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	Version: linux-6.0.1 spark-3.0.0 hadoop-3.2.0-src hadoop-3.3.0-src spark-2.4.7 linux-4.15.13 hadoop-2.7.4-src Revert   Change

 // SPDX-License-Identifier: GPL-2.0-only
 /*
  * Generic gameport layer
  *
  * Copyright (c) 1999-2002 Vojtech Pavlik
  * Copyright (c) 2005 Dmitry Torokhov
  */
 
 
 #define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
 
 #include <linux/stddef.h>
 #include <linux/module.h>
 #include <linux/ioport.h>
 #include <linux/init.h>
 #include <linux/gameport.h>
 #include <linux/slab.h>
 #include <linux/delay.h>
 #include <linux/workqueue.h>
 #include <linux/sched.h>    /* HZ */
 #include <linux/mutex.h>
 #include <linux/timekeeping.h>
 
 /*#include <asm/io.h>*/
 
 MODULE_AUTHOR("Vojtech Pavlik <vojtech@ucw.cz>");
 MODULE_DESCRIPTION("Generic gameport layer");
 MODULE_LICENSE("GPL");
 
 static bool use_ktime = true;
 module_param(use_ktime, bool, 0400);
 MODULE_PARM_DESC(use_ktime, "Use ktime for measuring I/O speed");
 
 /*
  * gameport_mutex protects entire gameport subsystem and is taken
  * every time gameport port or driver registrered or unregistered.
  */
 static DEFINE_MUTEX(gameport_mutex);
 
 static LIST_HEAD(gameport_list);
 
 static struct bus_type gameport_bus;
 
 static void gameport_add_port(struct gameport *gameport);
 static void gameport_attach_driver(struct gameport_driver *drv);
 static void gameport_reconnect_port(struct gameport *gameport);
 static void gameport_disconnect_port(struct gameport *gameport);
 
 #if defined(__i386__)
 
 #include <linux/i8253.h>
 
 #define DELTA(x,y)      ((y)-(x)+((y)<(x)?1193182/HZ:0))
 #define GET_TIME(x)     do { x = get_time_pit(); } while (0)
 
 static unsigned int get_time_pit(void)
 {
     unsigned long flags;
     unsigned int count;
 
     raw_spin_lock_irqsave(&i8253_lock, flags);
     outb_p(0x00, 0x43);
     count = inb_p(0x40);
     count |= inb_p(0x40) << 8;
     raw_spin_unlock_irqrestore(&i8253_lock, flags);
 
     return count;
 }
 
 #endif
 
 
 
 /*
  * gameport_measure_speed() measures the gameport i/o speed.
  */
 
 static int gameport_measure_speed(struct gameport *gameport)
 {
     unsigned int i, t, tx;
     u64 t1, t2, t3;
     unsigned long flags;
 
     if (gameport_open(gameport, NULL, GAMEPORT_MODE_RAW))
         return 0;
 
     tx = ~0;
 
     for (i = 0; i < 50; i++) {
         local_irq_save(flags);
         t1 = ktime_get_ns();
         for (t = 0; t < 50; t++)
             gameport_read(gameport);
         t2 = ktime_get_ns();
         t3 = ktime_get_ns();
         local_irq_restore(flags);
         udelay(i * 10);
         t = (t2 - t1) - (t3 - t2);
         if (t < tx)
             tx = t;
     }
 
     gameport_close(gameport);
     t = 1000000 * 50;
     if (tx)
         t /= tx;
     return t;
 }
 
 static int old_gameport_measure_speed(struct gameport *gameport)
 {
 #if defined(__i386__)
 
     unsigned int i, t, t1, t2, t3, tx;
     unsigned long flags;
 
     if (gameport_open(gameport, NULL, GAMEPORT_MODE_RAW))
         return 0;
 
     tx = 1 << 30;
 
     for(i = 0; i < 50; i++) {
         local_irq_save(flags);
         GET_TIME(t1);
         for (t = 0; t < 50; t++) gameport_read(gameport);
         GET_TIME(t2);
         GET_TIME(t3);
         local_irq_restore(flags);
         udelay(i * 10);
         if ((t = DELTA(t2,t1) - DELTA(t3,t2)) < tx) tx = t;
     }
 
     gameport_close(gameport);
     return 59659 / (tx < 1 ? 1 : tx);
 
