On 08 Dec 06:40, Gerhard Engleder wrote:
Implement ndo_xdp_xmit() for XDP TX support. Support for fragmented XDP
frames is included.
Signed-off-by: Gerhard Engleder <gerhard@xxxxxxxxxxxxxxxxxxxxx>
---
drivers/net/ethernet/engleder/tsnep.h | 12 +-
drivers/net/ethernet/engleder/tsnep_main.c | 204 ++++++++++++++++++++-
2 files changed, 207 insertions(+), 9 deletions(-)
diff --git a/drivers/net/ethernet/engleder/tsnep.h b/drivers/net/ethernet/engleder/tsnep.h
index f72c0c4da1a9..29b04127f529 100644
--- a/drivers/net/ethernet/engleder/tsnep.h
+++ b/drivers/net/ethernet/engleder/tsnep.h
@@ -57,6 +57,12 @@ struct tsnep_rxnfc_rule {
int location;
};
+enum tsnep_tx_type {
+ TSNEP_TX_TYPE_SKB,
+ TSNEP_TX_TYPE_XDP_TX,
+ TSNEP_TX_TYPE_XDP_NDO,
+};
+
struct tsnep_tx_entry {
struct tsnep_tx_desc *desc;
struct tsnep_tx_desc_wb *desc_wb;
@@ -65,7 +71,11 @@ struct tsnep_tx_entry {
u32 properties;
- struct sk_buff *skb;
+ enum tsnep_tx_type type;
+ union {
+ struct sk_buff *skb;
+ struct xdp_frame *xdpf;
+ };
size_t len;
DEFINE_DMA_UNMAP_ADDR(dma);
};
diff --git a/drivers/net/ethernet/engleder/tsnep_main.c b/drivers/net/ethernet/engleder/tsnep_main.c
index a28fde9fb060..b97cfd5fa1fa 100644
--- a/drivers/net/ethernet/engleder/tsnep_main.c
+++ b/drivers/net/ethernet/engleder/tsnep_main.c
@@ -310,10 +310,11 @@ static void tsnep_tx_activate(struct tsnep_tx *tx, int index, int length,
struct tsnep_tx_entry *entry = &tx->entry[index];
entry->properties = 0;
- if (entry->skb) {
+ if (entry->skb || entry->xdpf) {
entry->properties = length & TSNEP_DESC_LENGTH_MASK;
entry->properties |= TSNEP_DESC_INTERRUPT_FLAG;
- if (skb_shinfo(entry->skb)->tx_flags & SKBTX_IN_PROGRESS)
+ if (entry->type == TSNEP_TX_TYPE_SKB &&
+ skb_shinfo(entry->skb)->tx_flags & SKBTX_IN_PROGRESS)
entry->properties |= TSNEP_DESC_EXTENDED_WRITEBACK_FLAG;
/* toggle user flag to prevent false acknowledge
@@ -400,6 +401,8 @@ static int tsnep_tx_map(struct sk_buff *skb, struct tsnep_tx *tx, int count)
entry->desc->tx = __cpu_to_le64(dma);
+ entry->type = TSNEP_TX_TYPE_SKB;
+
map_len += len;
}
@@ -417,12 +420,13 @@ static int tsnep_tx_unmap(struct tsnep_tx *tx, int index, int count)
entry = &tx->entry[(index + i) % TSNEP_RING_SIZE];
if (entry->len) {
- if (i == 0)
+ if (i == 0 && entry->type == TSNEP_TX_TYPE_SKB)
dma_unmap_single(dmadev,
dma_unmap_addr(entry, dma),
dma_unmap_len(entry, len),
DMA_TO_DEVICE);
- else
+ else if (entry->type == TSNEP_TX_TYPE_SKB ||
+ entry->type == TSNEP_TX_TYPE_XDP_NDO)
dma_unmap_page(dmadev,
dma_unmap_addr(entry, dma),
dma_unmap_len(entry, len),
@@ -505,6 +509,122 @@ static netdev_tx_t tsnep_xmit_frame_ring(struct sk_buff *skb,
return NETDEV_TX_OK;
}
+static int tsnep_xdp_tx_map(struct xdp_frame *xdpf, struct tsnep_tx *tx,
+ struct skb_shared_info *shinfo, int count,
+ bool dma_map)
+{
+ struct device *dmadev = tx->adapter->dmadev;
+ skb_frag_t *frag;
+ unsigned int len;
+ struct tsnep_tx_entry *entry;
+ void *data;
+ struct page *page;
+ dma_addr_t dma;
+ int map_len = 0;
+ int i;
+
+ frag = NULL;
+ len = xdpf->len;
+ for (i = 0; i < count; i++) {
+ entry = &tx->entry[(tx->write + i) % TSNEP_RING_SIZE];
+ if (dma_map) {
wouldn't it have made more sense if you passed TSNEP_TX_TYPE instead of
bool dma_map ?
here and in tsnep_xdp_xmit_frame_ring as well..
