[PATCH net-next 0/6] ibmvnic: Update TX pool and TX routines

[PATCH net-next 0/6] ibmvnic: Update TX pool and TX routines

[Thomas Falcon]

This patch restructures the TX pool data structure and provides a
separate TX pool array for TSO transmissions. This is already used
in some way due to our unique DMA situation, namely that we cannot
use single DMA mappings for packet data. Previously, both buffer
arrays used the same pool entry. This restructuring allows for
some additional cleanup in the driver code, especially in some
places in the device transmit routine.

In addition, it allows us to more easily track the consumer
and producer indexes of a particular pool. This has been
further improved by better tracking of in-use buffers to
prevent possible data corruption in case an invalid buffer
entry is used.

Thomas Falcon (6):
  ibmvnic: Generalize TX pool structure
  ibmvnic: Update and clean up reset TX pool routine
  ibmvnic: Update release RX pool routine
  ibmvnic: Update TX pool initialization routine
  ibmvnic: Update TX and TX completion routines
  ibmvnic: Improve TX buffer accounting

 drivers/net/ethernet/ibm/ibmvnic.c | 235 +++++++++++++++++++++----------------
 drivers/net/ethernet/ibm/ibmvnic.h |   8 +-
 2 files changed, 136 insertions(+), 107 deletions(-)

-- 
1.8.3.1

[PATCH net-next 1/6] ibmvnic: Generalize TX pool structure

[Thomas Falcon]

Remove some unused fields in the structure and include values
describing the individual buffer size and number of buffers in
a TX pool. This allows us to use these fields for TX pool buffer
accounting as opposed to using hard coded values. Finally, split
TSO buffers out and provide an additional TX pool array for TSO.

Signed-off-by: Thomas Falcon <tlfalcon@linux.vnet.ibm.com>
---
 drivers/net/ethernet/ibm/ibmvnic.h | 7 +++----
 1 file changed, 3 insertions(+), 4 deletions(-)

diff --git a/drivers/net/ethernet/ibm/ibmvnic.h b/drivers/net/ethernet/ibm/ibmvnic.h
index 099c89d..a2e21b3 100644
--- a/drivers/net/ethernet/ibm/ibmvnic.h
+++ b/drivers/net/ethernet/ibm/ibmvnic.h
@@ -917,11 +917,9 @@ struct ibmvnic_tx_pool {
 	int *free_map;
 	int consumer_index;
 	int producer_index;
-	wait_queue_head_t ibmvnic_tx_comp_q;
-	struct task_struct *work_thread;
 	struct ibmvnic_long_term_buff long_term_buff;
-	struct ibmvnic_long_term_buff tso_ltb;
-	int tso_index;
+	int num_buffers;
+	int buf_size;
 };
 
 struct ibmvnic_rx_buff {
@@ -1044,6 +1042,7 @@ struct ibmvnic_adapter {
 	u64 promisc;
 
 	struct ibmvnic_tx_pool *tx_pool;
+	struct ibmvnic_tx_pool *tso_pool;
 	struct completion init_done;
 	int init_done_rc;
 
-- 
1.8.3.1

[PATCH net-next 2/6] ibmvnic: Update and clean up reset TX pool routine

[Thomas Falcon]

Update TX pool reset routine to accommodate new TSO pool array. Introduce
a function that resets one TX pool, and use that function to initialize
each pool in both pool arrays.

Signed-off-by: Thomas Falcon <tlfalcon@linux.vnet.ibm.com>
---
 drivers/net/ethernet/ibm/ibmvnic.c | 45 +++++++++++++++++++++-----------------
 1 file changed, 25 insertions(+), 20 deletions(-)

diff --git a/drivers/net/ethernet/ibm/ibmvnic.c b/drivers/net/ethernet/ibm/ibmvnic.c
index 6ff43d7..81a4cd9 100644
--- a/drivers/net/ethernet/ibm/ibmvnic.c
+++ b/drivers/net/ethernet/ibm/ibmvnic.c
@@ -557,36 +557,41 @@ static int init_rx_pools(struct net_device *netdev)
 	return 0;
 }
 
