6 files changed, 144 insertions, 1 deletions
diff --git a/drivers/scsi/ufs/Kconfig b/drivers/scsi/ufs/Kconfig
index e09fe6ab3572..2ddd426323e9 100644
--- a/drivers/scsi/ufs/Kconfig
+++ b/drivers/scsi/ufs/Kconfig
@@ -109,3 +109,22 @@ config SCSI_UFS_HISI
 
 	  Select this if you have UFS controller on Hisilicon chipset.
 	  If unsure, say N.
+
+config SCSI_UFS_BSG
+	bool "Universal Flash Storage BSG device node"
+	depends on SCSI_UFSHCD
+	select BLK_DEV_BSGLIB
+	help
+	  Universal Flash Storage (UFS) is SCSI transport specification for
+	  accessing flash storage on digital cameras, mobile phones and
+	  consumer electronic devices.
+	  A UFS controller communicates with a UFS device by exchanging
+	  UFS Protocol Information Units (UPIUs).
+	  UPIUs can not only be used as a transport layer for the SCSI protocol
+	  but are also used by the UFS native command set.
+	  This transport driver supports exchanging UFS protocol information units
+	  with a UFS device. See also the ufshcd driver, which is a SCSI driver
+	  that supports UFS devices.
+
+	  Select this if you need a bsg device node for your UFS controller.
+	  If unsure, say N.
diff --git a/drivers/scsi/ufs/Makefile b/drivers/scsi/ufs/Makefile
index 2c50f03d8c4a..aca481329828 100644
--- a/drivers/scsi/ufs/Makefile
+++ b/drivers/scsi/ufs/Makefile
@@ -4,7 +4,8 @@ obj-$(CONFIG_SCSI_UFS_DWC_TC_PCI) += tc-dwc-g210-pci.o ufshcd-dwc.o tc-dwc-g210.
 obj-$(CONFIG_SCSI_UFS_DWC_TC_PLATFORM) += tc-dwc-g210-pltfrm.o ufshcd-dwc.o tc-dwc-g210.o
 obj-$(CONFIG_SCSI_UFS_QCOM) += ufs-qcom.o
 obj-$(CONFIG_SCSI_UFSHCD) += ufshcd-core.o
-ufshcd-core-objs := ufshcd.o ufs-sysfs.o
+ufshcd-core-y				+= ufshcd.o ufs-sysfs.o
+ufshcd-core-$(CONFIG_SCSI_UFS_BSG)	+= ufs_bsg.o
 obj-$(CONFIG_SCSI_UFSHCD_PCI) += ufshcd-pci.o
 obj-$(CONFIG_SCSI_UFSHCD_PLATFORM) += ufshcd-pltfrm.o
 obj-$(CONFIG_SCSI_UFS_HISI) += ufs-hisi.o
diff --git a/drivers/scsi/ufs/ufs_bsg.c b/drivers/scsi/ufs/ufs_bsg.c
new file mode 100644
index 000000000000..1036c520d349
--- /dev/null
+++ b/drivers/scsi/ufs/ufs_bsg.c
@@ -0,0 +1,93 @@
+// SPDX-License-Identifier: GPL-2.0
+/*
+ * bsg endpoint that supports UPIUs
+ *
+ * Copyright (C) 2018 Western Digital Corporation
+ */
+#include "ufs_bsg.h"
+
+
+static int ufs_bsg_request(struct bsg_job *job)
+{
+	struct ufs_bsg_request *bsg_request = job->request;
+	struct ufs_bsg_reply *bsg_reply = job->reply;
+	int ret = -ENOTSUPP;
+
+	bsg_reply->reply_payload_rcv_len = 0;
+
+	/* Do Nothing for now */
+	dev_err(job->dev, "unsupported message_code 0x%x\n",
+		bsg_request->msgcode);
+
+	bsg_reply->result = ret;
+	job->reply_len = sizeof(struct ufs_bsg_reply) +
+			 bsg_reply->reply_payload_rcv_len;
+
+	bsg_job_done(job, ret, bsg_reply->reply_payload_rcv_len);
+
+	return ret;
+}
+
+/**
+ * ufs_bsg_remove - detach and remove the added ufs-bsg node
+ *
+ * Should be called when unloading the driver.
+ */
+void ufs_bsg_remove(struct ufs_hba *hba)
+{
+	struct device *bsg_dev = &hba->bsg_dev;
+
+	if (!hba->bsg_queue)
+		return;
+
+	bsg_unregister_queue(hba->bsg_queue);
+
+	device_del(bsg_dev);
+	put_device(bsg_dev);
+}
+
+static inline void ufs_bsg_node_release(struct device *dev)
+{
+	put_device(dev->parent);
+}
+
+/**
+ * ufs_bsg_probe - Add ufs bsg device node
+ * @hba: per adapter object
+ *
+ * Called during initial loading of the driver, and before scsi_scan_host.
+ */
+int ufs_bsg_probe(struct ufs_hba *hba)
+{
+	struct device *bsg_dev = &hba->bsg_dev;
+	struct Scsi_Host *shost = hba->host;
+	struct device *parent = &shost->shost_gendev;
+	struct request_queue *q;
+	int ret;
+
+	device_initialize(bsg_dev);
+
+	bsg_dev->parent = get_device(parent);
+	bsg_dev->release = ufs_bsg_node_release;
+
+	dev_set_name(bsg_dev, "ufs-bsg");
+
+	ret = device_add(bsg_dev);
+	if (ret)
+		goto out;
+
+	q = bsg_setup_queue(bsg_dev, dev_name(bsg_dev), ufs_bsg_request, 0);
+	if (IS_ERR(q)) {
+		ret = PTR_ERR(q);
+		goto out;
+	}
+
+	hba->bsg_queue = q;
+
+	return 0;
+
+out:
+	dev_err(bsg_dev, "fail to initialize a bsg dev %d\n", shost->host_no);
+	put_device(bsg_dev);
+	return ret;
+}
diff --git a/drivers/scsi/ufs/ufs_bsg.h b/drivers/scsi/ufs/ufs_bsg.h
new file mode 100644
index 000000000000..d09918758631
--- /dev/null
+++ b/drivers/scsi/ufs/ufs_bsg.h
@@ -0,0 +1,23 @@
+/* SPDX-License-Identifier: GPL-2.0 */
+/*
+ * Copyright (C) 2018 Western Digital Corporation
+ */
+#ifndef UFS_BSG_H
+#define UFS_BSG_H
+
+#include <linux/bsg-lib.h>
+#include <scsi/scsi.h>
+#include <scsi/scsi_host.h>
+
+#include "ufshcd.h"
+#include "ufs.h"
+
+#ifdef CONFIG_SCSI_UFS_BSG
+void ufs_bsg_remove(struct ufs_hba *hba);
+int ufs_bsg_probe(struct ufs_hba *hba);
+#else
+static inline void ufs_bsg_remove(struct ufs_hba *hba) {}
+static inline int ufs_bsg_probe(struct ufs_hba *hba) {return 0; }
+#endif
+
+#endif /* UFS_BSG_H */
diff --git a/drivers/scsi/ufs/ufshcd.c b/drivers/scsi/ufs/ufshcd.c
index d7e0155c9d1f..69d023788e14 100644
--- a/drivers/scsi/ufs/ufshcd.c
+++ b/drivers/scsi/ufs/ufshcd.c
@@ -46,6 +46,7 @@
 #include "ufs_quirks.h"
 #include "unipro.h"
 #include "ufs-sysfs.h"
+#include "ufs_bsg.h"
 
