drivers/hv/hv_util.c - linux - Git at Google

 // SPDX-License-Identifier: GPL-2.0-only
 /*
  * Copyright (c) 2010, Microsoft Corporation.
  *
  * Authors:
  *   Haiyang Zhang <haiyangz@microsoft.com>
  *   Hank Janssen  <hjanssen@microsoft.com>
  */
 #define pr_fmt(fmt) KBUILD_MODNAME ": " fmt

 #include <linux/kernel.h>
 #include <linux/init.h>
 #include <linux/module.h>
 #include <linux/slab.h>
 #include <linux/sysctl.h>
 #include <linux/reboot.h>
 #include <linux/hyperv.h>
 #include <linux/clockchips.h>
 #include <linux/ptp_clock_kernel.h>
 #include <clocksource/hyperv_timer.h>
 #include <asm/mshyperv.h>

 #include "hyperv_vmbus.h"

 #define SD_MAJOR	3
 #define SD_MINOR	0
 #define SD_VERSION	(SD_MAJOR << 16 | SD_MINOR)

 #define SD_MAJOR_1	1
 #define SD_VERSION_1	(SD_MAJOR_1 << 16 | SD_MINOR)

 #define TS_MAJOR	4
 #define TS_MINOR	0
 #define TS_VERSION	(TS_MAJOR << 16 | TS_MINOR)

 #define TS_MAJOR_1	1
 #define TS_VERSION_1	(TS_MAJOR_1 << 16 | TS_MINOR)

 #define TS_MAJOR_3	3
 #define TS_VERSION_3	(TS_MAJOR_3 << 16 | TS_MINOR)

 #define HB_MAJOR	3
 #define HB_MINOR	0
 #define HB_VERSION	(HB_MAJOR << 16 | HB_MINOR)

 #define HB_MAJOR_1	1
 #define HB_VERSION_1	(HB_MAJOR_1 << 16 | HB_MINOR)

 static int sd_srv_version;
 static int ts_srv_version;
 static int hb_srv_version;

 #define SD_VER_COUNT 2
 static const int sd_versions[] = {
 	SD_VERSION,
 	SD_VERSION_1
 };

 #define TS_VER_COUNT 3
 static const int ts_versions[] = {
 	TS_VERSION,
 	TS_VERSION_3,
 	TS_VERSION_1
 };

 #define HB_VER_COUNT 2
 static const int hb_versions[] = {
 	HB_VERSION,
 	HB_VERSION_1
 };

 #define FW_VER_COUNT 2
 static const int fw_versions[] = {
 	UTIL_FW_VERSION,
 	UTIL_WS2K8_FW_VERSION
 };

 static void shutdown_onchannelcallback(void *context);
 static struct hv_util_service util_shutdown = {
 	.util_cb = shutdown_onchannelcallback,
 };

 static int hv_timesync_init(struct hv_util_service *srv);
 static void hv_timesync_deinit(void);

 static void timesync_onchannelcallback(void *context);
 static struct hv_util_service util_timesynch = {
 	.util_cb = timesync_onchannelcallback,
 	.util_init = hv_timesync_init,
 	.util_deinit = hv_timesync_deinit,
 };

 static void heartbeat_onchannelcallback(void *context);
 static struct hv_util_service util_heartbeat = {
 	.util_cb = heartbeat_onchannelcallback,
 };

 static struct hv_util_service util_kvp = {
 	.util_cb = hv_kvp_onchannelcallback,
 	.util_init = hv_kvp_init,
 	.util_deinit = hv_kvp_deinit,
 };

 static struct hv_util_service util_vss = {
 	.util_cb = hv_vss_onchannelcallback,
 	.util_init = hv_vss_init,
 	.util_deinit = hv_vss_deinit,
 };

 static struct hv_util_service util_fcopy = {
 	.util_cb = hv_fcopy_onchannelcallback,
 	.util_init = hv_fcopy_init,
 	.util_deinit = hv_fcopy_deinit,
 };

 static void perform_shutdown(struct work_struct *dummy)
 {
 	orderly_poweroff(true);
 }

 /*
  * Perform the shutdown operation in a thread context.
  */
 static DECLARE_WORK(shutdown_work, perform_shutdown);

 static void shutdown_onchannelcallback(void *context)
 {
 	struct vmbus_channel *channel = context;
 	u32 recvlen;
 	u64 requestid;
 	bool execute_shutdown = false;
 	u8  *shut_txf_buf = util_shutdown.recv_buffer;

 	struct shutdown_msg_data *shutdown_msg;

 	struct icmsg_hdr *icmsghdrp;

 	vmbus_recvpacket(channel, shut_txf_buf,
 			 HV_HYP_PAGE_SIZE, &recvlen, &requestid);

