[PATCH net-next 04/12] ibmvnic: Introduce xmit_more support using batched subCRQ hcalls
Thomas Falcon
tlfalcon at linux.ibm.com
Fri Nov 13 06:09:59 AEDT 2020
Include support for the xmit_more feature utilizing the
H_SEND_SUB_CRQ_INDIRECT hypervisor call which allows the sending
of multiple subordinate Command Response Queue descriptors in one
hypervisor call via a DMA-mapped buffer. This update reduces hypervisor
calls and thus hypervisor call overhead per TX descriptor.
Signed-off-by: Thomas Falcon <tlfalcon at linux.ibm.com>
---
drivers/net/ethernet/ibm/ibmvnic.c | 151 +++++++++++++++++------------
1 file changed, 91 insertions(+), 60 deletions(-)
diff --git a/drivers/net/ethernet/ibm/ibmvnic.c b/drivers/net/ethernet/ibm/ibmvnic.c
index 524020691ef8..0f6aba760d65 100644
--- a/drivers/net/ethernet/ibm/ibmvnic.c
+++ b/drivers/net/ethernet/ibm/ibmvnic.c
@@ -1165,6 +1165,7 @@ static int __ibmvnic_open(struct net_device *netdev)
if (prev_state == VNIC_CLOSED)
enable_irq(adapter->tx_scrq[i]->irq);
enable_scrq_irq(adapter, adapter->tx_scrq[i]);
+ netdev_tx_reset_queue(netdev_get_tx_queue(netdev, i));
}
rc = set_link_state(adapter, IBMVNIC_LOGICAL_LNK_UP);
@@ -1529,10 +1530,12 @@ static netdev_tx_t ibmvnic_xmit(struct sk_buff *skb, struct net_device *netdev)
int queue_num = skb_get_queue_mapping(skb);
u8 *hdrs = (u8 *)&adapter->tx_rx_desc_req;
struct device *dev = &adapter->vdev->dev;
+ struct ibmvnic_ind_xmit_queue *ind_bufp;
struct ibmvnic_tx_buff *tx_buff = NULL;
struct ibmvnic_sub_crq_queue *tx_scrq;
struct ibmvnic_tx_pool *tx_pool;
unsigned int tx_send_failed = 0;
+ netdev_tx_t ret = NETDEV_TX_OK;
unsigned int tx_map_failed = 0;
unsigned int tx_dropped = 0;
unsigned int tx_packets = 0;
@@ -1547,7 +1550,7 @@ static netdev_tx_t ibmvnic_xmit(struct sk_buff *skb, struct net_device *netdev)
int index = 0;
u8 proto = 0;
u64 handle;
- netdev_tx_t ret = NETDEV_TX_OK;
+ int i;
if (test_bit(0, &adapter->resetting)) {
if (!netif_subqueue_stopped(netdev, skb))
@@ -1666,55 +1669,37 @@ static netdev_tx_t ibmvnic_xmit(struct sk_buff *skb, struct net_device *netdev)
tx_crq.v1.mss = cpu_to_be16(skb_shinfo(skb)->gso_size);
hdrs += 2;
}
- /* determine if l2/3/4 headers are sent to firmware */
- if ((*hdrs >> 7) & 1) {
+
+ if ((*hdrs >> 7) & 1)
build_hdr_descs_arr(tx_buff, &num_entries, *hdrs);
- tx_crq.v1.n_crq_elem = num_entries;
- tx_buff->num_entries = num_entries;
- tx_buff->indir_arr[0] = tx_crq;
- tx_buff->indir_dma = dma_map_single(dev, tx_buff->indir_arr,
- sizeof(tx_buff->indir_arr),
- DMA_TO_DEVICE);
- if (dma_mapping_error(dev, tx_buff->indir_dma)) {
- dev_kfree_skb_any(skb);
- tx_buff->skb = NULL;
- if (!firmware_has_feature(FW_FEATURE_CMO))
- dev_err(dev, "tx: unable to map descriptor array\n");
- tx_map_failed++;
- tx_dropped++;
- ret = NETDEV_TX_OK;
- goto tx_err_out;
- }
- lpar_rc = send_subcrq_indirect(adapter, handle,
- (u64)tx_buff->indir_dma,
- (u64)num_entries);
- dma_unmap_single(dev, tx_buff->indir_dma,
- sizeof(tx_buff->indir_arr), DMA_TO_DEVICE);
- } else {
- tx_buff->num_entries = num_entries;
- lpar_rc = send_subcrq(adapter, handle,
- &tx_crq);
- }
- if (lpar_rc != H_SUCCESS) {
- if (lpar_rc != H_CLOSED && lpar_rc != H_PARAMETER)
- dev_err_ratelimited(dev, "tx: send failed\n");
- dev_kfree_skb_any(skb);
- tx_buff->skb = NULL;
- if (lpar_rc == H_CLOSED || adapter->failover_pending) {
- /* Disable TX and report carrier off if queue is closed
- * or pending failover.
