/******************************************************************************
* evtchn.c
*
- * Xenolinux driver for receiving and demuxing event-channel signals.
+ * Driver for receiving and demuxing event-channel signals.
*
- * Copyright (c) 2004, K A Fraser
+ * Copyright (c) 2004-2005, K A Fraser
* Multi-process extensions Copyright (c) 2004, Steven Smith
*
- * This file may be distributed separately from the Linux kernel, or
- * incorporated into other software packages, subject to the following license:
+ * 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; or, when distributed
+ * separately from the Linux kernel or incorporated into other
+ * software packages, subject to the following license:
*
* Permission is hereby granted, free of charge, to any person obtaining a copy
* of this source file (the "Software"), to deal in the Software without
#include <linux/poll.h>
#include <linux/irq.h>
#include <linux/init.h>
-#define XEN_EVTCHN_MASK_OPS
-#include <asm-xen/evtchn.h>
-
-#if LINUX_VERSION_CODE < KERNEL_VERSION(2,6,0)
-#include <linux/devfs_fs_kernel.h>
-#define OLD_DEVFS
-#else
#include <linux/gfp.h>
-#endif
-
-#ifdef OLD_DEVFS
-/* NB. This must be shared amongst drivers if more things go in /dev/xen */
-static devfs_handle_t xen_dev_dir;
-#endif
+#include <xen/evtchn.h>
+#include <xen/public/evtchn.h>
struct per_user_data {
- /* Notification ring, accessed via /dev/xen/evtchn. */
-# define EVTCHN_RING_SIZE 2048 /* 2048 16-bit entries */
-# define EVTCHN_RING_MASK(_i) ((_i)&(EVTCHN_RING_SIZE-1))
- u16 *ring;
- unsigned int ring_cons, ring_prod, ring_overflow;
-
- /* Processes wait on this queue when ring is empty. */
- wait_queue_head_t evtchn_wait;
- struct fasync_struct *evtchn_async_queue;
+ /* Notification ring, accessed via /dev/xen/evtchn. */
+#define EVTCHN_RING_SIZE (PAGE_SIZE / sizeof(evtchn_port_t))
+#define EVTCHN_RING_MASK(_i) ((_i)&(EVTCHN_RING_SIZE-1))
+ evtchn_port_t *ring;
+ unsigned int ring_cons, ring_prod, ring_overflow;
+
+ /* Processes wait on this queue when ring is empty. */
+ wait_queue_head_t evtchn_wait;
+ struct fasync_struct *evtchn_async_queue;
};
/* Who's bound to each port? */
void evtchn_device_upcall(int port)
{
- struct per_user_data *u;
-
- spin_lock(&port_user_lock);
-
- mask_evtchn(port);
- clear_evtchn(port);
-
- if ( (u = port_user[port]) != NULL )
- {
- if ( (u->ring_prod - u->ring_cons) < EVTCHN_RING_SIZE )
- {
- u->ring[EVTCHN_RING_MASK(u->ring_prod)] = (u16)port;
- if ( u->ring_cons == u->ring_prod++ )
- {
- wake_up_interruptible(&u->evtchn_wait);
- kill_fasync(&u->evtchn_async_queue, SIGIO, POLL_IN);
- }
- }
- else
- {
- u->ring_overflow = 1;
- }
- }
-
- spin_unlock(&port_user_lock);
+ struct per_user_data *u;
+
+ spin_lock(&port_user_lock);
+
