SVM_FIFO_NO_DEQ_NOTIF = 0, /**< No notification requested */
SVM_FIFO_WANT_DEQ_NOTIF = 1, /**< Notify on dequeue */
SVM_FIFO_WANT_DEQ_NOTIF_IF_FULL = 2, /**< Notify on transition from full */
- SVM_FIFO_WANT_DEQ_NOTIF_IF_EMPTY = 4, /**< Notify on transition to empty */
+ SVM_FIFO_WANT_DEQ_NOTIF_IF_EMPTY = 4, /**< Notify on transition to empty */
} svm_fifo_deq_ntf_t;
typedef enum svm_fifo_flag_
}
always_inline svm_fifo_chunk_t *
-f_cptr (svm_fifo_t *f, svm_fifo_chunk_ptr_t cp)
+f_cptr (svm_fifo_t *f, fs_sptr_t cp)
{
return fs_chunk_ptr (f->fs_hdr, cp);
}
-always_inline svm_fifo_chunk_ptr_t
+always_inline fs_sptr_t
f_csptr (svm_fifo_t *f, svm_fifo_chunk_t *c)
{
return fs_chunk_sptr (f->fs_hdr, c);
}
always_inline void
-f_csptr_link (svm_fifo_t *f, svm_fifo_chunk_ptr_t cp, svm_fifo_chunk_t *c)
+f_csptr_link (svm_fifo_t *f, fs_sptr_t cp, svm_fifo_chunk_t *c)
{
fs_chunk_ptr (f->fs_hdr, cp)->next = fs_chunk_sptr (f->fs_hdr, c);
}
* @param max_bytes max bytes to be mapped to fifo segments
* @return number of bytes in fifo segments or SVM_FIFO_EEMPTY
*/
-int svm_fifo_segments (svm_fifo_t * f, u32 offset, svm_fifo_seg_t * fs,
- u32 n_segs, u32 max_bytes);
+int svm_fifo_segments (svm_fifo_t *f, u32 offset, svm_fifo_seg_t *fs,
+ u32 *n_segs, u32 max_bytes);
/**
* Add io events subscriber to list
*
*/
u32 svm_fifo_max_write_chunk (svm_fifo_t * f);
-/**
- * Fifo head chunk getter
- *
- * @param f fifo
- * @return head chunk pointer
- */
-static inline svm_fifo_chunk_t *
-svm_fifo_head_chunk (svm_fifo_t * f)
-{
- return f_head_cptr (f);
-}
-
-/**
- * Fifo head pointer getter
- *
- * @param f fifo
- * @return head pointer
- */
-static inline u8 *
-svm_fifo_head (svm_fifo_t * f)
-{
- svm_fifo_chunk_t *head_chunk;
- if (!f->shr->head_chunk)
- return 0;
- /* load-relaxed: consumer owned index */
- head_chunk = f_head_cptr (f);
- return (head_chunk->data + (f->shr->head - head_chunk->start_byte));
-}
-
-/**
- * Fifo tail chunk getter
- *
- * @param f fifo
- * @return tail chunk pointer
- */
-static inline svm_fifo_chunk_t *
-svm_fifo_tail_chunk (svm_fifo_t * f)
-{
- return f_tail_cptr (f);
-}
-
-/**
- * Fifo tail pointer getter
- *
- * @param f fifo
- * @return tail pointer
- */
-static inline u8 *
-svm_fifo_tail (svm_fifo_t * f)
-{
- svm_fifo_chunk_t *tail_chunk;
-
- /* load-relaxed: producer owned index */
- tail_chunk = f_tail_cptr (f);
- return (tail_chunk->data + (f->shr->tail - tail_chunk->start_byte));
-}
-
/**
* Fifo number of subscribers getter
*
static inline void
svm_fifo_add_want_deq_ntf (svm_fifo_t * f, u8 ntf_type)
{
- f->shr->want_deq_ntf |= ntf_type;
+ __atomic_or_fetch (&f->shr->want_deq_ntf, ntf_type, __ATOMIC_RELEASE);
}
/**
