[thirdparty/kernel/stable.git] / drivers / hv / hv_fcopy.c

// SPDX-License-Identifier: GPL-2.0-only
/*
 * An implementation of file copy service.
 *
 * Copyright (C) 2014, Microsoft, Inc.
 *
 * Author : K. Y. Srinivasan <ksrinivasan@novell.com>
 */

#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;

	case WRITE_TO_FILE:
		out_src = fcopy_transaction.fcopy_msg;
		out_len = sizeof(struct hv_do_fcopy);
		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);
}

/*
 * 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
43aa3132	1	// SPDX-License-Identifier: GPL-2.0-only
01325476 S	2	/*
	3	* An implementation of file copy service.
	4	*
	5	* Copyright (C) 2014, Microsoft, Inc.
	6	*
	7	* Author : K. Y. Srinivasan <ksrinivasan@novell.com>
01325476 S	8	*/
	9
	10	#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
	11
01325476 S	12	#include <linux/nls.h>
01325476 S	13	#include <linux/workqueue.h>
01325476 S	14	#include <linux/hyperv.h>
01325476 S	15	#include <linux/sched.h>
01325476 S	16
01325476 S	17	#include "hyperv_vmbus.h"
c7e490fc	18	#include "hv_utils_transport.h"
01325476 S	19
	20	#define WIN8_SRV_MAJOR 1
	21	#define WIN8_SRV_MINOR 1
	22	#define WIN8_SRV_VERSION (WIN8_SRV_MAJOR << 16 \| WIN8_SRV_MINOR)
	23
a1656454 AN	24	#define FCOPY_VER_COUNT 1
	25	static const int fcopy_versions[] = {
	26	WIN8_SRV_VERSION
	27	};
	28
	29	#define FW_VER_COUNT 1
	30	static const int fw_versions[] = {
	31	UTIL_FW_VERSION
	32	};
	33
01325476 S	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;
a4d1ee5b VK	64	/*
	65	* This state maintains the version number registered by the daemon.
	66	*/
	67	static int dm_reg_value;
01325476	68
3cace4a6 OH	69	static void fcopy_poll_wrapper(void *channel)
	70	{
	71	/* Transaction is finished, reset the state here to avoid races. */
	72	fcopy_transaction.state = HVUTIL_READY;
	73	hv_fcopy_onchannelcallback(channel);
	74	}
	75
1d072339	76	static void fcopy_timeout_func(struct work_struct *dummy)
01325476 S	77	{
	78	/*
	79	* If the timer fires, the user-mode component has not responded;
	80	* process the pending transaction.
	81	*/
	82	fcopy_respond_to_host(HV_E_FAIL);
3cace4a6	83	hv_poll_channel(fcopy_transaction.recv_channel, fcopy_poll_wrapper);
01325476 S	84	}
01325476 S	85
e0fa3e5e VK	86	static void fcopy_register_done(void)
	87	{
	88	pr_debug("FCP: userspace daemon registered\n");
	89	hv_poll_channel(fcopy_transaction.recv_channel, fcopy_poll_wrapper);
	90	}
	91
01325476 S	92	static int fcopy_handle_handshake(u32 version)
01325476 S	93	{
a4d1ee5b VK	94	u32 our_ver = FCOPY_CURRENT_VERSION;
a4d1ee5b VK	95
01325476	96	switch (version) {
a4d1ee5b VK	97	case FCOPY_VERSION_0:
	98	/* Daemon doesn't expect us to reply */
	99	dm_reg_value = version;
	100	break;
	101	case FCOPY_VERSION_1:
	102	/* Daemon expects us to reply with our own version */
e0fa3e5e VK	103	if (hvutil_transport_send(hvt, &our_ver, sizeof(our_ver),
e0fa3e5e VK	104	fcopy_register_done))
a4d1ee5b VK	105	return -EFAULT;
a4d1ee5b VK	106	dm_reg_value = version;
01325476 S	107	break;
	108	default:
	109	/*
	110	* For now we will fail the registration.
	111	* If and when we have multiple versions to
	112	* deal with, we will be backward compatible.
	113	* We will add this code when needed.
	114	*/
	115	return -EINVAL;
	116	}
e0fa3e5e	117	pr_debug("FCP: userspace daemon ver. %d connected\n", version);
01325476 S	118	return 0;
	119	}
	120
c7e490fc	121	static void fcopy_send_data(struct work_struct *dummy)
01325476	122	{
25ef06fe	123	struct hv_start_fcopy *smsg_out = NULL;
01325476 S	124	int operation = fcopy_transaction.fcopy_msg->operation;
01325476 S	125	struct hv_start_fcopy *smsg_in;
c7e490fc VK	126	void *out_src;
c7e490fc VK	127	int rc, out_len;
01325476 S	128
	129	/*
	130	* The strings sent from the host are encoded in
	131	* in utf16; convert it to utf8 strings.
