> From: Oreoluwa Babatunde <quic_obabatun@xxxxxxxxxxx>
> Sent: 2024年7月9日 7:06
>
> With recent changes made to initialize the cma regions before the page tables
> are setup, commit f2a524d9ef5b ("of: reserved_mem: Restructure code to call
> reserved mem init functions earlier"), an issue was introduced where the
> initialization of the cma regions fail and are initialized as "non-reusable"
> regions instead of "reusable". [1], [2]
>
> This issue occurs because the device_node of the regions are not yet created
> by the time the cma regions are being initialized.
>
> The cma regions need to be initialized before the page tables are setup for
> them to be configured correctly as was realized in [3].
>
> Hence, since the unflatten_devicetree APIs are not available until after the
> page tables have been setup, revert back to using the fdt APIs. This makes it
> possible to store a reference to each cma node in the reserved_mem array by
> the time it is needed in the init function.
>
> [1] https://lore.kernel.org/all/DU0PR04MB9299C3EC247E1FE2C373440F80DE2@xxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxx/
For CMA regressions issue, tested it worked.
Tested-by: Dong Aisheng <aisheng.dong@xxxxxxx>
Regards
Aisheng
>
> Oreoluwa Babatunde (4):
> Revert "of: reserved_mem: Restructure code to call reserved mem init
> functions earlier"
> Revert "of: reserved_mem: Rename fdt_* functions to refelct the change
> from using fdt APIs"
> Revert "of: reserved_mem: Use unflatten_devicetree APIs to scan
> reserved memory nodes"
> of: reserved_mem: Restructure code to call rmem init functions earlier
>
> drivers/of/fdt.c | 2 +-
> drivers/of/of_private.h | 2 +-
> drivers/of/of_reserved_mem.c | 103 +++++++++++++++++---------------
> include/linux/of_reserved_mem.h | 2 +-
> kernel/dma/coherent.c | 10 ++--
> kernel/dma/contiguous.c | 8 +--
> kernel/dma/swiotlb.c | 10 ++--
> 7 files changed, 72 insertions(+), 65 deletions(-)
>
> --
> 2.34.1
