Author | Tokens | Token Proportion | Commits | Commit Proportion |
---|---|---|---|---|
Ian Campbell | 1703 | 56.94% | 1 | 3.33% |
David Vrabel | 920 | 30.76% | 5 | 16.67% |
Jeremy Fitzhardinge | 148 | 4.95% | 7 | 23.33% |
Anoob Soman | 136 | 4.55% | 1 | 3.33% |
Wei Liu | 33 | 1.10% | 2 | 6.67% |
Joe Perches | 10 | 0.33% | 1 | 3.33% |
Michal Hocko | 7 | 0.23% | 1 | 3.33% |
Vitaly Kuznetsov | 6 | 0.20% | 1 | 3.33% |
Linus Torvalds | 5 | 0.17% | 1 | 3.33% |
Jan Beulich | 4 | 0.13% | 1 | 3.33% |
Daniel De Graaf | 4 | 0.13% | 1 | 3.33% |
Arnd Bergmann | 4 | 0.13% | 1 | 3.33% |
Juergen Gross | 2 | 0.07% | 1 | 3.33% |
Al Viro | 2 | 0.07% | 1 | 3.33% |
Kees Cook | 2 | 0.07% | 1 | 3.33% |
Geliang Tang | 2 | 0.07% | 1 | 3.33% |
Kirill Smelkov | 1 | 0.03% | 1 | 3.33% |
Bastian Blank | 1 | 0.03% | 1 | 3.33% |
Michael Opdenacker | 1 | 0.03% | 1 | 3.33% |
Total | 2991 | 30 |
/****************************************************************************** * evtchn.c * * Driver for receiving and demuxing event-channel signals. * * Copyright (c) 2004-2005, K A Fraser * Multi-process extensions Copyright (c) 2004, Steven Smith * * 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 * restriction, including without limitation the rights to use, copy, modify, * merge, publish, distribute, sublicense, and/or sell copies of the Software, * and to permit persons to whom the Software is furnished to do so, subject to * the following conditions: * * The above copyright notice and this permission notice shall be included in * all copies or substantial portions of the Software. * * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY, * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING * FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS * IN THE SOFTWARE. */ #define pr_fmt(fmt) "xen:" KBUILD_MODNAME ": " fmt #include <linux/module.h> #include <linux/kernel.h> #include <linux/sched.h> #include <linux/slab.h> #include <linux/string.h> #include <linux/errno.h> #include <linux/fs.h> #include <linux/miscdevice.h> #include <linux/major.h> #include <linux/proc_fs.h> #include <linux/stat.h> #include <linux/poll.h> #include <linux/irq.h> #include <linux/init.h> #include <linux/mutex.h> #include <linux/cpu.h> #include <linux/mm.h> #include <linux/vmalloc.h> #include <xen/xen.h> #include <xen/events.h> #include <xen/evtchn.h> #include <xen/xen-ops.h> #include <asm/xen/hypervisor.h> struct per_user_data { struct mutex bind_mutex; /* serialize bind/unbind operations */ struct rb_root evtchns; unsigned int nr_evtchns; /* Notification ring, accessed via /dev/xen/evtchn. */ unsigned int ring_size; evtchn_port_t *ring; unsigned int ring_cons, ring_prod, ring_overflow; struct mutex ring_cons_mutex; /* protect against concurrent readers */ spinlock_t ring_prod_lock; /* product against concurrent interrupts */ /* Processes wait on this queue when ring is empty. */ wait_queue_head_t evtchn_wait; struct fasync_struct *evtchn_async_queue; const char *name; domid_t restrict_domid; }; #define UNRESTRICTED_DOMID ((domid_t)-1) struct user_evtchn { struct rb_node node; struct per_user_data *user; unsigned port; bool enabled; }; static void evtchn_free_ring(evtchn_port_t *ring) { kvfree(ring); } static unsigned int evtchn_ring_offset(struct per_user_data *u, unsigned int idx) { return idx & (u->ring_size - 1); } static evtchn_port_t *evtchn_ring_entry(struct per_user_data *u, unsigned int idx) { return u->ring + evtchn_ring_offset(u, idx); } static int add_evtchn(struct per_user_data *u, struct user_evtchn *evtchn) { struct rb_node **new = &(u->evtchns.rb_node), *parent = NULL; u->nr_evtchns++; while (*new) { struct user_evtchn *this; this = rb_entry(*new, struct user_evtchn, node); parent = *new; if (this->port < evtchn->port) new = &((*new)->rb_left); else if (this->port > evtchn->port) new = &((*new)->rb_right); else return -EEXIST; } /* Add new node and rebalance tree. */ rb_link_node(&evtchn->node, parent, new); rb_insert_color(&evtchn->node, &u->evtchns); return 0; } static void del_evtchn(struct per_user_data *u, struct user_evtchn *evtchn) { u->nr_evtchns--; rb_erase(&evtchn->node, &u->evtchns); kfree(evtchn); } static struct user_evtchn *find_evtchn(struct per_user_data *u, unsigned port) { struct rb_node *node = u->evtchns.rb_node; while (node) { struct user_evtchn *evtchn; evtchn = rb_entry(node, struct user_evtchn, node); if (evtchn->port < port) node = node->rb_left; else if (evtchn->port > port) node = node->rb_right; else return evtchn; } return NULL; } static irqreturn_t evtchn_interrupt(int irq, void *data) { struct user_evtchn *evtchn = data; struct per_user_data *u = evtchn->user; WARN(!evtchn->enabled, "Interrupt for port %d, but apparently not enabled; per-user %p\n", evtchn->port, u); disable_irq_nosync(irq); evtchn->enabled = false; spin_lock(&u->ring_prod_lock); if ((u->ring_prod - u->ring_cons) < u->ring_size) { *evtchn_ring_entry(u, u->ring_prod) = evtchn->port; wmb(); /* Ensure ring contents visible */ 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(&u->ring_prod_lock); return IRQ_HANDLED; } 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; 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 (;;) { mutex_lock(&u->ring_cons_mutex); rc = -EFBIG; if (u->ring_overflow) goto unlock_out; c = u->ring_cons; p = u->ring_prod; if (c != p) break; mutex_unlock(&u->ring_cons_mutex); 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) & u->ring_size) != 0) { bytes1 = (u->ring_size - evtchn_ring_offset(u, c)) * sizeof(evtchn_port_t); bytes2 = evtchn_ring_offset(u, 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; } rc = -EFAULT; rmb(); /* Ensure that we see the port before we copy it. */ if (copy_to_user(buf, evtchn_ring_entry(u, c), bytes1) || ((bytes2 != 0) && copy_to_user(&buf[bytes1], &u->ring[0], bytes2))) goto unlock_out; u->ring_cons += (bytes1 + bytes2) / sizeof(evtchn_port_t); rc = bytes1 + bytes2; unlock_out: mutex_unlock(&u->ring_cons_mutex); return rc; } static ssize_t evtchn_write(struct file *file, const char __user *buf, size_t count, loff_t *ppos) { 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; /* Whole number of ports. */ count &= ~(sizeof(evtchn_port_t)-1); rc = 0; if (count == 0) goto out; if (count > PAGE_SIZE) count = PAGE_SIZE; rc = -EFAULT; if (copy_from_user(kbuf, buf, count) != 0) goto out; mutex_lock(&u->bind_mutex); for (i = 0; i < (count/sizeof(evtchn_port_t)); i++) { unsigned port = kbuf[i]; struct user_evtchn *evtchn; evtchn = find_evtchn(u, port); if (evtchn && !evtchn->enabled) { evtchn->enabled = true; enable_irq(irq_from_evtchn(port)); } } mutex_unlock(&u->bind_mutex); rc = count; out: free_page((unsigned long)kbuf); return rc; } static int evtchn_resize_ring(struct per_user_data *u) { unsigned int new_size; evtchn_port_t *new_ring, *old_ring; /* * Ensure the ring is large enough to capture all possible * events. i.e., one free slot for each bound event. */ if (u->nr_evtchns <= u->ring_size) return 0; if (u->ring_size == 0) new_size = 64; else new_size = 2 * u->ring_size; new_ring = kvmalloc_array(new_size, sizeof(*new_ring), GFP_KERNEL); if (!new_ring) return -ENOMEM; old_ring = u->ring; /* * Access to the ring contents is serialized by either the * prod /or/ cons lock so take both when resizing. */ mutex_lock(&u->ring_cons_mutex); spin_lock_irq(&u->ring_prod_lock); /* * Copy