 #elif defined (__x86_64__)
 
     unsigned int i, t;
     unsigned long tx, t1, t2, flags;
 
     if (gameport_open(gameport, NULL, GAMEPORT_MODE_RAW))
         return 0;
 
     tx = 1 << 30;
 
     for(i = 0; i < 50; i++) {
         local_irq_save(flags);
         t1 = rdtsc();
         for (t = 0; t < 50; t++) gameport_read(gameport);
         t2 = rdtsc();
         local_irq_restore(flags);
         udelay(i * 10);
         if (t2 - t1 < tx) tx = t2 - t1;
     }
 
     gameport_close(gameport);
     return (this_cpu_read(cpu_info.loops_per_jiffy) *
         (unsigned long)HZ / (1000 / 50)) / (tx < 1 ? 1 : tx);
 
 #else
 
     unsigned int j, t = 0;
 
     if (gameport_open(gameport, NULL, GAMEPORT_MODE_RAW))
         return 0;
 
     j = jiffies; while (j == jiffies);
     j = jiffies; while (j == jiffies) { t++; gameport_read(gameport); }
 
     gameport_close(gameport);
     return t * HZ / 1000;
 
 #endif
 }
 
 void gameport_start_polling(struct gameport *gameport)
 {
     spin_lock(&gameport->timer_lock);
 
     if (!gameport->poll_cnt++) {
         BUG_ON(!gameport->poll_handler);
         BUG_ON(!gameport->poll_interval);
         mod_timer(&gameport->poll_timer, jiffies + msecs_to_jiffies(gameport->poll_interval));
     }
 
     spin_unlock(&gameport->timer_lock);
 }
 EXPORT_SYMBOL(gameport_start_polling);
 
 void gameport_stop_polling(struct gameport *gameport)
 {
     spin_lock(&gameport->timer_lock);
 
     if (!--gameport->poll_cnt)
         del_timer(&gameport->poll_timer);
 
     spin_unlock(&gameport->timer_lock);
 }
 EXPORT_SYMBOL(gameport_stop_polling);
 
 static void gameport_run_poll_handler(struct timer_list *t)
 {
     struct gameport *gameport = from_timer(gameport, t, poll_timer);
 
     gameport->poll_handler(gameport);
     if (gameport->poll_cnt)
         mod_timer(&gameport->poll_timer, jiffies + msecs_to_jiffies(gameport->poll_interval));
 }
 
 /*
  * Basic gameport -> driver core mappings
  */
 
 static int gameport_bind_driver(struct gameport *gameport, struct gameport_driver *drv)
 {
     int error;
 
     gameport->dev.driver = &drv->driver;
     if (drv->connect(gameport, drv)) {
         gameport->dev.driver = NULL;
         return -ENODEV;
     }
 
     error = device_bind_driver(&gameport->dev);
     if (error) {
         dev_warn(&gameport->dev,
              "device_bind_driver() failed for %s (%s) and %s, error: %d\n",
             gameport->phys, gameport->name,
             drv->description, error);
         drv->disconnect(gameport);
         gameport->dev.driver = NULL;
         return error;
     }
 
     return 0;
 }
 
 static void gameport_find_driver(struct gameport *gameport)
 {
     int error;
 
     error = device_attach(&gameport->dev);
     if (error < 0)
         dev_warn(&gameport->dev,
              "device_attach() failed for %s (%s), error: %d\n",
              gameport->phys, gameport->name, error);
 }
 
