[Intel-wired-lan] [RFC PATCH bpf-next 06/12] xsk: add zero-copy support for Rx
Björn Töpel
bjorn.topel at gmail.com
Tue May 15 19:06:09 UTC 2018
From: Björn Töpel <bjorn.topel at intel.com>
Extend the xsk_rcv to support the new MEM_TYPE_ZERO_COPY memory, and
wireup ndo_bpf call in bind.
Signed-off-by: Björn Töpel <bjorn.topel at intel.com>
---
include/net/xdp_sock.h | 7 +++++
net/xdp/xdp_umem.c | 60 +++++++++++++++++++++++++++++++++++++++++++
net/xdp/xdp_umem.h | 3 +++
net/xdp/xsk.c | 69 ++++++++++++++++++++++++++++++++++++++++----------
4 files changed, 125 insertions(+), 14 deletions(-)
diff --git a/include/net/xdp_sock.h b/include/net/xdp_sock.h
index 09068c4f068e..644684eb2caf 100644
--- a/include/net/xdp_sock.h
+++ b/include/net/xdp_sock.h
@@ -31,6 +31,7 @@ struct xdp_umem_props {
struct xdp_umem_frame {
void *addr;
+ dma_addr_t dma;
};
struct xdp_umem {
@@ -47,6 +48,8 @@ struct xdp_umem {
size_t size;
atomic_t users;
struct work_struct work;
+ struct net_device *dev;
+ u16 queue_id;
};
struct xdp_sock {
@@ -69,6 +72,10 @@ int xsk_generic_rcv(struct xdp_sock *xs, struct xdp_buff *xdp);
int xsk_rcv(struct xdp_sock *xs, struct xdp_buff *xdp);
void xsk_flush(struct xdp_sock *xs);
bool xsk_is_setup_for_bpf_map(struct xdp_sock *xs);
+
+u32 *xsk_umem_peek_id(struct xdp_umem *umem);
+void xsk_umem_discard_id(struct xdp_umem *umem);
+
#else
static inline int xsk_generic_rcv(struct xdp_sock *xs, struct xdp_buff *xdp)
{
diff --git a/net/xdp/xdp_umem.c b/net/xdp/xdp_umem.c
index b426cbe3151a..f70cdaa2ef4d 100644
--- a/net/xdp/xdp_umem.c
+++ b/net/xdp/xdp_umem.c
@@ -26,6 +26,64 @@
#define XDP_UMEM_MIN_FRAME_SIZE 2048
+int xdp_umem_assign_dev(struct xdp_umem *umem, struct net_device *dev,
+ u16 queue_id)
+{
+ struct netdev_bpf bpf;
+ int err;
+
+ if (umem->dev) {
+ if (dev != umem->dev || queue_id != umem->queue_id)
+ return -EBUSY;
+ return 0;
+ }
+
+ dev_hold(dev);
+ if (dev->netdev_ops->ndo_bpf) {
+ bpf.command = XDP_SETUP_XSK_UMEM;
+ bpf.xsk.umem = umem;
+ bpf.xsk.queue_id = queue_id;
+
+ rtnl_lock();
+ err = dev->netdev_ops->ndo_bpf(dev, &bpf);
+ rtnl_unlock();
+
+ if (err) {
+ dev_put(dev);
+ return 0;
+ }
+
+ umem->dev = dev;
+ umem->queue_id = queue_id;
+ return 0;
+ }
+
+ dev_put(dev);
+ return 0;
+}
+
+void xdp_umem_clear_dev(struct xdp_umem *umem)
+{
+ struct netdev_bpf bpf;
+ int err;
+
+ if (umem->dev) {
+ bpf.command = XDP_SETUP_XSK_UMEM;
+ bpf.xsk.umem = NULL;
+ bpf.xsk.queue_id = umem->queue_id;
+
+ rtnl_lock();
+ err = umem->dev->netdev_ops->ndo_bpf(umem->dev, &bpf);
+ rtnl_unlock();
+
+ if (err)
+ WARN(1, "failed to disable umem!\n");
+
+ dev_put(umem->dev);
+ umem->dev = NULL;
+ }
+}
+
int xdp_umem_create(struct xdp_umem **umem)
{
*umem = kzalloc(sizeof(**umem), GFP_KERNEL);
@@ -66,6 +124,8 @@ static void xdp_umem_release(struct xdp_umem *umem)
struct task_struct *task;
struct mm_struct *mm;
+ xdp_umem_clear_dev(umem);
+
if (umem->fq) {
xskq_destroy(umem->fq);
umem->fq = NULL;
diff --git a/net/xdp/xdp_umem.h b/net/xdp/xdp_umem.h
index 0a969384af93..3bb96d156b40 100644
--- a/net/xdp/xdp_umem.h
+++ b/net/xdp/xdp_umem.h
@@ -34,4 +34,7 @@ void xdp_get_umem(struct xdp_umem *umem);
void xdp_put_umem(struct xdp_umem *umem);
