Re: [PATCH v2 4/5] arm64: Use __tlbi_dsb() macros in KVM code
On Fri, Jan 06, 2017 at 10:51:53AM -0500, Christopher Covington wrote:
> 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.
Ah, sorry. I hadn't spotted that it got folded into the __tlbi_dsb()
above.
Given the comment was previously attached to the DSB, it might make more
sense to fold it into the prior comment block, so that it remains
attached to the __tlbi_dsb(), which guarantees the completion that the
comment describes.
Thanks,
Mark.
Re: [PATCH v2 4/5] arm64: Use __tlbi_dsb() macros in KVM code
On Fri, Jan 06, 2017 at 10:51:53AM -0500, Christopher Covington wrote:
> 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.
Ah, sorry. I hadn't spotted that it got folded into the __tlbi_dsb()
above.
Given the comment was previously attached to the DSB, it might make more
sense to fold it into the prior comment block, so that it remains
attached to the __tlbi_dsb(), which guarantees the completion that the
comment describes.
Thanks,
Mark.
Re: [PATCH v2 4/5] arm64: Use __tlbi_dsb() macros in KVM code
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
--
Qualcomm Datacenter Technologies, Inc. as an affiliate of Qualcomm
Technologies, Inc. Qualcomm Technologies, Inc. is a member of the Code
Aurora Forum, a Linux Foundation Collaborative Project.
Re: [PATCH v2 4/5] arm64: Use __tlbi_dsb() macros in KVM code
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
--
Qualcomm Datacenter Technologies, Inc. as an affiliate of Qualcomm
Technologies, Inc. Qualcomm Technologies, Inc. is a member of the Code
Aurora Forum, a Linux Foundation Collaborative Project.
Re: [PATCH v2 4/5] arm64: Use __tlbi_dsb() macros in KVM code
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.
> @@ -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.
> - asm volatile("tlbi vmalle1is" : : );
> - dsb(ish);
> + __tlbi_dsb(vmalle1is, ish);
> isb();
Thanks,
Mark.
Re: [PATCH v2 4/5] arm64: Use __tlbi_dsb() macros in KVM code
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.
> @@ -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.
> - asm volatile("tlbi vmalle1is" : : );
> - dsb(ish);
> + __tlbi_dsb(vmalle1is, ish);
> isb();
Thanks,
Mark.
