[linux.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 <[email protected]>
 */

#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt

#include <linux/nls.h>
#include <linux/workqueue.h>
#include <linux/hyperv.h>
#include <linux/sched.h>
#include <asm/hyperv-tlfs.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;
	tasklet_schedule(&((struct vmbus_channel *)channel)->callback_event);
}

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, HV_HYP_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;
}

static void hv_fcopy_cancel_work(void)
{
	cancel_delayed_work_sync(&fcopy_timeout_work);
	cancel_work_sync(&fcopy_send_work);
}

int hv_fcopy_pre_suspend(void)
{
	struct vmbus_channel *channel = fcopy_transaction.recv_channel;
	struct hv_fcopy_hdr *fcopy_msg;

	/*
	 * Fake a CANCEL_FCOPY message for the user space daemon in case the
	 * daemon is in the middle of copying some file. It doesn't matter if
	 * there is already a message pending to be delivered to the user
	 * space since we force fcopy_transaction.state to be HVUTIL_READY, so
	 * the user space daemon's write() will fail with EINVAL (see
	 * fcopy_on_msg()), and the daemon will reset the device by closing
	 * and re-opening it.
	 */
	fcopy_msg = kzalloc(sizeof(*fcopy_msg), GFP_KERNEL);
	if (!fcopy_msg)
		return -ENOMEM;

	tasklet_disable(&channel->callback_event);

	fcopy_msg->operation = CANCEL_FCOPY;

	hv_fcopy_cancel_work();

	/* We don't care about the return value. */
	hvutil_transport_send(hvt, fcopy_msg, sizeof(*fcopy_msg), NULL);

	kfree(fcopy_msg);

	fcopy_transaction.state = HVUTIL_READY;

	/* tasklet_enable() will be called in hv_fcopy_pre_resume(). */
	return 0;
}

int hv_fcopy_pre_resume(void)
{
	struct vmbus_channel *channel = fcopy_transaction.recv_channel;

	tasklet_enable(&channel->callback_event);

	return 0;
}

void hv_fcopy_deinit(void)
{
	fcopy_transaction.state = HVUTIL_DEVICE_DYING;

