+/**
+ * mega_allocate_scb()
+ * @adapter - pointer to our soft state
+ * @cmd - scsi command from the mid-layer
+ *
+ * Allocate a SCB structure. This is the central structure for controller
+ * commands.
+ */
+static inline scb_t *
+mega_allocate_scb(adapter_t *adapter, Scsi_Cmnd *cmd)
+{
+ struct list_head *head = &adapter->free_list;
+ scb_t *scb;
+
+ /* Unlink command from Free List */
+ if( !list_empty(head) ) {
+
+ scb = list_entry(head->next, scb_t, list);
+
+ list_del_init(head->next);
+
+ scb->state = SCB_ACTIVE;
+ scb->cmd = cmd;
+ scb->dma_type = MEGA_DMA_TYPE_NONE;
+
+ return scb;
+ }
+
+ return NULL;
+}
+
+/**
+ * mega_get_ldrv_num()
+ * @adapter - pointer to our soft state
+ * @cmd - scsi mid layer command
+ * @channel - channel on the controller
+ *
+ * Calculate the logical drive number based on the information in scsi command
+ * and the channel number.
+ */
+static inline int
+mega_get_ldrv_num(adapter_t *adapter, Scsi_Cmnd *cmd, int channel)
+{
+ int tgt;
+ int ldrv_num;
+
+ tgt = cmd->device->id;
+
+ if ( tgt > adapter->this_id )
+ tgt--; /* we do not get inquires for initiator id */
+
+ ldrv_num = (channel * 15) + tgt;
+
+
+ /*
+ * If we have a logical drive with boot enabled, project it first
+ */
+ if( adapter->boot_ldrv_enabled ) {
+ if( ldrv_num == 0 ) {
+ ldrv_num = adapter->boot_ldrv;
+ }
+ else {
+ if( ldrv_num <= adapter->boot_ldrv ) {
+ ldrv_num--;
+ }
+ }
+ }
+
+ /*
+ * If "delete logical drive" feature is enabled on this controller.
+ * Do only if at least one delete logical drive operation was done.
+ *
+ * Also, after logical drive deletion, instead of logical drive number,
+ * the value returned should be 0x80+logical drive id.
+ *
+ * These is valid only for IO commands.
+ */
+
+ if (adapter->support_random_del && adapter->read_ldidmap )
+ switch (cmd->cmnd[0]) {
+ case READ_6: /* fall through */
+ case WRITE_6: /* fall through */
+ case READ_10: /* fall through */
+ case WRITE_10:
+ ldrv_num += 0x80;
+ }
+
+ return ldrv_num;
+}