PCI: Process control messages in the same context

Process control messages in the same kthread context instead of scheduling
a separate work for the same to improve performance.

Bug 200495545

Change-Id: Iac004bd313754e61d789dff233cf487b1f4710d2
Signed-off-by: Manikanta Maddireddy <mmaddireddy@nvidia.com>
Reviewed-on: https://git-master.nvidia.com/r/2183364
Reviewed-by: Automatic_Commit_Validation_User
GVS: Gerrit_Virtual_Submit
Tested-by: Vidya Sagar <vidyas@nvidia.com>
Reviewed-by: Bibek Basu <bbasu@nvidia.com>
Reviewed-by: mobile promotions <svcmobile_promotions@nvidia.com>
Tested-by: mobile promotions <svcmobile_promotions@nvidia.com>

2 files changed, 20 insertions, 47 deletions

diff --git a/drivers/net/ethernet/nvidia/pcie/tegra_vnet.c b/drivers/net/ethernet/nvidia/pcie/tegra_vnet.c
index 7b929c2fe..8bfa3460b 100644
--- a/drivers/net/ethernet/nvidia/pcie/tegra_vnet.c
+++ b/drivers/net/ethernet/nvidia/pcie/tegra_vnet.c
@@ -197,8 +197,6 @@ struct tvnet_priv {
         struct bar_md *bar_md;
         struct ep_ring_buf ep_mem;
         struct host_ring_buf host_mem;
-        struct work_struct ctrl_msg_work;
-        struct work_struct alloc_buf_work;
         struct list_head ep2h_empty_list;
         /* To protect ep2h empty list */
         spinlock_t ep2h_empty_lock;
@@ -466,7 +464,9 @@ static void tvnet_stop_tx_queue(struct tvnet_priv *tvnet)
 
 static void tvnet_stop_rx_work(struct tvnet_priv *tvnet)
 {
-        cancel_work_sync(&tvnet->alloc_buf_work);
+        /* wait for interrupt handle to return to ensure rx is stopped */
+        synchronize_irq(pci_irq_vector(tvnet->pdev, 0));
+        synchronize_irq(pci_irq_vector(tvnet->pdev, 1));
 }
 
 static void tvnet_clear_data_msg_counters(struct tvnet_priv *tvnet)
@@ -808,10 +808,8 @@ static void tvnet_setup_bar0_md(struct tvnet_priv *tvnet)
         tvnet->ep2h_full.wr = &ep_mem->ep_cnt->ep2h_full_wr_cnt;
 }
 
-static void process_ctrl_msg(struct work_struct *work)
+static void process_ctrl_msg(struct tvnet_priv *tvnet)
 {
-        struct tvnet_priv *tvnet =
-                container_of(work, struct tvnet_priv, ctrl_msg_work);
         struct ctrl_msg msg;
 
         while (tvnet_ivc_rd_available(&tvnet->ep2h_ctrl)) {
@@ -881,26 +879,11 @@ static int process_ep2h_msg(struct tvnet_priv *tvnet)
         return count;
 }
 
-static void alloc_ep2h_rx_buf(struct work_struct *work)
-{
-        struct tvnet_priv *tvnet =
-                container_of(work, struct tvnet_priv, alloc_buf_work);
-
-        if (tvnet->os_link_state == OS_LINK_STATE_UP)
-                tvnet_alloc_empty_buffers(tvnet);
-}
-
 static irqreturn_t tvnet_irq_ctrl(int irq, void *data)
 {
         struct net_device *ndev = data;
         struct tvnet_priv *tvnet = netdev_priv(ndev);
 
-        if (tvnet_ivc_rd_available(&tvnet->ep2h_ctrl))
-                schedule_work(&tvnet->ctrl_msg_work);
-
-        if (!tvnet_ivc_full(&tvnet->ep2h_empty))
-                schedule_work(&tvnet->alloc_buf_work);
-
         if (netif_queue_stopped(ndev)) {
                 if ((tvnet->os_link_state == OS_LINK_STATE_UP) &&
                     tvnet_ivc_rd_available(&tvnet->h2ep_empty) &&
@@ -910,6 +893,13 @@ static irqreturn_t tvnet_irq_ctrl(int irq, void *data)
                 }
         }
 
+        if (tvnet_ivc_rd_available(&tvnet->ep2h_ctrl))
+                process_ctrl_msg(tvnet);
+
+        if (!tvnet_ivc_full(&tvnet->ep2h_empty) &&
+            (tvnet->os_link_state == OS_LINK_STATE_UP))
+                tvnet_alloc_empty_buffers(tvnet);
+
         return IRQ_HANDLED;
 }
 
@@ -1053,8 +1043,6 @@ static int tvnet_probe(struct pci_dev *pdev, const struct pci_device_id *pci_id)
         tvnet_write_dma_msix_settings(tvnet);
 #endif
 
