diff options
author | Björn Töpel <bjorn.topel@intel.com> | 2018-10-02 10:00:32 +0200 |
---|---|---|
committer | Jeff Kirsher <jeffrey.t.kirsher@intel.com> | 2018-10-03 12:51:14 -0700 |
commit | d0bcacd0a130974f58a56318db7a5ca6a7ba1d5a (patch) | |
tree | 64fc0abfd96aa095b9c4134a27280322a4a0b0f2 /drivers/net/ethernet/intel/ixgbe/ixgbe_xsk.c | |
parent | 46515fdb1adff1cc0ac3d0656a7c3492017dfe4f (diff) |
ixgbe: add AF_XDP zero-copy Rx support
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, ixgbe_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 <bjorn.topel@intel.com>
Tested-by: William Tu <u9012063@gmail.com>
Tested-by: Andrew Bowers <andrewx.bowers@intel.com>
Signed-off-by: Jeff Kirsher <jeffrey.t.kirsher@intel.com>
Diffstat (limited to 'drivers/net/ethernet/intel/ixgbe/ixgbe_xsk.c')
-rw-r--r-- | drivers/net/ethernet/intel/ixgbe/ixgbe_xsk.c | 626 |
1 files changed, 626 insertions, 0 deletions
diff --git a/drivers/net/ethernet/intel/ixgbe/ixgbe_xsk.c b/drivers/net/ethernet/intel/ixgbe/ixgbe_xsk.c new file mode 100644 index 000000000000..e876ff120758 --- /dev/null +++ b/drivers/net/ethernet/intel/ixgbe/ixgbe_xsk.c @@ -0,0 +1,626 @@ +// SPDX-License-Identifier: GPL-2.0 +/* Copyright(c) 2018 Intel Corporation. */ + +#include <linux/bpf_trace.h> +#include <net/xdp_sock.h> +#include <net/xdp.h> + +#include "ixgbe.h" +#include "ixgbe_txrx_common.h" + +struct xdp_umem *ixgbe_xsk_umem(struct ixgbe_adapter *adapter, + struct ixgbe_ring *ring) +{ + bool xdp_on = READ_ONCE(adapter->xdp_prog); + int qid = ring->ring_idx; + + if (!adapter->xsk_umems || !adapter->xsk_umems[qid] || + qid >= adapter->num_xsk_umems || !xdp_on) + return NULL; + + return adapter->xsk_umems[qid]; +} + +static int ixgbe_alloc_xsk_umems(struct ixgbe_adapter *adapter) +{ + if (adapter->xsk_umems) + return 0; + + adapter->num_xsk_umems_used = 0; + adapter->num_xsk_umems = adapter->num_rx_queues; + adapter->xsk_umems = kcalloc(adapter->num_xsk_umems, + sizeof(*adapter->xsk_umems), + GFP_KERNEL); + if (!adapter->xsk_umems) { + adapter->num_xsk_umems = 0; + return -ENOMEM; + } + + return 0; +} + +static int ixgbe_add_xsk_umem(struct ixgbe_adapter *adapter, + struct xdp_umem *umem, + u16 qid) +{ + int err; + + err = ixgbe_alloc_xsk_umems(adapter); + if (err) + return err; + + adapter->xsk_umems[qid] = umem; + adapter->num_xsk_umems_used++; + + return 0; +} + +static void ixgbe_remove_xsk_umem(struct ixgbe_adapter *adapter, u16 qid) +{ + adapter->xsk_umems[qid] = NULL; + adapter->num_xsk_umems_used--; + + if (adapter->num_xsk_umems == 0) { + kfree(adapter->xsk_umems); + adapter->xsk_umems = NULL; + adapter->num_xsk_umems = 0; + } +} + +static int ixgbe_xsk_umem_dma_map(struct ixgbe_adapter *adapter, + struct xdp_umem *umem) +{ + struct device *dev = &adapter->pdev->dev; + unsigned int i, j; + dma_addr_t dma; + + for (i = 0; i < umem->npgs; i++) { + dma = dma_map_page_attrs(dev, umem->pgs[i], 0, PAGE_SIZE, + DMA_BIDIRECTIONAL, IXGBE_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, IXGBE_RX_DMA_ATTR); + umem->pages[i].dma = 0; + } + + return -1; +} + +static void ixgbe_xsk_umem_dma_unmap(struct ixgbe_adapter *adapter, + struct xdp_umem *umem) +{ + struct device *dev = &adapter->pdev->dev; + unsigned int i; + + for (i = 0; i < umem->npgs; i++) { + dma_unmap_page_attrs(dev, umem->pages[i].dma, PAGE_SIZE, + DMA_BIDIRECTIONAL, IXGBE_RX_DMA_ATTR); + + umem->pages[i].dma = 0; + } +} + +static int