Commit bec9ce34 authored by Ziyang Chen's avatar Ziyang Chen Committed by Jakub Kicinski
Browse files

nfp: prevent dropped counter increment during probe 



The dev_rx_discards counter will increment by one when an interface is
toggled up and down. The main reason is that the driver first sends a
`NFP_NET_CFG_CTRL_ENABLE` configuration packet to the NIC to perform port
initialisation when an interface is set up. But there is a race between
physical link up and free list queue initialization which may lead to the
configuration packet being discarded.

To address this problem a new bit NFP_NET_CFG_CTRL_FREELIST_EN is added to
perform free list initialisation on the NIC. The FREELIST_EN should be sent
in advance to initialize free list queue. When a port is set to down,
FREELIST_EN should be sent after CTRL_ENABLE to avoid packet discards.

Signed-off-by: default avatarZiyang Chen <ziyang.chen@corigine.com>
Acked-by: default avatarSimon Horman <simon.horman@corigine.com>
Signed-off-by: default avatarLouis Peens <louis.peens@corigine.com>
Link: https://lore.kernel.org/r/20230712123551.13858-1-louis.peens@corigine.com


Signed-off-by: default avatarJakub Kicinski <kuba@kernel.org>
parent 6f13b49b

drivers/net/ethernet/netronome/nfp/nfp_net_common.c

+47 −7
Original line number Diff line number Diff line
@@ -924,7 +924,7 @@ static void nfp_net_write_mac_addr(struct nfp_net *nn, const u8 *addr) 
 */

static void nfp_net_clear_config_and_disable(struct nfp_net *nn)

{

	u32 new_ctrl, update;

	u32 new_ctrl, new_ctrl_w1, update;

	unsigned int r;

	int err;
@@ -937,14 +937,29 @@ static void nfp_net_clear_config_and_disable(struct nfp_net *nn) 
	if (nn->cap & NFP_NET_CFG_CTRL_RINGCFG)

		new_ctrl &= ~NFP_NET_CFG_CTRL_RINGCFG;



	if (!(nn->cap_w1 & NFP_NET_CFG_CTRL_FREELIST_EN)) {

		nn_writeq(nn, NFP_NET_CFG_TXRS_ENABLE, 0);

		nn_writeq(nn, NFP_NET_CFG_RXRS_ENABLE, 0);

	}



	nn_writel(nn, NFP_NET_CFG_CTRL, new_ctrl);

	err = nfp_net_reconfig(nn, update);

	if (err)

		nn_err(nn, "Could not disable device: %d\n", err);



	if (nn->cap_w1 & NFP_NET_CFG_CTRL_FREELIST_EN) {

		new_ctrl_w1 = nn->dp.ctrl_w1;

		new_ctrl_w1 &= ~NFP_NET_CFG_CTRL_FREELIST_EN;

		nn_writeq(nn, NFP_NET_CFG_TXRS_ENABLE, 0);

		nn_writeq(nn, NFP_NET_CFG_RXRS_ENABLE, 0);



		nn_writel(nn, NFP_NET_CFG_CTRL_WORD1, new_ctrl_w1);

		err = nfp_net_reconfig(nn, update);

		if (err)

			nn_err(nn, "Could not disable FREELIST_EN: %d\n", err);

		nn->dp.ctrl_w1 = new_ctrl_w1;

	}



	for (r = 0; r < nn->dp.num_rx_rings; r++) {

		nfp_net_rx_ring_reset(&nn->dp.rx_rings[r]);

		if (nfp_net_has_xsk_pool_slow(&nn->dp, nn->dp.rx_rings[r].idx))
@@ -964,11 +979,12 @@ static void nfp_net_clear_config_and_disable(struct nfp_net *nn) 
 */

static int nfp_net_set_config_and_enable(struct nfp_net *nn)