	hv_fcopy_cancel_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 <[email protected]>
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>
b14d749a	16	#include <asm/hyperv-tlfs.h>
01325476 S	17
01325476 S	18	#include "hyperv_vmbus.h"
c7e490fc	19	#include "hv_utils_transport.h"
01325476 S	20
	21	#define WIN8_SRV_MAJOR 1
	22	#define WIN8_SRV_MINOR 1
	23	#define WIN8_SRV_VERSION (WIN8_SRV_MAJOR << 16 \| WIN8_SRV_MINOR)
	24
a1656454 AN	25	#define FCOPY_VER_COUNT 1
	26	static const int fcopy_versions[] = {
	27	WIN8_SRV_VERSION
	28	};
	29
	30	#define FW_VER_COUNT 1
	31	static const int fw_versions[] = {
	32	UTIL_FW_VERSION
	33	};
	34
01325476 S	35	/*
	36	* Global state maintained for transaction that is being processed.
	37	* For a class of integration services, including the "file copy service",
	38	* the specified protocol is a "request/response" protocol which means that
	39	* there can only be single outstanding transaction from the host at any
	40	* given point in time. We use this to simplify memory management in this
	41	* driver - we cache and process only one message at a time.
	42	*
	43	* While the request/response protocol is guaranteed by the host, we further
	44	* ensure this by serializing packet processing in this driver - we do not
	45	* read additional packets from the VMBUs until the current packet is fully
	46	* handled.
01325476 S	47	*/
	48
	49	static struct {
4c93cccc	50	int state; /* hvutil_device_state */
01325476 S	51	int recv_len; /* number of bytes received. */
01325476 S	52	struct hv_fcopy_hdr fcopy_msg; / current message */
01325476 S	53	struct vmbus_channel recv_channel; / chn we got the request */
01325476 S	54	u64 recv_req_id; /* request ID. */
01325476 S	55	} fcopy_transaction;
01325476 S	56
01325476	57	static void fcopy_respond_to_host(int error);
c7e490fc	58	static void fcopy_send_data(struct work_struct *dummy);
1d072339 VK	59	static void fcopy_timeout_func(struct work_struct *dummy);
1d072339 VK	60	static DECLARE_DELAYED_WORK(fcopy_timeout_work, fcopy_timeout_func);
c7e490fc VK	61	static DECLARE_WORK(fcopy_send_work, fcopy_send_data);
c7e490fc VK	62	static const char fcopy_devname[] = "vmbus/hv_fcopy";
01325476	63	static u8 *recv_buffer;
c7e490fc	64	static struct hvutil_transport *hvt;
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;
238d2ed8	74	tasklet_schedule(&((struct vmbus_channel *)channel)->callback_event);
3cace4a6 OH	75	}
3cace4a6 OH	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;
01325476 S	163
549e658a OH	164	case WRITE_TO_FILE:
	165	out_src = fcopy_transaction.fcopy_msg;
	166	out_len = sizeof(struct hv_do_fcopy);
	167	break;
01325476	168	default:
c7e490fc VK	169	out_src = fcopy_transaction.fcopy_msg;
c7e490fc VK	170	out_len = fcopy_transaction.recv_len;
01325476 S	171	break;
01325476 S	172	}
c7e490fc VK	173
c7e490fc VK	174	fcopy_transaction.state = HVUTIL_USERSPACE_REQ;
e0fa3e5e	175	rc = hvutil_transport_send(hvt, out_src, out_len, NULL);
c7e490fc VK	176	if (rc) {
	177	pr_debug("FCP: failed to communicate to the daemon: %d\n", rc);
	178	if (cancel_delayed_work_sync(&fcopy_timeout_work)) {
	179	fcopy_respond_to_host(HV_E_FAIL);
	180	fcopy_transaction.state = HVUTIL_READY;
	181	}
	182	}
25ef06fe	183	kfree(smsg_out);
01325476 S	184	}
	185
	186	/*
	187	* Send a response back to the host.
	188	*/
	189
	190	static void
	191	fcopy_respond_to_host(int error)
	192	{
	193	struct icmsg_hdr *icmsghdr;
	194	u32 buf_len;
	195	struct vmbus_channel *channel;
	196	u64 req_id;
	197
	198	/*
	199	* Copy the global state for completing the transaction. Note that
	200	* only one transaction can be active at a time. This is guaranteed
	201	* by the file copy protocol implemented by the host. Furthermore,
	202	* the "transaction active" state we maintain ensures that there can
	203	* only be one active transaction at a time.
	204	*/
	205
	206	buf_len = fcopy_transaction.recv_len;
	207	channel = fcopy_transaction.recv_channel;
	208	req_id = fcopy_transaction.recv_req_id;
	209
01325476 S	210	icmsghdr = (struct icmsg_hdr *)
	211	&recv_buffer[sizeof(struct vmbuspipe_hdr)];
	212
	213	if (channel->onchannel_callback == NULL)
	214	/*
	215	* We have raced with util driver being unloaded;
	216	* silently return.
	217	*/
	218	return;
	219
	220	icmsghdr->status = error;
	221	icmsghdr->icflags = ICMSGHDRFLAG_TRANSACTION \| ICMSGHDRFLAG_RESPONSE;
	222	vmbus_sendpacket(channel, recv_buffer, buf_len, req_id,
	223	VM_PKT_DATA_INBAND, 0);
	224	}
	225
	226	void hv_fcopy_onchannelcallback(void *context)
	227	{
	228	struct vmbus_channel *channel = context;
	229	u32 recvlen;
	230	u64 requestid;
	231	struct hv_fcopy_hdr *fcopy_msg;
	232	struct icmsg_hdr *icmsghdr;
01325476 S	233	int fcopy_srv_version;
01325476 S	234
3cace4a6	235	if (fcopy_transaction.state > HVUTIL_READY)
01325476	236	return;
01325476	237
b14d749a	238	vmbus_recvpacket(channel, recv_buffer, HV_HYP_PAGE_SIZE * 2, &recvlen,
01325476 S	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) {
1274a690	246	if (vmbus_prep_negotiate_resp(icmsghdr, recv_buffer,
