session/svm: apis for fifo shrinking

Change-Id: Ie519683bb90aae6fb95f2a09e251cded1890ed41
Signed-off-by: Florin Coras <fcoras@cisco.com>

3 files changed, 42 insertions, 1 deletions

diff --git a/src/svm/fifo_segment.c b/src/svm/fifo_segment.c
index 9c332d6f1fa..0263d1a57cc 100644
--- a/src/svm/fifo_segment.c
+++ b/src/svm/fifo_segment.c
@@ -570,6 +570,35 @@ fifo_segment_grow_fifo (fifo_segment_t * fs, svm_fifo_t * f, u32 chunk_size)
   return 0;
 }
 
+int
+fifo_segment_collect_fifo_chunks (fifo_segment_t * fs, svm_fifo_t * f)
+{
+  svm_fifo_chunk_t *cur, *next;
+  ssvm_shared_header_t *sh;
+  void *oldheap;
+  int fl_index;
+
+  sh = fs->ssvm.sh;
+  ssvm_lock_non_recursive (sh, 1);
+
+  oldheap = ssvm_push_heap (sh);
+  cur = svm_fifo_collect_chunks (f);
+
+  while (cur)
+    {
+      next = cur->next;
+      fl_index = fs_free_list_for_size (cur->length);
+      cur->next = fs->h->free_chunks[fl_index];
+      fs->h->free_chunks[fl_index] = cur;
+      cur = next;
+    }
+
+  ssvm_pop_heap (oldheap);
+  ssvm_unlock_non_recursive (sh);
+
+  return 0;
+}
+
 /**
  * Get number of active fifos
  */
diff --git a/src/svm/fifo_segment.h b/src/svm/fifo_segment.h
index 6ff538fcc07..bb4f4080502 100644
--- a/src/svm/fifo_segment.h
+++ b/src/svm/fifo_segment.h
@@ -128,6 +128,15 @@ void fifo_segment_preallocate_fifo_pairs (fifo_segment_t * fs,
  */
 int fifo_segment_grow_fifo (fifo_segment_t * fs, svm_fifo_t * f,
 			    u32 chunk_size);
+
+/**
+ * Collect unused chunks for fifo
+ *
+ * @param fs		fifo segment for fifo
+ * @param f		fifo whose chunks are to be collected
+ * @return		0 on success, error otherwise
+ */
+int fifo_segment_collect_fifo_chunks (fifo_segment_t * fs, svm_fifo_t * f);
 u8 fifo_segment_has_fifos (fifo_segment_t * fs);
 svm_fifo_t *fifo_segment_get_fifo_list (fifo_segment_t * fs);
 u32 fifo_segment_num_fifos (fifo_segment_t * fs);
diff --git a/src/svm/svm_fifo.c b/src/svm/svm_fifo.c
index e017b619d15..3824d998866 100644
--- a/src/svm/svm_fifo.c
+++ b/src/svm/svm_fifo.c
@@ -677,7 +677,10 @@ svm_fifo_reduce_size (svm_fifo_t * f, u32 len, u8 try_shrink)
   svm_fifo_chunk_t *cur;
   u32 actual_len = 0;
 
-  if (len > f->nitems)
+  /* Abort if trying to reduce by more than fifo size or if
+   * fifo is undergoing resizing already */
+  if (len >= f->size || f->size > f->nitems + 1
+      || (f->flags & SVM_FIFO_F_SHRINK) || (f->flags & SVM_FIFO_F_GROW))
     return 0;
 
   /* last chunk that will not be removed */