[PATCH v7 2/3] usb: Introduce Xen pvUSB frontend (xen hcd)

Juergen Gross
2021-11-23T13:21:00Z

Introduces the Xen pvUSB frontend. With pvUSB it is possible for a Xen
domU to communicate with a USB device assigned to that domU. The
communication is all done via the pvUSB backend in a driver domain
(usually Dom0) which is owner of the physical device.

The pvUSB frontend is a USB hcd for a virtual USB host connector.

The code is taken from the pvUSB implementation in Xen done by Fujitsu
based on Linux kernel 2.6.18.

Changes from the original version are:
- port to upstream kernel
- put all code in just one source file
- move module to appropriate location in kernel tree
- adapt to Linux style guide
- minor code modifications to increase readability

Signed-off-by: Juergen Gross <jgross@suse.com>
---
drivers/usb/host/Kconfig | 11 +
drivers/usb/host/Makefile | 1 +
drivers/usb/host/xen-hcd.c | 1606 ++++++++++++++++++++++++++++++++++++
3 files changed, 1618 insertions(+)
create mode 100644 drivers/usb/host/xen-hcd.c

diff --git a/drivers/usb/host/Kconfig b/drivers/usb/host/Kconfig
index d1d926f8f9c2..57ca5f97a3dc 100644
--- a/drivers/usb/host/Kconfig
+++ b/drivers/usb/host/Kconfig
@@ -772,3 +772,14 @@ config USB_HCD_TEST_MODE
This option is of interest only to developers who need to validate
their USB hardware designs. It is not needed for normal use. If
unsure, say N.
+
+config USB_XEN_HCD
+ tristate "Xen usb virtual host driver"
+ depends on XEN
+ select XEN_XENBUS_FRONTEND
+ help
+ The Xen usb virtual host driver serves as a frontend driver enabling
+ a Xen guest system to access USB Devices passed through to the guest
+ by the Xen host (usually Dom0).
+ Only needed if the kernel is running in a Xen guest and generic
+ access to a USB device is needed.
diff --git a/drivers/usb/host/Makefile b/drivers/usb/host/Makefile
index 171de4df50bd..2948983618fb 100644
--- a/drivers/usb/host/Makefile
+++ b/drivers/usb/host/Makefile
@@ -85,3 +85,4 @@ obj-$(CONFIG_USB_HCD_BCMA) += bcma-hcd.o
obj-$(CONFIG_USB_HCD_SSB) += ssb-hcd.o
obj-$(CONFIG_USB_FOTG210_HCD) += fotg210-hcd.o
obj-$(CONFIG_USB_MAX3421_HCD) += max3421-hcd.o
+obj-$(CONFIG_USB_XEN_HCD) += xen-hcd.o
diff --git a/drivers/usb/host/xen-hcd.c b/drivers/usb/host/xen-hcd.c
new file mode 100644
index 000000000000..7801dde6f5ee
--- /dev/null
+++ b/drivers/usb/host/xen-hcd.c
@@ -0,0 +1,1606 @@
+// SPDX-License-Identifier: GPL-2.0-or-later
+/*
+ * xen-hcd.c
+ *
+ * Xen USB Virtual Host Controller driver
+ *
+ * Copyright (C) 2009, FUJITSU LABORATORIES LTD.
+ * Author: Noboru Iwamatsu <n_iwamatsu@jp.fujitsu.com>
+ */
+
+#include <linux/module.h>
+#include <linux/usb.h>
+#include <linux/list.h>
+#include <linux/usb/hcd.h>
+#include <linux/io.h>
+
+#include <xen/xen.h>
+#include <xen/xenbus.h>
+#include <xen/grant_table.h>
+#include <xen/events.h>
+#include <xen/page.h>
+
+#include <xen/interface/io/usbif.h>
+
+/* Private per-URB data */
+struct urb_priv {
+ struct list_head list;
+ struct urb *urb;
+ int req_id; /* RING_REQUEST id for submitting */
+ int unlink_req_id; /* RING_REQUEST id for unlinking */
+ int status;
+ bool unlinked; /* dequeued marker */
+};
+
+/* virtual roothub port status */
+struct rhport_status {
+ __u32 status;
+ bool resuming; /* in resuming */
+ bool c_connection; /* connection changed */
+ unsigned long timeout;
+};
+
+/* status of attached device */
+struct vdevice_status {
+ int devnum;
+ enum usb_device_state status;
+ enum usb_device_speed speed;
+};
+
+/* RING request shadow */
+struct usb_shadow {
+ struct xenusb_urb_request req;
+ struct urb *urb;
+};
+
+struct xenhcd_info {
+ /* Virtual Host Controller has 4 urb queues */
+ struct list_head pending_submit_list;
+ struct list_head pending_unlink_list;
+ struct list_head in_progress_list;
+ struct list_head giveback_waiting_list;
+
+ spinlock_t lock;
+
+ /* timer that kick pending and giveback waiting urbs */
+ struct timer_list watchdog;
+ unsigned long actions;
+
+ /* virtual root hub */
+ int rh_numports;
+ struct rhport_status ports[XENUSB_MAX_PORTNR];
+ struct vdevice_status devices[XENUSB_MAX_PORTNR];
+
+ /* Xen related staff */
+ struct xenbus_device *xbdev;
+ int urb_ring_ref;
+ int conn_ring_ref;
+ struct xenusb_urb_front_ring urb_ring;
+ struct xenusb_conn_front_ring conn_ring;
+
+ unsigned int evtchn;
+ unsigned int irq;
+ struct usb_shadow shadow[XENUSB_URB_RING_SIZE];
+ unsigned int shadow_free;
+
+ bool error;
+};
+
+#define GRANT_INVALID_REF 0
+
+#define XENHCD_RING_JIFFIES (HZ/200)
+#define XENHCD_SCAN_JIFFIES 1
+
+enum xenhcd_timer_action {
+ TIMER_RING_WATCHDOG,
+ TIMER_SCAN_PENDING_URBS,
+};
+
+static struct kmem_cache *xenhcd_urbp_cachep;
+
+static inline struct xenhcd_info *xenhcd_hcd_to_info(struct usb_hcd *hcd)
+{
+ return (struct xenhcd_info *)hcd->hcd_priv;
+}
+
+static inline struct usb_hcd *xenhcd_info_to_hcd(struct xenhcd_info *info)
+{
+ return container_of((void *)info, struct usb_hcd, hcd_priv);
+}
+
+static void xenhcd_set_error(struct xenhcd_info *info, const char *msg)
+{
+ info->error = true;
+
+ pr_alert("xen-hcd: protocol error: %s!\n", msg);
+}
+
+static inline void xenhcd_timer_action_done(struct xenhcd_info *info,
+ enum xenhcd_timer_action action)
+{
+ clear_bit(action, &info->actions);
+}
+
+static void xenhcd_timer_action(struct xenhcd_info *info,
+ enum xenhcd_timer_action action)
+{
+ if (timer_pending(&info->watchdog) &&
+ test_bit(TIMER_SCAN_PENDING_URBS, &info->actions))
+ return;
+
+ if (!test_and_set_bit(action, &info->actions)) {
+ unsigned long t;
+
+ switch (action) {
+ case TIMER_RING_WATCHDOG:
+ t = XENHCD_RING_JIFFIES;
+ break;
+ default:
+ t = XENHCD_SCAN_JIFFIES;
+ break;
+ }
+ mod_timer(&info->watchdog, t + jiffies);
+ }
+}
+
+/*
+ * set virtual port connection status
+ */
+static void xenhcd_set_connect_state(struct xenhcd_info *info, int portnum)
+{
+ int port;
+
+ port = portnum - 1;
+ if (info->ports[port].status & USB_PORT_STAT_POWER) {
