[mirror_ubuntu-bionic-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)

#define FCOPY_VER_COUNT 1
static const int fcopy_versions[] = {
	WIN8_SRV_VERSION
};

#define FW_VER_COUNT 1
static const int fw_versions[] = {
	UTIL_FW_VERSION
};

/*
 * 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;
/*
 * 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;
	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) {
		if (vmbus_prep_negotiate_resp(icmsghdr, recv_buffer,
				fw_versions, FW_VER_COUNT,
				fcopy_versions, FCOPY_VER_COUNT,
				NULL, &fcopy_srv_version)) {

			pr_info("FCopy IC version %d.%d\n",
				fcopy_srv_version >> 16,
				fcopy_srv_version & 0xFFFF);
		}
	} 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);
}

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

	/*
	 * 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);
}
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
a1656454 AN	34	#define FCOPY_VER_COUNT 1
	35	static const int fcopy_versions[] = {
	36	WIN8_SRV_VERSION
	37	};
	38
	39	#define FW_VER_COUNT 1
	40	static const int fw_versions[] = {
	41	UTIL_FW_VERSION
	42	};
	43
01325476 S	44	/*
	45	* Global state maintained for transaction that is being processed.
	46	* For a class of integration services, including the "file copy service",
	47	* the specified protocol is a "request/response" protocol which means that
	48	* there can only be single outstanding transaction from the host at any
	49	* given point in time. We use this to simplify memory management in this
	50	* driver - we cache and process only one message at a time.
	51	*
	52	* While the request/response protocol is guaranteed by the host, we further
	53	* ensure this by serializing packet processing in this driver - we do not
	54	* read additional packets from the VMBUs until the current packet is fully
	55	* handled.
01325476 S	56	*/
	57
	58	static struct {
4c93cccc	59	int state; /* hvutil_device_state */
01325476 S	60	int recv_len; /* number of bytes received. */
01325476 S	61	struct hv_fcopy_hdr fcopy_msg; / current message */
01325476 S	62	struct vmbus_channel recv_channel; / chn we got the request */
01325476 S	63	u64 recv_req_id; /* request ID. */
01325476 S	64	} fcopy_transaction;
01325476 S	65
01325476	66	static void fcopy_respond_to_host(int error);
c7e490fc	67	static void fcopy_send_data(struct work_struct *dummy);
1d072339 VK	68	static void fcopy_timeout_func(struct work_struct *dummy);
1d072339 VK	69	static DECLARE_DELAYED_WORK(fcopy_timeout_work, fcopy_timeout_func);
c7e490fc VK	70	static DECLARE_WORK(fcopy_send_work, fcopy_send_data);
c7e490fc VK	71	static const char fcopy_devname[] = "vmbus/hv_fcopy";
01325476	72	static u8 *recv_buffer;
c7e490fc	73	static struct hvutil_transport *hvt;
a4d1ee5b VK	74	/*
	75	* This state maintains the version number registered by the daemon.
	76	*/
	77	static int dm_reg_value;
01325476	78
3cace4a6 OH	79	static void fcopy_poll_wrapper(void *channel)
	80	{
	81	/* Transaction is finished, reset the state here to avoid races. */
	82	fcopy_transaction.state = HVUTIL_READY;
	83	hv_fcopy_onchannelcallback(channel);
	84	}
	85
1d072339	86	static void fcopy_timeout_func(struct work_struct *dummy)
01325476 S	87	{
	88	/*
	89	* If the timer fires, the user-mode component has not responded;
	90	* process the pending transaction.
