1 files changed, 103 insertions, 0 deletions

diff --git a/drivers/scsi/ufs/ufshcd.c b/drivers/scsi/ufs/ufshcd.c
index dc89c486d40a..692fd7aee142 100644
--- a/drivers/scsi/ufs/ufshcd.c
+++ b/drivers/scsi/ufs/ufshcd.c
@@ -902,6 +902,17 @@ static int ufshcd_compose_upiu(struct ufs_hba *hba, struct ufshcd_lrb *lrbp)
 }
 
 /**
+ * ufshcd_upiu_wlun_to_scsi_wlun - maps UPIU W-LUN id to SCSI W-LUN ID
+ * @scsi_lun: UPIU W-LUN id
+ *
+ * Returns SCSI W-LUN id
+ */
+static inline u16 ufshcd_upiu_wlun_to_scsi_wlun(u8 upiu_wlun_id)
+{
+	return (upiu_wlun_id & ~UFS_UPIU_WLUN_ID) | SCSI_W_LUN_BASE;
+}
+
+/**
  * ufshcd_queuecommand - main entry point for SCSI requests
  * @cmd: command from SCSI Midlayer
  * @done: call back function
@@ -3384,6 +3395,93 @@ static void ufshcd_init_icc_levels(struct ufs_hba *hba)
 }
 
 /**
+ * ufshcd_scsi_add_wlus - Adds required W-LUs
+ * @hba: per-adapter instance
+ *
+ * UFS device specification requires the UFS devices to support 4 well known
+ * logical units:
+ *	"REPORT_LUNS" (address: 01h)
+ *	"UFS Device" (address: 50h)
+ *	"RPMB" (address: 44h)
+ *	"BOOT" (address: 30h)
+ * UFS device's power management needs to be controlled by "POWER CONDITION"
+ * field of SSU (START STOP UNIT) command. But this "power condition" field
+ * will take effect only when its sent to "UFS device" well known logical unit
+ * hence we require the scsi_device instance to represent this logical unit in
+ * order for the UFS host driver to send the SSU command for power management.
+
+ * We also require the scsi_device instance for "RPMB" (Replay Protected Memory
+ * Block) LU so user space process can control this LU. User space may also
+ * want to have access to BOOT LU.
+
+ * This function adds scsi device instances for each of all well known LUs
+ * (except "REPORT LUNS" LU).
+ *
+ * Returns zero on success (all required W-LUs are added successfully),
+ * non-zero error value on failure (if failed to add any of the required W-LU).
+ */
+static int ufshcd_scsi_add_wlus(struct ufs_hba *hba)
+{
+	int ret = 0;
+
+	hba->sdev_ufs_device = __scsi_add_device(hba->host, 0, 0,
+		ufshcd_upiu_wlun_to_scsi_wlun(UFS_UPIU_UFS_DEVICE_WLUN), NULL);
+	if (IS_ERR(hba->sdev_ufs_device)) {
+		ret = PTR_ERR(hba->sdev_ufs_device);
+		hba->sdev_ufs_device = NULL;
+		goto out;
+	}
+
+	hba->sdev_boot = __scsi_add_device(hba->host, 0, 0,
+		ufshcd_upiu_wlun_to_scsi_wlun(UFS_UPIU_BOOT_WLUN), NULL);
+	if (IS_ERR(hba->sdev_boot)) {
+		ret = PTR_ERR(hba->sdev_boot);
+		hba->sdev_boot = NULL;
+		goto remove_sdev_ufs_device;
+	}
+
+	hba->sdev_rpmb = __scsi_add_device(hba->host, 0, 0,
+		ufshcd_upiu_wlun_to_scsi_wlun(UFS_UPIU_RPMB_WLUN), NULL);
+	if (IS_ERR(hba->sdev_rpmb)) {
+		ret = PTR_ERR(hba->sdev_rpmb);
+		hba->sdev_rpmb = NULL;
+		goto remove_sdev_boot;
+	}
+	goto out;
+
+remove_sdev_boot:
+	scsi_remove_device(hba->sdev_boot);
+remove_sdev_ufs_device:
+	scsi_remove_device(hba->sdev_ufs_device);
+out:
+	return ret;
+}
+
+/**
+ * ufshcd_scsi_remove_wlus - Removes the W-LUs which were added by
+ *			     ufshcd_scsi_add_wlus()
+ * @hba: per-adapter instance
+ *
+ */
+static void ufshcd_scsi_remove_wlus(struct ufs_hba *hba)
+{
+	if (hba->sdev_ufs_device) {
+		scsi_remove_device(hba->sdev_ufs_device);
+		hba->sdev_ufs_device = NULL;
+	}
+
+	if (hba->sdev_boot) {
+		scsi_remove_device(hba->sdev_boot);
+		hba->sdev_boot = NULL;
+	}
+
+	if (hba->sdev_rpmb) {
+		scsi_remove_device(hba->sdev_rpmb);
+		hba->sdev_rpmb = NULL;
+	}
+}
+
+/**
  * ufshcd_probe_hba - probe hba to detect device and initialize
  * @hba: per-adapter instance
  *
@@ -3415,6 +3513,10 @@ static int ufshcd_probe_hba(struct ufs_hba *hba)
 		if (!hba->is_init_prefetch)
 			ufshcd_init_icc_levels(hba);
 
+		/* Add required well known logical units to scsi mid layer */
+		if (ufshcd_scsi_add_wlus(hba))
+			goto out;
+
 		scsi_scan_host(hba->host);
 		pm_runtime_put_sync(hba->dev);
 	}
@@ -3901,6 +4003,7 @@ EXPORT_SYMBOL(ufshcd_runtime_idle);
 void ufshcd_remove(struct ufs_hba *hba)
 {
 	scsi_remove_host(hba->host);
+	ufshcd_scsi_remove_wlus(hba);
 	/* disable interrupts */
 	ufshcd_disable_intr(hba, hba->intr_mask);
 	ufshcd_hba_stop(hba);