Re: [PATCH net-next v5 4/5] net: ti: icssg-prueth: Enable HSR Tx duplication, Tx Tag and Rx Tag offload

[Roger Quadros <rogerq@kernel.org>]

On 06/09/2024 14:15, MD Danish Anwar wrote:
> From: Ravi Gunasekaran <r-gunasekaran@ti.com>
> 
> The HSR stack allows to offload its Tx packet duplication functionality to
> the hardware. Enable this offloading feature for ICSSG driver. Add support
> to offload HSR Tx Tag Insertion and Rx Tag Removal and duplicate discard.
> 
> Inorder to enable hsr-tag-ins-offload, hsr-dup-offload must also be enabled

"In order"

> as these are tightly coupled in the firmware implementation.
> 
> Duplicate discard is done as part of RX tag removal and it is
> done by the firmware. When driver sends the r30 command
> ICSSG_EMAC_HSR_RX_OFFLOAD_ENABLE, firmware does RX tag removal as well as
> duplicate discard.
> 
> Signed-off-by: Ravi Gunasekaran <r-gunasekaran@ti.com>
> Signed-off-by: MD Danish Anwar <danishanwar@ti.com>
> ---
>  drivers/net/ethernet/ti/icssg/icssg_common.c | 18 ++++++++++---
>  drivers/net/ethernet/ti/icssg/icssg_config.c |  4 ++-
>  drivers/net/ethernet/ti/icssg/icssg_config.h |  2 ++
>  drivers/net/ethernet/ti/icssg/icssg_prueth.c | 28 +++++++++++++++++++-
>  drivers/net/ethernet/ti/icssg/icssg_prueth.h |  3 +++
>  5 files changed, 50 insertions(+), 5 deletions(-)
> 
> diff --git a/drivers/net/ethernet/ti/icssg/icssg_common.c b/drivers/net/ethernet/ti/icssg/icssg_common.c
> index b9d8a93d1680..fdebeb2f84e0 100644
> --- a/drivers/net/ethernet/ti/icssg/icssg_common.c
> +++ b/drivers/net/ethernet/ti/icssg/icssg_common.c
> @@ -660,14 +660,15 @@ enum netdev_tx icssg_ndo_start_xmit(struct sk_buff *skb, struct net_device *ndev
>  {
>  	struct cppi5_host_desc_t *first_desc, *next_desc, *cur_desc;
>  	struct prueth_emac *emac = netdev_priv(ndev);
> +	struct prueth *prueth = emac->prueth;
>  	struct netdev_queue *netif_txq;
>  	struct prueth_tx_chn *tx_chn;
>  	dma_addr_t desc_dma, buf_dma;
> +	u32 pkt_len, dst_tag_id;
>  	int i, ret = 0, q_idx;
>  	bool in_tx_ts = 0;
>  	int tx_ts_cookie;
>  	void **swdata;
> -	u32 pkt_len;
>  	u32 *epib;
>  
>  	pkt_len = skb_headlen(skb);
> @@ -712,9 +713,20 @@ enum netdev_tx icssg_ndo_start_xmit(struct sk_buff *skb, struct net_device *ndev
>  
>  	/* set dst tag to indicate internal qid at the firmware which is at
>  	 * bit8..bit15. bit0..bit7 indicates port num for directed
> -	 * packets in case of switch mode operation
> +	 * packets in case of switch mode operation and port num 0
> +	 * for undirected packets in case of HSR offload mode
>  	 */
> -	cppi5_desc_set_tags_ids(&first_desc->hdr, 0, (emac->port_id | (q_idx << 8)));
> +	dst_tag_id = emac->port_id | (q_idx << 8);
> +
> +	if (prueth->is_hsr_offload_mode &&
> +	    (ndev->features & NETIF_F_HW_HSR_DUP))
> +		dst_tag_id = PRUETH_UNDIRECTED_PKT_DST_TAG;
> +
> +	if (prueth->is_hsr_offload_mode &&
> +	    (ndev->features & NETIF_F_HW_HSR_TAG_INS))