+ switch (info->devices[port].speed) {
+ case XENUSB_SPEED_NONE:
+ info->ports[port].status &=
+ ~(USB_PORT_STAT_CONNECTION |
+ USB_PORT_STAT_ENABLE |
+ USB_PORT_STAT_LOW_SPEED |
+ USB_PORT_STAT_HIGH_SPEED |
+ USB_PORT_STAT_SUSPEND);
+ break;
+ case XENUSB_SPEED_LOW:
+ info->ports[port].status |= USB_PORT_STAT_CONNECTION;
+ info->ports[port].status |= USB_PORT_STAT_LOW_SPEED;
+ break;
+ case XENUSB_SPEED_FULL:
+ info->ports[port].status |= USB_PORT_STAT_CONNECTION;
+ break;
+ case XENUSB_SPEED_HIGH:
+ info->ports[port].status |= USB_PORT_STAT_CONNECTION;
+ info->ports[port].status |= USB_PORT_STAT_HIGH_SPEED;
+ break;
+ default: /* error */
+ return;
+ }
+ info->ports[port].status |= (USB_PORT_STAT_C_CONNECTION << 16);
+ }
+}
+
+/*
+ * set virtual device connection status
+ */
+static int xenhcd_rhport_connect(struct xenhcd_info *info, __u8 portnum,
+ __u8 speed)
+{
+ int port;
+
+ if (portnum < 1 || portnum > info->rh_numports)
+ return -EINVAL; /* invalid port number */
+
+ port = portnum - 1;
+ if (info->devices[port].speed != speed) {
+ switch (speed) {
+ case XENUSB_SPEED_NONE: /* disconnect */
+ info->devices[port].status = USB_STATE_NOTATTACHED;
+ break;
+ case XENUSB_SPEED_LOW:
+ case XENUSB_SPEED_FULL:
+ case XENUSB_SPEED_HIGH:
+ info->devices[port].status = USB_STATE_ATTACHED;
+ break;
+ default: /* error */
+ return -EINVAL;
+ }
+ info->devices[port].speed = speed;
+ info->ports[port].c_connection = true;
+
+ xenhcd_set_connect_state(info, portnum);
+ }
+
+ return 0;
+}
+
+/*
+ * SetPortFeature(PORT_SUSPENDED)
+ */
+static void xenhcd_rhport_suspend(struct xenhcd_info *info, int portnum)
+{
+ int port;
+
+ port = portnum - 1;
+ info->ports[port].status |= USB_PORT_STAT_SUSPEND;
+ info->devices[port].status = USB_STATE_SUSPENDED;
+}
+
+/*
+ * ClearPortFeature(PORT_SUSPENDED)
+ */
+static void xenhcd_rhport_resume(struct xenhcd_info *info, int portnum)
+{
+ int port;
+
+ port = portnum - 1;
+ if (info->ports[port].status & USB_PORT_STAT_SUSPEND) {
+ info->ports[port].resuming = true;
+ info->ports[port].timeout = jiffies + msecs_to_jiffies(20);
+ }
+}
+
+/*
+ * SetPortFeature(PORT_POWER)
+ */
+static void xenhcd_rhport_power_on(struct xenhcd_info *info, int portnum)
+{
+ int port;
+
+ port = portnum - 1;
+ if ((info->ports[port].status & USB_PORT_STAT_POWER) == 0) {
+ info->ports[port].status |= USB_PORT_STAT_POWER;
+ if (info->devices[port].status != USB_STATE_NOTATTACHED)
+ info->devices[port].status = USB_STATE_POWERED;
+ if (info->ports[port].c_connection)
+ xenhcd_set_connect_state(info, portnum);
+ }
+}
+
+/*
+ * ClearPortFeature(PORT_POWER)
+ * SetConfiguration(non-zero)
+ * Power_Source_Off
+ * Over-current
+ */
+static void xenhcd_rhport_power_off(struct xenhcd_info *info, int portnum)
+{
+ int port;
+
+ port = portnum - 1;
+ if (info->ports[port].status & USB_PORT_STAT_POWER) {
+ info->ports[port].status = 0;
+ if (info->devices[port].status != USB_STATE_NOTATTACHED)
+ info->devices[port].status = USB_STATE_ATTACHED;
+ }
+}
+
+/*
+ * ClearPortFeature(PORT_ENABLE)
+ */
+static void xenhcd_rhport_disable(struct xenhcd_info *info, int portnum)
+{
+ int port;
+
+ port = portnum - 1;
+ info->ports[port].status &= ~USB_PORT_STAT_ENABLE;
+ info->ports[port].status &= ~USB_PORT_STAT_SUSPEND;
+ info->ports[port].resuming = false;
+ if (info->devices[port].status != USB_STATE_NOTATTACHED)
+ info->devices[port].status = USB_STATE_POWERED;
+}
+
+/*
+ * SetPortFeature(PORT_RESET)
+ */
+static void xenhcd_rhport_reset(struct xenhcd_info *info, int portnum)
+{
+ int port;
+
+ port = portnum - 1;
+ info->ports[port].status &= ~(USB_PORT_STAT_ENABLE |
+ USB_PORT_STAT_LOW_SPEED |
+ USB_PORT_STAT_HIGH_SPEED);
+ info->ports[port].status |= USB_PORT_STAT_RESET;
+
+ if (info->devices[port].status != USB_STATE_NOTATTACHED)
+ info->devices[port].status = USB_STATE_ATTACHED;
+
+ /* 10msec reset signaling */
+ info->ports[port].timeout = jiffies + msecs_to_jiffies(10);
+}
+
+#ifdef CONFIG_PM
+static int xenhcd_bus_suspend(struct usb_hcd *hcd)
+{
+ struct xenhcd_info *info = xenhcd_hcd_to_info(hcd);
+ int ret = 0;
+ int i, ports;
+
+ ports = info->rh_numports;
+
+ spin_lock_irq(&info->lock);
+ if (!test_bit(HCD_FLAG_HW_ACCESSIBLE, &hcd->flags)) {
+ ret = -ESHUTDOWN;
+ } else {
+ /* suspend any active ports*/
+ for (i = 1; i <= ports; i++)
+ xenhcd_rhport_suspend(info, i);
+ }
+ spin_unlock_irq(&info->lock);
+
+ del_timer_sync(&info->watchdog);
+
+ return ret;
+}
+
+static int xenhcd_bus_resume(struct usb_hcd *hcd)
+{
+ struct xenhcd_info *info = xenhcd_hcd_to_info(hcd);
+ int ret = 0;
+ int i, ports;
+
+ ports = info->rh_numports;
+
+ spin_lock_irq(&info->lock);
+ if (!test_bit(HCD_FLAG_HW_ACCESSIBLE, &hcd->flags)) {
+ ret = -ESHUTDOWN;
+ } else {
+ /* resume any suspended ports*/
+ for (i = 1; i <= ports; i++)
+ xenhcd_rhport_resume(info, i);
+ }
+ spin_unlock_irq(&info->lock);
+
+ return ret;
+}
+#endif
+
+static void xenhcd_hub_descriptor(struct xenhcd_info *info,
+ struct usb_hub_descriptor *desc)
+{
+ __u16 temp;
+ int ports = info->rh_numports;
+
+ desc->bDescriptorType = 0x29;
+ desc->bPwrOn2PwrGood = 10; /* EHCI says 20ms max */
+ desc->bHubContrCurrent = 0;
+ desc->bNbrPorts = ports;
+
+ /* size of DeviceRemovable and PortPwrCtrlMask fields */
+ temp = 1 + (ports / 8);
+ desc->bDescLength = 7 + 2 * temp;
+
+ /* bitmaps for DeviceRemovable and PortPwrCtrlMask */
+ memset(&desc->u.hs.DeviceRemovable[0], 0, temp);
+ memset(&desc->u.hs.DeviceRemovable[temp], 0xff, temp);
+
+ /* per-port over current reporting and no power switching */
+ temp = 0x000a;
+ desc->wHubCharacteristics = cpu_to_le16(temp);
+}
+
+/* port status change mask for hub_status_data */
+#define PORT_C_MASK ((USB_PORT_STAT_C_CONNECTION | \
+ USB_PORT_STAT_C_ENABLE | \
+ USB_PORT_STAT_C_SUSPEND | \
+ USB_PORT_STAT_C_OVERCURRENT | \
+ USB_PORT_STAT_C_RESET) << 16)
+
+/*
+ * See USB 2.0 Spec, 11.12.4 Hub and Port Status Change Bitmap.
