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 10/09/2024 20:52, Anwar, Md Danish wrote:
> Hi Roger,
> 
> On 9/10/2024 11:08 PM, Roger Quadros wrote:
>>
>>
>> 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?
>>
> 
> Yes that does sound reasonable,
> How does below code look to you.
> 
> 	if (!(ndev->features & NETIF_F_HW_HSR_DUP) &&
> 	    !(ndev->features & NETIF_F_HW_HSR_TAG_INS))

While this is OK. it could also be
	if (!(ndev->features & (NETIF_F_HW_HSR_DUP | NETIF_F_HW_HSR_TAG_INS)))
Your choice.

> 		if ((features & NETIF_F_HW_HSR_DUP) ||
> 		    (features & NETIF_F_HW_HSR_TAG_INS)) {
> 			features |= NETIF_F_HW_HSR_DUP;
> 			features |= NETIF_F_HW_HSR_TAG_INS;
how about one line?
			features |= NETIF_F_HW_HSR_DUP | NETIF_F_HW_HSR_TAG_INS;
> 		}

then you can get rid of the braces.

> 
> 	if ((ndev->features & NETIF_F_HW_HSR_DUP) &&
> 	    (ndev->features & NETIF_F_HW_HSR_TAG_INS))
> 		if (!(features & NETIF_F_HW_HSR_DUP) ||
> 		    !(features & NETIF_F_HW_HSR_TAG_INS)) {
> 			features &= ~NETIF_F_HW_HSR_DUP;
> 			features &= ~NETIF_F_HW_HSR_TAG_INS;

			features &= ~(NETIF_F_HW_HSR_DUP | NETIF_F_HW_HSR_TAG_INS);

> 		}
> 
>>> +
>>> +	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