 	if (recvlen > 0) {
 		icmsghdrp = (struct icmsg_hdr *)&shut_txf_buf[
 			sizeof(struct vmbuspipe_hdr)];

 		if (icmsghdrp->icmsgtype == ICMSGTYPE_NEGOTIATE) {
 			if (vmbus_prep_negotiate_resp(icmsghdrp, shut_txf_buf,
 					fw_versions, FW_VER_COUNT,
 					sd_versions, SD_VER_COUNT,
 					NULL, &sd_srv_version)) {
 				pr_info("Shutdown IC version %d.%d\n",
 					sd_srv_version >> 16,
 					sd_srv_version & 0xFFFF);
 			}
 		} else {
 			shutdown_msg =
 				(struct shutdown_msg_data *)&shut_txf_buf[
 					sizeof(struct vmbuspipe_hdr) +
 					sizeof(struct icmsg_hdr)];

 			switch (shutdown_msg->flags) {
 			case 0:
 			case 1:
 				icmsghdrp->status = HV_S_OK;
 				execute_shutdown = true;

 				pr_info("Shutdown request received -"
 					    " graceful shutdown initiated\n");
 				break;
 			default:
 				icmsghdrp->status = HV_E_FAIL;
 				execute_shutdown = false;

 				pr_info("Shutdown request received -"
 					    " Invalid request\n");
 				break;
 			}
 		}

 		icmsghdrp->icflags = ICMSGHDRFLAG_TRANSACTION
 			| ICMSGHDRFLAG_RESPONSE;

 		vmbus_sendpacket(channel, shut_txf_buf,
 				       recvlen, requestid,
 				       VM_PKT_DATA_INBAND, 0);
 	}

 	if (execute_shutdown == true)
 		schedule_work(&shutdown_work);
 }

 /*
  * Set the host time in a process context.
  */
 static struct work_struct adj_time_work;

 /*
  * The last time sample, received from the host. PTP device responds to
  * requests by using this data and the current partition-wide time reference
  * count.
  */
 static struct {
 	u64				host_time;
 	u64				ref_time;
 	spinlock_t			lock;
 } host_ts;

 static struct timespec64 hv_get_adj_host_time(void)
 {
 	struct timespec64 ts;
 	u64 newtime, reftime;
 	unsigned long flags;

 	spin_lock_irqsave(&host_ts.lock, flags);
 	reftime = hyperv_cs->read(hyperv_cs);
 	newtime = host_ts.host_time + (reftime - host_ts.ref_time);
 	ts = ns_to_timespec64((newtime - WLTIMEDELTA) * 100);
 	spin_unlock_irqrestore(&host_ts.lock, flags);

 	return ts;
 }

 static void hv_set_host_time(struct work_struct *work)
 {
 	struct timespec64 ts = hv_get_adj_host_time();

 	do_settimeofday64(&ts);
 }

 /*
  * Synchronize time with host after reboot, restore, etc.
  *
  * ICTIMESYNCFLAG_SYNC flag bit indicates reboot, restore events of the VM.
  * After reboot the flag ICTIMESYNCFLAG_SYNC is included in the first time
  * message after the timesync channel is opened. Since the hv_utils module is
  * loaded after hv_vmbus, the first message is usually missed. This bit is
  * considered a hard request to discipline the clock.
  *
  * ICTIMESYNCFLAG_SAMPLE bit indicates a time sample from host. This is
  * typically used as a hint to the guest. The guest is under no obligation
  * to discipline the clock.
  */
 static inline void adj_guesttime(u64 hosttime, u64 reftime, u8 adj_flags)
 {
 	unsigned long flags;
 	u64 cur_reftime;

 	/*
 	 * Save the adjusted time sample from the host and the snapshot
 	 * of the current system time.
 	 */
 	spin_lock_irqsave(&host_ts.lock, flags);

 	cur_reftime = hyperv_cs->read(hyperv_cs);
 	host_ts.host_time = hosttime;
 	host_ts.ref_time = cur_reftime;

 	/*
 	 * TimeSync v4 messages contain reference time (guest's Hyper-V
 	 * clocksource read when the time sample was generated), we can
 	 * improve the precision by adding the delta between now and the
 	 * time of generation. For older protocols we set
 	 * reftime == cur_reftime on call.
 	 */
 	host_ts.host_time += (cur_reftime - reftime);

 	spin_unlock_irqrestore(&host_ts.lock, flags);

 	/* Schedule work to do do_settimeofday64() */
 	if (adj_flags & ICTIMESYNCFLAG_SYNC)
 		schedule_work(&adj_time_work);
 }

