// SPDX-License-Identifier: GPL-2.0 /* Copyright(c) 2013 - 2018 Intel Corporation. */ #include #include "iavf.h" #include "iavf_trace.h" #include "iavf_prototype.h" static inline __le64 build_ctob(u32 td_cmd, u32 td_offset, unsigned int size, u32 td_tag) { return cpu_to_le64(IAVF_TX_DESC_DTYPE_DATA | ((u64)td_cmd << IAVF_TXD_QW1_CMD_SHIFT) | ((u64)td_offset << IAVF_TXD_QW1_OFFSET_SHIFT) | ((u64)size << IAVF_TXD_QW1_TX_BUF_SZ_SHIFT) | ((u64)td_tag << IAVF_TXD_QW1_L2TAG1_SHIFT)); } #define IAVF_TXD_CMD (IAVF_TX_DESC_CMD_EOP | IAVF_TX_DESC_CMD_RS) /** * iavf_unmap_and_free_tx_resource - Release a Tx buffer * @ring: the ring that owns the buffer * @tx_buffer: the buffer to free **/ static void iavf_unmap_and_free_tx_resource(struct iavf_ring *ring, struct iavf_tx_buffer *tx_buffer) { if (tx_buffer->skb) { if (tx_buffer->tx_flags & IAVF_TX_FLAGS_FD_SB) kfree(tx_buffer->raw_buf); else dev_kfree_skb_any(tx_buffer->skb); if (dma_unmap_len(tx_buffer, len)) dma_unmap_single(ring->dev, dma_unmap_addr(tx_buffer, dma), dma_unmap_len(tx_buffer, len), DMA_TO_DEVICE); } else if (dma_unmap_len(tx_buffer, len)) { dma_unmap_page(ring->dev, dma_unmap_addr(tx_buffer, dma), dma_unmap_len(tx_buffer, len), DMA_TO_DEVICE); } tx_buffer->next_to_watch = NULL; tx_buffer->skb = NULL; dma_unmap_len_set(tx_buffer, len, 0); /* tx_buffer must be completely set up in the transmit path */ } /** * iavf_clean_tx_ring - Free any empty Tx buffers * @tx_ring: ring to be cleaned **/ void iavf_clean_tx_ring(struct iavf_ring *tx_ring) { unsigned long bi_size; u16 i; /* ring already cleared, nothing to do */ if (!tx_ring->tx_bi) return; /* Free all the Tx ring sk_buffs */ for (i = 0; i < tx_ring->count; i++) iavf_unmap_and_free_tx_resource(tx_ring, &tx_ring->tx_bi[i]); bi_size = sizeof(struct iavf_tx_buffer) * tx_ring->count; memset(tx_ring->tx_bi, 0, bi_size); /* Zero out the descriptor ring */ memset(tx_ring->desc, 0, tx_ring->size); tx_ring->next_to_use = 0; tx_ring->next_to_clean = 0; if (!tx_ring->netdev) return; /* cleanup Tx queue statistics */ netdev_tx_reset_queue(txring_txq(tx_ring)); } /** * iavf_free_tx_resources - Free Tx resources per queue * @tx_ring: Tx descriptor ring for a specific queue * * Free all transmit software resources **/ void iavf_free_tx_resources(struct iavf_ring *tx_ring) { iavf_clean_tx_ring(tx_ring); kfree(tx_ring->tx_bi); tx_ring->tx_bi = NULL; if (tx_ring->desc) { dma_free_coherent(tx_ring->dev, tx_ring->size, tx_ring->desc, tx_ring->dma); tx_ring->desc = NULL; } } /** * iavf_get_tx_pending - how many Tx descriptors not processed * @ring: the ring of descriptors * @in_sw: is tx_pending being checked in SW or HW * * Since there is no access to the ring head register * in XL710, we need to use our local copies **/ u32 iavf_get_tx_pending(struct iavf_ring *ring, bool in_sw) { u32 head, tail; head = ring->next_to_clean; tail = readl(ring->tail); if (head != tail) return (head < tail) ? tail - head : (tail + ring->count - head); return 0; } /** * iavf_detect_recover_hung - Function to detect and recover hung_queues * @vsi: pointer to vsi struct with tx queues * * VSI has netdev and netdev has TX queues. This function is to check each of * those TX queues if they are hung, trigger recovery by issuing SW interrupt. **/ void iavf_detect_recover_hung(struct iavf_vsi *vsi) { struct iavf_ring *tx_ring = NULL; struct net_device *netdev; unsigned int i; int packets; if (!vsi) return; if (test_bit(__IAVF_VSI_DOWN, vsi->state)) return; netdev = vsi->netdev; if (!netdev) return; if (!netif_carrier_ok(netdev)) return; for (i = 0; i < vsi->back->num_active_queues; i++) { tx_ring = &vsi->back->tx_rings[i]; if (tx_ring && tx_ring->desc) { /* If packet counter has not changed the queue is * likely stalled, so force an interrupt for this * queue. * * prev_pkt_ctr would be negative if there was no * pending work. */ packets = tx_ring->stats.packets & INT_MAX; if (tx_ring->tx_stats.prev_pkt_ctr == packets) { iavf_force_wb(vsi, tx_ring->q_vector); continue; } /* Memory barrier between read of packet count and call * to iavf_get_tx_pending() */ smp_rmb(); tx_ring->tx_stats.prev_pkt_ctr = iavf_get_tx_pending(tx_ring, true) ? packets : -1; } } } #define WB_STRIDE 4 /** * iavf_clean_tx_irq - Reclaim resources after transmit completes * @vsi: the VSI we care about * @tx_ring: Tx ring to clean * @napi_budget: Used to determine if we are in netpoll * * Returns true if there's any budget left (e.g. the clean is finished) **/ static bool iavf_clean_tx_irq(struct iavf_vsi *vsi, struct iavf_ring *tx_ring, int napi_budget) { int i = tx_ring->next_to_clean; struct iavf_tx_buffer *tx_buf; struct iavf_tx_desc *tx_desc; unsigned int total_bytes = 0, total_packets = 0; unsigned int budget = vsi->work_limit; tx_buf = &tx_ring->tx_bi[i]; tx_desc = IAVF_TX_DESC(tx_ring, i); i -= tx_ring->count; do { struct iavf_tx_desc *eop_desc = tx_buf->next_to_watch; /* if next_to_watch is not set then there is no work pending */ if (!eop_desc) break; /* prevent any other reads prior to eop_desc */ smp_rmb(); iavf_trace(clean_tx_irq, tx_ring, tx_desc, tx_buf); /* if the descriptor isn't done, no work yet to do */ if (!(eop_desc->cmd_type_offset_bsz & cpu_to_le64(IAVF_TX_DESC_DTYPE_DESC_DONE))) break; /* clear next_to_watch to prevent false hangs */ tx_buf->next_to_watch = NULL; /* update the statistics for this packet */ total_bytes += tx_buf->bytecount; total_packets += tx_buf->gso_segs; /* free the skb */ napi_consume_skb(tx_buf->skb, napi_budget); /* unmap skb header data */ dma_unmap_single(tx_ring->dev, dma_unmap_addr(tx_buf, dma), dma_unmap_len(tx_buf, len), DMA_TO_DEVICE); /* clear tx_buffer data */ tx_buf->skb = NULL; dma_unmap_len_set(tx_buf, len, 0); /* unmap remaining buffers */ while (tx_desc != eop_desc) { iavf_trace(clean_tx_irq_unmap, tx_ring, tx_desc, tx_buf); tx_buf++; tx_desc++; i++; if (unlikely(!i)) { i -= tx_ring->count; tx_buf = tx_ring->tx_bi; tx_desc = IAVF_TX_DESC(tx_ring, 0); } /* unmap any remaining paged data */ if (dma_unmap_len(tx_buf, len)) { dma_unmap_page(tx_ring->dev, dma_unmap_addr(tx_buf, dma), dma_unmap_len(tx_buf, len), DMA_TO_DEVICE); dma_unmap_len_set(tx_buf, len, 0); } } /* move us one more past the eop_desc for start of next pkt */ tx_buf++; tx_desc++; i++; if (unlikely(!i)) { i -= tx_ring->count; tx_buf = tx_ring->tx_bi; tx_desc = IAVF_TX_DESC(tx_ring, 0); } prefetch(tx_desc); /* update budget accounting */ budget--; } while (likely(budget)); i += tx_ring->count; tx_ring->next_to_clean = i; u64_stats_update_begin(&tx_ring->syncp); tx_ring->stats.bytes += total_bytes; tx_ring->stats.packets += total_packets; u64_stats_update_end(&tx_ring->syncp); tx_ring->q_vector->tx.total_bytes += total_bytes; tx_ring->q_vector->tx.total_packets += total_packets; if (tx_ring->flags & IAVF_TXR_FLAGS_WB_ON_ITR) { /* check to see if there are < 4 descriptors * waiting to be written back, then kick the hardware to force * them to be written back in case we stay in NAPI. * In this mode on X722 we do not enable Interrupt. */ unsigned int j = iavf_get_tx_pending(tx_ring, false); if (budget && ((j / WB_STRIDE) == 0) && (j > 0) && !test_bit(__IAVF_VSI_DOWN, vsi->state) && (IAVF_DESC_UNUSED(tx_ring) != tx_ring->count)) tx_ring->arm_wb = true; } /* notify netdev of completed buffers */ netdev_tx_completed_queue(txring_txq(tx_ring), total_packets, total_bytes); #define TX_WAKE_THRESHOLD ((s16)(DESC_NEEDED * 2)) if (unlikely(total_packets && netif_carrier_ok(tx_ring->netdev) && (IAVF_DESC_UNUSED(tx_ring) >= TX_WAKE_THRESHOLD))) { /* Make sure that anybody stopping the queue after this * sees the new next_to_clean. */ smp_mb(); if (__netif_subqueue_stopped(tx_ring->netdev, tx_ring->queue_index) && !test_bit(__IAVF_VSI_DOWN, vsi->state)) { netif_wake_subqueue(tx_ring->netdev, tx_ring->queue_index); ++tx_ring->tx_stats.restart_queue; } } return !!budget; } /** * iavf_enable_wb_on_itr - Arm hardware to do a wb, interrupts are not enabled * @vsi: the VSI we care about * @q_vector: the vector on which to enable writeback * **/ static void iavf_enable_wb_on_itr(struct iavf_vsi *vsi, struct iavf_q_vector *q_vector) { u16 flags = q_vector->tx.ring[0].flags; u32 val; if (!