Re: [PATCH net-next v2] net: ti: icssg_prueth: add TAPRIO offload support

[Roger Quadros]

On 22/09/2023 07:58, MD Danish Anwar wrote:
> On 21/09/23 16:12, Roger Quadros wrote:
>> Hi Danish,
>>
>> On 21/09/2023 10:00, MD Danish Anwar wrote:
>>
>> Can you please retain patch authorhsip?
>>
> 
> Sure Roger. This patch was not applying clearly on latest linux-next so
> I had to manually apply it. I must have lost authorship while doing
> this. I will reset the authorship.
> 
>>> ICSSG dual-emac f/w supports Enhanced Scheduled Traffic (EST – defined
>>> in P802.1Qbv/D2.2 that later got included in IEEE 802.1Q-2018)
>>> configuration. EST allows express queue traffic to be scheduled
>>> (placed) on the wire at specific repeatable time intervals. In
>>> Linux kernel, EST configuration is done through tc command and
>>> the taprio scheduler in the net core implements a software only
>>> scheduler (SCH_TAPRIO). If the NIC is capable of EST configuration,
>>> user indicate "flag 2" in the command which is then parsed by
>>> taprio scheduler in net core and indicate that the command is to
>>> be offloaded to h/w. taprio then offloads the command to the
>>> driver by calling ndo_setup_tc() ndo ops. This patch implements
>>> ndo_setup_tc() to offload EST configuration to ICSSG.
>>>
>>> Signed-off-by: Roger Quadros <rogerq@xxxxxx>
>>> Signed-off-by: Vignesh Raghavendra <vigneshr@xxxxxx>
>>> Signed-off-by: MD Danish Anwar <danishanwar@xxxxxx>
>>> ---
>>> Cc: Roger Quadros <rogerq@xxxxxx>
>>> Cc: Andrew Lunn <andrew@xxxxxxx>
>>>
>>> Changes from v1 to v2:
>>> *) Rebased on the latest next-20230821 linux-next.
>>> *) Dropped the RFC tag as merge window is open now.
>>> *) Splitted this patch from the switch mode series [v1].
>>> *) Removed TODO comment as asked by Andrew and Roger.
>>> *) Changed Copyright to 2023 as asked by Roger.
>>>
>>> v1: https://lore.kernel.org/all/20230830110847.1219515-1-danishanwar@xxxxxx/
>>>
>>>  drivers/net/ethernet/ti/Makefile             |   3 +-
>>>  drivers/net/ethernet/ti/icssg/icssg_prueth.c |   5 +-
>>>  drivers/net/ethernet/ti/icssg/icssg_prueth.h |   7 +
>>>  drivers/net/ethernet/ti/icssg/icssg_qos.c    | 286 +++++++++++++++++++
>>>  drivers/net/ethernet/ti/icssg/icssg_qos.h    | 119 ++++++++
>>>  5 files changed, 418 insertions(+), 2 deletions(-)
>>>  create mode 100644 drivers/net/ethernet/ti/icssg/icssg_qos.c
>>>  create mode 100644 drivers/net/ethernet/ti/icssg/icssg_qos.h
>>>
>>> diff --git a/drivers/net/ethernet/ti/Makefile b/drivers/net/ethernet/ti/Makefile
>>> index 34fd7a716ba6..0df60ded1b2d 100644
>>> --- a/drivers/net/ethernet/ti/Makefile
>>> +++ b/drivers/net/ethernet/ti/Makefile
>>> @@ -37,5 +37,6 @@ icssg-prueth-y := k3-cppi-desc-pool.o \
>>>  		  icssg/icssg_config.o \
>>>  		  icssg/icssg_mii_cfg.o \
>>>  		  icssg/icssg_stats.o \
>>> -		  icssg/icssg_ethtool.o
>>> +		  icssg/icssg_ethtool.o \
>>> +		  icssg/icssg_qos.o
>>>  obj-$(CONFIG_TI_ICSS_IEP) += icssg/icss_iep.o
>>> diff --git a/drivers/net/ethernet/ti/icssg/icssg_prueth.c b/drivers/net/ethernet/ti/icssg/icssg_prueth.c
