[mirror_ubuntu-zesty-kernel.git] / drivers / hv / hv_fcopy.c

/*
 * An implementation of file copy service.
 *
 * Copyright (C) 2014, Microsoft, Inc.
 *
 * Author : K. Y. Srinivasan <ksrinivasan@novell.com>
 *
 * This program is free software; you can redistribute it and/or modify it
 * under the terms of the GNU General Public License version 2 as published
 * by the Free Software Foundation.
 *
 * This program is distributed in the hope that it will be useful, but
 * WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY OR FITNESS FOR A PARTICULAR PURPOSE, GOOD TITLE or
 * NON INFRINGEMENT.  See the GNU General Public License for more
 * details.
 *
 */

#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt

#include <linux/nls.h>
#include <linux/workqueue.h>
#include <linux/hyperv.h>
#include <linux/sched.h>

#include "hyperv_vmbus.h"
#include "hv_utils_transport.h"

#define WIN8_SRV_MAJOR		1
#define WIN8_SRV_MINOR		1
#define WIN8_SRV_VERSION	(WIN8_SRV_MAJOR << 16 | WIN8_SRV_MINOR)

/*
 * Global state maintained for transaction that is being processed.
 * For a class of integration services, including the "file copy service",
 * the specified protocol is a "request/response" protocol which means that
 * there can only be single outstanding transaction from the host at any
 * given point in time. We use this to simplify memory management in this
 * driver - we cache and process only one message at a time.
 *
 * While the request/response protocol is guaranteed by the host, we further
 * ensure this by serializing packet processing in this driver - we do not
 * read additional packets from the VMBUs until the current packet is fully
 * handled.
 */

static struct {
	int state;   /* hvutil_device_state */
	int recv_len; /* number of bytes received. */
	struct hv_fcopy_hdr  *fcopy_msg; /* current message */
	struct vmbus_channel *recv_channel; /* chn we got the request */
	u64 recv_req_id; /* request ID. */
} fcopy_transaction;

static void fcopy_respond_to_host(int error);
static void fcopy_send_data(struct work_struct *dummy);
static void fcopy_timeout_func(struct work_struct *dummy);
static DECLARE_DELAYED_WORK(fcopy_timeout_work, fcopy_timeout_func);
static DECLARE_WORK(fcopy_send_work, fcopy_send_data);
static const char fcopy_devname[] = "vmbus/hv_fcopy";
static u8 *recv_buffer;
static struct hvutil_transport *hvt;
static struct completion release_event;
/*
 * This state maintains the version number registered by the daemon.
 */
static int dm_reg_value;

static void fcopy_poll_wrapper(void *channel)
{
	/* Transaction is finished, reset the state here to avoid races. */
	fcopy_transaction.state = HVUTIL_READY;
	hv_fcopy_onchannelcallback(channel);
}

static void fcopy_timeout_func(struct work_struct *dummy)
{
	/*
	 * If the timer fires, the user-mode component has not responded;
	 * process the pending transaction.
	 */
	fcopy_respond_to_host(HV_E_FAIL);
	hv_poll_channel(fcopy_transaction.recv_channel, fcopy_poll_wrapper);
}

static void fcopy_register_done(void)
{
	pr_debug("FCP: userspace daemon registered\n");
	hv_poll_channel(fcopy_transaction.recv_channel, fcopy_poll_wrapper);
}

static int fcopy_handle_handshake(u32 version)
{
	u32 our_ver = FCOPY_CURRENT_VERSION;

	switch (version) {
	case FCOPY_VERSION_0:
		/* Daemon doesn't expect us to reply */
		dm_reg_value = version;
		break;
	case FCOPY_VERSION_1:
		/* Daemon expects us to reply with our own version */
		if (hvutil_transport_send(hvt, &our_ver, sizeof(our_ver),
		    fcopy_register_done))
			return -EFAULT;
		dm_reg_value = version;
		break;
	default:
		/*
		 * For now we will fail the registration.
		 * If and when we have multiple versions to
		 * deal with, we will be backward compatible.
		 * We will add this code when needed.
		 */
		return -EINVAL;
	}
	pr_debug("FCP: userspace daemon ver. %d connected\n", version);
	return 0;
}

static void fcopy_send_data(struct work_struct *dummy)
{
	struct hv_start_fcopy *smsg_out = NULL;
	int operation = fcopy_transaction.fcopy_msg->operation;
	struct hv_start_fcopy *smsg_in;
	void *out_src;
	int rc, out_len;