int xdp_umem_create(struct xdp_umem **umem);
+int xdp_umem_assign_dev(struct xdp_umem *umem, struct net_device *dev,
+ u16 queue_id);
+
#endif /* XDP_UMEM_H_ */
diff --git a/net/xdp/xsk.c b/net/xdp/xsk.c
index e59ca8e2618d..a0cf9c042ed2 100644
--- a/net/xdp/xsk.c
+++ b/net/xdp/xsk.c
@@ -43,6 +43,18 @@ static struct xdp_sock *xdp_sk(struct sock *sk)
return (struct xdp_sock *)sk;
}
+u32 *xsk_umem_peek_id(struct xdp_umem *umem)
+{
+ return xskq_peek_id(umem->fq);
+}
+EXPORT_SYMBOL(xsk_umem_peek_id);
+
+void xsk_umem_discard_id(struct xdp_umem *umem)
+{
+ xskq_discard_id(umem->fq);
+}
+EXPORT_SYMBOL(xsk_umem_discard_id);
+
bool xsk_is_setup_for_bpf_map(struct xdp_sock *xs)
{
return !!xs->rx;
@@ -50,40 +62,54 @@ bool xsk_is_setup_for_bpf_map(struct xdp_sock *xs)
static int __xsk_rcv(struct xdp_sock *xs, struct xdp_buff *xdp)
{
- u32 *id, len = xdp->data_end - xdp->data;
+ u32 *id, len;
void *buffer;
int err = 0;
- if (xs->dev != xdp->rxq->dev || xs->queue_id != xdp->rxq->queue_index)
- return -EINVAL;
-
id = xskq_peek_id(xs->umem->fq);
if (!id)
return -ENOSPC;
buffer = xdp_umem_get_data_with_headroom(xs->umem, *id);
+ len = xdp->data_end - xdp->data;
memcpy(buffer, xdp->data, len);
err = xskq_produce_batch_desc(xs->rx, *id, len,
xs->umem->frame_headroom);
- if (!err)
+ if (!err) {
xskq_discard_id(xs->umem->fq);
+ xdp_return_buff(xdp);
+ return 0;
+ }
+ xs->rx_dropped++;
return err;
}
-int xsk_rcv(struct xdp_sock *xs, struct xdp_buff *xdp)
+static int __xsk_rcv_zc(struct xdp_sock *xs, struct xdp_buff *xdp)
{
+ u16 off = xdp->data - xdp->data_hard_start;
+ u32 len = xdp->data_end - xdp->data;
int err;
- err = __xsk_rcv(xs, xdp);
- if (likely(!err))
+ err = xskq_produce_batch_desc(xs->rx, (u32)xdp->handle, len,
+ xs->umem->frame_headroom + off);
+ if (err) {
xdp_return_buff(xdp);
- else
xs->rx_dropped++;
+ }
return err;
}
+int xsk_rcv(struct xdp_sock *xs, struct xdp_buff *xdp)
+{
+ if (xs->dev != xdp->rxq->dev || xs->queue_id != xdp->rxq->queue_index)
+ return -EINVAL;
+
+ return (xdp->rxq->mem.type == MEM_TYPE_ZERO_COPY) ?
+ __xsk_rcv_zc(xs, xdp) : __xsk_rcv(xs, xdp);
+}
+
void xsk_flush(struct xdp_sock *xs)
{
xskq_produce_flush_desc(xs->rx);
@@ -92,14 +118,26 @@ void xsk_flush(struct xdp_sock *xs)
int xsk_generic_rcv(struct xdp_sock *xs, struct xdp_buff *xdp)
{
- int err;
+ u32 *id, len;
+ void *buffer;
+ int err = 0;
- err = __xsk_rcv(xs, xdp);
- if (!err)
+ id = xskq_peek_id(xs->umem->fq);
+ if (!id)
+ return -ENOSPC;
+
+ buffer = xdp_umem_get_data_with_headroom(xs->umem, *id);
+ len = xdp->data_end - xdp->data;
+ memcpy(buffer, xdp->data, len);
+ err = xskq_produce_batch_desc(xs->rx, *id, len,
+ xs->umem->frame_headroom);
+ if (!err) {
+ xskq_discard_id(xs->umem->fq);
xsk_flush(xs);
- else
- xs->rx_dropped++;
+ return 0;
+ }
+ xs->rx_dropped++;
return err;
}
@@ -362,6 +400,9 @@ static int xsk_bind(struct socket *sock, struct sockaddr *addr, int addr_len)
xs->dev = dev;
xs->queue_id = sxdp->sxdp_queue_id;
+ err = xdp_umem_assign_dev(xs->umem, dev, xs->queue_id);
+ if (err)
+ goto out_unlock;
xskq_set_umem(xs->rx, &xs->umem->props);
xskq_set_umem(xs->tx, &xs->umem->props);
--
2.14.1
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