Subject: Re: [PATCH net-next v2 1/4] sfc: store PTP filters in a list

From: Martin Habets <[email-masked]>
Date: Thu, 2 Feb 2023 12:13:29 +0000

On Wed, Feb 01, 2023 at 09:08:46AM +0100, Íñigo Huguet wrote:
> Instead of using a fixed sized array for the PTP filters, use a list.
> 
> This is not actually necessary at this point because the filters for
> multicast PTP are a fixed number, but this is a preparation for the
> following patches adding support for unicast PTP.
> 
> To avoid confusion with the new struct type efx_ptp_rxfilter, change the
> name of some local variables from rxfilter to spec, given they're of the
> type efx_filter_spec.
> 
> Reported-by: Yalin Li <[email-masked]>
> Signed-off-by: Íñigo Huguet <[email-masked]>
> ---
>  drivers/net/ethernet/sfc/ptp.c | 72 ++++++++++++++++++++++------------
>  1 file changed, 46 insertions(+), 26 deletions(-)
> 
> diff --git a/drivers/net/ethernet/sfc/ptp.c b/drivers/net/ethernet/sfc/ptp.c
> index 9f07e1ba7780..53817b4350a5 100644
> --- a/drivers/net/ethernet/sfc/ptp.c
> +++ b/drivers/net/ethernet/sfc/ptp.c
> @@ -33,6 +33,7 @@
>  #include <linux/ip.h>
>  #include <linux/udp.h>
>  #include <linux/time.h>
> +#include <linux/errno.h>
>  #include <linux/ktime.h>
>  #include <linux/module.h>
>  #include <linux/pps_kernel.h>
> @@ -213,6 +214,16 @@ struct efx_ptp_timeset {
>  	u32 window;	/* Derived: end - start, allowing for wrap */
>  };
>  
> +/**
> + * struct efx_ptp_rxfilter - Filter for PTP packets
> + * @list: Node of the list where the filter is added
> + * @handle: Handle ID for the MCDI filters table
> + */
> +struct efx_ptp_rxfilter {
> +	struct list_head list;
> +	int handle;
> +};
> +
>  /**
>   * struct efx_ptp_data - Precision Time Protocol (PTP) state
>   * @efx: The NIC context
> @@ -229,8 +240,7 @@ struct efx_ptp_timeset {
>   * @work: Work task
>   * @reset_required: A serious error has occurred and the PTP task needs to be
>   *                  reset (disable, enable).
> - * @rxfilters: Receive filters when operating
> - * @rxfilters_count: Num of installed rxfilters, should be == PTP_RXFILTERS_LEN
> + * @rxfilters_mcast: Receive filters for multicast PTP packets
>   * @config: Current timestamp configuration
>   * @enabled: PTP operation enabled
>   * @mode: Mode in which PTP operating (PTP version)
> @@ -299,8 +309,7 @@ struct efx_ptp_data {
>  	struct workqueue_struct *workwq;
>  	struct work_struct work;
>  	bool reset_required;
> -	u32 rxfilters[PTP_RXFILTERS_LEN];

This is the onlu place PTP_RXFILTERS_LEN is used, so remove that
define in this patch.