	132	* The host assures us that the utf16 strings will not exceed
	133	* the max lengths specified. We will however, reserve room
	134	* for the string terminating character - in the utf16s_utf8s()
	135	* function we limit the size of the buffer where the converted
	136	* string is placed to W_MAX_PATH -1 to guarantee
	137	* that the strings can be properly terminated!
	138	*/
	139
	140	switch (operation) {
	141	case START_FILE_COPY:
c7e490fc	142	out_len = sizeof(struct hv_start_fcopy);
25ef06fe VK	143	smsg_out = kzalloc(sizeof(*smsg_out), GFP_KERNEL);
	144	if (!smsg_out)
	145	return;
	146
	147	smsg_out->hdr.operation = operation;
01325476 S	148	smsg_in = (struct hv_start_fcopy *)fcopy_transaction.fcopy_msg;
	149
	150	utf16s_to_utf8s((wchar_t *)smsg_in->file_name, W_MAX_PATH,
	151	UTF16_LITTLE_ENDIAN,
25ef06fe	152	(__u8 *)&smsg_out->file_name, W_MAX_PATH - 1);
01325476 S	153
	154	utf16s_to_utf8s((wchar_t *)smsg_in->path_name, W_MAX_PATH,
	155	UTF16_LITTLE_ENDIAN,
25ef06fe	156	(__u8 *)&smsg_out->path_name, W_MAX_PATH - 1);
01325476	157
25ef06fe VK	158	smsg_out->copy_flags = smsg_in->copy_flags;
	159	smsg_out->file_size = smsg_in->file_size;
	160	out_src = smsg_out;
01325476 S	161	break;
01325476 S	162
549e658a OH	163	case WRITE_TO_FILE:
	164	out_src = fcopy_transaction.fcopy_msg;
	165	out_len = sizeof(struct hv_do_fcopy);
	166	break;
01325476	167	default:
c7e490fc VK	168	out_src = fcopy_transaction.fcopy_msg;
c7e490fc VK	169	out_len = fcopy_transaction.recv_len;
01325476 S	170	break;
01325476 S	171	}
c7e490fc VK	172
c7e490fc VK	173	fcopy_transaction.state = HVUTIL_USERSPACE_REQ;
e0fa3e5e	174	rc = hvutil_transport_send(hvt, out_src, out_len, NULL);
c7e490fc VK	175	if (rc) {
	176	pr_debug("FCP: failed to communicate to the daemon: %d\n", rc);
	177	if (cancel_delayed_work_sync(&fcopy_timeout_work)) {
	178	fcopy_respond_to_host(HV_E_FAIL);
	179	fcopy_transaction.state = HVUTIL_READY;
	180	}
	181	}
25ef06fe	182	kfree(smsg_out);
01325476 S	183	}
	184
	185	/*
	186	* Send a response back to the host.
	187	*/
	188
	189	static void
	190	fcopy_respond_to_host(int error)
	191	{
	192	struct icmsg_hdr *icmsghdr;
	193	u32 buf_len;
	194	struct vmbus_channel *channel;
	195	u64 req_id;
	196
	197	/*
	198	* Copy the global state for completing the transaction. Note that
	199	* only one transaction can be active at a time. This is guaranteed
	200	* by the file copy protocol implemented by the host. Furthermore,
	201	* the "transaction active" state we maintain ensures that there can
	202	* only be one active transaction at a time.
	203	*/
	204
	205	buf_len = fcopy_transaction.recv_len;
	206	channel = fcopy_transaction.recv_channel;
	207	req_id = fcopy_transaction.recv_req_id;
	208
01325476 S	209	icmsghdr = (struct icmsg_hdr *)
	210	&recv_buffer[sizeof(struct vmbuspipe_hdr)];
	211
	212	if (channel->onchannel_callback == NULL)
	213	/*
	214	* We have raced with util driver being unloaded;
	215	* silently return.
	216	*/
	217	return;
	218
	219	icmsghdr->status = error;
	220	icmsghdr->icflags = ICMSGHDRFLAG_TRANSACTION \| ICMSGHDRFLAG_RESPONSE;
	221	vmbus_sendpacket(channel, recv_buffer, buf_len, req_id,
	222	VM_PKT_DATA_INBAND, 0);
	223	}
	224
	225	void hv_fcopy_onchannelcallback(void *context)
	226	{
	227	struct vmbus_channel *channel = context;
	228	u32 recvlen;
	229	u64 requestid;
	230	struct hv_fcopy_hdr *fcopy_msg;
	231	struct icmsg_hdr *icmsghdr;
01325476 S	232	int fcopy_srv_version;
01325476 S	233
3cace4a6	234	if (fcopy_transaction.state > HVUTIL_READY)
01325476	235	return;
01325476 S	236
	237	vmbus_recvpacket(channel, recv_buffer, PAGE_SIZE * 2, &recvlen,
	238	&requestid);
	239	if (recvlen <= 0)
	240	return;
	241
	242	icmsghdr = (struct icmsg_hdr *)&recv_buffer[
	243	sizeof(struct vmbuspipe_hdr)];
	244	if (icmsghdr->icmsgtype == ICMSGTYPE_NEGOTIATE) {
1274a690	245	if (vmbus_prep_negotiate_resp(icmsghdr, recv_buffer,
a1656454 AN	246	fw_versions, FW_VER_COUNT,
a1656454 AN	247	fcopy_versions, FCOPY_VER_COUNT,
1274a690 AN	248	NULL, &fcopy_srv_version)) {
	249
	250	pr_info("FCopy IC version %d.%d\n",
	251	fcopy_srv_version >> 16,
	252	fcopy_srv_version & 0xFFFF);
	253	}
01325476 S	254	} else {
	255	fcopy_msg = (struct hv_fcopy_hdr *)&recv_buffer[
	256	sizeof(struct vmbuspipe_hdr) +
	257	sizeof(struct icmsg_hdr)];
	258
	259	/*
	260	* Stash away this global state for completing the
	261	* transaction; note transactions are serialized.