+static int reset_one_tx_pool(struct ibmvnic_adapter *adapter,
+			     struct ibmvnic_tx_pool *tx_pool)
+{
+	int rc, i;
+
+	rc = reset_long_term_buff(adapter, &tx_pool->long_term_buff);
+	if (rc)
+		return rc;
+
+	memset(tx_pool->tx_buff, 0,
+	       tx_pool->num_buffers *
+	       sizeof(struct ibmvnic_tx_buff));
+
+	for (i = 0; i < tx_pool->num_buffers; i++)
+		tx_pool->free_map[i] = i;
+
+	tx_pool->consumer_index = 0;
+	tx_pool->producer_index = 0;
+
+	return 0;
+}
+
 static int reset_tx_pools(struct ibmvnic_adapter *adapter)
 {
-	struct ibmvnic_tx_pool *tx_pool;
 	int tx_scrqs;
-	int i, j, rc;
+	int i, rc;
 
 	tx_scrqs = be32_to_cpu(adapter->login_rsp_buf->num_txsubm_subcrqs);
 	for (i = 0; i < tx_scrqs; i++) {
-		netdev_dbg(adapter->netdev, "Re-setting tx_pool[%d]\n", i);
-
-		tx_pool = &adapter->tx_pool[i];
-
-		rc = reset_long_term_buff(adapter, &tx_pool->long_term_buff);
+		rc = reset_one_tx_pool(adapter, &adapter->tso_pool[i]);
 		if (rc)
 			return rc;
-
-		rc = reset_long_term_buff(adapter, &tx_pool->tso_ltb);
+		rc = reset_one_tx_pool(adapter, &adapter->tx_pool[i]);
 		if (rc)
 			return rc;
-
-		memset(tx_pool->tx_buff, 0,
-		       adapter->req_tx_entries_per_subcrq *
-		       sizeof(struct ibmvnic_tx_buff));
-
-		for (j = 0; j < adapter->req_tx_entries_per_subcrq; j++)
-			tx_pool->free_map[j] = j;
-
-		tx_pool->consumer_index = 0;
-		tx_pool->producer_index = 0;
-		tx_pool->tso_index = 0;
 	}
 
 	return 0;
-- 
1.8.3.1

[PATCH net-next 3/6] ibmvnic: Update release RX pool routine

[Thomas Falcon]

Introduce function that frees one TX pool.  Use that to release
each pool in both the standard TX pool and TSO pool arrays.

Signed-off-by: Thomas Falcon <tlfalcon@linux.vnet.ibm.com>
---
 drivers/net/ethernet/ibm/ibmvnic.c | 19 ++++++++++++-------
 1 file changed, 12 insertions(+), 7 deletions(-)

diff --git a/drivers/net/ethernet/ibm/ibmvnic.c b/drivers/net/ethernet/ibm/ibmvnic.c
index 81a4cd9..e6e934e 100644
--- a/drivers/net/ethernet/ibm/ibmvnic.c
+++ b/drivers/net/ethernet/ibm/ibmvnic.c
@@ -608,25 +608,30 @@ static void release_vpd_data(struct ibmvnic_adapter *adapter)
 	adapter->vpd = NULL;
 }
 
+static void release_one_tx_pool(struct ibmvnic_adapter *adapter,
+				struct ibmvnic_tx_pool *tx_pool)
+{
+	kfree(tx_pool->tx_buff);
+	kfree(tx_pool->free_map);
+	free_long_term_buff(adapter, &tx_pool->long_term_buff);
+}
+
 static void release_tx_pools(struct ibmvnic_adapter *adapter)
 {
-	struct ibmvnic_tx_pool *tx_pool;
 	int i;
 
 	if (!adapter->tx_pool)
 		return;
 
