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1244 lines
30 KiB
1244 lines
30 KiB
// SPDX-License-Identifier: GPL-2.0-or-later |
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/* |
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* (c) 2017 Stefano Stabellini <[email protected]> |
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*/ |
|
|
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#include <linux/inet.h> |
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#include <linux/kthread.h> |
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#include <linux/list.h> |
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#include <linux/radix-tree.h> |
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#include <linux/module.h> |
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#include <linux/semaphore.h> |
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#include <linux/wait.h> |
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#include <net/sock.h> |
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#include <net/inet_common.h> |
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#include <net/inet_connection_sock.h> |
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#include <net/request_sock.h> |
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|
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#include <xen/events.h> |
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#include <xen/grant_table.h> |
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#include <xen/xen.h> |
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#include <xen/xenbus.h> |
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#include <xen/interface/io/pvcalls.h> |
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|
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#define PVCALLS_VERSIONS "1" |
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#define MAX_RING_ORDER XENBUS_MAX_RING_GRANT_ORDER |
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|
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static struct pvcalls_back_global { |
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struct list_head frontends; |
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struct semaphore frontends_lock; |
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} pvcalls_back_global; |
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|
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/* |
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* Per-frontend data structure. It contains pointers to the command |
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* ring, its event channel, a list of active sockets and a tree of |
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* passive sockets. |
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*/ |
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struct pvcalls_fedata { |
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struct list_head list; |
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struct xenbus_device *dev; |
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struct xen_pvcalls_sring *sring; |
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struct xen_pvcalls_back_ring ring; |
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int irq; |
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struct list_head socket_mappings; |
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struct radix_tree_root socketpass_mappings; |
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struct semaphore socket_lock; |
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}; |
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|
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struct pvcalls_ioworker { |
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struct work_struct register_work; |
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struct workqueue_struct *wq; |
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}; |
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|
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struct sock_mapping { |
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struct list_head list; |
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struct pvcalls_fedata *fedata; |
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struct sockpass_mapping *sockpass; |
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struct socket *sock; |
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uint64_t id; |
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grant_ref_t ref; |
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struct pvcalls_data_intf *ring; |
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void *bytes; |
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struct pvcalls_data data; |
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uint32_t ring_order; |
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int irq; |
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atomic_t read; |
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atomic_t write; |
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atomic_t io; |
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atomic_t release; |
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atomic_t eoi; |
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void (*saved_data_ready)(struct sock *sk); |
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struct pvcalls_ioworker ioworker; |
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}; |
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|
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struct sockpass_mapping { |
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struct list_head list; |
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struct pvcalls_fedata *fedata; |
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struct socket *sock; |
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uint64_t id; |
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struct xen_pvcalls_request reqcopy; |
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spinlock_t copy_lock; |
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struct workqueue_struct *wq; |
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struct work_struct register_work; |
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void (*saved_data_ready)(struct sock *sk); |
