iwlwifi: pcie: implement GRO without NAPI

Use the new NAPI infrastructure added to mac80211 to get
GRO. We don't really implement NAPI since we don't have
a real poll function and we never schedule a NAPI poll.
Instead of this, we collect all the packets we got from a
single interrupt and then call napi_gro_flush().

This allows us to benefit from GRO. In half duplex medium
like WiFi, its main advantage is that it reduces the number
of TCP Acks, hence improving the TCP Rx performance.

Since we call the Rx path with a spinlock held, remove
the might_sleep mention from the op_mode's API.

Signed-off-by: Johannes Berg <johannes.berg@intel.com>
Reviewed-by: Ido Yariv <ido@wizery.com>
[Squash different patches and rewrite the commit message]
Signed-off-by: Emmanuel Grumbach <emmanuel.grumbach@intel.com>

diff --git a/drivers/net/wireless/iwlwifi/dvm/main.c b/drivers/net/wireless/iwlwifi/dvm/main.c
index 6a6df71af1d7ba6e4b4dfec16a2042c6cc357de4..6a00353768f328b1931d54a51eef8c7eb8bbc248 100644 (file)
--- a/drivers/net/wireless/iwlwifi/dvm/main.c
+++ b/drivers/net/wireless/iwlwifi/dvm/main.c
@@ -2053,6 +2053,17 @@ static bool iwl_set_hw_rfkill_state(struct iwl_op_mode *op_mode, bool state)
        return false;
 }
 
+static void iwl_napi_add(struct iwl_op_mode *op_mode,
+                        struct napi_struct *napi,
+                        struct net_device *napi_dev,
+                        int (*poll)(struct napi_struct *, int),
+                        int weight)
+{
+       struct iwl_priv *priv = IWL_OP_MODE_GET_DVM(op_mode);
+
+       ieee80211_napi_add(priv->hw, napi, napi_dev, poll, weight);
+}
+
 static const struct iwl_op_mode_ops iwl_dvm_ops = {
        .start = iwl_op_mode_dvm_start,
        .stop = iwl_op_mode_dvm_stop,
@@ -2065,6 +2076,7 @@ static const struct iwl_op_mode_ops iwl_dvm_ops = {
        .cmd_queue_full = iwl_cmd_queue_full,
        .nic_config = iwl_nic_config,
        .wimax_active = iwl_wimax_active,
+       .napi_add = iwl_napi_add,
 };
 
 /*****************************************************************************

diff --git a/drivers/net/wireless/iwlwifi/iwl-op-mode.h b/drivers/net/wireless/iwlwifi/iwl-op-mode.h
index ea29504ac61704c39c24a117dec0a5d92aa58376..99785c892f963c7435b0048c4a097f6cae9e7808 100644 (file)
--- a/drivers/net/wireless/iwlwifi/iwl-op-mode.h
+++ b/drivers/net/wireless/iwlwifi/iwl-op-mode.h
@@ -63,6 +63,7 @@
 #ifndef __iwl_op_mode_h__
 #define __iwl_op_mode_h__
 