 #define CREATE_TRACE_POINTS
 #include <trace/events/ufs.h>
@@ -6633,6 +6634,8 @@ static int ufshcd_probe_hba(struct ufs_hba *hba)
 			hba->clk_scaling.is_allowed = true;
 		}
 
+		ufs_bsg_probe(hba);
+
 		scsi_scan_host(hba->host);
 		pm_runtime_put_sync(hba->dev);
 	}
@@ -7854,6 +7857,7 @@ EXPORT_SYMBOL(ufshcd_shutdown);
  */
 void ufshcd_remove(struct ufs_hba *hba)
 {
+	ufs_bsg_remove(hba);
 	ufs_sysfs_remove_nodes(hba->dev);
 	scsi_remove_host(hba->host);
 	/* disable interrupts */
diff --git a/drivers/scsi/ufs/ufshcd.h b/drivers/scsi/ufs/ufshcd.h
index 33fdd3f281ae..54e6fe87954f 100644
--- a/drivers/scsi/ufs/ufshcd.h
+++ b/drivers/scsi/ufs/ufshcd.h
@@ -702,6 +702,9 @@ struct ufs_hba {
 	struct rw_semaphore clk_scaling_lock;
 	struct ufs_desc_size desc_size;
 	atomic_t scsi_block_reqs_cnt;
+
+	struct device		bsg_dev;
+	struct request_queue	*bsg_queue;
 };
 
 /* Returns true if clocks can be gated. Otherwise false */