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linux-next/include/linux/usb/serial.h
David Howells 7d12e780e0 IRQ: Maintain regs pointer globally rather than passing to IRQ handlers 
Maintain a per-CPU global "struct pt_regs *" variable which can be used instead
of passing regs around manually through all ~1800 interrupt handlers in the
Linux kernel.

The regs pointer is used in few places, but it potentially costs both stack
space and code to pass it around.  On the FRV arch, removing the regs parameter
from all the genirq function results in a 20% speed up of the IRQ exit path
(ie: from leaving timer_interrupt() to leaving do_IRQ()).

Where appropriate, an arch may override the generic storage facility and do
something different with the variable.  On FRV, for instance, the address is
maintained in GR28 at all times inside the kernel as part of general exception
handling.

Having looked over the code, it appears that the parameter may be handed down
through up to twenty or so layers of functions.  Consider a USB character
device attached to a USB hub, attached to a USB controller that posts its
interrupts through a cascaded auxiliary interrupt controller.  A character
device driver may want to pass regs to the sysrq handler through the input
layer which adds another few layers of parameter passing.

I've build this code with allyesconfig for x86_64 and i386.  I've runtested the
main part of the code on FRV and i386, though I can't test most of the drivers.
I've also done partial conversion for powerpc and MIPS - these at least compile
with minimal configurations.

This will affect all archs.  Mostly the changes should be relatively easy.
Take do_IRQ(), store the regs pointer at the beginning, saving the old one:

	struct pt_regs *old_regs = set_irq_regs(regs);

And put the old one back at the end:

	set_irq_regs(old_regs);

Don't pass regs through to generic_handle_irq() or __do_IRQ().

In timer_interrupt(), this sort of change will be necessary:

	-	update_process_times(user_mode(regs));
	-	profile_tick(CPU_PROFILING, regs);
	+	update_process_times(user_mode(get_irq_regs()));
	+	profile_tick(CPU_PROFILING);

I'd like to move update_process_times()'s use of get_irq_regs() into itself,
except that i386, alone of the archs, uses something other than user_mode().

Some notes on the interrupt handling in the drivers:

 (*) input_dev() is now gone entirely.  The regs pointer is no longer stored in
     the input_dev struct.

 (*) finish_unlinks() in drivers/usb/host/ohci-q.c needs checking.  It does
     something different depending on whether it's been supplied with a regs
     pointer or not.

 (*) Various IRQ handler function pointers have been moved to type
     irq_handler_t.

Signed-Off-By: David Howells <dhowells@redhat.com>
(cherry picked from 1b16e7ac850969f38b375e511e3fa2f474a33867 commit)
2006-10-05 15:10:12 +01:00

