ixgbe: Update the logic for ixgbe_cache_ring_dcb and DCB RSS configuration

This change cleans up some of the logic in an attempt to try and simplify
things for how we are configuring DCB w/ RSS.

In this patch I basically did 3 things.  I updated the logic for getting
the first register index.  I applied the fact that all TCs get the same
number of queues to simplify the looping logic in caching the DCB ring
register.  Finally I updated how we configure the RQTC register to match
the fact that all TCs are assigned the same number of queues.

Cc: John Fastabend <john.r.fastabend@intel.com>
Signed-off-by: Alexander Duyck <alexander.h.duyck@intel.com>
Tested-by: Phil Schmitt <phillip.j.schmitt@intel.com>
Tested-by: Ross Brattain <ross.b.brattain@intel.com>
Signed-off-by: Jeff Kirsher <jeffrey.t.kirsher@intel.com>

diff --git a/drivers/net/ethernet/intel/ixgbe/ixgbe_lib.c b/drivers/net/ethernet/intel/ixgbe/ixgbe_lib.c
index c03d771..4c3822f 100644 (file)
--- a/drivers/net/ethernet/intel/ixgbe/ixgbe_lib.c
+++ b/drivers/net/ethernet/intel/ixgbe/ixgbe_lib.c
@@ -42,42 +42,37 @@ static void ixgbe_get_first_reg_idx(struct ixgbe_adapter *adapter, u8 tc,
 
        switch (hw->mac.type) {
        case ixgbe_mac_82598EB:
-               *tx = tc << 2;
-               *rx = tc << 3;
+               /* TxQs/TC: 4   RxQs/TC: 8 */
+               *tx = tc << 2; /* 0, 4,  8, 12, 16, 20, 24, 28 */
+               *rx = tc << 3; /* 0, 8, 16, 24, 32, 40, 48, 56 */
                break;
        case ixgbe_mac_82599EB:
        case ixgbe_mac_X540:
                if (num_tcs > 4) {
-                       if (tc < 3) {
-                               *tx = tc << 5;
-                               *rx = tc << 4;
-                       } else if (tc <  5) {
-                               *tx = ((tc + 2) << 4);
-                               *rx = tc << 4;
-                       } else if (tc < num_tcs) {
-                               *tx = ((tc + 8) << 3);
-                               *rx = tc << 4;
-                       }
+                       /*
+                        * TCs    : TC0/1 TC2/3 TC4-7
+                        * TxQs/TC:    32    16     8
+                        * RxQs/TC:    16    16    16
+                        */
+                       *rx = tc << 4;
+                       if (tc < 3)
+                               *tx = tc << 5;          /*   0,  32,  64 */
+                       else if (tc < 5)
+                               *tx = (tc + 2) << 4;    /*  80,  96 */
+                       else
+                               *tx = (tc + 8) << 3;    /* 104, 112, 120 */
                } else {
-                       *rx =  tc << 5;
-                       switch (tc) {
-                       case 0:
-                               *tx =  0;
-                               break;
-                       case 1:
-                               *tx = 64;
-                               break;
-                       case 2:
-                               *tx = 96;
-                               break;
-                       case 3:
-                               *tx = 112;
-                               break;
-                       default:
-                               break;
-                       }
+                       /*
+                        * TCs    : TC0 TC1 TC2/3
+                        * TxQs/TC:  64  32    16
+                        * RxQs/TC:  32  32    32
+                        */
+                       *rx = tc << 5;
+                       if (tc < 2)
+                               *tx = tc << 6;          /*  0,  64 */
+                       else
+                               *tx = (tc + 4) << 4;    /* 96, 112 */
                }
-               break;
        default:
                break;
        }
@@ -90,25 +85,26 @@ static void ixgbe_get_first_reg_idx(struct ixgbe_adapter *adapter, u8 tc,
  * Cache the descriptor ring offsets for DCB to the assigned rings.
  *
  **/
-static inline bool ixgbe_cache_ring_dcb(struct ixgbe_adapter *adapter)
+static bool ixgbe_cache_ring_dcb(struct ixgbe_adapter *adapter)
 {
        struct net_device *dev = adapter->netdev;
-       int i, j, k;
+       unsigned int tx_idx, rx_idx;
+       int tc, offset, rss_i, i;
        u8 num_tcs = netdev_get_num_tc(dev);
 
-       if (!num_tcs)
+       /* verify we have DCB queueing enabled before proceeding */
+       if (num_tcs <= 1)
                return false;
 
-       for (i = 0, k = 0; i < num_tcs; i++) {
-               unsigned int tx_s, rx_s;
-               u16 count = dev->tc_to_txq[i].count;
+       rss_i = adapter->ring_feature[RING_F_RSS].indices;
 
-               ixgbe_get_first_reg_idx(adapter, i, &tx_s, &rx_s);
-               for (j = 0; j < count; j++, k++) {
-                       adapter->tx_ring[k]->reg_idx = tx_s + j;
-                       adapter->rx_ring[k]->reg_idx = rx_s + j;
-                       adapter->tx_ring[k]->dcb_tc = i;
-                       adapter->rx_ring[k]->dcb_tc = i;
+       for (tc = 0, offset = 0; tc < num_tcs; tc++, offset += rss_i) {
+               ixgbe_get_first_reg_idx(adapter, tc, &tx_idx, &rx_idx);
+               for (i = 0; i < rss_i; i++, tx_idx++, rx_idx++) {
+                       adapter->tx_ring[offset + i]->reg_idx = tx_idx;
+                       adapter->rx_ring[offset + i]->reg_idx = rx_idx;
+                       adapter->tx_ring[offset + i]->dcb_tc = tc;
+                       adapter->rx_ring[offset + i]->dcb_tc = tc;
                }
        }
 

diff --git a/drivers/net/ethernet/intel/ixgbe/ixgbe_main.c b/drivers/net/ethernet/intel/ixgbe/ixgbe_main.c
index 7f2aa22..32c8cd6 100644 (file)
--- a/drivers/net/ethernet/intel/ixgbe/ixgbe_main.c
+++ b/drivers/net/ethernet/intel/ixgbe/ixgbe_main.c
@@ -3608,20 +3608,16 @@ static void ixgbe_configure_dcb(struct ixgbe_adapter *adapter)
 
        /* Enable RSS Hash per TC */
        if (hw->mac.type != ixgbe_mac_82598EB) {
-               int i;
-               u32 reg = 0;
-               u8 msb = 0;
-               u8 rss_i = adapter->netdev->tc_to_txq[0].count - 1;
+               u32 msb = 0;
+               u16 rss_i = adapter->ring_feature[RING_F_RSS].indices - 1;
 
                while (rss_i) {
                        msb++;
                        rss_i >>= 1;
                }
 
-               for (i = 0; i < MAX_TRAFFIC_CLASS; i++)
-                       reg |= msb << IXGBE_RQTC_SHIFT_TC(i);
-
-               IXGBE_WRITE_REG(hw, IXGBE_RQTC, reg);
+               /* write msb to all 8 TCs in one write */
+               IXGBE_WRITE_REG(hw, IXGBE_RQTC, msb * 0x11111111);
        }
 }
 #endif