Commit 5ab073ff authored by Jesper Dangaard Brouer's avatar Jesper Dangaard Brouer Committed by David S. Miller

xdp: introduce xdp_return_frame API and use in cpumap

Introduce an xdp_return_frame API, and convert over cpumap as
the first user, given it have queued XDP frame structure to leverage.

V3: Cleanup and remove C99 style comments, pointed out by Alex Duyck.
V6: Remove comment that id will be added later (Req by Alex Duyck)
V8: Rename enum mem_type to xdp_mem_type (found by kbuild test robot)
Signed-off-by: default avatarJesper Dangaard Brouer <brouer@redhat.com>
Signed-off-by: default avatarDavid S. Miller <davem@davemloft.net>
parent 5168d732
......@@ -33,16 +33,43 @@
* also mandatory during RX-ring setup.
*/
enum xdp_mem_type {
MEM_TYPE_PAGE_SHARED = 0, /* Split-page refcnt based model */
MEM_TYPE_PAGE_ORDER0, /* Orig XDP full page model */
MEM_TYPE_MAX,
};
struct xdp_mem_info {
u32 type; /* enum xdp_mem_type, but known size type */
};
struct xdp_rxq_info {
struct net_device *dev;
u32 queue_index;
u32 reg_state;
struct xdp_mem_info mem;
} ____cacheline_aligned; /* perf critical, avoid false-sharing */
static inline
void xdp_return_frame(void *data, struct xdp_mem_info *mem)
{
if (mem->type == MEM_TYPE_PAGE_SHARED)
page_frag_free(data);
if (mem->type == MEM_TYPE_PAGE_ORDER0) {
struct page *page = virt_to_page(data); /* Assumes order0 page*/
put_page(page);
}
}
int xdp_rxq_info_reg(struct xdp_rxq_info *xdp_rxq,
struct net_device *dev, u32 queue_index);
void xdp_rxq_info_unreg(struct xdp_rxq_info *xdp_rxq);
void xdp_rxq_info_unused(struct xdp_rxq_info *xdp_rxq);
bool xdp_rxq_info_is_reg(struct xdp_rxq_info *xdp_rxq);
int xdp_rxq_info_reg_mem_model(struct xdp_rxq_info *xdp_rxq,
enum xdp_mem_type type, void *allocator);
#endif /* __LINUX_NET_XDP_H__ */
......@@ -19,6 +19,7 @@
#include <linux/bpf.h>
#include <linux/filter.h>
#include <linux/ptr_ring.h>
#include <net/xdp.h>
#include <linux/sched.h>
#include <linux/workqueue.h>
......@@ -137,27 +138,6 @@ static struct bpf_map *cpu_map_alloc(union bpf_attr *attr)
return ERR_PTR(err);
}
static void __cpu_map_queue_destructor(void *ptr)
{
/* The tear-down procedure should have made sure that queue is
* empty. See __cpu_map_entry_replace() and work-queue
* invoked cpu_map_kthread_stop(). Catch any broken behaviour
* gracefully and warn once.
*/
if (WARN_ON_ONCE(ptr))
page_frag_free(ptr);
}
static void put_cpu_map_entry(struct bpf_cpu_map_entry *rcpu)
{
if (atomic_dec_and_test(&rcpu->refcnt)) {
/* The queue should be empty at this point */
ptr_ring_cleanup(rcpu->queue, __cpu_map_queue_destructor);
kfree(rcpu->queue);
kfree(rcpu);
}
}
static void get_cpu_map_entry(struct bpf_cpu_map_entry *rcpu)
{
atomic_inc(&rcpu->refcnt);
......@@ -188,6 +168,10 @@ struct xdp_pkt {
u16 len;
u16 headroom;
u16 metasize;
/* Lifetime of xdp_rxq_info is limited to NAPI/enqueue time,
* while mem info is valid on remote CPU.
*/
struct xdp_mem_info mem;
struct net_device *dev_rx;
};
......@@ -213,6 +197,9 @@ static struct xdp_pkt *convert_to_xdp_pkt(struct xdp_buff *xdp)
xdp_pkt->headroom = headroom - sizeof(*xdp_pkt);
xdp_pkt->metasize = metasize;
/* rxq only valid until napi_schedule ends, convert to xdp_mem_info */
xdp_pkt->mem = xdp->rxq->mem;
return xdp_pkt;
}
......@@ -265,6 +252,31 @@ static struct sk_buff *cpu_map_build_skb(struct bpf_cpu_map_entry *rcpu,
return skb;
}
static void __cpu_map_ring_cleanup(struct ptr_ring *ring)
{
/* The tear-down procedure should have made sure that queue is
* empty. See __cpu_map_entry_replace() and work-queue
* invoked cpu_map_kthread_stop(). Catch any broken behaviour
* gracefully and warn once.
*/
struct xdp_pkt *xdp_pkt;
while ((xdp_pkt = ptr_ring_consume(ring)))
if (WARN_ON_ONCE(xdp_pkt))
xdp_return_frame(xdp_pkt, &xdp_pkt->mem);
}
static void put_cpu_map_entry(struct bpf_cpu_map_entry *rcpu)
{
if (atomic_dec_and_test(&rcpu->refcnt)) {
/* The queue should be empty at this point */
__cpu_map_ring_cleanup(rcpu->queue);
ptr_ring_cleanup(rcpu->queue, NULL);
kfree(rcpu->queue);
kfree(rcpu);
}
}
static int cpu_map_kthread_run(void *data)
{
struct bpf_cpu_map_entry *rcpu = data;
......@@ -307,7 +319,7 @@ static int cpu_map_kthread_run(void *data)
skb = cpu_map_build_skb(rcpu, xdp_pkt);
if (!skb) {
page_frag_free(xdp_pkt);
xdp_return_frame(xdp_pkt, &xdp_pkt->mem);
continue;
}
......@@ -604,13 +616,13 @@ static int bq_flush_to_queue(struct bpf_cpu_map_entry *rcpu,
spin_lock(&q->producer_lock);
for (i = 0; i < bq->count; i++) {
void *xdp_pkt = bq->q[i];
struct xdp_pkt *xdp_pkt = bq->q[i];
int err;
err = __ptr_ring_produce(q, xdp_pkt);
if (err) {
drops++;
page_frag_free(xdp_pkt); /* Free xdp_pkt */
xdp_return_frame(xdp_pkt->data, &xdp_pkt->mem);
}
processed++;
}
......
......@@ -71,3 +71,21 @@ bool xdp_rxq_info_is_reg(struct xdp_rxq_info *xdp_rxq)
return (xdp_rxq->reg_state == REG_STATE_REGISTERED);
}
EXPORT_SYMBOL_GPL(xdp_rxq_info_is_reg);
int xdp_rxq_info_reg_mem_model(struct xdp_rxq_info *xdp_rxq,
enum xdp_mem_type type, void *allocator)
{
if (type >= MEM_TYPE_MAX)
return -EINVAL;
xdp_rxq->mem.type = type;
if (allocator)
return -EOPNOTSUPP;
/* TODO: Allocate an ID that maps to allocator pointer
* See: https://www.kernel.org/doc/html/latest/core-api/idr.html
*/
return 0;
}
EXPORT_SYMBOL_GPL(xdp_rxq_info_reg_mem_model);
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