usb-ohci.c

qemu性能直逼VMware的仿真器QEMU 的模擬速度約為實機的 25％；約為 Bochs 的 60 倍。Plex86、User-Mode-Linux、VMware 和 Virtual PC 則比

    ptr = td->cbp;
    n = 0x1000 - (ptr & 0xfff);
    if (n > len)
        n = len;
    cpu_physical_memory_rw(ptr, buf, n, write);
    if (n == len)
        return;
    ptr = td->be & ~0xfffu;
    buf += n;
    cpu_physical_memory_rw(ptr, buf, len - n, write);
}

static void ohci_process_lists(OHCIState *ohci);

static void ohci_async_complete_packet(USBPacket * packet, void *opaque)
{
    OHCIState *ohci = opaque;
#ifdef DEBUG_PACKET
    dprintf("Async packet complete\n");
#endif
    ohci->async_complete = 1;
    ohci_process_lists(ohci);
}

/* Service a transport descriptor.
   Returns nonzero to terminate processing of this endpoint.  */

static int ohci_service_td(OHCIState *ohci, struct ohci_ed *ed)
{
    int dir;
    size_t len = 0;
    char *str = NULL;
    int pid;
    int ret;
    int i;
    USBDevice *dev;
    struct ohci_td td;
    uint32_t addr;
    int flag_r;
    int completion;

    addr = ed->head & OHCI_DPTR_MASK;
    /* See if this TD has already been submitted to the device.  */
    completion = (addr == ohci->async_td);
    if (completion && !ohci->async_complete) {
#ifdef DEBUG_PACKET
        dprintf("Skipping async TD\n");
#endif
        return 1;
    }
    if (!ohci_read_td(addr, &td)) {
        fprintf(stderr, "usb-ohci: TD read error at %x\n", addr);
        return 0;
    }

    dir = OHCI_BM(ed->flags, ED_D);
    switch (dir) {
    case OHCI_TD_DIR_OUT:
    case OHCI_TD_DIR_IN:
        /* Same value.  */
        break;
    default:
        dir = OHCI_BM(td.flags, TD_DP);
        break;
    }

    switch (dir) {
    case OHCI_TD_DIR_IN:
        str = "in";
        pid = USB_TOKEN_IN;
        break;
    case OHCI_TD_DIR_OUT:
        str = "out";
        pid = USB_TOKEN_OUT;
        break;
    case OHCI_TD_DIR_SETUP:
        str = "setup";
        pid = USB_TOKEN_SETUP;
        break;
    default:
        fprintf(stderr, "usb-ohci: Bad direction\n");
        return 1;
    }
    if (td.cbp && td.be) {
        if ((td.cbp & 0xfffff000) != (td.be & 0xfffff000)) {
            len = (td.be & 0xfff) + 0x1001 - (td.cbp & 0xfff);
        } else {
            len = (td.be - td.cbp) + 1;
        }

        if (len && dir != OHCI_TD_DIR_IN && !completion) {
            ohci_copy_td(&td, ohci->usb_buf, len, 0);
        }
    }

    flag_r = (td.flags & OHCI_TD_R) != 0;
#ifdef DEBUG_PACKET
    dprintf(" TD @ 0x%.8x %u bytes %s r=%d cbp=0x%.8x be=0x%.8x\n",
            addr, len, str, flag_r, td.cbp, td.be);

    if (len >= 0 && dir != OHCI_TD_DIR_IN) {
        dprintf("  data:");
        for (i = 0; i < len; i++)
            printf(" %.2x", ohci->usb_buf[i]);
        dprintf("\n");
    }
#endif
    if (completion) {
        ret = ohci->usb_packet.len;
        ohci->async_td = 0;
        ohci->async_complete = 0;
    } else {
        ret = USB_RET_NODEV;
        for (i = 0; i < ohci->num_ports; i++) {
            dev = ohci->rhport[i].port.dev;
            if ((ohci->rhport[i].ctrl & OHCI_PORT_PES) == 0)
                continue;

