Re: [PATCH 7/8] arm64: cpufeature: Relax checks for AArch32 support at EL[0-2]

From: Suzuki K Poulose
Date: Wed Apr 15 2020 - 07:33:14 EST


On 04/15/2020 11:58 AM, Will Deacon wrote:
On Wed, Apr 15, 2020 at 11:50:58AM +0100, Suzuki K Poulose wrote:
On 04/14/2020 10:31 PM, Will Deacon wrote:
We don't need to be quite as strict about mismatched AArch32 support,
which is good because the friendly hardware folks have been busy
mismatching this to their hearts' content.

* We don't care about EL2 or EL3 (there are silly comments concerning
the latter, so remove those)

* EL1 support is gated by the ARM64_HAS_32BIT_EL1 capability and handled
gracefully when a mismatch occurs

* EL1 support is gated by the ARM64_HAS_32BIT_EL0 capability and handled

s/EL1/EL0

gracefully when a mismatch occurs

Relax the AArch32 checks to FTR_NONSTRICT.

Agreed. We should do something similar for the features exposed by the
ELF_HWCAP, of course in a separate series.

Hmm, I didn't think we needed to touch the HWCAPs, as they're derived from
the sanitised feature register values. What am I missing?

sorry, that was cryptic. I was suggesting to relax the ftr fields to
NONSTRICT for the fields covered by ELF HWCAPs (and other CPU hwcaps).

Suzuki