From 0a714186d3c0f7c563a03537f98716457c1f5ae0 Mon Sep 17 00:00:00 2001 From: =?UTF-8?q?Bj=C3=B6rn=20T=C3=B6pel?= Date: Tue, 28 Aug 2018 14:44:32 +0200 Subject: [PATCH] i40e: add AF_XDP zero-copy Rx support MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit This patch adds zero-copy Rx support for AF_XDP sockets. Instead of allocating buffers of type MEM_TYPE_PAGE_SHARED, the Rx frames are allocated as MEM_TYPE_ZERO_COPY when AF_XDP is enabled for a certain queue. All AF_XDP specific functions are added to a new file, i40e_xsk.c. Note that when AF_XDP zero-copy is enabled, the XDP action XDP_PASS will allocate a new buffer and copy the zero-copy frame prior passing it to the kernel stack. Signed-off-by: Björn Töpel Signed-off-by: Alexei Starovoitov --- drivers/net/ethernet/intel/i40e/Makefile | 3 +- drivers/net/ethernet/intel/i40e/i40e.h | 19 + drivers/net/ethernet/intel/i40e/i40e_main.c | 53 +- drivers/net/ethernet/intel/i40e/i40e_txrx.c | 9 +- drivers/net/ethernet/intel/i40e/i40e_txrx.h | 20 +- drivers/net/ethernet/intel/i40e/i40e_xsk.c | 661 ++++++++++++++++++++ drivers/net/ethernet/intel/i40e/i40e_xsk.h | 21 + 7 files changed, 775 insertions(+), 11 deletions(-) create mode 100644 drivers/net/ethernet/intel/i40e/i40e_xsk.c create mode 100644 drivers/net/ethernet/intel/i40e/i40e_xsk.h diff --git a/drivers/net/ethernet/intel/i40e/Makefile b/drivers/net/ethernet/intel/i40e/Makefile index 14397e7e9925..50590e8d1fd1 100644 --- a/drivers/net/ethernet/intel/i40e/Makefile +++ b/drivers/net/ethernet/intel/i40e/Makefile @@ -22,6 +22,7 @@ i40e-objs := i40e_main.o \ i40e_txrx.o \ i40e_ptp.o \ i40e_client.o \ - i40e_virtchnl_pf.o + i40e_virtchnl_pf.o \ + i40e_xsk.o i40e-$(CONFIG_I40E_DCB) += i40e_dcb.o i40e_dcb_nl.o diff --git a/drivers/net/ethernet/intel/i40e/i40e.h b/drivers/net/ethernet/intel/i40e/i40e.h index 7a80652e2500..876cac317e79 100644 --- a/drivers/net/ethernet/intel/i40e/i40e.h +++ b/drivers/net/ethernet/intel/i40e/i40e.h @@ -786,6 +786,11 @@ struct i40e_vsi { /* VSI specific handlers */ irqreturn_t (*irq_handler)(int irq, void *data); + + /* AF_XDP zero-copy */ + struct xdp_umem **xsk_umems; + u16 num_xsk_umems_used; + u16 num_xsk_umems; } ____cacheline_internodealigned_in_smp; struct i40e_netdev_priv { @@ -1090,6 +1095,20 @@ static inline bool i40e_enabled_xdp_vsi(struct i40e_vsi *vsi) return !!vsi->xdp_prog; } +static inline struct xdp_umem *i40e_xsk_umem(struct i40e_ring *ring) +{ + bool xdp_on = i40e_enabled_xdp_vsi(ring->vsi); + int qid = ring->queue_index; + + if (ring_is_xdp(ring)) + qid -= ring->vsi->alloc_queue_pairs; + + if (!ring->vsi->xsk_umems || !ring->vsi->xsk_umems[qid] || !xdp_on) + return NULL; + + return ring->vsi->xsk_umems[qid]; +} + int i40e_create_queue_channel(struct i40e_vsi *vsi, struct i40e_channel *ch); int i40e_set_bw_limit(struct i40e_vsi *vsi, u16 seid, u64 max_tx_rate); int i40e_add_del_cloud_filter(struct i40e_vsi *vsi, diff --git a/drivers/net/ethernet/intel/i40e/i40e_main.c b/drivers/net/ethernet/intel/i40e/i40e_main.c index d8b5a6af72bd..848eea7c84db 100644 --- a/drivers/net/ethernet/intel/i40e/i40e_main.c +++ b/drivers/net/ethernet/intel/i40e/i40e_main.c @@ -9,7 +9,9 @@ /* Local includes */ #include "i40e.h" #include "i40e_diag.h" +#include "i40e_xsk.h" #include +#include /* All i40e tracepoints are defined by the include below, which * must be included exactly once across the whole kernel with * CREATE_TRACE_POINTS defined @@ -3181,13 +3183,46 @@ static int i40e_configure_rx_ring(struct i40e_ring *ring) struct i40e_hw *hw = &vsi->back->hw; struct i40e_hmc_obj_rxq rx_ctx; i40e_status err = 0; + bool ok; + int ret; bitmap_zero(ring->state, __I40E_RING_STATE_NBITS); /* clear the context structure first */ memset(&rx_ctx, 0, sizeof(rx_ctx)); - ring->rx_buf_len = vsi->rx_buf_len; + if (ring->vsi->type == I40E_VSI_MAIN) + xdp_rxq_info_unreg_mem_model(&ring->xdp_rxq); + + ring->xsk_umem = i40e_xsk_umem(ring); + if (ring->xsk_umem) { + ring->rx_buf_len = ring->xsk_umem->chunk_size_nohr - + XDP_PACKET_HEADROOM; + /* For AF_XDP ZC, we disallow packets to span on + * multiple buffers, thus letting us skip that + * handling in the fast-path. + */ + chain_len = 1; + ring->zca.free = i40e_zca_free; + ret = xdp_rxq_info_reg_mem_model(&ring->xdp_rxq, + MEM_TYPE_ZERO_COPY, + &ring->zca); + if (ret) + return ret; + dev_info(&vsi->back->pdev->dev, + "Registered XDP mem model MEM_TYPE_ZERO_COPY on Rx ring %d\n", + ring->queue_index); + + } else { + ring->rx_buf_len = vsi->rx_buf_len; + if (ring->vsi->type == I40E_VSI_MAIN) { + ret = xdp_rxq_info_reg_mem_model(&ring->xdp_rxq, + MEM_TYPE_PAGE_SHARED, + NULL); + if (ret) + return ret; + } + } rx_ctx.dbuff = DIV_ROUND_UP(ring->rx_buf_len, BIT_ULL(I40E_RXQ_CTX_DBUFF_SHIFT)); @@ -3243,7 +3278,15 @@ static int i40e_configure_rx_ring(struct i40e_ring *ring) ring->tail = hw->hw_addr + I40E_QRX_TAIL(pf_q); writel(0, ring->tail); - i40e_alloc_rx_buffers(ring, I40E_DESC_UNUSED(ring)); + ok = ring->xsk_umem ? + i40e_alloc_rx_buffers_zc(ring, I40E_DESC_UNUSED(ring)) : + !i40e_alloc_rx_buffers(ring, I40E_DESC_UNUSED(ring)); + if (!ok) { + dev_info(&vsi->back->pdev->dev, + "Failed allocate some buffers on %sRx ring %d (pf_q %d)\n", + ring->xsk_umem ? "UMEM enabled " : "", + ring->queue_index, pf_q); + } return 0; } @@ -12097,6 +12140,12 @@ static int i40e_xdp(struct net_device *dev, case XDP_QUERY_PROG: xdp->prog_id = vsi->xdp_prog ? vsi->xdp_prog->aux->id : 0; return 0; + case XDP_QUERY_XSK_UMEM: + return i40e_xsk_umem_query(vsi, &xdp->xsk.umem, + xdp->xsk.queue_id); + case XDP_SETUP_XSK_UMEM: + return i40e_xsk_umem_setup(vsi, xdp->xsk.umem, + xdp->xsk.queue_id); default: return -EINVAL; } diff --git a/drivers/net/ethernet/intel/i40e/i40e_txrx.c b/drivers/net/ethernet/intel/i40e/i40e_txrx.c index 878fb4b47484..2c4d179ffebf 100644 --- a/drivers/net/ethernet/intel/i40e/i40e_txrx.c +++ b/drivers/net/ethernet/intel/i40e/i40e_txrx.c @@ -9,6 +9,7 @@ #include "i40e_trace.h" #include "i40e_prototype.h" #include "i40e_txrx_common.h" +#include "i40e_xsk.h" static inline __le64 build_ctob(u32 td_cmd, u32 td_offset, unsigned int size, u32 td_tag) @@ -1380,6 +1381,9 @@ void i40e_clean_rx_ring(struct i40e_ring *rx_ring) rx_ring->skb = NULL; } + if (rx_ring->xsk_umem) + goto skip_free; + /* Free