lpfc: Utilize embedded CDB logic to minimize IO latency

Pass cmd iu payloads inline to adapter job structure rather than as
separate dma buffers.

Signed-off-by: Dick Kennedy <dick.kennedy@avagotech.com>
Signed-off-by: James Smart <james.smart@avagotech.com>
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>

5 files changed, 136 insertions, 20 deletions

diff --git a/drivers/scsi/lpfc/lpfc.h b/drivers/scsi/lpfc/lpfc.h
index 90a3ca5a4dbd..da237d9c4b55 100644
--- a/drivers/scsi/lpfc/lpfc.h
+++ b/drivers/scsi/lpfc/lpfc.h
@@ -694,6 +694,7 @@ struct lpfc_hba {
         uint8_t  wwnn[8];
         uint8_t  wwpn[8];
         uint32_t RandomData[7];
+        uint32_t fcp_embed_io;
 
         /* HBA Config Parameters */
         uint32_t cfg_ack0;
diff --git a/drivers/scsi/lpfc/lpfc_attr.c b/drivers/scsi/lpfc/lpfc_attr.c
index 343ae9482891..d4559a6175e2 100644
--- a/drivers/scsi/lpfc/lpfc_attr.c
+++ b/drivers/scsi/lpfc/lpfc_attr.c
@@ -5150,7 +5150,6 @@ lpfc_free_sysfs_attr(struct lpfc_vport *vport)
         sysfs_remove_bin_file(&shost->shost_dev.kobj, &sysfs_ctlreg_attr);
 }
 
-
 /*
  * Dynamic FC Host Attributes Support
  */
diff --git a/drivers/scsi/lpfc/lpfc_hw4.h b/drivers/scsi/lpfc/lpfc_hw4.h
index 608f9415fb08..aea00f8be9ac 100644
--- a/drivers/scsi/lpfc/lpfc_hw4.h
+++ b/drivers/scsi/lpfc/lpfc_hw4.h
@@ -2865,6 +2865,9 @@ struct lpfc_sli4_parameters {
         uint32_t word17;
         uint32_t word18;
         uint32_t word19;
+#define cfg_ext_embed_cb_SHIFT                  0
+#define cfg_ext_embed_cb_MASK                   0x00000001
+#define cfg_ext_embed_cb_WORD                   word19
 };
 
 struct lpfc_mbx_get_sli4_parameters {
@@ -3919,6 +3922,9 @@ union lpfc_wqe {
 union lpfc_wqe128 {
         uint32_t words[32];
         struct lpfc_wqe_generic generic;
+        struct fcp_icmnd64_wqe fcp_icmd;
+        struct fcp_iread64_wqe fcp_iread;
+        struct fcp_iwrite64_wqe fcp_iwrite;
         struct xmit_seq64_wqe xmit_sequence;
         struct gen_req64_wqe gen_req;
 };
diff --git a/drivers/scsi/lpfc/lpfc_init.c b/drivers/scsi/lpfc/lpfc_init.c
index f57d02c3b6cf..f0d0852bee0d 100644
--- a/drivers/scsi/lpfc/lpfc_init.c
+++ b/drivers/scsi/lpfc/lpfc_init.c
@@ -7264,8 +7264,15 @@ lpfc_sli4_queue_create(struct lpfc_hba *phba)
                 phba->sli4_hba.fcp_cq[idx] = qdesc;
 
