ixgbe: consolidate packet buffer allocation

Consolidate packet buffer allocation currently being
done in the DCB path and main path. This allows the
feature set and packet buffer requirements to be done
once.

This is prep work to allow DCB to coexist with other
features namely, flow director.

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

1 files changed, 66 insertions, 0 deletions

diff --git a/drivers/net/ixgbe/ixgbe_common.c b/drivers/net/ixgbe/ixgbe_common.c
index de65643b79a4..cc2a4a1528e2 100644
--- a/drivers/net/ixgbe/ixgbe_common.c
+++ b/drivers/net/ixgbe/ixgbe_common.c
@@ -3267,3 +3267,69 @@ s32 ixgbe_get_device_caps_generic(struct ixgbe_hw *hw, u16 *device_caps)
 
 	return 0;
 }
+
+/**
+ * ixgbe_set_rxpba_generic - Initialize RX packet buffer
+ * @hw: pointer to hardware structure
+ * @num_pb: number of packet buffers to allocate
+ * @headroom: reserve n KB of headroom
+ * @strategy: packet buffer allocation strategy
+ **/
+void ixgbe_set_rxpba_generic(struct ixgbe_hw *hw,
+			     int num_pb,
+			     u32 headroom,
+			     int strategy)
+{
+	u32 pbsize = hw->mac.rx_pb_size;
+	int i = 0;
+	u32 rxpktsize, txpktsize, txpbthresh;
+
+	/* Reserve headroom */
+	pbsize -= headroom;
+
+	if (!num_pb)
+		num_pb = 1;
+
+	/* Divide remaining packet buffer space amongst the number
+	 * of packet buffers requested using supplied strategy.
+	 */
+	switch (strategy) {
+	case (PBA_STRATEGY_WEIGHTED):
+		/* pba_80_48 strategy weight first half of packet buffer with
+		 * 5/8 of the packet buffer space.
+		 */
+		rxpktsize = ((pbsize * 5 * 2) / (num_pb * 8));
+		pbsize -= rxpktsize * (num_pb / 2);
+		rxpktsize <<= IXGBE_RXPBSIZE_SHIFT;
+		for (; i < (num_pb / 2); i++)
+			IXGBE_WRITE_REG(hw, IXGBE_RXPBSIZE(i), rxpktsize);
+		/* Fall through to configure remaining packet buffers */
+	case (PBA_STRATEGY_EQUAL):
+		/* Divide the remaining Rx packet buffer evenly among the TCs */
+		rxpktsize = (pbsize / (num_pb - i)) << IXGBE_RXPBSIZE_SHIFT;
+		for (; i < num_pb; i++)
+			IXGBE_WRITE_REG(hw, IXGBE_RXPBSIZE(i), rxpktsize);
+		break;
+	default:
+		break;
+	}
+
+	/*
+	 * Setup Tx packet buffer and threshold equally for all TCs
+	 * TXPBTHRESH register is set in K so divide by 1024 and subtract
+	 * 10 since the largest packet we support is just over 9K.
+	 */
+	txpktsize = IXGBE_TXPBSIZE_MAX / num_pb;
+	txpbthresh = (txpktsize / 1024) - IXGBE_TXPKT_SIZE_MAX;
+	for (i = 0; i < num_pb; i++) {
+		IXGBE_WRITE_REG(hw, IXGBE_TXPBSIZE(i), txpktsize);
+		IXGBE_WRITE_REG(hw, IXGBE_TXPBTHRESH(i), txpbthresh);
+	}
+
+	/* Clear unused TCs, if any, to zero buffer size*/
+	for (; i < IXGBE_MAX_PB; i++) {
+		IXGBE_WRITE_REG(hw, IXGBE_RXPBSIZE(i), 0);
+		IXGBE_WRITE_REG(hw, IXGBE_TXPBSIZE(i), 0);
+		IXGBE_WRITE_REG(hw, IXGBE_TXPBTHRESH(i), 0);
+	}
+}