Commit f6fe01d6 authored by Vladimir Oltean's avatar Vladimir Oltean Committed by Jakub Kicinski
Browse files

net: mscc: ocelot: auto-detect packet buffer size and number of frame references 



Instead of reading these values from the reference manual and writing
them down into the driver, it appears that the hardware gives us the
option of detecting them dynamically.

The number of frame references corresponds to what the reference manual
notes, however it seems that the frame buffers are reported as slightly
less than the books would indicate. On VSC9959 (Felix), the books say it
should have 128KB of packet buffer, but the registers indicate only
129840 bytes (126.79 KB). Also, the unit of measurement for FREECNT from
the documentation of all these devices is incorrect (taken from an older
generation). This was confirmed by Younes Leroul from Microchip support.

Not having anything better to do with these values at the moment* (this
will change soon), let's just print them.

*The frame buffer size is, in fact, used to calculate the tail dropping
watermarks.

Signed-off-by: default avatarVladimir Oltean <vladimir.oltean@nxp.com>
Reviewed-by: default avatarFlorian Fainelli <f.fainelli@gmail.com>
Signed-off-by: default avatarJakub Kicinski <kuba@kernel.org>
parent 2d9116be

drivers/net/dsa/ocelot/felix.c

+0 −1
Original line number Diff line number Diff line
@@ -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;

drivers/net/dsa/ocelot/felix.h

+0 −1
Original line number Diff line number Diff line
@@ -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;

drivers/net/dsa/ocelot/felix_vsc9959.c

+0 −1
Original line number Diff line number Diff line
@@ -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,

drivers/net/dsa/ocelot/seville_vsc9953.c

+0 −1
Original line number Diff line number Diff line
@@ -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,

drivers/net/ethernet/mscc/ocelot.c

+21 −1
Original line number Diff line number Diff line
@@ -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);