Subject: Re: [Intel-wired-lan] [PATCH iwl-next v5 4/5] ice: Add tx_scheduling_layers devlink param

From: Jiri Pirko <[email-masked]>
Date: Fri, 1 Mar 2024 16:46:58 +0100

Fri, Mar 01, 2024 at 02:41:56PM CET, [email-masked] wrote:
>
>
>On 2/28/2024 4:57 PM, Jiri Pirko wrote:
>> Wed, Feb 28, 2024 at 03:20:53PM CET, [email-masked] wrote:
>> > From: Lukasz Czapnik <[email-masked]>
>> > 
>> > It was observed that Tx performance was inconsistent across all queues
>> > and/or VSIs and that it was directly connected to existing 9-layer
>> > topology of the Tx scheduler.
>> > 
>> > Introduce new private devlink param - tx_scheduling_layers. This parameter
>> > gives user flexibility to choose the 5-layer transmit scheduler topology
>> > which helps to smooth out the transmit performance.
>> > 
>> > Allowed parameter values are 5 and 9.
>> > 
>> > Example usage:
>> > 
>> > Show:
>> > devlink dev param show pci/0000:4b:00.0 name tx_scheduling_layers
>> > pci/0000:4b:00.0:
>> >   name tx_scheduling_layers type driver-specific
>> >     values:
>> >       cmode permanent value 9
>> > 
>> > Set:
>> > devlink dev param set pci/0000:4b:00.0 name tx_scheduling_layers value 5
>> > cmode permanent
>> > 
>> > devlink dev param set pci/0000:4b:00.0 name tx_scheduling_layers value 9
>> > cmode permanent
>> > 
>> > Signed-off-by: Lukasz Czapnik <[email-masked]>
>> > Co-developed-by: Mateusz Polchlopek <[email-masked]>
>> > Signed-off-by: Mateusz Polchlopek <[email-masked]>
>> > ---
>> > .../net/ethernet/intel/ice/ice_adminq_cmd.h   |   8 +
>> > drivers/net/ethernet/intel/ice/ice_devlink.c  | 169 ++++++++++++++++++
>> > .../net/ethernet/intel/ice/ice_fw_update.c    |   7 +-
>> > .../net/ethernet/intel/ice/ice_fw_update.h    |   3 +
>> > drivers/net/ethernet/intel/ice/ice_nvm.c      |   7 +-
>> > drivers/net/ethernet/intel/ice/ice_nvm.h      |   3 +
>> > 6 files changed, 189 insertions(+), 8 deletions(-)
>> > 
>> > diff --git a/drivers/net/ethernet/intel/ice/ice_adminq_cmd.h b/drivers/net/ethernet/intel/ice/ice_adminq_cmd.h
>> > index 02102e937b30..4143b50bd15d 100644
>> > --- a/drivers/net/ethernet/intel/ice/ice_adminq_cmd.h
>> > +++ b/drivers/net/ethernet/intel/ice/ice_adminq_cmd.h
>> > @@ -1692,6 +1692,14 @@ struct ice_aqc_nvm {
>> > };
>> > 
>> > #define ICE_AQC_NVM_START_POINT			0
>> > +#define ICE_AQC_NVM_TX_TOPO_MOD_ID             0x14B
>> > +
>> > +struct ice_aqc_nvm_tx_topo_user_sel {
>> > +	__le16 length;
>> > +	u8 data;
>> > +#define ICE_AQC_NVM_TX_TOPO_USER_SEL	BIT(4)
>> > +	u8 reserved;
>> > +};
>> > 
>> > /* NVM Checksum Command (direct, 0x0706) */
>> > struct ice_aqc_nvm_checksum {
>> > diff --git a/drivers/net/ethernet/intel/ice/ice_devlink.c b/drivers/net/ethernet/intel/ice/ice_devlink.c
>> > index cc717175178b..db4872990e51 100644
>> > --- a/drivers/net/ethernet/intel/ice/ice_devlink.c
>> > +++ b/drivers/net/ethernet/intel/ice/ice_devlink.c
>> > @@ -770,6 +770,167 @@ ice_devlink_port_unsplit(struct devlink *devlink, struct devlink_port *port,
>> > 	return ice_devlink_port_split(devlink, port, 1, extack);
>> > }
>> > 
>> > +/**
>> > + * ice_get_tx_topo_user_sel - Read user's choice from flash
>> > + * @pf: pointer to pf structure
>> > + * @layers: value read from flash will be saved here
>> > + *
>> > + * Reads user's preference for Tx Scheduler Topology Tree from PFA TLV.
>> > + *
>> > + * Returns zero when read was successful, negative values otherwise.