static inline void
svm_fifo_del_want_deq_ntf (svm_fifo_t * f, u8 ntf_type)
{
- f->shr->want_deq_ntf &= ~ntf_type;
+ __atomic_and_fetch (&f->shr->want_deq_ntf, ~ntf_type, __ATOMIC_RELEASE);
+}
+
+/**
+ * Get want notification flag
+ *
+ * Done atomically with acquire memory ordering
+ *
+ * @param f fifo
+ * @return value of want_deq_ntf flag
+ */
+static inline u32
+svm_fifo_get_want_deq_ntf (svm_fifo_t *f)
+{
+ return clib_atomic_load_acq_n (&f->shr->want_deq_ntf);
}
/**
static inline void
svm_fifo_clear_deq_ntf (svm_fifo_t * f)
{
- /* Set the flag if want_notif_if_full was the only ntf requested */
- f->shr->has_deq_ntf =
- f->shr->want_deq_ntf == SVM_FIFO_WANT_DEQ_NOTIF_IF_FULL;
- svm_fifo_del_want_deq_ntf (f, SVM_FIFO_WANT_DEQ_NOTIF);
+ u32 want_deq_ntf = svm_fifo_get_want_deq_ntf (f);
+ /* Set the flag if want ntf if full or empty was requested */
+ if (want_deq_ntf &
+ (SVM_FIFO_WANT_DEQ_NOTIF_IF_FULL | SVM_FIFO_WANT_DEQ_NOTIF_IF_EMPTY))
+ clib_atomic_store_rel_n (&f->shr->has_deq_ntf, 1);
+ if (want_deq_ntf & SVM_FIFO_WANT_DEQ_NOTIF)
+ svm_fifo_del_want_deq_ntf (f, SVM_FIFO_WANT_DEQ_NOTIF);
+}
+
+/**
+ * Get has dequeue notification flag
+ *
+ * Done atomically with acquire memory ordering
+ *
+ * @param f fifo
+ * @return has_deq_ntf flag
+ */
+static inline u32
+svm_fifo_has_deq_ntf (svm_fifo_t *f)
+{
+ return clib_atomic_load_acq_n (&f->shr->has_deq_ntf);
}
/**
static inline u8
svm_fifo_needs_deq_ntf (svm_fifo_t * f, u32 n_last_deq)
{
- u8 want_ntf = f->shr->want_deq_ntf;
+ u32 want_ntf = svm_fifo_get_want_deq_ntf (f);
- if (PREDICT_TRUE (want_ntf == SVM_FIFO_NO_DEQ_NOTIF))
+ if (want_ntf == SVM_FIFO_NO_DEQ_NOTIF)
return 0;
else if (want_ntf & SVM_FIFO_WANT_DEQ_NOTIF)
- return 1;
+ return (svm_fifo_max_enqueue (f) >= f->shr->deq_thresh);
if (want_ntf & SVM_FIFO_WANT_DEQ_NOTIF_IF_FULL)
{
u32 max_deq = svm_fifo_max_dequeue_cons (f);
u32 size = f->shr->size;
- if (!f->shr->has_deq_ntf && max_deq < size &&
- max_deq + n_last_deq >= size)
+ if (max_deq < size && max_deq + n_last_deq >= size &&
+ !svm_fifo_has_deq_ntf (f))
return 1;
}
if (want_ntf & SVM_FIFO_WANT_DEQ_NOTIF_IF_EMPTY)
{
- if (!f->shr->has_deq_ntf && svm_fifo_is_empty (f))
+ if (!svm_fifo_has_deq_ntf (f) && svm_fifo_is_empty (f))
return 1;
}
return 0;
}
+/**
+ * Set the fifo dequeue threshold which will be used for notifications.
+ *
+ * Note: If not set, by default threshold is zero, equivalent to
+ * generating notification on each dequeue event.
+ */
+static inline void
+svm_fifo_set_deq_thresh (svm_fifo_t *f, u32 thresh)
+{
+ f->shr->deq_thresh = thresh;
+}
+
#endif /* __included_ssvm_fifo_h__ */
/*
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