Update Linux to v5.4.2

Change-Id: Idf6911045d9d382da2cfe01b1edff026404ac8fd
diff --git a/drivers/scsi/storvsc_drv.c b/drivers/scsi/storvsc_drv.c
index f03dc03..542d2ba 100644
--- a/drivers/scsi/storvsc_drv.c
+++ b/drivers/scsi/storvsc_drv.c
@@ -1,19 +1,7 @@
+// SPDX-License-Identifier: GPL-2.0-only
 /*
  * Copyright (c) 2009, 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>
@@ -385,8 +373,9 @@
  * This is the end of Protocol specific defines.
  */
 
-static int storvsc_ringbuffer_size = (256 * PAGE_SIZE);
+static int storvsc_ringbuffer_size = (128 * 1024);
 static u32 max_outstanding_req_per_channel;
+static int storvsc_change_queue_depth(struct scsi_device *sdev, int queue_depth);
 
 static int storvsc_vcpus_per_sub_channel = 4;
 
@@ -446,7 +435,6 @@
 
 	bool	 destroy;
 	bool	 drain_notify;
-	bool	 open_sub_channel;
 	atomic_t num_outstanding_req;
 	struct Scsi_Host *host;
 
@@ -636,41 +624,55 @@
 static void handle_sc_creation(struct vmbus_channel *new_sc)
 {
 	struct hv_device *device = new_sc->primary_channel->device_obj;
+	struct device *dev = &device->device;
 	struct storvsc_device *stor_device;
 	struct vmstorage_channel_properties props;
+	int ret;
 
 	stor_device = get_out_stor_device(device);
 	if (!stor_device)
 		return;
 
-	if (stor_device->open_sub_channel == false)
-		return;
-
 	memset(&props, 0, sizeof(struct vmstorage_channel_properties));
 
-	vmbus_open(new_sc,
-		   storvsc_ringbuffer_size,
-		   storvsc_ringbuffer_size,
-		   (void *)&props,
-		   sizeof(struct vmstorage_channel_properties),
-		   storvsc_on_channel_callback, new_sc);
+	ret = vmbus_open(new_sc,
+			 storvsc_ringbuffer_size,
+			 storvsc_ringbuffer_size,
+			 (void *)&props,
+			 sizeof(struct vmstorage_channel_properties),
+			 storvsc_on_channel_callback, new_sc);
 
-	if (new_sc->state == CHANNEL_OPENED_STATE) {
-		stor_device->stor_chns[new_sc->target_cpu] = new_sc;
-		cpumask_set_cpu(new_sc->target_cpu, &stor_device->alloced_cpus);
+	/* In case vmbus_open() fails, we don't use the sub-channel. */
+	if (ret != 0) {
+		dev_err(dev, "Failed to open sub-channel: err=%d\n", ret);
+		return;
 	}
+
+	/* Add the sub-channel to the array of available channels. */
+	stor_device->stor_chns[new_sc->target_cpu] = new_sc;
+	cpumask_set_cpu(new_sc->target_cpu, &stor_device->alloced_cpus);
 }
 
 static void  handle_multichannel_storage(struct hv_device *device, int max_chns)
 {
+	struct device *dev = &device->device;
 	struct storvsc_device *stor_device;
-	int num_cpus = num_online_cpus();
 	int num_sc;
 	struct storvsc_cmd_request *request;
 	struct vstor_packet *vstor_packet;
 	int ret, t;
 
-	num_sc = ((max_chns > num_cpus) ? num_cpus : max_chns);
+	/*
+	 * If the number of CPUs is artificially restricted, such as
+	 * with maxcpus=1 on the kernel boot line, Hyper-V could offer
+	 * sub-channels >= the number of CPUs. These sub-channels
+	 * should not be created. The primary channel is already created
+	 * and assigned to one CPU, so check against # CPUs - 1.
+	 */
+	num_sc = min((int)(num_online_cpus() - 1), max_chns);
+	if (!num_sc)
+		return;
+
 	stor_device = get_out_stor_device(device);
 	if (!stor_device)
 		return;
@@ -679,22 +681,12 @@
 	request = &stor_device->init_request;
 	vstor_packet = &request->vstor_packet;
 