+ * If port status changed, writes the bitmap to buf and return
+ * that length(number of bytes).
+ * If Nothing changed, return 0.
+ */
+static int xenhcd_hub_status_data(struct usb_hcd *hcd, char *buf)
+{
+ struct xenhcd_info *info = xenhcd_hcd_to_info(hcd);
+ int ports;
+ int i;
+ unsigned long flags;
+ int ret;
+ int changed = 0;
+
+ /* initialize the status to no-changes */
+ ports = info->rh_numports;
+ ret = 1 + (ports / 8);
+ memset(buf, 0, ret);
+
+ spin_lock_irqsave(&info->lock, flags);
+
+ for (i = 0; i < ports; i++) {
+ /* check status for each port */
+ if (info->ports[i].status & PORT_C_MASK) {
+ buf[(i + 1) / 8] |= 1 << (i + 1) % 8;
+ changed = 1;
+ }
+ }
+
+ if ((hcd->state == HC_STATE_SUSPENDED) && (changed == 1))
+ usb_hcd_resume_root_hub(hcd);
+
+ spin_unlock_irqrestore(&info->lock, flags);
+
+ return changed ? ret : 0;
+}
+
+static int xenhcd_hub_control(struct usb_hcd *hcd, __u16 typeReq, __u16 wValue,
+ __u16 wIndex, char *buf, __u16 wLength)
+{
+ struct xenhcd_info *info = xenhcd_hcd_to_info(hcd);
+ int ports = info->rh_numports;
+ unsigned long flags;
+ int ret = 0;
+ int i;
+ int changed = 0;
+
+ spin_lock_irqsave(&info->lock, flags);
+ switch (typeReq) {
+ case ClearHubFeature:
+ /* ignore this request */
+ break;
+ case ClearPortFeature:
+ if (!wIndex || wIndex > ports)
+ goto error;
+
+ switch (wValue) {
+ case USB_PORT_FEAT_SUSPEND:
+ xenhcd_rhport_resume(info, wIndex);
+ break;
+ case USB_PORT_FEAT_POWER:
+ xenhcd_rhport_power_off(info, wIndex);
+ break;
+ case USB_PORT_FEAT_ENABLE:
+ xenhcd_rhport_disable(info, wIndex);
+ break;
+ case USB_PORT_FEAT_C_CONNECTION:
+ info->ports[wIndex - 1].c_connection = false;
+ fallthrough;
+ default:
+ info->ports[wIndex - 1].status &= ~(1 << wValue);
+ break;
+ }
+ break;
+ case GetHubDescriptor:
+ xenhcd_hub_descriptor(info, (struct usb_hub_descriptor *)buf);
+ break;
+ case GetHubStatus:
+ /* always local power supply good and no over-current exists. */
+ *(__le32 *)buf = cpu_to_le32(0);
+ break;
+ case GetPortStatus:
+ if (!wIndex || wIndex > ports)
+ goto error;
+
+ wIndex--;
+
+ /* resume completion */
+ if (info->ports[wIndex].resuming &&
+ time_after_eq(jiffies, info->ports[wIndex].timeout)) {
+ info->ports[wIndex].status |=
+ USB_PORT_STAT_C_SUSPEND << 16;
+ info->ports[wIndex].status &= ~USB_PORT_STAT_SUSPEND;
+ }
+
+ /* reset completion */
+ if ((info->ports[wIndex].status & USB_PORT_STAT_RESET) != 0 &&
+ time_after_eq(jiffies, info->ports[wIndex].timeout)) {
+ info->ports[wIndex].status |=
+ USB_PORT_STAT_C_RESET << 16;
+ info->ports[wIndex].status &= ~USB_PORT_STAT_RESET;
+
+ if (info->devices[wIndex].status !=
+ USB_STATE_NOTATTACHED) {
+ info->ports[wIndex].status |=
+ USB_PORT_STAT_ENABLE;
+ info->devices[wIndex].status =
+ USB_STATE_DEFAULT;
+ }
+
+ switch (info->devices[wIndex].speed) {
+ case XENUSB_SPEED_LOW:
+ info->ports[wIndex].status |=
+ USB_PORT_STAT_LOW_SPEED;
+ break;
+ case XENUSB_SPEED_HIGH:
+ info->ports[wIndex].status |=
+ USB_PORT_STAT_HIGH_SPEED;
+ break;
+ default:
+ break;
+ }
+ }
+
+ *(__le32 *)buf = cpu_to_le32(info->ports[wIndex].status);
+ break;
+ case SetPortFeature:
+ if (!wIndex || wIndex > ports)
+ goto error;
+
+ switch (wValue) {
+ case USB_PORT_FEAT_POWER:
+ xenhcd_rhport_power_on(info, wIndex);
+ break;
+ case USB_PORT_FEAT_RESET:
+ xenhcd_rhport_reset(info, wIndex);
+ break;
+ case USB_PORT_FEAT_SUSPEND:
+ xenhcd_rhport_suspend(info, wIndex);
+ break;
+ default:
+ if (info->ports[wIndex-1].status & USB_PORT_STAT_POWER)
+ info->ports[wIndex-1].status |= (1 << wValue);
+ }
+ break;
+
+ case SetHubFeature:
+ /* not supported */
+ default:
+error:
+ ret = -EPIPE;
+ }
+ spin_unlock_irqrestore(&info->lock, flags);
+
+ /* check status for each port */
+ for (i = 0; i < ports; i++) {
+ if (info->ports[i].status & PORT_C_MASK)
+ changed = 1;
+ }
+ if (changed)
+ usb_hcd_poll_rh_status(hcd);
+
+ return ret;
+}
+
+static void xenhcd_free_urb_priv(struct urb_priv *urbp)
+{
+ urbp->urb->hcpriv = NULL;
+ kmem_cache_free(xenhcd_urbp_cachep, urbp);
+}
+
+static inline unsigned int xenhcd_get_id_from_freelist(struct xenhcd_info *info)
+{
+ unsigned int free;
+
+ free = info->shadow_free;
+ info->shadow_free = info->shadow[free].req.id;
+ info->shadow[free].req.id = 0x0fff; /* debug */
+ return free;
+}
+
+static inline void xenhcd_add_id_to_freelist(struct xenhcd_info *info,
+ unsigned int id)
+{
+ info->shadow[id].req.id = info->shadow_free;
+ info->shadow[id].urb = NULL;
+ info->shadow_free = id;
+}
+
+static inline int xenhcd_count_pages(void *addr, int length)
+{
+ unsigned long vaddr = (unsigned long)addr;
+
+ return PFN_UP(vaddr + length) - PFN_DOWN(vaddr);
+}
+
+static void xenhcd_gnttab_map(struct xenhcd_info *info, void *addr, int length,
+ grant_ref_t *gref_head,
+ struct xenusb_request_segment *seg,
+ int nr_pages, int flags)