	/*
	 * The  strings sent from the host are encoded in
	 * in utf16; convert it to utf8 strings.
	 * The host assures us that the utf16 strings will not exceed
	 * the max lengths specified. We will however, reserve room
	 * for the string terminating character - in the utf16s_utf8s()
	 * function we limit the size of the buffer where the converted
	 * string is placed to W_MAX_PATH -1 to guarantee
	 * that the strings can be properly terminated!
	 */

	switch (operation) {
	case START_FILE_COPY:
		out_len = sizeof(struct hv_start_fcopy);
		smsg_out = kzalloc(sizeof(*smsg_out), GFP_KERNEL);
		if (!smsg_out)
			return;

		smsg_out->hdr.operation = operation;
		smsg_in = (struct hv_start_fcopy *)fcopy_transaction.fcopy_msg;

		utf16s_to_utf8s((wchar_t *)smsg_in->file_name, W_MAX_PATH,
				UTF16_LITTLE_ENDIAN,
				(__u8 *)&smsg_out->file_name, W_MAX_PATH - 1);

		utf16s_to_utf8s((wchar_t *)smsg_in->path_name, W_MAX_PATH,
				UTF16_LITTLE_ENDIAN,
				(__u8 *)&smsg_out->path_name, W_MAX_PATH - 1);

		smsg_out->copy_flags = smsg_in->copy_flags;
		smsg_out->file_size = smsg_in->file_size;
		out_src = smsg_out;
		break;

	default:
		out_src = fcopy_transaction.fcopy_msg;
		out_len = fcopy_transaction.recv_len;
		break;
	}

	fcopy_transaction.state = HVUTIL_USERSPACE_REQ;
	rc = hvutil_transport_send(hvt, out_src, out_len, NULL);
	if (rc) {
		pr_debug("FCP: failed to communicate to the daemon: %d\n", rc);
		if (cancel_delayed_work_sync(&fcopy_timeout_work)) {
			fcopy_respond_to_host(HV_E_FAIL);
			fcopy_transaction.state = HVUTIL_READY;
		}
	}
	kfree(smsg_out);

	return;
}

/*
 * Send a response back to the host.
 */

static void
fcopy_respond_to_host(int error)
{
	struct icmsg_hdr *icmsghdr;
	u32 buf_len;
	struct vmbus_channel *channel;
	u64 req_id;

	/*
	 * Copy the global state for completing the transaction. Note that
	 * only one transaction can be active at a time. This is guaranteed
	 * by the file copy protocol implemented by the host. Furthermore,
	 * the "transaction active" state we maintain ensures that there can
	 * only be one active transaction at a time.
	 */

	buf_len = fcopy_transaction.recv_len;
	channel = fcopy_transaction.recv_channel;
	req_id = fcopy_transaction.recv_req_id;

	icmsghdr = (struct icmsg_hdr *)
			&recv_buffer[sizeof(struct vmbuspipe_hdr)];

	if (channel->onchannel_callback == NULL)
		/*
		 * We have raced with util driver being unloaded;
		 * silently return.
		 */
		return;

	icmsghdr->status = error;
	icmsghdr->icflags = ICMSGHDRFLAG_TRANSACTION | ICMSGHDRFLAG_RESPONSE;
	vmbus_sendpacket(channel, recv_buffer, buf_len, req_id,
				VM_PKT_DATA_INBAND, 0);
}

void hv_fcopy_onchannelcallback(void *context)
{
	struct vmbus_channel *channel = context;
	u32 recvlen;
	u64 requestid;
	struct hv_fcopy_hdr *fcopy_msg;
	struct icmsg_hdr *icmsghdr;
	struct icmsg_negotiate *negop = NULL;
	int util_fw_version;
	int fcopy_srv_version;

