[PATCH v2] armv8: always use current exception level for TCR_ELx access

[Tom Rini]

On Tue, Jun 14, 2022 at 12:11:10AM +0100, Andre Przywara wrote:

> Currently get_tcr() takes an "el" parameter, to select the proper
> version of the TCR_ELx system register.
> This is problematic in case of the Apple M1, since it runs with
> HCR_EL2.E2H fixed to 1, so TCR_EL2 is actually using the TCR_EL1 layout,
> and we get the wrong version.
> 
> For U-Boot's purposes the only sensible choice here is the current
> exception level, and indeed most callers treat it like that, so let's
> remove that parameter and read the current EL inside the function.
> This allows us to check for the E2H bit, and pretend it's EL1 in this
> case.
> 
> There are two callers which don't care about the EL, and they pass 0,
> which looks wrong, but is irrelevant in these two cases, since we don't
> use the return value there. So the change cannot affect those two.
> 
> Signed-off-by: Andre Przywara <andre.przywara at arm.com>
> Reviewed-by: Mark Kettenis <kettenis at openbsd.org>
> Tested-by: Mark Kettenis <kettenis at openbsd.org>

Applied to u-boot/master, thanks!

-- 
Tom
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