+{
+ grant_ref_t ref;
+ unsigned long buffer_mfn;
+ unsigned int offset;
+ unsigned int len = length;
+ unsigned int bytes;
+ int i;
+
+ for (i = 0; i < nr_pages; i++) {
+ buffer_mfn = PFN_DOWN(arbitrary_virt_to_machine(addr).maddr);
+ offset = offset_in_page(addr);
+
+ bytes = PAGE_SIZE - offset;
+ if (bytes > len)
+ bytes = len;
+
+ ref = gnttab_claim_grant_reference(gref_head);
+ gnttab_grant_foreign_access_ref(ref, info->xbdev->otherend_id,
+ buffer_mfn, flags);
+ seg[i].gref = ref;
+ seg[i].offset = (__u16)offset;
+ seg[i].length = (__u16)bytes;
+
+ addr += bytes;
+ len -= bytes;
+ }
+}
+
+static __u32 xenhcd_pipe_urb_to_xenusb(__u32 urb_pipe, __u8 port)
+{
+ static __u32 pipe;
+
+ pipe = usb_pipedevice(urb_pipe) << XENUSB_PIPE_DEV_SHIFT;
+ pipe |= usb_pipeendpoint(urb_pipe) << XENUSB_PIPE_EP_SHIFT;
+ if (usb_pipein(urb_pipe))
+ pipe |= XENUSB_PIPE_DIR;
+ switch (usb_pipetype(urb_pipe)) {
+ case PIPE_ISOCHRONOUS:
+ pipe |= XENUSB_PIPE_TYPE_ISOC << XENUSB_PIPE_TYPE_SHIFT;
+ break;
+ case PIPE_INTERRUPT:
+ pipe |= XENUSB_PIPE_TYPE_INT << XENUSB_PIPE_TYPE_SHIFT;
+ break;
+ case PIPE_CONTROL:
+ pipe |= XENUSB_PIPE_TYPE_CTRL << XENUSB_PIPE_TYPE_SHIFT;
+ break;
+ case PIPE_BULK:
+ pipe |= XENUSB_PIPE_TYPE_BULK << XENUSB_PIPE_TYPE_SHIFT;
+ break;
+ }
+ pipe = xenusb_setportnum_pipe(pipe, port);
+
+ return pipe;
+}
+
+static int xenhcd_map_urb_for_request(struct xenhcd_info *info, struct urb *urb,
+ struct xenusb_urb_request *req)
+{
+ grant_ref_t gref_head;
+ int nr_buff_pages = 0;
+ int nr_isodesc_pages = 0;
+ int nr_grants = 0;
+
+ if (urb->transfer_buffer_length) {
+ nr_buff_pages = xenhcd_count_pages(urb->transfer_buffer,
+ urb->transfer_buffer_length);
+
+ if (usb_pipeisoc(urb->pipe))
+ nr_isodesc_pages = xenhcd_count_pages(
+ &urb->iso_frame_desc[0],
+ sizeof(struct usb_iso_packet_descriptor) *
+ urb->number_of_packets);
+
+ nr_grants = nr_buff_pages + nr_isodesc_pages;
+ if (nr_grants > XENUSB_MAX_SEGMENTS_PER_REQUEST) {
+ pr_err("xenhcd: error: %d grants\n", nr_grants);
+ return -E2BIG;
+ }
+
+ if (gnttab_alloc_grant_references(nr_grants, &gref_head)) {
+ pr_err("xenhcd: gnttab_alloc_grant_references() error\n");
+ return -ENOMEM;
+ }
+
+ xenhcd_gnttab_map(info, urb->transfer_buffer,
+ urb->transfer_buffer_length, &gref_head,
+ &req->seg[0], nr_buff_pages,
+ usb_pipein(urb->pipe) ? 0 : GTF_readonly);
+ }
+
+ req->pipe = xenhcd_pipe_urb_to_xenusb(urb->pipe, urb->dev->portnum);
+ req->transfer_flags = 0;
+ if (urb->transfer_flags & URB_SHORT_NOT_OK)
+ req->transfer_flags |= XENUSB_SHORT_NOT_OK;
+ req->buffer_length = urb->transfer_buffer_length;
+ req->nr_buffer_segs = nr_buff_pages;
+
+ switch (usb_pipetype(urb->pipe)) {
+ case PIPE_ISOCHRONOUS:
+ req->u.isoc.interval = urb->interval;
+ req->u.isoc.start_frame = urb->start_frame;
+ req->u.isoc.number_of_packets = urb->number_of_packets;
+ req->u.isoc.nr_frame_desc_segs = nr_isodesc_pages;
+
+ xenhcd_gnttab_map(info, &urb->iso_frame_desc[0],
+ sizeof(struct usb_iso_packet_descriptor) *
+ urb->number_of_packets,
+ &gref_head, &req->seg[nr_buff_pages],
+ nr_isodesc_pages, 0);
+ break;
+ case PIPE_INTERRUPT:
+ req->u.intr.interval = urb->interval;
+ break;
+ case PIPE_CONTROL:
+ if (urb->setup_packet)
+ memcpy(req->u.ctrl, urb->setup_packet, 8);
+ break;
+ case PIPE_BULK:
+ break;
+ default:
+ break;
+ }
+
+ if (nr_grants)
+ gnttab_free_grant_references(gref_head);
+
+ return 0;
+}
+
+static void xenhcd_gnttab_done(struct usb_shadow *shadow)
+{
+ int nr_segs = 0;
+ int i;
+
+ nr_segs = shadow->req.nr_buffer_segs;
+
+ if (xenusb_pipeisoc(shadow->req.pipe))
+ nr_segs += shadow->req.u.isoc.nr_frame_desc_segs;
+
+ for (i = 0; i < nr_segs; i++)
+ gnttab_end_foreign_access(shadow->req.seg[i].gref, 0, 0UL);
+
+ shadow->req.nr_buffer_segs = 0;
+ shadow->req.u.isoc.nr_frame_desc_segs = 0;
+}
+
+static int xenhcd_translate_status(int status)
+{
+ switch (status) {
+ case XENUSB_STATUS_OK:
+ return 0;
+ case XENUSB_STATUS_NODEV:
+ return -ENODEV;
+ case XENUSB_STATUS_INVAL:
+ return -EINVAL;
+ case XENUSB_STATUS_STALL:
+ return -EPIPE;
+ case XENUSB_STATUS_IOERROR:
+ return -EPROTO;
+ case XENUSB_STATUS_BABBLE:
+ return -EOVERFLOW;
+ default:
+ return -ESHUTDOWN;
+ }
+}
+
+static void xenhcd_giveback_urb(struct xenhcd_info *info, struct urb *urb,
+ int status)
+{
+ struct urb_priv *urbp = (struct urb_priv *)urb->hcpriv;
+ int priv_status = urbp->status;
+
+ list_del_init(&urbp->list);
+ xenhcd_free_urb_priv(urbp);
+
+ if (urb->status == -EINPROGRESS)
+ urb->status = xenhcd_translate_status(status);
+
+ spin_unlock(&info->lock);
+ usb_hcd_giveback_urb(xenhcd_info_to_hcd(info), urb,
+ priv_status <= 0 ? priv_status : urb->status);
+ spin_lock(&info->lock);
+}
+
+static int xenhcd_do_request(struct xenhcd_info *info, struct urb_priv *urbp)
+{
+ struct xenusb_urb_request *req;
