fd5f33323e
Syncing the values by adding c11 atomic memory barriers to make sure the values being synced before updating fifo_write and fifo_read. Signed-off-by: Phil Yang <phil.yang@arm.com> Reviewed-by: Honnappa Nagarahalli <honnappa.nagarahalli@arm.com> Reviewed-by: Gavin Hu <gavin.hu@arm.com> Reviewed-by: Ola Liljedahl <ola.liljedahl@arm.com> Reviewed-by: Ferruh Yigit <ferruh.yigit@intel.com>
107 lines
2.7 KiB
C
107 lines
2.7 KiB
C
/* 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
|
|
*/
|
|
static void
|
|
kni_fifo_init(struct rte_kni_fifo *fifo, unsigned size)
|
|
{
|
|
/* Ensure size is power of 2 */
|
|
if (size & (size - 1))
|
|
rte_panic("KNI fifo size must be power of 2\n");
|
|
|
|
fifo->write = 0;
|
|
fifo->read = 0;
|
|
fifo->len = size;
|
|
fifo->elem_size = sizeof(void *);
|
|
}
|
|
|
|
/**
|
|
* Adds num elements into the fifo. Return the number actually written
|
|
*/
|
|
static inline unsigned
|
|
kni_fifo_put(struct rte_kni_fifo *fifo, void **data, unsigned num)
|
|
{
|
|
unsigned i = 0;
|
|
unsigned fifo_write = fifo->write;
|
|
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);
|
|
|
|
if (new_write == fifo_read)
|
|
break;
|
|
fifo->buffer[fifo_write] = data[i];
|
|
fifo_write = new_write;
|
|
}
|
|
__KNI_STORE_RELEASE(&fifo->write, fifo_write);
|
|
return i;
|
|
}
|
|
|
|
/**
|
|
* 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 = __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);
|
|
}
|
|
__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);
|
|
}
|