 
 /*
  * Gameport event processing.
  */
 
 enum gameport_event_type {
     GAMEPORT_REGISTER_PORT,
     GAMEPORT_ATTACH_DRIVER,
 };
 
 struct gameport_event {
     enum gameport_event_type type;
     void *object;
     struct module *owner;
     struct list_head node;
 };
 
 static DEFINE_SPINLOCK(gameport_event_lock);    /* protects gameport_event_list */
 static LIST_HEAD(gameport_event_list);
 
 static struct gameport_event *gameport_get_event(void)
 {
     struct gameport_event *event = NULL;
     unsigned long flags;
 
     spin_lock_irqsave(&gameport_event_lock, flags);
 
     if (!list_empty(&gameport_event_list)) {
         event = list_first_entry(&gameport_event_list,
                      struct gameport_event, node);
         list_del_init(&event->node);
     }
 
     spin_unlock_irqrestore(&gameport_event_lock, flags);
     return event;
 }
 
 static void gameport_free_event(struct gameport_event *event)
 {
     module_put(event->owner);
     kfree(event);
 }
 
 static void gameport_remove_duplicate_events(struct gameport_event *event)
 {
     struct gameport_event *e, *next;
     unsigned long flags;
 
     spin_lock_irqsave(&gameport_event_lock, flags);
 
     list_for_each_entry_safe(e, next, &gameport_event_list, node) {
         if (event->object == e->object) {
             /*
              * If this event is of different type we should not
              * look further - we only suppress duplicate events
              * that were sent back-to-back.
              */
             if (event->type != e->type)
                 break;
 
             list_del_init(&e->node);
             gameport_free_event(e);
         }
     }
 
     spin_unlock_irqrestore(&gameport_event_lock, flags);
 }
 
 
 static void gameport_handle_events(struct work_struct *work)
 {
     struct gameport_event *event;
 
     mutex_lock(&gameport_mutex);
 
     /*
      * Note that we handle only one event here to give swsusp
      * a chance to freeze kgameportd thread. Gameport events
      * should be pretty rare so we are not concerned about
      * taking performance hit.
      */
     if ((event = gameport_get_event())) {
 
         switch (event->type) {
 
         case GAMEPORT_REGISTER_PORT:
             gameport_add_port(event->object);
             break;
 
         case GAMEPORT_ATTACH_DRIVER:
             gameport_attach_driver(event->object);
             break;
         }
 
         gameport_remove_duplicate_events(event);
         gameport_free_event(event);
     }
 
     mutex_unlock(&gameport_mutex);
 }
 
 static DECLARE_WORK(gameport_event_work, gameport_handle_events);
 
 static int gameport_queue_event(void *object, struct module *owner,
                 enum gameport_event_type event_type)
 {
     unsigned long flags;
     struct gameport_event *event;
     int retval = 0;
 
     spin_lock_irqsave(&gameport_event_lock, flags);
 
     /*
      * Scan event list for the other events for the same gameport port,
      * starting with the most recent one. If event is the same we
      * do not need add new one. If event is of different type we
      * need to add this event and should not look further because
      * we need to preserve sequence of distinct events.
      */
     list_for_each_entry_reverse(event, &gameport_event_list, node) {
         if (event->object == object) {
             if (event->type == event_type)
                 goto out;
             break;
         }
     }
 
     event = kmalloc(sizeof(struct gameport_event), GFP_ATOMIC);
     if (!event) {
         pr_err("Not enough memory to queue event %d\n", event_type);
         retval = -ENOMEM;
         goto out;
     }
 
     if (!try_module_get(owner)) {
         pr_warn("Can't get module reference, dropping event %d\n",
             event_type);
         kfree(event);
         retval = -EINVAL;
         goto out;
     }
 
     event->type = event_type;
     event->object = object;
     event->owner = owner;
 
     list_add_tail(&event->node, &gameport_event_list);
     queue_work(system_long_wq, &gameport_event_work);
 
 out:
     spin_unlock_irqrestore(&gameport_event_lock, flags);
     return retval;
 }
 
 /*
  * Remove all events that have been submitted for a given object,
  * be it a gameport port or a driver.
  */
 static void gameport_remove_pending_events(void *object)
 {
     struct gameport_event *event, *next;
     unsigned long flags;
 
     spin_lock_irqsave(&gameport_event_lock, flags);
 
     list_for_each_entry_safe(event, next, &gameport_event_list, node) {
         if (event->object == object) {
             list_del_init(&event->node);
             gameport_free_event(event);
         }
     }
 
     spin_unlock_irqrestore(&gameport_event_lock, flags);
 }
 
 /*
  * Destroy child gameport port (if any) that has not been fully registered yet.
  *
  * Note that we rely on the fact that port can have only one child and therefore
  * only one child registration request can be pending. Additionally, children
  * are registered by driver's connect() handler so there can't be a grandchild
  * pending registration together with a child.
  */
 static struct gameport *gameport_get_pending_child(struct gameport *parent)
 {
     struct gameport_event *event;
     struct gameport *gameport, *child = NULL;
     unsigned long flags;
 
