-/*-
- * BSD LICENSE
- *
- * Copyright(c) 2010-2014 Intel Corporation. All rights reserved.
- * All rights reserved.
- *
- * Redistribution and use in source and binary forms, with or without
- * modification, are permitted provided that the following conditions
- * are met:
- *
- * * Redistributions of source code must retain the above copyright
- * notice, this list of conditions and the following disclaimer.
- * * 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.
- * * Neither the name of Intel Corporation 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
- * OWNER 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.
+/* SPDX-License-Identifier: BSD-3-Clause
+ * Copyright(c) 2010-2014 Intel Corporation
*/
+/**
+ * @internal when c11 memory model enabled use c11 atomic memory barrier.
+ * when under non c11 memory model use rte_smp_* memory barrier.
+ *
+ * @param src
+ * Pointer to the source data.
+ * @param dst
+ * Pointer to the destination data.
+ * @param value
+ * Data value.
+ */
+#ifdef RTE_USE_C11_MEM_MODEL
+#define __KNI_LOAD_ACQUIRE(src) ({ \
+ __atomic_load_n((src), __ATOMIC_ACQUIRE); \
+ })
+#define __KNI_STORE_RELEASE(dst, value) do { \
+ __atomic_store_n((dst), value, __ATOMIC_RELEASE); \
+ } while(0)
+#else
+#define __KNI_LOAD_ACQUIRE(src) ({ \
+ typeof (*(src)) val = *(src); \
+ rte_smp_rmb(); \
+ val; \
+ })
+#define __KNI_STORE_RELEASE(dst, value) do { \
+ *(dst) = value; \
+ rte_smp_wmb(); \
+ } while(0)
+#endif
+
/**
* Initializes the kni fifo structure
*/
{
unsigned i = 0;
unsigned fifo_write = fifo->write;
- unsigned fifo_read = fifo->read;
unsigned new_write = fifo_write;
+ unsigned fifo_read = __KNI_LOAD_ACQUIRE(&fifo->read);
for (i = 0; i < num; i++) {
new_write = (new_write + 1) & (fifo->len - 1);
fifo->buffer[fifo_write] = data[i];
fifo_write = new_write;
}
- fifo->write = fifo_write;
+ __KNI_STORE_RELEASE(&fifo->write, fifo_write);
return i;
}
/**
- * Get up to num elements from the fifo. Return the number actully read
+ * Get up to num elements from the fifo. Return the number actually read
*/
static inline unsigned
kni_fifo_get(struct rte_kni_fifo *fifo, void **data, unsigned num)
{
unsigned i = 0;
unsigned new_read = fifo->read;
- unsigned fifo_write = fifo->write;
+ unsigned fifo_write = __KNI_LOAD_ACQUIRE(&fifo->write);
+
for (i = 0; i < num; i++) {
if (new_read == fifo_write)
break;
data[i] = fifo->buffer[new_read];
new_read = (new_read + 1) & (fifo->len - 1);
}
- fifo->read = new_read;
+ __KNI_STORE_RELEASE(&fifo->read, new_read);
return i;
}
+
+/**
+ * Get the num of elements in the fifo
+ */
+static inline uint32_t
+kni_fifo_count(struct rte_kni_fifo *fifo)
+{
+ unsigned fifo_write = __KNI_LOAD_ACQUIRE(&fifo->write);
+ unsigned fifo_read = __KNI_LOAD_ACQUIRE(&fifo->read);
+ return (fifo->len + fifo_write - fifo_read) & (fifo->len - 1);
+}
+
+/**
+ * Get the num of available elements in the fifo
+ */
+static inline uint32_t
+kni_fifo_free_count(struct rte_kni_fifo *fifo)
+{
+ uint32_t fifo_write = __KNI_LOAD_ACQUIRE(&fifo->write);
+ uint32_t fifo_read = __KNI_LOAD_ACQUIRE(&fifo->read);
+ return (fifo_read - fifo_write - 1) & (fifo->len - 1);
+}