	if (fcopy_transaction.state > HVUTIL_READY)
		return;

	vmbus_recvpacket(channel, recv_buffer, PAGE_SIZE * 2, &recvlen,
			 &requestid);
	if (recvlen <= 0)
		return;

	icmsghdr = (struct icmsg_hdr *)&recv_buffer[
			sizeof(struct vmbuspipe_hdr)];
	if (icmsghdr->icmsgtype == ICMSGTYPE_NEGOTIATE) {
		util_fw_version = UTIL_FW_VERSION;
		fcopy_srv_version = WIN8_SRV_VERSION;
		vmbus_prep_negotiate_resp(icmsghdr, negop, recv_buffer,
				util_fw_version, fcopy_srv_version);
	} else {
		fcopy_msg = (struct hv_fcopy_hdr *)&recv_buffer[
				sizeof(struct vmbuspipe_hdr) +
				sizeof(struct icmsg_hdr)];

		/*
		 * Stash away this global state for completing the
		 * transaction; note transactions are serialized.
		 */

		fcopy_transaction.recv_len = recvlen;
		fcopy_transaction.recv_req_id = requestid;
		fcopy_transaction.fcopy_msg = fcopy_msg;

		if (fcopy_transaction.state < HVUTIL_READY) {
			/* Userspace is not registered yet */
			fcopy_respond_to_host(HV_E_FAIL);
			return;
		}
		fcopy_transaction.state = HVUTIL_HOSTMSG_RECEIVED;

		/*
		 * Send the information to the user-level daemon.
		 */
		schedule_work(&fcopy_send_work);
		schedule_delayed_work(&fcopy_timeout_work,
				      HV_UTIL_TIMEOUT * HZ);
		return;
	}
	icmsghdr->icflags = ICMSGHDRFLAG_TRANSACTION | ICMSGHDRFLAG_RESPONSE;
	vmbus_sendpacket(channel, recv_buffer, recvlen, requestid,
			VM_PKT_DATA_INBAND, 0);
}

/* Callback when data is received from userspace */
static int fcopy_on_msg(void *msg, int len)
{
	int *val = (int *)msg;

	if (len != sizeof(int))
		return -EINVAL;

	if (fcopy_transaction.state == HVUTIL_DEVICE_INIT)
		return fcopy_handle_handshake(*val);

	if (fcopy_transaction.state != HVUTIL_USERSPACE_REQ)
		return -EINVAL;

	/*
	 * Complete the transaction by forwarding the result
	 * to the host. But first, cancel the timeout.
	 */
	if (cancel_delayed_work_sync(&fcopy_timeout_work)) {
		fcopy_transaction.state = HVUTIL_USERSPACE_RECV;
		fcopy_respond_to_host(*val);
		hv_poll_channel(fcopy_transaction.recv_channel,
				fcopy_poll_wrapper);
	}

	return 0;
}

static void fcopy_on_reset(void)
{
	/*
	 * The daemon has exited; reset the state.
	 */
	fcopy_transaction.state = HVUTIL_DEVICE_INIT;

	if (cancel_delayed_work_sync(&fcopy_timeout_work))
		fcopy_respond_to_host(HV_E_FAIL);
	complete(&release_event);
}

int hv_fcopy_init(struct hv_util_service *srv)
{
	recv_buffer = srv->recv_buffer;
	fcopy_transaction.recv_channel = srv->channel;

	init_completion(&release_event);
	/*
	 * When this driver loads, the user level daemon that
	 * processes the host requests may not yet be running.
	 * Defer processing channel callbacks until the daemon
	 * has registered.
	 */
	fcopy_transaction.state = HVUTIL_DEVICE_INIT;

	hvt = hvutil_transport_init(fcopy_devname, 0, 0,
				    fcopy_on_msg, fcopy_on_reset);
	if (!hvt)
		return -EFAULT;