(flags & IAVF_TXR_FLAGS_WB_ON_ITR)) return; if (q_vector->arm_wb_state) return; val = IAVF_VFINT_DYN_CTLN1_WB_ON_ITR_MASK | IAVF_VFINT_DYN_CTLN1_ITR_INDX_MASK; /* set noitr */ wr32(&vsi->back->hw, IAVF_VFINT_DYN_CTLN1(q_vector->reg_idx), val); q_vector->arm_wb_state = true; } /** * iavf_force_wb - Issue SW Interrupt so HW does a wb * @vsi: the VSI we care about * @q_vector: the vector on which to force writeback * **/ void iavf_force_wb(struct iavf_vsi *vsi, struct iavf_q_vector *q_vector) { u32 val = IAVF_VFINT_DYN_CTLN1_INTENA_MASK | IAVF_VFINT_DYN_CTLN1_ITR_INDX_MASK | /* set noitr */ IAVF_VFINT_DYN_CTLN1_SWINT_TRIG_MASK | IAVF_VFINT_DYN_CTLN1_SW_ITR_INDX_ENA_MASK /* allow 00 to be written to the index */; wr32(&vsi->back->hw, IAVF_VFINT_DYN_CTLN1(q_vector->reg_idx), val); } static inline bool iavf_container_is_rx(struct iavf_q_vector *q_vector, struct iavf_ring_container *rc) { return &q_vector->rx == rc; } #define IAVF_AIM_MULTIPLIER_100G 2560 #define IAVF_AIM_MULTIPLIER_50G 1280 #define IAVF_AIM_MULTIPLIER_40G 1024 #define IAVF_AIM_MULTIPLIER_20G 512 #define IAVF_AIM_MULTIPLIER_10G 256 #define IAVF_AIM_MULTIPLIER_1G 32 static unsigned int iavf_mbps_itr_multiplier(u32 speed_mbps) { switch (speed_mbps) { case SPEED_100000: return IAVF_AIM_MULTIPLIER_100G; case SPEED_50000: return IAVF_AIM_MULTIPLIER_50G; case SPEED_40000: return IAVF_AIM_MULTIPLIER_40G; case SPEED_25000: case SPEED_20000: return IAVF_AIM_MULTIPLIER_20G; case SPEED_10000: default: return IAVF_AIM_MULTIPLIER_10G; case SPEED_1000: case SPEED_100: return IAVF_AIM_MULTIPLIER_1G; } } static unsigned int iavf_virtchnl_itr_multiplier(enum virtchnl_link_speed speed_virtchnl) { switch (speed_virtchnl) { case VIRTCHNL_LINK_SPEED_40GB: return IAVF_AIM_MULTIPLIER_40G; case VIRTCHNL_LINK_SPEED_25GB: case VIRTCHNL_LINK_SPEED_20GB: return IAVF_AIM_MULTIPLIER_20G; case VIRTCHNL_LINK_SPEED_10GB: default: return IAVF_AIM_MULTIPLIER_10G; case VIRTCHNL_LINK_SPEED_1GB: case VIRTCHNL_LINK_SPEED_100MB: return IAVF_AIM_MULTIPLIER_1G; } } static unsigned int iavf_itr_divisor(struct iavf_adapter *adapter) { if (ADV_LINK_SUPPORT(adapter)) return IAVF_ITR_ADAPTIVE_MIN_INC * iavf_mbps_itr_multiplier(adapter->link_speed_mbps); else return IAVF_ITR_ADAPTIVE_MIN_INC * iavf_virtchnl_itr_multiplier(adapter->link_speed); } /** * iavf_update_itr - update the dynamic ITR value based on statistics * @q_vector: structure containing interrupt and ring information * @rc: structure containing ring performance data * * Stores a new ITR value based on packets and byte * counts during the last interrupt. The advantage of per interrupt * computation is faster updates and more accurate ITR for the current * traffic pattern. Constants in this function were computed * based on theoretical maximum wire speed and thresholds were set based * on testing data as well as attempting to minimize response time * while increasing bulk throughput. **/ static void iavf_update_itr(struct iavf_q_vector *q_vector, struct iavf_ring_container *rc) { unsigned int avg_wire_size, packets, bytes, itr; unsigned long next_update = jiffies; /* If we don't have any rings just leave ourselves set for maximum * possible latency so we take ourselves out of the equation. */ if (!rc->ring || !ITR_IS_DYNAMIC(rc->ring->itr_setting)) return; /* For Rx we want to push the delay up and default to low latency. * for Tx we want to pull the delay down and default to high latency. */ itr = iavf_container_is_rx(q_vector, rc) ? IAVF_ITR_ADAPTIVE_MIN_USECS | IAVF_ITR_ADAPTIVE_LATENCY : IAVF_ITR_ADAPTIVE_MAX_USECS | IAVF_ITR_ADAPTIVE_LATENCY; /* If we didn't update within up to 1 - 2 jiffies we can assume * that either packets are coming in so slow there hasn't been * any work, or that there is so much work that NAPI is dealing * with interrupt moderation and we don't need to do anything. */ if (time_after(next_update, rc->next_update)) goto clear_counts; /* If itr_countdown is set it means we programmed an ITR within * the last 4 interrupt cycles. This has a side effect of us * potentially firing an early interrupt. In order to work around * this we need to throw out any data received for a few * interrupts following the update. */ if (q_vector->itr_countdown) { itr = rc->target_itr; goto clear_counts; } packets = rc->total_packets; bytes = rc->total_bytes; if (iavf_container_is_rx(q_vector, rc)) { /* If Rx there are 1 to 4 packets and bytes are less than * 9000 assume insufficient data to use bulk rate limiting * approach unless Tx is already in bulk rate limiting. We * are likely latency driven. */ if (packets && packets < 4 && bytes < 9000 && (q_vector->tx.target_itr & IAVF_ITR_ADAPTIVE_LATENCY)) { itr = IAVF_ITR_ADAPTIVE_LATENCY; goto adjust_by_size; } } else if (packets < 4) { /* If we have Tx and Rx ITR maxed and Tx ITR is running in * bulk mode and we are receiving 4 or fewer packets just * reset the ITR_ADAPTIVE_LATENCY bit for latency mode so * that the Rx can relax. */ if (rc->target_itr == IAVF_ITR_ADAPTIVE_MAX_USECS && (q_vector->rx.target_itr & IAVF_ITR_MASK) == IAVF_ITR_ADAPTIVE_MAX_USECS) goto clear_counts; } else if (packets > 32) { /* If we have processed over 32 packets in a single interrupt * for Tx assume we need to switch over to "bulk" mode. */ rc->target_itr &= ~IAVF_ITR_ADAPTIVE_LATENCY; } /* We have no packets to actually measure against. This means * either one of the other queues on this vector is active or * we are a Tx queue doing TSO with too high of an interrupt rate. * * Between 4 and 56 we can assume that our current interrupt delay * is only slightly too low. As such we should increase it by a small * fixed amount. */ if (packets < 56) { itr = rc->target_itr + IAVF_ITR_ADAPTIVE_MIN_INC; if ((itr & IAVF_ITR_MASK) > IAVF_ITR_ADAPTIVE_MAX_USECS) { itr &= IAVF_ITR_ADAPTIVE_LATENCY; itr += IAVF_ITR_ADAPTIVE_MAX_USECS; } goto clear_counts; } if (packets <= 256) { itr = min(q_vector->tx.current_itr, q_vector->rx.current_itr); itr &= IAVF_ITR_MASK; /* Between 56 and 112 is our "goldilocks" zone where we are * working out "just right". Just report that our current * ITR is good for us. */ if (packets <= 112) goto clear_counts; /* If packet count is 128 or greater we are likely looking * at a slight overrun of the delay we want. Try halving * our delay to see if that will cut the number of packets * in half per interrupt. */ itr /= 2; itr &= IAVF_ITR_MASK; if (itr < IAVF_ITR_ADAPTIVE_MIN_USECS) itr = IAVF_ITR_ADAPTIVE_MIN_USECS; goto clear_counts; } /* The paths below assume we are dealing with a bulk ITR since * number of packets is greater than 256. We are just going to have * to compute a value and try to bring the count under control, * though for smaller packet sizes there isn't much we can do as * NAPI polling will likely be kicking in sooner rather than later. */ itr = IAVF_ITR_ADAPTIVE_BULK; adjust_by_size: /* If packet counts are 256 or greater we can assume we have a gross * overestimation of what the rate should be. Instead of trying to fine * tune it just use the formula below to try and dial in an exact value * give the current packet size of the frame. */ avg_wire_size = bytes / packets; /* The following is a crude approximation of: * wmem_default / (size + overhead) = desired_pkts_per_int * rate / bits_per_byte / (size + ethernet overhead) = pkt_rate * (desired_pkt_rate / pkt_rate) * usecs_per_sec = ITR value * * Assuming wmem_default is 212992 and overhead is 640 bytes per * packet, (256 skb, 64 headroom, 320 shared info), we can reduce the * formula down to * * (170 * (size + 24)) / (size + 640) = ITR * * We first do some math on the packet size and then finally bitshift * by 8 after rounding up. We also have to account for PCIe link speed * difference as ITR scales based on this. */ if (avg_wire_size <= 60) { /* Start at 250k ints/sec */ avg_wire_size = 4096; } else if (avg_wire_size <= 380) { /* 250K ints/sec to 60K ints/sec */ avg_wire_size *= 40; avg_wire_size += 1696; } else if (avg_wire_size <= 1084) { /* 60K ints/sec to 36K ints/sec */ avg_wire_size *= 15; avg_wire_size += 11452; } else if (avg_wire_size <= 1980) { /* 36K ints/sec to 30K ints/sec */ avg_wire_size *= 5; avg_wire_size += 22420; } else { /* plateau at a limit of 30K ints/sec */ avg_wire_size = 32256; } /* If we are in low latency mode halve our delay which doubles the * rate to somewhere between 100K to 16K ints/sec */ if (itr & IAVF_ITR_ADAPTIVE_LATENCY) avg_wire_size /= 2; /* Resultant value is 256 times larger than it needs to be. This * gives us room to adjust the value as needed to either increase * or decrease the value based on link speeds of 10G, 2.5G, 1G, etc. * * Use addition as we have already recorded the new latency flag * for the ITR value. */ itr += DIV_ROUND_UP(avg_wire_size, iavf_itr_divisor(q_vector->adapter)) * IAVF_ITR_ADAPTIVE_MIN_INC; if ((itr & IAVF_ITR_MASK) > IAVF_ITR_ADAPTIVE_MAX_USECS) { itr &= IAVF_ITR_ADAPTIVE_LATENCY; itr += IAVF_ITR_ADAPTIVE_MAX_USECS; } clear_counts: /* write back value */ rc->target_itr = itr; /* next update should occur within next jiffy */ rc->next_update = next_update + 1; rc->total_bytes = 0; rc->total_packets = 0; } /** * iavf_setup_tx_descriptors - Allocate the Tx descriptors * @tx_ring: the tx ring to set up * * Return 0 on success, negative on error **/ int iavf_setup_tx_descriptors(struct iavf_ring *tx_ring) { struct device *dev = tx_ring->dev; int bi_size; if (!dev) return -ENOMEM; /* warn if we are about to overwrite the pointer */ WARN_ON(tx_ring->tx_bi); bi_size = sizeof(struct iavf_tx_buffer) * tx_ring->count; tx_ring->tx_bi = kzalloc(bi_size, GFP_KERNEL); if (!tx_ring->tx_bi) goto err; /* round up to nearest 4K */ tx_ring->size = tx_ring->count * sizeof(struct iavf_tx_desc); tx_ring->size = ALIGN(tx_ring->size, 4096); tx_ring->desc = dma_alloc_coherent(dev, tx_ring->size, &tx_ring->dma, GFP_KERNEL); if (!tx_ring->desc) { dev_info(dev, "Unable to allocate memory for the Tx descriptor ring, size=%d\n", tx_ring->size); goto err; } tx_ring->next_to_use = 0; tx_ring->next_to_clean = 0; tx_ring->tx_stats.prev_pkt_ctr = -1; return 0; err: kfree(tx_ring->tx_bi); tx_ring->tx_bi = NULL; return -ENOMEM; } /** * iavf_clean_rx_ring - Free Rx buffers * @rx_ring: ring to be cleaned **/ void iavf_clean_rx_ring(struct iavf_ring *rx_ring) { unsigned long bi_size; u16 i; /* ring already cleared, nothing to do */ if (!rx_ring->rx_bi) return; if (rx_ring->skb) { dev_kfree_skb(rx_ring->skb); rx_ring->skb = NULL; } /* Free all the Rx ring sk_buffs */ for (i = 0; i < rx_ring->count; i++) { struct iavf_rx_buffer *rx_bi = &rx_ring->rx_bi[i]; if (!rx_bi->page) continue; /* Invalidate cache lines that may have been written to by * device so that we avoid corrupting memory. */ dma_sync_single_range_for_cpu(rx_ring->dev, rx_bi->dma, rx_bi->page_offset, rx_ring->rx_buf_len, DMA_FROM_DEVICE); /* free resources associated with mapping */ dma_unmap_page_attrs(rx_ring->dev, rx_bi->dma, iavf_rx_pg_size(rx_ring), DMA_FROM_DEVICE, IAVF_RX_DMA_ATTR); __page_frag_cache_drain(rx_bi->page, rx_bi->pagecnt_bias); rx_bi->page = NULL; rx_bi->page_offset = 0; } bi_size = sizeof(struct iavf_rx_buffer) * rx_ring->count; memset(rx_ring->rx_bi, 0, bi_size); /* Zero out the descriptor ring */ memset(rx_ring->desc, 0, rx_ring->size); rx_ring->next_to_alloc = 0; rx_ring->next_to_clean = 0; rx_ring->next_to_use = 0; } /** * iavf_free_rx_resources - Free Rx resources * @rx_ring: ring to clean the resources from * * Free all receive software resources **/ void iavf_free_rx_resources(struct iavf_ring *rx_ring) { iavf_clean_rx_ring(rx_ring); kfree(rx_ring->rx_bi); rx_ring->rx_bi = NULL; if (rx_ring->desc) { dma_free_coherent(rx_ring->dev, rx_ring->size, rx_ring->desc, rx_ring->dma); rx_ring->desc = NULL; } } /** * iavf_setup_rx_descriptors - Allocate Rx descriptors * @rx_ring: Rx descriptor ring (for a specific queue) to setup * * Returns 0 on success, negative on failure **/ int iavf_setup_rx_descriptors(struct iavf_ring *rx_ring) { struct device *dev = rx_ring->dev; int bi_size; /* warn if we are about to overwrite the pointer */ WARN_ON(rx_ring->rx_bi); bi_size = sizeof(struct iavf_rx_buffer) * rx_ring->count; rx_ring->rx_bi = kzalloc(bi_size, GFP_KERNEL); if (!rx_ring->rx_bi) goto err; u64_stats_init(&rx_ring->syncp); /* Round up to nearest 4K */ rx_ring->size = rx_ring->count * sizeof(union iavf_32byte_rx_desc); rx_ring->size = ALIGN(rx_ring->size, 4096); rx_ring->desc = dma_alloc_coherent(dev, rx_ring->size, &rx_ring->dma, GFP_KERNEL); if (!rx_ring->desc) { dev_info(dev, "Unable to allocate memory for the Rx descriptor ring, size=%d\n", rx_ring->size); goto err; } rx_ring->next_to_alloc = 0; rx_ring->next_to_clean = 0; rx_ring->next_to_use = 0; return 0; err: kfree(rx_ring->rx_bi); rx_ring->rx_bi = NULL; return -ENOMEM; } /** * iavf_release_rx_desc - Store the new tail and head values * @rx_ring: ring to bump * @val: new head index **/ static inline void iavf_release_rx_desc(struct iavf_ring *rx_ring, u32 val) { rx_ring->next_to_use = val; /* update next to alloc since we have filled the ring */ rx_ring->next_to_alloc = val; /* 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(val, rx_ring->tail); } /** * iavf_rx_offset - Return expected offset into page to access data * @rx_ring: Ring we are requesting offset of * * Returns the offset value for ring into the data buffer. */ static inline unsigned int iavf_rx_offset(struct iavf_ring *rx_ring) { return ring_uses_build_skb(rx_ring) ? IAVF_SKB_PAD : 0; } /** * iavf_alloc_mapped_page - recycle or make a new page * @rx_ring: ring to use * @bi: rx_buffer struct to modify * * Returns true if the page was successfully allocated or * reused. **/ static bool iavf_alloc_mapped_page(struct iavf_ring *rx_ring, struct iavf_rx_buffer *bi) { struct page *page = bi->page; dma_addr_t dma; /* since we are recycling buffers we should seldom need to alloc */ if (likely(page)) { rx_ring->rx_stats.page_reuse_count++; return true; } /* alloc new page for storage */ page = dev_alloc_pages(iavf_rx_pg_order(rx_ring)); if (unlikely(!page)) { rx_ring->rx_stats.alloc_page_failed++; return false; } /* map page for use */ dma = dma_map_page_attrs(rx_ring->dev, page, 0, iavf_rx_pg_size(rx_ring), DMA_FROM_DEVICE, IAVF_RX_DMA_ATTR); /* if mapping failed free memory back to system since * there isn't much point in holding memory we can't use */ if (dma_mapping_error(rx_ring->dev, dma)) { __free_pages(page, iavf_rx_pg_order(rx_ring)); rx_ring->rx_stats.alloc_page_failed++; return false; } bi->dma = dma; bi->page = page; bi->page_offset = iavf_rx_offset(rx_ring); /* initialize pagecnt_bias to 1 representing we fully own page */ bi->pagecnt_bias = 1; return true; } /** * iavf_receive_skb - Send a completed packet up the stack * @rx_ring: rx ring in play * @skb: packet to send up * @vlan_tag: vlan tag for packet **/ static void iavf_receive_skb(struct iavf_ring *rx_ring, struct sk_buff *skb, u16 vlan_tag) { struct iavf_q_vector *q_vector = rx_ring->q_vector; if ((rx_ring->netdev->features & NETIF_F_HW_VLAN_CTAG_RX) && (vlan_tag & VLAN_VID_MASK)) __vlan_hwaccel_put_tag(skb, htons(ETH_P_8021Q), vlan_tag); else if ((rx_ring->netdev->features & NETIF_F_HW_VLAN_STAG_RX) && vlan_tag & VLAN_VID_MASK) __vlan_hwaccel_put_tag(skb, htons(ETH_P_8021AD), vlan_tag); napi_gro_receive(&q_vector->napi, skb); } /** * iavf_alloc_rx_buffers - Replace used receive buffers * @rx_ring: ring to place buffers on * @cleaned_count: number of buffers to replace * * Returns false if all allocations were successful, true if any fail **/ bool iavf_alloc_rx_buffers(struct iavf_ring *rx_ring, u16 cleaned_count) { u16 ntu = rx_ring->next_to_use; union iavf_rx_desc *rx_desc; struct iavf_rx_buffer *bi; /* do nothing if no valid netdev defined */ if (!rx_ring->netdev || !cleaned_count) return false; rx_desc = IAVF_RX_DESC(rx_ring, ntu); bi = &rx_ring->rx_bi[ntu]; do { if (!iavf_alloc_mapped_page(rx_ring, bi)) goto no_buffers; /* 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_FROM_DEVICE); /* 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 + bi->page_offset); rx_desc++; bi++; ntu++; if (unlikely(ntu == rx_ring->count)) { rx_desc = IAVF_RX_DESC(rx_ring, 0); bi = rx_ring->rx_bi; ntu = 0; } /* clear the status bits for the next_to_use descriptor */ rx_desc->wb.qword1.status_error_len = 0; cleaned_count--; } while (cleaned_count); if (rx_ring->next_to_use != ntu) iavf_release_rx_desc(rx_ring, ntu); return false; no_buffers: if (rx_ring->next_to_use != ntu) iavf_release_rx_desc(rx_ring, ntu); /* make sure to come back via polling to try again after * allocation failure */ return true; } /** * iavf_rx_checksum - Indicate in skb if hw indicated a good cksum * @vsi: the VSI we care about * @skb: skb currently being received and modified * @rx_desc: the receive descriptor **/ static inline void iavf_rx_checksum(struct iavf_vsi *vsi, struct sk_buff *skb, union iavf_rx_desc *rx_desc) { struct iavf_rx_ptype_decoded decoded; u32 rx_error, rx_status; bool ipv4, ipv6; u8 ptype; u64 qword; qword = le64_to_cpu(rx_desc->wb.qword1.status_error_len); ptype = (qword & IAVF_RXD_QW1_PTYPE_MASK) >> IAVF_RXD_QW1_PTYPE_SHIFT; rx_error = (qword & IAVF_RXD_QW1_ERROR_MASK) >> IAVF_RXD_QW1_ERROR_SHIFT; rx_status = (qword & IAVF_RXD_QW1_STATUS_MASK) >> IAVF_RXD_QW1_STATUS_SHIFT; decoded = decode_rx_desc_ptype(ptype); skb->ip_summed = CHECKSUM_NONE; skb_checksum_none_assert(skb); /* Rx csum enabled and ip headers found? */ if (!