scsi: cxlflash: Allocate memory instead of using command pool for AFU sync

As staging for the removal of the AFU command pool, remove the reliance
upon the pool for the internal AFU sync command. Instead of obtaining an
AFU command from the pool, dynamically allocate memory with the appropriate
alignment requirements. Since the AFU sync service is only executed from
the process environment, blocking is acceptable.
Signed-off-by: Matthew R. Ochs <mrochs@linux.vnet.ibm.com>
Acked-by: Uma Krishnan <ukrishn@linux.vnet.ibm.com>
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>

drivers/scsi/cxlflash/main.c

@@ -1823,8 +1823,8 @@ int cxlflash_afu_sync(struct afu *afu, ctx_hndl_t ctx_hndl_u,
 	struct cxlflash_cfg *cfg = afu->parent;
 	struct device *dev = &cfg->dev->dev;
 	struct afu_cmd *cmd = NULL;
+	char *buf = NULL;
 	int rc = 0;
-	int retry_cnt = 0;
 	static DEFINE_MUTEX(sync_active);
 
 	if (cfg->state != STATE_NORMAL) {
@@ -1833,23 +1833,23 @@ int cxlflash_afu_sync(struct afu *afu, ctx_hndl_t ctx_hndl_u,
 	}
 
 	mutex_lock(&sync_active);
-retry:
-	cmd = cmd_checkout(afu);
-	if (unlikely(!cmd)) {
-		retry_cnt++;
-		udelay(1000 * retry_cnt);
-		if (retry_cnt < MC_RETRY_CNT)
-			goto retry;
-		dev_err(dev, "%s: could not get a free command\n", __func__);
+	buf = kzalloc(sizeof(*cmd) + __alignof__(*cmd) - 1, GFP_KERNEL);
+	if (unlikely(!buf)) {
+		dev_err(dev, "%s: no memory for command\n", __func__);
 		rc = -1;
 		goto out;
 	}
 
-	pr_debug("%s: afu=%p cmd=%p %d\n", __func__, afu, cmd, ctx_hndl_u);
+	cmd = (struct afu_cmd *)PTR_ALIGN(buf, __alignof__(*cmd));
+	init_completion(&cmd->cevent);
+	spin_lock_init(&cmd->slock);
+	cmd->parent = afu;
 
-	memset(cmd->rcb.cdb, 0, sizeof(cmd->rcb.cdb));
+	pr_debug("%s: afu=%p cmd=%p %d\n", __func__, afu, cmd, ctx_hndl_u);
 
 	cmd->rcb.req_flags = SISL_REQ_FLAGS_AFU_CMD;
+	cmd->rcb.ctx_id = afu->ctx_hndl;
+	cmd->rcb.msi = SISL_MSI_RRQ_UPDATED;
 	cmd->rcb.port_sel = 0x0;	/* NA */
 	cmd->rcb.lun_id = 0x0;	/* NA */
 	cmd->rcb.data_len = 0x0;
@@ -1875,8 +1875,7 @@ int cxlflash_afu_sync(struct afu *afu, ctx_hndl_t ctx_hndl_u,
 		rc = -1;
 out:
 	mutex_unlock(&sync_active);
-	if (cmd)
-		cmd_checkin(cmd);
+	kfree(buf);
 	pr_debug("%s: returning rc=%d\n", __func__, rc);
 	return rc;
 }