From b54de55990b0467538c6bb33523b28816384958a Mon Sep 17 00:00:00 2001 From: Edward Cree Date: Wed, 7 Aug 2024 17:06:12 +0100 Subject: net: ethtool: fix off-by-one error in max RSS context IDs Both ethtool_ops.rxfh_max_context_id and the default value used when it's not specified are supposed to be exclusive maxima (the former is documented as such; the latter, U32_MAX, cannot be used as an ID since it equals ETH_RXFH_CONTEXT_ALLOC), but xa_alloc() expects an inclusive maximum. Subtract one from 'limit' to produce an inclusive maximum, and pass that to xa_alloc(). Increase bnxt's max by one to prevent a (very minor) regression, as BNXT_MAX_ETH_RSS_CTX is an inclusive max. This is safe since bnxt is not actually hard-limited; BNXT_MAX_ETH_RSS_CTX is just a leftover from old driver code that managed context IDs itself. Rename rxfh_max_context_id to rxfh_max_num_contexts to make its semantics (hopefully) more obvious. Fixes: 847a8ab18676 ("net: ethtool: let the core choose RSS context IDs") Signed-off-by: Edward Cree Link: https://patch.msgid.link/5a2d11a599aa5b0cc6141072c01accfb7758650c.1723045898.git.ecree.xilinx@gmail.com Signed-off-by: Jakub Kicinski --- include/linux/ethtool.h | 10 +++++----- 1 file changed, 5 insertions(+), 5 deletions(-) (limited to 'include/linux') diff --git a/include/linux/ethtool.h b/include/linux/ethtool.h index 303fda54ef17..989c94eddb2b 100644 --- a/include/linux/ethtool.h +++ b/include/linux/ethtool.h @@ -736,10 +736,10 @@ struct kernel_ethtool_ts_info { * @rxfh_key_space: same as @rxfh_indir_space, but for the key. * @rxfh_priv_size: size of the driver private data area the core should * allocate for an RSS context (in &struct ethtool_rxfh_context). - * @rxfh_max_context_id: maximum (exclusive) supported RSS context ID. If this - * is zero then the core may choose any (nonzero) ID, otherwise the core - * will only use IDs strictly less than this value, as the @rss_context - * argument to @create_rxfh_context and friends. + * @rxfh_max_num_contexts: maximum (exclusive) supported RSS context ID. + * If this is zero then the core may choose any (nonzero) ID, otherwise + * the core will only use IDs strictly less than this value, as the + * @rss_context argument to @create_rxfh_context and friends. * @supported_coalesce_params: supported types of interrupt coalescing. * @supported_ring_params: supported ring params. * @get_drvinfo: Report driver/device information. Modern drivers no @@ -954,7 +954,7 @@ struct ethtool_ops { u32 rxfh_indir_space; u16 rxfh_key_space; u16 rxfh_priv_size; - u32 rxfh_max_context_id; + u32 rxfh_max_num_contexts; u32 supported_coalesce_params; u32 supported_ring_params; void (*get_drvinfo)(struct net_device *, struct ethtool_drvinfo *); -- cgit v1.2.3