the old ring contents to the new ring. * * To take care of wrapping, a full ring, and the new index * pointing into the second half, simply copy the old contents * twice. * * +---------+ +------------------+ * |34567 12| -> |34567 1234567 12| * +-----p-c-+ +-------c------p---+ */ memcpy(new_ring, old_ring, u->ring_size * sizeof(*u->ring)); memcpy(new_ring + u->ring_size, old_ring, u->ring_size * sizeof(*u->ring)); u->ring = new_ring; u->ring_size = new_size; spin_unlock_irq(&u->ring_prod_lock); mutex_unlock(&u->ring_cons_mutex); evtchn_free_ring(old_ring); return 0; } static int evtchn_bind_to_user(struct per_user_data *u, int port) { struct user_evtchn *evtchn; struct evtchn_close close; int rc = 0; /* * Ports are never reused, so every caller should pass in a * unique port. * * (Locking not necessary because we haven't registered the * interrupt handler yet, and our caller has already * serialized bind operations.) */ evtchn = kzalloc(sizeof(*evtchn), GFP_KERNEL); if (!evtchn) return -ENOMEM; evtchn->user = u; evtchn->port = port; evtchn->enabled = true; /* start enabled */ rc = add_evtchn(u, evtchn); if (rc < 0) goto err; rc = evtchn_resize_ring(u); if (rc < 0) goto err; rc = bind_evtchn_to_irqhandler(port, evtchn_interrupt, 0, u->name, evtchn); if (rc < 0) goto err; rc = evtchn_make_refcounted(port); return rc; err: /* bind failed, should close the port now */ close.port = port; if (HYPERVISOR_event_channel_op(EVTCHNOP_close, &close) != 0) BUG(); del_evtchn(u, evtchn); return rc; } static void evtchn_unbind_from_user(struct per_user_data *u, struct user_evtchn *evtchn) { int irq = irq_from_evtchn(evtchn->port); BUG_ON(irq < 0); unbind_from_irqhandler(irq, evtchn); del_evtchn(u, evtchn); } static DEFINE_PER_CPU(int, bind_last_selected_cpu); static void evtchn_bind_interdom_next_vcpu(int evtchn) { unsigned int selected_cpu, irq; struct irq_desc *desc; unsigned long flags; irq = irq_from_evtchn(evtchn); desc = irq_to_desc(irq); if (!desc) return; raw_spin_lock_irqsave(&desc->lock, flags); selected_cpu = this_cpu_read(bind_last_selected_cpu); selected_cpu = cpumask_next_and(selected_cpu, desc->irq_common_data.affinity, cpu_online_mask); if (unlikely(selected_cpu >= nr_cpu_ids)) selected_cpu = cpumask_first_and(desc->irq_common_data.affinity, cpu_online_mask); this_cpu_write(bind_last_selected_cpu, selected_cpu); /* unmask expects irqs to be disabled */ xen_set_affinity_evtchn(desc, selected_cpu); raw_spin_unlock_irqrestore(&desc->lock, flags); } static long evtchn_ioctl(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; /* Prevent bind from racing with unbind */ mutex_lock(&u->bind_mutex); switch (cmd) { case IOCTL_EVTCHN_BIND_VIRQ: { struct ioctl_evtchn_bind_virq bind; struct evtchn_bind_virq bind_virq; rc = -EACCES; if (u->restrict_domid != UNRESTRICTED_DOMID) break; rc = -EFAULT; if (copy_from_user(&bind, uarg, sizeof(bind))) break; bind_virq.virq = bind.virq; bind_virq.vcpu = xen_vcpu_nr(0); rc = HYPERVISOR_event_channel_op(EVTCHNOP_bind_virq, &bind_virq); if (rc != 0) break; rc = evtchn_bind_to_user(u, bind_virq.port); if (rc == 0) rc = bind_virq.port; 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; rc = -EACCES; if (u->restrict_domid != UNRESTRICTED_DOMID && u->restrict_domid != bind.remote_domain) 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 = evtchn_bind_to_user(u, bind_interdomain.local_port); if (rc == 0) { rc = bind_interdomain.local_port; evtchn_bind_interdom_next_vcpu(rc); } break; } case IOCTL_EVTCHN_BIND_UNBOUND_PORT: { struct ioctl_evtchn_bind_unbound_port bind; struct evtchn_alloc_unbound alloc_unbound; rc = -EACCES; if (u->restrict_domid != UNRESTRICTED_DOMID) break; 