S2io: Multiqueue network device support implementation

- Resubmit #3
Multiqueue netwrok device support implementation.
- Added a loadable parameter "multiq" to enable/disable multiqueue support,
  by default it is disabled.
- skb->queue_mapping is not used for queue/fifo selection. FIFO selection is
  based on skb->priority.
- Added per FIFO flags FIFO_QUEUE_START and FIFO_QUEUE_STOP. Check this flag
  for starting and stopping netif queue and update the flags accordingly.
- In tx_intr_handler added a check to ensure that we have free TXDs before wak-
  ing up the queue.
- Added helper functions for queue manipulation(start/stop/wakeup) to invoke
  appropriate netif_ functions.
- Calling netif_start/stop for link up/down case respectively.

- As per Andi kleen's review comments, using skb->priority field for FIFO
  selection.

Signed-off-by: Surjit Reang <surjit.reang@neterion.com>
Signed-off-by: Ramkrishna Vepa <ram.vepa@neterion.com>
Signed-off-by: Jeff Garzik <jeff@garzik.org>

2 files changed, 186 insertions, 30 deletions

diff --git a/drivers/net/s2io.c b/drivers/net/s2io.c
index c72787adeba3..3ddc0aae60b6 100644
--- a/drivers/net/s2io.c
+++ b/drivers/net/s2io.c
@@ -50,6 +50,8 @@
  *                 Possible values '1' for enable , '0' for disable.
  *                 Default is '2' - which means disable in promisc mode
  *                 and enable in non-promiscuous mode.
+ * multiq: This parameter used to enable/disable MULTIQUEUE support.
+ *      Possible values '1' for enable and '0' for disable. Default is '0'
  ************************************************************************/
 
 #include <linux/module.h>
@@ -458,8 +460,7 @@ MODULE_VERSION(DRV_VERSION);
 /* Module Loadable parameters. */
 S2IO_PARM_INT(tx_fifo_num, 1);
 S2IO_PARM_INT(rx_ring_num, 1);
-
-
+S2IO_PARM_INT(multiq, 0);
 S2IO_PARM_INT(rx_ring_mode, 1);
 S2IO_PARM_INT(use_continuous_tx_intrs, 1);
 S2IO_PARM_INT(rmac_pause_time, 0x100);
@@ -533,6 +534,101 @@ static struct pci_driver s2io_driver = {
 /* A simplifier macro used both by init and free shared_mem Fns(). */
 #define TXD_MEM_PAGE_CNT(len, per_each) ((len+per_each - 1) / per_each)
 