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}; |
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|
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static irqreturn_t pvcalls_back_conn_event(int irq, void *sock_map); |
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static int pvcalls_back_release_active(struct xenbus_device *dev, |
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struct pvcalls_fedata *fedata, |
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struct sock_mapping *map); |
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|
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static bool pvcalls_conn_back_read(void *opaque) |
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{ |
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struct sock_mapping *map = (struct sock_mapping *)opaque; |
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struct msghdr msg; |
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struct kvec vec[2]; |
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RING_IDX cons, prod, size, wanted, array_size, masked_prod, masked_cons; |
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int32_t error; |
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struct pvcalls_data_intf *intf = map->ring; |
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struct pvcalls_data *data = &map->data; |
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unsigned long flags; |
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int ret; |
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|
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array_size = XEN_FLEX_RING_SIZE(map->ring_order); |
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cons = intf->in_cons; |
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prod = intf->in_prod; |
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error = intf->in_error; |
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/* read the indexes first, then deal with the data */ |
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virt_mb(); |
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|
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if (error) |
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return false; |
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|
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size = pvcalls_queued(prod, cons, array_size); |
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if (size >= array_size) |
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return false; |
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spin_lock_irqsave(&map->sock->sk->sk_receive_queue.lock, flags); |
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if (skb_queue_empty(&map->sock->sk->sk_receive_queue)) { |
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atomic_set(&map->read, 0); |
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spin_unlock_irqrestore(&map->sock->sk->sk_receive_queue.lock, |
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flags); |
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return true; |
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} |
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spin_unlock_irqrestore(&map->sock->sk->sk_receive_queue.lock, flags); |
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wanted = array_size - size; |
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masked_prod = pvcalls_mask(prod, array_size); |
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masked_cons = pvcalls_mask(cons, array_size); |
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|
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memset(&msg, 0, sizeof(msg)); |
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if (masked_prod < masked_cons) { |
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vec[0].iov_base = data->in + masked_prod; |
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vec[0].iov_len = wanted; |
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iov_iter_kvec(&msg.msg_iter, WRITE, vec, 1, wanted); |
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} else { |
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vec[0].iov_base = data->in + masked_prod; |
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vec[0].iov_len = array_size - masked_prod; |
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vec[1].iov_base = data->in; |
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vec[1].iov_len = wanted - vec[0].iov_len; |
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iov_iter_kvec(&msg.msg_iter, WRITE, vec, 2, wanted); |
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} |
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|
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atomic_set(&map->read, 0); |
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ret = inet_recvmsg(map->sock, &msg, wanted, MSG_DONTWAIT); |
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WARN_ON(ret > wanted); |
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if (ret == -EAGAIN) /* shouldn't happen */ |
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return true; |
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if (!ret) |
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ret = -ENOTCONN; |
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spin_lock_irqsave(&map->sock->sk->sk_receive_queue.lock, flags); |
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if (ret > 0 && !skb_queue_empty(&map->sock->sk->sk_receive_queue)) |
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atomic_inc(&map->read); |
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spin_unlock_irqrestore(&map->sock->sk->sk_receive_queue.lock, flags); |
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|
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/* write the data, then modify the indexes */ |
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virt_wmb(); |
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if (ret < 0) { |
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atomic_set(&map->read, 0); |
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intf->in_error = ret; |
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} else |
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intf->in_prod = prod + ret; |
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/* update the indexes, then notify the other end */ |