            if (ohci->async_td) {
                /* ??? The hardware should allow one active packet per
                   endpoint.  We only allow one active packet per controller.
                   This should be sufficient as long as devices respond in a
                   timely manner.
                 */
#ifdef DEBUG_PACKET
                dprintf("Too many pending packets\n");
#endif
                return 1;
            }
            ohci->usb_packet.pid = pid;
            ohci->usb_packet.devaddr = OHCI_BM(ed->flags, ED_FA);
            ohci->usb_packet.devep = OHCI_BM(ed->flags, ED_EN);
            ohci->usb_packet.data = ohci->usb_buf;
            ohci->usb_packet.len = len;
            ohci->usb_packet.complete_cb = ohci_async_complete_packet;
            ohci->usb_packet.complete_opaque = ohci;
            ret = dev->handle_packet(dev, &ohci->usb_packet);
            if (ret != USB_RET_NODEV)
                break;
        }
#ifdef DEBUG_PACKET
        dprintf("ret=%d\n", ret);
#endif
        if (ret == USB_RET_ASYNC) {
            ohci->async_td = addr;
            return 1;
        }
    }
    if (ret >= 0) {
        if (dir == OHCI_TD_DIR_IN) {
            ohci_copy_td(&td, ohci->usb_buf, ret, 1);
#ifdef DEBUG_PACKET
            dprintf("  data:");
            for (i = 0; i < ret; i++)
                printf(" %.2x", ohci->usb_buf[i]);
            dprintf("\n");
#endif
        } else {
            ret = len;
        }
    }

    /* Writeback */
    if (ret == len || (dir == OHCI_TD_DIR_IN && ret >= 0 && flag_r)) {
        /* Transmission succeeded.  */
        if (ret == len) {
            td.cbp = 0;
        } else {
            td.cbp += ret;
            if ((td.cbp & 0xfff) + ret > 0xfff) {
                td.cbp &= 0xfff;
                td.cbp |= td.be & ~0xfff;
            }
        }
        td.flags |= OHCI_TD_T1;
        td.flags ^= OHCI_TD_T0;
        OHCI_SET_BM(td.flags, TD_CC, OHCI_CC_NOERROR);
        OHCI_SET_BM(td.flags, TD_EC, 0);

        ed->head &= ~OHCI_ED_C;
        if (td.flags & OHCI_TD_T0)
            ed->head |= OHCI_ED_C;
    } else {
        if (ret >= 0) {
            dprintf("usb-ohci: Underrun\n");
            OHCI_SET_BM(td.flags, TD_CC, OHCI_CC_DATAUNDERRUN);
        } else {
            switch (ret) {
            case USB_RET_NODEV:
                OHCI_SET_BM(td.flags, TD_CC, OHCI_CC_DEVICENOTRESPONDING);
            case USB_RET_NAK:
                dprintf("usb-ohci: got NAK\n");
                return 1;
            case USB_RET_STALL:
                dprintf("usb-ohci: got STALL\n");
                OHCI_SET_BM(td.flags, TD_CC, OHCI_CC_STALL);
                break;
            case USB_RET_BABBLE:
                dprintf("usb-ohci: got BABBLE\n");
                OHCI_SET_BM(td.flags, TD_CC, OHCI_CC_DATAOVERRUN);
                break;
            default:
                fprintf(stderr, "usb-ohci: Bad device response %d\n", ret);
                OHCI_SET_BM(td.flags, TD_CC, OHCI_CC_UNDEXPETEDPID);
                OHCI_SET_BM(td.flags, TD_EC, 3);
                break;
            }
        }
        ed->head |= OHCI_ED_H;
    }

