[linux-2.6-block.git] / drivers / hv / channel_mgmt.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, write to the Free Software Foundation, Inc., 59 Temple
 * Place - Suite 330, Boston, MA 02111-1307 USA.
 *
 * 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/slab.h>
#include <linux/list.h>
#include <linux/module.h>
#include <linux/completion.h>
#include <linux/hyperv.h>

#include "hyperv_vmbus.h"

struct vmbus_channel_message_table_entry {
	enum vmbus_channel_message_type message_type;
	void (*message_handler)(struct vmbus_channel_message_header *msg);
};


/**
 * vmbus_prep_negotiate_resp() - Create default response for Hyper-V Negotiate message
 * @icmsghdrp: Pointer to msg header structure
 * @icmsg_negotiate: Pointer to negotiate message structure
 * @buf: Raw buffer channel data
 *
 * @icmsghdrp is of type &struct icmsg_hdr.
 * @negop is of type &struct icmsg_negotiate.
 * Set up and fill in default negotiate response message.
 *
 * The max_fw_version specifies the maximum framework version that
 * we can support and max _srv_version specifies the maximum service
 * version we can support. A special value MAX_SRV_VER can be
 * specified to indicate that we can handle the maximum version
 * exposed by the host.
 *
 * Mainly used by Hyper-V drivers.
 */
void vmbus_prep_negotiate_resp(struct icmsg_hdr *icmsghdrp,
				struct icmsg_negotiate *negop, u8 *buf,
				int max_fw_version, int max_srv_version)
{
	int icframe_vercnt;
	int icmsg_vercnt;
	int i;

	icmsghdrp->icmsgsize = 0x10;

	negop = (struct icmsg_negotiate *)&buf[
		sizeof(struct vmbuspipe_hdr) +
		sizeof(struct icmsg_hdr)];

	icframe_vercnt = negop->icframe_vercnt;
	icmsg_vercnt = negop->icmsg_vercnt;

	/*
	 * Select the framework version number we will
	 * support.
	 */

	for (i = 0; i < negop->icframe_vercnt; i++) {
		if (negop->icversion_data[i].major <= max_fw_version)
			icframe_vercnt = negop->icversion_data[i].major;
	}

	for (i = negop->icframe_vercnt;
		 (i < negop->icframe_vercnt + negop->icmsg_vercnt); i++) {
		if (negop->icversion_data[i].major <= max_srv_version)
			icmsg_vercnt = negop->icversion_data[i].major;
	}

	/*
	 * Respond with the maximum framework and service
	 * version numbers we can support.
	 */
	negop->icframe_vercnt = 1;
	negop->icmsg_vercnt = 1;
	negop->icversion_data[0].major = icframe_vercnt;
	negop->icversion_data[0].minor = 0;
	negop->icversion_data[1].major = icmsg_vercnt;
	negop->icversion_data[1].minor = 0;
}

EXPORT_SYMBOL_GPL(vmbus_prep_negotiate_resp);

/*
 * alloc_channel - Allocate and initialize a vmbus channel object
 */
static struct vmbus_channel *alloc_channel(void)
{
	struct vmbus_channel *channel;

	channel = kzalloc(sizeof(*channel), GFP_ATOMIC);
	if (!channel)
		return NULL;

	spin_lock_init(&channel->inbound_lock);

	channel->controlwq = create_workqueue("hv_vmbus_ctl");
	if (!channel->controlwq) {
		kfree(channel);
		return NULL;
	}

	return channel;
}

/*
 * release_hannel - Release the vmbus channel object itself
 */
static void release_channel(struct work_struct *work)
{
	struct vmbus_channel *channel = container_of(work,
						     struct vmbus_channel,
						     work);

	destroy_workqueue(channel->controlwq);

	kfree(channel);
}

/*
 * free_channel - Release the resources used by the vmbus channel object
 */
static void free_channel(struct vmbus_channel *channel)
{

	/*
	 * We have to release the channel's workqueue/thread in the vmbus's
	 * workqueue/thread context
	 * ie we can't destroy ourselves.
	 */
	INIT_WORK(&channel->work, release_channel);
	queue_work(vmbus_connection.work_queue, &channel->work);
}


/*
 * vmbus_process_rescind_offer -
 * Rescind the offer by initiating a device removal
 */
static void vmbus_process_rescind_offer(struct work_struct *work)
{
	struct vmbus_channel *channel = container_of(work,
						     struct vmbus_channel,
						     work);

	vmbus_device_unregister(channel->device_obj);
}

void vmbus_free_channels(void)
{
	struct vmbus_channel *channel;

	list_for_each_entry(channel, &vmbus_connection.chn_list, listentry) {
		vmbus_device_unregister(channel->device_obj);
		kfree(channel->device_obj);
		free_channel(channel);
	}
}

/*
 * vmbus_process_offer - Process the offer by creating a channel/device
 * associated with this offer
 */
static void vmbus_process_offer(struct work_struct *work)
{
	struct vmbus_channel *newchannel = container_of(work,
							struct vmbus_channel,
							work);
	struct vmbus_channel *channel;
	bool fnew = true;
	int ret;
	unsigned long flags;

