Merge Linus master into drm-next

The merge is clean, but the arm build fails afterwards,
due to API changes in the regulator tree.

I've included the patch into the merge to fix the build.

Signed-off-by: Dave Airlie <airlied@redhat.com>

1 files changed, 182 insertions, 37 deletions

diff --git a/drivers/scsi/xen-scsifront.c b/drivers/scsi/xen-scsifront.c
index 34199d206ba6..fad22caf0eff 100644
--- a/drivers/scsi/xen-scsifront.c
+++ b/drivers/scsi/xen-scsifront.c
@@ -63,6 +63,7 @@
 
 #define VSCSIFRONT_OP_ADD_LUN	1
 #define VSCSIFRONT_OP_DEL_LUN	2
+#define VSCSIFRONT_OP_READD_LUN	3
 
 /* Tuning point. */
 #define VSCSIIF_DEFAULT_CMD_PER_LUN 10
@@ -113,8 +114,13 @@ struct vscsifrnt_info {
 	DECLARE_BITMAP(shadow_free_bitmap, VSCSIIF_MAX_REQS);
 	struct vscsifrnt_shadow *shadow[VSCSIIF_MAX_REQS];
 
+	/* Following items are protected by the host lock. */
 	wait_queue_head_t wq_sync;
+	wait_queue_head_t wq_pause;
 	unsigned int wait_ring_available:1;
+	unsigned int waiting_pause:1;
+	unsigned int pause:1;
+	unsigned callers;
 
 	char dev_state_path[64];
 	struct task_struct *curr;
@@ -274,31 +280,31 @@ static void scsifront_sync_cmd_done(struct vscsifrnt_info *info,
 	wake_up(&shadow->wq_reset);
 }
 
-static int scsifront_cmd_done(struct vscsifrnt_info *info)
+static void scsifront_do_response(struct vscsifrnt_info *info,
+				  struct vscsiif_response *ring_rsp)
+{
+	if (WARN(ring_rsp->rqid >= VSCSIIF_MAX_REQS ||
+		 test_bit(ring_rsp->rqid, info->shadow_free_bitmap),
+		 "illegal rqid %u returned by backend!\n", ring_rsp->rqid))
+		return;
+
+	if (info->shadow[ring_rsp->rqid]->act == VSCSIIF_ACT_SCSI_CDB)
+		scsifront_cdb_cmd_done(info, ring_rsp);
+	else
+		scsifront_sync_cmd_done(info, ring_rsp);
+}
+
+static int scsifront_ring_drain(struct vscsifrnt_info *info)
 {
 	struct vscsiif_response *ring_rsp;
 	RING_IDX i, rp;
 	int more_to_do = 0;
-	unsigned long flags;
-
-	spin_lock_irqsave(info->host->host_lock, flags);
 
 	rp = info->ring.sring->rsp_prod;
 	rmb();	/* ordering required respective to dom0 */
 	for (i = info->ring.rsp_cons; i != rp; i++) {
-
 		ring_rsp = RING_GET_RESPONSE(&info->ring, i);
-
-		if (WARN(ring_rsp->rqid >= VSCSIIF_MAX_REQS ||
-			 test_bit(ring_rsp->rqid, info->shadow_free_bitmap),
-			 "illegal rqid %u returned by backend!\n",
-			 ring_rsp->rqid))
-			continue;
-
-		if (info->shadow[ring_rsp->rqid]->act == VSCSIIF_ACT_SCSI_CDB)
-			scsifront_cdb_cmd_done(info, ring_rsp);
-		else
-			scsifront_sync_cmd_done(info, ring_rsp);
+		scsifront_do_response(info, ring_rsp);
 	}
 
 	info->ring.rsp_cons = i;
@@ -308,6 +314,18 @@ static int scsifront_cmd_done(struct vscsifrnt_info *info)
 	else
 		info->ring.sring->rsp_event = i + 1;
 
+	return more_to_do;
+}
+
+static int scsifront_cmd_done(struct vscsifrnt_info *info)
+{
+	int more_to_do;
+	unsigned long flags;
+
+	spin_lock_irqsave(info->host->host_lock, flags);
+
+	more_to_do = scsifront_ring_drain(info);
+
 	info->wait_ring_available = 0;
 
 	spin_unlock_irqrestore(info->host->host_lock, flags);
@@ -328,6 +346,24 @@ static irqreturn_t scsifront_irq_fn(int irq, void *dev_id)
 	return IRQ_HANDLED;
 }
 