 	for (i = 0; i < adapter->num_active_tx_pools; i++) {
-		netdev_dbg(adapter->netdev, "Releasing tx_pool[%d]\n", i);
-		tx_pool = &adapter->tx_pool[i];
-		kfree(tx_pool->tx_buff);
-		free_long_term_buff(adapter, &tx_pool->long_term_buff);
-		free_long_term_buff(adapter, &tx_pool->tso_ltb);
-		kfree(tx_pool->free_map);
+		release_one_tx_pool(adapter, &adapter->tx_pool[i]);
+		release_one_tx_pool(adapter, &adapter->tso_pool[i]);
 	}
 
 	kfree(adapter->tx_pool);
 	adapter->tx_pool = NULL;
+	kfree(adapter->tso_pool);
+	adapter->tso_pool = NULL;
 	adapter->num_active_tx_pools = 0;
 }
 
-- 
1.8.3.1

[PATCH net-next 4/6] ibmvnic: Update TX pool initialization routine

[Thomas Falcon]

Introduce function that initializes one TX pool. Use that to
create each pool entry in both the standard TX pool and TSO
pool arrays.

Signed-off-by: Thomas Falcon <tlfalcon@linux.vnet.ibm.com>
---
 drivers/net/ethernet/ibm/ibmvnic.c | 90 ++++++++++++++++++++------------------
 1 file changed, 48 insertions(+), 42 deletions(-)

diff --git a/drivers/net/ethernet/ibm/ibmvnic.c b/drivers/net/ethernet/ibm/ibmvnic.c
index e6e934e..cda5bf0 100644
--- a/drivers/net/ethernet/ibm/ibmvnic.c
+++ b/drivers/net/ethernet/ibm/ibmvnic.c
@@ -635,13 +635,43 @@ static void release_tx_pools(struct ibmvnic_adapter *adapter)
 	adapter->num_active_tx_pools = 0;
 }
 
+static int init_one_tx_pool(struct net_device *netdev,
+			    struct ibmvnic_tx_pool *tx_pool,
+			    int num_entries, int buf_size)
+{
+	struct ibmvnic_adapter *adapter = netdev_priv(netdev);
+	int i;
+
+	tx_pool->tx_buff = kcalloc(num_entries,
+				   sizeof(struct ibmvnic_tx_buff),
+				   GFP_KERNEL);
+	if (!tx_pool->tx_buff)
+		return -1;
+
+	if (alloc_long_term_buff(adapter, &tx_pool->long_term_buff,
+				 num_entries * buf_size))
+		return -1;
+
+	tx_pool->free_map = kcalloc(num_entries, sizeof(int), GFP_KERNEL);
+	if (!tx_pool->free_map)
+		return -1;
+
+	for (i = 0; i < num_entries; i++)
+		tx_pool->free_map[i] = i;
+
+	tx_pool->consumer_index = 0;
+	tx_pool->producer_index = 0;
+	tx_pool->num_buffers = num_entries;
+	tx_pool->buf_size = buf_size;
+
+	return 0;
+}
+
 static int init_tx_pools(struct net_device *netdev)
 {
 	struct ibmvnic_adapter *adapter = netdev_priv(netdev);
-	struct device *dev = &adapter->vdev->dev;
-	struct ibmvnic_tx_pool *tx_pool;
 	int tx_subcrqs;
-	int i, j;
+	int i, rc;
 
 	tx_subcrqs = be32_to_cpu(adapter->login_rsp_buf->num_txsubm_subcrqs);
 	adapter->tx_pool = kcalloc(tx_subcrqs,
@@ -649,53 +679,29 @@ static int init_tx_pools(struct net_device *netdev)
 	if (!adapter->tx_pool)
 		return -1;
 