+ struct urb *urb = urbp->urb;
+ unsigned int id;
+ int notify;
+ int ret;
+
+ id = xenhcd_get_id_from_freelist(info);
+ req = &info->shadow[id].req;
+ req->id = id;
+
+ if (unlikely(urbp->unlinked)) {
+ req->u.unlink.unlink_id = urbp->req_id;
+ req->pipe = xenusb_setunlink_pipe(xenhcd_pipe_urb_to_xenusb(
+ urb->pipe, urb->dev->portnum));
+ urbp->unlink_req_id = id;
+ } else {
+ ret = xenhcd_map_urb_for_request(info, urb, req);
+ if (ret) {
+ xenhcd_add_id_to_freelist(info, id);
+ return ret;
+ }
+ urbp->req_id = id;
+ }
+
+ req = RING_GET_REQUEST(&info->urb_ring, info->urb_ring.req_prod_pvt);
+ *req = info->shadow[id].req;
+
+ info->urb_ring.req_prod_pvt++;
+ info->shadow[id].urb = urb;
+
+ RING_PUSH_REQUESTS_AND_CHECK_NOTIFY(&info->urb_ring, notify);
+ if (notify)
+ notify_remote_via_irq(info->irq);
+
+ return 0;
+}
+
+static void xenhcd_kick_pending_urbs(struct xenhcd_info *info)
+{
+ struct urb_priv *urbp;
+
+ while (!list_empty(&info->pending_submit_list)) {
+ if (RING_FULL(&info->urb_ring)) {
+ xenhcd_timer_action(info, TIMER_RING_WATCHDOG);
+ return;
+ }
+
+ urbp = list_entry(info->pending_submit_list.next,
+ struct urb_priv, list);
+ if (!xenhcd_do_request(info, urbp))
+ list_move_tail(&urbp->list, &info->in_progress_list);
+ else
+ xenhcd_giveback_urb(info, urbp->urb, -ESHUTDOWN);
+ }
+ xenhcd_timer_action_done(info, TIMER_SCAN_PENDING_URBS);
+}
+
+/*
+ * caller must lock info->lock
+ */
+static void xenhcd_cancel_all_enqueued_urbs(struct xenhcd_info *info)
+{
+ struct urb_priv *urbp, *tmp;
+ int req_id;
+
+ list_for_each_entry_safe(urbp, tmp, &info->in_progress_list, list) {
+ req_id = urbp->req_id;
+ if (!urbp->unlinked) {
+ xenhcd_gnttab_done(&info->shadow[req_id]);
+ if (urbp->urb->status == -EINPROGRESS)
+ /* not dequeued */
+ xenhcd_giveback_urb(info, urbp->urb,
+ -ESHUTDOWN);
+ else /* dequeued */
+ xenhcd_giveback_urb(info, urbp->urb,
+ urbp->urb->status);
+ }
+ info->shadow[req_id].urb = NULL;
+ }
+
+ list_for_each_entry_safe(urbp, tmp, &info->pending_submit_list, list)
+ xenhcd_giveback_urb(info, urbp->urb, -ESHUTDOWN);
+}
+
+/*
+ * caller must lock info->lock
+ */
+static void xenhcd_giveback_unlinked_urbs(struct xenhcd_info *info)
+{
+ struct urb_priv *urbp, *tmp;
+
+ list_for_each_entry_safe(urbp, tmp, &info->giveback_waiting_list, list)
+ xenhcd_giveback_urb(info, urbp->urb, urbp->urb->status);
+}
+
+static int xenhcd_submit_urb(struct xenhcd_info *info, struct urb_priv *urbp)
+{
+ int ret;
+
+ if (RING_FULL(&info->urb_ring)) {
+ list_add_tail(&urbp->list, &info->pending_submit_list);
+ xenhcd_timer_action(info, TIMER_RING_WATCHDOG);
+ return 0;
+ }
+
+ if (!list_empty(&info->pending_submit_list)) {
+ list_add_tail(&urbp->list, &info->pending_submit_list);
+ xenhcd_timer_action(info, TIMER_SCAN_PENDING_URBS);
+ return 0;
+ }
+
+ ret = xenhcd_do_request(info, urbp);
+ if (ret == 0)
+ list_add_tail(&urbp->list, &info->in_progress_list);
+
+ return ret;
+}
+
+static int xenhcd_unlink_urb(struct xenhcd_info *info, struct urb_priv *urbp)
+{
+ int ret;
+
+ /* already unlinked? */
+ if (urbp->unlinked)
+ return -EBUSY;
+
+ urbp->unlinked = true;
+
+ /* the urb is still in pending_submit queue */
+ if (urbp->req_id == ~0) {
+ list_move_tail(&urbp->list, &info->giveback_waiting_list);
+ xenhcd_timer_action(info, TIMER_SCAN_PENDING_URBS);
+ return 0;
+ }
+
+ /* send unlink request to backend */
+ if (RING_FULL(&info->urb_ring)) {
+ list_move_tail(&urbp->list, &info->pending_unlink_list);
+ xenhcd_timer_action(info, TIMER_RING_WATCHDOG);
+ return 0;
+ }
+
+ if (!list_empty(&info->pending_unlink_list)) {
+ list_move_tail(&urbp->list, &info->pending_unlink_list);
+ xenhcd_timer_action(info, TIMER_SCAN_PENDING_URBS);
+ return 0;
+ }
+
+ ret = xenhcd_do_request(info, urbp);
+ if (ret == 0)
+ list_move_tail(&urbp->list, &info->in_progress_list);
+
+ return ret;
+}
+
+static int xenhcd_urb_request_done(struct xenhcd_info *info)
+{
+ struct xenusb_urb_response res;
+ struct urb *urb;
+ RING_IDX i, rp;
+ __u16 id;
+ int more_to_do = 0;
+ unsigned long flags;
+
+ spin_lock_irqsave(&info->lock, flags);
+
+ rp = info->urb_ring.sring->rsp_prod;
+ if (RING_RESPONSE_PROD_OVERFLOW(&info->urb_ring, rp)) {
+ xenhcd_set_error(info, "Illegal index on urb-ring");
+ return 0;
+ }
+ rmb(); /* ensure we see queued responses up to "rp" */
+
+ for (i = info->urb_ring.rsp_cons; i != rp; i++) {
+ RING_COPY_RESPONSE(&info->urb_ring, i, &res);
+ id = res.id;
+ if (id >= XENUSB_URB_RING_SIZE) {
+ xenhcd_set_error(info, "Illegal data on urb-ring");
+ continue;
+ }
+
+ if (likely(xenusb_pipesubmit(info->shadow[id].req.pipe))) {
+ xenhcd_gnttab_done(&info->shadow[id]);
+ urb = info->shadow[id].urb;
+ if (likely(urb)) {
+ urb->actual_length = res.actual_length;
+ urb->error_count = res.error_count;
+ urb->start_frame = res.start_frame;
+ xenhcd_giveback_urb(info, urb, res.status);