     spin_lock_irqsave(&gameport_event_lock, flags);
 
     list_for_each_entry(event, &gameport_event_list, node) {
         if (event->type == GAMEPORT_REGISTER_PORT) {
             gameport = event->object;
             if (gameport->parent == parent) {
                 child = gameport;
                 break;
             }
         }
     }
 
     spin_unlock_irqrestore(&gameport_event_lock, flags);
     return child;
 }
 
 /*
  * Gameport port operations
  */
 
 static ssize_t gameport_description_show(struct device *dev, struct device_attribute *attr, char *buf)
 {
     struct gameport *gameport = to_gameport_port(dev);
 
     return sprintf(buf, "%s\n", gameport->name);
 }
 static DEVICE_ATTR(description, S_IRUGO, gameport_description_show, NULL);
 
 static ssize_t drvctl_store(struct device *dev, struct device_attribute *attr, const char *buf, size_t count)
 {
     struct gameport *gameport = to_gameport_port(dev);
     struct device_driver *drv;
     int error;
 
     error = mutex_lock_interruptible(&gameport_mutex);
     if (error)
         return error;
 
     if (!strncmp(buf, "none", count)) {
         gameport_disconnect_port(gameport);
     } else if (!strncmp(buf, "reconnect", count)) {
         gameport_reconnect_port(gameport);
     } else if (!strncmp(buf, "rescan", count)) {
         gameport_disconnect_port(gameport);
         gameport_find_driver(gameport);
     } else if ((drv = driver_find(buf, &gameport_bus)) != NULL) {
         gameport_disconnect_port(gameport);
         error = gameport_bind_driver(gameport, to_gameport_driver(drv));
     } else {
         error = -EINVAL;
     }
 
     mutex_unlock(&gameport_mutex);
 
     return error ? error : count;
 }
 static DEVICE_ATTR_WO(drvctl);
 
 static struct attribute *gameport_device_attrs[] = {
     &dev_attr_description.attr,
     &dev_attr_drvctl.attr,
     NULL,
 };
 ATTRIBUTE_GROUPS(gameport_device);
 
 static void gameport_release_port(struct device *dev)
 {
     struct gameport *gameport = to_gameport_port(dev);
 
     kfree(gameport);
     module_put(THIS_MODULE);
 }
 
 void gameport_set_phys(struct gameport *gameport, const char *fmt, ...)
 {
     va_list args;
 
     va_start(args, fmt);
     vsnprintf(gameport->phys, sizeof(gameport->phys), fmt, args);
     va_end(args);
 }
 EXPORT_SYMBOL(gameport_set_phys);
 
 /*
  * Prepare gameport port for registration.
  */
 static void gameport_init_port(struct gameport *gameport)
 {
     static atomic_t gameport_no = ATOMIC_INIT(-1);
 
     __module_get(THIS_MODULE);
 
     mutex_init(&gameport->drv_mutex);
     device_initialize(&gameport->dev);
     dev_set_name(&gameport->dev, "gameport%lu",
             (unsigned long)atomic_inc_return(&gameport_no));
     gameport->dev.bus = &gameport_bus;
     gameport->dev.release = gameport_release_port;
     if (gameport->parent)
         gameport->dev.parent = &gameport->parent->dev;
 
     INIT_LIST_HEAD(&gameport->node);
     spin_lock_init(&gameport->timer_lock);
     timer_setup(&gameport->poll_timer, gameport_run_poll_handler, 0);
 }
 