+	adapter->tso_pool = kcalloc(tx_subcrqs,
+				    sizeof(struct ibmvnic_tx_pool), GFP_KERNEL);
+	if (!adapter->tso_pool)
+		return -1;
+
 	adapter->num_active_tx_pools = tx_subcrqs;
 
 	for (i = 0; i < tx_subcrqs; i++) {
-		tx_pool = &adapter->tx_pool[i];
-
-		netdev_dbg(adapter->netdev,
-			   "Initializing tx_pool[%d], %lld buffs\n",
-			   i, adapter->req_tx_entries_per_subcrq);
-
-		tx_pool->tx_buff = kcalloc(adapter->req_tx_entries_per_subcrq,
-					   sizeof(struct ibmvnic_tx_buff),
-					   GFP_KERNEL);
-		if (!tx_pool->tx_buff) {
-			dev_err(dev, "tx pool buffer allocation failed\n");
-			release_tx_pools(adapter);
-			return -1;
-		}
-
-		if (alloc_long_term_buff(adapter, &tx_pool->long_term_buff,
-					 adapter->req_tx_entries_per_subcrq *
-					 (adapter->req_mtu + VLAN_HLEN))) {
-			release_tx_pools(adapter);
-			return -1;
-		}
-
-		/* alloc TSO ltb */
-		if (alloc_long_term_buff(adapter, &tx_pool->tso_ltb,
-					 IBMVNIC_TSO_BUFS *
-					 IBMVNIC_TSO_BUF_SZ)) {
+		rc = init_one_tx_pool(netdev, &adapter->tx_pool[i],
+				      adapter->req_tx_entries_per_subcrq,
+				      adapter->req_mtu + VLAN_HLEN);
+		if (rc) {
 			release_tx_pools(adapter);
-			return -1;
+			return rc;
 		}
 
-		tx_pool->tso_index = 0;
-
-		tx_pool->free_map = kcalloc(adapter->req_tx_entries_per_subcrq,
-					    sizeof(int), GFP_KERNEL);
-		if (!tx_pool->free_map) {
+		init_one_tx_pool(netdev, &adapter->tso_pool[i],
+				 IBMVNIC_TSO_BUFS,
+				 IBMVNIC_TSO_BUF_SZ);
+		if (rc) {
 			release_tx_pools(adapter);
-			return -1;
+			return rc;
 		}
-
-		for (j = 0; j < adapter->req_tx_entries_per_subcrq; j++)
-			tx_pool->free_map[j] = j;
-
-		tx_pool->consumer_index = 0;
-		tx_pool->producer_index = 0;
 	}
 
 	return 0;
-- 
1.8.3.1

[PATCH net-next 5/6] ibmvnic: Update TX and TX completion routines

[Thomas Falcon]

Update TX and TX completion routines to account for TX pool
restructuring. TX routine first chooses the pool depending
on whether a packet is GSO or not, then uses it accordingly.

For the completion routine to know which pool it needs to use,
set the most significant bit of the correlator index to one
if the packet uses the TSO pool. On completion, unset the bit
and use the correlator index to release the buffer pool entry.

Signed-off-by: Thomas Falcon <tlfalcon@linux.vnet.ibm.com>
---
 drivers/net/ethernet/ibm/ibmvnic.c | 55 +++++++++++++++++++-------------------
 drivers/net/ethernet/ibm/ibmvnic.h |  1 +
 2 files changed, 29 insertions(+), 27 deletions(-)

diff --git a/drivers/net/ethernet/ibm/ibmvnic.c b/drivers/net/ethernet/ibm/ibmvnic.c
index cda5bf0..3b752e3 100644
--- a/drivers/net/ethernet/ibm/ibmvnic.c
+++ b/drivers/net/ethernet/ibm/ibmvnic.c
@@ -1414,8 +1414,11 @@ static int ibmvnic_xmit(struct sk_buff *skb, struct net_device *netdev)
 		ret = NETDEV_TX_OK;
 		goto out;
 	}
+	if (skb_is_gso(skb))
+		tx_pool = &adapter->tso_pool[queue_num];
+	else
+		tx_pool = &adapter->tx_pool[queue_num];
 