> +		epib[1] |= PRUETH_UNDIRECTED_PKT_TAG_INS;
> +
> +	cppi5_desc_set_tags_ids(&first_desc->hdr, 0, dst_tag_id);
>  	k3_udma_glue_tx_dma_to_cppi5_addr(tx_chn->tx_chn, &buf_dma);
>  	cppi5_hdesc_attach_buf(first_desc, buf_dma, pkt_len, buf_dma, pkt_len);
>  	swdata = cppi5_hdesc_get_swdata(first_desc);
> diff --git a/drivers/net/ethernet/ti/icssg/icssg_config.c b/drivers/net/ethernet/ti/icssg/icssg_config.c
> index 7b2e6c192ff3..72ace151d8e9 100644
> --- a/drivers/net/ethernet/ti/icssg/icssg_config.c
> +++ b/drivers/net/ethernet/ti/icssg/icssg_config.c
> @@ -531,7 +531,9 @@ static const struct icssg_r30_cmd emac_r32_bitmask[] = {
>  	{{EMAC_NONE,  0xffff4000, EMAC_NONE, EMAC_NONE}},	/* Preemption on Tx ENABLE*/
>  	{{EMAC_NONE,  0xbfff0000, EMAC_NONE, EMAC_NONE}},	/* Preemption on Tx DISABLE*/
>  	{{0xffff0010,  EMAC_NONE, 0xffff0010, EMAC_NONE}},	/* VLAN AWARE*/
> -	{{0xffef0000,  EMAC_NONE, 0xffef0000, EMAC_NONE}}	/* VLAN UNWARE*/
> +	{{0xffef0000,  EMAC_NONE, 0xffef0000, EMAC_NONE}},	/* VLAN UNWARE*/
> +	{{0xffff2000, EMAC_NONE, EMAC_NONE, EMAC_NONE}},	/* HSR_RX_OFFLOAD_ENABLE */
> +	{{0xdfff0000, EMAC_NONE, EMAC_NONE, EMAC_NONE}}		/* HSR_RX_OFFLOAD_DISABLE */
>  };
>  
>  int icssg_set_port_state(struct prueth_emac *emac,
> diff --git a/drivers/net/ethernet/ti/icssg/icssg_config.h b/drivers/net/ethernet/ti/icssg/icssg_config.h
> index 1ac60283923b..92c2deaa3068 100644
> --- a/drivers/net/ethernet/ti/icssg/icssg_config.h
> +++ b/drivers/net/ethernet/ti/icssg/icssg_config.h
> @@ -80,6 +80,8 @@ enum icssg_port_state_cmd {
>  	ICSSG_EMAC_PORT_PREMPT_TX_DISABLE,
>  	ICSSG_EMAC_PORT_VLAN_AWARE_ENABLE,
>  	ICSSG_EMAC_PORT_VLAN_AWARE_DISABLE,
> +	ICSSG_EMAC_HSR_RX_OFFLOAD_ENABLE,
> +	ICSSG_EMAC_HSR_RX_OFFLOAD_DISABLE,
>  	ICSSG_EMAC_PORT_MAX_COMMANDS
>  };
>  
> diff --git a/drivers/net/ethernet/ti/icssg/icssg_prueth.c b/drivers/net/ethernet/ti/icssg/icssg_prueth.c
> index 676168d6fded..9af06454ba64 100644
> --- a/drivers/net/ethernet/ti/icssg/icssg_prueth.c
> +++ b/drivers/net/ethernet/ti/icssg/icssg_prueth.c
> @@ -41,7 +41,10 @@
>  #define DEFAULT_PORT_MASK	1
>  #define DEFAULT_UNTAG_MASK	1
>  
> -#define NETIF_PRUETH_HSR_OFFLOAD_FEATURES	NETIF_F_HW_HSR_FWD
> +#define NETIF_PRUETH_HSR_OFFLOAD_FEATURES	(NETIF_F_HW_HSR_FWD | \
> +						 NETIF_F_HW_HSR_DUP | \
> +						 NETIF_F_HW_HSR_TAG_INS | \
> +						 NETIF_F_HW_HSR_TAG_RM)
>  
>  /* CTRLMMR_ICSSG_RGMII_CTRL register bits */
>  #define ICSSG_CTRL_RGMII_ID_MODE                BIT(24)
> @@ -758,6 +761,21 @@ static void emac_change_hsr_feature(struct net_device *ndev,
>  	}
>  }
>  
> +static netdev_features_t emac_ndo_fix_features(struct net_device *ndev,
> +					       netdev_features_t features)
> +{
> +	/* In order to enable hsr tag insertion offload, hsr dup offload must
> +	 * also be enabled as these two are tightly coupled in firmware
> +	 * implementation.
> +	 */
> +	if (features & NETIF_F_HW_HSR_TAG_INS)
> +		features |= NETIF_F_HW_HSR_DUP;

