path: root/drivers/net/hyperv/netvsc.c

/*
 * Copyright (c) 2009, Microsoft Corporation.
 *
 * This program is free software; you can redistribute it and/or modify it
 * under the terms and conditions of the GNU General Public License,
 * version 2, as published by the Free Software Foundation.
 *
 * This program is distributed in the hope it will be useful, but WITHOUT
 * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
 * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License for
 * more details.
 *
 * You should have received a copy of the GNU General Public License along with
 * this program; if not, see <http://www.gnu.org/licenses/>.
 *
 * Authors:
 *   Haiyang Zhang <haiyangz@microsoft.com>
 *   Hank Janssen  <hjanssen@microsoft.com>
 */
#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt

#include <linux/kernel.h>
#include <linux/sched.h>
#include <linux/wait.h>
#include <linux/mm.h>
#include <linux/delay.h>
#include <linux/io.h>
#include <linux/slab.h>
#include <linux/netdevice.h>
#include <linux/if_ether.h>
#include <asm/sync_bitops.h>

#include "hyperv_net.h"


static struct netvsc_device *alloc_net_device(struct hv_device *device)
{
	struct netvsc_device *net_device;
	struct net_device *ndev = hv_get_drvdata(device);

	net_device = kzalloc(sizeof(struct netvsc_device), GFP_KERNEL);
	if (!net_device)
		return NULL;

	init_waitqueue_head(&net_device->wait_drain);
	net_device->start_remove = false;
	net_device->destroy = false;
	net_device->dev = device;
	net_device->ndev = ndev;

	hv_set_drvdata(device, net_device);
	return net_device;
}

static struct netvsc_device *get_outbound_net_device(struct hv_device *device)
{
	struct netvsc_device *net_device;

	net_device = hv_get_drvdata(device);
	if (net_device && net_device->destroy)
		net_device = NULL;

	return net_device;
}

static struct netvsc_device *get_inbound_net_device(struct hv_device *device)
{
	struct netvsc_device *net_device;

	net_device = hv_get_drvdata(device);

	if (!net_device)
		goto get_in_err;

	if (net_device->destroy &&
		atomic_read(&net_device->num_outstanding_sends) == 0)
		net_device = NULL;

get_in_err:
	return net_device;
}


static int netvsc_destroy_buf(struct netvsc_device *net_device)
{
	struct nvsp_message *revoke_packet;
	int ret = 0;
	struct net_device *ndev = net_device->ndev;

	/*
	 * If we got a section count, it means we received a
	 * SendReceiveBufferComplete msg (ie sent
	 * NvspMessage1TypeSendReceiveBuffer msg) therefore, we need
	 * to send a revoke msg here
	 */
	if (net_device->recv_section_cnt) {
		/* Send the revoke receive buffer */
		revoke_packet = &net_device->revoke_packet;
		memset(revoke_packet, 0, sizeof(struct nvsp_message));

		revoke_packet->hdr.msg_type =
			NVSP_MSG1_TYPE_REVOKE_RECV_BUF;
		revoke_packet->msg.v1_msg.
		revoke_recv_buf.id = NETVSC_RECEIVE_BUFFER_ID;

		ret = vmbus_sendpacket(net_device->dev->channel,
				       revoke_packet,
				       sizeof(struct nvsp_message),
				       (unsigned long)revoke_packet,
				       VM_PKT_DATA_INBAND, 0);
		/*
		 * If we failed here, we might as well return and
		 * have a leak rather than continue and a bugchk
		 */
		if (ret != 0) {
			netdev_err(ndev, "unable to send "
				"revoke receive buffer to netvsp\n");
			return ret;
		}
	}

	/* Teardown the gpadl on the vsp end */
	if (net_device->recv_buf_gpadl_handle) {
		ret = vmbus_teardown_gpadl(net_device->dev->channel,
			   net_device->recv_buf_gpadl_handle);

		/* If we failed here, we might as well return and have a leak
		 * rather than continue and a bugchk
		 */
		if (ret != 0) {
			netdev_err(ndev,
				   "unable to teardown receive buffer's gpadl\n");
			return ret;
		}
		net_device->recv_buf_gpadl_handle = 0;
	}

	if (net_device->recv_buf) {
		/* Free up the receive buffer */
		vfree(net_device->recv_buf);
		net_device->recv_buf = NULL;
	}

	if (net_device->recv_section) {
		net_device->recv_section_cnt = 0;
		kfree(net_device->recv_section);
		net_device->recv_section = NULL;
	}