoint_descriptor *epdesc)
+{
+    struct usb_ehci_s *cntl = container_of(
+        usbdev->hub->cntl, struct usb_ehci_s, usb);
+    int frameexp = usb_get_period(usbdev, epdesc);
+    dprintf(7, "ehci_alloc_intr_pipe %p %d\n", &cntl->usb, frameexp);
+
+    if (frameexp > 10)
+        frameexp = 10;
+    int maxpacket = epdesc->wMaxPacketSize;
+    // Determine number of entries needed for 2 timer ticks.
+    int ms = 1<<frameexp;
+    int count = DIV_ROUND_UP(ticks_to_ms(2), ms);
+    struct ehci_pipe *pipe = memalign_low(EHCI_QH_ALIGN, sizeof(*pipe));
+    struct ehci_qtd *tds = memalign_low(EHCI_QTD_ALIGN, sizeof(*tds) * count);
+    void *data = malloc_low(maxpacket * count);
+    if (!pipe || !tds || !data) {
+        warn_noalloc();
+        goto fail;
+    }
+    memset(pipe, 0, sizeof(*pipe));
+    memset(tds, 0, sizeof(*tds) * count);
+    memset(data, 0, maxpacket * count);
+    ehci_desc2pipe(pipe, usbdev, epdesc);
+    pipe->next_td = pipe->tds = tds;
+    pipe->data = data;
+    pipe->qh.qtd_next = (u32)tds;
+
+    int i;
+    for (i=0; i<count; i++) {
+        struct ehci_qtd *td = &tds[i];
+        td->qtd_next = (i==count-1 ? (u32)tds : (u32)&td[1]);
+        td->alt_next = EHCI_PTR_TERM;
+        td->token = (ehci_explen(maxpacket) | QTD_STS_ACTIVE
+                     | QTD_PID_IN | ehci_maxerr(3));
+        td->buf[0] = (u32)data + maxpacket * i;
+    }
+
+    // Add to interrupt schedule.
+    struct ehci_framelist *fl = (void*)readl(&cntl->regs->periodiclistbase);
+    if (frameexp == 0) {
+        // Add to existing interrupt entry.
+        struct ehci_qh *intr_qh = (void*)(fl->links[0] & ~EHCI_PTR_BITS);
+        pipe->qh.next = intr_qh->next;
+        barrier();
+        intr_qh->next = (u32)&pipe->qh | EHCI_PTR_QH;
+    } else {
+        int startpos = 1<<(frameexp-1);
+        pipe->qh.next = fl->links[startpos];
+        barrier();
+        for (i=startpos; i<ARRAY_SIZE(fl->links); i+=ms)
+            fl->links[i] = (u32)&pipe->qh | EHCI_PTR_QH;
+    }
+
+    return &pipe->pipe;
+fail:
+    free(pipe);
+    free(tds);
+    free(data);
+    return NULL;
+}
+
+struct usb_pipe *
+ehci_realloc_pipe(struct usbdevice_s *usbdev, struct usb_pipe *upipe
+                  , struct usb_endpoint_descriptor *epdesc)
+{
+    if (! CONFIG_USB_EHCI)
+        return NULL;
+    usb_add_freelist(upipe);
+    if (!epdesc)
+        return NULL;
+    u8 eptype = epdesc->bmAttributes & USB_ENDPOINT_XFERTYPE_MASK;
+    if (eptype == USB_ENDPOINT_XFER_INT)
+        return ehci_alloc_intr_pipe(usbdev, epdesc);
+    struct usb_ehci_s *cntl = container_of(
+        usbdev->hub->cntl, struct usb_ehci_s, usb);
+    dprintf(7, "ehci_alloc_async_pipe %p %d\n", &cntl->usb, eptype);
+
+    struct usb_pipe *usbpipe = usb_get_freelist(&cntl->usb, eptype);
+    if (usbpipe) {
+        // Use previously allocated pipe.
+        struct ehci_pipe *pipe = container_of(usbpipe, struct ehci_pipe, pipe);
+        ehci_desc2pipe(pipe, usbdev, epdesc);
+        return usbpipe;
+    }
+
+    // Allocate a new queue head.
