[RFC PATCH 02/11] net: Create netqueue.h and define NO_QUEUE

[Tom Herbert <tom@herbertland.com>]

Create linux/netqueue.h to hold generic network queue definitions.

Define NO_QUEUE to replace NO_QUEUE_MAPPING in net/sock.h. NO_QUEUE
can generally be used to indicate that a 16 bit queue index does not
refer to a queue.

Also, define net_queue_pair which will be used as a generic way to store a
transmit/receive pair of network queues.
---
 include/linux/netdevice.h |  1 +
 include/linux/netqueue.h  | 25 +++++++++++++++++++++++++
 include/net/sock.h        | 12 +++++-------
 net/core/filter.c         |  4 ++--
 4 files changed, 33 insertions(+), 9 deletions(-)
 create mode 100644 include/linux/netqueue.h

diff --git a/include/linux/netdevice.h b/include/linux/netdevice.h
index 6fc613ed8eae..bf5f2a85da97 100644
--- a/include/linux/netdevice.h
+++ b/include/linux/netdevice.h
@@ -32,6 +32,7 @@
 #include <linux/percpu.h>
 #include <linux/rculist.h>
 #include <linux/workqueue.h>
+#include <linux/netqueue.h>
 #include <linux/dynamic_queue_limits.h>
 
 #include <linux/ethtool.h>
diff --git a/include/linux/netqueue.h b/include/linux/netqueue.h
new file mode 100644
index 000000000000..5a4d39821ada
--- /dev/null
+++ b/include/linux/netqueue.h
@@ -0,0 +1,25 @@
+/* SPDX-License-Identifier: GPL-2.0-or-later */
+/*
+ * Network queue identifier definitions
+ *
+ * Copyright (c) 2020 Tom Herbert <tom@herbertland.com>
+ */
+
+#ifndef _LINUX_NETQUEUE_H
+#define _LINUX_NETQUEUE_H
+
+/* Indicates no network queue is present in 16 bit queue number */
+#define NO_QUEUE	USHRT_MAX
+
+struct net_queue_pair {
+	unsigned short txq_id;
+	unsigned short rxq_id;
+};
+
+static inline void init_net_queue_pair(struct net_queue_pair *qpair)
+{
+	qpair->rxq_id = NO_QUEUE;
+	qpair->txq_id = NO_QUEUE;
+}
+
+#endif /* _LINUX_NETQUEUE_H */
diff --git a/include/net/sock.h b/include/net/sock.h
index c53cc42b5ab9..acb76cfaae1b 100644
--- a/include/net/sock.h
+++ b/include/net/sock.h
@@ -1800,16 +1800,14 @@ static inline void sk_tx_queue_set(struct sock *sk, int tx_queue)
 	sk->sk_tx_queue_mapping = tx_queue;
 }
 
-#define NO_QUEUE_MAPPING	USHRT_MAX
-
 static inline void sk_tx_queue_clear(struct sock *sk)
 {
-	sk->sk_tx_queue_mapping = NO_QUEUE_MAPPING;
+	sk->sk_tx_queue_mapping = NO_QUEUE;
 }
 
 static inline int sk_tx_queue_get(const struct sock *sk)
 {
-	if (sk && sk->sk_tx_queue_mapping != NO_QUEUE_MAPPING)
+	if (sk && sk->sk_tx_queue_mapping != NO_QUEUE)
 		return sk->sk_tx_queue_mapping;
 
 	return -1;
@@ -1821,7 +1819,7 @@ static inline void sk_rx_queue_set(struct sock *sk, const struct sk_buff *skb)
 	if (skb_rx_queue_recorded(skb)) {
 		u16 rx_queue = skb_get_rx_queue(skb);
 
-		if (WARN_ON_ONCE(rx_queue == NO_QUEUE_MAPPING))
+		if (WARN_ON_ONCE(rx_queue == NO_QUEUE))
 			return;
 
 		sk->sk_rx_queue_mapping = rx_queue;
@@ -1832,14 +1830,14 @@ static inline void sk_rx_queue_set(struct sock *sk, const struct sk_buff *skb)
 static inline void sk_rx_queue_clear(struct sock *sk)
 {
 #ifdef CONFIG_XPS
-	sk->sk_rx_queue_mapping = NO_QUEUE_MAPPING;
+	sk->sk_rx_queue_mapping = NO_QUEUE;
 #endif
 }
 
 #ifdef CONFIG_XPS
 static inline int sk_rx_queue_get(const struct sock *sk)
 {
-	if (sk && sk->sk_rx_queue_mapping != NO_QUEUE_MAPPING)
+	if (sk && sk->sk_rx_queue_mapping != NO_QUEUE)
 		return sk->sk_rx_queue_mapping;
 
 	return -1;
diff --git a/net/core/filter.c b/net/core/filter.c
index 73395384afe2..d696aaabe3af 100644
--- a/net/core/filter.c
+++ b/net/core/filter.c
@@ -7544,7 +7544,7 @@ static u32 bpf_convert_ctx_access(enum bpf_access_type type,
 
 	case offsetof(struct __sk_buff, queue_mapping):
 		if (type == BPF_WRITE) {
-			*insn++ = BPF_JMP_IMM(BPF_JGE, si->src_reg, NO_QUEUE_MAPPING, 1);
+			*insn++ = BPF_JMP_IMM(BPF_JGE, si->src_reg, NO_QUEUE, 1);
 			*insn++ = BPF_STX_MEM(BPF_H, si->dst_reg, si->src_reg,
 					      bpf_target_off(struct sk_buff,
 							     queue_mapping,
@@ -7981,7 +7981,7 @@ u32 bpf_sock_convert_ctx_access(enum bpf_access_type type,
 				       sizeof_field(struct sock,
 						    sk_rx_queue_mapping),
 				       target_size));
-		*insn++ = BPF_JMP_IMM(BPF_JNE, si->dst_reg, NO_QUEUE_MAPPING,
+		*insn++ = BPF_JMP_IMM(BPF_JNE, si->dst_reg, NO_QUEUE,
 				      1);
 		*insn++ = BPF_MOV64_IMM(si->dst_reg, -1);
 #else
-- 
2.25.1