+#include <linux/netdevice.h>
 #include <linux/debugfs.h>
 
 struct iwl_op_mode;
@@ -112,8 +113,11 @@ struct iwl_cfg;
  * @stop: stop the op_mode. Must free all the memory allocated.
  *     May sleep
  * @rx: Rx notification to the op_mode. rxb is the Rx buffer itself. Cmd is the
- *     HCMD this Rx responds to.
- *     This callback may sleep, it is called from a threaded IRQ handler.
+ *     HCMD this Rx responds to. Can't sleep.
+ * @napi_add: NAPI initialisation. The transport is fully responsible for NAPI,
+ *     but the higher layers need to know about it (in particular mac80211 to
+ *     to able to call the right NAPI RX functions); this function is needed
+ *     to eventually call netif_napi_add() with higher layer involvement.
  * @queue_full: notifies that a HW queue is full.
  *     Must be atomic and called with BH disabled.
  * @queue_not_full: notifies that a HW queue is not full any more.
@@ -143,6 +147,11 @@ struct iwl_op_mode_ops {
        void (*stop)(struct iwl_op_mode *op_mode);
        int (*rx)(struct iwl_op_mode *op_mode, struct iwl_rx_cmd_buffer *rxb,
                  struct iwl_device_cmd *cmd);
+       void (*napi_add)(struct iwl_op_mode *op_mode,
+                        struct napi_struct *napi,
+                        struct net_device *napi_dev,
+                        int (*poll)(struct napi_struct *, int),
+                        int weight);
        void (*queue_full)(struct iwl_op_mode *op_mode, int queue);
        void (*queue_not_full)(struct iwl_op_mode *op_mode, int queue);
        bool (*hw_rf_kill)(struct iwl_op_mode *op_mode, bool state);
@@ -180,7 +189,6 @@ static inline int iwl_op_mode_rx(struct iwl_op_mode *op_mode,
                                  struct iwl_rx_cmd_buffer *rxb,
                                  struct iwl_device_cmd *cmd)
 {
-       might_sleep();
        return op_mode->ops->rx(op_mode, rxb, cmd);
 }
 
@@ -249,4 +257,15 @@ static inline int iwl_op_mode_exit_d0i3(struct iwl_op_mode *op_mode)
        return op_mode->ops->exit_d0i3(op_mode);
 }
 
+static inline void iwl_op_mode_napi_add(struct iwl_op_mode *op_mode,
+                                       struct napi_struct *napi,
+                                       struct net_device *napi_dev,
+                                       int (*poll)(struct napi_struct *, int),
+                                       int weight)
+{
+       if (!op_mode->ops->napi_add)
+               return;
+       op_mode->ops->napi_add(op_mode, napi, napi_dev, poll, weight);
+}
+
 #endif /* __iwl_op_mode_h__ */

diff --git a/drivers/net/wireless/iwlwifi/mvm/ops.c b/drivers/net/wireless/iwlwifi/mvm/ops.c
index 9545d7fdd4bfc69dfb1fb8c4e07de097d58b6ea7..e436c04083c289d5a304e3b29bb9d2ee5ac55900 100644 (file)
--- a/drivers/net/wireless/iwlwifi/mvm/ops.c
+++ b/drivers/net/wireless/iwlwifi/mvm/ops.c
@@ -1183,6 +1183,17 @@ out:
        return ret;
 }
 
+static void iwl_mvm_napi_add(struct iwl_op_mode *op_mode,
+                            struct napi_struct *napi,
+                            struct net_device *napi_dev,
+                            int (*poll)(struct napi_struct *, int),
+                            int weight)
+{
+       struct iwl_mvm *mvm = IWL_OP_MODE_GET_MVM(op_mode);
+
+       ieee80211_napi_add(mvm->hw, napi, napi_dev, poll, weight);
+}
+
 static const struct iwl_op_mode_ops iwl_mvm_ops = {
        .start = iwl_op_mode_mvm_start,
        .stop = iwl_op_mode_mvm_stop,
@@ -1196,4 +1207,5 @@ static const struct iwl_op_mode_ops iwl_mvm_ops = {
        .nic_config = iwl_mvm_nic_config,
        .enter_d0i3 = iwl_mvm_enter_d0i3,
        .exit_d0i3 = iwl_mvm_exit_d0i3,
+       .napi_add = iwl_mvm_napi_add,
 };

diff --git a/drivers/net/wireless/iwlwifi/mvm/rx.c b/drivers/net/wireless/iwlwifi/mvm/rx.c
index 6061553a5e444956c7b5d626695a2950fb1f3fd1..69f6aa694bfe57eb42fccd6783090f0806d86f17 100644 (file)
--- a/drivers/net/wireless/iwlwifi/mvm/rx.c
+++ b/drivers/net/wireless/iwlwifi/mvm/rx.c
@@ -130,7 +130,7 @@ static void iwl_mvm_pass_packet_to_mac80211(struct iwl_mvm *mvm,
 
        memcpy(IEEE80211_SKB_RXCB(skb), stats, sizeof(*stats));
 
