cxgb3: separate TX and RX reclaim handlers

Separate TX and RX reclaim handlers
Don't disable interrupts in RX reclaim handler.

Signed-off-by: Divy Le Ray <divy@chelsio.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

2 files changed, 89 insertions, 40 deletions

diff --git a/drivers/net/cxgb3/adapter.h b/drivers/net/cxgb3/adapter.h
index 95dce4832478..66ce456614a8 100644
--- a/drivers/net/cxgb3/adapter.h
+++ b/drivers/net/cxgb3/adapter.h
@@ -197,6 +197,7 @@ struct sge_qset {		/* an SGE queue set */
         struct netdev_queue *tx_q;      /* associated netdev TX queue */
         unsigned long txq_stopped;      /* which Tx queues are stopped */
         struct timer_list tx_reclaim_timer;     /* reclaims TX buffers */
+        struct timer_list rx_reclaim_timer;     /* reclaims RX buffers */
         unsigned long port_stats[SGE_PSTAT_MAX];
 } ____cacheline_aligned;
 
diff --git a/drivers/net/cxgb3/sge.c b/drivers/net/cxgb3/sge.c
index a482429846eb..7d779d18e137 100644
--- a/drivers/net/cxgb3/sge.c
+++ b/drivers/net/cxgb3/sge.c
@@ -61,6 +61,7 @@
 #define FL1_PG_ORDER (PAGE_SIZE > 8192 ? 0 : 1)
 
 #define SGE_RX_DROP_THRES 16
+#define RX_RECLAIM_PERIOD (HZ/4)
 
 /*
  * Max number of Rx buffers we replenish at a time.
@@ -71,6 +72,8 @@
  * frequently as Tx buffers are usually reclaimed by new Tx packets.
  */
 #define TX_RECLAIM_PERIOD (HZ / 4)
+#define TX_RECLAIM_TIMER_CHUNK 64U
+#define TX_RECLAIM_CHUNK 16U
 
 /* WR size in bytes */
 #define WR_LEN (WR_FLITS * 8)
@@ -308,21 +311,25 @@ static void free_tx_desc(struct adapter *adapter, struct sge_txq *q,
  *      reclaim_completed_tx - reclaims completed Tx descriptors
  *      @adapter: the adapter
  *      @q: the Tx queue to reclaim completed descriptors from
+ *      @chunk: maximum number of descriptors to reclaim
  *
  *      Reclaims Tx descriptors that the SGE has indicated it has processed,
  *      and frees the associated buffers if possible.  Called with the Tx
  *      queue's lock held.
  */
-static inline void reclaim_completed_tx(struct adapter *adapter,
-                                        struct sge_txq *q)
+static inline unsigned int reclaim_completed_tx(struct adapter *adapter,
+                                                struct sge_txq *q,
+                                                unsigned int chunk)
 {
         unsigned int reclaim = q->processed - q->cleaned;
 
+        reclaim = min(chunk, reclaim);
         if (reclaim) {
                 free_tx_desc(adapter, q, reclaim);
                 q->cleaned += reclaim;
                 q->in_use -= reclaim;
         }
+        return q->processed - q->cleaned;
 }
 
 /**
@@ -601,6 +608,7 @@ static void t3_reset_qset(struct sge_qset *q)
         memset(q->txq, 0, sizeof(struct sge_txq) * SGE_TXQ_PER_SET);
         q->txq_stopped = 0;
         q->tx_reclaim_timer.function = NULL; /* for t3_stop_sge_timers() */
+        q->rx_reclaim_timer.function = NULL;
         q->lro_frag_tbl.nr_frags = q->lro_frag_tbl.len = 0;
 }
 
@@ -1179,7 +1187,7 @@ int t3_eth_xmit(struct sk_buff *skb, struct net_device *dev)
         txq = netdev_get_tx_queue(dev, qidx);
 
         spin_lock(&q->lock);
-        reclaim_completed_tx(adap, q);
+        reclaim_completed_tx(adap, q, TX_RECLAIM_CHUNK);
 
         credits = q->size - q->in_use;
         ndesc = calc_tx_descs(skb);
@@ -1588,7 +1596,7 @@ static int ofld_xmit(struct adapter *adap, struct sge_txq *q,
         unsigned int ndesc = calc_tx_descs_ofld(skb), pidx, gen;
 
