Re: [PATCH 0/5] of: reserved_mem: Provide more control about allocation behavior

[Konrad Dybcio]

On 15.05.2023 12:12, Stephan Gerhold wrote:
> Provide more control about the allocation behavior for dynamically 
> allocated reserved memory by adding a "alloc-bottom-up" and 
> "alloc-top-down" option and by making the allocation order 
> deterministic.
> 
> The motivation for this patch series are the many different reserved 
> firmware regions on Qualcomm platforms. Currently it is often necessary 
> to duplicate them into each board DT, because minor differences for 
> some of the firmware regions (e.g. the firmware size) requires shifting
> the base address of all following firmware regions as well.
> 
> I propose describing the actual requirements (size, alignment, 
> alloc-ranges) instead and allocating the reserved regions at runtime. 
> This allows defining only the actual device-specific part in the board 
> DT and having everything else shared in the SoC.dtsi.
> 
> The series starts with two minor additions to the of_reserved_mem code. 
> The last two patches are examples that are meant to show the motivation
> more clearly for the MSM8916 SoC. PATCH 4/5 shows the current (static) 
> approach, then PATCH 5/5 switches to the dynamic allocation based on
> the first 3 patches.
> 
> If the first 3 patches are accepted I would send the full MSM8916 DT
> changes in a separate series.
> 
> Signed-off-by: Stephan Gerhold <stephan@xxxxxxxxxxx>
> ---
Sounds great!

Konrad
> Stephan Gerhold (5):
>       dt-bindings: reserved-memory: Add alloc-{bottom-up,top-down}
>       of: reserved_mem: Implement alloc-{bottom-up,top-down}
>       of: reserved_mem: Use stable allocation order
>       [RFC] arm64: dts: qcom: msm8916: Enable modem on two phones
>       [RFC] arm64: dts: qcom: msm8916: Reserve firmware memory dynamically
> 
>  .../bindings/reserved-memory/reserved-memory.yaml  | 39 ++++++++++++++++++++
>  arch/arm64/boot/dts/qcom/apq8016-sbc.dts           | 13 +++++++
>  .../boot/dts/qcom/msm8916-longcheer-l8150.dts      | 31 ++++++++++++++--
>  .../boot/dts/qcom/msm8916-samsung-serranove.dts    | 21 +++++++++++
>  arch/arm64/boot/dts/qcom/msm8916-ufi.dtsi          | 29 ++++++++-------
>  arch/arm64/boot/dts/qcom/msm8916.dtsi              | 42 ++++++++++++++++------
>  drivers/of/of_reserved_mem.c                       | 14 +++++++-
>  7 files changed, 163 insertions(+), 26 deletions(-)
> ---
> base-commit: 715abedee4cd660ad390659aefa7482f05275bbd
> change-id: 20230510-dt-resv-bottom-up-68d71ff6628f
> 
> Best regards,