octeontx2-af: Set NIX link credits based on max LMAC

When number of LMACs active on a CGX/RPM are 3, then
current NIX link credit config based on per lmac fifo
length which inturn  is calculated as
'lmac_fifo_len = total_fifo_len / 3', is incorrect. In HW
one of the LMAC gets half of the FIFO and rest gets 1/4th.
Signed-off-by: Nithin Dabilpuram <ndabilpuram@marvell.com>
Signed-off-by: Sunil Goutham <sgoutham@marvell.com>
Signed-off-by: Geetha Sowjanya <gakula@marvell.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

drivers/net/ethernet/marvell/octeontx2/af/cgx.c

@@ -498,6 +498,32 @@ static u8 cgx_get_lmac_type(void *cgxd, int lmac_id)
 	return (cfg >> CGX_LMAC_TYPE_SHIFT) & CGX_LMAC_TYPE_MASK;
 }
 
+static u32 cgx_get_lmac_fifo_len(void *cgxd, int lmac_id)
+{
+	struct cgx *cgx = cgxd;
+	u8 num_lmacs;
+	u32 fifo_len;
+
+	fifo_len = cgx->mac_ops->fifo_len;
+	num_lmacs = cgx->mac_ops->get_nr_lmacs(cgx);
+
+	switch (num_lmacs) {
+	case 1:
+		return fifo_len;
+	case 2:
+		return fifo_len / 2;
+	case 3:
+		/* LMAC0 gets half of the FIFO, reset 1/4th */
+		if (lmac_id == 0)
+			return fifo_len / 2;
+		return fifo_len / 4;
+	case 4:
+	default:
+		return fifo_len / 4;
+	}
+	return 0;
+}
+
 /* Configure CGX LMAC in internal loopback mode */
 int cgx_lmac_internal_loopback(void *cgxd, int lmac_id, bool enable)
 {
@@ -1704,6 +1730,7 @@ static struct mac_ops	cgx_mac_ops    = {
 	.tx_stats_cnt   =       18,
 	.get_nr_lmacs	=	cgx_get_nr_lmacs,
 	.get_lmac_type  =       cgx_get_lmac_type,
+	.lmac_fifo_len	=	cgx_get_lmac_fifo_len,
 	.mac_lmac_intl_lbk =    cgx_lmac_internal_loopback,
 	.mac_get_rx_stats  =	cgx_get_rx_stats,
 	.mac_get_tx_stats  =	cgx_get_tx_stats,

drivers/net/ethernet/marvell/octeontx2/af/lmac_common.h

@@ -80,6 +80,7 @@ struct mac_ops {
 	 */
 	int			(*get_nr_lmacs)(void *cgx);
 	u8                      (*get_lmac_type)(void *cgx, int lmac_id);
+	u32                     (*lmac_fifo_len)(void *cgx, int lmac_id);
 	int                     (*mac_lmac_intl_lbk)(void *cgx, int lmac_id,
 						     bool enable);
 	/* Register Stats related functions */

drivers/net/ethernet/marvell/octeontx2/af/rpm.c

@@ -22,6 +22,7 @@ static struct mac_ops	rpm_mac_ops   = {
 	.tx_stats_cnt   =       34,
 	.get_nr_lmacs	=	rpm_get_nr_lmacs,
 	.get_lmac_type  =       rpm_get_lmac_type,
+	.lmac_fifo_len	=	rpm_get_lmac_fifo_len,
 	.mac_lmac_intl_lbk =    rpm_lmac_internal_loopback,
 	.mac_get_rx_stats  =	rpm_get_rx_stats,
 	.mac_get_tx_stats  =	rpm_get_tx_stats,
@@ -350,6 +351,35 @@ u8 rpm_get_lmac_type(void *rpmd, int lmac_id)
 	return err;
 }
 
+u32 rpm_get_lmac_fifo_len(void *rpmd, int lmac_id)
+{
+	rpm_t *rpm = rpmd;
+	u64 hi_perf_lmac;
+	u8 num_lmacs;
+	u32 fifo_len;
+
+	fifo_len = rpm->mac_ops->fifo_len;
+	num_lmacs = rpm->mac_ops->get_nr_lmacs(rpm);
+
+	switch (num_lmacs) {
+	case 1:
+		return fifo_len;
+	case 2:
+		return fifo_len / 2;
+	case 3:
+		/* LMAC marked as hi_perf gets half of the FIFO and rest 1/4th */
+		hi_perf_lmac = rpm_read(rpm, 0, CGXX_CMRX_RX_LMACS);
+		hi_perf_lmac = (hi_perf_lmac >> 4) & 0x3ULL;
+		if (lmac_id == hi_perf_lmac)
+			return fifo_len / 2;
+		return fifo_len / 4;
+	case 4:
+	default:
+		return fifo_len / 4;
+	}
+	return 0;
+}
+
 int rpm_lmac_internal_loopback(void *rpmd, int lmac_id, bool enable)
 {
 	rpm_t *rpm = rpmd;

drivers/net/ethernet/marvell/octeontx2/af/rpm.h

@@ -75,6 +75,7 @@
 /* Function Declarations */
 int rpm_get_nr_lmacs(void *rpmd);
 u8 rpm_get_lmac_type(void *rpmd, int lmac_id);
+u32 rpm_get_lmac_fifo_len(void *rpmd, int lmac_id);
 int rpm_lmac_internal_loopback(void *rpmd, int lmac_id, bool enable);
 void rpm_lmac_enadis_rx_pause_fwding(void *rpmd, int lmac_id, bool enable);
 int rpm_lmac_get_pause_frm_status(void *cgxd, int lmac_id, u8 *tx_pause,