>>> index 6635b28bc672..89c301716926 100644
>>> --- a/drivers/net/ethernet/ti/icssg/icssg_prueth.c
>>> +++ b/drivers/net/ethernet/ti/icssg/icssg_prueth.c
>>> @@ -1166,7 +1166,7 @@ static int emac_phy_connect(struct prueth_emac *emac)
>>>  	return 0;
>>>  }
>>>  
>>> -static u64 prueth_iep_gettime(void *clockops_data, struct ptp_system_timestamp *sts)
>>> +u64 prueth_iep_gettime(void *clockops_data, struct ptp_system_timestamp *sts)
>>>  {
>>>  	u32 hi_rollover_count, hi_rollover_count_r;
>>>  	struct prueth_emac *emac = clockops_data;
>>> @@ -1403,6 +1403,8 @@ static int emac_ndo_open(struct net_device *ndev)
>>>  		napi_enable(&emac->tx_chns[i].napi_tx);
>>>  	napi_enable(&emac->napi_rx);
>>>  
>>> +	icssg_qos_tas_init(ndev);
>>> +
>>>  	/* start PHY */
>>>  	phy_start(ndev->phydev);
>>>  
>>> @@ -1669,6 +1671,7 @@ static const struct net_device_ops emac_netdev_ops = {
>>>  	.ndo_set_rx_mode = emac_ndo_set_rx_mode,
>>>  	.ndo_eth_ioctl = emac_ndo_ioctl,
>>>  	.ndo_get_stats64 = emac_ndo_get_stats64,
>>> +	.ndo_setup_tc = icssg_qos_ndo_setup_tc,
>>>  };
>>>  
>>>  /* get emac_port corresponding to eth_node name */
>>> diff --git a/drivers/net/ethernet/ti/icssg/icssg_prueth.h b/drivers/net/ethernet/ti/icssg/icssg_prueth.h
>>> index 8b6d6b497010..5712a65bced4 100644
>>> --- a/drivers/net/ethernet/ti/icssg/icssg_prueth.h
>>> +++ b/drivers/net/ethernet/ti/icssg/icssg_prueth.h
>>> @@ -37,6 +37,7 @@
>>>  #include "icssg_config.h"
>>>  #include "icss_iep.h"
>>>  #include "icssg_switch_map.h"
>>> +#include "icssg_qos.h"
>>>  
>>>  #define PRUETH_MAX_MTU          (2000 - ETH_HLEN - ETH_FCS_LEN)
>>>  #define PRUETH_MIN_PKT_SIZE     (VLAN_ETH_ZLEN)
>>> @@ -174,6 +175,9 @@ struct prueth_emac {
>>>  
>>>  	struct pruss_mem_region dram;
>>>  
>>> +	struct prueth_qos qos;
>>> +	struct work_struct ts_work;
>>> +
>>>  	struct delayed_work stats_work;
>>>  	u64 stats[ICSSG_NUM_STATS];
>>>  };
>>> @@ -285,4 +289,7 @@ u32 icssg_queue_level(struct prueth *prueth, int queue);
>>>  void emac_stats_work_handler(struct work_struct *work);
>>>  void emac_update_hardware_stats(struct prueth_emac *emac);
>>>  int emac_get_stat_by_name(struct prueth_emac *emac, char *stat_name);
>>> +
>>> +u64 prueth_iep_gettime(void *clockops_data, struct ptp_system_timestamp *sts);
>>> +
>>>  #endif /* __NET_TI_ICSSG_PRUETH_H */
>>> diff --git a/drivers/net/ethernet/ti/icssg/icssg_qos.c b/drivers/net/ethernet/ti/icssg/icssg_qos.c
>>> new file mode 100644
>>> index 000000000000..63a19142ee69
>>> --- /dev/null
>>> +++ b/drivers/net/ethernet/ti/icssg/icssg_qos.c
>>> @@ -0,0 +1,286 @@
>>> +// SPDX-License-Identifier: GPL-2.0
>>> +/* Texas Instruments ICSSG PRUETH QoS submodule
>>> + * Copyright (C) 2023 Texas Instruments Incorporated - http://www.ti.com/
>>> + */
>>> +
>>> +#include <linux/printk.h>
>>> +#include "icssg_prueth.h"
>>> +#include "icssg_switch_map.h"
>>> +
>>> +static void tas_update_fw_list_pointers(struct prueth_emac *emac)
>>> +{
>>> +	struct tas_config *tas = &emac->qos.tas.config;
