From 8542db05dbc99f603889c349e5cf8f3f81cddbf5 Mon Sep 17 00:00:00 2001 From: Alexander Duyck Date: Fri, 26 Aug 2011 07:44:43 +0000 Subject: [PATCH] igb: Make first and tx_buffer_info->next_to_watch into pointers This change converts two tx_buffer_info index values into pointers. The advantage to this is that we reduce unnecessary computations and in the case of next_to_watch we get an added bonus of the value being able to provide additional information as a NULL value indicates it is unset versus a 0 not having any meaning for the index value. Signed-off-by: Alexander Duyck Tested-by: Aaron Brown Signed-off-by: Jeff Kirsher --- drivers/net/ethernet/intel/igb/igb.h | 2 +- drivers/net/ethernet/intel/igb/igb_main.c | 66 ++++++++++++----------- 2 files changed, 37 insertions(+), 31 deletions(-) diff --git a/drivers/net/ethernet/intel/igb/igb.h b/drivers/net/ethernet/intel/igb/igb.h index 56c68fc8bca..7185667bf26 100644 --- a/drivers/net/ethernet/intel/igb/igb.h +++ b/drivers/net/ethernet/intel/igb/igb.h @@ -133,7 +133,7 @@ struct vf_data_storage { /* wrapper around a pointer to a socket buffer, * so a DMA handle can be stored along with the buffer */ struct igb_tx_buffer { - u16 next_to_watch; + union e1000_adv_tx_desc *next_to_watch; unsigned long time_stamp; dma_addr_t dma; u32 length; diff --git a/drivers/net/ethernet/intel/igb/igb_main.c b/drivers/net/ethernet/intel/igb/igb_main.c index a0bb81d9ef1..edc2caeb6c1 100644 --- a/drivers/net/ethernet/intel/igb/igb_main.c +++ b/drivers/net/ethernet/intel/igb/igb_main.c @@ -381,7 +381,7 @@ static void igb_dump(struct igb_adapter *adapter) struct igb_tx_buffer *buffer_info; tx_ring = adapter->tx_ring[n]; buffer_info = &tx_ring->tx_buffer_info[tx_ring->next_to_clean]; - printk(KERN_INFO " %5d %5X %5X %016llX %04X %3X %016llX\n", + printk(KERN_INFO " %5d %5X %5X %016llX %04X %p %016llX\n", n, tx_ring->next_to_use, tx_ring->next_to_clean, (u64)buffer_info->dma, buffer_info->length, @@ -421,7 +421,7 @@ static void igb_dump(struct igb_adapter *adapter) buffer_info = &tx_ring->tx_buffer_info[i]; u0 = (struct my_u0 *)tx_desc; printk(KERN_INFO "T [0x%03X] %016llX %016llX %016llX" - " %04X %3X %016llX %p", i, + " %04X %p %016llX %p", i, le64_to_cpu(u0->a), le64_to_cpu(u0->b), (u64)buffer_info->dma, @@ -3161,7 +3161,7 @@ void igb_unmap_and_free_tx_resource(struct igb_ring *tx_ring, } buffer_info->time_stamp = 0; buffer_info->length = 0; - buffer_info->next_to_watch = 0; + buffer_info->next_to_watch = NULL; buffer_info->mapped_as_page = false; } @@ -4107,7 +4107,7 @@ static inline bool igb_tx_csum(struct igb_ring *tx_ring, #define IGB_MAX_DATA_PER_TXD (1<dev; @@ -4121,7 +4121,6 @@ static inline int igb_tx_map(struct igb_ring *tx_ring, struct sk_buff *skb, buffer_info = &tx_ring->tx_buffer_info[i]; BUG_ON(hlen >= IGB_MAX_DATA_PER_TXD); buffer_info->length = hlen; - buffer_info->next_to_watch = i; buffer_info->dma = dma_map_single(dev, skb->data, hlen, DMA_TO_DEVICE); if (dma_mapping_error(dev, buffer_info->dma)) @@ -4139,7 +4138,6 @@ static inline int igb_tx_map(struct igb_ring *tx_ring, struct sk_buff *skb, buffer_info = &tx_ring->tx_buffer_info[i]; BUG_ON(len >= IGB_MAX_DATA_PER_TXD); buffer_info->length = len; - buffer_info->next_to_watch = i; buffer_info->mapped_as_page = true; buffer_info->dma = skb_frag_dma_map(dev, frag, 0, len, DMA_TO_DEVICE); @@ -4153,8 +4151,12 @@ static inline int igb_tx_map(struct igb_ring *tx_ring, struct sk_buff *skb, /* multiply data chunks by size of headers */ buffer_info->bytecount = ((gso_segs - 1) * hlen) + skb->len; buffer_info->gso_segs = gso_segs; - tx_ring->tx_buffer_info[first].next_to_watch = i; - tx_ring->tx_buffer_info[first].time_stamp = jiffies; + + /* set the timestamp */ + first->time_stamp = jiffies; + + /* set next_to_watch value indicating a packet is present */ + first->next_to_watch = IGB_TX_DESC(tx_ring, i); return ++count; @@ -4165,7 +4167,6 @@ dma_error: buffer_info->dma = 0; buffer_info->time_stamp = 0; buffer_info->length = 0; - buffer_info->next_to_watch = 0; buffer_info->mapped_as_page = false; /* clear timestamp