 /*
  * Complete gameport port registration.
  * Driver core will attempt to find appropriate driver for the port.
  */
 static void gameport_add_port(struct gameport *gameport)
 {
     int error;
 
     if (gameport->parent)
         gameport->parent->child = gameport;
 
     gameport->speed = use_ktime ?
         gameport_measure_speed(gameport) :
         old_gameport_measure_speed(gameport);
 
     list_add_tail(&gameport->node, &gameport_list);
 
     if (gameport->io)
         dev_info(&gameport->dev, "%s is %s, io %#x, speed %dkHz\n",
              gameport->name, gameport->phys, gameport->io, gameport->speed);
     else
         dev_info(&gameport->dev, "%s is %s, speed %dkHz\n",
             gameport->name, gameport->phys, gameport->speed);
 
     error = device_add(&gameport->dev);
     if (error)
         dev_err(&gameport->dev,
             "device_add() failed for %s (%s), error: %d\n",
             gameport->phys, gameport->name, error);
 }
 
 /*
  * gameport_destroy_port() completes deregistration process and removes
  * port from the system
  */
 static void gameport_destroy_port(struct gameport *gameport)
 {
     struct gameport *child;
 
     child = gameport_get_pending_child(gameport);
     if (child) {
         gameport_remove_pending_events(child);
         put_device(&child->dev);
     }
 
     if (gameport->parent) {
         gameport->parent->child = NULL;
         gameport->parent = NULL;
     }
 
     if (device_is_registered(&gameport->dev))
         device_del(&gameport->dev);
 
     list_del_init(&gameport->node);
 
     gameport_remove_pending_events(gameport);
     put_device(&gameport->dev);
 }
 
 /*
  * Reconnect gameport port and all its children (re-initialize attached devices)
  */
 static void gameport_reconnect_port(struct gameport *gameport)
 {
     do {
         if (!gameport->drv || !gameport->drv->reconnect || gameport->drv->reconnect(gameport)) {
             gameport_disconnect_port(gameport);
             gameport_find_driver(gameport);
             /* Ok, old children are now gone, we are done */
             break;
         }
         gameport = gameport->child;
     } while (gameport);
 }
 
 /*
  * gameport_disconnect_port() unbinds a port from its driver. As a side effect
  * all child ports are unbound and destroyed.
  */
 static void gameport_disconnect_port(struct gameport *gameport)
 {
     struct gameport *s, *parent;
 
     if (gameport->child) {
         /*
          * Children ports should be disconnected and destroyed
          * first, staring with the leaf one, since we don't want
          * to do recursion
          */
         for (s = gameport; s->child; s = s->child)
             /* empty */;
 
         do {
             parent = s->parent;
 
             device_release_driver(&s->dev);
             gameport_destroy_port(s);
         } while ((s = parent) != gameport);
     }
 
     /*
      * Ok, no children left, now disconnect this port
      */
     device_release_driver(&gameport->dev);
 }
 
 /*
  * Submits register request to kgameportd for subsequent execution.
  * Note that port registration is always asynchronous.
  */
 void __gameport_register_port(struct gameport *gameport, struct module *owner)
 {
     gameport_init_port(gameport);
     gameport_queue_event(gameport, owner, GAMEPORT_REGISTER_PORT);
 }
 EXPORT_SYMBOL(__gameport_register_port);
 
 /*
  * Synchronously unregisters gameport port.
  */
 void gameport_unregister_port(struct gameport *gameport)
 {
     mutex_lock(&gameport_mutex);
     gameport_disconnect_port(gameport);
     gameport_destroy_port(gameport);
     mutex_unlock(&gameport_mutex);
 }
 EXPORT_SYMBOL(gameport_unregister_port);
 
 
 /*
  * Gameport driver operations
  */
 
 static ssize_t description_show(struct device_driver *drv, char *buf)
 {
     struct gameport_driver *driver = to_gameport_driver(drv);
     return sprintf(buf, "%s\n", driver->description ? driver->description : "(none)");
 }
 static DRIVER_ATTR_RO(description);
 
 static struct attribute *gameport_driver_attrs[] = {
     &driver_attr_description.attr,
     NULL
 };
 ATTRIBUTE_GROUPS(gameport_driver);
 
 static int gameport_driver_probe(struct device *dev)
 {
     struct gameport *gameport = to_gameport_port(dev);
     struct gameport_driver *drv = to_gameport_driver(dev->driver);
 
     drv->connect(gameport, drv);
     return gameport->drv ? 0 : -ENODEV;
 }
 
 static void gameport_driver_remove(struct device *dev)
 {
     struct gameport *gameport = to_gameport_port(dev);
     struct gameport_driver *drv = to_gameport_driver(dev->driver);
 
