From bf8dae83fea151ebd74492740733e2ed62dc9f51 Mon Sep 17 00:00:00 2001
From: James Smart <james.smart@emulex.com>
Date: Fri, 3 Aug 2012 12:36:24 -0400
Subject: [SCSI] lpfc 8.3.33: Allow per-hba interrupt rate tuning

Signed-off-by: James Smart <james.smart@emulex.com>
Signed-off-by: James Bottomley <JBottomley@Parallels.com>

diff --git a/drivers/scsi/lpfc/lpfc_attr.c b/drivers/scsi/lpfc/lpfc_attr.c
index 2910208..f7c5531 100644
--- a/drivers/scsi/lpfc/lpfc_attr.c
+++ b/drivers/scsi/lpfc/lpfc_attr.c
@@ -3643,14 +3643,21 @@ lpfc_fcp_imax_store(struct device *dev, struct device_attribute *attr,
 	struct lpfc_hba *phba = vport->phba;
 	int val = 0, i;
 
+	/* fcp_imax is only valid for SLI4 */
+	if (phba->sli_rev != LPFC_SLI_REV4)
+		return -EINVAL;
+
 	/* Sanity check on user data */
 	if (!isdigit(buf[0]))
 		return -EINVAL;
 	if (sscanf(buf, "%i", &val) != 1)
 		return -EINVAL;
 
-	/* Value range is [636,651042] */
-	if (val < LPFC_MIM_IMAX || val > LPFC_DMULT_CONST)
+	/*
+	 * Value range for the HBA is [5000,5000000]
+	 * The value for each EQ depends on how many EQs are configured.
+	 */
+	if (val < LPFC_MIN_IMAX || val > LPFC_MAX_IMAX)
 		return -EINVAL;
 
 	phba->cfg_fcp_imax = (uint32_t)val;
@@ -3662,13 +3669,14 @@ lpfc_fcp_imax_store(struct device *dev, struct device_attribute *attr,
 
 /*
 # lpfc_fcp_imax: The maximum number of fast-path FCP interrupts per second
+# for the HBA.
 #
-# Value range is [636,651042]. Default value is 10000.
+# Value range is [5,000 to 5,000,000]. Default value is 50,000.
 */
-static int lpfc_fcp_imax = LPFC_FP_DEF_IMAX;
+static int lpfc_fcp_imax = LPFC_DEF_IMAX;
 module_param(lpfc_fcp_imax, int, S_IRUGO|S_IWUSR);
 MODULE_PARM_DESC(lpfc_fcp_imax,
-	    "Set the maximum number of fast-path FCP interrupts per second");
+	    "Set the maximum number of FCP interrupts per second per HBA");
 lpfc_param_show(fcp_imax)
 
 /**
@@ -3687,14 +3695,19 @@ lpfc_param_show(fcp_imax)
 static int
 lpfc_fcp_imax_init(struct lpfc_hba *phba, int val)
 {
-	if (val >= LPFC_MIM_IMAX && val <= LPFC_DMULT_CONST) {
+	if (phba->sli_rev != LPFC_SLI_REV4) {
+		phba->cfg_fcp_imax = 0;
+		return 0;
+	}
+
+	if (val >= LPFC_MIN_IMAX && val <= LPFC_MAX_IMAX) {
 		phba->cfg_fcp_imax = val;
 		return 0;
 	}
 
 	lpfc_printf_log(phba, KERN_ERR, LOG_INIT,
 			"3016 fcp_imax: %d out of range, using default\n", val);
-	phba->cfg_fcp_imax = LPFC_FP_DEF_IMAX;
+	phba->cfg_fcp_imax = LPFC_DEF_IMAX;
 
 	return 0;
 }
diff --git a/drivers/scsi/lpfc/lpfc_hw4.h b/drivers/scsi/lpfc/lpfc_hw4.h
index 9f5c93c..821262d 100644
--- a/drivers/scsi/lpfc/lpfc_hw4.h
+++ b/drivers/scsi/lpfc/lpfc_hw4.h
@@ -189,9 +189,11 @@ struct lpfc_sli_intf {
 
 /* Delay Multiplier constant */
 #define LPFC_DMULT_CONST       651042
-#define LPFC_MIM_IMAX          636
-#define LPFC_FP_DEF_IMAX       10000
-#define LPFC_SP_DEF_IMAX       10000
+
+/* Configuration of Interrupts / sec for entire HBA port */
+#define LPFC_MIN_IMAX          5000
+#define LPFC_MAX_IMAX          5000000
+#define LPFC_DEF_IMAX          50000
 
 /* PORT_CAPABILITIES constants. */
 #define LPFC_MAX_SUPPORTED_PAGES	8
diff --git a/drivers/scsi/lpfc/lpfc_init.c b/drivers/scsi/lpfc/lpfc_init.c
index 164aa87..3dad5ff 100644
--- a/drivers/scsi/lpfc/lpfc_init.c
+++ b/drivers/scsi/lpfc/lpfc_init.c
@@ -6927,7 +6927,7 @@ lpfc_sli4_queue_setup(struct lpfc_hba *phba)
 			goto out_destroy_hba_eq;
 		}
 		rc = lpfc_eq_create(phba, phba->sli4_hba.hba_eq[fcp_eqidx],
-				    phba->cfg_fcp_imax);
+			 (phba->cfg_fcp_imax / phba->cfg_fcp_io_channel));
 		if (rc) {
 			lpfc_printf_log(phba, KERN_ERR, LOG_INIT,
 					"0523 Failed setup of fast-path EQ "
diff --git a/drivers/scsi/lpfc/lpfc_sli.c b/drivers/scsi/lpfc/lpfc_sli.c
index 8cbbd81..0d5dab3 100644
--- a/drivers/scsi/lpfc/lpfc_sli.c
+++ b/drivers/scsi/lpfc/lpfc_sli.c
@@ -12079,7 +12079,8 @@ lpfc_modify_fcp_eq_delay(struct lpfc_hba *phba, uint16_t startq)
 	eq_delay = &mbox->u.mqe.un.eq_delay;
 
 	/* Calculate delay multiper from maximum interrupt per second */
-	dmult = LPFC_DMULT_CONST/phba->cfg_fcp_imax - 1;
+	dmult = phba->cfg_fcp_imax / phba->cfg_fcp_io_channel;
+	dmult = LPFC_DMULT_CONST/dmult - 1;
 
 	cnt = 0;
 	for (fcp_eqidx = startq; fcp_eqidx < phba->cfg_fcp_io_channel;
-- 
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