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 = evtchn_bind_to_user(u, alloc_unbound.port); if (rc == 0) rc = alloc_unbound.port; break; } case IOCTL_EVTCHN_UNBIND: { struct ioctl_evtchn_unbind unbind; struct user_evtchn *evtchn; rc = -EFAULT; if (copy_from_user(&unbind, uarg, sizeof(unbind))) break; rc = -EINVAL; if (unbind.port >= xen_evtchn_nr_channels()) break; rc = -ENOTCONN; evtchn = find_evtchn(u, unbind.port); if (!evtchn) break; disable_irq(irq_from_evtchn(unbind.port)); evtchn_unbind_from_user(u, evtchn); rc = 0; break; } case IOCTL_EVTCHN_NOTIFY: { struct ioctl_evtchn_notify notify; struct user_evtchn *evtchn; rc = -EFAULT; if (copy_from_user(¬ify, uarg, sizeof(notify))) break; rc = -ENOTCONN; evtchn = find_evtchn(u, notify.port); if (evtchn) { notify_remote_via_evtchn(notify.port); rc = 0; } break; } case IOCTL_EVTCHN_RESET: { /* Initialise the ring to empty. Clear errors. */ mutex_lock(&u->ring_cons_mutex); spin_lock_irq(&u->ring_prod_lock); u->ring_cons = u->ring_prod = u->ring_overflow = 0; spin_unlock_irq(&u->ring_prod_lock); mutex_unlock(&u->ring_cons_mutex); rc = 0; break; } case IOCTL_EVTCHN_RESTRICT_DOMID: { struct ioctl_evtchn_restrict_domid ierd; rc = -EACCES; if (u->restrict_domid != UNRESTRICTED_DOMID) break; rc = -EFAULT; if (copy_from_user(&ierd, uarg, sizeof(ierd))) break; rc = -EINVAL; if (ierd.domid == 0 || ierd.domid >= DOMID_FIRST_RESERVED) break; u->restrict_domid = ierd.domid; rc = 0; break; } default: rc = -ENOSYS; break; } mutex_unlock(&u->bind_mutex); return rc; } static __poll_t evtchn_poll(struct file *file, poll_table *wait) { __poll_t mask = EPOLLOUT | EPOLLWRNORM; struct per_user_data *u = file->private_data; poll_wait(file, &u->evtchn_wait, wait); if (u->ring_cons != u->ring_prod) mask |= EPOLLIN | EPOLLRDNORM; if (u->ring_overflow) mask = EPOLLERR; 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); } static int evtchn_open(struct inode *inode, struct file *filp) { struct per_user_data *u; u = kzalloc(sizeof(*u), GFP_KERNEL); if (u == NULL) return -ENOMEM; u->name = kasprintf(GFP_KERNEL, "evtchn:%s", current->comm); if (u->name == NULL) { kfree(u); return -ENOMEM; } init_waitqueue_head(&u->evtchn_wait); mutex_init(&u->bind_mutex); mutex_init(&u->ring_cons_mutex); spin_lock_init(&u->ring_prod_lock); u->restrict_domid = UNRESTRICTED_DOMID; filp->private_data = u; return stream_open(inode, filp); } static int evtchn_release(struct inode *inode, struct file *filp) { struct per_user_data *u = filp->private_data; struct rb_node *node; while ((node = u->evtchns.rb_node)) { struct user_evtchn *evtchn; evtchn = rb_entry(node, struct user_evtchn, node); disable_irq(irq_from_evtchn(evtchn->port)); evtchn_unbind_from_user(u, evtchn); } evtchn_free_ring(u->ring); kfree(u->name); kfree(u); return 0; } static const struct file_operations evtchn_fops = { .owner = THIS_MODULE, .read = evtchn_read, .write = evtchn_write, .unlocked_ioctl = evtchn_ioctl, .poll = evtchn_poll, .fasync = evtchn_fasync, .open = evtchn_open, .release = evtchn_release, .llseek = no_llseek, }; static struct miscdevice evtchn_miscdev = { .minor = MISC_DYNAMIC_MINOR, .name = "xen/evtchn", .fops = &evtchn_fops, }; static int __init evtchn_init(void) { int err; if (!xen_domain()) return -ENODEV; /* Create '/dev/xen/evtchn'. */ err = misc_register(&evtchn_miscdev); if (err != 0) { pr_err("Could not register /dev/xen/evtchn\n"); return err; } pr_info("Event-channel device installed\n"); return 0; } static void __exit evtchn_cleanup(void) { misc_deregister(&evtchn_miscdev); } module_init(evtchn_init); module_exit(evtchn_cleanup); MODULE_LICENSE("GPL");
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