 /*
  * Time Sync Channel message handler.
  */
 static void timesync_onchannelcallback(void *context)
 {
 	struct vmbus_channel *channel = context;
 	u32 recvlen;
 	u64 requestid;
 	struct icmsg_hdr *icmsghdrp;
 	struct ictimesync_data *timedatap;
 	struct ictimesync_ref_data *refdata;
 	u8 *time_txf_buf = util_timesynch.recv_buffer;

 	vmbus_recvpacket(channel, time_txf_buf,
 			 HV_HYP_PAGE_SIZE, &recvlen, &requestid);

 	if (recvlen > 0) {
 		icmsghdrp = (struct icmsg_hdr *)&time_txf_buf[
 				sizeof(struct vmbuspipe_hdr)];

 		if (icmsghdrp->icmsgtype == ICMSGTYPE_NEGOTIATE) {
 			if (vmbus_prep_negotiate_resp(icmsghdrp, time_txf_buf,
 						fw_versions, FW_VER_COUNT,
 						ts_versions, TS_VER_COUNT,
 						NULL, &ts_srv_version)) {
 				pr_info("TimeSync IC version %d.%d\n",
 					ts_srv_version >> 16,
 					ts_srv_version & 0xFFFF);
 			}
 		} else {
 			if (ts_srv_version > TS_VERSION_3) {
 				refdata = (struct ictimesync_ref_data *)
 					&time_txf_buf[
 					sizeof(struct vmbuspipe_hdr) +
 					sizeof(struct icmsg_hdr)];

 				adj_guesttime(refdata->parenttime,
 						refdata->vmreferencetime,
 						refdata->flags);
 			} else {
 				timedatap = (struct ictimesync_data *)
 					&time_txf_buf[
 					sizeof(struct vmbuspipe_hdr) +
 					sizeof(struct icmsg_hdr)];
 				adj_guesttime(timedatap->parenttime,
 					      hyperv_cs->read(hyperv_cs),
 					      timedatap->flags);
 			}
 		}

 		icmsghdrp->icflags = ICMSGHDRFLAG_TRANSACTION
 			| ICMSGHDRFLAG_RESPONSE;

 		vmbus_sendpacket(channel, time_txf_buf,
 				recvlen, requestid,
 				VM_PKT_DATA_INBAND, 0);
 	}
 }

 /*
  * Heartbeat functionality.
  * Every two seconds, Hyper-V send us a heartbeat request message.
  * we respond to this message, and Hyper-V knows we are alive.
  */
 static void heartbeat_onchannelcallback(void *context)
 {
 	struct vmbus_channel *channel = context;
 	u32 recvlen;
 	u64 requestid;
 	struct icmsg_hdr *icmsghdrp;
 	struct heartbeat_msg_data *heartbeat_msg;
 	u8 *hbeat_txf_buf = util_heartbeat.recv_buffer;

 	while (1) {

 		vmbus_recvpacket(channel, hbeat_txf_buf,
 				 HV_HYP_PAGE_SIZE, &recvlen, &requestid);

 		if (!recvlen)
 			break;

 		icmsghdrp = (struct icmsg_hdr *)&hbeat_txf_buf[
 				sizeof(struct vmbuspipe_hdr)];

 		if (icmsghdrp->icmsgtype == ICMSGTYPE_NEGOTIATE) {
 			if (vmbus_prep_negotiate_resp(icmsghdrp,
 					hbeat_txf_buf,
 					fw_versions, FW_VER_COUNT,
 					hb_versions, HB_VER_COUNT,
 					NULL, &hb_srv_version)) {

 				pr_info("Heartbeat IC version %d.%d\n",
 					hb_srv_version >> 16,
 					hb_srv_version & 0xFFFF);
 			}
 		} else {
 			heartbeat_msg =
 				(struct heartbeat_msg_data *)&hbeat_txf_buf[
 					sizeof(struct vmbuspipe_hdr) +
 					sizeof(struct icmsg_hdr)];

 			heartbeat_msg->seq_num += 1;
 		}

 		icmsghdrp->icflags = ICMSGHDRFLAG_TRANSACTION
 			| ICMSGHDRFLAG_RESPONSE;

 		vmbus_sendpacket(channel, hbeat_txf_buf,
 				       recvlen, requestid,
 				       VM_PKT_DATA_INBAND, 0);
 	}
 }

 static int util_probe(struct hv_device *dev,
 			const struct hv_vmbus_device_id *dev_id)
 {
 	struct hv_util_service *srv =
 		(struct hv_util_service *)dev_id->driver_data;
 	int ret;

 	srv->recv_buffer = kmalloc(HV_HYP_PAGE_SIZE * 4, GFP_KERNEL);
 	if (!srv->recv_buffer)
 		return -ENOMEM;
 	srv->channel = dev->channel;
 	if (srv->util_init) {
 		ret = srv->util_init(srv);
 		if (ret) {
 			ret = -ENODEV;
 			goto error1;
 		}
 	}

