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path: root/drivers/net/ethernet/intel/i40evf/i40e_txrx.c
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Diffstat (limited to 'drivers/net/ethernet/intel/i40evf/i40e_txrx.c')
-rw-r--r--drivers/net/ethernet/intel/i40evf/i40e_txrx.c154
1 files changed, 86 insertions, 68 deletions
diff --git a/drivers/net/ethernet/intel/i40evf/i40e_txrx.c b/drivers/net/ethernet/intel/i40evf/i40e_txrx.c
index 75f2a2cdd738..c4b174afd253 100644
--- a/drivers/net/ethernet/intel/i40evf/i40e_txrx.c
+++ b/drivers/net/ethernet/intel/i40evf/i40e_txrx.c
@@ -150,7 +150,7 @@ u32 i40evf_get_tx_pending(struct i40e_ring *ring, bool in_sw)
return 0;
}
-#define WB_STRIDE 0x3
+#define WB_STRIDE 4
/**
* i40e_clean_tx_irq - Reclaim resources after transmit completes
@@ -266,7 +266,7 @@ static bool i40e_clean_tx_irq(struct i40e_vsi *vsi,
unsigned int j = i40evf_get_tx_pending(tx_ring, false);
if (budget &&
- ((j / (WB_STRIDE + 1)) == 0) && (j > 0) &&
+ ((j / WB_STRIDE) == 0) && (j > 0) &&
!test_bit(__I40E_DOWN, &vsi->state) &&
(I40E_DESC_UNUSED(tx_ring) != tx_ring->count))
tx_ring->arm_wb = true;
@@ -705,7 +705,6 @@ bool i40evf_alloc_rx_buffers(struct i40e_ring *rx_ring, u16 cleaned_count)
* because each write-back erases this info.
*/
rx_desc->read.pkt_addr = cpu_to_le64(bi->dma + bi->page_offset);
- rx_desc->read.hdr_addr = 0;
rx_desc++;
bi++;
@@ -1209,7 +1208,6 @@ static int i40e_clean_rx_irq(struct i40e_ring *rx_ring, int budget)
while (likely(total_rx_packets < budget)) {
union i40e_rx_desc *rx_desc;
struct sk_buff *skb;
- u32 rx_status;
u16 vlan_tag;
u8 rx_ptype;
u64 qword;
@@ -1223,21 +1221,13 @@ static int i40e_clean_rx_irq(struct i40e_ring *rx_ring, int budget)
rx_desc = I40E_RX_DESC(rx_ring, rx_ring->next_to_clean);
- qword = le64_to_cpu(rx_desc->wb.qword1.status_error_len);
- rx_ptype = (qword & I40E_RXD_QW1_PTYPE_MASK) >>
- I40E_RXD_QW1_PTYPE_SHIFT;
- rx_status = (qword & I40E_RXD_QW1_STATUS_MASK) >>
- I40E_RXD_QW1_STATUS_SHIFT;
-
- if (!(rx_status & BIT(I40E_RX_DESC_STATUS_DD_SHIFT)))
- break;
-
/* 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 it will be non-zero
*/
- if (!rx_desc->wb.qword1.status_error_len)
+ if (!i40e_test_staterr(rx_desc,
+ BIT(I40E_RX_DESC_STATUS_DD_SHIFT)))
break;
/* This memory barrier is needed to keep us from reading
@@ -1271,6 +1261,10 @@ static int i40e_clean_rx_irq(struct i40e_ring *rx_ring, int budget)
/* 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 & I40E_RXD_QW1_PTYPE_MASK) >>
+ I40E_RXD_QW1_PTYPE_SHIFT;
+
/* populate checksum, VLAN, and protocol */
i40evf_process_skb_fields(rx_ring, rx_desc, skb, rx_ptype);
@@ -1461,12 +1455,24 @@ int i40evf_napi_poll(struct napi_struct *napi, int budget)
/* If work not completed, return budget and polling will return */
if (!clean_complete) {
+ const cpumask_t *aff_mask = &q_vector->affinity_mask;
+ 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 (likely(cpumask_test_cpu(cpu_id, aff_mask))) {
tx_only:
- if (arm_wb) {
- q_vector->tx.ring[0].tx_stats.tx_force_wb++;
- i40e_enable_wb_on_itr(vsi, q_vector);
+ if (arm_wb) {
+ q_vector->tx.ring[0].tx_stats.tx_force_wb++;
+ i40e_enable_wb_on_itr(vsi, q_vector);
+ }
+ return budget;
}
- return budget;
}
if (vsi->back->flags & I40E_TXR_FLAGS_WB_ON_ITR)
@@ -1474,7 +1480,16 @@ tx_only:
/* Work is done so exit the polling mode and re-enable the interrupt */
napi_complete_done(napi, work_done);
- i40e_update_enable_itr(vsi, q_vector);
+
+ /* If we're prematurely stopping polling to fix the interrupt
+ * affinity we want to make sure polling starts back up so we
+ * issue a call to i40evf_force_wb which triggers a SW interrupt.