+ data = unlikely(frag) ? skb_frag_address(frag) :
+ xdpf->data;
+ dma = dma_map_single(dmadev, data, len, DMA_TO_DEVICE);
+ if (dma_mapping_error(dmadev, dma))
+ return -ENOMEM;
+
+ entry->type = TSNEP_TX_TYPE_XDP_NDO;
+ } else {
+ page = unlikely(frag) ? skb_frag_page(frag) :
+ virt_to_page(xdpf->data);
+ dma = page_pool_get_dma_addr(page);
+ if (unlikely(frag))
+ dma += skb_frag_off(frag);
+ else
+ dma += sizeof(*xdpf) + xdpf->headroom;
+ dma_sync_single_for_device(dmadev, dma, len,
+ DMA_BIDIRECTIONAL);
+
+ entry->type = TSNEP_TX_TYPE_XDP_TX;
+ }
+
+ entry->len = len;
+ dma_unmap_addr_set(entry, dma, dma);
+
+ entry->desc->tx = __cpu_to_le64(dma);
+
+ map_len += len;
+
+ if ((i + 1) < count) {
+ frag = &shinfo->frags[i];
+ len = skb_frag_size(frag);
+ }
+ }
+
+ return map_len;
+}
+
+/* This function requires __netif_tx_lock is held by the caller. */
+static int tsnep_xdp_xmit_frame_ring(struct xdp_frame *xdpf,
+ struct tsnep_tx *tx, bool dma_map)
+{
+ struct skb_shared_info *shinfo = xdp_get_shared_info_from_frame(xdpf);
+ unsigned long flags;
+ int count = 1;
+ struct tsnep_tx_entry *entry;
+ int length;
+ int i;
+ int retval;
Maciiej already commented on this, and i agree with him, the whole series
needs some work on rev xmas tree variable declaration, code will look much
neater.
+
+ if (unlikely(xdp_frame_has_frags(xdpf)))
+ count += shinfo->nr_frags;
+
+ spin_lock_irqsave(&tx->lock, flags);
+
+ if (tsnep_tx_desc_available(tx) < (MAX_SKB_FRAGS + 1 + count)) {
+ /* prevent full TX ring due to XDP */
+ spin_unlock_irqrestore(&tx->lock, flags);
+
+ return -EBUSY;
You don't really do anything with the retval, so just return a boolean.
+ }
+
+ entry = &tx->entry[tx->write];
+ entry->xdpf = xdpf;
+
+ retval = tsnep_xdp_tx_map(xdpf, tx, shinfo, count, dma_map);
+ if (retval < 0) {
+ tsnep_tx_unmap(tx, tx->write, count);
+ entry->xdpf = NULL;
+
+ tx->dropped++;
+
+ spin_unlock_irqrestore(&tx->lock, flags);
+
+ netdev_err(tx->adapter->netdev, "XDP TX DMA map failed\n");
please avoid printing in data path, find other means to expose such info.
stats
tracepoints
debug_message rate limited, etc ..
