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SubjectRe: [PATCH v6 06/21] arm64: Move VHE-specific SPE setup to mutate_to_vhe()
On 2021-02-04 09:34, Will Deacon wrote:
> On Thu, Feb 04, 2021 at 09:30:08AM +0000, Marc Zyngier wrote:

[...]

>> I think the following patch addresses the above issue, which I'll
>> squash
>> with the original patch. Please shout if I missed anything.
>>
>> Thanks,
>>
>> M.
>>
>> diff --git a/arch/arm64/kernel/hyp-stub.S
>> b/arch/arm64/kernel/hyp-stub.S
>> index aa7e8d592295..3e08dcc924b5 100644
>> --- a/arch/arm64/kernel/hyp-stub.S
>> +++ b/arch/arm64/kernel/hyp-stub.S
>> @@ -115,29 +115,9 @@ SYM_CODE_START_LOCAL(mutate_to_vhe)
>> mrs_s x0, SYS_VBAR_EL12
>> msr vbar_el1, x0
>>
>> - // Fixup SPE configuration, if supported...
>> - mrs x1, id_aa64dfr0_el1
>> - ubfx x1, x1, #ID_AA64DFR0_PMSVER_SHIFT, #4
>> - mov x2, xzr
>> - cbz x1, skip_spe
>> -
>> - // ... and not owned by EL3
>> - mrs_s x0, SYS_PMBIDR_EL1
>> - and x0, x0, #(1 << SYS_PMBIDR_EL1_P_SHIFT)
>> - cbnz x0, skip_spe
>> -
>> - // Let the SPE driver in control of the sampling
>> - mrs_s x0, SYS_PMSCR_EL1
>> - bic x0, x0, #(1 << SYS_PMSCR_EL2_PCT_SHIFT)
>> - bic x0, x0, #(1 << SYS_PMSCR_EL2_PA_SHIFT)
>> - msr_s SYS_PMSCR_EL1, x0
>> - mov x2, #MDCR_EL2_TPMS
>> -
>> -skip_spe:
>> - // For VHE, use EL2 translation and disable access from EL1
>> + // Use EL2 translations for SPE and disable access from EL1
>> mrs x0, mdcr_el2
>> bic x0, x0, #(MDCR_EL2_E2PB_MASK << MDCR_EL2_E2PB_SHIFT)
>> - orr x0, x0, x2
>> msr mdcr_el2, x0
>
> Looks a tonne better, thanks! Be nice if somebody could test it for us.

SPE-equipped machines are the silicon equivalent of hen's teeth...

Alex, any chance you could give this a go?

M.
--
Jazz is not dead. It just smells funny...

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