[PATCH net-next 4/4] mvpp2: XDP TX support

From: Matteo Croce
Date: Tue Jun 30 2020 - 14:14:51 EST

From: Matteo Croce <mcroce@xxxxxxxxxxxxx>

Add the transmit part of XDP support, which includes:
- support for XDP_TX in mvpp2_xdp()
- .ndo_xdp_xmit hook for AF_XDP and XDP_REDIRECT with mvpp2 as destination

mvpp2_xdp_submit_frame() is a generic function which is called by
mvpp2_xdp_xmit_back() when doing XDP_TX, and by mvpp2_xdp_xmit when
doing AF_XDP or XDP_REDIRECT target.

The buffer allocation has been reworked to be able to map the buffers
as DMA_FROM_DEVICE or DMA_BIDIRECTIONAL depending if a BPF program
is loaded or not.

Co-developed-by: Sven Auhagen <sven.auhagen@xxxxxxxxxxxx>
Signed-off-by: Sven Auhagen <sven.auhagen@xxxxxxxxxxxx>
Signed-off-by: Matteo Croce <mcroce@xxxxxxxxxxxxx>
---
drivers/net/ethernet/marvell/mvpp2/mvpp2.h | 13 +-
.../net/ethernet/marvell/mvpp2/mvpp2_main.c | 312 +++++++++++++++---
2 files changed, 280 insertions(+), 45 deletions(-)

diff --git a/drivers/net/ethernet/marvell/mvpp2/mvpp2.h b/drivers/net/ethernet/marvell/mvpp2/mvpp2.h
index f351e41c9da6..c52955b33fab 100644
--- a/drivers/net/ethernet/marvell/mvpp2/mvpp2.h
+++ b/drivers/net/ethernet/marvell/mvpp2/mvpp2.h
@@ -1082,9 +1082,20 @@ struct mvpp2_rx_desc {
};
};

+enum mvpp2_tx_buf_type {
+ MVPP2_TYPE_SKB,
+ MVPP2_TYPE_XDP_TX,
+ MVPP2_TYPE_XDP_NDO,
+};
+
struct mvpp2_txq_pcpu_buf {
+ enum mvpp2_tx_buf_type type;
+
/* Transmitted SKB */
- struct sk_buff *skb;
+ union {
+ struct xdp_frame *xdpf;
+ struct sk_buff *skb;
+ };

/* Physical address of transmitted buffer */
dma_addr_t dma;
diff --git a/drivers/net/ethernet/marvell/mvpp2/mvpp2_main.c b/drivers/net/ethernet/marvell/mvpp2/mvpp2_main.c
index 864d4789a0b3..ffc2a220613d 100644
--- a/drivers/net/ethernet/marvell/mvpp2/mvpp2_main.c
+++ b/drivers/net/ethernet/marvell/mvpp2/mvpp2_main.c
@@ -97,7 +97,8 @@ static inline u32 mvpp2_cpu_to_thread(struct mvpp2 *priv, int cpu)
}

static struct page_pool *
-mvpp2_create_page_pool(struct device *dev, int num, int len)
+mvpp2_create_page_pool(struct device *dev, int num, int len,
+ enum dma_data_direction dma_dir)
{
struct page_pool_params pp_params = {
/* internal DMA mapping in page_pool */
@@ -105,7 +106,7 @@ mvpp2_create_page_pool(struct device *dev, int num, int len)
.pool_size = num,
.nid = NUMA_NO_NODE,
.dev = dev,
- .dma_dir = DMA_FROM_DEVICE,
+ .dma_dir = dma_dir,
.offset = MVPP2_SKB_HEADROOM,
.max_len = len,
};
@@ -299,12 +300,17 @@ static void mvpp2_txq_inc_get(struct mvpp2_txq_pcpu *txq_pcpu)

