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Message-Id: <1438880430-5480-3-git-send-email-mw@semihalf.com>
Date: Thu, 6 Aug 2015 19:00:29 +0200
From: Marcin Wojtas <mw@...ihalf.com>
To: linux-arm-kernel@...ts.infradead.org, netdev@...r.kernel.org
Cc: davem@...emloft.net, jason@...edaemon.net,
thomas.petazzoni@...e-electrons.com,
gregory.clement@...e-electrons.com,
ezequiel.garcia@...e-electrons.com, alior@...vell.com,
jaz@...ihalf.com, Marcin Wojtas <mw@...ihalf.com>
Subject: [PATCH 2/3] net: mvpp2: enable proper per-CPU TX buffers unmapping
mvpp2 driver allows usage of per-CPU TX processing. Once the packets are
prepared independetly on each CPU, the hardware enqueues the descriptors in
common TX queue. After they are sent, the buffers and associated sk_buffs
should be released on the corresponding CPU.
This is why a special index is maintained in order to point to the right data to
be released after transmission takes place. Each per-CPU TX queue comprise an
array of sent sk_buffs, freed in mvpp2_txq_bufs_free function. However, the
index was used there also for obtaining a descriptor (and therefore a buffer to
be DMA-unmapped) from common TX queue, which was wrong, because it was not
referring to the current CPU.
This commit enables proper unmapping of sent data buffers by indexing them in
per-CPU queues using a dedicated array for keeping their physical addresses.
Signed-off-by: Marcin Wojtas <mw@...ihalf.com>
---
drivers/net/ethernet/marvell/mvpp2.c | 52 +++++++++++++++++++++++++-----------
1 file changed, 37 insertions(+), 15 deletions(-)
diff --git a/drivers/net/ethernet/marvell/mvpp2.c b/drivers/net/ethernet/marvell/mvpp2.c
index f94bd12..3e25d314 100644
--- a/drivers/net/ethernet/marvell/mvpp2.c
+++ b/drivers/net/ethernet/marvell/mvpp2.c
@@ -776,6 +776,9 @@ struct mvpp2_txq_pcpu {
/* Array of transmitted skb */
struct sk_buff **tx_skb;
+ /* Array of transmitted buffers' physical addresses */
+ dma_addr_t *tx_buffs;
+
/* Index of last TX DMA descriptor that was inserted */
int txq_put_index;
@@ -961,9 +964,13 @@ static void mvpp2_txq_inc_get(struct mvpp2_txq_pcpu *txq_pcpu)
}
static void mvpp2_txq_inc_put(struct mvpp2_txq_pcpu *txq_pcpu,
- struct sk_buff *skb)
+ struct sk_buff *skb,
+ struct mvpp2_tx_desc *tx_desc)
{
txq_pcpu->tx_skb[txq_pcpu->txq_put_index] = skb;
+ if (skb)
+ txq_pcpu->tx_buffs[txq_pcpu->txq_put_index] =
+ tx_desc->buf_phys_addr;
txq_pcpu->txq_put_index++;
if (txq_pcpu->txq_put_index == txq_pcpu->size)
txq_pcpu->txq_put_index = 0;
@@ -4392,8 +4399,8 @@ static void mvpp2_txq_bufs_free(struct mvpp2_port *port,
int i;
for (i = 0; i < num; i++) {
- struct mvpp2_tx_desc *tx_desc = txq->descs +
- txq_pcpu->txq_get_index;
+ dma_addr_t buf_phys_addr =