	262	*/
	263
01325476	264	fcopy_transaction.recv_len = recvlen;
01325476 S	265	fcopy_transaction.recv_req_id = requestid;
	266	fcopy_transaction.fcopy_msg = fcopy_msg;
	267
4c93cccc VK	268	if (fcopy_transaction.state < HVUTIL_READY) {
	269	/* Userspace is not registered yet */
	270	fcopy_respond_to_host(HV_E_FAIL);
	271	return;
	272	}
	273	fcopy_transaction.state = HVUTIL_HOSTMSG_RECEIVED;
	274
01325476 S	275	/*
	276	* Send the information to the user-level daemon.
	277	*/
c7e490fc	278	schedule_work(&fcopy_send_work);
c0b200cf S	279	schedule_delayed_work(&fcopy_timeout_work,
c0b200cf S	280	HV_UTIL_TIMEOUT * HZ);
01325476 S	281	return;
	282	}
	283	icmsghdr->icflags = ICMSGHDRFLAG_TRANSACTION \| ICMSGHDRFLAG_RESPONSE;
	284	vmbus_sendpacket(channel, recv_buffer, recvlen, requestid,
	285	VM_PKT_DATA_INBAND, 0);
	286	}
	287
c7e490fc VK	288	/* Callback when data is received from userspace */
c7e490fc VK	289	static int fcopy_on_msg(void *msg, int len)
01325476	290	{
c7e490fc	291	int val = (int )msg;
01325476	292
c7e490fc	293	if (len != sizeof(int))
01325476 S	294	return -EINVAL;
01325476 S	295
c7e490fc VK	296	if (fcopy_transaction.state == HVUTIL_DEVICE_INIT)
c7e490fc VK	297	return fcopy_handle_handshake(*val);
01325476	298
4c93cccc VK	299	if (fcopy_transaction.state != HVUTIL_USERSPACE_REQ)
	300	return -EINVAL;
	301
01325476 S	302	/*
	303	* Complete the transaction by forwarding the result
	304	* to the host. But first, cancel the timeout.
	305	*/
4c93cccc VK	306	if (cancel_delayed_work_sync(&fcopy_timeout_work)) {
4c93cccc VK	307	fcopy_transaction.state = HVUTIL_USERSPACE_RECV;
c7e490fc	308	fcopy_respond_to_host(*val);
3cace4a6 OH	309	hv_poll_channel(fcopy_transaction.recv_channel,
3cace4a6 OH	310	fcopy_poll_wrapper);
242f3122	311	}
01325476	312
01325476 S	313	return 0;
	314	}
	315
c7e490fc	316	static void fcopy_on_reset(void)
01325476 S	317	{
	318	/*
	319	* The daemon has exited; reset the state.
	320	*/
4c93cccc	321	fcopy_transaction.state = HVUTIL_DEVICE_INIT;
d9b16529	322
c7e490fc	323	if (cancel_delayed_work_sync(&fcopy_timeout_work))
d9b16529	324	fcopy_respond_to_host(HV_E_FAIL);
01325476 S	325	}
	326
	327	int hv_fcopy_init(struct hv_util_service *srv)
	328	{
	329	recv_buffer = srv->recv_buffer;
b9830d12	330	fcopy_transaction.recv_channel = srv->channel;
01325476 S	331
	332	/*
	333	* When this driver loads, the user level daemon that
	334	* processes the host requests may not yet be running.
	335	* Defer processing channel callbacks until the daemon
	336	* has registered.
	337	*/
4c93cccc	338	fcopy_transaction.state = HVUTIL_DEVICE_INIT;
01325476	339
c7e490fc VK	340	hvt = hvutil_transport_init(fcopy_devname, 0, 0,
	341	fcopy_on_msg, fcopy_on_reset);
	342	if (!hvt)
	343	return -EFAULT;
	344
	345	return 0;
01325476 S	346	}
	347
	348	void hv_fcopy_deinit(void)
	349	{
4c93cccc	350	fcopy_transaction.state = HVUTIL_DEVICE_DYING;
1d072339	351	cancel_delayed_work_sync(&fcopy_timeout_work);
c7e490fc	352	hvutil_transport_destroy(hvt);
01325476	353	}