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https://github.com/AuxXxilium/linux_dsm_epyc7002.git
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4097461897
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>
167 lines
4.4 KiB
C
167 lines
4.4 KiB
C
/*
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* Copyright (C) 1999-2002 Vojtech Pavlik
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*
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* This program is free software; you can redistribute it and/or modify it
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* under the terms of the GNU General Public License version 2 as published by
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* the Free Software Foundation.
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*/
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#ifndef _SERIO_H
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#define _SERIO_H
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#include <linux/types.h>
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#include <linux/interrupt.h>
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#include <linux/list.h>
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#include <linux/spinlock.h>
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#include <linux/mutex.h>
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#include <linux/device.h>
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#include <linux/mod_devicetable.h>
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#include <uapi/linux/serio.h>
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extern struct bus_type serio_bus;
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struct serio {
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void *port_data;
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char name[32];
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char phys[32];
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char firmware_id[128];
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bool manual_bind;
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struct serio_device_id id;
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/* Protects critical sections from port's interrupt handler */
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spinlock_t lock;
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int (*write)(struct serio *, unsigned char);
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int (*open)(struct serio *);
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void (*close)(struct serio *);
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int (*start)(struct serio *);
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void (*stop)(struct serio *);
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struct serio *parent;
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/* Entry in parent->children list */
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struct list_head child_node;
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struct list_head children;
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/* Level of nesting in serio hierarchy */
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unsigned int depth;
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/*
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* serio->drv is accessed from interrupt handlers; when modifying
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* caller should acquire serio->drv_mutex and serio->lock.
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*/
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struct serio_driver *drv;
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/* Protects serio->drv so attributes can pin current driver */
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struct mutex drv_mutex;
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struct device dev;
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struct list_head node;
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/*
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* For use by PS/2 layer when several ports share hardware and
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* may get indigestion when exposed to concurrent access (i8042).
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*/
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struct mutex *ps2_cmd_mutex;
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};
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#define to_serio_port(d) container_of(d, struct serio, dev)
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struct serio_driver {
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const char *description;
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const struct serio_device_id *id_table;
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bool manual_bind;
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void (*write_wakeup)(struct serio *);
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irqreturn_t (*interrupt)(struct serio *, unsigned char, unsigned int);
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int (*connect)(struct serio *, struct serio_driver *drv);
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int (*reconnect)(struct serio *);
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void (*disconnect)(struct serio *);
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void (*cleanup)(struct serio *);
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struct device_driver driver;
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};
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#define to_serio_driver(d) container_of(d, struct serio_driver, driver)
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int serio_open(struct serio *serio, struct serio_driver *drv);
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void serio_close(struct serio *serio);
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void serio_rescan(struct serio *serio);
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void serio_reconnect(struct serio *serio);
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irqreturn_t serio_interrupt(struct serio *serio, unsigned char data, unsigned int flags);
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void __serio_register_port(struct serio *serio, struct module *owner);
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/* use a define to avoid include chaining to get THIS_MODULE */
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#define serio_register_port(serio) \
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__serio_register_port(serio, THIS_MODULE)
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void serio_unregister_port(struct serio *serio);
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void serio_unregister_child_port(struct serio *serio);
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int __must_check __serio_register_driver(struct serio_driver *drv,
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struct module *owner, const char *mod_name);
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/* use a define to avoid include chaining to get THIS_MODULE & friends */
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#define serio_register_driver(drv) \
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__serio_register_driver(drv, THIS_MODULE, KBUILD_MODNAME)
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void serio_unregister_driver(struct serio_driver *drv);
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/**
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* module_serio_driver() - Helper macro for registering a serio driver
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* @__serio_driver: serio_driver struct
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*
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* Helper macro for serio drivers which do not do anything special in
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* module init/exit. This eliminates a lot of boilerplate. Each module
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* may only use this macro once, and calling it replaces module_init()
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* and module_exit().
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*/
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#define module_serio_driver(__serio_driver) \
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module_driver(__serio_driver, serio_register_driver, \
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serio_unregister_driver)
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static inline int serio_write(struct serio *serio, unsigned char data)
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{
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if (serio->write)
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return serio->write(serio, data);
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else
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return -1;
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}
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static inline void serio_drv_write_wakeup(struct serio *serio)
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{
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if (serio->drv && serio->drv->write_wakeup)
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serio->drv->write_wakeup(serio);
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}
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/*
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* Use the following functions to manipulate serio's per-port
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* driver-specific data.
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*/
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static inline void *serio_get_drvdata(struct serio *serio)
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{
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return dev_get_drvdata(&serio->dev);
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}
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static inline void serio_set_drvdata(struct serio *serio, void *data)
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{
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dev_set_drvdata(&serio->dev, data);
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}
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/*
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* Use the following functions to protect critical sections in
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* driver code from port's interrupt handler
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*/
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static inline void serio_pause_rx(struct serio *serio)
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{
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spin_lock_irq(&serio->lock);
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}
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static inline void serio_continue_rx(struct serio *serio)
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{
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spin_unlock_irq(&serio->lock);
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}
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#endif
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