all the Rx ring sk_buffs */ for (i = 0; i < rx_ring->count; i++) { struct i40e_rx_buffer *rx_bi = &rx_ring->rx_bi[i]; @@ -1408,6 +1412,7 @@ void i40e_clean_rx_ring(struct i40e_ring *rx_ring) rx_bi->page_offset = 0; } +skip_free: bi_size = sizeof(struct i40e_rx_buffer) * rx_ring->count; memset(rx_ring->rx_bi, 0, bi_size); @@ -2641,7 +2646,9 @@ int i40e_napi_poll(struct napi_struct *napi, int budget) budget_per_ring = max(budget/q_vector->num_ringpairs, 1); i40e_for_each_ring(ring, q_vector->rx) { - int cleaned = i40e_clean_rx_irq(ring, budget_per_ring); + int cleaned = ring->xsk_umem ? + i40e_clean_rx_irq_zc(ring, budget_per_ring) : + i40e_clean_rx_irq(ring, budget_per_ring); work_done += cleaned; /* if we clean as many as budgeted, we must not be done */ diff --git a/drivers/net/ethernet/intel/i40e/i40e_txrx.h b/drivers/net/ethernet/intel/i40e/i40e_txrx.h index bb04f6a731fe..100e92d2982f 100644 --- a/drivers/net/ethernet/intel/i40e/i40e_txrx.h +++ b/drivers/net/ethernet/intel/i40e/i40e_txrx.h @@ -296,13 +296,17 @@ struct i40e_tx_buffer { struct i40e_rx_buffer { dma_addr_t dma; - struct page *page; -#if (BITS_PER_LONG > 32) || (PAGE_SIZE >= 65536) - __u32 page_offset; -#else - __u16 page_offset; -#endif - __u16 pagecnt_bias; + union { + struct { + struct page *page; + __u32 page_offset; + __u16 pagecnt_bias; + }; + struct { + void *addr; + u64 handle; + }; + }; }; struct i40e_queue_stats { @@ -414,6 +418,8 @@ struct i40e_ring { struct i40e_channel *ch; struct xdp_rxq_info xdp_rxq; + struct xdp_umem *xsk_umem; + struct zero_copy_allocator zca; /* ZC allocator anchor */ } ____cacheline_internodealigned_in_smp; static inline bool ring_uses_build_skb(struct i40e_ring *ring) diff --git a/drivers/net/ethernet/intel/i40e/i40e_xsk.c b/drivers/net/ethernet/intel/i40e/i40e_xsk.c new file mode 100644 index 000000000000..bf502f2307c2 --- /dev/null +++ b/drivers/net/ethernet/intel/i40e/i40e_xsk.c @@ -0,0 +1,661 @@ +// SPDX-License-Identifier: GPL-2.0 +/* Copyright(c) 2018 Intel Corporation. */ + +#include +#include +#include + +#include "i40e.h" +#include "i40e_txrx_common.h" +#include "i40e_xsk.h" + +/** + * i40e_alloc_xsk_umems - Allocate an array to store per ring UMEMs + * @vsi: Current VSI + * + * Returns 0 on success, <0 on failure + **/ +static int i40e_alloc_xsk_umems(struct i40e_vsi *vsi) +{ + if (vsi->xsk_umems) + return 0; + + vsi->num_xsk_umems_used = 0; + vsi->num_xsk_umems = vsi->alloc_queue_pairs; + vsi->xsk_umems = kcalloc(vsi->num_xsk_umems, sizeof(*vsi->xsk_umems), + GFP_KERNEL); + if (!vsi->xsk_umems) { + vsi->num_xsk_umems = 0; + return -ENOMEM; + } + + return 0; +} + +/** + * i40e_add_xsk_umem - Store an UMEM for a certain ring/qid + * @vsi: Current VSI + * @umem: UMEM to store + * @qid: Ring/qid to associate with the UMEM + * + * Returns 0 on success, <0 on failure + **/ +static int i40e_add_xsk_umem(struct i40e_vsi *vsi, struct xdp_umem *umem, + u16 qid) +{ + int err; + + err = i40e_alloc_xsk_umems(vsi); + if (err) + return err; + + vsi->xsk_umems[qid] = umem; + vsi->num_xsk_umems_used++; + + return 0; +} + +/** + * i40e_remove_xsk_umem - Remove an UMEM for a