>> > + */
>> > +static int ice_get_tx_topo_user_sel(struct ice_pf *pf, uint8_t *layers)
>> > +{
>> > +	struct ice_aqc_nvm_tx_topo_user_sel usr_sel = {};
>> > +	struct ice_hw *hw = &pf->hw;
>> > +	int err;
>> > +
>> > +	err = ice_acquire_nvm(hw, ICE_RES_READ);
>> > +	if (err)
>> > +		return err;
>> > +
>> > +	err = ice_aq_read_nvm(hw, ICE_AQC_NVM_TX_TOPO_MOD_ID, 0,
>> > +			     sizeof(usr_sel), &usr_sel, true, true, NULL);
>> > +	if (err)
>> > +		goto exit_release_res;
>> > +
>> > +	if (usr_sel.data & ICE_AQC_NVM_TX_TOPO_USER_SEL)
>> > +		*layers = ICE_SCHED_5_LAYERS;
>> > +       else
>> > +		*layers = ICE_SCHED_9_LAYERS;
>> > +
>> > +exit_release_res:
>> > +	ice_release_nvm(hw);
>> > +
>> > +	return err;
>> > +}
>> > +
>> > +/**
>> > + * ice_update_tx_topo_user_sel - Save user's preference in flash
>> > + * @pf: pointer to pf structure
>> > + * @layers: value to be saved in flash
>> > + *
>> > + * Variable "layers" defines user's preference about number of layers in Tx
>> > + * Scheduler Topology Tree. This choice should be stored in PFA TLV field
>> > + * and be picked up by driver, next time during init.
>> > + *
>> > + * Returns zero when save was successful, negative values otherwise.
>> > + */
>> > +static int ice_update_tx_topo_user_sel(struct ice_pf *pf, int layers)
>> > +{
>> > +	struct ice_aqc_nvm_tx_topo_user_sel usr_sel = {};
>> > +	struct ice_hw *hw = &pf->hw;
>> > +	int err;
>> > +
>> > +	err = ice_acquire_nvm(hw, ICE_RES_WRITE);
>> > +	if (err)
>> > +		return err;
>> > +
>> > +	err = ice_aq_read_nvm(hw, ICE_AQC_NVM_TX_TOPO_MOD_ID, 0,
>> > +			      sizeof(usr_sel), &usr_sel, true, true, NULL);
>> > +	if (err)
>> > +		goto exit_release_res;
>> > +
>> > +	if (layers == ICE_SCHED_5_LAYERS)
>> > +		usr_sel.data |= ICE_AQC_NVM_TX_TOPO_USER_SEL;
>> > +	else
>> > +		usr_sel.data &= ~ICE_AQC_NVM_TX_TOPO_USER_SEL;
>> > +
>> > +	err = ice_write_one_nvm_block(pf, ICE_AQC_NVM_TX_TOPO_MOD_ID, 2,
>> > +				      sizeof(usr_sel.data), &usr_sel.data,
>> > +				      true, NULL, NULL);
>> > +	if (err)
>> > +		err = -EIO;
>> > +
>> > +exit_release_res:
>> > +	ice_release_nvm(hw);
>> > +
>> > +	return err;
>> > +}
>> > +
>> > +/**
>> > + * ice_devlink_tx_sched_layers_get - Get tx_scheduling_layers parameter
>> > + * @devlink: pointer to the devlink instance
>> > + * @id: the parameter ID to set
>> > + * @ctx: context to store the parameter value
>> > + *
>> > + * Returns zero on success and negative value on failure.
>> > + */
>> > +static int ice_devlink_tx_sched_layers_get(struct devlink *devlink, u32 id,
>> > +					   struct devlink_param_gset_ctx *ctx)
>> > +{
>> > +	struct ice_pf *pf = devlink_priv(devlink);
>> > +	struct device *dev = ice_pf_to_dev(pf);
>> > +	int err;
>> > +
>> > +	err = ice_get_tx_topo_user_sel(pf, &ctx->val.vu8);
>> > +	if (err) {
>> > +		dev_warn(dev, "Failed to read Tx Scheduler Tree - User Selection data from flash\n");
>> 
>> I wonder why we don't propagate extack to these callbacks. Care to add
>> it and use it instead of dmesg please?
>> 
>> 
>
>Good point Jiri, but it is 'get' (in 'set' the same situation) function from
>DEVLINK_PARAM_DRIVER which defines that in 'set'/'get' there is no extack

So add it.

>parameter. From 'get' function I can probably remove this message as it is
>not so important and just return error code...
>
>> > +		return -EIO;
>> > +	}
>> > +
>> > +	return 0;
>> > +}
>> > +
>> > +/**
>> > + * ice_devlink_tx_sched_layers_set - Set tx_scheduling_layers parameter
>> > + * @devlink: pointer to the devlink instance
>> > + * @id: the parameter ID to set
>> > + * @ctx: context to get the parameter value
>> > + *
>> > + * Returns zero on success and negative value on failure.
