[SCSI] lpfc 8.1.1 : Add polled-mode support

- Add functionality to run in polled mode only. Includes run time
  attribute to enable mode.
- Enable runtime writable hba settings for coallescing and delay parameters

Customers have requested a mode in the driver to run strictly polled.
This is generally to support an environment where the server is extremely
loaded and is looking to reclaim some cpu cycles from adapter interrupt
handling.

This patch adds a new "poll" attribute, and the following behavior:

if value is 0 (default):
  The driver uses the normal method for i/o completion. It uses the
  firmware feature of interrupt coalesing. The firmware allows a
  minimum number of i/o completions before an interrupt, or a maximum
  time delay between interrupts.  By default, the driver sets these
  to no delay (disabled) or 1 i/o - meaning coalescing is disabled.

  Attributes were provided to change the coalescing values, but it was
  a module-load time only and global across all adapters.
  This patch allows them to be writable on a per-adapter basis.

if value is 1 :
  Interrupts are left enabled, expecting that the user has tuned the
  interrupt coalescing values. When this setting is enabled, the driver
  will attempt to service completed i/o whenever new i/o is submitted
  to the adapter. If the coalescing values are large, and the i/o
  generation rate steady, an interrupt will be avoided by servicing
  completed i/o prior to the coalescing thresholds kicking in. However,
  if the i/o completion load is high enough or i/o generation slow, the
  coalescion values will ensure that completed i/o is serviced in a timely
  fashion.

if value is 3 :
  Turns off FCP i/o interrupts altogether. The coalescing values now have
  no effect. A new attribute "poll_tmo" (default 10ms) exists to set
  the polling interval for i/o completion. When this setting is enabled,
  the driver will attempt to service completed i/o and restart the
  interval timer whenever new i/o is submitted. This behavior allows for
  servicing of completed i/o sooner than the interval timer, but ensures
  that if no i/o is being issued, then the interval timer will kick in
  to service the outstanding i/o.

Signed-off-by: James Smart <James.Smart@emulex.com>
Signed-off-by: James Bottomley <James.Bottomley@SteelEye.com>

1 files changed, 196 insertions, 21 deletions

diff --git a/drivers/scsi/lpfc/lpfc_sli.c b/drivers/scsi/lpfc/lpfc_sli.c
index e2c08c5d83fb..7b785ade8b07 100644
--- a/drivers/scsi/lpfc/lpfc_sli.c
+++ b/drivers/scsi/lpfc/lpfc_sli.c
@@ -886,6 +886,182 @@ lpfc_sli_process_sol_iocb(struct lpfc_hba * phba, struct lpfc_sli_ring * pring,
         return rc;
 }
 