-       ieee80211_rx_ni(mvm->hw, skb);
+       ieee80211_rx(mvm->hw, skb);
 }
 
 static void iwl_mvm_calc_rssi(struct iwl_mvm *mvm,

diff --git a/drivers/net/wireless/iwlwifi/mvm/tx.c b/drivers/net/wireless/iwlwifi/mvm/tx.c
index 0a4ad45949d599cbf4bbe76e2a25fff8b022dbf0..ff1b630e130eed5ab07a2bbcb222088df410d557 100644 (file)
--- a/drivers/net/wireless/iwlwifi/mvm/tx.c
+++ b/drivers/net/wireless/iwlwifi/mvm/tx.c
@@ -640,7 +640,7 @@ static void iwl_mvm_rx_tx_cmd_single(struct iwl_mvm *mvm,
                info->status.status_driver_data[0] =
                                (void *)(uintptr_t)tx_resp->reduced_tpc;
 
-               ieee80211_tx_status_ni(mvm->hw, skb);
+               ieee80211_tx_status(mvm->hw, skb);
        }
 
        if (txq_id >= mvm->first_agg_queue) {
@@ -944,7 +944,7 @@ int iwl_mvm_rx_ba_notif(struct iwl_mvm *mvm, struct iwl_rx_cmd_buffer *rxb,
 
        while (!skb_queue_empty(&reclaimed_skbs)) {
                skb = __skb_dequeue(&reclaimed_skbs);
-               ieee80211_tx_status_ni(mvm->hw, skb);
+               ieee80211_tx_status(mvm->hw, skb);
        }
 
        return 0;

diff --git a/drivers/net/wireless/iwlwifi/pcie/internal.h b/drivers/net/wireless/iwlwifi/pcie/internal.h
index 9091513ea7388ce11f2294fbb609b3581073e2a0..e2694686ebfc5b78847b48c77664c88fd037dbfd 100644 (file)
--- a/drivers/net/wireless/iwlwifi/pcie/internal.h
+++ b/drivers/net/wireless/iwlwifi/pcie/internal.h
@@ -270,6 +270,9 @@ struct iwl_trans_pcie {
        struct iwl_trans *trans;
        struct iwl_drv *drv;
 
+       struct net_device napi_dev;
+       struct napi_struct napi;
+
        /* INT ICT Table */
        __le32 *ict_tbl;
        dma_addr_t ict_tbl_dma;

diff --git a/drivers/net/wireless/iwlwifi/pcie/rx.c b/drivers/net/wireless/iwlwifi/pcie/rx.c
index fdfa3969cac986c1824bd65c41512a9ac4ba7b39..e8e5afcaf42bac10a622a4bc195f416b1ed30411 100644 (file)
--- a/drivers/net/wireless/iwlwifi/pcie/rx.c
+++ b/drivers/net/wireless/iwlwifi/pcie/rx.c
@@ -673,7 +673,6 @@ static void iwl_pcie_rx_handle_rb(struct iwl_trans *trans,
        /* Reuse the page if possible. For notification packets and
         * SKBs that fail to Rx correctly, add them back into the
         * rx_free list for reuse later. */
-       spin_lock(&rxq->lock);
        if (rxb->page != NULL) {
                rxb->page_dma =
                        dma_map_page(trans->dev, rxb->page, 0,
@@ -694,7 +693,6 @@ static void iwl_pcie_rx_handle_rb(struct iwl_trans *trans,
                }
        } else
                list_add_tail(&rxb->list, &rxq->rx_used);
-       spin_unlock(&rxq->lock);
 }
 
 /*
@@ -709,6 +707,8 @@ static void iwl_pcie_rx_handle(struct iwl_trans *trans)
        u32 count = 8;
        int total_empty;
 
