linux/drivers/usb/usbip/usbip_common.h
Nobuo Iwata bb7871ad99 usbip: event handler as one thread
Dear all,

1. Overview

In current USB/IP implementation, event kernel threads are created for
each port. The functions of the threads are closing connection and
error handling so they don't have not so many events to handle. There's
no need to have thread for each port.

BEFORE) vhci side - VHCI_NPORTS(8) threads are created.
$ ps aux | grep usbip
root     10059  0.0  0.0      0     0 ?        S    17:06   0:00 [usbip_eh]
root     10060  0.0  0.0      0     0 ?        S    17:06   0:00 [usbip_eh]
root     10061  0.0  0.0      0     0 ?        S    17:06   0:00 [usbip_eh]
root     10062  0.0  0.0      0     0 ?        S    17:06   0:00 [usbip_eh]
root     10063  0.0  0.0      0     0 ?        S    17:06   0:00 [usbip_eh]
root     10064  0.0  0.0      0     0 ?        S    17:06   0:00 [usbip_eh]
root     10065  0.0  0.0      0     0 ?        S    17:06   0:00 [usbip_eh]
root     10066  0.0  0.0      0     0 ?        S    17:06   0:00 [usbip_eh]

BEFORE) stub side - threads will be created every bind operation.
$ ps aux | grep usbip
root      8368  0.0  0.0      0     0 ?        S    17:56   0:00 [usbip_eh]
root      8399  0.0  0.0      0     0 ?        S    17:56   0:00 [usbip_eh]

This patch put event threads of stub and vhci driver as one workqueue.

AFTER) only one event threads in each vhci and stub side.
$ ps aux | grep usbip
root     10457  0.0  0.0      0     0 ?        S<   17:47   0:00 [usbip_event]

2. Modification to usbip_event.c

BEFORE) kernel threads are created in usbip_start_eh().

AFTER) one workqueue is created in new usbip_init_eh().

Event handler which was main loop of kernel thread is modified to
workqueue handler.

Events themselves are stored in struct usbip_device - same as before.
usbip_devices which have event are listed in event_list.

The handler picks an element from the list and wakeup usbip_device. The
wakeup method is same as before.

usbip_in_eh() substitutes statement which checks whether functions are
called from eh_ops or not. In this function, the worker context is used
for the checking. The context will be set in a variable in the
beginning of first event handling. usbip_in_eh() is used in event
handler so it works well.

3. Modifications to programs using usbip_event.c

Initialization and termination of workqueue are added to init and exit
routine of usbip_core respectively.

A. version info

v2)
# Merged 1/2 event handler itself and 2/2 user programs because of auto
build fail at 1/2 casued unmodified user programs in 1/2.

Signed-off-by: Nobuo Iwata <nobuo.iwata@fujixerox.co.jp>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2016-04-19 04:33:15 +09:00

