be2net: Add MCC queue mechanism for BE cmds

Currenlty all cmds use the blocking MCC mbox to post cmds. An mbox cmd is protected
via a spin_lock(cmd_lock) and not spin_lock_bh() as it is undesirable
to disable BHs while a blocking mbox cmd is in progress (and take long to finish.)
This can lockup a cmd in progress in process context. Instead cmds that may be
called in BH context must use the MCC queue to post cmds. The cmd completions
are rcvd in a separate completion queue and the events are placed in the tx-event
queue.

Signed-off-by: Sathya Perla <sathyap@serverengines.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

1 files changed, 145 insertions, 70 deletions

diff --git a/drivers/net/benet/be_main.c b/drivers/net/benet/be_main.c
index 66bb56874d9b..a4ce80e776b6 100644
--- a/drivers/net/benet/be_main.c
+++ b/drivers/net/benet/be_main.c
@@ -60,26 +60,6 @@ static int be_queue_alloc(struct be_adapter *adapter, struct be_queue_info *q,
         return 0;
 }
 
-static inline void *queue_head_node(struct be_queue_info *q)
-{
-        return q->dma_mem.va + q->head * q->entry_size;
-}
-
-static inline void *queue_tail_node(struct be_queue_info *q)
-{
-        return q->dma_mem.va + q->tail * q->entry_size;
-}
-
-static inline void queue_head_inc(struct be_queue_info *q)
-{
-        index_inc(&q->head, q->len);
-}
-
-static inline void queue_tail_inc(struct be_queue_info *q)
-{
-        index_inc(&q->tail, q->len);
-}
-
 static void be_intr_set(struct be_ctrl_info *ctrl, bool enable)
 {
         u8 __iomem *addr = ctrl->pcicfg + PCICFG_MEMBAR_CTRL_INT_CTRL_OFFSET;
@@ -127,7 +107,7 @@ static void be_eq_notify(struct be_ctrl_info *ctrl, u16 qid,
         iowrite32(val, ctrl->db + DB_EQ_OFFSET);
 }
 
-static void be_cq_notify(struct be_ctrl_info *ctrl, u16 qid,
+void be_cq_notify(struct be_ctrl_info *ctrl, u16 qid,
                 bool arm, u16 num_popped)
 {
         u32 val = 0;
@@ -960,10 +940,8 @@ static void be_post_rx_frags(struct be_adapter *adapter)
         return;
 }
 
-static struct be_eth_tx_compl *
-be_tx_compl_get(struct be_adapter *adapter)
+static struct be_eth_tx_compl *be_tx_compl_get(struct be_queue_info *tx_cq)
 {
-        struct be_queue_info *tx_cq = &adapter->tx_obj.cq;
         struct be_eth_tx_compl *txcp = queue_tail_node(tx_cq);
 
         if (txcp->dw[offsetof(struct amap_eth_tx_compl, valid) / 32] == 0)
@@ -1051,6 +1029,59 @@ static void be_tx_q_clean(struct be_adapter *adapter)
         }
 }
 
