diff mbox

[v4,12/14] ARM64: KVM: vgic_elrsr and vgic_eisr need to be byteswapped in BE case

Message ID 1402590613-3341-13-git-send-email-victor.kamensky@linaro.org (mailing list archive)
State New, archived
Headers show

Commit Message

Victor Kamensky June 12, 2014, 4:30 p.m. UTC
On arm64 'u32 vgic_eisr[2];' and 'u32 vgic_elrsr[2]' are accessed as
one 'unsigned long *' bit fields, which has 64bit size. So we need to
swap least significant word with most significant word when code reads
those registers from h/w.

Signed-off-by: Victor Kamensky <victor.kamensky@linaro.org>
---
 arch/arm64/kvm/hyp.S | 7 +++++++
 1 file changed, 7 insertions(+)

Comments

Christoffer Dall June 14, 2014, 3:04 p.m. UTC | #1
On Thu, Jun 12, 2014 at 09:30:11AM -0700, Victor Kamensky wrote:
> On arm64 'u32 vgic_eisr[2];' and 'u32 vgic_elrsr[2]' are accessed as
> one 'unsigned long *' bit fields, which has 64bit size. So we need to
> swap least significant word with most significant word when code reads
> those registers from h/w.
> 
> Signed-off-by: Victor Kamensky <victor.kamensky@linaro.org>
> ---
>  arch/arm64/kvm/hyp.S | 7 +++++++
>  1 file changed, 7 insertions(+)
> 
> diff --git a/arch/arm64/kvm/hyp.S b/arch/arm64/kvm/hyp.S
> index 0620691..5035b41 100644
> --- a/arch/arm64/kvm/hyp.S
> +++ b/arch/arm64/kvm/hyp.S
> @@ -415,10 +415,17 @@ CPU_BE(	rev	w11, w11 )
>  	str	w4, [x3, #VGIC_CPU_HCR]
>  	str	w5, [x3, #VGIC_CPU_VMCR]
>  	str	w6, [x3, #VGIC_CPU_MISR]
> +#ifndef CONFIG_CPU_BIG_ENDIAN
>  	str	w7, [x3, #VGIC_CPU_EISR]
>  	str	w8, [x3, #(VGIC_CPU_EISR + 4)]
>  	str	w9, [x3, #VGIC_CPU_ELRSR]
>  	str	w10, [x3, #(VGIC_CPU_ELRSR + 4)]
> +#else
> +	str	w7, [x3, #(VGIC_CPU_EISR + 4)]
> +	str	w8, [x3, #VGIC_CPU_EISR]
> +	str	w9, [x3, #(VGIC_CPU_ELRSR + 4)]
> +	str	w10, [x3, #VGIC_CPU_ELRSR]
> +#endif
>  	str	w11, [x3, #VGIC_CPU_APR]
>  
>  	/* Clear GICH_HCR */
> -- 
> 1.8.1.4
> 
I thought Marc had something here which allowed you to deal with the
conversion in the accessor functions and avoid this patch?

