hyperv: Use standard taskqueue instead of hv_work_queue

HyperV code was ported from Linux.  There is an implementation of
work queue called hv_work_queue.  In FreeBSD, taskqueue could be
used for the same purpose.  Convert all the consumer of hv_work_queue
to use taskqueue, and remove work queue implementation.

Submitted by:	Jun Su <junsu microsoft com>
Reviewed by:	adrian, Hongjiang Zhang <honzhan microsoft com>
Approved by:	adrian (mentor)
MFC after:	1 week
Sponsored by:	Microsoft OSTC
Differential Revision:	https://reviews.freebsd.org/D4963

2 files changed, 29 insertions, 64 deletions

diff --git a/sys/dev/hyperv/utilities/hv_kvp.c b/sys/dev/hyperv/utilities/hv_kvp.c
index 58d565c4..86e037a 100644
--- a/sys/dev/hyperv/utilities/hv_kvp.c
+++ b/sys/dev/hyperv/utilities/hv_kvp.c
@@ -98,7 +98,7 @@ static d_poll_t		hv_kvp_dev_daemon_poll;
 static int	hv_kvp_req_in_progress(void);
 static void	hv_kvp_transaction_init(uint32_t, hv_vmbus_channel *, uint64_t, uint8_t *);
 static void	hv_kvp_send_msg_to_daemon(void);
-static void	hv_kvp_process_request(void *context);
+static void	hv_kvp_process_request(void *context, int pending);
 
 /* hv_kvp character device structure */
 static struct cdevsw hv_kvp_cdevsw =
@@ -123,9 +123,6 @@ static struct selinfo hv_kvp_selinfo;
  */
 static struct {
 
-	/* Pre-allocated work item for queue */
-	hv_work_item		work_item;	
-
 	/* Unless specified the pending mutex should be 
 	 * used to alter the values of the following paramters:
 	 * 1. req_in_progress
@@ -642,7 +639,7 @@ hv_kvp_send_msg_to_daemon(void)
  * and interact with daemon
  */
 static void
-hv_kvp_process_request(void *context)
+hv_kvp_process_request(void *context, int pending)
 {
 	uint8_t *kvp_buf;
 	hv_vmbus_channel *channel = context;
@@ -756,23 +753,18 @@ hv_kvp_callback(void *context)
 	uint64_t pending_cnt = 0;
 
 	if (kvp_globals.register_done == false) {
-		
 		kvp_globals.channelp = context;
+		TASK_INIT(&service_table[HV_KVP].task, 0, hv_kvp_process_request, context);
 	} else {
-		
 		mtx_lock(&kvp_globals.pending_mutex);
 		kvp_globals.pending_reqs = kvp_globals.pending_reqs + 1;
 		pending_cnt = kvp_globals.pending_reqs;
 		mtx_unlock(&kvp_globals.pending_mutex);
 		if (pending_cnt == 1) {
 			hv_kvp_log_info("%s: Queuing work item\n", __func__);
-			hv_queue_work_item(
-					service_table[HV_KVP].work_queue,
-					hv_kvp_process_request,
-					context
-					);
+			taskqueue_enqueue(taskqueue_thread, &service_table[HV_KVP].task);
 		}
-	}	
+	}
 }
 
 
@@ -977,26 +969,13 @@ int
 hv_kvp_init(hv_vmbus_service *srv)
 {
 	int error = 0;
-	hv_work_queue *work_queue = NULL;
-	
-	memset(&kvp_globals, 0, sizeof(kvp_globals));
 
-	work_queue = hv_work_queue_create("KVP Service");
-	if (work_queue == NULL) {
-		hv_kvp_log_info("%s: Work queue alloc failed\n", __func__);
-		error = ENOMEM;
-		hv_kvp_log_error("%s: ENOMEM\n", __func__);
-		goto Finish;
-	}
-	srv->work_queue = work_queue;
+	memset(&kvp_globals, 0, sizeof(kvp_globals));
 
 	error = hv_kvp_dev_init();
 	mtx_init(&kvp_globals.pending_mutex, "hv-kvp pending mutex",
-		       	NULL, MTX_DEF);	
-	kvp_globals.pending_reqs = 0;
-
+		NULL, MTX_DEF);
 
-Finish:
 	return (error);
 }
 
diff --git a/sys/dev/hyperv/utilities/hv_util.c b/sys/dev/hyperv/utilities/hv_util.c
index dc4b1e2..38054ca 100644
--- a/sys/dev/hyperv/utilities/hv_util.c
+++ b/sys/dev/hyperv/utilities/hv_util.c
@@ -52,6 +52,8 @@ static void hv_heartbeat_cb(void *context);
 static void hv_timesync_cb(void *context);
 
 static int hv_timesync_init(hv_vmbus_service *serv);
+static int hv_timesync_uninit(hv_vmbus_service *serv);
+static void hv_set_host_time(void *context, int pending);
 
