diff --git a/drivers/net/ethernet/microsoft/mana/mana_bpf.c b/drivers/net/ethernet/microsoft/mana/mana_bpf.c index 5c9961ee9747..b27fd9b8c4f6 100644 --- a/drivers/net/ethernet/microsoft/mana/mana_bpf.c +++ b/drivers/net/ethernet/microsoft/mana/mana_bpf.c @@ -91,7 +91,7 @@ u32 mana_run_xdp(struct net_device *ndev, struct mana_rxq *rxq, goto out; xdp_init_buff(xdp, PAGE_SIZE, &rxq->xdp_rxq); - xdp_prepare_buff(xdp, buf_va, XDP_PACKET_HEADROOM, pkt_len, true); + xdp_prepare_buff(xdp, buf_va, rxq->headroom, pkt_len, true); act = bpf_prog_run_xdp(prog, xdp); @@ -183,9 +183,9 @@ static int mana_xdp_set(struct net_device *ndev, struct bpf_prog *prog, if (!old_prog && !prog) return 0; - if (prog && ndev->mtu > MANA_XDP_MTU_MAX) { + if (prog && ndev->mtu > MANA_XDP_MTU_MAX(ndev)) { netdev_err(ndev, "XDP: mtu:%u too large, mtu_max:%lu\n", - ndev->mtu, MANA_XDP_MTU_MAX); + ndev->mtu, MANA_XDP_MTU_MAX(ndev)); NL_SET_ERR_MSG_MOD(extack, "XDP: mtu too large"); return -EOPNOTSUPP; @@ -238,7 +238,7 @@ static int mana_xdp_set(struct net_device *ndev, struct bpf_prog *prog, bpf_prog_put(old_prog); if (prog) - ndev->max_mtu = min_t(unsigned int, MANA_XDP_MTU_MAX, + ndev->max_mtu = min_t(unsigned int, MANA_XDP_MTU_MAX(ndev), gc->adapter_mtu - ETH_HLEN); else ndev->max_mtu = gc->adapter_mtu - ETH_HLEN; diff --git a/drivers/net/ethernet/microsoft/mana/mana_en.c b/drivers/net/ethernet/microsoft/mana/mana_en.c index 591fb4191d90..a1fb06b23947 100644 --- a/drivers/net/ethernet/microsoft/mana/mana_en.c +++ b/drivers/net/ethernet/microsoft/mana/mana_en.c @@ -758,6 +758,44 @@ static void *mana_get_rxbuf_pre(struct mana_rxq *rxq, dma_addr_t *da) return va; } +/* Reserve enough headroom to satisfy the skb_cow() in ip_forward() and avoid + * reallocation: the TX path keeps the SGE DMA mappings in struct mana_skb_head + * at skb->head, so the port advertises ndev->needed_headroom = MANA_HEADROOM. + */ +static u32 mana_get_rxbuf_headroom(struct mana_port_context *apc) +{ + if (mana_xdp_get(apc)) + return mana_xdp_headroom(apc->ndev); + + return LL_RESERVED_SPACE(apc->ndev); +} + +static u32 mana_get_rxbuf_size(struct mana_port_context *apc, u32 mtu) +{ + u32 len = SKB_DATA_ALIGN(mtu + MANA_RXBUF_PAD + + mana_get_rxbuf_headroom(apc)); + + return ALIGN(len, MANA_RX_FRAG_ALIGNMENT); +} + +/* Returns true when one RX buffer per page is already required by XDP or by + * the buffer size implied by the MTU, i.e. regardless of the + * MANA_PRIV_FLAG_USE_FULL_PAGE_RXBUF private flag. + */ +bool mana_single_rxbuf_per_page_forced(struct mana_port_context *apc, u32 mtu) +{ + /* For xdp make sure only one packet fits per page. */ + if (mana_xdp_get(apc)) + return true; + + /* Only use the page_pool fragment path when at least two buffers, + * including the headroom each of them has to reserve, actually fit + * into one page. Otherwise the fragment path degenerates into one + * buffer per page while still paying the fragment accounting cost. + */ + return PAGE_SIZE / mana_get_rxbuf_size(apc, mtu) < 2; +} + static bool mana_use_single_rxbuf_per_page(struct mana_port_context *apc, u32 mtu) { @@ -770,32 +808,27 @@ mana_use_single_rxbuf_per_page(struct mana_port_context *apc, u32 mtu) if (apc->priv_flags & BIT(MANA_PRIV_FLAG_USE_FULL_PAGE_RXBUF)) return true; - /* For xdp and jumbo frames make sure only one packet fits per page. */ - if (mtu + MANA_RXBUF_PAD > PAGE_SIZE / 2 || mana_xdp_get(apc)) - return true; - - return false; + return mana_single_rxbuf_per_page_forced(apc, mtu); } -/* Get RX buffer's data size, alloc size, XDP headroom based on MTU */ +/* Get RX buffer's