menuconfig ION bool "Ion Memory Manager" depends on HAVE_MEMBLOCK && HAS_DMA && MMU select GENERIC_ALLOCATOR select DMA_SHARED_BUFFER ---help--- Chose this option to enable the ION Memory Manager, used by Android to efficiently allocate buffers from userspace that can be shared between drivers. If you're not using Android its probably safe to say N here. config ION_SYSTEM_HEAP bool "Ion system heap" depends on ION help Choose this option to enable the Ion system heap. The system heap is backed by pages from the buddy allocator. If in doubt, say Y. config ION_CARVEOUT_HEAP bool "Ion carveout heap support" depends on ION help Choose this option to enable carveout heaps with Ion. Carveout heaps are backed by memory reserved from the system. Allocation times are typically faster at the cost of memory not being used. Unless you know your system has these regions, you should say N here. config ION_CHUNK_HEAP bool "Ion chunk heap support" depends on ION help Choose this option to enable chunk heaps with Ion. This heap is similar in function the carveout heap but memory is broken down into smaller chunk sizes, typically corresponding to a TLB size. Unless you know your system has these regions, you should say N here. config ION_CMA_HEAP bool "Ion CMA heap support" depends on ION && CMA help Choose this option to enable CMA heaps with Ion. This heap is backed by the Contiguous Memory Allocator (CMA). If your system has these regions, you should say Y here.