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virt_wmb(); |
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notify_remote_via_irq(map->irq); |
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|
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return true; |
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} |
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|
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static bool pvcalls_conn_back_write(struct sock_mapping *map) |
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{ |
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struct pvcalls_data_intf *intf = map->ring; |
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struct pvcalls_data *data = &map->data; |
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struct msghdr msg; |
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struct kvec vec[2]; |
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RING_IDX cons, prod, size, array_size; |
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int ret; |
|
|
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cons = intf->out_cons; |
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prod = intf->out_prod; |
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/* read the indexes before dealing with the data */ |
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virt_mb(); |
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|
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array_size = XEN_FLEX_RING_SIZE(map->ring_order); |
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size = pvcalls_queued(prod, cons, array_size); |
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if (size == 0) |
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return false; |
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|
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memset(&msg, 0, sizeof(msg)); |
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msg.msg_flags |= MSG_DONTWAIT; |
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if (pvcalls_mask(prod, array_size) > pvcalls_mask(cons, array_size)) { |
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vec[0].iov_base = data->out + pvcalls_mask(cons, array_size); |
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vec[0].iov_len = size; |
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iov_iter_kvec(&msg.msg_iter, READ, vec, 1, size); |
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} else { |
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vec[0].iov_base = data->out + pvcalls_mask(cons, array_size); |
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vec[0].iov_len = array_size - pvcalls_mask(cons, array_size); |
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vec[1].iov_base = data->out; |
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vec[1].iov_len = size - vec[0].iov_len; |
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iov_iter_kvec(&msg.msg_iter, READ, vec, 2, size); |
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} |
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|
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atomic_set(&map->write, 0); |
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ret = inet_sendmsg(map->sock, &msg, size); |
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if (ret == -EAGAIN) { |
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atomic_inc(&map->write); |
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atomic_inc(&map->io); |
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return true; |
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} |
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|
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/* write the data, then update the indexes */ |
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virt_wmb(); |
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if (ret < 0) { |
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intf->out_error = ret; |
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} else { |
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intf->out_error = 0; |
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intf->out_cons = cons + ret; |
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prod = intf->out_prod; |
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} |
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/* update the indexes, then notify the other end */ |
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virt_wmb(); |
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if (prod != cons + ret) { |
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atomic_inc(&map->write); |
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atomic_inc(&map->io); |
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} |
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notify_remote_via_irq(map->irq); |
|
|
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return true; |
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} |
|
|
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static void pvcalls_back_ioworker(struct work_struct *work) |
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{ |
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struct pvcalls_ioworker *ioworker = container_of(work, |
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struct pvcalls_ioworker, register_work); |
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struct sock_mapping *map = container_of(ioworker, struct sock_mapping, |
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ioworker); |
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unsigned int eoi_flags = XEN_EOI_FLAG_SPURIOUS; |
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|
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while (atomic_read(&map->io) > 0) { |
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if (atomic_read(&map->release) > 0) { |
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atomic_set(&map->release, 0); |
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return; |
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} |
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|
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if (atomic_read(&map->read) > 0 && |
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pvcalls_conn_back_read(map)) |