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/*
* USB Serial Converter stuff
*
* Copyright (C) 1999 - 2005
* Greg Kroah-Hartman (greg@kroah.com)
*
* 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; version 2 of the License.
*
*/
#ifndef __LINUX_USB_SERIAL_H
#define __LINUX_USB_SERIAL_H
#include <linux/kref.h>
#include <linux/mutex.h>
#define SERIAL_TTY_MAJOR 188 /* Nice legal number now */
#define SERIAL_TTY_MINORS 255 /* loads of devices :) */
#define MAX_NUM_PORTS 8 /* The maximum number of ports one device can grab at once */
/* parity check flag */
#define RELEVANT_IFLAG(iflag) (iflag & (IGNBRK|BRKINT|IGNPAR|PARMRK|INPCK))
/**
* usb_serial_port: structure for the specific ports of a device.
* @serial: pointer back to the struct usb_serial owner of this port.
* @tty: pointer to the corresponding tty for this port.
* @lock: spinlock to grab when updating portions of this structure.
* @mutex: mutex used to synchronize serial_open() and serial_close()
* access for this port.
* @number: the number of the port (the minor number).
* @interrupt_in_buffer: pointer to the interrupt in buffer for this port.
* @interrupt_in_urb: pointer to the interrupt in struct urb for this port.
* @interrupt_in_endpointAddress: endpoint address for the interrupt in pipe
* for this port.
* @interrupt_out_buffer: pointer to the interrupt out buffer for this port.
* @interrupt_out_size: the size of the interrupt_out_buffer, in bytes.
* @interrupt_out_urb: pointer to the interrupt out struct urb for this port.
* @interrupt_out_endpointAddress: endpoint address for the interrupt out pipe
* for this port.
* @bulk_in_buffer: pointer to the bulk in buffer for this port.
* @read_urb: pointer to the bulk in struct urb for this port.
* @bulk_in_endpointAddress: endpoint address for the bulk in pipe for this
* port.
* @bulk_out_buffer: pointer to the bulk out buffer for this port.
* @bulk_out_size: the size of the bulk_out_buffer, in bytes.
* @write_urb: pointer to the bulk out struct urb for this port.
* @bulk_out_endpointAddress: endpoint address for the bulk out pipe for this
* port.
* @write_wait: a wait_queue_head_t used by the port.
* @work: work queue entry for the line discipline waking up.
* @open_count: number of times this port has been opened.
*
* This structure is used by the usb-serial core and drivers for the specific
* ports of a device.
*/
struct usb_serial_port {
struct usb_serial * serial;
struct tty_struct * tty;
spinlock_t lock;
struct mutex mutex;
unsigned char number;
unsigned char * interrupt_in_buffer;
struct urb * interrupt_in_urb;
__u8 interrupt_in_endpointAddress;
unsigned char * interrupt_out_buffer;
int interrupt_out_size;
struct urb * interrupt_out_urb;
__u8 interrupt_out_endpointAddress;
unsigned char * bulk_in_buffer;
int bulk_in_size;
struct urb * read_urb;
__u8 bulk_in_endpointAddress;
unsigned char * bulk_out_buffer;
int bulk_out_size;
struct urb * write_urb;
int write_urb_busy;
__u8 bulk_out_endpointAddress;
wait_queue_head_t write_wait;
struct work_struct work;
int open_count;
struct device dev;
};
#define to_usb_serial_port(d) container_of(d, struct usb_serial_port, dev)
/* get and set the port private data pointer helper functions */
static inline void *usb_get_serial_port_data (struct usb_serial_port *port)
{
return dev_get_drvdata(&port->dev);
}
static inline void usb_set_serial_port_data (struct usb_serial_port *port, void *data)
{
dev_set_drvdata(&port->dev, data);
}
/**
* usb_serial - structure used by the usb-serial core for a device
* @dev: pointer to the struct usb_device for this device
* @type: pointer to the struct usb_serial_driver for this device
* @interface: pointer to the struct usb_interface for this device
* @minor: the starting minor number for this device
* @num_ports: the number of ports this device has
* @num_interrupt_in: number of interrupt in endpoints we have
* @num_interrupt_out: number of interrupt out endpoints we have
* @num_bulk_in: number of bulk in endpoints we have
* @num_bulk_out: number of bulk out endpoints we have
* @port: array of struct usb_serial_port structures for the different ports.
* @private: place to put any driver specific information that is needed. The
* usb-serial driver is required to manage this data, the usb-serial core
* will not touch this. Use usb_get_serial_data() and
* usb_set_serial_data() to access this.
*/
struct usb_serial {
struct usb_device * dev;
struct usb_serial_driver * type;
struct usb_interface * interface;
unsigned char minor;
unsigned char num_ports;
unsigned char num_port_pointers;
char num_interrupt_in;
char num_interrupt_out;
char num_bulk_in;
char num_bulk_out;
struct usb_serial_port * port[MAX_NUM_PORTS];
struct kref kref;
void * private;
};
#define to_usb_serial(d) container_of(d, struct usb_serial, kref)
#define NUM_DONT_CARE (-1)
/* get and set the serial private data pointer helper functions */
static inline void *usb_get_serial_data (struct usb_serial *serial)
{
return serial->private;
}
static inline void usb_set_serial_data (struct usb_serial *serial, void *data)
{
serial->private = data;
}
/**
* usb_serial_driver - describes a usb serial driver
* @description: pointer to a string that describes this driver. This string used
* in the syslog messages when a device is inserted or removed.
* @id_table: pointer to a list of usb_device_id structures that define all
* of the devices this structure can support.
* @num_interrupt_in: the number of interrupt in endpoints this device will
* have.
* @num_interrupt_out: the number of interrupt out endpoints this device will
* have.
* @num_bulk_in: the number of bulk in endpoints this device will have.
* @num_bulk_out: the number of bulk out endpoints this device will have.
* @num_ports: the number of different ports this device will have.
* @calc_num_ports: pointer to a function to determine how many ports this
* device has dynamically. It will be called after the probe()
