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-rw-r--r--include/net/busy_poll.h177
1 files changed, 177 insertions, 0 deletions
diff --git a/include/net/busy_poll.h b/include/net/busy_poll.h
new file mode 100644
index 000000000..f90f0021f
--- /dev/null
+++ b/include/net/busy_poll.h
@@ -0,0 +1,177 @@
+/* SPDX-License-Identifier: GPL-2.0-only */
+/*
+ * net busy poll support
+ * Copyright(c) 2013 Intel Corporation.
+ *
+ * Author: Eliezer Tamir
+ *
+ * Contact Information:
+ * e1000-devel Mailing List <e1000-devel@lists.sourceforge.net>
+ */
+
+#ifndef _LINUX_NET_BUSY_POLL_H
+#define _LINUX_NET_BUSY_POLL_H
+
+#include <linux/netdevice.h>
+#include <linux/sched/clock.h>
+#include <linux/sched/signal.h>
+#include <net/ip.h>
+
+/* 0 - Reserved to indicate value not set
+ * 1..NR_CPUS - Reserved for sender_cpu
+ * NR_CPUS+1..~0 - Region available for NAPI IDs
+ */
+#define MIN_NAPI_ID ((unsigned int)(NR_CPUS + 1))
+
+#define BUSY_POLL_BUDGET 8
+
+#ifdef CONFIG_NET_RX_BUSY_POLL
+
+struct napi_struct;
+extern unsigned int sysctl_net_busy_read __read_mostly;
+extern unsigned int sysctl_net_busy_poll __read_mostly;
+
+static inline bool net_busy_loop_on(void)
+{
+ return READ_ONCE(sysctl_net_busy_poll);
+}
+
+static inline bool sk_can_busy_loop(const struct sock *sk)
+{
+ return READ_ONCE(sk->sk_ll_usec) && !signal_pending(current);
+}
+
+bool sk_busy_loop_end(void *p, unsigned long start_time);
+
+void napi_busy_loop(unsigned int napi_id,
+ bool (*loop_end)(void *, unsigned long),
+ void *loop_end_arg, bool prefer_busy_poll, u16 budget);
+
+#else /* CONFIG_NET_RX_BUSY_POLL */
+static inline unsigned long net_busy_loop_on(void)
+{
+ return 0;
+}
+
+static inline bool sk_can_busy_loop(struct sock *sk)
+{
+ return false;
+}
+
+#endif /* CONFIG_NET_RX_BUSY_POLL */
+
+static inline unsigned long busy_loop_current_time(void)
+{
+#ifdef CONFIG_NET_RX_BUSY_POLL
+ return (unsigned long)(local_clock() >> 10);
+#else
+ return 0;
+#endif
+}
+
+/* in poll/select we use the global sysctl_net_ll_poll value */
+static inline bool busy_loop_timeout(unsigned long start_time)
+{
+#ifdef CONFIG_NET_RX_BUSY_POLL
+ unsigned long bp_usec = READ_ONCE(sysctl_net_busy_poll);
+
+ if (bp_usec) {
+ unsigned long end_time = start_time + bp_usec;
+ unsigned long now = busy_loop_current_time();
+
+ return time_after(now, end_time);
+ }
+#endif
+ return true;
+}
+
+static inline bool sk_busy_loop_timeout(struct sock *sk,
+ unsigned long start_time)
+{
+#ifdef CONFIG_NET_RX_BUSY_POLL
+ unsigned long bp_usec = READ_ONCE(sk->sk_ll_usec);
+
+ if (bp_usec) {
+ unsigned long end_time = start_time + bp_usec;
+ unsigned long now = busy_loop_current_time();
+
+ return time_after(now, end_time);
+ }
+#endif
+ return true;
+}
+
+static inline void sk_busy_loop(struct sock *sk, int nonblock)
+{
+#ifdef CONFIG_NET_RX_BUSY_POLL
+ unsigned int napi_id = READ_ONCE(sk->sk_napi_id);
+
+ if (napi_id >= MIN_NAPI_ID)
+ napi_busy_loop(napi_id, nonblock ? NULL : sk_busy_loop_end, sk,
+ READ_ONCE(sk->sk_prefer_busy_poll),
+ READ_ONCE(sk->sk_busy_poll_budget) ?: BUSY_POLL_BUDGET);
+#endif
+}
+
+/* used in the NIC receive handler to mark the skb */
+static inline void skb_mark_napi_id(struct sk_buff *skb,
+ struct napi_struct *napi)
+{
+#ifdef CONFIG_NET_RX_BUSY_POLL
+ /* If the skb was already marked with a valid NAPI ID, avoid overwriting
+ * it.
+ */
+ if (skb->napi_id < MIN_NAPI_ID)
+ skb->napi_id = napi->napi_id;
+#endif
+}
+
+/* used in the protocol hanlder to propagate the napi_id to the socket */
+static inline void sk_mark_napi_id(struct sock *sk, const struct sk_buff *skb)
+{
+#ifdef CONFIG_NET_RX_BUSY_POLL
+ if (unlikely(READ_ONCE(sk->sk_napi_id) != skb->napi_id))
+ WRITE_ONCE(sk->sk_napi_id, skb->napi_id);
+#endif
+ sk_rx_queue_update(sk, skb);
+}
+
+/* Variant of sk_mark_napi_id() for passive flow setup,
+ * as sk->sk_napi_id and sk->sk_rx_queue_mapping content
+ * needs to be set.
+ */
+static inline void sk_mark_napi_id_set(struct sock *sk,
+ const struct sk_buff *skb)
+{
+#ifdef CONFIG_NET_RX_BUSY_POLL
+ WRITE_ONCE(sk->sk_napi_id, skb->napi_id);
+#endif
+ sk_rx_queue_set(sk, skb);
+}
+
+static inline void __sk_mark_napi_id_once(struct sock *sk, unsigned int napi_id)
+{
+#ifdef CONFIG_NET_RX_BUSY_POLL
+ if (!READ_ONCE(sk->sk_napi_id))
+ WRITE_ONCE(sk->sk_napi_id, napi_id);
+#endif
+}
+
+/* variant used for unconnected sockets */
+static inline void sk_mark_napi_id_once(struct sock *sk,
+ const struct sk_buff *skb)
+{
+#ifdef CONFIG_NET_RX_BUSY_POLL
+ __sk_mark_napi_id_once(sk, skb->napi_id);
+#endif
+}
+
+static inline void sk_mark_napi_id_once_xdp(struct sock *sk,
+ const struct xdp_buff *xdp)
+{
+#ifdef CONFIG_NET_RX_BUSY_POLL
+ __sk_mark_napi_id_once(sk, xdp->rxq->napi_id);
+#endif
+}
+
+#endif /* _LINUX_NET_BUSY_POLL_H */