bnxt_en: Update VNIC resource calculation for VFs

Newer versions of firmware will pre-reserve 1 VNIC for every possible
PF and VF function.  Update the driver logic to take this into account
when assigning VNICs to the VFs.  These pre-reserved VNICs for the
inactive VFs should be subtracted from the global pool before
assigning them to the active VFs.

Not doing so may cause discrepancies that ultimately may cause some VFs to
have insufficient VNICs to support features such as aRFS.
Signed-off-by: Vikas Gupta <vikas.gupta@broadcom.com>
Signed-off-by: Michael Chan <michael.chan@broadcom.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

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

@@ -12215,6 +12215,20 @@ static void bnxt_init_dflt_coal(struct bnxt *bp)
 	bp->stats_coal_ticks = BNXT_DEF_STATS_COAL_TICKS;
 }
 
+/* FW that pre-reserves 1 VNIC per function */
+static bool bnxt_fw_pre_resv_vnics(struct bnxt *bp)
+{
+	u16 fw_maj = BNXT_FW_MAJ(bp), fw_bld = BNXT_FW_BLD(bp);
+
+	if (!(bp->flags & BNXT_FLAG_CHIP_P5) &&
+	    (fw_maj > 218 || (fw_maj == 218 && fw_bld >= 18)))
+		return true;
+	if ((bp->flags & BNXT_FLAG_CHIP_P5) &&
+	    (fw_maj > 216 || (fw_maj == 216 && fw_bld >= 172)))
+		return true;
+	return false;
+}
+
 static int bnxt_fw_init_one_p1(struct bnxt *bp)
 {
 	int rc;
@@ -12271,6 +12285,9 @@ static int bnxt_fw_init_one_p2(struct bnxt *bp)
 	if (rc)
 		return -ENODEV;
 
+	if (bnxt_fw_pre_resv_vnics(bp))
+		bp->fw_cap |= BNXT_FW_CAP_PRE_RESV_VNICS;
+
 	bnxt_hwrm_func_qcfg(bp);
 	bnxt_hwrm_vnic_qcaps(bp);
 	bnxt_hwrm_port_led_qcaps(bp);

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

@@ -2014,6 +2014,7 @@ struct bnxt {
 	#define BNXT_FW_CAP_PTP				BIT_ULL(32)
 	#define BNXT_FW_CAP_THRESHOLD_TEMP_SUPPORTED	BIT_ULL(33)
 	#define BNXT_FW_CAP_DFLT_VLAN_TPID_PCP		BIT_ULL(34)
+	#define BNXT_FW_CAP_PRE_RESV_VNICS		BIT_ULL(35)
 
 	u32			fw_dbg_cap;
 
@@ -2054,6 +2055,7 @@ struct bnxt {
 #define BNXT_FW_VER_CODE(maj, min, bld, rsv)			\
 	((u64)(maj) << 48 | (u64)(min) << 32 | (u64)(bld) << 16 | (rsv))
 #define BNXT_FW_MAJ(bp)		((bp)->fw_ver_code >> 48)
+#define BNXT_FW_BLD(bp)		(((bp)->fw_ver_code >> 16) & 0xffff)
 
 	u16			vxlan_fw_dst_port_id;
 	u16			nge_fw_dst_port_id;

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

@@ -552,7 +552,6 @@ static int bnxt_hwrm_func_vf_resc_cfg(struct bnxt *bp, int num_vfs, bool reset)
 		vf_rx_rings = hw_resc->max_rx_rings - bp->rx_nr_rings;
 	vf_tx_rings = hw_resc->max_tx_rings - bp->tx_nr_rings;
 	vf_vnics = hw_resc->max_vnics - bp->nr_vnics;
-	vf_vnics = min_t(u16, vf_vnics, vf_rx_rings);
 	vf_rss = hw_resc->max_rsscos_ctxs - bp->rsscos_nr_ctxs;
 
 	req->min_rsscos_ctx = cpu_to_le16(BNXT_VF_MIN_RSS_CTX);
@@ -574,11 +573,20 @@ static int bnxt_hwrm_func_vf_resc_cfg(struct bnxt *bp, int num_vfs, bool reset)
 		vf_cp_rings /= num_vfs;
 		vf_tx_rings /= num_vfs;
 		vf_rx_rings /= num_vfs;
-		vf_vnics /= num_vfs;
+		if ((bp->fw_cap & BNXT_FW_CAP_PRE_RESV_VNICS) &&
+		    vf_vnics >= pf->max_vfs) {
+			/* Take into account that FW has pre-reserved 1 VNIC for
+			 * each pf->max_vfs.
+			 */
+			vf_vnics = (vf_vnics - pf->max_vfs + num_vfs) / num_vfs;
+		} else {
+			vf_vnics /= num_vfs;
+		}
 		vf_stat_ctx /= num_vfs;
 		vf_ring_grps /= num_vfs;
 		vf_rss /= num_vfs;
 
+		vf_vnics = min_t(u16, vf_vnics, vf_rx_rings);
 		req->min_cmpl_rings = cpu_to_le16(vf_cp_rings);
 		req->min_tx_rings = cpu_to_le16(vf_tx_rings);
 		req->min_rx_rings = cpu_to_le16(vf_rx_rings);