of: reserved_mem: only support one <base size> entry in reg property

A /reserved-memory child node may have multiple <base size> tuples in
'reg' property, but multiple entries in 'reg' have never been fully
functional:
 - fdt_scan_reserved_mem() in the early pass loops over every
   tuple and reserves them all.

 - fdt_scan_reserved_mem_late() reads 'reg' by
   of_flat_dt_get_addr_size(), which returns false if entries != 1.
   So 'reg' property with multiple <base size> entries will be
   skipped, no reserved_mem entry is created in reserved_mem[].

Supporting multiple <base size> tuples is not a good idea:
  - It requires reserved_mem_ops->node_init support. Currently,
    CMA(rmem_cma_setup) and DMA(rmem_dma_setup) are not supported.

  - of_reserved_mem_lookup() is name-based, only the first entry in
    multiple <base size> tuples will be found.

So change to support one <base size> entry in 'reg' property.

Also update dt binding:
  https://github.com/devicetree-org/dt-schema/pull/197

Suggested-by: Rob Herring <robh@kernel.org>
Signed-off-by: Wandun Chen <chenwandun@lixiang.com>
Tested-by: Meijing Zhao <zhaomeijing@lixiang.com>
Link: https://lore.kernel.org/all/20260506014752.GA280279-robh@kernel.org/
Link: https://patch.msgid.link/20260525121700.2706141-1-chenwandun1@gmail.com
Signed-off-by: Rob Herring (Arm) <robh@kernel.org>

0 files changed, 0 insertions, 0 deletions