drivers/dma-buf/heaps/cma_heap.c

File Facts

System

Linux kernel

Corpus path

drivers/dma-buf/heaps/cma_heap.c

Extension

.c

Size

9617 bytes

Lines

426

Domain

Driver Families

Bucket

drivers/dma-buf

Inferred role

Driver Families: exported/initcall integration point

Status

integration implementation candidate

Why This File Exists

Repeatable hardware-adapter layer. Deep compatibility for every driver is out of scope; this atlas records patterns, probe lifecycles, bus glue, IRQ/DMA usage, and links back to core abstractions.

• Repeatable hardware-adapter layer. Deep compatibility for every driver is out of scope; this atlas records patterns, probe lifecycles, bus glue, IRQ/DMA usage, and links back to core abstractions.
• Exports symbols or registers init work; inspect boot/module ordering and who consumes the exported contract.
• Uses kernel synchronization; read lock ordering, sleepability, and interrupt context assumptions before translating.
• Touches IRQ or DMA behavior; this matters for the representative real-device path.
• Allocates kernel memory; connect allocation flags and lifetime to context constraints.
• Defines or uses C structs; map object ownership, embedded links, reference counts, and lock ownership.

Dependency Surface

• linux/cma.h
• linux/dma-buf.h
• linux/dma-heap.h
• linux/dma-map-ops.h
• linux/err.h
• linux/highmem.h
• linux/io.h
• linux/mm.h
• linux/module.h
• linux/of.h
• linux/of_reserved_mem.h
• linux/scatterlist.h
• linux/slab.h
• linux/vmalloc.h

Detected Declarations

• struct cma_heap
• struct cma_heap_buffer
• struct dma_heap_attachment
• function cma_heap_attach
• function cma_heap_detach
• function cma_heap_unmap_dma_buf
• function cma_heap_dma_buf_begin_cpu_access
• function list_for_each_entry
• function cma_heap_dma_buf_end_cpu_access
• function list_for_each_entry
• function cma_heap_vm_fault
• function cma_heap_mmap
• function cma_heap_vmap
• function cma_heap_vunmap
• function cma_heap_dma_buf_release
• function __add_cma_heap
• function add_cma_heaps
• module init add_cma_heaps

Annotated Snippet

module_init(add_cma_heaps);
MODULE_DESCRIPTION("DMA-BUF CMA Heap");
MODULE_LICENSE("GPL");
MODULE_IMPORT_NS("DMA_BUF");
MODULE_IMPORT_NS("DMA_BUF_HEAP");

Annotation

• Immediate include surface: `linux/cma.h`, `linux/dma-buf.h`, `linux/dma-heap.h`, `linux/dma-map-ops.h`, `linux/err.h`, `linux/highmem.h`, `linux/io.h`, `linux/mm.h`.
• Detected declarations: `struct cma_heap`, `struct cma_heap_buffer`, `struct dma_heap_attachment`, `function cma_heap_attach`, `function cma_heap_detach`, `function cma_heap_unmap_dma_buf`, `function cma_heap_dma_buf_begin_cpu_access`, `function list_for_each_entry`, `function cma_heap_dma_buf_end_cpu_access`, `function list_for_each_entry`.
• Atlas domain: Driver Families / drivers/dma-buf.
• Implementation status: integration implementation candidate.
• Synchronization appears in or near this file; preserve lock ordering, sleepability, and interrupt-context constraints.
• IRQ or DMA behavior appears here, which is relevant to the selected PCIe/NVMe device path.

Implementation Notes

• This generated page is the file-by-file coverage layer; curated subsystem chapters should link here when they synthesize a multi-file control flow.
• Core OS pages should be promoted from atlas-only to deep-reviewed when they explain data structures, invariants, locking, lifecycle, and C implementation snippets.
• Driver-family pages are intentionally pattern-oriented unless they are part of the selected PCIe/NVMe representative device path.