+ */
+ if (!clean_complete)
+ i40evf_force_wb(vsi, q_vector);
+ else
+ i40e_update_enable_itr(vsi, q_vector);
+
return 0;
}
@@ -1935,9 +1950,7 @@ static inline void i40evf_tx_map(struct i40e_ring *tx_ring, struct sk_buff *skb,
u32 td_tag = 0;
dma_addr_t dma;
u16 gso_segs;
- u16 desc_count = 0;
- bool tail_bump = true;
- bool do_rs = false;
+ u16 desc_count = 1;
if (tx_flags & I40E_TX_FLAGS_HW_VLAN) {
td_cmd |= I40E_TX_DESC_CMD_IL2TAG1;
@@ -2020,8 +2033,7 @@ static inline void i40evf_tx_map(struct i40e_ring *tx_ring, struct sk_buff *skb,
tx_bi = &tx_ring->tx_bi[i];
}
- /* set next_to_watch value indicating a packet is present */
- first->next_to_watch = tx_desc;
+ netdev_tx_sent_queue(txring_txq(tx_ring), first->bytecount);
i++;
if (i == tx_ring->count)
@@ -2029,66 +2041,72 @@ static inline void i40evf_tx_map(struct i40e_ring *tx_ring, struct sk_buff *skb,
tx_ring->next_to_use = i;
- netdev_tx_sent_queue(txring_txq(tx_ring), first->bytecount);
i40e_maybe_stop_tx(tx_ring, DESC_NEEDED);
+ /* write last descriptor with EOP bit */
+ td_cmd |= I40E_TX_DESC_CMD_EOP;
+
+ /* We can OR these values together as they both are checked against
+ * 4 below and at this point desc_count will be used as a boolean value
+ * after this if/else block.
+ */
+ desc_count |= ++tx_ring->packet_stride;
+
/* Algorithm to optimize tail and RS bit setting:
- * if xmit_more is supported
- * if xmit_more is true
- * do not update tail and do not mark RS bit.
- * if xmit_more is false and last xmit_more was false
- * if every packet spanned less than 4 desc
- * then set RS bit on 4th packet and update tail
- * on every packet
- * else
- * update tail and set RS bit on every packet.
- * if xmit_more is false and last_xmit_more was true
- * update tail and set RS bit.
+ * if queue is stopped
+ * mark RS bit
+ * reset packet counter
+ * else if xmit_more is supported and is true
+ * advance packet counter to 4
+ * reset desc_count to 0
*
- * Optimization: wmb to be issued only in case of tail update.
- * Also optimize the Descriptor WB path for RS bit with the same
- * algorithm.
+ * if desc_count >= 4
+ * mark RS bit
+ * reset packet counter
+ * if desc_count > 0
+ * update tail
*
- * Note: If there are less than 4 packets
+ * Note: If there are less than 4 descriptors
* pending and interrupts were disabled the service task will
* trigger a force WB.
*/
- if (skb->xmit_more &&
- !netif_xmit_stopped(txring_txq(tx_ring))) {
- tx_ring->flags |= I40E_TXR_FLAGS_LAST_XMIT_MORE_SET;
- tail_bump = false;
- } else if (!skb->xmit_more &&
- !netif_xmit_stopped(txring_txq(tx_ring)) &&
- (!(tx_ring->flags & I40E_TXR_FLAGS_LAST_XMIT_MORE_SET)) &&
- (tx_ring->packet_stride < WB_STRIDE) &&
- (desc_count < WB_STRIDE)) {
- tx_ring->packet_stride++;
- } else {
+ if (netif_xmit_stopped(txring_txq(tx_ring))) {
+ goto do_rs;
+ } else if (skb->xmit_more) {
+ /* set stride to arm on next packet and reset desc_count */
+ tx_ring->packet_stride = WB_STRIDE;
+ desc_count = 0;
+ } else if (desc_count >= WB_STRIDE) {
+do_rs:
+ /* write last descriptor with RS bit set */
+ td_cmd |= I40E_TX_DESC_CMD_RS;
tx_ring->packet_stride = 0;
- tx_ring->flags &= ~I40E_TXR_FLAGS_LAST_XMIT_MORE_SET;
- do_rs = true;
}
- if (do_rs)
- tx_ring->packet_stride = 0;
tx_desc->cmd_type_offset_bsz =
- build_ctob(td_cmd, td_offset, size, td_tag) |
- cpu_to_le64((u64)(do_rs ? I40E_TXD_CMD :
- I40E_TX_DESC_CMD_EOP) <<
- I40E_TXD_QW1_CMD_SHIFT);
+ build_ctob(td_cmd, td_offset, size, td_tag);
+
+ /* 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 (!tail_bump) {
- prefetchw(tx_desc + 1);
- } else {
- /* 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();
+ if (desc_count) {
writel(i, tx_ring->tail);
+
+ /* we need this if more than one processor can write to our tail
+ * at a time, it synchronizes IO on IA64/Altix systems
+ */
+ mmiowb();
}
+
return;
dma_error:
Copyright © 1996 – 2023 Jason A. Donenfeld. All Rights Reverse Engineered.