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eoi_flags = 0; |
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if (atomic_read(&map->write) > 0 && |
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pvcalls_conn_back_write(map)) |
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eoi_flags = 0; |
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|
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if (atomic_read(&map->eoi) > 0 && !atomic_read(&map->write)) { |
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atomic_set(&map->eoi, 0); |
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xen_irq_lateeoi(map->irq, eoi_flags); |
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eoi_flags = XEN_EOI_FLAG_SPURIOUS; |
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} |
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|
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atomic_dec(&map->io); |
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} |
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} |
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|
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static int pvcalls_back_socket(struct xenbus_device *dev, |
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struct xen_pvcalls_request *req) |
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{ |
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struct pvcalls_fedata *fedata; |
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int ret; |
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struct xen_pvcalls_response *rsp; |
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|
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fedata = dev_get_drvdata(&dev->dev); |
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|
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if (req->u.socket.domain != AF_INET || |
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req->u.socket.type != SOCK_STREAM || |
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(req->u.socket.protocol != IPPROTO_IP && |
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req->u.socket.protocol != AF_INET)) |
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ret = -EAFNOSUPPORT; |
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else |
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ret = 0; |
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|
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/* leave the actual socket allocation for later */ |
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|
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rsp = RING_GET_RESPONSE(&fedata->ring, fedata->ring.rsp_prod_pvt++); |
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rsp->req_id = req->req_id; |
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rsp->cmd = req->cmd; |
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rsp->u.socket.id = req->u.socket.id; |
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rsp->ret = ret; |
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|
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return 0; |
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} |
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static void pvcalls_sk_state_change(struct sock *sock) |
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{ |
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struct sock_mapping *map = sock->sk_user_data; |
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|
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if (map == NULL) |
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return; |
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|
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atomic_inc(&map->read); |
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notify_remote_via_irq(map->irq); |
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} |
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|
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static void pvcalls_sk_data_ready(struct sock *sock) |
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{ |
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struct sock_mapping *map = sock->sk_user_data; |
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struct pvcalls_ioworker *iow; |
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|
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if (map == NULL) |
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return; |
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|
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iow = &map->ioworker; |
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atomic_inc(&map->read); |
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atomic_inc(&map->io); |
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queue_work(iow->wq, &iow->register_work); |
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} |
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|
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static struct sock_mapping *pvcalls_new_active_socket( |
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struct pvcalls_fedata *fedata, |
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uint64_t id, |
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grant_ref_t ref, |
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evtchn_port_t evtchn, |
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struct socket *sock) |
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{ |
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int ret; |
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struct sock_mapping *map; |
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void *page; |
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|
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map = kzalloc(sizeof(*map), GFP_KERNEL); |
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if (map == NULL) |
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return NULL; |
|
|
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map->fedata = fedata; |
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map->sock = sock; |
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map->id = id; |
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map->ref = ref; |
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|