+static void scsifront_finish_all(struct vscsifrnt_info *info)
+{
+	unsigned i;
+	struct vscsiif_response resp;
+
+	scsifront_ring_drain(info);
+
+	for (i = 0; i < VSCSIIF_MAX_REQS; i++) {
+		if (test_bit(i, info->shadow_free_bitmap))
+			continue;
+		resp.rqid = i;
+		resp.sense_len = 0;
+		resp.rslt = DID_RESET << 16;
+		resp.residual_len = 0;
+		scsifront_do_response(info, &resp);
+	}
+}
+
 static int map_data_for_request(struct vscsifrnt_info *info,
 				struct scsi_cmnd *sc,
 				struct vscsiif_request *ring_req,
@@ -475,6 +511,27 @@ static struct vscsiif_request *scsifront_command2ring(
 	return ring_req;
 }
 
+static int scsifront_enter(struct vscsifrnt_info *info)
+{
+	if (info->pause)
+		return 1;
+	info->callers++;
+	return 0;
+}
+
+static void scsifront_return(struct vscsifrnt_info *info)
+{
+	info->callers--;
+	if (info->callers)
+		return;
+
+	if (!info->waiting_pause)
+		return;
+
+	info->waiting_pause = 0;
+	wake_up(&info->wq_pause);
+}
+
 static int scsifront_queuecommand(struct Scsi_Host *shost,
 				  struct scsi_cmnd *sc)
 {
@@ -486,6 +543,10 @@ static int scsifront_queuecommand(struct Scsi_Host *shost,
 	uint16_t rqid;
 
 	spin_lock_irqsave(shost->host_lock, flags);
+	if (scsifront_enter(info)) {
+		spin_unlock_irqrestore(shost->host_lock, flags);
+		return SCSI_MLQUEUE_HOST_BUSY;
+	}
 	if (RING_FULL(&info->ring))
 		goto busy;
 
@@ -505,6 +566,7 @@ static int scsifront_queuecommand(struct Scsi_Host *shost,
 	if (err < 0) {
 		pr_debug("%s: err %d\n", __func__, err);
 		scsifront_put_rqid(info, rqid);
+		scsifront_return(info);
 		spin_unlock_irqrestore(shost->host_lock, flags);
 		if (err == -ENOMEM)
 			return SCSI_MLQUEUE_HOST_BUSY;
@@ -514,11 +576,13 @@ static int scsifront_queuecommand(struct Scsi_Host *shost,
 	}
 
 	scsifront_do_request(info);
+	scsifront_return(info);
 	spin_unlock_irqrestore(shost->host_lock, flags);
 
 	return 0;
 
 busy:
+	scsifront_return(info);
 	spin_unlock_irqrestore(shost->host_lock, flags);
 	pr_debug("%s: busy\n", __func__);
 	return SCSI_MLQUEUE_HOST_BUSY;
@@ -549,7 +613,7 @@ static int scsifront_action_handler(struct scsi_cmnd *sc, uint8_t act)
 			if (ring_req)
 				break;
 		}
-		if (err) {
+		if (err || info->pause) {
 			spin_unlock_irq(host->host_lock);
 			kfree(shadow);
 			return FAILED;
@@ -561,6 +625,11 @@ static int scsifront_action_handler(struct scsi_cmnd *sc, uint8_t act)
 		spin_lock_irq(host->host_lock);
 	}
 
+	if (scsifront_enter(info)) {
+		spin_unlock_irq(host->host_lock);
+		return FAILED;
+	}
+
 	ring_req->act = act;
 	ring_req->ref_rqid = s->rqid;
 
@@ -587,6 +656,7 @@ static int scsifront_action_handler(struct scsi_cmnd *sc, uint8_t act)
 		err = FAILED;
 	}
 
+	scsifront_return(info);
 	spin_unlock_irq(host->host_lock);
 	return err;
 }
@@ -644,6 +714,7 @@ static int scsifront_alloc_ring(struct vscsifrnt_info *info)
 {
 	struct xenbus_device *dev = info->dev;
 	struct vscsiif_sring *sring;
+	grant_ref_t gref;
 	int err = -ENOMEM;
 
