+/* Criterias for calculating Rx buffer size -
+ * 1) rx_buf_size should not exceed the size of mbuf
+ * 2) In scattered_rx mode - minimum rx_buf_size should be
+ * (MTU + Maximum L2 Header Size + 2) / ETH_RX_MAX_BUFF_PER_PKT
+ * 3) In regular mode - minimum rx_buf_size should be
+ * (MTU + Maximum L2 Header Size + 2)
+ * In above cases +2 corrosponds to 2 bytes padding in front of L2
+ * header.
+ * 4) rx_buf_size should be cacheline-size aligned. So considering
+ * criteria 1, we need to adjust the size to floor instead of ceil,
+ * so that we don't exceed mbuf size while ceiling rx_buf_size.
+ */
+int
+qede_calc_rx_buf_size(struct rte_eth_dev *dev, uint16_t mbufsz,
+ uint16_t max_frame_size)
+{
+ struct qede_dev *qdev = QEDE_INIT_QDEV(dev);
+ struct ecore_dev *edev = QEDE_INIT_EDEV(qdev);
+ int rx_buf_size;
+
+ if (dev->data->scattered_rx) {
+ /* per HW limitation, only ETH_RX_MAX_BUFF_PER_PKT number of
+ * bufferes can be used for single packet. So need to make sure
+ * mbuf size is sufficient enough for this.
+ */
+ if ((mbufsz * ETH_RX_MAX_BUFF_PER_PKT) <
+ (max_frame_size + QEDE_ETH_OVERHEAD)) {
+ DP_ERR(edev, "mbuf %d size is not enough to hold max fragments (%d) for max rx packet length (%d)\n",
+ mbufsz, ETH_RX_MAX_BUFF_PER_PKT, max_frame_size);
+ return -EINVAL;
+ }
+
+ rx_buf_size = RTE_MAX(mbufsz,
+ (max_frame_size + QEDE_ETH_OVERHEAD) /
+ ETH_RX_MAX_BUFF_PER_PKT);
+ } else {
+ rx_buf_size = max_frame_size + QEDE_ETH_OVERHEAD;
+ }
+
+ /* Align to cache-line size if needed */
+ return QEDE_FLOOR_TO_CACHE_LINE_SIZE(rx_buf_size);
+}
+