                 /* Create Fast Path FCP WQs */
-                qdesc = lpfc_sli4_queue_alloc(phba, phba->sli4_hba.wq_esize,
-                                              phba->sli4_hba.wq_ecount);
+                if (phba->fcp_embed_io) {
+                        qdesc = lpfc_sli4_queue_alloc(phba,
+                                                      LPFC_WQE128_SIZE,
+                                                      LPFC_WQE128_DEF_COUNT);
+                } else {
+                        qdesc = lpfc_sli4_queue_alloc(phba,
+                                                      phba->sli4_hba.wq_esize,
+                                                      phba->sli4_hba.wq_ecount);
+                }
                 if (!qdesc) {
                         lpfc_printf_log(phba, KERN_ERR, LOG_INIT,
                                         "0503 Failed allocate fast-path FCP "
@@ -9510,6 +9517,15 @@ lpfc_get_sli4_parameters(struct lpfc_hba *phba, LPFC_MBOXQ_t *mboxq)
         if (sli4_params->sge_supp_len > LPFC_MAX_SGE_SIZE)
                 sli4_params->sge_supp_len = LPFC_MAX_SGE_SIZE;
 
+        /*
+         * Issue IOs with CDB embedded in WQE to minimized the number
+         * of DMAs the firmware has to do. Setting this to 1 also forces
+         * the driver to use 128 bytes WQEs for FCP IOs.
+         */
+        if (bf_get(cfg_ext_embed_cb, mbx_sli4_parameters))
+                phba->fcp_embed_io = 1;
+        else
+                phba->fcp_embed_io = 0;
         return 0;
 }
 
diff --git a/drivers/scsi/lpfc/lpfc_sli.c b/drivers/scsi/lpfc/lpfc_sli.c
index 035105a24298..9c8368a7149a 100644
--- a/drivers/scsi/lpfc/lpfc_sli.c
+++ b/drivers/scsi/lpfc/lpfc_sli.c
@@ -4689,6 +4689,7 @@ lpfc_sli_hba_setup(struct lpfc_hba *phba)
 
                 break;
         }
+        phba->fcp_embed_io = 0; /* SLI4 FC support only */
 
         rc = lpfc_sli_config_port(phba, mode);
 
@@ -6321,10 +6322,12 @@ lpfc_sli4_hba_setup(struct lpfc_hba *phba)
 
         mqe = &mboxq->u.mqe;
         phba->sli_rev = bf_get(lpfc_mbx_rd_rev_sli_lvl, &mqe->un.read_rev);
-        if (bf_get(lpfc_mbx_rd_rev_fcoe, &mqe->un.read_rev))
+        if (bf_get(lpfc_mbx_rd_rev_fcoe, &mqe->un.read_rev)) {
                 phba->hba_flag |= HBA_FCOE_MODE;
-        else
+                phba->fcp_embed_io = 0; /* SLI4 FC support only */
+        } else {
                 phba->hba_flag &= ~HBA_FCOE_MODE;
+        }
 
         if (bf_get(lpfc_mbx_rd_rev_cee_ver, &mqe->un.read_rev) ==
                 LPFC_DCBX_CEE_MODE)
@@ -8219,12 +8222,15 @@ lpfc_sli4_iocb2wqe(struct lpfc_hba *phba, struct lpfc_iocbq *iocbq,
         else
                 command_type = ELS_COMMAND_NON_FIP;
 
