[Date Prev][Date Next][Thread Prev][Thread Next][Date Index][Thread Index] Re: [Xen-devel] [Patch V3 2/3] usb: Introduce Xen pvUSB frontend (xen hcd)
On 06/16/2015 04:45 PM, Greg KH wrote: On Tue, Jun 16, 2015 at 04:32:34PM +0200, Juergen Gross wrote: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@xxxxxxxx> --- drivers/usb/host/Kconfig | 11 + drivers/usb/host/Makefile | 1 + drivers/usb/host/xen-hcd.c | 1638 ++++++++++++++++++++++++++++++++++++++++++++ 3 files changed, 1650 insertions(+) create mode 100644 drivers/usb/host/xen-hcd.c diff --git a/drivers/usb/host/Kconfig b/drivers/usb/host/Kconfig index 197a6a3..3361b4b 100644 --- a/drivers/usb/host/Kconfig +++ b/drivers/usb/host/Kconfig @@ -788,3 +788,14 @@ 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 65b0b6a..3779696 100644 --- a/drivers/usb/host/Makefile +++ b/drivers/usb/host/Makefile @@ -75,3 +75,4 @@ obj-$(CONFIG_USB_HCD_SSB) += ssb-hcd.o obj-$(CONFIG_USB_FUSBH200_HCD) += fusbh200-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 0000000..9da2856 --- /dev/null +++ b/drivers/usb/host/xen-hcd.c @@ -0,0 +1,1638 @@ +/* + * xen-hcd.c + * + * Xen USB Virtual Host Controller driver + * + * Copyright (C) 2009, FUJITSU LABORATORIES LTD. + * Author: Noboru Iwamatsu <n_iwamatsu@xxxxxxxxxxxxxx> + * + * This program is free software; you can redistribute it and/or modify + * it under the terms of the GNU General Public License as published by + * the Free Software Foundation; either version 2 of the License, or + * (at your option) any later version. + * + * This program is distributed in the hope that it will be useful, + * but WITHOUT ANY WARRANTY; without even the implied warranty of + * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the + * GNU General Public License for more details. + * + * You should have received a copy of the GNU General Public License + * along with this program; if not, see <http://www.gnu.org/licenses/>. + * + * Or, by your choice: + * + * When distributed separately from the Linux kernel or incorporated into + * other software packages, subject to the following license: + * + * Permission is hereby granted, free of charge, to any person obtaining a copy + * of this software and associated documentation files (the "Software"), to + * deal in the Software without restriction, including without limitation the + * rights to use, copy, modify, merge, publish, distribute, sublicense, and/or + * sell copies of the Software, and to permit persons to whom the Software is + * furnished to do so, subject to the following conditions: + * + * The above copyright notice and this permission notice shall be included in + * all copies or substantial portions of the Software. + * + * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR + * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY, + * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE + * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER + * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING + * FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER + * DEALINGS IN THE SOFTWARE. + */ + +#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; + unsigned unlinked:1; /* dequeued marker */ +}; + +/* virtual roothub port status */ +struct rhport_status { + __u32 status; + unsigned resuming:1; /* in resuming */ + unsigned c_connection:1; /* 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 shadow_free; +}; + +#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 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); + } +} + +static ssize_t xenhcd_show_statistics(struct device *dev, + struct device_attribute *attr, char *buf) +{ + struct usb_hcd *hcd; + struct xenhcd_info *info; + unsigned long flags; + unsigned size; + + hcd = dev_get_drvdata(dev); + info = xenhcd_hcd_to_info(hcd); + + spin_lock_irqsave(&info->lock, flags); + + size = scnprintf(buf, PAGE_SIZE, "bus %s, device %s\n%s\n" + "xenhcd, hcd state %d\n", + hcd->self.controller->bus->name, + dev_name(hcd->self.controller), hcd->product_desc, + hcd->state); + + spin_unlock_irqrestore(&info->lock, flags); + + return size; +} + +static DEVICE_ATTR(statistics, S_IRUGO, xenhcd_show_statistics, NULL);DEVICE_ATTR_RO() please. Okay. As you are adding new sysfs files, we need Documentation/ABI/ entries. Okay. Also note that I will reject this sysfs file for the obvious reasons that it violates the one-value-per-file sysfs rule. Nice try to sneak this one by, don't ever do that again. Lesson learned. Hmm, I'm beginning to question the value of that file. May be I should just throw it away. Thanks for the quick feedback. Juergen _______________________________________________ Xen-devel mailing list Xen-devel@xxxxxxxxxxxxx http://lists.xen.org/xen-devel
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