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ret = xenbus_map_ring_valloc(fedata->dev, &ref, 1, &page); |
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if (ret < 0) |
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goto out; |
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map->ring = page; |
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map->ring_order = map->ring->ring_order; |
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/* first read the order, then map the data ring */ |
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virt_rmb(); |
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if (map->ring_order > MAX_RING_ORDER) { |
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pr_warn("%s frontend requested ring_order %u, which is > MAX (%u)\n", |
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__func__, map->ring_order, MAX_RING_ORDER); |
|
goto out; |
|
} |
|
ret = xenbus_map_ring_valloc(fedata->dev, map->ring->ref, |
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(1 << map->ring_order), &page); |
|
if (ret < 0) |
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goto out; |
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map->bytes = page; |
|
|
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ret = bind_interdomain_evtchn_to_irqhandler_lateeoi( |
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fedata->dev, evtchn, |
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pvcalls_back_conn_event, 0, "pvcalls-backend", map); |
|
if (ret < 0) |
|
goto out; |
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map->irq = ret; |
|
|
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map->data.in = map->bytes; |
|
map->data.out = map->bytes + XEN_FLEX_RING_SIZE(map->ring_order); |
|
|
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map->ioworker.wq = alloc_workqueue("pvcalls_io", WQ_UNBOUND, 1); |
|
if (!map->ioworker.wq) |
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goto out; |
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atomic_set(&map->io, 1); |
|
INIT_WORK(&map->ioworker.register_work, pvcalls_back_ioworker); |
|
|
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down(&fedata->socket_lock); |
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list_add_tail(&map->list, &fedata->socket_mappings); |
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up(&fedata->socket_lock); |
|
|
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write_lock_bh(&map->sock->sk->sk_callback_lock); |
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map->saved_data_ready = map->sock->sk->sk_data_ready; |
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map->sock->sk->sk_user_data = map; |
|
map->sock->sk->sk_data_ready = pvcalls_sk_data_ready; |
|
map->sock->sk->sk_state_change = pvcalls_sk_state_change; |
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write_unlock_bh(&map->sock->sk->sk_callback_lock); |
|
|
|
return map; |
|
out: |
|
down(&fedata->socket_lock); |
|
list_del(&map->list); |
|
pvcalls_back_release_active(fedata->dev, fedata, map); |
|
up(&fedata->socket_lock); |
|
return NULL; |
|
} |
|
|
|
static int pvcalls_back_connect(struct xenbus_device *dev, |
|
struct xen_pvcalls_request *req) |
|
{ |
|
struct pvcalls_fedata *fedata; |
|
int ret = -EINVAL; |
|
struct socket *sock; |
|
struct sock_mapping *map; |
|
struct xen_pvcalls_response *rsp; |
|
struct sockaddr *sa = (struct sockaddr *)&req->u.connect.addr; |
|
|
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fedata = dev_get_drvdata(&dev->dev); |
|
|
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if (req->u.connect.len < sizeof(sa->sa_family) || |
|
req->u.connect.len > sizeof(req->u.connect.addr) || |
|
sa->sa_family != AF_INET) |
|
goto out; |
|
|
|
ret = sock_create(AF_INET, SOCK_STREAM, 0, &sock); |
|
if (ret < 0) |
|
goto out; |
|
ret = inet_stream_connect(sock, sa, req->u.connect.len, 0); |
|
if (ret < 0) { |
|
sock_release(sock); |
|
goto out; |
|
} |
|
|
|
map = pvcalls_new_active_socket(fedata, |
|
req->u.connect.id, |
|
req->u.connect.ref, |
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req->u.connect.evtchn, |
|
sock); |
|
if (!map) { |
|
ret = -EFAULT; |
|
sock_release(sock); |
|
} |
|
|
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out: |
|
rsp = RING_GET_RESPONSE(&fedata->ring, fedata->ring.rsp_prod_pvt++); |
|
rsp->req_id = req->req_id; |
|
rsp->cmd = req->cmd; |
|
rsp->u.connect.id = req->u.connect.id; |
|
rsp->ret = ret; |
|
|
|
return 0; |
|
} |
|
|
|
static int pvcalls_back_release_active(struct xenbus_device *dev, |
|
struct pvcalls_fedata *fedata, |
|
struct sock_mapping *map) |
|
{ |
|
disable_irq(map->irq); |
|
if (map->sock->sk != NULL) { |
|
write_lock_bh(&map->sock->sk->sk_callback_lock); |
|
map->sock->sk->sk_user_data = NULL; |
|
map->sock->sk->sk_data_ready = map->saved_data_ready; |
|
write_unlock_bh(&map->sock->sk->sk_callback_lock); |
|
} |
|
|
|
atomic_set(&map->release, 1); |
|
flush_work(&map->ioworker.register_work); |
|
|
|
xenbus_unmap_ring_vfree(dev, map->bytes); |
|
xenbus_unmap_ring_vfree(dev, (void *)map->ring); |
|
unbind_from_irqhandler(map->irq, map); |
|
|
|
sock_release(map->sock); |
|
kfree(map); |
|
|
|
return 0; |
|
} |
|
|
|
static int pvcalls_back_release_passive(struct xenbus_device *dev, |
|
struct pvcalls_fedata *fedata, |
|
struct sockpass_mapping *mappass) |
|
{ |
|
if (mappass->sock->sk != NULL) { |
|
write_lock_bh(&mappass->sock->sk->sk_callback_lock); |
|
mappass->sock->sk->sk_user_data = NULL; |
|
mappass->sock->sk->sk_data_ready = mappass->saved_data_ready; |
|
write_unlock_bh(&mappass->sock->sk->sk_callback_lock); |
|
} |
|
sock_release(mappass->sock); |
|
flush_workqueue(mappass->wq); |
|
destroy_workqueue(mappass->wq); |
|
kfree(mappass); |
|
|
|
return 0; |
|
} |
|
|
|
static int pvcalls_back_release(struct xenbus_device *dev, |
|
struct xen_pvcalls_request *req) |
|
{ |
|
struct pvcalls_fedata *fedata; |
|
struct sock_mapping *map, *n; |
|
struct sockpass_mapping *mappass; |
|
int ret = 0; |
|
struct xen_pvcalls_response *rsp; |
|
|
|
fedata = dev_get_drvdata(&dev->dev); |
|
|
|
down(&fedata->socket_lock); |
|
list_for_each_entry_safe(map, n, &fedata->socket_mappings, list) { |
|
if (map->id == req->u.release.id) { |
|
list_del(&map->list); |
|
up(&fedata->socket_lock); |
|
ret = pvcalls_back_release_active(dev, fedata, map); |
|
goto out; |
|
} |
|
} |
|
mappass = radix_tree_lookup(&fedata->socketpass_mappings, |
|
req->u.release.id); |
|
