Re: [PATCH v2 2/2] arm64: dts: broadcom: bcmbca: bcm4908: Protect cpu-release-addr

From: Florian Fainelli
Date: Sun Nov 24 2024 - 12:56:56 EST


From: Florian Fainelli <f.fainelli@xxxxxxxxx>

On Fri, 4 Oct 2024 22:01:55 -0700, Sam Edwards <cfsworks@xxxxxxxxx> wrote:
> The `cpu-release-addr` property is relevant only when the "spin-table"
> enable method is used. It is the physical address where the bootloader
> expects Linux to write the secondary CPU entry point's physical address.
> On this platform, only the CFE bootloader uses this method: U-Boot uses
> PSCI instead.
>
> CFE actually walks the FDT to learn this address, so we're free to put
> it wherever we want. We only need to make sure that it goes in a
> reserved-memory block so that writing to it during early boot does not
> risk conflicting with an unrelated memory allocation: this was not done.
>
> Since the previous patch reserved the first page of memory for CFE's
> secondary-CPU init stub, which is actually much smaller than a page,
> just put this address at the end of that page and it shall be so
> protected.
>
> Signed-off-by: Sam Edwards <CFSworks@xxxxxxxxx>
> ---

Applied to https://github.com/Broadcom/stblinux/commits/devicetree-arm64/next, thanks!
--
Florian