static void mvpp2_txq_inc_put(struct mvpp2_port *port,
struct mvpp2_txq_pcpu *txq_pcpu,
- struct sk_buff *skb,
- struct mvpp2_tx_desc *tx_desc)
+ void *data,
+ struct mvpp2_tx_desc *tx_desc,
+ enum mvpp2_tx_buf_type buf_type)
{
struct mvpp2_txq_pcpu_buf *tx_buf =
txq_pcpu->buffs + txq_pcpu->txq_put_index;
- tx_buf->skb = skb;
+ tx_buf->type = buf_type;
+ if (buf_type == MVPP2_TYPE_SKB)
+ tx_buf->skb = data;
+ else
+ tx_buf->xdpf = data;
tx_buf->size = mvpp2_txdesc_size_get(port, tx_desc);
tx_buf->dma = mvpp2_txdesc_dma_addr_get(port, tx_desc) +
mvpp2_txdesc_offset_get(port, tx_desc);
@@ -528,9 +534,6 @@ static int mvpp2_bm_pool_destroy(struct device *dev, struct mvpp2 *priv,
int buf_num;
u32 val;

- if (priv->percpu_pools)
- page_pool_destroy(priv->page_pool[bm_pool->id]);
-
buf_num = mvpp2_check_hw_buf_num(priv, bm_pool);
mvpp2_bm_bufs_free(dev, priv, bm_pool, buf_num);

@@ -546,6 +549,9 @@ static int mvpp2_bm_pool_destroy(struct device *dev, struct mvpp2 *priv,
val |= MVPP2_BM_STOP_MASK;
mvpp2_write(priv, MVPP2_BM_POOL_CTRL_REG(bm_pool->id), val);

+ if (priv->percpu_pools)
+ page_pool_destroy(priv->page_pool[bm_pool->id]);
+
dma_free_coherent(dev, bm_pool->size_bytes,
bm_pool->virt_addr,
bm_pool->dma_addr);
@@ -581,9 +587,19 @@ static int mvpp2_bm_pools_init(struct device *dev, struct mvpp2 *priv)

static int mvpp2_bm_init(struct device *dev, struct mvpp2 *priv)
{
+ enum dma_data_direction dma_dir = DMA_FROM_DEVICE;
int i, err, poolnum = MVPP2_BM_POOLS_NUM;
+ struct mvpp2_port *port;

if (priv->percpu_pools) {
+ for (i = 0; i < priv->port_count; i++) {
+ port = priv->port_list[i];
+ if (port->xdp_prog) {
+ dma_dir = DMA_BIDIRECTIONAL;
+ break;
+ }
+ }
+
poolnum = mvpp2_get_nrxqs(priv) * 2;
for (i = 0; i < poolnum; i++) {
/* the pool in use */
@@ -592,7 +608,8 @@ static int mvpp2_bm_init(struct device *dev, struct mvpp2 *priv)
priv->page_pool[i] =
mvpp2_create_page_pool(dev,
mvpp2_pools[pn].buf_num,
- mvpp2_pools[pn].pkt_size);
+ mvpp2_pools[pn].pkt_size,
+ dma_dir);
if (IS_ERR(priv->page_pool[i]))
return PTR_ERR(priv->page_pool[i]);
}
@@ -2319,11 +2336,15 @@ static void mvpp2_txq_bufs_free(struct mvpp2_port *port,
struct mvpp2_txq_pcpu_buf *tx_buf =
txq_pcpu->buffs + txq_pcpu->txq_get_index;

- if (!IS_TSO_HEADER(txq_pcpu, tx_buf->dma))
+ if (!IS_TSO_HEADER(txq_pcpu, tx_buf->dma) &&
+ tx_buf->type != MVPP2_TYPE_XDP_TX)
dma_unmap_single(port->dev->dev.parent, tx_buf->dma,
tx_buf->size, DMA_TO_DEVICE);
- if (tx_buf->skb)
+ if (tx_buf->type == MVPP2_TYPE_SKB && tx_buf->skb)
dev_kfree_skb_any(tx_buf->skb);
+ else if (tx_buf->type == MVPP2_TYPE_XDP_TX ||
+ tx_buf->type == MVPP2_TYPE_XDP_NDO)
+ xdp_return_frame(tx_buf->xdpf);

mvpp2_txq_inc_get(txq_pcpu);
}
@@ -2809,7 +2830,7 @@ static int mvpp2_setup_rxqs(struct mvpp2_port *port)
static int mvpp2_setup_txqs(struct mvpp2_port *port)
{
struct mvpp2_tx_queue *txq;
- int queue, err, cpu;
+ int queue, err;

for (queue = 0; queue < port->ntxqs; queue++) {
txq = port->txqs[queue];
@@ -2818,8 +2839,8 @@ static int mvpp2_setup_txqs(struct mvpp2_port *port)
goto err_cleanup;