	/* The next possible work is rescind handling */
	INIT_WORK(&newchannel->work, vmbus_process_rescind_offer);

	/* Make sure this is a new offer */
	spin_lock_irqsave(&vmbus_connection.channel_lock, flags);

	list_for_each_entry(channel, &vmbus_connection.chn_list, listentry) {
		if (!uuid_le_cmp(channel->offermsg.offer.if_type,
			newchannel->offermsg.offer.if_type) &&
			!uuid_le_cmp(channel->offermsg.offer.if_instance,
				newchannel->offermsg.offer.if_instance)) {
			fnew = false;
			break;
		}
	}

	if (fnew)
		list_add_tail(&newchannel->listentry,
			      &vmbus_connection.chn_list);

	spin_unlock_irqrestore(&vmbus_connection.channel_lock, flags);

	if (!fnew) {
		free_channel(newchannel);
		return;
	}

	/*
	 * Start the process of binding this offer to the driver
	 * We need to set the DeviceObject field before calling
	 * vmbus_child_dev_add()
	 */
	newchannel->device_obj = vmbus_device_create(
		&newchannel->offermsg.offer.if_type,
		&newchannel->offermsg.offer.if_instance,
		newchannel);

	/*
	 * Add the new device to the bus. This will kick off device-driver
	 * binding which eventually invokes the device driver's AddDevice()
	 * method.
	 */
	ret = vmbus_device_register(newchannel->device_obj);
	if (ret != 0) {
		pr_err("unable to add child device object (relid %d)\n",
			   newchannel->offermsg.child_relid);

		spin_lock_irqsave(&vmbus_connection.channel_lock, flags);
		list_del(&newchannel->listentry);
		spin_unlock_irqrestore(&vmbus_connection.channel_lock, flags);
		kfree(newchannel->device_obj);

		free_channel(newchannel);
	} else {
		/*
		 * This state is used to indicate a successful open
		 * so that when we do close the channel normally, we
		 * can cleanup properly
		 */
		newchannel->state = CHANNEL_OPEN_STATE;
	}
}

/*
 * vmbus_onoffer - Handler for channel offers from vmbus in parent partition.
 *
 */
static void vmbus_onoffer(struct vmbus_channel_message_header *hdr)
{
	struct vmbus_channel_offer_channel *offer;
	struct vmbus_channel *newchannel;

	offer = (struct vmbus_channel_offer_channel *)hdr;

	/* Allocate the channel object and save this offer. */
	newchannel = alloc_channel();
	if (!newchannel) {
		pr_err("Unable to allocate channel object\n");
		return;
	}

	memcpy(&newchannel->offermsg, offer,
	       sizeof(struct vmbus_channel_offer_channel));
	newchannel->monitor_grp = (u8)offer->monitorid / 32;
	newchannel->monitor_bit = (u8)offer->monitorid % 32;

	INIT_WORK(&newchannel->work, vmbus_process_offer);
	queue_work(newchannel->controlwq, &newchannel->work);
}

/*
 * vmbus_onoffer_rescind - Rescind offer handler.
 *
 * We queue a work item to process this offer synchronously
 */
static void vmbus_onoffer_rescind(struct vmbus_channel_message_header *hdr)
{
	struct vmbus_channel_rescind_offer *rescind;
	struct vmbus_channel *channel;

	rescind = (struct vmbus_channel_rescind_offer *)hdr;
	channel = relid2channel(rescind->child_relid);

	if (channel == NULL)
		/* Just return here, no channel found */
		return;

	/* work is initialized for vmbus_process_rescind_offer() from
	 * vmbus_process_offer() where the channel got created */
	queue_work(channel->controlwq, &channel->work);
}

/*
 * vmbus_onoffers_delivered -
 * This is invoked when all offers have been delivered.
 *
 * Nothing to do here.
 */
static void vmbus_onoffers_delivered(
			struct vmbus_channel_message_header *hdr)
{
}

/*
 * vmbus_onopen_result - Open result handler.
 *
 * This is invoked when we received a response to our channel open request.
 * Find the matching request, copy the response and signal the requesting
 * thread.
 */
static void vmbus_onopen_result(struct vmbus_channel_message_header *hdr)
{
	struct vmbus_channel_open_result *result;
	struct vmbus_channel_msginfo *msginfo;
	struct vmbus_channel_message_header *requestheader;
	struct vmbus_channel_open_channel *openmsg;
	unsigned long flags;

	result = (struct vmbus_channel_open_result *)hdr;

	/*
	 * Find the open msg, copy the result and signal/unblock the wait event
	 */
	spin_lock_irqsave(&vmbus_connection.channelmsg_lock, flags);

	list_for_each_entry(msginfo, &vmbus_connection.chn_msg_list,
				msglistentry) {
		requestheader =
			(struct vmbus_channel_message_header *)msginfo->msg;

		if (requestheader->msgtype == CHANNELMSG_OPENCHANNEL) {
			openmsg =
			(struct vmbus_channel_open_channel *)msginfo->msg;
			if (openmsg->child_relid == result->child_relid &&
			    openmsg->openid == result->openid) {
				memcpy(&msginfo->response.open_result,
				       result,
				       sizeof(
					struct vmbus_channel_open_result));
				complete(&msginfo->waitevent);
				break;
			}
		}
	}
	spin_unlock_irqrestore(&vmbus_connection.channelmsg_lock, flags);
}