	return 0;
}

void hv_fcopy_deinit(void)
{
	fcopy_transaction.state = HVUTIL_DEVICE_DYING;
	cancel_delayed_work_sync(&fcopy_timeout_work);
	hvutil_transport_destroy(hvt);
	wait_for_completion(&release_event);
}
Commit	Line	Data
01325476 S	1	/*
	2	* An implementation of file copy service.
	3	*
	4	* Copyright (C) 2014, Microsoft, Inc.
	5	*
	6	* Author : K. Y. Srinivasan <ksrinivasan@novell.com>
	7	*
	8	* This program is free software; you can redistribute it and/or modify it
	9	* under the terms of the GNU General Public License version 2 as published
	10	* by the Free Software Foundation.
	11	*
	12	* This program is distributed in the hope that it will be useful, but
	13	* WITHOUT ANY WARRANTY; without even the implied warranty of
	14	* MERCHANTABILITY OR FITNESS FOR A PARTICULAR PURPOSE, GOOD TITLE or
	15	* NON INFRINGEMENT. See the GNU General Public License for more
	16	* details.
	17	*
	18	*/
	19
	20	#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
	21
01325476 S	22	#include <linux/nls.h>
01325476 S	23	#include <linux/workqueue.h>
01325476 S	24	#include <linux/hyperv.h>
01325476 S	25	#include <linux/sched.h>
01325476 S	26
01325476 S	27	#include "hyperv_vmbus.h"
c7e490fc	28	#include "hv_utils_transport.h"
01325476 S	29
	30	#define WIN8_SRV_MAJOR 1
	31	#define WIN8_SRV_MINOR 1
	32	#define WIN8_SRV_VERSION (WIN8_SRV_MAJOR << 16 \| WIN8_SRV_MINOR)
	33
	34	/*
	35	* Global state maintained for transaction that is being processed.
	36	* For a class of integration services, including the "file copy service",
	37	* the specified protocol is a "request/response" protocol which means that
	38	* there can only be single outstanding transaction from the host at any
	39	* given point in time. We use this to simplify memory management in this
	40	* driver - we cache and process only one message at a time.
	41	*
	42	* While the request/response protocol is guaranteed by the host, we further
	43	* ensure this by serializing packet processing in this driver - we do not
	44	* read additional packets from the VMBUs until the current packet is fully
	45	* handled.
01325476 S	46	*/
	47
	48	static struct {
4c93cccc	49	int state; /* hvutil_device_state */
01325476 S	50	int recv_len; /* number of bytes received. */
01325476 S	51	struct hv_fcopy_hdr fcopy_msg; / current message */
01325476 S	52	struct vmbus_channel recv_channel; / chn we got the request */
01325476 S	53	u64 recv_req_id; /* request ID. */
01325476 S	54	} fcopy_transaction;
01325476 S	55
01325476	56	static void fcopy_respond_to_host(int error);
c7e490fc	57	static void fcopy_send_data(struct work_struct *dummy);
1d072339 VK	58	static void fcopy_timeout_func(struct work_struct *dummy);
1d072339 VK	59	static DECLARE_DELAYED_WORK(fcopy_timeout_work, fcopy_timeout_func);
c7e490fc VK	60	static DECLARE_WORK(fcopy_send_work, fcopy_send_data);
c7e490fc VK	61	static const char fcopy_devname[] = "vmbus/hv_fcopy";
01325476	62	static u8 *recv_buffer;
c7e490fc	63	static struct hvutil_transport *hvt;
1d4a207c	64	static struct completion release_event;
a4d1ee5b VK	65	/*
	66	* This state maintains the version number registered by the daemon.
	67	*/
	68	static int dm_reg_value;
