File-copy from v4.4.100

This is the result of 'cp' from a linux-stable tree with the 'v4.4.100'
tag checked out (commit 26d6298789e695c9f627ce49a7bbd2286405798a) on
git://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git

Please refer to that tree for all history prior to this point.

Change-Id: I8a9ee2aea93cd29c52c847d0ce33091a73ae6afe
diff --git a/drivers/hv/hv_util.c b/drivers/hv/hv_util.c
new file mode 100644
index 0000000..41f5896
--- /dev/null
+++ b/drivers/hv/hv_util.c
@@ -0,0 +1,451 @@
+/*
+ * Copyright (c) 2010, Microsoft Corporation.
+ *
+ * This program is free software; you can redistribute it and/or modify it
+ * under the terms and conditions of the GNU General Public License,
+ * version 2, as published by the Free Software Foundation.
+ *
+ * This program is distributed in the hope it will be useful, but WITHOUT
+ * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
+ * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License for
+ * more details.
+ *
+ * You should have received a copy of the GNU General Public License along with
+ * this program; if not, write to the Free Software Foundation, Inc., 59 Temple
+ * Place - Suite 330, Boston, MA 02111-1307 USA.
+ *
+ * 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 "hyperv_vmbus.h"
+
+#define SD_MAJOR	3
+#define SD_MINOR	0
+#define SD_VERSION	(SD_MAJOR << 16 | SD_MINOR)
+
+#define SD_WS2008_MAJOR		1
+#define SD_WS2008_VERSION	(SD_WS2008_MAJOR << 16 | SD_MINOR)
+
+#define TS_MAJOR	3
+#define TS_MINOR	0
+#define TS_VERSION	(TS_MAJOR << 16 | TS_MINOR)
+
+#define TS_WS2008_MAJOR		1
+#define TS_WS2008_VERSION	(TS_WS2008_MAJOR << 16 | TS_MINOR)
+
+#define HB_MAJOR	3
+#define HB_MINOR 0
+#define HB_VERSION	(HB_MAJOR << 16 | HB_MINOR)
+
+#define HB_WS2008_MAJOR	1
+#define HB_WS2008_VERSION	(HB_WS2008_MAJOR << 16 | HB_MINOR)
+
+static int sd_srv_version;
+static int ts_srv_version;
+static int hb_srv_version;
+static int util_fw_version;
+
+static void shutdown_onchannelcallback(void *context);
+static struct hv_util_service util_shutdown = {
+	.util_cb = shutdown_onchannelcallback,
+};
+
+static void timesync_onchannelcallback(void *context);
+static struct hv_util_service util_timesynch = {
+	.util_cb = timesync_onchannelcallback,
+};
+
+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;
+	struct icmsg_negotiate *negop = NULL;
+
+	vmbus_recvpacket(channel, shut_txf_buf,
+			 PAGE_SIZE, &recvlen, &requestid);
+
+	if (recvlen > 0) {
+		icmsghdrp = (struct icmsg_hdr *)&shut_txf_buf[
+			sizeof(struct vmbuspipe_hdr)];
+
+		if (icmsghdrp->icmsgtype == ICMSGTYPE_NEGOTIATE) {
+			vmbus_prep_negotiate_resp(icmsghdrp, negop,
+					shut_txf_buf, util_fw_version,
+					sd_srv_version);
+		} 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 guest time to host UTC time.
+ */
+static inline void do_adj_guesttime(u64 hosttime)
+{
+	s64 host_tns;
+	struct timespec host_ts;
+
+	host_tns = (hosttime - WLTIMEDELTA) * 100;
+	host_ts = ns_to_timespec(host_tns);
+
+	do_settimeofday(&host_ts);
+}
+
+/*
+ * Set the host time in a process context.
+ */
+
+struct adj_time_work {
+	struct work_struct work;
+	u64	host_time;
+};
+
+static void hv_set_host_time(struct work_struct *work)