-        INIT_WORK(&tvnet->ctrl_msg_work, process_ctrl_msg);
-        INIT_WORK(&tvnet->alloc_buf_work, alloc_ep2h_rx_buf);
         INIT_LIST_HEAD(&tvnet->ep2h_empty_list);
         spin_lock_init(&tvnet->ep2h_empty_lock);
 
diff --git a/drivers/pci/endpoint/functions/pci-epf-tegra-vnet.c b/drivers/pci/endpoint/functions/pci-epf-tegra-vnet.c
index d3cca653a..026402166 100644
--- a/drivers/pci/endpoint/functions/pci-epf-tegra-vnet.c
+++ b/drivers/pci/endpoint/functions/pci-epf-tegra-vnet.c
@@ -253,8 +253,6 @@ struct pci_epf_tvnet {
         /* To synchronize network link state machine*/
         struct mutex link_state_lock;
         wait_queue_head_t link_state_wq;
-        struct work_struct ctrl_msg_work;
-        struct work_struct alloc_buf_work;
         struct list_head h2ep_empty_list;
 #if ENABLE_DMA
         struct dma_desc_cnt desc_cnt;
@@ -569,7 +567,7 @@ static void tvnet_stop_tx_queue(struct pci_epf_tvnet *tvnet)
 
 static void tvnet_stop_rx_work(struct pci_epf_tvnet *tvnet)
 {
-        cancel_work_sync(&tvnet->alloc_buf_work);
+        /* TODO wait for syncpoint interrupt handlers */
 }
 
 static void tvnet_clear_data_msg_counters(struct pci_epf_tvnet *tvnet)
@@ -884,10 +882,8 @@ static const struct net_device_ops tvnet_netdev_ops = {
         .ndo_start_xmit = tvnet_start_xmit,
 };
 
-static void process_ctrl_msg(struct work_struct *work)
+static void process_ctrl_msg(struct pci_epf_tvnet *tvnet)
 {
-        struct pci_epf_tvnet *tvnet =
-                container_of(work, struct pci_epf_tvnet, ctrl_msg_work);
         struct ctrl_msg msg;
 
         while (tvnet_ivc_rd_available(&tvnet->h2ep_ctrl)) {
@@ -978,15 +974,6 @@ static int process_h2ep_msg(struct pci_epf_tvnet *tvnet)
         return count;
 }
 
-static void alloc_h2ep_rx_buf(struct work_struct *work)
-{
-        struct pci_epf_tvnet *tvnet =
-                container_of(work, struct pci_epf_tvnet, alloc_buf_work);
-
-        if (tvnet->os_link_state == OS_LINK_STATE_UP)
-                tvnet_alloc_empty_buffers(tvnet);
-}
-
 #if ENABLE_DMA
 static void tvnet_setup_ep_dma(struct pci_epf_tvnet *tvnet)
 {
@@ -1067,12 +1054,6 @@ static void ctrl_irqsp_callback(void *private_data)
         struct pci_epf_tvnet *tvnet = dev_get_drvdata(data_irqsp->dev);
         struct net_device *ndev = tvnet->ndev;
 
-        if (tvnet_ivc_rd_available(&tvnet->h2ep_ctrl))
-                schedule_work(&tvnet->ctrl_msg_work);
-
-        if (!tvnet_ivc_full(&tvnet->h2ep_empty))
-                schedule_work(&tvnet->alloc_buf_work);
-
         if (netif_queue_stopped(ndev)) {
                 if ((tvnet->os_link_state == OS_LINK_STATE_UP) &&
                     tvnet_ivc_rd_available(&tvnet->ep2h_empty) &&
@@ -1081,6 +1062,13 @@ static void ctrl_irqsp_callback(void *private_data)
                 }
         }
 
+        if (tvnet_ivc_rd_available(&tvnet->h2ep_ctrl))
+                process_ctrl_msg(tvnet);
+
+        if (!tvnet_ivc_full(&tvnet->h2ep_empty) &&
+            (tvnet->os_link_state == OS_LINK_STATE_UP))
+                tvnet_alloc_empty_buffers(tvnet);
+
         schedule_work(&data_irqsp->reprime_work);
 }
 
@@ -1605,8 +1593,6 @@ static int pci_epf_tvnet_bind(struct pci_epf *epf)
         mutex_init(&tvnet->link_state_lock);
         init_waitqueue_head(&tvnet->link_state_wq);
 
-        INIT_WORK(&tvnet->ctrl_msg_work, process_ctrl_msg);
-        INIT_WORK(&tvnet->alloc_buf_work, alloc_h2ep_rx_buf);
         INIT_LIST_HEAD(&tvnet->h2ep_empty_list);
         spin_lock_init(&tvnet->h2ep_empty_lock);
 
@@ -1683,7 +1669,6 @@ static void pci_epf_tvnet_unbind(struct pci_epf *epf)
 
         cancel_work_sync(&tvnet->ctrl_irqsp->reprime_work);
         cancel_work_sync(&tvnet->data_irqsp->reprime_work);
-        cancel_work_sync(&tvnet->alloc_buf_work);
         pci_epc_stop(epc);
         pci_epc_clear_bar(epc, BAR_0);
         dma_free_coherent(cdev,