+        if (phba->fcp_embed_io)
+                memset(wqe, 0, sizeof(union lpfc_wqe128));
         /* Some of the fields are in the right position already */
         memcpy(wqe, &iocbq->iocb, sizeof(union lpfc_wqe));
-        abort_tag = (uint32_t) iocbq->iotag;
-        xritag = iocbq->sli4_xritag;
         wqe->generic.wqe_com.word7 = 0; /* The ct field has moved so reset */
         wqe->generic.wqe_com.word10 = 0;
+
+        abort_tag = (uint32_t) iocbq->iotag;
+        xritag = iocbq->sli4_xritag;
         /* words0-2 bpl convert bde */
         if (iocbq->iocb.un.genreq64.bdl.bdeFlags == BUFF_TYPE_BLP_64) {
                 numBdes = iocbq->iocb.un.genreq64.bdl.bdeSize /
@@ -8373,11 +8379,9 @@ lpfc_sli4_iocb2wqe(struct lpfc_hba *phba, struct lpfc_iocbq *iocbq,
                        iocbq->iocb.ulpFCP2Rcvy);
                 bf_set(wqe_lnk, &wqe->fcp_iwrite.wqe_com, iocbq->iocb.ulpXS);
                 /* Always open the exchange */
-                bf_set(wqe_xc, &wqe->fcp_iwrite.wqe_com, 0);
                 bf_set(wqe_iod, &wqe->fcp_iwrite.wqe_com, LPFC_WQE_IOD_WRITE);
                 bf_set(wqe_lenloc, &wqe->fcp_iwrite.wqe_com,
                        LPFC_WQE_LENLOC_WORD4);
-                bf_set(wqe_ebde_cnt, &wqe->fcp_iwrite.wqe_com, 0);
                 bf_set(wqe_pu, &wqe->fcp_iwrite.wqe_com, iocbq->iocb.ulpPU);
                 bf_set(wqe_dbde, &wqe->fcp_iwrite.wqe_com, 1);
                 if (iocbq->iocb_flag & LPFC_IO_OAS) {
@@ -8388,6 +8392,35 @@ lpfc_sli4_iocb2wqe(struct lpfc_hba *phba, struct lpfc_iocbq *iocbq,
                                        (phba->cfg_XLanePriority << 1));
                         }
                 }
+                /* Note, word 10 is already initialized to 0 */
+
+                if (phba->fcp_embed_io) {
+                        struct lpfc_scsi_buf *lpfc_cmd;
+                        struct sli4_sge *sgl;
+                        union lpfc_wqe128 *wqe128;
+                        struct fcp_cmnd *fcp_cmnd;
+                        uint32_t *ptr;
+
+                        /* 128 byte wqe support here */
+                        wqe128 = (union lpfc_wqe128 *)wqe;
+
+                        lpfc_cmd = iocbq->context1;
+                        sgl = (struct sli4_sge *)lpfc_cmd->fcp_bpl;
+                        fcp_cmnd = lpfc_cmd->fcp_cmnd;
+
+                        /* Word 0-2 - FCP_CMND */
+                        wqe128->generic.bde.tus.f.bdeFlags =
+                                BUFF_TYPE_BDE_IMMED;
+                        wqe128->generic.bde.tus.f.bdeSize = sgl->sge_len;
+                        wqe128->generic.bde.addrHigh = 0;
+                        wqe128->generic.bde.addrLow =  88;  /* Word 22 */
+
+                        bf_set(wqe_wqes, &wqe128->fcp_iwrite.wqe_com, 1);
+
+                        /* Word 22-29  FCP CMND Payload */
+                        ptr = &wqe128->words[22];
+                        memcpy(ptr, fcp_cmnd, sizeof(struct fcp_cmnd));
+                }
                 break;
         case CMD_FCP_IREAD64_CR:
                 /* word3 iocb=iotag wqe=payload_offset_len */
@@ -8402,11 +8435,9 @@ lpfc_sli4_iocb2wqe(struct lpfc_hba *phba, struct lpfc_iocbq *iocbq,
                        iocbq->iocb.ulpFCP2Rcvy);
                 bf_set(wqe_lnk, &wqe->fcp_iread.wqe_com, iocbq->iocb.ulpXS);
                 /* Always open the exchange */
-                bf_set(wqe_xc, &wqe->fcp_iread.wqe_com, 0);
                 bf_set(wqe_iod, &wqe->fcp_iread.wqe_com, LPFC_WQE_IOD_READ);
                 bf_set(wqe_lenloc, &wqe->fcp_iread.wqe_com,
                        LPFC_WQE_LENLOC_WORD4);
-                bf_set(wqe_ebde_cnt, &wqe->fcp_iread.wqe_com, 0);
                 bf_set(wqe_pu, &wqe->fcp_iread.wqe_com, iocbq->iocb.ulpPU);
                 bf_set(wqe_dbde, &wqe->fcp_iread.wqe_com, 1);
                 if (iocbq->iocb_flag & LPFC_IO_OAS) {
@@ -8417,6 +8448,35 @@ lpfc_sli4_iocb2wqe(struct lpfc_hba *phba, struct lpfc_iocbq *iocbq,
                                        (phba->cfg_XLanePriority << 1));
                         }
                 }
+                /* Note, word 10 is already initialized to 0 */
+
+                if (phba->fcp_embed_io) {