+static void be_mcc_queues_destroy(struct be_adapter *adapter)
+{
+        struct be_queue_info *q;
+        struct be_ctrl_info *ctrl = &adapter->ctrl;
+
+        q = &ctrl->mcc_obj.q;
+        if (q->created)
+                be_cmd_q_destroy(ctrl, q, QTYPE_MCCQ);
+        be_queue_free(adapter, q);
+
+        q = &ctrl->mcc_obj.cq;
+        if (q->created)
+                be_cmd_q_destroy(ctrl, q, QTYPE_CQ);
+        be_queue_free(adapter, q);
+}
+
+/* Must be called only after TX qs are created as MCC shares TX EQ */
+static int be_mcc_queues_create(struct be_adapter *adapter)
+{
+        struct be_queue_info *q, *cq;
+        struct be_ctrl_info *ctrl = &adapter->ctrl;
+
+        /* Alloc MCC compl queue */
+        cq = &ctrl->mcc_obj.cq;
+        if (be_queue_alloc(adapter, cq, MCC_CQ_LEN,
+                        sizeof(struct be_mcc_cq_entry)))
+                goto err;
+
+        /* Ask BE to create MCC compl queue; share TX's eq */
+        if (be_cmd_cq_create(ctrl, cq, &adapter->tx_eq.q, false, true, 0))
+                goto mcc_cq_free;
+
+        /* Alloc MCC queue */
+        q = &ctrl->mcc_obj.q;
+        if (be_queue_alloc(adapter, q, MCC_Q_LEN, sizeof(struct be_mcc_wrb)))
+                goto mcc_cq_destroy;
+
+        /* Ask BE to create MCC queue */
+        if (be_cmd_mccq_create(ctrl, q, cq))
+                goto mcc_q_free;
+
+        return 0;
+
+mcc_q_free:
+        be_queue_free(adapter, q);
+mcc_cq_destroy:
+        be_cmd_q_destroy(ctrl, cq, QTYPE_CQ);
+mcc_cq_free:
+        be_queue_free(adapter, cq);
+err:
+        return -1;
+}
+
 static void be_tx_queues_destroy(struct be_adapter *adapter)
 {
         struct be_queue_info *q;
@@ -1263,7 +1294,7 @@ static irqreturn_t be_msix_rx(int irq, void *dev)
         return IRQ_HANDLED;
 }
 
-static irqreturn_t be_msix_tx(int irq, void *dev)
+static irqreturn_t be_msix_tx_mcc(int irq, void *dev)
 {
         struct be_adapter *adapter = dev;
 
@@ -1324,40 +1355,51 @@ int be_poll_rx(struct napi_struct *napi, int budget)
         return work_done;
 }
 
-/* For TX we don't honour budget; consume everything */
-int be_poll_tx(struct napi_struct *napi, int budget)
+void be_process_tx(struct be_adapter *adapter)
 {
-        struct be_eq_obj *tx_eq = container_of(napi, struct be_eq_obj, napi);
-        struct be_adapter *adapter =
-                container_of(tx_eq, struct be_adapter, tx_eq);
-        struct be_tx_obj *tx_obj = &adapter->tx_obj;
-        struct be_queue_info *tx_cq = &tx_obj->cq;
-        struct be_queue_info *txq = &tx_obj->q;
+        struct be_queue_info *txq = &adapter->tx_obj.q;
+        struct be_queue_info *tx_cq = &adapter->tx_obj.cq;
         struct be_eth_tx_compl *txcp;
         u32 num_cmpl = 0;
         u16 end_idx;
 
-        while ((txcp = be_tx_compl_get(adapter))) {
+        while ((txcp = be_tx_compl_get(tx_cq))) {
                 end_idx = AMAP_GET_BITS(struct amap_eth_tx_compl,
                                         wrb_index, txcp);
                 be_tx_compl_process(adapter, end_idx);
                 num_cmpl++;
         }
 
-        /* As Tx wrbs have been freed up, wake up netdev queue if
-         * it was stopped due to lack of tx wrbs.
-         */
-        if (netif_queue_stopped(adapter->netdev) &&
+        if (num_cmpl) {
+                be_cq_notify(&adapter->ctrl, tx_cq->id, true, num_cmpl);
+
+                /* As Tx wrbs have been freed up, wake up netdev queue if
+                 * it was stopped due to lack of tx wrbs.
+                 */
+                if (netif_queue_stopped(adapter->netdev) &&
                         atomic_read(&txq->used) < txq->len / 2) {
-                netif_wake_queue(adapter->netdev);
+                        netif_wake_queue(adapter->netdev);
+                }
+
+                drvr_stats(adapter)->be_tx_events++;
+                drvr_stats(adapter)->be_tx_compl += num_cmpl;
         }
+}
+
+/* As TX and MCC share the same EQ check for both TX and MCC completions.
+ * For TX/MCC we don't honour budget; consume everything
+ */
+static int be_poll_tx_mcc(struct napi_struct *napi, int budget)
+{
+        struct be_eq_obj *tx_eq = container_of(napi, struct be_eq_obj, napi);
+        struct be_adapter *adapter =
+                container_of(tx_eq, struct be_adapter, tx_eq);
 
         napi_complete(napi);
 
