From 51b9d3f948b8182a52c1711755ca41b9e9fd166f Mon Sep 17 00:00:00 2001 From: Michael Chan Date: Thu, 8 Jan 2026 10:35:20 -0800 Subject: [PATCH] bnxt_en: Use a larger RSS indirection table on P5_PLUS chips The driver currently uses a chip supported RSS indirection table size just big enough to cover the number of RX rings. Each table with 64 entries requires one HW RSS context. The HW supported table sizes are 64, 128, 256, and 512 entries. Using the smallest table size can cause unbalanced RSS packet distributions. For example, if the number of rings is 48, the table size using existing logic will be 64. 32 rings will have a weight of 1 and 16 rings will have a weight of 2 when set to default even distribution. This represents a 100% difference in weights between some of the rings. Newer FW has increased the RSS indirection table resource. When the increased resource is detected, use the largest RSS indirection table size (512 entries) supported by the chip. Using the same example above, the weights of the 48 rings will be either 10 or 11 when set to default even distribution. The weight difference is only 10%. If there are thousands of VFs, there is a possiblity that we may not be able to allocate this larger RSS indirection table from the FW, so we add a check to fall back to the legacy scheme. Reviewed-by: Somnath Kotur Signed-off-by: Michael Chan Link: https://patch.msgid.link/20260108183521.215610-6-michael.chan@broadcom.com Signed-off-by: Jakub Kicinski --- drivers/net/ethernet/broadcom/bnxt/bnxt.c | 12 ++++++++++++ drivers/net/ethernet/broadcom/bnxt/bnxt.h | 3 +++ 2 files changed, 15 insertions(+) diff --git a/drivers/net/ethernet/broadcom/bnxt/bnxt.c b/drivers/net/ethernet/broadcom/bnxt/bnxt.c index 6aba1967ba00..9902babd82cb 100644 --- a/drivers/net/ethernet/broadcom/bnxt/bnxt.c +++ b/drivers/net/ethernet/broadcom/bnxt/bnxt.c @@ -6567,6 +6567,9 @@ int bnxt_get_nr_rss_ctxs(struct bnxt *bp, int rx_rings) if (bp->flags & BNXT_FLAG_CHIP_P5_PLUS) { if (!rx_rings) return 0; + if (bp->rss_cap & BNXT_RSS_CAP_LARGE_RSS_CTX) + return BNXT_RSS_TABLE_MAX_TBL_P5; + return bnxt_calc_nr_ring_pages(rx_rings - 1, BNXT_RSS_TABLE_ENTRIES_P5); } @@ -8077,6 +8080,11 @@ static int __bnxt_reserve_rings(struct bnxt *bp) bp->rx_nr_rings = rx_rings; bp->cp_nr_rings = hwr.cp; + /* Fall back if we cannot reserve enough HW RSS contexts */ + if ((bp->rss_cap & BNXT_RSS_CAP_LARGE_RSS_CTX) && + hwr.rss_ctx < bnxt_get_total_rss_ctxs(bp, &hwr)) + bp->rss_cap &= ~BNXT_RSS_CAP_LARGE_RSS_CTX; + if (!bnxt_rings_ok(bp, &hwr)) return -ENOMEM; @@ -9567,6 +9575,10 @@ int bnxt_hwrm_func_resc_qcaps(struct bnxt *bp, bool all) hw_resc->min_stat_ctxs = le16_to_cpu(resp->min_stat_ctx); hw_resc->max_stat_ctxs = le16_to_cpu(resp->max_stat_ctx); + if (hw_resc->max_rsscos_ctxs >= + hw_resc->max_vnics * BNXT_LARGE_RSS_TO_VNIC_RATIO) + bp->rss_cap |= BNXT_RSS_CAP_LARGE_RSS_CTX; + if (bp->flags & BNXT_FLAG_CHIP_P5_PLUS) { u16 max_msix = le16_to_cpu(resp->max_msix); diff --git a/drivers/net/ethernet/broadcom/bnxt/bnxt.h b/drivers/net/ethernet/broadcom/bnxt/bnxt.h index b8f1c78b92e8..3afd1d5e364a 100644 --- a/drivers/net/ethernet/broadcom/bnxt/bnxt.h +++ b/drivers/net/ethernet/broadcom/bnxt/bnxt.h @@ -1367,6 +1367,8 @@ struct bnxt_hw_resc { u32 max_rx_wm_flows; }; +#define BNXT_LARGE_RSS_TO_VNIC_RATIO 7 + #if defined(CONFIG_BNXT_SRIOV) struct bnxt_vf_info { u16 fw_fid; @@ -2410,6 +2412,7 @@ struct bnxt { #define BNXT_RSS_CAP_ESP_V6_RSS_CAP BIT(7) #define BNXT_RSS_CAP_MULTI_RSS_CTX BIT(8) #define BNXT_RSS_CAP_IPV6_FLOW_LABEL_RSS_CAP BIT(9) +#define BNXT_RSS_CAP_LARGE_RSS_CTX BIT(10) u8 rss_hash_key[HW_HASH_KEY_SIZE]; u8 rss_hash_key_valid:1; -- 2.47.3