* [RFC][PATCH] Remove duplicate setting of the B field in tlbie
@ 2016-09-13 7:45 ` Balbir Singh
0 siblings, 0 replies; 6+ messages in thread
From: Balbir Singh @ 2016-09-13 7:45 UTC (permalink / raw)
To: Paul Mackerras; +Cc: kvm, kvm-ppc, Aneesh Kumar K.V
Remove duplicate setting of the the "B" field when doing a tlbie(l).
In compute_tlbie_rb(), the "B" field is set again just before
returning the rb value to be used for tlbie(l).
Signed-off-by: Balbir Singh <bsingharora@gmail.com>
---
Quickly boot tested a VM with these changes in kvm with 64k
as the page size for the guest.
arch/powerpc/include/asm/kvm_book3s_64.h | 1 -
1 file changed, 1 deletion(-)
diff --git a/arch/powerpc/include/asm/kvm_book3s_64.h b/arch/powerpc/include/asm/kvm_book3s_64.h
index 88d17b4..63b6900 100644
--- a/arch/powerpc/include/asm/kvm_book3s_64.h
+++ b/arch/powerpc/include/asm/kvm_book3s_64.h
@@ -159,7 +159,6 @@ static inline unsigned long compute_tlbie_rb(unsigned long v, unsigned long r,
/* This covers 14..54 bits of va*/
rb = (v & ~0x7fUL) << 16; /* AVA field */
- rb |= (v >> HPTE_V_SSIZE_SHIFT) << 8; /* B field */
/*
* AVA in v had cleared lower 23 bits. We need to derive
* that from pteg index
--
2.5.5
^ permalink raw reply related [flat|nested] 6+ messages in thread
* [RFC][PATCH] Remove duplicate setting of the B field in tlbie
@ 2016-09-13 7:45 ` Balbir Singh
0 siblings, 0 replies; 6+ messages in thread
From: Balbir Singh @ 2016-09-13 7:45 UTC (permalink / raw)
To: Paul Mackerras; +Cc: kvm, kvm-ppc, Aneesh Kumar K.V
Remove duplicate setting of the the "B" field when doing a tlbie(l).
In compute_tlbie_rb(), the "B" field is set again just before
returning the rb value to be used for tlbie(l).
Signed-off-by: Balbir Singh <bsingharora@gmail.com>
---
Quickly boot tested a VM with these changes in kvm with 64k
as the page size for the guest.
arch/powerpc/include/asm/kvm_book3s_64.h | 1 -
1 file changed, 1 deletion(-)
diff --git a/arch/powerpc/include/asm/kvm_book3s_64.h b/arch/powerpc/include/asm/kvm_book3s_64.h
index 88d17b4..63b6900 100644
--- a/arch/powerpc/include/asm/kvm_book3s_64.h
+++ b/arch/powerpc/include/asm/kvm_book3s_64.h
@@ -159,7 +159,6 @@ static inline unsigned long compute_tlbie_rb(unsigned long v, unsigned long r,
/* This covers 14..54 bits of va*/
rb = (v & ~0x7fUL) << 16; /* AVA field */
- rb |= (v >> HPTE_V_SSIZE_SHIFT) << 8; /* B field */
/*
* AVA in v had cleared lower 23 bits. We need to derive
* that from pteg index
--
2.5.5
^ permalink raw reply related [flat|nested] 6+ messages in thread
* Re: [RFC][PATCH] Remove duplicate setting of the B field in tlbie
2016-09-13 7:45 ` Balbir Singh
@ 2016-09-14 4:55 ` Aneesh Kumar K.V
-1 siblings, 0 replies; 6+ messages in thread
From: Aneesh Kumar K.V @ 2016-09-14 4:55 UTC (permalink / raw)
To: Balbir Singh, Paul Mackerras; +Cc: kvm, kvm-ppc
Balbir Singh <bsingharora@gmail.com> writes:
> Remove duplicate setting of the the "B" field when doing a tlbie(l).
> In compute_tlbie_rb(), the "B" field is set again just before
> returning the rb value to be used for tlbie(l).
>
> Signed-off-by: Balbir Singh <bsingharora@gmail.com>
> ---
> Quickly boot tested a VM with these changes in kvm with 64k
> as the page size for the guest.