         spin_lock(&q->lock);
-      again:reclaim_completed_tx(adap, q);
+again:  reclaim_completed_tx(adap, q, TX_RECLAIM_CHUNK);
 
         ret = check_desc_avail(adap, q, skb, ndesc, TXQ_OFLD);
         if (unlikely(ret)) {
@@ -1630,7 +1638,7 @@ static void restart_offloadq(unsigned long data)
         struct adapter *adap = pi->adapter;
 
         spin_lock(&q->lock);
-      again:reclaim_completed_tx(adap, q);
+again:  reclaim_completed_tx(adap, q, TX_RECLAIM_CHUNK);
 
         while ((skb = skb_peek(&q->sendq)) != NULL) {
                 unsigned int gen, pidx;
@@ -2747,13 +2755,13 @@ void t3_sge_err_intr_handler(struct adapter *adapter)
 }
 
 /**
- *      sge_timer_cb - perform periodic maintenance of an SGE qset
+ *      sge_timer_tx - perform periodic maintenance of an SGE qset
  *      @data: the SGE queue set to maintain
  *
  *      Runs periodically from a timer to perform maintenance of an SGE queue
  *      set.  It performs two tasks:
  *
- *      a) Cleans up any completed Tx descriptors that may still be pending.
+ *      Cleans up any completed Tx descriptors that may still be pending.
  *      Normal descriptor cleanup happens when new packets are added to a Tx
  *      queue so this timer is relatively infrequent and does any cleanup only
  *      if the Tx queue has not seen any new packets in a while.  We make a
@@ -2763,51 +2771,87 @@ void t3_sge_err_intr_handler(struct adapter *adapter)
  *      up).  Since control queues use immediate data exclusively we don't
  *      bother cleaning them up here.
  *
- *      b) Replenishes Rx queues that have run out due to memory shortage.
- *      Normally new Rx buffers are added when existing ones are consumed but
- *      when out of memory a queue can become empty.  We try to add only a few
- *      buffers here, the queue will be replenished fully as these new buffers
- *      are used up if memory shortage has subsided.
  */
-static void sge_timer_cb(unsigned long data)
+static void sge_timer_tx(unsigned long data)
 {
-        spinlock_t *lock;
         struct sge_qset *qs = (struct sge_qset *)data;
-        struct adapter *adap = qs->adap;
+        struct port_info *pi = netdev_priv(qs->netdev);
+        struct adapter *adap = pi->adapter;
+        unsigned int tbd[SGE_TXQ_PER_SET] = {0, 0};
+        unsigned long next_period;
 