01325476	69
3cace4a6 OH	70	static void fcopy_poll_wrapper(void *channel)
	71	{
	72	/* Transaction is finished, reset the state here to avoid races. */
	73	fcopy_transaction.state = HVUTIL_READY;
	74	hv_fcopy_onchannelcallback(channel);
	75	}
	76
1d072339	77	static void fcopy_timeout_func(struct work_struct *dummy)
01325476 S	78	{
	79	/*
	80	* If the timer fires, the user-mode component has not responded;
	81	* process the pending transaction.
	82	*/
	83	fcopy_respond_to_host(HV_E_FAIL);
3cace4a6	84	hv_poll_channel(fcopy_transaction.recv_channel, fcopy_poll_wrapper);
01325476 S	85	}
01325476 S	86
e0fa3e5e VK	87	static void fcopy_register_done(void)
	88	{
	89	pr_debug("FCP: userspace daemon registered\n");
	90	hv_poll_channel(fcopy_transaction.recv_channel, fcopy_poll_wrapper);
	91	}
	92
01325476 S	93	static int fcopy_handle_handshake(u32 version)
01325476 S	94	{
a4d1ee5b VK	95	u32 our_ver = FCOPY_CURRENT_VERSION;
a4d1ee5b VK	96
01325476	97	switch (version) {
a4d1ee5b VK	98	case FCOPY_VERSION_0:
	99	/* Daemon doesn't expect us to reply */
	100	dm_reg_value = version;
	101	break;
	102	case FCOPY_VERSION_1:
	103	/* Daemon expects us to reply with our own version */
e0fa3e5e VK	104	if (hvutil_transport_send(hvt, &our_ver, sizeof(our_ver),
e0fa3e5e VK	105	fcopy_register_done))
a4d1ee5b VK	106	return -EFAULT;
a4d1ee5b VK	107	dm_reg_value = version;
01325476 S	108	break;
	109	default:
	110	/*
	111	* For now we will fail the registration.
	112	* If and when we have multiple versions to
	113	* deal with, we will be backward compatible.
	114	* We will add this code when needed.
	115	*/
	116	return -EINVAL;
	117	}
e0fa3e5e	118	pr_debug("FCP: userspace daemon ver. %d connected\n", version);
01325476 S	119	return 0;
	120	}
	121
c7e490fc	122	static void fcopy_send_data(struct work_struct *dummy)
01325476	123	{
25ef06fe	124	struct hv_start_fcopy *smsg_out = NULL;
01325476 S	125	int operation = fcopy_transaction.fcopy_msg->operation;
01325476 S	126	struct hv_start_fcopy *smsg_in;
c7e490fc VK	127	void *out_src;
c7e490fc VK	128	int rc, out_len;
01325476 S	129
	130	/*
	131	* The strings sent from the host are encoded in
	132	* in utf16; convert it to utf8 strings.
	133	* The host assures us that the utf16 strings will not exceed
	134	* the max lengths specified. We will however, reserve room
	135	* for the string terminating character - in the utf16s_utf8s()
	136	* function we limit the size of the buffer where the converted
	137	* string is placed to W_MAX_PATH -1 to guarantee
	138	* that the strings can be properly terminated!
	139	*/
	140
	141	switch (operation) {
	142	case START_FILE_COPY:
c7e490fc	143	out_len = sizeof(struct hv_start_fcopy);
25ef06fe VK	144	smsg_out = kzalloc(sizeof(*smsg_out), GFP_KERNEL);
	145	if (!smsg_out)
	146	return;
	147
	148	smsg_out->hdr.operation = operation;
01325476 S	149	smsg_in = (struct hv_start_fcopy *)fcopy_transaction.fcopy_msg;
	150
	151	utf16s_to_utf8s((wchar_t *)smsg_in->file_name, W_MAX_PATH,
	152	UTF16_LITTLE_ENDIAN,
25ef06fe	153	(__u8 *)&smsg_out->file_name, W_MAX_PATH - 1);
01325476 S	154
	155	utf16s_to_utf8s((wchar_t *)smsg_in->path_name, W_MAX_PATH,
	156	UTF16_LITTLE_ENDIAN,