>
> arch/powerpc/include/asm/kvm_book3s_64.h | 1 -
> 1 file changed, 1 deletion(-)
>
> diff --git a/arch/powerpc/include/asm/kvm_book3s_64.h b/arch/powerpc/include/asm/kvm_book3s_64.h
> index 88d17b4..63b6900 100644
> --- a/arch/powerpc/include/asm/kvm_book3s_64.h
> +++ b/arch/powerpc/include/asm/kvm_book3s_64.h
> @@ -159,7 +159,6 @@ static inline unsigned long compute_tlbie_rb(unsigned long v, unsigned long r,
> /* This covers 14..54 bits of va*/
> rb = (v & ~0x7fUL) << 16; /* AVA field */
>
> - rb |= (v >> HPTE_V_SSIZE_SHIFT) << 8; /* B field */
> /*
> * AVA in v had cleared lower 23 bits. We need to derive
> * that from pteg index
Can we keep this and remove the other. This is much easier to follow
than
rb |= (v >> 54) & 0x300; /* B field */
-aneesh
^ permalink raw reply [flat|nested] 6+ messages in thread
* Re: [RFC][PATCH] Remove duplicate setting of the B field in tlbie
@ 2016-09-14 4:55 ` Aneesh Kumar K.V
0 siblings, 0 replies; 6+ messages in thread
From: Aneesh Kumar K.V @ 2016-09-14 4:55 UTC (permalink / raw)
To: Balbir Singh, Paul Mackerras; +Cc: kvm, kvm-ppc
Balbir Singh <bsingharora@gmail.com> writes:
> Remove duplicate setting of the the "B" field when doing a tlbie(l).
> In compute_tlbie_rb(), the "B" field is set again just before
> returning the rb value to be used for tlbie(l).
>
> Signed-off-by: Balbir Singh <bsingharora@gmail.com>
> ---
> Quickly boot tested a VM with these changes in kvm with 64k
> as the page size for the guest.
>
> arch/powerpc/include/asm/kvm_book3s_64.h | 1 -
> 1 file changed, 1 deletion(-)
>
> diff --git a/arch/powerpc/include/asm/kvm_book3s_64.h b/arch/powerpc/include/asm/kvm_book3s_64.h
> index 88d17b4..63b6900 100644
> --- a/arch/powerpc/include/asm/kvm_book3s_64.h
> +++ b/arch/powerpc/include/asm/kvm_book3s_64.h
> @@ -159,7 +159,6 @@ static inline unsigned long compute_tlbie_rb(unsigned long v, unsigned long r,
> /* This covers 14..54 bits of va*/
> rb = (v & ~0x7fUL) << 16; /* AVA field */
>
> - rb |= (v >> HPTE_V_SSIZE_SHIFT) << 8; /* B field */
> /*
> * AVA in v had cleared lower 23 bits. We need to derive
> * that from pteg index
Can we keep this and remove the other. This is much easier to follow
than
rb |= (v >> 54) & 0x300; /* B field */
-aneesh
^ permalink raw reply [flat|nested] 6+ messages in thread
* Re: [RFC][PATCH] Remove duplicate setting of the B field in tlbie
2016-09-14 4:55 ` Aneesh Kumar K.V
@ 2016-09-14 6:15 ` Balbir Singh
-1 siblings, 0 replies; 6+ messages in thread
From: Balbir Singh @ 2016-09-14 6:15 UTC (permalink / raw)
To: Aneesh Kumar K.V, Paul Mackerras; +Cc: kvm, kvm-ppc
On 14/09/16 14:55, Aneesh Kumar K.V wrote:
> Balbir Singh <bsingharora@gmail.com> writes:
>
>> Remove duplicate setting of the the "B" field when doing a tlbie(l).
>> In compute_tlbie_rb(), the "B" field is set again just before
>> returning the rb value to be used for tlbie(l).
>>
>> Signed-off-by: Balbir Singh <bsingharora@gmail.com>
>> ---
>> Quickly boot tested a VM with these changes in kvm with 64k
>> as the page size for the guest.