+{
+	struct adj_time_work	*wrk;
+
+	wrk = container_of(work, struct adj_time_work, work);
+	do_adj_guesttime(wrk->host_time);
+	kfree(wrk);
+}
+
+/*
+ * 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. The other
+ * thing is, systime is automatically set to emulated hardware clock which may
+ * not be UTC time or in the same time zone. So, to override these effects, we
+ * use the first 50 time samples for initial system time setting.
+ */
+static inline void adj_guesttime(u64 hosttime, u8 flags)
+{
+	struct adj_time_work    *wrk;
+	static s32 scnt = 50;
+
+	wrk = kmalloc(sizeof(struct adj_time_work), GFP_ATOMIC);
+	if (wrk == NULL)
+		return;
+
+	wrk->host_time = hosttime;
+	if ((flags & ICTIMESYNCFLAG_SYNC) != 0) {
+		INIT_WORK(&wrk->work, hv_set_host_time);
+		schedule_work(&wrk->work);
+		return;
+	}
+
+	if ((flags & ICTIMESYNCFLAG_SAMPLE) != 0 && scnt > 0) {
+		scnt--;
+		INIT_WORK(&wrk->work, hv_set_host_time);
+		schedule_work(&wrk->work);
+	} else
+		kfree(wrk);
+}
+
+/*
+ * 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;
+	u8 *time_txf_buf = util_timesynch.recv_buffer;
+	struct icmsg_negotiate *negop = NULL;
+
+	vmbus_recvpacket(channel, time_txf_buf,
+			 PAGE_SIZE, &recvlen, &requestid);
+
+	if (recvlen > 0) {
+		icmsghdrp = (struct icmsg_hdr *)&time_txf_buf[
+				sizeof(struct vmbuspipe_hdr)];
+
+		if (icmsghdrp->icmsgtype == ICMSGTYPE_NEGOTIATE) {
+			vmbus_prep_negotiate_resp(icmsghdrp, negop,
+						time_txf_buf,
+						util_fw_version,
+						ts_srv_version);
+		} else {
+			timedatap = (struct ictimesync_data *)&time_txf_buf[
+				sizeof(struct vmbuspipe_hdr) +
+				sizeof(struct icmsg_hdr)];
+			adj_guesttime(timedatap->parenttime, 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;
+	struct icmsg_negotiate *negop = NULL;
+
+	while (1) {
+
+		vmbus_recvpacket(channel, hbeat_txf_buf,
+				 PAGE_SIZE, &recvlen, &requestid);
+
+		if (!recvlen)
+			break;
+
+		icmsghdrp = (struct icmsg_hdr *)&hbeat_txf_buf[
+				sizeof(struct vmbuspipe_hdr)];
+
+		if (icmsghdrp->icmsgtype == ICMSGTYPE_NEGOTIATE) {
+			vmbus_prep_negotiate_resp(icmsghdrp, negop,
+				hbeat_txf_buf, util_fw_version,
+				hb_srv_version);
+		} 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(PAGE_SIZE * 4, GFP_KERNEL);
+	if (!srv->recv_buffer)
+		return -ENOMEM;
+	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_state(dev->channel, false);
+
+	hv_set_drvdata(dev, srv);
+
+	/*
+	 * Based on the host; initialize the framework and
+	 * service version numbers we will negotiate.
+	 */
+	switch (vmbus_proto_version) {
+	case (VERSION_WS2008):
+		util_fw_version = UTIL_WS2K8_FW_VERSION;
+		sd_srv_version = SD_WS2008_VERSION;
+		ts_srv_version = TS_WS2008_VERSION;
+		hb_srv_version = HB_WS2008_VERSION;
+		break;
+
+	default:
+		util_fw_version = UTIL_FW_VERSION;
+		sd_srv_version = SD_VERSION;
+		ts_srv_version = TS_VERSION;
+		hb_srv_version = HB_VERSION;
+	}
+
+	ret = vmbus_open(dev->channel, 4 * PAGE_SIZE, 4 * 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_util",
+	.id_table = id_table,
+	.probe =  util_probe,
+	.remove =  util_remove,
+};
+
+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");