+static void lpfc_sli_rsp_pointers_error(struct lpfc_hba * phba,
+                                        struct lpfc_sli_ring * pring)
+{
+        struct lpfc_pgp *pgp = &phba->slim2p->mbx.us.s2.port[pring->ringno];
+        /*
+         * Ring <ringno> handler: portRspPut <portRspPut> is bigger then
+         * rsp ring <portRspMax>
+         */
+        lpfc_printf_log(phba, KERN_ERR, LOG_SLI,
+                        "%d:0312 Ring %d handler: portRspPut %d "
+                        "is bigger then rsp ring %d\n",
+                        phba->brd_no, pring->ringno,
+                        le32_to_cpu(pgp->rspPutInx),
+                        pring->numRiocb);
+
+        phba->hba_state = LPFC_HBA_ERROR;
+
+        /*
+         * All error attention handlers are posted to
+         * worker thread
+         */
+        phba->work_ha |= HA_ERATT;
+        phba->work_hs = HS_FFER3;
+        if (phba->work_wait)
+                wake_up(phba->work_wait);
+
+        return;
+}
+
+void lpfc_sli_poll_fcp_ring(struct lpfc_hba * phba)
+{
+        struct lpfc_sli      * psli   = &phba->sli;
+        struct lpfc_sli_ring * pring = &psli->ring[LPFC_FCP_RING];
+        IOCB_t *irsp = NULL;
+        IOCB_t *entry = NULL;
+        struct lpfc_iocbq *cmdiocbq = NULL;
+        struct lpfc_iocbq rspiocbq;
+        struct lpfc_pgp *pgp;
+        uint32_t status;
+        uint32_t portRspPut, portRspMax;
+        int type;
+        uint32_t rsp_cmpl = 0;
+        void __iomem *to_slim;
+        uint32_t ha_copy;
+
+        pring->stats.iocb_event++;
+
+        /* The driver assumes SLI-2 mode */
+        pgp =  &phba->slim2p->mbx.us.s2.port[pring->ringno];
+
+        /*
+         * The next available response entry should never exceed the maximum
+         * entries.  If it does, treat it as an adapter hardware error.
+         */
+        portRspMax = pring->numRiocb;
+        portRspPut = le32_to_cpu(pgp->rspPutInx);
+        if (unlikely(portRspPut >= portRspMax)) {
+                lpfc_sli_rsp_pointers_error(phba, pring);
+                return;
+        }
+
+        rmb();
+        while (pring->rspidx != portRspPut) {
+
+                entry = IOCB_ENTRY(pring->rspringaddr, pring->rspidx);
+
+                if (++pring->rspidx >= portRspMax)
+                        pring->rspidx = 0;
+
+                lpfc_sli_pcimem_bcopy((uint32_t *) entry,
+                                      (uint32_t *) &rspiocbq.iocb,
+                                      sizeof (IOCB_t));
+                irsp = &rspiocbq.iocb;
+                type = lpfc_sli_iocb_cmd_type(irsp->ulpCommand & CMD_IOCB_MASK);
+                pring->stats.iocb_rsp++;
+                rsp_cmpl++;
+
+                if (unlikely(irsp->ulpStatus)) {
+                        /* Rsp ring <ringno> error: IOCB */
+                        lpfc_printf_log(phba, KERN_WARNING, LOG_SLI,
+                                        "%d:0326 Rsp Ring %d error: IOCB Data: "
+                                        "x%x x%x x%x x%x x%x x%x x%x x%x\n",
+                                        phba->brd_no, pring->ringno,
+                                        irsp->un.ulpWord[0],
+                                        irsp->un.ulpWord[1],
+                                        irsp->un.ulpWord[2],
+                                        irsp->un.ulpWord[3],
+                                        irsp->un.ulpWord[4],
+                                        irsp->un.ulpWord[5],
+                                        *(((uint32_t *) irsp) + 6),
+                                        *(((uint32_t *) irsp) + 7));
+                }
+
+                switch (type) {
+                case LPFC_ABORT_IOCB:
+                case LPFC_SOL_IOCB:
+                        /*
+                         * Idle exchange closed via ABTS from port.  No iocb
+                         * resources need to be recovered.
+                         */
+                        if (unlikely(irsp->ulpCommand == CMD_XRI_ABORTED_CX)) {
+                                printk(KERN_INFO "%s: IOCB cmd 0x%x processed."
+                                       " Skipping completion\n", __FUNCTION__,
+                                       irsp->ulpCommand);
+                                break;
+                        }
+
+                        cmdiocbq = lpfc_sli_iocbq_lookup(phba, pring,
+                                                         &rspiocbq);
+                        if ((cmdiocbq) && (cmdiocbq->iocb_cmpl)) {
+                                (cmdiocbq->iocb_cmpl)(phba, cmdiocbq,
+                                                      &rspiocbq);
+                        }
+                        break;
+                default:
+                        if (irsp->ulpCommand == CMD_ADAPTER_MSG) {
+                                char adaptermsg[LPFC_MAX_ADPTMSG];
+                                memset(adaptermsg, 0, LPFC_MAX_ADPTMSG);
+                                memcpy(&adaptermsg[0], (uint8_t *) irsp,
+                                       MAX_MSG_DATA);
+                                dev_warn(&((phba->pcidev)->dev), "lpfc%d: %s",
+                                         phba->brd_no, adaptermsg);
+                        } else {
+                                /* Unknown IOCB command */
+                                lpfc_printf_log(phba, KERN_ERR, LOG_SLI,
+                                                "%d:0321 Unknown IOCB command "
+                                                "Data: x%x, x%x x%x x%x x%x\n",
+                                                phba->brd_no, type,
+                                                irsp->ulpCommand,
+                                                irsp->ulpStatus,
+                                                irsp->ulpIoTag,
+                                                irsp->ulpContext);
+                        }
+                        break;
+                }
+
+                /*
+                 * The response IOCB has been processed.  Update the ring
+                 * pointer in SLIM.  If the port response put pointer has not
+                 * been updated, sync the pgp->rspPutInx and fetch the new port
+                 * response put pointer.
+                 */
+                to_slim = phba->MBslimaddr +
+                        (SLIMOFF + (pring->ringno * 2) + 1) * 4;
+                writeb(pring->rspidx, to_slim);
+
+                if (pring->rspidx == portRspPut)
+                        portRspPut = le32_to_cpu(pgp->rspPutInx);
+        }
+
+        ha_copy = readl(phba->HAregaddr);
+        ha_copy >>= (LPFC_FCP_RING * 4);
+
+        if ((rsp_cmpl > 0) && (ha_copy & HA_R0RE_REQ)) {
+                pring->stats.iocb_rsp_full++;
+                status = ((CA_R0ATT | CA_R0RE_RSP) << (LPFC_FCP_RING * 4));
+                writel(status, phba->CAregaddr);
+                readl(phba->CAregaddr);
+        }
+        if ((ha_copy & HA_R0CE_RSP) &&
+            (pring->flag & LPFC_CALL_RING_AVAILABLE)) {
+                pring->flag &= ~LPFC_CALL_RING_AVAILABLE;
+                pring->stats.iocb_cmd_empty++;
+
+                /* Force update of the local copy of cmdGetInx */
+                pring->local_getidx = le32_to_cpu(pgp->cmdGetInx);
+                lpfc_sli_resume_iocb(phba, pring);
+
+                if ((pring->lpfc_sli_cmd_available))
+                        (pring->lpfc_sli_cmd_available) (phba, pring);
+
+        }
+
+        return;
+}
+
 /*
  * This routine presumes LPFC_FCP_RING handling and doesn't bother
  * to check it explicitly.
@@ -917,24 +1093,7 @@ lpfc_sli_handle_fast_ring_event(struct lpfc_hba * phba,
         portRspMax = pring->numRiocb;
         portRspPut = le32_to_cpu(pgp->rspPutInx);
         if (unlikely(portRspPut >= portRspMax)) {
-                /*
-                 * Ring <ringno> handler: portRspPut <portRspPut> is bigger then
-                 * rsp ring <portRspMax>
-                 */
-                lpfc_printf_log(phba, KERN_ERR, LOG_SLI,
-                                "%d:0312 Ring %d handler: portRspPut %d "
-                                "is bigger then rsp ring %d\n",
-                                phba->brd_no, pring->ringno, portRspPut,
-                                portRspMax);
-
-                phba->hba_state = LPFC_HBA_ERROR;
-
-                /* All error attention handlers are posted to worker thread */
-                phba->work_ha |= HA_ERATT;
-                phba->work_hs = HS_FFER3;
-                if (phba->work_wait)
-                        wake_up(phba->work_wait);
-
+                lpfc_sli_rsp_pointers_error(phba, pring);
                 spin_unlock_irqrestore(phba->host->host_lock, iflag);
                 return 1;
         }
@@ -947,6 +1106,10 @@ lpfc_sli_handle_fast_ring_event(struct lpfc_hba * phba,
                  * network byte order and pci byte orders are different.
                  */
                 entry = IOCB_ENTRY(pring->rspringaddr, pring->rspidx);
+
+                if (++pring->rspidx >= portRspMax)
+                        pring->rspidx = 0;
+
                 lpfc_sli_pcimem_bcopy((uint32_t *) entry,
                                       (uint32_t *) &rspiocbq.iocb,
                                       sizeof (IOCB_t));
@@ -1020,9 +1183,6 @@ lpfc_sli_handle_fast_ring_event(struct lpfc_hba * phba,
                  * been updated, sync the pgp->rspPutInx and fetch the new port
                  * response put pointer.
                  */
-                if (++pring->rspidx >= portRspMax)
-                        pring->rspidx = 0;
-
                 to_slim = phba->MBslimaddr +
                         (SLIMOFF + (pring->ringno * 2) + 1) * 4;
                 writel(pring->rspidx, to_slim);
@@ -2615,6 +2775,7 @@ lpfc_sli_issue_iocb_wait(struct lpfc_hba * phba,
         DECLARE_WAIT_QUEUE_HEAD(done_q);
         long timeleft, timeout_req = 0;
         int retval = IOCB_SUCCESS;
+        uint32_t creg_val;
 
