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Diffstat (limited to 'drivers/net/wireguard/queueing.c')
-rw-r--r--drivers/net/wireguard/queueing.c109
1 files changed, 109 insertions, 0 deletions
diff --git a/drivers/net/wireguard/queueing.c b/drivers/net/wireguard/queueing.c
new file mode 100644
index 0000000000..26d235d152
--- /dev/null
+++ b/drivers/net/wireguard/queueing.c
@@ -0,0 +1,109 @@
+// SPDX-License-Identifier: GPL-2.0
+/*
+ * Copyright (C) 2015-2019 Jason A. Donenfeld <Jason@zx2c4.com>. All Rights Reserved.
+ */
+
+#include "queueing.h"
+#include <linux/skb_array.h>
+
+struct multicore_worker __percpu *
+wg_packet_percpu_multicore_worker_alloc(work_func_t function, void *ptr)
+{
+ int cpu;
+ struct multicore_worker __percpu *worker = alloc_percpu(struct multicore_worker);
+
+ if (!worker)
+ return NULL;
+
+ for_each_possible_cpu(cpu) {
+ per_cpu_ptr(worker, cpu)->ptr = ptr;
+ INIT_WORK(&per_cpu_ptr(worker, cpu)->work, function);
+ }
+ return worker;
+}
+
+int wg_packet_queue_init(struct crypt_queue *queue, work_func_t function,
+ unsigned int len)
+{
+ int ret;
+
+ memset(queue, 0, sizeof(*queue));
+ queue->last_cpu = -1;
+ ret = ptr_ring_init(&queue->ring, len, GFP_KERNEL);
+ if (ret)
+ return ret;
+ queue->worker = wg_packet_percpu_multicore_worker_alloc(function, queue);
+ if (!queue->worker) {
+ ptr_ring_cleanup(&queue->ring, NULL);
+ return -ENOMEM;
+ }
+ return 0;
+}
+
+void wg_packet_queue_free(struct crypt_queue *queue, bool purge)
+{
+ free_percpu(queue->worker);
+ WARN_ON(!purge && !__ptr_ring_empty(&queue->ring));
+ ptr_ring_cleanup(&queue->ring, purge ? __skb_array_destroy_skb : NULL);
+}
+
+#define NEXT(skb) ((skb)->prev)
+#define STUB(queue) ((struct sk_buff *)&queue->empty)
+
+void wg_prev_queue_init(struct prev_queue *queue)
+{
+ NEXT(STUB(queue)) = NULL;
+ queue->head = queue->tail = STUB(queue);
+ queue->peeked = NULL;
+ atomic_set(&queue->count, 0);
+ BUILD_BUG_ON(
+ offsetof(struct sk_buff, next) != offsetof(struct prev_queue, empty.next) -
+ offsetof(struct prev_queue, empty) ||
+ offsetof(struct sk_buff, prev) != offsetof(struct prev_queue, empty.prev) -
+ offsetof(struct prev_queue, empty));
+}
+
+static void __wg_prev_queue_enqueue(struct prev_queue *queue, struct sk_buff *skb)
+{
+ WRITE_ONCE(NEXT(skb), NULL);
+ WRITE_ONCE(NEXT(xchg_release(&queue->head, skb)), skb);
+}
+
+bool wg_prev_queue_enqueue(struct prev_queue *queue, struct sk_buff *skb)
+{
+ if (!atomic_add_unless(&queue->count, 1, MAX_QUEUED_PACKETS))
+ return false;
+ __wg_prev_queue_enqueue(queue, skb);
+ return true;
+}
+
+struct sk_buff *wg_prev_queue_dequeue(struct prev_queue *queue)
+{
+ struct sk_buff *tail = queue->tail, *next = smp_load_acquire(&NEXT(tail));
+
+ if (tail == STUB(queue)) {
+ if (!next)
+ return NULL;
+ queue->tail = next;
+ tail = next;
+ next = smp_load_acquire(&NEXT(next));
+ }
+ if (next) {
+ queue->tail = next;
+ atomic_dec(&queue->count);
+ return tail;
+ }
+ if (tail != READ_ONCE(queue->head))
+ return NULL;
+ __wg_prev_queue_enqueue(queue, STUB(queue));
+ next = smp_load_acquire(&NEXT(tail));
+ if (next) {
+ queue->tail = next;
+ atomic_dec(&queue->count);
+ return tail;
+ }
+ return NULL;
+}
+
+#undef NEXT
+#undef STUB