-	stor_device->open_sub_channel = true;
 	/*
 	 * Establish a handler for dealing with subchannels.
 	 */
 	vmbus_set_sc_create_callback(device->channel, handle_sc_creation);
 
 	/*
-	 * Check to see if sub-channels have already been created. This
-	 * can happen when this driver is re-loaded after unloading.
-	 */
-
-	if (vmbus_are_subchannels_present(device->channel))
-		return;
-
-	stor_device->open_sub_channel = false;
-	/*
 	 * Request the host to create sub-channels.
 	 */
 	memset(request, 0, sizeof(struct storvsc_cmd_request));
@@ -710,23 +702,29 @@
 			       VM_PKT_DATA_INBAND,
 			       VMBUS_DATA_PACKET_FLAG_COMPLETION_REQUESTED);
 
-	if (ret != 0)
+	if (ret != 0) {
+		dev_err(dev, "Failed to create sub-channel: err=%d\n", ret);
 		return;
+	}
 
 	t = wait_for_completion_timeout(&request->wait_event, 10*HZ);
-	if (t == 0)
+	if (t == 0) {
+		dev_err(dev, "Failed to create sub-channel: timed out\n");
 		return;
+	}
 
 	if (vstor_packet->operation != VSTOR_OPERATION_COMPLETE_IO ||
-	    vstor_packet->status != 0)
+	    vstor_packet->status != 0) {
+		dev_err(dev, "Failed to create sub-channel: op=%d, sts=%d\n",
+			vstor_packet->operation, vstor_packet->status);
 		return;
+	}
 
 	/*
-	 * Now that we created the sub-channels, invoke the check; this
-	 * may trigger the callback.
+	 * We need to do nothing here, because vmbus_process_offer()
+	 * invokes channel->sc_creation_callback, which will open and use
+	 * the sub-channel(s).
 	 */
-	stor_device->open_sub_channel = true;
-	vmbus_are_subchannels_present(device->channel);
 }
 
 static void cache_wwn(struct storvsc_device *stor_device,
@@ -1425,9 +1423,6 @@
 {
 	blk_queue_rq_timeout(sdevice->request_queue, (storvsc_timeout * HZ));
 
-	/* Ensure there are no gaps in presented sgls */
-	blk_queue_virt_boundary(sdevice->request_queue, PAGE_SIZE - 1);
-
 	sdevice->no_write_same = 1;
 
 	/*
@@ -1698,11 +1693,13 @@
 	.slave_configure =	storvsc_device_configure,
 	.cmd_per_lun =		2048,
 	.this_id =		-1,
-	.use_clustering =	ENABLE_CLUSTERING,
 	/* Make sure we dont get a sg segment crosses a page boundary */
 	.dma_boundary =		PAGE_SIZE-1,
+	/* Ensure there are no gaps in presented sgls */
+	.virt_boundary_mask =	PAGE_SIZE-1,
 	.no_write_same =	1,
 	.track_queue_depth =	1,
+	.change_queue_depth =	storvsc_change_queue_depth,
 };
 
 enum {
@@ -1794,7 +1791,6 @@
 	}
 
 	stor_device->destroy = false;
-	stor_device->open_sub_channel = false;
 	init_waitqueue_head(&stor_device->waiting_to_drain);
 	stor_device->device = device;
 	stor_device->host = host;
@@ -1841,8 +1837,7 @@
 	/*
 	 * Set the number of HW queues we are supporting.
 	 */
-	if (stor_device->num_sc != 0)
-		host->nr_hw_queues = stor_device->num_sc + 1;
+	host->nr_hw_queues = num_present_cpus();
 
 	/*
 	 * Set the error handler work queue.
@@ -1910,6 +1905,15 @@
 	return ret;
 }
 
+/* Change a scsi target's queue depth */
+static int storvsc_change_queue_depth(struct scsi_device *sdev, int queue_depth)
+{
+	if (queue_depth > scsi_driver.can_queue)
+		queue_depth = scsi_driver.can_queue;
+
+	return scsi_change_queue_depth(sdev, queue_depth);
+}
+
 static int storvsc_remove(struct hv_device *dev)
 {
 	struct storvsc_device *stor_device = hv_get_drvdata(dev);