 	/***** Frontend to Backend ring start *****/
@@ -656,14 +727,14 @@ static int scsifront_alloc_ring(struct vscsifrnt_info *info)
 	SHARED_RING_INIT(sring);
 	FRONT_RING_INIT(&info->ring, sring, PAGE_SIZE);
 
-	err = xenbus_grant_ring(dev, virt_to_mfn(sring));
+	err = xenbus_grant_ring(dev, sring, 1, &gref);
 	if (err < 0) {
 		free_page((unsigned long)sring);
 		xenbus_dev_fatal(dev, err,
 			"fail to grant shared ring (Front to Back)");
 		return err;
 	}
-	info->ring_ref = err;
+	info->ring_ref = gref;
 
 	err = xenbus_alloc_evtchn(dev, &info->evtchn);
 	if (err) {
@@ -698,6 +769,13 @@ free_gnttab:
 	return err;
 }
 
+static void scsifront_free_ring(struct vscsifrnt_info *info)
+{
+	unbind_from_irqhandler(info->irq, info);
+	gnttab_end_foreign_access(info->ring_ref, 0,
+				  (unsigned long)info->ring.sring);
+}
+
 static int scsifront_init_ring(struct vscsifrnt_info *info)
 {
 	struct xenbus_device *dev = info->dev;
@@ -744,9 +822,7 @@ again:
 fail:
 	xenbus_transaction_end(xbt, 1);
 free_sring:
-	unbind_from_irqhandler(info->irq, info);
-	gnttab_end_foreign_access(info->ring_ref, 0,
-				  (unsigned long)info->ring.sring);
+	scsifront_free_ring(info);
 
 	return err;
 }
@@ -779,6 +855,7 @@ static int scsifront_probe(struct xenbus_device *dev,
 	}
 
 	init_waitqueue_head(&info->wq_sync);
+	init_waitqueue_head(&info->wq_pause);
 	spin_lock_init(&info->shadow_lock);
 
 	snprintf(name, TASK_COMM_LEN, "vscsiif.%d", host->host_no);
@@ -802,13 +879,60 @@ static int scsifront_probe(struct xenbus_device *dev,
 	return 0;
 
 free_sring:
-	unbind_from_irqhandler(info->irq, info);
-	gnttab_end_foreign_access(info->ring_ref, 0,
-				  (unsigned long)info->ring.sring);
+	scsifront_free_ring(info);
 	scsi_host_put(host);
 	return err;
 }
 
+static int scsifront_resume(struct xenbus_device *dev)
+{
+	struct vscsifrnt_info *info = dev_get_drvdata(&dev->dev);
+	struct Scsi_Host *host = info->host;
+	int err;
+
+	spin_lock_irq(host->host_lock);
+
+	/* Finish all still pending commands. */
+	scsifront_finish_all(info);
+
+	spin_unlock_irq(host->host_lock);
+
+	/* Reconnect to dom0. */
+	scsifront_free_ring(info);
+	err = scsifront_init_ring(info);
+	if (err) {
+		dev_err(&dev->dev, "fail to resume %d\n", err);
+		scsi_host_put(host);
+		return err;
+	}
+
+	xenbus_switch_state(dev, XenbusStateInitialised);
+
+	return 0;
+}
+
+static int scsifront_suspend(struct xenbus_device *dev)
+{
+	struct vscsifrnt_info *info = dev_get_drvdata(&dev->dev);
+	struct Scsi_Host *host = info->host;
+	int err = 0;
+
+	/* No new commands for the backend. */
+	spin_lock_irq(host->host_lock);
+	info->pause = 1;
+	while (info->callers && !err) {
+		info->waiting_pause = 1;
+		info->wait_ring_available = 0;
+		spin_unlock_irq(host->host_lock);
+		wake_up(&info->wq_sync);
+		err = wait_event_interruptible(info->wq_pause,
+					       !info->waiting_pause);
+		spin_lock_irq(host->host_lock);
+	}
+	spin_unlock_irq(host->host_lock);
+	return err;
+}
+
 static int scsifront_remove(struct xenbus_device *dev)
 {
 	struct vscsifrnt_info *info = dev_get_drvdata(&dev->dev);
@@ -823,10 +947,7 @@ static int scsifront_remove(struct xenbus_device *dev)
 	}
 	mutex_unlock(&scsifront_mutex);
 