-	tx_pool = &adapter->tx_pool[queue_num];
 	tx_scrq = adapter->tx_scrq[queue_num];
 	txq = netdev_get_tx_queue(netdev, skb_get_queue_mapping(skb));
 	handle_array = (u64 *)((u8 *)(adapter->login_rsp_buf) +
@@ -1423,20 +1426,10 @@ static int ibmvnic_xmit(struct sk_buff *skb, struct net_device *netdev)
 
 	index = tx_pool->free_map[tx_pool->consumer_index];
 
-	if (skb_is_gso(skb)) {
-		offset = tx_pool->tso_index * IBMVNIC_TSO_BUF_SZ;
-		dst = tx_pool->tso_ltb.buff + offset;
-		memset(dst, 0, IBMVNIC_TSO_BUF_SZ);
-		data_dma_addr = tx_pool->tso_ltb.addr + offset;
-		tx_pool->tso_index++;
-		if (tx_pool->tso_index == IBMVNIC_TSO_BUFS)
-			tx_pool->tso_index = 0;
-	} else {
-		offset = index * (adapter->req_mtu + VLAN_HLEN);
-		dst = tx_pool->long_term_buff.buff + offset;
-		memset(dst, 0, adapter->req_mtu + VLAN_HLEN);
-		data_dma_addr = tx_pool->long_term_buff.addr + offset;
-	}
+	offset = index * tx_pool->buf_size;
+	dst = tx_pool->long_term_buff.buff + offset;
+	memset(dst, 0, tx_pool->buf_size);
+	data_dma_addr = tx_pool->long_term_buff.addr + offset;
 
 	if (skb_shinfo(skb)->nr_frags) {
 		int cur, i;
@@ -1459,8 +1452,7 @@ static int ibmvnic_xmit(struct sk_buff *skb, struct net_device *netdev)
 	}
 
 	tx_pool->consumer_index =
-	    (tx_pool->consumer_index + 1) %
-		adapter->req_tx_entries_per_subcrq;
+	    (tx_pool->consumer_index + 1) % tx_pool->num_buffers;
 
 	tx_buff = &tx_pool->tx_buff[index];
 	tx_buff->skb = skb;
@@ -1476,11 +1468,13 @@ static int ibmvnic_xmit(struct sk_buff *skb, struct net_device *netdev)
 	tx_crq.v1.n_crq_elem = 1;
 	tx_crq.v1.n_sge = 1;
 	tx_crq.v1.flags1 = IBMVNIC_TX_COMP_NEEDED;
-	tx_crq.v1.correlator = cpu_to_be32(index);
+
 	if (skb_is_gso(skb))
-		tx_crq.v1.dma_reg = cpu_to_be16(tx_pool->tso_ltb.map_id);
+		tx_crq.v1.correlator =
+			cpu_to_be32(index | IBMVNIC_TSO_POOL_MASK);
 	else
-		tx_crq.v1.dma_reg = cpu_to_be16(tx_pool->long_term_buff.map_id);
+		tx_crq.v1.correlator = cpu_to_be32(index);
+	tx_crq.v1.dma_reg = cpu_to_be16(tx_pool->long_term_buff.map_id);
 	tx_crq.v1.sge_len = cpu_to_be32(skb->len);
 	tx_crq.v1.ioba = cpu_to_be64(data_dma_addr);
 
@@ -1543,7 +1537,7 @@ static int ibmvnic_xmit(struct sk_buff *skb, struct net_device *netdev)
 
 		if (tx_pool->consumer_index == 0)
 			tx_pool->consumer_index =
-				adapter->req_tx_entries_per_subcrq - 1;
+				tx_pool->num_buffers - 1;
 		else
 			tx_pool->consumer_index--;
 