338 lines
10 KiB
C

/*
* Copyright (C) 2003-2008 Takahiro Hirofuchi
*
* This 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 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, write to the Free Software
* Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307,
* USA.
*/
#ifndef __USBIP_COMMON_H
#define __USBIP_COMMON_H
#include <linux/compiler.h>
#include <linux/device.h>
#include <linux/interrupt.h>
#include <linux/net.h>
#include <linux/printk.h>
#include <linux/spinlock.h>
#include <linux/types.h>
#include <linux/usb.h>
#include <linux/wait.h>
#include <uapi/linux/usbip.h>
#define USBIP_VERSION "1.0.0"
#undef pr_fmt
#ifdef DEBUG
#define pr_fmt(fmt) KBUILD_MODNAME ": %s:%d: " fmt, __func__, __LINE__
#else
#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
#endif
enum {
usbip_debug_xmit = (1 << 0),
usbip_debug_sysfs = (1 << 1),
usbip_debug_urb = (1 << 2),
usbip_debug_eh = (1 << 3),
usbip_debug_stub_cmp = (1 << 8),
usbip_debug_stub_dev = (1 << 9),
usbip_debug_stub_rx = (1 << 10),
usbip_debug_stub_tx = (1 << 11),
usbip_debug_vhci_rh = (1 << 8),
usbip_debug_vhci_hc = (1 << 9),
usbip_debug_vhci_rx = (1 << 10),
usbip_debug_vhci_tx = (1 << 11),
usbip_debug_vhci_sysfs = (1 << 12)
};
#define usbip_dbg_flag_xmit (usbip_debug_flag & usbip_debug_xmit)
#define usbip_dbg_flag_vhci_rh (usbip_debug_flag & usbip_debug_vhci_rh)
#define usbip_dbg_flag_vhci_hc (usbip_debug_flag & usbip_debug_vhci_hc)
#define usbip_dbg_flag_vhci_rx (usbip_debug_flag & usbip_debug_vhci_rx)
#define usbip_dbg_flag_vhci_tx (usbip_debug_flag & usbip_debug_vhci_tx)
#define usbip_dbg_flag_stub_rx (usbip_debug_flag & usbip_debug_stub_rx)
#define usbip_dbg_flag_stub_tx (usbip_debug_flag & usbip_debug_stub_tx)
#define usbip_dbg_flag_vhci_sysfs (usbip_debug_flag & usbip_debug_vhci_sysfs)
extern unsigned long usbip_debug_flag;
extern struct device_attribute dev_attr_usbip_debug;
#define usbip_dbg_with_flag(flag, fmt, args...) \
do { \
if (flag & usbip_debug_flag) \
pr_debug(fmt, ##args); \
} while (0)
#define usbip_dbg_sysfs(fmt, args...) \
usbip_dbg_with_flag(usbip_debug_sysfs, fmt , ##args)
#define usbip_dbg_xmit(fmt, args...) \
usbip_dbg_with_flag(usbip_debug_xmit, fmt , ##args)
#define usbip_dbg_urb(fmt, args...) \
usbip_dbg_with_flag(usbip_debug_urb, fmt , ##args)
#define usbip_dbg_eh(fmt, args...) \
usbip_dbg_with_flag(usbip_debug_eh, fmt , ##args)
#define usbip_dbg_vhci_rh(fmt, args...) \
usbip_dbg_with_flag(usbip_debug_vhci_rh, fmt , ##args)
#define usbip_dbg_vhci_hc(fmt, args...) \
usbip_dbg_with_flag(usbip_debug_vhci_hc, fmt , ##args)
#define usbip_dbg_vhci_rx(fmt, args...) \
usbip_dbg_with_flag(usbip_debug_vhci_rx, fmt , ##args)
#define usbip_dbg_vhci_tx(fmt, args...) \
usbip_dbg_with_flag(usbip_debug_vhci_tx, fmt , ##args)
#define usbip_dbg_vhci_sysfs(fmt, args...) \
usbip_dbg_with_flag(usbip_debug_vhci_sysfs, fmt , ##args)
#define usbip_dbg_stub_cmp(fmt, args...) \
usbip_dbg_with_flag(usbip_debug_stub_cmp, fmt , ##args)
#define usbip_dbg_stub_rx(fmt, args...) \
usbip_dbg_with_flag(usbip_debug_stub_rx, fmt , ##args)
#define usbip_dbg_stub_tx(fmt, args...) \
usbip_dbg_with_flag(usbip_debug_stub_tx, fmt , ##args)
/*
* USB/IP request headers
*
* Each request is transferred across the network to its counterpart, which
* facilitates the normal USB communication. The values contained in the headers
* are basically the same as in a URB. Currently, four request types are
* defined:
*
* - USBIP_CMD_SUBMIT: a USB request block, corresponds to usb_submit_urb()
* (client to server)
*
* - USBIP_RET_SUBMIT: the result of USBIP_CMD_SUBMIT
* (server to client)
*
* - USBIP_CMD_UNLINK: an unlink request of a pending USBIP_CMD_SUBMIT,
* corresponds to usb_unlink_urb()
* (client to server)
*
* - USBIP_RET_UNLINK: the result of USBIP_CMD_UNLINK
* (server to client)
*
*/
#define USBIP_CMD_SUBMIT 0x0001
#define USBIP_CMD_UNLINK 0x0002
#define USBIP_RET_SUBMIT 0x0003
#define USBIP_RET_UNLINK 0x0004
#define USBIP_DIR_OUT 0x00
#define USBIP_DIR_IN 0x01
/**
* struct usbip_header_basic - data pertinent to every request
* @command: the usbip request type
* @seqnum: sequential number that identifies requests; incremented per
* connection
* @devid: specifies a remote USB device uniquely instead of busnum and devnum;
* in the stub driver, this value is ((busnum << 16) | devnum)
* @direction: direction of the transfer
* @ep: endpoint number
*/
struct usbip_header_basic {
__u32 command;
__u32 seqnum;
__u32 devid;
__u32 direction;
__u32 ep;
} __packed;
/**
* struct usbip_header_cmd_submit - USBIP_CMD_SUBMIT packet header
* @transfer_flags: URB flags
* @transfer_buffer_length: the data size for (in) or (out) transfer
* @start_frame: initial frame for isochronous or interrupt transfers
