[PATCH v10 11/13] lpfc: vmid: Timeout implementation for vmid

Muneendra
2021-04-28T05:35:59Z

This patch implements the timeout functionality for the vmid. After the
set time period of inactivity, the vmid is deregistered from the switch.

Reviewed-by: Hannes Reinecke <hare@suse.de>
Signed-off-by: Gaurav Srivastava <gaurav.srivastava@broadcom.com>
Signed-off-by: James Smart <jsmart2021@gmail.com>

---
v10:
No change

v9:
Modified code for use of hashtable

v8:
Fixed the uninitialized variable

v7:
No change

v6:
Added Forward declarations

v5:
No change

v4:
No change

v3:
No change

v2:
Ported the patch on top of 5.10/scsi-queue
---
drivers/scsi/lpfc/lpfc_hbadisc.c | 105 +++++++++++++++++++++++++++++++
drivers/scsi/lpfc/lpfc_init.c | 40 ++++++++++++
2 files changed, 145 insertions(+)

diff --git a/drivers/scsi/lpfc/lpfc_hbadisc.c b/drivers/scsi/lpfc/lpfc_hbadisc.c
index f5a898c2c904..7011fb5c08d1 100644
--- a/drivers/scsi/lpfc/lpfc_hbadisc.c
+++ b/drivers/scsi/lpfc/lpfc_hbadisc.c
@@ -72,6 +72,7 @@ static void lpfc_disc_flush_list(struct lpfc_vport *vport);
static void lpfc_unregister_fcfi_cmpl(struct lpfc_hba *, LPFC_MBOXQ_t *);
static int lpfc_fcf_inuse(struct lpfc_hba *);
static void lpfc_mbx_cmpl_read_sparam(struct lpfc_hba *, LPFC_MBOXQ_t *);
+static void lpfc_check_inactive_vmid(struct lpfc_hba *phba);

static int
lpfc_valid_xpt_node(struct lpfc_nodelist *ndlp)
@@ -236,6 +237,110 @@ lpfc_dev_loss_tmo_callbk(struct fc_rport *rport)
return;
}

+/**
+ * lpfc_check_inactive_vmid_one - VMID inactivity checker for a vport
+ * @vport: Pointer to vport context object.
+ *
+ * This function checks for idle vmid entries related to a particular vport. If
+ * found unused/idle, it frees them accordingly.
+ **/
+static void lpfc_check_inactive_vmid_one(struct lpfc_vport *vport)
+{
+ u16 keep;
+ u32 difftime = 0, r, bucket;
+ u64 *lta;
+ int cpu;
+ struct lpfc_vmid *vmp;
+
+ write_lock(&vport->vmid_lock);
+
+ if (!vport->cur_vmid_cnt)
+ goto out;
+
+ /* iterate through the table */
+ hash_for_each(vport->hash_table, bucket, vmp, hnode) {
+ keep = 0;
+ if (vmp->flag & LPFC_VMID_REGISTERED) {
+ /* check if the particular vmid is in use */
+ /* for all available per cpu variable */
+ for_each_possible_cpu(cpu) {
+ /* if last access time is less than timeout */
+ lta = per_cpu_ptr(vmp->last_io_time, cpu);
+ if (!lta)
+ continue;
+ difftime = (jiffies) - (*lta);
+ if ((vport->vmid_inactivity_timeout *
+ JIFFIES_PER_HR) > difftime) {
+ keep = 1;
+ break;
+ }
+ }
+
+ /* if none of the cpus have been used by the vm, */
+ /* remove the entry if already registered */
+ if (!keep) {
+ /* mark the entry for deregistration */
+ vmp->flag = LPFC_VMID_DE_REGISTER;
+ write_unlock(&vport->vmid_lock);
+ if (vport->vmid_priority_tagging)
+ r = lpfc_vmid_uvem(vport, vmp, false);
+ else
+ r = lpfc_vmid_cmd(vport,
+ SLI_CTAS_DAPP_IDENT,
+ vmp);
+
+ /* decrement number of active vms and mark */
+ /* entry in slot as free */
+ write_lock(&vport->vmid_lock);
+ if (!r) {
+ struct lpfc_vmid *ht = vmp;
+
+ vport->cur_vmid_cnt--;
+ ht->flag = LPFC_VMID_SLOT_FREE;
+ free_percpu(ht->last_io_time);
+ ht->last_io_time = NULL;
+ hash_del(&ht->hnode);
+ }
+ }
+ }
+ }
+ out:
+ write_unlock(&vport->vmid_lock);
+}
+
+/**
+ * lpfc_check_inactive_vmid - VMID inactivity checker
+ * @phba: Pointer to hba context object.
+ *
+ * This function is called from the worker thread to determine if an entry in
+ * the vmid table can be released since there was no IO activity seen from that
+ * particular VM for the specified time. When this happens, the entry in the
+ * table is released and also the resources on the switch cleared.
+ **/
+
+static void lpfc_check_inactive_vmid(struct lpfc_hba *phba)
+{
+ struct lpfc_vport *vport;
+ struct lpfc_vport **vports;
+ int i;
+
+ vports = lpfc_create_vport_work_array(phba);
+ if (!vports)
+ return;
+
+ for (i = 0; i <= phba->max_vports; i++) {
+ if ((!vports[i]) && (i == 0))
+ vport = phba->pport;
+ else
+ vport = vports[i];
+ if (!vport)
+ break;
+
+ lpfc_check_inactive_vmid_one(vport);
+ }
+ lpfc_destroy_vport_work_array(phba, vports);
+}
+
/**
* lpfc_dev_loss_tmo_handler - Remote node devloss timeout handler
* @ndlp: Pointer to remote node object.
diff --git a/drivers/scsi/lpfc/lpfc_init.c b/drivers/scsi/lpfc/lpfc_init.c
index 3032ad094c00..69a8fe919b02 100644
--- a/drivers/scsi/lpfc/lpfc_init.c
+++ b/drivers/scsi/lpfc/lpfc_init.c
@@ -4852,6 +4852,42 @@ lpfc_sli4_fcf_redisc_wait_tmo(struct timer_list *t)
lpfc_worker_wake_up(phba);
}