/* Assign this queue to a CPU */
- cpu = queue % num_present_cpus();
- netif_set_xps_queue(port->dev, cpumask_of(cpu), queue);
+ if (queue < num_possible_cpus())
+ netif_set_xps_queue(port->dev, cpumask_of(queue), queue);
}

if (port->has_tx_irqs) {
@@ -3038,6 +3059,165 @@ static u32 mvpp2_skb_tx_csum(struct mvpp2_port *port, struct sk_buff *skb)
return MVPP2_TXD_L4_CSUM_NOT | MVPP2_TXD_IP_CSUM_DISABLE;
}

+static void mvpp2_xdp_finish_tx(struct mvpp2_port *port, u16 txq_id, int nxmit, int nxmit_byte)
+{
+ unsigned int thread = mvpp2_cpu_to_thread(port->priv, smp_processor_id());
+ struct mvpp2_pcpu_stats *stats = per_cpu_ptr(port->stats, thread);
+ struct mvpp2_tx_queue *aggr_txq;
+ struct mvpp2_txq_pcpu *txq_pcpu;
+ struct mvpp2_tx_queue *txq;
+ struct netdev_queue *nq;
+
+ txq = port->txqs[txq_id];
+ txq_pcpu = per_cpu_ptr(txq->pcpu, thread);
+ nq = netdev_get_tx_queue(port->dev, txq_id);
+ aggr_txq = &port->priv->aggr_txqs[thread];
+
+ txq_pcpu->reserved_num -= nxmit;
+ txq_pcpu->count += nxmit;
+ aggr_txq->count += nxmit;
+
+ /* Enable transmit */
+ wmb();
+ mvpp2_aggr_txq_pend_desc_add(port, nxmit);
+
+ if (txq_pcpu->count >= txq_pcpu->stop_threshold)
+ netif_tx_stop_queue(nq);
+
+ u64_stats_update_begin(&stats->syncp);
+ stats->tx_bytes += nxmit_byte;
+ stats->tx_packets += nxmit;
+ u64_stats_update_end(&stats->syncp);
+
+ /* Finalize TX processing */
+ if (!port->has_tx_irqs && txq_pcpu->count >= txq->done_pkts_coal)
+ mvpp2_txq_done(port, txq, txq_pcpu);
+}
+
+static int
+mvpp2_xdp_submit_frame(struct mvpp2_port *port, u16 txq_id,
+ struct xdp_frame *xdpf, bool dma_map)
+{
+ struct mvpp2_tx_desc *tx_desc;
+ struct mvpp2_tx_queue *aggr_txq;
+ struct mvpp2_tx_queue *txq;
+ struct mvpp2_txq_pcpu *txq_pcpu;
+ dma_addr_t dma_addr;
+ u32 tx_cmd = MVPP2_TXD_L4_CSUM_NOT | MVPP2_TXD_IP_CSUM_DISABLE |
+ MVPP2_TXD_F_DESC | MVPP2_TXD_L_DESC;
+ enum mvpp2_tx_buf_type buf_type;
+ int ret = MVPP2_XDP_TX;
+
+ unsigned int thread = mvpp2_cpu_to_thread(port->priv, smp_processor_id());
+
+ txq = port->txqs[txq_id];
+ txq_pcpu = per_cpu_ptr(txq->pcpu, thread);
+ aggr_txq = &port->priv->aggr_txqs[thread];
+
+ /* Check number of available descriptors */
+ if (mvpp2_aggr_desc_num_check(port, aggr_txq, 1) ||
+ mvpp2_txq_reserved_desc_num_proc(port, txq, txq_pcpu, 1)) {
+ ret = MVPP2_XDP_DROPPED;
+ goto out;
+ }
+
+ /* Get a descriptor for the first part of the packet */
+ tx_desc = mvpp2_txq_next_desc_get(aggr_txq);
+ mvpp2_txdesc_txq_set(port, tx_desc, txq->id);
+ mvpp2_txdesc_size_set(port, tx_desc, xdpf->len);
+
+ if (dma_map) {
+ /* XDP_REDIRECT or AF_XDP */
+ dma_addr = dma_map_single(port->dev->dev.parent, xdpf->data,
+ xdpf->len, DMA_TO_DEVICE);
+
+ if (unlikely(dma_mapping_error(port->dev->dev.parent, dma_addr))) {
+ mvpp2_txq_desc_put(txq);
+ ret = MVPP2_XDP_DROPPED;
+ goto out;
+ }
+
