sfc: Cleanup RX event processing

Make efx_process_channel() and falcon_process_eventq() return the
number of packets received rather than updating the quota, consistent
with new NAPI.

Since channels and RX queues are mapped one-to-one, remove return
value from falcon_handle_rx_event() and add a warning for events
with the wrong RX queue number.

Signed-off-by: Ben Hutchings <bhutchings@solarflare.com>
Signed-off-by: Jeff Garzik <jgarzik@redhat.com>

3 files changed, 23 insertions, 36 deletions

diff --git a/drivers/net/sfc/efx.c b/drivers/net/sfc/efx.c
index 22004a612d2c..864095ea5b37 100644
--- a/drivers/net/sfc/efx.c
+++ b/drivers/net/sfc/efx.c
@@ -160,14 +160,16 @@ static void efx_fini_channels(struct efx_nic *efx);
  */
 static int efx_process_channel(struct efx_channel *channel, int rx_quota)
 {
-        int rxdmaqs;
-        struct efx_rx_queue *rx_queue;
+        struct efx_nic *efx = channel->efx;
+        int rx_packets;
 
-        if (unlikely(channel->efx->reset_pending != RESET_TYPE_NONE ||
+        if (unlikely(efx->reset_pending != RESET_TYPE_NONE ||
                      !channel->enabled))
-                return rx_quota;
+                return 0;
 
-        rxdmaqs = falcon_process_eventq(channel, &rx_quota);
+        rx_packets = falcon_process_eventq(channel, rx_quota);
+        if (rx_packets == 0)
+                return 0;
 
         /* Deliver last RX packet. */
         if (channel->rx_pkt) {
@@ -179,16 +181,9 @@ static int efx_process_channel(struct efx_channel *channel, int rx_quota)
         efx_flush_lro(channel);
         efx_rx_strategy(channel);
 
-        /* Refill descriptor rings as necessary */
-        rx_queue = &channel->efx->rx_queue[0];
-        while (rxdmaqs) {
-                if (rxdmaqs & 0x01)
-                        efx_fast_push_rx_descriptors(rx_queue);
-                rx_queue++;
-                rxdmaqs >>= 1;
-        }
+        efx_fast_push_rx_descriptors(&efx->rx_queue[channel->channel]);
 
-        return rx_quota;
+        return rx_packets;
 }
 
 /* Mark channel as finished processing
@@ -218,14 +213,12 @@ static int efx_poll(struct napi_struct *napi, int budget)
         struct efx_channel *channel =
                 container_of(napi, struct efx_channel, napi_str);
         struct net_device *napi_dev = channel->napi_dev;
-        int unused;
         int rx_packets;
 
         EFX_TRACE(channel->efx, "channel %d NAPI poll executing on CPU %d\n",
                   channel->channel, raw_smp_processor_id());
 
-        unused = efx_process_channel(channel, budget);
-        rx_packets = (budget - unused);
+        rx_packets = efx_process_channel(channel, budget);
 
         if (rx_packets < budget) {
                 /* There is no race here; although napi_disable() will
diff --git a/drivers/net/sfc/falcon.c b/drivers/net/sfc/falcon.c
index 7b1c387ff8ef..96cb5d031ed7 100644
--- a/drivers/net/sfc/falcon.c
+++ b/drivers/net/sfc/falcon.c
@@ -952,10 +952,10 @@ static void falcon_handle_rx_bad_index(struct efx_rx_queue *rx_queue,
  * Also "is multicast" and "matches multicast filter" flags can be used to
  * discard non-matching multicast packets.
  */
-static int falcon_handle_rx_event(struct efx_channel *channel,
-                                  const efx_qword_t *event)
+static void falcon_handle_rx_event(struct efx_channel *channel,
+                                   const efx_qword_t *event)
 {
-        unsigned int rx_ev_q_label, rx_ev_desc_ptr, rx_ev_byte_cnt;
+        unsigned int rx_ev_desc_ptr, rx_ev_byte_cnt;
         unsigned int rx_ev_hdr_type, rx_ev_mcast_pkt;
         unsigned expected_ptr;
         bool rx_ev_pkt_ok, discard = false, checksummed;
@@ -968,16 +968,14 @@ static int falcon_handle_rx_event(struct efx_channel *channel,
         rx_ev_hdr_type = EFX_QWORD_FIELD(*event, RX_EV_HDR_TYPE);
         WARN_ON(EFX_QWORD_FIELD(*event, RX_EV_JUMBO_CONT));
         WARN_ON(EFX_QWORD_FIELD(*event, RX_EV_SOP) != 1);
+        WARN_ON(EFX_QWORD_FIELD(*event, RX_EV_Q_LABEL) != channel->channel);
 