-	gnttab_end_foreign_access(info->ring_ref, 0,
-				  (unsigned long)info->ring.sring);
-	unbind_from_irqhandler(info->irq, info);
-
+	scsifront_free_ring(info);
 	scsi_host_put(info->host);
 
 	return 0;
@@ -919,6 +1040,12 @@ static void scsifront_do_lun_hotplug(struct vscsifrnt_info *info, int op)
 				scsi_device_put(sdev);
 			}
 			break;
+		case VSCSIFRONT_OP_READD_LUN:
+			if (device_state == XenbusStateConnected)
+				xenbus_printf(XBT_NIL, dev->nodename,
+					      info->dev_state_path,
+					      "%d", XenbusStateConnected);
+			break;
 		default:
 			break;
 		}
@@ -932,21 +1059,29 @@ static void scsifront_do_lun_hotplug(struct vscsifrnt_info *info, int op)
 static void scsifront_read_backend_params(struct xenbus_device *dev,
 					  struct vscsifrnt_info *info)
 {
-	unsigned int sg_grant;
+	unsigned int sg_grant, nr_segs;
 	int ret;
 	struct Scsi_Host *host = info->host;
 
 	ret = xenbus_scanf(XBT_NIL, dev->otherend, "feature-sg-grant", "%u",
 			   &sg_grant);
-	if (ret == 1 && sg_grant) {
-		sg_grant = min_t(unsigned int, sg_grant, SG_ALL);
-		sg_grant = max_t(unsigned int, sg_grant, VSCSIIF_SG_TABLESIZE);
-		host->sg_tablesize = min_t(unsigned int, sg_grant,
+	if (ret != 1)
+		sg_grant = 0;
+	nr_segs = min_t(unsigned int, sg_grant, SG_ALL);
+	nr_segs = max_t(unsigned int, nr_segs, VSCSIIF_SG_TABLESIZE);
+	nr_segs = min_t(unsigned int, nr_segs,
 			VSCSIIF_SG_TABLESIZE * PAGE_SIZE /
 			sizeof(struct scsiif_request_segment));
-		host->max_sectors = (host->sg_tablesize - 1) * PAGE_SIZE / 512;
-	}
-	dev_info(&dev->dev, "using up to %d SG entries\n", host->sg_tablesize);
+
+	if (!info->pause && sg_grant)
+		dev_info(&dev->dev, "using up to %d SG entries\n", nr_segs);
+	else if (info->pause && nr_segs < host->sg_tablesize)
+		dev_warn(&dev->dev,
+			 "SG entries decreased from %d to %u - device may not work properly anymore\n",
+			 host->sg_tablesize, nr_segs);
+
+	host->sg_tablesize = nr_segs;
+	host->max_sectors = (nr_segs - 1) * PAGE_SIZE / 512;
 }
 
 static void scsifront_backend_changed(struct xenbus_device *dev,
@@ -965,6 +1100,14 @@ static void scsifront_backend_changed(struct xenbus_device *dev,
 
 	case XenbusStateConnected:
 		scsifront_read_backend_params(dev, info);
+
+		if (info->pause) {
+			scsifront_do_lun_hotplug(info, VSCSIFRONT_OP_READD_LUN);
+			xenbus_switch_state(dev, XenbusStateConnected);
+			info->pause = 0;
+			return;
+		}
+
 		if (xenbus_read_driver_state(dev->nodename) ==
 		    XenbusStateInitialised)
 			scsifront_do_lun_hotplug(info, VSCSIFRONT_OP_ADD_LUN);
@@ -1002,6 +1145,8 @@ static struct xenbus_driver scsifront_driver = {
 	.ids			= scsifront_ids,
 	.probe			= scsifront_probe,
 	.remove			= scsifront_remove,
+	.resume			= scsifront_resume,
+	.suspend		= scsifront_suspend,
 	.otherend_changed	= scsifront_backend_changed,
 };