* @number_of_packets: number of isochronous packets
* @interval: maximum time for the request on the server-side host controller
* @setup: setup data for a control request
*/
struct usbip_header_cmd_submit {
__u32 transfer_flags;
__s32 transfer_buffer_length;
/* it is difficult for usbip to sync frames (reserved only?) */
__s32 start_frame;
__s32 number_of_packets;
__s32 interval;
unsigned char setup[8];
} __packed;
/**
* struct usbip_header_ret_submit - USBIP_RET_SUBMIT packet header
* @status: return status of a non-iso request
* @actual_length: number of bytes transferred
* @start_frame: initial frame for isochronous or interrupt transfers
* @number_of_packets: number of isochronous packets
* @error_count: number of errors for isochronous transfers
*/
struct usbip_header_ret_submit {
__s32 status;
__s32 actual_length;
__s32 start_frame;
__s32 number_of_packets;
__s32 error_count;
} __packed;
/**
* struct usbip_header_cmd_unlink - USBIP_CMD_UNLINK packet header
* @seqnum: the URB seqnum to unlink
*/
struct usbip_header_cmd_unlink {
__u32 seqnum;
} __packed;
/**
* struct usbip_header_ret_unlink - USBIP_RET_UNLINK packet header
* @status: return status of the request
*/
struct usbip_header_ret_unlink {
__s32 status;
} __packed;
/**
* struct usbip_header - common header for all usbip packets
* @base: the basic header
* @u: packet type dependent header
*/
struct usbip_header {
struct usbip_header_basic base;
union {
struct usbip_header_cmd_submit cmd_submit;
struct usbip_header_ret_submit ret_submit;
struct usbip_header_cmd_unlink cmd_unlink;
struct usbip_header_ret_unlink ret_unlink;
} u;
} __packed;
/*
* This is the same as usb_iso_packet_descriptor but packed for pdu.
*/
struct usbip_iso_packet_descriptor {
__u32 offset;
__u32 length; /* expected length */
__u32 actual_length;
__u32 status;
} __packed;
enum usbip_side {
USBIP_VHCI,
USBIP_STUB,
};
/* event handler */
#define USBIP_EH_SHUTDOWN (1 << 0)
#define USBIP_EH_BYE (1 << 1)
#define USBIP_EH_RESET (1 << 2)
#define USBIP_EH_UNUSABLE (1 << 3)
#define SDEV_EVENT_REMOVED (USBIP_EH_SHUTDOWN | USBIP_EH_RESET | USBIP_EH_BYE)
#define SDEV_EVENT_DOWN (USBIP_EH_SHUTDOWN | USBIP_EH_RESET)
#define SDEV_EVENT_ERROR_TCP (USBIP_EH_SHUTDOWN | USBIP_EH_RESET)
#define SDEV_EVENT_ERROR_SUBMIT (USBIP_EH_SHUTDOWN | USBIP_EH_RESET)
#define SDEV_EVENT_ERROR_MALLOC (USBIP_EH_SHUTDOWN | USBIP_EH_UNUSABLE)
#define VDEV_EVENT_REMOVED (USBIP_EH_SHUTDOWN | USBIP_EH_BYE)
#define VDEV_EVENT_DOWN (USBIP_EH_SHUTDOWN | USBIP_EH_RESET)
#define VDEV_EVENT_ERROR_TCP (USBIP_EH_SHUTDOWN | USBIP_EH_RESET)
#define VDEV_EVENT_ERROR_MALLOC (USBIP_EH_SHUTDOWN | USBIP_EH_UNUSABLE)
/* a common structure for stub_device and vhci_device */
struct usbip_device {
enum usbip_side side;
enum usbip_device_status status;
/* lock for status */
spinlock_t lock;
struct socket *tcp_socket;
struct task_struct *tcp_rx;
struct task_struct *tcp_tx;
unsigned long event;
wait_queue_head_t eh_waitq;
struct eh_ops {
void (*shutdown)(struct usbip_device *);
void (*reset)(struct usbip_device *);
void (*unusable)(struct usbip_device *);
} eh_ops;
};
#define kthread_get_run(threadfn, data, namefmt, ...) \
({ \
struct task_struct *__k \
= kthread_create(threadfn, data, namefmt, ## __VA_ARGS__); \
if (!IS_ERR(__k)) { \
get_task_struct(__k); \
wake_up_process(__k); \
} \
__k; \
})
#define kthread_stop_put(k) \
do { \
kthread_stop(k); \
put_task_struct(k); \
} while (0)
/* usbip_common.c */
void usbip_dump_urb(struct urb *purb);
void usbip_dump_header(struct usbip_header *pdu);
int usbip_recv(struct socket *sock, void *buf, int size);
void usbip_pack_pdu(struct usbip_header *pdu, struct urb *urb, int cmd,
int pack);
void usbip_header_correct_endian(struct usbip_header *pdu, int send);
struct usbip_iso_packet_descriptor*
usbip_alloc_iso_desc_pdu(struct urb *urb, ssize_t *bufflen);
/* some members of urb must be substituted before. */
int usbip_recv_iso(struct usbip_device *ud, struct urb *urb);
void usbip_pad_iso(struct usbip_device *ud, struct urb *urb);
int usbip_recv_xbuff(struct usbip_device *ud, struct urb *urb);
/* usbip_event.c */
int usbip_init_eh(void);
void usbip_finish_eh(void);
int usbip_start_eh(struct usbip_device *ud);
void usbip_stop_eh(struct usbip_device *ud);
void usbip_event_add(struct usbip_device *ud, unsigned long event);
int usbip_event_happened(struct usbip_device *ud);
int usbip_in_eh(struct task_struct *task);
static inline int interface_to_busnum(struct usb_interface *interface)
{
struct usb_device *udev = interface_to_usbdev(interface);
return udev->bus->busnum;
}
static inline int interface_to_devnum(struct usb_interface *interface)
{
struct usb_device *udev = interface_to_usbdev(interface);
return udev->devnum;
}
#endif /* __USBIP_COMMON_H */