+/**
+ * lpfc_vmid_poll - VMID timeout detection
+ * @ptr: Map to lpfc_hba data structure pointer.
+ *
+ * This routine is invoked when there is no IO on by a VM for the specified
+ * amount of time. When this situation is detected, the VMID has to be
+ * deregistered from the switch and all the local resources freed. The VMID
+ * will be reassigned to the VM once the IO begins.
+ **/
+static void
+lpfc_vmid_poll(struct timer_list *t)
+{
+ struct lpfc_hba *phba = from_timer(phba, t, inactive_vmid_poll);
+ u32 wake_up = 0;
+
+ /* check if there is a need to issue QFPA */
+ if (phba->pport->vmid_priority_tagging) {
+ wake_up = 1;
+ phba->pport->work_port_events |= WORKER_CHECK_VMID_ISSUE_QFPA;
+ }
+
+ /* Is the vmid inactivity timer enabled */
+ if (phba->pport->vmid_inactivity_timeout ||
+ phba->pport->load_flag & FC_DEREGISTER_ALL_APP_ID) {
+ wake_up = 1;
+ phba->pport->work_port_events |= WORKER_CHECK_INACTIVE_VMID;
+ }
+
+ if (wake_up)
+ lpfc_worker_wake_up(phba);
+
+ /* restart the timer for the next iteration */
+ mod_timer(&phba->inactive_vmid_poll, jiffies + msecs_to_jiffies(1000 *
+ LPFC_VMID_TIMER));
+}
+
/**
* lpfc_sli4_parse_latt_fault - Parse sli4 link-attention link fault code
* @phba: pointer to lpfc hba data structure.
@@ -6700,6 +6736,10 @@ lpfc_sli4_driver_resource_setup(struct lpfc_hba *phba)
phba->hbqs[LPFC_ELS_HBQ].hbq_alloc_buffer = lpfc_sli4_rb_alloc;
phba->hbqs[LPFC_ELS_HBQ].hbq_free_buffer = lpfc_sli4_rb_free;

+ /* for VMID idle timeout if VMID is enabled */
+ if (lpfc_is_vmid_enabled(phba))
+ timer_setup(&phba->inactive_vmid_poll, lpfc_vmid_poll, 0);
+
/*
* Initialize the SLI Layer to run with lpfc SLI4 HBAs.
*/
--
2.26.2