bnxt_en: Add helper function to return the number of RSS contexts.

On some chips, this varies based on the number of RX rings.  Add this
helper function and refactor the existing code to use it.
Signed-off-by: NMichael Chan <michael.chan@broadcom.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

drivers/net/ethernet/broadcom/bnxt/bnxt.c

@@ -4869,6 +4869,15 @@ static void bnxt_set_dflt_rss_indir_tbl(struct bnxt *bp)
 		memset(&bp->rss_indir_tbl[i], 0, pad * sizeof(u16));
 }
 
+int bnxt_get_nr_rss_ctxs(struct bnxt *bp, int rx_rings)
+{
+	if (bp->flags & BNXT_FLAG_CHIP_P5)
+		return DIV_ROUND_UP(rx_rings, BNXT_RSS_TABLE_ENTRIES_P5);
+	if (BNXT_CHIP_TYPE_NITRO_A0(bp))
+		return 2;
+	return 1;
+}
+
 static int bnxt_hwrm_vnic_set_rss(struct bnxt *bp, u16 vnic_id, bool set_rss)
 {
 	u32 i, j, max_rings;
@@ -4924,7 +4933,7 @@ static int bnxt_hwrm_vnic_set_rss_p5(struct bnxt *bp, u16 vnic_id, bool set_rss)
 	req.hash_mode_flags = VNIC_RSS_CFG_REQ_HASH_MODE_FLAGS_DEFAULT;
 	req.ring_grp_tbl_addr = cpu_to_le64(vnic->rss_table_dma_addr);
 	req.hash_key_tbl_addr = cpu_to_le64(vnic->rss_hash_key_dma_addr);
-	nr_ctxs = DIV_ROUND_UP(bp->rx_nr_rings, 64);
+	nr_ctxs = bnxt_get_nr_rss_ctxs(bp, bp->rx_nr_rings);
 	for (i = 0, k = 0; i < nr_ctxs; i++) {
 		__le16 *ring_tbl = vnic->rss_table;
 		int rc;
@@ -7677,7 +7686,7 @@ static int __bnxt_setup_vnic_p5(struct bnxt *bp, u16 vnic_id)
 {
 	int rc, i, nr_ctxs;
 
-	nr_ctxs = DIV_ROUND_UP(bp->rx_nr_rings, 64);
+	nr_ctxs = bnxt_get_nr_rss_ctxs(bp, bp->rx_nr_rings);
 	for (i = 0; i < nr_ctxs; i++) {
 		rc = bnxt_hwrm_vnic_ctx_alloc(bp, vnic_id, i);
 		if (rc) {

drivers/net/ethernet/broadcom/bnxt/bnxt.h

@@ -2039,6 +2039,7 @@ int hwrm_send_message(struct bnxt *, void *, u32, int);
 int hwrm_send_message_silent(struct bnxt *, void *, u32, int);
 int bnxt_hwrm_func_drv_rgtr(struct bnxt *bp, unsigned long *bmap,
 			    int bmap_size, bool async_only);
+int bnxt_get_nr_rss_ctxs(struct bnxt *bp, int rx_rings);
 int bnxt_hwrm_vnic_cfg(struct bnxt *bp, u16 vnic_id);
 int __bnxt_hwrm_get_tx_rings(struct bnxt *bp, u16 fid, int *tx_rings);
 int bnxt_nq_rings_in_use(struct bnxt *bp);