+/* netqueue manipulation helper functions */
+static inline void s2io_stop_all_tx_queue(struct s2io_nic *sp)
+{
+        int i;
+#ifdef CONFIG_NETDEVICES_MULTIQUEUE
+        if (sp->config.multiq) {
+                for (i = 0; i < sp->config.tx_fifo_num; i++)
+                        netif_stop_subqueue(sp->dev, i);
+        } else
+#endif
+        {
+                for (i = 0; i < sp->config.tx_fifo_num; i++)
+                        sp->mac_control.fifos[i].queue_state = FIFO_QUEUE_STOP;
+                netif_stop_queue(sp->dev);
+        }
+}
+
+static inline void s2io_stop_tx_queue(struct s2io_nic *sp, int fifo_no)
+{
+#ifdef CONFIG_NETDEVICES_MULTIQUEUE
+        if (sp->config.multiq)
+                netif_stop_subqueue(sp->dev, fifo_no);
+        else
+#endif
+        {
+                sp->mac_control.fifos[fifo_no].queue_state =
+                        FIFO_QUEUE_STOP;
+                netif_stop_queue(sp->dev);
+        }
+}
+
+static inline void s2io_start_all_tx_queue(struct s2io_nic *sp)
+{
+        int i;
+#ifdef CONFIG_NETDEVICES_MULTIQUEUE
+        if (sp->config.multiq) {
+                for (i = 0; i < sp->config.tx_fifo_num; i++)
+                        netif_start_subqueue(sp->dev, i);
+        } else
+#endif
+        {
+                for (i = 0; i < sp->config.tx_fifo_num; i++)
+                        sp->mac_control.fifos[i].queue_state = FIFO_QUEUE_START;
+                netif_start_queue(sp->dev);
+        }
+}
+
+static inline void s2io_start_tx_queue(struct s2io_nic *sp, int fifo_no)
+{
+#ifdef CONFIG_NETDEVICES_MULTIQUEUE
+        if (sp->config.multiq)
+                netif_start_subqueue(sp->dev, fifo_no);
+        else
+#endif
+        {
+                sp->mac_control.fifos[fifo_no].queue_state =
+                        FIFO_QUEUE_START;
+                netif_start_queue(sp->dev);
+        }
+}
+
+static inline void s2io_wake_all_tx_queue(struct s2io_nic *sp)
+{
+        int i;
+#ifdef CONFIG_NETDEVICES_MULTIQUEUE
+        if (sp->config.multiq) {
+                for (i = 0; i < sp->config.tx_fifo_num; i++)
+                        netif_wake_subqueue(sp->dev, i);
+        } else
+#endif
+        {
+                for (i = 0; i < sp->config.tx_fifo_num; i++)
+                        sp->mac_control.fifos[i].queue_state = FIFO_QUEUE_START;
+                netif_wake_queue(sp->dev);
+        }
+}
+
+static inline void s2io_wake_tx_queue(
+        struct fifo_info *fifo, int cnt, u8 multiq)
+{
+
+#ifdef CONFIG_NETDEVICES_MULTIQUEUE
+        if (multiq) {
+                if (cnt && __netif_subqueue_stopped(fifo->dev, fifo->fifo_no))
+                        netif_wake_subqueue(fifo->dev, fifo->fifo_no);
+        } else
+#endif
+        if (cnt && (fifo->queue_state == FIFO_QUEUE_STOP)) {
+                if (netif_queue_stopped(fifo->dev)) {
+                        fifo->queue_state = FIFO_QUEUE_START;
+                        netif_wake_queue(fifo->dev);
+                }
+        }
+}
+
 /**
  * init_shared_mem - Allocation and Initialization of Memory
  * @nic: Device private variable.
@@ -614,6 +710,7 @@ static int init_shared_mem(struct s2io_nic *nic)
                 mac_control->fifos[i].fifo_no = i;
                 mac_control->fifos[i].nic = nic;
                 mac_control->fifos[i].max_txds = MAX_SKB_FRAGS + 2;
+                mac_control->fifos[i].dev = dev;
 
                 for (j = 0; j < page_num; j++) {
                         int k = 0;
@@ -2972,10 +3069,10 @@ static void rx_intr_handler(struct ring_info *ring_data)
 static void tx_intr_handler(struct fifo_info *fifo_data)
 {
         struct s2io_nic *nic = fifo_data->nic;
-        struct net_device *dev = (struct net_device *) nic->dev;
         struct tx_curr_get_info get_info, put_info;
-        struct sk_buff *skb;
+        struct sk_buff *skb = NULL;
         struct TxD *txdlp;
+        int pkt_cnt = 0;
         unsigned long flags = 0;
         u8 err_mask;
 
@@ -3036,6 +3133,7 @@ static void tx_intr_handler(struct fifo_info *fifo_data)
                         DBG_PRINT(ERR_DBG, "in Tx Free Intr\n");
                         return;
                 }
+                pkt_cnt++;
 
                 /* Updating the statistics block */
                 nic->stats.tx_bytes += skb->len;
@@ -3051,8 +3149,7 @@ static void tx_intr_handler(struct fifo_info *fifo_data)
                     get_info.offset;
         }
 
-        if (netif_queue_stopped(dev))
-                netif_wake_queue(dev);
+        s2io_wake_tx_queue(fifo_data, pkt_cnt, nic->config.multiq);
 
         spin_unlock_irqrestore(&fifo_data->tx_lock, flags);
 }
@@ -3933,8 +4030,7 @@ static int s2io_open(struct net_device *dev)
                 err = -ENODEV;
                 goto hw_init_failed;
         }
-
-        netif_start_queue(dev);
+        s2io_start_all_tx_queue(sp);
         return 0;
 
 hw_init_failed:
@@ -3979,8 +4075,7 @@ static int s2io_close(struct net_device *dev)
         if (!is_s2io_card_up(sp))
                 return 0;
 
