[SCSI] lpfc 8.3.32: Fix ability to change FCP EQ delay multiplier

Fix fcp_imax module parameter to dynamically change FCP EQ delay multiplier

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

1 files changed, 85 insertions, 8 deletions

diff --git a/drivers/scsi/lpfc/lpfc_attr.c b/drivers/scsi/lpfc/lpfc_attr.c
index 5eb2bc116183..adef5bb2100e 100644
--- a/drivers/scsi/lpfc/lpfc_attr.c
+++ b/drivers/scsi/lpfc/lpfc_attr.c
@@ -3617,6 +3617,91 @@ lpfc_sriov_nr_virtfn_init(struct lpfc_hba *phba, int val)
 static DEVICE_ATTR(lpfc_sriov_nr_virtfn, S_IRUGO | S_IWUSR,
 		   lpfc_sriov_nr_virtfn_show, lpfc_sriov_nr_virtfn_store);
 
+/**
+ * lpfc_fcp_imax_store
+ *
+ * @dev: class device that is converted into a Scsi_host.
+ * @attr: device attribute, not used.
+ * @buf: string with the number of fast-path FCP interrupts per second.
+ * @count: unused variable.
+ *
+ * Description:
+ * If val is in a valid range [636,651042], then set the adapter's
+ * maximum number of fast-path FCP interrupts per second.
+ *
+ * Returns:
+ * length of the buf on success if val is in range the intended mode
+ * is supported.
+ * -EINVAL if val out of range or intended mode is not supported.
+ **/
+static ssize_t
+lpfc_fcp_imax_store(struct device *dev, struct device_attribute *attr,
+			 const char *buf, size_t count)
+{
+	struct Scsi_Host *shost = class_to_shost(dev);
+	struct lpfc_vport *vport = (struct lpfc_vport *)shost->hostdata;
+	struct lpfc_hba *phba = vport->phba;
+	int val = 0, i;
+
+	/* 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)
+		return -EINVAL;
+
+	phba->cfg_fcp_imax = (uint32_t)val;
+	for (i = 0; i < phba->cfg_fcp_eq_count; i += LPFC_MAX_EQ_DELAY)
+		lpfc_modify_fcp_eq_delay(phba, i);
+
+	return strlen(buf);
+}
+
+/*
+# lpfc_fcp_imax: The maximum number of fast-path FCP interrupts per second
+#
+# Value range is [636,651042]. Default value is 10000.
+*/
+static int lpfc_fcp_imax = LPFC_FP_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");
+lpfc_param_show(fcp_imax)
+
+/**
+ * lpfc_fcp_imax_init - Set the initial sr-iov virtual function enable
+ * @phba: lpfc_hba pointer.
+ * @val: link speed value.
+ *
+ * Description:
+ * If val is in a valid range [636,651042], then initialize the adapter's
+ * maximum number of fast-path FCP interrupts per second.
+ *
+ * Returns:
+ * zero if val saved.
+ * -EINVAL val out of range
+ **/
+static int
+lpfc_fcp_imax_init(struct lpfc_hba *phba, int val)
+{
+	if (val >= LPFC_MIM_IMAX && val <= LPFC_DMULT_CONST) {
+		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;
+
+	return 0;
+}
+
+static DEVICE_ATTR(lpfc_fcp_imax, S_IRUGO | S_IWUSR,
+		   lpfc_fcp_imax_show, lpfc_fcp_imax_store);
+
 /*
 # lpfc_fcp_class:  Determines FC class to use for the FCP protocol.
 # Value range is [2,3]. Default value is 3.
@@ -3758,14 +3843,6 @@ LPFC_ATTR_R(use_msi, 2, 0, 2, "Use Message Signaled Interrupts (1) or "
 	    "MSI-X (2), if possible");
 
 /*
-# lpfc_fcp_imax: Set the maximum number of fast-path FCP interrupts per second
-#
-# Value range is [636,651042]. Default value is 10000.
-*/
-LPFC_ATTR_R(fcp_imax, LPFC_FP_DEF_IMAX, LPFC_MIM_IMAX, LPFC_DMULT_CONST,
-	    "Set the maximum number of fast-path FCP interrupts per second");
-
-/*
 # lpfc_fcp_wq_count: Set the number of fast-path FCP work queues
 #
 # Value range is [1,31]. Default value is 4.