diff options
| -rw-r--r-- | drivers/scsi/scsi_lib.c | 48 | ||||
| -rw-r--r-- | include/scsi/scsi_device.h | 1 |
2 files changed, 49 insertions, 0 deletions
diff --git a/drivers/scsi/scsi_lib.c b/drivers/scsi/scsi_lib.c index e352c2b7deaf..fa6b2c4eb7a2 100644 --- a/drivers/scsi/scsi_lib.c +++ b/drivers/scsi/scsi_lib.c @@ -23,6 +23,7 @@ #include <linux/scatterlist.h> #include <linux/blk-mq.h> #include <linux/ratelimit.h> +#include <asm/unaligned.h> #include <scsi/scsi.h> #include <scsi/scsi_cmnd.h> @@ -3294,3 +3295,50 @@ next_desig: return id_size; } EXPORT_SYMBOL(scsi_vpd_lun_id); + +/* + * scsi_vpd_tpg_id - return a target port group identifier + * @sdev: SCSI device + * + * Returns the Target Port Group identifier from the information + * froom VPD page 0x83 of the device. + * + * Returns the identifier or error on failure. + */ +int scsi_vpd_tpg_id(struct scsi_device *sdev, int *rel_id) +{ + unsigned char *d; + unsigned char __rcu *vpd_pg83; + int group_id = -EAGAIN, rel_port = -1; + + rcu_read_lock(); + vpd_pg83 = rcu_dereference(sdev->vpd_pg83); + if (!vpd_pg83) { + rcu_read_unlock(); + return -ENXIO; + } + + d = sdev->vpd_pg83 + 4; + while (d < sdev->vpd_pg83 + sdev->vpd_pg83_len) { + switch (d[1] & 0xf) { + case 0x4: + /* Relative target port */ + rel_port = get_unaligned_be16(&d[6]); + break; + case 0x5: + /* Target port group */ + group_id = get_unaligned_be16(&d[6]); + break; + default: + break; + } + d += d[3] + 4; + } + rcu_read_unlock(); + + if (group_id >= 0 && rel_id && rel_port != -1) + *rel_id = rel_port; + + return group_id; +} +EXPORT_SYMBOL(scsi_vpd_tpg_id); diff --git a/include/scsi/scsi_device.h b/include/scsi/scsi_device.h index 4c49cfa25cac..f63a16760ae9 100644 --- a/include/scsi/scsi_device.h +++ b/include/scsi/scsi_device.h @@ -416,6 +416,7 @@ static inline int scsi_execute_req(struct scsi_device *sdev, extern void sdev_disable_disk_events(struct scsi_device *sdev); extern void sdev_enable_disk_events(struct scsi_device *sdev); extern int scsi_vpd_lun_id(struct scsi_device *, char *, size_t); +extern int scsi_vpd_tpg_id(struct scsi_device *, int *); #ifdef CONFIG_PM extern int scsi_autopm_get_device(struct scsi_device *); |