 	/*
 	 * The set of services managed by the util driver are not performance
 	 * critical and do not need batched reading. Furthermore, some services
 	 * such as KVP can only handle one message from the host at a time.
 	 * Turn off batched reading for all util drivers before we open the
 	 * channel.
 	 */
 	set_channel_read_mode(dev->channel, HV_CALL_DIRECT);

 	hv_set_drvdata(dev, srv);

 	ret = vmbus_open(dev->channel, 4 * HV_HYP_PAGE_SIZE,
 			 4 * HV_HYP_PAGE_SIZE, NULL, 0, srv->util_cb,
 			 dev->channel);
 	if (ret)
 		goto error;

 	return 0;

 error:
 	if (srv->util_deinit)
 		srv->util_deinit();
 error1:
 	kfree(srv->recv_buffer);
 	return ret;
 }

 static int util_remove(struct hv_device *dev)
 {
 	struct hv_util_service *srv = hv_get_drvdata(dev);

 	if (srv->util_deinit)
 		srv->util_deinit();
 	vmbus_close(dev->channel);
 	kfree(srv->recv_buffer);

 	return 0;
 }

 static const struct hv_vmbus_device_id id_table[] = {
 	/* Shutdown guid */
 	{ HV_SHUTDOWN_GUID,
 	  .driver_data = (unsigned long)&util_shutdown
 	},
 	/* Time synch guid */
 	{ HV_TS_GUID,
 	  .driver_data = (unsigned long)&util_timesynch
 	},
 	/* Heartbeat guid */
 	{ HV_HEART_BEAT_GUID,
 	  .driver_data = (unsigned long)&util_heartbeat
 	},
 	/* KVP guid */
 	{ HV_KVP_GUID,
 	  .driver_data = (unsigned long)&util_kvp
 	},
 	/* VSS GUID */
 	{ HV_VSS_GUID,
 	  .driver_data = (unsigned long)&util_vss
 	},
 	/* File copy GUID */
 	{ HV_FCOPY_GUID,
 	  .driver_data = (unsigned long)&util_fcopy
 	},
 	{ },
 };

 MODULE_DEVICE_TABLE(vmbus, id_table);

 /* The one and only one */
 static  struct hv_driver util_drv = {
 	.name = "hv_utils",
 	.id_table = id_table,
 	.probe =  util_probe,
 	.remove =  util_remove,
 	.driver = {
 		.probe_type = PROBE_PREFER_ASYNCHRONOUS,
 	},
 };

 static int hv_ptp_enable(struct ptp_clock_info *info,
 			 struct ptp_clock_request *request, int on)
 {
 	return -EOPNOTSUPP;
 }

 static int hv_ptp_settime(struct ptp_clock_info *p, const struct timespec64 *ts)
 {
 	return -EOPNOTSUPP;
 }

 static int hv_ptp_adjfreq(struct ptp_clock_info *ptp, s32 delta)
 {
 	return -EOPNOTSUPP;
 }
 static int hv_ptp_adjtime(struct ptp_clock_info *ptp, s64 delta)
 {
 	return -EOPNOTSUPP;
 }

 static int hv_ptp_gettime(struct ptp_clock_info *info, struct timespec64 *ts)
 {
 	*ts = hv_get_adj_host_time();

 	return 0;
 }

 static struct ptp_clock_info ptp_hyperv_info = {
 	.name		= "hyperv",
 	.enable         = hv_ptp_enable,
 	.adjtime        = hv_ptp_adjtime,
 	.adjfreq        = hv_ptp_adjfreq,
 	.gettime64      = hv_ptp_gettime,
 	.settime64      = hv_ptp_settime,
 	.owner		= THIS_MODULE,
 };

 static struct ptp_clock *hv_ptp_clock;

 static int hv_timesync_init(struct hv_util_service *srv)
 {
 	/* TimeSync requires Hyper-V clocksource. */
 	if (!hyperv_cs)
 		return -ENODEV;

 	spin_lock_init(&host_ts.lock);

 	INIT_WORK(&adj_time_work, hv_set_host_time);

 	/*
 	 * ptp_clock_register() returns NULL when CONFIG_PTP_1588_CLOCK is
 	 * disabled but the driver is still useful without the PTP device
 	 * as it still handles the ICTIMESYNCFLAG_SYNC case.
 	 */
 	hv_ptp_clock = ptp_clock_register(&ptp_hyperv_info, NULL);
 	if (IS_ERR_OR_NULL(hv_ptp_clock)) {
 		pr_err("cannot register PTP clock: %ld\n",
 		       PTR_ERR(hv_ptp_clock));
 		hv_ptp_clock = NULL;
 	}

 	return 0;
 }

 static void hv_timesync_deinit(void)
 {
 	if (hv_ptp_clock)
 		ptp_clock_unregister(hv_ptp_clock);
 	cancel_work_sync(&adj_time_work);
 }

 static int __init init_hyperv_utils(void)
 {
 	pr_info("Registering HyperV Utility Driver\n");

 	return vmbus_driver_register(&util_drv);
 }

 static void exit_hyperv_utils(void)
 {
 	pr_info("De-Registered HyperV Utility Driver\n");

 	vmbus_driver_unregister(&util_drv);
 }

 module_init(init_hyperv_utils);
 module_exit(exit_hyperv_utils);