+ }
+ }
+
+ xenhcd_add_id_to_freelist(info, id);
+ }
+ info->urb_ring.rsp_cons = i;
+
+ if (i != info->urb_ring.req_prod_pvt)
+ RING_FINAL_CHECK_FOR_RESPONSES(&info->urb_ring, more_to_do);
+ else
+ info->urb_ring.sring->rsp_event = i + 1;
+
+ spin_unlock_irqrestore(&info->lock, flags);
+
+ return more_to_do;
+}
+
+static int xenhcd_conn_notify(struct xenhcd_info *info)
+{
+ struct xenusb_conn_response res;
+ struct xenusb_conn_request *req;
+ RING_IDX rc, rp;
+ __u16 id;
+ __u8 portnum, speed;
+ int more_to_do = 0;
+ int notify;
+ int port_changed = 0;
+ unsigned long flags;
+
+ spin_lock_irqsave(&info->lock, flags);
+
+ rc = info->conn_ring.rsp_cons;
+ rp = info->conn_ring.sring->rsp_prod;
+ if (RING_RESPONSE_PROD_OVERFLOW(&info->conn_ring, rp)) {
+ xenhcd_set_error(info, "Illegal index on conn-ring");
+ return 0;
+ }
+ rmb(); /* ensure we see queued responses up to "rp" */
+
+ while (rc != rp) {
+ RING_COPY_RESPONSE(&info->conn_ring, rc, &res);
+ id = res.id;
+ portnum = res.portnum;
+ speed = res.speed;
+ info->conn_ring.rsp_cons = ++rc;
+
+ if (xenhcd_rhport_connect(info, portnum, speed)) {
+ xenhcd_set_error(info, "Illegal data on conn-ring");
+ return 0;
+ }
+
+ if (info->ports[portnum - 1].c_connection)
+ port_changed = 1;
+
+ barrier();
+
+ req = RING_GET_REQUEST(&info->conn_ring,
+ info->conn_ring.req_prod_pvt);
+ req->id = id;
+ info->conn_ring.req_prod_pvt++;
+ }
+
+ if (rc != info->conn_ring.req_prod_pvt)
+ RING_FINAL_CHECK_FOR_RESPONSES(&info->conn_ring, more_to_do);
+ else
+ info->conn_ring.sring->rsp_event = rc + 1;
+
+ RING_PUSH_REQUESTS_AND_CHECK_NOTIFY(&info->conn_ring, notify);
+ if (notify)
+ notify_remote_via_irq(info->irq);
+
+ spin_unlock_irqrestore(&info->lock, flags);
+
+ if (port_changed)
+ usb_hcd_poll_rh_status(xenhcd_info_to_hcd(info));
+
+ return more_to_do;
+}
+
+static irqreturn_t xenhcd_int(int irq, void *dev_id)
+{
+ struct xenhcd_info *info = (struct xenhcd_info *)dev_id;
+
+ if (unlikely(info->error))
+ return IRQ_HANDLED;
+
+ while (xenhcd_urb_request_done(info) | xenhcd_conn_notify(info))
+ /* Yield point for this unbounded loop. */
+ cond_resched();
+
+ return IRQ_HANDLED;
+}
+
+static void xenhcd_destroy_rings(struct xenhcd_info *info)
+{
+ if (info->irq)
+ unbind_from_irqhandler(info->irq, info);
+ info->irq = 0;
+
+ if (info->urb_ring_ref != GRANT_INVALID_REF) {
+ gnttab_end_foreign_access(info->urb_ring_ref, 0,
+ (unsigned long)info->urb_ring.sring);
+ info->urb_ring_ref = GRANT_INVALID_REF;
+ }
+ info->urb_ring.sring = NULL;
+
+ if (info->conn_ring_ref != GRANT_INVALID_REF) {
+ gnttab_end_foreign_access(info->conn_ring_ref, 0,
+ (unsigned long)info->conn_ring.sring);
+ info->conn_ring_ref = GRANT_INVALID_REF;
+ }
+ info->conn_ring.sring = NULL;
+}
+
+static int xenhcd_setup_rings(struct xenbus_device *dev,
+ struct xenhcd_info *info)
+{
+ struct xenusb_urb_sring *urb_sring;
+ struct xenusb_conn_sring *conn_sring;
+ grant_ref_t gref;
+ int err;
+
+ info->urb_ring_ref = GRANT_INVALID_REF;
+ info->conn_ring_ref = GRANT_INVALID_REF;
+
+ urb_sring = (struct xenusb_urb_sring *)get_zeroed_page(
+ GFP_NOIO | __GFP_HIGH);
+ if (!urb_sring) {
+ xenbus_dev_fatal(dev, -ENOMEM, "allocating urb ring");
+ return -ENOMEM;
+ }
+ SHARED_RING_INIT(urb_sring);
+ FRONT_RING_INIT(&info->urb_ring, urb_sring, PAGE_SIZE);
+
+ err = xenbus_grant_ring(dev, urb_sring, 1, &gref);
+ if (err < 0) {
+ free_page((unsigned long)urb_sring);
+ info->urb_ring.sring = NULL;
+ goto fail;
+ }
+ info->urb_ring_ref = gref;
+
+ conn_sring = (struct xenusb_conn_sring *)get_zeroed_page(
+ GFP_NOIO | __GFP_HIGH);
+ if (!conn_sring) {
+ xenbus_dev_fatal(dev, -ENOMEM, "allocating conn ring");
+ err = -ENOMEM;
+ goto fail;
+ }
+ SHARED_RING_INIT(conn_sring);
+ FRONT_RING_INIT(&info->conn_ring, conn_sring, PAGE_SIZE);
+
+ err = xenbus_grant_ring(dev, conn_sring, 1, &gref);
+ if (err < 0) {
+ free_page((unsigned long)conn_sring);
+ info->conn_ring.sring = NULL;
+ goto fail;
+ }
+ info->conn_ring_ref = gref;
+
+ err = xenbus_alloc_evtchn(dev, &info->evtchn);
+ if (err) {
+ xenbus_dev_fatal(dev, err, "xenbus_alloc_evtchn");
+ goto fail;
+ }
+
+ err = bind_evtchn_to_irq(info->evtchn);
+ if (err <= 0) {
+ xenbus_dev_fatal(dev, err, "bind_evtchn_to_irq");
+ goto fail;
+ }
+
+ info->irq = err;
+
+ err = request_threaded_irq(info->irq, NULL, xenhcd_int,
+ IRQF_ONESHOT, "xenhcd", info);
+ if (err) {
+ xenbus_dev_fatal(dev, err, "request_threaded_irq");
+ goto free_irq;
+ }
+
+ return 0;
+
+free_irq:
+ unbind_from_irqhandler(info->irq, info);
+fail:
+ xenhcd_destroy_rings(info);
+ return err;
+}
+
+static int xenhcd_talk_to_backend(struct xenbus_device *dev,
+ struct xenhcd_info *info)
+{
+ const char *message;
+ struct xenbus_transaction xbt;
+ int err;
+
+ err = xenhcd_setup_rings(dev, info);
+ if (err)
+ return err;
+
+again:
+ err = xenbus_transaction_start(&xbt);
+ if (err) {
+ xenbus_dev_fatal(dev, err, "starting transaction");
+ goto destroy_ring;
+ }
+
+ err = xenbus_printf(xbt, dev->nodename, "urb-ring-ref", "%u",
+ info->urb_ring_ref);
+ if (err) {
+ message = "writing urb-ring-ref";
+ goto abort_transaction;
+ }
+
+ err = xenbus_printf(xbt, dev->nodename, "conn-ring-ref", "%u",
+ info->conn_ring_ref);
+ if (err) {
+ message = "writing conn-ring-ref";
+ goto abort_transaction;
+ }
+
+ err = xenbus_printf(xbt, dev->nodename, "event-channel", "%u",
+ info->evtchn);
+ if (err) {
+ message = "writing event-channel";
+ goto abort_transaction;
+ }
+
+ err = xenbus_transaction_end(xbt, 0);
+ if (err) {
+ if (err == -EAGAIN)
+ goto again;
+ xenbus_dev_fatal(dev, err, "completing transaction");
+ goto destroy_ring;
+ }
+
+ return 0;
+
+abort_transaction:
+ xenbus_transaction_end(xbt, 1);
+ xenbus_dev_fatal(dev, err, "%s", message);
+
+destroy_ring:
+ xenhcd_destroy_rings(info);
+
+ return err;
+}
+
+static int xenhcd_connect(struct xenbus_device *dev)
+{
+ struct xenhcd_info *info = dev_get_drvdata(&dev->dev);
+ struct xenusb_conn_request *req;
+ int idx, err;
+ int notify;
+ char name[TASK_COMM_LEN];
+ struct usb_hcd *hcd;
+
+ hcd = xenhcd_info_to_hcd(info);
+ snprintf(name, TASK_COMM_LEN, "xenhcd.%d", hcd->self.busnum);
+
+ err = xenhcd_talk_to_backend(dev, info);
+ if (err)
+ return err;
+
+ /* prepare ring for hotplug notification */
+ for (idx = 0; idx < XENUSB_CONN_RING_SIZE; idx++) {
+ req = RING_GET_REQUEST(&info->conn_ring, idx);
+ req->id = idx;
+ }
+ info->conn_ring.req_prod_pvt = idx;
+
+ RING_PUSH_REQUESTS_AND_CHECK_NOTIFY(&info->conn_ring, notify);
+ if (notify)
+ notify_remote_via_irq(info->irq);
+
+ return 0;
+}
+
+static void xenhcd_disconnect(struct xenbus_device *dev)
+{
+ struct xenhcd_info *info = dev_get_drvdata(&dev->dev);
+ struct usb_hcd *hcd = xenhcd_info_to_hcd(info);
+
+ usb_remove_hcd(hcd);
+ xenbus_frontend_closed(dev);
+}
+
+static void xenhcd_watchdog(struct timer_list *timer)
+{
+ struct xenhcd_info *info = from_timer(info, timer, watchdog);
+ unsigned long flags;
+
+ spin_lock_irqsave(&info->lock, flags);
+ if (likely(HC_IS_RUNNING(xenhcd_info_to_hcd(info)->state))) {
+ xenhcd_timer_action_done(info, TIMER_RING_WATCHDOG);
+ xenhcd_giveback_unlinked_urbs(info);
+ xenhcd_kick_pending_urbs(info);
+ }
+ spin_unlock_irqrestore(&info->lock, flags);
+}
+
+/*
+ * one-time HC init
+ */
+static int xenhcd_setup(struct usb_hcd *hcd)
+{
+ struct xenhcd_info *info = xenhcd_hcd_to_info(hcd);
+
+ spin_lock_init(&info->lock);
+ INIT_LIST_HEAD(&info->pending_submit_list);
+ INIT_LIST_HEAD(&info->pending_unlink_list);
+ INIT_LIST_HEAD(&info->in_progress_list);
+ INIT_LIST_HEAD(&info->giveback_waiting_list);
+ timer_setup(&info->watchdog, xenhcd_watchdog, 0);
+
+ hcd->has_tt = (hcd->driver->flags & HCD_MASK) != HCD_USB11;
+
+ return 0;
+}
+
+/*
+ * start HC running
+ */
+static int xenhcd_run(struct usb_hcd *hcd)
+{
+ hcd->uses_new_polling = 1;
+ clear_bit(HCD_FLAG_POLL_RH, &hcd->flags);
+ hcd->state = HC_STATE_RUNNING;
+ return 0;
+}
+
+/*
+ * stop running HC
+ */
+static void xenhcd_stop(struct usb_hcd *hcd)
+{
+ struct xenhcd_info *info = xenhcd_hcd_to_info(hcd);
+
+ del_timer_sync(&info->watchdog);
+ spin_lock_irq(&info->lock);
+ /* cancel all urbs */
+ hcd->state = HC_STATE_HALT;
+ xenhcd_cancel_all_enqueued_urbs(info);
+ xenhcd_giveback_unlinked_urbs(info);
+ spin_unlock_irq(&info->lock);
+}
+
+/*
+ * called as .urb_enqueue()
+ * non-error returns are promise to giveback the urb later
+ */
+static int xenhcd_urb_enqueue(struct usb_hcd *hcd, struct urb *urb,
+ gfp_t mem_flags)
+{
+ struct xenhcd_info *info = xenhcd_hcd_to_info(hcd);
+ struct urb_priv *urbp;
+ unsigned long flags;
+ int ret;
+
+ if (unlikely(info->error))
+ return -ESHUTDOWN;
+
+ urbp = kmem_cache_zalloc(xenhcd_urbp_cachep, mem_flags);
+ if (!urbp)
+ return -ENOMEM;
+
+ spin_lock_irqsave(&info->lock, flags);
+
+ urbp->urb = urb;
+ urb->hcpriv = urbp;
+ urbp->req_id = ~0;
+ urbp->unlink_req_id = ~0;
+ INIT_LIST_HEAD(&urbp->list);
+ urbp->status = 1;
+ urb->unlinked = false;
+
+ ret = xenhcd_submit_urb(info, urbp);
+
+ if (ret)
+ xenhcd_free_urb_priv(urbp);
+
+ spin_unlock_irqrestore(&info->lock, flags);
+
+ return ret;
+}
+
+/*
+ * called as .urb_dequeue()
+ */
+static int xenhcd_urb_dequeue(struct usb_hcd *hcd, struct urb *urb, int status)
+{
+ struct xenhcd_info *info = xenhcd_hcd_to_info(hcd);
+ struct urb_priv *urbp;
+ unsigned long flags;
+ int ret = 0;
+
+ spin_lock_irqsave(&info->lock, flags);
+
+ urbp = urb->hcpriv;
+ if (urbp) {
+ urbp->status = status;
+ ret = xenhcd_unlink_urb(info, urbp);
+ }
+
+ spin_unlock_irqrestore(&info->lock, flags);
+
+ return ret;
+}
+
+/*
+ * called from usb_get_current_frame_number(),
+ * but, almost all drivers not use such function.
