[UNIKRAFT PATCH 3/5] lib/ukmpi: Provide ring buffer allocation and free methods

[Alexander Jung <a.jung@xxxxxxxxxxx>]

From: Alexander Jung <alexander.jung@xxxxxxxxx>

This commit introduces two new methods for initializing and
de-initializing ring buffers.

Signed-off-by: Alexander Jung <alexander.jung@xxxxxxxxx>
---
 lib/ukmpi/ring.c | 87 ++++++++++++++++++++++++++++++++++++++++++++++++++++++++
 1 file changed, 87 insertions(+)
 create mode 100644 lib/ukmpi/ring.c

diff --git a/lib/ukmpi/ring.c b/lib/ukmpi/ring.c
new file mode 100644
index 0000000..1fbb81e
--- /dev/null
+++ b/lib/ukmpi/ring.c
@@ -0,0 +1,87 @@
+/* SPDX-License-Identifier: BSD-3-Clause */
+/*
+ * Authors: Kip Macy <kmacy@xxxxxxxxxxx>
+ *          Simon Kuenzer <simon.kuenzer@xxxxxxxxx>
+ *          Alexander Jung <alexander.jung@xxxxxxxxx>
+ *
+ * Copyright (c) 2007-2009, Kip Macy <kmacy@xxxxxxxxxxx>
+ *               2018-2020, NEC Laboratories Europe GmbH, NEC Corporation.
+ *               All rights reserved.
+ *
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions
+ * are met:
+ *
+ * 1. Redistributions of source code must retain the above copyright
+ *    notice, this list of conditions and the following disclaimer.
+ * 2. Redistributions in binary form must reproduce the above copyright
+ *    notice, this list of conditions and the following disclaimer in the
+ *    documentation and/or other materials provided with the distribution.
+ * 3. Neither the name of the copyright holder nor the names of its
+ *    contributors may be used to endorse or promote products derived from
+ *    this software without specific prior written permission.
+ *
+ * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS"
+ * AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
+ * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
+ * ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT HOLDER OR CONTRIBUTORS BE
+ * LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
+ * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
+ * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
+ * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
+ * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
+ * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
+ * POSSIBILITY OF SUCH DAMAGE.
+ */
+/*
+ * Simple ring implementation to handle object references.
+ *
+ * Inspired by FreeBSD and modified (commit-id: c45cce1).
+ */
+
+
+#include <sys/param.h>
+#include <uk/ring.h>
+#include <uk/assert.h>
+#include <uk/alloc.h>
+#include <uk/mutex.h>
+#include <uk/config.h>
+#include <uk/print.h>
+
+#ifndef POWER_OF_2
+#define POWER_OF_2(x)   (((x)) && (!((x) & ((x) - 1))))
+#endif
+
+struct uk_ring *
+uk_ring_alloc(int count, struct uk_alloc *a, int flags, struct uk_mutex *lock)
+{
+  struct uk_ring *br;
+
+  UK_ASSERT(a);
+  /* Buf ring must be size power of 2 */
+  UK_ASSERT(POWER_OF_2(count));
+  
+  br = uk_malloc(a, sizeof(struct uk_ring) + count * sizeof(caddr_t));
+  if (br == NULL) {
+    uk_pr_err("Could not allocate ring: out of memory\n");
+    return NULL;
+  }
+
+#ifdef CONFIG_LIBUKMPI_RING_DEBUG
+  br->lock = lock;
+#endif  
+
+  br->prod_size = br->cons_size = count;
+  br->prod_mask = br->cons_mask = count - 1;
+  br->prod_head = br->cons_head = 0;
+  br->prod_tail = br->cons_tail = 0;
+
+  return br;
+}
+
+void
+uk_ring_free(struct uk_ring *br, struct uk_alloc *a)
+{
+  UK_ASSERT(a);
+  uk_free(a, br);
+}
-- 
2.11.0