         if (spin_trylock(&qs->txq[TXQ_ETH].lock)) {
-                reclaim_completed_tx(adap, &qs->txq[TXQ_ETH]);
+                tbd[TXQ_ETH] = reclaim_completed_tx(adap, &qs->txq[TXQ_ETH],
+                                                    TX_RECLAIM_TIMER_CHUNK);
                 spin_unlock(&qs->txq[TXQ_ETH].lock);
         }
         if (spin_trylock(&qs->txq[TXQ_OFLD].lock)) {
-                reclaim_completed_tx(adap, &qs->txq[TXQ_OFLD]);
+                tbd[TXQ_OFLD] = reclaim_completed_tx(adap, &qs->txq[TXQ_OFLD],
+                                                     TX_RECLAIM_TIMER_CHUNK);
                 spin_unlock(&qs->txq[TXQ_OFLD].lock);
         }
-        lock = (adap->flags & USING_MSIX) ? &qs->rspq.lock :
-                                            &adap->sge.qs[0].rspq.lock;
-        if (spin_trylock_irq(lock)) {
-                if (!napi_is_scheduled(&qs->napi)) {
-                        u32 status = t3_read_reg(adap, A_SG_RSPQ_FL_STATUS);
-
-                        if (qs->fl[0].credits < qs->fl[0].size)
-                                __refill_fl(adap, &qs->fl[0]);
-                        if (qs->fl[1].credits < qs->fl[1].size)
-                                __refill_fl(adap, &qs->fl[1]);
-
-                        if (status & (1 << qs->rspq.cntxt_id)) {
-                                qs->rspq.starved++;
-                                if (qs->rspq.credits) {
-                                        refill_rspq(adap, &qs->rspq, 1);
-                                        qs->rspq.credits--;
-                                        qs->rspq.restarted++;
-                                        t3_write_reg(adap, A_SG_RSPQ_FL_STATUS,
-                                                     1 << qs->rspq.cntxt_id);
-                                }
+
+        next_period = TX_RECLAIM_PERIOD >>
+                      (max(tbd[TXQ_ETH], tbd[TXQ_OFLD]) /
+                       TX_RECLAIM_TIMER_CHUNK);
+        mod_timer(&qs->tx_reclaim_timer, jiffies + next_period);
+}
+
+/*
+ *      sge_timer_rx - perform periodic maintenance of an SGE qset
+ *      @data: the SGE queue set to maintain
+ *
+ *      a) Replenishes Rx queues that have run out due to memory shortage.
+ *      Normally new Rx buffers are added when existing ones are consumed but
+ *      when out of memory a queue can become empty.  We try to add only a few
+ *      buffers here, the queue will be replenished fully as these new buffers
+ *      are used up if memory shortage has subsided.
+ *
+ *      b) Return coalesced response queue credits in case a response queue is
+ *      starved.
+ *
+ */
+static void sge_timer_rx(unsigned long data)
+{
+        spinlock_t *lock;
+        struct sge_qset *qs = (struct sge_qset *)data;
+        struct port_info *pi = netdev_priv(qs->netdev);
+        struct adapter *adap = pi->adapter;
+        u32 status;
+
+        lock = adap->params.rev > 0 ?
+               &qs->rspq.lock : &adap->sge.qs[0].rspq.lock;
+
+        if (!spin_trylock_irq(lock))
+                goto out;
+
+        if (napi_is_scheduled(&qs->napi))
+                goto unlock;
+
+        if (adap->params.rev < 4) {
+                status = t3_read_reg(adap, A_SG_RSPQ_FL_STATUS);
+
+                if (status & (1 << qs->rspq.cntxt_id)) {
+                        qs->rspq.starved++;
+                        if (qs->rspq.credits) {
+                                qs->rspq.credits--;
+                                refill_rspq(adap, &qs->rspq, 1);
+                                qs->rspq.restarted++;
+                                t3_write_reg(adap, A_SG_RSPQ_FL_STATUS,
+                                             1 << qs->rspq.cntxt_id);
                         }
                 }
-                spin_unlock_irq(lock);
         }
-        mod_timer(&qs->tx_reclaim_timer, jiffies + TX_RECLAIM_PERIOD);
+
+        if (qs->fl[0].credits < qs->fl[0].size)
+                __refill_fl(adap, &qs->fl[0]);
+        if (qs->fl[1].credits < qs->fl[1].size)
+                __refill_fl(adap, &qs->fl[1]);
+
+unlock:
+        spin_unlock_irq(lock);
+out:
+        mod_timer(&qs->rx_reclaim_timer, jiffies + RX_RECLAIM_PERIOD);
 }
 
 /**
@@ -2850,7 +2894,8 @@ int t3_sge_alloc_qset(struct adapter *adapter, unsigned int id, int nports,
         struct sge_qset *q = &adapter->sge.qs[id];
 
         init_qset_cntxt(q, id);
-        setup_timer(&q->tx_reclaim_timer, sge_timer_cb, (unsigned long)q);
+        setup_timer(&q->tx_reclaim_timer, sge_timer_tx, (unsigned long)q);
+        setup_timer(&q->rx_reclaim_timer, sge_timer_rx, (unsigned long)q);
 
         q->fl[0].desc = alloc_ring(adapter->pdev, p->fl_size,
                                    sizeof(struct rx_desc),
@@ -2999,6 +3044,7 @@ int t3_sge_alloc_qset(struct adapter *adapter, unsigned int id, int nports,
                      V_NEWTIMER(q->rspq.holdoff_tmr));
 
         mod_timer(&q->tx_reclaim_timer, jiffies + TX_RECLAIM_PERIOD);
+        mod_timer(&q->rx_reclaim_timer, jiffies + RX_RECLAIM_PERIOD);
 
         return 0;
 
@@ -3024,6 +3070,8 @@ void t3_stop_sge_timers(struct adapter *adap)
 
                 if (q->tx_reclaim_timer.function)
                         del_timer_sync(&q->tx_reclaim_timer);
+                if (q->rx_reclaim_timer.function)
+                        del_timer_sync(&q->rx_reclaim_timer);
         }
 }