diff --git a/Documentation/kbuild/llvm.rst b/Documentation/kbuild/llvm.rst
index bf02347d1eb2..310b9fbee38b 100644
--- a/Documentation/kbuild/llvm.rst
+++ b/Documentation/kbuild/llvm.rst
@@ -61,8 +61,71 @@ They can be enabled individually. The full list of the parameters: ::
 	  READELF=llvm-readelf HOSTCC=clang HOSTCXX=clang++ HOSTAR=llvm-ar \
 	  HOSTLD=ld.lld
 
-Currently, the integrated assembler is disabled by default. You can pass
-``LLVM_IAS=1`` to enable it.
+The integrated assembler is enabled by default. You can pass ``LLVM_IAS=0`` to
+disable it.
+
+Omitting CROSS_COMPILE
+----------------------
+
+As explained above, ``CROSS_COMPILE`` is used to set ``--target=<triple>``.
+
+If ``CROSS_COMPILE`` is not specified, the ``--target=<triple>`` is inferred
+from ``ARCH``.
+
+That means if you use only LLVM tools, ``CROSS_COMPILE`` becomes unnecessary.
+
+For example, to cross-compile the arm64 kernel::
+
+	make ARCH=arm64 LLVM=1
+
+If ``LLVM_IAS=0`` is specified, ``CROSS_COMPILE`` is also used to derive
+``--prefix=<path>`` to search for the GNU assembler and linker. ::
+
+	make ARCH=arm64 LLVM=1 LLVM_IAS=0 CROSS_COMPILE=aarch64-linux-gnu-
+
+Supported Architectures
+-----------------------
+
+LLVM does not target all of the architectures that Linux supports and
+just because a target is supported in LLVM does not mean that the kernel
+will build or work without any issues. Below is a general summary of
+architectures that currently work with ``CC=clang`` or ``LLVM=1``. Level
+of support corresponds to "S" values in the MAINTAINERS files. If an
+architecture is not present, it either means that LLVM does not target
+it or there are known issues. Using the latest stable version of LLVM or
+even the development tree will generally yield the best results.
+An architecture's ``defconfig`` is generally expected to work well,
+certain configurations may have problems that have not been uncovered
+yet. Bug reports are always welcome at the issue tracker below!
+
+.. list-table::
+   :widths: 10 10 10
+   :header-rows: 1
+
+   * - Architecture
+     - Level of support
+     - ``make`` command
+   * - arm
+     - Supported
+     - ``LLVM=1``
+   * - arm64
+     - Supported
+     - ``LLVM=1``
+   * - mips
+     - Maintained
+     - ``CC=clang``
+   * - powerpc
+     - Maintained
+     - ``CC=clang``
+   * - riscv
+     - Maintained
+     - ``CC=clang``
+   * - s390
+     - Maintained
+     - ``CC=clang``
+   * - x86
+     - Supported
+     - ``LLVM=1``
 
 Getting Help
 ------------
diff --git a/Makefile b/Makefile
index 41821aa6c947..df40004dd283 100644
--- a/Makefile
+++ b/Makefile
@@ -584,7 +584,7 @@ else
 CLANG_FLAGS	+= --target=$(notdir $(CROSS_COMPILE:%-=%))
 endif # CROSS_COMPILE
 
-ifneq ($(LLVM_IAS),1)
+ifeq ($(LLVM_IAS),0)
 CLANG_FLAGS	+= -no-integrated-as
 GCC_TOOLCHAIN_DIR := $(dir $(shell which $(CROSS_COMPILE)elfedit))
 CLANG_FLAGS	+= --prefix=$(GCC_TOOLCHAIN_DIR)$(notdir $(CROSS_COMPILE))