Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1751829AbdFOTLN (ORCPT ); Thu, 15 Jun 2017 15:11:13 -0400 Received: from mail.kernel.org ([198.145.29.99]:52554 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752545AbdFOTKD (ORCPT ); Thu, 15 Jun 2017 15:10:03 -0400 DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org 3AB0D239DA Authentication-Results: mail.kernel.org; dmarc=none (p=none dis=none) header.from=kernel.org Authentication-Results: mail.kernel.org; spf=none smtp.mailfrom=sstabellini@kernel.org From: Stefano Stabellini To: xen-devel@lists.xen.org Cc: linux-kernel@vger.kernel.org, sstabellini@kernel.org, jgross@suse.com, boris.ostrovsky@oracle.com, Stefano Stabellini Subject: [PATCH v4 16/18] xen/pvcalls: implement read Date: Thu, 15 Jun 2017 12:09:45 -0700 Message-Id: <1497553787-3709-16-git-send-email-sstabellini@kernel.org> X-Mailer: git-send-email 1.9.1 In-Reply-To: <1497553787-3709-1-git-send-email-sstabellini@kernel.org> References: <1497553787-3709-1-git-send-email-sstabellini@kernel.org> Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 3541 Lines: 120 When an active socket has data available, increment the io and read counters, and schedule the ioworker. Implement the read function by reading from the socket, writing the data to the data ring. Set in_error on error. Signed-off-by: Stefano Stabellini CC: boris.ostrovsky@oracle.com CC: jgross@suse.com --- drivers/xen/pvcalls-back.c | 85 ++++++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 85 insertions(+) diff --git a/drivers/xen/pvcalls-back.c b/drivers/xen/pvcalls-back.c index b9a10b9..65d9eba 100644 --- a/drivers/xen/pvcalls-back.c +++ b/drivers/xen/pvcalls-back.c @@ -100,6 +100,81 @@ static int pvcalls_back_release_active(struct xenbus_device *dev, static void pvcalls_conn_back_read(void *opaque) { + struct sock_mapping *map = (struct sock_mapping *)opaque; + struct msghdr msg; + struct kvec vec[2]; + RING_IDX cons, prod, size, wanted, array_size, masked_prod, masked_cons; + int32_t error; + struct pvcalls_data_intf *intf = map->ring; + struct pvcalls_data *data = &map->data; + unsigned long flags; + int ret; + + array_size = XEN_FLEX_RING_SIZE(map->ring_order); + cons = intf->in_cons; + prod = intf->in_prod; + error = intf->in_error; + /* read the indexes first, then deal with the data */ + virt_mb(); + + if (error) + return; + + size = pvcalls_queued(prod, cons, array_size); + if (size >= array_size) + return; + spin_lock_irqsave(&map->sock->sk->sk_receive_queue.lock, flags); + if (skb_queue_empty(&map->sock->sk->sk_receive_queue)) { + atomic_set(&map->read, 0); + spin_unlock_irqrestore(&map->sock->sk->sk_receive_queue.lock, + flags); + return; + } + spin_unlock_irqrestore(&map->sock->sk->sk_receive_queue.lock, flags); + wanted = array_size - size; + masked_prod = pvcalls_mask(prod, array_size); + masked_cons = pvcalls_mask(cons, array_size); + + memset(&msg, 0, sizeof(msg)); + msg.msg_iter.type = ITER_KVEC|WRITE; + msg.msg_iter.count = wanted; + if (masked_prod < masked_cons) { + vec[0].iov_base = data->in + masked_prod; + vec[0].iov_len = wanted; + msg.msg_iter.kvec = vec; + msg.msg_iter.nr_segs = 1; + } else { + vec[0].iov_base = data->in + masked_prod; + vec[0].iov_len = array_size - masked_prod; + vec[1].iov_base = data->in; + vec[1].iov_len = wanted - vec[0].iov_len; + msg.msg_iter.kvec = vec; + msg.msg_iter.nr_segs = 2; + } + + atomic_set(&map->read, 0); + ret = inet_recvmsg(map->sock, &msg, wanted, MSG_DONTWAIT); + WARN_ON(ret > wanted); + if (ret == -EAGAIN) /* shouldn't happen */ + return; + if (!ret) + ret = -ENOTCONN; + spin_lock_irqsave(&map->sock->sk->sk_receive_queue.lock, flags); + if (ret > 0 && !skb_queue_empty(&map->sock->sk->sk_receive_queue)) + atomic_inc(&map->read); + spin_unlock_irqrestore(&map->sock->sk->sk_receive_queue.lock, flags); + + /* write the data, then modify the indexes */ + virt_wmb(); + if (ret < 0) + intf->in_error = ret; + else + intf->in_prod = prod + ret; + /* update the indexes, then notify the other end */ + virt_wmb(); + notify_remote_via_irq(map->irq); + + return; } static int pvcalls_conn_back_write(struct sock_mapping *map) @@ -172,6 +247,16 @@ static void pvcalls_sk_state_change(struct sock *sock) static void pvcalls_sk_data_ready(struct sock *sock) { + struct sock_mapping *map = sock->sk_user_data; + struct pvcalls_ioworker *iow; + + if (map == NULL) + return; + + iow = &map->ioworker; + atomic_inc(&map->read); + atomic_inc(&map->io); + queue_work(iow->wq, &iow->register_work); } static struct sock_mapping *pvcalls_new_active_socket( -- 1.9.1