certain ring/qid + * @vsi: Current VSI + * @qid: Ring/qid associated with the UMEM + **/ +static void i40e_remove_xsk_umem(struct i40e_vsi *vsi, u16 qid) +{ + vsi->xsk_umems[qid] = NULL; + vsi->num_xsk_umems_used--; + + if (vsi->num_xsk_umems == 0) { + kfree(vsi->xsk_umems); + vsi->xsk_umems = NULL; + vsi->num_xsk_umems = 0; + } +} + +/** + * i40e_xsk_umem_dma_map - DMA maps all UMEM memory for the netdev + * @vsi: Current VSI + * @umem: UMEM to DMA map + * + * Returns 0 on success, <0 on failure + **/ +static int i40e_xsk_umem_dma_map(struct i40e_vsi *vsi, struct xdp_umem *umem) +{ + struct i40e_pf *pf = vsi->back; + struct device *dev; + unsigned int i, j; + dma_addr_t dma; + + dev = &pf->pdev->dev; + for (i = 0; i < umem->npgs; i++) { + dma = dma_map_page_attrs(dev, umem->pgs[i], 0, PAGE_SIZE, + DMA_BIDIRECTIONAL, I40E_RX_DMA_ATTR); + if (dma_mapping_error(dev, dma)) + goto out_unmap; + + umem->pages[i].dma = dma; + } + + return 0; + +out_unmap: + for (j = 0; j < i; j++) { + dma_unmap_page_attrs(dev, umem->pages[i].dma, PAGE_SIZE, + DMA_BIDIRECTIONAL, I40E_RX_DMA_ATTR); + umem->pages[i].dma = 0; + } + + return -1; +} + +/** + * i40e_xsk_umem_dma_unmap - DMA unmaps all UMEM memory for the netdev + * @vsi: Current VSI + * @umem: UMEM to DMA map + **/ +static void i40e_xsk_umem_dma_unmap(struct i40e_vsi *vsi, struct xdp_umem *umem) +{ + struct i40e_pf *pf = vsi->back; + struct device *dev; + unsigned int i; + + dev = &pf->pdev->dev; + + for (i = 0; i < umem->npgs; i++) { + dma_unmap_page_attrs(dev, umem->pages[i].dma, PAGE_SIZE, + DMA_BIDIRECTIONAL, I40E_RX_DMA_ATTR); + + umem->pages[i].dma = 0; + } +} + +/** + * i40e_xsk_umem_enable - Enable/associate an UMEM to a certain ring/qid + * @vsi: Current VSI + * @umem: UMEM + * @qid: Rx ring to associate UMEM to + * + * Returns 0 on success, <0 on failure + **/ +static int i40e_xsk_umem_enable(struct i40e_vsi *vsi, struct xdp_umem *umem, + u16 qid) +{ + bool if_running; + int err; + + if (vsi->type != I40E_VSI_MAIN) + return -EINVAL; + + if (qid >= vsi->num_queue_pairs) + return -EINVAL; + + if (vsi->xsk_umems) { + if (qid >= vsi->num_xsk_umems) + return -EINVAL; + if (vsi->xsk_umems[qid]) + return -EBUSY; + } + + err = i40e_xsk_umem_dma_map(vsi, umem); + if (err) + return err; + + if_running = netif_running(vsi->netdev) && i40e_enabled_xdp_vsi(vsi); + + if (if_running) { + err = i40e_queue_pair_disable(vsi, qid); + if (err) + return err; + } + + err = i40e_add_xsk_umem(vsi, umem, qid); + if (err) + return err; + + if (if_running) { + err = i40e_queue_pair_enable(vsi, qid); + if (err) + return err; + } + + return 0; +} + +/** + * i40e_xsk_umem_disable - Diassociate an UMEM from a certain ring/qid + * @vsi: Current VSI + * @qid: Rx ring to associate UMEM to + * + * Returns 0 on success, <0 on failure + **/ +static int i40e_xsk_umem_disable(struct i40e_vsi *vsi, u16 qid) +{ + bool if_running; + int err; + + if (!vsi->xsk_umems || qid >= vsi->num_xsk_umems || + !vsi->xsk_umems[qid]) + return -EINVAL; + + if_running = netif_running(vsi->netdev) && i40e_enabled_xdp_vsi(vsi); + + if (if_running) { + err = i40e_queue_pair_disable(vsi, qid); + if (err) + return err; + } + + i40e_xsk_umem_dma_unmap(vsi, vsi->xsk_umems[qid]); + i40e_remove_xsk_umem(vsi, qid); + + if (if_running) { + err = i40e_queue_pair_enable(vsi, qid); + if (err) + return err; + } + + return 0; +} + +/** + * i40e_xsk_umem_query - Queries a certain ring/qid for its UMEM + * @vsi: Current VSI + * @umem: UMEM associated to the ring, if any + * @qid: Rx ring to associate UMEM to + * + * This function will store, if any, the UMEM associated to certain ring. + * + * Returns 0 on success, <0 on failure + **/ +int i40e_xsk_umem_query(struct i40e_vsi *vsi, struct xdp_umem **umem, + u16 qid) +{ + if (vsi->type != I40E_VSI_MAIN) + return -EINVAL; + + if (qid >= vsi->num_queue_pairs) + return -EINVAL; + + if (vsi->xsk_umems) { + if (qid >= vsi->num_xsk_umems) + return -EINVAL; + *umem = vsi->xsk_umems[qid]; + return 0; + } + + *umem = NULL; + return 0; +} + +/** + * i40e_xsk_umem_query - Queries a certain ring/qid for its UMEM + * @vsi: Current VSI + * @umem: UMEM to enable/associate to a ring, or NULL to disable + * @qid: Rx ring to (dis)associate UMEM (from)to + * + * This function enables or disables an UMEM to a certain ring. + * + * Returns 0 on success, <0 on failure + **/ +int i40e_xsk_umem_setup(struct i40e_vsi *vsi, struct xdp_umem *umem, + u16 qid) +{ + return umem ? i40e_xsk_umem_enable(vsi, umem, qid) : + i40e_xsk_umem_disable(vsi, qid); +} + +/** + * i40e_run_xdp_zc - Executes an XDP program on an xdp_buff + * @rx_ring: Rx ring + * @xdp: xdp_buff used as input to the XDP program + * + * This function enables or disables an UMEM to a certain ring. + * + * Returns any of I40E_XDP_{PASS, CONSUMED, TX, REDIR} + **/ +static int i40e_run_xdp_zc(struct i40e_ring *rx_ring, struct xdp_buff *xdp) +{ + int err, result = I40E_XDP_PASS; + struct i40e_ring *xdp_ring; + struct bpf_prog *xdp_prog; + u32 act; + + rcu_read_lock(); + /* NB! xdp_prog will always be !NULL, due to the fact that + * this path is enabled by setting an XDP program. + */ + xdp_prog = READ_ONCE(rx_ring->xdp_prog); + act = bpf_prog_run_xdp(xdp_prog, xdp); + xdp->handle += xdp->data - xdp->data_hard_start; + switch (act) { + case XDP_PASS: + break; + case XDP_TX: + xdp_ring = rx_ring->vsi->xdp_rings[rx_ring->queue_index]; + result = i40e_xmit_xdp_tx_ring(xdp, xdp_ring); + break; + case XDP_REDIRECT: + err = xdp_do_redirect(rx_ring->netdev, xdp, xdp_prog); + result = !err ? I40E_XDP_REDIR : I40E_XDP_CONSUMED; + break; + default: + bpf_warn_invalid_xdp_action(act); + case XDP_ABORTED: + trace_xdp_exception(rx_ring->netdev, xdp_prog, act); + /* fallthrough -- handle aborts by dropping packet */ + case XDP_DROP: + result = I40E_XDP_CONSUMED; + break; + } + rcu_read_unlock(); + return result; +} + +/** + * i40e_alloc_buffer_zc - Allocates an i40e_rx_buffer + * @rx_ring: Rx ring + * @bi: Rx buffer to populate + * + * This function allocates an Rx buffer. The buffer can come from fill + * queue, or via the recycle queue (next_to_alloc). + * + * Returns true for a successful allocation, false otherwise + **/ +static bool i40e_alloc_buffer_zc(struct i40e_ring *rx_ring, + struct i40e_rx_buffer *bi) +{ + struct xdp_umem *umem = rx_ring->xsk_umem; + void *addr = bi->addr; + u64 handle, hr; + + if (addr) { + rx_ring->rx_stats.page_reuse_count++; + return true; + } + + if (!xsk_umem_peek_addr(umem, &handle)) { + rx_ring->rx_stats.alloc_page_failed++; + return false; + } + + hr = umem->headroom + XDP_PACKET_HEADROOM; + + bi->dma = xdp_umem_get_dma(umem, handle); + bi->dma += hr; + + bi->addr = xdp_umem_get_data(umem, handle); + bi->addr += hr; + + bi->handle = handle + umem->headroom; + + xsk_umem_discard_addr(umem); + return true; +} + +/** + * i40e_alloc_rx_buffers_zc - Allocates a number of Rx buffers + * @rx_ring: Rx ring + * @count: The number of buffers to allocate + * + * This function allocates a number of Rx buffers and places them on + * the Rx ring. + * + * Returns true for a successful allocation, false otherwise + **/ +bool i40e_alloc_rx_buffers_zc(struct i40e_ring *rx_ring, u16 count) +{ + u16 ntu = rx_ring->next_to_use; + union i40e_rx_desc *rx_desc; + struct i40e_rx_buffer *bi; + bool ok = true; + + rx_desc = I40E_RX_DESC(rx_ring, ntu); + bi = &rx_ring->rx_bi[ntu]; + do { + if (!i40e_alloc_buffer_zc(rx_ring, bi)) { + ok = false; + goto no_buffers; + } + + dma_sync_single_range_for_device(rx_ring->dev, bi->dma, 0, + rx_ring->rx_buf_len, + DMA_BIDIRECTIONAL); + + rx_desc->read.pkt_addr = cpu_to_le64(bi->dma); + + rx_desc++; + bi++; + ntu++; + + if (unlikely(ntu == rx_ring->count)) { + rx_desc = I40E_RX_DESC(rx_ring, 0); + bi = rx_ring->rx_bi; + ntu = 0; + } + + rx_desc->wb.qword1.status_error_len = 0; + count--; + } while (count); + +no_buffers: + if (rx_ring->next_to_use != ntu) + i40e_release_rx_desc(rx_ring, ntu); + + return ok; +} + +/** + * i40e_get_rx_buffer_zc - Return the current Rx buffer + * @rx_ring: Rx ring + * @size: The size of the rx buffer (read from descriptor) + * + * This function returns the current, received Rx buffer, and also + * does DMA synchronization. the Rx ring. + * + * Returns the received Rx buffer + **/ +static struct i40e_rx_buffer *i40e_get_rx_buffer_zc(struct i40e_ring *rx_ring, + const unsigned int size) +{ + struct i40e_rx_buffer *bi; + + bi = &rx_ring->rx_bi[rx_ring->next_to_clean]; + + /* we are reusing so sync this buffer for CPU use */ + dma_sync_single_range_for_cpu(rx_ring->dev, + bi->dma, 0, + size, + DMA_BIDIRECTIONAL); + + return bi; +} + +/** + * i40e_reuse_rx_buffer_zc - Recycle an Rx buffer + * @rx_ring: Rx ring + * @old_bi: The Rx buffer to recycle + * + * This function recycles a finished Rx buffer, and places it on the + * recycle queue (next_to_alloc). + **/ +static void i40e_reuse_rx_buffer_zc(struct i40e_ring *rx_ring, + struct i40e_rx_buffer *old_bi) +{ + struct i40e_rx_buffer *new_bi = &rx_ring->rx_bi[rx_ring->next_to_alloc]; + unsigned long mask = (unsigned long)rx_ring->xsk_umem->props.chunk_mask; + u64 hr = rx_ring->xsk_umem->headroom + XDP_PACKET_HEADROOM; + u16 nta = rx_ring->next_to_alloc; + + /* update, and store next to alloc */ + nta++; + rx_ring->next_to_alloc = (nta < rx_ring->count) ? nta : 0; + + /* transfer page from old buffer to new buffer */ + new_bi->dma = old_bi->dma & mask; + new_bi->dma += hr; + + new_bi->addr = (void *)((unsigned long)old_bi->addr & mask); + new_bi->addr += hr; + + new_bi->handle = old_bi->handle & mask; + new_bi->handle += rx_ring->xsk_umem->headroom; + + old_bi->addr = NULL; +} + +/** + * i40e_zca_free - Free callback for MEM_TYPE_ZERO_COPY allocations + * @alloc: Zero-copy allocator + * @handle: Buffer handle + **/ +void i40e_zca_free(struct zero_copy_allocator *alloc, unsigned long handle) +{ + struct i40e_rx_buffer *bi; + struct i40e_ring *rx_ring; + u64 hr, mask; + u16 nta; + + rx_ring = container_of(alloc, struct i40e_ring, zca); + hr = rx_ring->xsk_umem->headroom + XDP_PACKET_HEADROOM; + mask = rx_ring->xsk_umem->props.chunk_mask; + + nta = rx_ring->next_to_alloc; + bi = &rx_ring->rx_bi[nta]; + + nta++; + rx_ring->next_to_alloc = (nta < rx_ring->count) ? nta : 0; + + handle &= mask; + + bi->dma = xdp_umem_get_dma(rx_ring->xsk_umem, handle); + bi->dma += hr; + + bi->addr = xdp_umem_get_data(rx_ring->xsk_umem, handle); + bi->addr += hr; + + bi->handle = (u64)handle + rx_ring->xsk_umem->headroom; +} + +/** + * i40e_construct_skb_zc - Create skbufff from zero-copy Rx buffer + * @rx_ring: Rx ring + * @bi: Rx buffer + * @xdp: xdp_buff + * + * This functions allocates a new skb from a zero-copy Rx buffer. + * + * Returns the skb, or NULL on failure. + **/ +static struct sk_buff *i40e_construct_skb_zc(struct i40e_ring *rx_ring, + struct i40e_rx_buffer *bi, + struct xdp_buff *xdp) +{ + unsigned int metasize = xdp->data - xdp->data_meta; + unsigned int datasize = xdp->data_end - xdp->data; + struct sk_buff *skb; + + /* allocate a skb to store the frags */ + skb = __napi_alloc_skb(&rx_ring->q_vector->napi, + xdp->data_end - xdp->data_hard_start, + GFP_ATOMIC | __GFP_NOWARN); + if (unlikely(!skb)) + return NULL; + + skb_reserve(skb, xdp->data - xdp->data_hard_start); + memcpy(__skb_put(skb, datasize), xdp->data, datasize); + if (metasize) + skb_metadata_set(skb, metasize); + + i40e_reuse_rx_buffer_zc(rx_ring, bi); + return skb; +} + +/** + * i40e_inc_ntc: Advance the next_to_clean index + * @rx_ring: Rx ring + **/ +static void i40e_inc_ntc(struct i40e_ring *rx_ring) +{ + u32 ntc = rx_ring->next_to_clean + 1; + + ntc = (ntc < rx_ring->count) ? ntc : 0; + rx_ring->next_to_clean = ntc; + prefetch(I40E_RX_DESC(rx_ring, ntc)); +} + +/** + * i40e_clean_rx_irq_zc - Consumes Rx packets from the hardware ring + * @rx_ring: Rx ring + * @budget: NAPI budget + * + * Returns amount of work completed + **/ +int i40e_clean_rx_irq_zc(struct i40e_ring *rx_ring, int budget) +{ + unsigned int total_rx_bytes = 0, total_rx_packets = 0; + u16 cleaned_count = I40E_DESC_UNUSED(rx_ring); + unsigned int xdp_res, xdp_xmit = 0; + bool failure = false; + struct sk_buff *skb; + struct xdp_buff xdp; + + xdp.rxq = &rx_ring->xdp_rxq; + + while (likely(total_rx_packets < (unsigned int)budget)) { + struct i40e_rx_buffer *bi; + union i40e_rx_desc *rx_desc; + unsigned int size; + u16 vlan_tag; + u8 rx_ptype; + u64 qword; + + if (cleaned_count >= I40E_RX_BUFFER_WRITE) { + failure = failure || + !i40e_alloc_rx_buffers_zc(rx_ring, + cleaned_count); + cleaned_count = 0; + } + + rx_desc = I40E_RX_DESC(rx_ring, rx_ring->next_to_clean); + qword = le64_to_cpu(rx_desc->wb.qword1.status_error_len); + + /* This memory barrier is needed to keep us from reading + * any other fields out of the rx_desc until we have + * verified the descriptor has been written back. + */ + dma_rmb(); + + bi = i40e_clean_programming_status(rx_ring, rx_desc, + qword); + if (unlikely(bi)) { + i40e_reuse_rx_buffer_zc(rx_ring, bi); + cleaned_count++; + continue; + } + + size = (qword & I40E_RXD_QW1_LENGTH_PBUF_MASK) >> + I40E_RXD_QW1_LENGTH_PBUF_SHIFT; + if (!size) + break; + + bi = i40e_get_rx_buffer_zc(rx_ring, size); + xdp.data = bi->addr; + xdp.data_meta = xdp.data; + xdp.data_hard_start = xdp.data - XDP_PACKET_HEADROOM; + xdp.data_end = xdp.data + size; + xdp.handle = bi->handle; + + xdp_res = i40e_run_xdp_zc(rx_ring, &xdp); + if (xdp_res) { + if (xdp_res & (I40E_XDP_TX | I40E_XDP_REDIR)) { + xdp_xmit |= xdp_res; + bi->addr = NULL; + } else { + i40e_reuse_rx_buffer_zc(rx_ring, bi); + } + + total_rx_bytes += size; + total_rx_packets++; + + cleaned_count++; + i40e_inc_ntc(rx_ring); + continue; + } + + /* XDP_PASS path */ + + /* NB! We are not checking for errors using + * i40e_test_staterr with + * BIT(I40E_RXD_QW1_ERROR_SHIFT). This is due to that + * SBP is *not* set in PRT_SBPVSI (default not set). + */ + skb = i40e_construct_skb_zc(rx_ring, bi, &xdp); + if (!skb) { + rx_ring->rx_stats.alloc_buff_failed++; + break; + } + + cleaned_count++; + i40e_inc_ntc(rx_ring); + + if (eth_skb_pad(skb)) + continue; + + total_rx_bytes += skb->len; + total_rx_packets++; + + qword = le64_to_cpu(rx_desc->wb.qword1.status_error_len); + rx_ptype = (qword & I40E_RXD_QW1_PTYPE_MASK) >> + I40E_RXD_QW1_PTYPE_SHIFT; + i40e_process_skb_fields(rx_ring, rx_desc, skb, rx_ptype); + + vlan_tag = (qword & BIT(I40E_RX_DESC_STATUS_L2TAG1P_SHIFT)) ? + le16_to_cpu(rx_desc->wb.qword0.lo_dword.l2tag1) : 0; + i40e_receive_skb(rx_ring, skb, vlan_tag); + } + + i40e_finalize_xdp_rx(rx_ring, xdp_xmit); + i40e_update_rx_stats(rx_ring, total_rx_bytes, total_rx_packets); + return failure ? budget : (int)total_rx_packets; +} + diff --git a/drivers/net/ethernet/intel/i40e/i40e_xsk.h b/drivers/net/ethernet/intel/i40e/i40e_xsk.h new file mode 100644 index 000000000000..427a844f78a7 --- /dev/null +++ b/drivers/net/ethernet/intel/i40e/i40e_xsk.h @@ -0,0 +1,21 @@ +/* SPDX-License-Identifier: GPL-2.0 */ +/* Copyright(c) 2018 Intel Corporation. */ + +#ifndef _I40E_XSK_H_ +#define _I40E_XSK_H_ + +struct i40e_vsi; +struct xdp_umem; +struct zero_copy_allocator; + +int i40e_queue_pair_disable(struct i40e_vsi *vsi, int queue_pair); +int i40e_queue_pair_enable(struct i40e_vsi *vsi, int queue_pair); +int i40e_xsk_umem_query(struct i40e_vsi *vsi, struct xdp_umem **umem, + u16 qid); +int i40e_xsk_umem_setup(struct i40e_vsi *vsi, struct xdp_umem *umem, + u16 qid); +void i40e_zca_free(struct zero_copy_allocator *alloc, unsigned long handle); +bool i40e_alloc_rx_buffers_zc(struct i40e_ring *rx_ring, u16 cleaned_count); +int i40e_clean_rx_irq_zc(struct i40e_ring *rx_ring, int budget); + +#endif /* _I40E_XSK_H_ */ -- GitLab