svm: change fifo pointers to offsets

Type: improvement

Signed-off-by: Florin Coras <fcoras@cisco.com>
Change-Id: I113a630d6db4741f54e508f7e0ed77be139df0e4

1 files changed, 23 insertions, 8 deletions

diff --git a/src/svm/fifo_types.h b/src/svm/fifo_types.h
index 434b2c38b4c..a65b3a8831a 100644
--- a/src/svm/fifo_types.h
+++ b/src/svm/fifo_types.h
@@ -33,16 +33,18 @@ STATIC_ASSERT ((FS_MAX_LOG2_CHUNK_SZ - FS_MIN_LOG2_CHUNK_SZ) ==
 #define SVM_FIFO_MAX_EVT_SUBSCRIBERS	7
 
 typedef struct fifo_segment_header_ fifo_segment_header_t;
+typedef struct svm_fifo_chunk_ svm_fifo_chunk_t;
+typedef svm_fifo_chunk_t *svm_fifo_chunk_ptr_t;
 
-typedef struct svm_fifo_chunk_
+struct svm_fifo_chunk_
 {
   u32 start_byte;		/**< chunk start byte */
   u32 length;			/**< length of chunk in bytes */
-  struct svm_fifo_chunk_ *next;	/**< pointer to next chunk in linked-lists */
+  svm_fifo_chunk_ptr_t next;	/**< pointer to next chunk in linked-lists */
   rb_node_index_t enq_rb_index;	/**< enq node index if chunk in rbtree */
   rb_node_index_t deq_rb_index;	/**< deq node index if chunk in rbtree */
   u8 data[0];			/**< start of chunk data */
-} svm_fifo_chunk_t;
+};
 
 typedef struct
 {
@@ -62,8 +64,8 @@ typedef struct
 typedef struct svm_fifo_shr_
 {
   CLIB_CACHE_LINE_ALIGN_MARK (shared);
-  svm_fifo_chunk_t *start_chunk;/**< first chunk in fifo chunk list */
-  svm_fifo_chunk_t *end_chunk;	/**< end chunk in fifo chunk list */
+  svm_fifo_chunk_ptr_t start_chunk; /**< first chunk in fifo chunk list */
+  svm_fifo_chunk_ptr_t end_chunk;   /**< end chunk in fifo chunk list */
   volatile u32 has_event;	/**< non-zero if deq event exists */
   u32 min_alloc;		/**< min chunk alloc if space available */
   u32 size;			/**< size of the fifo in bytes */
@@ -73,14 +75,14 @@ typedef struct svm_fifo_shr_
   struct svm_fifo_shr_ *next;	/**< next in freelist/active chain */
 
   CLIB_CACHE_LINE_ALIGN_MARK (consumer);
-  svm_fifo_chunk_t *head_chunk;	/**< tracks chunk where head lands */
+  svm_fifo_chunk_ptr_t head_chunk; /**< tracks chunk where head lands */
   u32 head;			/**< fifo head position/byte */
   volatile u32 want_deq_ntf;	/**< producer wants nudge */
   volatile u32 has_deq_ntf;
 
   CLIB_CACHE_LINE_ALIGN_MARK (producer);
   u32 tail;			/**< fifo tail position/byte */
-  svm_fifo_chunk_t *tail_chunk;	/**< tracks chunk where tail lands */
+  svm_fifo_chunk_ptr_t tail_chunk; /**< tracks chunk where tail lands */
   volatile u8 n_subscribers;	/**< Number of subscribers for io events */
   u8 subscribers[SVM_FIFO_MAX_EVT_SUBSCRIBERS];
 } svm_fifo_shared_t;
@@ -115,7 +117,8 @@ typedef struct _svm_fifo
 
 typedef struct fifo_segment_slice_
 {
-  svm_fifo_chunk_t *free_chunks[FS_CHUNK_VEC_LEN]; /**< Free chunks by size */
+  svm_fifo_chunk_ptr_t
+    free_chunks[FS_CHUNK_VEC_LEN];	/**< Free chunks by size */
   svm_fifo_t *fifos;			/**< Linked list of active RX fifos */
   svm_fifo_shared_t *free_fifos;	/**< Freelists of fifo shared hdrs  */
   uword n_fl_chunk_bytes;		/**< Chunk bytes on freelist */
@@ -153,6 +156,18 @@ struct fifo_segment_header_
 void fsh_virtual_mem_update (fifo_segment_header_t * fsh, u32 slice_index,
 			     int n_bytes);
 
+always_inline svm_fifo_chunk_t *
+fs_chunk_ptr (fifo_segment_header_t *fsh, svm_fifo_chunk_ptr_t cp)
+{
+  return cp ? (svm_fifo_chunk_t *) ((u8 *) fsh + pointer_to_uword (cp)) : 0;
+}
+
+always_inline svm_fifo_chunk_ptr_t
+fs_chunk_sptr (fifo_segment_header_t *fsh, svm_fifo_chunk_t *c)
+{
+  return c ? (svm_fifo_chunk_ptr_t) ((u8 *) c - (u8 *) fsh) : 0;
+}
+
 #endif /* SRC_SVM_FIFO_TYPES_H_ */
 
 /*