25ef06fe	157	(__u8 *)&smsg_out->path_name, W_MAX_PATH - 1);
01325476	158
25ef06fe VK	159	smsg_out->copy_flags = smsg_in->copy_flags;
	160	smsg_out->file_size = smsg_in->file_size;
	161	out_src = smsg_out;
01325476 S	162	break;
	163
	164	default:
c7e490fc VK	165	out_src = fcopy_transaction.fcopy_msg;
c7e490fc VK	166	out_len = fcopy_transaction.recv_len;
01325476 S	167	break;
01325476 S	168	}
c7e490fc VK	169
c7e490fc VK	170	fcopy_transaction.state = HVUTIL_USERSPACE_REQ;
e0fa3e5e	171	rc = hvutil_transport_send(hvt, out_src, out_len, NULL);
c7e490fc VK	172	if (rc) {
	173	pr_debug("FCP: failed to communicate to the daemon: %d\n", rc);
	174	if (cancel_delayed_work_sync(&fcopy_timeout_work)) {
	175	fcopy_respond_to_host(HV_E_FAIL);
	176	fcopy_transaction.state = HVUTIL_READY;
	177	}
	178	}
25ef06fe VK	179	kfree(smsg_out);
25ef06fe VK	180
01325476 S	181	return;
	182	}
	183
	184	/*
	185	* Send a response back to the host.
	186	*/
	187
	188	static void
	189	fcopy_respond_to_host(int error)
	190	{
	191	struct icmsg_hdr *icmsghdr;
	192	u32 buf_len;
	193	struct vmbus_channel *channel;
	194	u64 req_id;
	195
	196	/*
	197	* Copy the global state for completing the transaction. Note that
	198	* only one transaction can be active at a time. This is guaranteed
	199	* by the file copy protocol implemented by the host. Furthermore,
	200	* the "transaction active" state we maintain ensures that there can
	201	* only be one active transaction at a time.
	202	*/
	203
	204	buf_len = fcopy_transaction.recv_len;
	205	channel = fcopy_transaction.recv_channel;
	206	req_id = fcopy_transaction.recv_req_id;
	207
01325476 S	208	icmsghdr = (struct icmsg_hdr *)
	209	&recv_buffer[sizeof(struct vmbuspipe_hdr)];
	210
	211	if (channel->onchannel_callback == NULL)
	212	/*
	213	* We have raced with util driver being unloaded;
	214	* silently return.
	215	*/
	216	return;
	217
	218	icmsghdr->status = error;
	219	icmsghdr->icflags = ICMSGHDRFLAG_TRANSACTION \| ICMSGHDRFLAG_RESPONSE;
	220	vmbus_sendpacket(channel, recv_buffer, buf_len, req_id,
	221	VM_PKT_DATA_INBAND, 0);
	222	}
	223
	224	void hv_fcopy_onchannelcallback(void *context)
	225	{
	226	struct vmbus_channel *channel = context;
	227	u32 recvlen;
	228	u64 requestid;
	229	struct hv_fcopy_hdr *fcopy_msg;
	230	struct icmsg_hdr *icmsghdr;
	231	struct icmsg_negotiate *negop = NULL;
	232	int util_fw_version;
	233	int fcopy_srv_version;
	234
3cace4a6	235	if (fcopy_transaction.state > HVUTIL_READY)
01325476	236	return;
01325476 S	237
	238	vmbus_recvpacket(channel, recv_buffer, PAGE_SIZE * 2, &recvlen,
	239	&requestid);
	240	if (recvlen <= 0)
	241	return;
	242
	243	icmsghdr = (struct icmsg_hdr *)&recv_buffer[
	244	sizeof(struct vmbuspipe_hdr)];
	245	if (icmsghdr->icmsgtype == ICMSGTYPE_NEGOTIATE) {
	246	util_fw_version = UTIL_FW_VERSION;
	247	fcopy_srv_version = WIN8_SRV_VERSION;
	248	vmbus_prep_negotiate_resp(icmsghdr, negop, recv_buffer,
	249	util_fw_version, fcopy_srv_version);
	250	} else {
	251	fcopy_msg = (struct hv_fcopy_hdr *)&recv_buffer[
	252	sizeof(struct vmbuspipe_hdr) +
	253	sizeof(struct icmsg_hdr)];
	254
	255	/*
	256	* Stash away this global state for completing the