+ mask_evtchn(port);
+ clear_evtchn(port);
+
+ if ((u = port_user[port]) != NULL) {
+ if ((u->ring_prod - u->ring_cons) < EVTCHN_RING_SIZE) {
+ u->ring[EVTCHN_RING_MASK(u->ring_prod)] = port;
+ if (u->ring_cons == u->ring_prod++) {
+ wake_up_interruptible(&u->evtchn_wait);
+ kill_fasync(&u->evtchn_async_queue,
+ SIGIO, POLL_IN);
+ }
+ } else {
+ u->ring_overflow = 1;
+ }
+ }
+
+ spin_unlock(&port_user_lock);
}
-static ssize_t evtchn_read(struct file *file, char *buf,
- size_t count, loff_t *ppos)
+static ssize_t evtchn_read(struct file *file, char __user *buf,
+ size_t count, loff_t *ppos)
{
- int rc;
- unsigned int c, p, bytes1 = 0, bytes2 = 0;
- DECLARE_WAITQUEUE(wait, current);
- struct per_user_data *u = file->private_data;
-
- add_wait_queue(&u->evtchn_wait, &wait);
-
- count &= ~1; /* even number of bytes */
-
- if ( count == 0 )
- {
- rc = 0;
- goto out;
- }
-
- if ( count > PAGE_SIZE )
- count = PAGE_SIZE;
-
- for ( ; ; )
- {
- set_current_state(TASK_INTERRUPTIBLE);
-
- if ( (c = u->ring_cons) != (p = u->ring_prod) )
- break;
-
- if ( u->ring_overflow )
- {
- rc = -EFBIG;
- goto out;
- }
-
- if ( file->f_flags & O_NONBLOCK )
- {
- rc = -EAGAIN;
- goto out;
- }
-
- if ( signal_pending(current) )
- {
- rc = -ERESTARTSYS;
- goto out;
- }
-
- schedule();
- }
-
- /* Byte lengths of two chunks. Chunk split (if any) is at ring wrap. */
- if ( ((c ^ p) & EVTCHN_RING_SIZE) != 0 )
- {
- bytes1 = (EVTCHN_RING_SIZE - EVTCHN_RING_MASK(c)) * sizeof(u16);
- bytes2 = EVTCHN_RING_MASK(p) * sizeof(u16);
- }
- else
- {
- bytes1 = (p - c) * sizeof(u16);
- bytes2 = 0;
- }
-
- /* Truncate chunks according to caller's maximum byte count. */
- if ( bytes1 > count )
- {
- bytes1 = count;
- bytes2 = 0;
- }
- else if ( (bytes1 + bytes2) > count )
- {
- bytes2 = count - bytes1;
- }
-
- if ( copy_to_user(buf, &u->ring[EVTCHN_RING_MASK(c)], bytes1) ||
- ((bytes2 != 0) && copy_to_user(&buf[bytes1], &u->ring[0], bytes2)) )
- {
- rc = -EFAULT;
- goto out;
- }
-
- u->ring_cons += (bytes1 + bytes2) / sizeof(u16);
-
- rc = bytes1 + bytes2;
-
- out:
- __set_current_state(TASK_RUNNING);
- remove_wait_queue(&u->evtchn_wait, &wait);
- return rc;
+ int rc;
+ unsigned int c, p, bytes1 = 0, bytes2 = 0;
+ struct per_user_data *u = file->private_data;
+
+ /* Whole number of ports. */
+ count &= ~(sizeof(evtchn_port_t)-1);
+
+ if (count == 0)
+ return 0;
+
+ if (count > PAGE_SIZE)
+ count = PAGE_SIZE;
+
+ for (;;) {
+ if (u->ring_overflow)
+ return -EFBIG;
+
+ if ((c = u->ring_cons) != (p = u->ring_prod))
+ break;
+
+ if (file->f_flags & O_NONBLOCK)
+ return -EAGAIN;
+
+ rc = wait_event_interruptible(
+ u->evtchn_wait, u->ring_cons != u->ring_prod);
+ if (rc)
+ return rc;
+ }
+
+ /* Byte lengths of two chunks. Chunk split (if any) is at ring wrap. */
