On Tue, Dec 01, 2020 at 09:51:44AM -0800, Minchan Kim wrote:

From: Hyesoo Yu <redacted>

This patch supports chunk heap that allocates the buffers that
arranged into a list a fixed size chunks taken from CMA.

The chunk heap doesn't use heap-helper although it can remove
duplicated code since heap-helper is under deprecated process.[1]

NOTE: This patch only adds the default CMA heap to allocate chunk
pages. We will add another CMA memory regions to the dmabuf heaps
interface with a later patch (which requires a dt binding)

This new heap seems to largely duplicate the exsting cma_heap.c
file.  Why can't you reuse the code and allow creating different
heaps with different chunk sizes or max numbers of segments?

+config DMABUF_HEAPS_CHUNK_ORDER
+	int "Chunk page order for dmabuf chunk heap"
+	default 4
+	depends on DMABUF_HEAPS_CHUNK
+	help
+	  Set page order of fixed chunk size to allocate from CMA.

Using a config option for this is just broken.  It needs to be runtime
or at very least boot time / DT controllable.

+ * ION Memory Allocator chunk heap exporter

This comment seems wrong.