[v3,0/4] Expose GT CNTFRQ as a CPU property to support AST2600

Message

Andrew Jeffery Dec. 13, 2019, 5:49 a.m. UTC

Hello,

This is a v3 of the belated follow-up from a few of my earlier attempts to fix
up the ARM generic timer for correct behaviour on the ASPEED AST2600 SoC. The
AST2600 clocks the generic timer at the rate of HPLL, which is configured to
1125MHz.  This is significantly quicker than the currently hard-coded generic
timer rate of 62.5MHz and so we see "sticky" behaviour in the guest.

v2 can be found here:

https://patchwork.ozlabs.org/cover/1203474/

Changes since v2:

* Address some minor review comments from Philippe and add tags

Changes since v1:

* Fix a user mode build failure from partial renaming of gt_cntfrq_period_ns()
* Add tags from Cedric and Richard

Please review.

Andrew

Andrew Jeffery (4):
  target/arm: Remove redundant scaling of nexttick
  target/arm: Abstract the generic timer frequency
  target/arm: Prepare generic timer for per-platform CNTFRQ
  ast2600: Configure CNTFRQ at 1125MHz

 hw/arm/aspeed_ast2600.c |  3 ++-
 target/arm/cpu.c        | 65 ++++++++++++++++++++++++++++++++++++------
 target/arm/cpu.h        |  5 +++-
 target/arm/helper.c     | 24 ++++++++++++----
 4 files changed, 83 insertions(+), 14 deletions(-)

base-commit: 04c9c81b8fa2ee33f59a26265700fae6fc646062

Comments

Peter Maydell Dec. 17, 2019, 3:25 p.m. UTC | #1

On Fri, 13 Dec 2019 at 05:48, Andrew Jeffery <[e-mail]> wrote:
>
> Hello,
>
> This is a v3 of the belated follow-up from a few of my earlier attempts to fix
> up the ARM generic timer for correct behaviour on the ASPEED AST2600 SoC. The
> AST2600 clocks the generic timer at the rate of HPLL, which is configured to
> 1125MHz.  This is significantly quicker than the currently hard-coded generic
> timer rate of 62.5MHz and so we see "sticky" behaviour in the guest.
>
> v2 can be found here:
>
> https://patchwork.ozlabs.org/cover/1203474/
>
> Changes since v2:
>
> * Address some minor review comments from Philippe and add tags
>
> Changes since v1:
>
> * Fix a user mode build failure from partial renaming of gt_cntfrq_period_ns()
> * Add tags from Cedric and Richard
>
> Please review.
>
> Andrew
>
> Andrew Jeffery (4):
>   target/arm: Remove redundant scaling of nexttick
>   target/arm: Abstract the generic timer frequency
>   target/arm: Prepare generic timer for per-platform CNTFRQ
>   ast2600: Configure CNTFRQ at 1125MHz




Applied to target-arm.next, thanks.

-- PMM

Andrew Jeffery Dec. 17, 2019, 10:57 p.m. UTC | #2

On Wed, 18 Dec 2019, at 01:55, Peter Maydell wrote:
> On Fri, 13 Dec 2019 at 05:48, Andrew Jeffery <[e-mail]> wrote:
> >
> > Hello,
> >
> > This is a v3 of the belated follow-up from a few of my earlier attempts to fix
> > up the ARM generic timer for correct behaviour on the ASPEED AST2600 SoC. The
> > AST2600 clocks the generic timer at the rate of HPLL, which is configured to
> > 1125MHz.  This is significantly quicker than the currently hard-coded generic
> > timer rate of 62.5MHz and so we see "sticky" behaviour in the guest.
> >
> > v2 can be found here:
> >
> > https://patchwork.ozlabs.org/cover/1203474/
> >
> > Changes since v2:
> >
> > * Address some minor review comments from Philippe and add tags
> >
> > Changes since v1:
> >
> > * Fix a user mode build failure from partial renaming of gt_cntfrq_period_ns()
> > * Add tags from Cedric and Richard
> >
> > Please review.
> >
> > Andrew
> >
> > Andrew Jeffery (4):
> >   target/arm: Remove redundant scaling of nexttick
> >   target/arm: Abstract the generic timer frequency
> >   target/arm: Prepare generic timer for per-platform CNTFRQ
> >   ast2600: Configure CNTFRQ at 1125MHz
> 
> 
> 
> 
> Applied to target-arm.next, thanks.

Thanks for your feedback throughout.

Andrew