-        be_cq_notify(&adapter->ctrl, tx_cq->id, true, num_cmpl);
+        be_process_tx(adapter);
 
-        drvr_stats(adapter)->be_tx_events++;
-        drvr_stats(adapter)->be_tx_compl += num_cmpl;
+        be_process_mcc(&adapter->ctrl);
 
         return 1;
 }
@@ -1419,7 +1461,7 @@ static int be_msix_register(struct be_adapter *adapter)
 
         sprintf(tx_eq->desc, "%s-tx", netdev->name);
         vec = be_msix_vec_get(adapter, tx_eq->q.id);
-        status = request_irq(vec, be_msix_tx, 0, tx_eq->desc, adapter);
+        status = request_irq(vec, be_msix_tx_mcc, 0, tx_eq->desc, adapter);
         if (status)
                 goto err;
 
@@ -1495,6 +1537,34 @@ static int be_open(struct net_device *netdev)
         struct be_ctrl_info *ctrl = &adapter->ctrl;
         struct be_eq_obj *rx_eq = &adapter->rx_eq;
         struct be_eq_obj *tx_eq = &adapter->tx_eq;
+
+        /* First time posting */
+        be_post_rx_frags(adapter);
+
+        napi_enable(&rx_eq->napi);
+        napi_enable(&tx_eq->napi);
+
+        be_irq_register(adapter);
+
+        be_intr_set(ctrl, true);
+
+        /* The evt queues are created in unarmed state; arm them */
+        be_eq_notify(ctrl, rx_eq->q.id, true, false, 0);
+        be_eq_notify(ctrl, tx_eq->q.id, true, false, 0);
+
+        /* Rx compl queue may be in unarmed state; rearm it */
+        be_cq_notify(ctrl, adapter->rx_obj.cq.id, true, 0);
+
+        be_link_status_update(adapter);
+
+        schedule_delayed_work(&adapter->work, msecs_to_jiffies(100));
+        return 0;
+}
+
+static int be_setup(struct be_adapter *adapter)
+{
+        struct be_ctrl_info *ctrl = &adapter->ctrl;
+        struct net_device *netdev = adapter->netdev;
         u32 if_flags;
         int status;
 
@@ -1521,29 +1591,14 @@ static int be_open(struct net_device *netdev)
         if (status != 0)
                 goto tx_qs_destroy;
 
-        /* First time posting */
-        be_post_rx_frags(adapter);
-
-        napi_enable(&rx_eq->napi);
-        napi_enable(&tx_eq->napi);
-
-        be_irq_register(adapter);
-
-        be_intr_set(ctrl, true);
-
-        /* The evt queues are created in the unarmed state; arm them */
-        be_eq_notify(ctrl, rx_eq->q.id, true, false, 0);
-        be_eq_notify(ctrl, tx_eq->q.id, true, false, 0);
-
-        /* The compl queues are created in the unarmed state; arm them */
-        be_cq_notify(ctrl, adapter->rx_obj.cq.id, true, 0);
-        be_cq_notify(ctrl, adapter->tx_obj.cq.id, true, 0);
-
-        be_link_status_update(adapter);
+        status = be_mcc_queues_create(adapter);
+        if (status != 0)
+                goto rx_qs_destroy;
 
-        schedule_delayed_work(&adapter->work, msecs_to_jiffies(100));
         return 0;
 
+rx_qs_destroy:
+        be_rx_queues_destroy(adapter);
 tx_qs_destroy:
         be_tx_queues_destroy(adapter);
 if_destroy:
@@ -1552,6 +1607,19 @@ do_none:
         return status;
 }
 