+ if (((c ^ p) & EVTCHN_RING_SIZE) != 0) {
+ bytes1 = (EVTCHN_RING_SIZE - EVTCHN_RING_MASK(c)) *
+ sizeof(evtchn_port_t);
+ bytes2 = EVTCHN_RING_MASK(p) * sizeof(evtchn_port_t);
+ } else {
+ bytes1 = (p - c) * sizeof(evtchn_port_t);
+ bytes2 = 0;
+ }
+
+ /* Truncate chunks according to caller's maximum byte count. */
+ if (bytes1 > count) {
+ bytes1 = count;
+ bytes2 = 0;
+ } else if ((bytes1 + bytes2) > count) {
+ bytes2 = count - bytes1;
+ }
+
+ if (copy_to_user(buf, &u->ring[EVTCHN_RING_MASK(c)], bytes1) ||
+ ((bytes2 != 0) &&
+ copy_to_user(&buf[bytes1], &u->ring[0], bytes2)))
+ return -EFAULT;
+
+ u->ring_cons += (bytes1 + bytes2) / sizeof(evtchn_port_t);
+
+ return bytes1 + bytes2;
}
-static ssize_t evtchn_write(struct file *file, const char *buf,
- size_t count, loff_t *ppos)
+static ssize_t evtchn_write(struct file *file, const char __user *buf,
+ size_t count, loff_t *ppos)
{
- int rc, i;
- u16 *kbuf = (u16 *)__get_free_page(GFP_KERNEL);
- struct per_user_data *u = file->private_data;
+ int rc, i;
+ evtchn_port_t *kbuf = (evtchn_port_t *)__get_free_page(GFP_KERNEL);
+ struct per_user_data *u = file->private_data;
- if ( kbuf == NULL )
- return -ENOMEM;
+ if (kbuf == NULL)
+ return -ENOMEM;
- count &= ~1; /* even number of bytes */
+ /* Whole number of ports. */
+ count &= ~(sizeof(evtchn_port_t)-1);
- if ( count == 0 )
- {
- rc = 0;
- goto out;
- }
+ if (count == 0) {
+ rc = 0;
+ goto out;
+ }
- if ( count > PAGE_SIZE )
- count = PAGE_SIZE;
+ if (count > PAGE_SIZE)
+ count = PAGE_SIZE;
- if ( copy_from_user(kbuf, buf, count) != 0 )
- {
- rc = -EFAULT;
- goto out;
- }
+ if (copy_from_user(kbuf, buf, count) != 0) {
+ rc = -EFAULT;
+ goto out;
+ }
- spin_lock_irq(&port_user_lock);
- for ( i = 0; i < (count/2); i++ )
- if ( (kbuf[i] < NR_EVENT_CHANNELS) && (port_user[kbuf[i]] == u) )
- unmask_evtchn(kbuf[i]);
- spin_unlock_irq(&port_user_lock);
+ spin_lock_irq(&port_user_lock);
+ for (i = 0; i < (count/sizeof(evtchn_port_t)); i++)
+ if ((kbuf[i] < NR_EVENT_CHANNELS) && (port_user[kbuf[i]] == u))
+ unmask_evtchn(kbuf[i]);
+ spin_unlock_irq(&port_user_lock);
- rc = count;
+ rc = count;
out:
- free_page((unsigned long)kbuf);
- return rc;
+ free_page((unsigned long)kbuf);
+ return rc;
}
-static int evtchn_ioctl(struct inode *inode, struct file *file,
- unsigned int cmd, unsigned long arg)
+static void evtchn_bind_to_user(struct per_user_data *u, int port)
{
- int rc = 0;
- struct per_user_data *u = file->private_data;
+ spin_lock_irq(&port_user_lock);
+ BUG_ON(port_user[port] != NULL);
+ port_user[port] = u;
+ unmask_evtchn(port);
+ spin_unlock_irq(&port_user_lock);
+}
- spin_lock_irq(&port_user_lock);
+static int evtchn_ioctl(struct inode *inode, struct file *file,
+ unsigned int cmd, unsigned long arg)
+{
