From c0f031bc88660e8b96060b76aa72fbe8859bdcc8 Mon Sep 17 00:00:00 2001 From: Jakub Kicinski Date: Mon, 31 Oct 2016 20:43:15 +0000 Subject: [PATCH] nfp: use alloc_frag() and build_skb() Speed up RX processing by moving to the alloc_frag()/build_skb() paradigm. Since we're no longer mapping the entire buffer for DMA add helpers which take care of calculating offsets and lengths. Signed-off-by: Jakub Kicinski Signed-off-by: David S. Miller --- drivers/net/ethernet/netronome/nfp/nfp_net.h | 8 +- .../net/ethernet/netronome/nfp/nfp_net_common.c | 115 +++++++++++++-------- .../net/ethernet/netronome/nfp/nfp_net_debugfs.c | 9 +- 3 files changed, 82 insertions(+), 50 deletions(-) diff --git a/drivers/net/ethernet/netronome/nfp/nfp_net.h b/drivers/net/ethernet/netronome/nfp/nfp_net.h index 9b90fab8a6df..9ca066b29f07 100644 --- a/drivers/net/ethernet/netronome/nfp/nfp_net.h +++ b/drivers/net/ethernet/netronome/nfp/nfp_net.h @@ -101,6 +101,10 @@ /* Offload definitions */ #define NFP_NET_N_VXLAN_PORTS (NFP_NET_CFG_VXLAN_SZ / sizeof(__be16)) +#define NFP_NET_RX_BUF_HEADROOM (NET_SKB_PAD + NET_IP_ALIGN) +#define NFP_NET_RX_BUF_NON_DATA (NFP_NET_RX_BUF_HEADROOM + \ + SKB_DATA_ALIGN(sizeof(struct skb_shared_info))) + /* Forward declarations */ struct nfp_net; struct nfp_net_r_vector; @@ -277,11 +281,11 @@ struct nfp_net_rx_hash { /** * struct nfp_net_rx_buf - software RX buffer descriptor - * @skb: sk_buff associated with this buffer + * @frag: page fragment buffer * @dma_addr: DMA mapping address of the buffer */ struct nfp_net_rx_buf { - struct sk_buff *skb; + void *frag; dma_addr_t dma_addr; }; diff --git a/drivers/net/ethernet/netronome/nfp/nfp_net_common.c b/drivers/net/ethernet/netronome/nfp/nfp_net_common.c index abd4f17e89c7..449ec798a9b7 100644 --- a/drivers/net/ethernet/netronome/nfp/nfp_net_common.c +++ b/drivers/net/ethernet/netronome/nfp/nfp_net_common.c @@ -50,6 +50,7 @@ #include #include #include +#include #include #include #include @@ -80,6 +81,22 @@ void nfp_net_get_fw_version(struct nfp_net_fw_version *fw_ver, put_unaligned_le32(reg, fw_ver); } +static dma_addr_t +nfp_net_dma_map_rx(struct nfp_net *nn, void *frag, unsigned int bufsz, + int direction) +{ + return dma_map_single(&nn->pdev->dev, frag + NFP_NET_RX_BUF_HEADROOM, + bufsz - NFP_NET_RX_BUF_NON_DATA, direction); +} + +static void +nfp_net_dma_unmap_rx(struct nfp_net *nn, dma_addr_t dma_addr, + unsigned int bufsz, int direction) +{ + dma_unmap_single(&nn->pdev->dev, dma_addr, + bufsz - NFP_NET_RX_BUF_NON_DATA, direction); +} + /* Firmware reconfig * * Firmware reconfig may take a while so we have two versions of it - @@ -1035,64 +1052,67 @@ nfp_net_calc_fl_bufsz(struct nfp_net *nn, unsigned int mtu) { unsigned int fl_bufsz; + fl_bufsz = NFP_NET_RX_BUF_HEADROOM; if (nn->rx_offset == NFP_NET_CFG_RX_OFFSET_DYNAMIC) - fl_bufsz = NFP_NET_MAX_PREPEND; + fl_bufsz += NFP_NET_MAX_PREPEND; else - fl_bufsz = nn->rx_offset; + fl_bufsz += nn->rx_offset; fl_bufsz += ETH_HLEN + VLAN_HLEN * 2 + mtu; + fl_bufsz = SKB_DATA_ALIGN(fl_bufsz); + fl_bufsz += SKB_DATA_ALIGN(sizeof(struct skb_shared_info)); + return fl_bufsz; } /** - * nfp_net_rx_alloc_one() - Allocate and map skb for RX + * nfp_net_rx_alloc_one() - Allocate and map page frag for RX * @rx_ring: RX ring structure of the skb * @dma_addr: Pointer to storage for DMA address (output param) * @fl_bufsz: size of freelist buffers * - * This function will allcate a new skb, map it for DMA. + * This function will allcate a new page frag, map it for DMA. * - * Return: allocated skb or NULL on failure. + * Return: allocated page frag or NULL on failure. */ -static struct sk_buff * +static void * nfp_net_rx_alloc_one(struct nfp_net_rx_ring *rx_ring, dma_addr_t *dma_addr, unsigned int fl_bufsz) { struct nfp_net *nn = rx_ring->r_vec->nfp_net; - struct sk_buff *skb; + void *frag; - skb = netdev_alloc_skb(nn->netdev, fl_bufsz); - if (!skb) { - nn_warn_ratelimit(nn, "Failed to alloc receive SKB\n"); + frag = netdev_alloc_frag(fl_bufsz); + if (!frag) { + nn_warn_ratelimit(nn, "Failed to alloc receive page frag\n"); return NULL; } - *dma_addr = dma_map_single(&nn->pdev->dev, skb->data, - fl_bufsz, DMA_FROM_DEVICE); + *dma_addr = nfp_net_dma_map_rx(nn, frag, fl_bufsz, DMA_FROM_DEVICE); if (dma_mapping_error(&nn->pdev->dev, *dma_addr)) { - dev_kfree_skb_any(skb); + skb_free_frag(frag); nn_warn_ratelimit(nn, "Failed to map DMA RX buffer\n"); return NULL; } - return skb; + return frag; } /** * nfp_net_rx_give_one() - Put mapped skb on the software and hardware rings * @rx_ring: RX ring structure - * @skb: Skb to put on rings + * @frag: page fragment buffer * @dma_addr: DMA address of skb mapping */ static void nfp_net_rx_give_one(struct nfp_net_rx_ring *rx_ring, - struct sk_buff *skb, dma_addr_t dma_addr) + void *frag, dma_addr_t dma_addr) { unsigned int wr_idx; wr_idx = rx_ring->wr_p % rx_ring->cnt; /* Stash SKB and DMA address away */ - rx_ring->rxbufs[wr_idx].skb = skb; + rx_ring->rxbufs[wr_idx].frag = frag; rx_ring->rxbufs[wr_idx].dma_addr = dma_addr; /* Fill freelist descriptor */ @@ -1127,9 +1147,9 @@ static void nfp_net_rx_ring_reset(struct nfp_net_rx_ring *rx_ring) wr_idx = rx_ring->wr_p % rx_ring->cnt; last_idx = rx_ring->cnt - 1; rx_ring->rxbufs[wr_idx].dma_addr = rx_ring->rxbufs[last_idx].dma_addr; - rx_ring->rxbufs[wr_idx].skb = rx_ring->rxbufs[last_idx].skb; + rx_ring->rxbufs[wr_idx].frag = rx_ring->rxbufs[last_idx].frag; rx_ring->rxbufs[last_idx].dma_addr = 0; - rx_ring->rxbufs[last_idx].skb = NULL; + rx_ring->rxbufs[last_idx].frag = NULL; memset(rx_ring->rxds, 0, sizeof(*rx_ring->rxds) * rx_ring->cnt); rx_ring->wr_p = 0; @@ -1149,7 +1169,6 @@ static void nfp_net_rx_ring_reset(struct nfp_net_rx_ring *rx_ring) static void nfp_net_rx_ring_bufs_free(struct nfp_net *nn, struct nfp_net_rx_ring *rx_ring) { - struct pci_dev *pdev = nn->pdev; unsigned int i; for (i = 0; i < rx_ring->cnt - 1; i++) { @@ -1157,14 +1176,14 @@ nfp_net_rx_ring_bufs_free(struct nfp_net *nn, struct nfp_net_rx_ring *rx_ring) * fails to allocate enough buffers and calls here to free * already allocated ones. */ - if (!rx_ring->rxbufs[i].skb) + if (!rx_ring->rxbufs[i].frag) continue; - dma_unmap_single(&pdev->dev, rx_ring->rxbufs[i].dma_addr, - rx_ring->bufsz, DMA_FROM_DEVICE); - dev_kfree_skb_any(rx_ring->rxbufs[i].skb); + nfp_net_dma_unmap_rx(nn, rx_ring->rxbufs[i].dma_addr, + rx_ring->bufsz, DMA_FROM_DEVICE); + skb_free_frag(rx_ring->rxbufs[i].frag); rx_ring->rxbufs[i].dma_addr = 0; - rx_ring->rxbufs[i].skb = NULL; + rx_ring->rxbufs[i].frag = NULL; } } @@ -1182,10 +1201,10 @@ nfp_net_rx_ring_bufs_alloc(struct nfp_net *nn, struct nfp_net_rx_ring *rx_ring) rxbufs = rx_ring->rxbufs; for (i = 0; i < rx_ring->cnt - 1; i++) { - rxbufs[i].skb = + rxbufs[i].frag = nfp_net_rx_alloc_one(rx_ring, &rxbufs[i].dma_addr, rx_ring->bufsz); - if (!rxbufs[i].skb) { + if (!rxbufs[i].frag) { nfp_net_rx_ring_bufs_free(nn, rx_ring); return -ENOMEM; } @@ -1203,7 +1222,7 @@ static void nfp_net_rx_ring_fill_freelist(struct nfp_net_rx_ring *rx_ring) unsigned int i; for (i = 0; i < rx_ring->cnt - 1; i++) - nfp_net_rx_give_one(rx_ring, rx_ring->rxbufs[i].skb, + nfp_net_rx_give_one(rx_ring, rx_ring->rxbufs[i].frag, rx_ring->rxbufs[i].dma_addr); } @@ -1338,8 +1357,13 @@ nfp_net_rx_drop(struct nfp_net_r_vector *r_vec, struct nfp_net_rx_ring *rx_ring, r_vec->rx_drops++; u64_stats_update_end(&r_vec->rx_sync); + /* skb is build based on the frag, free_skb() would free the frag + * so to be able to reuse it we need an extra ref. + */ + if (skb && rxbuf && skb->head == rxbuf->frag) + page_ref_inc(virt_to_head_page(rxbuf->frag)); if (rxbuf) - nfp_net_rx_give_one(rx_ring, rxbuf->skb, rxbuf->dma_addr); + nfp_net_rx_give_one(rx_ring, rxbuf->frag, rxbuf->dma_addr); if (skb) dev_kfree_skb_any(skb); } @@ -1360,10 +1384,12 @@ static int nfp_net_rx(struct nfp_net_rx_ring *rx_ring, int budget) struct nfp_net_r_vector *r_vec = rx_ring->r_vec; struct nfp_net *nn = r_vec->nfp_net; unsigned int data_len, meta_len; - struct