-        rx_ev_q_label = EFX_QWORD_FIELD(*event, RX_EV_Q_LABEL);
-        rx_queue = &efx->rx_queue[rx_ev_q_label];
+        rx_queue = &efx->rx_queue[channel->channel];
 
         rx_ev_desc_ptr = EFX_QWORD_FIELD(*event, RX_EV_DESC_PTR);
         expected_ptr = rx_queue->removed_count & FALCON_RXD_RING_MASK;
-        if (unlikely(rx_ev_desc_ptr != expected_ptr)) {
+        if (unlikely(rx_ev_desc_ptr != expected_ptr))
                 falcon_handle_rx_bad_index(rx_queue, rx_ev_desc_ptr);
-                return rx_ev_q_label;
-        }
 
         if (likely(rx_ev_pkt_ok)) {
                 /* If packet is marked as OK and packet type is TCP/IPv4 or
@@ -1003,8 +1001,6 @@ static int falcon_handle_rx_event(struct efx_channel *channel,
         /* Handle received packet */
         efx_rx_packet(rx_queue, rx_ev_desc_ptr, rx_ev_byte_cnt,
                       checksummed, discard);
-
-        return rx_ev_q_label;
 }
 
 /* Global events are basically PHY events */
@@ -1109,13 +1105,12 @@ static void falcon_handle_driver_event(struct efx_channel *channel,
         }
 }
 
-int falcon_process_eventq(struct efx_channel *channel, int *rx_quota)
+int falcon_process_eventq(struct efx_channel *channel, int rx_quota)
 {
         unsigned int read_ptr;
         efx_qword_t event, *p_event;
         int ev_code;
-        int rxq;
-        int rxdmaqs = 0;
+        int rx_packets = 0;
 
         read_ptr = channel->eventq_read_ptr;
 
@@ -1137,9 +1132,8 @@ int falcon_process_eventq(struct efx_channel *channel, int *rx_quota)
 
                 switch (ev_code) {
                 case RX_IP_EV_DECODE:
-                        rxq = falcon_handle_rx_event(channel, &event);
-                        rxdmaqs |= (1 << rxq);
-                        (*rx_quota)--;
+                        falcon_handle_rx_event(channel, &event);
+                        ++rx_packets;
                         break;
                 case TX_IP_EV_DECODE:
                         falcon_handle_tx_event(channel, &event);
@@ -1166,10 +1160,10 @@ int falcon_process_eventq(struct efx_channel *channel, int *rx_quota)
                 /* Increment read pointer */
                 read_ptr = (read_ptr + 1) & FALCON_EVQ_MASK;
 
-        } while (*rx_quota);
+        } while (rx_packets < rx_quota);
 
         channel->eventq_read_ptr = read_ptr;
-        return rxdmaqs;
+        return rx_packets;
 }
 
 void falcon_set_int_moderation(struct efx_channel *channel)
diff --git a/drivers/net/sfc/falcon.h b/drivers/net/sfc/falcon.h
index a72f50e3e6eb..4cf05d0b5cfa 100644
--- a/drivers/net/sfc/falcon.h
+++ b/drivers/net/sfc/falcon.h
@@ -57,7 +57,7 @@ extern int falcon_probe_eventq(struct efx_channel *channel);
 extern int falcon_init_eventq(struct efx_channel *channel);
 extern void falcon_fini_eventq(struct efx_channel *channel);
 extern void falcon_remove_eventq(struct efx_channel *channel);
-extern int falcon_process_eventq(struct efx_channel *channel, int *rx_quota);
+extern int falcon_process_eventq(struct efx_channel *channel, int rx_quota);
 extern void falcon_eventq_read_ack(struct efx_channel *channel);
 
 /* Ports */