+ int rc;
+ struct per_user_data *u = file->private_data;
+ void __user *uarg = (void __user *) arg;
+
+ switch (cmd) {
+ case IOCTL_EVTCHN_BIND_VIRQ: {
+ struct ioctl_evtchn_bind_virq bind;
+ struct evtchn_bind_virq bind_virq;
+
+ rc = -EFAULT;
+ if (copy_from_user(&bind, uarg, sizeof(bind)))
+ break;
+
+ bind_virq.virq = bind.virq;
+ bind_virq.vcpu = 0;
+ rc = HYPERVISOR_event_channel_op(EVTCHNOP_bind_virq,
+ &bind_virq);
+ if (rc != 0)
+ break;
+
+ rc = bind_virq.port;
+ evtchn_bind_to_user(u, rc);
+ break;
+ }
+
+ case IOCTL_EVTCHN_BIND_INTERDOMAIN: {
+ struct ioctl_evtchn_bind_interdomain bind;
+ struct evtchn_bind_interdomain bind_interdomain;
+
+ rc = -EFAULT;
+ if (copy_from_user(&bind, uarg, sizeof(bind)))
+ break;
+
+ bind_interdomain.remote_dom = bind.remote_domain;
+ bind_interdomain.remote_port = bind.remote_port;
+ rc = HYPERVISOR_event_channel_op(EVTCHNOP_bind_interdomain,
+ &bind_interdomain);
+ if (rc != 0)
+ break;
+
+ rc = bind_interdomain.local_port;
+ evtchn_bind_to_user(u, rc);
+ break;
+ }
+
+ case IOCTL_EVTCHN_BIND_UNBOUND_PORT: {
+ struct ioctl_evtchn_bind_unbound_port bind;
+ struct evtchn_alloc_unbound alloc_unbound;
+
+ rc = -EFAULT;
+ if (copy_from_user(&bind, uarg, sizeof(bind)))
+ break;
+
+ alloc_unbound.dom = DOMID_SELF;
+ alloc_unbound.remote_dom = bind.remote_domain;
+ rc = HYPERVISOR_event_channel_op(EVTCHNOP_alloc_unbound,
+ &alloc_unbound);
+ if (rc != 0)
+ break;
+
+ rc = alloc_unbound.port;
+ evtchn_bind_to_user(u, rc);
+ break;
+ }
+
+ case IOCTL_EVTCHN_UNBIND: {
+ struct ioctl_evtchn_unbind unbind;
+ struct evtchn_close close;
+ int ret;
+
+ rc = -EFAULT;
+ if (copy_from_user(&unbind, uarg, sizeof(unbind)))
+ break;
+
+ rc = -EINVAL;
+ if (unbind.port >= NR_EVENT_CHANNELS)
+ break;
+
+ spin_lock_irq(&port_user_lock);
- switch ( cmd )
- {
- case EVTCHN_RESET:
- /* Initialise the ring to empty. Clear errors. */
- u->ring_cons = u->ring_prod = u->ring_overflow = 0;
- break;
-
- case EVTCHN_BIND:
- if ( arg >= NR_EVENT_CHANNELS )
- {
- rc = -EINVAL;
- }
- else if ( port_user[arg] != NULL )
- {
- rc = -EISCONN;
- }
- else
- {
- port_user[arg] = u;
- unmask_evtchn(arg);
- }
- break;
-
- case EVTCHN_UNBIND:
- if ( arg >= NR_EVENT_CHANNELS )
- {
- rc = -EINVAL;
- }
- else if ( port_user[arg] != u )
- {
- rc = -ENOTCONN;
- }
- else
- {
- port_user[arg] = NULL;
- mask_evtchn(arg);
- }
- break;
-
- default:
- rc = -ENOSYS;
- break;
- }
-
- spin_unlock_irq(&port_user_lock);
-
- return rc;
+ rc = -ENOTCONN;
+ if (port_user[unbind.port] != u) {
+ spin_unlock_irq(&port_user_lock);
+ break;
+ }
+
+ port_user[unbind.port] = NULL;
+ mask_evtchn(unbind.port);
+
+ spin_unlock_irq(&port_user_lock);
+
+ close.port = unbind.port;
+ ret = HYPERVISOR_event_channel_op(EVTCHNOP_close, &close);
