scsi: ufs: core: Fix RPMB region size detection for UFS 2.2

Older UFS spec devices (2.2 and earlier) do not expose per-region RPMB
sizes, as only one RPMB region is supported. In such cases, the size of the
single RPMB region can be deduced from the Logical Block Count and Logical
Block Size fields in the RPMB Unit Descriptor.

Add a fallback mechanism to calculate the RPMB region size from these
fields if the device implements an older spec, so that the RPMB driver can
work with such devices - otherwise it silently skips the whole RPMB.

        Section 14.1.4.6 (RPMB Unit Descriptor)

Link: https://www.jedec.org/system/files/docs/JESD220C-2_2.pdf
Cc: stable@vger.kernel.org
Fixes: b06b8c4 ("scsi: ufs: core: Add OP-TEE based RPMB driver for UFS devices")
Reviewed-by: Bean Huo <beanhuo@micron.com>
Signed-off-by: Alexey Charkov <alchark@flipper.net>
Link: https://patch.msgid.link/20260209-ufs-rpmb-v3-1-b1804e71bd38@flipper.net
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>

Author: alchark

drivers/ufs/core/ufshcd.c

@@ -23,6 +23,7 @@
 #include <linux/pm_opp.h>
 #include <linux/regulator/consumer.h>
 #include <linux/sched/clock.h>
+#include <linux/sizes.h>
 #include <linux/iopoll.h>
 #include <scsi/scsi_cmnd.h>
 #include <scsi/scsi_dbg.h>
@@ -5248,6 +5249,25 @@ static void ufshcd_lu_init(struct ufs_hba *hba, struct scsi_device *sdev)
 		hba->dev_info.rpmb_region_size[1] = desc_buf[RPMB_UNIT_DESC_PARAM_REGION1_SIZE];
 		hba->dev_info.rpmb_region_size[2] = desc_buf[RPMB_UNIT_DESC_PARAM_REGION2_SIZE];
 		hba->dev_info.rpmb_region_size[3] = desc_buf[RPMB_UNIT_DESC_PARAM_REGION3_SIZE];
+
+		if (hba->dev_info.wspecversion <= 0x0220) {
+			/*
+			 * These older spec chips have only one RPMB region,
+			 * sized between 128 kB minimum and 16 MB maximum.
+			 * No per region size fields are provided (respective
+			 * REGIONX_SIZE fields always contain zeros), so get
+			 * it from the logical block count and size fields for
+			 * compatibility
+			 *
+			 * (See JESD220C-2_2 Section 14.1.4.6
+			 * RPMB Unit Descriptor,* offset 13h, 4 bytes)
+			 */
+			hba->dev_info.rpmb_region_size[0] =
+				(get_unaligned_be64(desc_buf
+					+ RPMB_UNIT_DESC_PARAM_LOGICAL_BLK_COUNT)
+				<< desc_buf[RPMB_UNIT_DESC_PARAM_LOGICAL_BLK_SIZE])
+				/ SZ_128K;
+		}
 	}