if (mappass != NULL) { |
|
radix_tree_delete(&fedata->socketpass_mappings, mappass->id); |
|
up(&fedata->socket_lock); |
|
ret = pvcalls_back_release_passive(dev, fedata, mappass); |
|
} else |
|
up(&fedata->socket_lock); |
|
|
|
out: |
|
rsp = RING_GET_RESPONSE(&fedata->ring, fedata->ring.rsp_prod_pvt++); |
|
rsp->req_id = req->req_id; |
|
rsp->u.release.id = req->u.release.id; |
|
rsp->cmd = req->cmd; |
|
rsp->ret = ret; |
|
return 0; |
|
} |
|
|
|
static void __pvcalls_back_accept(struct work_struct *work) |
|
{ |
|
struct sockpass_mapping *mappass = container_of( |
|
work, struct sockpass_mapping, register_work); |
|
struct sock_mapping *map; |
|
struct pvcalls_ioworker *iow; |
|
struct pvcalls_fedata *fedata; |
|
struct socket *sock; |
|
struct xen_pvcalls_response *rsp; |
|
struct xen_pvcalls_request *req; |
|
int notify; |
|
int ret = -EINVAL; |
|
unsigned long flags; |
|
|
|
fedata = mappass->fedata; |
|
/* |
|
* __pvcalls_back_accept can race against pvcalls_back_accept. |
|
* We only need to check the value of "cmd" on read. It could be |
|
* done atomically, but to simplify the code on the write side, we |
|
* use a spinlock. |
|
*/ |
|
spin_lock_irqsave(&mappass->copy_lock, flags); |
|
req = &mappass->reqcopy; |
|
if (req->cmd != PVCALLS_ACCEPT) { |
|
spin_unlock_irqrestore(&mappass->copy_lock, flags); |
|
return; |
|
} |
|
spin_unlock_irqrestore(&mappass->copy_lock, flags); |
|
|
|
sock = sock_alloc(); |
|
if (sock == NULL) |
|
goto out_error; |
|
sock->type = mappass->sock->type; |
|
sock->ops = mappass->sock->ops; |
|
|
|
ret = inet_accept(mappass->sock, sock, O_NONBLOCK, true); |
|
if (ret == -EAGAIN) { |
|
sock_release(sock); |
|
return; |
|
} |
|
|
|
map = pvcalls_new_active_socket(fedata, |
|
req->u.accept.id_new, |
|
req->u.accept.ref, |
|
req->u.accept.evtchn, |
|
sock); |
|
if (!map) { |
|
ret = -EFAULT; |
|
sock_release(sock); |
|
goto out_error; |
|
} |
|
|
|
map->sockpass = mappass; |
|
iow = &map->ioworker; |
|
atomic_inc(&map->read); |
|
atomic_inc(&map->io); |
|
queue_work(iow->wq, &iow->register_work); |
|
|
|
out_error: |
|
rsp = RING_GET_RESPONSE(&fedata->ring, fedata->ring.rsp_prod_pvt++); |
|
rsp->req_id = req->req_id; |
|
rsp->cmd = req->cmd; |
|
rsp->u.accept.id = req->u.accept.id; |
|
rsp->ret = ret; |
|
RING_PUSH_RESPONSES_AND_CHECK_NOTIFY(&fedata->ring, notify); |
|
if (notify) |
|
notify_remote_via_irq(fedata->irq); |
|
|
|
mappass->reqcopy.cmd = 0; |
|
} |
|
|
|
static void pvcalls_pass_sk_data_ready(struct sock *sock) |
|
{ |
|
struct sockpass_mapping *mappass = sock->sk_user_data; |
|
struct pvcalls_fedata *fedata; |
|
struct xen_pvcalls_response *rsp; |
|
unsigned long flags; |
|
int notify; |
|
|
|
if (mappass == NULL) |
|
return; |
|
|
|
fedata = mappass->fedata; |
|
spin_lock_irqsave(&mappass->copy_lock, flags); |
|
if (mappass->reqcopy.cmd == PVCALLS_POLL) { |
|
rsp = RING_GET_RESPONSE(&fedata->ring, |
|
fedata->ring.rsp_prod_pvt++); |
|
rsp->req_id = mappass->reqcopy.req_id; |
|
rsp->u.poll.id = mappass->reqcopy.u.poll.id; |
|
rsp->cmd = mappass->reqcopy.cmd; |
|
rsp->ret = 0; |
|
|
|
mappass->reqcopy.cmd = 0; |
|
spin_unlock_irqrestore(&mappass->copy_lock, flags); |
|
|
|
RING_PUSH_RESPONSES_AND_CHECK_NOTIFY(&fedata->ring, notify); |
|
if (notify) |
|
notify_remote_via_irq(mappass->fedata->irq); |
|
} else { |
|
spin_unlock_irqrestore(&mappass->copy_lock, flags); |
|
queue_work(mappass->wq, &mappass->register_work); |
|
} |
|
} |
|
|
|
static int pvcalls_back_bind(struct xenbus_device *dev, |
|
struct xen_pvcalls_request *req) |
|
{ |
|
struct pvcalls_fedata *fedata; |
|
int ret; |
|
struct sockpass_mapping *map; |
|
struct xen_pvcalls_response *rsp; |
|
|
|
fedata = dev_get_drvdata(&dev->dev); |
|
|
|
map = kzalloc(sizeof(*map), GFP_KERNEL); |
|
if (map == NULL) { |
|
ret = -ENOMEM; |
|
goto out; |
|
} |
|
|
|
INIT_WORK(&map->register_work, __pvcalls_back_accept); |
|
spin_lock_init(&map->copy_lock); |
|
map->wq = alloc_workqueue("pvcalls_wq", WQ_UNBOUND, 1); |
|
if (!map->wq) { |
|
ret = -ENOMEM; |
|
goto out; |
|
} |
|
|
|
ret = sock_create(AF_INET, SOCK_STREAM, 0, &map->sock); |
|
if (ret < 0) |
|
goto out; |
|
|
|
ret = inet_bind(map->sock, (struct sockaddr *)&req->u.bind.addr, |
|
req->u.bind.len); |
|
if (ret < 0) |
|
goto out; |
|
|
|
map->fedata = fedata; |
|
map->id = req->u.bind.id; |
|
|
|
down(&fedata->socket_lock); |
|
ret = radix_tree_insert(&fedata->socketpass_mappings, map->id, |
|
map); |
|
up(&fedata->socket_lock); |
|
if (ret) |
|
goto out; |
|
|
|
write_lock_bh(&map->sock->sk->sk_callback_lock); |
|
map->saved_data_ready = map->sock->sk->sk_data_ready; |
|
map->sock->sk->sk_user_data = map; |
|
map->sock->sk->sk_data_ready = pvcalls_pass_sk_data_ready; |
|
write_unlock_bh(&map->sock->sk->sk_callback_lock); |
|
|
|
out: |
|
if (ret) { |
|
if (map && map->sock) |
|
sock_release(map->sock); |
|
if (map && map->wq) |
|
destroy_workqueue(map->wq); |
|
kfree(map); |
|
} |
|
rsp = RING_GET_RESPONSE(&fedata->ring, fedata->ring.rsp_prod_pvt++); |
|
rsp->req_id = req->req_id; |
|
rsp->cmd = req->cmd; |
|
rsp->u.bind.id = req->u.bind.id; |
|
rsp->ret = ret; |
|
return 0; |
|
} |
|
|
|
static int pvcalls_back_listen(struct xenbus_device *dev, |
|
struct xen_pvcalls_request *req) |
|
{ |
|
struct pvcalls_fedata *fedata; |
|
int ret = -EINVAL; |
|
struct sockpass_mapping *map; |
|
struct xen_pvcalls_response *rsp; |
|
|
|
fedata = dev_get_drvdata(&dev->dev); |
|
|
|
down(&fedata->socket_lock); |
|
map = radix_tree_lookup(&fedata->socketpass_mappings, req->u.listen.id); |
|
up(&fedata->socket_lock); |
|
if (map == NULL) |
|
goto out; |
|
|
|
ret = inet_listen(map->sock, req->u.listen.backlog); |
|
|
|
out: |
|
rsp = RING_GET_RESPONSE(&fedata->ring, fedata->ring.rsp_prod_pvt++); |
|
rsp->req_id = req->req_id; |
|
rsp->cmd = req->cmd; |
|
rsp->u.listen.id = req->u.listen.id; |
|
rsp->ret = ret; |
|
return 0; |
|
} |
|
|
|
static int pvcalls_back_accept(struct xenbus_device *dev, |
|
struct xen_pvcalls_request *req) |
|
{ |
|
struct pvcalls_fedata *fedata; |
|
struct sockpass_mapping *mappass; |
|
int ret = -EINVAL; |
|
struct xen_pvcalls_response *rsp; |
|
unsigned long flags; |
|
|
|
fedata = dev_get_drvdata(&dev->dev); |
|
|
|
down(&fedata->socket_lock); |
|
mappass = radix_tree_lookup(&fedata->socketpass_mappings, |
|
req->u.accept.id); |
|
up(&fedata->socket_lock); |
|
if (mappass == NULL) |
|
goto out_error; |
|
|
|
/* |
|
* Limitation of the current implementation: only support one |
|
* concurrent accept or poll call on one socket. |
