The core locks ctx->indir_size when an RSS context is created. Some NICs (e.g. bnxt) change their indirection table size based on the channel count, because the hardware table is a shared resource. This forces drivers to reject channel changes when RSS contexts exist.
Add driver helpers to resize indirection tables: ethtool_rxfh_indir_can_resize() checks whether the default context indirection table can be resized. ethtool_rxfh_indir_resize() resizes the default context table in place. Folding (shrink) requires the table to be periodic at the new size; non-periodic tables are rejected. Unfolding (grow) replicates the existing pattern. Sizes must be multiples of each other. ethtool_rxfh_ctxs_can_resize() validates all non-default RSS contexts can be resized. ethtool_rxfh_ctxs_resize() applies the resize. Signed-off-by: Björn Töpel <[email protected]> --- include/linux/ethtool.h | 6 ++ net/ethtool/common.c | 155 ++++++++++++++++++++++++++++++++++++++++ 2 files changed, 161 insertions(+) diff --git a/include/linux/ethtool.h b/include/linux/ethtool.h index d4d3c57bc7c0..51107b7e739e 100644 --- a/include/linux/ethtool.h +++ b/include/linux/ethtool.h @@ -218,6 +218,12 @@ static inline u8 *ethtool_rxfh_context_key(struct ethtool_rxfh_context *ctx) void ethtool_rxfh_context_lost(struct net_device *dev, u32 context_id); void ethtool_rxfh_indir_clear(struct net_device *dev); +bool ethtool_rxfh_indir_can_resize(struct net_device *dev, const u32 *tbl, + u32 old_size, u32 new_size); +void ethtool_rxfh_indir_resize(struct net_device *dev, u32 *tbl, + u32 old_size, u32 new_size); +int ethtool_rxfh_ctxs_can_resize(struct net_device *dev, u32 new_indir_size); +void ethtool_rxfh_ctxs_resize(struct net_device *dev, u32 new_indir_size); struct link_mode_info { int speed; diff --git a/net/ethtool/common.c b/net/ethtool/common.c index ee91f1155830..bf795766f526 100644 --- a/net/ethtool/common.c +++ b/net/ethtool/common.c @@ -1224,6 +1224,161 @@ void ethtool_rxfh_indir_clear(struct net_device *dev) } EXPORT_SYMBOL(ethtool_rxfh_indir_clear); +static bool ethtool_rxfh_is_periodic(const u32 *tbl, u32 old_size, u32 new_size) +{ + u32 i; + + for (i = new_size; i < old_size; i++) + if (tbl[i] != tbl[i % new_size]) + return false; + return true; +} + +static bool ethtool_rxfh_can_resize(const u32 *tbl, u32 old_size, u32 new_size, + u32 user_size) +{ + if (new_size == old_size) + return true; + + if (!user_size) + return true; + + if (new_size < old_size) { + if (new_size < user_size) + return false; + if (old_size % new_size) + return false; + if (!ethtool_rxfh_is_periodic(tbl, old_size, new_size)) + return false; + return true; + } + + if (new_size % old_size) + return false; + return true; +} + +/* Resize without validation; caller must have called can_resize first */ +static void ethtool_rxfh_resize(u32 *tbl, u32 old_size, u32 new_size) +{ + u32 i; + + /* Grow: replicate existing pattern; shrink is a no-op on the data */ + for (i = old_size; i < new_size; i++) + tbl[i] = tbl[i % old_size]; +} + +/** + * ethtool_rxfh_indir_can_resize - Check if context 0 indir table can resize + * @dev: network device + * @tbl: indirection table + * @old_size: current number of entries in the table + * @new_size: desired number of entries + * + * Validate that @tbl can be resized from @old_size to @new_size without + * data loss. Uses the user_size floor from context 0. When