	91	*/
	92	fcopy_respond_to_host(HV_E_FAIL);
3cace4a6	93	hv_poll_channel(fcopy_transaction.recv_channel, fcopy_poll_wrapper);
01325476 S	94	}
01325476 S	95
e0fa3e5e VK	96	static void fcopy_register_done(void)
	97	{
	98	pr_debug("FCP: userspace daemon registered\n");
	99	hv_poll_channel(fcopy_transaction.recv_channel, fcopy_poll_wrapper);
	100	}
	101
01325476 S	102	static int fcopy_handle_handshake(u32 version)
01325476 S	103	{
a4d1ee5b VK	104	u32 our_ver = FCOPY_CURRENT_VERSION;
a4d1ee5b VK	105
01325476	106	switch (version) {
a4d1ee5b VK	107	case FCOPY_VERSION_0:
	108	/* Daemon doesn't expect us to reply */
	109	dm_reg_value = version;
	110	break;
	111	case FCOPY_VERSION_1:
	112	/* Daemon expects us to reply with our own version */
e0fa3e5e VK	113	if (hvutil_transport_send(hvt, &our_ver, sizeof(our_ver),
e0fa3e5e VK	114	fcopy_register_done))
a4d1ee5b VK	115	return -EFAULT;
a4d1ee5b VK	116	dm_reg_value = version;
01325476 S	117	break;
	118	default:
	119	/*
	120	* For now we will fail the registration.
	121	* If and when we have multiple versions to
	122	* deal with, we will be backward compatible.
	123	* We will add this code when needed.
	124	*/
	125	return -EINVAL;
	126	}
e0fa3e5e	127	pr_debug("FCP: userspace daemon ver. %d connected\n", version);
01325476 S	128	return 0;
	129	}
	130
c7e490fc	131	static void fcopy_send_data(struct work_struct *dummy)
01325476	132	{
25ef06fe	133	struct hv_start_fcopy *smsg_out = NULL;
01325476 S	134	int operation = fcopy_transaction.fcopy_msg->operation;
01325476 S	135	struct hv_start_fcopy *smsg_in;
c7e490fc VK	136	void *out_src;
c7e490fc VK	137	int rc, out_len;
01325476 S	138
	139	/*
	140	* The strings sent from the host are encoded in
	141	* in utf16; convert it to utf8 strings.
	142	* The host assures us that the utf16 strings will not exceed
	143	* the max lengths specified. We will however, reserve room
	144	* for the string terminating character - in the utf16s_utf8s()
	145	* function we limit the size of the buffer where the converted
	146	* string is placed to W_MAX_PATH -1 to guarantee
	147	* that the strings can be properly terminated!
	148	*/
	149
	150	switch (operation) {
	151	case START_FILE_COPY:
c7e490fc	152	out_len = sizeof(struct hv_start_fcopy);
25ef06fe VK	153	smsg_out = kzalloc(sizeof(*smsg_out), GFP_KERNEL);
	154	if (!smsg_out)
	155	return;
	156
	157	smsg_out->hdr.operation = operation;
01325476 S	158	smsg_in = (struct hv_start_fcopy *)fcopy_transaction.fcopy_msg;
	159
	160	utf16s_to_utf8s((wchar_t *)smsg_in->file_name, W_MAX_PATH,
	161	UTF16_LITTLE_ENDIAN,
25ef06fe	162	(__u8 *)&smsg_out->file_name, W_MAX_PATH - 1);
01325476 S	163
	164	utf16s_to_utf8s((wchar_t *)smsg_in->path_name, W_MAX_PATH,
	165	UTF16_LITTLE_ENDIAN,
25ef06fe	166	(__u8 *)&smsg_out->path_name, W_MAX_PATH - 1);
01325476	167
25ef06fe VK	168	smsg_out->copy_flags = smsg_in->copy_flags;
	169	smsg_out->file_size = smsg_in->file_size;
	170	out_src = smsg_out;
01325476 S	171	break;
	172
	173	default:
c7e490fc VK	174	out_src = fcopy_transaction.fcopy_msg;
c7e490fc VK	175	out_len = fcopy_transaction.recv_len;
01325476 S	176	break;
01325476 S	177	}
c7e490fc VK	178
c7e490fc VK	179	fcopy_transaction.state = HVUTIL_USERSPACE_REQ;
e0fa3e5e	180	rc = hvutil_transport_send(hvt, out_src, out_len, NULL);
c7e490fc VK	181	if (rc) {
	182	pr_debug("FCP: failed to communicate to the daemon: %d\n", rc);
	183	if (cancel_delayed_work_sync(&fcopy_timeout_work)) {
	184	fcopy_respond_to_host(HV_E_FAIL);
	185	fcopy_transaction.state = HVUTIL_READY;
	186	}
	187	}
25ef06fe VK	188	kfree(smsg_out);
25ef06fe VK	189
01325476 S	190	return;
	191	}
	192
	193	/*
	194	* Send a response back to the host.