    /* Retire this TD */
    ed->head &= ~OHCI_DPTR_MASK;
    ed->head |= td.next & OHCI_DPTR_MASK;
    td.next = ohci->done;
    ohci->done = addr;
    i = OHCI_BM(td.flags, TD_DI);
    if (i < ohci->done_count)
        ohci->done_count = i;
    ohci_put_td(addr, &td);
    return OHCI_BM(td.flags, TD_CC) != OHCI_CC_NOERROR;
}

/* Service an endpoint list.  Returns nonzero if active TD were found.  */
static int ohci_service_ed_list(OHCIState *ohci, uint32_t head)
{
    struct ohci_ed ed;
    uint32_t next_ed;
    uint32_t cur;
    int active;

    active = 0;

    if (head == 0)
        return 0;

    for (cur = head; cur; cur = next_ed) {
        if (!ohci_read_ed(cur, &ed)) {
            fprintf(stderr, "usb-ohci: ED read error at %x\n", cur);
            return 0;
        }

        next_ed = ed.next & OHCI_DPTR_MASK;

        if ((ed.head & OHCI_ED_H) || (ed.flags & OHCI_ED_K)) {
            uint32_t addr;
            /* Cancel pending packets for ED that have been paused.  */
            addr = ed.head & OHCI_DPTR_MASK;
            if (ohci->async_td && addr == ohci->async_td) {
                usb_cancel_packet(&ohci->usb_packet);
                ohci->async_td = 0;
            }
            continue;
        }

        /* Skip isochronous endpoints.  */
        if (ed.flags & OHCI_ED_F)
          continue;

        while ((ed.head & OHCI_DPTR_MASK) != ed.tail) {
#ifdef DEBUG_PACKET
            dprintf("ED @ 0x%.8x fa=%u en=%u d=%u s=%u k=%u f=%u mps=%u "
                    "h=%u c=%u\n  head=0x%.8x tailp=0x%.8x next=0x%.8x\n", cur,
                    OHCI_BM(ed.flags, ED_FA), OHCI_BM(ed.flags, ED_EN),
                    OHCI_BM(ed.flags, ED_D), (ed.flags & OHCI_ED_S)!= 0,
                    (ed.flags & OHCI_ED_K) != 0, (ed.flags & OHCI_ED_F) != 0,
                    OHCI_BM(ed.flags, ED_MPS), (ed.head & OHCI_ED_H) != 0,
                    (ed.head & OHCI_ED_C) != 0, ed.head & OHCI_DPTR_MASK,
                    ed.tail & OHCI_DPTR_MASK, ed.next & OHCI_DPTR_MASK);
#endif
            active = 1;

            if (ohci_service_td(ohci, &ed))
                break;
        }

        ohci_put_ed(cur, &ed);
    }

    return active;
}

/* Generate a SOF event, and set a timer for EOF */
static void ohci_sof(OHCIState *ohci)
{
    ohci->sof_time = qemu_get_clock(vm_clock);
    qemu_mod_timer(ohci->eof_timer, ohci->sof_time + usb_frame_time);
    ohci_set_interrupt(ohci, OHCI_INTR_SF);
}

/* Process Control and Bulk lists.  */
static void ohci_process_lists(OHCIState *ohci)
{
    if ((ohci->ctl & OHCI_CTL_CLE) && (ohci->status & OHCI_STATUS_CLF)) {
        if (ohci->ctrl_cur && ohci->ctrl_cur != ohci->ctrl_head)
          dprintf("usb-ohci: head %x, cur %x\n", ohci->ctrl_head, ohci->ctrl_cur);
        if (!ohci_service_ed_list(ohci, ohci->ctrl_head)) {
            ohci->ctrl_cur = 0;
            ohci->status &= ~OHCI_STATUS_CLF;
        }
    }

    if ((ohci->ctl & OHCI_CTL_BLE) && (ohci->status & OHCI_STATUS_BLF)) {
        if (!ohci_service_ed_list(ohci, ohci->bulk_head)) {
            ohci->bulk_cur = 0;
            ohci->status &= ~OHCI_STATUS_BLF;
        }
    }
}

