Subject: Re: [PATCH net-next] net: sfc: use ethtool string helpers

From: Martin Habets <[email-masked]>
Date: Tue, 5 Nov 2024 09:48:55 +0000

On Mon, Nov 04, 2024 at 12:27:05PM -0800, Rosen Penev wrote:
> 
> The latter is the preferred way to copy ethtool strings.
> 
> Avoids manually incrementing the pointer. Cleans up the code quite well.
> 
> Signed-off-by: Rosen Penev <[email-masked]>
> ---
>  drivers/net/ethernet/sfc/ethtool_common.c     | 34 +++++++------------
>  drivers/net/ethernet/sfc/falcon/ethtool.c     | 24 +++++--------
>  drivers/net/ethernet/sfc/falcon/nic.c         |  7 ++--
>  drivers/net/ethernet/sfc/nic.c                |  7 ++--
>  .../net/ethernet/sfc/siena/ethtool_common.c   | 34 +++++++------------
>  drivers/net/ethernet/sfc/siena/nic.c          |  7 ++--
>  6 files changed, 40 insertions(+), 73 deletions(-)
> 
> diff --git a/drivers/net/ethernet/sfc/ethtool_common.c b/drivers/net/ethernet/sfc/ethtool_common.c
> index ae32e08540fa..d46972f45ec1 100644
> --- a/drivers/net/ethernet/sfc/ethtool_common.c
> +++ b/drivers/net/ethernet/sfc/ethtool_common.c
> @@ -403,24 +403,19 @@ static size_t efx_describe_per_queue_stats(struct efx_nic *efx, u8 *strings)
>  	efx_for_each_channel(channel, efx) {
>  		if (efx_channel_has_tx_queues(channel)) {
>  			n_stats++;
> -			if (strings != NULL) {
> -				snprintf(strings, ETH_GSTRING_LEN,
> -					 "tx-%u.tx_packets",
> -					 channel->tx_queue[0].queue /
> -					 EFX_MAX_TXQ_PER_CHANNEL);
> -
> -				strings += ETH_GSTRING_LEN;
> -			}
> +			if (strings)
> +				ethtool_sprintf(
> +					&strings, "tx-%u.tx_packets",

This still fits after the opening parentheses above within 80 characters.
I would prefer that style.