{

	u32 bufsz, new_ctrl, update = 0;

	u32 bufsz, new_ctrl, new_ctrl_w1, update = 0;

	unsigned int r;

	int err;



	new_ctrl = nn->dp.ctrl;

	new_ctrl_w1 = nn->dp.ctrl_w1;



	if (nn->dp.ctrl & NFP_NET_CFG_CTRL_RSS_ANY) {

		nfp_net_rss_write_key(nn);
@@ -1001,7 +1017,13 @@ static int nfp_net_set_config_and_enable(struct nfp_net *nn) 
	bufsz = nn->dp.fl_bufsz - nn->dp.rx_dma_off - NFP_NET_RX_BUF_NON_DATA;

	nn_writel(nn, NFP_NET_CFG_FLBUFSZ, bufsz);



	/* Enable device */

	/* Enable device

	 * Step 1: Replace the CTRL_ENABLE by NFP_NET_CFG_CTRL_FREELIST_EN if

	 * FREELIST_EN exits.

	 */

	if (nn->cap_w1 & NFP_NET_CFG_CTRL_FREELIST_EN)

		new_ctrl_w1 |= NFP_NET_CFG_CTRL_FREELIST_EN;

	else

		new_ctrl |= NFP_NET_CFG_CTRL_ENABLE;

	update |= NFP_NET_CFG_UPDATE_GEN;

	update |= NFP_NET_CFG_UPDATE_MSIX;
@@ -1009,8 +1031,11 @@ static int nfp_net_set_config_and_enable(struct nfp_net *nn) 
	if (nn->cap & NFP_NET_CFG_CTRL_RINGCFG)

		new_ctrl |= NFP_NET_CFG_CTRL_RINGCFG;



	/* Step 2: Send the configuration and write the freelist.

	 * - The freelist only need to be written once.

	 */

	nn_writel(nn, NFP_NET_CFG_CTRL, new_ctrl);

	nn_writel(nn, NFP_NET_CFG_CTRL_WORD1, nn->dp.ctrl_w1);

	nn_writel(nn, NFP_NET_CFG_CTRL_WORD1, new_ctrl_w1);

	err = nfp_net_reconfig(nn, update);

	if (err) {

		nfp_net_clear_config_and_disable(nn);
@@ -1018,10 +1043,25 @@ static int nfp_net_set_config_and_enable(struct nfp_net *nn) 
	}



	nn->dp.ctrl = new_ctrl;

	nn->dp.ctrl_w1 = new_ctrl_w1;



	for (r = 0; r < nn->dp.num_rx_rings; r++)

		nfp_net_rx_ring_fill_freelist(&nn->dp, &nn->dp.rx_rings[r]);



	/* Step 3: Do the NFP_NET_CFG_CTRL_ENABLE. Send the configuration.

	 */

	if (nn->cap_w1 & NFP_NET_CFG_CTRL_FREELIST_EN) {

		new_ctrl |= NFP_NET_CFG_CTRL_ENABLE;

		nn_writel(nn, NFP_NET_CFG_CTRL, new_ctrl);



		err = nfp_net_reconfig(nn, update);

		if (err) {

			nfp_net_clear_config_and_disable(nn);

			return err;

		}

		nn->dp.ctrl = new_ctrl;

	}



	return 0;

}

drivers/net/ethernet/netronome/nfp/nfp_net_ctrl.h

+1 −0
Original line number Diff line number Diff line
@@ -268,6 +268,7 @@ 
#define   NFP_NET_CFG_CTRL_PKT_TYPE	  (0x1 << 0) /* Pkttype offload */

#define   NFP_NET_CFG_CTRL_IPSEC	  (0x1 << 1) /* IPsec offload */

#define   NFP_NET_CFG_CTRL_MCAST_FILTER	  (0x1 << 2) /* Multicast Filter */

#define   NFP_NET_CFG_CTRL_FREELIST_EN	  (0x1 << 6) /* Freelist enable flag bit */



#define NFP_NET_CFG_CAP_WORD1		0x00a4