/*
 * vmbus_ongpadl_created - GPADL created handler.
 *
 * This is invoked when we received a response to our gpadl create request.
 * Find the matching request, copy the response and signal the requesting
 * thread.
 */
static void vmbus_ongpadl_created(struct vmbus_channel_message_header *hdr)
{
	struct vmbus_channel_gpadl_created *gpadlcreated;
	struct vmbus_channel_msginfo *msginfo;
	struct vmbus_channel_message_header *requestheader;
	struct vmbus_channel_gpadl_header *gpadlheader;
	unsigned long flags;

	gpadlcreated = (struct vmbus_channel_gpadl_created *)hdr;

	/*
	 * Find the establish msg, copy the result and signal/unblock the wait
	 * event
	 */
	spin_lock_irqsave(&vmbus_connection.channelmsg_lock, flags);

	list_for_each_entry(msginfo, &vmbus_connection.chn_msg_list,
				msglistentry) {
		requestheader =
			(struct vmbus_channel_message_header *)msginfo->msg;

		if (requestheader->msgtype == CHANNELMSG_GPADL_HEADER) {
			gpadlheader =
			(struct vmbus_channel_gpadl_header *)requestheader;

			if ((gpadlcreated->child_relid ==
			     gpadlheader->child_relid) &&
			    (gpadlcreated->gpadl == gpadlheader->gpadl)) {
				memcpy(&msginfo->response.gpadl_created,
				       gpadlcreated,
				       sizeof(
					struct vmbus_channel_gpadl_created));
				complete(&msginfo->waitevent);
				break;
			}
		}
	}
	spin_unlock_irqrestore(&vmbus_connection.channelmsg_lock, flags);
}

/*
 * vmbus_ongpadl_torndown - GPADL torndown handler.
 *
 * This is invoked when we received a response to our gpadl teardown request.
 * Find the matching request, copy the response and signal the requesting
 * thread.
 */
static void vmbus_ongpadl_torndown(
			struct vmbus_channel_message_header *hdr)
{
	struct vmbus_channel_gpadl_torndown *gpadl_torndown;
	struct vmbus_channel_msginfo *msginfo;
	struct vmbus_channel_message_header *requestheader;
	struct vmbus_channel_gpadl_teardown *gpadl_teardown;
	unsigned long flags;

	gpadl_torndown = (struct vmbus_channel_gpadl_torndown *)hdr;

	/*
	 * Find the open msg, copy the result and signal/unblock the wait event
	 */
	spin_lock_irqsave(&vmbus_connection.channelmsg_lock, flags);

	list_for_each_entry(msginfo, &vmbus_connection.chn_msg_list,
				msglistentry) {
		requestheader =
			(struct vmbus_channel_message_header *)msginfo->msg;

		if (requestheader->msgtype == CHANNELMSG_GPADL_TEARDOWN) {
			gpadl_teardown =
			(struct vmbus_channel_gpadl_teardown *)requestheader;

			if (gpadl_torndown->gpadl == gpadl_teardown->gpadl) {
				memcpy(&msginfo->response.gpadl_torndown,
				       gpadl_torndown,
				       sizeof(
					struct vmbus_channel_gpadl_torndown));
				complete(&msginfo->waitevent);
				break;
			}
		}
	}
	spin_unlock_irqrestore(&vmbus_connection.channelmsg_lock, flags);
}

/*
 * vmbus_onversion_response - Version response handler
 *
 * This is invoked when we received a response to our initiate contact request.
 * Find the matching request, copy the response and signal the requesting
 * thread.
 */
static void vmbus_onversion_response(
		struct vmbus_channel_message_header *hdr)
{
	struct vmbus_channel_msginfo *msginfo;
	struct vmbus_channel_message_header *requestheader;
	struct vmbus_channel_version_response *version_response;
	unsigned long flags;

	version_response = (struct vmbus_channel_version_response *)hdr;
	spin_lock_irqsave(&vmbus_connection.channelmsg_lock, flags);

	list_for_each_entry(msginfo, &vmbus_connection.chn_msg_list,
				msglistentry) {
		requestheader =
			(struct vmbus_channel_message_header *)msginfo->msg;

		if (requestheader->msgtype ==
		    CHANNELMSG_INITIATE_CONTACT) {
			memcpy(&msginfo->response.version_response,
			      version_response,
			      sizeof(struct vmbus_channel_version_response));
			complete(&msginfo->waitevent);
		}
	}
	spin_unlock_irqrestore(&vmbus_connection.channelmsg_lock, flags);
}

