scsi: qla2xxx: Fix firmware resource tracking

commit e370b64c7db96384a0886a09a9d80406e4c663d7 upstream.

The storage was not draining I/Os and the work load was not spread out
across different CPUs evenly. This led to firmware resource counters
getting overrun on the busy CPU. This overrun prevented error recovery from
happening in a timely manner.

By switching the counter to atomic, it allows the count to be little more
accurate to prevent the overrun.

Cc: stable@vger.kernel.org
Fixes: da7c21b72aa8 ("scsi: qla2xxx: Fix command flush during TMF")
Signed-off-by: Quinn Tran <qutran@marvell.com>
Signed-off-by: Nilesh Javali <njavali@marvell.com>
Link: https://lore.kernel.org/r/20230821130045.34850-4-njavali@marvell.com
Reviewed-by: Himanshu Madhani <himanshu.madhani@oracle.com>
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

diff --git a/drivers/scsi/qla2xxx/qla_def.h b/drivers/scsi/qla2xxx/qla_def.h
index 66f66bb777a0db00534f5cc63c472359add5db7b..d70c2f4ba718e0d4f3babf8e5629df0596aca4c9 100644 (file)
--- a/drivers/scsi/qla2xxx/qla_def.h
+++ b/drivers/scsi/qla2xxx/qla_def.h
@@ -3726,6 +3726,16 @@ struct qla_fw_resources {
        u16 pad;
 };
 
+struct qla_fw_res {
+       u16      iocb_total;
+       u16      iocb_limit;
+       atomic_t iocb_used;
+
+       u16      exch_total;
+       u16      exch_limit;
+       atomic_t exch_used;
+};
+
 #define QLA_IOCB_PCT_LIMIT 95
 
 /*Queue pair data structure */
@@ -4768,6 +4778,7 @@ struct qla_hw_data {
        spinlock_t sadb_lock;   /* protects list */
        struct els_reject elsrej;
        u8 edif_post_stop_cnt_down;
+       struct qla_fw_res fwres ____cacheline_aligned;
 };
 
 #define RX_ELS_SIZE (roundup(sizeof(struct enode) + ELS_MAX_PAYLOAD, SMP_CACHE_BYTES))

diff --git a/drivers/scsi/qla2xxx/qla_dfs.c b/drivers/scsi/qla2xxx/qla_dfs.c
index 8f6f56c9584ce44e2af3254016327e367c0249b9..aa9d69e5274d8284016f08ff049ba9f63534c075 100644 (file)
--- a/drivers/scsi/qla2xxx/qla_dfs.c
+++ b/drivers/scsi/qla2xxx/qla_dfs.c
@@ -276,6 +276,16 @@ qla_dfs_fw_resource_cnt_show(struct seq_file *s, void *unused)
 
                seq_printf(s, "estimate exchange used[%d] high water limit [%d] n",
                           exch_used, ha->base_qpair->fwres.exch_limit);
+
+               if (ql2xenforce_iocb_limit == 2) {
+                       iocbs_used = atomic_read(&ha->fwres.iocb_used);
+                       exch_used  = atomic_read(&ha->fwres.exch_used);
+                       seq_printf(s, "        estimate iocb2 used [%d] high water limit [%d]\n",
+                                       iocbs_used, ha->fwres.iocb_limit);
+
+                       seq_printf(s, "        estimate exchange2 used[%d] high water limit [%d] \n",
+                                       exch_used, ha->fwres.exch_limit);
+               }
        }
 
        return 0;

diff --git a/drivers/scsi/qla2xxx/qla_init.c b/drivers/scsi/qla2xxx/qla_init.c
index 42de404fadae80028784f260c4518cf4ea8cce48..1a2ceef92bf07cbc5569f797b98f0da4fba48438 100644 (file)
--- a/drivers/scsi/qla2xxx/qla_init.c
+++ b/drivers/scsi/qla2xxx/qla_init.c
@@ -4218,6 +4218,14 @@ void qla_init_iocb_limit(scsi_qla_host_t *vha)
                        ha->queue_pair_map[i]->fwres.exch_used = 0;
                }
        }
+
+       ha->fwres.iocb_total = ha->orig_fw_iocb_count;
+       ha->fwres.iocb_limit = (ha->orig_fw_iocb_count * QLA_IOCB_PCT_LIMIT) / 100;
+       ha->fwres.exch_total = ha->orig_fw_xcb_count;
+       ha->fwres.exch_limit = (ha->orig_fw_xcb_count * QLA_IOCB_PCT_LIMIT) / 100;
+
+       atomic_set(&ha->fwres.iocb_used, 0);
+       atomic_set(&ha->fwres.exch_used, 0);
 }
 
 void qla_adjust_iocb_limit(scsi_qla_host_t *vha)

