[PATCH v2 0/9] dma-buf: heaps: Turn heaps into modules

[Maxime Ripard]

Hi,

The recent introduction of heaps in the optee driver [1] made possible
the creation of heaps as modules.

It's generally a good idea if possible, including for the already
existing system and CMA heaps.

The system one is pretty trivial, the CMA one is a bit more involved,
especially since we have a call from kernel/dma/contiguous.c to the CMA
heap code. This was solved by turning the logic around and making the
CMA heap call into the contiguous DMA code.

Let me know what you think,
Maxime

1: https://lore.kernel.org/dri-devel/20250911135007.1275833-4-jens.wiklander@xxxxxxxxxx/

Signed-off-by: Maxime Ripard <mripard@xxxxxxxxxx>
---
Changes in v2:
- Collect tags
- Don't export dma_contiguous_default_area anymore, but export
  dev_get_cma_area instead
- Mentioned that heap modules can't be removed
- Link to v1: https://lore.kernel.org/r/20260225-dma-buf-heaps-as-modules-v1-0-2109225a090d@xxxxxxxxxx

---
Maxime Ripard (9):
      dma: contiguous: Turn heap registration logic around
      dma: contiguous: Make dev_get_cma_area() a proper function
      dma: contiguous: Make dma_contiguous_default_area static
      mm: cma: Export dev_get_cma_area()
      mm: cma: Export cma_alloc and cma_release
      mm: cma: Export cma_get_name
      dma-buf: heaps: Export mem_accounting parameter
      dma-buf: heaps: cma: Turn the heap into a module
      dma-buf: heaps: system: Turn the heap into a module

 drivers/dma-buf/dma-heap.c          |  1 +
 drivers/dma-buf/heaps/Kconfig       |  4 ++--
 drivers/dma-buf/heaps/cma_heap.c    | 21 +++++----------------
 drivers/dma-buf/heaps/system_heap.c |  5 +++++
 include/linux/dma-map-ops.h         | 14 ++++++--------
 kernel/dma/contiguous.c             | 37 ++++++++++++++++++++++++++++++++++---
 mm/cma.c                            |  3 +++
 7 files changed, 56 insertions(+), 29 deletions(-)
---
base-commit: 499a718536dc0e1c1d1b6211847207d58acd9916
change-id: 20260225-dma-buf-heaps-as-modules-1034b3ec9f2a

Best regards,
-- 
Maxime Ripard <mripard@xxxxxxxxxx>