Based on kernel version 6.15
. Page generated on 2025-05-29 09:09 EST
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1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 | .. SPDX-License-Identifier: GPL-2.0 ============================== Allocating dma-buf using heaps ============================== Dma-buf Heaps are a way for userspace to allocate dma-buf objects. They are typically used to allocate buffers from a specific allocation pool, or to share buffers across frameworks. Heaps ===== A heap represents a specific allocator. The Linux kernel currently supports the following heaps: - The ``system`` heap allocates virtually contiguous, cacheable, buffers. - The ``cma`` heap allocates physically contiguous, cacheable, buffers. Only present if a CMA region is present. Such a region is usually created either through the kernel commandline through the `cma` parameter, a memory region Device-Tree node with the `linux,cma-default` property set, or through the `CMA_SIZE_MBYTES` or `CMA_SIZE_PERCENTAGE` Kconfig options. Depending on the platform, it might be called ``reserved``, ``linux,cma``, or ``default-pool``. |