diff options
Diffstat (limited to 'kernel')
| -rw-r--r-- | kernel/bpf/cpumap.c | 132 |
1 files changed, 50 insertions, 82 deletions
diff --git a/kernel/bpf/cpumap.c b/kernel/bpf/cpumap.c index a4bb0b34375a..c95b04ec103e 100644 --- a/kernel/bpf/cpumap.c +++ b/kernel/bpf/cpumap.c @@ -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 @@ free_cmap: 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); @@ -179,45 +159,8 @@ static void cpu_map_kthread_stop(struct work_struct *work) kthread_stop(rcpu->kthread); } -/* For now, xdp_pkt is a cpumap internal data structure, with info - * carried between enqueue to dequeue. It is mapped into the top - * headroom of the packet, to avoid allocating separate mem. - */ -struct xdp_pkt { - void *data; - u16 len; - u16 headroom; - u16 metasize; - struct net_device *dev_rx; -}; - -/* Convert xdp_buff to xdp_pkt */ -static struct xdp_pkt *convert_to_xdp_pkt(struct xdp_buff *xdp) -{ - struct xdp_pkt *xdp_pkt; - int metasize; - int headroom; - - /* Assure headroom is available for storing info */ - headroom = xdp->data - xdp->data_hard_start; - metasize = xdp->data - xdp->data_meta; - metasize = metasize > 0 ? metasize : 0; - if (unlikely((headroom - metasize) < sizeof(*xdp_pkt))) - return NULL; - - /* Store info in top of packet */ - xdp_pkt = xdp->data_hard_start; - - xdp_pkt->data = xdp->data; - xdp_pkt->len = xdp->data_end - xdp->data; - xdp_pkt->headroom = headroom - sizeof(*xdp_pkt); - xdp_pkt->metasize = metasize; - - return xdp_pkt; -} - static struct sk_buff *cpu_map_build_skb(struct bpf_cpu_map_entry *rcpu, - struct xdp_pkt *xdp_pkt) + struct xdp_frame *xdpf) { unsigned int frame_size; void *pkt_data_start; @@ -232,7 +175,7 @@ static struct sk_buff *cpu_map_build_skb(struct bpf_cpu_map_entry *rcpu, * would be preferred to set frame_size to 2048 or 4096 * depending on the driver. * frame_size = 2048; - * frame_len = frame_size - sizeof(*xdp_pkt); + * frame_len = frame_size - sizeof(*xdp_frame); * * Instead, with info avail, skb_shared_info in placed after * packet len. This, unfortunately fakes the truesize. @@ -240,21 +183,21 @@ static struct sk_buff *cpu_map_build_skb(struct bpf_cpu_map_entry *rcpu, * is not at a fixed memory location, with mixed length * packets, which is bad for cache-line hotness. */ - frame_size = SKB_DATA_ALIGN(xdp_pkt->len) + xdp_pkt->headroom + + frame_size = SKB_DATA_ALIGN(xdpf->len) + xdpf->headroom + SKB_DATA_ALIGN(sizeof(struct skb_shared_info)); - pkt_data_start = xdp_pkt->data - xdp_pkt->headroom; + pkt_data_start = xdpf->data - xdpf->headroom; skb = build_skb(pkt_data_start, frame_size); if (!skb) return NULL; - skb_reserve(skb, xdp_pkt->headroom); - __skb_put(skb, xdp_pkt->len); - if (xdp_pkt->metasize) - skb_metadata_set(skb, xdp_pkt->metasize); + skb_reserve(skb, xdpf->headroom); + __skb_put(skb, xdpf->len); + if (xdpf->metasize) + skb_metadata_set(skb, xdpf->metasize); /* Essential SKB info: protocol and skb->dev */ - skb->protocol = eth_type_trans(skb, xdp_pkt->dev_rx); + skb->protocol = eth_type_trans(skb, xdpf->dev_rx); /* Optional SKB info, currently missing: * - HW checksum info (skb->ip_summed) @@ -265,6 +208,31 @@ 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_frame *xdpf; + + while ((xdpf = ptr_ring_consume(ring))) + if (WARN_ON_ONCE(xdpf)) + xdp_return_frame(xdpf); +} + +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; @@ -278,7 +246,7 @@ static int cpu_map_kthread_run(void *data) */ while (!kthread_should_stop() || !__ptr_ring_empty(rcpu->queue)) { unsigned int processed = 0, drops = 0, sched = 0; - struct xdp_pkt *xdp_pkt; + struct xdp_frame *xdpf; /* Release CPU reschedule checks */ if (__ptr_ring_empty(rcpu->queue)) { @@ -301,13 +269,13 @@ static int cpu_map_kthread_run(void *data) * kthread CPU pinned. Lockless access to ptr_ring * consume side valid as no-resize allowed of queue. */ - while ((xdp_pkt = __ptr_ring_consume(rcpu->queue))) { + while ((xdpf = __ptr_ring_consume(rcpu->queue))) { struct sk_buff *skb; int ret; - skb = cpu_map_build_skb(rcpu, xdp_pkt); + skb = cpu_map_build_skb(rcpu, xdpf); if (!skb) { - page_frag_free(xdp_pkt); + xdp_return_frame(xdpf); continue; } @@ -604,13 +572,13 @@ 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_frame *xdpf = bq->q[i]; int err; - err = __ptr_ring_produce(q, xdp_pkt); + err = __ptr_ring_produce(q, xdpf); if (err) { drops++; - page_frag_free(xdp_pkt); /* Free xdp_pkt */ + xdp_return_frame(xdpf); } processed++; } @@ -625,7 +593,7 @@ static int bq_flush_to_queue(struct bpf_cpu_map_entry *rcpu, /* Runs under RCU-read-side, plus in softirq under NAPI protection. * Thus, safe percpu variable access. */ -static int bq_enqueue(struct bpf_cpu_map_entry *rcpu, struct xdp_pkt *xdp_pkt) +static int bq_enqueue(struct bpf_cpu_map_entry *rcpu, struct xdp_frame *xdpf) { struct xdp_bulk_queue *bq = this_cpu_ptr(rcpu->bulkq); @@ -636,28 +604,28 @@ static int bq_enqueue(struct bpf_cpu_map_entry *rcpu, struct xdp_pkt *xdp_pkt) * driver to code invoking us to finished, due to driver * (e.g. ixgbe) recycle tricks based on page-refcnt. * - * Thus, incoming xdp_pkt is always queued here (else we race + * Thus, incoming xdp_frame is always queued here (else we race * with another CPU on page-refcnt and remaining driver code). * Queue time is very short, as driver will invoke flush * operation, when completing napi->poll call. */ - bq->q[bq->count++] = xdp_pkt; + bq->q[bq->count++] = xdpf; return 0; } int cpu_map_enqueue(struct bpf_cpu_map_entry *rcpu, struct xdp_buff *xdp, struct net_device *dev_rx) { - struct xdp_pkt *xdp_pkt; + struct xdp_frame *xdpf; - xdp_pkt = convert_to_xdp_pkt(xdp); - if (unlikely(!xdp_pkt)) + xdpf = convert_to_xdp_frame(xdp); + if (unlikely(!xdpf)) return -EOVERFLOW; /* Info needed when constructing SKB on remote CPU */ - xdp_pkt->dev_rx = dev_rx; + xdpf->dev_rx = dev_rx; - bq_enqueue(rcpu, xdp_pkt); + bq_enqueue(rcpu, xdpf); return 0; } |