6 files changed, 21 insertions, 6 deletions
diff --git a/drivers/net/dsa/ocelot/felix.c b/drivers/net/dsa/ocelot/felix.c
index 8492151f8133..cf9317110591 100644
--- a/drivers/net/dsa/ocelot/felix.c
+++ b/drivers/net/dsa/ocelot/felix.c
@@ -422,7 +422,6 @@ static int felix_init_structs(struct felix *felix, int num_phys_ports)
 	ocelot->map		= felix->info->map;
 	ocelot->stats_layout	= felix->info->stats_layout;
 	ocelot->num_stats	= felix->info->num_stats;
-	ocelot->shared_queue_sz	= felix->info->shared_queue_sz;
 	ocelot->num_mact_rows	= felix->info->num_mact_rows;
 	ocelot->vcap		= felix->info->vcap;
 	ocelot->ops		= felix->info->ops;
diff --git a/drivers/net/dsa/ocelot/felix.h b/drivers/net/dsa/ocelot/felix.h
index 4c717324ac2f..5434fe278d2c 100644
--- a/drivers/net/dsa/ocelot/felix.h
+++ b/drivers/net/dsa/ocelot/felix.h
@@ -15,7 +15,6 @@ struct felix_info {
 	const struct reg_field		*regfields;
 	const u32 *const		*map;
 	const struct ocelot_ops		*ops;
-	int				shared_queue_sz;
 	int				num_mact_rows;
 	const struct ocelot_stat_layout	*stats_layout;
 	unsigned int			num_stats;
diff --git a/drivers/net/dsa/ocelot/felix_vsc9959.c b/drivers/net/dsa/ocelot/felix_vsc9959.c
index a87597eef8cf..b68df85e01a1 100644
--- a/drivers/net/dsa/ocelot/felix_vsc9959.c
+++ b/drivers/net/dsa/ocelot/felix_vsc9959.c
@@ -1356,7 +1356,6 @@ static const struct felix_info felix_info_vsc9959 = {
 	.stats_layout		= vsc9959_stats_layout,
 	.num_stats		= ARRAY_SIZE(vsc9959_stats_layout),
 	.vcap			= vsc9959_vcap_props,
-	.shared_queue_sz	= 128 * 1024,
 	.num_mact_rows		= 2048,
 	.num_ports		= 6,
 	.num_tx_queues		= FELIX_NUM_TC,
diff --git a/drivers/net/dsa/ocelot/seville_vsc9953.c b/drivers/net/dsa/ocelot/seville_vsc9953.c
index ebbaf6817ec8..b72813da6d9f 100644
--- a/drivers/net/dsa/ocelot/seville_vsc9953.c
+++ b/drivers/net/dsa/ocelot/seville_vsc9953.c
@@ -1181,7 +1181,6 @@ static const struct felix_info seville_info_vsc9953 = {
 	.stats_layout		= vsc9953_stats_layout,
 	.num_stats		= ARRAY_SIZE(vsc9953_stats_layout),
 	.vcap			= vsc9953_vcap_props,
-	.shared_queue_sz	= 256 * 1024,
 	.num_mact_rows		= 2048,
 	.num_ports		= 10,
 	.mdio_bus_alloc		= vsc9953_mdio_bus_alloc,
diff --git a/drivers/net/ethernet/mscc/ocelot.c b/drivers/net/ethernet/mscc/ocelot.c
index af620f7ce469..3af8e607c8a9 100644
--- a/drivers/net/ethernet/mscc/ocelot.c
+++ b/drivers/net/ethernet/mscc/ocelot.c
@@ -1354,7 +1354,7 @@ void ocelot_port_set_maxlen(struct ocelot *ocelot, int port, size_t sdu)
 			    pause_stop);
 
 	/* Tail dropping watermarks */
-	atop_tot = (ocelot->shared_queue_sz - 9 * maxlen) /
+	atop_tot = (ocelot->packet_buffer_size - 9 * maxlen) /
 		   OCELOT_BUFFER_CELL_SZ;
 	atop = (9 * maxlen) / OCELOT_BUFFER_CELL_SZ;
 	ocelot_write_rix(ocelot, ocelot->ops->wm_enc(atop), SYS_ATOP, port);
@@ -1467,6 +1467,25 @@ static void ocelot_cpu_port_init(struct ocelot *ocelot)
 			 ANA_PORT_VLAN_CFG, cpu);
 }
 
+static void ocelot_detect_features(struct ocelot *ocelot)
+{
+	int mmgt, eq_ctrl;
+
+	/* For Ocelot, Felix, Seville, Serval etc, SYS:MMGT:MMGT:FREECNT holds
+	 * the number of 240-byte free memory words (aka 4-cell chunks) and not
+	 * 192 bytes as the documentation incorrectly says.
+	 */
+	mmgt = ocelot_read(ocelot, SYS_MMGT);
+	ocelot->packet_buffer_size = 240 * SYS_MMGT_FREECNT(mmgt);
+
+	eq_ctrl = ocelot_read(ocelot, QSYS_EQ_CTRL);
+	ocelot->num_frame_refs = QSYS_MMGT_EQ_CTRL_FP_FREE_CNT(eq_ctrl);
+
+	dev_info(ocelot->dev,
+		 "Detected %d bytes of packet buffer and %d frame references\n",
+		 ocelot->packet_buffer_size, ocelot->num_frame_refs);
+}
+
 int ocelot_init(struct ocelot *ocelot)
 {
 	char queue_name[32];
@@ -1509,6 +1528,7 @@ int ocelot_init(struct ocelot *ocelot)
 
 	INIT_LIST_HEAD(&ocelot->multicast);
 	INIT_LIST_HEAD(&ocelot->pgids);
+	ocelot_detect_features(ocelot);
 	ocelot_mact_init(ocelot);
 	ocelot_vlan_init(ocelot);
 	ocelot_vcap_init(ocelot);
diff --git a/drivers/net/ethernet/mscc/ocelot_vsc7514.c b/drivers/net/ethernet/mscc/ocelot_vsc7514.c
index 9cf2bc5f4289..7135ad18affe 100644
--- a/drivers/net/ethernet/mscc/ocelot_vsc7514.c
+++ b/drivers/net/ethernet/mscc/ocelot_vsc7514.c
@@ -517,7 +517,6 @@ static int ocelot_chip_init(struct ocelot *ocelot, const struct ocelot_ops *ops)
 	ocelot->map = ocelot_regmap;
 	ocelot->stats_layout = ocelot_stats_layout;
 	ocelot->num_stats = ARRAY_SIZE(ocelot_stats_layout);
-	ocelot->shared_queue_sz = 224 * 1024;
 	ocelot->num_mact_rows = 1024;
 	ocelot->ops = ops;