---
include/linux/ptr_ring_ll.h | 136 +++++++++++++++++++++++++++++++++++++++++++
include/linux/skb_array.h | 25 ++++++++
2 files changed, 161 insertions(+)
create mode 100644 include/linux/ptr_ring_ll.h
diff --git a/include/linux/ptr_ring_ll.h b/include/linux/ptr_ring_ll.h
new file mode 100644
index 0000000..bcb11f3
--- /dev/null
+++ b/include/linux/ptr_ring_ll.h
@@ -0,0 +1,136 @@
+/*
+ * Definitions for the 'struct ptr_ring_ll' datastructure.
+ *
+ * Author:
+ * John Fastabend <john.r.fastab...@intel.com>
+ *
+ * Copyright (C) 2016 Intel Corp.
+ *
+ * This program is free software; you can redistribute it and/or modify it
+ * under the terms of the GNU General Public License as published by the
+ * Free Software Foundation; either version 2 of the License, or (at your
+ * option) any later version.
+ *
+ * This is a limited-size FIFO maintaining pointers in FIFO order, with
+ * one CPU producing entries and another consuming entries from a FIFO.
+ * extended from ptr_ring_ll to use cmpxchg over spin lock.
+ */
+
+#ifndef _LINUX_PTR_RING_LL_H
+#define _LINUX_PTR_RING_LL_H 1
+
+#ifdef __KERNEL__
+#include <linux/spinlock.h>
+#include <linux/cache.h>
+#include <linux/types.h>
+#include <linux/compiler.h>
+#include <linux/cache.h>
+#include <linux/slab.h>
+#include <asm/errno.h>
+#endif
+
+struct ptr_ring_ll {
+ u32 prod_size;
+ u32 prod_mask;
+ u32 prod_head;
+ u32 prod_tail;
+ u32 cons_size;
+ u32 cons_mask;
+ u32 cons_head;
+ u32 cons_tail;
+
+ void **queue;
+};
+
+/* Note: callers invoking this in a loop must use a compiler barrier,
+ * for example cpu_relax(). Callers must hold producer_lock.
+ */
+static inline int __ptr_ring_ll_produce(struct ptr_ring_ll *r, void *ptr)
+{
+ u32 ret, head, tail, next, slots, mask;
+
+ do {
+ head = READ_ONCE(r->prod_head);
+ mask = READ_ONCE(r->prod_mask);
+ tail = READ_ONCE(r->cons_tail);
+
+ slots = mask + tail - head;
+ if (slots < 1)
+ return -ENOMEM;
+
+ next = head + 1;
+ ret = cmpxchg(&r->prod_head, head, next);
+ } while (ret != head);
+
+ r->queue[head & mask] = ptr;
+ smp_wmb();
+
+ while (r->prod_tail != head)
+ cpu_relax();
+
+ r->prod_tail = next;
+ return 0;
+}
+
+static inline void *__ptr_ring_ll_consume(struct ptr_ring_ll *r)
+{
+ u32 ret, head, tail, next, slots, mask;
+ void *ptr;
+
+ do {
+ head = READ_ONCE(r->cons_head);
+ mask = READ_ONCE(r->cons_mask);
+ tail = READ_ONCE(r->prod_tail);
+
+ slots = tail - head;
+ if (slots < 1)
+ return ERR_PTR(-ENOMEM);
+
+ next = head + 1;
+ ret = cmpxchg(&r->cons_head, head, next);
+ } while (ret != head);
+
+ ptr = r->queue[head & mask];
+ smp_rmb();
+
+ while (r->cons_tail != head)
+ cpu_relax();
+
+ r->cons_tail = next;
+ return ptr;
+}
+
+static inline void **__ptr_ring_ll_init_queue_alloc(int size, gfp_t gfp)
+{
+ return kzalloc(ALIGN(size * sizeof(void *), SMP_CACHE_BYTES), gfp);
+}
+
+static inline int ptr_ring_ll_init(struct ptr_ring_ll *r, int size, gfp_t gfp)
+{
+ r->queue = __ptr_ring_init_queue_alloc(size, gfp);
+ if (!r->queue)
+ return -ENOMEM;
+
+ r->prod_size = r->cons_size = size;
+ r->prod_mask = r->cons_mask = size - 1;
+ r->prod_tail = r->prod_head = 0;
+ r->cons_tail = r->prod_tail = 0;
+
+ return 0;
+}
+
+static inline void ptr_ring_ll_cleanup(struct ptr_ring_ll *r, void
(*destroy)(void *))
+{
+ if (destroy) {
+ void *ptr;
+
+ ptr = __ptr_ring_ll_consume(r);
+ while (!IS_ERR_OR_NULL(ptr)) {
+ destroy(ptr);
+ ptr = __ptr_ring_ll_consume(r);
+ }
+ }
+ kfree(r->queue);
+}
+
+#endif /* _LINUX_PTR_RING_LL_H */
diff --git a/include/linux/skb_array.h b/include/linux/skb_array.h
index f4dfade..9b43dfd 100644
--- a/include/linux/skb_array.h
+++ b/include/linux/skb_array.h
@@ -22,6 +22,7 @@
#ifdef __KERNEL__
#include <linux/ptr_ring.h>
+#include <linux/ptr_ring_ll.h>
#include <linux/skbuff.h>
#include <linux/if_vlan.h>
#endif
@@ -30,6 +31,10 @@ struct skb_array {
struct ptr_ring ring;
};
+struct skb_array_ll {
+ struct ptr_ring_ll ring;
+};
+
/* Might be slightly faster than skb_array_full below, but callers invoking
* this in a loop must use a compiler barrier, for example cpu_relax().
*/
@@ -43,6 +48,11 @@ static inline bool skb_array_full(struct skb_array *a)
return ptr_ring_full(&a->ring);
}
+static inline int skb_array_ll_produce(struct skb_array_ll *a, struct sk_buff
*skb)
+{
+ return __ptr_ring_ll_produce(&a->ring, skb);
+}
+
static inline int skb_array_produce(struct skb_array *a, struct sk_buff *skb)
{
return ptr_ring_produce(&a->ring, skb);
@@ -92,6 +102,11 @@ static inline bool skb_array_empty_any(struct skb_array *a)
return ptr_ring_empty_any(&a->ring);
}
+static inline struct sk_buff *skb_array_ll_consume(struct skb_array_ll *a)
+{
+ return __ptr_ring_ll_consume(&a->ring);
+}
+
static inline struct sk_buff *skb_array_consume(struct skb_array *a)
{
return ptr_ring_consume(&a->ring);
@@ -146,6 +161,11 @@ static inline int skb_array_peek_len_any(struct skb_array
*a)
return PTR_RING_PEEK_CALL_ANY(&a->ring, __skb_array_len_with_tag);
}
+static inline int skb_array_ll_init(struct skb_array_ll *a, int size, gfp_t
gfp)
+{
+ return ptr_ring_ll_init(&a->ring, size, gfp);
+}
+
static inline int skb_array_init(struct skb_array *a, int size, gfp_t gfp)
{
return ptr_ring_init(&a->ring, size, gfp);
@@ -170,6 +190,11 @@ static inline int skb_array_resize_multiple(struct
skb_array **rings,
__skb_array_destroy_skb);
}
+static inline void skb_array_ll_cleanup(struct skb_array_ll *a)
+{
+ ptr_ring_ll_cleanup(&a->ring, __skb_array_destroy_skb);
+}
+
static inline void skb_array_cleanup(struct skb_array *a)
{
ptr_ring_cleanup(&a->ring, __skb_array_destroy_skb);