>>> +
>>> +	if ((readb(tas->active_list)) == TAS_LIST0) {
>>> +		tas->fw_active_list = emac->dram.va + TAS_GATE_MASK_LIST0;
>>> +		tas->fw_shadow_list = emac->dram.va + TAS_GATE_MASK_LIST1;
>>> +	} else {
>>> +		tas->fw_active_list = emac->dram.va + TAS_GATE_MASK_LIST1;
>>> +		tas->fw_shadow_list = emac->dram.va + TAS_GATE_MASK_LIST0;
>>> +	}
>>> +}
>>> +
>>> +static void tas_update_maxsdu_table(struct prueth_emac *emac)
>>> +{
>>> +	struct tas_config *tas = &emac->qos.tas.config;
>>> +	u16 __iomem *max_sdu_tbl_ptr;
>>> +	u8 gate_idx;
>>> +
>>> +	/* update the maxsdu table */
>>> +	max_sdu_tbl_ptr = emac->dram.va + TAS_QUEUE_MAX_SDU_LIST;
>>> +
>>> +	for (gate_idx = 0; gate_idx < TAS_MAX_NUM_QUEUES; gate_idx++)
>>> +		writew(tas->max_sdu_table.max_sdu[gate_idx], &max_sdu_tbl_ptr[gate_idx]);
>>> +}
>>> +
>>> +static void tas_reset(struct prueth_emac *emac)
>>> +{
>>> +	struct tas_config *tas = &emac->qos.tas.config;
>>> +	int i;
>>> +
>>> +	for (i = 0; i < TAS_MAX_NUM_QUEUES; i++)
>>> +		tas->max_sdu_table.max_sdu[i] = 2048;
>>> +
>>> +	tas_update_maxsdu_table(emac);
>>> +
>>> +	writeb(TAS_LIST0, tas->active_list);
>>> +
>>> +	memset_io(tas->fw_active_list, 0, sizeof(*tas->fw_active_list));
>>> +	memset_io(tas->fw_shadow_list, 0, sizeof(*tas->fw_shadow_list));
>>> +}
>>> +
>>> +static int tas_set_state(struct prueth_emac *emac, enum tas_state state)
>>> +{
>>> +	struct tas_config *tas = &emac->qos.tas.config;
>>> +	int ret;
>>> +
>>> +	if (tas->state == state)
>>> +		return 0;
>>> +
>>> +	switch (state) {
>>> +	case TAS_STATE_RESET:
>>> +		tas_reset(emac);
>>> +		ret = emac_set_port_state(emac, ICSSG_EMAC_PORT_TAS_RESET);
>>> +		tas->state = TAS_STATE_RESET;
>>> +		break;
>>> +	case TAS_STATE_ENABLE:
>>> +		ret = emac_set_port_state(emac, ICSSG_EMAC_PORT_TAS_ENABLE);
>>> +		tas->state = TAS_STATE_ENABLE;
>>> +		break;
>>> +	case TAS_STATE_DISABLE:
>>> +		ret = emac_set_port_state(emac, ICSSG_EMAC_PORT_TAS_DISABLE);
>>> +		tas->state = TAS_STATE_DISABLE;
>>> +		break;
>>> +	default:
>>> +		netdev_err(emac->ndev, "%s: unsupported state\n", __func__);
>>> +		ret = -EINVAL;
>>> +		break;
>>> +	}
>>> +
>>> +	if (ret)
>>> +		netdev_err(emac->ndev, "TAS set state failed %d\n", ret);
>>> +	return ret;
>>> +}
>>> +
>>> +static int tas_set_trigger_list_change(struct prueth_emac *emac)
>>> +{
>>> +	struct tc_taprio_qopt_offload *admin_list = emac->qos.tas.taprio_admin;
>>> +	struct tas_config *tas = &emac->qos.tas.config;
>>> +	struct ptp_system_timestamp sts;
>>> +	u32 change_cycle_count;
>>> +	u32 cycle_time;
>>> +	u64 base_time;
>>> +	u64 cur_time;
>>> +
>>> +	cycle_time = admin_list->cycle_time - 4; /* -4ns to compensate for IEP wraparound time */
>>> +	base_time = admin_list->base_time;
>>> +	cur_time = prueth_iep_gettime(emac, &sts);
>>> +
>>> +	if (base_time > cur_time)
>>> +		change_cycle_count = DIV_ROUND_UP_ULL(base_time - cur_time, cycle_time);
>>> +	else
>>> +		change_cycle_count = 1;
>>> +
>>> +	writel(cycle_time, emac->dram.va + TAS_ADMIN_CYCLE_TIME);
