These patch series to introduce a new dma heap, chunk heap. That heap is needed for special HW that requires bulk allocation of fixed high order pages. For example, 64MB dma-buf pages are made up to fixed order-4 pages * 1024. The chunk heap uses alloc_pages_bulk to allocate high order page. https://lore.kernel.org/linux-mm/20200814173131.2803002-1-minchan@xxxxxxxxxx The chunk heap is registered by device tree with alignment and memory node of contiguous memory allocator(CMA). Alignment defines chunk page size. For example, alignment 0x1_0000 means chunk page size is 64KB. The phandle to memory node indicates contiguous memory allocator(CMA). If device node doesn't have cma, the registration of chunk heap fails. The patchset includes the following: - export dma-heap API to register kernel module dma heap. - add chunk heap implementation. - document of device tree to register chunk heap Hyesoo Yu (3): dma-buf: add missing EXPORT_SYMBOL_GPL() for dma heaps dma-buf: heaps: add chunk heap to dmabuf heaps dma-heap: Devicetree binding for chunk heap .../devicetree/bindings/dma-buf/chunk_heap.yaml | 46 +++++ drivers/dma-buf/dma-heap.c | 2 + drivers/dma-buf/heaps/Kconfig | 9 + drivers/dma-buf/heaps/Makefile | 1 + drivers/dma-buf/heaps/chunk_heap.c | 222 +++++++++++++++++++++ drivers/dma-buf/heaps/heap-helpers.c | 2 + 6 files changed, 282 insertions(+) create mode 100644 Documentation/devicetree/bindings/dma-buf/chunk_heap.yaml create mode 100644 drivers/dma-buf/heaps/chunk_heap.c -- 2.7.4