sk_buff *skb, *new_skb; + struct nfp_net_rx_buf *rxbuf; struct nfp_net_rx_desc *rxd; dma_addr_t new_dma_addr; + struct sk_buff *skb; int pkts_polled = 0; + void *new_frag; int idx; while (pkts_polled < budget) { @@ -1381,21 +1407,23 @@ static int nfp_net_rx(struct nfp_net_rx_ring *rx_ring, int budget) rx_ring->rd_p++; pkts_polled++; - skb = rx_ring->rxbufs[idx].skb; - - new_skb = nfp_net_rx_alloc_one(rx_ring, &new_dma_addr, - nn->fl_bufsz); - if (!new_skb) { - nfp_net_rx_drop(r_vec, rx_ring, &rx_ring->rxbufs[idx], - NULL); + rxbuf = &rx_ring->rxbufs[idx]; + skb = build_skb(rxbuf->frag, nn->fl_bufsz); + if (unlikely(!skb)) { + nfp_net_rx_drop(r_vec, rx_ring, rxbuf, NULL); + continue; + } + new_frag = nfp_net_rx_alloc_one(rx_ring, &new_dma_addr, + nn->fl_bufsz); + if (unlikely(!new_frag)) { + nfp_net_rx_drop(r_vec, rx_ring, rxbuf, skb); continue; } - dma_unmap_single(&nn->pdev->dev, - rx_ring->rxbufs[idx].dma_addr, - nn->fl_bufsz, DMA_FROM_DEVICE); + nfp_net_dma_unmap_rx(nn, rx_ring->rxbufs[idx].dma_addr, + nn->fl_bufsz, DMA_FROM_DEVICE); - nfp_net_rx_give_one(rx_ring, new_skb, new_dma_addr); + nfp_net_rx_give_one(rx_ring, new_frag, new_dma_addr); /* < meta_len > * <-- [rx_offset] --> @@ -1413,9 +1441,10 @@ static int nfp_net_rx(struct nfp_net_rx_ring *rx_ring, int budget) data_len = le16_to_cpu(rxd->rxd.data_len); if (nn->rx_offset == NFP_NET_CFG_RX_OFFSET_DYNAMIC) - skb_reserve(skb, meta_len); + skb_reserve(skb, NFP_NET_RX_BUF_HEADROOM + meta_len); else - skb_reserve(skb, nn->rx_offset); + skb_reserve(skb, + NFP_NET_RX_BUF_HEADROOM + nn->rx_offset); skb_put(skb, data_len - meta_len); /* Stats update */ diff --git a/drivers/net/ethernet/netronome/nfp/nfp_net_debugfs.c b/drivers/net/ethernet/netronome/nfp/nfp_net_debugfs.c index f7c9a5bc4aa3..180cf70f0093 100644 --- a/drivers/net/ethernet/netronome/nfp/nfp_net_debugfs.c +++ b/drivers/net/ethernet/netronome/nfp/nfp_net_debugfs.c @@ -44,8 +44,8 @@ static int nfp_net_debugfs_rx_q_read(struct seq_file *file, void *data) struct nfp_net_r_vector *r_vec = file->private; struct nfp_net_rx_ring *rx_ring; struct nfp_net_rx_desc *rxd; - struct sk_buff *skb; struct nfp_net *nn; + void *frag; int i; rtnl_lock(); @@ -73,10 +73,9 @@ static int nfp_net_debugfs_rx_q_read(struct seq_file *file, void *data) seq_printf(file, "%04d: 0x%08x 0x%08x", i, rxd->vals[0], rxd->vals[1]); - skb = READ_ONCE(rx_ring->rxbufs[i].skb); - if (skb) - seq_printf(file, " skb->head=%p skb->data=%p", - skb->head, skb->data); + frag = READ_ONCE(rx_ring->rxbufs[i].frag); + if (frag) + seq_printf(file, " frag=%p", frag); if (rx_ring->rxbufs[i].dma_addr) seq_printf(file, " dma_addr=%pad", -- 2.11.0