+    struct ehci_pipe *pipe;
+    if (eptype == USB_ENDPOINT_XFER_CONTROL)
+        pipe = memalign_tmphigh(EHCI_QH_ALIGN, sizeof(*pipe));
+    else
+        pipe = memalign_low(EHCI_QH_ALIGN, sizeof(*pipe));
+    if (!pipe) {
+        warn_noalloc();
+        return NULL;
+    }
+    memset(pipe, 0, sizeof(*pipe));
+    ehci_desc2pipe(pipe, usbdev, epdesc);
+    pipe->qh.qtd_next = pipe->qh.alt_next = EHCI_PTR_TERM;
+
+    // Add queue head to controller list.
+    struct ehci_qh *async_qh = cntl->async_qh;
+    pipe->qh.next = async_qh->next;
+    barrier();
+    async_qh->next = (u32)&pipe->qh | EHCI_PTR_QH;
+    return &pipe->pipe;
+}
+
+static void
+ehci_reset_pipe(struct ehci_pipe *pipe)
+{
+    SET_LOWFLAT(pipe->qh.qtd_next, EHCI_PTR_TERM);
+    SET_LOWFLAT(pipe->qh.alt_next, EHCI_PTR_TERM);
+    barrier();
+    SET_LOWFLAT(pipe->qh.token, GET_LOWFLAT(pipe->qh.token) & QTD_TOGGLE);
+}
+
+static int
+ehci_wait_td(struct ehci_pipe *pipe, struct ehci_qtd *td, u32 end)
+{
+    u32 status;
+    for (;;) {
+        status = td->token;
+        if (!(status & QTD_STS_ACTIVE))
+            break;
+        if (timer_check(end)) {
+            u32 cur = GET_LOWFLAT(pipe->qh.current);
+            u32 tok = GET_LOWFLAT(pipe->qh.token);
+            u32 next = GET_LOWFLAT(pipe->qh.qtd_next);
+            warn_timeout();
+            dprintf(1, "ehci pipe=%p cur=%08x tok=%08x next=%x td=%p status=%x\n"
+                    , pipe, cur, tok, next, td, status);
+            ehci_reset_pipe(pipe);
+            struct usb_ehci_s *cntl = container_of(
+                GET_LOWFLAT(pipe->pipe.cntl), struct usb_ehci_s, usb);
+            ehci_waittick(cntl);
+            return -1;
+        }
+        yield();
+    }
+    if (status & QTD_STS_HALT) {
+        dprintf(1, "ehci_wait_td error - status=%x\n", status);
+        ehci_reset_pipe(pipe);
+        return -2;
+    }
+    return 0;
+}
+
+static void
+ehci_fill_tdbuf(struct ehci_qtd *td, u32 dest, int transfer)
+{
+    u32 *pos = td->buf, end = dest + transfer;
+    for (; dest < end; dest = ALIGN_DOWN(dest + PAGE_SIZE, PAGE_SIZE))
+        *pos++ = dest;
+}
+
+#define STACKQTDS 6
+
+int
+ehci_send_pipe(struct usb_pipe *p, int dir, const void *cmd
+               , void *data, int datasize)
+{
+    if (! CONFIG_USB_EHCI)
+        return -1;
+    struct ehci_pipe *pipe = container_of(p, struct ehci_pipe, pipe);
+    dprintf(7, "ehci_send_pipe qh=%p dir=%d data=%p size=%d\n"
+            , &pipe->qh, dir, data, datasize);
+
+    // Allocate tds on stack (with required alignment)
+    u8 tdsbuf[sizeof(struct ehci_qtd) * STACKQTDS + EHCI_QTD_ALIGN - 1];
+    struct ehci_qtd *tds = (void*)ALIGN((u32)tdsbuf, EHCI_QTD_ALIGN), *td = tds;
+    memset(tds, 0, sizeof(*tds) * STACKQTDS);
+
+    // Setup transfer descriptors
+    u16 maxpacket = GET_LOWFLAT(pipe->pipe.maxpacket);
+    u32 toggle = 0;
+    if (cmd) {
+        // Send setup pid on control transfers