|
*/ |
|
spin_lock_irqsave(&mappass->copy_lock, flags); |
|
if (mappass->reqcopy.cmd != 0) { |
|
spin_unlock_irqrestore(&mappass->copy_lock, flags); |
|
ret = -EINTR; |
|
goto out_error; |
|
} |
|
|
|
mappass->reqcopy = *req; |
|
spin_unlock_irqrestore(&mappass->copy_lock, flags); |
|
queue_work(mappass->wq, &mappass->register_work); |
|
|
|
/* Tell the caller we don't need to send back a notification yet */ |
|
return -1; |
|
|
|
out_error: |
|
rsp = RING_GET_RESPONSE(&fedata->ring, fedata->ring.rsp_prod_pvt++); |
|
rsp->req_id = req->req_id; |
|
rsp->cmd = req->cmd; |
|
rsp->u.accept.id = req->u.accept.id; |
|
rsp->ret = ret; |
|
return 0; |
|
} |
|
|
|
static int pvcalls_back_poll(struct xenbus_device *dev, |
|
struct xen_pvcalls_request *req) |
|
{ |
|
struct pvcalls_fedata *fedata; |
|
struct sockpass_mapping *mappass; |
|
struct xen_pvcalls_response *rsp; |
|
struct inet_connection_sock *icsk; |
|
struct request_sock_queue *queue; |
|
unsigned long flags; |
|
int ret; |
|
bool data; |
|
|
|
fedata = dev_get_drvdata(&dev->dev); |
|
|
|
down(&fedata->socket_lock); |
|
mappass = radix_tree_lookup(&fedata->socketpass_mappings, |
|
req->u.poll.id); |
|
up(&fedata->socket_lock); |
|
if (mappass == NULL) |
|
return -EINVAL; |
|
|
|
/* |
|
* Limitation of the current implementation: only support one |
|
* concurrent accept or poll call on one socket. |
|
*/ |
|
spin_lock_irqsave(&mappass->copy_lock, flags); |
|
if (mappass->reqcopy.cmd != 0) { |
|
ret = -EINTR; |
|
goto out; |
|
} |
|
|
|
mappass->reqcopy = *req; |
|
icsk = inet_csk(mappass->sock->sk); |
|
queue = &icsk->icsk_accept_queue; |
|
data = READ_ONCE(queue->rskq_accept_head) != NULL; |
|
if (data) { |
|
mappass->reqcopy.cmd = 0; |
|
ret = 0; |
|
goto out; |
|
} |
|
spin_unlock_irqrestore(&mappass->copy_lock, flags); |
|
|
|
/* Tell the caller we don't need to send back a notification yet */ |
|
return -1; |
|
|
|
out: |
|
spin_unlock_irqrestore(&mappass->copy_lock, flags); |
|
|
|
rsp = RING_GET_RESPONSE(&fedata->ring, fedata->ring.rsp_prod_pvt++); |
|
rsp->req_id = req->req_id; |
|
rsp->cmd = req->cmd; |
|
rsp->u.poll.id = req->u.poll.id; |
|
rsp->ret = ret; |
|
return 0; |
|
} |
|
|
|
static int pvcalls_back_handle_cmd(struct xenbus_device *dev, |
|
struct xen_pvcalls_request *req) |
|
{ |
|
int ret = 0; |
|
|
|
switch (req->cmd) { |
|
case PVCALLS_SOCKET: |
|
ret = pvcalls_back_socket(dev, req); |
|
break; |
|
case PVCALLS_CONNECT: |
|
ret = pvcalls_back_connect(dev, req); |
|
break; |
|
case PVCALLS_RELEASE: |
|
ret = pvcalls_back_release(dev, req); |
|
break; |
|
case PVCALLS_BIND: |
|
ret = pvcalls_back_bind(dev, req); |
|
break; |
|
case PVCALLS_LISTEN: |
|
ret = pvcalls_back_listen(dev, req); |
|
break; |
|
case PVCALLS_ACCEPT: |
|
ret = pvcalls_back_accept(dev, req); |
|
break; |
|
case PVCALLS_POLL: |
|
ret = pvcalls_back_poll(dev, req); |
|
break; |
|
default: |
|
{ |
|
struct pvcalls_fedata *fedata; |
|
struct xen_pvcalls_response *rsp; |
|
|
|
fedata = dev_get_drvdata(&dev->dev); |
|
rsp = RING_GET_RESPONSE( |
|
&fedata->ring, fedata->ring.rsp_prod_pvt++); |
|
rsp->req_id = req->req_id; |
|
rsp->cmd = req->cmd; |
|
rsp->ret = -ENOTSUPP; |
|
break; |
|
} |
|
} |
|
return ret; |
|
} |
|
|
|
static void pvcalls_back_work(struct pvcalls_fedata *fedata) |
|
{ |
|
int notify, notify_all = 0, more = 1; |
|
struct xen_pvcalls_request req; |
|
struct xenbus_device *dev = fedata->dev; |
|
|
|
while (more) { |
|
while (RING_HAS_UNCONSUMED_REQUESTS(&fedata->ring)) { |
|
RING_COPY_REQUEST(&fedata->ring, |
|
fedata->ring.req_cons++, |
|
&req); |
|
|
|
if (!pvcalls_back_handle_cmd(dev, &req)) { |
|
RING_PUSH_RESPONSES_AND_CHECK_NOTIFY( |
|
&fedata->ring, notify); |
|
notify_all += notify; |
|
} |
|
} |
|
|
|
if (notify_all) { |
|
notify_remote_via_irq(fedata->irq); |
|
notify_all = 0; |
|
} |
|
|
|
RING_FINAL_CHECK_FOR_REQUESTS(&fedata->ring, more); |
|
} |
|
} |
|
|
|
static irqreturn_t pvcalls_back_event(int irq, void *dev_id) |
|
{ |
|
struct xenbus_device *dev = dev_id; |
|
struct pvcalls_fedata *fedata = NULL; |
|
unsigned int eoi_flags = XEN_EOI_FLAG_SPURIOUS; |
|
|
|
if (dev) { |
|
fedata = dev_get_drvdata(&dev->dev); |
|
if (fedata) { |
|
pvcalls_back_work(fedata); |
|
eoi_flags = 0; |
|
} |
|
} |
|
|
|
xen_irq_lateeoi(irq, eoi_flags); |
|
|
|
return IRQ_HANDLED; |
|
} |
|
|
|
static irqreturn_t pvcalls_back_conn_event(int irq, void *sock_map) |
|
{ |
|
struct sock_mapping *map = sock_map; |
|
struct pvcalls_ioworker *iow; |
|
|
|
if (map == NULL || map->sock == NULL || map->sock->sk == NULL || |
|
map->sock->sk->sk_user_data != map) { |
|
xen_irq_lateeoi(irq, 0); |
|
return IRQ_HANDLED; |
|
} |
|
|
|
iow = &map->ioworker; |
|
|
|
atomic_inc(&map->write); |
|
atomic_inc(&map->eoi); |
|
atomic_inc(&map->io); |
|
queue_work(iow->wq, &iow->register_work); |
|
|
|
return IRQ_HANDLED; |
|
} |
|
|
|
static int backend_connect(struct xenbus_device *dev) |
|
{ |
|
int err; |
|
evtchn_port_t evtchn; |
|
grant_ref_t ring_ref; |
|
struct pvcalls_fedata *fedata = NULL; |
|
|
|
fedata = kzalloc(sizeof(struct pvcalls_fedata), GFP_KERNEL); |
|
if (!fedata) |
|
return -ENOMEM; |
|
|
|
fedata->irq = -1; |
|
err = xenbus_scanf(XBT_NIL, dev->otherend, "port", "%u", |
|
&evtchn); |
|
if (err != 1) { |
|
err = -EINVAL; |
|
xenbus_dev_fatal(dev, err, "reading %s/event-channel", |
|
dev->otherend); |
|
goto error; |
|
} |
|
|
|
err = xenbus_scanf(XBT_NIL, dev->otherend, "ring-ref", "%u", &ring_ref); |
|
if (err != 1) { |
|
err = -EINVAL; |
|
xenbus_dev_fatal(dev, err, "reading %s/ring-ref", |
|
dev->otherend); |
|
goto error; |
|
} |
|
|
|
err = bind_interdomain_evtchn_to_irq_lateeoi(dev, evtchn); |
|
if (err < 0) |
|
goto error; |
|
fedata->irq = err; |
|
|
|
err = request_threaded_irq(fedata->irq, NULL, pvcalls_back_event, |
|
IRQF_ONESHOT, "pvcalls-back", dev); |
|
if (err < 0) |
|
goto error; |
|
|
|
err = xenbus_map_ring_valloc(dev, &ring_ref, 1, |
|
(void **)&fedata->sring); |
|
if (err < 0) |
|
goto error; |
|
|
|
BACK_RING_INIT(&fedata->ring, fedata->sring, XEN_PAGE_SIZE * 1); |
|
fedata->dev = dev; |
|
|
|
INIT_LIST_HEAD(&fedata->socket_mappings); |
|
INIT_RADIX_TREE(&fedata->socketpass_mappings, GFP_KERNEL); |
|
sema_init(&fedata->socket_lock, 1); |
|
dev_set_drvdata(&dev->dev, fedata); |
|
|
|
down(&pvcalls_back_global.frontends_lock); |
|
list_add_tail(&fedata->list, &pvcalls_back_global.frontends); |
|
up(&pvcalls_back_global.frontends_lock); |
|
|
|
return 0; |
|
|
|
error: |
|
if (fedata->irq >= 0) |