/* Channel message dispatch table */
static struct vmbus_channel_message_table_entry
	channel_message_table[CHANNELMSG_COUNT] = {
	{CHANNELMSG_INVALID,			NULL},
	{CHANNELMSG_OFFERCHANNEL,		vmbus_onoffer},
	{CHANNELMSG_RESCIND_CHANNELOFFER,	vmbus_onoffer_rescind},
	{CHANNELMSG_REQUESTOFFERS,		NULL},
	{CHANNELMSG_ALLOFFERS_DELIVERED,	vmbus_onoffers_delivered},
	{CHANNELMSG_OPENCHANNEL,		NULL},
	{CHANNELMSG_OPENCHANNEL_RESULT,	vmbus_onopen_result},
	{CHANNELMSG_CLOSECHANNEL,		NULL},
	{CHANNELMSG_GPADL_HEADER,		NULL},
	{CHANNELMSG_GPADL_BODY,		NULL},
	{CHANNELMSG_GPADL_CREATED,		vmbus_ongpadl_created},
	{CHANNELMSG_GPADL_TEARDOWN,		NULL},
	{CHANNELMSG_GPADL_TORNDOWN,		vmbus_ongpadl_torndown},
	{CHANNELMSG_RELID_RELEASED,		NULL},
	{CHANNELMSG_INITIATE_CONTACT,		NULL},
	{CHANNELMSG_VERSION_RESPONSE,		vmbus_onversion_response},
	{CHANNELMSG_UNLOAD,			NULL},
};

/*
 * vmbus_onmessage - Handler for channel protocol messages.
 *
 * This is invoked in the vmbus worker thread context.
 */
void vmbus_onmessage(void *context)
{
	struct hv_message *msg = context;
	struct vmbus_channel_message_header *hdr;
	int size;

	hdr = (struct vmbus_channel_message_header *)msg->u.payload;
	size = msg->header.payload_size;

	if (hdr->msgtype >= CHANNELMSG_COUNT) {
		pr_err("Received invalid channel message type %d size %d\n",
			   hdr->msgtype, size);
		print_hex_dump_bytes("", DUMP_PREFIX_NONE,
				     (unsigned char *)msg->u.payload, size);
		return;
	}

	if (channel_message_table[hdr->msgtype].message_handler)
		channel_message_table[hdr->msgtype].message_handler(hdr);
	else
		pr_err("Unhandled channel message type %d\n", hdr->msgtype);
}

/*
 * vmbus_request_offers - Send a request to get all our pending offers.
 */
int vmbus_request_offers(void)
{
	struct vmbus_channel_message_header *msg;
	struct vmbus_channel_msginfo *msginfo;
	int ret, t;

	msginfo = kmalloc(sizeof(*msginfo) +
			  sizeof(struct vmbus_channel_message_header),
			  GFP_KERNEL);
	if (!msginfo)
		return -ENOMEM;

	init_completion(&msginfo->waitevent);

	msg = (struct vmbus_channel_message_header *)msginfo->msg;

	msg->msgtype = CHANNELMSG_REQUESTOFFERS;


	ret = vmbus_post_msg(msg,
			       sizeof(struct vmbus_channel_message_header));
	if (ret != 0) {
		pr_err("Unable to request offers - %d\n", ret);

		goto cleanup;
	}

	t = wait_for_completion_timeout(&msginfo->waitevent, 5*HZ);
	if (t == 0) {
		ret = -ETIMEDOUT;
		goto cleanup;
	}


cleanup:
	kfree(msginfo);