- * Firmware guarantees that a signal will be sent to the
- * driver, triggering a reset or some other action.
- */
- netif_tx_stop_all_queues(netdev);
- netif_carrier_off(netdev);
- }
+ netdev_tx_sent_queue(txq, skb->len);
- tx_send_failed++;
- tx_dropped++;
- ret = NETDEV_TX_OK;
- goto tx_err_out;
+ tx_crq.v1.n_crq_elem = num_entries;
+ tx_buff->num_entries = num_entries;
+ ind_bufp = &tx_scrq->ind_buf;
+ /* flush buffer if current entry can not fit */
+ if (num_entries + ind_bufp->index > IBMVNIC_MAX_IND_DESCS) {
+ lpar_rc = send_subcrq_indirect(adapter, handle,
+ (u64)ind_bufp->indir_dma,
+ (u64)ind_bufp->index);
+ if (lpar_rc != H_SUCCESS)
+ goto tx_flush_err;
+ ind_bufp->index = 0;
+ }
+
+ tx_buff->indir_arr[0] = tx_crq;
+ memcpy(&ind_bufp->indir_arr[ind_bufp->index], tx_buff->indir_arr,
+ num_entries * sizeof(struct ibmvnic_generic_scrq));
+ ind_bufp->index += num_entries;
+ if (!netdev_xmit_more() || netif_xmit_stopped(txq) ||
+ ind_bufp->index == IBMVNIC_MAX_IND_DESCS) {
+ lpar_rc = send_subcrq_indirect(adapter, handle,
+ (u64)ind_bufp->indir_dma,
+ (u64)ind_bufp->index);
+ ind_bufp->index = 0;
+ if (lpar_rc != H_SUCCESS)
+ goto tx_err;
}
if (atomic_add_return(num_entries, &tx_scrq->used)
@@ -1729,14 +1714,51 @@ static netdev_tx_t ibmvnic_xmit(struct sk_buff *skb, struct net_device *netdev)
ret = NETDEV_TX_OK;
goto out;
-tx_err_out:
- /* roll back consumer index and map array*/
- if (tx_pool->consumer_index == 0)
- tx_pool->consumer_index =
- tx_pool->num_buffers - 1;
- else
- tx_pool->consumer_index--;
- tx_pool->free_map[tx_pool->consumer_index] = index;
+tx_flush_err:
+ dev_kfree_skb_any(skb);
+ tx_buff->skb = NULL;
+ tx_pool->consumer_index = tx_pool->consumer_index == 0 ?
