Add docs

Author: tiran

Doc/c-api/type.rst

@@ -272,12 +272,6 @@ The following functions and structs are used to create
       * :c:member:`~PyTypeObject.tp_vectorcall_offset`
         (see :ref:`PyMemberDef <pymemberdef-offsets>`)
 
-      The following fields cannot be set using :c:type:`PyType_Spec` and
-      :c:type:`PyType_Slot` under the limited API:
-
-      * :c:member:`~PyBufferProcs.bf_getbuffer`
-      * :c:member:`~PyBufferProcs.bf_releasebuffer`
-
       Setting :c:data:`Py_tp_bases` or :c:data:`Py_tp_base` may be
       problematic on some platforms.
       To avoid issues, use the *bases* argument of
@@ -287,6 +281,11 @@ The following functions and structs are used to create
 
         Slots in :c:type:`PyBufferProcs` in may be set in the unlimited API.
 
+     .. versionchanged:: 3.11
+        :c:member:`~PyBufferProcs.bf_getbuffer` and
+        :c:member:`~PyBufferProcs.bf_releasebuffer` are now available
+        under limited API.
+
    .. c:member:: void *PyType_Slot.pfunc
 
       The desired value of the slot. In most cases, this is a pointer

Doc/whatsnew/3.11.rst

@@ -657,6 +657,26 @@ New Features
   :c:macro:`PY_VERSION_HEX`.
   (Contributed by  Gabriele N. Tornetta in :issue:`43931`.)
 
+* :c:type:`Py_buffer` and APIs are now part of the limited API and the stable
+  ABI:
+
+  * :c:func:`PyObject_CheckBuffer`
+  * :c:func:`PyObject_GetBuffer`
+  * :c:func:`PyBuffer_GetPointer`
+  * :c:func:`PyBuffer_SizeFromFormat`
+  * :c:func:`PyBuffer_ToContiguous`
+  * :c:func:`PyBuffer_FromContiguous`
+  * :c:func:`PyBuffer_CopyData`
+  * :c:func:`PyBuffer_IsContiguous`
+  * :c:func:`PyBuffer_FillContiguousStrides`
+  * :c:func:`PyBuffer_FillInfo`
+  * :c:func:`PyBuffer_Release`
+  * :c:func:`PyMemoryView_FromBuffer`
+  * :c:member:`~PyBufferProcs.bf_getbuffer` and
+    :c:member:`~PyBufferProcs.bf_releasebuffer` type slots
+
+  (Contributed by Christian Heimes in :issue:`45459`.)
+
 
 Porting to Python 3.11
 ----------------------

Misc/NEWS.d/next/C API/2021-10-18-16-54-24.bpo-45459.Y1pEZs.rst

@@ -1 +1,2 @@
-Add :c:type:`Py_buffer` to limited API / stable ABI.
+:c:type:`Py_buffer` and various ``Py_buffer`` related functions are now
+part of the limited API and stable ABI.