Re: [PATCH v2 4/5] arm64: Use __tlbi_dsb() macros in KVM code

Christopher Covington
2017-01-06T15:51:57Z

On 01/03/2017 10:57 AM, Mark Rutland wrote:
> On Thu, Dec 29, 2016 at 05:43:34PM -0500, Christopher Covington wrote:
>> Refactor the KVM code to use the newly introduced __tlbi_dsb macros, which
>> will allow an errata workaround that repeats tlbi dsb sequences to only
>> change one location. This is not intended to change the generated assembly
>> and comparing before and after vmlinux objdump shows no functional changes.

@@ -32,7 +33,7 @@ void __hyp_text __kvm_tlb_flush_vmid_ipa(struct kvm *kvm, phys_addr_t ipa)
* whole of Stage-1. Weep...
*/
ipa >>= 12;
- asm volatile("tlbi ipas2e1is, %0" : : "r" (ipa));
+ __tlbi_dsb(ipas2e1is, ish, ipa);

/*
* We have to ensure completion of the invalidation at Stage-2,

>> @@ -40,9 +41,7 @@ void __hyp_text __kvm_tlb_flush_vmid_ipa(struct kvm *kvm, phys_addr_t ipa)
>> * complete (S1 + S2) walk based on the old Stage-2 mapping if
>> * the Stage-1 invalidation happened first.
>> */
>> - dsb(ish);
>
> Looks like this got accidentally removed. AFAICT it is still necessary.

Not removed, just hoisted above the comment block to the previous patch hunk.

>> - asm volatile("tlbi vmalle1is" : : );
>> - dsb(ish);
>> + __tlbi_dsb(vmalle1is, ish);
>> isb();

Thanks,
Cov

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