-Christoffer
Victor Kamensky June 14, 2014, 3:42 p.m. UTC | #2
On 14 June 2014 08:04, Christoffer Dall <christoffer.dall@linaro.org> wrote:
> On Thu, Jun 12, 2014 at 09:30:11AM -0700, Victor Kamensky wrote:
>> On arm64 'u32 vgic_eisr[2];' and 'u32 vgic_elrsr[2]' are accessed as
>> one 'unsigned long *' bit fields, which has 64bit size. So we need to
>> swap least significant word with most significant word when code reads
>> those registers from h/w.
>>
>> Signed-off-by: Victor Kamensky <victor.kamensky@linaro.org>
>> ---
>>  arch/arm64/kvm/hyp.S | 7 +++++++
>>  1 file changed, 7 insertions(+)
>>
>> diff --git a/arch/arm64/kvm/hyp.S b/arch/arm64/kvm/hyp.S
>> index 0620691..5035b41 100644
>> --- a/arch/arm64/kvm/hyp.S
>> +++ b/arch/arm64/kvm/hyp.S
>> @@ -415,10 +415,17 @@ CPU_BE( rev     w11, w11 )
>>       str     w4, [x3, #VGIC_CPU_HCR]
>>       str     w5, [x3, #VGIC_CPU_VMCR]
>>       str     w6, [x3, #VGIC_CPU_MISR]
>> +#ifndef CONFIG_CPU_BIG_ENDIAN
>>       str     w7, [x3, #VGIC_CPU_EISR]
>>       str     w8, [x3, #(VGIC_CPU_EISR + 4)]
>>       str     w9, [x3, #VGIC_CPU_ELRSR]
>>       str     w10, [x3, #(VGIC_CPU_ELRSR + 4)]
>> +#else
>> +     str     w7, [x3, #(VGIC_CPU_EISR + 4)]
>> +     str     w8, [x3, #VGIC_CPU_EISR]
>> +     str     w9, [x3, #(VGIC_CPU_ELRSR + 4)]
>> +     str     w10, [x3, #VGIC_CPU_ELRSR]
>> +#endif
>>       str     w11, [x3, #VGIC_CPU_APR]
>>
>>       /* Clear GICH_HCR */
>> --
>> 1.8.1.4
>>
> I thought Marc had something here which allowed you to deal with the
> conversion in the accessor functions and avoid this patch?

Christoffer, I appreciate your review comments.

I think I was missing something. Yes, Marc mentioned in [1] about
his new changes in vgic3 series. But just after rereading it now, I
realized that he was suggesting to pick up his commits and add
them to this series. Is it my right understanding that they should
be [2] and [3] ... looking a bit closer to it, it seems that [4] is needed
as well. I am concerned that I don't understand all dependencies
and impact of those. Wondering about other way around. When vgic3
series introduced could we just back off above change and do it in
new right way?

[1] https://lists.cs.columbia.edu/pipermail/kvmarm/2014-May/009618.html
[2] https://lists.cs.columbia.edu/pipermail/kvmarm/2014-May/009475.html
[3] https://lists.cs.columbia.edu/pipermail/kvmarm/2014-May/009472.html
[4] https://lists.cs.columbia.edu/pipermail/kvmarm/2014-May/009473.html

Other question: I was testing all this directly on vanilla v3.15, should I
use some other armkvm specific integration branch to make sure it works
with all other in a queue armkvm changes.

In mean time I will try to pick up [4], [2], and [3] into v3.15 and see
how it goes.