	return ret;
}

/* eof */
Commit	Line	Data
	1	/*
	2	* Copyright (c) 2009, Microsoft Corporation.
	3	*
	4	* This program is free software; you can redistribute it and/or modify it
	5	* under the terms and conditions of the GNU General Public License,
	6	* version 2, as published by the Free Software Foundation.
	7	*
	8	* This program is distributed in the hope it will be useful, but WITHOUT
	9	* ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
	10	* FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License for
	11	* more details.
	12	*
	13	* You should have received a copy of the GNU General Public License along with
	14	* this program; if not, write to the Free Software Foundation, Inc., 59 Temple
	15	* Place - Suite 330, Boston, MA 02111-1307 USA.
	16	*
	17	* Authors:
	18	* Haiyang Zhang <haiyangz@microsoft.com>
	19	* Hank Janssen <hjanssen@microsoft.com>
	20	*/
	21	#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
	22
	23	#include <linux/kernel.h>
	24	#include <linux/sched.h>
	25	#include <linux/wait.h>
	26	#include <linux/mm.h>
	27	#include <linux/slab.h>
	28	#include <linux/list.h>
	29	#include <linux/module.h>
	30	#include <linux/completion.h>
	31	#include <linux/hyperv.h>
	32
	33	#include "hyperv_vmbus.h"
	34
	35	struct vmbus_channel_message_table_entry {
	36	enum vmbus_channel_message_type message_type;
	37	void (message_handler)(struct vmbus_channel_message_header msg);
	38	};
	39
	40
	41	/**
	42	* vmbus_prep_negotiate_resp() - Create default response for Hyper-V Negotiate message
	43	* @icmsghdrp: Pointer to msg header structure
	44	* @icmsg_negotiate: Pointer to negotiate message structure
	45	* @buf: Raw buffer channel data
	46	*
	47	* @icmsghdrp is of type &struct icmsg_hdr.
	48	* @negop is of type &struct icmsg_negotiate.
	49	* Set up and fill in default negotiate response message.
	50	*
	51	* The max_fw_version specifies the maximum framework version that
	52	* we can support and max _srv_version specifies the maximum service
	53	* version we can support. A special value MAX_SRV_VER can be
	54	* specified to indicate that we can handle the maximum version
	55	* exposed by the host.
	56	*
	57	* Mainly used by Hyper-V drivers.
	58	*/
	59	void vmbus_prep_negotiate_resp(struct icmsg_hdr *icmsghdrp,
	60	struct icmsg_negotiate negop, u8 buf,
	61	int max_fw_version, int max_srv_version)
	62	{
	63	int icframe_vercnt;
	64	int icmsg_vercnt;
	65	int i;
	66
	67	icmsghdrp->icmsgsize = 0x10;
	68
	69	negop = (struct icmsg_negotiate *)&buf[
	70	sizeof(struct vmbuspipe_hdr) +
	71	sizeof(struct icmsg_hdr)];
	72
	73	icframe_vercnt = negop->icframe_vercnt;
	74	icmsg_vercnt = negop->icmsg_vercnt;
	75
	76	/*
	77	* Select the framework version number we will
	78	* support.
	79	*/
	80
	81	for (i = 0; i < negop->icframe_vercnt; i++) {
	82	if (negop->icversion_data[i].major <= max_fw_version)
	83	icframe_vercnt = negop->icversion_data[i].major;
	84	}
	85
	86	for (i = negop->icframe_vercnt;
	87	(i < negop->icframe_vercnt + negop->icmsg_vercnt); i++) {
	88	if (negop->icversion_data[i].major <= max_srv_version)
	89	icmsg_vercnt = negop->icversion_data[i].major;
	90	}
	91
	92	/*
	93	* Respond with the maximum framework and service
	94	* version numbers we can support.
	95	*/
	96	negop->icframe_vercnt = 1;
	97	negop->icmsg_vercnt = 1;
	98	negop->icversion_data[0].major = icframe_vercnt;
	99	negop->icversion_data[0].minor = 0;
	100	negop->icversion_data[1].major = icmsg_vercnt;
	101	negop->icversion_data[1].minor = 0;
	102	}
	103
	104	EXPORT_SYMBOL_GPL(vmbus_prep_negotiate_resp);
	105
	106	/*
	107	* alloc_channel - Allocate and initialize a vmbus channel object
	108	*/
	109	static struct vmbus_channel *alloc_channel(void)
	110	{
	111	struct vmbus_channel *channel;
	112
	113	channel = kzalloc(sizeof(*channel), GFP_ATOMIC);
	114	if (!channel)
	115	return NULL;
	116
	117	spin_lock_init(&channel->inbound_lock);
	118
	119	channel->controlwq = create_workqueue("hv_vmbus_ctl");
	120	if (!channel->controlwq) {
	121	kfree(channel);
	122	return NULL;
	123	}
	124
	125	return channel;
	126	}
	127
	128	/*
	129	* release_hannel - Release the vmbus channel object itself
	130	*/
	131	static void release_channel(struct work_struct *work)
	132	{
	133	struct vmbus_channel *channel = container_of(work,
	134	struct vmbus_channel,
	135	work);
	136
	137	destroy_workqueue(channel->controlwq);
	138
	139	kfree(channel);
	140	}
	141
	142	/*
	143	* free_channel - Release the resources used by the vmbus channel object
	144	*/
	145	static void free_channel(struct vmbus_channel *channel)
	146	{