What if only NETIF_F_HW_HSR_DUP was set? Don't you have to set NETIF_F_HW_HSR_TAG_INS as well?

> +	else
> +		features &= ~NETIF_F_HW_HSR_DUP;

what if NETIF_F_HW_HSR_DUP was still set?

I think you need to write a logic like follows.
	if both are already cleared in ndev->features and any one is set in features you set both in features.
	if both are already set in ndev->features and any one is cleared in features you clear both in features.

is this reasonable?

> +
> +	return features;
> +}
> +
>  static int emac_ndo_set_features(struct net_device *ndev,
>  				 netdev_features_t features)
>  {
> @@ -780,6 +798,7 @@ static const struct net_device_ops emac_netdev_ops = {
>  	.ndo_eth_ioctl = icssg_ndo_ioctl,
>  	.ndo_get_stats64 = icssg_ndo_get_stats64,
>  	.ndo_get_phys_port_name = icssg_ndo_get_phys_port_name,
> +	.ndo_fix_features = emac_ndo_fix_features,
>  	.ndo_set_features = emac_ndo_set_features,
>  };
>  
> @@ -1007,6 +1026,13 @@ static void icssg_change_mode(struct prueth *prueth)
>  
>  	for (mac = PRUETH_MAC0; mac < PRUETH_NUM_MACS; mac++) {
>  		emac = prueth->emac[mac];
> +		if (prueth->is_hsr_offload_mode) {
> +			if (emac->ndev->features & NETIF_F_HW_HSR_TAG_RM)
> +				icssg_set_port_state(emac, ICSSG_EMAC_HSR_RX_OFFLOAD_ENABLE);
> +			else
> +				icssg_set_port_state(emac, ICSSG_EMAC_HSR_RX_OFFLOAD_DISABLE);
> +		}
> +
>  		if (netif_running(emac->ndev)) {
>  			icssg_fdb_add_del(emac, eth_stp_addr, prueth->default_vlan,
>  					  ICSSG_FDB_ENTRY_P0_MEMBERSHIP |
> diff --git a/drivers/net/ethernet/ti/icssg/icssg_prueth.h b/drivers/net/ethernet/ti/icssg/icssg_prueth.h
> index a4b025fae797..bba6da2e6bd8 100644
> --- a/drivers/net/ethernet/ti/icssg/icssg_prueth.h
> +++ b/drivers/net/ethernet/ti/icssg/icssg_prueth.h
> @@ -59,6 +59,9 @@
>  
>  #define IEP_DEFAULT_CYCLE_TIME_NS	1000000	/* 1 ms */
>  
> +#define PRUETH_UNDIRECTED_PKT_DST_TAG	0
> +#define PRUETH_UNDIRECTED_PKT_TAG_INS	BIT(30)
> +
>  /* Firmware status codes */
>  #define ICSS_HS_FW_READY 0x55555555
>  #define ICSS_HS_FW_DEAD 0xDEAD0000	/* lower 16 bits contain error code */

-- 
cheers,
-roger