-        netif_stop_queue(dev);
-
+        s2io_stop_all_tx_queue(sp);
         /* delete all populated mac entries */
         for (offset = 1; offset < config->max_mc_addr; offset++) {
                 tmp64 = do_s2io_read_unicast_mc(sp, offset);
@@ -4016,7 +4111,6 @@ static int s2io_xmit(struct sk_buff *skb, struct net_device *dev)
         struct TxFIFO_element __iomem *tx_fifo;
         unsigned long flags = 0;
         u16 vlan_tag = 0;
-        int vlan_priority = 0;
         struct fifo_info *fifo = NULL;
         struct mac_info *mac_control;
         struct config_param *config;
@@ -4043,14 +4137,29 @@ static int s2io_xmit(struct sk_buff *skb, struct net_device *dev)
 
         queue = 0;
         /* Get Fifo number to Transmit based on vlan priority */
-        if (sp->vlgrp && vlan_tx_tag_present(skb)) {
+        if (sp->vlgrp && vlan_tx_tag_present(skb))
                 vlan_tag = vlan_tx_tag_get(skb);
-                vlan_priority = vlan_tag >> 13;
-                queue = config->fifo_mapping[vlan_priority];
-        }
+
+        /* get fifo number based on skb->priority value */
+        queue = config->fifo_mapping[skb->priority & (MAX_TX_FIFOS - 1)];
 
         fifo = &mac_control->fifos[queue];
         spin_lock_irqsave(&fifo->tx_lock, flags);
+#ifdef CONFIG_NETDEVICES_MULTIQUEUE
+        if (sp->config.multiq) {
+                if (__netif_subqueue_stopped(dev, fifo->fifo_no)) {
+                        spin_unlock_irqrestore(&fifo->tx_lock, flags);
+                        return NETDEV_TX_BUSY;
+                }
+        } else
+#endif
+        if (unlikely(fifo->queue_state == FIFO_QUEUE_STOP)) {
+                if (netif_queue_stopped(dev)) {
+                        spin_unlock_irqrestore(&fifo->tx_lock, flags);
+                        return NETDEV_TX_BUSY;
+                }
+        }
+
         put_off = (u16) fifo->tx_curr_put_info.offset;
         get_off = (u16) fifo->tx_curr_get_info.offset;
         txdp = (struct TxD *) fifo->list_info[put_off].list_virt_addr;
@@ -4060,7 +4169,7 @@ static int s2io_xmit(struct sk_buff *skb, struct net_device *dev)
         if (txdp->Host_Control ||
                    ((put_off+1) == queue_len ? 0 : (put_off+1)) == get_off) {
                 DBG_PRINT(TX_DBG, "Error in xmit, No free TXDs.\n");
-                netif_stop_queue(dev);
+                s2io_stop_tx_queue(sp, fifo->fifo_no);
                 dev_kfree_skb(skb);
                 spin_unlock_irqrestore(&fifo->tx_lock, flags);
                 return 0;
@@ -4080,7 +4189,7 @@ static int s2io_xmit(struct sk_buff *skb, struct net_device *dev)
         txdp->Control_1 |= TXD_LIST_OWN_XENA;
         txdp->Control_2 |= TXD_INT_NUMBER(fifo->fifo_no);
 
-        if (sp->vlgrp && vlan_tx_tag_present(skb)) {
+        if (vlan_tag) {
                 txdp->Control_2 |= TXD_VLAN_ENABLE;
                 txdp->Control_2 |= TXD_VLAN_TAG(vlan_tag);
         }
@@ -4166,7 +4275,7 @@ static int s2io_xmit(struct sk_buff *skb, struct net_device *dev)
                 DBG_PRINT(TX_DBG,
                           "No free TxDs for xmit, Put: 0x%x Get:0x%x\n",
                           put_off, get_off);
-                netif_stop_queue(dev);
+                s2io_stop_tx_queue(sp, fifo->fifo_no);
         }
         mac_control->stats_info->sw_stat.mem_allocated += skb->truesize;
         dev->trans_start = jiffies;
@@ -4175,7 +4284,7 @@ static int s2io_xmit(struct sk_buff *skb, struct net_device *dev)
         return 0;
 pci_map_failed:
         stats->pci_map_fail_cnt++;
-        netif_stop_queue(dev);
+        s2io_stop_tx_queue(sp, fifo->fifo_no);
         stats->mem_freed += skb->truesize;
         dev_kfree_skb(skb);
         spin_unlock_irqrestore(&fifo->tx_lock, flags);
@@ -4587,7 +4696,7 @@ static void s2io_handle_errors(void * dev_id)
         return;
 
 reset:
-        netif_stop_queue(dev);
+        s2io_stop_all_tx_queue(sp);
         schedule_work(&sp->rst_timer_task);
         sw_stat->soft_reset_cnt++;
         return;
@@ -6574,16 +6683,15 @@ static int s2io_change_mtu(struct net_device *dev, int new_mtu)
 