>>> +	writel(change_cycle_count, emac->dram.va + TAS_CONFIG_CHANGE_CYCLE_COUNT);
>>> +	writeb(admin_list->num_entries, emac->dram.va + TAS_ADMIN_LIST_LENGTH);
>>> +
>>> +	/* config_change cleared by f/w to ack reception of new shadow list */
>>> +	writeb(1, &tas->config_list->config_change);
>>> +	/* config_pending cleared by f/w when new shadow list is copied to active list */
>>> +	writeb(1, &tas->config_list->config_pending);
>>> +
>>> +	return emac_set_port_state(emac, ICSSG_EMAC_PORT_TAS_TRIGGER);
>>> +}
>>> +
>>> +static int tas_update_oper_list(struct prueth_emac *emac)
>>> +{
>>> +	struct tc_taprio_qopt_offload *admin_list = emac->qos.tas.taprio_admin;
>>> +	struct tas_config *tas = &emac->qos.tas.config;
>>> +	u32 tas_acc_gate_close_time = 0;
>>> +	u8 idx, gate_idx, val;
>>> +	int ret;
>>> +
>>> +	tas_update_fw_list_pointers(emac);
>>> +
>>> +	for (idx = 0; idx < admin_list->num_entries; idx++) {
>>> +		writeb(admin_list->entries[idx].gate_mask,
>>> +		       &tas->fw_shadow_list->gate_mask_list[idx]);
>>> +		tas_acc_gate_close_time += admin_list->entries[idx].interval;
>>> +
>>> +		/* extend last entry till end of cycle time */
>>> +		if (idx == admin_list->num_entries - 1)
>>> +			writel(admin_list->cycle_time,
>>> +			       &tas->fw_shadow_list->win_end_time_list[idx]);
>>> +		else
>>> +			writel(tas_acc_gate_close_time,
>>> +			       &tas->fw_shadow_list->win_end_time_list[idx]);
>>> +	}
>>> +
>>> +	/* clear remaining entries */
>>> +	for (idx = admin_list->num_entries; idx < TAS_MAX_CMD_LISTS; idx++) {
>>> +		writeb(0, &tas->fw_shadow_list->gate_mask_list[idx]);
>>> +		writel(0, &tas->fw_shadow_list->win_end_time_list[idx]);
>>> +	}
>>> +
>>> +	/* update the Array of gate close time for each queue in each window */
>>> +	for (idx = 0 ; idx < admin_list->num_entries; idx++) {
>>> +		/* On Linux, only PRUETH_MAX_TX_QUEUES are supported per port */
>>> +		for (gate_idx = 0; gate_idx < PRUETH_MAX_TX_QUEUES; gate_idx++) {
>>> +			u8 gate_mask_list_idx = readb(&tas->fw_shadow_list->gate_mask_list[idx]);
>>> +			u32 gate_close_time = 0;
>>> +
>>> +			if (gate_mask_list_idx & BIT(gate_idx))
>>> +				gate_close_time = readl(&tas->fw_shadow_list->win_end_time_list[idx]);
>>> +
>>> +			writel(gate_close_time,
>>> +			       &tas->fw_shadow_list->gate_close_time_list[idx][gate_idx]);
>>> +		}
>>> +	}
>>> +
>>> +	/* tell f/w to swap active & shadow list */
>>> +	ret = tas_set_trigger_list_change(emac);
>>> +	if (ret) {
>>> +		netdev_err(emac->ndev, "failed to swap f/w config list: %d\n", ret);
>>> +		return ret;
>>> +	}
>>> +
>>> +	/* Wait for completion */
>>> +	ret = readb_poll_timeout(&tas->config_list->config_change, val, !val,
>>> +				 USEC_PER_MSEC, 10 * USEC_PER_MSEC);
>>> +	if (ret) {
>>> +		netdev_err(emac->ndev, "TAS list change completion time out\n");
>>> +		return ret;
>>> +	}
>>> +
>>> +	tas_update_fw_list_pointers(emac);
>>> +
>>> +	return 0;
>>> +}
>>> +
>>> +static int emac_set_taprio(struct prueth_emac *emac)
>>> +{
>>> +	struct tc_taprio_qopt_offload *taprio = emac->qos.tas.taprio_admin;
