memzone: clarify support for zero-length memzones

Currently, memzone allocation with length set to 0 that are also
IOVA-contiguous is not supported. Document this limitation.

Signed-off-by: Anatoly Burakov <anatoly.burakov@intel.com>

diff --git a/lib/librte_eal/common/include/rte_memzone.h b/lib/librte_eal/common/include/rte_memzone.h
index a4c9bd6..ef370fa 100644 (file)
--- a/lib/librte_eal/common/include/rte_memzone.h
+++ b/lib/librte_eal/common/include/rte_memzone.h
@@ -81,6 +81,9 @@ struct rte_memzone {
  *   memzones from memory that is already available. It will not trigger any
  *   new allocations.
  *
+ * @note Reserving IOVA-contiguous memzones with len set to 0 is not currently
+ *   supported.
+ *
  * @param name
  *   The name of the memzone. If it already exists, the function will
  *   fail and return NULL.
@@ -138,6 +141,9 @@ const struct rte_memzone *rte_memzone_reserve(const char *name,
  *   memzones from memory that is already available. It will not trigger any
  *   new allocations.
  *
+ * @note Reserving IOVA-contiguous memzones with len set to 0 is not currently
+ *   supported.
+ *
  * @param name
  *   The name of the memzone. If it already exists, the function will
  *   fail and return NULL.
@@ -200,6 +206,9 @@ const struct rte_memzone *rte_memzone_reserve_aligned(const char *name,
  *   memzones from memory that is already available. It will not trigger any
  *   new allocations.
  *
+ * @note Reserving IOVA-contiguous memzones with len set to 0 is not currently
+ *   supported.
+ *
  * @param name
  *   The name of the memzone. If it already exists, the function will
  *   fail and return NULL.