Re: [PATCH v9 8/9] arm64: dts: ti: k3-am62p: Split r5f memory region

[sashiko-bot@kernel.org]

Thank you for your contribution! Sashiko AI review found 1 potential issue(s) to consider:
- [High] remoteproc: k3: Fractured memory regions break ELF segment loading
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commit b4b7a5f900d44d8b6be48d2b954e57774fd913af
Author: Markus Schneider-Pargmann (TI) <msp@baylibre.com>

arm64: dts: ti: k3-am62p: Split r5f memory region

This commit splits the firmware memory region in more specific parts so it
is better described where to find which information. This allows bootloader
software like U-Boot to know where the LPM metadata is located.

> diff --git a/arch/arm64/boot/dts/ti/k3-am62p-ti-ipc-firmware.dtsi b/arch/arm64/boot/dts/ti/k3-am62p-ti-ipc-firmware.dtsi
> index 5d7f701420e2d..84dfbfd1986ce 100644
> --- a/arch/arm64/boot/dts/ti/k3-am62p-ti-ipc-firmware.dtsi
> +++ b/arch/arm64/boot/dts/ti/k3-am62p-ti-ipc-firmware.dtsi
> @@ -44,8 +44,14 @@ &wkup_r5fss0 {
>  &wkup_r5fss0_core0 {
>  	mboxes = <&mailbox0_cluster0 &mbox_r5_0>;
>  	memory-region = <&wkup_r5fss0_core0_dma_memory_region>,
> -			<&wkup_r5fss0_core0_memory_region>;
> -	memory-region-names = "dma", "firmware";
> +			<&wkup_r5fss0_core0_ipc_region>,
> +			<&wkup_r5fss0_core0_lpm_fs_stub_region>,
> +			<&wkup_r5fss0_core0_lpm_metadata_region>,
> +			<&wkup_r5fss0_core0_lpm_rest_region>,
> +			<&wkup_r5fss0_core0_dm_region>;
> +	memory-region-names = "dma", "ipc", "lpm-stub",
> +			      "lpm-metadata", "lpm-context",
> +			      "dm-firmware";

[Severity: High]
Does splitting the contiguous memory region break the loading of existing
firmware ELF binaries?

When rproc_elf_load_segments() attempts to map an ELF segment, the bounds
check in k3_rproc_da_to_va() ensures the entire segment fits within a single
device-tree memory region:

drivers/remoteproc/ti_k3_common.c:k3_rproc_da_to_va()
    if (da >= dev_addr && ((da + len) <= (dev_addr + size))) {

If an existing firmware binary contains a PT_LOAD segment that spans across
these newly introduced region boundaries (for example, crossing from the
ipc_region into the lpm_fs_stub_region), this strict bounds check will fail
and return NULL. The remoteproc ELF loader will then reject the firmware and
fail to boot the R5F cores.

>  	status = "okay";
>  };

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Sashiko AI review · https://sashiko.dev/#/patchset/20260918-topic-am62a-ioddr-dt-v6-19-v9-0-40972ef1f663@baylibre.com?part=8