diff --git a/drivers/scsi/qla2xxx/qla_inline.h b/drivers/scsi/qla2xxx/qla_inline.h
index a034699e58ae9eb17e3999b238fedfe854518567..a7b5d1114682716e99104b7f905a49004b1967b7 100644 (file)
--- a/drivers/scsi/qla2xxx/qla_inline.h
+++ b/drivers/scsi/qla2xxx/qla_inline.h
@@ -386,6 +386,7 @@ enum {
        RESOURCE_IOCB = BIT_0,
        RESOURCE_EXCH = BIT_1,  /* exchange */
        RESOURCE_FORCE = BIT_2,
+       RESOURCE_HA = BIT_3,
 };
 
 static inline int
@@ -393,7 +394,7 @@ qla_get_fw_resources(struct qla_qpair *qp, struct iocb_resource *iores)
 {
        u16 iocbs_used, i;
        u16 exch_used;
-       struct qla_hw_data *ha = qp->vha->hw;
+       struct qla_hw_data *ha = qp->hw;
 
        if (!ql2xenforce_iocb_limit) {
                iores->res_type = RESOURCE_NONE;
@@ -428,15 +429,69 @@ qla_get_fw_resources(struct qla_qpair *qp, struct iocb_resource *iores)
                        return -ENOSPC;
                }
        }
+
+       if (ql2xenforce_iocb_limit == 2) {
+               if ((iores->iocb_cnt + atomic_read(&ha->fwres.iocb_used)) >=
+                   ha->fwres.iocb_limit) {
+                       iores->res_type = RESOURCE_NONE;
+                       return -ENOSPC;
+               }
+
+               if (iores->res_type & RESOURCE_EXCH) {
+                       if ((iores->exch_cnt + atomic_read(&ha->fwres.exch_used)) >=
+                           ha->fwres.exch_limit) {
+                               iores->res_type = RESOURCE_NONE;
+                               return -ENOSPC;
+                       }
+               }
+       }
+
 force:
        qp->fwres.iocbs_used += iores->iocb_cnt;
        qp->fwres.exch_used += iores->exch_cnt;
+       if (ql2xenforce_iocb_limit == 2) {
+               atomic_add(iores->iocb_cnt, &ha->fwres.iocb_used);
+               atomic_add(iores->exch_cnt, &ha->fwres.exch_used);
+               iores->res_type |= RESOURCE_HA;
+       }
        return 0;
 }
 
+/*
+ * decrement to zero.  This routine will not decrement below zero
+ * @v:  pointer of type atomic_t
+ * @amount: amount to decrement from v
+ */
+static void qla_atomic_dtz(atomic_t *v, int amount)
+{
+       int c, old, dec;
+
+       c = atomic_read(v);
+       for (;;) {
+               dec = c - amount;
+               if (unlikely(dec < 0))
+                       dec = 0;
+
+               old = atomic_cmpxchg((v), c, dec);
+               if (likely(old == c))
+                       break;
+               c = old;
+       }
+}
+
 static inline void
 qla_put_fw_resources(struct qla_qpair *qp, struct iocb_resource *iores)
 {
+       struct qla_hw_data *ha = qp->hw;
+
+       if (iores->res_type & RESOURCE_HA) {
+               if (iores->res_type & RESOURCE_IOCB)
+                       qla_atomic_dtz(&ha->fwres.iocb_used, iores->iocb_cnt);
+
+               if (iores->res_type & RESOURCE_EXCH)
+                       qla_atomic_dtz(&ha->fwres.exch_used, iores->exch_cnt);
+       }
+
        if (iores->res_type & RESOURCE_IOCB) {
                if (qp->fwres.iocbs_used >= iores->iocb_cnt) {
                        qp->fwres.iocbs_used -= iores->iocb_cnt;

diff --git a/drivers/scsi/qla2xxx/qla_os.c b/drivers/scsi/qla2xxx/qla_os.c
index efceaeab17ca6efdea68533b6f3eadbae3bb5aa7..a40af9b832ab416cd29bb23e94f812985e8b5ce6 100644 (file)
--- a/drivers/scsi/qla2xxx/qla_os.c
+++ b/drivers/scsi/qla2xxx/qla_os.c
@@ -40,10 +40,11 @@ module_param(ql2xfulldump_on_mpifail, int, S_IRUGO | S_IWUSR);
 MODULE_PARM_DESC(ql2xfulldump_on_mpifail,
                 "Set this to take full dump on MPI hang.");
 
-int ql2xenforce_iocb_limit = 1;
+int ql2xenforce_iocb_limit = 2;
 module_param(ql2xenforce_iocb_limit, int, S_IRUGO | S_IWUSR);
 MODULE_PARM_DESC(ql2xenforce_iocb_limit,
-                "Enforce IOCB throttling, to avoid FW congestion. (default: 1)");
+                "Enforce IOCB throttling, to avoid FW congestion. (default: 2) "
+                "1: track usage per queue, 2: track usage per adapter");
 
 /*
  * CT6 CTX allocation cache