scsi: fnic: Add and use fnic number

Add fnic_num in fnic.h to identify fnic in a multi-fnic environment.
Increment and set the fnic number during driver load in fnic_probe.
Replace the host number with fnic number in debugfs.

Reviewed-by: Sesidhar Baddela <sebaddel@cisco.com>
Reviewed-by: Arulprabhu Ponnusamy <arulponn@cisco.com>
Signed-off-by: Karan Tilak Kumar <kartilak@cisco.com>
Link: https://lore.kernel.org/r/20231211173617.932990-3-kartilak@cisco.com
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>

Author: kartilak

drivers/scsi/fnic/fnic.h

@@ -216,6 +216,7 @@ struct fnic_event {
 
 /* Per-instance private data structure */
 struct fnic {
+	int fnic_num;
 	struct fc_lport *lport;
 	struct fcoe_ctlr ctlr;		/* FIP FCoE controller structure */
 	struct vnic_dev_bar bar0;

drivers/scsi/fnic/fnic_main.c

@@ -39,6 +39,7 @@ static struct kmem_cache *fnic_sgl_cache[FNIC_SGL_NUM_CACHES];
 static struct kmem_cache *fnic_io_req_cache;
 static LIST_HEAD(fnic_list);
 static DEFINE_SPINLOCK(fnic_list_lock);
+static DEFINE_IDA(fnic_ida);
 
 /* Supported devices by fnic module */
 static struct pci_device_id fnic_id_table[] = {
@@ -583,7 +584,8 @@ static int fnic_probe(struct pci_dev *pdev, const struct pci_device_id *ent)
 	struct fc_lport *lp;
 	struct fnic *fnic;
 	mempool_t *pool;
-	int err;
+	int err = 0;
+	int fnic_id = 0;
 	int i;
 	unsigned long flags;
 
@@ -597,8 +599,16 @@ static int fnic_probe(struct pci_dev *pdev, const struct pci_device_id *ent)
 		err = -ENOMEM;
 		goto err_out;
 	}
+
 	host = lp->host;
 	fnic = lport_priv(lp);
+
+	fnic_id = ida_alloc(&fnic_ida, GFP_KERNEL);
+	if (fnic_id < 0) {
+		pr_err("Unable to alloc fnic ID\n");
+		err = fnic_id;
+		goto err_out_ida_alloc;
+	}
 	fnic->lport = lp;
 	fnic->ctlr.lp = lp;
 
@@ -608,7 +618,7 @@ static int fnic_probe(struct pci_dev *pdev, const struct pci_device_id *ent)
 		 host->host_no);
 
 	host->transportt = fnic_fc_transport;
-
+	fnic->fnic_num = fnic_id;
 	fnic_stats_debugfs_init(fnic);
 
 	/* Setup PCI resources */
@@ -951,6 +961,8 @@ static int fnic_probe(struct pci_dev *pdev, const struct pci_device_id *ent)
 	pci_disable_device(pdev);
 err_out_free_hba:
 	fnic_stats_debugfs_remove(fnic);
+	ida_free(&fnic_ida, fnic->fnic_num);
+err_out_ida_alloc:
 	scsi_host_put(lp->host);
 err_out:
 	return err;
@@ -1031,6 +1043,7 @@ static void fnic_remove(struct pci_dev *pdev)
 	fnic_iounmap(fnic);
 	pci_release_regions(pdev);
 	pci_disable_device(pdev);
+	ida_free(&fnic_ida, fnic->fnic_num);
 	scsi_host_put(lp->host);
 }
 
@@ -1168,6 +1181,7 @@ static void __exit fnic_cleanup_module(void)
 	fnic_trace_free();
 	fnic_fc_trace_free();
 	fnic_debugfs_terminate();
+	ida_destroy(&fnic_ida);
 }
 
 module_init(fnic_init_module);