bnxt_en: Remove atomic operations on ptp->tx_avail

Now that we require the spinlock to protect ptp->txts_prod, change
ptp->tx_avail to non-atomic and protect it under the same spinlock.
Add a new helper function bnxt_ptp_get_txts_prod() to decrement
ptp->tx_avail under spinlock and return the producer.

Signed-off-by: Pavan Chebbi <pavan.chebbi@broadcom.com>
Signed-off-by: Michael Chan <michael.chan@broadcom.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

diff --git a/drivers/net/ethernet/broadcom/bnxt/bnxt.c b/drivers/net/ethernet/broadcom/bnxt/bnxt.c
index 9cb81b74fac91bde0b7e3d84b2f58cb2bc9f13dd..a1690207d7935f1a9b34409e1a9180c703d61123 100644 (file)
--- a/drivers/net/ethernet/broadcom/bnxt/bnxt.c
+++ b/drivers/net/ethernet/broadcom/bnxt/bnxt.c
@@ -519,34 +519,20 @@ static netdev_tx_t bnxt_start_xmit(struct sk_buff *skb, struct net_device *dev)
                } else if (!skb_is_gso(skb)) {
                        u16 seq_id, hdr_off;
 
-                       if (atomic_dec_if_positive(&ptp->tx_avail) < 0) {
-                               atomic64_inc(&ptp->stats.ts_err);
-                               goto tx_no_ts;
-                       }
-
-                       if (!bnxt_ptp_parse(skb, &seq_id, &hdr_off)) {
+                       if (!bnxt_ptp_parse(skb, &seq_id, &hdr_off) &&
+                           !bnxt_ptp_get_txts_prod(ptp, &txts_prod)) {
                                if (vlan_tag_flags)
                                        hdr_off += VLAN_HLEN;
                                lflags |= cpu_to_le32(TX_BD_FLAGS_STAMP);
                                tx_buf->is_ts_pkt = 1;
                                skb_shinfo(skb)->tx_flags |= SKBTX_IN_PROGRESS;
 
-                               spin_lock_bh(&ptp->ptp_tx_lock);
-                               txts_prod = ptp->txts_prod;
-                               ptp->txts_prod = NEXT_TXTS(txts_prod);
-                               spin_unlock_bh(&ptp->ptp_tx_lock);
-
                                ptp->txts_req[txts_prod].tx_seqid = seq_id;
                                ptp->txts_req[txts_prod].tx_hdr_off = hdr_off;
                                tx_buf->txts_prod = txts_prod;
-
-                       } else {
-                               atomic_inc(&bp->ptp_cfg->tx_avail);
                        }
                }
        }
-
-tx_no_ts:
        if (unlikely(skb->no_fcs))
                lflags |= cpu_to_le32(TX_BD_FLAGS_NO_CRC);
 
@@ -12183,7 +12169,7 @@ static int __bnxt_open_nic(struct bnxt *bp, bool irq_re_init, bool link_re_init)
        if (BNXT_PF(bp))
                bnxt_vf_reps_open(bp);
        if (bp->ptp_cfg && !(bp->fw_cap & BNXT_FW_CAP_TX_TS_CMP))
-               atomic_set(&bp->ptp_cfg->tx_avail, BNXT_MAX_TX_TS);
+               WRITE_ONCE(bp->ptp_cfg->tx_avail, BNXT_MAX_TX_TS);
        bnxt_ptp_init_rtc(bp, true);
        bnxt_ptp_cfg_tstamp_filters(bp);
        if (BNXT_SUPPORTS_MULTI_RSS_CTX(bp))

diff --git a/drivers/net/ethernet/broadcom/bnxt/bnxt_ptp.c b/drivers/net/ethernet/broadcom/bnxt/bnxt_ptp.c
index 9e93dc8b2b573901b8103a3a78383bb67589a51a..37d42423459c8eb1e35df763b4dd1a09bceed80a 100644 (file)
--- a/drivers/net/ethernet/broadcom/bnxt/bnxt_ptp.c
+++ b/drivers/net/ethernet/broadcom/bnxt/bnxt_ptp.c
@@ -730,10 +730,10 @@ static long bnxt_ptp_ts_aux_work(struct ptp_clock_info *ptp_info)
        unsigned long now = jiffies;
        struct bnxt *bp = ptp->bp;
        u16 cons = ptp->txts_cons;
-       u8 num_requests;
+       u32 num_requests;
        int rc = 0;
 