+        td->qtd_next = (u32)MAKE_FLATPTR(GET_SEG(SS), td+1);
+        td->alt_next = EHCI_PTR_TERM;
+        td->token = (ehci_explen(USB_CONTROL_SETUP_SIZE) | QTD_STS_ACTIVE
+                     | QTD_PID_SETUP | ehci_maxerr(3));
+        ehci_fill_tdbuf(td, (u32)cmd, USB_CONTROL_SETUP_SIZE);
+        td++;
+        toggle = QTD_TOGGLE;
+    }
+    u32 dest = (u32)data, dataend = dest + datasize;
+    while (dest < dataend) {
+        // Send data pids
+        if (td >= &tds[STACKQTDS]) {
+            warn_noalloc();
+            return -1;
+        }
+        int maxtransfer = 5*PAGE_SIZE - (dest & (PAGE_SIZE-1));
+        int transfer = dataend - dest;
+        if (transfer > maxtransfer)
+            transfer = ALIGN_DOWN(maxtransfer, maxpacket);
+        td->qtd_next = (u32)MAKE_FLATPTR(GET_SEG(SS), td+1);
+        td->alt_next = EHCI_PTR_TERM;
+        td->token = (ehci_explen(transfer) | toggle | QTD_STS_ACTIVE
+                     | (dir ? QTD_PID_IN : QTD_PID_OUT) | ehci_maxerr(3));
+        ehci_fill_tdbuf(td, dest, transfer);
+        td++;
+        dest += transfer;
+    }
+    if (cmd) {
+        // Send status pid on control transfers
+        if (td >= &tds[STACKQTDS]) {
+            warn_noalloc();
+            return -1;
+        }
+        td->qtd_next = EHCI_PTR_TERM;
+        td->alt_next = EHCI_PTR_TERM;
+        td->token = (QTD_TOGGLE | QTD_STS_ACTIVE
+                     | (dir ? QTD_PID_OUT : QTD_PID_IN) | ehci_maxerr(3));
+        td++;
+    }
+
+    // Transfer data
+    (td-1)->qtd_next = EHCI_PTR_TERM;
+    barrier();
+    SET_LOWFLAT(pipe->qh.qtd_next, (u32)MAKE_FLATPTR(GET_SEG(SS), tds));
+    u32 end = timer_calc(usb_xfer_time(p, datasize));
+    int i;
+    for (i=0, td=tds; i<STACKQTDS; i++, td++) {
+        int ret = ehci_wait_td(pipe, td, end);
+        if (ret)
+            return -1;
+    }
+
+    return 0;
+}
+
+int
+ehci_poll_intr(struct usb_pipe *p, void *data)
+{
+    ASSERT16();
+    if (! CONFIG_USB_EHCI)
+        return -1;
+    struct ehci_pipe *pipe = container_of(p, struct ehci_pipe, pipe);
+    struct ehci_qtd *td = GET_LOWFLAT(pipe->next_td);
+    u32 token = GET_LOWFLAT(td->token);
+    if (token & QTD_STS_ACTIVE)
+        // No intrs found.
+        return -1;
+    // XXX - check for errors.
+
+    // Copy data.
+    int maxpacket = GET_LOWFLAT(pipe->pipe.maxpacket);
+    int pos = td - GET_LOWFLAT(pipe->tds);
+    void *tddata = GET_LOWFLAT(pipe->data) + maxpacket * pos;
+    memcpy_far(GET_SEG(SS), data, SEG_LOW, LOWFLAT2LOW(tddata), maxpacket);
+
+    // Reenable this td.
+    struct ehci_qtd *next = (void*)(GET_LOWFLAT(td->qtd_next) & ~EHCI_PTR_BITS);
+    SET_LOWFLAT(pipe->next_td, next);
+    SET_LOWFLAT(td->buf[0], (u32)tddata);
+    barrier();
+    SET_LOWFLAT(td->token, (ehci_explen(maxpacket) | QTD_STS_ACTIVE
+                            | QTD_PID_IN | ehci_maxerr(3)));
+
+    return 0;
+}