scsi: mpi3mr: Add bsg device support

Create bsg device per controller for controller management purposes.

bsg device nodes will be named /dev/bsg/mpi3mrctl0, /dev/bsg/mpi3mrctl1,
etc.

Link: https://lore.kernel.org/r/20220429211641.642010-2-sumit.saxena@broadcom.com
Reported-by: kernel test robot <lkp@intel.com>
Reviewed-by: Hannes Reinecke <hare@suse.de>
Reviewed-by: Himanshu Madhani <himanshu.madhani@oracle.com>
Signed-off-by: Sumit Saxena <sumit.saxena@broadcom.com>
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>

1 files changed, 105 insertions, 0 deletions

diff --git a/drivers/scsi/mpi3mr/mpi3mr_app.c b/drivers/scsi/mpi3mr/mpi3mr_app.c
new file mode 100644
index 000000000000..948d4ff2ea06
--- /dev/null
+++ b/drivers/scsi/mpi3mr/mpi3mr_app.c
@@ -0,0 +1,105 @@
+// SPDX-License-Identifier: GPL-2.0-or-later
+/*
+ * Driver for Broadcom MPI3 Storage Controllers
+ *
+ * Copyright (C) 2017-2022 Broadcom Inc.
+ *  (mailto: mpi3mr-linuxdrv.pdl@broadcom.com)
+ *
+ */
+
+#include "mpi3mr.h"
+#include <linux/bsg-lib.h>
+
+/**
+ * mpi3mr_bsg_request - bsg request entry point
+ * @job: BSG job reference
+ *
+ * This is driver's entry point for bsg requests
+ *
+ * Return: 0 on success and proper error codes on failure
+ */
+static int mpi3mr_bsg_request(struct bsg_job *job)
+{
+	return 0;
+}
+
+/**
+ * mpi3mr_bsg_exit - de-registration from bsg layer
+ *
+ * This will be called during driver unload and all
+ * bsg resources allocated during load will be freed.
+ *
+ * Return:Nothing
+ */
+void mpi3mr_bsg_exit(struct mpi3mr_ioc *mrioc)
+{
+	if (!mrioc->bsg_queue)
+		return;
+
+	bsg_remove_queue(mrioc->bsg_queue);
+	mrioc->bsg_queue = NULL;
+
+	device_del(mrioc->bsg_dev);
+	put_device(mrioc->bsg_dev);
+	kfree(mrioc->bsg_dev);
+}
+
+/**
+ * mpi3mr_bsg_node_release -release bsg device node
+ * @dev: bsg device node
+ *
+ * decrements bsg dev reference count
+ *
+ * Return:Nothing
+ */
+static void mpi3mr_bsg_node_release(struct device *dev)
+{
+	put_device(dev);
+}
+
+/**
+ * mpi3mr_bsg_init -  registration with bsg layer
+ *
+ * This will be called during driver load and it will
+ * register driver with bsg layer
+ *
+ * Return:Nothing
+ */
+void mpi3mr_bsg_init(struct mpi3mr_ioc *mrioc)
+{
+	mrioc->bsg_dev = kzalloc(sizeof(struct device), GFP_KERNEL);
+	if (!mrioc->bsg_dev) {
+		ioc_err(mrioc, "bsg device mem allocation failed\n");
+		return;
+	}
+
+	device_initialize(mrioc->bsg_dev);
+	dev_set_name(mrioc->bsg_dev, "mpi3mrctl%u", mrioc->id);
+
+	if (device_add(mrioc->bsg_dev)) {
+		ioc_err(mrioc, "%s: bsg device add failed\n",
+		    dev_name(mrioc->bsg_dev));
+		goto err_device_add;
+	}
+
+	mrioc->bsg_dev->release = mpi3mr_bsg_node_release;
+
+	mrioc->bsg_queue = bsg_setup_queue(mrioc->bsg_dev, dev_name(mrioc->bsg_dev),
+			mpi3mr_bsg_request, NULL, 0);
+	if (!mrioc->bsg_queue) {
+		ioc_err(mrioc, "%s: bsg registration failed\n",
+		    dev_name(mrioc->bsg_dev));
+		goto err_setup_queue;
+	}
+
+	blk_queue_max_segments(mrioc->bsg_queue, MPI3MR_MAX_APP_XFER_SEGMENTS);
+	blk_queue_max_hw_sectors(mrioc->bsg_queue, MPI3MR_MAX_APP_XFER_SECTORS);
+
+	return;
+
+err_setup_queue:
+	device_del(mrioc->bsg_dev);
+	put_device(mrioc->bsg_dev);
+err_device_add:
+	kfree(mrioc->bsg_dev);
+}