	195	*/
	196
	197	static void
	198	fcopy_respond_to_host(int error)
	199	{
	200	struct icmsg_hdr *icmsghdr;
	201	u32 buf_len;
	202	struct vmbus_channel *channel;
	203	u64 req_id;
	204
	205	/*
	206	* Copy the global state for completing the transaction. Note that
	207	* only one transaction can be active at a time. This is guaranteed
	208	* by the file copy protocol implemented by the host. Furthermore,
	209	* the "transaction active" state we maintain ensures that there can
	210	* only be one active transaction at a time.
	211	*/
	212
	213	buf_len = fcopy_transaction.recv_len;
	214	channel = fcopy_transaction.recv_channel;
	215	req_id = fcopy_transaction.recv_req_id;
	216
01325476 S	217	icmsghdr = (struct icmsg_hdr *)
	218	&recv_buffer[sizeof(struct vmbuspipe_hdr)];
	219
	220	if (channel->onchannel_callback == NULL)
	221	/*
	222	* We have raced with util driver being unloaded;
	223	* silently return.
	224	*/
	225	return;
	226
	227	icmsghdr->status = error;
	228	icmsghdr->icflags = ICMSGHDRFLAG_TRANSACTION \| ICMSGHDRFLAG_RESPONSE;
	229	vmbus_sendpacket(channel, recv_buffer, buf_len, req_id,
	230	VM_PKT_DATA_INBAND, 0);
	231	}
	232
	233	void hv_fcopy_onchannelcallback(void *context)
	234	{
	235	struct vmbus_channel *channel = context;
	236	u32 recvlen;
	237	u64 requestid;
	238	struct hv_fcopy_hdr *fcopy_msg;
	239	struct icmsg_hdr *icmsghdr;
01325476 S	240	int fcopy_srv_version;
01325476 S	241
3cace4a6	242	if (fcopy_transaction.state > HVUTIL_READY)
01325476	243	return;
01325476 S	244
	245	vmbus_recvpacket(channel, recv_buffer, PAGE_SIZE * 2, &recvlen,
	246	&requestid);
	247	if (recvlen <= 0)
	248	return;
	249
	250	icmsghdr = (struct icmsg_hdr *)&recv_buffer[
	251	sizeof(struct vmbuspipe_hdr)];
	252	if (icmsghdr->icmsgtype == ICMSGTYPE_NEGOTIATE) {
1274a690	253	if (vmbus_prep_negotiate_resp(icmsghdr, recv_buffer,
a1656454 AN	254	fw_versions, FW_VER_COUNT,
a1656454 AN	255	fcopy_versions, FCOPY_VER_COUNT,
1274a690 AN	256	NULL, &fcopy_srv_version)) {
	257
	258	pr_info("FCopy IC version %d.%d\n",
	259	fcopy_srv_version >> 16,
	260	fcopy_srv_version & 0xFFFF);
	261	}
01325476 S	262	} else {
	263	fcopy_msg = (struct hv_fcopy_hdr *)&recv_buffer[
	264	sizeof(struct vmbuspipe_hdr) +
	265	sizeof(struct icmsg_hdr)];
	266
	267	/*
	268	* Stash away this global state for completing the
	269	* transaction; note transactions are serialized.