Martin

> -	size_t rxfilters_count;
> +	struct list_head rxfilters_mcast;
>  	struct hwtstamp_config config;
>  	bool enabled;
>  	unsigned int mode;
> @@ -1292,11 +1301,13 @@ static inline void efx_ptp_process_rx(struct efx_nic *efx, struct sk_buff *skb)
>  static void efx_ptp_remove_multicast_filters(struct efx_nic *efx)
>  {
>  	struct efx_ptp_data *ptp = efx->ptp_data;
> +	struct efx_ptp_rxfilter *rxfilter, *tmp;
>  
> -	while (ptp->rxfilters_count) {
> -		ptp->rxfilters_count--;
> +	list_for_each_entry_safe(rxfilter, tmp, &ptp->rxfilters_mcast, list) {
>  		efx_filter_remove_id_safe(efx, EFX_FILTER_PRI_REQUIRED,
> -					  ptp->rxfilters[ptp->rxfilters_count]);
> +					  rxfilter->handle);
> +		list_del(&rxfilter->list);
> +		kfree(rxfilter);
>  	}
>  }
>  
> @@ -1311,48 +1322,55 @@ static void efx_ptp_init_filter(struct efx_nic *efx,
>  }
>  
>  static int efx_ptp_insert_filter(struct efx_nic *efx,
> -				 struct efx_filter_spec *rxfilter)
> +				 struct efx_filter_spec *spec)
>  {
>  	struct efx_ptp_data *ptp = efx->ptp_data;
> +	struct efx_ptp_rxfilter *rxfilter;
>  
> -	int rc = efx_filter_insert_filter(efx, rxfilter, true);
> +	int rc = efx_filter_insert_filter(efx, spec, true);
>  	if (rc < 0)
>  		return rc;
> -	ptp->rxfilters[ptp->rxfilters_count] = rc;
> -	ptp->rxfilters_count++;
> +
> +	rxfilter = kzalloc(sizeof(*rxfilter), GFP_KERNEL);
> +	if (!rxfilter)
> +		return -ENOMEM;
> +
> +	rxfilter->handle = rc;
> +	list_add(&rxfilter->list, &ptp->rxfilters_mcast);
> +
>  	return 0;
>  }
>  
>  static int efx_ptp_insert_ipv4_filter(struct efx_nic *efx, u16 port)
>  {
> -	struct efx_filter_spec rxfilter;
> +	struct efx_filter_spec spec;
>  
> -	efx_ptp_init_filter(efx, &rxfilter);
> -	efx_filter_set_ipv4_local(&rxfilter, IPPROTO_UDP, htonl(PTP_ADDR_IPV4),
> +	efx_ptp_init_filter(efx, &spec);
> +	efx_filter_set_ipv4_local(&spec, IPPROTO_UDP, htonl(PTP_ADDR_IPV4),
>  				  htons(port));
> -	return efx_ptp_insert_filter(efx, &rxfilter);
> +	return efx_ptp_insert_filter(efx, &spec);
>  }
>  
>  static int efx_ptp_insert_ipv6_filter(struct efx_nic *efx, u16 port)
>  {
>  	const struct in6_addr addr = {{PTP_ADDR_IPV6}};
> -	struct efx_filter_spec rxfilter;
> +	struct efx_filter_spec spec;
>  
> -	efx_ptp_init_filter(efx, &rxfilter);
> -	efx_filter_set_ipv6_local(&rxfilter, IPPROTO_UDP, &addr, htons(port));
> -	return efx_ptp_insert_filter(efx, &rxfilter);
> +	efx_ptp_init_filter(efx, &spec);
> +	efx_filter_set_ipv6_local(&spec, IPPROTO_UDP, &addr, htons(port));
> +	return efx_ptp_insert_filter(efx, &spec);
>  }
>  
>  static int efx_ptp_insert_eth_filter(struct efx_nic *efx)
>  {
>  	const u8 addr[ETH_ALEN] = PTP_ADDR_ETHER;
> -	struct efx_filter_spec rxfilter;
> +	struct efx_filter_spec spec;
>  
> -	efx_ptp_init_filter(efx, &rxfilter);
> -	efx_filter_set_eth_local(&rxfilter, EFX_FILTER_VID_UNSPEC, addr);
> -	rxfilter.match_flags |= EFX_FILTER_MATCH_ETHER_TYPE;
> -	rxfilter.ether_type = htons(ETH_P_1588);
> -	return efx_ptp_insert_filter(efx, &rxfilter);
> +	efx_ptp_init_filter(efx, &spec);
> +	efx_filter_set_eth_local(&spec, EFX_FILTER_VID_UNSPEC, addr);
> +	spec.match_flags |= EFX_FILTER_MATCH_ETHER_TYPE;
> +	spec.ether_type = htons(ETH_P_1588);
> +	return efx_ptp_insert_filter(efx, &spec);
>  }
>  
>  static int efx_ptp_insert_multicast_filters(struct efx_nic *efx)
> @@ -1360,7 +1378,7 @@ static int efx_ptp_insert_multicast_filters(struct efx_nic *efx)
>  	struct efx_ptp_data *ptp = efx->ptp_data;
>  	int rc;
>  
> -	if (!ptp->channel || ptp->rxfilters_count)
> +	if (!ptp->channel || !list_empty(&ptp->rxfilters_mcast))
>  		return 0;
>  
>  	/* Must filter on both event and general ports to ensure
> @@ -1566,6 +1584,8 @@ int efx_ptp_probe(struct efx_nic *efx, struct efx_channel *channel)
>  	for (pos = 0; pos < MAX_RECEIVE_EVENTS; pos++)
>  		list_add(&ptp->rx_evts[pos].link, &ptp->evt_free_list);
>  
> +	INIT_LIST_HEAD(&ptp->rxfilters_mcast);
> +
>  	/* Get the NIC PTP attributes and set up time conversions */
>  	rc = efx_ptp_get_attributes(efx);
>  	if (rc < 0)
> -- 
> 2.34.3