user_size is + * zero the table is not user-configured and resize always succeeds. + * Read-only; does not modify the table. + * + * Return: true if resize is possible, false otherwise. + */ +bool ethtool_rxfh_indir_can_resize(struct net_device *dev, const u32 *tbl, + u32 old_size, u32 new_size) +{ + return ethtool_rxfh_can_resize(tbl, old_size, new_size, + dev->ethtool->rss_indir_user_size); +} +EXPORT_SYMBOL(ethtool_rxfh_indir_can_resize); + +/** + * ethtool_rxfh_indir_resize - Fold or unfold context 0 indirection table + * @dev: network device + * @tbl: indirection table (must have room for max(old_size, new_size) entries) + * @old_size: current number of entries in the table + * @new_size: desired number of entries + * + * Resize the default RSS context indirection table in place. Caller + * must have validated with ethtool_rxfh_indir_can_resize() first. + */ +void ethtool_rxfh_indir_resize(struct net_device *dev, u32 *tbl, + u32 old_size, u32 new_size) +{ + if (!dev->ethtool->rss_indir_user_size) + return; + + ethtool_rxfh_resize(tbl, old_size, new_size); +} +EXPORT_SYMBOL(ethtool_rxfh_indir_resize); + +/** + * ethtool_rxfh_ctxs_can_resize - Validate resize for all RSS contexts + * @dev: network device + * @new_indir_size: new indirection table size + * + * Validate that the indirection tables of all non-default RSS contexts + * can be resized to @new_indir_size. Read-only; does not modify any + * context. Intended to be paired with ethtool_rxfh_ctxs_resize(). + * + * Return: 0 if all contexts can be resized, negative errno on failure. + */ +int ethtool_rxfh_ctxs_can_resize(struct net_device *dev, u32 new_indir_size) +{ + struct ethtool_rxfh_context *ctx; + unsigned long context; + int ret = 0; + + if (!dev->ethtool_ops->rxfh_indir_space || + new_indir_size > dev->ethtool_ops->rxfh_indir_space) + return -EINVAL; + + mutex_lock(&dev->ethtool->rss_lock); + xa_for_each(&dev->ethtool->rss_ctx, context, ctx) { + u32 *indir = ethtool_rxfh_context_indir(ctx); + + if (!ethtool_rxfh_can_resize(indir, ctx->indir_size, + new_indir_size, + ctx->indir_user_size)) { + ret = -EINVAL; + goto unlock; + } + } +unlock: + mutex_unlock(&dev->ethtool->rss_lock); + return ret; +} +EXPORT_SYMBOL(ethtool_rxfh_ctxs_can_resize); + +/** + * ethtool_rxfh_ctxs_resize - Resize all RSS context indirection tables + * @dev: network device + * @new_indir_size: new indirection table size + * + * Resize the indirection table of every non-default RSS context to + * @new_indir_size. Caller must have validated with + * ethtool_rxfh_ctxs_can_resize() first. An %ETHTOOL_MSG_RSS_NTF is + * sent for each resized context. + * + * Notifications are sent outside the RSS lock to avoid holding the + * mutex during notification delivery. + */ +void ethtool_rxfh_ctxs_resize(struct net_device *dev, u32 new_indir_size) +{ + struct ethtool_rxfh_context *ctx; + unsigned long context; + + mutex_lock(&dev->ethtool->rss_lock); + xa_for_each(&dev->ethtool->rss_ctx, context, ctx) { + ethtool_rxfh_resize(ethtool_rxfh_context_indir(ctx), + ctx->indir_size, new_indir_size); + ctx->indir_size = new_indir_size; + } + mutex_unlock(&dev->ethtool->rss_lock); + + xa_for_each(&dev->ethtool->rss_ctx, context, ctx) + ethtool_rss_notify(dev, ETHTOOL_MSG_RSS_NTF, context); +} +EXPORT_SYMBOL(ethtool_rxfh_ctxs_resize); + enum ethtool_link_medium ethtool_str_to_medium(const char *str) { int i; -- 2.53.0