 MODULE_DESCRIPTION("Hyper-V Utilities");
 MODULE_LICENSE("GPL");
	// SPDX-License-Identifier: GPL-2.0-only
	/*
	* Copyright (c) 2010, Microsoft Corporation.
	*
	* Authors:
	* Haiyang Zhang <haiyangz@microsoft.com>
	* Hank Janssen <hjanssen@microsoft.com>
	*/
	#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt

	#include <linux/kernel.h>
	#include <linux/init.h>
	#include <linux/module.h>
	#include <linux/slab.h>
	#include <linux/sysctl.h>
	#include <linux/reboot.h>
	#include <linux/hyperv.h>
	#include <linux/clockchips.h>
	#include <linux/ptp_clock_kernel.h>
	#include <clocksource/hyperv_timer.h>
	#include <asm/mshyperv.h>

	#include "hyperv_vmbus.h"

	#define SD_MAJOR 3
	#define SD_MINOR 0
	#define SD_VERSION (SD_MAJOR << 16 \| SD_MINOR)

	#define SD_MAJOR_1 1
	#define SD_VERSION_1 (SD_MAJOR_1 << 16 \| SD_MINOR)

	#define TS_MAJOR 4
	#define TS_MINOR 0
	#define TS_VERSION (TS_MAJOR << 16 \| TS_MINOR)

	#define TS_MAJOR_1 1
	#define TS_VERSION_1 (TS_MAJOR_1 << 16 \| TS_MINOR)

	#define TS_MAJOR_3 3
	#define TS_VERSION_3 (TS_MAJOR_3 << 16 \| TS_MINOR)

	#define HB_MAJOR 3
	#define HB_MINOR 0
	#define HB_VERSION (HB_MAJOR << 16 \| HB_MINOR)

	#define HB_MAJOR_1 1
	#define HB_VERSION_1 (HB_MAJOR_1 << 16 \| HB_MINOR)

	static int sd_srv_version;
	static int ts_srv_version;
	static int hb_srv_version;

	#define SD_VER_COUNT 2
	static const int sd_versions[] = {
	SD_VERSION,
	SD_VERSION_1
	};

	#define TS_VER_COUNT 3
	static const int ts_versions[] = {
	TS_VERSION,
	TS_VERSION_3,
	TS_VERSION_1
	};

	#define HB_VER_COUNT 2
	static const int hb_versions[] = {
	HB_VERSION,
	HB_VERSION_1
	};

	#define FW_VER_COUNT 2
	static const int fw_versions[] = {
	UTIL_FW_VERSION,
	UTIL_WS2K8_FW_VERSION
	};

	static void shutdown_onchannelcallback(void *context);
	static struct hv_util_service util_shutdown = {
	.util_cb = shutdown_onchannelcallback,
	};

	static int hv_timesync_init(struct hv_util_service *srv);
	static void hv_timesync_deinit(void);

	static void timesync_onchannelcallback(void *context);
	static struct hv_util_service util_timesynch = {
	.util_cb = timesync_onchannelcallback,
	.util_init = hv_timesync_init,
	.util_deinit = hv_timesync_deinit,
	};

	static void heartbeat_onchannelcallback(void *context);
	static struct hv_util_service util_heartbeat = {
	.util_cb = heartbeat_onchannelcallback,
	};

	static struct hv_util_service util_kvp = {
	.util_cb = hv_kvp_onchannelcallback,
	.util_init = hv_kvp_init,
	.util_deinit = hv_kvp_deinit,
	};

	static struct hv_util_service util_vss = {
	.util_cb = hv_vss_onchannelcallback,
	.util_init = hv_vss_init,
	.util_deinit = hv_vss_deinit,
	};

	static struct hv_util_service util_fcopy = {
	.util_cb = hv_fcopy_onchannelcallback,
	.util_init = hv_fcopy_init,
	.util_deinit = hv_fcopy_deinit,
	};

	static void perform_shutdown(struct work_struct *dummy)
	{
	orderly_poweroff(true);
	}