         dev->mtu = new_mtu;
         if (netif_running(dev)) {
+                s2io_stop_all_tx_queue(sp);
                 s2io_card_down(sp);
-                netif_stop_queue(dev);
                 ret = s2io_card_up(sp);
                 if (ret) {
                         DBG_PRINT(ERR_DBG, "%s: Device bring up failed\n",
                                   __FUNCTION__);
                         return ret;
                 }
-                if (netif_queue_stopped(dev))
-                        netif_wake_queue(dev);
+                s2io_wake_all_tx_queue(sp);
         } else { /* Device is down */
                 struct XENA_dev_config __iomem *bar0 = sp->bar0;
                 u64 val64 = new_mtu;
@@ -6691,7 +6799,7 @@ static void s2io_set_link(struct work_struct *work)
                         } else {
                                 DBG_PRINT(ERR_DBG, "%s: Error: ", dev->name);
                                 DBG_PRINT(ERR_DBG, "device is not Quiescent\n");
-                                netif_stop_queue(dev);
+                                s2io_stop_all_tx_queue(nic);
                         }
                 }
                 val64 = readq(&bar0->adapter_control);
@@ -7181,7 +7289,7 @@ static void s2io_restart_nic(struct work_struct *work)
                 DBG_PRINT(ERR_DBG, "%s: Device bring up failed\n",
                           dev->name);
         }
-        netif_wake_queue(dev);
+        s2io_wake_all_tx_queue(sp);
         DBG_PRINT(ERR_DBG, "%s: was reset by Tx watchdog timer\n",
                   dev->name);
 out_unlock:
@@ -7460,6 +7568,7 @@ static void s2io_link(struct s2io_nic * sp, int link)
                 init_tti(sp, link);
                 if (link == LINK_DOWN) {
                         DBG_PRINT(ERR_DBG, "%s: Link down\n", dev->name);
+                        s2io_stop_all_tx_queue(sp);
                         netif_carrier_off(dev);
                         if(sp->mac_control.stats_info->sw_stat.link_up_cnt)
                         sp->mac_control.stats_info->sw_stat.link_up_time =
@@ -7472,6 +7581,7 @@ static void s2io_link(struct s2io_nic * sp, int link)
                                 jiffies - sp->start_time;
                         sp->mac_control.stats_info->sw_stat.link_up_cnt++;
                         netif_carrier_on(dev);
+                        s2io_wake_all_tx_queue(sp);
                 }
         }
         sp->last_link_state = link;
@@ -7508,7 +7618,8 @@ static void s2io_init_pci(struct s2io_nic * sp)
         pci_read_config_word(sp->pdev, PCI_COMMAND, &pci_cmd);
 }
 
-static int s2io_verify_parm(struct pci_dev *pdev, u8 *dev_intr_type)
+static int s2io_verify_parm(struct pci_dev *pdev, u8 *dev_intr_type,
+        u8 *dev_multiq)
 {
         if ((tx_fifo_num > MAX_TX_FIFOS) ||
                 (tx_fifo_num < FIFO_DEFAULT_NUM)) {
@@ -7522,6 +7633,18 @@ static int s2io_verify_parm(struct pci_dev *pdev, u8 *dev_intr_type)
                 DBG_PRINT(ERR_DBG, "tx fifos\n");
         }
 
+#ifndef CONFIG_NETDEVICES_MULTIQUEUE
+        if (multiq) {
+                DBG_PRINT(ERR_DBG, "s2io: Multiqueue support not enabled\n");
+                multiq = 0;
+        }
+#endif
+        /* if multiqueue is enabled configure all fifos */
+        if (multiq) {
+                tx_fifo_num = MAX_TX_FIFOS;
+                *dev_multiq = multiq;
+        }
+
         if ( rx_ring_num > 8) {
                 DBG_PRINT(ERR_DBG, "s2io: Requested number of Rx rings not "
                          "supported\n");
@@ -7613,9 +7736,11 @@ s2io_init_nic(struct pci_dev *pdev, const struct pci_device_id *pre)
         struct config_param *config;
         int mode;
         u8 dev_intr_type = intr_type;
+        u8 dev_multiq = 0;
         DECLARE_MAC_BUF(mac);
 
-        if ((ret = s2io_verify_parm(pdev, &dev_intr_type)))
+        ret = s2io_verify_parm(pdev, &dev_intr_type, &dev_multiq);
+        if (ret)
                 return ret;
 
         if ((ret = pci_enable_device(pdev))) {
@@ -7646,7 +7771,11 @@ s2io_init_nic(struct pci_dev *pdev, const struct pci_device_id *pre)
                 pci_disable_device(pdev);
                 return -ENODEV;
         }
-
+#ifdef CONFIG_NETDEVICES_MULTIQUEUE
+        if (dev_multiq)
+                dev = alloc_etherdev_mq(sizeof(struct s2io_nic), MAX_TX_FIFOS);
+        else
+#endif
         dev = alloc_etherdev(sizeof(struct s2io_nic));
         if (dev == NULL) {
                 DBG_PRINT(ERR_DBG, "Device allocation failed\n");
@@ -7698,6 +7827,7 @@ s2io_init_nic(struct pci_dev *pdev, const struct pci_device_id *pre)
 