-       num_requests = BNXT_MAX_TX_TS - atomic_read(&ptp->tx_avail);
+       num_requests = BNXT_MAX_TX_TS - READ_ONCE(ptp->tx_avail);
        while (num_requests--) {
                if (IS_ERR(ptp->txts_req[cons].tx_skb))
                        goto next_slot;
@@ -743,7 +743,7 @@ static long bnxt_ptp_ts_aux_work(struct ptp_clock_info *ptp_info)
                if (rc == -EAGAIN)
                        break;
 next_slot:
-               atomic_inc(&ptp->tx_avail);
+               BNXT_PTP_INC_TX_AVAIL(ptp);
                cons = NEXT_TXTS(cons);
        }
        ptp->txts_cons = cons;
@@ -767,6 +767,21 @@ next_slot:
        return HZ;
 }
 
+int bnxt_ptp_get_txts_prod(struct bnxt_ptp_cfg *ptp, u16 *prod)
+{
+       spin_lock_bh(&ptp->ptp_tx_lock);
+       if (ptp->tx_avail) {
+               *prod = ptp->txts_prod;
+               ptp->txts_prod = NEXT_TXTS(*prod);
+               ptp->tx_avail--;
+               spin_unlock_bh(&ptp->ptp_tx_lock);
+               return 0;
+       }
+       spin_unlock_bh(&ptp->ptp_tx_lock);
+       atomic64_inc(&ptp->stats.ts_err);
+       return -ENOSPC;
+}
+
 void bnxt_get_tx_ts_p5(struct bnxt *bp, struct sk_buff *skb, u16 prod)
 {
        struct bnxt_ptp_cfg *ptp = bp->ptp_cfg;
@@ -1014,7 +1029,7 @@ int bnxt_ptp_init(struct bnxt *bp, bool phc_cfg)
 
        bnxt_ptp_free(bp);
 
-       atomic_set(&ptp->tx_avail, BNXT_MAX_TX_TS);
+       WRITE_ONCE(ptp->tx_avail, BNXT_MAX_TX_TS);
        spin_lock_init(&ptp->ptp_lock);
        spin_lock_init(&ptp->ptp_tx_lock);
 

diff --git a/drivers/net/ethernet/broadcom/bnxt/bnxt_ptp.h b/drivers/net/ethernet/broadcom/bnxt/bnxt_ptp.h
index a1910ce86cbb8fb4f75a2f97903c1578c55fbd53..a9a2f9a18c9ca120258d1d79aa49e3a0deaaca18 100644 (file)
--- a/drivers/net/ethernet/broadcom/bnxt/bnxt_ptp.h
+++ b/drivers/net/ethernet/broadcom/bnxt/bnxt_ptp.h
@@ -116,7 +116,7 @@ struct bnxt_ptp_cfg {
        struct bnxt_ptp_tx_req  txts_req[BNXT_MAX_TX_TS];
 
        struct bnxt             *bp;
-       atomic_t                tx_avail;
+       u32                     tx_avail;
        u16                     rxctl;
 #define BNXT_PTP_MSG_SYNC                      (1 << 0)
 #define BNXT_PTP_MSG_DELAY_REQ                 (1 << 1)
@@ -157,6 +157,13 @@ do {                                               \
        ((dst) = READ_ONCE(src))
 #endif
 
+#define BNXT_PTP_INC_TX_AVAIL(ptp)             \
+do {                                           \
+       spin_lock_bh(&(ptp)->ptp_tx_lock);      \
+       (ptp)->tx_avail++;                      \
+       spin_unlock_bh(&(ptp)->ptp_tx_lock);    \
+} while (0)
+
 int bnxt_ptp_parse(struct sk_buff *skb, u16 *seq_id, u16 *hdr_off);
 void bnxt_ptp_update_current_time(struct bnxt *bp);
 void bnxt_ptp_pps_event(struct bnxt *bp, u32 data1, u32 data2);
@@ -164,6 +171,7 @@ int bnxt_ptp_cfg_tstamp_filters(struct bnxt *bp);
 void bnxt_ptp_reapply_pps(struct bnxt *bp);
 int bnxt_hwtstamp_set(struct net_device *dev, struct ifreq *ifr);
 int bnxt_hwtstamp_get(struct net_device *dev, struct ifreq *ifr);
+int bnxt_ptp_get_txts_prod(struct bnxt_ptp_cfg *ptp, u16 *prod);
 void bnxt_get_tx_ts_p5(struct bnxt *bp, struct sk_buff *skb, u16 prod);
 int bnxt_get_rx_ts_p5(struct bnxt *bp, u64 *ts, u32 pkt_ts);
 void bnxt_tx_ts_cmp(struct bnxt *bp, struct bnxt_napi *bnapi,