         /*
          * If the caller has provided a response iocbq buffer, then context2
@@ -2630,6 +2791,13 @@ lpfc_sli_issue_iocb_wait(struct lpfc_hba * phba,
         piocb->context_un.wait_queue = &done_q;
         piocb->iocb_flag &= ~LPFC_IO_WAKE;
 
+        if (phba->cfg_poll & DISABLE_FCP_RING_INT) {
+                creg_val = readl(phba->HCregaddr);
+                creg_val |= (HC_R0INT_ENA << LPFC_FCP_RING);
+                writel(creg_val, phba->HCregaddr);
+                readl(phba->HCregaddr); /* flush */
+        }
+
         retval = lpfc_sli_issue_iocb(phba, pring, piocb, 0);
         if (retval == IOCB_SUCCESS) {
                 timeout_req = timeout * HZ;
@@ -2663,6 +2831,13 @@ lpfc_sli_issue_iocb_wait(struct lpfc_hba * phba,
                 retval = IOCB_ERROR;
         }
 
+        if (phba->cfg_poll & DISABLE_FCP_RING_INT) {
+                creg_val = readl(phba->HCregaddr);
+                creg_val &= ~(HC_R0INT_ENA << LPFC_FCP_RING);
+                writel(creg_val, phba->HCregaddr);
+                readl(phba->HCregaddr); /* flush */
+        }
+
         if (prspiocbq)
                 piocb->context2 = NULL;