1 files changed, 104 insertions, 0 deletions
diff --git a/lib/sprt/sprt_queue.c b/lib/sprt/sprt_queue.c
new file mode 100644
index 00000000..2bd4139e
--- /dev/null
+++ b/lib/sprt/sprt_queue.c
@@ -0,0 +1,104 @@
+/*
+ * Copyright (c) 2018, Arm Limited. All rights reserved.
+ *
+ * SPDX-License-Identifier: BSD-3-Clause
+ */
+
+#include <assert.h>
+#include <errno.h>
+#include <stdint.h>
+#include <string.h>
+
+#include "sprt_queue.h"
+
+void sprt_queue_init(void *queue_base, uint32_t entry_num, uint32_t entry_size)
+{
+	assert(queue_base != NULL);
+	assert(entry_size > 0U);
+	assert(entry_num > 0U);
+
+	struct sprt_queue *queue = (struct sprt_queue *)queue_base;
+
+	queue->entry_num = entry_num;
+	queue->entry_size = entry_size;
+	queue->idx_write = 0U;
+	queue->idx_read = 0U;
+
+	memset(queue->data, 0, entry_num * entry_size);
+}
+
+int sprt_queue_is_empty(void *queue_base)
+{
+	assert(queue_base != NULL);
+
+	struct sprt_queue *queue = (struct sprt_queue *)queue_base;
+
+	return (queue->idx_write == queue->idx_read);
+}
+
+int sprt_queue_is_full(void *queue_base)
+{
+	assert(queue_base != NULL);
+
+	struct sprt_queue *queue = (struct sprt_queue *)queue_base;
+
+	uint32_t idx_next_write = (queue->idx_write + 1) % queue->entry_num;
+
+	return (idx_next_write == queue->idx_read);
+}
+
+int sprt_queue_push(void *queue_base, const void *entry)
+{
+	assert(entry != NULL);
+	assert(queue_base != NULL);
+
+	if (sprt_queue_is_full(queue_base) != 0) {
+		return -ENOMEM;
+	}
+
+	struct sprt_queue *queue = (struct sprt_queue *)queue_base;
+
+	uint8_t *dst_entry = &queue->data[queue->entry_size * queue->idx_write];
+
+	memcpy(dst_entry, entry, queue->entry_size);
+
+	/*
+	 * Make sure that the message data is visible before increasing the
+	 * counter of available messages.
+	 */
+	__asm__ volatile("dmb st" ::: "memory");
+
+	queue->idx_write = (queue->idx_write + 1) % queue->entry_num;
+
+	__asm__ volatile("dmb st" ::: "memory");
+
+	return 0;
+}
+
+int sprt_queue_pop(void *queue_base, void *entry)
+{
+	assert(entry != NULL);
+	assert(queue_base != NULL);
+
+	if (sprt_queue_is_empty(queue_base) != 0) {
+		return -ENOENT;
+	}
+
+	struct sprt_queue *queue = (struct sprt_queue *)queue_base;
+
+	uint8_t *src_entry = &queue->data[queue->entry_size * queue->idx_read];
+
+	memcpy(entry, src_entry, queue->entry_size);
+
+	/*
+	 * Make sure that the message data is visible before increasing the
+	 * counter of read messages.
+	 */
+	__asm__ volatile("dmb st" ::: "memory");
+
+	queue->idx_read = (queue->idx_read + 1) % queue->entry_num;
+
+	__asm__ volatile("dmb st" ::: "memory");
+
+	return 0;
+}