+ BUG_ON(ret);
+
+ rc = 0;
+ break;
+ }
+
+ case IOCTL_EVTCHN_NOTIFY: {
+ struct ioctl_evtchn_notify notify;
+
+ rc = -EFAULT;
+ if (copy_from_user(¬ify, uarg, sizeof(notify)))
+ break;
+
+ if (notify.port >= NR_EVENT_CHANNELS) {
+ rc = -EINVAL;
+ } else if (port_user[notify.port] != u) {
+ rc = -ENOTCONN;
+ } else {
+ notify_remote_via_evtchn(notify.port);
+ rc = 0;
+ }
+ break;
+ }
+
+ case IOCTL_EVTCHN_RESET: {
+ /* Initialise the ring to empty. Clear errors. */
+ spin_lock_irq(&port_user_lock);
+ u->ring_cons = u->ring_prod = u->ring_overflow = 0;
+ spin_unlock_irq(&port_user_lock);
+ rc = 0;
+ break;
+ }
+
+ default:
+ rc = -ENOSYS;
+ break;
+ }
+
+ return rc;
}
static unsigned int evtchn_poll(struct file *file, poll_table *wait)
{
- unsigned int mask = POLLOUT | POLLWRNORM;
- struct per_user_data *u = file->private_data;
-
- poll_wait(file, &u->evtchn_wait, wait);
- if ( u->ring_cons != u->ring_prod )
- mask |= POLLIN | POLLRDNORM;
- if ( u->ring_overflow )
- mask = POLLERR;
- return mask;
+ unsigned int mask = POLLOUT | POLLWRNORM;
+ struct per_user_data *u = file->private_data;
+
+ poll_wait(file, &u->evtchn_wait, wait);
+ if (u->ring_cons != u->ring_prod)
+ mask |= POLLIN | POLLRDNORM;
+ if (u->ring_overflow)
+ mask = POLLERR;
+ return mask;
}
static int evtchn_fasync(int fd, struct file *filp, int on)
{
- struct per_user_data *u = filp->private_data;
- return fasync_helper(fd, filp, on, &u->evtchn_async_queue);
+ struct per_user_data *u = filp->private_data;
+ return fasync_helper(fd, filp, on, &u->evtchn_async_queue);
}
static int evtchn_open(struct inode *inode, struct file *filp)
{
- struct per_user_data *u;
+ struct per_user_data *u;
- if ( (u = kmalloc(sizeof(*u), GFP_KERNEL)) == NULL )
- return -ENOMEM;
+ if ((u = kmalloc(sizeof(*u), GFP_KERNEL)) == NULL)
+ return -ENOMEM;
- memset(u, 0, sizeof(*u));
- init_waitqueue_head(&u->evtchn_wait);
+ memset(u, 0, sizeof(*u));
+ init_waitqueue_head(&u->evtchn_wait);
- if ( (u->ring = (u16 *)__get_free_page(GFP_KERNEL)) == NULL )
- {
- kfree(u);
- return -ENOMEM;
- }
+ u->ring = (evtchn_port_t *)__get_free_page(GFP_KERNEL);
+ if (u->ring == NULL) {
+ kfree(u);
+ return -ENOMEM;
+ }
- filp->private_data = u;
+ filp->private_data = u;
- return 0;
+ return 0;
}
static int evtchn_release(struct inode *inode, struct file *filp)
{
- int i;
- struct per_user_data *u = filp->private_data;
+ int i;
+ struct per_user_data *u = filp->private_data;
+ struct evtchn_close close;
+
+ spin_lock_irq(&port_user_lock);
- spin_lock_irq(&port_user_lock);
+ free_page((unsigned long)u->ring);
- free_page((unsigned long)u->ring);
+ for (i = 0; i < NR_EVENT_CHANNELS; i++) {
+ int ret;
+ if (port_user[i] != u)
+ continue;
- for ( i = 0; i < NR_EVENT_CHANNELS; i++ )
- {
- if ( port_user[i] == u )
