scsi: lpfc: Enlarge nvmet asynchronous receive buffer counts

Under large io load, the current sizing of asynchronous buffer counts
could be exceeded, indicated by a 2885 log message:

  2885 Port Status Event: port status reg 0x81800000, port smphr
      reg 0xc000, error 1=0x52004a01, error 2=0x0

Enlarge the async receive queue size.  Allow for a configurable number
of buffers to be posted to each RQ, using the new attribute
lpfc_nvmet_mrq_post.
Signed-off-by: Dick Kennedy <dick.kennedy@broadcom.com>
Signed-off-by: James Smart <james.smart@broadcom.com>
Reviewed-by: Hannes Reinecke <hare@suse.com>
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>

drivers/scsi/lpfc/lpfc.h

@@ -782,6 +782,7 @@ struct lpfc_hba {
 	uint32_t cfg_nvme_oas;
 	uint32_t cfg_nvme_embed_cmd;
 	uint32_t cfg_nvme_io_channel;
+	uint32_t cfg_nvmet_mrq_post;
 	uint32_t cfg_nvmet_mrq;
 	uint32_t cfg_enable_nvmet;
 	uint32_t cfg_nvme_enable_fb;

drivers/scsi/lpfc/lpfc_attr.c

@@ -3423,6 +3423,15 @@ LPFC_ATTR_R(nvmet_mrq,
 	    LPFC_NVMET_MRQ_AUTO, LPFC_NVMET_MRQ_AUTO, LPFC_NVMET_MRQ_MAX,
 	    "Specify number of RQ pairs for processing NVMET cmds");
 
+/*
+ * lpfc_nvmet_mrq_post: Specify number of RQ buffer to initially post
+ * to each NVMET RQ. Range 64 to 2048, default is 512.
+ */
+LPFC_ATTR_R(nvmet_mrq_post,
+	    LPFC_NVMET_RQE_DEF_POST, LPFC_NVMET_RQE_MIN_POST,
+	    LPFC_NVMET_RQE_DEF_COUNT,
+	    "Specify number of RQ buffers to initially post");
+
 /*
  * lpfc_enable_fc4_type: Defines what FC4 types are supported.
  * Supported Values:  1 - register just FCP
@@ -5353,6 +5362,7 @@ struct device_attribute *lpfc_hba_attrs[] = {
 	&dev_attr_lpfc_suppress_rsp,
 	&dev_attr_lpfc_nvme_io_channel,
 	&dev_attr_lpfc_nvmet_mrq,
+	&dev_attr_lpfc_nvmet_mrq_post,
 	&dev_attr_lpfc_nvme_enable_fb,
 	&dev_attr_lpfc_nvmet_fb_size,
 	&dev_attr_lpfc_enable_bg,
@@ -6403,6 +6413,7 @@ lpfc_get_cfgparam(struct lpfc_hba *phba)
 
 	lpfc_enable_fc4_type_init(phba, lpfc_enable_fc4_type);
 	lpfc_nvmet_mrq_init(phba, lpfc_nvmet_mrq);
+	lpfc_nvmet_mrq_post_init(phba, lpfc_nvmet_mrq_post);
 
 	/* Initialize first burst. Target vs Initiator are different. */
 	lpfc_nvme_enable_fb_init(phba, lpfc_nvme_enable_fb);

drivers/scsi/lpfc/lpfc_nvmet.h

@@ -22,8 +22,10 @@
  ********************************************************************/
 
 #define LPFC_NVMET_DEFAULT_SEGS		(64 + 1)	/* 256K IOs */
-#define LPFC_NVMET_RQE_DEF_COUNT	512
-#define LPFC_NVMET_SUCCESS_LEN	12
+#define LPFC_NVMET_RQE_MIN_POST		128
+#define LPFC_NVMET_RQE_DEF_POST		512
+#define LPFC_NVMET_RQE_DEF_COUNT	2048
+#define LPFC_NVMET_SUCCESS_LEN		12
 
 #define LPFC_NVMET_MRQ_OFF		0xffff
 #define LPFC_NVMET_MRQ_AUTO		0

drivers/scsi/lpfc/lpfc_sli.c

@@ -7199,7 +7199,7 @@ lpfc_sli4_hba_setup(struct lpfc_hba *phba)
 			lpfc_post_rq_buffer(
 				phba, phba->sli4_hba.nvmet_mrq_hdr[i],
 				phba->sli4_hba.nvmet_mrq_data[i],
-				LPFC_NVMET_RQE_DEF_COUNT, i);
+				phba->cfg_nvmet_mrq_post, i);
 		}
 	}