Add specification for cl_ext_immutable_memory_objects (KhronosGroup#1280)

Fixes KhronosGroup#1110

Change-Id: I120f66ad20f977c251b77cc42a32021cb407518e

Signed-off-by: Kevin Petit <kevin.petit@arm.com>

Author: kpet

api/cl_ext_immutable_memory_objects.asciidoc

@@ -0,0 +1,43 @@
+// Copyright 2024 The Khronos Group Inc.
+// SPDX-License-Identifier: CC-BY-4.0
+
+include::{generated}/meta/{refprefix}cl_ext_immutable_memory_objects.txt[]
+
+=== Other Extension Metadata
+
+*Last Modified Date*::
+    2024-11-06
+*IP Status*::
+    No known IP claims.
+*Contributors*::
+  - Kevin Petit, Arm Ltd.
+  - Ahmed Hesham, Arm Ltd.
+  - Michael Rizkalla, Arm Ltd.
+*Interactions*::
+  - This extension interacts with {cl_khr_egl_image_EXT}.
+
+=== Description
+
+{cl_ext_immutable_memory_objects_EXT} provides a mechanism to create memory
+objects that cannot be modified by the implementation after creation. This,
+for example, enables implementation to support image formats for which no write
+operations can be supported.
+
+=== New Enums
+
+  * {cl_mem_flags_TYPE}
+  ** {CL_MEM_IMMUTABLE_EXT}
+
+=== Issues
+
+1) Can {CL_MEM_READ_ONLY} be used instead of {CL_MEM_IMMUTABLE_EXT}?
+--
+*RESOLVED*: No. Memory objects created with {CL_MEM_READ_ONLY} can be modified
+by copy or fill commands and this behaviour cannot be changed without breaking
+backwards compatibility.
+--
+
+=== Version History
+
+  * Revision 1.0.0, 2024-11-06
+  ** Initial version

api/glossary.asciidoc

@@ -336,6 +336,16 @@ The elements of an image are selected from a list of predefined image
 formats.
 --
 
+ifdef::cl_ext_immutable_memory_objects[]
+Immutable Memory Object ::
+    A _memory object_ whose contents cannot be altered by the implementation
+    after creation.
+ifdef::cl_khr_external_memory[]
+    External entities may change the contents of
+    _immutable memory objects_ created from external handles.
+endif::cl_khr_external_memory[]
+endif::cl_ext_immutable_memory_objects[]
+
 Implementation-Defined ::
     Behavior that is explicitly allowed to vary between conforming
     implementations of OpenCL.