- {
- port_user[i] = NULL;
- mask_evtchn(i);
- }
- }
+ port_user[i] = NULL;
+ mask_evtchn(i);
- spin_unlock_irq(&port_user_lock);
+ close.port = i;
+ ret = HYPERVISOR_event_channel_op(EVTCHNOP_close, &close);
+ BUG_ON(ret);
+ }
- return 0;
+ spin_unlock_irq(&port_user_lock);
+
+ kfree(u);
+
+ return 0;
}
static struct file_operations evtchn_fops = {
- owner: THIS_MODULE,
- read: evtchn_read,
- write: evtchn_write,
- ioctl: evtchn_ioctl,
- poll: evtchn_poll,
- fasync: evtchn_fasync,
- open: evtchn_open,
- release: evtchn_release
+ .owner = THIS_MODULE,
+ .read = evtchn_read,
+ .write = evtchn_write,
+ .ioctl = evtchn_ioctl,
+ .poll = evtchn_poll,
+ .fasync = evtchn_fasync,
+ .open = evtchn_open,
+ .release = evtchn_release,
};
static struct miscdevice evtchn_miscdev = {
- .minor = EVTCHN_MINOR,
- .name = "evtchn",
- .fops = &evtchn_fops,
-#if LINUX_VERSION_CODE >= KERNEL_VERSION(2,6,0)
- .devfs_name = "misc/evtchn",
-#endif
+ .minor = EVTCHN_MINOR,
+ .name = "evtchn",
+ .fops = &evtchn_fops,
+ .devfs_name = "misc/evtchn",
};
static int __init evtchn_init(void)
{
-#ifdef OLD_DEVFS
- devfs_handle_t symlink_handle;
- int pos;
- char link_dest[64];
-#endif
- int err;
-
- spin_lock_init(&port_user_lock);
- memset(port_user, 0, sizeof(port_user));
-
- /* (DEVFS) create '/dev/misc/evtchn'. */
- err = misc_register(&evtchn_miscdev);
- if ( err != 0 )
- {
- printk(KERN_ALERT "Could not register /dev/misc/evtchn\n");
- return err;
- }
-
-#ifdef OLD_DEVFS
- /* (DEVFS) create directory '/dev/xen'. */
- xen_dev_dir = devfs_mk_dir(NULL, "xen", NULL);
-
- /* (DEVFS) &link_dest[pos] == '../misc/evtchn'. */
- pos = devfs_generate_path(evtchn_miscdev.devfs_handle,
- &link_dest[3],
- sizeof(link_dest) - 3);
- if ( pos >= 0 )
- strncpy(&link_dest[pos], "../", 3);
-
- /* (DEVFS) symlink '/dev/xen/evtchn' -> '../misc/evtchn'. */
- (void)devfs_mk_symlink(xen_dev_dir,
- "evtchn",
- DEVFS_FL_DEFAULT,
- &link_dest[pos],
- &symlink_handle,
- NULL);
-
- /* (DEVFS) automatically destroy the symlink with its destination. */
- devfs_auto_unregister(evtchn_miscdev.devfs_handle, symlink_handle);
-#endif
-
- printk("Event-channel device installed.\n");
-
- return 0;
+ int err;
+
+ if (!is_running_on_xen())
+ return -ENODEV;
+
+ spin_lock_init(&port_user_lock);
+ memset(port_user, 0, sizeof(port_user));
+
+ /* Create '/dev/misc/evtchn'. */
+ err = misc_register(&evtchn_miscdev);
+ if (err != 0) {
+ printk(KERN_ALERT "Could not register /dev/misc/evtchn\n");
+ return err;
+ }
+
+ printk("Event-channel device installed.\n");
+
+ return 0;
}
static void evtchn_cleanup(void)
{
- misc_deregister(&evtchn_miscdev);
+ misc_deregister(&evtchn_miscdev);
}
module_init(evtchn_init);
module_exit(evtchn_cleanup);
+
+MODULE_LICENSE("Dual BSD/GPL");