* callback is called, but before attach()
* @probe: pointer to the driver's probe function.
* This will be called when the device is inserted into the system,
* but before the device has been fully initialized by the usb_serial
* subsystem. Use this function to download any firmware to the device,
* or any other early initialization that might be needed.
* Return 0 to continue on with the initialization sequence. Anything
* else will abort it.
* @attach: pointer to the driver's attach function.
* This will be called when the struct usb_serial structure is fully set
* set up. Do any local initialization of the device, or any private
* memory structure allocation at this point in time.
* @shutdown: pointer to the driver's shutdown function. This will be
* called when the device is removed from the system.
*
* This structure is defines a USB Serial driver. It provides all of
* the information that the USB serial core code needs. If the function
* pointers are defined, then the USB serial core code will call them when
* the corresponding tty port functions are called. If they are not
* called, the generic serial function will be used instead.
*
* The driver.owner field should be set to the module owner of this driver.
* The driver.name field should be set to the name of this driver (remember
* it will show up in sysfs, so it needs to be short and to the point.
* Useing the module name is a good idea.)
*/
struct usb_serial_driver {
const char *description;
const struct usb_device_id *id_table;
char num_interrupt_in;
char num_interrupt_out;
char num_bulk_in;
char num_bulk_out;
char num_ports;
struct list_head driver_list;
struct device_driver driver;
int (*probe) (struct usb_serial *serial, const struct usb_device_id *id);
int (*attach) (struct usb_serial *serial);
int (*calc_num_ports) (struct usb_serial *serial);
void (*shutdown) (struct usb_serial *serial);
int (*port_probe) (struct usb_serial_port *port);
int (*port_remove) (struct usb_serial_port *port);
/* serial function calls */
int (*open) (struct usb_serial_port *port, struct file * filp);
void (*close) (struct usb_serial_port *port, struct file * filp);
int (*write) (struct usb_serial_port *port, const unsigned char *buf, int count);
int (*write_room) (struct usb_serial_port *port);
int (*ioctl) (struct usb_serial_port *port, struct file * file, unsigned int cmd, unsigned long arg);
void (*set_termios) (struct usb_serial_port *port, struct termios * old);
void (*break_ctl) (struct usb_serial_port *port, int break_state);
int (*chars_in_buffer) (struct usb_serial_port *port);
void (*throttle) (struct usb_serial_port *port);
void (*unthrottle) (struct usb_serial_port *port);
int (*tiocmget) (struct usb_serial_port *port, struct file *file);
int (*tiocmset) (struct usb_serial_port *port, struct file *file, unsigned int set, unsigned int clear);
void (*read_int_callback)(struct urb *urb);
void (*write_int_callback)(struct urb *urb);
void (*read_bulk_callback)(struct urb *urb);
void (*write_bulk_callback)(struct urb *urb);
};
#define to_usb_serial_driver(d) container_of(d, struct usb_serial_driver, driver)
extern int usb_serial_register(struct usb_serial_driver *driver);
extern void usb_serial_deregister(struct usb_serial_driver *driver);
extern void usb_serial_port_softint(struct usb_serial_port *port);
extern int usb_serial_probe(struct usb_interface *iface, const struct usb_device_id *id);
extern void usb_serial_disconnect(struct usb_interface *iface);
extern int ezusb_writememory (struct usb_serial *serial, int address, unsigned char *data, int length, __u8 bRequest);
extern int ezusb_set_reset (struct usb_serial *serial, unsigned char reset_bit);
/* USB Serial console functions */
#ifdef CONFIG_USB_SERIAL_CONSOLE
extern void usb_serial_console_init (int debug, int minor);
extern void usb_serial_console_exit (void);
extern void usb_serial_console_disconnect(struct usb_serial *serial);
#else
static inline void usb_serial_console_init (int debug, int minor) { }
static inline void usb_serial_console_exit (void) { }
static inline void usb_serial_console_disconnect(struct usb_serial *serial) {}
#endif
/* Functions needed by other parts of the usbserial core */
extern struct usb_serial *usb_serial_get_by_index (unsigned int minor);
extern void usb_serial_put(struct usb_serial *serial);
extern int usb_serial_generic_open (struct usb_serial_port *port, struct file *filp);
extern int usb_serial_generic_write (struct usb_serial_port *port, const unsigned char *buf, int count);
extern void usb_serial_generic_close (struct usb_serial_port *port, struct file *filp);
extern int usb_serial_generic_write_room (struct usb_serial_port *port);
extern int usb_serial_generic_chars_in_buffer (struct usb_serial_port *port);
extern void usb_serial_generic_read_bulk_callback (struct urb *urb);
extern void usb_serial_generic_write_bulk_callback (struct urb *urb);
extern void usb_serial_generic_shutdown (struct usb_serial *serial);
extern int usb_serial_generic_register (int debug);
extern void usb_serial_generic_deregister (void);
extern int usb_serial_bus_register (struct usb_serial_driver *device);
extern void usb_serial_bus_deregister (struct usb_serial_driver *device);
extern struct usb_serial_driver usb_serial_generic_device;
extern struct bus_type usb_serial_bus_type;
extern struct tty_driver *usb_serial_tty_driver;
static inline void usb_serial_debug_data(int debug,
struct device *dev,
const char *function, int size,
const unsigned char *data)
{
int i;
if (debug) {
dev_printk(KERN_DEBUG, dev, "%s - length = %d, data = ", function, size);
for (i = 0; i < size; ++i)
printk ("%.2x ", data[i]);
printk ("\n");
}
}
/* Use our own dbg macro */
#undef dbg
#define dbg(format, arg...) do { if (debug) printk(KERN_DEBUG "%s: " format "\n" , __FILE__ , ## arg); } while (0)
#endif /* ifdef __LINUX_USB_SERIAL_H */
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