+                        struct lpfc_scsi_buf *lpfc_cmd;
+                        struct sli4_sge *sgl;
+                        union lpfc_wqe128 *wqe128;
+                        struct fcp_cmnd *fcp_cmnd;
+                        uint32_t *ptr;
+
+                        /* 128 byte wqe support here */
+                        wqe128 = (union lpfc_wqe128 *)wqe;
+
+                        lpfc_cmd = iocbq->context1;
+                        sgl = (struct sli4_sge *)lpfc_cmd->fcp_bpl;
+                        fcp_cmnd = lpfc_cmd->fcp_cmnd;
+
+                        /* Word 0-2 - FCP_CMND */
+                        wqe128->generic.bde.tus.f.bdeFlags =
+                                BUFF_TYPE_BDE_IMMED;
+                        wqe128->generic.bde.tus.f.bdeSize = sgl->sge_len;
+                        wqe128->generic.bde.addrHigh = 0;
+                        wqe128->generic.bde.addrLow =  88;  /* Word 22 */
+
+                        bf_set(wqe_wqes, &wqe128->fcp_iread.wqe_com, 1);
+
+                        /* Word 22-29  FCP CMND Payload */
+                        ptr = &wqe128->words[22];
+                        memcpy(ptr, fcp_cmnd, sizeof(struct fcp_cmnd));
+                }
                 break;
         case CMD_FCP_ICMND64_CR:
                 /* word3 iocb=iotag wqe=payload_offset_len */
@@ -8428,13 +8488,11 @@ lpfc_sli4_iocb2wqe(struct lpfc_hba *phba, struct lpfc_iocbq *iocbq,
                 /* word3 iocb=IO_TAG wqe=reserved */
                 bf_set(wqe_pu, &wqe->fcp_icmd.wqe_com, 0);
                 /* Always open the exchange */
-                bf_set(wqe_xc, &wqe->fcp_icmd.wqe_com, 0);
                 bf_set(wqe_dbde, &wqe->fcp_icmd.wqe_com, 1);
                 bf_set(wqe_iod, &wqe->fcp_icmd.wqe_com, LPFC_WQE_IOD_WRITE);
                 bf_set(wqe_qosd, &wqe->fcp_icmd.wqe_com, 1);
                 bf_set(wqe_lenloc, &wqe->fcp_icmd.wqe_com,
                        LPFC_WQE_LENLOC_NONE);
-                bf_set(wqe_ebde_cnt, &wqe->fcp_icmd.wqe_com, 0);
                 bf_set(wqe_erp, &wqe->fcp_icmd.wqe_com,
                        iocbq->iocb.ulpFCP2Rcvy);
                 if (iocbq->iocb_flag & LPFC_IO_OAS) {
@@ -8445,6 +8503,35 @@ lpfc_sli4_iocb2wqe(struct lpfc_hba *phba, struct lpfc_iocbq *iocbq,
                                        (phba->cfg_XLanePriority << 1));
                         }
                 }
+                /* Note, word 10 is already initialized to 0 */
+
+                if (phba->fcp_embed_io) {
+                        struct lpfc_scsi_buf *lpfc_cmd;
+                        struct sli4_sge *sgl;
+                        union lpfc_wqe128 *wqe128;
+                        struct fcp_cmnd *fcp_cmnd;
+                        uint32_t *ptr;
+
+                        /* 128 byte wqe support here */
+                        wqe128 = (union lpfc_wqe128 *)wqe;
+
+                        lpfc_cmd = iocbq->context1;
+                        sgl = (struct sli4_sge *)lpfc_cmd->fcp_bpl;
+                        fcp_cmnd = lpfc_cmd->fcp_cmnd;
+
+                        /* Word 0-2 - FCP_CMND */
+                        wqe128->generic.bde.tus.f.bdeFlags =
+                                BUFF_TYPE_BDE_IMMED;
+                        wqe128->generic.bde.tus.f.bdeSize = sgl->sge_len;
+                        wqe128->generic.bde.addrHigh = 0;
+                        wqe128->generic.bde.addrLow =  88;  /* Word 22 */
+
+                        bf_set(wqe_wqes, &wqe128->fcp_icmd.wqe_com, 1);
+
+                        /* Word 22-29  FCP CMND Payload */
+                        ptr = &wqe128->words[22];
+                        memcpy(ptr, fcp_cmnd, sizeof(struct fcp_cmnd));
+                }
                 break;
         case CMD_GEN_REQUEST64_CR:
                 /* For this command calculate the xmit length of the
@@ -8676,12 +8763,19 @@ __lpfc_sli_issue_iocb_s4(struct lpfc_hba *phba, uint32_t ring_number,
                          struct lpfc_iocbq *piocb, uint32_t flag)
 {
         struct lpfc_sglq *sglq;
-        union lpfc_wqe wqe;
+        union lpfc_wqe *wqe;
+        union lpfc_wqe128 wqe128;
         struct lpfc_queue *wq;
         struct lpfc_sli_ring *pring = &phba->sli.ring[ring_number];
 