	/*
	* Perform the shutdown operation in a thread context.
	*/
	static DECLARE_WORK(shutdown_work, perform_shutdown);

	static void shutdown_onchannelcallback(void *context)
	{
	struct vmbus_channel *channel = context;
	u32 recvlen;
	u64 requestid;
	bool execute_shutdown = false;
	u8 *shut_txf_buf = util_shutdown.recv_buffer;

	struct shutdown_msg_data *shutdown_msg;

	struct icmsg_hdr *icmsghdrp;

	vmbus_recvpacket(channel, shut_txf_buf,
	HV_HYP_PAGE_SIZE, &recvlen, &requestid);

	if (recvlen > 0) {
	icmsghdrp = (struct icmsg_hdr *)&shut_txf_buf[
	sizeof(struct vmbuspipe_hdr)];

	if (icmsghdrp->icmsgtype == ICMSGTYPE_NEGOTIATE) {
	if (vmbus_prep_negotiate_resp(icmsghdrp, shut_txf_buf,
	fw_versions, FW_VER_COUNT,
	sd_versions, SD_VER_COUNT,
	NULL, &sd_srv_version)) {
	pr_info("Shutdown IC version %d.%d\n",
	sd_srv_version >> 16,
	sd_srv_version & 0xFFFF);
	}
	} else {
	shutdown_msg =
	(struct shutdown_msg_data *)&shut_txf_buf[
	sizeof(struct vmbuspipe_hdr) +
	sizeof(struct icmsg_hdr)];

	switch (shutdown_msg->flags) {
	case 0:
	case 1:
	icmsghdrp->status = HV_S_OK;
	execute_shutdown = true;

	pr_info("Shutdown request received -"
	" graceful shutdown initiated\n");
	break;
	default:
	icmsghdrp->status = HV_E_FAIL;
	execute_shutdown = false;

	pr_info("Shutdown request received -"
	" Invalid request\n");
	break;
	}
	}

	icmsghdrp->icflags = ICMSGHDRFLAG_TRANSACTION
	\| ICMSGHDRFLAG_RESPONSE;

	vmbus_sendpacket(channel, shut_txf_buf,
	recvlen, requestid,
	VM_PKT_DATA_INBAND, 0);
	}

	if (execute_shutdown == true)
	schedule_work(&shutdown_work);
	}

	/*
	* Set the host time in a process context.
	*/
	static struct work_struct adj_time_work;

	/*
	* The last time sample, received from the host. PTP device responds to
	* requests by using this data and the current partition-wide time reference
	* count.
	*/
	static struct {
	u64 host_time;
	u64 ref_time;
	spinlock_t lock;
	} host_ts;

	static struct timespec64 hv_get_adj_host_time(void)
	{
	struct timespec64 ts;
	u64 newtime, reftime;
	unsigned long flags;

	spin_lock_irqsave(&host_ts.lock, flags);
	reftime = hyperv_cs->read(hyperv_cs);
	newtime = host_ts.host_time + (reftime - host_ts.ref_time);
	ts = ns_to_timespec64((newtime - WLTIMEDELTA) * 100);
	spin_unlock_irqrestore(&host_ts.lock, flags);

	return ts;
	}

	static void hv_set_host_time(struct work_struct *work)
	{
	struct timespec64 ts = hv_get_adj_host_time();

	do_settimeofday64(&ts);
	}

	/*
	* Synchronize time with host after reboot, restore, etc.
	*
	* ICTIMESYNCFLAG_SYNC flag bit indicates reboot, restore events of the VM.
	* After reboot the flag ICTIMESYNCFLAG_SYNC is included in the first time
	* message after the timesync channel is opened. Since the hv_utils module is
	* loaded after hv_vmbus, the first message is usually missed. This bit is
	* considered a hard request to discipline the clock.
	*
	* ICTIMESYNCFLAG_SAMPLE bit indicates a time sample from host. This is
	* typically used as a hint to the guest. The guest is under no obligation
	* to discipline the clock.
	*/
	static inline void adj_guesttime(u64 hosttime, u64 reftime, u8 adj_flags)
	{
	unsigned long flags;
	u64 cur_reftime;

	/*
	* Save the adjusted time sample from the host and the snapshot
	* of the current system time.
	*/
	spin_lock_irqsave(&host_ts.lock, flags);

	cur_reftime = hyperv_cs->read(hyperv_cs);
	host_ts.host_time = hosttime;
	host_ts.ref_time = cur_reftime;

	/*
	* TimeSync v4 messages contain reference time (guest's Hyper-V
	* clocksource read when the time sample was generated), we can
	* improve the precision by adding the delta between now and the
	* time of generation. For older protocols we set
	* reftime == cur_reftime on call.
	*/
	host_ts.host_time += (cur_reftime - reftime);

	spin_unlock_irqrestore(&host_ts.lock, flags);

	/* Schedule work to do do_settimeofday64() */
	if (adj_flags & ICTIMESYNCFLAG_SYNC)
	schedule_work(&adj_time_work);
	}