>> > + */
>> > +static int ice_devlink_tx_sched_layers_set(struct devlink *devlink, u32 id,
>> > +					   struct devlink_param_gset_ctx *ctx)
>> > +{
>> > +	struct ice_pf *pf = devlink_priv(devlink);
>> > +	struct device *dev = ice_pf_to_dev(pf);
>> > +	int err;
>> > +
>> > +	err = ice_update_tx_topo_user_sel(pf, ctx->val.vu8);
>> > +	if (err)
>> > +		return -EIO;
>> > +
>> > +	dev_warn(dev, "Tx scheduling layers have been changed on this device. You must reboot the system for the change to take effect.");
>> 
>> Reboot the system? Why not re-plug the whole building while you are at
>> it? :)
>> 
>> 
>
>... but what about 'set' function? The information about reboot has to stay
>and still - there is no extack in 'set' function.

My point is, do you really need to "reboot"? Message like this sounds
very odd coming from a nic driver. Woundn't pci slot powercycle do the
trick for example?

>
>> > +
>> > +	return 0;
>> > +}
>> > +
>> > +/**
>> > + * ice_devlink_tx_sched_layers_validate - Validate passed tx_scheduling_layers
>> > + *                                       parameter value
>> > + * @devlink: unused pointer to devlink instance
>> > + * @id: the parameter ID to validate
>> > + * @val: value to validate
>> > + * @extack: netlink extended ACK structure
>> > + *
>> > + * Supported values are:
>> > + * - 5 - five layers Tx Scheduler Topology Tree
>> > + * - 9 - nine layers Tx Scheduler Topology Tree
>> > + *
>> > + * Returns zero when passed parameter value is supported. Negative value on
>> > + * error.
>> > + */
>> > +static int ice_devlink_tx_sched_layers_validate(struct devlink *devlink, u32 id,
>> > +					        union devlink_param_value val,
>> > +					        struct netlink_ext_ack *extack)
>> > +{
>> > +	struct ice_pf *pf = devlink_priv(devlink);
>> > +	struct ice_hw *hw = &pf->hw;
>> > +
>> > +	if (!hw->func_caps.common_cap.tx_sched_topo_comp_mode_en) {
>> > +		NL_SET_ERR_MSG_MOD(extack, "Error: Requested feature is not supported by the FW on this device. Update the FW and run this command again.");
>> 
>> Drop the "Error: " prefix. Does not make sense to have it. Also, "Update
>> FW" remark looks quite odd.
>> 
>> > +		return -EOPNOTSUPP;
>> > +	}
>> > +
>> > +	if (val.vu8 != ICE_SCHED_5_LAYERS && val.vu8 != ICE_SCHED_9_LAYERS) {
>> > +		NL_SET_ERR_MSG_MOD(extack, "Error: Wrong number of tx scheduler layers provided.");
>> 
>> Drop the "Error: " prefix. Does not make sense to have it.
>> 
>> 
>> > +		return -EINVAL;
>> > +	}
>> > +
>> > +	return 0;
>> > +}
>> > +
>> > /**
>> >   * ice_tear_down_devlink_rate_tree - removes devlink-rate exported tree
>> >   * @pf: pf struct
>> > @@ -1601,6 +1762,7 @@ static int ice_devlink_loopback_validate(struct devlink *devlink, u32 id,
>> > enum ice_param_id {
>> > 	ICE_DEVLINK_PARAM_ID_BASE = DEVLINK_PARAM_GENERIC_ID_MAX,
>> > 	ICE_DEVLINK_PARAM_ID_LOOPBACK,
>> > +	ICE_DEVLINK_PARAM_ID_TX_BALANCE,
>> > };
>> > 
>> > static const struct devlink_param ice_devlink_params[] = {
>> > @@ -1618,6 +1780,13 @@ static const struct devlink_param ice_devlink_params[] = {
>> > 			     ice_devlink_loopback_get,
>> > 			     ice_devlink_loopback_set,
>> > 			     ice_devlink_loopback_validate),
>> > +	DEVLINK_PARAM_DRIVER(ICE_DEVLINK_PARAM_ID_TX_BALANCE,
>> > +			     "tx_scheduling_layers",
>> > +			     DEVLINK_PARAM_TYPE_U8,
>> > +			     BIT(DEVLINK_PARAM_CMODE_PERMANENT),
>> > +			     ice_devlink_tx_sched_layers_get,
>> > +			     ice_devlink_tx_sched_layers_set,
>> > +			     ice_devlink_tx_sched_layers_validate),
>> > };
>> > 
>> > static void ice_devlink_free(void *devlink_ptr)
>> > diff --git a/drivers/net/ethernet/intel/ice/ice_fw_update.c b/drivers/net/ethernet/intel/ice/ice_fw_update.c
>> > index 319a2d6fe26c..f81db6c107c8 100644
>> > --- a/drivers/net/ethernet/intel/ice/ice_fw_update.c
>> > +++ b/drivers/net/ethernet/intel/ice/ice_fw_update.c
>> > @@ -286,10 +286,9 @@ ice_send_component_table(struct pldmfw *context, struct pldmfw_component *compon
>> >   *
>> >   * Returns: zero on success, or a negative error code on failure.