>>
>> arch/powerpc/include/asm/kvm_book3s_64.h | 1 -
>> 1 file changed, 1 deletion(-)
>>
>> diff --git a/arch/powerpc/include/asm/kvm_book3s_64.h b/arch/powerpc/include/asm/kvm_book3s_64.h
>> index 88d17b4..63b6900 100644
>> --- a/arch/powerpc/include/asm/kvm_book3s_64.h
>> +++ b/arch/powerpc/include/asm/kvm_book3s_64.h
>> @@ -159,7 +159,6 @@ static inline unsigned long compute_tlbie_rb(unsigned long v, unsigned long r,
>> /* This covers 14..54 bits of va*/
>> rb = (v & ~0x7fUL) << 16; /* AVA field */
>>
>> - rb |= (v >> HPTE_V_SSIZE_SHIFT) << 8; /* B field */
>> /*
>> * AVA in v had cleared lower 23 bits. We need to derive
>> * that from pteg index
>
> Can we keep this and remove the other. This is much easier to follow
> than
>
> rb |= (v >> 54) & 0x300; /* B field */
>
OK, but I think for 64K page size
rb &= ~((1ul << mmu_psize_defs[a_psize].shift) - 1);
ends up cleaning up the "B" field. That is why we've had the two "B" field settings.
Let me double check with some coffee.
Balbir Singh.
^ permalink raw reply [flat|nested] 6+ messages in thread* Re: [RFC][PATCH] Remove duplicate setting of the B field in tlbie
@ 2016-09-14 6:15 ` Balbir Singh
0 siblings, 0 replies; 6+ messages in thread
From: Balbir Singh @ 2016-09-14 6:15 UTC (permalink / raw)
To: Aneesh Kumar K.V, Paul Mackerras; +Cc: kvm, kvm-ppc
On 14/09/16 14:55, Aneesh Kumar K.V wrote:
> Balbir Singh <bsingharora@gmail.com> writes:
>
>> Remove duplicate setting of the the "B" field when doing a tlbie(l).
>> In compute_tlbie_rb(), the "B" field is set again just before
>> returning the rb value to be used for tlbie(l).
>>
>> Signed-off-by: Balbir Singh <bsingharora@gmail.com>
>> ---
>> Quickly boot tested a VM with these changes in kvm with 64k
>> as the page size for the guest.
>>
>> arch/powerpc/include/asm/kvm_book3s_64.h | 1 -
>> 1 file changed, 1 deletion(-)
>>
>> diff --git a/arch/powerpc/include/asm/kvm_book3s_64.h b/arch/powerpc/include/asm/kvm_book3s_64.h
>> index 88d17b4..63b6900 100644
>> --- a/arch/powerpc/include/asm/kvm_book3s_64.h
>> +++ b/arch/powerpc/include/asm/kvm_book3s_64.h
>> @@ -159,7 +159,6 @@ static inline unsigned long compute_tlbie_rb(unsigned long v, unsigned long r,
>> /* This covers 14..54 bits of va*/
>> rb = (v & ~0x7fUL) << 16; /* AVA field */
>>
>> - rb |= (v >> HPTE_V_SSIZE_SHIFT) << 8; /* B field */
>> /*
>> * AVA in v had cleared lower 23 bits. We need to derive
>> * that from pteg index
>
> Can we keep this and remove the other. This is much easier to follow
> than
>
> rb |= (v >> 54) & 0x300; /* B field */
>
OK, but I think for 64K page size
rb &= ~((1ul << mmu_psize_defs[a_psize].shift) - 1);
ends up cleaning up the "B" field. That is why we've had the two "B" field settings.
Let me double check with some coffee.
Balbir Singh.
^ permalink raw reply [flat|nested] 6+ messages in thread
end of thread, other threads:[~2016-09-14 6:15 UTC | newest]
Thread overview: 6+ messages (download: mbox.gz / follow: Atom feed)
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2016-09-13 7:45 [RFC][PATCH] Remove duplicate setting of the B field in tlbie Balbir Singh
2016-09-13 7:45 ` Balbir Singh
2016-09-14 4:55 ` Aneesh Kumar K.V
2016-09-14 4:55 ` Aneesh Kumar K.V
2016-09-14 6:15 ` Balbir Singh
2016-09-14 6:15 ` Balbir Singh
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