         lockdep_assert_held(&phba->hbalock);
 
+        /*
+         * The WQE can be either 64 or 128 bytes,
+         * so allocate space on the stack assuming the largest.
+         */
+        wqe = (union lpfc_wqe *)&wqe128;
+
         if (piocb->sli4_xritag == NO_XRI) {
                 if (piocb->iocb.ulpCommand == CMD_ABORT_XRI_CN ||
                     piocb->iocb.ulpCommand == CMD_CLOSE_XRI_CN)
@@ -8728,7 +8822,7 @@ __lpfc_sli_issue_iocb_s4(struct lpfc_hba *phba, uint32_t ring_number,
                         return IOCB_ERROR;
         }
 
-        if (lpfc_sli4_iocb2wqe(phba, piocb, &wqe))
+        if (lpfc_sli4_iocb2wqe(phba, piocb, wqe))
                 return IOCB_ERROR;
 
         if ((piocb->iocb_flag & LPFC_IO_FCP) ||
@@ -8738,12 +8832,12 @@ __lpfc_sli_issue_iocb_s4(struct lpfc_hba *phba, uint32_t ring_number,
                 } else {
                         wq = phba->sli4_hba.oas_wq;
                 }
-                if (lpfc_sli4_wq_put(wq, &wqe))
+                if (lpfc_sli4_wq_put(wq, wqe))
                         return IOCB_ERROR;
         } else {
                 if (unlikely(!phba->sli4_hba.els_wq))
                         return IOCB_ERROR;
-                if (lpfc_sli4_wq_put(phba->sli4_hba.els_wq, &wqe))
+                if (lpfc_sli4_wq_put(phba->sli4_hba.els_wq, wqe))
                         return IOCB_ERROR;
         }
         lpfc_sli_ringtxcmpl_put(phba, pring, piocb);
@@ -8758,9 +8852,9 @@ __lpfc_sli_issue_iocb_s4(struct lpfc_hba *phba, uint32_t ring_number,
  * pointer from the lpfc_hba struct.
  *
  * Return codes:
- *      IOCB_ERROR - Error
- *      IOCB_SUCCESS - Success
- *      IOCB_BUSY - Busy
+ * IOCB_ERROR - Error
+ * IOCB_SUCCESS - Success
+ * IOCB_BUSY - Busy
  **/
 int
 __lpfc_sli_issue_iocb(struct lpfc_hba *phba, uint32_t ring_number,