+restart:
+       spin_lock(&rxq->lock);
        /* uCode's read index (stored in shared DRAM) indicates the last Rx
         * buffer that the driver may process (last buffer filled by ucode). */
        r = le16_to_cpu(ACCESS_ONCE(rxq->rb_stts->closed_rb_num)) & 0x0FFF;
@@ -743,18 +743,25 @@ static void iwl_pcie_rx_handle(struct iwl_trans *trans)
                        count++;
                        if (count >= 8) {
                                rxq->read = i;
+                               spin_unlock(&rxq->lock);
                                iwl_pcie_rx_replenish_now(trans);
                                count = 0;
+                               goto restart;
                        }
                }
        }
 
        /* Backtrack one entry */
        rxq->read = i;
+       spin_unlock(&rxq->lock);
+
        if (fill_rx)
                iwl_pcie_rx_replenish_now(trans);
        else
                iwl_pcie_rxq_restock(trans);
+
+       if (trans_pcie->napi.poll)
+               napi_gro_flush(&trans_pcie->napi, false);
 }
 
 /*
@@ -1068,8 +1075,6 @@ irqreturn_t iwl_pcie_irq_handler(int irq, void *dev_id)
                iwl_write8(trans, CSR_INT_PERIODIC_REG,
                            CSR_INT_PERIODIC_DIS);
 
-               iwl_pcie_rx_handle(trans);
-
                /*
                 * Enable periodic interrupt in 8 msec only if we received
                 * real RX interrupt (instead of just periodic int), to catch
@@ -1082,6 +1087,10 @@ irqreturn_t iwl_pcie_irq_handler(int irq, void *dev_id)
                                   CSR_INT_PERIODIC_ENA);
 
                isr_stats->rx++;
+
+               local_bh_disable();
+               iwl_pcie_rx_handle(trans);
+               local_bh_enable();
        }
 
        /* This "Tx" DMA channel is used only for loading uCode */

diff --git a/drivers/net/wireless/iwlwifi/pcie/trans.c b/drivers/net/wireless/iwlwifi/pcie/trans.c
index dcfd6d866d095081d7001795c4ec802c3044926f..97e6bd8268803bc021f705d311c9307333de2549 100644 (file)
--- a/drivers/net/wireless/iwlwifi/pcie/trans.c
+++ b/drivers/net/wireless/iwlwifi/pcie/trans.c
@@ -1053,6 +1053,12 @@ static void iwl_trans_pcie_write_prph(struct iwl_trans *trans, u32 addr,
        iwl_trans_pcie_write32(trans, HBUS_TARG_PRPH_WDAT, val);
 }
 
+static int iwl_pcie_dummy_napi_poll(struct napi_struct *napi, int budget)
+{
+       WARN_ON(1);
+       return 0;
+}
+
 static void iwl_trans_pcie_configure(struct iwl_trans *trans,
                                     const struct iwl_trans_config *trans_cfg)
 {
@@ -1079,6 +1085,18 @@ static void iwl_trans_pcie_configure(struct iwl_trans *trans,
 
        trans_pcie->command_names = trans_cfg->command_names;
        trans_pcie->bc_table_dword = trans_cfg->bc_table_dword;
+
+       /* Initialize NAPI here - it should be before registering to mac80211
+        * in the opmode but after the HW struct is allocated.
+        * As this function may be called again in some corner cases don't
+        * do anything if NAPI was already initialized.
+        */
+       if (!trans_pcie->napi.poll && trans->op_mode->ops->napi_add) {
+               init_dummy_netdev(&trans_pcie->napi_dev);
+               iwl_op_mode_napi_add(trans->op_mode, &trans_pcie->napi,
+                                    &trans_pcie->napi_dev,
+                                    iwl_pcie_dummy_napi_poll, 64);
+       }
 }
 
 void iwl_trans_pcie_free(struct iwl_trans *trans)
@@ -1099,6 +1117,9 @@ void iwl_trans_pcie_free(struct iwl_trans *trans)
        pci_disable_device(trans_pcie->pci_dev);
        kmem_cache_destroy(trans->dev_cmd_pool);
 
+       if (trans_pcie->napi.poll)
+               netif_napi_del(&trans_pcie->napi);
+
        kfree(trans);
 }