Martin

> +					channel->tx_queue[0].queue /
> +						EFX_MAX_TXQ_PER_CHANNEL);
>  		}
>  	}
>  	efx_for_each_channel(channel, efx) {
>  		if (efx_channel_has_rx_queue(channel)) {
>  			n_stats++;
> -			if (strings != NULL) {
> -				snprintf(strings, ETH_GSTRING_LEN,
> -					 "rx-%d.rx_packets", channel->channel);
> -				strings += ETH_GSTRING_LEN;
> -			}
> +			if (strings)
> +				ethtool_sprintf(&strings, "rx-%d.rx_packets",
> +						channel->channel);
>  		}
>  	}
>  	if (efx->xdp_tx_queue_count && efx->xdp_tx_queues) {
> @@ -428,11 +423,10 @@ static size_t efx_describe_per_queue_stats(struct efx_nic *efx, u8 *strings)
>  
>  		for (xdp = 0; xdp < efx->xdp_tx_queue_count; xdp++) {
>  			n_stats++;
> -			if (strings) {
> -				snprintf(strings, ETH_GSTRING_LEN,
> -					 "tx-xdp-cpu-%hu.tx_packets", xdp);
> -				strings += ETH_GSTRING_LEN;
> -			}
> +			if (strings)
> +				ethtool_sprintf(&strings,
> +						"tx-xdp-cpu-%hu.tx_packets",
> +						xdp);
>  		}
>  	}
>  
> @@ -467,9 +461,7 @@ void efx_ethtool_get_strings(struct net_device *net_dev,
>  		strings += (efx->type->describe_stats(efx, strings) *
>  			    ETH_GSTRING_LEN);
>  		for (i = 0; i < EFX_ETHTOOL_SW_STAT_COUNT; i++)
> -			strscpy(strings + i * ETH_GSTRING_LEN,
> -				efx_sw_stat_desc[i].name, ETH_GSTRING_LEN);
> -		strings += EFX_ETHTOOL_SW_STAT_COUNT * ETH_GSTRING_LEN;
> +			ethtool_puts(&strings, efx_sw_stat_desc[i].name);
>  		strings += (efx_describe_per_queue_stats(efx, strings) *
>  			    ETH_GSTRING_LEN);
>  		efx_ptp_describe_stats(efx, strings);
> diff --git a/drivers/net/ethernet/sfc/falcon/ethtool.c b/drivers/net/ethernet/sfc/falcon/ethtool.c
> index f4db683b80f7..41bd63d0c40c 100644
> --- a/drivers/net/ethernet/sfc/falcon/ethtool.c
> +++ b/drivers/net/ethernet/sfc/falcon/ethtool.c
> @@ -361,24 +361,18 @@ static size_t ef4_describe_per_queue_stats(struct ef4_nic *efx, u8 *strings)
>  	ef4_for_each_channel(channel, efx) {
>  		if (ef4_channel_has_tx_queues(channel)) {
>  			n_stats++;
> -			if (strings != NULL) {
> -				snprintf(strings, ETH_GSTRING_LEN,
> -					 "tx-%u.tx_packets",
> -					 channel->tx_queue[0].queue /
> -					 EF4_TXQ_TYPES);
> -
> -				strings += ETH_GSTRING_LEN;
> -			}
> +			if (strings)
> +				ethtool_sprintf(&strings, "tx-%u.tx_packets",
> +						channel->tx_queue[0].queue /
> +							EF4_TXQ_TYPES);
>  		}
>  	}
>  	ef4_for_each_channel(channel, efx) {
>  		if (ef4_channel_has_rx_queue(channel)) {
>  			n_stats++;
> -			if (strings != NULL) {
> -				snprintf(strings, ETH_GSTRING_LEN,
> -					 "rx-%d.rx_packets", channel->channel);
> -				strings += ETH_GSTRING_LEN;
> -			}
> +			if (strings)
> +				ethtool_sprintf(&strings, "rx-%d.rx_packets",
> +						channel->channel);
>  		}
>  	}
>  	return n_stats;
> @@ -412,9 +406,7 @@ static void ef4_ethtool_get_strings(struct net_device *net_dev,
>  		strings += (efx->type->describe_stats(efx, strings) *
>  			    ETH_GSTRING_LEN);
>  		for (i = 0; i < EF4_ETHTOOL_SW_STAT_COUNT; i++)
> -			strscpy(strings + i * ETH_GSTRING_LEN,
> -				ef4_sw_stat_desc[i].name, ETH_GSTRING_LEN);
> -		strings += EF4_ETHTOOL_SW_STAT_COUNT * ETH_GSTRING_LEN;
> +			ethtool_puts(&strings, ef4_sw_stat_desc[i].name);
>  		strings += (ef4_describe_per_queue_stats(efx, strings) *
>  			    ETH_GSTRING_LEN);
>  		break;
> diff --git a/drivers/net/ethernet/sfc/falcon/nic.c b/drivers/net/ethernet/sfc/falcon/nic.c
> index 78c851b5a56f..a7f0caa8710f 100644
> --- a/drivers/net/ethernet/sfc/falcon/nic.c
> +++ b/drivers/net/ethernet/sfc/falcon/nic.c
> @@ -451,11 +451,8 @@ size_t ef4_nic_describe_stats(const struct ef4_hw_stat_desc *desc, size_t count,
>  
>  	for_each_set_bit(index, mask, count) {
>  		if (desc[index].name) {
> -			if (names) {
> -				strscpy(names, desc[index].name,
