From 278bc4296bd64ffd1d3913b487dc8a520e423a7a Mon Sep 17 00:00:00 2001 From: Ben Hutchings Date: Thu, 15 Dec 2011 13:56:49 +0000 Subject: ethtool: Define and apply a default policy for RX flow hash indirection All drivers that support modification of the RX flow hash indirection table initialise it in the same way: RX rings are assigned to table entries in rotation. Make that default policy explicit by having them call a ethtool_rxfh_indir_default() function. In the ethtool core, add support for a zero size value for ETHTOOL_SRXFHINDIR, which resets the table to this default. Partly-suggested-by: Matt Carlson Signed-off-by: Ben Hutchings Acked-by: Shreyas N Bhatewara Signed-off-by: David S. Miller --- include/linux/ethtool.h | 23 ++++++++++++++++++++--- 1 file changed, 20 insertions(+), 3 deletions(-) (limited to 'include') diff --git a/include/linux/ethtool.h b/include/linux/ethtool.h index 3b9f09d55b5c..b38bf69310ee 100644 --- a/include/linux/ethtool.h +++ b/include/linux/ethtool.h @@ -543,10 +543,15 @@ struct compat_ethtool_rxnfc { /** * struct ethtool_rxfh_indir - command to get or set RX flow hash indirection * @cmd: Specific command number - %ETHTOOL_GRXFHINDIR or %ETHTOOL_SRXFHINDIR - * @size: On entry, the array size of the user buffer, which may be zero - * for %ETHTOOL_GRXFHINDIR. On return from %ETHTOOL_GRXFHINDIR, the - * array size of the hardware indirection table. + * @size: On entry, the array size of the user buffer, which may be zero. + * On return from %ETHTOOL_GRXFHINDIR, the array size of the hardware + * indirection table. * @ring_index: RX ring/queue index for each hash value + * + * For %ETHTOOL_GRXFHINDIR, a @size of zero means that only the size + * should be returned. For %ETHTOOL_SRXFHINDIR, a @size of zero means + * the table should be reset to default values. This last feature + * is not supported by the original implementations. */ struct ethtool_rxfh_indir { __u32 cmd; @@ -749,6 +754,18 @@ struct net_device; /* Some generic methods drivers may use in their ethtool_ops */ u32 ethtool_op_get_link(struct net_device *dev); +/** + * ethtool_rxfh_indir_default - get default value for RX flow hash indirection + * @index: Index in RX flow hash indirection table + * @n_rx_rings: Number of RX rings to use + * + * This function provides the default policy for RX flow hash indirection. + */ +static inline u32 ethtool_rxfh_indir_default(u32 index, u32 n_rx_rings) +{ + return index % n_rx_rings; +} + /** * struct ethtool_ops - optional netdev operations * @get_settings: Get various device settings including Ethernet link -- cgit v1.2.3