	/*
	* Time Sync Channel message handler.
	*/
	static void timesync_onchannelcallback(void *context)
	{
	struct vmbus_channel *channel = context;
	u32 recvlen;
	u64 requestid;
	struct icmsg_hdr *icmsghdrp;
	struct ictimesync_data *timedatap;
	struct ictimesync_ref_data *refdata;
	u8 *time_txf_buf = util_timesynch.recv_buffer;

	vmbus_recvpacket(channel, time_txf_buf,
	HV_HYP_PAGE_SIZE, &recvlen, &requestid);

	if (recvlen > 0) {
	icmsghdrp = (struct icmsg_hdr *)&time_txf_buf[
	sizeof(struct vmbuspipe_hdr)];

	if (icmsghdrp->icmsgtype == ICMSGTYPE_NEGOTIATE) {
	if (vmbus_prep_negotiate_resp(icmsghdrp, time_txf_buf,
	fw_versions, FW_VER_COUNT,
	ts_versions, TS_VER_COUNT,
	NULL, &ts_srv_version)) {
	pr_info("TimeSync IC version %d.%d\n",
	ts_srv_version >> 16,
	ts_srv_version & 0xFFFF);
	}
	} else {
	if (ts_srv_version > TS_VERSION_3) {
	refdata = (struct ictimesync_ref_data *)
	&time_txf_buf[
	sizeof(struct vmbuspipe_hdr) +
	sizeof(struct icmsg_hdr)];

	adj_guesttime(refdata->parenttime,
	refdata->vmreferencetime,
	refdata->flags);
	} else {
	timedatap = (struct ictimesync_data *)
	&time_txf_buf[
	sizeof(struct vmbuspipe_hdr) +
	sizeof(struct icmsg_hdr)];
	adj_guesttime(timedatap->parenttime,
	hyperv_cs->read(hyperv_cs),
	timedatap->flags);
	}
	}

	icmsghdrp->icflags = ICMSGHDRFLAG_TRANSACTION
	\| ICMSGHDRFLAG_RESPONSE;

	vmbus_sendpacket(channel, time_txf_buf,
	recvlen, requestid,
	VM_PKT_DATA_INBAND, 0);
	}
	}

	/*
	* Heartbeat functionality.
	* Every two seconds, Hyper-V send us a heartbeat request message.
	* we respond to this message, and Hyper-V knows we are alive.
	*/
	static void heartbeat_onchannelcallback(void *context)
	{
	struct vmbus_channel *channel = context;
	u32 recvlen;
	u64 requestid;
	struct icmsg_hdr *icmsghdrp;
	struct heartbeat_msg_data *heartbeat_msg;
	u8 *hbeat_txf_buf = util_heartbeat.recv_buffer;

	while (1) {

	vmbus_recvpacket(channel, hbeat_txf_buf,
	HV_HYP_PAGE_SIZE, &recvlen, &requestid);

	if (!recvlen)
	break;

	icmsghdrp = (struct icmsg_hdr *)&hbeat_txf_buf[
	sizeof(struct vmbuspipe_hdr)];

	if (icmsghdrp->icmsgtype == ICMSGTYPE_NEGOTIATE) {
	if (vmbus_prep_negotiate_resp(icmsghdrp,
	hbeat_txf_buf,
	fw_versions, FW_VER_COUNT,
	hb_versions, HB_VER_COUNT,
	NULL, &hb_srv_version)) {

	pr_info("Heartbeat IC version %d.%d\n",
	hb_srv_version >> 16,
	hb_srv_version & 0xFFFF);
	}
	} else {
	heartbeat_msg =
	(struct heartbeat_msg_data *)&hbeat_txf_buf[
	sizeof(struct vmbuspipe_hdr) +
	sizeof(struct icmsg_hdr)];

	heartbeat_msg->seq_num += 1;
	}

	icmsghdrp->icflags = ICMSGHDRFLAG_TRANSACTION
	\| ICMSGHDRFLAG_RESPONSE;

	vmbus_sendpacket(channel, hbeat_txf_buf,
	recvlen, requestid,
	VM_PKT_DATA_INBAND, 0);
	}
	}

	static int util_probe(struct hv_device *dev,
	const struct hv_vmbus_device_id *dev_id)
	{
	struct hv_util_service *srv =
	(struct hv_util_service *)dev_id->driver_data;
	int ret;

	srv->recv_buffer = kmalloc(HV_HYP_PAGE_SIZE * 4, GFP_KERNEL);
	if (!srv->recv_buffer)
	return -ENOMEM;
	srv->channel = dev->channel;
	if (srv->util_init) {
	ret = srv->util_init(srv);
	if (ret) {
	ret = -ENODEV;
	goto error1;
	}
	}