+static int be_clear(struct be_adapter *adapter)
+{
+        struct be_ctrl_info *ctrl = &adapter->ctrl;
+
+        be_rx_queues_destroy(adapter);
+        be_tx_queues_destroy(adapter);
+
+        be_cmd_if_destroy(ctrl, adapter->if_handle);
+
+        be_mcc_queues_destroy(adapter);
+        return 0;
+}
+
 static int be_close(struct net_device *netdev)
 {
         struct be_adapter *adapter = netdev_priv(netdev);
@@ -1581,10 +1649,6 @@ static int be_close(struct net_device *netdev)
         napi_disable(&rx_eq->napi);
         napi_disable(&tx_eq->napi);
 
-        be_rx_queues_destroy(adapter);
-        be_tx_queues_destroy(adapter);
-
-        be_cmd_if_destroy(ctrl, adapter->if_handle);
         return 0;
 }
 
@@ -1673,7 +1737,7 @@ static void be_netdev_init(struct net_device *netdev)
 
         netif_napi_add(netdev, &adapter->rx_eq.napi, be_poll_rx,
                 BE_NAPI_WEIGHT);
-        netif_napi_add(netdev, &adapter->tx_eq.napi, be_poll_tx,
+        netif_napi_add(netdev, &adapter->tx_eq.napi, be_poll_tx_mcc,
                 BE_NAPI_WEIGHT);
 
         netif_carrier_off(netdev);
@@ -1755,7 +1819,9 @@ static int be_ctrl_init(struct be_adapter *adapter)
         mbox_mem_align->va = PTR_ALIGN(mbox_mem_alloc->va, 16);
         mbox_mem_align->dma = PTR_ALIGN(mbox_mem_alloc->dma, 16);
         memset(mbox_mem_align->va, 0, sizeof(struct be_mcc_mailbox));
-        spin_lock_init(&ctrl->cmd_lock);
+        spin_lock_init(&ctrl->mbox_lock);
+        spin_lock_init(&ctrl->mcc_lock);
+        spin_lock_init(&ctrl->mcc_cq_lock);
 
         val = ioread32(ctrl->pcicfg + PCICFG_MEMBAR_CTRL_INT_CTRL_OFFSET);
         ctrl->pci_func = (val >> MEMBAR_CTRL_INT_CTRL_PFUNC_SHIFT) &
@@ -1793,6 +1859,8 @@ static void __devexit be_remove(struct pci_dev *pdev)
 
         unregister_netdev(adapter->netdev);
 
+        be_clear(adapter);
+
         be_stats_cleanup(adapter);
 
         be_ctrl_cleanup(adapter);
@@ -1890,13 +1958,18 @@ static int __devinit be_probe(struct pci_dev *pdev,
         be_netdev_init(netdev);
         SET_NETDEV_DEV(netdev, &adapter->pdev->dev);
 
+        status = be_setup(adapter);
+        if (status)
+                goto stats_clean;
         status = register_netdev(netdev);
         if (status != 0)
-                goto stats_clean;
+                goto unsetup;
 
         dev_info(&pdev->dev, "%s port %d\n", nic_name(pdev), adapter->port_num);
         return 0;
 
+unsetup:
+        be_clear(adapter);
 stats_clean:
         be_stats_cleanup(adapter);
 ctrl_clean:
@@ -1921,6 +1994,7 @@ static int be_suspend(struct pci_dev *pdev, pm_message_t state)
         if (netif_running(netdev)) {
                 rtnl_lock();
                 be_close(netdev);
+                be_clear(adapter);
                 rtnl_unlock();
         }
 
@@ -1947,6 +2021,7 @@ static int be_resume(struct pci_dev *pdev)
 
         if (netif_running(netdev)) {
                 rtnl_lock();
+                be_setup(adapter);
                 be_open(netdev);
                 rtnl_unlock();
         }