 /*
  * Note: GUID codes below are predefined by the host hypervisor
@@ -73,6 +75,7 @@ hv_vmbus_service service_table[] = {
 	  .enabled = TRUE,
 	  .init = hv_timesync_init,
 	  .callback = hv_timesync_cb,
+	  .uninit = hv_timesync_uninit,
 	},
 
         /* Heartbeat Service */
@@ -111,10 +114,16 @@ struct hv_ictimesync_data {
 static int
 hv_timesync_init(hv_vmbus_service *serv)
 {
+	void *time_msg = malloc(sizeof(time_sync_data), M_DEVBUF, M_WAITOK);
+	TASK_INIT(&serv->task, 1, hv_set_host_time, time_msg);
+	return (0);
+}
 
-	serv->work_queue = hv_work_queue_create("Time Sync");
-	if (serv->work_queue == NULL)
-		return (ENOMEM);
+static int
+hv_timesync_uninit(hv_vmbus_service *serv)
+{
+	taskqueue_drain(taskqueue_thread, &serv->task);
+	free(serv->task.ta_context, M_DEVBUF);
 	return (0);
 }
 
@@ -152,9 +161,9 @@ hv_negotiate_version(
  * Set host time based on time sync message from host
  */
 static void
-hv_set_host_time(void *context)
+hv_set_host_time(void *context, int pending)
 {
- 	time_sync_data* time_msg = (time_sync_data*) context;	
+	time_sync_data* time_msg = (time_sync_data*) context;
 	uint64_t hosttime = time_msg->data;
 	struct timespec guest_ts, host_ts;
 	uint64_t host_tns;
@@ -166,7 +175,7 @@ hv_set_host_time(void *context)
 	host_ts.tv_nsec = (long)(host_tns%HV_NANO_SEC_PER_SEC);
 
 	nanotime(&guest_ts);
-	
+
 	diff = (int64_t)host_ts.tv_sec - (int64_t)guest_ts.tv_sec;
 
 	/*
@@ -175,12 +184,7 @@ hv_set_host_time(void *context)
 	if (diff > 5 || diff < -5) {
 		error = kern_clock_settime(curthread, CLOCK_REALTIME,
 		    &host_ts);
-	} 
-
-	/*
-	 * Free the hosttime that was allocated in hv_adj_guesttime()
-	 */
-	free(time_msg, M_DEVBUF);
+	}
 }
 
 /**
@@ -197,23 +201,13 @@ hv_set_host_time(void *context)
 static inline
 void hv_adj_guesttime(uint64_t hosttime, uint8_t flags)
 {
-	time_sync_data* time_msg;
-
-	time_msg = malloc(sizeof(time_sync_data), M_DEVBUF, M_NOWAIT);
+	time_sync_data* time_msg = service_table[HV_TIME_SYNCH].task.ta_context;
 
-	if (time_msg == NULL)
-		return;
-	
 	time_msg->data = hosttime;
 
-	if ((flags & HV_ICTIMESYNCFLAG_SYNC) != 0) {
-		hv_queue_work_item(service_table[HV_TIME_SYNCH].work_queue,
-		    hv_set_host_time, time_msg);
-	} else if ((flags & HV_ICTIMESYNCFLAG_SAMPLE) != 0) {
-		hv_queue_work_item(service_table[HV_TIME_SYNCH].work_queue,
-		    hv_set_host_time, time_msg);
-	} else {
-		free(time_msg, M_DEVBUF);
+	if (((flags & HV_ICTIMESYNCFLAG_SYNC) != 0) ||
+		((flags & HV_ICTIMESYNCFLAG_SAMPLE) != 0)) {
+		taskqueue_enqueue(taskqueue_thread, &service_table[HV_TIME_SYNCH].task);
 	}
 }
 
@@ -452,19 +446,14 @@ hv_util_detach(device_t dev)
 	service = device_get_softc(dev);
 	receive_buffer_offset = service - &service_table[0];
 
-	if (service->work_queue != NULL)
-	    hv_work_queue_close(service->work_queue);
+	if (service->uninit != NULL)
+	    service->uninit(service);
 
 	free(receive_buffer[receive_buffer_offset], M_DEVBUF);
 	receive_buffer[receive_buffer_offset] = NULL;
 	return (0);
 }
 
-static void
-hv_util_init(void)
-{
-}
-
 static int
 hv_util_modevent(module_t mod, int event, void *arg)
 {
@@ -495,6 +484,3 @@ static devclass_t util_devclass;
 DRIVER_MODULE(hv_utils, vmbus, util_driver, util_devclass, hv_util_modevent, 0);
 MODULE_VERSION(hv_utils, 1);
 MODULE_DEPEND(hv_utils, vmbus, 1, 1, 1);
-
-SYSINIT(hv_util_initx, SI_SUB_KTHREAD_IDLE, SI_ORDER_MIDDLE + 1,
-	hv_util_init, NULL);