On Tue, May 30, 2023 at 12:34:36PM -0700, Bjorn Andersson wrote:
> In some configurations, the exact placement of the rmtfs shared memory
> region isn't so strict. In the current implementation the author of the
> DeviceTree source is forced to make up a memory region.
>
> Extend the rmtfs memory driver to relieve the author of this
> responsibility by introducing support for using dynamic allocation in
> the driver.
>
> Signed-off-by: Bjorn Andersson <quic_bjorande@xxxxxxxxxxx>
> ---
> arch/arm64/boot/dts/qcom/sdm845-mtp.dts | 10 ++++
> drivers/soc/qcom/rmtfs_mem.c | 66 +++++++++++++++++++------
> 2 files changed, 61 insertions(+), 15 deletions(-)
>
> diff --git a/arch/arm64/boot/dts/qcom/sdm845-mtp.dts b/arch/arm64/boot/dts/qcom/sdm845-mtp.dts
> index d1440b790fa6..e6191b8ba4c6 100644
> --- a/arch/arm64/boot/dts/qcom/sdm845-mtp.dts
> +++ b/arch/arm64/boot/dts/qcom/sdm845-mtp.dts
> @@ -12,6 +12,8 @@
> #include "pm8998.dtsi"
> #include "pmi8998.dtsi"
>
> +/delete-node/ &rmtfs_mem;
> +
> / {
> model = "Qualcomm Technologies, Inc. SDM845 MTP";
> compatible = "qcom,sdm845-mtp", "qcom,sdm845";
> @@ -48,6 +50,14 @@ vreg_s4a_1p8: pm8998-smps4 {
> vin-supply = <&vph_pwr>;
> };
>
> + rmtfs {
> + compatible = "qcom,rmtfs-mem";
> +
> + qcom,alloc-size = <(2*1024*1024)>;
> + qcom,client-id = <1>;
> + qcom,vmid = <15>;
> + };
> +
Couldn't you just use the existing dynamic allocation of
reserved-memory, without any driver changes?
/ {
reserved-memory {
rmtfs {
compatible = "qcom,rmtfs-mem";
size = <0x0 (2*1024*1024)>;
alignment = <0x0 ...>; // if you want a special one
no-map; // don't we want to map this actually?
qcom,client-id = <1>;
qcom,vmid = <15>;
};
};
};
You won't get the 4K empty pages but I guess you just have them because
you allocate the memory without proper alignment?
Related patch series where I propose using it for most firmware memory
regions:
https://lore.kernel.org/linux-arm-msm/20230510-dt-resv-bottom-up-v1-5-3bf68873dbed@xxxxxxxxxxx/
Thanks,
Stephan
