scsi: lpfc: Fix kdump hang on PPC

When the kdump kernel shuts down lpfc calls flush_work_queue on an
interrupt to schedule the cq handler. When there is only one CPU active on
the kdump kernel, it is possible for the work_on to get scheduled on a
non-active CPU causing it to never be scheduled.

When in the kdump environment, per-CPU affinity of cq's to cpus is not
necessary. In those cases, use a general queue_work rather than a
queue_work_on().

Link: https://lore.kernel.org/r/20200630215001.70793-9-jsmart2021@gmail.com
Signed-off-by: Dick Kennedy <dick.kennedy@broadcom.com>
Signed-off-by: James Smart <jsmart2021@gmail.com>
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>

diff --git a/drivers/scsi/lpfc/lpfc_sli.c b/drivers/scsi/lpfc/lpfc_sli.c
index 88e78ff..4fd106c 100644 (file)
--- a/drivers/scsi/lpfc/lpfc_sli.c
+++ b/drivers/scsi/lpfc/lpfc_sli.c
@@ -35,6 +35,7 @@
 #include <scsi/scsi_transport_fc.h>
 #include <scsi/fc/fc_fs.h>
 #include <linux/aer.h>
+#include <linux/crash_dump.h>
 #ifdef CONFIG_X86
 #include <asm/set_memory.h>
 #endif
@@ -13702,6 +13703,7 @@ lpfc_sli4_sp_handle_eqe(struct lpfc_hba *phba, struct lpfc_eqe *eqe,
 {
        struct lpfc_queue *cq = NULL, *childq;
        uint16_t cqid;
+       int ret = 0;
 
        /* Get the reference to the corresponding CQ */
        cqid = bf_get_le32(lpfc_eqe_resource_id, eqe);
@@ -13723,7 +13725,12 @@ lpfc_sli4_sp_handle_eqe(struct lpfc_hba *phba, struct lpfc_eqe *eqe,
        /* Save EQ associated with this CQ */
        cq->assoc_qp = speq;
 
-       if (!queue_work_on(cq->chann, phba->wq, &cq->spwork))
+       if (is_kdump_kernel())
+               ret = queue_work(phba->wq, &cq->spwork);
+       else
+               ret = queue_work_on(cq->chann, phba->wq, &cq->spwork);
+
+       if (!ret)
                lpfc_printf_log(phba, KERN_ERR, LOG_SLI,
                                "0390 Cannot schedule soft IRQ "
                                "for CQ eqcqid=%d, cqid=%d on CPU %d\n",
@@ -13836,6 +13843,7 @@ __lpfc_sli4_sp_process_cq(struct lpfc_queue *cq)
        struct lpfc_hba *phba = cq->phba;
        unsigned long delay;
        bool workposted = false;
+       int ret = 0;
 
        /* Process and rearm the CQ */
        switch (cq->type) {
@@ -13862,8 +13870,13 @@ __lpfc_sli4_sp_process_cq(struct lpfc_queue *cq)
        }
 
        if (delay) {
-               if (!queue_delayed_work_on(cq->chann, phba->wq,
-                                          &cq->sched_spwork, delay))
+               if (is_kdump_kernel())
+                       ret = queue_delayed_work(phba->wq, &cq->sched_spwork,
+                                               delay);
+               else
+                       ret = queue_delayed_work_on(cq->chann, phba->wq,
+                                               &cq->sched_spwork, delay);
+               if (!ret)
                        lpfc_printf_log(phba, KERN_ERR, LOG_SLI,
                                "0394 Cannot schedule soft IRQ "
                                "for cqid=%d on CPU %d\n",
@@ -14215,6 +14228,7 @@ lpfc_sli4_hba_handle_eqe(struct lpfc_hba *phba, struct lpfc_queue *eq,
        struct lpfc_queue *cq = NULL;
        uint32_t qidx = eq->hdwq;
        uint16_t cqid, id;
+       int ret = 0;
 
        if (unlikely(bf_get_le32(lpfc_eqe_major_code, eqe) != 0)) {
                lpfc_printf_log(phba, KERN_ERR, LOG_SLI,
@@ -14274,7 +14288,11 @@ work_cq:
        else
                cq->isr_timestamp = 0;
 #endif
-       if (!queue_work_on(cq->chann, phba->wq, &cq->irqwork))
+       if (is_kdump_kernel())
+               ret = queue_work(phba->wq, &cq->irqwork);
+       else
+               ret = queue_work_on(cq->chann, phba->wq, &cq->irqwork);
+       if (!ret)
                lpfc_printf_log(phba, KERN_ERR, LOG_SLI,
                                "0363 Cannot schedule soft IRQ "
                                "for CQ eqcqid=%d, cqid=%d on CPU %d\n",
@@ -14302,14 +14320,20 @@ __lpfc_sli4_hba_process_cq(struct lpfc_queue *cq)
        struct lpfc_hba *phba = cq->phba;
        unsigned long delay;
        bool workposted = false;
+       int ret = 0;
 
        /* process and rearm the CQ */
        workposted |= __lpfc_sli4_process_cq(phba, cq, lpfc_sli4_fp_handle_cqe,
                                             &delay);
 
        if (delay) {
-               if (!queue_delayed_work_on(cq->chann, phba->wq,
-                                          &cq->sched_irqwork, delay))
+               if (is_kdump_kernel())
+                       ret = queue_delayed_work(phba->wq, &cq->sched_irqwork,
+                                               delay);
+               else
+                       ret = queue_delayed_work_on(cq->chann, phba->wq,
+                                               &cq->sched_irqwork, delay);
+               if (!ret)
                        lpfc_printf_log(phba, KERN_ERR, LOG_SLI,
                                "0367 Cannot schedule soft IRQ "
                                "for cqid=%d on CPU %d\n",