+ buf_type = MVPP2_TYPE_XDP_NDO;
+ } else {
+ /* XDP_TX */
+ struct page *page = virt_to_page(xdpf->data);
+
+ dma_addr = page_pool_get_dma_addr(page) +
+ sizeof(*xdpf) + xdpf->headroom;
+ dma_sync_single_for_device(port->dev->dev.parent, dma_addr,
+ xdpf->len, DMA_BIDIRECTIONAL);
+
+ buf_type = MVPP2_TYPE_XDP_TX;
+ }
+
+ mvpp2_txdesc_dma_addr_set(port, tx_desc, dma_addr);
+
+ mvpp2_txdesc_cmd_set(port, tx_desc, tx_cmd);
+ mvpp2_txq_inc_put(port, txq_pcpu, xdpf, tx_desc, buf_type);
+
+out:
+ return ret;
+}
+
+static int
+mvpp2_xdp_xmit_back(struct mvpp2_port *port, struct xdp_buff *xdp)
+{
+ struct xdp_frame *xdpf;
+ u16 txq_id;
+ int ret;
+
+ xdpf = xdp_convert_buff_to_frame(xdp);
+ if (unlikely(!xdpf))
+ return MVPP2_XDP_DROPPED;
+
+ /* The first of the TX queues are used for XPS,
+ * the second half for XDP_TX
+ */
+ txq_id = mvpp2_cpu_to_thread(port->priv, smp_processor_id()) + (port->ntxqs / 2);
+
+ ret = mvpp2_xdp_submit_frame(port, txq_id, xdpf, false);
+ if (ret == MVPP2_XDP_TX)
+ mvpp2_xdp_finish_tx(port, txq_id, 1, xdpf->len);
+
+ return ret;
+}
+
+static int
+mvpp2_xdp_xmit(struct net_device *dev, int num_frame,
+ struct xdp_frame **frames, u32 flags)
+{
+ struct mvpp2_port *port = netdev_priv(dev);
+ int i, nxmit_byte = 0, nxmit = num_frame;
+ u32 ret;
+ u16 txq_id;
+
+ if (unlikely(test_bit(0, &port->state)))
+ return -ENETDOWN;
+
+ if (unlikely(flags & ~XDP_XMIT_FLAGS_MASK))
+ return -EINVAL;
+
+ /* The first of the TX queues are used for XPS,
+ * the second half for XDP_TX
+ */
+ txq_id = mvpp2_cpu_to_thread(port->priv, smp_processor_id()) + (port->ntxqs / 2);
+
+ for (i = 0; i < num_frame; i++) {
+ ret = mvpp2_xdp_submit_frame(port, txq_id, frames[i], true);
+ if (ret == MVPP2_XDP_TX) {
+ nxmit_byte += frames[i]->len;
+ } else {
+ xdp_return_frame_rx_napi(frames[i]);
+ nxmit--;
+ }
+ }
+
+ if (nxmit > 0)
+ mvpp2_xdp_finish_tx(port, txq_id, nxmit, nxmit_byte);
+
+ return nxmit;
+}
+
static int
mvpp2_run_xdp(struct mvpp2_port *port, struct mvpp2_rx_queue *rxq,
struct bpf_prog *prog, struct xdp_buff *xdp,
@@ -3068,6 +3248,13 @@ mvpp2_run_xdp(struct mvpp2_port *port, struct mvpp2_rx_queue *rxq,
ret = MVPP2_XDP_REDIR;
}
break;
+ case XDP_TX:
+ ret = mvpp2_xdp_xmit_back(port, xdp);
+ if (ret != MVPP2_XDP_TX) {
+ page = virt_to_head_page(xdp->data);
+ page_pool_put_page(pp, page, sync, true);
+ }
+ break;
default:
bpf_warn_invalid_xdp_action(act);
fallthrough;
@@ -3089,6 +3276,7 @@ static int mvpp2_rx(struct mvpp2_port *port, struct napi_struct *napi,
int rx_todo, struct mvpp2_rx_queue *rxq)
{
struct net_device *dev = port->dev;
+ enum dma_data_direction dma_dir;
struct bpf_prog *xdp_prog;
struct xdp_buff xdp;
int rx_received;
@@ -3138,13 +3326,19 @@ static int mvpp2_rx(struct mvpp2_port *port, struct napi_struct *napi,
if (rx_status & MVPP2_RXD_ERR_SUMMARY)
goto err_drop_frame;