@@ -2545,6 +2539,7 @@ static int ibmvnic_complete_tx(struct ibmvnic_adapter *adapter,
 			       struct ibmvnic_sub_crq_queue *scrq)
 {
 	struct device *dev = &adapter->vdev->dev;
+	struct ibmvnic_tx_pool *tx_pool;
 	struct ibmvnic_tx_buff *txbuff;
 	union sub_crq *next;
 	int index;
@@ -2564,7 +2559,14 @@ static int ibmvnic_complete_tx(struct ibmvnic_adapter *adapter,
 				continue;
 			}
 			index = be32_to_cpu(next->tx_comp.correlators[i]);
-			txbuff = &adapter->tx_pool[pool].tx_buff[index];
+			if (index & IBMVNIC_TSO_POOL_MASK) {
+				tx_pool = &adapter->tso_pool[pool];
+				index &= ~IBMVNIC_TSO_POOL_MASK;
+			} else {
+				tx_pool = &adapter->tx_pool[pool];
+			}
+
+			txbuff = &tx_pool->tx_buff[index];
 
 			for (j = 0; j < IBMVNIC_MAX_FRAGS_PER_CRQ; j++) {
 				if (!txbuff->data_dma[j])
@@ -2587,11 +2589,10 @@ static int ibmvnic_complete_tx(struct ibmvnic_adapter *adapter,
 
 			num_entries += txbuff->num_entries;
 
-			adapter->tx_pool[pool].free_map[adapter->tx_pool[pool].
-						     producer_index] = index;
-			adapter->tx_pool[pool].producer_index =
-			    (adapter->tx_pool[pool].producer_index + 1) %
-			    adapter->req_tx_entries_per_subcrq;
+			tx_pool->free_map[tx_pool->producer_index] = index;
+			tx_pool->producer_index =
+				(tx_pool->producer_index + 1) %
+					tx_pool->num_buffers;
 		}
 		/* remove tx_comp scrq*/
 		next->tx_comp.first = 0;
diff --git a/drivers/net/ethernet/ibm/ibmvnic.h b/drivers/net/ethernet/ibm/ibmvnic.h
index a2e21b3..89efe70 100644
--- a/drivers/net/ethernet/ibm/ibmvnic.h
+++ b/drivers/net/ethernet/ibm/ibmvnic.h
@@ -43,6 +43,7 @@
 
 #define IBMVNIC_TSO_BUF_SZ	65536
 #define IBMVNIC_TSO_BUFS	64
+#define IBMVNIC_TSO_POOL_MASK	0x80000000
 
 #define IBMVNIC_MAX_LTB_SIZE ((1 << (MAX_ORDER - 1)) * PAGE_SIZE)
 #define IBMVNIC_BUFFER_HLEN 500
-- 
1.8.3.1

[PATCH net-next 6/6] ibmvnic: Improve TX buffer accounting

[Thomas Falcon]

Improve TX pool buffer accounting to prevent the producer
index from overruning the consumer. First, set the next free
index to an invalid value if it is in use. If next buffer
to be consumed is in use, drop the packet.

Finally, if the transmit fails for some other reason, roll
back the consumer index and set the free map entry to its original
value. This should also be done if the DMA map fails.

Signed-off-by: Thomas Falcon <tlfalcon@linux.vnet.ibm.com>
---
 drivers/net/ethernet/ibm/ibmvnic.c | 30 +++++++++++++++++++++---------
 1 file changed, 21 insertions(+), 9 deletions(-)

diff --git a/drivers/net/ethernet/ibm/ibmvnic.c b/drivers/net/ethernet/ibm/ibmvnic.c
index 3b752e3..f599dad 100644
--- a/drivers/net/ethernet/ibm/ibmvnic.c
+++ b/drivers/net/ethernet/ibm/ibmvnic.c
@@ -1426,6 +1426,16 @@ static int ibmvnic_xmit(struct sk_buff *skb, struct net_device *netdev)
 
 	index = tx_pool->free_map[tx_pool->consumer_index];
 