|
unbind_from_irqhandler(fedata->irq, dev); |
|
if (fedata->sring != NULL) |
|
xenbus_unmap_ring_vfree(dev, fedata->sring); |
|
kfree(fedata); |
|
return err; |
|
} |
|
|
|
static int backend_disconnect(struct xenbus_device *dev) |
|
{ |
|
struct pvcalls_fedata *fedata; |
|
struct sock_mapping *map, *n; |
|
struct sockpass_mapping *mappass; |
|
struct radix_tree_iter iter; |
|
void **slot; |
|
|
|
|
|
fedata = dev_get_drvdata(&dev->dev); |
|
|
|
down(&fedata->socket_lock); |
|
list_for_each_entry_safe(map, n, &fedata->socket_mappings, list) { |
|
list_del(&map->list); |
|
pvcalls_back_release_active(dev, fedata, map); |
|
} |
|
|
|
radix_tree_for_each_slot(slot, &fedata->socketpass_mappings, &iter, 0) { |
|
mappass = radix_tree_deref_slot(slot); |
|
if (!mappass) |
|
continue; |
|
if (radix_tree_exception(mappass)) { |
|
if (radix_tree_deref_retry(mappass)) |
|
slot = radix_tree_iter_retry(&iter); |
|
} else { |
|
radix_tree_delete(&fedata->socketpass_mappings, |
|
mappass->id); |
|
pvcalls_back_release_passive(dev, fedata, mappass); |
|
} |
|
} |
|
up(&fedata->socket_lock); |
|
|
|
unbind_from_irqhandler(fedata->irq, dev); |
|
xenbus_unmap_ring_vfree(dev, fedata->sring); |
|
|
|
list_del(&fedata->list); |
|
kfree(fedata); |
|
dev_set_drvdata(&dev->dev, NULL); |
|
|
|
return 0; |
|
} |
|
|
|
static int pvcalls_back_probe(struct xenbus_device *dev, |
|
const struct xenbus_device_id *id) |
|
{ |
|
int err, abort; |
|
struct xenbus_transaction xbt; |
|
|
|
again: |
|
abort = 1; |
|
|
|
err = xenbus_transaction_start(&xbt); |
|
if (err) { |
|
pr_warn("%s cannot create xenstore transaction\n", __func__); |
|
return err; |
|
} |
|
|
|
err = xenbus_printf(xbt, dev->nodename, "versions", "%s", |
|
PVCALLS_VERSIONS); |
|
if (err) { |
|
pr_warn("%s write out 'versions' failed\n", __func__); |
|
goto abort; |
|
} |
|
|
|
err = xenbus_printf(xbt, dev->nodename, "max-page-order", "%u", |
|
MAX_RING_ORDER); |
|
if (err) { |
|
pr_warn("%s write out 'max-page-order' failed\n", __func__); |
|
goto abort; |
|
} |
|
|
|
err = xenbus_printf(xbt, dev->nodename, "function-calls", |
|
XENBUS_FUNCTIONS_CALLS); |
|
if (err) { |
|
pr_warn("%s write out 'function-calls' failed\n", __func__); |
|
goto abort; |
|
} |
|
|
|
abort = 0; |
|
abort: |
|
err = xenbus_transaction_end(xbt, abort); |
|
if (err) { |
|
if (err == -EAGAIN && !abort) |
|
goto again; |
|
pr_warn("%s cannot complete xenstore transaction\n", __func__); |
|
return err; |
|
} |
|
|
|
if (abort) |
|
return -EFAULT; |
|
|
|
xenbus_switch_state(dev, XenbusStateInitWait); |
|
|
|
return 0; |
|
} |
|
|
|
static void set_backend_state(struct xenbus_device *dev, |
|
enum xenbus_state state) |
|
{ |
|
while (dev->state != state) { |
|
switch (dev->state) { |
|
case XenbusStateClosed: |
|
switch (state) { |
|
case XenbusStateInitWait: |
|
case XenbusStateConnected: |
|
xenbus_switch_state(dev, XenbusStateInitWait); |
|
break; |
|
case XenbusStateClosing: |
|
xenbus_switch_state(dev, XenbusStateClosing); |
|
break; |
|
default: |
|
WARN_ON(1); |
|
} |
|
break; |
|
case XenbusStateInitWait: |
|
case XenbusStateInitialised: |
|
switch (state) { |
|
case XenbusStateConnected: |
|
if (backend_connect(dev)) |
|
return; |
|
xenbus_switch_state(dev, XenbusStateConnected); |
|
break; |
|
case XenbusStateClosing: |
|
case XenbusStateClosed: |
|
xenbus_switch_state(dev, XenbusStateClosing); |
|
break; |
|
default: |
|
WARN_ON(1); |
|
} |
|
break; |
|
case XenbusStateConnected: |
|
switch (state) { |
|
case XenbusStateInitWait: |
|
case XenbusStateClosing: |
|
case XenbusStateClosed: |
|
down(&pvcalls_back_global.frontends_lock); |
|
backend_disconnect(dev); |
|
up(&pvcalls_back_global.frontends_lock); |
|
xenbus_switch_state(dev, XenbusStateClosing); |
|
break; |
|
default: |
|
WARN_ON(1); |
|
} |
|
break; |
|
case XenbusStateClosing: |
|
switch (state) { |
|
case XenbusStateInitWait: |
|
case XenbusStateConnected: |
|
case XenbusStateClosed: |
|
xenbus_switch_state(dev, XenbusStateClosed); |
|
break; |
|
default: |
|
WARN_ON(1); |
|
} |
|
break; |
|
default: |
|
WARN_ON(1); |
|
} |
|
} |
|
} |
|
|
|
static void pvcalls_back_changed(struct xenbus_device *dev, |
|
enum xenbus_state frontend_state) |
|
{ |
|
switch (frontend_state) { |
|
case XenbusStateInitialising: |
|
set_backend_state(dev, XenbusStateInitWait); |
|
break; |
|
|
|
case XenbusStateInitialised: |
|
case XenbusStateConnected: |
|
set_backend_state(dev, XenbusStateConnected); |
|
break; |
|
|
|
case XenbusStateClosing: |
|
set_backend_state(dev, XenbusStateClosing); |
|
break; |
|
|
|
case XenbusStateClosed: |
|
set_backend_state(dev, XenbusStateClosed); |
|
if (xenbus_dev_is_online(dev)) |
|
break; |
|
device_unregister(&dev->dev); |
|
break; |
|
case XenbusStateUnknown: |
|
set_backend_state(dev, XenbusStateClosed); |
|
device_unregister(&dev->dev); |
|
break; |
|
|
|
default: |
|
xenbus_dev_fatal(dev, -EINVAL, "saw state %d at frontend", |
|
frontend_state); |
|
break; |
|
} |
|
} |
|
|
|
static int pvcalls_back_remove(struct xenbus_device *dev) |
|
{ |
|
return 0; |
|
} |
|
|
|
static int pvcalls_back_uevent(struct xenbus_device *xdev, |
|
struct kobj_uevent_env *env) |
|
{ |
|
return 0; |
|
} |
|
|
|
static const struct xenbus_device_id pvcalls_back_ids[] = { |
|
{ "pvcalls" }, |
|
{ "" } |
|
}; |
|
|
|
static struct xenbus_driver pvcalls_back_driver = { |
|
.ids = pvcalls_back_ids, |
|
.probe = pvcalls_back_probe, |
|
.remove = pvcalls_back_remove, |
|
.uevent = pvcalls_back_uevent, |
|
.otherend_changed = pvcalls_back_changed, |
|
}; |
|
|
|
static int __init pvcalls_back_init(void) |
|
{ |
|
int ret; |
|
|
|
if (!xen_domain()) |
|
return -ENODEV; |
|
|
|
ret = xenbus_register_backend(&pvcalls_back_driver); |
|
if (ret < 0) |
|
return ret; |
|
|
|
sema_init(&pvcalls_back_global.frontends_lock, 1); |
|
INIT_LIST_HEAD(&pvcalls_back_global.frontends); |
|
return 0; |
|
} |
|
module_init(pvcalls_back_init); |
|
|
|
static void __exit pvcalls_back_fin(void) |
|
{ |
|
struct pvcalls_fedata *fedata, *nfedata; |
|
|
|
down(&pvcalls_back_global.frontends_lock); |
|
list_for_each_entry_safe(fedata, nfedata, |
|
&pvcalls_back_global.frontends, list) { |
|
backend_disconnect(fedata->dev); |
|
} |
|
up(&pvcalls_back_global.frontends_lock); |
|
|
|
xenbus_unregister_driver(&pvcalls_back_driver); |
|
} |
|
|
|
module_exit(pvcalls_back_fin); |
|
|
|
MODULE_DESCRIPTION("Xen PV Calls backend driver"); |
|
MODULE_AUTHOR("Stefano Stabellini <[email protected]>"); |
|
MODULE_LICENSE("GPL");
|
|
|