	147
	148	/*
	149	* We have to release the channel's workqueue/thread in the vmbus's
	150	* workqueue/thread context
	151	* ie we can't destroy ourselves.
	152	*/
	153	INIT_WORK(&channel->work, release_channel);
	154	queue_work(vmbus_connection.work_queue, &channel->work);
	155	}
	156
	157
	158
	159	/*
	160	* vmbus_process_rescind_offer -
	161	* Rescind the offer by initiating a device removal
	162	*/
	163	static void vmbus_process_rescind_offer(struct work_struct *work)
	164	{
	165	struct vmbus_channel *channel = container_of(work,
	166	struct vmbus_channel,
	167	work);
	168
	169	vmbus_device_unregister(channel->device_obj);
	170	}
	171
	172	void vmbus_free_channels(void)
	173	{
	174	struct vmbus_channel *channel;
	175
	176	list_for_each_entry(channel, &vmbus_connection.chn_list, listentry) {
	177	vmbus_device_unregister(channel->device_obj);
	178	kfree(channel->device_obj);
	179	free_channel(channel);
	180	}
	181	}
	182
	183	/*
	184	* vmbus_process_offer - Process the offer by creating a channel/device
	185	* associated with this offer
	186	*/
	187	static void vmbus_process_offer(struct work_struct *work)
	188	{
	189	struct vmbus_channel *newchannel = container_of(work,
	190	struct vmbus_channel,
	191	work);
	192	struct vmbus_channel *channel;
	193	bool fnew = true;
	194	int ret;
	195	unsigned long flags;
	196
	197	/* The next possible work is rescind handling */
	198	INIT_WORK(&newchannel->work, vmbus_process_rescind_offer);
	199
	200	/* Make sure this is a new offer */
	201	spin_lock_irqsave(&vmbus_connection.channel_lock, flags);
	202
	203	list_for_each_entry(channel, &vmbus_connection.chn_list, listentry) {
	204	if (!uuid_le_cmp(channel->offermsg.offer.if_type,
	205	newchannel->offermsg.offer.if_type) &&
	206	!uuid_le_cmp(channel->offermsg.offer.if_instance,
	207	newchannel->offermsg.offer.if_instance)) {
	208	fnew = false;
	209	break;
	210	}
	211	}
	212
	213	if (fnew)
	214	list_add_tail(&newchannel->listentry,
	215	&vmbus_connection.chn_list);
	216
	217	spin_unlock_irqrestore(&vmbus_connection.channel_lock, flags);
	218
	219	if (!fnew) {
	220	free_channel(newchannel);
	221	return;
	222	}
	223
	224	/*
	225	* Start the process of binding this offer to the driver
	226	* We need to set the DeviceObject field before calling
	227	* vmbus_child_dev_add()
	228	*/
	229	newchannel->device_obj = vmbus_device_create(
	230	&newchannel->offermsg.offer.if_type,
	231	&newchannel->offermsg.offer.if_instance,
	232	newchannel);
	233
	234	/*
	235	* Add the new device to the bus. This will kick off device-driver
	236	* binding which eventually invokes the device driver's AddDevice()
	237	* method.
	238	*/
	239	ret = vmbus_device_register(newchannel->device_obj);
	240	if (ret != 0) {
	241	pr_err("unable to add child device object (relid %d)\n",
	242	newchannel->offermsg.child_relid);
	243
	244	spin_lock_irqsave(&vmbus_connection.channel_lock, flags);
	245	list_del(&newchannel->listentry);
	246	spin_unlock_irqrestore(&vmbus_connection.channel_lock, flags);
	247	kfree(newchannel->device_obj);
	248
	249	free_channel(newchannel);
	250	} else {
	251	/*
	252	* This state is used to indicate a successful open
	253	* so that when we do close the channel normally, we
	254	* can cleanup properly
	255	*/
	256	newchannel->state = CHANNEL_OPEN_STATE;
	257	}
	258	}
	259
	260	/*
	261	* vmbus_onoffer - Handler for channel offers from vmbus in parent partition.
	262	*
	263	*/
	264	static void vmbus_onoffer(struct vmbus_channel_message_header *hdr)
	265	{
	266	struct vmbus_channel_offer_channel *offer;
	267	struct vmbus_channel *newchannel;
	268
	269	offer = (struct vmbus_channel_offer_channel *)hdr;
	270
	271	/* Allocate the channel object and save this offer. */
	272	newchannel = alloc_channel();
	273	if (!newchannel) {
	274	pr_err("Unable to allocate channel object\n");
	275	return;
	276	}
	277
	278	memcpy(&newchannel->offermsg, offer,
	279	sizeof(struct vmbus_channel_offer_channel));
	280	newchannel->monitor_grp = (u8)offer->monitorid / 32;
	281	newchannel->monitor_bit = (u8)offer->monitorid % 32;
	282
	283	INIT_WORK(&newchannel->work, vmbus_process_offer);
	284	queue_work(newchannel->controlwq, &newchannel->work);
	285	}
	286
	287	/*
	288	* vmbus_onoffer_rescind - Rescind offer handler.
	289	*
	290	* We queue a work item to process this offer synchronously
	291	*/
	292	static void vmbus_onoffer_rescind(struct vmbus_channel_message_header *hdr)
	293	{
	294	struct vmbus_channel_rescind_offer *rescind;
	295	struct vmbus_channel *channel;
	296
	297	rescind = (struct vmbus_channel_rescind_offer *)hdr;