drivers/net/ethernet/marvell/octeontx2/af/rvu.h

@@ -827,7 +827,7 @@ int rvu_cgx_config_tx(void *cgxd, int lmac_id, bool enable);
 int rvu_cgx_prio_flow_ctrl_cfg(struct rvu *rvu, u16 pcifunc, u8 tx_pause, u8 rx_pause,
 			       u16 pfc_en);
 int rvu_cgx_cfg_pause_frm(struct rvu *rvu, u16 pcifunc, u8 tx_pause, u8 rx_pause);
-
+u32 rvu_cgx_get_lmac_fifolen(struct rvu *rvu, int cgx, int lmac);
 int npc_get_nixlf_mcam_index(struct npc_mcam *mcam, u16 pcifunc, int nixlf,
 			     int type);
 bool is_mcam_entry_enabled(struct rvu *rvu, struct npc_mcam *mcam, int blkaddr,

drivers/net/ethernet/marvell/octeontx2/af/rvu_cgx.c

@@ -861,6 +861,22 @@ u32 rvu_cgx_get_fifolen(struct rvu *rvu)
 	return fifo_len;
 }
 
+u32 rvu_cgx_get_lmac_fifolen(struct rvu *rvu, int cgx, int lmac)
+{
+	struct mac_ops *mac_ops;
+	void *cgxd;
+
+	cgxd = rvu_cgx_pdata(cgx, rvu);
+	if (!cgxd)
+		return 0;
+
+	mac_ops = get_mac_ops(cgxd);
+	if (!mac_ops->lmac_fifo_len)
+		return 0;
+
+	return mac_ops->lmac_fifo_len(cgxd, lmac);
+}
+
 static int rvu_cgx_config_intlbk(struct rvu *rvu, u16 pcifunc, bool en)
 {
 	int pf = rvu_get_pf(pcifunc);

drivers/net/ethernet/marvell/octeontx2/af/rvu_nix.c

@@ -4010,9 +4010,13 @@ int rvu_mbox_handler_nix_set_hw_frs(struct rvu *rvu, struct nix_frs_cfg *req,
 		return 0;
 
 	/* Update transmit credits for CGX links */
-	lmac_fifo_len =
-		rvu_cgx_get_fifolen(rvu) /
-		cgx_get_lmac_cnt(rvu_cgx_pdata(cgx, rvu));
+	lmac_fifo_len = rvu_cgx_get_lmac_fifolen(rvu, cgx, lmac);
+	if (!lmac_fifo_len) {
+		dev_err(rvu->dev,
+			"%s: Failed to get CGX/RPM%d:LMAC%d FIFO size\n",
+			__func__, cgx, lmac);
+		return 0;
+	}
 	return nix_config_link_credits(rvu, blkaddr, link, pcifunc,
 				       (lmac_fifo_len - req->maxlen) / 16);
 }
@@ -4064,7 +4068,10 @@ static void nix_link_config(struct rvu *rvu, int blkaddr,
 	struct rvu_hwinfo *hw = rvu->hw;
 	int cgx, lmac_cnt, slink, link;
 	u16 lbk_max_frs, lmac_max_frs;
+	unsigned long lmac_bmap;
 	u64 tx_credits, cfg;
+	u64 lmac_fifo_len;
+	int iter;
 
 	rvu_get_lbk_link_max_frs(rvu, &lbk_max_frs);
 	rvu_get_lmac_link_max_frs(rvu, &lmac_max_frs);
@@ -4098,12 +4105,23 @@ static void nix_link_config(struct rvu *rvu, int blkaddr,
 		/* Skip when cgx is not available or lmac cnt is zero */
 		if (lmac_cnt <= 0)
 			continue;
-		tx_credits = ((rvu_cgx_get_fifolen(rvu) / lmac_cnt) -
-			       lmac_max_frs) / 16;
+		slink = cgx * hw->lmac_per_cgx;
+
+		/* Get LMAC id's from bitmap */
+		lmac_bmap = cgx_get_lmac_bmap(rvu_cgx_pdata(cgx, rvu));
+		for_each_set_bit(iter, &lmac_bmap, MAX_LMAC_PER_CGX) {
+			lmac_fifo_len = rvu_cgx_get_lmac_fifolen(rvu, cgx, iter);
+			if (!lmac_fifo_len) {
+				dev_err(rvu->dev,
+					"%s: Failed to get CGX/RPM%d:LMAC%d FIFO size\n",
+					__func__, cgx, iter);
+				continue;
+			}
+			tx_credits = (lmac_fifo_len - lmac_max_frs) / 16;
 			/* Enable credits and set credit pkt count to max allowed */
 			cfg =  (tx_credits << 12) | (0x1FF << 2) | BIT_ULL(1);
-		slink = cgx * hw->lmac_per_cgx;
-		for (link = slink; link < (slink + lmac_cnt); link++) {
+
+			link = iter + slink;
 			nix_hw->tx_credits[link] = tx_credits;
 			rvu_write64(rvu, blkaddr,
 				    NIX_AF_TX_LINKX_NORM_CREDIT(link), cfg);