+ if (port->priv->percpu_pools) {
+ pp = port->priv->page_pool[pool];
+ dma_dir = page_pool_get_dma_dir(pp);
+ } else {
+ dma_dir = DMA_FROM_DEVICE;
+ }
+
dma_sync_single_for_cpu(dev->dev.parent, dma_addr,
rx_bytes + MVPP2_MH_SIZE,
- DMA_FROM_DEVICE);
- prefetch(data);
+ dma_dir);

- if (port->priv->percpu_pools)
- pp = port->priv->page_pool[pool];
+ /* Prefetch header */
+ prefetch(data);

if (bm_pool->frag_size > PAGE_SIZE)
frag_size = 0;
@@ -3217,6 +3411,9 @@ static int mvpp2_rx(struct mvpp2_port *port, struct napi_struct *napi,

rcu_read_unlock();

+ if (xdp_ret & MVPP2_XDP_REDIR)
+ xdp_do_flush_map();
+
if (rcvd_pkts) {
struct mvpp2_pcpu_stats *stats = this_cpu_ptr(port->stats);

@@ -3283,11 +3480,11 @@ static int mvpp2_tx_frag_process(struct mvpp2_port *port, struct sk_buff *skb,
/* Last descriptor */
mvpp2_txdesc_cmd_set(port, tx_desc,
MVPP2_TXD_L_DESC);
- mvpp2_txq_inc_put(port, txq_pcpu, skb, tx_desc);
+ mvpp2_txq_inc_put(port, txq_pcpu, skb, tx_desc, MVPP2_TYPE_SKB);
} else {
/* Descriptor in the middle: Not First, Not Last */
mvpp2_txdesc_cmd_set(port, tx_desc, 0);
- mvpp2_txq_inc_put(port, txq_pcpu, NULL, tx_desc);
+ mvpp2_txq_inc_put(port, txq_pcpu, NULL, tx_desc, MVPP2_TYPE_SKB);
}
}

@@ -3325,7 +3522,7 @@ static inline void mvpp2_tso_put_hdr(struct sk_buff *skb,
mvpp2_txdesc_cmd_set(port, tx_desc, mvpp2_skb_tx_csum(port, skb) |
MVPP2_TXD_F_DESC |
MVPP2_TXD_PADDING_DISABLE);
- mvpp2_txq_inc_put(port, txq_pcpu, NULL, tx_desc);
+ mvpp2_txq_inc_put(port, txq_pcpu, NULL, tx_desc, MVPP2_TYPE_SKB);
}

static inline int mvpp2_tso_put_data(struct sk_buff *skb,
@@ -3354,14 +3551,14 @@ static inline int mvpp2_tso_put_data(struct sk_buff *skb,
if (!left) {
mvpp2_txdesc_cmd_set(port, tx_desc, MVPP2_TXD_L_DESC);
if (last) {
- mvpp2_txq_inc_put(port, txq_pcpu, skb, tx_desc);
+ mvpp2_txq_inc_put(port, txq_pcpu, skb, tx_desc, MVPP2_TYPE_SKB);
return 0;
}
} else {
mvpp2_txdesc_cmd_set(port, tx_desc, 0);
}

- mvpp2_txq_inc_put(port, txq_pcpu, NULL, tx_desc);
+ mvpp2_txq_inc_put(port, txq_pcpu, NULL, tx_desc, MVPP2_TYPE_SKB);
return 0;
}