	257	* transaction; note transactions are serialized.
	258	*/
	259
01325476	260	fcopy_transaction.recv_len = recvlen;
01325476 S	261	fcopy_transaction.recv_req_id = requestid;
	262	fcopy_transaction.fcopy_msg = fcopy_msg;
	263
4c93cccc VK	264	if (fcopy_transaction.state < HVUTIL_READY) {
	265	/* Userspace is not registered yet */
	266	fcopy_respond_to_host(HV_E_FAIL);
	267	return;
	268	}
	269	fcopy_transaction.state = HVUTIL_HOSTMSG_RECEIVED;
	270
01325476 S	271	/*
	272	* Send the information to the user-level daemon.
	273	*/
c7e490fc	274	schedule_work(&fcopy_send_work);
c0b200cf S	275	schedule_delayed_work(&fcopy_timeout_work,
c0b200cf S	276	HV_UTIL_TIMEOUT * HZ);
01325476 S	277	return;
	278	}
	279	icmsghdr->icflags = ICMSGHDRFLAG_TRANSACTION \| ICMSGHDRFLAG_RESPONSE;
	280	vmbus_sendpacket(channel, recv_buffer, recvlen, requestid,
	281	VM_PKT_DATA_INBAND, 0);
	282	}
	283
c7e490fc VK	284	/* Callback when data is received from userspace */
c7e490fc VK	285	static int fcopy_on_msg(void *msg, int len)
01325476	286	{
c7e490fc	287	int val = (int )msg;
01325476	288
c7e490fc	289	if (len != sizeof(int))
01325476 S	290	return -EINVAL;
01325476 S	291
c7e490fc VK	292	if (fcopy_transaction.state == HVUTIL_DEVICE_INIT)
c7e490fc VK	293	return fcopy_handle_handshake(*val);
01325476	294
4c93cccc VK	295	if (fcopy_transaction.state != HVUTIL_USERSPACE_REQ)
	296	return -EINVAL;
	297
01325476 S	298	/*
	299	* Complete the transaction by forwarding the result
	300	* to the host. But first, cancel the timeout.
	301	*/
4c93cccc VK	302	if (cancel_delayed_work_sync(&fcopy_timeout_work)) {
4c93cccc VK	303	fcopy_transaction.state = HVUTIL_USERSPACE_RECV;
c7e490fc	304	fcopy_respond_to_host(*val);
3cace4a6 OH	305	hv_poll_channel(fcopy_transaction.recv_channel,
3cace4a6 OH	306	fcopy_poll_wrapper);
242f3122	307	}
01325476	308
01325476 S	309	return 0;
	310	}
	311
c7e490fc	312	static void fcopy_on_reset(void)
01325476 S	313	{
	314	/*
	315	* The daemon has exited; reset the state.
	316	*/
4c93cccc	317	fcopy_transaction.state = HVUTIL_DEVICE_INIT;
d9b16529	318
c7e490fc	319	if (cancel_delayed_work_sync(&fcopy_timeout_work))
d9b16529	320	fcopy_respond_to_host(HV_E_FAIL);
1d4a207c	321	complete(&release_event);
01325476 S	322	}
	323
	324	int hv_fcopy_init(struct hv_util_service *srv)
	325	{
	326	recv_buffer = srv->recv_buffer;
b9830d12	327	fcopy_transaction.recv_channel = srv->channel;
01325476	328
1d4a207c	329	init_completion(&release_event);
01325476 S	330	/*
	331	* When this driver loads, the user level daemon that
	332	* processes the host requests may not yet be running.
	333	* Defer processing channel callbacks until the daemon
	334	* has registered.
	335	*/
4c93cccc	336	fcopy_transaction.state = HVUTIL_DEVICE_INIT;
01325476	337
c7e490fc VK	338	hvt = hvutil_transport_init(fcopy_devname, 0, 0,
	339	fcopy_on_msg, fcopy_on_reset);
	340	if (!hvt)
	341	return -EFAULT;
	342
	343	return 0;
01325476 S	344	}
	345
	346	void hv_fcopy_deinit(void)
	347	{
4c93cccc	348	fcopy_transaction.state = HVUTIL_DEVICE_DYING;
1d072339	349	cancel_delayed_work_sync(&fcopy_timeout_work);
c7e490fc	350	hvutil_transport_destroy(hvt);
1d4a207c	351	wait_for_completion(&release_event);
01325476	352	}