a1656454 AN	247	fw_versions, FW_VER_COUNT,
a1656454 AN	248	fcopy_versions, FCOPY_VER_COUNT,
1274a690 AN	249	NULL, &fcopy_srv_version)) {
	250
	251	pr_info("FCopy IC version %d.%d\n",
	252	fcopy_srv_version >> 16,
	253	fcopy_srv_version & 0xFFFF);
	254	}
01325476 S	255	} else {
	256	fcopy_msg = (struct hv_fcopy_hdr *)&recv_buffer[
	257	sizeof(struct vmbuspipe_hdr) +
	258	sizeof(struct icmsg_hdr)];
	259
	260	/*
	261	* Stash away this global state for completing the
	262	* transaction; note transactions are serialized.
	263	*/
	264
01325476	265	fcopy_transaction.recv_len = recvlen;
01325476 S	266	fcopy_transaction.recv_req_id = requestid;
	267	fcopy_transaction.fcopy_msg = fcopy_msg;
	268
4c93cccc VK	269	if (fcopy_transaction.state < HVUTIL_READY) {
	270	/* Userspace is not registered yet */
	271	fcopy_respond_to_host(HV_E_FAIL);
	272	return;
	273	}
	274	fcopy_transaction.state = HVUTIL_HOSTMSG_RECEIVED;
	275
01325476 S	276	/*
	277	* Send the information to the user-level daemon.
	278	*/
c7e490fc	279	schedule_work(&fcopy_send_work);
c0b200cf S	280	schedule_delayed_work(&fcopy_timeout_work,
c0b200cf S	281	HV_UTIL_TIMEOUT * HZ);
01325476 S	282	return;
	283	}
	284	icmsghdr->icflags = ICMSGHDRFLAG_TRANSACTION \| ICMSGHDRFLAG_RESPONSE;
	285	vmbus_sendpacket(channel, recv_buffer, recvlen, requestid,
	286	VM_PKT_DATA_INBAND, 0);
	287	}
	288
c7e490fc VK	289	/* Callback when data is received from userspace */
c7e490fc VK	290	static int fcopy_on_msg(void *msg, int len)
01325476	291	{
c7e490fc	292	int val = (int )msg;
01325476	293
c7e490fc	294	if (len != sizeof(int))
01325476 S	295	return -EINVAL;
01325476 S	296
c7e490fc VK	297	if (fcopy_transaction.state == HVUTIL_DEVICE_INIT)
c7e490fc VK	298	return fcopy_handle_handshake(*val);
01325476	299
4c93cccc VK	300	if (fcopy_transaction.state != HVUTIL_USERSPACE_REQ)
	301	return -EINVAL;
	302
01325476 S	303	/*
	304	* Complete the transaction by forwarding the result
	305	* to the host. But first, cancel the timeout.
	306	*/
4c93cccc VK	307	if (cancel_delayed_work_sync(&fcopy_timeout_work)) {
4c93cccc VK	308	fcopy_transaction.state = HVUTIL_USERSPACE_RECV;
c7e490fc	309	fcopy_respond_to_host(*val);
3cace4a6 OH	310	hv_poll_channel(fcopy_transaction.recv_channel,
3cace4a6 OH	311	fcopy_poll_wrapper);
242f3122	312	}
01325476	313
01325476 S	314	return 0;
	315	}
	316
c7e490fc	317	static void fcopy_on_reset(void)
01325476 S	318	{
	319	/*
	320	* The daemon has exited; reset the state.
	321	*/
4c93cccc	322	fcopy_transaction.state = HVUTIL_DEVICE_INIT;
d9b16529	323
c7e490fc	324	if (cancel_delayed_work_sync(&fcopy_timeout_work))
d9b16529	325	fcopy_respond_to_host(HV_E_FAIL);
01325476 S	326	}
	327
	328	int hv_fcopy_init(struct hv_util_service *srv)
	329	{
	330	recv_buffer = srv->recv_buffer;
b9830d12	331	fcopy_transaction.recv_channel = srv->channel;
01325476 S	332
	333	/*
	334	* When this driver loads, the user level daemon that
	335	* processes the host requests may not yet be running.
	336	* Defer processing channel callbacks until the daemon
	337	* has registered.
	338	*/
4c93cccc	339	fcopy_transaction.state = HVUTIL_DEVICE_INIT;
01325476	340
c7e490fc VK	341	hvt = hvutil_transport_init(fcopy_devname, 0, 0,
	342	fcopy_on_msg, fcopy_on_reset);
	343	if (!hvt)
	344	return -EFAULT;
	345
	346	return 0;
01325476 S	347	}
01325476 S	348
54e19d34 DC	349	static void hv_fcopy_cancel_work(void)
	350	{
	351	cancel_delayed_work_sync(&fcopy_timeout_work);
	352	cancel_work_sync(&fcopy_send_work);
	353	}
	354
	355	int hv_fcopy_pre_suspend(void)
	356	{
	357	struct vmbus_channel *channel = fcopy_transaction.recv_channel;
	358	struct hv_fcopy_hdr *fcopy_msg;
	359
	360	/*
	361	* Fake a CANCEL_FCOPY message for the user space daemon in case the
	362	* daemon is in the middle of copying some file. It doesn't matter if
	363	* there is already a message pending to be delivered to the user
	364	* space since we force fcopy_transaction.state to be HVUTIL_READY, so
	365	* the user space daemon's write() will fail with EINVAL (see
	366	* fcopy_on_msg()), and the daemon will reset the device by closing
	367	* and re-opening it.
	368	*/
	369	fcopy_msg = kzalloc(sizeof(*fcopy_msg), GFP_KERNEL);
	370	if (!fcopy_msg)
	371	return -ENOMEM;
	372
	373	tasklet_disable(&channel->callback_event);
	374
	375	fcopy_msg->operation = CANCEL_FCOPY;
	376
	377	hv_fcopy_cancel_work();
	378
	379	/* We don't care about the return value. */
	380	hvutil_transport_send(hvt, fcopy_msg, sizeof(*fcopy_msg), NULL);
	381
	382	kfree(fcopy_msg);
	383
	384	fcopy_transaction.state = HVUTIL_READY;
	385
	386	/* tasklet_enable() will be called in hv_fcopy_pre_resume(). */
	387	return 0;
	388	}
	389
	390	int hv_fcopy_pre_resume(void)
	391	{
	392	struct vmbus_channel *channel = fcopy_transaction.recv_channel;
	393
	394	tasklet_enable(&channel->callback_event);
	395
	396	return 0;
	397	}
	398
01325476 S	399	void hv_fcopy_deinit(void)
01325476 S	400	{
4c93cccc	401	fcopy_transaction.state = HVUTIL_DEVICE_DYING;
54e19d34 DC	402
	403	hv_fcopy_cancel_work();
	404
c7e490fc	405	hvutil_transport_destroy(hvt);
01325476	406	}