>>> +	int ret;
>>> +
>>> +	if (taprio->cmd == TAPRIO_CMD_DESTROY)
>>> +		return tas_set_state(emac, TAS_STATE_DISABLE);
>>> +
>>> +	if (taprio->cmd != TAPRIO_CMD_REPLACE)
>>> +		return -EOPNOTSUPP;
>>> +
>>> +	ret = tas_update_oper_list(emac);
>>> +	if (ret)
>>> +		return ret;
>>> +
>>> +	return tas_set_state(emac, TAS_STATE_ENABLE);
>>> +}
>>> +
>>> +static void emac_cp_taprio(struct tc_taprio_qopt_offload *from,
>>> +			   struct tc_taprio_qopt_offload *to)
>>> +{
>>> +	int i;
>>> +
>>> +	*to = *from;
>>> +	for (i = 0; i < from->num_entries; i++)
>>> +		to->entries[i] = from->entries[i];
>>> +}
>>> +
>>> +static int emac_setup_taprio(struct net_device *ndev, struct tc_taprio_qopt_offload *taprio)
>>
>> Please change this to
>> 	static int emac_setup_taprio(struct net_device *ndev, void *type_data)
>>
>> and later add
>> 	struct tc_taprio_qopt_offload *taprio = type_data;
> 
> Sure.
> 
>>> +{
>>> +	struct prueth_emac *emac = netdev_priv(ndev);
>>> +	struct tc_taprio_qopt_offload *est_new;
>>> +	int ret, idx;
>>> +
>>> +	if (!netif_running(ndev)) {
>>> +		netdev_err(ndev, "interface is down, link speed unknown\n");
>>> +		return -ENETDOWN;
>>> +	}
>>
>> Do we really need this?
>>
>> How about handling the taprio->cmd with a switch statement
>> and adding helper functions for each case?
>>
> 
> emac_set_taprio() is already doing something like this.
> It only implements TAPRIO_CMD_REPLACE and TAPRIO_CMD_DESTROY. Others are
> not supported.
> 
> static int emac_set_taprio(struct prueth_emac *emac)
> {
> 	struct tc_taprio_qopt_offload *taprio = emac->qos.tas.taprio_admin;
> 	int ret;
> 
> 	if (taprio->cmd == TAPRIO_CMD_DESTROY)
> 		return tas_set_state(emac, TAS_STATE_DISABLE);
> 
> 	if (taprio->cmd != TAPRIO_CMD_REPLACE)
> 		return -EOPNOTSUPP;
> 
> 	ret = tas_update_oper_list(emac);
> 	if (ret)
> 		return ret;
> 
> 	return tas_set_state(emac, TAS_STATE_ENABLE);
> }
> 
> emac_setup_taprio() is first doing all the neccessary check and then
> calling emac_set_taprio(), which actually perform actions based on the
> taprio->cmd. I think I'll keep this as it is.

OK but pleae at least use switch statement in emac_set_taprio()
and error out in default: case.

> 
>> So emac_setup_taprio() reduces to
>>
>> static int emac_setup_taprio(struct net_device *ndev, void *type_data)
>> {
>> 	struct tc_taprio_qopt_offload *taprio = type_data;
>> 	int err = 0;
>>
>>         switch (taprio->cmd) {
>>         case TAPRIO_CMD_REPLACE:
>>                 err = emac_taprio_replace(ndev, taprio);
>>                 break;
>>         case TAPRIO_CMD_DESTROY:
>>                 emac_taprio_destroy(ndev);
>>                 break;
>>         case TAPRIO_CMD_STATS:
>>                 emac_taprio_stats(ndev, &taprio->stats);
>>                 break;
>>         case TAPRIO_CMD_QUEUE_STATS:
>>                 emac_taprio_queue_stats(ndev, &taprio->queue_stats);
>>                 break;
>>         default:
>>                 err = -EOPNOTSUPP;
>>         }
>>
>> 	return err;
>> }
>>

-- 
cheers,
-roger