@@ -3474,12 +3671,12 @@ static netdev_tx_t mvpp2_tx(struct sk_buff *skb, struct net_device *dev)
/* First and Last descriptor */
tx_cmd |= MVPP2_TXD_F_DESC | MVPP2_TXD_L_DESC;
mvpp2_txdesc_cmd_set(port, tx_desc, tx_cmd);
- mvpp2_txq_inc_put(port, txq_pcpu, skb, tx_desc);
+ mvpp2_txq_inc_put(port, txq_pcpu, skb, tx_desc, MVPP2_TYPE_SKB);
} else {
/* First but not Last */
tx_cmd |= MVPP2_TXD_F_DESC | MVPP2_TXD_PADDING_DISABLE;
mvpp2_txdesc_cmd_set(port, tx_desc, tx_cmd);
- mvpp2_txq_inc_put(port, txq_pcpu, NULL, tx_desc);
+ mvpp2_txq_inc_put(port, txq_pcpu, NULL, tx_desc, MVPP2_TYPE_SKB);

/* Continue with other skb fragments */
if (mvpp2_tx_frag_process(port, skb, aggr_txq, txq)) {
@@ -4158,6 +4355,39 @@ static int mvpp2_change_mtu(struct net_device *dev, int mtu)
return err;
}

+static int mvpp2_check_pagepool_dma(struct mvpp2_port *port)
+{
+ enum dma_data_direction dma_dir = DMA_FROM_DEVICE;
+ struct mvpp2 *priv = port->priv;
+ struct page_pool *page_pool;
+ int err = -1, i;
+
+ if (!priv->percpu_pools) {
+ netdev_warn(port->dev, "can not change pagepool it is not enabled");
+ } else {
+ for (i = 0; i < priv->port_count; i++) {
+ port = priv->port_list[i];
+ if (port->xdp_prog) {
+ dma_dir = DMA_BIDIRECTIONAL;
+ break;
+ }
+ }
+
+ if (!priv->page_pool)
+ return -ENOMEM;
+
+ /* All pools are equal in terms of dma direction */
+ page_pool = priv->page_pool[0];
+
+ if (page_pool->p.dma_dir != dma_dir) {
+ netdev_info(port->dev, "Changing pagepool dma to %d\n", dma_dir);
+ err = mvpp2_bm_switch_buffers(priv, true);
+ }
+ }
+
+ return err;
+}
+
static void
mvpp2_get_stats64(struct net_device *dev, struct rtnl_link_stats64 *stats)
{
@@ -4268,13 +4498,16 @@ static int mvpp2_xdp_setup(struct mvpp2_port *port, struct netdev_bpf *bpf)
return -EOPNOTSUPP;
}

- /* device is up and bpf is added/removed, must setup the RX queues */
- if (running && reset) {
- mvpp2_stop_dev(port);
- mvpp2_cleanup_rxqs(port);
- mvpp2_cleanup_txqs(port);
+ if (port->ntxqs < num_possible_cpus() * 2) {
+ netdev_err(port->dev, "XDP_TX needs twice the CPU TX queues, but only %d queues available.\n",
+ port->ntxqs);
+ return -EOPNOTSUPP;
}

+ /* device is up and bpf is added/removed, must setup the RX queues */
+ if (running && reset)
+ mvpp2_stop(port->dev);
+
old_prog = xchg(&port->xdp_prog, prog);
if (old_prog)
bpf_prog_put(old_prog);
@@ -4284,21 +4517,11 @@ static int mvpp2_xdp_setup(struct mvpp2_port *port, struct netdev_bpf *bpf)
return 0;

/* device was up, restore the link */
- if (running) {
- int ret = mvpp2_setup_rxqs(port);
-
- if (ret) {
- netdev_err(port->dev, "mvpp2_setup_rxqs failed\n");
- return ret;
- }
- ret = mvpp2_setup_txqs(port);
- if (ret) {
- netdev_err(port->dev, "mvpp2_setup_txqs failed\n");
- return ret;
- }
+ if (running)
+ mvpp2_open(port->dev);

- mvpp2_start_dev(port);
- }
+ /* Check Page Pool DMA Direction */
+ mvpp2_check_pagepool_dma(port);

return 0;
}
@@ -4669,6 +4892,7 @@ static const struct net_device_ops mvpp2_netdev_ops = {
.ndo_vlan_rx_kill_vid = mvpp2_vlan_rx_kill_vid,
.ndo_set_features = mvpp2_set_features,
.ndo_bpf = mvpp2_xdp,
+ .ndo_xdp_xmit = mvpp2_xdp_xmit,
};

static const struct ethtool_ops mvpp2_eth_tool_ops = {
--
2.26.2