and dma mappings for remaining portion of packet */ @@ -4283,9 +4284,9 @@ static inline int igb_maybe_stop_tx(struct igb_ring *tx_ring, int size) netdev_tx_t igb_xmit_frame_ring(struct sk_buff *skb, struct igb_ring *tx_ring) { + struct igb_tx_buffer *first; int tso, count; u32 tx_flags = 0; - u16 first; u8 hdr_len = 0; /* need: 1 descriptor per page, @@ -4311,7 +4312,8 @@ netdev_tx_t igb_xmit_frame_ring(struct sk_buff *skb, if (skb->protocol == htons(ETH_P_IP)) tx_flags |= IGB_TX_FLAGS_IPV4; - first = tx_ring->next_to_use; + /* record the location of the first descriptor for this packet */ + first = &tx_ring->tx_buffer_info[tx_ring->next_to_use]; tso = igb_tso(tx_ring, skb, tx_flags, &hdr_len); @@ -4330,8 +4332,8 @@ netdev_tx_t igb_xmit_frame_ring(struct sk_buff *skb, count = igb_tx_map(tx_ring, skb, first); if (!count) { dev_kfree_skb_any(skb); - tx_ring->tx_buffer_info[first].time_stamp = 0; - tx_ring->next_to_use = first; + first->time_stamp = 0; + tx_ring->next_to_use = first - tx_ring->tx_buffer_info; return NETDEV_TX_OK; } @@ -5568,29 +5570,34 @@ static bool igb_clean_tx_irq(struct igb_q_vector *q_vector) struct igb_adapter *adapter = q_vector->adapter; struct igb_ring *tx_ring = q_vector->tx_ring; struct igb_tx_buffer *tx_buffer; - union e1000_adv_tx_desc *tx_desc; + union e1000_adv_tx_desc *tx_desc, *eop_desc; unsigned int total_bytes = 0, total_packets = 0; unsigned int budget = q_vector->tx_work_limit; - u16 i = tx_ring->next_to_clean; + unsigned int i = tx_ring->next_to_clean; if (test_bit(__IGB_DOWN, &adapter->state)) return true; tx_buffer = &tx_ring->tx_buffer_info[i]; tx_desc = IGB_TX_DESC(tx_ring, i); + i -= tx_ring->count; for (; budget; budget--) { - u16 eop = tx_buffer->next_to_watch; - union e1000_adv_tx_desc *eop_desc; + eop_desc = tx_buffer->next_to_watch; - eop_desc = IGB_TX_DESC(tx_ring, eop); + /* prevent any other reads prior to eop_desc */ + rmb(); + + /* if next_to_watch is not set then there is no work pending */ + if (!eop_desc) + break; /* if DD is not set pending work has not been completed */ if (!(eop_desc->wb.status & cpu_to_le32(E1000_TXD_STAT_DD))) break; - /* prevent any other reads prior to eop_desc being verified */ - rmb(); + /* clear next_to_watch to prevent false hangs */ + tx_buffer->next_to_watch = NULL; do { tx_desc->wb.status = 0; @@ -5607,14 +5614,15 @@ static bool igb_clean_tx_irq(struct igb_q_vector *q_vector) tx_buffer++; tx_desc++; i++; - if (unlikely(i == tx_ring->count)) { - i = 0; + if (unlikely(!i)) { + i -= tx_ring->count; tx_buffer = tx_ring->tx_buffer_info; tx_desc = IGB_TX_DESC(tx_ring, 0); } } while (eop_desc); } + i += tx_ring->count; tx_ring->next_to_clean = i; u64_stats_update_begin(&tx_ring->tx_syncp); tx_ring->tx_stats.bytes += total_bytes; @@ -5625,16 +5633,14 @@ static bool igb_clean_tx_irq(struct igb_q_vector *q_vector) if (tx_ring->detect_tx_hung) { struct e1000_hw *hw = &adapter->hw; - u16 eop = tx_ring->tx_buffer_info[i].next_to_watch; - union e1000_adv_tx_desc *eop_desc; - eop_desc = IGB_TX_DESC(tx_ring, eop); + eop_desc = tx_buffer->next_to_watch; /* Detect a transmit hang in hardware, this serializes the * check with the clearing of time_stamp and movement of i */ tx_ring->detect_tx_hung = false; - if (tx_ring->tx_buffer_info[i].time_stamp && - time_after(jiffies, tx_ring->tx_buffer_info[i].time_stamp + + if (eop_desc && + time_after(jiffies, tx_buffer->time_stamp + (adapter->tx_timeout_factor * HZ)) && !(rd32(E1000_STATUS) & E1000_STATUS_TXOFF)) { @@ -5648,7 +5654,7 @@ static bool igb_clean_tx_irq(struct igb_q_vector *q_vector) " next_to_clean <%x>\n" "buffer_info[next_to_clean]\n" " time_stamp <%lx>\n" - " next_to_watch <%x>\n" + " next_to_watch <%p>\n" " jiffies <%lx>\n" " desc.status <%x>\n", tx_ring->queue_index, @@ -5656,8 +5662,8 @@ static bool igb_clean_tx_irq(struct igb_q_vector *q_vector) readl(tx_ring->tail), tx_ring->next_to_use, tx_ring->next_to_clean, - tx_ring->tx_buffer_info[eop].time_stamp, - eop, + tx_buffer->time_stamp, + eop_desc, jiffies, eop_desc->wb.status); netif_stop_subqueue(tx_ring->netdev, -- 2.46.0