mirror of
https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git
synced 2024-08-25 18:30:06 +00:00
![Dmitry Torokhov](/assets/img/avatar_default.png)
As explained in 1407814240-4275-1-git-send-email-decui@microsoft.com we have a hard load dependency between i8042 and atkbd which prevents keyboard from working on Gen2 Hyper-V VMs. > hyperv_keyboard invokes serio_interrupt(), which needs a valid serio > driver like atkbd.c. atkbd.c depends on libps2.c because it invokes > ps2_command(). libps2.c depends on i8042.c because it invokes > i8042_check_port_owner(). As a result, hyperv_keyboard actually > depends on i8042.c. > > For a Generation 2 Hyper-V VM (meaning no i8042 device emulated), if a > Linux VM (like Arch Linux) happens to configure CONFIG_SERIO_I8042=m > rather than =y, atkbd.ko can't load because i8042.ko can't load(due to > no i8042 device emulated) and finally hyperv_keyboard can't work and > the user can't input: https://bugs.archlinux.org/task/39820 > (Ubuntu/RHEL/SUSE aren't affected since they use CONFIG_SERIO_I8042=y) To break the dependency we move away from using i8042_check_port_owner() and instead allow serio port owner specify a mutex that clients should use to serialize PS/2 command stream. Reported-by: Mark Laws <mdl@60hz.org> Tested-by: Mark Laws <mdl@60hz.org> Cc: stable@vger.kernel.org Signed-off-by: Dmitry Torokhov <dmitry.torokhov@gmail.com>
166 lines
4.4 KiB
C
166 lines
4.4 KiB
C
/*
|
|
* 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>
|
|
|
|
extern struct bus_type serio_bus;
|
|
|
|
struct serio {
|
|
void *port_data;
|
|
|
|
char name[32];
|
|
char phys[32];
|
|
char firmware_id[128];
|
|
|
|
bool manual_bind;
|
|
|
|
struct serio_device_id id;
|
|
|
|
/* Protects critical sections from port's interrupt handler */
|
|
spinlock_t lock;
|
|
|
|
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;
|
|
/* Entry in parent->children list */
|
|
struct list_head child_node;
|
|
struct list_head children;
|
|
/* Level of nesting in serio hierarchy */
|
|
unsigned int depth;
|
|
|
|
/*
|
|
* serio->drv is accessed from interrupt handlers; when modifying
|
|
* caller should acquire serio->drv_mutex and serio->lock.
|
|
*/
|
|
struct serio_driver *drv;
|
|
/* Protects serio->drv so attributes can pin current driver */
|
|
struct mutex drv_mutex;
|
|
|
|
struct device dev;
|
|
|
|
struct list_head node;
|
|
|
|
/*
|
|
* For use by PS/2 layer when several ports share hardware and
|
|
* may get indigestion when exposed to concurrent access (i8042).
|
|
*/
|
|
struct mutex *ps2_cmd_mutex;
|
|
};
|
|
#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 *);
|
|
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);
|
|
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
|