+	if (index == IBMVNIC_INVALID_MAP) {
+		dev_kfree_skb_any(skb);
+		tx_send_failed++;
+		tx_dropped++;
+		ret = NETDEV_TX_OK;
+		goto out;
+	}
+
+	tx_pool->free_map[tx_pool->consumer_index] = IBMVNIC_INVALID_MAP;
+
 	offset = index * tx_pool->buf_size;
 	dst = tx_pool->long_term_buff.buff + offset;
 	memset(dst, 0, tx_pool->buf_size);
@@ -1522,7 +1532,7 @@ static int ibmvnic_xmit(struct sk_buff *skb, struct net_device *netdev)
 			tx_map_failed++;
 			tx_dropped++;
 			ret = NETDEV_TX_OK;
-			goto out;
+			goto tx_err_out;
 		}
 		lpar_rc = send_subcrq_indirect(adapter, handle_array[queue_num],
 					       (u64)tx_buff->indir_dma,
@@ -1534,13 +1544,6 @@ static int ibmvnic_xmit(struct sk_buff *skb, struct net_device *netdev)
 	}
 	if (lpar_rc != H_SUCCESS) {
 		dev_err(dev, "tx failed with code %ld\n", lpar_rc);
-
-		if (tx_pool->consumer_index == 0)
-			tx_pool->consumer_index =
-				tx_pool->num_buffers - 1;
-		else
-			tx_pool->consumer_index--;
-
 		dev_kfree_skb_any(skb);
 		tx_buff->skb = NULL;
 
@@ -1556,7 +1559,7 @@ static int ibmvnic_xmit(struct sk_buff *skb, struct net_device *netdev)
 		tx_send_failed++;
 		tx_dropped++;
 		ret = NETDEV_TX_OK;
-		goto out;
+		goto tx_err_out;
 	}
 
 	if (atomic_add_return(num_entries, &tx_scrq->used)
@@ -1569,7 +1572,16 @@ static int ibmvnic_xmit(struct sk_buff *skb, struct net_device *netdev)
 	tx_bytes += skb->len;
 	txq->trans_start = jiffies;
 	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;
 out:
 	netdev->stats.tx_dropped += tx_dropped;
 	netdev->stats.tx_bytes += tx_bytes;
-- 
1.8.3.1

Re: [PATCH net-next 0/6] ibmvnic: Update TX pool and TX routines

[David Miller]

From: Thomas Falcon <tlfalcon@linux.vnet.ibm.com>
Date: Tue, 13 Mar 2018 19:34:17 -0500

> This patch restructures the TX pool data structure and provides a
> separate TX pool array for TSO transmissions. This is already used
> in some way due to our unique DMA situation, namely that we cannot
> use single DMA mappings for packet data. Previously, both buffer
> arrays used the same pool entry. This restructuring allows for
> some additional cleanup in the driver code, especially in some
> places in the device transmit routine.
> 
> In addition, it allows us to more easily track the consumer
> and producer indexes of a particular pool. This has been
> further improved by better tracking of in-use buffers to
> prevent possible data corruption in case an invalid buffer
> entry is used.
 ...
>   ibmvnic: Update release RX pool routine

I think you need to fix up this Subject line to say TX instead
of RX.

Thanks.

Re: [PATCH net-next 0/6] ibmvnic: Update TX pool and TX routines

[Thomas Falcon]

On 03/14/2018 01:03 PM, David Miller wrote:
> From: Thomas Falcon <tlfalcon@linux.vnet.ibm.com>
> Date: Tue, 13 Mar 2018 19:34:17 -0500
>
>> This patch restructures the TX pool data structure and provides a
>> separate TX pool array for TSO transmissions. This is already used
>> in some way due to our unique DMA situation, namely that we cannot
>> use single DMA mappings for packet data. Previously, both buffer
>> arrays used the same pool entry. This restructuring allows for
>> some additional cleanup in the driver code, especially in some
>> places in the device transmit routine.
>>
>> In addition, it allows us to more easily track the consumer
>> and producer indexes of a particular pool. This has been
>> further improved by better tracking of in-use buffers to
>> prevent possible data corruption in case an invalid buffer
>> entry is used.
>  ...
>>   ibmvnic: Update release RX pool routine
> I think you need to fix up this Subject line to say TX instead
> of RX.
>
> Thanks.
>
Drat, I missed that.  I'll send another version shortly. Thanks.