data size, alloc size, headroom and frag count based on MTU */ static void mana_get_rxbuf_cfg(struct mana_port_context *apc, int mtu, u32 *datasize, u32 *alloc_size, u32 *headroom, u32 *frag_count) { - u32 len, buf_size; + u32 buf_size; /* Calculate datasize first (consistent across all cases) */ *datasize = mtu + ETH_HLEN; + *headroom = mana_get_rxbuf_headroom(apc); + if (mana_use_single_rxbuf_per_page(apc, mtu)) { - if (mana_xdp_get(apc)) { - *headroom = XDP_PACKET_HEADROOM; + if (mana_xdp_get(apc)) *alloc_size = PAGE_SIZE; - } else { - *headroom = 0; /* no support for XDP */ + else *alloc_size = SKB_DATA_ALIGN(mtu + MANA_RXBUF_PAD + *headroom); - } *frag_count = 1; @@ -809,11 +842,7 @@ static void mana_get_rxbuf_cfg(struct mana_port_context *apc, } /* Standard MTU case - optimize for multiple packets per page */ - *headroom = 0; - - /* Calculate base buffer size needed */ - len = SKB_DATA_ALIGN(mtu + MANA_RXBUF_PAD + *headroom); - buf_size = ALIGN(len, MANA_RX_FRAG_ALIGNMENT); + buf_size = mana_get_rxbuf_size(apc, mtu); /* Calculate how many packets can fit in a page */ *frag_count = PAGE_SIZE / buf_size; diff --git a/drivers/net/ethernet/microsoft/mana/mana_ethtool.c b/drivers/net/ethernet/microsoft/mana/mana_ethtool.c index ece7ff9cc409..33db79569d3b 100644 --- a/drivers/net/ethernet/microsoft/mana/mana_ethtool.c +++ b/drivers/net/ethernet/microsoft/mana/mana_ethtool.c @@ -815,12 +815,12 @@ static int mana_set_priv_flags(struct net_device *ndev, u32 priv_flags) if (!apc->port_is_up) return 0; - /* If XDP is attached or MTU is jumbo, single-buffer-per-page - * is already forced regardless of this flag. Skip the - * expensive detach/attach cycle since nothing changes. + /* If XDP is attached or the MTU already forces one buffer per + * page, single-buffer-per-page is used regardless of this + * flag. Skip the expensive detach/attach cycle since nothing + * changes. */ - if (ndev->mtu + MANA_RXBUF_PAD > PAGE_SIZE / 2 || - mana_xdp_get(apc)) + if (mana_single_rxbuf_per_page_forced(apc, ndev->mtu)) return 0; /* Block RDMA from grabbing the vport during detach/attach */ diff --git a/include/net/mana/mana.h b/include/net/mana/mana.h index 83b7eff4646e..8c3dc9d0b299 100644 --- a/include/net/mana/mana.h +++ b/include/net/mana/mana.h @@ -377,7 +377,18 @@ struct mana_recv_buf_oob { #define MANA_RXBUF_PAD (SKB_DATA_ALIGN(sizeof(struct skb_shared_info)) \ + ETH_HLEN) -#define MANA_XDP_MTU_MAX (PAGE_SIZE - MANA_RXBUF_PAD - XDP_PACKET_HEADROOM) +/* Headroom an RX buffer has to reserve while XDP is attached: the XDP program + * needs XDP_PACKET_HEADROOM, and the TX path needs LL_RESERVED_SPACE() (see + * mana_get_rxbuf_headroom()). LL_RESERVED_SPACE() grows with MAX_SKB_FRAGS and + * exceeds XDP_PACKET_HEADROOM once CONFIG_MAX_SKB_FRAGS is 19 or more. + */ +static inline u32 mana_xdp_headroom(struct net_device *ndev) +{ + return max_t(u32, LL_RESERVED_SPACE(ndev), XDP_PACKET_HEADROOM); +} + +#define MANA_XDP_MTU_MAX(ndev) \ + (PAGE_SIZE - MANA_RXBUF_PAD - mana_xdp_headroom(ndev)) struct mana_rxq { struct gdma_queue *gdma_rq; @@ -691,6 +702,7 @@ int mana_query_link_cfg(struct mana_port_context *apc); int mana_set_bw_clamp(struct mana_port_context *apc, u32 speed, int enable_clamping); void mana_query_phy_stats(struct mana_port_context *apc); +bool mana_single_rxbuf_per_page_forced(struct mana_port_context *apc, u32 mtu); int mana_pre_alloc_rxbufs(struct mana_port_context *apc, int mtu, int num_queues); void mana_pre_dealloc_rxbufs(struct mana_port_context *apc); void mana_unmap_skb(struct sk_buff *skb, struct mana_port_context *apc);