scsi: cxlflash: Separate AFU internal command handling from AFU sync specifics

To date the only supported internal AFU command is AFU sync. The logic
to send an internal AFU command is embedded in the specific AFU sync
handler and would need to be duplicated for new internal AFU commands.

In order to support new internal AFU commands, separate code that is
common for AFU internal commands into a generic transmission routine
and support passing back command status through an IOASA structure.
The first user of this new routine is the existing AFU sync command.
As a cleanup, use a descriptive name for the AFU sync command instead
of a magic number.

Signed-off-by: Matthew R. Ochs <mrochs@linux.vnet.ibm.com>
Signed-off-by: Uma Krishnan <ukrishn@linux.vnet.ibm.com>
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>

drivers/scsi/cxlflash/main.c

@@ -2212,28 +2212,22 @@ static void cxlflash_schedule_async_reset(struct cxlflash_cfg *cfg)
 }
 
 /**
- * cxlflash_afu_sync() - builds and sends an AFU sync command
+ * send_afu_cmd() - builds and sends an internal AFU command
  * @afu:	AFU associated with the host.
- * @ctx_hndl_u:	Identifies context requesting sync.
- * @res_hndl_u:	Identifies resource requesting sync.
- * @mode:	Type of sync to issue (lightweight, heavyweight, global).
+ * @rcb:	Pre-populated IOARCB describing command to send.
  *
- * The AFU can only take 1 sync command at a time. This routine enforces this
- * limitation by using a mutex to provide exclusive access to the AFU during
- * the sync. This design point requires calling threads to not be on interrupt
- * context due to the possibility of sleeping during concurrent sync operations.
+ * The AFU can only take one internal AFU command at a time. This limitation is
+ * enforced by using a mutex to provide exclusive access to the AFU during the
+ * operation. This design point requires calling threads to not be on interrupt
+ * context due to the possibility of sleeping during concurrent AFU operations.
  *
- * AFU sync operations are only necessary and allowed when the device is
- * operating normally. When not operating normally, sync requests can occur as
- * part of cleaning up resources associated with an adapter prior to removal.
- * In this scenario, these requests are simply ignored (safe due to the AFU
- * going away).
+ * The command status is optionally passed back to the caller when the caller
+ * populates the IOASA field of the IOARCB with a pointer to an IOASA structure.
  *
  * Return:
  *	0 on success, -errno on failure
  */
-int cxlflash_afu_sync(struct afu *afu, ctx_hndl_t ctx_hndl_u,
-		      res_hndl_t res_hndl_u, u8 mode)
+static int send_afu_cmd(struct afu *afu, struct sisl_ioarcb *rcb)
 {
 	struct cxlflash_cfg *cfg = afu->parent;
 	struct device *dev = &cfg->dev->dev;
@@ -2263,25 +2257,15 @@ int cxlflash_afu_sync(struct afu *afu, ctx_hndl_t ctx_hndl_u,
 
 retry:
 	memset(cmd, 0, sizeof(*cmd));
+	memcpy(&cmd->rcb, rcb, sizeof(*rcb));
 	INIT_LIST_HEAD(&cmd->queue);
 	init_completion(&cmd->cevent);
 	cmd->parent = afu;
 	cmd->hwq_index = hwq->index;
-
-	dev_dbg(dev, "%s: afu=%p cmd=%p ctx=%d nretry=%d\n",
-		__func__, afu, cmd, ctx_hndl_u, nretry);
-
-	cmd->rcb.req_flags = SISL_REQ_FLAGS_AFU_CMD;
 	cmd->rcb.ctx_id = hwq->ctx_hndl;
-	cmd->rcb.msi = SISL_MSI_RRQ_UPDATED;
-	cmd->rcb.timeout = MC_AFU_SYNC_TIMEOUT;
-
-	cmd->rcb.cdb[0] = 0xC0;	/* AFU Sync */
-	cmd->rcb.cdb[1] = mode;
 
-	/* The cdb is aligned, no unaligned accessors required */
-	*((__be16 *)&cmd->rcb.cdb[2]) = cpu_to_be16(ctx_hndl_u);
-	*((__be32 *)&cmd->rcb.cdb[4]) = cpu_to_be32(res_hndl_u);
+	dev_dbg(dev, "%s: afu=%p cmd=%p type=%02x nretry=%d\n",
+		__func__, afu, cmd, cmd->rcb.cdb[0], nretry);
 
 	rc = afu->send_cmd(afu, cmd);
 	if (unlikely(rc)) {
@@ -2306,6 +2290,8 @@ retry:
 		break;
 	}
 
+	if (rcb->ioasa)
+		*rcb->ioasa = cmd->sa;
 out:
 	atomic_dec(&afu->cmds_active);
 	mutex_unlock(&sync_active);
@@ -2314,6 +2300,43 @@ out:
 	return rc;
 }
 
+/**
+ * cxlflash_afu_sync() - builds and sends an AFU sync command
+ * @afu:	AFU associated with the host.
+ * @ctx:	Identifies context requesting sync.
+ * @res:	Identifies resource requesting sync.
+ * @mode:	Type of sync to issue (lightweight, heavyweight, global).
+ *
+ * AFU sync operations are only necessary and allowed when the device is
+ * operating normally. When not operating normally, sync requests can occur as
+ * part of cleaning up resources associated with an adapter prior to removal.
+ * In this scenario, these requests are simply ignored (safe due to the AFU
+ * going away).
+ *
+ * Return:
+ *	0 on success, -errno on failure
+ */
+int cxlflash_afu_sync(struct afu *afu, ctx_hndl_t ctx, res_hndl_t res, u8 mode)
+{
+	struct cxlflash_cfg *cfg = afu->parent;
+	struct device *dev = &cfg->dev->dev;
+	struct sisl_ioarcb rcb = { 0 };
+
+	dev_dbg(dev, "%s: afu=%p ctx=%u res=%u mode=%u\n",
+		__func__, afu, ctx, res, mode);
+
+	rcb.req_flags = SISL_REQ_FLAGS_AFU_CMD;
+	rcb.msi = SISL_MSI_RRQ_UPDATED;
+	rcb.timeout = MC_AFU_SYNC_TIMEOUT;
+
+	rcb.cdb[0] = SISL_AFU_CMD_SYNC;
+	rcb.cdb[1] = mode;
+	put_unaligned_be16(ctx, &rcb.cdb[2]);
+	put_unaligned_be32(res, &rcb.cdb[4]);
+
+	return send_afu_cmd(afu, &rcb);
+}
+
 /**
  * cxlflash_eh_abort_handler() - abort a SCSI command
  * @scp:	SCSI command to abort.

drivers/scsi/cxlflash/sislite.h

@@ -72,6 +72,8 @@ struct sisl_ioarcb {
 	u16 timeout;		/* in units specified by req_flags */
 	u32 rsvd1;
 	u8 cdb[16];		/* must be in big endian */
+#define SISL_AFU_CMD_SYNC		0xC0	/* AFU sync command */
+
 	union {
 		u64 reserved;			/* Reserved for IOARRIN mode */
 		struct sisl_ioasa *ioasa;	/* IOASA EA for SQ Mode */