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linux-next/include/linux/serio.h

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/*
* Copyright (C) 1999-2002 Vojtech Pavlik
*
* This program is free software; you can redistribute it and/or modify it
* under the terms of the GNU General Public License version 2 as published by
* the Free Software Foundation.
*/
#ifndef _SERIO_H
#define _SERIO_H
#include <linux/types.h>
#include <linux/interrupt.h>
#include <linux/list.h>
#include <linux/spinlock.h>
#include <linux/mutex.h>
#include <linux/device.h>
#include <linux/mod_devicetable.h>
#include <uapi/linux/serio.h>
struct serio {
void *port_data;
char name[32];
char phys[32];
bool manual_bind;
struct serio_device_id id;
spinlock_t lock; /* protects critical sections from port's interrupt handler */
int (*write)(struct serio *, unsigned char);
int (*open)(struct serio *);
void (*close)(struct serio *);
int (*start)(struct serio *);
void (*stop)(struct serio *);
struct serio *parent;
struct list_head child_node; /* Entry in parent->children list */
struct list_head children;
unsigned int depth; /* level of nesting in serio hierarchy */
struct serio_driver *drv; /* accessed from interrupt, must be protected by serio->lock and serio->sem */
struct mutex drv_mutex; /* protects serio->drv so attributes can pin driver */
struct device dev;
struct list_head node;
};
#define to_serio_port(d) container_of(d, struct serio, dev)
struct serio_driver {
const char *description;
const struct serio_device_id *id_table;
bool manual_bind;
void (*write_wakeup)(struct serio *);
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 21:55:46 +08:00
irqreturn_t (*interrupt)(struct serio *, unsigned char, unsigned int);
int (*connect)(struct serio *, struct serio_driver *drv);
int (*reconnect)(struct serio *);
void (*disconnect)(struct serio *);
void (*cleanup)(struct serio *);
struct device_driver driver;
};
#define to_serio_driver(d) container_of(d, struct serio_driver, driver)
int serio_open(struct serio *serio, struct serio_driver *drv);
void serio_close(struct serio *serio);
void serio_rescan(struct serio *serio);
void serio_reconnect(struct serio *serio);
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 21:55:46 +08:00
irqreturn_t serio_interrupt(struct serio *serio, unsigned char data, unsigned int flags);
void __serio_register_port(struct serio *serio, struct module *owner);
/* use a define to avoid include chaining to get THIS_MODULE */
#define serio_register_port(serio) \
__serio_register_port(serio, THIS_MODULE)
void serio_unregister_port(struct serio *serio);
void serio_unregister_child_port(struct serio *serio);
int __must_check __serio_register_driver(struct serio_driver *drv,
struct module *owner, const char *mod_name);
/* use a define to avoid include chaining to get THIS_MODULE & friends */
#define serio_register_driver(drv) \
__serio_register_driver(drv, THIS_MODULE, KBUILD_MODNAME)
void serio_unregister_driver(struct serio_driver *drv);
/**
* module_serio_driver() - Helper macro for registering a serio driver
* @__serio_driver: serio_driver struct
*
* Helper macro for serio drivers which do not do anything special in
* module init/exit. This eliminates a lot of boilerplate. Each module
* may only use this macro once, and calling it replaces module_init()
* and module_exit().
*/
#define module_serio_driver(__serio_driver) \
module_driver(__serio_driver, serio_register_driver, \
serio_unregister_driver)
static inline int serio_write(struct serio *serio, unsigned char data)
{
if (serio->write)
return serio->write(serio, data);
else
return -1;
}
static inline void serio_drv_write_wakeup(struct serio *serio)
{
if (serio->drv && serio->drv->write_wakeup)
serio->drv->write_wakeup(serio);
}
/*
* Use the following functions to manipulate serio's per-port
* driver-specific data.
*/
static inline void *serio_get_drvdata(struct serio *serio)
{
return dev_get_drvdata(&serio->dev);
}
static inline void serio_set_drvdata(struct serio *serio, void *data)
{
dev_set_drvdata(&serio->dev, data);
}
/*
* Use the following functions to protect critical sections in
* driver code from port's interrupt handler
*/
static inline void serio_pause_rx(struct serio *serio)
{
spin_lock_irq(&serio->lock);
}
static inline void serio_continue_rx(struct serio *serio)
{
spin_unlock_irq(&serio->lock);
}
#endif