+ txq_pcpu->tx_buffs[txq_pcpu->txq_get_index];
struct sk_buff *skb = txq_pcpu->tx_skb[txq_pcpu->txq_get_index];
mvpp2_txq_inc_get(txq_pcpu);
@@ -4401,8 +4408,8 @@ static void mvpp2_txq_bufs_free(struct mvpp2_port *port,
if (!skb)
continue;
- dma_unmap_single(port->dev->dev.parent, tx_desc->buf_phys_addr,
- tx_desc->data_size, DMA_TO_DEVICE);
+ dma_unmap_single(port->dev->dev.parent, buf_phys_addr,
+ skb_headlen(skb), DMA_TO_DEVICE);
dev_kfree_skb_any(skb);
}
}
@@ -4634,12 +4641,13 @@ static int mvpp2_txq_init(struct mvpp2_port *port,
txq_pcpu->tx_skb = kmalloc(txq_pcpu->size *
sizeof(*txq_pcpu->tx_skb),
GFP_KERNEL);
- if (!txq_pcpu->tx_skb) {
- dma_free_coherent(port->dev->dev.parent,
- txq->size * MVPP2_DESC_ALIGNED_SIZE,
- txq->descs, txq->descs_phys);
- return -ENOMEM;
- }
+ if (!txq_pcpu->tx_skb)
+ goto error;
+
+ txq_pcpu->tx_buffs = kmalloc(txq_pcpu->size *
+ sizeof(dma_addr_t), GFP_KERNEL);
+ if (!txq_pcpu->tx_buffs)
+ goto error;
txq_pcpu->count = 0;
txq_pcpu->reserved_num = 0;
@@ -4648,6 +4656,19 @@ static int mvpp2_txq_init(struct mvpp2_port *port,
}
return 0;
+
+error:
+ for_each_present_cpu(cpu) {
+ txq_pcpu = per_cpu_ptr(txq->pcpu, cpu);
+ kfree(txq_pcpu->tx_skb);
+ kfree(txq_pcpu->tx_buffs);
+ }
+
+ dma_free_coherent(port->dev->dev.parent,
+ txq->size * MVPP2_DESC_ALIGNED_SIZE,
+ txq->descs, txq->descs_phys);
+
+ return -ENOMEM;
}
/* Free allocated TXQ resources */
@@ -4660,6 +4681,7 @@ static void mvpp2_txq_deinit(struct mvpp2_port *port,
for_each_present_cpu(cpu) {
txq_pcpu = per_cpu_ptr(txq->pcpu, cpu);
kfree(txq_pcpu->tx_skb);
+ kfree(txq_pcpu->tx_buffs);
}
if (txq->descs)
@@ -5129,11 +5151,11 @@ static int mvpp2_tx_frag_process(struct mvpp2_port *port, struct sk_buff *skb,
if (i == (skb_shinfo(skb)->nr_frags - 1)) {
/* Last descriptor */
tx_desc->command = MVPP2_TXD_L_DESC;
- mvpp2_txq_inc_put(txq_pcpu, skb);
+ mvpp2_txq_inc_put(txq_pcpu, skb, tx_desc);
} else {
/* Descriptor in the middle: Not First, Not Last */
tx_desc->command = 0;
- mvpp2_txq_inc_put(txq_pcpu, NULL);
+ mvpp2_txq_inc_put(txq_pcpu, NULL, tx_desc);
}
}
@@ -5199,12 +5221,12 @@ static int mvpp2_tx(struct sk_buff *skb, struct net_device *dev)
/* First and Last descriptor */
tx_cmd |= MVPP2_TXD_F_DESC | MVPP2_TXD_L_DESC;
tx_desc->command = tx_cmd;
- mvpp2_txq_inc_put(txq_pcpu, skb);
+ mvpp2_txq_inc_put(txq_pcpu, skb, tx_desc);
} else {
/* First but not Last */
tx_cmd |= MVPP2_TXD_F_DESC | MVPP2_TXD_PADDING_DISABLE;
tx_desc->command = tx_cmd;
- mvpp2_txq_inc_put(txq_pcpu, NULL);
+ mvpp2_txq_inc_put(txq_pcpu, NULL, tx_desc);
/* Continue with other skb fragments */
if (mvpp2_tx_frag_process(port, skb, aggr_txq, txq)) {
--
1.8.3.1
--
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