/* Do frame processing on frame boundary */
static void ohci_frame_boundary(void *opaque)
{
    OHCIState *ohci = opaque;
    struct ohci_hcca hcca;

    cpu_physical_memory_rw(ohci->hcca, (uint8_t *)&hcca, sizeof(hcca), 0);

    /* Process all the lists at the end of the frame */
    if (ohci->ctl & OHCI_CTL_PLE) {
        int n;

        n = ohci->frame_number & 0x1f;
        ohci_service_ed_list(ohci, le32_to_cpu(hcca.intr[n]));
    }

    /* Cancel all pending packets if either of the lists has been disabled.  */
    if (ohci->async_td &&
        ohci->old_ctl & (~ohci->ctl) & (OHCI_CTL_BLE | OHCI_CTL_CLE)) {
        usb_cancel_packet(&ohci->usb_packet);
        ohci->async_td = 0;
    }
    ohci->old_ctl = ohci->ctl;
    ohci_process_lists(ohci);

    /* Frame boundary, so do EOF stuf here */
    ohci->frt = ohci->fit;

    /* XXX: endianness */
    ohci->frame_number = (ohci->frame_number + 1) & 0xffff;
    hcca.frame = cpu_to_le32(ohci->frame_number);

    if (ohci->done_count == 0 && !(ohci->intr_status & OHCI_INTR_WD)) {
        if (!ohci->done)
            abort();
        if (ohci->intr & ohci->intr_status)
            ohci->done |= 1;
        hcca.done = cpu_to_le32(ohci->done);
        ohci->done = 0;
        ohci->done_count = 7;
        ohci_set_interrupt(ohci, OHCI_INTR_WD);
    }

    if (ohci->done_count != 7 && ohci->done_count != 0)
        ohci->done_count--;

    /* Do SOF stuff here */
    ohci_sof(ohci);

    /* Writeback HCCA */
    cpu_physical_memory_rw(ohci->hcca, (uint8_t *)&hcca, sizeof(hcca), 1);
}

/* Start sending SOF tokens across the USB bus, lists are processed in
 * next frame
 */
static int ohci_bus_start(OHCIState *ohci)
{
    ohci->eof_timer = qemu_new_timer(vm_clock,
                    ohci_frame_boundary,
                    ohci);

    if (ohci->eof_timer == NULL) {
        fprintf(stderr, "usb-ohci: %s: qemu_new_timer failed\n",
            ohci->pci_dev.name);
        /* TODO: Signal unrecoverable error */
        return 0;
    }

    dprintf("usb-ohci: %s: USB Operational\n", ohci->pci_dev.name);

    ohci_sof(ohci);

    return 1;
}

/* Stop sending SOF tokens on the bus */
static void ohci_bus_stop(OHCIState *ohci)
{
    if (ohci->eof_timer)
        qemu_del_timer(ohci->eof_timer);
}

/* Sets a flag in a port status register but only set it if the port is
 * connected, if not set ConnectStatusChange flag. If flag is enabled
 * return 1.
 */
static int ohci_port_set_if_connected(OHCIState *ohci, int i, uint32_t val)
{
    int ret = 1;

    /* writing a 0 has no effect */
    if (val == 0)
        return 0;

    /* If CurrentConnectStatus is cleared we set
     * ConnectStatusChange
     */
    if (!(ohci->rhport[i].ctrl & OHCI_PORT_CCS)) {
        ohci->rhport[i].ctrl |= OHCI_PORT_CSC;
        if (ohci->rhstatus & OHCI_RHS_DRWE) {
            /* TODO: CSC is a wakeup event */
        }
        return 0;
    }

    if (ohci->rhport[i].ctrl & val)
        ret = 0;

    /* set the bit */
    ohci->rhport[i].ctrl |= val;

    return ret;
}