	/*
	* The set of services managed by the util driver are not performance
	* critical and do not need batched reading. Furthermore, some services
	* such as KVP can only handle one message from the host at a time.
	* Turn off batched reading for all util drivers before we open the
	* channel.
	*/
	set_channel_read_mode(dev->channel, HV_CALL_DIRECT);

	hv_set_drvdata(dev, srv);

	ret = vmbus_open(dev->channel, 4 * HV_HYP_PAGE_SIZE,
	4 * HV_HYP_PAGE_SIZE, NULL, 0, srv->util_cb,
	dev->channel);
	if (ret)
	goto error;

	return 0;

	error:
	if (srv->util_deinit)
	srv->util_deinit();
	error1:
	kfree(srv->recv_buffer);
	return ret;
	}

	static int util_remove(struct hv_device *dev)
	{
	struct hv_util_service *srv = hv_get_drvdata(dev);

	if (srv->util_deinit)
	srv->util_deinit();
	vmbus_close(dev->channel);
	kfree(srv->recv_buffer);

	return 0;
	}

	static const struct hv_vmbus_device_id id_table[] = {
	/* Shutdown guid */
	{ HV_SHUTDOWN_GUID,
	.driver_data = (unsigned long)&util_shutdown
	},
	/* Time synch guid */
	{ HV_TS_GUID,
	.driver_data = (unsigned long)&util_timesynch
	},
	/* Heartbeat guid */
	{ HV_HEART_BEAT_GUID,
	.driver_data = (unsigned long)&util_heartbeat
	},
	/* KVP guid */
	{ HV_KVP_GUID,
	.driver_data = (unsigned long)&util_kvp
	},
	/* VSS GUID */
	{ HV_VSS_GUID,
	.driver_data = (unsigned long)&util_vss
	},
	/* File copy GUID */
	{ HV_FCOPY_GUID,
	.driver_data = (unsigned long)&util_fcopy
	},
	{ },
	};

	MODULE_DEVICE_TABLE(vmbus, id_table);

	/* The one and only one */
	static struct hv_driver util_drv = {
	.name = "hv_utils",
	.id_table = id_table,
	.probe = util_probe,
	.remove = util_remove,
	.driver = {
	.probe_type = PROBE_PREFER_ASYNCHRONOUS,
	},
	};

	static int hv_ptp_enable(struct ptp_clock_info *info,
	struct ptp_clock_request *request, int on)
	{
	return -EOPNOTSUPP;
	}

	static int hv_ptp_settime(struct ptp_clock_info p, const struct timespec64 ts)
	{
	return -EOPNOTSUPP;
	}

	static int hv_ptp_adjfreq(struct ptp_clock_info *ptp, s32 delta)
	{
	return -EOPNOTSUPP;
	}
	static int hv_ptp_adjtime(struct ptp_clock_info *ptp, s64 delta)
	{
	return -EOPNOTSUPP;
	}

	static int hv_ptp_gettime(struct ptp_clock_info info, struct timespec64 ts)
	{
	*ts = hv_get_adj_host_time();

	return 0;
	}

	static struct ptp_clock_info ptp_hyperv_info = {
	.name = "hyperv",
	.enable = hv_ptp_enable,
	.adjtime = hv_ptp_adjtime,
	.adjfreq = hv_ptp_adjfreq,
	.gettime64 = hv_ptp_gettime,
	.settime64 = hv_ptp_settime,
	.owner = THIS_MODULE,
	};

	static struct ptp_clock *hv_ptp_clock;

	static int hv_timesync_init(struct hv_util_service *srv)
	{
	/* TimeSync requires Hyper-V clocksource. */
	if (!hyperv_cs)
	return -ENODEV;

	spin_lock_init(&host_ts.lock);

	INIT_WORK(&adj_time_work, hv_set_host_time);

	/*
	* ptp_clock_register() returns NULL when CONFIG_PTP_1588_CLOCK is
	* disabled but the driver is still useful without the PTP device
	* as it still handles the ICTIMESYNCFLAG_SYNC case.
	*/
	hv_ptp_clock = ptp_clock_register(&ptp_hyperv_info, NULL);
	if (IS_ERR_OR_NULL(hv_ptp_clock)) {
	pr_err("cannot register PTP clock: %ld\n",
	PTR_ERR(hv_ptp_clock));
	hv_ptp_clock = NULL;
	}

	return 0;
	}

	static void hv_timesync_deinit(void)
	{
	if (hv_ptp_clock)
	ptp_clock_unregister(hv_ptp_clock);
	cancel_work_sync(&adj_time_work);
	}

	static int __init init_hyperv_utils(void)
	{
	pr_info("Registering HyperV Utility Driver\n");

	return vmbus_driver_register(&util_drv);
	}

	static void exit_hyperv_utils(void)
	{
	pr_info("De-Registered HyperV Utility Driver\n");

	vmbus_driver_unregister(&util_drv);
	}

	module_init(init_hyperv_utils);
	module_exit(exit_hyperv_utils);

	MODULE_DESCRIPTION("Hyper-V Utilities");
	MODULE_LICENSE("GPL");