(vsi->netdev->features & NETIF_F_RXCSUM)) return; /* did the hardware decode the packet and checksum? */ if (!(rx_status & BIT(IAVF_RX_DESC_STATUS_L3L4P_SHIFT))) return; /* both known and outer_ip must be set for the below code to work */ if (!(decoded.known && decoded.outer_ip)) return; ipv4 = (decoded.outer_ip == IAVF_RX_PTYPE_OUTER_IP) && (decoded.outer_ip_ver == IAVF_RX_PTYPE_OUTER_IPV4); ipv6 = (decoded.outer_ip == IAVF_RX_PTYPE_OUTER_IP) && (decoded.outer_ip_ver == IAVF_RX_PTYPE_OUTER_IPV6); if (ipv4 && (rx_error & (BIT(IAVF_RX_DESC_ERROR_IPE_SHIFT) | BIT(IAVF_RX_DESC_ERROR_EIPE_SHIFT)))) goto checksum_fail; /* likely incorrect csum if alternate IP extension headers found */ if (ipv6 && rx_status & BIT(IAVF_RX_DESC_STATUS_IPV6EXADD_SHIFT)) /* don't increment checksum err here, non-fatal err */ return; /* there was some L4 error, count error and punt packet to the stack */ if (rx_error & BIT(IAVF_RX_DESC_ERROR_L4E_SHIFT)) goto checksum_fail; /* handle packets that were not able to be checksummed due * to arrival speed, in this case the stack can compute * the csum. */ if (rx_error & BIT(IAVF_RX_DESC_ERROR_PPRS_SHIFT)) return; /* Only report checksum unnecessary for TCP, UDP, or SCTP */ switch (decoded.inner_prot) { case IAVF_RX_PTYPE_INNER_PROT_TCP: case IAVF_RX_PTYPE_INNER_PROT_UDP: case IAVF_RX_PTYPE_INNER_PROT_SCTP: skb->ip_summed = CHECKSUM_UNNECESSARY; fallthrough; default: break; } return; checksum_fail: vsi->back->hw_csum_rx_error++; } /** * iavf_ptype_to_htype - get a hash type * @ptype: the ptype value from the descriptor * * Returns a hash type to be used by skb_set_hash **/ static inline int iavf_ptype_to_htype(u8 ptype) { struct iavf_rx_ptype_decoded decoded = decode_rx_desc_ptype(ptype); if (!decoded.known) return PKT_HASH_TYPE_NONE; if (decoded.outer_ip == IAVF_RX_PTYPE_OUTER_IP && decoded.payload_layer == IAVF_RX_PTYPE_PAYLOAD_LAYER_PAY4) return PKT_HASH_TYPE_L4; else if (decoded.outer_ip == IAVF_RX_PTYPE_OUTER_IP && decoded.payload_layer == IAVF_RX_PTYPE_PAYLOAD_LAYER_PAY3) return PKT_HASH_TYPE_L3; else return PKT_HASH_TYPE_L2; } /** * iavf_rx_hash - set the hash value in the skb * @ring: descriptor ring * @rx_desc: specific descriptor * @skb: skb currently being received and modified * @rx_ptype: Rx packet type **/ static inline void iavf_rx_hash(struct iavf_ring *ring, union iavf_rx_desc *rx_desc, struct sk_buff *skb, u8 rx_ptype) { u32 hash; const __le64 rss_mask = cpu_to_le64((u64)IAVF_RX_DESC_FLTSTAT_RSS_HASH << IAVF_RX_DESC_STATUS_FLTSTAT_SHIFT); if (ring->netdev->features & NETIF_F_RXHASH) return; if ((rx_desc->wb.qword1.status_error_len & rss_mask) == rss_mask) { hash = le32_to_cpu(rx_desc->wb.qword0.hi_dword.rss); skb_set_hash(skb, hash, iavf_ptype_to_htype(rx_ptype)); } } /** * iavf_process_skb_fields - Populate skb header fields from Rx descriptor * @rx_ring: rx descriptor ring packet is being transacted on * @rx_desc: pointer to the EOP Rx descriptor * @skb: pointer to current skb being populated * @rx_ptype: the packet type decoded by hardware * * This function checks the ring, descriptor, and packet information in * order to populate the hash, checksum, VLAN, protocol, and * other fields within the skb. **/ static inline void iavf_process_skb_fields(struct iavf_ring *rx_ring, union iavf_rx_desc *rx_desc, struct sk_buff *skb, u8 rx_ptype) { iavf_rx_hash(rx_ring, rx_desc, skb, rx_ptype); iavf_rx_checksum(rx_ring->vsi, skb, rx_desc); skb_record_rx_queue(skb, rx_ring->queue_index); /* modifies the skb - consumes the enet header */ skb->protocol = eth_type_trans(skb, rx_ring->netdev); } /** * iavf_cleanup_headers - Correct empty headers * @rx_ring: rx descriptor ring packet is being transacted on * @skb: pointer to current skb being fixed * * Also address the case where we are pulling data in on pages only * and as such no data is present in the skb header. * * In addition if skb is not at least 60 bytes we need to pad it so that * it is large enough to qualify as a valid Ethernet frame. * * Returns true if an error was encountered and skb was freed. **/ static bool iavf_cleanup_headers(struct iavf_ring *rx_ring, struct sk_buff *skb) { /* if eth_skb_pad returns an error the skb was freed */ if (eth_skb_pad(skb)) return true; return false; } /** * iavf_reuse_rx_page - page flip buffer and store it back on the ring * @rx_ring: rx descriptor ring to store buffers on * @old_buff: donor buffer to have page reused * * Synchronizes page for reuse by the adapter **/ static void iavf_reuse_rx_page(struct iavf_ring *rx_ring, struct iavf_rx_buffer *old_buff) { struct iavf_rx_buffer *new_buff; u16 nta = rx_ring->next_to_alloc; new_buff = &rx_ring->rx_bi[nta]; /* 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_buff->dma = old_buff->dma; new_buff->page = old_buff->page; new_buff->page_offset = old_buff->page_offset; new_buff->pagecnt_bias = old_buff->pagecnt_bias; } /** * iavf_can_reuse_rx_page - Determine if this page can be reused by * the adapter for another receive * * @rx_buffer: buffer containing the page * * If page is reusable, rx_buffer->page_offset is adjusted to point to * an unused region in the page. * * For small pages, @truesize will be a constant value, half the size * of the memory at page. We'll attempt to alternate between high and * low halves of the page, with one half ready for use by the hardware * and the other half being consumed by the stack. We use the page * ref count to determine whether the stack has finished consuming the * portion of this page that was passed up with a previous packet. If * the page ref count is >1, we'll assume the "other" half page is * still busy, and this page cannot be reused. * * For larger pages, @truesize will be the actual space used by the * received packet (adjusted upward to an even multiple of the cache * line size). This will advance through the page by the amount * actually consumed by the received packets while there is still * space for a buffer. Each region of larger pages will be used at * most once, after which the page will not be reused. * * In either case, if the page is reusable its refcount is increased. **/ static bool iavf_can_reuse_rx_page(struct iavf_rx_buffer *rx_buffer) { unsigned int pagecnt_bias = rx_buffer->pagecnt_bias; struct page *page = rx_buffer->page; /* Is any reuse possible? */ if (!dev_page_is_reusable(page)) return false; #if (PAGE_SIZE < 8192) /* if we are only owner of page we can reuse it */ if (unlikely((page_count(page) - pagecnt_bias) > 1)) return false; #else #define IAVF_LAST_OFFSET \ (SKB_WITH_OVERHEAD(PAGE_SIZE) - IAVF_RXBUFFER_2048) if (rx_buffer->page_offset > IAVF_LAST_OFFSET) return false; #endif /* If we have drained the page fragment pool we need to update * the pagecnt_bias and page count so that we fully restock the * number of references the driver holds. */ if (unlikely(!pagecnt_bias)) { page_ref_add(page, USHRT_MAX); rx_buffer->pagecnt_bias = USHRT_MAX; } return true; } /** * iavf_add_rx_frag - Add contents of Rx buffer to sk_buff * @rx_ring: rx descriptor ring to transact packets on * @rx_buffer: buffer containing page to add * @skb: sk_buff to place the data into * @size: packet length from rx_desc * * This function will add the data contained in rx_buffer->page to the skb. * It will just attach the page as a frag to the skb. * * The function will then update the page offset. **/ static void iavf_add_rx_frag(struct iavf_ring *rx_ring, struct iavf_rx_buffer *rx_buffer, struct sk_buff *skb, unsigned int size) { #if (PAGE_SIZE < 8192) unsigned int truesize = iavf_rx_pg_size(rx_ring) / 2; #else unsigned int truesize = SKB_DATA_ALIGN(size + iavf_rx_offset(rx_ring)); #endif if (!size) return; skb_add_rx_frag(skb, skb_shinfo(skb)->nr_frags, rx_buffer->page, rx_buffer->page_offset, size, truesize); /* page is being used so we must update the page offset */ #if (PAGE_SIZE < 8192) rx_buffer->page_offset ^= truesize; #else rx_buffer->page_offset += truesize; #endif } /** * iavf_get_rx_buffer - Fetch Rx buffer and synchronize data for use * @rx_ring: rx descriptor ring to transact packets on * @size: size of buffer to add to skb * * This function will pull an Rx buffer from the ring and synchronize it * for use by the CPU. */ static struct iavf_rx_buffer *iavf_get_rx_buffer(struct iavf_ring *rx_ring, const