         /* Tx side parameters. */
         config->tx_fifo_num = tx_fifo_num;
+        config->multiq = dev_multiq;
         for (i = 0; i < MAX_TX_FIFOS; i++) {
                 config->tx_cfg[i].fifo_len = tx_fifo_len[i];
                 config->tx_cfg[i].fifo_priority = i;
@@ -7705,7 +7835,7 @@ s2io_init_nic(struct pci_dev *pdev, const struct pci_device_id *pre)
 
         /* mapping the QoS priority to the configured fifos */
         for (i = 0; i < MAX_TX_FIFOS; i++)
-                config->fifo_mapping[i] = fifo_map[config->tx_fifo_num][i];
+                config->fifo_mapping[i] = fifo_map[config->tx_fifo_num - 1][i];
 
         config->tx_intr_type = TXD_INT_TYPE_UTILZ;
         for (i = 0; i < config->tx_fifo_num; i++) {
@@ -7810,7 +7940,10 @@ s2io_init_nic(struct pci_dev *pdev, const struct pci_device_id *pre)
                 dev->features |= NETIF_F_UFO;
                 dev->features |= NETIF_F_HW_CSUM;
         }
-
+#ifdef CONFIG_NETDEVICES_MULTIQUEUE
+        if (config->multiq)
+                dev->features |= NETIF_F_MULTI_QUEUE;
+#endif
         dev->tx_timeout = &s2io_tx_watchdog;
         dev->watchdog_timeo = WATCH_DOG_TIMEOUT;
         INIT_WORK(&sp->rst_timer_task, s2io_restart_nic);
@@ -7959,6 +8092,10 @@ s2io_init_nic(struct pci_dev *pdev, const struct pci_device_id *pre)
 
         if (napi)
                 DBG_PRINT(ERR_DBG, "%s: NAPI enabled\n", dev->name);
+
+        DBG_PRINT(ERR_DBG, "%s: Using %d Tx fifo(s)\n", dev->name,
+                sp->config.tx_fifo_num);
+
         switch(sp->config.intr_type) {
                 case INTA:
                     DBG_PRINT(ERR_DBG, "%s: Interrupt type INTA\n", dev->name);
@@ -7967,6 +8104,15 @@ s2io_init_nic(struct pci_dev *pdev, const struct pci_device_id *pre)
                     DBG_PRINT(ERR_DBG, "%s: Interrupt type MSI-X\n", dev->name);
                     break;
         }
+        if (sp->config.multiq) {
+        for (i = 0; i < sp->config.tx_fifo_num; i++)
+                mac_control->fifos[i].multiq = config->multiq;
+                DBG_PRINT(ERR_DBG, "%s: Multiqueue support enabled\n",
+                        dev->name);
+        } else
+                DBG_PRINT(ERR_DBG, "%s: Multiqueue support disabled\n",
+                        dev->name);
+
         if (sp->lro)
                 DBG_PRINT(ERR_DBG, "%s: Large receive offload enabled\n",
                           dev->name);
diff --git a/drivers/net/s2io.h b/drivers/net/s2io.h
index 64b88eb48287..fdc0a94d0a89 100644
--- a/drivers/net/s2io.h
+++ b/drivers/net/s2io.h
@@ -464,6 +464,7 @@ struct config_param {
         int max_mc_addr;        /* xena=64 herc=256 */
         int max_mac_addr;       /* xena=16 herc=64 */
         int mc_start_offset;    /* xena=16 herc=64 */
+        u8 multiq;
 };
 
 /* Structure representing MAC Addrs */
@@ -720,6 +721,15 @@ struct fifo_info {
          * the buffers
          */
         struct tx_curr_get_info tx_curr_get_info;
+#define FIFO_QUEUE_START 0
+#define FIFO_QUEUE_STOP 1
+        int queue_state;
+
+        /* copy of sp->dev pointer */
+        struct net_device *dev;
+
+        /* copy of multiq status */
+        u8 multiq;
 
         /* Per fifo lock */
         spinlock_t tx_lock;