>> >   */
>> > -static int
>> > -ice_write_one_nvm_block(struct ice_pf *pf, u16 module, u32 offset,
>> > -			u16 block_size, u8 *block, bool last_cmd,
>> > -			u8 *reset_level, struct netlink_ext_ack *extack)
>> > +int ice_write_one_nvm_block(struct ice_pf *pf, u16 module, u32 offset,
>> > +			    u16 block_size, u8 *block, bool last_cmd,
>> > +			    u8 *reset_level, struct netlink_ext_ack *extack)
>> > {
>> > 	u16 completion_module, completion_retval;
>> > 	struct device *dev = ice_pf_to_dev(pf);
>> > diff --git a/drivers/net/ethernet/intel/ice/ice_fw_update.h b/drivers/net/ethernet/intel/ice/ice_fw_update.h
>> > index 750574885716..04b200462757 100644
>> > --- a/drivers/net/ethernet/intel/ice/ice_fw_update.h
>> > +++ b/drivers/net/ethernet/intel/ice/ice_fw_update.h
>> > @@ -9,5 +9,8 @@ int ice_devlink_flash_update(struct devlink *devlink,
>> > 			     struct netlink_ext_ack *extack);
>> > int ice_get_pending_updates(struct ice_pf *pf, u8 *pending,
>> > 			    struct netlink_ext_ack *extack);
>> > +int ice_write_one_nvm_block(struct ice_pf *pf, u16 module, u32 offset,
>> > +			    u16 block_size, u8 *block, bool last_cmd,
>> > +			    u8 *reset_level, struct netlink_ext_ack *extack);
>> > 
>> > #endif
>> > diff --git a/drivers/net/ethernet/intel/ice/ice_nvm.c b/drivers/net/ethernet/intel/ice/ice_nvm.c
>> > index d4e05d2cb30c..84eab92dc03c 100644
>> > --- a/drivers/net/ethernet/intel/ice/ice_nvm.c
>> > +++ b/drivers/net/ethernet/intel/ice/ice_nvm.c
>> > @@ -18,10 +18,9 @@
>> >   *
>> >   * Read the NVM using the admin queue commands (0x0701)
>> >   */
>> > -static int
>> > -ice_aq_read_nvm(struct ice_hw *hw, u16 module_typeid, u32 offset, u16 length,
>> > -		void *data, bool last_command, bool read_shadow_ram,
>> > -		struct ice_sq_cd *cd)
>> > +int ice_aq_read_nvm(struct ice_hw *hw, u16 module_typeid, u32 offset,
>> > +		    u16 length, void *data, bool last_command,
>> > +		    bool read_shadow_ram, struct ice_sq_cd *cd)
>> > {
>> > 	struct ice_aq_desc desc;
>> > 	struct ice_aqc_nvm *cmd;
>> > diff --git a/drivers/net/ethernet/intel/ice/ice_nvm.h b/drivers/net/ethernet/intel/ice/ice_nvm.h
>> > index 774c2317967d..63cdc6bdac58 100644
>> > --- a/drivers/net/ethernet/intel/ice/ice_nvm.h
>> > +++ b/drivers/net/ethernet/intel/ice/ice_nvm.h
>> > @@ -14,6 +14,9 @@ struct ice_orom_civd_info {
>> > 
>> > int ice_acquire_nvm(struct ice_hw *hw, enum ice_aq_res_access_type access);
>> > void ice_release_nvm(struct ice_hw *hw);
>> > +int ice_aq_read_nvm(struct ice_hw *hw, u16 module_typeid, u32 offset,
>> > +		    u16 length, void *data, bool last_command,
>> > +		    bool read_shadow_ram, struct ice_sq_cd *cd);
>> > int
>> > ice_read_flat_nvm(struct ice_hw *hw, u32 offset, u32 *length, u8 *data,
>> > 		  bool read_shadow_ram);
>> > -- 
>> > 2.38.1
>> > 
>
>Other comments will be resolved in the next version.
>Thanks