unsigned int size) { struct iavf_rx_buffer *rx_buffer; if (!size) return NULL; rx_buffer = &rx_ring->rx_bi[rx_ring->next_to_clean]; prefetchw(rx_buffer->page); /* we are reusing so sync this buffer for CPU use */ dma_sync_single_range_for_cpu(rx_ring->dev, rx_buffer->dma, rx_buffer->page_offset, size, DMA_FROM_DEVICE); /* We have pulled a buffer for use, so decrement pagecnt_bias */ rx_buffer->pagecnt_bias--; return rx_buffer; } /** * iavf_construct_skb - Allocate skb and populate it * @rx_ring: rx descriptor ring to transact packets on * @rx_buffer: rx buffer to pull data from * @size: size of buffer to add to skb * * This function allocates an skb. It then populates it with the page * data from the current receive descriptor, taking care to set up the * skb correctly. */ static struct sk_buff *iavf_construct_skb(struct iavf_ring *rx_ring, struct iavf_rx_buffer *rx_buffer, unsigned int size) { void *va; #if (PAGE_SIZE < 8192) unsigned int truesize = iavf_rx_pg_size(rx_ring) / 2; #else unsigned int truesize = SKB_DATA_ALIGN(size); #endif unsigned int headlen; struct sk_buff *skb; if (!rx_buffer) return NULL; /* prefetch first cache line of first page */ va = page_address(rx_buffer->page) + rx_buffer->page_offset; net_prefetch(va); /* allocate a skb to store the frags */ skb = __napi_alloc_skb(&rx_ring->q_vector->napi, IAVF_RX_HDR_SIZE, GFP_ATOMIC | __GFP_NOWARN); if (unlikely(!skb)) return NULL; /* Determine available headroom for copy */ headlen = size; if (headlen > IAVF_RX_HDR_SIZE) headlen = eth_get_headlen(skb->dev, va, IAVF_RX_HDR_SIZE); /* align pull length to size of long to optimize memcpy performance */ memcpy(__skb_put(skb, headlen), va, ALIGN(headlen, sizeof(long))); /* update all of the pointers */ size -= headlen; if (size) { skb_add_rx_frag(skb, 0, rx_buffer->page, rx_buffer->page_offset + headlen, size, truesize); /* buffer is used by skb, update page_offset */ #if (PAGE_SIZE < 8192) rx_buffer->page_offset ^= truesize; #else rx_buffer->page_offset += truesize; #endif } else { /* buffer is unused, reset bias back to rx_buffer */ rx_buffer->pagecnt_bias++; } return skb; } /** * iavf_build_skb - Build skb around an existing buffer * @rx_ring: Rx descriptor ring to transact packets on * @rx_buffer: Rx buffer to pull data from * @size: size of buffer to add to skb * * This function builds an skb around an existing Rx buffer, taking care * to set up the skb correctly and avoid any memcpy overhead. */ static struct sk_buff *iavf_build_skb(struct iavf_ring *rx_ring, struct iavf_rx_buffer *rx_buffer, unsigned int size) { void *va; #if (PAGE_SIZE < 8192) unsigned int truesize = iavf_rx_pg_size(rx_ring) / 2; #else unsigned int truesize = SKB_DATA_ALIGN(sizeof(struct skb_shared_info)) + SKB_DATA_ALIGN(IAVF_SKB_PAD + size); #endif struct sk_buff *skb; if (!rx_buffer) return NULL; /* prefetch first cache line of first page */ va = page_address(rx_buffer->page) + rx_buffer->page_offset; net_prefetch(va); /* build an skb around the page buffer */ skb = napi_build_skb(va - IAVF_SKB_PAD, truesize); if (unlikely(!skb)) return NULL; /* update pointers within the skb to store the data */ skb_reserve(skb, IAVF_SKB_PAD); __skb_put(skb, size); /* buffer is used by skb, update page_offset */ #if (PAGE_SIZE < 8192) rx_buffer->page_offset ^= truesize; #else rx_buffer->page_offset += truesize; #endif return skb; } /** * iavf_put_rx_buffer - Clean up used buffer and either recycle or free * @rx_ring: rx descriptor ring to transact packets on * @rx_buffer: rx buffer to pull data from * * This function will clean up the contents of the rx_buffer. It will * either recycle the buffer or unmap it and free the associated resources. */ static void iavf_put_rx_buffer(struct iavf_ring *rx_ring, struct iavf_rx_buffer *rx_buffer) { if (!rx_buffer) return; if (iavf_can_reuse_rx_page(rx_buffer)) { /* hand second half of page back to the ring */ iavf_reuse_rx_page(rx_ring, rx_buffer); rx_ring->rx_stats.page_reuse_count++; } else { /* we are not reusing the buffer so unmap it */ dma_unmap_page_attrs(rx_ring->dev, rx_buffer->dma, iavf_rx_pg_size(rx_ring), DMA_FROM_DEVICE, IAVF_RX_DMA_ATTR); __page_frag_cache_drain(rx_buffer->page, rx_buffer->pagecnt_bias); } /* clear contents of buffer_info */ rx_buffer->page = NULL; } /** * iavf_is_non_eop - process handling of non-EOP buffers * @rx_ring: Rx ring being processed * @rx_desc: Rx descriptor for current buffer * @skb: Current socket buffer containing buffer in progress * * This function updates next to clean. If the buffer is an EOP buffer * this function exits returning false, otherwise it will place the * sk_buff in the next buffer to be chained and return true indicating * that this is in fact a non-EOP buffer. **/ static bool iavf_is_non_eop(struct iavf_ring *rx_ring, union iavf_rx_desc *rx_desc, struct sk_buff *skb) { u32 ntc = rx_ring->next_to_clean + 1; /* fetch, update, and store next to clean */ ntc = (ntc < rx_ring->count) ? ntc : 0; rx_ring->next_to_clean = ntc; prefetch(IAVF_RX_DESC(rx_ring, ntc)); /* if we are the last buffer then there is nothing else to do */ #define IAVF_RXD_EOF BIT(IAVF_RX_DESC_STATUS_EOF_SHIFT) if (likely(iavf_test_staterr(rx_desc, IAVF_RXD_EOF))) return false; rx_ring->rx_stats.non_eop_descs++; return true; } /** * iavf_clean_rx_irq - Clean completed descriptors from Rx ring - bounce buf * @rx_ring: rx descriptor ring to transact packets on * @budget: Total limit on number of packets to process * * This function provides a "bounce buffer" approach to Rx interrupt * processing. The advantage to this is that on systems that have * expensive overhead for IOMMU access this provides a means of avoiding * it by maintaining the mapping of the page to the system. * * Returns amount of work completed **/ static int iavf_clean_rx_irq(struct iavf_ring *rx_ring, int budget) { unsigned int total_rx_bytes = 0, total_rx_packets = 0; struct sk_buff *skb = rx_ring->skb; u16 cleaned_count = IAVF_DESC_UNUSED(rx_ring); bool failure = false; while (likely(total_rx_packets < (unsigned int)budget)) { struct iavf_rx_buffer *rx_buffer; union iavf_rx_desc *rx_desc; unsigned int size; u16 vlan_tag = 0; u8 rx_ptype; u64 qword; /* return some buffers to hardware, one at a time is too slow */ if (cleaned_count >= IAVF_RX_BUFFER_WRITE) { failure = failure || iavf_alloc_rx_buffers(rx_ring, cleaned_count); cleaned_count = 0; } rx_desc = IAVF_RX_DESC(rx_ring, rx_ring->next_to_clean); /* status_error_len will always be zero for unused descriptors * because it's cleared in cleanup, and overlaps with hdr_addr * which is always zero because packet split isn't used, if the * hardware wrote DD then the length will be non-zero */ 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(); #define IAVF_RXD_DD BIT(IAVF_RX_DESC_STATUS_DD_SHIFT) if (!iavf_test_staterr(rx_desc, IAVF_RXD_DD)) break; size = (qword & IAVF_RXD_QW1_LENGTH_PBUF_MASK) >> IAVF_RXD_QW1_LENGTH_PBUF_SHIFT; iavf_trace(clean_rx_irq, rx_ring, rx_desc, skb); rx_buffer = iavf_get_rx_buffer(rx_ring, size); /* retrieve a buffer from the ring */ if (skb) iavf_add_rx_frag(rx_ring, rx_buffer, skb, size); else if (ring_uses_build_skb(rx_ring)) skb = iavf_build_skb(rx_ring, rx_buffer, size); else skb = iavf_construct_skb(rx_ring, rx_buffer, size); /* exit if we failed to retrieve a buffer */ if (!skb) { rx_ring->rx_stats.alloc_buff_failed++; if (rx_buffer) rx_buffer->pagecnt_bias++; break; } iavf_put_rx_buffer(rx_ring, rx_buffer); cleaned_count++; if (iavf_is_non_eop(rx_ring, rx_desc, skb)) continue; /* ERR_MASK will only have valid bits if EOP set, and * what we are doing here is actually checking * IAVF_RX_DESC_ERROR_RXE_SHIFT, since it is the zeroth bit in * the error field */ if (unlikely(iavf_test_staterr(rx_desc, BIT(IAVF_RXD_QW1_ERROR_SHIFT)))) { dev_kfree_skb_any(skb); skb = NULL; continue; } if (iavf_cleanup_headers(rx_ring, skb)) { skb = NULL; continue; } /* probably a little skewed due to removing CRC */ total_rx_bytes += skb->len; qword = le64_to_cpu(rx_desc->wb.qword1.status_error_len); rx_ptype = (qword & IAVF_RXD_QW1_PTYPE_MASK) >> IAVF_RXD_QW1_PTYPE_SHIFT; /* populate checksum, VLAN, and protocol */ iavf_process_skb_fields(rx_ring, rx_desc, skb, rx_ptype); if (qword & BIT(IAVF_RX_DESC_STATUS_L2TAG1P_SHIFT) && rx_ring->flags & IAVF_TXRX_FLAGS_VLAN_TAG_LOC_L2TAG1) vlan_tag = le16_to_cpu(rx_desc->wb.qword0.lo_dword.l2tag1); if (rx_desc->wb.qword2.ext_status & cpu_to_le16(BIT(IAVF_RX_DESC_EXT_STATUS_L2TAG2P_SHIFT)) && rx_ring->flags & IAVF_RXR_FLAGS_VLAN_TAG_LOC_L2TAG2_2) vlan_tag = le16_to_cpu(rx_desc->wb.qword2.l2tag2_2); iavf_trace(clean_rx_irq_rx, rx_ring, rx_desc, skb); iavf_receive_skb(rx_ring, skb, vlan_tag); skb = NULL; /* update budget accounting */ total_rx_packets++; } rx_ring->skb = skb; 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); rx_ring->q_vector->rx.total_packets += total_rx_packets; rx_ring->q_vector->rx.total_bytes += total_rx_bytes; /* guarantee a trip back through this routine if there was a failure */ return failure ? budget : (int)total_rx_packets; } static inline u32 iavf_buildreg_itr(const int type, u16 itr) { u32 val; /* We don't bother with setting the CLEARPBA bit as the data sheet * points out doing so is "meaningless since it was already * auto-cleared". The auto-clearing happens when the interrupt is * asserted. * * Hardware errata 28 for also indicates that writing to a * xxINT_DYN_CTLx CSR with INTENA_MSK (bit 31) set to 0 will clear * an event in the PBA anyway so we need to rely on the automask * to hold pending events for us until the interrupt is re-enabled * * The itr value is reported in microseconds, and the register * value is recorded in 2 microsecond units. For this reason we * only need to shift by the interval shift - 1 instead of the * full value. */ itr &= IAVF_ITR_MASK; val = IAVF_VFINT_DYN_CTLN1_INTENA_MASK | (type << IAVF_VFINT_DYN_CTLN1_ITR_INDX_SHIFT) | (itr << (IAVF_VFINT_DYN_CTLN1_INTERVAL_SHIFT - 1)); return val; } /* a small macro to shorten up some long lines */ #define INTREG IAVF_VFINT_DYN_CTLN1 /* The act of updating the ITR will cause it to immediately trigger. In order * to prevent this from throwing off adaptive update statistics we defer the * update so that it can only happen so often. So after either Tx or Rx are * updated we make the adaptive scheme wait until either the ITR completely * expires via the next_update expiration or we have been through at least * 3 interrupts. */ #define ITR_COUNTDOWN_START 3 /** * iavf_update_enable_itr - Update itr and re-enable MSIX interrupt * @vsi: the VSI we care about * @q_vector: q_vector for which itr is being updated and interrupt enabled * **/ static inline void iavf_update_enable_itr(struct iavf_vsi *vsi, struct iavf_q_vector *q_vector) { struct iavf_hw *hw = &vsi->back->hw; u32 intval; /* These will do nothing if dynamic updates are not enabled */ iavf_update_itr(q_vector, &q_vector->tx); iavf_update_itr(q_vector, &q_vector->rx); /* This block of logic allows us to get away with only updating * one ITR value with each interrupt. The idea is to perform a * pseudo-lazy update with the following criteria. * * 1. Rx is given higher priority than Tx if both are in same state * 2. If we must reduce an ITR that is given highest priority. * 3. We then give priority to increasing ITR based on amount. */ if (q_vector->rx.target_itr < q_vector->rx.current_itr) { /* Rx ITR needs to be reduced, this is highest priority */ intval = iavf_buildreg_itr(IAVF_RX_ITR, q_vector->rx.target_itr); q_vector->rx.current_itr = q_vector->rx.target_itr; q_vector->itr_countdown = ITR_COUNTDOWN_START; } else if ((q_vector->tx.target_itr < q_vector->tx.current_itr) || ((q_vector->rx.target_itr - q_vector->rx.current_itr) < (q_vector->tx.target_itr - q_vector->tx.current_itr))) { /* Tx ITR needs to be reduced, this is second priority * Tx ITR needs to be increased more than Rx, fourth priority */ intval = iavf_buildreg_itr(IAVF_TX_ITR, q_vector->tx.target_itr); q_vector->tx.current_itr = q_vector->tx.target_itr; q_vector->itr_countdown = ITR_COUNTDOWN_START; } else if (q_vector->rx.current_itr != q_vector->rx.target_itr) { /* Rx ITR needs to be increased, third priority */ intval = iavf_buildreg_itr(IAVF_RX_ITR, q_vector->rx.target_itr); q_vector->rx.current_itr = q_vector->rx.target_itr; q_vector->itr_countdown = ITR_COUNTDOWN_START; } else { /* No ITR update, lowest priority */ intval = iavf_buildreg_itr(IAVF_ITR_NONE, 0); if (q_vector->itr_countdown) q_vector->itr_countdown--; } if (!test_bit(__IAVF_VSI_DOWN, vsi->state)) wr32(hw, INTREG(q_vector->reg_idx), intval); } /** * iavf_napi_poll - NAPI polling Rx/Tx cleanup routine * @napi: napi struct with our devices info in it * @budget: amount of work driver is allowed to do this pass, in packets * * This function will clean all queues associated with a q_vector. * * Returns the amount of work done **/ int iavf_napi_poll(struct napi_struct *napi, int budget) { struct iavf_q_vector *q_vector = container_of(napi, struct iavf_q_vector, napi); struct iavf_vsi *vsi = q_vector->vsi; struct iavf_ring *ring; bool clean_complete = true; bool arm_wb = false; int budget_per_ring; int work_done = 0; if (test_bit(__IAVF_VSI_DOWN, vsi->state)) { napi_complete(napi); return 0; } /* Since the actual Tx work is minimal, we can give the Tx a larger * budget and be more aggressive about cleaning up the Tx descriptors. */ iavf_for_each_ring(ring, q_vector->tx) { if (!iavf_clean_tx_irq(vsi, ring, budget)) { clean_complete = false; continue; } arm_wb |= ring->arm_wb; ring->arm_wb = false; } /* Handle case where we are called by netpoll with a budget of 0 */ if (budget <= 0) goto tx_only; /* We attempt to distribute budget to each Rx queue fairly, but don't * allow the budget to go below 1 because that would exit polling early. */ budget_per_ring = max(budget/q_vector->num_ringpairs, 1); iavf_for_each_ring(ring, q_vector->rx) { int cleaned = iavf_clean_rx_irq(ring, budget_per_ring); work_done += cleaned; /* if we clean as many as budgeted, we must not be done */ if (cleaned >= budget_per_ring) clean_complete = false; } /* If work not completed, return budget and polling will return */ if (!clean_complete) { int cpu_id = smp_processor_id(); /* It is possible that the interrupt affinity has changed but, * if the cpu is pegged at 100%, polling will never exit while * traffic continues and the interrupt will be stuck on this * cpu. We check to make sure affinity is correct before we * continue to poll, otherwise we must stop polling so the * interrupt can move to the correct cpu. */ if (!cpumask_test_cpu(cpu_id, &q_vector->affinity_mask)) { /* Tell napi that we are done polling */ napi_complete_done(napi, work_done); /* Force an interrupt */ iavf_force_wb(vsi, q_vector); /* Return budget-1 so that polling stops */ return budget - 1; } tx_only: if (arm_wb) { q_vector->tx.ring[0].tx_stats.tx_force_wb++; iavf_enable_wb_on_itr(vsi, q_vector); } return budget; } if (vsi->back->flags & IAVF_TXR_FLAGS_WB_ON_ITR) q_vector->arm_wb_state = false; /* Exit the polling mode, but don't re-enable interrupts if stack might * poll us due to busy-polling */ if (likely(napi_complete_done(napi, work_done))) iavf_update_enable_itr(vsi, q_vector); return min_t(int, work_done, budget - 1); } /** * iavf_tx_prepare_vlan_flags - prepare generic TX VLAN tagging flags for HW * @skb: send buffer * @tx_ring: ring to send buffer on * @flags: the tx flags to be set * * Checks the skb and set up correspondingly several generic transmit flags * related to VLAN tagging for the HW, such as VLAN, DCB, etc. * * Returns error code indicate the frame should be dropped upon error and the * otherwise returns 0 to indicate the flags has been set properly. **/ static void iavf_tx_prepare_vlan_flags(struct sk_buff *skb, struct iavf_ring *tx_ring, u32 *flags) { u32 tx_flags = 0; /* stack will only request hardware VLAN insertion offload for protocols * that the driver supports and has enabled */ if (!skb_vlan_tag_present(skb)) return; tx_flags |= skb_vlan_tag_get(skb) << IAVF_TX_FLAGS_VLAN_SHIFT; if (tx_ring->flags & IAVF_TXR_FLAGS_VLAN_TAG_LOC_L2TAG2) { tx_flags |= IAVF_TX_FLAGS_HW_OUTER_SINGLE_VLAN; } else if (tx_ring->flags & IAVF_TXRX_FLAGS_VLAN_TAG_LOC_L2TAG1) { tx_flags |= IAVF_TX_FLAGS_HW_VLAN; } else { dev_dbg(tx_ring->dev, "Unsupported Tx VLAN tag location requested\n"); return; } *flags = tx_flags; } /** * iavf_tso - set up the tso context descriptor * @first: pointer to first Tx buffer for xmit * @hdr_len: ptr to the size of the packet header * @cd_type_cmd_tso_mss: Quad Word 1 * * Returns 0 if no TSO can happen, 1 if tso is going, or error **/ static int iavf_tso(struct iavf_tx_buffer *first, u8 *hdr_len, u64 *cd_type_cmd_tso_mss) { struct sk_buff *skb = first->skb; u64 cd_cmd, cd_tso_len, cd_mss; union { struct iphdr *v4; struct ipv6hdr *v6; unsigned char *hdr; } ip; union { struct tcphdr *tcp; struct udphdr *udp; unsigned char *hdr; } l4; u32 paylen, l4_offset; u16 gso_segs, gso_size; int err; if (skb->ip_summed != CHECKSUM_PARTIAL) return 0; if (!skb_is_gso(skb)) return 0; err = skb_cow_head(skb, 0); if (err < 0) return err; ip.hdr = skb_network_header(skb); l4.hdr = skb_transport_header(skb); /* initialize outer IP header fields */ if (ip.v4->version == 4) { ip.v4->tot_len = 0; ip.v4->check = 0; } else { ip.v6->payload_len = 0; } if (skb_shinfo(skb)->gso_type & (SKB_GSO_GRE | SKB_GSO_GRE_CSUM | SKB_GSO_IPXIP4 | SKB_GSO_IPXIP6 | SKB_GSO_UDP_TUNNEL | SKB_GSO_UDP_TUNNEL_CSUM)) { if (!