On 12/13/2017 3:20 AM, Jesper Dangaard Brouer wrote:
Hook points for xdp_rxq_info:
* init+reg: netif_alloc_rx_queues
* unreg : netif_free_rx_queues
The net_device have some members (num_rx_queues + real_num_rx_queues)
and data-area (dev->_rx with struct netdev_rx_queue's) that were
primarily used for exporting information about RPS (CONFIG_RPS) queues
to sysfs (CONFIG_SYSFS).
For generic XDP extend struct netdev_rx_queue with the xdp_rxq_info,
and remove some of the CONFIG_SYSFS ifdefs.
Signed-off-by: Jesper Dangaard Brouer <bro...@redhat.com>
---
include/linux/netdevice.h | 2 ++
net/core/dev.c | 60 ++++++++++++++++++++++++++++++++++++++-------
2 files changed, 52 insertions(+), 10 deletions(-)
diff --git a/include/linux/netdevice.h b/include/linux/netdevice.h
index cc4ce7456e38..43595b037872 100644
--- a/include/linux/netdevice.h
+++ b/include/linux/netdevice.h
@@ -44,6 +44,7 @@
#include <net/dcbnl.h>
#endif
#include <net/netprio_cgroup.h>
+#include <net/xdp.h>
#include <linux/netdev_features.h>
#include <linux/neighbour.h>
@@ -686,6 +687,7 @@ struct netdev_rx_queue {
#endif
struct kobject kobj;
struct net_device *dev;
+ struct xdp_rxq_info xdp_rxq;
} ____cacheline_aligned_in_smp;
Instead of duplicating this xdp_rxq_info and have 2 instances of it for
drivers that do support XDP (the generic one and the driver internal
xdp_rxq_info), drivers can use the generic netdev_rx_queue.xdp_rxq to
register their own xdp_rxq_info.
I suggest the following API for drivers to use:
xdp_rxq_info_reg(netdev, rxq_index)
{
rxqueue = dev->_rx + rxq_index;
xdp_rxq = rxqueue.xdp_rxq;
xdp_rxq_info_init(xdp_rxq);
xdp_rxq.dev = netdev;
xdp_rxq.queue_index = rxq_index;
}
xdp_rxq_info_unreg(netdev, rxq_index)
{
...
}
This way you can avoid the xdp_rxq_info structure management by the
drivers them selves and reduce duplicated code to init, fill the
xdp_rxq_info per driver.
-Saeed.
/*
diff --git a/net/core/dev.c b/net/core/dev.c
index 6bea8931bb62..44932d6194a2 100644
--- a/net/core/dev.c
+++ b/net/core/dev.c
@@ -3873,9 +3873,33 @@ static int enqueue_to_backlog(struct sk_buff *skb, int
cpu,
return NET_RX_DROP;
}
+static struct netdev_rx_queue *netif_get_rxqueue(struct sk_buff *skb)
+{
+ struct net_device *dev = skb->dev;
+ struct netdev_rx_queue *rxqueue;
+
+ rxqueue = dev->_rx;
+
+ if (skb_rx_queue_recorded(skb)) {
+ u16 index = skb_get_rx_queue(skb);
+
+ if (unlikely(index >= dev->real_num_rx_queues)) {
+ WARN_ONCE(dev->real_num_rx_queues > 1,
+ "%s received packet on queue %u, but number "
+ "of RX queues is %u\n",
+ dev->name, index, dev->real_num_rx_queues);
+
+ return rxqueue; /* Return first rxqueue */
+ }
+ rxqueue += index;
+ }
+ return rxqueue;
+}
+
static u32 netif_receive_generic_xdp(struct sk_buff *skb,
struct bpf_prog *xdp_prog)
{
+ struct netdev_rx_queue *rxqueue;
u32 metalen, act = XDP_DROP;
struct xdp_buff xdp;
void *orig_data;
@@ -3919,6 +3943,9 @@ static u32 netif_receive_generic_xdp(struct sk_buff *skb,
xdp.data_hard_start = skb->data - skb_headroom(skb);
orig_data = xdp.data;
+ rxqueue = netif_get_rxqueue(skb);
+ xdp.rxq = &rxqueue->xdp_rxq;
+
act = bpf_prog_run_xdp(xdp_prog, &xdp);
off = xdp.data - orig_data;
@@ -7538,7 +7565,6 @@ void netif_stacked_transfer_operstate(const struct
net_device *rootdev,
}
EXPORT_SYMBOL(netif_stacked_transfer_operstate);
-#ifdef CONFIG_SYSFS
static int netif_alloc_rx_queues(struct net_device *dev)
{
unsigned int i, count = dev->num_rx_queues;
@@ -7553,11 +7579,31 @@ static int netif_alloc_rx_queues(struct net_device *dev)
dev->_rx = rx;
- for (i = 0; i < count; i++)
+ for (i = 0; i < count; i++) {
rx[i].dev = dev;
+
+ /* XDP RX-queue setup */
+ xdp_rxq_info_init(&rx[i].xdp_rxq);
+ rx[i].xdp_rxq.dev = dev;
+ rx[i].xdp_rxq.queue_index = i;
+ xdp_rxq_info_reg(&rx[i].xdp_rxq);
+ }
return 0;
}
-#endif
+
+static void netif_free_rx_queues(struct net_device *dev)
+{
+ unsigned int i, count = dev->num_rx_queues;
+ struct netdev_rx_queue *rx;
+
+ if (!dev->_rx) /* netif_alloc_rx_queues alloc failed */
+ return;
+
+ rx = dev->_rx;
+
+ for (i = 0; i < count; i++)
+ xdp_rxq_info_unreg(&rx[i].xdp_rxq);
+}
static void netdev_init_one_queue(struct net_device *dev,
struct netdev_queue *queue, void *_unused)
@@ -8118,12 +8164,10 @@ struct net_device *alloc_netdev_mqs(int sizeof_priv,
const char *name,
return NULL;
}
-#ifdef CONFIG_SYSFS
if (rxqs < 1) {
pr_err("alloc_netdev: Unable to allocate device with zero RX
queues\n");
return NULL;
}
-#endif
alloc_size = sizeof(struct net_device);
if (sizeof_priv) {
@@ -8180,12 +8224,10 @@ struct net_device *alloc_netdev_mqs(int sizeof_priv,
const char *name,
if (netif_alloc_netdev_queues(dev))
goto free_all;
-#ifdef CONFIG_SYSFS
dev->num_rx_queues = rxqs;
dev->real_num_rx_queues = rxqs;
if (netif_alloc_rx_queues(dev))
goto free_all;
-#endif
strcpy(dev->name, name);
dev->name_assign_type = name_assign_type;
@@ -8224,9 +8266,7 @@ void free_netdev(struct net_device *dev)
might_sleep();
netif_free_tx_queues(dev);
-#ifdef CONFIG_SYSFS
- kvfree(dev->_rx);
-#endif
+ netif_free_rx_queues(dev);
kfree(rcu_dereference_protected(dev->ingress_queue, 1));