Thanks,
Victor

> -Christoffer
Christoffer Dall June 14, 2014, 3:47 p.m. UTC | #3
On Sat, Jun 14, 2014 at 08:42:58AM -0700, Victor Kamensky wrote:
> On 14 June 2014 08:04, Christoffer Dall <christoffer.dall@linaro.org> wrote:
> > On Thu, Jun 12, 2014 at 09:30:11AM -0700, Victor Kamensky wrote:
> >> On arm64 'u32 vgic_eisr[2];' and 'u32 vgic_elrsr[2]' are accessed as
> >> one 'unsigned long *' bit fields, which has 64bit size. So we need to
> >> swap least significant word with most significant word when code reads
> >> those registers from h/w.
> >>
> >> Signed-off-by: Victor Kamensky <victor.kamensky@linaro.org>
> >> ---
> >>  arch/arm64/kvm/hyp.S | 7 +++++++
> >>  1 file changed, 7 insertions(+)
> >>
> >> diff --git a/arch/arm64/kvm/hyp.S b/arch/arm64/kvm/hyp.S
> >> index 0620691..5035b41 100644
> >> --- a/arch/arm64/kvm/hyp.S
> >> +++ b/arch/arm64/kvm/hyp.S
> >> @@ -415,10 +415,17 @@ CPU_BE( rev     w11, w11 )
> >>       str     w4, [x3, #VGIC_CPU_HCR]
> >>       str     w5, [x3, #VGIC_CPU_VMCR]
> >>       str     w6, [x3, #VGIC_CPU_MISR]
> >> +#ifndef CONFIG_CPU_BIG_ENDIAN
> >>       str     w7, [x3, #VGIC_CPU_EISR]
> >>       str     w8, [x3, #(VGIC_CPU_EISR + 4)]
> >>       str     w9, [x3, #VGIC_CPU_ELRSR]
> >>       str     w10, [x3, #(VGIC_CPU_ELRSR + 4)]
> >> +#else
> >> +     str     w7, [x3, #(VGIC_CPU_EISR + 4)]
> >> +     str     w8, [x3, #VGIC_CPU_EISR]
> >> +     str     w9, [x3, #(VGIC_CPU_ELRSR + 4)]
> >> +     str     w10, [x3, #VGIC_CPU_ELRSR]
> >> +#endif
> >>       str     w11, [x3, #VGIC_CPU_APR]
> >>
> >>       /* Clear GICH_HCR */
> >> --
> >> 1.8.1.4
> >>
> > I thought Marc had something here which allowed you to deal with the
> > conversion in the accessor functions and avoid this patch?
> 
> Christoffer, I appreciate your review comments.
> 
> I think I was missing something. Yes, Marc mentioned in [1] about
> his new changes in vgic3 series. But just after rereading it now, I
> realized that he was suggesting to pick up his commits and add
> them to this series. Is it my right understanding that they should
> be [2] and [3] ... looking a bit closer to it, it seems that [4] is needed
> as well. I am concerned that I don't understand all dependencies
> and impact of those. Wondering about other way around. When vgic3
> series introduced could we just back off above change and do it in
> new right way?
> 
> [1] https://lists.cs.columbia.edu/pipermail/kvmarm/2014-May/009618.html
> [2] https://lists.cs.columbia.edu/pipermail/kvmarm/2014-May/009475.html
> [3] https://lists.cs.columbia.edu/pipermail/kvmarm/2014-May/009472.html
> [4] https://lists.cs.columbia.edu/pipermail/kvmarm/2014-May/009473.html
> 
> Other question: I was testing all this directly on vanilla v3.15, should I
> use some other armkvm specific integration branch to make sure it works
> with all other in a queue armkvm changes.
> 
> In mean time I will try to pick up [4], [2], and [3] into v3.15 and see
> how it goes.
> 
ok, thanks.  I'm ok with potentially adjusting this later if it turns
out to be a pain, depends on what Marc says.

I can probably fix up any conflicts when I apply the patches, but I do
appreciate getting patches that apply to the next branch in [1].  (But
wait until the next branch merges 3.16-rc1).

-Christoffer

[1]: https://git.kernel.org/cgit/linux/kernel/git/kvmarm/kvmarm.git/
diff mbox

Patch

diff --git a/arch/arm64/kvm/hyp.S b/arch/arm64/kvm/hyp.S
index 0620691..5035b41 100644
--- a/arch/arm64/kvm/hyp.S
+++ b/arch/arm64/kvm/hyp.S
@@ -415,10 +415,17 @@  CPU_BE(	rev	w11, w11 )
 	str	w4, [x3, #VGIC_CPU_HCR]
 	str	w5, [x3, #VGIC_CPU_VMCR]
 	str	w6, [x3, #VGIC_CPU_MISR]
+#ifndef CONFIG_CPU_BIG_ENDIAN
 	str	w7, [x3, #VGIC_CPU_EISR]
 	str	w8, [x3, #(VGIC_CPU_EISR + 4)]
 	str	w9, [x3, #VGIC_CPU_ELRSR]
 	str	w10, [x3, #(VGIC_CPU_ELRSR + 4)]
+#else
+	str	w7, [x3, #(VGIC_CPU_EISR + 4)]
+	str	w8, [x3, #VGIC_CPU_EISR]
+	str	w9, [x3, #(VGIC_CPU_ELRSR + 4)]
+	str	w10, [x3, #VGIC_CPU_ELRSR]
+#endif
 	str	w11, [x3, #VGIC_CPU_APR]
 
 	/* Clear GICH_HCR */