> -					ETH_GSTRING_LEN);
> -				names += ETH_GSTRING_LEN;
> -			}
> +			if (names)
> +				ethtool_puts(&names, desc[index].name);
>  			++visible;
>  		}
>  	}
> diff --git a/drivers/net/ethernet/sfc/nic.c b/drivers/net/ethernet/sfc/nic.c
> index a33ed473cc8a..51c975cff4fe 100644
> --- a/drivers/net/ethernet/sfc/nic.c
> +++ b/drivers/net/ethernet/sfc/nic.c
> @@ -306,11 +306,8 @@ size_t efx_nic_describe_stats(const struct efx_hw_stat_desc *desc, size_t count,
>  
>  	for_each_set_bit(index, mask, count) {
>  		if (desc[index].name) {
> -			if (names) {
> -				strscpy(names, desc[index].name,
> -					ETH_GSTRING_LEN);
> -				names += ETH_GSTRING_LEN;
> -			}
> +			if (names)
> +				ethtool_puts(&names, desc[index].name);
>  			++visible;
>  		}
>  	}
> diff --git a/drivers/net/ethernet/sfc/siena/ethtool_common.c b/drivers/net/ethernet/sfc/siena/ethtool_common.c
> index 075fef64de68..53b1cdf872d8 100644
> --- a/drivers/net/ethernet/sfc/siena/ethtool_common.c
> +++ b/drivers/net/ethernet/sfc/siena/ethtool_common.c
> @@ -403,24 +403,19 @@ static size_t efx_describe_per_queue_stats(struct efx_nic *efx, u8 *strings)
>  	efx_for_each_channel(channel, efx) {
>  		if (efx_channel_has_tx_queues(channel)) {
>  			n_stats++;
> -			if (strings != NULL) {
> -				snprintf(strings, ETH_GSTRING_LEN,
> -					 "tx-%u.tx_packets",
> -					 channel->tx_queue[0].queue /
> -					 EFX_MAX_TXQ_PER_CHANNEL);
> -
> -				strings += ETH_GSTRING_LEN;
> -			}
> +			if (strings)
> +				ethtool_sprintf(
> +					&strings, "tx-%u.tx_packets",
> +					channel->tx_queue[0].queue /
> +						EFX_MAX_TXQ_PER_CHANNEL);
>  		}
>  	}
>  	efx_for_each_channel(channel, efx) {
>  		if (efx_channel_has_rx_queue(channel)) {
>  			n_stats++;
> -			if (strings != NULL) {
> -				snprintf(strings, ETH_GSTRING_LEN,
> -					 "rx-%d.rx_packets", channel->channel);
> -				strings += ETH_GSTRING_LEN;
> -			}
> +			if (strings)
> +				ethtool_sprintf(&strings, "rx-%d.rx_packets",
> +						channel->channel);
>  		}
>  	}
>  	if (efx->xdp_tx_queue_count && efx->xdp_tx_queues) {
> @@ -428,11 +423,10 @@ static size_t efx_describe_per_queue_stats(struct efx_nic *efx, u8 *strings)
>  
>  		for (xdp = 0; xdp < efx->xdp_tx_queue_count; xdp++) {
>  			n_stats++;
> -			if (strings) {
> -				snprintf(strings, ETH_GSTRING_LEN,
> -					 "tx-xdp-cpu-%hu.tx_packets", xdp);
> -				strings += ETH_GSTRING_LEN;
> -			}
> +			if (strings)
> +				ethtool_sprintf(&strings,
> +						"tx-xdp-cpu-%hu.tx_packets",
> +						xdp);
>  		}
>  	}
>  
> @@ -467,9 +461,7 @@ void efx_siena_ethtool_get_strings(struct net_device *net_dev,
>  		strings += (efx->type->describe_stats(efx, strings) *
>  			    ETH_GSTRING_LEN);
>  		for (i = 0; i < EFX_ETHTOOL_SW_STAT_COUNT; i++)
> -			strscpy(strings + i * ETH_GSTRING_LEN,
> -				efx_sw_stat_desc[i].name, ETH_GSTRING_LEN);
> -		strings += EFX_ETHTOOL_SW_STAT_COUNT * ETH_GSTRING_LEN;
> +			ethtool_puts(&strings, efx_sw_stat_desc[i].name);
>  		strings += (efx_describe_per_queue_stats(efx, strings) *
>  			    ETH_GSTRING_LEN);
>  		efx_siena_ptp_describe_stats(efx, strings);
> diff --git a/drivers/net/ethernet/sfc/siena/nic.c b/drivers/net/ethernet/sfc/siena/nic.c
> index 0ea0433a6230..06b97218b490 100644
> --- a/drivers/net/ethernet/sfc/siena/nic.c
> +++ b/drivers/net/ethernet/sfc/siena/nic.c
> @@ -457,11 +457,8 @@ size_t efx_siena_describe_stats(const struct efx_hw_stat_desc *desc, size_t coun
>  
>  	for_each_set_bit(index, mask, count) {
>  		if (desc[index].name) {
> -			if (names) {
> -				strscpy(names, desc[index].name,
> -					ETH_GSTRING_LEN);
> -				names += ETH_GSTRING_LEN;
> -			}
> +			if (names)
> +				ethtool_puts(&names, desc[index].name);
>  			++visible;
>  		}
>  	}
> -- 
> 2.47.0
>