+ */
+static int xenhcd_get_frame(struct usb_hcd *hcd)
+{
+ /* it means error, but probably no problem :-) */
+ return 0;
+}
+
+static struct hc_driver xenhcd_usb20_hc_driver = {
+ .description = "xen-hcd",
+ .product_desc = "Xen USB2.0 Virtual Host Controller",
+ .hcd_priv_size = sizeof(struct xenhcd_info),
+ .flags = HCD_USB2,
+
+ /* basic HC lifecycle operations */
+ .reset = xenhcd_setup,
+ .start = xenhcd_run,
+ .stop = xenhcd_stop,
+
+ /* managing urb I/O */
+ .urb_enqueue = xenhcd_urb_enqueue,
+ .urb_dequeue = xenhcd_urb_dequeue,
+ .get_frame_number = xenhcd_get_frame,
+
+ /* root hub operations */
+ .hub_status_data = xenhcd_hub_status_data,
+ .hub_control = xenhcd_hub_control,
+#ifdef CONFIG_PM
+ .bus_suspend = xenhcd_bus_suspend,
+ .bus_resume = xenhcd_bus_resume,
+#endif
+};
+
+static struct hc_driver xenhcd_usb11_hc_driver = {
+ .description = "xen-hcd",
+ .product_desc = "Xen USB1.1 Virtual Host Controller",
+ .hcd_priv_size = sizeof(struct xenhcd_info),
+ .flags = HCD_USB11,
+
+ /* basic HC lifecycle operations */
+ .reset = xenhcd_setup,
+ .start = xenhcd_run,
+ .stop = xenhcd_stop,
+
+ /* managing urb I/O */
+ .urb_enqueue = xenhcd_urb_enqueue,
+ .urb_dequeue = xenhcd_urb_dequeue,
+ .get_frame_number = xenhcd_get_frame,
+
+ /* root hub operations */
+ .hub_status_data = xenhcd_hub_status_data,
+ .hub_control = xenhcd_hub_control,
+#ifdef CONFIG_PM
+ .bus_suspend = xenhcd_bus_suspend,
+ .bus_resume = xenhcd_bus_resume,
+#endif
+};
+
+static struct usb_hcd *xenhcd_create_hcd(struct xenbus_device *dev)
+{
+ int i;
+ int err = 0;
+ int num_ports;
+ int usb_ver;
+ struct usb_hcd *hcd = NULL;
+ struct xenhcd_info *info;
+
+ err = xenbus_scanf(XBT_NIL, dev->otherend, "num-ports", "%d",
+ &num_ports);
+ if (err != 1) {
+ xenbus_dev_fatal(dev, err, "reading num-ports");
+ return ERR_PTR(-EINVAL);
+ }
+ if (num_ports < 1 || num_ports > XENUSB_MAX_PORTNR) {
+ xenbus_dev_fatal(dev, err, "invalid num-ports");
+ return ERR_PTR(-EINVAL);
+ }
+
+ err = xenbus_scanf(XBT_NIL, dev->otherend, "usb-ver", "%d", &usb_ver);
+ if (err != 1) {
+ xenbus_dev_fatal(dev, err, "reading usb-ver");
+ return ERR_PTR(-EINVAL);
+ }
+ switch (usb_ver) {
+ case XENUSB_VER_USB11:
+ hcd = usb_create_hcd(&xenhcd_usb11_hc_driver, &dev->dev,
+ dev_name(&dev->dev));
+ break;
+ case XENUSB_VER_USB20:
+ hcd = usb_create_hcd(&xenhcd_usb20_hc_driver, &dev->dev,
+ dev_name(&dev->dev));
+ break;
+ default:
+ xenbus_dev_fatal(dev, err, "invalid usb-ver");
+ return ERR_PTR(-EINVAL);
+ }
+ if (!hcd) {
+ xenbus_dev_fatal(dev, err,
+ "fail to allocate USB host controller");
+ return ERR_PTR(-ENOMEM);
+ }
+
+ info = xenhcd_hcd_to_info(hcd);
+ info->xbdev = dev;
+ info->rh_numports = num_ports;
+
+ for (i = 0; i < XENUSB_URB_RING_SIZE; i++) {
+ info->shadow[i].req.id = i + 1;
+ info->shadow[i].urb = NULL;
+ }
+ info->shadow[XENUSB_URB_RING_SIZE - 1].req.id = 0x0fff;
+
+ return hcd;
+}
+
+static void xenhcd_backend_changed(struct xenbus_device *dev,
+ enum xenbus_state backend_state)
+{
+ switch (backend_state) {
+ case XenbusStateInitialising:
+ case XenbusStateReconfiguring:
+ case XenbusStateReconfigured:
+ case XenbusStateUnknown:
+ break;
+
+ case XenbusStateInitWait:
+ case XenbusStateInitialised:
+ case XenbusStateConnected:
+ if (dev->state != XenbusStateInitialising)
+ break;
+ if (!xenhcd_connect(dev))
+ xenbus_switch_state(dev, XenbusStateConnected);
+ break;
+
+ case XenbusStateClosed:
+ if (dev->state == XenbusStateClosed)
+ break;
+ fallthrough; /* Missed the backend's Closing state. */
+ case XenbusStateClosing:
+ xenhcd_disconnect(dev);
+ break;
+
+ default:
+ xenbus_dev_fatal(dev, -EINVAL, "saw state %d at frontend",
+ backend_state);
+ break;
+ }
+}
+
+static int xenhcd_remove(struct xenbus_device *dev)
+{
+ struct xenhcd_info *info = dev_get_drvdata(&dev->dev);
+ struct usb_hcd *hcd = xenhcd_info_to_hcd(info);
+
+ xenhcd_destroy_rings(info);
+ usb_put_hcd(hcd);
+
+ return 0;
+}
+
+static int xenhcd_probe(struct xenbus_device *dev,
+ const struct xenbus_device_id *id)
+{
+ int err;
+ struct usb_hcd *hcd;
+ struct xenhcd_info *info;
+
+ if (usb_disabled())
+ return -ENODEV;
+
+ hcd = xenhcd_create_hcd(dev);
+ if (IS_ERR(hcd)) {
+ err = PTR_ERR(hcd);
+ xenbus_dev_fatal(dev, err,
+ "fail to create usb host controller");
+ return err;
+ }
+
+ info = xenhcd_hcd_to_info(hcd);
+ dev_set_drvdata(&dev->dev, info);
+
+ err = usb_add_hcd(hcd, 0, 0);
+ if (err) {
+ xenbus_dev_fatal(dev, err, "fail to add USB host controller");
+ usb_put_hcd(hcd);
+ dev_set_drvdata(&dev->dev, NULL);
+ }
+
+ return err;
+}
+
+static const struct xenbus_device_id xenhcd_ids[] = {
+ { "vusb" },
+ { "" },
+};
+
+static struct xenbus_driver xenhcd_driver = {
+ .ids = xenhcd_ids,
+ .probe = xenhcd_probe,
+ .otherend_changed = xenhcd_backend_changed,
+ .remove = xenhcd_remove,
+};
+
+static int __init xenhcd_init(void)
+{
+ if (!xen_domain())
+ return -ENODEV;
+
+ xenhcd_urbp_cachep = kmem_cache_create("xenhcd_urb_priv",
+ sizeof(struct urb_priv), 0, 0, NULL);
+ if (!xenhcd_urbp_cachep) {
+ pr_err("xenhcd failed to create kmem cache\n");
+ return -ENOMEM;
+ }
+
+ return xenbus_register_frontend(&xenhcd_driver);
+}
+module_init(xenhcd_init);
+
+static void __exit xenhcd_exit(void)
+{
+ kmem_cache_destroy(xenhcd_urbp_cachep);
+ xenbus_unregister_driver(&xenhcd_driver);
+}
+module_exit(xenhcd_exit);
+
+MODULE_ALIAS("xen:vusb");
+MODULE_AUTHOR("Juergen Gross <jgross@suse.com>");
+MODULE_DESCRIPTION("Xen USB Virtual Host Controller driver (xen-hcd)");
+MODULE_LICENSE("Dual BSD/GPL");
--
2.26.2