+
+ return retval;
+ }
+ length = retval;
+
+ for (i = 0; i < count; i++)
+ tsnep_tx_activate(tx, (tx->write + i) % TSNEP_RING_SIZE, length,
+ i == (count - 1));
+ tx->write = (tx->write + count) % TSNEP_RING_SIZE;
+
+ /* descriptor properties shall be valid before hardware is notified */
+ dma_wmb();
+
+ spin_unlock_irqrestore(&tx->lock, flags);
+
+ return 0;
+}
+
+static void tsnep_xdp_xmit_flush(struct tsnep_tx *tx)
+{
+ iowrite32(TSNEP_CONTROL_TX_ENABLE, tx->addr + TSNEP_CONTROL);
+}
+
static bool tsnep_tx_poll(struct tsnep_tx *tx, int napi_budget)
{
unsigned long flags;
@@ -512,6 +632,11 @@ static bool tsnep_tx_poll(struct tsnep_tx *tx, int napi_budget)
struct tsnep_tx_entry *entry;
int count;
int length;
+ struct xdp_frame_bulk bq;
+
+ xdp_frame_bulk_init(&bq);
+
+ rcu_read_lock(); /* need for xdp_return_frame_bulk */
spin_lock_irqsave(&tx->lock, flags);
@@ -531,12 +656,17 @@ static bool tsnep_tx_poll(struct tsnep_tx *tx, int napi_budget)
dma_rmb();
count = 1;
- if (skb_shinfo(entry->skb)->nr_frags > 0)
+ if (entry->type == TSNEP_TX_TYPE_SKB &&
+ skb_shinfo(entry->skb)->nr_frags > 0)
count += skb_shinfo(entry->skb)->nr_frags;
+ else if (entry->type != TSNEP_TX_TYPE_SKB &&
+ xdp_frame_has_frags(entry->xdpf))
+ count += xdp_get_shared_info_from_frame(entry->xdpf)->nr_frags;
length = tsnep_tx_unmap(tx, tx->read, count);
- if ((skb_shinfo(entry->skb)->tx_flags & SKBTX_IN_PROGRESS) &&
+ if (entry->type == TSNEP_TX_TYPE_SKB &&
+ (skb_shinfo(entry->skb)->tx_flags & SKBTX_IN_PROGRESS) &&
(__le32_to_cpu(entry->desc_wb->properties) &
TSNEP_DESC_EXTENDED_WRITEBACK_FLAG)) {
struct skb_shared_hwtstamps hwtstamps;
@@ -556,8 +686,20 @@ static bool tsnep_tx_poll(struct tsnep_tx *tx, int napi_budget)
skb_tstamp_tx(entry->skb, &hwtstamps);
}
- napi_consume_skb(entry->skb, budget);
- entry->skb = NULL;
+ switch (entry->type) {
+ case TSNEP_TX_TYPE_SKB:
+ napi_consume_skb(entry->skb, budget);
+ entry->skb = NULL;
+ break;
+ case TSNEP_TX_TYPE_XDP_TX:
+ xdp_return_frame_rx_napi(entry->xdpf);
+ entry->xdpf = NULL;
+ break;
+ case TSNEP_TX_TYPE_XDP_NDO:
+ xdp_return_frame_bulk(entry->xdpf, &bq);
+ entry->xdpf = NULL;
+ break;
+ }
tx->read = (tx->read + count) % TSNEP_RING_SIZE;
@@ -574,6 +716,10 @@ static bool tsnep_tx_poll(struct tsnep_tx *tx, int napi_budget)
spin_unlock_irqrestore(&tx->lock, flags);
+ xdp_flush_frame_bulk(&bq);
+
+ rcu_read_unlock();
+
return (budget != 0);
}
@@ -1335,6 +1481,47 @@ static ktime_t tsnep_netdev_get_tstamp(struct net_device *netdev,
return ns_to_ktime(timestamp);
}
+static int tsnep_netdev_xdp_xmit(struct net_device *dev, int n,
+ struct xdp_frame **xdp, u32 flags)
+{
+ struct tsnep_adapter *adapter = netdev_priv(dev);
+ int cpu = smp_processor_id();
+ int queue;
+ struct netdev_queue *nq;
+ int nxmit = 0;
+ int i;
+ int retval;
+
+ if (unlikely(test_bit(__TSNEP_DOWN, &adapter->state)))
+ return -ENETDOWN;
+
+ if (unlikely(flags & ~XDP_XMIT_FLAGS_MASK))
+ return -EINVAL;
+
+ queue = cpu % adapter->num_tx_queues;
+ nq = netdev_get_tx_queue(adapter->netdev, queue);
+
+ __netif_tx_lock(nq, cpu);
+
+ /* Avoid transmit queue timeout since we share it with the slow path */
+ txq_trans_cond_update(nq);
+
+ for (i = 0; i < n; i++) {
+ retval = tsnep_xdp_xmit_frame_ring(xdp[i], &adapter->tx[queue], true);
+ if (retval)
+ break;
+
+ nxmit++;
you could just use the loop iterator and drop nxmit.
+ }
+
+ if (flags & XDP_XMIT_FLUSH)
+ tsnep_xdp_xmit_flush(&adapter->tx[queue]);
+
+ __netif_tx_unlock(nq);
+
+ return nxmit;
[ ... ]