     drv->disconnect(gameport);
 }
 
 static void gameport_attach_driver(struct gameport_driver *drv)
 {
     int error;
 
     error = driver_attach(&drv->driver);
     if (error)
         pr_err("driver_attach() failed for %s, error: %d\n",
             drv->driver.name, error);
 }
 
 int __gameport_register_driver(struct gameport_driver *drv, struct module *owner,
                 const char *mod_name)
 {
     int error;
 
     drv->driver.bus = &gameport_bus;
     drv->driver.owner = owner;
     drv->driver.mod_name = mod_name;
 
     /*
      * Temporarily disable automatic binding because probing
      * takes long time and we are better off doing it in kgameportd
      */
     drv->ignore = true;
 
     error = driver_register(&drv->driver);
     if (error) {
         pr_err("driver_register() failed for %s, error: %d\n",
             drv->driver.name, error);
         return error;
     }
 
     /*
      * Reset ignore flag and let kgameportd bind the driver to free ports
      */
     drv->ignore = false;
     error = gameport_queue_event(drv, NULL, GAMEPORT_ATTACH_DRIVER);
     if (error) {
         driver_unregister(&drv->driver);
         return error;
     }
 
     return 0;
 }
 EXPORT_SYMBOL(__gameport_register_driver);
 
 void gameport_unregister_driver(struct gameport_driver *drv)
 {
     struct gameport *gameport;
 
     mutex_lock(&gameport_mutex);
 
     drv->ignore = true; /* so gameport_find_driver ignores it */
     gameport_remove_pending_events(drv);
 
 start_over:
     list_for_each_entry(gameport, &gameport_list, node) {
         if (gameport->drv == drv) {
             gameport_disconnect_port(gameport);
             gameport_find_driver(gameport);
             /* we could've deleted some ports, restart */
             goto start_over;
         }
     }
 
     driver_unregister(&drv->driver);
 
     mutex_unlock(&gameport_mutex);
 }
 EXPORT_SYMBOL(gameport_unregister_driver);
 
 static int gameport_bus_match(struct device *dev, struct device_driver *drv)
 {
     struct gameport_driver *gameport_drv = to_gameport_driver(drv);
 
     return !gameport_drv->ignore;
 }
 
 static struct bus_type gameport_bus = {
     .name       = "gameport",
     .dev_groups = gameport_device_groups,
     .drv_groups = gameport_driver_groups,
     .match      = gameport_bus_match,
     .probe      = gameport_driver_probe,
     .remove     = gameport_driver_remove,
 };
 
 static void gameport_set_drv(struct gameport *gameport, struct gameport_driver *drv)
 {
     mutex_lock(&gameport->drv_mutex);
     gameport->drv = drv;
     mutex_unlock(&gameport->drv_mutex);
 }
 
 int gameport_open(struct gameport *gameport, struct gameport_driver *drv, int mode)
 {
     if (gameport->open) {
         if (gameport->open(gameport, mode)) {
             return -1;
         }
     } else {
         if (mode != GAMEPORT_MODE_RAW)
             return -1;
     }
 
     gameport_set_drv(gameport, drv);
     return 0;
 }
 EXPORT_SYMBOL(gameport_open);
 
 void gameport_close(struct gameport *gameport)
 {
     del_timer_sync(&gameport->poll_timer);
     gameport->poll_handler = NULL;
     gameport->poll_interval = 0;
     gameport_set_drv(gameport, NULL);
     if (gameport->close)
         gameport->close(gameport);
 }
 EXPORT_SYMBOL(gameport_close);
 
 static int __init gameport_init(void)
 {
     int error;
 
     error = bus_register(&gameport_bus);
     if (error) {
         pr_err("failed to register gameport bus, error: %d\n", error);
         return error;
     }
 
 
     return 0;
 }
 
 static void __exit gameport_exit(void)
 {
     bus_unregister(&gameport_bus);
 
     /*
      * There should not be any outstanding events but work may
      * still be scheduled so simply cancel it.
      */
     cancel_work_sync(&gameport_event_work);
 }
 
 subsys_initcall(gameport_init);
 module_exit(gameport_exit);

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