	270	*/
	271
01325476	272	fcopy_transaction.recv_len = recvlen;
01325476 S	273	fcopy_transaction.recv_req_id = requestid;
	274	fcopy_transaction.fcopy_msg = fcopy_msg;
	275
4c93cccc VK	276	if (fcopy_transaction.state < HVUTIL_READY) {
	277	/* Userspace is not registered yet */
	278	fcopy_respond_to_host(HV_E_FAIL);
	279	return;
	280	}
	281	fcopy_transaction.state = HVUTIL_HOSTMSG_RECEIVED;
	282
01325476 S	283	/*
	284	* Send the information to the user-level daemon.
	285	*/
c7e490fc	286	schedule_work(&fcopy_send_work);
c0b200cf S	287	schedule_delayed_work(&fcopy_timeout_work,
c0b200cf S	288	HV_UTIL_TIMEOUT * HZ);
01325476 S	289	return;
	290	}
	291	icmsghdr->icflags = ICMSGHDRFLAG_TRANSACTION \| ICMSGHDRFLAG_RESPONSE;
	292	vmbus_sendpacket(channel, recv_buffer, recvlen, requestid,
	293	VM_PKT_DATA_INBAND, 0);
	294	}
	295
c7e490fc VK	296	/* Callback when data is received from userspace */
c7e490fc VK	297	static int fcopy_on_msg(void *msg, int len)
01325476	298	{
c7e490fc	299	int val = (int )msg;
01325476	300
c7e490fc	301	if (len != sizeof(int))
01325476 S	302	return -EINVAL;
01325476 S	303
c7e490fc VK	304	if (fcopy_transaction.state == HVUTIL_DEVICE_INIT)
c7e490fc VK	305	return fcopy_handle_handshake(*val);
01325476	306
4c93cccc VK	307	if (fcopy_transaction.state != HVUTIL_USERSPACE_REQ)
	308	return -EINVAL;
	309
01325476 S	310	/*
	311	* Complete the transaction by forwarding the result
	312	* to the host. But first, cancel the timeout.
	313	*/
4c93cccc VK	314	if (cancel_delayed_work_sync(&fcopy_timeout_work)) {
4c93cccc VK	315	fcopy_transaction.state = HVUTIL_USERSPACE_RECV;
c7e490fc	316	fcopy_respond_to_host(*val);
3cace4a6 OH	317	hv_poll_channel(fcopy_transaction.recv_channel,
3cace4a6 OH	318	fcopy_poll_wrapper);
242f3122	319	}
01325476	320
01325476 S	321	return 0;
	322	}
	323
c7e490fc	324	static void fcopy_on_reset(void)
01325476 S	325	{
	326	/*
	327	* The daemon has exited; reset the state.
	328	*/
4c93cccc	329	fcopy_transaction.state = HVUTIL_DEVICE_INIT;
d9b16529	330
c7e490fc	331	if (cancel_delayed_work_sync(&fcopy_timeout_work))
d9b16529	332	fcopy_respond_to_host(HV_E_FAIL);
01325476 S	333	}
	334
	335	int hv_fcopy_init(struct hv_util_service *srv)
	336	{
	337	recv_buffer = srv->recv_buffer;
b9830d12	338	fcopy_transaction.recv_channel = srv->channel;
01325476 S	339
	340	/*
	341	* When this driver loads, the user level daemon that
	342	* processes the host requests may not yet be running.
	343	* Defer processing channel callbacks until the daemon
	344	* has registered.
	345	*/
4c93cccc	346	fcopy_transaction.state = HVUTIL_DEVICE_INIT;
01325476	347
c7e490fc VK	348	hvt = hvutil_transport_init(fcopy_devname, 0, 0,
	349	fcopy_on_msg, fcopy_on_reset);
	350	if (!hvt)
	351	return -EFAULT;
	352
	353	return 0;
01325476 S	354	}
	355
	356	void hv_fcopy_deinit(void)
	357	{
4c93cccc	358	fcopy_transaction.state = HVUTIL_DEVICE_DYING;
1d072339	359	cancel_delayed_work_sync(&fcopy_timeout_work);
c7e490fc	360	hvutil_transport_destroy(hvt);
01325476	361	}