	298	channel = relid2channel(rescind->child_relid);
	299
	300	if (channel == NULL)
	301	/* Just return here, no channel found */
	302	return;
	303
	304	/* work is initialized for vmbus_process_rescind_offer() from
	305	* vmbus_process_offer() where the channel got created */
	306	queue_work(channel->controlwq, &channel->work);
	307	}
	308
	309	/*
	310	* vmbus_onoffers_delivered -
	311	* This is invoked when all offers have been delivered.
	312	*
	313	* Nothing to do here.
	314	*/
	315	static void vmbus_onoffers_delivered(
	316	struct vmbus_channel_message_header *hdr)
	317	{
	318	}
	319
	320	/*
	321	* vmbus_onopen_result - Open result handler.
	322	*
	323	* This is invoked when we received a response to our channel open request.
	324	* Find the matching request, copy the response and signal the requesting
	325	* thread.
	326	*/
	327	static void vmbus_onopen_result(struct vmbus_channel_message_header *hdr)
	328	{
	329	struct vmbus_channel_open_result *result;
	330	struct vmbus_channel_msginfo *msginfo;
	331	struct vmbus_channel_message_header *requestheader;
	332	struct vmbus_channel_open_channel *openmsg;
	333	unsigned long flags;
	334
	335	result = (struct vmbus_channel_open_result *)hdr;
	336
	337	/*
	338	* Find the open msg, copy the result and signal/unblock the wait event
	339	*/
	340	spin_lock_irqsave(&vmbus_connection.channelmsg_lock, flags);
	341
	342	list_for_each_entry(msginfo, &vmbus_connection.chn_msg_list,
	343	msglistentry) {
	344	requestheader =
	345	(struct vmbus_channel_message_header *)msginfo->msg;
	346
	347	if (requestheader->msgtype == CHANNELMSG_OPENCHANNEL) {
	348	openmsg =
	349	(struct vmbus_channel_open_channel *)msginfo->msg;
	350	if (openmsg->child_relid == result->child_relid &&
	351	openmsg->openid == result->openid) {
	352	memcpy(&msginfo->response.open_result,
	353	result,
	354	sizeof(
	355	struct vmbus_channel_open_result));
	356	complete(&msginfo->waitevent);
	357	break;
	358	}
	359	}
	360	}
	361	spin_unlock_irqrestore(&vmbus_connection.channelmsg_lock, flags);
	362	}
	363
	364	/*
	365	* vmbus_ongpadl_created - GPADL created handler.
	366	*
	367	* This is invoked when we received a response to our gpadl create request.
	368	* Find the matching request, copy the response and signal the requesting
	369	* thread.
	370	*/
	371	static void vmbus_ongpadl_created(struct vmbus_channel_message_header *hdr)
	372	{
	373	struct vmbus_channel_gpadl_created *gpadlcreated;
	374	struct vmbus_channel_msginfo *msginfo;
	375	struct vmbus_channel_message_header *requestheader;
	376	struct vmbus_channel_gpadl_header *gpadlheader;
	377	unsigned long flags;
	378
	379	gpadlcreated = (struct vmbus_channel_gpadl_created *)hdr;
	380
	381	/*
	382	* Find the establish msg, copy the result and signal/unblock the wait
	383	* event
	384	*/
	385	spin_lock_irqsave(&vmbus_connection.channelmsg_lock, flags);
	386
	387	list_for_each_entry(msginfo, &vmbus_connection.chn_msg_list,
	388	msglistentry) {
	389	requestheader =
	390	(struct vmbus_channel_message_header *)msginfo->msg;
	391
	392	if (requestheader->msgtype == CHANNELMSG_GPADL_HEADER) {
	393	gpadlheader =
	394	(struct vmbus_channel_gpadl_header *)requestheader;
	395
	396	if ((gpadlcreated->child_relid ==
	397	gpadlheader->child_relid) &&
	398	(gpadlcreated->gpadl == gpadlheader->gpadl)) {
	399	memcpy(&msginfo->response.gpadl_created,
	400	gpadlcreated,
	401	sizeof(
	402	struct vmbus_channel_gpadl_created));
	403	complete(&msginfo->waitevent);
	404	break;
	405	}
	406	}
	407	}
	408	spin_unlock_irqrestore(&vmbus_connection.channelmsg_lock, flags);
	409	}
	410
	411	/*
	412	* vmbus_ongpadl_torndown - GPADL torndown handler.
	413	*
	414	* This is invoked when we received a response to our gpadl teardown request.
	415	* Find the matching request, copy the response and signal the requesting
	416	* thread.
	417	*/
	418	static void vmbus_ongpadl_torndown(
	419	struct vmbus_channel_message_header *hdr)
	420	{
	421	struct vmbus_channel_gpadl_torndown *gpadl_torndown;
	422	struct vmbus_channel_msginfo *msginfo;
	423	struct vmbus_channel_message_header *requestheader;
	424	struct vmbus_channel_gpadl_teardown *gpadl_teardown;
	425	unsigned long flags;
	426
	427	gpadl_torndown = (struct vmbus_channel_gpadl_torndown *)hdr;
	428
	429	/*
	430	* Find the open msg, copy the result and signal/unblock the wait event
	431	*/
	432	spin_lock_irqsave(&vmbus_connection.channelmsg_lock, flags);
	433
	434	list_for_each_entry(msginfo, &vmbus_connection.chn_msg_list,
	435	msglistentry) {
	436	requestheader =