(skb_shinfo(skb)->gso_type & SKB_GSO_PARTIAL) && (skb_shinfo(skb)->gso_type & SKB_GSO_UDP_TUNNEL_CSUM)) { l4.udp->len = 0; /* determine offset of outer transport header */ l4_offset = l4.hdr - skb->data; /* remove payload length from outer checksum */ paylen = skb->len - l4_offset; csum_replace_by_diff(&l4.udp->check, (__force __wsum)htonl(paylen)); } /* reset pointers to inner headers */ ip.hdr = skb_inner_network_header(skb); l4.hdr = skb_inner_transport_header(skb); /* initialize inner IP header fields */ if (ip.v4->version == 4) { ip.v4->tot_len = 0; ip.v4->check = 0; } else { ip.v6->payload_len = 0; } } /* determine offset of inner transport header */ l4_offset = l4.hdr - skb->data; /* remove payload length from inner checksum */ paylen = skb->len - l4_offset; if (skb_shinfo(skb)->gso_type & SKB_GSO_UDP_L4) { csum_replace_by_diff(&l4.udp->check, (__force __wsum)htonl(paylen)); /* compute length of UDP segmentation header */ *hdr_len = (u8)sizeof(l4.udp) + l4_offset; } else { csum_replace_by_diff(&l4.tcp->check, (__force __wsum)htonl(paylen)); /* compute length of TCP segmentation header */ *hdr_len = (u8)((l4.tcp->doff * 4) + l4_offset); } /* pull values out of skb_shinfo */ gso_size = skb_shinfo(skb)->gso_size; gso_segs = skb_shinfo(skb)->gso_segs; /* update GSO size and bytecount with header size */ first->gso_segs = gso_segs; first->bytecount += (first->gso_segs - 1) * *hdr_len; /* find the field values */ cd_cmd = IAVF_TX_CTX_DESC_TSO; cd_tso_len = skb->len - *hdr_len; cd_mss = gso_size; *cd_type_cmd_tso_mss |= (cd_cmd << IAVF_TXD_CTX_QW1_CMD_SHIFT) | (cd_tso_len << IAVF_TXD_CTX_QW1_TSO_LEN_SHIFT) | (cd_mss << IAVF_TXD_CTX_QW1_MSS_SHIFT); return 1; } /** * iavf_tx_enable_csum - Enable Tx checksum offloads * @skb: send buffer * @tx_flags: pointer to Tx flags currently set * @td_cmd: Tx descriptor command bits to set * @td_offset: Tx descriptor header offsets to set * @tx_ring: Tx descriptor ring * @cd_tunneling: ptr to context desc bits **/ static int iavf_tx_enable_csum(struct sk_buff *skb, u32 *tx_flags, u32 *td_cmd, u32 *td_offset, struct iavf_ring *tx_ring, u32 *cd_tunneling) { union { struct iphdr *v4; struct ipv6hdr *v6; unsigned char *hdr; } ip; union { struct tcphdr *tcp; struct udphdr *udp; unsigned char *hdr; } l4; unsigned char *exthdr; u32 offset, cmd = 0; __be16 frag_off; u8 l4_proto = 0; if (skb->ip_summed != CHECKSUM_PARTIAL) return 0; ip.hdr = skb_network_header(skb); l4.hdr = skb_transport_header(skb); /* compute outer L2 header size */ offset = ((ip.hdr - skb->data) / 2) << IAVF_TX_DESC_LENGTH_MACLEN_SHIFT; if (skb->encapsulation) { u32 tunnel = 0; /* define outer network header type */ if (*tx_flags & IAVF_TX_FLAGS_IPV4) { tunnel |= (*tx_flags & IAVF_TX_FLAGS_TSO) ? IAVF_TX_CTX_EXT_IP_IPV4 : IAVF_TX_CTX_EXT_IP_IPV4_NO_CSUM; l4_proto = ip.v4->protocol; } else if (*tx_flags & IAVF_TX_FLAGS_IPV6) { tunnel |= IAVF_TX_CTX_EXT_IP_IPV6; exthdr = ip.hdr + sizeof(*ip.v6); l4_proto = ip.v6->nexthdr; if (l4.hdr != exthdr) ipv6_skip_exthdr(skb, exthdr - skb->data, &l4_proto, &frag_off); } /* define outer transport */ switch (l4_proto) { case IPPROTO_UDP: tunnel |= IAVF_TXD_CTX_UDP_TUNNELING; *tx_flags |= IAVF_TX_FLAGS_VXLAN_TUNNEL; break; case IPPROTO_GRE: tunnel |= IAVF_TXD_CTX_GRE_TUNNELING; *tx_flags |= IAVF_TX_FLAGS_VXLAN_TUNNEL; break; case IPPROTO_IPIP: case IPPROTO_IPV6: *tx_flags |= IAVF_TX_FLAGS_VXLAN_TUNNEL; l4.hdr = skb_inner_network_header(skb); break; default: if (*tx_flags & IAVF_TX_FLAGS_TSO) return -1; skb_checksum_help(skb); return 0; } /* compute outer L3 header size */ tunnel |= ((l4.hdr - ip.hdr) / 4) << IAVF_TXD_CTX_QW0_EXT_IPLEN_SHIFT; /* switch IP header pointer from outer to inner header */ ip.hdr = skb_inner_network_header(skb); /* compute tunnel header size */ tunnel |= ((ip.hdr - l4.hdr) / 2) << IAVF_TXD_CTX_QW0_NATLEN_SHIFT; /* indicate if we need to offload outer UDP header */ if ((*tx_flags & IAVF_TX_FLAGS_TSO) && !(skb_shinfo(skb)->gso_type & SKB_GSO_PARTIAL) && (skb_shinfo(skb)->gso_type & SKB_GSO_UDP_TUNNEL_CSUM)) tunnel |= IAVF_TXD_CTX_QW0_L4T_CS_MASK; /* record tunnel offload values */ *cd_tunneling |= tunnel; /* switch L4 header pointer from outer to inner */ l4.hdr = skb_inner_transport_header(skb); l4_proto = 0; /* reset type as we transition from outer to inner headers */ *tx_flags &= ~(IAVF_TX_FLAGS_IPV4 | IAVF_TX_FLAGS_IPV6); if (ip.v4->version == 4) *tx_flags |= IAVF_TX_FLAGS_IPV4; if (ip.v6->version == 6) *tx_flags |= IAVF_TX_FLAGS_IPV6; } /* Enable IP checksum offloads */ if (*tx_flags & IAVF_TX_FLAGS_IPV4) { l4_proto = ip.v4->protocol; /* the stack computes the IP header already, the only time we * need the hardware to recompute it is in the case of TSO. */ cmd |= (*tx_flags & IAVF_TX_FLAGS_TSO) ? IAVF_TX_DESC_CMD_IIPT_IPV4_CSUM : IAVF_TX_DESC_CMD_IIPT_IPV4; } else if (*tx_flags & IAVF_TX_FLAGS_IPV6) { cmd |= IAVF_TX_DESC_CMD_IIPT_IPV6; exthdr = ip.hdr + sizeof(*ip.v6); l4_proto = ip.v6->nexthdr; if (l4.hdr != exthdr) ipv6_skip_exthdr(skb, exthdr - skb->data, &l4_proto, &frag_off); } /* compute inner L3 header size */ offset |= ((l4.hdr - ip.hdr) / 4) << IAVF_TX_DESC_LENGTH_IPLEN_SHIFT; /* Enable L4 checksum offloads */ switch (l4_proto) { case IPPROTO_TCP: /* enable checksum offloads */ cmd |= IAVF_TX_DESC_CMD_L4T_EOFT_TCP; offset |= l4.tcp->doff << IAVF_TX_DESC_LENGTH_L4_FC_LEN_SHIFT; break; case IPPROTO_SCTP: /* enable SCTP checksum offload */ cmd |= IAVF_TX_DESC_CMD_L4T_EOFT_SCTP; offset |= (sizeof(struct sctphdr) >> 2) << IAVF_TX_DESC_LENGTH_L4_FC_LEN_SHIFT; break; case IPPROTO_UDP: /* enable UDP checksum offload */ cmd |= IAVF_TX_DESC_CMD_L4T_EOFT_UDP; offset |= (sizeof(struct udphdr) >> 2) << IAVF_TX_DESC_LENGTH_L4_FC_LEN_SHIFT; break; default: if (*tx_flags & IAVF_TX_FLAGS_TSO) return -1; skb_checksum_help(skb); return 0; } *td_cmd |= cmd; *td_offset |= offset; return 1; } /** * iavf_create_tx_ctx - Build the Tx context descriptor * @tx_ring: ring to create the descriptor on * @cd_type_cmd_tso_mss: Quad Word 1 * @cd_tunneling: Quad Word 0 - bits 0-31 * @cd_l2tag2: Quad Word 0 - bits 32-63 **/ static void iavf_create_tx_ctx(struct iavf_ring *tx_ring, const u64 cd_type_cmd_tso_mss, const u32 cd_tunneling, const u32 cd_l2tag2) { struct iavf_tx_context_desc *context_desc; int i = tx_ring->next_to_use; if ((cd_type_cmd_tso_mss == IAVF_TX_DESC_DTYPE_CONTEXT) && !cd_tunneling && !cd_l2tag2) return; /* grab the next descriptor */ context_desc = IAVF_TX_CTXTDESC(tx_ring, i); i++; tx_ring->next_to_use = (i < tx_ring->count) ? i : 0; /* cpu_to_le32 and assign to struct fields */ context_desc->tunneling_params = cpu_to_le32(cd_tunneling); context_desc->l2tag2 = cpu_to_le16(cd_l2tag2); context_desc->rsvd = cpu_to_le16(0); context_desc->type_cmd_tso_mss = cpu_to_le64(cd_type_cmd_tso_mss); } /** * __iavf_chk_linearize - Check if there are more than 8 buffers per packet * @skb: send buffer * * Note: Our HW can't DMA more than 8 buffers to build a packet on the wire * and so we need to figure out the cases where we need to linearize the skb. * * For TSO we need to count the TSO header and segment payload separately. * As such we need to check cases where we have 7 fragments or more as we * can potentially require 9 DMA transactions, 1 for the TSO header, 1 for * the segment payload in the first descriptor, and another 7 for the * fragments. **/ bool __iavf_chk_linearize(struct sk_buff *skb) { const skb_frag_t *frag, *stale; int nr_frags, sum; /* no need to check if number of frags is less than 7 */ nr_frags = skb_shinfo(skb)->nr_frags; if (nr_frags < (IAVF_MAX_BUFFER_TXD - 1)) return false; /* We need to walk through the list and validate that each group * of 6 fragments totals at least gso_size. */ nr_frags -= IAVF_MAX_BUFFER_TXD - 2; frag = &skb_shinfo(skb)->frags[0]; /* Initialize size to the negative value of gso_size minus 1. We * use this as the worst case scenerio in which the frag ahead * of us only provides one byte