ixgbe_xsk_umem_enable(struct ixgbe_adapter *adapter, + struct xdp_umem *umem, + u16 qid) +{ + struct xdp_umem_fq_reuse *reuseq; + bool if_running; + int err; + + if (qid >= adapter->num_rx_queues) + return -EINVAL; + + if (adapter->xsk_umems) { + if (qid >= adapter->num_xsk_umems) + return -EINVAL; + if (adapter->xsk_umems[qid]) + return -EBUSY; + } + + reuseq = xsk_reuseq_prepare(adapter->rx_ring[0]->count); + if (!reuseq) + return -ENOMEM; + + xsk_reuseq_free(xsk_reuseq_swap(umem, reuseq)); + + err = ixgbe_xsk_umem_dma_map(adapter, umem); + if (err) + return err; + + if_running = netif_running(adapter->netdev) && + READ_ONCE(adapter->xdp_prog); + + if (if_running) + ixgbe_txrx_ring_disable(adapter, qid); + + err = ixgbe_add_xsk_umem(adapter, umem, qid); + + if (if_running) + ixgbe_txrx_ring_enable(adapter, qid); + + return err; +} + +static int ixgbe_xsk_umem_disable(struct ixgbe_adapter *adapter, u16 qid) +{ + bool if_running; + + if (!adapter->xsk_umems || qid >= adapter->num_xsk_umems || + !adapter->xsk_umems[qid]) + return -EINVAL; + + if_running = netif_running(adapter->netdev) && + READ_ONCE(adapter->xdp_prog); + + if (if_running) + ixgbe_txrx_ring_disable(adapter, qid); + + ixgbe_xsk_umem_dma_unmap(adapter, adapter->xsk_umems[qid]); + ixgbe_remove_xsk_umem(adapter, qid); + + if (if_running) + ixgbe_txrx_ring_enable(adapter, qid); + + return 0; +} + +int ixgbe_xsk_umem_query(struct ixgbe_adapter *adapter, struct xdp_umem **umem, + u16 qid) +{ + if (qid >= adapter->num_rx_queues) + return -EINVAL; + + if (adapter->xsk_umems) { + if (qid >= adapter->num_xsk_umems) + return -EINVAL; + *umem = adapter->xsk_umems[qid]; + return 0; + } + + *umem = NULL; + return 0; +} + +int ixgbe_xsk_umem_setup(struct ixgbe_adapter *adapter, struct xdp_umem *umem, + u16 qid) +{ + return umem ? ixgbe_xsk_umem_enable(adapter, umem, qid) : + ixgbe_xsk_umem_disable(adapter, qid); +} + +static int ixgbe_run_xdp_zc(struct ixgbe_adapter *adapter, + struct ixgbe_ring *rx_ring, + struct xdp_buff *xdp) +{ + int err, result = IXGBE_XDP_PASS; + struct bpf_prog *xdp_prog; + struct xdp_frame *xdpf; + u32 act; + + rcu_read_lock(); + 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: + xdpf = convert_to_xdp_frame(xdp); + if (unlikely(!xdpf)) { + result = IXGBE_XDP_CONSUMED; + break; + } + result = ixgbe_xmit_xdp_ring(adapter, xdpf); + break; + case XDP_REDIRECT: + err = xdp_do_redirect(rx_ring->netdev, xdp, xdp_prog); + result = !err ? IXGBE_XDP_REDIR : IXGBE_XDP_CONSUMED; + break; + default: + bpf_warn_invalid_xdp_action(act); + /* fallthrough */ + case XDP_ABORTED: + trace_xdp_exception(rx_ring->netdev, xdp_prog, act); + /* fallthrough -- handle aborts by dropping packet */ + case XDP_DROP: + result = IXGBE_XDP_CONSUMED; + break; + } + rcu_read_unlock(); + return result; +} + +static struct +ixgbe_rx_buffer *ixgbe_get_rx_buffer_zc(struct ixgbe_ring *rx_ring, + unsigned int size) +{ + struct ixgbe_rx_buffer *bi; + + bi = &rx_ring->rx_buffer_info[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; +} + +static void ixgbe_reuse_rx_buffer_zc(struct ixgbe_ring *rx_ring, + struct ixgbe_rx_buffer *obi) +{ + unsigned long mask = (unsigned long)rx_ring->xsk_umem->chunk_mask; + u64 hr = rx_ring->xsk_umem->headroom + XDP_PACKET_HEADROOM; + u16 nta = rx_ring->next_to_alloc; + struct ixgbe_rx_buffer *nbi; + + nbi = &rx_ring->rx_buffer_info[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 */ + nbi->dma = obi->dma & mask; + nbi->dma += hr; + + nbi->addr = (void *)((unsigned long)obi->addr & mask); + nbi->addr += hr; + + nbi->handle = obi->handle & mask; + nbi->handle += rx_ring->xsk_umem->headroom; + + obi->addr = NULL; + obi->skb = NULL; +} + +void ixgbe_zca_free(struct zero_copy_allocator *alloc, unsigned long handle) +{ + struct ixgbe_rx_buffer *bi; + struct ixgbe_ring *rx_ring; + u64 hr, mask; + u16 nta; + + rx_ring = container_of(alloc, struct ixgbe_ring, zca); + hr = rx_ring->xsk_umem->headroom + XDP_PACKET_HEADROOM; + mask = rx_ring->xsk_umem->chunk_mask; + + nta = rx_ring->next_to_alloc; + bi = rx_ring->rx_buffer_info; + + 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; +} + +static bool ixgbe_alloc_buffer_zc(struct ixgbe_ring *rx_ring, + struct ixgbe_rx_buffer *bi) +{ + struct xdp_umem *umem = rx_ring->xsk_umem; + void *addr = bi->addr; + u64 handle, hr; + + if (addr) + return true; + + if (!xsk_umem_peek_addr(umem, &handle)) { + rx_ring->rx_stats.alloc_rx_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; +} + +static bool ixgbe_alloc_buffer_slow_zc(struct ixgbe_ring *rx_ring, + struct ixgbe_rx_buffer *bi) +{ + struct xdp_umem *umem = rx_ring->xsk_umem; + u64 handle, hr; + + if (!xsk_umem_peek_addr_rq(umem, &handle)) { + rx_ring->rx_stats.alloc_rx_page_failed++; + return false; + } + + handle &= rx_ring->xsk_umem->chunk_mask; + + 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_rq(umem); + return true; +} + +static __always_inline bool +__ixgbe_alloc_rx_buffers_zc(struct ixgbe_ring *rx_ring, u16 cleaned_count, + bool alloc(struct ixgbe_ring *rx_ring, + struct ixgbe_rx_buffer *bi)) +{ + union ixgbe_adv_rx_desc *rx_desc; + struct ixgbe_rx_buffer *bi; + u16 i = rx_ring->next_to_use; + bool ok = true; + + /* nothing to do */ + if (!cleaned_count) + return true; + + rx_desc = IXGBE_RX_DESC(rx_ring, i); + bi = &rx_ring->rx_buffer_info[i]; + i -= rx_ring->count; + + do { + if (!alloc(rx_ring, bi)) { + ok = false; + break; + } + + /* sync the buffer for use by the device */ + dma_sync_single_range_for_device(rx_ring->dev, bi->dma, + bi->page_offset, + rx_ring->rx_buf_len, + DMA_BIDIRECTIONAL); + + /* Refresh the desc even if buffer_addrs didn't change + * because each write-back erases this info. + */ + rx_desc->read.pkt_addr = cpu_to_le64(bi->dma); + + rx_desc++; + bi++; + i++; + if (unlikely(!i)) { + rx_desc = IXGBE_RX_DESC(rx_ring, 0); + bi = rx_ring->rx_buffer_info; + i -= rx_ring->count; + } + + /* clear the length for the next_to_use descriptor */ + rx_desc->wb.upper.length = 0; + + cleaned_count--; + } while (cleaned_count); + + i += rx_ring->count; + + if (rx_ring->next_to_use != i) { + rx_ring->next_to_use = i; + + /* update next to alloc since we have filled the ring */ + rx_ring->next_to_alloc = i; + + /* Force memory writes to complete before letting h/w + * know there are new descriptors to fetch. (Only + * applicable for weak-ordered memory model archs, + * such as IA-64). + */ + wmb(); + writel(i, rx_ring->tail); + } + + return ok; +} + +void ixgbe_alloc_rx_buffers_zc(struct ixgbe_ring *rx_ring, u16 count) +{ + __ixgbe_alloc_rx_buffers_zc(rx_ring, count, + ixgbe_alloc_buffer_slow_zc); +} + +static bool ixgbe_alloc_rx_buffers_fast_zc(struct ixgbe_ring *rx_ring, + u16 count) +{ + return __ixgbe_alloc_rx_buffers_zc(rx_ring, count, + ixgbe_alloc_buffer_zc); +} + +static struct sk_buff *ixgbe_construct_skb_zc(struct ixgbe_ring *rx_ring, + struct ixgbe_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); + + ixgbe_reuse_rx_buffer_zc(rx_ring, bi); + return skb; +} + +static void ixgbe_inc_ntc(struct ixgbe_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(IXGBE_RX_DESC(rx_ring, ntc)); +} + +int ixgbe_clean_rx_irq_zc(struct ixgbe_q_vector *q_vector, + struct ixgbe_ring *rx_ring, + const int budget) +{ + unsigned int total_rx_bytes = 0, total_rx_packets = 0; + struct ixgbe_adapter *adapter = q_vector->adapter; + u16 cleaned_count = ixgbe_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 < budget)) { + union ixgbe_adv_rx_desc *rx_desc; + struct ixgbe_rx_buffer *bi; + unsigned int size; + + /* return some buffers to hardware, one at a time is too slow */ + if (cleaned_count >= IXGBE_RX_BUFFER_WRITE) { + failure = failure || + !ixgbe_alloc_rx_buffers_fast_zc(rx_ring, + cleaned_count); + cleaned_count = 0; + } + + rx_desc = IXGBE_RX_DESC(rx_ring, rx_ring->next_to_clean); + size = le16_to_cpu(rx_desc->wb.upper.length); + if (!size) + break; + + /* This memory barrier is needed to keep us from reading + * any other fields out of the rx_desc until we know the + * descriptor has been written back + */ + dma_rmb(); + + bi = ixgbe_get_rx_buffer_zc(rx_ring, size); + + if (unlikely(!ixgbe_test_staterr(rx_desc, + IXGBE_RXD_STAT_EOP))) { + struct ixgbe_rx_buffer *next_bi; + + ixgbe_reuse_rx_buffer_zc(rx_ring, bi); + ixgbe_inc_ntc(rx_ring); + next_bi = + &rx_ring->rx_buffer_info[rx_ring->next_to_clean]; + next_bi->skb = ERR_PTR(-EINVAL); + continue; + } + + if (unlikely(bi->skb)) { + ixgbe_reuse_rx_buffer_zc(rx_ring, bi); + ixgbe_inc_ntc(rx_ring); + continue; + } + + 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 = ixgbe_run_xdp_zc(adapter, rx_ring, &xdp); + + if (xdp_res) { + if (xdp_res & (IXGBE_XDP_TX | IXGBE_XDP_REDIR)) { + xdp_xmit |= xdp_res; + bi->addr = NULL; + bi->skb = NULL; + } else { + ixgbe_reuse_rx_buffer_zc(rx_ring, bi); + } + total_rx_packets++; + total_rx_bytes += size; + + cleaned_count++; + ixgbe_inc_ntc(rx_ring); + continue; + } + + /* XDP_PASS path */ + skb = ixgbe_construct_skb_zc(rx_ring, bi, &xdp); + if (!skb) { + rx_ring->rx_stats.alloc_rx_buff_failed++; + break; + } + + cleaned_count++; + ixgbe_inc_ntc(rx_ring); + + if (eth_skb_pad(skb)) + continue; + + total_rx_bytes += skb->len; + total_rx_packets++; + + ixgbe_process_skb_fields(rx_ring, rx_desc, skb); + ixgbe_rx_skb(q_vector, skb); + } + + if (xdp_xmit & IXGBE_XDP_REDIR) + xdp_do_flush_map(); + + if (xdp_xmit & IXGBE_XDP_TX) { + struct ixgbe_ring *ring = adapter->xdp_ring[smp_processor_id()]; + + /* Force memory writes to complete before letting h/w + * know there are new descriptors to fetch. + */ + wmb(); + writel(ring->next_to_use, ring->tail); + } + + u64_stats_update_begin(&rx_ring->syncp); + rx_ring->stats.packets += total_rx_packets; + rx_ring->stats.bytes += total_rx_bytes; + u64_stats_update_end(&rx_ring->syncp); + q_vector->rx.total_packets += total_rx_packets; + q_vector->rx.total_bytes += total_rx_bytes; + + return failure ? budget : (int)total_rx_packets; +} + +void ixgbe_xsk_clean_rx_ring(struct ixgbe_ring *rx_ring) +{ + u16 i = rx_ring->next_to_clean; + struct ixgbe_rx_buffer *bi = &rx_ring->rx_buffer_info[i]; + + while (i != rx_ring->next_to_alloc) { + xsk_umem_fq_reuse(rx_ring->xsk_umem, bi->handle); + i++; + bi++; + if (i == rx_ring->count) { + i = 0; + bi = rx_ring->rx_buffer_info; + } + } +} |