	437	(struct vmbus_channel_message_header *)msginfo->msg;
	438
	439	if (requestheader->msgtype == CHANNELMSG_GPADL_TEARDOWN) {
	440	gpadl_teardown =
	441	(struct vmbus_channel_gpadl_teardown *)requestheader;
	442
	443	if (gpadl_torndown->gpadl == gpadl_teardown->gpadl) {
	444	memcpy(&msginfo->response.gpadl_torndown,
	445	gpadl_torndown,
	446	sizeof(
	447	struct vmbus_channel_gpadl_torndown));
	448	complete(&msginfo->waitevent);
	449	break;
	450	}
	451	}
	452	}
	453	spin_unlock_irqrestore(&vmbus_connection.channelmsg_lock, flags);
	454	}
	455
	456	/*
	457	* vmbus_onversion_response - Version response handler
	458	*
	459	* This is invoked when we received a response to our initiate contact request.
	460	* Find the matching request, copy the response and signal the requesting
	461	* thread.
	462	*/
	463	static void vmbus_onversion_response(
	464	struct vmbus_channel_message_header *hdr)
	465	{
	466	struct vmbus_channel_msginfo *msginfo;
	467	struct vmbus_channel_message_header *requestheader;
	468	struct vmbus_channel_version_response *version_response;
	469	unsigned long flags;
	470
	471	version_response = (struct vmbus_channel_version_response *)hdr;
	472	spin_lock_irqsave(&vmbus_connection.channelmsg_lock, flags);
	473
	474	list_for_each_entry(msginfo, &vmbus_connection.chn_msg_list,
	475	msglistentry) {
	476	requestheader =
	477	(struct vmbus_channel_message_header *)msginfo->msg;
	478
	479	if (requestheader->msgtype ==
	480	CHANNELMSG_INITIATE_CONTACT) {
	481	memcpy(&msginfo->response.version_response,
	482	version_response,
	483	sizeof(struct vmbus_channel_version_response));
	484	complete(&msginfo->waitevent);
	485	}
	486	}
	487	spin_unlock_irqrestore(&vmbus_connection.channelmsg_lock, flags);
	488	}
	489
	490	/* Channel message dispatch table */
	491	static struct vmbus_channel_message_table_entry
	492	channel_message_table[CHANNELMSG_COUNT] = {
	493	{CHANNELMSG_INVALID, NULL},
	494	{CHANNELMSG_OFFERCHANNEL, vmbus_onoffer},
	495	{CHANNELMSG_RESCIND_CHANNELOFFER, vmbus_onoffer_rescind},
	496	{CHANNELMSG_REQUESTOFFERS, NULL},
	497	{CHANNELMSG_ALLOFFERS_DELIVERED, vmbus_onoffers_delivered},
	498	{CHANNELMSG_OPENCHANNEL, NULL},
	499	{CHANNELMSG_OPENCHANNEL_RESULT, vmbus_onopen_result},
	500	{CHANNELMSG_CLOSECHANNEL, NULL},
	501	{CHANNELMSG_GPADL_HEADER, NULL},
	502	{CHANNELMSG_GPADL_BODY, NULL},
	503	{CHANNELMSG_GPADL_CREATED, vmbus_ongpadl_created},
	504	{CHANNELMSG_GPADL_TEARDOWN, NULL},
	505	{CHANNELMSG_GPADL_TORNDOWN, vmbus_ongpadl_torndown},
	506	{CHANNELMSG_RELID_RELEASED, NULL},
	507	{CHANNELMSG_INITIATE_CONTACT, NULL},
	508	{CHANNELMSG_VERSION_RESPONSE, vmbus_onversion_response},
	509	{CHANNELMSG_UNLOAD, NULL},
	510	};
	511
	512	/*
	513	* vmbus_onmessage - Handler for channel protocol messages.
	514	*
	515	* This is invoked in the vmbus worker thread context.
	516	*/
	517	void vmbus_onmessage(void *context)
	518	{
	519	struct hv_message *msg = context;
	520	struct vmbus_channel_message_header *hdr;
	521	int size;
	522
	523	hdr = (struct vmbus_channel_message_header *)msg->u.payload;
	524	size = msg->header.payload_size;
	525
	526	if (hdr->msgtype >= CHANNELMSG_COUNT) {
	527	pr_err("Received invalid channel message type %d size %d\n",
	528	hdr->msgtype, size);
	529	print_hex_dump_bytes("", DUMP_PREFIX_NONE,
	530	(unsigned char *)msg->u.payload, size);
	531	return;
	532	}
	533
	534	if (channel_message_table[hdr->msgtype].message_handler)
	535	channel_message_table[hdr->msgtype].message_handler(hdr);
	536	else
	537	pr_err("Unhandled channel message type %d\n", hdr->msgtype);
	538	}
	539
	540	/*
	541	* vmbus_request_offers - Send a request to get all our pending offers.
	542	*/
	543	int vmbus_request_offers(void)
	544	{
	545	struct vmbus_channel_message_header *msg;
	546	struct vmbus_channel_msginfo *msginfo;
	547	int ret, t;
	548
	549	msginfo = kmalloc(sizeof(*msginfo) +
	550	sizeof(struct vmbus_channel_message_header),
	551	GFP_KERNEL);
	552	if (!msginfo)
	553	return -ENOMEM;
	554
	555	init_completion(&msginfo->waitevent);
	556
	557	msg = (struct vmbus_channel_message_header *)msginfo->msg;
	558
	559	msg->msgtype = CHANNELMSG_REQUESTOFFERS;
	560
	561
	562	ret = vmbus_post_msg(msg,
	563	sizeof(struct vmbus_channel_message_header));
	564	if (ret != 0) {
	565	pr_err("Unable to request offers - %d\n", ret);
	566
	567	goto cleanup;
	568	}
	569
	570	t = wait_for_completion_timeout(&msginfo->waitevent, 5*HZ);
	571	if (t == 0) {
	572	ret = -ETIMEDOUT;
	573	goto cleanup;
	574	}
	575
	576
	577
	578	cleanup:
	579	kfree(msginfo);
	580
	581	return ret;
	582	}
	583
	584	/* eof */