svm vcl: allow random offsets for fifo segments in apps

Type: improvement

Signed-off-by: Florin Coras <fcoras@cisco.com>
Change-Id: I1658a9c19d8eae4c9a42c0a111d4ad343b8eb8a4

2 files changed, 34 insertions, 10 deletions

diff --git a/src/svm/fifo_segment.c b/src/svm/fifo_segment.c
index 0c3a79a613b..4ffec7c86d0 100644
--- a/src/svm/fifo_segment.c
+++ b/src/svm/fifo_segment.c
@@ -278,7 +278,11 @@ fifo_segment_init (fifo_segment_t * fs)
   ASSERT (fsh->max_byte_index <= sh->ssvm_size - offset);
 
   fs->max_byte_index = fsh->max_byte_index;
-  fs->h = sh->opaque[0] = fsh;
+  fs->h = fsh;
+  sh->opaque[0] = (void *) ((u8 *) fsh - (u8 *) fs->ssvm.sh);
+
+  /* Allow random offsets */
+  fs->ssvm.sh->ssvm_va = 0;
 
   vec_validate (fs->slices, fs->n_slices - 1);
   for (i = 0; i < fs->n_slices; i++)
@@ -338,7 +342,7 @@ fifo_segment_attach (fifo_segment_main_t * sm, fifo_segment_create_args_t * a)
   fs->ssvm.ssvm_size = a->segment_size;
   fs->ssvm.my_pid = getpid ();
   fs->ssvm.name = format (0, "%s%c", a->segment_name, 0);
-  fs->ssvm.requested_va = sm->next_baseva;
+  fs->ssvm.requested_va = 0;
   if (a->segment_type == SSVM_SEGMENT_MEMFD)
     fs->ssvm.fd = a->memfd_fd;
   else
@@ -346,17 +350,15 @@ fifo_segment_attach (fifo_segment_main_t * sm, fifo_segment_create_args_t * a)
 
   if ((rv = ssvm_client_init (&fs->ssvm, a->segment_type)))
     {
-      _vec_len (fs) = vec_len (fs) - 1;
+      pool_put (sm->segments, fs);
       return (rv);
     }
 
-  /* Fish the segment header */
-  fsh = fs->h = fs->ssvm.sh->opaque[0];
-
   /* Probably a segment without fifos */
-  if (!fsh)
+  if (!fs->ssvm.sh->opaque[0])
     goto done;
 
+  fsh = fs->h = (void *) fs->ssvm.sh + (uword) fs->ssvm.sh->opaque[0];
   fs->max_byte_index = fsh->max_byte_index;
   vec_validate (fs->slices, 0);
   fs->slices[0].fifos =
@@ -824,9 +826,12 @@ done:
 }
 
 svm_fifo_t *
-fifo_segment_alloc_fifo_w_shared (fifo_segment_t *fs, svm_fifo_shared_t *sf)
+fifo_segment_alloc_fifo_w_offset (fifo_segment_t *fs, uword offset)
 {
   svm_fifo_t *f = fs_fifo_alloc (fs, 0);
+  svm_fifo_shared_t *sf;
+
+  sf = (svm_fifo_shared_t *) ((u8 *) fs->h + offset);
   f->fs_hdr = fs->h;
   f->shr = sf;
 
@@ -950,6 +955,12 @@ fifo_segment_attach_fifo (fifo_segment_t * fs, svm_fifo_t * f,
     }
 }
 
+uword
+fifo_segment_fifo_offset (svm_fifo_t *f)
+{
+  return (u8 *) f->shr - (u8 *) f->fs_hdr;
+}
+
 svm_msg_q_t *
 fifo_segment_msg_q_alloc (fifo_segment_t *fs, u32 mq_index,
 			  svm_msg_q_cfg_t *cfg)
diff --git a/src/svm/fifo_segment.h b/src/svm/fifo_segment.h
index 195869a25dd..8266690d4ed 100644
--- a/src/svm/fifo_segment.h
+++ b/src/svm/fifo_segment.h
@@ -104,6 +104,18 @@ fifo_segment_t *fifo_segment_get_segment (fifo_segment_main_t * sm,
 u32 fifo_segment_index (fifo_segment_main_t * sm, fifo_segment_t * fs);
 void fifo_segment_info (fifo_segment_t * seg, char **address, size_t * size);
 
+always_inline void *
+fifo_segment_ptr (fifo_segment_t *fs, uword offset)
+{
+  return (void *) ((u8 *) fs->h + offset);
+}
+
+always_inline uword
+fifo_segment_offset (fifo_segment_t *fs, void *p)
+{
+  return (uword) ((u8 *) p - (u8 *) fs->h);
+}
+
 /**
  * Allocate fifo in fifo segment
  *
@@ -116,8 +128,8 @@ svm_fifo_t *fifo_segment_alloc_fifo_w_slice (fifo_segment_t * fs,
 					     u32 slice_index,
 					     u32 data_bytes,
 					     fifo_segment_ftype_t ftype);
-svm_fifo_t *fifo_segment_alloc_fifo_w_shared (fifo_segment_t *fs,
-					      svm_fifo_shared_t *sf);
+svm_fifo_t *fifo_segment_alloc_fifo_w_offset (fifo_segment_t *fs,
+					      uword offset);
 
 /**
  * Free fifo allocated in fifo segment
@@ -130,6 +142,7 @@ void fifo_segment_free_fifo (fifo_segment_t * fs, svm_fifo_t * f);
 void fifo_segment_detach_fifo (fifo_segment_t * fs, svm_fifo_t * f);
 void fifo_segment_attach_fifo (fifo_segment_t * fs, svm_fifo_t * f,
 			       u32 slice_index);
+uword fifo_segment_fifo_offset (svm_fifo_t *f);
 
 /**
  * Allocate message queue on segment