+ tx_pool->num_buffers - 1 :
+ tx_pool->consumer_index - 1;
+ tx_dropped++;
+tx_err:
+ if (lpar_rc != H_CLOSED && lpar_rc != H_PARAMETER)
+ dev_err_ratelimited(dev, "tx: send failed\n");
+ for (i = ind_bufp->index - 1; i >= 0; --i) {
+ tx_crq = ind_bufp->indir_arr[i];
+ if (tx_crq.v1.type != IBMVNIC_TX_DESC)
+ continue;
+ index = be32_to_cpu(tx_crq.v1.correlator);
+ if (index & IBMVNIC_TSO_POOL_MASK) {
+ tx_pool = &adapter->tso_pool[queue_num];
+ index &= ~IBMVNIC_TSO_POOL_MASK;
+ } else {
+ tx_pool = &adapter->tx_pool[queue_num];
+ }
+ tx_pool->free_map[tx_pool->consumer_index] = index;
+ tx_pool->consumer_index = tx_pool->consumer_index == 0 ?
+ tx_pool->num_buffers - 1 :
+ tx_pool->consumer_index - 1;
+ tx_buff = &tx_pool->tx_buff[index];
+ netdev->stats.tx_packets--;
+ netdev->stats.tx_bytes -= tx_buff->skb->len;
+ adapter->tx_stats_buffers[queue_num].packets--;
+ adapter->tx_stats_buffers[queue_num].bytes -= tx_buff->skb->len;
+ dev_kfree_skb_any(tx_buff->skb);
+ tx_buff->skb = NULL;
+ tx_dropped++;
+ }
+ ind_bufp->index = 0;
+
+ if (lpar_rc == H_CLOSED || adapter->failover_pending) {
+ /* Disable TX and report carrier off if queue is closed
+ * or pending failover.
+ * Firmware guarantees that a signal will be sent to the
+ * driver, triggering a reset or some other action.
+ */
+ netif_tx_stop_all_queues(netdev);
+ netif_carrier_off(netdev);
+ }
out:
netdev->stats.tx_dropped += tx_dropped;
netdev->stats.tx_bytes += tx_bytes;
@@ -3115,6 +3137,7 @@ static int ibmvnic_complete_tx(struct ibmvnic_adapter *adapter,
struct device *dev = &adapter->vdev->dev;
struct ibmvnic_tx_pool *tx_pool;
struct ibmvnic_tx_buff *txbuff;
+ struct netdev_queue *txq;
union sub_crq *next;
int index;
int i, j;
@@ -3123,6 +3146,8 @@ static int ibmvnic_complete_tx(struct ibmvnic_adapter *adapter,
while (pending_scrq(adapter, scrq)) {
unsigned int pool = scrq->pool_index;
int num_entries = 0;
+ int total_bytes = 0;
+ int num_packets = 0;
next = ibmvnic_next_scrq(adapter, scrq);
/* ensure that we are reading the correct queue entry */
@@ -3150,13 +3175,16 @@ static int ibmvnic_complete_tx(struct ibmvnic_adapter *adapter,
txbuff->data_dma[j] = 0;
}
- if (txbuff->last_frag) {
- dev_kfree_skb_any(txbuff->skb);
+ num_packets++;
+ num_entries += txbuff->num_entries;
+ if (txbuff->skb) {
+ total_bytes += txbuff->skb->len;
+ dev_consume_skb_irq(txbuff->skb);
txbuff->skb = NULL;
+ } else {
+ netdev_warn(adapter->netdev,
+ "TX completion received with NULL socket buffer\n");
}
-
- num_entries += txbuff->num_entries;
-
tx_pool->free_map[tx_pool->producer_index] = index;
tx_pool->producer_index =
(tx_pool->producer_index + 1) %
@@ -3165,6 +3193,9 @@ static int ibmvnic_complete_tx(struct ibmvnic_adapter *adapter,
/* remove tx_comp scrq*/
next->tx_comp.first = 0;
+ txq = netdev_get_tx_queue(adapter->netdev, scrq->pool_index);
+ netdev_tx_completed_queue(txq, num_packets, total_bytes);
+
if (atomic_sub_return(num_entries, &scrq->used) <=
(adapter->req_tx_entries_per_subcrq / 2) &&
__netif_subqueue_stopped(adapter->netdev,
--
2.26.2
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