which is why we are limited to 6 * descriptors for a single transmit as the header and previous * fragment are already consuming 2 descriptors. */ sum = 1 - skb_shinfo(skb)->gso_size; /* Add size of frags 0 through 4 to create our initial sum */ sum += skb_frag_size(frag++); sum += skb_frag_size(frag++); sum += skb_frag_size(frag++); sum += skb_frag_size(frag++); sum += skb_frag_size(frag++); /* Walk through fragments adding latest fragment, testing it, and * then removing stale fragments from the sum. */ for (stale = &skb_shinfo(skb)->frags[0];; stale++) { int stale_size = skb_frag_size(stale); sum += skb_frag_size(frag++); /* The stale fragment may present us with a smaller * descriptor than the actual fragment size. To account * for that we need to remove all the data on the front and * figure out what the remainder would be in the last * descriptor associated with the fragment. */ if (stale_size > IAVF_MAX_DATA_PER_TXD) { int align_pad = -(skb_frag_off(stale)) & (IAVF_MAX_READ_REQ_SIZE - 1); sum -= align_pad; stale_size -= align_pad; do { sum -= IAVF_MAX_DATA_PER_TXD_ALIGNED; stale_size -= IAVF_MAX_DATA_PER_TXD_ALIGNED; } while (stale_size > IAVF_MAX_DATA_PER_TXD); } /* if sum is negative we failed to make sufficient progress */ if (sum < 0) return true; if (!nr_frags--) break; sum -= stale_size; } return false; } /** * __iavf_maybe_stop_tx - 2nd level check for tx stop conditions * @tx_ring: the ring to be checked * @size: the size buffer we want to assure is available * * Returns -EBUSY if a stop is needed, else 0 **/ int __iavf_maybe_stop_tx(struct iavf_ring *tx_ring, int size) { netif_stop_subqueue(tx_ring->netdev, tx_ring->queue_index); /* Memory barrier before checking head and tail */ smp_mb(); /* Check again in a case another CPU has just made room available. */ if (likely(IAVF_DESC_UNUSED(tx_ring) < size)) return -EBUSY; /* A reprieve! - use start_queue because it doesn't call schedule */ netif_start_subqueue(tx_ring->netdev, tx_ring->queue_index); ++tx_ring->tx_stats.restart_queue; return 0; } /** * iavf_tx_map - Build the Tx descriptor * @tx_ring: ring to send buffer on * @skb: send buffer * @first: first buffer info buffer to use * @tx_flags: collected send information * @hdr_len: size of the packet header * @td_cmd: the command field in the descriptor * @td_offset: offset for checksum or crc **/ static inline void iavf_tx_map(struct iavf_ring *tx_ring, struct sk_buff *skb, struct iavf_tx_buffer *first, u32 tx_flags, const u8 hdr_len, u32 td_cmd, u32 td_offset) { unsigned int data_len = skb->data_len; unsigned int size = skb_headlen(skb); skb_frag_t *frag; struct iavf_tx_buffer *tx_bi; struct iavf_tx_desc *tx_desc; u16 i = tx_ring->next_to_use; u32 td_tag = 0; dma_addr_t dma; if (tx_flags & IAVF_TX_FLAGS_HW_VLAN) { td_cmd |= IAVF_TX_DESC_CMD_IL2TAG1; td_tag = (tx_flags & IAVF_TX_FLAGS_VLAN_MASK) >> IAVF_TX_FLAGS_VLAN_SHIFT; } first->tx_flags = tx_flags; dma = dma_map_single(tx_ring->dev, skb->data, size, DMA_TO_DEVICE); tx_desc = IAVF_TX_DESC(tx_ring, i); tx_bi = first; for (frag = &skb_shinfo(skb)->frags[0];; frag++) { unsigned int max_data = IAVF_MAX_DATA_PER_TXD_ALIGNED; if (dma_mapping_error(tx_ring->dev, dma)) goto dma_error; /* record length, and DMA address */ dma_unmap_len_set(tx_bi, len, size); dma_unmap_addr_set(tx_bi, dma, dma); /* align size to end of page */ max_data += -dma & (IAVF_MAX_READ_REQ_SIZE - 1); tx_desc->buffer_addr = cpu_to_le64(dma); while (unlikely(size > IAVF_MAX_DATA_PER_TXD)) { tx_desc->cmd_type_offset_bsz = build_ctob(td_cmd, td_offset, max_data, td_tag); tx_desc++; i++; if (i == tx_ring->count) { tx_desc = IAVF_TX_DESC(tx_ring, 0); i = 0; } dma += max_data; size -= max_data; max_data = IAVF_MAX_DATA_PER_TXD_ALIGNED; tx_desc->buffer_addr = cpu_to_le64(dma); } if (likely(!data_len)) break; tx_desc->cmd_type_offset_bsz = build_ctob(td_cmd, td_offset, size, td_tag); tx_desc++; i++; if (i == tx_ring->count) { tx_desc = IAVF_TX_DESC(tx_ring, 0); i = 0; } size = skb_frag_size(frag); data_len -= size; dma = skb_frag_dma_map(tx_ring->dev, frag, 0, size, DMA_TO_DEVICE); tx_bi = &tx_ring->tx_bi[i]; } netdev_tx_sent_queue(txring_txq(tx_ring), first->bytecount); i++; if (i == tx_ring->count) i = 0; tx_ring->next_to_use = i; iavf_maybe_stop_tx(tx_ring, DESC_NEEDED); /* write last descriptor with RS and EOP bits */ td_cmd |= IAVF_TXD_CMD; tx_desc->cmd_type_offset_bsz = build_ctob(td_cmd, td_offset, size, td_tag); skb_tx_timestamp(skb); /* Force memory writes to complete before letting h/w know there * are new descriptors to fetch. * * We also use this memory barrier to make certain all of the * status bits have been updated before next_to_watch is written. */ wmb(); /* set next_to_watch value indicating a packet is present */ first->next_to_watch = tx_desc; /* notify HW of packet */ if (netif_xmit_stopped(txring_txq(tx_ring)) || !netdev_xmit_more()) { writel(i, tx_ring->tail); } return; dma_error: dev_info(tx_ring->dev, "TX DMA map failed\n"); /* clear dma mappings for failed tx_bi map */ for (;;) { tx_bi = &tx_ring->tx_bi[i]; iavf_unmap_and_free_tx_resource(tx_ring, tx_bi); if (tx_bi == first) break; if (i == 0) i = tx_ring->count; i--; } tx_ring->next_to_use = i; } /** * iavf_xmit_frame_ring - Sends buffer on Tx ring * @skb: send buffer * @tx_ring: ring to send buffer on * * Returns NETDEV_TX_OK if sent, else an error code **/ static netdev_tx_t iavf_xmit_frame_ring(struct sk_buff *skb, struct iavf_ring *tx_ring) { u64 cd_type_cmd_tso_mss = IAVF_TX_DESC_DTYPE_CONTEXT; u32 cd_tunneling = 0, cd_l2tag2 = 0; struct iavf_tx_buffer *first; u32 td_offset = 0; u32 tx_flags = 0; __be16 protocol; u32 td_cmd = 0; u8 hdr_len = 0; int tso, count; /* prefetch the data, we'll need it later */ prefetch(skb->data); iavf_trace(xmit_frame_ring, skb, tx_ring); count = iavf_xmit_descriptor_count(skb); if (iavf_chk_linearize(skb, count)) { if (__skb_linearize(skb)) { dev_kfree_skb_any(skb); return NETDEV_TX_OK; } count = iavf_txd_use_count(skb->len); tx_ring->tx_stats.tx_linearize++; } /* need: 1 descriptor per page * PAGE_SIZE/IAVF_MAX_DATA_PER_TXD, * + 1 desc for skb_head_len/IAVF_MAX_DATA_PER_TXD, * + 4 desc gap to avoid the cache line where head is, * + 1 desc for context descriptor, * otherwise try next time */ if (iavf_maybe_stop_tx(tx_ring, count + 4 + 1)) { tx_ring->tx_stats.tx_busy++; return NETDEV_TX_BUSY; } /* record the location of the first descriptor for this packet */ first = &tx_ring->tx_bi[tx_ring->next_to_use]; first->skb = skb; first->bytecount = skb->len; first->gso_segs = 1; /* prepare the xmit flags */ iavf_tx_prepare_vlan_flags(skb, tx_ring, &tx_flags); if (tx_flags & IAVF_TX_FLAGS_HW_OUTER_SINGLE_VLAN) { cd_type_cmd_tso_mss |= IAVF_TX_CTX_DESC_IL2TAG2 << IAVF_TXD_CTX_QW1_CMD_SHIFT; cd_l2tag2 = (tx_flags & IAVF_TX_FLAGS_VLAN_MASK) >> IAVF_TX_FLAGS_VLAN_SHIFT; } /* obtain protocol of skb */ protocol = vlan_get_protocol(skb); /* setup IPv4/IPv6 offloads */ if (protocol == htons(ETH_P_IP)) tx_flags |= IAVF_TX_FLAGS_IPV4; else if (protocol == htons(ETH_P_IPV6)) tx_flags |= IAVF_TX_FLAGS_IPV6; tso = iavf_tso(first, &hdr_len, &cd_type_cmd_tso_mss); if (tso < 0) goto out_drop; else if (tso) tx_flags |= IAVF_TX_FLAGS_TSO; /* Always offload the checksum, since it's in the data descriptor */ tso = iavf_tx_enable_csum(skb, &tx_flags, &td_cmd, &td_offset, tx_ring, &cd_tunneling); if (tso < 0) goto out_drop; /* always enable CRC insertion offload */ td_cmd |= IAVF_TX_DESC_CMD_ICRC; iavf_create_tx_ctx(tx_ring, cd_type_cmd_tso_mss, cd_tunneling, cd_l2tag2); iavf_tx_map(tx_ring, skb, first, tx_flags, hdr_len, td_cmd, td_offset); return NETDEV_TX_OK; out_drop: iavf_trace(xmit_frame_ring_drop, first->skb, tx_ring); dev_kfree_skb_any(first->skb); first->skb = NULL; return NETDEV_TX_OK; } /** * iavf_xmit_frame - Selects the correct VSI and Tx queue to send buffer * @skb: send buffer * @netdev: network interface device structure * * Returns NETDEV_TX_OK if sent, else an error code **/ netdev_tx_t iavf_xmit_frame(struct sk_buff *skb, struct net_device *netdev) { struct iavf_adapter *adapter = netdev_priv(netdev); struct iavf_ring *tx_ring = &adapter->tx_rings[skb->queue_mapping]; /* hardware can't handle really short frames, hardware padding works * beyond this point */ if (unlikely(skb->len < IAVF_MIN_TX_LEN)) { if (skb_pad(skb, IAVF_MIN_TX_LEN - skb->len)) return NETDEV_TX_OK; skb->len = IAVF_MIN_TX_LEN; skb_set_tail_pointer(skb, IAVF_MIN_TX_LEN); } return iavf_xmit_frame_ring(skb, tx_ring); }